To investigate groundwater flow and solute transport characteristics of the karst trough zone in China,tracer experiments were conducted at two adjacent typical karst groundwater flow systems(Yuquandong(YQD)and Migong...To investigate groundwater flow and solute transport characteristics of the karst trough zone in China,tracer experiments were conducted at two adjacent typical karst groundwater flow systems(Yuquandong(YQD)and Migongquan(MGQ))in Sixi valley,western Hubei,China.Highresolution continuous monitoring was utilized to obtain breakthrough curves(BTCs),which were then analyzed using the multi-dispersion model(MDM)and the two-region nonequilibrium model(2RNE)with basic parameters calculated by CXTFIT and QTRACER2.Results showed that:(1)YQD flow system had a complex infiltration matrix with overland flow,conduit flow and fracture flow,while the MGQ flow system was dominated by conduit flow with fast flow transport velocity,but also small amount of fracture flow there;(2)They were well fitted based on the MDM(R^2=0.928)and 2RNE(R^2=0.947)models,indicating that they had strong adaptability in the karst trough zone;(3)conceptual models for YQD and MGQ groundwater systems were generalized.In YQD system,the solute was transported via overland flow during intense rainfall,while some infiltrated down into fissures and conduits.In MGQ system,most were directly transported to spring outlet in the fissureconduit network.展开更多
Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.T...Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.展开更多
BACKGROUND Ulcerative colitis(UC)is a chronic inflammatory condition requiring continuous treatment and monitoring.There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thio...BACKGROUND Ulcerative colitis(UC)is a chronic inflammatory condition requiring continuous treatment and monitoring.There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thiopurines on vedolizumab trough concentrations is unknown.AIM To investigate the exposure-response relationship of vedolizumab and the impact of thiopurine withdrawal in UC patients who have achieved sustained clinical and endoscopic remission during maintenance therapy.METHODS This is a post-hoc analysis of prospective randomized clinical trial(VIEWS)involving UC patients across 8 centers in Australia from 2018 to 2022.Patients in clinical and endoscopic remission were randomized to continue or withdraw thiopurine while receiving vedolizumab.We evaluated vedolizumab serum trough concentrations,presence of anti-vedolizumab antibodies,and clinical outcomes over 48 weeks to assess exposure-response asso-ciation and impact of thiopurine withdrawal.RESULTS There were 62 UC participants with mean age of 43.4 years and 42%were females.All participants received vedolizumab as maintenance therapy with 67.7%withdrew thiopurine.Vedolizumab serum trough concentrations remained stable over 48 weeks regardless of thiopurine use,with no anti-vedolizumab antibodies detected.Pa-tients with clinical remission had higher trough concentrations at week 48.In quartile analysis,a threshold of>11.3μg/mL was associated with sustained clinical remission,showing a sensitivity of 82.4%,specificity of 60.0%,and an area of receiver operating characteristic of 0.71(95%CI:0.49-0.93).Patients discontinuing thiopurine required higher vedolizumab concentrations for achieving remission.CONCLUSION A positive exposure-response relationship between vedolizumab trough concentrations and UC outcomes suggests that monitoring drug levels may be beneficial.While thiopurine did not influence vedolizumab levels,its with-drawal may necessitate higher vedolizumab trough concentrations to maintain remission.展开更多
Three extreme cold events occurred in eastern Asia in January 2016,January 2021,and December 2023.As important factors in atmospheric circulation anomalies,the Blocking High and East Asian Trough(BH-ET)structure playe...Three extreme cold events occurred in eastern Asia in January 2016,January 2021,and December 2023.As important factors in atmospheric circulation anomalies,the Blocking High and East Asian Trough(BH-ET)structure played key roles during these three extreme cold wave events.Among these two dynamic patterns,the BH affected the development of the cold waves in two different ways:(1)before the cold waves in 2016 and 2023,the BH pushed the cold air southward,resulting in a slow and gradual cooling,with a cooling rate(CR)in eastern Asia of 1.34℃d^(-1)and 1.2℃d^(-1),respectively,and(2)in January 2021,the sudden collapse of BH caused the cold air to rapidly attack mid-latitude regions,with a CR of 1.87℃d^(-1).In terms of the spatial CR,the temperature drop in 2021 occurred 38.8%and 55%faster than those in 2016 and 2023,respectively.At the same time,the ET influences the wind direction of cold waves by modulating the pressure gradient.Before the cold waves occurred,the meridional wind field near the ET showed negative values,forming northwesterly or northeasterly winds,which continued to affect the southern part of East Asia.The meridional wind in January 2021 was stronger than those in 2016 and 2023,which is thought to be the reason for the strength of the 2021 cold wave.Finally,results from the temperature Empirical Orthogonal Function(EOF)analysis from 1980-2023 verify an obvious BH-ET structure in the three cold wave events,which suggests that this particular climatological state provides a climatic background for the occurrence of cold waves.展开更多
The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between...The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between intra-and extra-trough reservoirs within the Deyang-Anyue Rift Trough.These variations were primarily determined by divergences in the sedimentary environments developed during the evolution of the rift trough,which were a main factor in fostering the heterogeneous distribution of shale gas enrichment found today.However,the genetic mechanisms that govern reservoir heterogeneity across distinct structural domains(intra-trough,trough margin,and extra-trough)remain poorly understood,particularly regarding the coupling relationships between depositional environments,reservoir characteristics,and gas-bearing properties.This study adopts a multidisciplinary approach to investigating this issue that integrates core analysis,well-log interpretations,and geochemical data.Through systematic comparisons conducted using X-ray diffraction mineralogy,organic carbon quantification,and spontaneous imbibition experiments,we characterize the mineral assemblages,organic geochemical signatures,and pore structures found across the three structural domains of the Deyang-Anyue Rift Trough.The key findings are as follows:(1)The depositional environment is the main influence on reservoir distribution and organic matter enrichment,with intra-trough shales exhibiting a higher abundance of organic matter than their trough-margin and extra-trough counterparts.(2)Enhanced brittleness in intra-trough zones correlates with the predominance of biogenic silica therein.(3)Synergistic organic-inorganic interactions govern pore system development.(4)Gas-bearing capacity is jointly determined by effective porosity and organic matter content.These findings establish the rift trough as a preferential exploration target,providing critical geological guidance for optimizing shale gas exploration strategies in the Cambrian Qiongzhusi Formation.展开更多
BACKGROUND Plasma concentration monitoring is crucial for optimizing vancomycin use,particularly in patients in the intensive care unit(ICU).However,the reference interval for vancomycin plasma concentration remains u...BACKGROUND Plasma concentration monitoring is crucial for optimizing vancomycin use,particularly in patients in the intensive care unit(ICU).However,the reference interval for vancomycin plasma concentration remains undetermined.AIM To evaluate the correlations of area under the curve(AUC_(0-24))and trough concentration(C_(min))with efficacy and nephrotoxicity in patients in the ICU.METHODS A total of 103 patients treated with vancomycin for methicillin-resistant Staphylococcus aureus infections were analyzed in this study.The associations of clinicodemographic characteristics(including sex,age,weight,infection sites,main etiologies of ICU cases,comorbidities,acute physiological chronic health evaluation II score,and mechanical ventilation)and pharmacokinetics(daily dose,C_(min),AUC_(0-24),and AUC_(0-24)/minimum inhibitory concentration)with efficacy and nephrotoxicity of vancomycin were evaluated with univariate and multivariate logistic regression analyses.AUC_(0-24)was calculated using VCM-TDM software based on vancomycin population pharmacokinetics and Bayesian feedback method.RESULTS Cmin over 9.4μg/mL and AUC_(0-24)exceeding 359.6μg×hour/mL indicated good efficacy against infection.Cmin below 14.0μg/mL predicted no significant nephrotoxicity.CONCLUSION In this study,the effective and safe concentration interval for vancomycin in patients in the ICU was Cmin 9.4-14.0μg/mL.Close attention should be paid to adverse effects and renal function during vancomycin treatment.展开更多
Taking the natural gas reservoirs of the Sinian Dengying Formation on the east and west sides(Gaoshiti-Moxi area and north slope of central Sichuan paleo-uplift on the east;Weiyuan and Well Datan-1 block on the west)o...Taking the natural gas reservoirs of the Sinian Dengying Formation on the east and west sides(Gaoshiti-Moxi area and north slope of central Sichuan paleo-uplift on the east;Weiyuan and Well Datan-1 block on the west)of the Deyang-Anyue rift trough in the Sichuan Basin,China,as the research object,the geochemical parameters(component,isotopic composition)of natural gas from the Dengying Formation in different areas are compared,and then the differences in geochemical characteristics of Dengying natural gas on the east and west sides of the Deyang-Anyue rift trough and their genesis are clarified.First,the Dengying gas reservoirs on both sides of the rift trough are predominantly composed of oil-cracking gas with high maturity,which is typical dry gas.Second,severely modified by thermochemical sulfate reduction(TSR)reaction,the Dengying gas reservoirs on the east side exhibit high H2S and CO_(2) contents,with an elevated δ^(13)C_(2) value(average value higher than-29‰).The Dengying gas reservoirs in the Weiyuan area are less affected by TSR modification,though the δ^(13)C_(1) values are slightly greater than that of the reservoirs on the east side with partial reversal of carbon isotope composition,likely due to the water-soluble gas precipitation and accumulation mechanism.The Dengying gas reservoir of Well Datan-1 shows no influence from TSR.Third,the Dengying gas reservoirs reflect high helium contents(significantly higher than that on the east side)in the Weiyuan and Datan-1 areas on the west side,which is supposed to attribute to the widespread granites in basement and efficient vertical transport along faults.Fourth,controlled by the paleo-salinity of water medium in the depositional period of the source rock,the δ^(2)HCH_(4) values of the Dengying gas reservoirs on the west side are slightly lighter than those on the east side.Fifth,the Dengying natural gas in the Datan-1 area is contributed by the source rocks of the Sinian Doushantuo Formation and the third member of the Dengying Formation,in addition to the Cambrian Qiongzhusi Formation.展开更多
The coal resources of Nigeria occur mainly within the Benue Trough which includes the Anambra Basin. In the Lower Benue Trough/Anambra Basin, sub-bituminous coals occur within the Maastrichtian Mamu Formation in Enugu...The coal resources of Nigeria occur mainly within the Benue Trough which includes the Anambra Basin. In the Lower Benue Trough/Anambra Basin, sub-bituminous coals occur within the Maastrichtian Mamu Formation in Enugu (Enugu State), Owukpa (Benue State), Okaba (Kogi State) and Ogboyaga (Kogi State). High-volatile bituminous coals occur within the Turonian-Coniacian Awgu Formation in the Middle Benue Trough around Obi/Lafia (Nasarawa State) with outcrop exposures at Jangwa-Shankodi. Organic petrographic results show that huminites dominate the maceral composition of the Anambra Basin coals and have vitrinite reflectance values that range from 0.40% to 0.63 Ro%. In the coals from the Middle Benue Trough, vitrinite macerals predominate the petrographic composition and Ro values range from 0.81% to 1.25%. Based on the petrographic composition and rank evaluation, the sub-bituminous coals in Enugu, Owukpa, Okaba and Ogboyaga (Anambra Basin) are optimum for combustion and electric power generation and sub-optimum for liquefaction, while the high-volatile bituminous coals in the Obi/Lafia area (Middle Benue Trough), apart from being optimum for liquefaction, are the most suitable as raw material for coke making (carbonization) in steel manufacture and as exploration targets for coal-bed methane gas and liquid hydrocarbons.展开更多
Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southe...Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.展开更多
Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflict...Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 (TS9909 hereinafter). Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex (MCC) on the warm, moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.展开更多
The complex tunnelling constructive environment in urban area in similar green field situations is faced through analytical evaluations in order to control the design calculation process and subsequently manage the in...The complex tunnelling constructive environment in urban area in similar green field situations is faced through analytical evaluations in order to control the design calculation process and subsequently manage the interventions techniques with the aim of totally reducing the typical settlements trough above the tunnel either during the construction stage or during the serviceability stage. Recently, the author has proposed an operative and mathematical method by an opportune choice of tensioned anchors to control the tunnel lining settlements. In order to completely eliminate the remainder typical soft soil trough which is normal to the line of the tunnel, it is here proposed to use and properly calculate the interventions of stone columns by the SAVE (silent, advanced, vibration-erasing) Compozer method, in combination with the anchorages.展开更多
Objectives: The aim of this study was to assess the ability of a vancomycin nomogram to effectively predict vancomycin serum trough concentrations within the desired 15-20 mg/L therapeutic range. Methods: A retrospe...Objectives: The aim of this study was to assess the ability of a vancomycin nomogram to effectively predict vancomycin serum trough concentrations within the desired 15-20 mg/L therapeutic range. Methods: A retrospective chart review was performed on a randomized sample of trough concentrations from adult patients at HVMC (Holston Valley Medical Center) receiving intravenous vancomycin dosing regimens determined by the vancomycin nomogram over an eight-month span. Key findings: 102 patients were included in the study. Trough concentrations ranged fi:om 3.5 mg/L to 40.8 mg/L with 36 (35.2%) patients having trough levels within the desired range of 15-20 mg/L. In addition, 75 (73.5%) patients had trough levels within the range of 10-25 mg/L. Conclusion: This study demonstrated that the vancomycin nomogram at HVMC is an effective dosing tool that provides consistency among multiple pharmacists and predictable serum trough concentrations.展开更多
Okinawa Trough is a back-arc, initial marginal sea basin, located behind the Ryukyu Arc-Trench System. The formation and evolution of the Okinawa Trough is intimately related to the subduction process of the Philippin...Okinawa Trough is a back-arc, initial marginal sea basin, located behind the Ryukyu Arc-Trench System. The formation and evolution of the Okinawa Trough is intimately related to the subduction process of the Philippine Sea Plate beneath the Eurasian Plate since the late Miocene. The tectonic evolution of the trough is similar to other active back-arcs, such as the Mariana Trough and southern Lau Basin, all of which are experiencing the initial rifting and subsequent spreading process. This study reviews all petrologic and geochemical data of mafic volcanic lavas from the Okinawa Trough, Ryukyu Arc, and Philippine Sea Plate, combined with geophysical data to indicate the relationship between the subduction sources (input) and arc or back-arc magmas (output) in the Philippine Sea Plate-Ryukyu Arc-Okinawa Trough system (PROS). The results obtained showed that several components were variably involved in the petrogenesis of the Oki-nawa Trough lavas:sub-continental lithospheric mantle underlying the Eurasian Plate, Indian mid-oceanic ridge basalt (MORB)-type mantle, and Pacific MORB-type mantle. The addition of shallow aqueous fluids and deep hydrous melts from subducted components with the characteristics of Indian MORB-type mantle into the mantle source of lavas variably modifies the primitive mantle wedge beneath the Ryukyu and sub-continental lithospheric mantle (SCLM) beneath the Okinawa Trough. In the northeastern end of the trough and arc, instead of Indian MORB-type mantle, Pacific MORB-type mantle dominates the magma source. Along the strike of the Ryukyu Arc and Okinawa Trough, the systematic variations in trace element ratios and isotopic compositions reflect the first-order effect of variable subduction input on the magma source. In general, petrologic data, combined with geophysical data, imply that the Okinawa Trough is experiencing the"seafloor spreading"process in the southwest segment,"rift propagation"process in the middle seg-ment, and"crustal extension"process in the northeast segment, and a nascent ocean basin occurs in the southwest segment.展开更多
Volcanic rocks both from the northern East China Sea (NECS) shelf margin and the northern Okinawa Trough are subalkaline less aluminous,and lower in High Field Strength Elements (HFSE).These rocks are higher in La...Volcanic rocks both from the northern East China Sea (NECS) shelf margin and the northern Okinawa Trough are subalkaline less aluminous,and lower in High Field Strength Elements (HFSE).These rocks are higher in Large Ion Lithophile Elements (LILE),thorium and uranium contents,positive lead anomalies,negative Nb-Ta anomalies,and enrichment in Light Rare Earth Elements (LREE).Basalts from the NECS shelf margin are akin to Indian Ocean Mid-Ocean Ridge Basalt (MORB),and rhyolites from the northern Okinawa Trough have the highest 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios.The NECS shelf margin basalts have lower 87 Sr/ 86 Sr ratios,ε N d and σ 18 O than the northern Okinawa Trough silicic rocks.According to 40 K– 40 Ar isotopic ages of basalts from the NECS shelf margin,rifting of the Okinawa Trough may have been active since at least 3.65–3.86 Ma.The origin of the NECS shelf margin basalt can be explained by the interaction of melt derived from Indian Ocean MORB-like mantle with enriched subcontinental lithosphere.The basalts from both sides of the Okinawa Trough may have a similar origin during the initial rifting of the Okinawa Trough,and the formation of basaltic magmas closely relates to the thinning of continental crust.The source of the formation of the northern Okinawa Trough silicic rocks was different from that of the middle Okinawa Trough,which could have been generated by the interaction of basaltic melt with an enriched crustal component.From the Ryukyu island arc to East China,the Cenozoic basalts have apparently increasing trends of MgO contents and ratios of LREE to Heavy Rare Earth Elements (HREE),suggesting that the trace element variabilities of basalts may have been influenced by the subduction of the Philippine Sea plate,and that the effects of subduction of the Philippine Sea plate on the chemical composition of basaltic melts have had a decreasing effect from the Ryukyu island arc to East China.展开更多
AIM: To evaluate the effect of releasing the orbicularis retaining ligament(ORL) complex of the tear trough combined with the transconjunctival blepharoplasty in the surgical management of tear trough deformity compar...AIM: To evaluate the effect of releasing the orbicularis retaining ligament(ORL) complex of the tear trough combined with the transconjunctival blepharoplasty in the surgical management of tear trough deformity compared with the effect of blepharoplasty alone. METHODS: A prospective, randomized(by closed envelope technique), controlled surgical trial which included 50 patients(100 eyes) with bilateral visible tear trough deformity and lower eyelid fat bulging, was divided into two groups where 25 patients(50 eyes) had tear trough-ORL release with blepharoplasty and 25 patients(50 eyes) didn't. Qualitative and quantitative assessments of tear trough deformity were done at 6 mo postoperatively, achieving grade 0 or 1 of Barton's classification was considered a success. Standardized photographic documentation of each patient was done pre and postoperatively, also assessment of the patients' satisfaction postoperatively was done and ranked as excellent, very good, good or fair. RESULTS: There was statistically significant difference between the two groups in the overall aesthetic results postoperatively regarding the qualitative and quantitative analysis of the tear trough deformity, where patients who had tear trough-ORL complex release had more successful outcomes than those of the second group. CONCLUSION: ORL release should be done in patients with tear trough deformity in order to release the tethering effect of this ligament which causes the prominence of the naso jugal groove.展开更多
Rare earth elements (REE) compositions and discriminant function were successfully used to examine high resolution sediment source changes in the northern Okinawa Trough over the last 24.1 ka, especially for the inf...Rare earth elements (REE) compositions and discriminant function were successfully used to examine high resolution sediment source changes in the northern Okinawa Trough over the last 24.1 ka, especially for the influence from the Yellow River and the Tsushima Warm Current (TWC) that has not been well solved. Variations of these parameters were clearly divided into three distinct depositional units. During Interval 1 (24.1-16.0 ka BP), the paleo-Yellow River and the paleo-Yangtze River mouths were situated near the studied area and could have played major roles in the sedimentation therein. In Interval 2 (16.0-7.3 ka BP), these river mouths gradually retreated with global sea-level rise, leading to less fluvial inputs from them to the northern Okinawa Trough. Meanwhile, formation of the TWC could carry some sediment loads of Taiwan to the studied core, especially during its late phase (8.0-7.3 ka BP). Modem oceanographic conditions, with a predominance of the TWC, were finally established since the beginning of Interval 3, causing more ten'igenous contribution from Taiwan to the studied area. Subsequently, modem depositional environments mainly influenced by the Yellow River, the Yangtze River, and the TWC were finally formed.展开更多
The paper focuses on the characteristics of faulting and magmatism of the Okinawa Trough and the relation between them. En-echelon grabens are ranked oblique to the continental shelf edge uplift, and the Longwang upli...The paper focuses on the characteristics of faulting and magmatism of the Okinawa Trough and the relation between them. En-echelon grabens are ranked oblique to the continental shelf edge uplift, and the Longwang uplift, the rifting block ridge in the northern segment and the "Mianhua uplift" in the southern segment have possibly preserved characteristics of volcanism and magmatism occurring with those rifting phases. The clockwise rotation of the southern Ryukyu Islands, driven by collision between Luzon and Taiwan, has played a key role in the crustal oceanization, enhancing the crustal extension of the southern segment and inducing volcanic magmatism in those grabens, among which the Yaeyama graben is a typical example of the presence of oceanic crust. Faulting and magmatism were mainly migrating towards the island arc asymmetrically. The crustal oceanization of the Okinawa Trough is difficultly interpreted by the linear magnetic anomaly model, which is fit for the symmetric spreading of the mid-oceanic ridges.展开更多
The monsoon trough (MT) is one of the large-scale patterns favorable for tropical cyclone (TC) formation over the western North Pacific (WNP). This study re-examines TC formation by treating the MT as a large-sc...The monsoon trough (MT) is one of the large-scale patterns favorable for tropical cyclone (TC) formation over the western North Pacific (WNP). This study re-examines TC formation by treating the MT as a large-scale background for TC activity during May-October. Over an 11-year (2000-10) period, 8.3 TC formation events on average per year are identified to occur within MTs, accounting for 43.1% of the total TC formation events in the WNP basin. This percentage is much lower than those reported in previous studies. Further analysis indicates that TC formation events in monsoon gyres were included at least in some previous studies. The MT includes a monsoon confluence zone where westerlies meet easterlies and a monsoon shear line where the trade easterlies lie north of the monsoon westerlies. In this study, the large-scale flow pattern associated with TC formation in the MT is composited based on the reference point in the confluence zone where both the zonal and meridional wind components are zero with positive vorticity. While previous studies have found that many TCs form in the confluence zone, the composite analysis indicates that nearly all of the TCs formed in the shear region, since the shear region is associated with stronger low-level relative vorticity than the confluence zone. The prevailing easterly vertical shear of zonal wind and barotropic instability may also be conducive to TC formation in the shear region, through the development of synoptic-scale tropical disturbances in the MT that are necessary for TC formation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42007178 and 41907327)the Natural Science Foundation of Hubei(Nos.2020CFB463 and 2019CFB372)+4 种基金China Geological Survey(Nos.DD20160304 and DD20190824)Fundamental Research Funds for the Central Universities(Nos.CUG 190644 and CUGL180817)National Key Research and Development Program(No.2019YFC1805502)Key Laboratory of Karst Dynamics,MNR and GZAR(Institute of Karst Geology,CAGS)Guilin(No.KDL201703)Key Laboratory of Karst Ecosystem and Treatment of Rocky Desertification,MNR and IRCK by UNESCO(No.KDL201903)。
文摘To investigate groundwater flow and solute transport characteristics of the karst trough zone in China,tracer experiments were conducted at two adjacent typical karst groundwater flow systems(Yuquandong(YQD)and Migongquan(MGQ))in Sixi valley,western Hubei,China.Highresolution continuous monitoring was utilized to obtain breakthrough curves(BTCs),which were then analyzed using the multi-dispersion model(MDM)and the two-region nonequilibrium model(2RNE)with basic parameters calculated by CXTFIT and QTRACER2.Results showed that:(1)YQD flow system had a complex infiltration matrix with overland flow,conduit flow and fracture flow,while the MGQ flow system was dominated by conduit flow with fast flow transport velocity,but also small amount of fracture flow there;(2)They were well fitted based on the MDM(R^2=0.928)and 2RNE(R^2=0.947)models,indicating that they had strong adaptability in the karst trough zone;(3)conceptual models for YQD and MGQ groundwater systems were generalized.In YQD system,the solute was transported via overland flow during intense rainfall,while some infiltrated down into fissures and conduits.In MGQ system,most were directly transported to spring outlet in the fissureconduit network.
基金supported by the National Key R&D Program of China(2022YFF0504400)the National Natural Science Foundation of China(42188101,42274195,42174193)+2 种基金the International Partnership Program Of Chinese Academy of Sciences(Grant No.183311KYSB20200003)the USTC Research Funds of the Double First-Class Initiative(YD2080002013)the Joint Open Fund of Mengcheng National Geophysical Observatory(MENGO-202408).
文摘Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.
基金Supported by Takeda Australia,No.IISR-2016-101883.
文摘BACKGROUND Ulcerative colitis(UC)is a chronic inflammatory condition requiring continuous treatment and monitoring.There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thiopurines on vedolizumab trough concentrations is unknown.AIM To investigate the exposure-response relationship of vedolizumab and the impact of thiopurine withdrawal in UC patients who have achieved sustained clinical and endoscopic remission during maintenance therapy.METHODS This is a post-hoc analysis of prospective randomized clinical trial(VIEWS)involving UC patients across 8 centers in Australia from 2018 to 2022.Patients in clinical and endoscopic remission were randomized to continue or withdraw thiopurine while receiving vedolizumab.We evaluated vedolizumab serum trough concentrations,presence of anti-vedolizumab antibodies,and clinical outcomes over 48 weeks to assess exposure-response asso-ciation and impact of thiopurine withdrawal.RESULTS There were 62 UC participants with mean age of 43.4 years and 42%were females.All participants received vedolizumab as maintenance therapy with 67.7%withdrew thiopurine.Vedolizumab serum trough concentrations remained stable over 48 weeks regardless of thiopurine use,with no anti-vedolizumab antibodies detected.Pa-tients with clinical remission had higher trough concentrations at week 48.In quartile analysis,a threshold of>11.3μg/mL was associated with sustained clinical remission,showing a sensitivity of 82.4%,specificity of 60.0%,and an area of receiver operating characteristic of 0.71(95%CI:0.49-0.93).Patients discontinuing thiopurine required higher vedolizumab concentrations for achieving remission.CONCLUSION A positive exposure-response relationship between vedolizumab trough concentrations and UC outcomes suggests that monitoring drug levels may be beneficial.While thiopurine did not influence vedolizumab levels,its with-drawal may necessitate higher vedolizumab trough concentrations to maintain remission.
基金supported by the National Natural Science Foundation of China under Grant No.41821004,the National Key Research and Development Program of China under contract No.2022YFE0140500the National Key R&D Program of China under contract No.2022YFA1004403+2 种基金the Laoshan Laboratory Science and Technology Innovation Project No.LSKJ202202104the National Nature Science Foundation of China No.42130406the Project of Doctoral Found of Qingdao University of Science and Technology under contract No.210010022746.
文摘Three extreme cold events occurred in eastern Asia in January 2016,January 2021,and December 2023.As important factors in atmospheric circulation anomalies,the Blocking High and East Asian Trough(BH-ET)structure played key roles during these three extreme cold wave events.Among these two dynamic patterns,the BH affected the development of the cold waves in two different ways:(1)before the cold waves in 2016 and 2023,the BH pushed the cold air southward,resulting in a slow and gradual cooling,with a cooling rate(CR)in eastern Asia of 1.34℃d^(-1)and 1.2℃d^(-1),respectively,and(2)in January 2021,the sudden collapse of BH caused the cold air to rapidly attack mid-latitude regions,with a CR of 1.87℃d^(-1).In terms of the spatial CR,the temperature drop in 2021 occurred 38.8%and 55%faster than those in 2016 and 2023,respectively.At the same time,the ET influences the wind direction of cold waves by modulating the pressure gradient.Before the cold waves occurred,the meridional wind field near the ET showed negative values,forming northwesterly or northeasterly winds,which continued to affect the southern part of East Asia.The meridional wind in January 2021 was stronger than those in 2016 and 2023,which is thought to be the reason for the strength of the 2021 cold wave.Finally,results from the temperature Empirical Orthogonal Function(EOF)analysis from 1980-2023 verify an obvious BH-ET structure in the three cold wave events,which suggests that this particular climatological state provides a climatic background for the occurrence of cold waves.
基金supported by the National Natural Science Foundation of China(No.24A20592).
文摘The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between intra-and extra-trough reservoirs within the Deyang-Anyue Rift Trough.These variations were primarily determined by divergences in the sedimentary environments developed during the evolution of the rift trough,which were a main factor in fostering the heterogeneous distribution of shale gas enrichment found today.However,the genetic mechanisms that govern reservoir heterogeneity across distinct structural domains(intra-trough,trough margin,and extra-trough)remain poorly understood,particularly regarding the coupling relationships between depositional environments,reservoir characteristics,and gas-bearing properties.This study adopts a multidisciplinary approach to investigating this issue that integrates core analysis,well-log interpretations,and geochemical data.Through systematic comparisons conducted using X-ray diffraction mineralogy,organic carbon quantification,and spontaneous imbibition experiments,we characterize the mineral assemblages,organic geochemical signatures,and pore structures found across the three structural domains of the Deyang-Anyue Rift Trough.The key findings are as follows:(1)The depositional environment is the main influence on reservoir distribution and organic matter enrichment,with intra-trough shales exhibiting a higher abundance of organic matter than their trough-margin and extra-trough counterparts.(2)Enhanced brittleness in intra-trough zones correlates with the predominance of biogenic silica therein.(3)Synergistic organic-inorganic interactions govern pore system development.(4)Gas-bearing capacity is jointly determined by effective porosity and organic matter content.These findings establish the rift trough as a preferential exploration target,providing critical geological guidance for optimizing shale gas exploration strategies in the Cambrian Qiongzhusi Formation.
基金Supported by the Key Project Plan of Health and Medical Science Research in Hebei Provincial Health Commission,No.20190745.
文摘BACKGROUND Plasma concentration monitoring is crucial for optimizing vancomycin use,particularly in patients in the intensive care unit(ICU).However,the reference interval for vancomycin plasma concentration remains undetermined.AIM To evaluate the correlations of area under the curve(AUC_(0-24))and trough concentration(C_(min))with efficacy and nephrotoxicity in patients in the ICU.METHODS A total of 103 patients treated with vancomycin for methicillin-resistant Staphylococcus aureus infections were analyzed in this study.The associations of clinicodemographic characteristics(including sex,age,weight,infection sites,main etiologies of ICU cases,comorbidities,acute physiological chronic health evaluation II score,and mechanical ventilation)and pharmacokinetics(daily dose,C_(min),AUC_(0-24),and AUC_(0-24)/minimum inhibitory concentration)with efficacy and nephrotoxicity of vancomycin were evaluated with univariate and multivariate logistic regression analyses.AUC_(0-24)was calculated using VCM-TDM software based on vancomycin population pharmacokinetics and Bayesian feedback method.RESULTS Cmin over 9.4μg/mL and AUC_(0-24)exceeding 359.6μg×hour/mL indicated good efficacy against infection.Cmin below 14.0μg/mL predicted no significant nephrotoxicity.CONCLUSION In this study,the effective and safe concentration interval for vancomycin in patients in the ICU was Cmin 9.4-14.0μg/mL.Close attention should be paid to adverse effects and renal function during vancomycin treatment.
基金Supported by the National Natural Science Foundation of China(42272161)PetroChina Science and Technology Major Project(2023ZZ16)Research Institute of Exploration and Development,PetroChina Southwest Oil&Gasfield Company(2024D101-01-06)。
文摘Taking the natural gas reservoirs of the Sinian Dengying Formation on the east and west sides(Gaoshiti-Moxi area and north slope of central Sichuan paleo-uplift on the east;Weiyuan and Well Datan-1 block on the west)of the Deyang-Anyue rift trough in the Sichuan Basin,China,as the research object,the geochemical parameters(component,isotopic composition)of natural gas from the Dengying Formation in different areas are compared,and then the differences in geochemical characteristics of Dengying natural gas on the east and west sides of the Deyang-Anyue rift trough and their genesis are clarified.First,the Dengying gas reservoirs on both sides of the rift trough are predominantly composed of oil-cracking gas with high maturity,which is typical dry gas.Second,severely modified by thermochemical sulfate reduction(TSR)reaction,the Dengying gas reservoirs on the east side exhibit high H2S and CO_(2) contents,with an elevated δ^(13)C_(2) value(average value higher than-29‰).The Dengying gas reservoirs in the Weiyuan area are less affected by TSR modification,though the δ^(13)C_(1) values are slightly greater than that of the reservoirs on the east side with partial reversal of carbon isotope composition,likely due to the water-soluble gas precipitation and accumulation mechanism.The Dengying gas reservoir of Well Datan-1 shows no influence from TSR.Third,the Dengying gas reservoirs reflect high helium contents(significantly higher than that on the east side)in the Weiyuan and Datan-1 areas on the west side,which is supposed to attribute to the widespread granites in basement and efficient vertical transport along faults.Fourth,controlled by the paleo-salinity of water medium in the depositional period of the source rock,the δ^(2)HCH_(4) values of the Dengying gas reservoirs on the west side are slightly lighter than those on the east side.Fifth,the Dengying natural gas in the Datan-1 area is contributed by the source rocks of the Sinian Doushantuo Formation and the third member of the Dengying Formation,in addition to the Cambrian Qiongzhusi Formation.
文摘The coal resources of Nigeria occur mainly within the Benue Trough which includes the Anambra Basin. In the Lower Benue Trough/Anambra Basin, sub-bituminous coals occur within the Maastrichtian Mamu Formation in Enugu (Enugu State), Owukpa (Benue State), Okaba (Kogi State) and Ogboyaga (Kogi State). High-volatile bituminous coals occur within the Turonian-Coniacian Awgu Formation in the Middle Benue Trough around Obi/Lafia (Nasarawa State) with outcrop exposures at Jangwa-Shankodi. Organic petrographic results show that huminites dominate the maceral composition of the Anambra Basin coals and have vitrinite reflectance values that range from 0.40% to 0.63 Ro%. In the coals from the Middle Benue Trough, vitrinite macerals predominate the petrographic composition and Ro values range from 0.81% to 1.25%. Based on the petrographic composition and rank evaluation, the sub-bituminous coals in Enugu, Owukpa, Okaba and Ogboyaga (Anambra Basin) are optimum for combustion and electric power generation and sub-optimum for liquefaction, while the high-volatile bituminous coals in the Obi/Lafia area (Middle Benue Trough), apart from being optimum for liquefaction, are the most suitable as raw material for coke making (carbonization) in steel manufacture and as exploration targets for coal-bed methane gas and liquid hydrocarbons.
文摘Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.
基金sponsored jointly by the Natural Science Foundation of China (Grant 4040950009402050084)the Project of Planned National Key Basic Research/Development (2004CB418301)
文摘Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 (TS9909 hereinafter). Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex (MCC) on the warm, moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.
文摘The complex tunnelling constructive environment in urban area in similar green field situations is faced through analytical evaluations in order to control the design calculation process and subsequently manage the interventions techniques with the aim of totally reducing the typical settlements trough above the tunnel either during the construction stage or during the serviceability stage. Recently, the author has proposed an operative and mathematical method by an opportune choice of tensioned anchors to control the tunnel lining settlements. In order to completely eliminate the remainder typical soft soil trough which is normal to the line of the tunnel, it is here proposed to use and properly calculate the interventions of stone columns by the SAVE (silent, advanced, vibration-erasing) Compozer method, in combination with the anchorages.
文摘Objectives: The aim of this study was to assess the ability of a vancomycin nomogram to effectively predict vancomycin serum trough concentrations within the desired 15-20 mg/L therapeutic range. Methods: A retrospective chart review was performed on a randomized sample of trough concentrations from adult patients at HVMC (Holston Valley Medical Center) receiving intravenous vancomycin dosing regimens determined by the vancomycin nomogram over an eight-month span. Key findings: 102 patients were included in the study. Trough concentrations ranged fi:om 3.5 mg/L to 40.8 mg/L with 36 (35.2%) patients having trough levels within the desired range of 15-20 mg/L. In addition, 75 (73.5%) patients had trough levels within the range of 10-25 mg/L. Conclusion: This study demonstrated that the vancomycin nomogram at HVMC is an effective dosing tool that provides consistency among multiple pharmacists and predictable serum trough concentrations.
基金The National Natural Science Foundation of China under contract Nos 41322036,41230960,40906034,41276003 and 41176058China Ocean Mineral Resources R&D Association(COMRA)under contract No.DY125-12-R-05
文摘Okinawa Trough is a back-arc, initial marginal sea basin, located behind the Ryukyu Arc-Trench System. The formation and evolution of the Okinawa Trough is intimately related to the subduction process of the Philippine Sea Plate beneath the Eurasian Plate since the late Miocene. The tectonic evolution of the trough is similar to other active back-arcs, such as the Mariana Trough and southern Lau Basin, all of which are experiencing the initial rifting and subsequent spreading process. This study reviews all petrologic and geochemical data of mafic volcanic lavas from the Okinawa Trough, Ryukyu Arc, and Philippine Sea Plate, combined with geophysical data to indicate the relationship between the subduction sources (input) and arc or back-arc magmas (output) in the Philippine Sea Plate-Ryukyu Arc-Okinawa Trough system (PROS). The results obtained showed that several components were variably involved in the petrogenesis of the Oki-nawa Trough lavas:sub-continental lithospheric mantle underlying the Eurasian Plate, Indian mid-oceanic ridge basalt (MORB)-type mantle, and Pacific MORB-type mantle. The addition of shallow aqueous fluids and deep hydrous melts from subducted components with the characteristics of Indian MORB-type mantle into the mantle source of lavas variably modifies the primitive mantle wedge beneath the Ryukyu and sub-continental lithospheric mantle (SCLM) beneath the Okinawa Trough. In the northeastern end of the trough and arc, instead of Indian MORB-type mantle, Pacific MORB-type mantle dominates the magma source. Along the strike of the Ryukyu Arc and Okinawa Trough, the systematic variations in trace element ratios and isotopic compositions reflect the first-order effect of variable subduction input on the magma source. In general, petrologic data, combined with geophysical data, imply that the Okinawa Trough is experiencing the"seafloor spreading"process in the southwest segment,"rift propagation"process in the middle seg-ment, and"crustal extension"process in the northeast segment, and a nascent ocean basin occurs in the southwest segment.
基金The Pilot Project of Knowledge Innovation Project,Chinese Academy of Sciences under contract Nos KZCX2- YW-211 and KZCX3-SW-223the National Natural Science Foundation of China under contract Nos 40830849 and 40976027+1 种基金Shandong Province Natural Science Foundation of China for Distinguished Young Scholars under contract No.JQ200913the National Major Fundamental Research and Development Project under contract No.G2000046701
文摘Volcanic rocks both from the northern East China Sea (NECS) shelf margin and the northern Okinawa Trough are subalkaline less aluminous,and lower in High Field Strength Elements (HFSE).These rocks are higher in Large Ion Lithophile Elements (LILE),thorium and uranium contents,positive lead anomalies,negative Nb-Ta anomalies,and enrichment in Light Rare Earth Elements (LREE).Basalts from the NECS shelf margin are akin to Indian Ocean Mid-Ocean Ridge Basalt (MORB),and rhyolites from the northern Okinawa Trough have the highest 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios.The NECS shelf margin basalts have lower 87 Sr/ 86 Sr ratios,ε N d and σ 18 O than the northern Okinawa Trough silicic rocks.According to 40 K– 40 Ar isotopic ages of basalts from the NECS shelf margin,rifting of the Okinawa Trough may have been active since at least 3.65–3.86 Ma.The origin of the NECS shelf margin basalt can be explained by the interaction of melt derived from Indian Ocean MORB-like mantle with enriched subcontinental lithosphere.The basalts from both sides of the Okinawa Trough may have a similar origin during the initial rifting of the Okinawa Trough,and the formation of basaltic magmas closely relates to the thinning of continental crust.The source of the formation of the northern Okinawa Trough silicic rocks was different from that of the middle Okinawa Trough,which could have been generated by the interaction of basaltic melt with an enriched crustal component.From the Ryukyu island arc to East China,the Cenozoic basalts have apparently increasing trends of MgO contents and ratios of LREE to Heavy Rare Earth Elements (HREE),suggesting that the trace element variabilities of basalts may have been influenced by the subduction of the Philippine Sea plate,and that the effects of subduction of the Philippine Sea plate on the chemical composition of basaltic melts have had a decreasing effect from the Ryukyu island arc to East China.
文摘AIM: To evaluate the effect of releasing the orbicularis retaining ligament(ORL) complex of the tear trough combined with the transconjunctival blepharoplasty in the surgical management of tear trough deformity compared with the effect of blepharoplasty alone. METHODS: A prospective, randomized(by closed envelope technique), controlled surgical trial which included 50 patients(100 eyes) with bilateral visible tear trough deformity and lower eyelid fat bulging, was divided into two groups where 25 patients(50 eyes) had tear trough-ORL release with blepharoplasty and 25 patients(50 eyes) didn't. Qualitative and quantitative assessments of tear trough deformity were done at 6 mo postoperatively, achieving grade 0 or 1 of Barton's classification was considered a success. Standardized photographic documentation of each patient was done pre and postoperatively, also assessment of the patients' satisfaction postoperatively was done and ranked as excellent, very good, good or fair. RESULTS: There was statistically significant difference between the two groups in the overall aesthetic results postoperatively regarding the qualitative and quantitative analysis of the tear trough deformity, where patients who had tear trough-ORL complex release had more successful outcomes than those of the second group. CONCLUSION: ORL release should be done in patients with tear trough deformity in order to release the tethering effect of this ligament which causes the prominence of the naso jugal groove.
基金supported by the Public Science and Technology Research Funds Projects of Ocean,State Oceanic Administration of the People’s Republic of China (201005003)the National Natural Science Foundation of China (41230959,41106043,41076030)the National Basic Research Program of China (2007CB815903)
文摘Rare earth elements (REE) compositions and discriminant function were successfully used to examine high resolution sediment source changes in the northern Okinawa Trough over the last 24.1 ka, especially for the influence from the Yellow River and the Tsushima Warm Current (TWC) that has not been well solved. Variations of these parameters were clearly divided into three distinct depositional units. During Interval 1 (24.1-16.0 ka BP), the paleo-Yellow River and the paleo-Yangtze River mouths were situated near the studied area and could have played major roles in the sedimentation therein. In Interval 2 (16.0-7.3 ka BP), these river mouths gradually retreated with global sea-level rise, leading to less fluvial inputs from them to the northern Okinawa Trough. Meanwhile, formation of the TWC could carry some sediment loads of Taiwan to the studied core, especially during its late phase (8.0-7.3 ka BP). Modem oceanographic conditions, with a predominance of the TWC, were finally established since the beginning of Interval 3, causing more ten'igenous contribution from Taiwan to the studied area. Subsequently, modem depositional environments mainly influenced by the Yellow River, the Yangtze River, and the TWC were finally formed.
基金The National Major Fundamental Research and Development Project of China under contract Nos G2000046703 and 2007CB411702the Scientific Research Fund of the Second Institute of Oceanography, State Oceanic Administration under contract No.JT0705
文摘The paper focuses on the characteristics of faulting and magmatism of the Okinawa Trough and the relation between them. En-echelon grabens are ranked oblique to the continental shelf edge uplift, and the Longwang uplift, the rifting block ridge in the northern segment and the "Mianhua uplift" in the southern segment have possibly preserved characteristics of volcanism and magmatism occurring with those rifting phases. The clockwise rotation of the southern Ryukyu Islands, driven by collision between Luzon and Taiwan, has played a key role in the crustal oceanization, enhancing the crustal extension of the southern segment and inducing volcanic magmatism in those grabens, among which the Yaeyama graben is a typical example of the presence of oceanic crust. Faulting and magmatism were mainly migrating towards the island arc asymmetrically. The crustal oceanization of the Okinawa Trough is difficultly interpreted by the linear magnetic anomaly model, which is fit for the symmetric spreading of the mid-oceanic ridges.
基金supported by the National Basic Research Program of China (Grant Nos. 2013CB430103, 2015CB452803)the National Natural Science Foundation of China (Grant No. 41275093)the project of the "Specially-Appointed Professorship" of Jiangsu Province
文摘The monsoon trough (MT) is one of the large-scale patterns favorable for tropical cyclone (TC) formation over the western North Pacific (WNP). This study re-examines TC formation by treating the MT as a large-scale background for TC activity during May-October. Over an 11-year (2000-10) period, 8.3 TC formation events on average per year are identified to occur within MTs, accounting for 43.1% of the total TC formation events in the WNP basin. This percentage is much lower than those reported in previous studies. Further analysis indicates that TC formation events in monsoon gyres were included at least in some previous studies. The MT includes a monsoon confluence zone where westerlies meet easterlies and a monsoon shear line where the trade easterlies lie north of the monsoon westerlies. In this study, the large-scale flow pattern associated with TC formation in the MT is composited based on the reference point in the confluence zone where both the zonal and meridional wind components are zero with positive vorticity. While previous studies have found that many TCs form in the confluence zone, the composite analysis indicates that nearly all of the TCs formed in the shear region, since the shear region is associated with stronger low-level relative vorticity than the confluence zone. The prevailing easterly vertical shear of zonal wind and barotropic instability may also be conducive to TC formation in the shear region, through the development of synoptic-scale tropical disturbances in the MT that are necessary for TC formation.