检索结果-南通市图书馆

A phylogenetic approach identifies patterns of beta diversity and floristic subregions of the Qinghai-Tibet Plateau

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Diversity 2024年第1期46卷 59-69页

作者： haibin Yu Man Yang Zixin lu Weitao Wang Fangyuan Yu Yonghua Zhang Xue Yin hongjun Yu Junjie hu David c.Deane Key Laboratory of conservation and Application in Biodiversity of South china School of Life SciencesGuangzhou UniversityGuangzhou 510006China School of Ecology Sun Yat-Sen UniversityShenzhen 510275China School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006China college of Life and Environmental Science Wenzhou UniversityWenzhou 325035China centre for Future Landscapes and Department of Environment and Genetics La Trobe UniversityBundooraVIC 3083Australia

Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional *** Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic *** this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet *** also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the *** also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic *** environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic *** dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the *** results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.

关键词： Biogeographical regionalization Phylogenetic beta diversity Seed plants Sørensen dissimilarity Qinghai-Tibet Plateau

Photocatalytic reduction of cO_(2) with h_(2)O into c_(2)h_(6) mediated by dual metalation strategy

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2024年第5期67卷 1381-1383页

作者： Mei Wang Tong-Bu lu School of Materials Science and Engineering Institute for New Energy Materials&Low Carbon TechnologiesTianjin University of TechnologyTianjin 300384China

Artificial solar-energy-driven cO_(2) reduction into value-added fuels under mild conditions provides a promising strategy to mitigate energy crisis and alleviate environmental issues around the world. Among diverse products of cO_(2) reduction reaction, c_(2+) compounds are more desirable in terms of their high energy density and commercial value [1].Thus far, various photocatalysts have been constructed for cO_(2) reduction.

关键词： reduction desirable value

Deformable microlaser force sensing

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第6期13卷 1196-1209页

作者： Eleni Dalaka Joseph Shill Jonathan h.h.Booth Anna Popczyk Stefan R.Pulver Malte c.Gather Marcel Schubert centre of Biophotonics SUPASchool of Physics and AstronomyUniversity of St AndrewsNorth HaughSt AndrewsUK humboldt centre for Nano-and Biophotonics Department of ChemistryUniversity of CologneKölnGermany School of Psychology and Neuroscience University of St AndrewsSt Mary’s QuadSouth StreetSt AndrewsUK Institute for Bioengineering of catalonia BarcelonaSpain

Mechanical forces are key regulators of cellular behavior and function,affecting many fundamental biological processes such as cell migration,embryogenesis,immunological responses,and pathological *** force sensors and imaging techniques have been developed to quantify these otherwise invisible forces in single cells and in ***,current techniques rely heavily on high-resolution microscopy and do not allow interrogation of optically dense tissue,reducing their application to 2D cell cultures and highly transparent biological ***,we introduce DEFORM,deformable microlaser force sensing,a spectroscopic technique that detects sub-nanonewton forces with unprecedented spatio-temporal *** is based on the spectral analysis of laser emission from dye-doped oil microdroplets and uses the force-induced lifting of laser mode degeneracy in these droplets to detect nanometer *** validation by atomic force microscopy and development of a model that links changes in laser spectrum to applied force,DEFORM is used to measure forces in 3D and at depths of hundreds of microns within tumor spheroids and late-stage Drosophila *** furthermore show continuous force sensing with single-cell spatial and millisecond temporal resolution,thus paving the way for non-invasive studies of biomechanical forces in advanced stages of embryogenesis,tissue remodeling,and tumor invasion.

关键词： invasion otherwise hundreds

APPROXIMATION PROBLEMS ON ThE SMOOThNESS cLASSES

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第5期44卷 1721-1734页

作者： Yongping LIU Man lu School of Mathematical Sciences Beijing Normal UniversityBeijing100875China

This paper investigates the relative Kolmogorov n-widths of 2π-periodic smooth classes in■.We estimate the relative widths of■and its generalized class K_(p)■(P_(r)),where K_(p)h^(ω)(Pr)is defined by a self-conjugate differential operator P_(r)(D)induced by■Also,the modulus of continuity of the r-th derivative,or r-th self-conjugate differential,does not exceed a given modulus of continuityω.Then we obtain the asymptotic results,especially for the case p=∞,1≤q≤∞.

关键词： relative width self-conjugate differential operator asymptotic estimate

A numerical model study on the spatial and temporal variabilities of dissolved oxygen in Qinzhou Bay of the northern Beibu Gulf

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第6期43卷 49-59页

作者： Gaolei cheng Shiqiu Peng Bin Yang Dongliang lu State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Guangxi Key Laboratory of Marine Environmental change and Disaster in the Beibu Gulf Beibu Gulf UniversityQinzhou 535011China

Oxygen facilitates the breakdown of the organic material to provide energy for *** concentration of dissolved oxygen(DO) in the water must exceed a certain threshold to support the normal metabolism of marine *** in the northern B eibu Gulf,Qinzhou B ay receives abundant freshwater and nutrients from several rivers which significantly influence the level of the dissolved ***,the spatial-temporal variations of DO as well as the associated driving mechanisms have been rarely studied through field *** this study,a three-dimension al coupled physical-biogeochemical model is used to investigate the spatial and seasonal variations of the DO and the associated driving mechanisms in Qinzhou B *** validation against observations indicates that the model can capture the seasonal and inter-annual variability of the DO concentration with the range of 5-10 mg/*** experiments show that the river discharges,winds and tides play crucial roles in the seasonal variability of the DO by changing the vertical mixing and stratification of the water column and the circulation *** winter,the tide and wind forces have strong effects on the DO distribution by enhancing the vertical mixing,especially near the bay *** summer,the river discharges play a dominant role in the DO distribution by inhibiting the vertical water exchange and delivering more nutrients to the Bay,which increases the DO depletion and results in lower DO on the bottom of the estuary salt *** findings can contribute to the preservation and management of the coastal environment in the northern Beibu Gulf.

关键词： river plume dissolved oxygen stratification physical-biological model

Severe liver injury and clinical characteristics of occupational exposure to 2-amino-5-chloro-N,3-dimethylbenzamide: A case series

在线全文

学校读者我要写书评

暂无评论

hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 186-194页

作者： Meng-Xiao Feng hua Zou Yuan-Qiang lu Department of Emergency Medicine The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Key Laboratory for Diagnosis and Treatment of Aging and Physic-chemical Injury Diseases of Zhejiang Province Hangzhou 310003China Occupational health and Radiation Protection Institute Zhejiang Provincial Center for Disease Control and PreventionHangzhou 310051China

Background:The 2-amino-5-chloro-N,3-dimethylbenzamide is a key intermediate in the synthesis of pesticides and ***,no literature currently exists on 2-amino-5-chloro-N,3-dimethylbenzamide poisoning in *** study aimed to reveal the health hazard of this chemical for humans and summarize the clinical characteristics of patients with occupational 2-amino-5-chloro-N,3-dimethylbenzamide ***:This observational study included four patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning from June 2022 to July *** entire course of the incidents was described in *** 2-amino-5-chloro-N,3-dimethylbenzamide concentrations were detected by a mass ***-toxylin and eosin staining was performed to assess liver injury,and immunofluorescence was used to evaluate hepatic ***:The 2-amino-5-chloro-N,3-dimethylbenzamide powder(99%purity)entered the human body mainly via the skin and respiratory tract due to poor personal protective *** typical course of 2-amino-5-chloro-N,3-dimethylbenzamide poisoning was divided into latency,rash,fever,organic dam-age,and recovery phases in accordance with the clinical *** and fever may be the important premonitory symptoms for further organ *** chemical was detected in the blood of all patients and caused multiple organ injuries,predominantly liver injury,including kidney,myocardium,and *** patients recovered smoothly after comprehensive treatments,including artificial liver therapy,continuous renal replacement therapy,glucocorticoids,and other symptomatic and supportive *** patient survived by liver *** postoperative pathological findings of the removed liver showed acute liver failure,and immunofluorescence staining confirmed the abundance of mitophagy in residual ***:This study is the first to elaborate the clinical characteristics of patients with 2-amino-5-chloro-N,

关键词： 2-amino-5-chloro-N,3-dimethylbenzamide Poisoning clinical characteristics Liver injury

Effect of(cr,V)_(2)(c,N)on the Microstructure and Mechanical Properties of Wc-10co cemented carbides

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1138-1148页

作者： LI Xiangkun WANG lu YE Jinwen School of Materials Science and Engineering Sichuan UniversityChengdu 610065China

Wc-10co cemented carbides with finer Wc and narrower grain size distributions are produced by using(cr,V)_(2)(c,N)as grain growth *** a result,with the increase of(cr_(0.9),V_(0.1))_(2)(c,N)and(V_(0.9),cr_(0.1))_(2)(c,N),the grains size of Wc and mean free path of co phase decrease,and adjacency of Wc *** and homogenization of grains enhance the transverse rupture strength(TRS)and the ***,the deflection and bridging of cracks keep the fracture toughness at a respectable *** Wc-10co-0.6(cr_(0.9),V_(0.1))_(2)(c,N)-0.025(V_(0.9),cr_(0.1))_(2)(c,N)cemented carbides exhibit excellent comprehensive mechanical properties with the TRS of 4602.6 MPa,hardness of 1835 kg/mm^(2),and fracture toughness of 10.39 MPa·m^(1/2),***,the large pores are caused by excess N larger than 0.03 wt%and deteriorates the mechanical *** provide a new approach to Wc-co cemented carbides preparation with a narrow grain size distribution by adding novel grain growth inhibitors.

关键词： (cr,V)_(2)(c,N) nutrient content Wc grains size microstructure mechanical properties

cobalt-catalyzed reductive alkynylation to construct c(sp)-c(sp^(3))and c(sp)-c(sp^(2))bonds

在线全文

学校读者我要写书评

暂无评论

chinese chemical Letters 2024年第7期35卷 253-258页

作者： Lei Wan Yizhou Tong Xi lu Yao Fu hefei National Research center for Physical Sciences at the Microscale iChEMCAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Precision and Intelligent chemistry School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China

Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon ***,we report a general method,cobalt-catalyzed reductive alkynylation,to construct c(sp)-c(sp^(3))and c(sp)-c(sp^(2))*** presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl(pseudo)*** presented reaction is conducted under mild conditions,tolerating many functional groups,thus suitable for the modification and synthesis of biologically active molecules.

关键词： cobalt-catalysis cross-electrophile coupling carbon-carbon bond formation Reductive alkynylation Alkyne synthesis

Nitrogen isotope stratigraphy of the Early cambrian successions in the Tarim Basin:Spatial variability of nitrogen cycling and its implication for paleo-oceanic redox conditions

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第4期43卷 785-801页

作者： Bi Zhu Xuefeng Li lu Ge Yongquan chen Institute of Earth’s critical Zone School of Earth Sciences and EngineeringHohai UniversityNanjing 210098China Research Institute of Exploration and Development Tarim Oil Field CompanyPetroChinaKorlaChina

The Early cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in *** isotopic signatures of ancient sediments have the potential to elucidate the evolutionary path of marine redox states and the biogeochemical nitrogen cycle within the water column of the Early cambrian *** existing research on this topic has predominantly focused on South china,the exploration of other continental margins has been limited,leaving contradictory hypotheses *** this study,pairedδ^(15)N andδ^(13)c org analyses were performed on the Lower cambrian successions from the Shiairike section(inner ramp)and Well Tadong 2(deep shelf/basin)in the northwestern and eastern Tarim Basin,*** data from the Shiairike section reveal a discernible shift in the operation of different nitrogen cycles for the black chert-shale unit,also referred to as the black rock series in chinese literature,of the Yurtus Formation(Fortunian stage to lower Stage 3).Oscillatingδ^(15)N values for its lower part are suggestive of alternating anaerobic assimilation of Nh 4+and denitrification/*** is likely attributed to a shallow,unstable chemocline consistent with the upwelling and incursion of deep,anoxic waters during a major *** contrast,aerobic nitrogen cycling,indicated by positiveδ^(15)N values of>2‰,dominated the upper part alongside a reduction in upwelling *** the other hand,theδ^(15)N signatures of Xishanbulake and Xidashan Formations of Well Tadong 2,which encompass a time interval from the cambrian Fortunian Age to Age 4,are indicative of N_(2)fixation by diazotrophs as the major nitrogen *** two studied intervals,although not time-equivalent,exhibit separated states of nitrogen cycling at least during the deposition of the Yurtus black rock *** spatially different nitrogen cycling of the studied sections is compatible with a redox-stratified ocean dur

关键词： Nitrogen isotopes Early cambrian Tarim Black rock series