Based on the method of composite analysis, the onset process and preceding signs of summer monsoon over the South China Sea (SCS) is investigated. The result indicates that convection activities appear first over the ...Based on the method of composite analysis, the onset process and preceding signs of summer monsoon over the South China Sea (SCS) is investigated. The result indicates that convection activities appear first over the Indo-China Peninsula prior to the onset of the monsoon, then around the Philippines just at the point of onset, implying that the convection activities around the Philippines serve as one of the reasons leading to the SCS monsoon onset. Before the SCS monsoon onset, the equatorial westerly over the Indian Ocean (75(E ～ 95(E ) experiences noticeable enhancement and plays an important role on the SCS monsoon onset. It propagates eastward rapidly and causes the establishment and strengthening of equatorial westerly in the southern SCS, on the one hand, it results in the migration southward of the westerly on south side of the south-China stationary front by means of shift northeastward of the westerly and convection over the Bay of Bengal, on the other. Further study also shows that the intensification of equatorial westerly in the Indian Ocean (75(E ～ 95(E) and the southern SCS is closely related to the reinforcement of the Southern-Hemisphere Mascarene high and Australian high, and cross-equatorial flow northward around Somali, at 85(E and 105(E, respectively.展开更多
This paper uses the ARW-WRF model to carry out a numerical simulation of a warm-sector heavy rainfall event over southern China on the 22-23 May, 2014. A composite analysis method was used to analyze the evolution pro...This paper uses the ARW-WRF model to carry out a numerical simulation of a warm-sector heavy rainfall event over southern China on the 22-23 May, 2014. A composite analysis method was used to analyze the evolution process and structural features of the convective cells on a convection line during this rainfall event. This analysis identified three stages:(1) Stage of activation: the equivalent potential temperature surfaces as lower layers start to bulge and form warm cells and weak vertical convective cloud towers which are subject to the impact of low-level warm moist updrafts in the rainfall sector;(2) Stage of development: the warm cells continue to bulge and form warm air columns and the convective cloud towers develop upwards becoming stronger as they rise;(3) Stage of maturity: the warm air columns start to connect with the stable layer in the upper air; the convective cloud tower will bend and tilt westward with each increasing in height, and the convection cell is characterized by a "crescent-shaped echo" above the 700 h Pa plane. During this stage the internal temperature of the cell is higher than the ambient temperature and the dynamic structural field is manifested as intensive vertical upward movement. The large-value centers of the northerly and westerly winds in the middle layer correspond to the warm moist center in the cells and the relatively cold center south of the warm air column. Further analysis shows that the formation of the "crescent-shaped" convective cell is associated with horizontal vorticity. Horizontal vorticity in the center and west of the warm cell experiences stronger cyclonic and anticyclonic shear transformation over time; this not only causes the original suborbicular cell echo shape to develop into a crescent-like shape, but also makes a convection line consisting of cells that develop to the northwest.展开更多
[Objective] The aim was to study the sea breeze front storm and its composite analysis in Beibu Gulf. [Method] By dint of routine observation data, ground automatic meteorology data and European numerical mode grid da...[Objective] The aim was to study the sea breeze front storm and its composite analysis in Beibu Gulf. [Method] By dint of routine observation data, ground automatic meteorology data and European numerical mode grid data, rainstorm caused by sea breeze in Guangxi during 1990 and 2007 and the strong convection triggered by sea breeze on June 5 in 2008 were expounded. The main characteristics of the configuration of circulation in the low and high latitude of breeze front of middle scale were summarized. [Result] Sea breeze front storm system was an important middle scale sea breeze front system that triggered storm in the Beibu Gulf. Sea breeze in Beibu Gulf occurred most easily during the southwest monsoon eruption period. Case study pointed out that after sunrise, the continental and island temperature in Beibu Gulf turned from warm-ocean-cold-island into warm-island-cold-ocean. The southerly airstream of high temperature and high humidity met with the relatively low temperature and dry northerly airstream in Beibu Gulf, and triggered vertical circulation and stimulated ground middle scale sea breeze front system. Composite analysis referred to the circulation characteristics of the ocean and continental temperature in Beibu Gulf. The upper air of south China was in strong divergence center. The air pressure was high in the east and low in the west. Beibu Gulf was in the southerly torrent belt in front of the trough and after the latitude in cyclonic circulation convergence area. The strata unstable structure of the divergence in the upper air and the convergence in the lower layer and the 'pumping effect' provided upward dynamics for the ocean circulation development. The southerly brought rich water vapor to the Beibu Gulf, which was conductive to the formation of strong convective cloud system in the lower layer and the generation of precipitation. [Conclusion] The research provided references for the study on the characteristics of middle scale convective system.展开更多
BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s...BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s disease(AD)remains relatively unexplored.AIM To explore the clinical efficacy of BCA-based dietary nutrition scheme on bone metabolism in AD patients.METHODS This retrospective study included 96 patients with AD complicated by osteoporosis who were admitted to The Third Hospital of Quzhou between January 2023 and December 2024.Based on data from previous similar studies,the patients were randomly assigned to either a routine diet(RD)group(n=48)or a personalized nutrition(PN)group(n=48).The RD group received conventional dietary guidance,while the PN group received individualized diet intervention measures based on human BCA.The intervention period lasted for 12 weeks.Bone mineral density(BMD),body mass index(BMI),muscle mass,mineral content,osteocalcin,25-hydroxyvitamin D,procollagen type I N-terminal propeptide(PINP),beta C-terminal telopeptide of type I collagen(β-CTX),and serum calcium were measured and compared between the two groups before and 12 weeks after the intervention.RESULTS No significant differences were observed between groups in terms of age,sex,height,BMI,or other baseline data(P>0.05).In both groups,BMI did not show significant changes after the intervention(P>0.05),whereas muscle mass and mineral content were significantly increased(P<0.05).After the intervention,BMI in the PN group did not differ significantly from that of the RD group,but muscle mass and mineral content were significantly higher in the PN group(P<0.05).After the intervention,a higher proportion of patients in the PN group had a T score>-1 compared to the RD group(P<0.05).The mini-mental state examination(MMSE)score was similar in both groups before the intervention.However,12 weeks after the intervention,the MMSE score in the PN group was significantly higher than that in the RD group(P<0.05).In both groups,the MMSE score significantly increased 12 weeks post-intervention compared to pre-intervention levels(P<0.05).Before the intervention,the levels of osteocalcin,serum calcium,PINP,β-CTX,and 25-hydroxyvitamin D were not significantly different between the two groups(P>0.05).After 12 weeks of intervention,the PN group exhibited higher levels of osteocalcin,serum calcium,and 25-hydroxyvitamin D,as well as lower levels of PINP andβ-CTX,compared to the RD group(P<0.05).In both groups,osteocalcin,serum calcium,and 25-hydroxyvitamin D levels were significantly higher,while PINP andβ-CTX levels were significantly lower after 12 weeks of intervention compared to baseline(P<0.05).CONCLUSION The human BCA-based dietary nutrition regimen plays a crucial role in improving BMD and bone metabolism,with effects that surpass those of conventional nutrition strategies.The findings of this study provide strong evidence for the nutritional management of AD patients.展开更多
Objective:To analyze the effect of Shiwei Powder combined with stone composition analysis on stone removal efficiency and complication rates after ureteroscopic holmium laser lithotripsy(FURL).Methods:Ninety six patie...Objective:To analyze the effect of Shiwei Powder combined with stone composition analysis on stone removal efficiency and complication rates after ureteroscopic holmium laser lithotripsy(FURL).Methods:Ninety six patients with FURL admitted to the hospital from March 2023 to March 2025 were selected and randomly divided into two groups.The observation group was treated with FURL combined with Shiwei Powder,while the control group was treated with FURL monotherapy.Based on the stone composition of the two groups,the stone removal efficiency,complication rates,recurrence rates,TCM syndrome scores,and inflammatory factor levels were compared.Results:The stone removal efficiency of the observation group was higher than that of the control group.The stone composition was mainly calcium oxalate monohydrate and composite stones containing calcium oxalate monohydrate.The incidence of postoperative complications was lower in the observation group than in the control group(P<0.05).After 3–6 months of follow-up,the recurrence rate in the observation group was lower than that in the control group(P<0.05).After treatment,the TCM syndrome scores and inflammatory factor levels in the observation group were lower than those in the control group(P<0.05).Conclusion:Based on the results of urinary stone composition analysis,patients treated with Shiwei Powder after FURL have higher stone removal efficiency.The most significant effect is observed in urinary stones composed of calcium oxalate monohydrate and composite stones containing calcium oxalate monohydrate.This treatment can improve stone removal,prevent complications,reduce recurrences,effectively improve disease symptoms,and reduce inflammation.展开更多
Investigating the influence of radiation on glass fibre composites is essential for their use in space and aerospace environment.Gaining insight into the damage mechanisms caused by gamma irradiation,can improve the s...Investigating the influence of radiation on glass fibre composites is essential for their use in space and aerospace environment.Gaining insight into the damage mechanisms caused by gamma irradiation,can improve the safety and resilience of structures.This paper is aimed at investigating the failure mode and damage of gamma-irradiated repurposed pultruded glass fibre-reinforced polyester subjected to lowvelocity impact using three types of non-destructive techniques.Three sets of differently layered configurations(CRC,WCRW,W2CR2C)consisting of chopped(c),roving(r),and weaved(w)fibre-reinforced polyester are applied in this study.Drop hammer test is applied to evaluate the low-impact resistance properties of Gamma-irradiated composite at 100 kGy,500 kGy,and 1000 kGy.Preliminary flexural and hardness tests are conducted to further assess the behaviour of irradiated polymer composites.Further,the damage modes associated with the low-impact test are characterised using infrared thermography,flat panel digital radiography,and microscope observation.The results show that the composites irradiated with various doses display good impact resistance at 20 J,presenting minor damages in the form of dents on the surface.The irradiated CRC and WCRW display best impact resistance at 500 kGy,while W2CR2C at 1000 kGy.This shows that the layering sequence of reinforcement fibre can influence the impact resistance of irradiated composites.Apart from that,the application of non-destructive techniques show different damage mechanisms in the form resin cracks,yarn splitting/fracture,and matrix splitting when the composites are exposed at high and low irradiation doses.These findings offer valuable data for the defence industry,particularly in the areas of repair,maintenance,and the development of new materials.展开更多
For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can b...For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can be completely absorbed or dissipated for the aim of safety. Two composite structures(circumscribed circle structure and inscribed circle structure) were constructed. In addition, comparison and optimization of the crashworthy characteristic of the two structures were carried out based on the method of explicit finite element analysis(FEA) and Kriging surrogate model. According to the result of Kriging surrogate model, conclusions can be safely drawn that the specific energy absorption(SEA) and ratio of specific energy absorption to initial peak force(REAF) of circumscribed circle structure are lager than those of inscribed circle structure under the same design parameters. In other words, circumscribed circle structure has better performances with higher energy-absorbing ability and lower initial peak force. Besides, error analysis was adopted and the result of which indicates that the Kriging surrogate model has high nonlinear fitting precision. What is more, the SEA and REAF optimum values of the two structures have been obtained through analysis, and the crushing results have been illustrated when the two structures reach optimum SEA and REAF.展开更多
Compound Shenhua Tablet,a medicine comprising seven herbs,is employed in treating IgA nephropathy.This study aimed to meticulously analyze its chemical composition.Based on a list of candidate compounds,identified thr...Compound Shenhua Tablet,a medicine comprising seven herbs,is employed in treating IgA nephropathy.This study aimed to meticulously analyze its chemical composition.Based on a list of candidate compounds,identified through extensive literature review pertinent to the tablet’s herbal components,the composition analysis entailed the systematic identification,characterization,and quantification of the constituents.The analyte-capacity of LC/ESI-MS-based and GC/EI-MS-based assays was evaluated.The identified and characterized constituents were quantified to determine their content levels and were ranked based on the constituents’daily doses.A total of 283 constituents,classified into 12 distinct categories,were identified and characterized in the Compound Shenhua Tablet.These constituents exhibited content levels of 1−10982μg·g^(−1),with daily doses of 0.01−395μmol·d^(−1).The predominant constituents,with daily doses of≥10μmol·d^(−1),include nine organic acids(citric acid,quinic acid,chlorogenic acid,cryptochlorogenic acid,gallic acid,neochlorogenic acid,isochlorogenic acid C,isochlorogenic acid B,and linoleic acid),five iridoids(specnuezhenide,nuezhenoside G13,nuezhenidic acid,secoxyloganin,and secologanoside),two monoterpene glycosides(paeoniflorin and albiflorin),a sesquiterpenoid(curzerenone),a triterpenoid(oleanolic acid),and a phenylethanoid(salidroside).Additionally,there were 83,126,and 55 constituents detected in the medicine with daily doses of 1–10,0.1–1,and 0.01–0.1μmol·d^(−1),respectively.The combination of the LC/ESI-MS-based and GC/EI-MS-based assays demonstrated a complementary relationship in their analyte-capacity for detecting the constituents present in the medicine.This comprehensive composition analysis establishes a solid foundation for further pharmacological research on Compound Shenhua Tablet and facilitates the quality evaluation of this complex herbal medicine.展开更多
The influence of the injection of reinforcing particles (for the production of metal matrix composites and of the droplets-to-substrate heat transfer on the resulting microstructural uniformity of spray atomized and c...The influence of the injection of reinforcing particles (for the production of metal matrix composites and of the droplets-to-substrate heat transfer on the resulting microstructural uniformity of spray atomized and codeposited composite material is analyzed. The reinforcement particles injection velocity has to be limited between an upper and a lower critical values. in order to ensure entrapment into the matrix droplets in flight. The thermal history of the injected droplets during the deposition stage is calculated with the assumption that the in-flight solidifying droplets reach the substrate while containing still at least 20% liquid volume fraction, in order to avoid porosity of the deposited material. The substrate to pouring-tube orifice distance where that condition is achieved depends strongly on the atomization pressure and the convective heat transfer coefficient of the substrate. It is demonstrated that 'tailoring' the microstructures and the reinforcement volume percent in the deposited material is feasible. The critical process parameters : the atomization pressure, the melt flow rate. the substrate to pouring-tube orifice distance, the reinforcement particles injection location and rate can all be adequately chosen in order to obtain any desired microstructure, grain size, reinforcement volume percent, with the additional benefit, if wanted, of rapid solidification processing展开更多
Fluid mechanics, heat transfer and liquid-to-solid phase transformation are assessed in optimizing the spray atomization and codeposition process parameters for size refinement and microstructural uniformity of the de...Fluid mechanics, heat transfer and liquid-to-solid phase transformation are assessed in optimizing the spray atomization and codeposition process parameters for size refinement and microstructural uniformity of the deposited material. Atomization gas velocities, atomized droplets velocities, convective heat transfer coefficients, thermal histories of the solidifying droplets, freezing rates, fraction solid evolution and solid-liquid interface propagation velocity are calculated. The influence, on the deposit microstructural features, of process parameters like the atomization gas pressure, the pouring tube orifice diameter, the geometrical features of the atomization device,the potency of , pre-existing or injected as reinforcement, nucleation sites, the wetting angle between the liquid melt bnd impurity particles acting as preferred nucleation sites, the in-flight distance of the solidifying droplets in the atomization chamber, i5 evaluated. As a result of the evaluation, appropriate choice of the adjustable process parameters for the production of powders and/or deposits with desired grain size and microstructure, can be made.展开更多
Background:The aim of this study was to investigate the influence of marking meth-ods on the outcomes of body composition analysis and provide guidance for the se-lection of marking methods in mouse body composition a...Background:The aim of this study was to investigate the influence of marking meth-ods on the outcomes of body composition analysis and provide guidance for the se-lection of marking methods in mouse body composition analysis.Methods:Male C57BL/6J mice aged 6 weeks were randomly assigned for pre-and post-ear tagging measurements.The body composition of the mice was measured using a small animal body composition analyzer,which provided measurements of the mass of fat,lean,and free fluid.Then,the mass of fat,lean and free fluid to body weight ratio was gained.Further data analysis was conducted to obtain the range and coeffi-cient of variation in body composition measurements for each mouse.The distribution of fat and lean tissue in the mice was also analyzed by comparing the fat-to-lean ratio.Results:(1)The mass of all body composition components in the ear tagging group was significantly lower than that in the control group.(2)There was a significant in-crease in the range and coefficient of variation of body composition measurements between the ear tagging group and the control group.(3)The fat-to-lean ratio in the ear tagging group was significantly lower than that in the control group.Conclusions:Ear tagging significantly lowered the results of body composition analy-sis in mice and higher the results of measurement error.Therefore,ear tagging should be avoided as much as possible when conducting body composition analysis experi-ments in mice.展开更多
Articular cartilage is a layer of low-friction,load-bearing soft hydrated tissue covering bone-ends in diarthrosis,which plays an important role in spreading the load,reducing the joint contact stress,joint friction a...Articular cartilage is a layer of low-friction,load-bearing soft hydrated tissue covering bone-ends in diarthrosis,which plays an important role in spreading the load,reducing the joint contact stress,joint friction and wear during exercise.The vital mechanical function展开更多
Persistent(5-day or longer)extreme cold events(ECEs)over northeastern China during the boreal winter of 1979–2020 are investigated using daily minimum temperature(Tmin)from the China Meteorological Data Network.The e...Persistent(5-day or longer)extreme cold events(ECEs)over northeastern China during the boreal winter of 1979–2020 are investigated using daily minimum temperature(Tmin)from the China Meteorological Data Network.The extreme cooling area and intensity indices associated with the ECEs exhibit a dominant 10–40-day periodicity,indicating a close link with atmospheric intraseasonal oscillations(ISOs).The ECEs are categorized into W-and N-type.In the former,the low-frequency cooling associated with the ISO first penetrates into the western boundary of the northeastern China domain and later occupies the entire domain at its peak phase.The upper-tropospheric circulation associated with this type is characterized by a northwest–southeast-oriented Rossby wave train,expanding from the Ural Mountains to the western Pacific Ocean.In the latter,the cooling invades the northern boundary first and then penetrates into the entire domain.The upper tropospheric precursory signal associated with this type is a zonally oriented negative geopotential height anomaly,which slowly moves southward.A downward-propagating signal is observed in the stratospheric potential vorticity field prior to the peak cooling,implying a possible stratospheric impact.In addition to the W-and N-types,ECEs can also occur in a localized region near either at the northern or southern boundary of the domain.展开更多
Based on the Tropical Cyclone(TC) Yearbooks data and JRA-25 reanalysis data from the Japan Meteorological Agency(JMA) during 1979-2008, dynamic composite analysis and computation of kinetic energy budget are used to s...Based on the Tropical Cyclone(TC) Yearbooks data and JRA-25 reanalysis data from the Japan Meteorological Agency(JMA) during 1979-2008, dynamic composite analysis and computation of kinetic energy budget are used to study the intensifying and weakening TCs during Extratropical Transition over China. The TCI shows strong upper-level divergence, strengthened low-level convergence and significantly enhanced upward motion under the influence of strong upper-level troughs and high-level jets. The TCI is correspondingly intensified after Extratropical Transition(ET); TCW exhibits strong upper-level divergence, subdued low-level convergence and slightly enhanced upward motion under the influence of weak upper-level troughs and high-level jets. It then weakens after ET. The increase(decrease) of the generation of kinetic energy by divergence wind in TCI(TCW) at low level is one of the major reasons for TCI's intensification(TCW's weakening) after transformation. The generation of kinetic energy by divergence wind is closely related to the development of a low-level baroclinic frontal zone. The growth of the generation of kinetic energy by rotational wind in TCI at upper level is favorable for TCI's maintenance, which is affected by strong upper-level troughs. The dissipation of the generation of kinetic energy by rotational wind in TCW at upper level is unfavorable for TCW's maintenance, which is affected by weak upper-level troughs.展开更多
A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon durin...A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon during1988 to 2009.Based on the data of the numerical simulation,composite analysis and correlation analysis are used to make diagnostic study of climate dynamics.Results show that the month of maximum emission of the mean column burden of the anthropogenic aerosol in the main emission areas of South Asia is opposite in phase to that in China.Summer is the season of maximum emission amount in China,but the emission amounts are more in South Asia in spring and winter.On the whole,the mean column burden of the anthropogenic aerosol in China is relatively high compared with that in South Asia.The trend of distribution of aerosol is SW-NE in China,and Sichuan Basin is the emission center of aerosol.The effect of negative short wave radiative forcing alters the gradient of pressure between land and sea,weakening the development of East Asian summer monsoon over the northern part of Yangtze-Huaihe River Basin.We also discuss the feedback effect of East-Asian summer monsoon which is changed by the anthropogenic aerosol on the concentration and distribution of aerosol in China.展开更多
Fifty-eight extratropical transition(ET) cases in the years 2000-2008, including 2,021 observations(at 6-hour intervals), over the western North Pacific are analyzed using the cyclone phase space(CPS) method, in an ef...Fifty-eight extratropical transition(ET) cases in the years 2000-2008, including 2,021 observations(at 6-hour intervals), over the western North Pacific are analyzed using the cyclone phase space(CPS) method, in an effort to get the characteristics of the structure evolution and environmental conditions of tropical cyclones(TCs) during ET over this area. Cluster analysis of the CPS dataset shows that strong TCs are more likely to undergo ET. ET begins with the increment of thermal asymmetry in TCs, along with the generation and intensification of an upper-level cold core, and ends with the occurrence of a lower-level cold core. ET lasts an average duration of about 28 hours. Dynamic composite analysis of the environmental field of different clusters shows that, in general, when TCs move northward,they are gradually embedded in the westerlies and gradually transform into extratropical cyclones under the influence of the mid-and higher-latitude baroclinic systems. As for those TCs which complete ET, there is always much greater potential vorticity gradient in the northwest of them and obvious water vapor transport channels in the environment.展开更多
The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental condition...The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental conditions.However,a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking.In the present study,we utilized data obtained from paddy fields of different rice cultivation years(0-23 years)to investigate the compositional and functional succession of soil bacterial communities.We focused on core bacterial taxa that were specifically enriched at different successional stages.Generalized joint attribute modeling(GJAM)was used to identify core bacterial taxa.Results indicated that the bare saline-alkali soil(0 year,prior to any rice cultivation)shared few core amplicon sequence variants(ASVs)with paddy fields.In the bare saline-alkali soil,Longimicrobiaceae from the phylum Gemmatimonadetes was dominant,while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae--phyla affiliated with Proteobacteria and Verrucomicrobia--after 5 and 23 years of rice cultivation,respectively.The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages,while sulfur metabolism functions exhibited the opposite trend.These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established.Redundancy analysis(RDA)indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0,2 and 4,6,8,10,and 12,and 20 and 23 years were driven by soil nitrate nitrogen content,pH,available phosphorus content,and the ratio of total carbon to total nitrogen,respectively.In summary,the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.展开更多
Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a l...Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy （LIBS） apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the ＇drift＇ obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants.展开更多
Groundwater reservoir is a kind of important engineering, which can optimize water resources arran- gement by means of artificial regulation. Regulated water is the blood and value performance of groundwater reservoir...Groundwater reservoir is a kind of important engineering, which can optimize water resources arran- gement by means of artificial regulation. Regulated water is the blood and value performance of groundwater reservoir. To resolve the problem of real-time quantification of regulated water, the paper analyzed sources and compositions of regulated water in detail. Then, under the conditions of satisfying water demand inside research area, the paper analyzed quantity available and regulation coefficient of different regulated water and established a formula to calculate regulated water. At last, based on a pore groundwater reservoir in the middle reaches of the Yinma River, Jilin Province, the paper calculated regulated water with the formula and the result shows that the method is feasible. With some constraint conditions, the formula can be adopted in other similar areas.展开更多
This paper seeks to outline the temperature effect on the buckling properties of ultra-thin-walled lenticular collapsible composite tube（LCCT） subjected to axial compression.The buckling tests of the LCCT specimens ...This paper seeks to outline the temperature effect on the buckling properties of ultra-thin-walled lenticular collapsible composite tube（LCCT） subjected to axial compression.The buckling tests of the LCCT specimens subjected to axial compression were carried out on INSTRON-500 N servo-hydraulic machine in dry state and at the temperatures of 25 C, 100 C and 80 C. The load–displacement curves and buckling initiation loads were measured and the buckling initiation mechanism was discussed from experimental observations. Experiments show that the buckling initiation load, on average, is only about 2.2% greater at the low temperature of 80 C than at the room temperature of 25 C due to the material hardening, demonstrating an insignificant increase in the buckling initiation load, whereas it is about 19.5% lower at the high temperature of 100 C than at the room temperature owing to the material softening, implying a significant decrease in the buckling initiation load. The failure mode of the LCCT in axial compression tests at three different temperatures can be reckoned to be characteristic of the buckling initiation and propagation around the central region until rupture. The finite element（FE） model is presented to simulate the buckling initiation mechanism based on the eigenvalue-based methodology. Good correlation between experimental and numerical results is achieved.展开更多
基金National Scaling Project A - South China Sea Monsoon Experiment Development Plan of Key National Fundamental Research - Study o
文摘Based on the method of composite analysis, the onset process and preceding signs of summer monsoon over the South China Sea (SCS) is investigated. The result indicates that convection activities appear first over the Indo-China Peninsula prior to the onset of the monsoon, then around the Philippines just at the point of onset, implying that the convection activities around the Philippines serve as one of the reasons leading to the SCS monsoon onset. Before the SCS monsoon onset, the equatorial westerly over the Indian Ocean (75(E ～ 95(E ) experiences noticeable enhancement and plays an important role on the SCS monsoon onset. It propagates eastward rapidly and causes the establishment and strengthening of equatorial westerly in the southern SCS, on the one hand, it results in the migration southward of the westerly on south side of the south-China stationary front by means of shift northeastward of the westerly and convection over the Bay of Bengal, on the other. Further study also shows that the intensification of equatorial westerly in the Indian Ocean (75(E ～ 95(E) and the southern SCS is closely related to the reinforcement of the Southern-Hemisphere Mascarene high and Australian high, and cross-equatorial flow northward around Somali, at 85(E and 105(E, respectively.
基金National Basic Research Program of China(Project 973:2013CB430103)National Natural Science Foundation of China(41530427)+1 种基金Chinese Academy of Meteorological Sciences(2015LASW-A07)State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences
文摘This paper uses the ARW-WRF model to carry out a numerical simulation of a warm-sector heavy rainfall event over southern China on the 22-23 May, 2014. A composite analysis method was used to analyze the evolution process and structural features of the convective cells on a convection line during this rainfall event. This analysis identified three stages:(1) Stage of activation: the equivalent potential temperature surfaces as lower layers start to bulge and form warm cells and weak vertical convective cloud towers which are subject to the impact of low-level warm moist updrafts in the rainfall sector;(2) Stage of development: the warm cells continue to bulge and form warm air columns and the convective cloud towers develop upwards becoming stronger as they rise;(3) Stage of maturity: the warm air columns start to connect with the stable layer in the upper air; the convective cloud tower will bend and tilt westward with each increasing in height, and the convection cell is characterized by a "crescent-shaped echo" above the 700 h Pa plane. During this stage the internal temperature of the cell is higher than the ambient temperature and the dynamic structural field is manifested as intensive vertical upward movement. The large-value centers of the northerly and westerly winds in the middle layer correspond to the warm moist center in the cells and the relatively cold center south of the warm air column. Further analysis shows that the formation of the "crescent-shaped" convective cell is associated with horizontal vorticity. Horizontal vorticity in the center and west of the warm cell experiences stronger cyclonic and anticyclonic shear transformation over time; this not only causes the original suborbicular cell echo shape to develop into a crescent-like shape, but also makes a convection line consisting of cells that develop to the northwest.
基金Supported by National Natural Fund in 2010 (40965003)Guangxi Science and Technology Project in Guangxi in 2007 (Guangxi Science Project 0719005-3-2)
文摘[Objective] The aim was to study the sea breeze front storm and its composite analysis in Beibu Gulf. [Method] By dint of routine observation data, ground automatic meteorology data and European numerical mode grid data, rainstorm caused by sea breeze in Guangxi during 1990 and 2007 and the strong convection triggered by sea breeze on June 5 in 2008 were expounded. The main characteristics of the configuration of circulation in the low and high latitude of breeze front of middle scale were summarized. [Result] Sea breeze front storm system was an important middle scale sea breeze front system that triggered storm in the Beibu Gulf. Sea breeze in Beibu Gulf occurred most easily during the southwest monsoon eruption period. Case study pointed out that after sunrise, the continental and island temperature in Beibu Gulf turned from warm-ocean-cold-island into warm-island-cold-ocean. The southerly airstream of high temperature and high humidity met with the relatively low temperature and dry northerly airstream in Beibu Gulf, and triggered vertical circulation and stimulated ground middle scale sea breeze front system. Composite analysis referred to the circulation characteristics of the ocean and continental temperature in Beibu Gulf. The upper air of south China was in strong divergence center. The air pressure was high in the east and low in the west. Beibu Gulf was in the southerly torrent belt in front of the trough and after the latitude in cyclonic circulation convergence area. The strata unstable structure of the divergence in the upper air and the convergence in the lower layer and the 'pumping effect' provided upward dynamics for the ocean circulation development. The southerly brought rich water vapor to the Beibu Gulf, which was conductive to the formation of strong convective cloud system in the lower layer and the generation of precipitation. [Conclusion] The research provided references for the study on the characteristics of middle scale convective system.
基金Supported by Science and Technology Bureau of Quzhou,No.2022079.
文摘BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s disease(AD)remains relatively unexplored.AIM To explore the clinical efficacy of BCA-based dietary nutrition scheme on bone metabolism in AD patients.METHODS This retrospective study included 96 patients with AD complicated by osteoporosis who were admitted to The Third Hospital of Quzhou between January 2023 and December 2024.Based on data from previous similar studies,the patients were randomly assigned to either a routine diet(RD)group(n=48)or a personalized nutrition(PN)group(n=48).The RD group received conventional dietary guidance,while the PN group received individualized diet intervention measures based on human BCA.The intervention period lasted for 12 weeks.Bone mineral density(BMD),body mass index(BMI),muscle mass,mineral content,osteocalcin,25-hydroxyvitamin D,procollagen type I N-terminal propeptide(PINP),beta C-terminal telopeptide of type I collagen(β-CTX),and serum calcium were measured and compared between the two groups before and 12 weeks after the intervention.RESULTS No significant differences were observed between groups in terms of age,sex,height,BMI,or other baseline data(P>0.05).In both groups,BMI did not show significant changes after the intervention(P>0.05),whereas muscle mass and mineral content were significantly increased(P<0.05).After the intervention,BMI in the PN group did not differ significantly from that of the RD group,but muscle mass and mineral content were significantly higher in the PN group(P<0.05).After the intervention,a higher proportion of patients in the PN group had a T score>-1 compared to the RD group(P<0.05).The mini-mental state examination(MMSE)score was similar in both groups before the intervention.However,12 weeks after the intervention,the MMSE score in the PN group was significantly higher than that in the RD group(P<0.05).In both groups,the MMSE score significantly increased 12 weeks post-intervention compared to pre-intervention levels(P<0.05).Before the intervention,the levels of osteocalcin,serum calcium,PINP,β-CTX,and 25-hydroxyvitamin D were not significantly different between the two groups(P>0.05).After 12 weeks of intervention,the PN group exhibited higher levels of osteocalcin,serum calcium,and 25-hydroxyvitamin D,as well as lower levels of PINP andβ-CTX,compared to the RD group(P<0.05).In both groups,osteocalcin,serum calcium,and 25-hydroxyvitamin D levels were significantly higher,while PINP andβ-CTX levels were significantly lower after 12 weeks of intervention compared to baseline(P<0.05).CONCLUSION The human BCA-based dietary nutrition regimen plays a crucial role in improving BMD and bone metabolism,with effects that surpass those of conventional nutrition strategies.The findings of this study provide strong evidence for the nutritional management of AD patients.
文摘Objective:To analyze the effect of Shiwei Powder combined with stone composition analysis on stone removal efficiency and complication rates after ureteroscopic holmium laser lithotripsy(FURL).Methods:Ninety six patients with FURL admitted to the hospital from March 2023 to March 2025 were selected and randomly divided into two groups.The observation group was treated with FURL combined with Shiwei Powder,while the control group was treated with FURL monotherapy.Based on the stone composition of the two groups,the stone removal efficiency,complication rates,recurrence rates,TCM syndrome scores,and inflammatory factor levels were compared.Results:The stone removal efficiency of the observation group was higher than that of the control group.The stone composition was mainly calcium oxalate monohydrate and composite stones containing calcium oxalate monohydrate.The incidence of postoperative complications was lower in the observation group than in the control group(P<0.05).After 3–6 months of follow-up,the recurrence rate in the observation group was lower than that in the control group(P<0.05).After treatment,the TCM syndrome scores and inflammatory factor levels in the observation group were lower than those in the control group(P<0.05).Conclusion:Based on the results of urinary stone composition analysis,patients treated with Shiwei Powder after FURL have higher stone removal efficiency.The most significant effect is observed in urinary stones composed of calcium oxalate monohydrate and composite stones containing calcium oxalate monohydrate.This treatment can improve stone removal,prevent complications,reduce recurrences,effectively improve disease symptoms,and reduce inflammation.
基金funded by Universiti Tenaga Nasional(UNITEN),Malaysia for supporting this research under the Dato'Low Tuck Kwong International Grant,project code 20238002DLTKsupport for this work from the Ministry of Higher EducationMalaysia through the Higher Institution Center of Excellence(HICoE 2023-JPT(BPKI)1000/016/018/34(5))program+2 种基金supported by Tenaga Nasional Berhad(TNB)and UNITEN through the BOLD Refresh Postdoctoral Fellowships under Grant J510050002-IC-6 BOLDREFRESH2023-Centre of ExcellencePrince Sultan University for their supportIndustrial Technology Division,Malaysian Nuclear Agency for their support in this research work.
文摘Investigating the influence of radiation on glass fibre composites is essential for their use in space and aerospace environment.Gaining insight into the damage mechanisms caused by gamma irradiation,can improve the safety and resilience of structures.This paper is aimed at investigating the failure mode and damage of gamma-irradiated repurposed pultruded glass fibre-reinforced polyester subjected to lowvelocity impact using three types of non-destructive techniques.Three sets of differently layered configurations(CRC,WCRW,W2CR2C)consisting of chopped(c),roving(r),and weaved(w)fibre-reinforced polyester are applied in this study.Drop hammer test is applied to evaluate the low-impact resistance properties of Gamma-irradiated composite at 100 kGy,500 kGy,and 1000 kGy.Preliminary flexural and hardness tests are conducted to further assess the behaviour of irradiated polymer composites.Further,the damage modes associated with the low-impact test are characterised using infrared thermography,flat panel digital radiography,and microscope observation.The results show that the composites irradiated with various doses display good impact resistance at 20 J,presenting minor damages in the form of dents on the surface.The irradiated CRC and WCRW display best impact resistance at 500 kGy,while W2CR2C at 1000 kGy.This shows that the layering sequence of reinforcement fibre can influence the impact resistance of irradiated composites.Apart from that,the application of non-destructive techniques show different damage mechanisms in the form resin cracks,yarn splitting/fracture,and matrix splitting when the composites are exposed at high and low irradiation doses.These findings offer valuable data for the defence industry,particularly in the areas of repair,maintenance,and the development of new materials.
基金Projects(51405516,U1334208)supported by the National Natural Science Foundation of ChinaProject(2013GK2001)supported by the Science and Technology Program for Hunan Provincial Science and Technology Department,ChinaProject(2013zzts040)supported by the Graduate Degree Thesis Innovation Foundation of Central South University,China
文摘For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can be completely absorbed or dissipated for the aim of safety. Two composite structures(circumscribed circle structure and inscribed circle structure) were constructed. In addition, comparison and optimization of the crashworthy characteristic of the two structures were carried out based on the method of explicit finite element analysis(FEA) and Kriging surrogate model. According to the result of Kriging surrogate model, conclusions can be safely drawn that the specific energy absorption(SEA) and ratio of specific energy absorption to initial peak force(REAF) of circumscribed circle structure are lager than those of inscribed circle structure under the same design parameters. In other words, circumscribed circle structure has better performances with higher energy-absorbing ability and lower initial peak force. Besides, error analysis was adopted and the result of which indicates that the Kriging surrogate model has high nonlinear fitting precision. What is more, the SEA and REAF optimum values of the two structures have been obtained through analysis, and the crushing results have been illustrated when the two structures reach optimum SEA and REAF.
基金supported by the National Natural Science Foundation of China(Nos.82192912,82074273)the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(No.ZYYCXTD-C-202009)the Program of State Key Laboratory of Drug Research(No.SIMM2103ZZ-06).
文摘Compound Shenhua Tablet,a medicine comprising seven herbs,is employed in treating IgA nephropathy.This study aimed to meticulously analyze its chemical composition.Based on a list of candidate compounds,identified through extensive literature review pertinent to the tablet’s herbal components,the composition analysis entailed the systematic identification,characterization,and quantification of the constituents.The analyte-capacity of LC/ESI-MS-based and GC/EI-MS-based assays was evaluated.The identified and characterized constituents were quantified to determine their content levels and were ranked based on the constituents’daily doses.A total of 283 constituents,classified into 12 distinct categories,were identified and characterized in the Compound Shenhua Tablet.These constituents exhibited content levels of 1−10982μg·g^(−1),with daily doses of 0.01−395μmol·d^(−1).The predominant constituents,with daily doses of≥10μmol·d^(−1),include nine organic acids(citric acid,quinic acid,chlorogenic acid,cryptochlorogenic acid,gallic acid,neochlorogenic acid,isochlorogenic acid C,isochlorogenic acid B,and linoleic acid),five iridoids(specnuezhenide,nuezhenoside G13,nuezhenidic acid,secoxyloganin,and secologanoside),two monoterpene glycosides(paeoniflorin and albiflorin),a sesquiterpenoid(curzerenone),a triterpenoid(oleanolic acid),and a phenylethanoid(salidroside).Additionally,there were 83,126,and 55 constituents detected in the medicine with daily doses of 1–10,0.1–1,and 0.01–0.1μmol·d^(−1),respectively.The combination of the LC/ESI-MS-based and GC/EI-MS-based assays demonstrated a complementary relationship in their analyte-capacity for detecting the constituents present in the medicine.This comprehensive composition analysis establishes a solid foundation for further pharmacological research on Compound Shenhua Tablet and facilitates the quality evaluation of this complex herbal medicine.
文摘The influence of the injection of reinforcing particles (for the production of metal matrix composites and of the droplets-to-substrate heat transfer on the resulting microstructural uniformity of spray atomized and codeposited composite material is analyzed. The reinforcement particles injection velocity has to be limited between an upper and a lower critical values. in order to ensure entrapment into the matrix droplets in flight. The thermal history of the injected droplets during the deposition stage is calculated with the assumption that the in-flight solidifying droplets reach the substrate while containing still at least 20% liquid volume fraction, in order to avoid porosity of the deposited material. The substrate to pouring-tube orifice distance where that condition is achieved depends strongly on the atomization pressure and the convective heat transfer coefficient of the substrate. It is demonstrated that 'tailoring' the microstructures and the reinforcement volume percent in the deposited material is feasible. The critical process parameters : the atomization pressure, the melt flow rate. the substrate to pouring-tube orifice distance, the reinforcement particles injection location and rate can all be adequately chosen in order to obtain any desired microstructure, grain size, reinforcement volume percent, with the additional benefit, if wanted, of rapid solidification processing
文摘Fluid mechanics, heat transfer and liquid-to-solid phase transformation are assessed in optimizing the spray atomization and codeposition process parameters for size refinement and microstructural uniformity of the deposited material. Atomization gas velocities, atomized droplets velocities, convective heat transfer coefficients, thermal histories of the solidifying droplets, freezing rates, fraction solid evolution and solid-liquid interface propagation velocity are calculated. The influence, on the deposit microstructural features, of process parameters like the atomization gas pressure, the pouring tube orifice diameter, the geometrical features of the atomization device,the potency of , pre-existing or injected as reinforcement, nucleation sites, the wetting angle between the liquid melt bnd impurity particles acting as preferred nucleation sites, the in-flight distance of the solidifying droplets in the atomization chamber, i5 evaluated. As a result of the evaluation, appropriate choice of the adjustable process parameters for the production of powders and/or deposits with desired grain size and microstructure, can be made.
文摘Background:The aim of this study was to investigate the influence of marking meth-ods on the outcomes of body composition analysis and provide guidance for the se-lection of marking methods in mouse body composition analysis.Methods:Male C57BL/6J mice aged 6 weeks were randomly assigned for pre-and post-ear tagging measurements.The body composition of the mice was measured using a small animal body composition analyzer,which provided measurements of the mass of fat,lean,and free fluid.Then,the mass of fat,lean and free fluid to body weight ratio was gained.Further data analysis was conducted to obtain the range and coeffi-cient of variation in body composition measurements for each mouse.The distribution of fat and lean tissue in the mice was also analyzed by comparing the fat-to-lean ratio.Results:(1)The mass of all body composition components in the ear tagging group was significantly lower than that in the control group.(2)There was a significant in-crease in the range and coefficient of variation of body composition measurements between the ear tagging group and the control group.(3)The fat-to-lean ratio in the ear tagging group was significantly lower than that in the control group.Conclusions:Ear tagging significantly lowered the results of body composition analy-sis in mice and higher the results of measurement error.Therefore,ear tagging should be avoided as much as possible when conducting body composition analysis experi-ments in mice.
基金National Natural Science Foundation of China,10872147Natural Science Foundation of Tianjin,09JCYBJC1400
文摘Articular cartilage is a layer of low-friction,load-bearing soft hydrated tissue covering bone-ends in diarthrosis,which plays an important role in spreading the load,reducing the joint contact stress,joint friction and wear during exercise.The vital mechanical function
基金supported by the National Natural Science Foundation of China(Grant Nos.42088101 and 42075032).
文摘Persistent(5-day or longer)extreme cold events(ECEs)over northeastern China during the boreal winter of 1979–2020 are investigated using daily minimum temperature(Tmin)from the China Meteorological Data Network.The extreme cooling area and intensity indices associated with the ECEs exhibit a dominant 10–40-day periodicity,indicating a close link with atmospheric intraseasonal oscillations(ISOs).The ECEs are categorized into W-and N-type.In the former,the low-frequency cooling associated with the ISO first penetrates into the western boundary of the northeastern China domain and later occupies the entire domain at its peak phase.The upper-tropospheric circulation associated with this type is characterized by a northwest–southeast-oriented Rossby wave train,expanding from the Ural Mountains to the western Pacific Ocean.In the latter,the cooling invades the northern boundary first and then penetrates into the entire domain.The upper tropospheric precursory signal associated with this type is a zonally oriented negative geopotential height anomaly,which slowly moves southward.A downward-propagating signal is observed in the stratospheric potential vorticity field prior to the peak cooling,implying a possible stratospheric impact.In addition to the W-and N-types,ECEs can also occur in a localized region near either at the northern or southern boundary of the domain.
基金National Key Technology R&D Program(2012BAC22B03)NSFC General Program(41275094)
文摘Based on the Tropical Cyclone(TC) Yearbooks data and JRA-25 reanalysis data from the Japan Meteorological Agency(JMA) during 1979-2008, dynamic composite analysis and computation of kinetic energy budget are used to study the intensifying and weakening TCs during Extratropical Transition over China. The TCI shows strong upper-level divergence, strengthened low-level convergence and significantly enhanced upward motion under the influence of strong upper-level troughs and high-level jets. The TCI is correspondingly intensified after Extratropical Transition(ET); TCW exhibits strong upper-level divergence, subdued low-level convergence and slightly enhanced upward motion under the influence of weak upper-level troughs and high-level jets. It then weakens after ET. The increase(decrease) of the generation of kinetic energy by divergence wind in TCI(TCW) at low level is one of the major reasons for TCI's intensification(TCW's weakening) after transformation. The generation of kinetic energy by divergence wind is closely related to the development of a low-level baroclinic frontal zone. The growth of the generation of kinetic energy by rotational wind in TCI at upper level is favorable for TCI's maintenance, which is affected by strong upper-level troughs. The dissipation of the generation of kinetic energy by rotational wind in TCW at upper level is unfavorable for TCW's maintenance, which is affected by weak upper-level troughs.
基金National Key Fundamental Research Development and Planning 973 Project(2011CB403405)Natural Science Foundation of China(41075039+2 种基金41175065)Specialized Project of Public Welfare Industries(GYHY200806009)"Qing-lan"Project of Jiangsu Province(2009)
文摘A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon during1988 to 2009.Based on the data of the numerical simulation,composite analysis and correlation analysis are used to make diagnostic study of climate dynamics.Results show that the month of maximum emission of the mean column burden of the anthropogenic aerosol in the main emission areas of South Asia is opposite in phase to that in China.Summer is the season of maximum emission amount in China,but the emission amounts are more in South Asia in spring and winter.On the whole,the mean column burden of the anthropogenic aerosol in China is relatively high compared with that in South Asia.The trend of distribution of aerosol is SW-NE in China,and Sichuan Basin is the emission center of aerosol.The effect of negative short wave radiative forcing alters the gradient of pressure between land and sea,weakening the development of East Asian summer monsoon over the northern part of Yangtze-Huaihe River Basin.We also discuss the feedback effect of East-Asian summer monsoon which is changed by the anthropogenic aerosol on the concentration and distribution of aerosol in China.
基金National Natural Science Foundation of China(40805018)National Basic Research Program of China(2013CB430104)Special Fund for Scientific Research in the Public Interest(GYHY201106035)
文摘Fifty-eight extratropical transition(ET) cases in the years 2000-2008, including 2,021 observations(at 6-hour intervals), over the western North Pacific are analyzed using the cyclone phase space(CPS) method, in an effort to get the characteristics of the structure evolution and environmental conditions of tropical cyclones(TCs) during ET over this area. Cluster analysis of the CPS dataset shows that strong TCs are more likely to undergo ET. ET begins with the increment of thermal asymmetry in TCs, along with the generation and intensification of an upper-level cold core, and ends with the occurrence of a lower-level cold core. ET lasts an average duration of about 28 hours. Dynamic composite analysis of the environmental field of different clusters shows that, in general, when TCs move northward,they are gradually embedded in the westerlies and gradually transform into extratropical cyclones under the influence of the mid-and higher-latitude baroclinic systems. As for those TCs which complete ET, there is always much greater potential vorticity gradient in the northwest of them and obvious water vapor transport channels in the environment.
基金supported by the National Natural Science Foundation of China(Nos.32371734,42007034,41920104008,and U22A20593)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA28020400)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2023205)the Young Scientist Group Project of Northeast Institute of Geography and Agroecology of China(No.2022QNXZ04)the Science and Technology Development Project of Jilin Province of China(No.YDZJ202101ZYTS006).
文摘The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental conditions.However,a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking.In the present study,we utilized data obtained from paddy fields of different rice cultivation years(0-23 years)to investigate the compositional and functional succession of soil bacterial communities.We focused on core bacterial taxa that were specifically enriched at different successional stages.Generalized joint attribute modeling(GJAM)was used to identify core bacterial taxa.Results indicated that the bare saline-alkali soil(0 year,prior to any rice cultivation)shared few core amplicon sequence variants(ASVs)with paddy fields.In the bare saline-alkali soil,Longimicrobiaceae from the phylum Gemmatimonadetes was dominant,while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae--phyla affiliated with Proteobacteria and Verrucomicrobia--after 5 and 23 years of rice cultivation,respectively.The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages,while sulfur metabolism functions exhibited the opposite trend.These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established.Redundancy analysis(RDA)indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0,2 and 4,6,8,10,and 12,and 20 and 23 years were driven by soil nitrate nitrogen content,pH,available phosphorus content,and the ratio of total carbon to total nitrogen,respectively.In summary,the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.
基金supported by National Natural Science Foundation of China(Nos.61127017,61378047,61205216,61178009,61108030,61475093,and 61275213)the National Key Technology R&D Program of China(No.2013BAC14B01)+2 种基金the 973 Program of China(No.2012CB921603)the Shanxi Natural Science Foundation,China(Nos.2013021004-1,2012021022-1)the Shanxi Scholarship Council of China(Nos.2013-011 and 2013-01)
文摘Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy （LIBS） apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the ＇drift＇ obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants.
基金Under the auspices of Scientific & Technological Development Project of Science & Technology Office, JilinProvince (No. 200104032)
文摘Groundwater reservoir is a kind of important engineering, which can optimize water resources arran- gement by means of artificial regulation. Regulated water is the blood and value performance of groundwater reservoir. To resolve the problem of real-time quantification of regulated water, the paper analyzed sources and compositions of regulated water in detail. Then, under the conditions of satisfying water demand inside research area, the paper analyzed quantity available and regulation coefficient of different regulated water and established a formula to calculate regulated water. At last, based on a pore groundwater reservoir in the middle reaches of the Yinma River, Jilin Province, the paper calculated regulated water with the formula and the result shows that the method is feasible. With some constraint conditions, the formula can be adopted in other similar areas.
基金supported by the National Natural Science Foundation of China (Nos. 51075019 and 51375033)Aeronautical Science Foundation (No. 20095251024) of Chinathe Fundamental Research Funds for the Central Universities (No. YWF-13-T-RSC-121) of China
文摘This paper seeks to outline the temperature effect on the buckling properties of ultra-thin-walled lenticular collapsible composite tube（LCCT） subjected to axial compression.The buckling tests of the LCCT specimens subjected to axial compression were carried out on INSTRON-500 N servo-hydraulic machine in dry state and at the temperatures of 25 C, 100 C and 80 C. The load–displacement curves and buckling initiation loads were measured and the buckling initiation mechanism was discussed from experimental observations. Experiments show that the buckling initiation load, on average, is only about 2.2% greater at the low temperature of 80 C than at the room temperature of 25 C due to the material hardening, demonstrating an insignificant increase in the buckling initiation load, whereas it is about 19.5% lower at the high temperature of 100 C than at the room temperature owing to the material softening, implying a significant decrease in the buckling initiation load. The failure mode of the LCCT in axial compression tests at three different temperatures can be reckoned to be characteristic of the buckling initiation and propagation around the central region until rupture. The finite element（FE） model is presented to simulate the buckling initiation mechanism based on the eigenvalue-based methodology. Good correlation between experimental and numerical results is achieved.
