Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods...Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods of the coal-bearing formations were determined,and the fault systems were divided.Combined with the coal seam thickness and actual gas indication in logging,the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified.The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture,and contains coal-bearing formations and five sub-types of fault systems under three types.The horizontal extension strength,vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences,accumulation intensity,and accumulation frequency of coal seam in rift basin.The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts.The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area.The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane.The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source,affecting the enrichment degree of coal-rock gas.The vertical sealing of the faults was evaluated by using shale smear factor(SSF),and the evaluation criterion was established.It is indicated that the SSF is below 1.1 in major coal areas,indicating favorable preservation conditions for coal-rock gas.Based on the influence factors such as fault activity,segmentation and sealing,the coal-rock gas accumulation model of rift basin was established.展开更多
In this paper, a typical mei-yu front process with heavy rainfall from June 12 to 15 in 1998 is analyzed. The results show that the mei-yu front is a front system which consists of an iso-theta(e) dense area with stro...In this paper, a typical mei-yu front process with heavy rainfall from June 12 to 15 in 1998 is analyzed. The results show that the mei-yu front is a front system which consists of an iso-theta(e) dense area with strong horizontal gradient, a deep-convective cloud tower band, a passageway transporting warm and moist air flow from the summer monsoon surge in the mid and low levels to the south of the mei-yu front, and a migrating synoptic scale trough to the north of the mei-yu front, which transports cold and dry air southward in the mid and upper levels. The maintenance of the mei-yu front is realized by: (1) is a positive feedback between the moist physical process enhancing frontogenesis and the development of the strong convective system in front of the mei-yu front; (2) the sustaining system to the north of the mei-yu front which is a migrating synoptic scale trough transporting cold and dry air to the mei-yu front and positive vorticity to the mesoscale system in front of the mei-yu front.展开更多
Based on 2D and 3D seismic data,the latest drilling data and field outcrop data of the northern slope of the Central Sichuan paleo-uplift,the structural analysis method is used to analyze unconformity development char...Based on 2D and 3D seismic data,the latest drilling data and field outcrop data of the northern slope of the Central Sichuan paleo-uplift,the structural analysis method is used to analyze unconformity development characteristics and fault characteristics during the key structural transformation period,discussing the influence of the structural characteristics on the hydrocarbon accumulation of deep carbonate rocks.The results show that:(1)The two key unconformities of the Tongwan and Caledonian periods were primarily developed in deep carbonate rocks.Firstly,Tongwan’s unconformities are characterized by regional disconformities between the second and third members of the Dengying Formation,the top formation of the Sinian and the lower Cambrian,strips of which zigzag through the north and south sides of the study area.Secondly,the Caledonian unconformity is characterized by a regional unconformable contact between the lower Permian and the ower Paleozoic strata.From NE to SW,the age of the strata,which were subject to erosion,changes from new to old,the denudation distribution showing as a nose-shaped structure which inclines towards the ENE.(2)Boundary fault and transtensional strike-slip faults developed in the Sinian to Paleozoic strata.In profile,there are three types of structural styles:steep and erect,flower structures,’Y’and reversed’Y’type faults.In plane view,the Sinian developed extensional boundary faults extending in an almost NS direction,strike-slip faults developing and extending linearly in approximately EW,WNW and NE strikes in the Cambrian,with characteristically more in the south and less in the north.(3)The faults in the northern slope show obvious zonal deformations in transverse view as well as significant stages and stratified activity in a longitudinal direction.Among them,the activity of faults in the Sinian was the strongest,followed by the activity in the Cambrian period,the activity intensity of faults in the Permian period being the weakest.This fault activity can be divided into four periods:Sinian,Cambrian-Permian,the early Indosinian period and the late Indosinian-Himalayan period,the transtensional strikeslip faults being the products of oblique extensions of pre-existing weak zones in the Xingkai and Emei taphrogenesis,with a particular inheritance in the main faults.(4)Combined with hydrocarbon accumulation factors,it is considered that the epigenetic karstification of the Tongwan and Caledonian unconformities in the northern slope controlled the formation and distribution of carbonate karst reservoirs over a large area,also acting as a good pathway for oil and gas migration.The extensional faults developed at the margin of the NS trending rift,controlling the sag-platform sedimentary pattern in the Dengying Formation of the Sinian.Strike-slip faults in NE,WNW and ENE directions may control the microgeomorphological pattern inside the platform and intensify the differential distribution of grain beach facies.The multi-stage hereditary activity of strike-slip faults not only improved the porosity and permeability of the reservoirs,but also acted as the main channel of oil and gas migration,providing favorable conditions for the development of the current multi-layer gasbearing scenario in the northern slope of the Central Sichuan Basin.展开更多
The effect of application of pig manure (PM) on the structural characteristics of humic acids (HAs) of brown soil was studied in field and incubation experiments. The results showed that the number-average molecular w...The effect of application of pig manure (PM) on the structural characteristics of humic acids (HAs) of brown soil was studied in field and incubation experiments. The results showed that the number-average molecular weights (Mn), the ratios of C/ H, C/ N and O/C, the contents of carboxyl and phenolic hydroxyl groups, the content ofaromatic C, the values of E2, E4and λ Exmax of HAs all decreased; whereas, the contents of alkyl C and O-alkyl C, the ratio of carboxyl to phenolic hydroxyl groups, the degree of oxidation stability, the absorption intensity at 285 mμ (UV), and 2920cm-1 of HAs increased after the application of PM. The above results indicated that the molecular structure of HAs tended to be more aliphatic and simpler after the application of PM.展开更多
To improve the adaptability of TBMs in diverse geological environments,this paper proposes a reconfigurable Type-V thrust mechanism(V-TM)with rearrangeable working states,in which structural stiffness can be automatic...To improve the adaptability of TBMs in diverse geological environments,this paper proposes a reconfigurable Type-V thrust mechanism(V-TM)with rearrangeable working states,in which structural stiffness can be automatically altered during operation.Therefore,millions of configurations can be obtained,and thousands of instances of working status per configuration can be set respectively.Nonetheless,the complexity of configurations and diversity of working states contributes to further complications for the structural stiffness algorithm.This results in challenges such as difficulty calculating the payload compliance index and the environment adaptability index.To solve this problem,we use the configuration matrix to describe the relationship between propelling jacks under reconfiguration and adopt pattern vectors to describe the working state of each hydraulic cylinder.Then,both the dynamic compatible equation between propeller forces of the hydraulic cylinders and driving forces,and the kinematic harmonizing equation between the hydraulic cylinder displacements and their deformations are established.Next,we derive the stiffness analytical equation using Hooke’s law and the Jacobian Matrix.The proposed approach provides an effective algorithm to support structural rigidity analysis,and lays a solid theoretical foundation for calculating the performance indexes of the V-TM.We then analyze the rigidity characteristics of typical configurations under different working states,and obtain the main factors affecting structural stiffness of the V-TM.The results show the deviation degree of structural parameters in hydraulic cylinders within the same group,and the working status of propelling jacks.Finally,our constructive conclusions contribute valuable information for matching and optimization by drawing on the factors that affect the structural rigidity of the V-TM.展开更多
By employing the NCEP/NCAR reanalysis data sets (1000-10hPa, 2.5°× 2.5°), the characteristics have been analyzed of the structure and evolution of an easterly vortex over the tropical upper troposphere ...By employing the NCEP/NCAR reanalysis data sets (1000-10hPa, 2.5°× 2.5°), the characteristics have been analyzed of the structure and evolution of an easterly vortex over the tropical upper troposphere relating to the east-west direction shift of the subtropical anticyclone over the Western Pacific Ocean. It is shown that there exists a westward shift simultaneously between the anticyclone and the vortex locating south of it. The anticyclone retreats eastward abnormally while the easterly encounters with the westerly around the same longitudes as they move from the opposite directions. The former is an upper weather system, extending from mid-troposphere to the height of 50 hPa with the center locating on 200 hPa. The vertical thermal distribution illustrates the characteristics of being"warm in the upper layer but cold in the lower layer". The divergence effect and the vertical motion change largely within the east and west sides of the easterly vortex and ascending branch transforms to descending branch near its center.展开更多
Doxorubicin(DOX)is a widely employed tumor therapy,yet its substantial toxic side effects pose a considerable challenge.Bletilla striata has demonstrated efficacy in preventing and treating these toxic side effects in...Doxorubicin(DOX)is a widely employed tumor therapy,yet its substantial toxic side effects pose a considerable challenge.Bletilla striata has demonstrated efficacy in preventing and treating these toxic side effects in clinical practice,with polysaccharides identified as the principal active component.In the present study,16 fractions of B.striata polysaccharides(BsPs)were extracted using diverse methods,including hot-water extraction(HWE),ultrasonic-assisted extraction(UAE),enzyme-assisted extraction(EAE),dilute acid-water extraction(ACWE),and dilute alkali-water extraction(ALWE).These extractions were subsequently precipitated at final ethanol concentrations of 80%and 95%,respectively.The investigation encompassed yields,total carbohydrate content(TCC),total protein content(TPC),preliminary structural properties,and anti-DOX myocardial cytotoxic activity.Results indicated that the extraction method significantly influenced the physicochemical properties,associated functional properties,and anti-DOX myocardial cytotoxic activity of BsPs.HWE and UAE yielded higher BsPs quantities.The relative molecular weight(RMW)distribution of BsPs differed notably between HWE or UAE,EAE,ACWE,and ALWE.The RMW of primary BsPs obtained from HWE and UAE(1.9×10^(7)-1.7×10^(7) Da)exceeded that from EAE(7.5×10^(3)-2.8×10^(4) Da)and ALWE(5.1×10^(4)-1.7×10^(4) Da),with smaller molecular weights primarily precipitated by higher ethanol concentrations.BsPs were composed of Man and Glu,with partial fractions containing small amounts of Gal or Ara,displaying varying molar ratios.Notably,BsPs from ACWE exhibited the most significant structural differences,lacking 1,4-α-D-Glcp and a triple-helical structure.Furthermore,BsPs obtained from HWE,UAE,and EAE demonstrated heightened anti-DOX myocardial cytotoxic activity compared to other methods.This study underscored the influence of extraction methods on BsPs’structure and myocardial protective activity,offering a foundation for exploring structural diversity and employing specific extraction methods to extract polysaccharides with robust myocardial protective properties efficiently.展开更多
Two-dimensional disordered granular assemblies composed of 2048 polydispersed frictionless disks are simulated using the discrete element method. The height of the first peak of the pair correlation function, gl, the ...Two-dimensional disordered granular assemblies composed of 2048 polydispersed frictionless disks are simulated using the discrete element method. The height of the first peak of the pair correlation function, gl, the local and global bond orientational parameters ψ6^1 and ψ6^g, and the fluctuations of these parameters decrease with increasing polydispersity s, implying the transition from a polycrystalline state to an amorphous state in the system. As s increases, the peak position of the boson peak aJBp shifts towards a lower frequency and the intensity of the boson peak D（ωBP）/ωBp increases, indicating that the position and the strength of the boson peak are controlled by the polydispersity of the system. Moreover, the inverse of the boson peak intensity ωBP/D（ωBP）, the shear modulus G, and the basin curvature SIS all have a similar dependence on s, implying that the s dependence of the vibrational density of states at low frequencies likely originates from the s dependence of the basin curvature.展开更多
BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes ...BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes in neurotransmitters,brain structural characteristics,and the scores of the Positive and Negative Symptom Scale(PANSS)in patients with first-episode schizophrenia.METHODS The case group comprised 97 patients with schizophrenia,who were evaluated using the Canadian Neurological Scale and confirmed by laboratory tests at Ningbo Mental Hospital from January 2020 to July 2022.The control group comprised 100 healthy participants.For all participants,brain structural characteristics were explored by measuring brain dopamine(DA),glutamic acid(Glu),and gamma-aminobutyric acid(GABA)levels,with magnetic resonance imaging.The case group was divided into negative and positive symptom subgroups using PANSS scores for hierarchical analysis.Linear correlation analysis was used to analyze the correlations between neurotransmitters,brain structural character istics,and PANSS scores.RESULTS Patients in the case group had higher levels of DA and lower levels of Glu and GABA,greater vertical and horizontal distances between the corpus callosum and the inferior part of the fornix and larger ventricle area than patients in the control group(P<0.05).Patients with positive schizophrenia symptoms had significantly higher levels of DA,Glu,and GABA than those with negative symptoms(P<0.05).In patients with positive schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical and horizontal distances between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).In patients with negative schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical distance between the corpus callosum and the infrafornix,horizontal distance between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).CONCLUSION In patients with first-episode schizophrenia,DA levels increased,Glu and GABA levels decreased,the thickness of the corpus callosum increased,and these variables were correlated with PANSS scores.展开更多
Using the NCEP 1°×1°reanalysis data,several obvious differences of the structural characteristics of developed versus undeveloped mid-level vortexes are studied.First,the central vorticity of the develo...Using the NCEP 1°×1°reanalysis data,several obvious differences of the structural characteristics of developed versus undeveloped mid-level vortexes are studied.First,the central vorticity of the developed mid-level vortex increases towards higher levels while the undeveloped one decreases.The low-level convergence structure maintains well in the developed mid-level vortex whereas the undeveloped one does badly.Second,on the one hand,according to the symmetric analysis,the horizontal wind field and wind vertical section of the developed mid-level vortex are well symmetric while those of the undeveloped one are less symmetric.Meanwhile,weak wind vertical shear help the developed mid-level vortex to establish a warm core in upper-and mid-levels of the troposphere.On the other hand,according to the balance analysis,better balance between wind and pressure is shown in the mid-and lower-levels of the troposphere of the developed mid-level vortex than in those of the undeveloped vortex.Third,positive anomaly of potential vorticity is enhanced and developed in the vertical direction of the developed vortex.However,the undeveloped vortex weakens with a weak positive anomaly.展开更多
The pinna of Cycasferruginea F.N. Wei （Cycadaceae）, pinnas or rachises ofStangeria eriopus （Kune） Baill. （Stangeriaceae）, Dioon holmgrenii De Luca, Sabato ＆ Vazq. Torres, Macrozamia moorei F. Muell. ex C. Moore...The pinna of Cycasferruginea F.N. Wei （Cycadaceae）, pinnas or rachises ofStangeria eriopus （Kune） Baill. （Stangeriaceae）, Dioon holmgrenii De Luca, Sabato ＆ Vazq. Torres, Macrozamia moorei F. Muell. ex C. Moore （Zamiaceae） were macerated and dissociated by Jeffrey＇s technique, rinsed with water, dehydrated and gold-plated for observation with scanning electron microscopes. The results showed that the pinna and rachis of the leaf tissues of the four cycad species possess many vessel elements and a few tracheid elements in the conducting tissue of the xylem. Annular, spiral, scalariform, pitted and reticulate vessels and some transitional types, including scalariform-pitted, scalariform-reticulate and reticulate-pitted vessels, were observed in the conducting tissues. The characteristics of the vessels of each species, and the evolutionary relation of four genera of cycads were analyzed. Compared with those of angiosperms, the structural characters of vessels of cycad are at the moderate level of evolution and more advanced than some primitive taxa of angiosperms and ferns. Vessels have been discovered in many genera of ferns, which are even more primitive than cycads. In many ferns, only vessel elements, but no tracheids are found in vascular tissue. In the present study, the authors discovered vessels in different genera of three families ofcycads which showed that the existence of vessels in primitive plant taxa is a widespread phenomenon. Vessel elements in vascular tissues of cycads have probably allowed cycads to adapt to various environmental stresses and enabled their persistence over their long evolutionary history. Cycads are the most primitive of the extant seed plants and the widespread existence of vessels in the group has broad implications for plant systematics, evolution and comparative morphology.展开更多
The Suoluogou gold deposit in Muli County of Sichuan Province is located in the southern section of the Ganzi- Litang suture zone （Figs. la, b）, which is the largest gold deposit discovered in this suture zone in re...The Suoluogou gold deposit in Muli County of Sichuan Province is located in the southern section of the Ganzi- Litang suture zone （Figs. la, b）, which is the largest gold deposit discovered in this suture zone in recent years. At present, the exploration of the Suoluogou gold deposit is still in progress, and the amount of resource is increasing.展开更多
Structural characteristics of the Jurassic basins of Xining, Minhe, and Xiji in the east of middle Qilian were researched based on the data obtained by gravitational, magnetic, and seismic methods. The result shows th...Structural characteristics of the Jurassic basins of Xining, Minhe, and Xiji in the east of middle Qilian were researched based on the data obtained by gravitational, magnetic, and seismic methods. The result shows that each of these three basins is an independent structural unit with a NW strike and being separated by upheavals. Two groups of faults with NW and NE directions are developed in the basin, which controls the formation and evolution of the (Jurassic basins). The NW faults are the main ones while the NE faults are the secondary for controlling the sedimentation. Of the three basins, the Minhe basin is the favorable prospecting area.展开更多
Semen coicis resistant starch is a type of starch which has undergone retrogradation. In this study,the structural characteristics of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Seme...Semen coicis resistant starch is a type of starch which has undergone retrogradation. In this study,the structural characteristics of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Semen coicis resistant starch were investigated. The field emission scanning electron microscopy results indicated that compared to Semen coicis native starch and high-amylose maize starch,the surface of heat-moisture treated Semen coicis resistant starch was rough and full of irregular layered strips. The Fourier transform infrared spectroscopy measurements indicated the degree of ordered structure values of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Semen coicis resistant starch are 1.355,1.372,and 1.410,respectively,and the degree of double helix values is 1.931,1.942,and 2.027,respectively,indicating that the degree of ordered structure and double helix structure of heat-moisture treated Semen coicis resistant starch is both higher than those of Semen coicis native starch and high-amylose maize starch. ^（13） C nuclear magnetic resonance spectroscopy showed that Semen coicis native starch and high-amylose maize starch exhibited A-type crystal structures,while heat-moisture treated Semen coicis resistant starch displayed B-type crystal structures. The relative crystallinity of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Semen coicis resistant starch is 76.41,85.36,and 87.25,respectively,and the percentages of amorphous region are 5.78,4.72,and 4.39,respectively. Additionally,heat-moisture treated Semen coicis resistant starch could increase the proliferation of Bifidobacterium bifidum more than Semen coicis native starch or high-amylose maize starch. Bifidobacterium bifidum displayed a higher tolerance under simulated gastrointestinal tract conditions such as low p H,bile acid,pepsin,and trypsin in heat-moisture treated Semen coicis resistant starch medium than in Semen coicis native starch or high-amylose maize starch media.展开更多
Exploration and development practices prove that intracratonic strikeeslip faults control the development of carbonate reservoirs and the enrichment of oil and gas in the Tarim Basin.Intracratonic strikeeslip faults a...Exploration and development practices prove that intracratonic strikeeslip faults control the development of carbonate reservoirs and the enrichment of oil and gas in the Tarim Basin.Intracratonic strikeeslip faults are characterized by short displacement,small throw and great burial depth,so there are still many controversies on their structural evolution and formation mechanisms.In order to settle these controversies,this paper firstly analyzes the geometric and kinematic characteristics of the intracratonic strikeeslip faults in the central Tarim Basin.Then,based on extensive high-accuracy 3D seismic data and 2D seismic data,the formation and evolution process of the intracratonic strikeeslip faults in the Tarim Basin are discussed deeply,and their genetic mechanisms are explored.Moreover,the following research results are obtained.First,the strikeeslip faults in the study area have the characteristics of vertical stratification,plane zonation and segmentation along the strike.Second,the movement directions of the deep transpressional strikeeslip faults are simple.The NE and NNE strikeeslip faults are sinistral,and the NNW strikeeslip faults are dextral.However,the shallow transtensional faults are more different in the movement direction.The strikeeslip faults have displacements of 400e1500 m,and they are classified as intracratonic strikeeslip faults with small slip distance.Third,the strikeeslip faults were formed in the middle Caledonian,and some faults were reactivated in the late Caledonianeearly Hercynian,late Hercynian,and Yanshanianeearly Himalayan.The distribution of faults is different in different periods.Fourth,the formation of the strikeeslip faults in the middle Caledonian is controlled by the basement heterogeneity and the compression action from the closure and subduction of the Proto-Tethys Ocean.The transtensional faults are R-shear branch faults or tensile break faults generated by the later activation of middle Caledonian strike-slip faults,and their formation is controlled by the subduction and closure of oceanic basins around the basins in different periods.In conclusion,the structural characteristics,formation&evolution and genetic mechanisms of intracratonic strikeeslip faults are in close relation to oil and gas,where great benefit of oil and gas exploration and development is achieved.Besides the Tarim Basin,the Sichuan Basin and the Ordos Basin have similar geological and structural settings,so the studies on typical basins will surely enrich and complete the theories on the intracratonic strikeeslip faults in domestic micro land blocks and multi-cycle basins and point out the direction for the discovery of more oil and gas resource.展开更多
For the sake of figuring out the influential mechanisms of structural characteristics on the productivity of shale gas wells,the structural characteristics of the Jiaoshiba Block in the Fuling shale gasfield,Sichuan B...For the sake of figuring out the influential mechanisms of structural characteristics on the productivity of shale gas wells,the structural characteristics of the Jiaoshiba Block in the Fuling shale gasfield,Sichuan Basin,were analyzed.Then,based on well test data of more than 190 horizontal wells,the effects of structures on shale gas well productivity were discussed systematically,and the main structural factors of different structural units in the Jiaoshiba Block that influence the productivity of shale gas wells were clarified.The following results were obtained.First,the structural units in the Jiaoshiba Block were obviously different in structural characteristics and their deformation strength is different.Second,the influence of structural characteristics on shale gas well productivity is directly manifested in gas-bearing property and fracturing effect.The stronger the structural deformation and the more developed the large faults and natural fractures,the more easily shale gas escapes and the poorer the gas bearing property will be,and vice versa.Third,The stronger the structural deformation,the more developed the fractures,the greater the burial depth and the higher the compressive stress of negative structures,the worse the fracturing effect will be,and vice versa.And fourth,Tectonics is the key factor controlling the difference of shale gas productivity between different structural units in the Jiaoshiba Block,but the main structural factors influencing the productivity are different in different structural units.展开更多
The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural...The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The 'optimum surface' is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center.展开更多
It is known that structural stiffness and strength distributions have an important role in the seismic response of buildings. The effect of using different code-specified lateral load patterns on the seismic performan...It is known that structural stiffness and strength distributions have an important role in the seismic response of buildings. The effect of using different code-specified lateral load patterns on the seismic performance of fixed-base buildings has been investigated by researchers during the past two decades. However, no investigation has yet been carried out for the case of soil-structure systems. In the present study, through intensive parametric analyses of 21,600 linear and nonlinear MDOF systems and considering five different shear strength and stiffness distribution patterns, including three code-specified patterns as well as uniform and concentric patterns subjected to a group of earthquakes recorded on alluvium and soft soils, the effect of structural characteristics distribution on the strength demand and ductility reduction factor of MDOF fixed-base and soil-structure systems are parametrically investigated. The results of this study show that depending on the level of inelasticity, soil flexibility and number of degrees-of-freedoms (DOFs), structural characteristics distribution can significantly affect the strength demand and ductility reduction factor of MDOF systems. It is also found that at high levels of inelasticity, the ductility reduction factor of low-rise MDOF soil-structure systems could be significantly less than that of fixed-base structures and the reduction is less pronounced as the number of stories increases.展开更多
The Zhaotong National Shale Gas Demonstration Area along the southern margin of the Sichuan Basin is located in the complex marine tectonic area of South China,where shale deformation and reformation are intense and t...The Zhaotong National Shale Gas Demonstration Area along the southern margin of the Sichuan Basin is located in the complex marine tectonic area of South China,where shale deformation and reformation are intense and the factors controlling sweet spots are complex,so the preservation conditions have an important impact on the enrichment of shale gas.In order to support the selection and evaluation of shale gas sweet spots in this area and improve the success rate of drilling,this paper carried out a geological survey onfield outcrops.Then,based on drilling,mud logging and physical property test data,the structural deformation pattern and the regional deformation characteristics of this demonstration area were analyzed,and the development characteristics of formation joints and fractures,the sealing capacity of shale sur-rounding rock and the distribution characteristics of gas reservoirs were studied.Finally,the preservation conditions of shale gas in the Wufeng Formation of Upper Ordovician and the Longmaxi Formation of Lower Silurian were discussed.And the following research results were ob-tained.First,in the Zhaotong National Shale Gas Demonstration Area,three structural deformation patterns are developed from south to north,including trough type,equal amplitude type and baffle type,which are distributed in three major deformation zones,respectively,i.e.,the shear deformation zone of Central Guizhou Uplift,the compressionetorsion deformation zone of northern YunnaneGuizhou Depression and the compression deformation zone of Southern Sichuan Depression.Second,three types of joints and fractures whose relationships with the di-rection of strata are high angle,middleelow angle and bedding intersection are developed in the WufengeLongmaxi formations and its overlying strata,and their occurrence characteristics are basically consistent with those of the three major deformation zones.Third,the shale of WufengeLongmaxi formations is thick in the north and thin in the south and possesses the preservation conditions of sourceereservoir inte-gration and self-sealing hydrocarbon accumulation.And combined with the sealing ability of the overburden strata and the roof andfloor,its preservation conditions are overall better.Fourth,from the perspective of shale gas component,this area can be divided into three belts,i.e.,methane,methaneþnitrogen mixture and nitrogen from north to south.And the preservation conditions of shale gas are generally better in the north and worse in the south.In conclusion,the shale in the centralenorthern part of Zhaotong National Shale Gas Demonstration Area(compression deformation area and its southern margin)is the most favorable area because of its large shale thickness,weak reformation and deformation,bedding development of joints and fractures,good sealing performance and excellent preservation conditions.The compressionetorsion deformation zone of northern YunnaneGuizhou Depression in the central part is moderate in preservation conditions,and it is the relatively favorable area.The shear deformation zone of Central Guizhou Uplift in the southern part has poor preservation conditions,and it is a prospective area.展开更多
This study selected the Sino-US route data from the top 30 global container liner companies between December 1,2019,and December 29,2019,as the data source utilizing the complex network research methodology.It constru...This study selected the Sino-US route data from the top 30 global container liner companies between December 1,2019,and December 29,2019,as the data source utilizing the complex network research methodology.It constructs a Sino-US container shipping network through voyage weighting and analyzes the essential structural characteristics to explore the network’s complex structural fea-tures.The network’s evolution is examined from three perspectives,namely,time,space,and event influence,aiming to comprehens-ively explore the network’s evolution mechanism.The results revealed that:1)the weighted Sino-US container shipping network exhib-its small-world and scale-free properties.Key hub ports in the United States include NEW YORK NY,SAVANNAH GA,LOS ANGELES CA,and OAKLAND CA,whereas SHANGHAI serving as the hub port in China.The geographical distribution of these hub ports is uneven.2)Concerning the evolution of the weighted Sino-US container shipping network,from a temporal perspective,the evolution of the regional structure of the entire Sino-US region and the Inland United States is in a stage of radiative expansion and de-velopment,with a need for further enhancement in competitiveness and development speed.The evolution of the regional structure of southern China and Europe is transitioning from the stage of radiative expansion and development to an advanced equilibrium stage.The shipping development in Northern China,the Western and Eastern United States,and Asia is undergoing significant changes but faces challenges of fierce competition and imbalances.From a spatial perspective,the rationality and effectiveness of the improved weighted Barrat-Barthelemy-Vespignani(BBV)model are confirmed through theoretical derivation.The applicability of the improved evolution model is verified by simulating the evolution of the weighted Sino-US container shipping network.From an event impact per-spective,the Corona Virus Disease 2019(COVID-19)pandemic has not fundamentally affected the spatial pattern of the weighted Sino-US container shipping network but has significantly impacted the network’s connectivity.The network lacks sufficient resilience and stability in emergency situations.3)Based on the analysis of the structural characteristics and evolution of the weighted Sino-US con-tainer shipping network,recommendations for network development are proposed from three aspects:emphasizing the development of hub ports,focusing on the balanced development of the network,and optimizing the layout of Chinese ports.展开更多
基金Supported by the National Natural Science Foundation of China(42472190)Chongqing Natural Science Foundation Innovation and Development Joint Fund Project(CSTB2022NSCQ-LZX0020)Chongqing Talent Innovation and Entrepreneurship Leading Talent Project(0255-19230101042)。
文摘Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods of the coal-bearing formations were determined,and the fault systems were divided.Combined with the coal seam thickness and actual gas indication in logging,the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified.The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture,and contains coal-bearing formations and five sub-types of fault systems under three types.The horizontal extension strength,vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences,accumulation intensity,and accumulation frequency of coal seam in rift basin.The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts.The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area.The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane.The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source,affecting the enrichment degree of coal-rock gas.The vertical sealing of the faults was evaluated by using shale smear factor(SSF),and the evaluation criterion was established.It is indicated that the SSF is below 1.1 in major coal areas,indicating favorable preservation conditions for coal-rock gas.Based on the influence factors such as fault activity,segmentation and sealing,the coal-rock gas accumulation model of rift basin was established.
文摘In this paper, a typical mei-yu front process with heavy rainfall from June 12 to 15 in 1998 is analyzed. The results show that the mei-yu front is a front system which consists of an iso-theta(e) dense area with strong horizontal gradient, a deep-convective cloud tower band, a passageway transporting warm and moist air flow from the summer monsoon surge in the mid and low levels to the south of the mei-yu front, and a migrating synoptic scale trough to the north of the mei-yu front, which transports cold and dry air southward in the mid and upper levels. The maintenance of the mei-yu front is realized by: (1) is a positive feedback between the moist physical process enhancing frontogenesis and the development of the strong convective system in front of the mei-yu front; (2) the sustaining system to the north of the mei-yu front which is a migrating synoptic scale trough transporting cold and dry air to the mei-yu front and positive vorticity to the mesoscale system in front of the mei-yu front.
基金funded by the National Key Research and Development Program‘Deep Land Resources Exploration and Exploitation’special project(2017YFC0603106)the Project of Science and Technology Department of the Southwest Oil and Gas Field Company,Petrochina(20210301-02)。
文摘Based on 2D and 3D seismic data,the latest drilling data and field outcrop data of the northern slope of the Central Sichuan paleo-uplift,the structural analysis method is used to analyze unconformity development characteristics and fault characteristics during the key structural transformation period,discussing the influence of the structural characteristics on the hydrocarbon accumulation of deep carbonate rocks.The results show that:(1)The two key unconformities of the Tongwan and Caledonian periods were primarily developed in deep carbonate rocks.Firstly,Tongwan’s unconformities are characterized by regional disconformities between the second and third members of the Dengying Formation,the top formation of the Sinian and the lower Cambrian,strips of which zigzag through the north and south sides of the study area.Secondly,the Caledonian unconformity is characterized by a regional unconformable contact between the lower Permian and the ower Paleozoic strata.From NE to SW,the age of the strata,which were subject to erosion,changes from new to old,the denudation distribution showing as a nose-shaped structure which inclines towards the ENE.(2)Boundary fault and transtensional strike-slip faults developed in the Sinian to Paleozoic strata.In profile,there are three types of structural styles:steep and erect,flower structures,’Y’and reversed’Y’type faults.In plane view,the Sinian developed extensional boundary faults extending in an almost NS direction,strike-slip faults developing and extending linearly in approximately EW,WNW and NE strikes in the Cambrian,with characteristically more in the south and less in the north.(3)The faults in the northern slope show obvious zonal deformations in transverse view as well as significant stages and stratified activity in a longitudinal direction.Among them,the activity of faults in the Sinian was the strongest,followed by the activity in the Cambrian period,the activity intensity of faults in the Permian period being the weakest.This fault activity can be divided into four periods:Sinian,Cambrian-Permian,the early Indosinian period and the late Indosinian-Himalayan period,the transtensional strikeslip faults being the products of oblique extensions of pre-existing weak zones in the Xingkai and Emei taphrogenesis,with a particular inheritance in the main faults.(4)Combined with hydrocarbon accumulation factors,it is considered that the epigenetic karstification of the Tongwan and Caledonian unconformities in the northern slope controlled the formation and distribution of carbonate karst reservoirs over a large area,also acting as a good pathway for oil and gas migration.The extensional faults developed at the margin of the NS trending rift,controlling the sag-platform sedimentary pattern in the Dengying Formation of the Sinian.Strike-slip faults in NE,WNW and ENE directions may control the microgeomorphological pattern inside the platform and intensify the differential distribution of grain beach facies.The multi-stage hereditary activity of strike-slip faults not only improved the porosity and permeability of the reservoirs,but also acted as the main channel of oil and gas migration,providing favorable conditions for the development of the current multi-layer gasbearing scenario in the northern slope of the Central Sichuan Basin.
文摘The effect of application of pig manure (PM) on the structural characteristics of humic acids (HAs) of brown soil was studied in field and incubation experiments. The results showed that the number-average molecular weights (Mn), the ratios of C/ H, C/ N and O/C, the contents of carboxyl and phenolic hydroxyl groups, the content ofaromatic C, the values of E2, E4and λ Exmax of HAs all decreased; whereas, the contents of alkyl C and O-alkyl C, the ratio of carboxyl to phenolic hydroxyl groups, the degree of oxidation stability, the absorption intensity at 285 mμ (UV), and 2920cm-1 of HAs increased after the application of PM. The above results indicated that the molecular structure of HAs tended to be more aliphatic and simpler after the application of PM.
基金Supported by National Natural Science Foundation of China(Grant No.51675180)National Key Basic Research Program of China(973 Program,Grant No.2013CB037503)
文摘To improve the adaptability of TBMs in diverse geological environments,this paper proposes a reconfigurable Type-V thrust mechanism(V-TM)with rearrangeable working states,in which structural stiffness can be automatically altered during operation.Therefore,millions of configurations can be obtained,and thousands of instances of working status per configuration can be set respectively.Nonetheless,the complexity of configurations and diversity of working states contributes to further complications for the structural stiffness algorithm.This results in challenges such as difficulty calculating the payload compliance index and the environment adaptability index.To solve this problem,we use the configuration matrix to describe the relationship between propelling jacks under reconfiguration and adopt pattern vectors to describe the working state of each hydraulic cylinder.Then,both the dynamic compatible equation between propeller forces of the hydraulic cylinders and driving forces,and the kinematic harmonizing equation between the hydraulic cylinder displacements and their deformations are established.Next,we derive the stiffness analytical equation using Hooke’s law and the Jacobian Matrix.The proposed approach provides an effective algorithm to support structural rigidity analysis,and lays a solid theoretical foundation for calculating the performance indexes of the V-TM.We then analyze the rigidity characteristics of typical configurations under different working states,and obtain the main factors affecting structural stiffness of the V-TM.The results show the deviation degree of structural parameters in hydraulic cylinders within the same group,and the working status of propelling jacks.Finally,our constructive conclusions contribute valuable information for matching and optimization by drawing on the factors that affect the structural rigidity of the V-TM.
基金Open Research Fund for 2006 from State Key Laboratory Severe Weather, Chinese Academyof Meteorological Sciences (2006LASW08)Development and Planning Project for Key State FundamentalResearch (2006CB403607 2004CB418300)
文摘By employing the NCEP/NCAR reanalysis data sets (1000-10hPa, 2.5°× 2.5°), the characteristics have been analyzed of the structure and evolution of an easterly vortex over the tropical upper troposphere relating to the east-west direction shift of the subtropical anticyclone over the Western Pacific Ocean. It is shown that there exists a westward shift simultaneously between the anticyclone and the vortex locating south of it. The anticyclone retreats eastward abnormally while the easterly encounters with the westerly around the same longitudes as they move from the opposite directions. The former is an upper weather system, extending from mid-troposphere to the height of 50 hPa with the center locating on 200 hPa. The vertical thermal distribution illustrates the characteristics of being"warm in the upper layer but cold in the lower layer". The divergence effect and the vertical motion change largely within the east and west sides of the easterly vortex and ascending branch transforms to descending branch near its center.
基金Science and Technology Foundation of Guizhou Province(Grant No.QKHJC-ZK[2023]YB524)Science and Technology Plan Project of Guizhou,China(Grant No.QKPTRC[2019]035)+2 种基金Science and Technology Foundation of Guizhou Province(Grant No.QKH[2019]1346)Science and Technology Department of Zunyi city of Guizhou province of China(Grant No.[2020]7)Undergraduate Training Program for Innovation and Entrepreneurship of Zunyi Medical University(Grant No.S202310661248).
文摘Doxorubicin(DOX)is a widely employed tumor therapy,yet its substantial toxic side effects pose a considerable challenge.Bletilla striata has demonstrated efficacy in preventing and treating these toxic side effects in clinical practice,with polysaccharides identified as the principal active component.In the present study,16 fractions of B.striata polysaccharides(BsPs)were extracted using diverse methods,including hot-water extraction(HWE),ultrasonic-assisted extraction(UAE),enzyme-assisted extraction(EAE),dilute acid-water extraction(ACWE),and dilute alkali-water extraction(ALWE).These extractions were subsequently precipitated at final ethanol concentrations of 80%and 95%,respectively.The investigation encompassed yields,total carbohydrate content(TCC),total protein content(TPC),preliminary structural properties,and anti-DOX myocardial cytotoxic activity.Results indicated that the extraction method significantly influenced the physicochemical properties,associated functional properties,and anti-DOX myocardial cytotoxic activity of BsPs.HWE and UAE yielded higher BsPs quantities.The relative molecular weight(RMW)distribution of BsPs differed notably between HWE or UAE,EAE,ACWE,and ALWE.The RMW of primary BsPs obtained from HWE and UAE(1.9×10^(7)-1.7×10^(7) Da)exceeded that from EAE(7.5×10^(3)-2.8×10^(4) Da)and ALWE(5.1×10^(4)-1.7×10^(4) Da),with smaller molecular weights primarily precipitated by higher ethanol concentrations.BsPs were composed of Man and Glu,with partial fractions containing small amounts of Gal or Ara,displaying varying molar ratios.Notably,BsPs from ACWE exhibited the most significant structural differences,lacking 1,4-α-D-Glcp and a triple-helical structure.Furthermore,BsPs obtained from HWE,UAE,and EAE demonstrated heightened anti-DOX myocardial cytotoxic activity compared to other methods.This study underscored the influence of extraction methods on BsPs’structure and myocardial protective activity,offering a foundation for exploring structural diversity and employing specific extraction methods to extract polysaccharides with robust myocardial protective properties efficiently.
基金supported by the National Natural Science Foundation of China(Grant Nos.11272048,51239006,and 11034010)the European Commission MarieCurie Actions(Grant No.IRSES-294976)the National Basic Research Program of China(Grant No.2010CB731504)
文摘Two-dimensional disordered granular assemblies composed of 2048 polydispersed frictionless disks are simulated using the discrete element method. The height of the first peak of the pair correlation function, gl, the local and global bond orientational parameters ψ6^1 and ψ6^g, and the fluctuations of these parameters decrease with increasing polydispersity s, implying the transition from a polycrystalline state to an amorphous state in the system. As s increases, the peak position of the boson peak aJBp shifts towards a lower frequency and the intensity of the boson peak D（ωBP）/ωBp increases, indicating that the position and the strength of the boson peak are controlled by the polydispersity of the system. Moreover, the inverse of the boson peak intensity ωBP/D（ωBP）, the shear modulus G, and the basin curvature SIS all have a similar dependence on s, implying that the s dependence of the vibrational density of states at low frequencies likely originates from the s dependence of the basin curvature.
文摘BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes in neurotransmitters,brain structural characteristics,and the scores of the Positive and Negative Symptom Scale(PANSS)in patients with first-episode schizophrenia.METHODS The case group comprised 97 patients with schizophrenia,who were evaluated using the Canadian Neurological Scale and confirmed by laboratory tests at Ningbo Mental Hospital from January 2020 to July 2022.The control group comprised 100 healthy participants.For all participants,brain structural characteristics were explored by measuring brain dopamine(DA),glutamic acid(Glu),and gamma-aminobutyric acid(GABA)levels,with magnetic resonance imaging.The case group was divided into negative and positive symptom subgroups using PANSS scores for hierarchical analysis.Linear correlation analysis was used to analyze the correlations between neurotransmitters,brain structural character istics,and PANSS scores.RESULTS Patients in the case group had higher levels of DA and lower levels of Glu and GABA,greater vertical and horizontal distances between the corpus callosum and the inferior part of the fornix and larger ventricle area than patients in the control group(P<0.05).Patients with positive schizophrenia symptoms had significantly higher levels of DA,Glu,and GABA than those with negative symptoms(P<0.05).In patients with positive schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical and horizontal distances between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).In patients with negative schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical distance between the corpus callosum and the infrafornix,horizontal distance between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).CONCLUSION In patients with first-episode schizophrenia,DA levels increased,Glu and GABA levels decreased,the thickness of the corpus callosum increased,and these variables were correlated with PANSS scores.
基金Program for Key National Fundamental Research"Program 973"(2009CB421501)Natural Science Foundation of China(40875026)+1 种基金Specialized Scientific Research for Public Welfare Industry(Meteorological Sector)(GYHY200906008)Meteorological Sciences Research Project on Early Warning and Forecasting Technology for Marine Meteorology of the Guangdong Provincial Bureau of Meteorology
文摘Using the NCEP 1°×1°reanalysis data,several obvious differences of the structural characteristics of developed versus undeveloped mid-level vortexes are studied.First,the central vorticity of the developed mid-level vortex increases towards higher levels while the undeveloped one decreases.The low-level convergence structure maintains well in the developed mid-level vortex whereas the undeveloped one does badly.Second,on the one hand,according to the symmetric analysis,the horizontal wind field and wind vertical section of the developed mid-level vortex are well symmetric while those of the undeveloped one are less symmetric.Meanwhile,weak wind vertical shear help the developed mid-level vortex to establish a warm core in upper-and mid-levels of the troposphere.On the other hand,according to the balance analysis,better balance between wind and pressure is shown in the mid-and lower-levels of the troposphere of the developed mid-level vortex than in those of the undeveloped vortex.Third,positive anomaly of potential vorticity is enhanced and developed in the vertical direction of the developed vortex.However,the undeveloped vortex weakens with a weak positive anomaly.
基金There are 8 projects supported by National Natural Science Foundation of China which Dr. Y.Y. Huang have taken charge of and/or taken part in Dr. Y.Y. Huang have published 5 bookmakings and more than 100 papers.
文摘The pinna of Cycasferruginea F.N. Wei （Cycadaceae）, pinnas or rachises ofStangeria eriopus （Kune） Baill. （Stangeriaceae）, Dioon holmgrenii De Luca, Sabato ＆ Vazq. Torres, Macrozamia moorei F. Muell. ex C. Moore （Zamiaceae） were macerated and dissociated by Jeffrey＇s technique, rinsed with water, dehydrated and gold-plated for observation with scanning electron microscopes. The results showed that the pinna and rachis of the leaf tissues of the four cycad species possess many vessel elements and a few tracheid elements in the conducting tissue of the xylem. Annular, spiral, scalariform, pitted and reticulate vessels and some transitional types, including scalariform-pitted, scalariform-reticulate and reticulate-pitted vessels, were observed in the conducting tissues. The characteristics of the vessels of each species, and the evolutionary relation of four genera of cycads were analyzed. Compared with those of angiosperms, the structural characters of vessels of cycad are at the moderate level of evolution and more advanced than some primitive taxa of angiosperms and ferns. Vessels have been discovered in many genera of ferns, which are even more primitive than cycads. In many ferns, only vessel elements, but no tracheids are found in vascular tissue. In the present study, the authors discovered vessels in different genera of three families ofcycads which showed that the existence of vessels in primitive plant taxa is a widespread phenomenon. Vessel elements in vascular tissues of cycads have probably allowed cycads to adapt to various environmental stresses and enabled their persistence over their long evolutionary history. Cycads are the most primitive of the extant seed plants and the widespread existence of vessels in the group has broad implications for plant systematics, evolution and comparative morphology.
基金financially supported by the Program of the China Geological Survey (grant No.12120114012501 and 1212011120608)
文摘The Suoluogou gold deposit in Muli County of Sichuan Province is located in the southern section of the Ganzi- Litang suture zone （Figs. la, b）, which is the largest gold deposit discovered in this suture zone in recent years. At present, the exploration of the Suoluogou gold deposit is still in progress, and the amount of resource is increasing.
文摘Structural characteristics of the Jurassic basins of Xining, Minhe, and Xiji in the east of middle Qilian were researched based on the data obtained by gravitational, magnetic, and seismic methods. The result shows that each of these three basins is an independent structural unit with a NW strike and being separated by upheavals. Two groups of faults with NW and NE directions are developed in the basin, which controls the formation and evolution of the (Jurassic basins). The NW faults are the main ones while the NE faults are the secondary for controlling the sedimentation. Of the three basins, the Minhe basin is the favorable prospecting area.
基金Supported by the National Natural Science Fund of China(No.31301441)the Cooperation in Production,Study and Research of Science and Technology Major Projects of Fujian Province(2012N5004)+2 种基金the Natural Science Foundation of Fujian Province(2012J01081)the Scientific and Technological Innovation Team Support Plan of Institution of Higher Learning in Fujian Province([2012]03)the Scientific and Technological Innovation Team Support Plan of Fujian Agriculture and Forestry University(cxtd12009)
文摘Semen coicis resistant starch is a type of starch which has undergone retrogradation. In this study,the structural characteristics of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Semen coicis resistant starch were investigated. The field emission scanning electron microscopy results indicated that compared to Semen coicis native starch and high-amylose maize starch,the surface of heat-moisture treated Semen coicis resistant starch was rough and full of irregular layered strips. The Fourier transform infrared spectroscopy measurements indicated the degree of ordered structure values of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Semen coicis resistant starch are 1.355,1.372,and 1.410,respectively,and the degree of double helix values is 1.931,1.942,and 2.027,respectively,indicating that the degree of ordered structure and double helix structure of heat-moisture treated Semen coicis resistant starch is both higher than those of Semen coicis native starch and high-amylose maize starch. ^（13） C nuclear magnetic resonance spectroscopy showed that Semen coicis native starch and high-amylose maize starch exhibited A-type crystal structures,while heat-moisture treated Semen coicis resistant starch displayed B-type crystal structures. The relative crystallinity of Semen coicis native starch,high-amylose maize starch,and heat-moisture treated Semen coicis resistant starch is 76.41,85.36,and 87.25,respectively,and the percentages of amorphous region are 5.78,4.72,and 4.39,respectively. Additionally,heat-moisture treated Semen coicis resistant starch could increase the proliferation of Bifidobacterium bifidum more than Semen coicis native starch or high-amylose maize starch. Bifidobacterium bifidum displayed a higher tolerance under simulated gastrointestinal tract conditions such as low p H,bile acid,pepsin,and trypsin in heat-moisture treated Semen coicis resistant starch medium than in Semen coicis native starch or high-amylose maize starch media.
基金Project supported by the National Major Science and Technology Project"Hydrocarbon Accumulation Law,Key Technologies and Target Evaluation of Lower PaleozoicePrecambrian Carbonate Rocks"(No.:2016ZX05004-001)PetroChina Major Science and Technology Project in the 13th Five-Year Plan"Distribution Law and Key Technologies of Ancient Carbonate Reservoirs"(No.:2019B-04).
文摘Exploration and development practices prove that intracratonic strikeeslip faults control the development of carbonate reservoirs and the enrichment of oil and gas in the Tarim Basin.Intracratonic strikeeslip faults are characterized by short displacement,small throw and great burial depth,so there are still many controversies on their structural evolution and formation mechanisms.In order to settle these controversies,this paper firstly analyzes the geometric and kinematic characteristics of the intracratonic strikeeslip faults in the central Tarim Basin.Then,based on extensive high-accuracy 3D seismic data and 2D seismic data,the formation and evolution process of the intracratonic strikeeslip faults in the Tarim Basin are discussed deeply,and their genetic mechanisms are explored.Moreover,the following research results are obtained.First,the strikeeslip faults in the study area have the characteristics of vertical stratification,plane zonation and segmentation along the strike.Second,the movement directions of the deep transpressional strikeeslip faults are simple.The NE and NNE strikeeslip faults are sinistral,and the NNW strikeeslip faults are dextral.However,the shallow transtensional faults are more different in the movement direction.The strikeeslip faults have displacements of 400e1500 m,and they are classified as intracratonic strikeeslip faults with small slip distance.Third,the strikeeslip faults were formed in the middle Caledonian,and some faults were reactivated in the late Caledonianeearly Hercynian,late Hercynian,and Yanshanianeearly Himalayan.The distribution of faults is different in different periods.Fourth,the formation of the strikeeslip faults in the middle Caledonian is controlled by the basement heterogeneity and the compression action from the closure and subduction of the Proto-Tethys Ocean.The transtensional faults are R-shear branch faults or tensile break faults generated by the later activation of middle Caledonian strike-slip faults,and their formation is controlled by the subduction and closure of oceanic basins around the basins in different periods.In conclusion,the structural characteristics,formation&evolution and genetic mechanisms of intracratonic strikeeslip faults are in close relation to oil and gas,where great benefit of oil and gas exploration and development is achieved.Besides the Tarim Basin,the Sichuan Basin and the Ordos Basin have similar geological and structural settings,so the studies on typical basins will surely enrich and complete the theories on the intracratonic strikeeslip faults in domestic micro land blocks and multi-cycle basins and point out the direction for the discovery of more oil and gas resource.
基金Project supported by National Science and Technology Major Project“Demonstration Project of Fuling Shale Gas Development”(No.:2016ZX05060).
文摘For the sake of figuring out the influential mechanisms of structural characteristics on the productivity of shale gas wells,the structural characteristics of the Jiaoshiba Block in the Fuling shale gasfield,Sichuan Basin,were analyzed.Then,based on well test data of more than 190 horizontal wells,the effects of structures on shale gas well productivity were discussed systematically,and the main structural factors of different structural units in the Jiaoshiba Block that influence the productivity of shale gas wells were clarified.The following results were obtained.First,the structural units in the Jiaoshiba Block were obviously different in structural characteristics and their deformation strength is different.Second,the influence of structural characteristics on shale gas well productivity is directly manifested in gas-bearing property and fracturing effect.The stronger the structural deformation and the more developed the large faults and natural fractures,the more easily shale gas escapes and the poorer the gas bearing property will be,and vice versa.Third,The stronger the structural deformation,the more developed the fractures,the greater the burial depth and the higher the compressive stress of negative structures,the worse the fracturing effect will be,and vice versa.And fourth,Tectonics is the key factor controlling the difference of shale gas productivity between different structural units in the Jiaoshiba Block,but the main structural factors influencing the productivity are different in different structural units.
文摘The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The 'optimum surface' is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center.
文摘It is known that structural stiffness and strength distributions have an important role in the seismic response of buildings. The effect of using different code-specified lateral load patterns on the seismic performance of fixed-base buildings has been investigated by researchers during the past two decades. However, no investigation has yet been carried out for the case of soil-structure systems. In the present study, through intensive parametric analyses of 21,600 linear and nonlinear MDOF systems and considering five different shear strength and stiffness distribution patterns, including three code-specified patterns as well as uniform and concentric patterns subjected to a group of earthquakes recorded on alluvium and soft soils, the effect of structural characteristics distribution on the strength demand and ductility reduction factor of MDOF fixed-base and soil-structure systems are parametrically investigated. The results of this study show that depending on the level of inelasticity, soil flexibility and number of degrees-of-freedoms (DOFs), structural characteristics distribution can significantly affect the strength demand and ductility reduction factor of MDOF systems. It is also found that at high levels of inelasticity, the ductility reduction factor of low-rise MDOF soil-structure systems could be significantly less than that of fixed-base structures and the reduction is less pronounced as the number of stories increases.
基金supported by the National Major Science and Technology Project"Zhaotong Shale Gas Exploration&Development Demonstration Project"(No.2017ZX05063)CNPC Major Field Test Project"Research and Test of Key Effective Expoitation Techniques of Deep Shale Gas"(No.:2019F-13)。
文摘The Zhaotong National Shale Gas Demonstration Area along the southern margin of the Sichuan Basin is located in the complex marine tectonic area of South China,where shale deformation and reformation are intense and the factors controlling sweet spots are complex,so the preservation conditions have an important impact on the enrichment of shale gas.In order to support the selection and evaluation of shale gas sweet spots in this area and improve the success rate of drilling,this paper carried out a geological survey onfield outcrops.Then,based on drilling,mud logging and physical property test data,the structural deformation pattern and the regional deformation characteristics of this demonstration area were analyzed,and the development characteristics of formation joints and fractures,the sealing capacity of shale sur-rounding rock and the distribution characteristics of gas reservoirs were studied.Finally,the preservation conditions of shale gas in the Wufeng Formation of Upper Ordovician and the Longmaxi Formation of Lower Silurian were discussed.And the following research results were ob-tained.First,in the Zhaotong National Shale Gas Demonstration Area,three structural deformation patterns are developed from south to north,including trough type,equal amplitude type and baffle type,which are distributed in three major deformation zones,respectively,i.e.,the shear deformation zone of Central Guizhou Uplift,the compressionetorsion deformation zone of northern YunnaneGuizhou Depression and the compression deformation zone of Southern Sichuan Depression.Second,three types of joints and fractures whose relationships with the di-rection of strata are high angle,middleelow angle and bedding intersection are developed in the WufengeLongmaxi formations and its overlying strata,and their occurrence characteristics are basically consistent with those of the three major deformation zones.Third,the shale of WufengeLongmaxi formations is thick in the north and thin in the south and possesses the preservation conditions of sourceereservoir inte-gration and self-sealing hydrocarbon accumulation.And combined with the sealing ability of the overburden strata and the roof andfloor,its preservation conditions are overall better.Fourth,from the perspective of shale gas component,this area can be divided into three belts,i.e.,methane,methaneþnitrogen mixture and nitrogen from north to south.And the preservation conditions of shale gas are generally better in the north and worse in the south.In conclusion,the shale in the centralenorthern part of Zhaotong National Shale Gas Demonstration Area(compression deformation area and its southern margin)is the most favorable area because of its large shale thickness,weak reformation and deformation,bedding development of joints and fractures,good sealing performance and excellent preservation conditions.The compressionetorsion deformation zone of northern YunnaneGuizhou Depression in the central part is moderate in preservation conditions,and it is the relatively favorable area.The shear deformation zone of Central Guizhou Uplift in the southern part has poor preservation conditions,and it is a prospective area.
基金Under the auspices of National Natural Science Foundation of China(No.41201473,41371975)。
文摘This study selected the Sino-US route data from the top 30 global container liner companies between December 1,2019,and December 29,2019,as the data source utilizing the complex network research methodology.It constructs a Sino-US container shipping network through voyage weighting and analyzes the essential structural characteristics to explore the network’s complex structural fea-tures.The network’s evolution is examined from three perspectives,namely,time,space,and event influence,aiming to comprehens-ively explore the network’s evolution mechanism.The results revealed that:1)the weighted Sino-US container shipping network exhib-its small-world and scale-free properties.Key hub ports in the United States include NEW YORK NY,SAVANNAH GA,LOS ANGELES CA,and OAKLAND CA,whereas SHANGHAI serving as the hub port in China.The geographical distribution of these hub ports is uneven.2)Concerning the evolution of the weighted Sino-US container shipping network,from a temporal perspective,the evolution of the regional structure of the entire Sino-US region and the Inland United States is in a stage of radiative expansion and de-velopment,with a need for further enhancement in competitiveness and development speed.The evolution of the regional structure of southern China and Europe is transitioning from the stage of radiative expansion and development to an advanced equilibrium stage.The shipping development in Northern China,the Western and Eastern United States,and Asia is undergoing significant changes but faces challenges of fierce competition and imbalances.From a spatial perspective,the rationality and effectiveness of the improved weighted Barrat-Barthelemy-Vespignani(BBV)model are confirmed through theoretical derivation.The applicability of the improved evolution model is verified by simulating the evolution of the weighted Sino-US container shipping network.From an event impact per-spective,the Corona Virus Disease 2019(COVID-19)pandemic has not fundamentally affected the spatial pattern of the weighted Sino-US container shipping network but has significantly impacted the network’s connectivity.The network lacks sufficient resilience and stability in emergency situations.3)Based on the analysis of the structural characteristics and evolution of the weighted Sino-US con-tainer shipping network,recommendations for network development are proposed from three aspects:emphasizing the development of hub ports,focusing on the balanced development of the network,and optimizing the layout of Chinese ports.
