检索结果-南通市图书馆

Why can some countries perform better in resolving some social problems:A comparative study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Economic and Political Studies 2024年第3期12卷 250-266页

作者： Wilson X.B.Li tina t.he Faculty of Business and Management BNU-HKBU United International CollegeZhuhaiChina

this study explores the rationale why some countries fare better in resolving social problems such as poverty and the COVID-19 *** simple model introduces the term of resident viability and points out that the solution to a social problem with a large ratio of nonviable to viable residents requires the mobilisation of more societal resources,and the affordable price ratio of societal to individual resources is determined by country characteristics such as the cultural background,political regime,ideology towards the free-market mechanism,government efficiency and social *** study also makes between-country comparisons and conducts preliminary regression analyses with cross-country data,and all the results are consistent with the model predictions on the relationship between country characteristics and country performances in fighting poverty and handling the COVID-19 pandemic.

关键词： Social problems COVID-19 poverty eradication viability between-country comparison

CONVERGENCE ANALYSIS OF SOME FINItE ELEMENt PARALLEL ALGORItHMS FOR the StAtIONARY INCOMPRESSIBLE MHD EQUAtIONS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第1期42卷 49-70页

作者： Xiaojing Dong Yinnian he Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing&Information Processing of Ministry of EducationSchool of Mathematics and Computational ScienceXiangtan UniversityXiangtan 411105China Institute of Applied Physics and Computational Mathematics Beijing 100088China School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'an 710049China

By combination of iteration methods with the partition of unity method(PUM),some finite element parallel algorithms for the stationary incompressible magnetohydrodynamics(MHD)with different physical parameters are presented and *** algorithms are highly *** first,a global solution is obtained on a coarse grid for all approaches by one of the iteration *** parallelized residual schemes,local corrected solutions are calculated on finer meshes with overlapping *** subdomains can be achieved flexibly by a class of *** proposed algorithm is proved to be uniformly stable and ***,one numerical example is presented to confirm the theoretical findings.

关键词： Partition of unity method Local and parallel algorithm Finite element method Iteration methods Magnetohydrodynamics

Study of primordial deuterium abundance in Big Bang nucleosynthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and techniques 2024年第3期35卷 208-215页

作者： Zhi-Lin Shen Jian-Jun he Key Laboratory of Beam technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)he,^(4)he,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAt was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)he,d(d,p)t,d(p,γ)^(3)he,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) he *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

the Minimum Centroid Branch Spanning tree Problem

在线全文

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2024年第2期12卷 528-539页

作者： Hao Lin Cheng he School of Science Henan University of TechnologyZhengzhou450001HenanChina

For a spanning tree t of graph G,the centroid of t is a vertex v for which the largest component of t-v has as few vertices as *** number of vertices of this component is called the centroid branch weight of *** minimum centroid branch spanning tree problem is to find a spanning tree t of G such that the centroid branch weight is *** application to design of communication networks,the loads of all branches leading from the switch center should be as balanced as *** this paper,we prove that the problem is strongly NP-hard even for bipartite ***,the problem is shown to be polynomially solvable for split graphs,and exact formulae for special graph familis,say Kn_(1),n_(2),...,n_(k)and P_(m)×P_(n),are presented.

关键词： Spanning tree optimization Centroid branch-NP-hardness Polynomial-time algorithm

D-type neuropeptide decorated AIEgen/RENP hybrid nanoprobes with light-driven ROS generation ability for NIR-Ⅱ fluorescence imaging-guided through-skull photodynamic therapy of gliomas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aggregate

Aggregate 2024年第1期5卷 185-195页

作者： Xuelu he Yuan Luo Yanying Li Yuanbo Pan Ryan t.K.Kwok Lulu he Xiaolin Duan Pengfei Zhang Aiguo Wu Ben Zhong tang Juan Li Ningbo Key Laboratory of Biomedical Imaging Probe Materials and technology Zhejiang International Cooperation Base of Biomedical Materials Technology and ApplicationChinese Academy of Sciences(CAS)Key Laboratory of Magnetic Materials and DevicesNingbo Cixi Institute of Biomedical EngineeringZhejiang Engineering Research Center for Biomedical MaterialsNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingboP.R.China Guangdong Key Laboratory of Nanomedicine Shenzhen Engineering Laboratory of Nanomedicine and NanoformulationsCAS-HK Joint Lab for BiomaterialsResearch Laboratory for Biomedical Optics and Molecular ImagingShenzhen Key Laboratory for Molecular ImagingCAS Key Lab for Health InformaticsShenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhenP.R.China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced StudyThe Hong Kong University of Science and Technology(HKUST)KowloonP.R.China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenP.R.China

Glioma is one of the most common malignant tumors of the central nervous system,leading high mortality rates in ***-induced emission(AIE)photosensitizers-based photodynamic therapy(PDt)has emerged as a promising therapeutic strategy for least-invasive treatment of glioma,which involves local irradiation of the tumor using an external near-infrared(NIR)***,most AIE photosensitizers suffered from poorly penetration of the visible light excitation,bad spatiotemporal resolution in deep tissues and low efficient blood-brain barrier(BBB)crossing ability,which greatly limited the clinical practice of AIE photosensitizers for especially deep-seated brain tumor *** this work,we developed a multifunctional NIR-driven theranostic agent through hybrid of AIE photosensitizers tIND with rare-earth doping nanoparticles(RENPs)NaGdF4:Nd/Yb/tm with up/down dual-mode conversion *** theranostic agent was further decorated with D-type neuropeptide DNPY for crossing BBB and targeting *** the 808-nm light irradiation,the down-conversion NIR-II luminescence could indicate the position glioma and the upconversion NIR-I luminescence could trigger the AIE photosensitizers producing reactive oxygen species to inhibit orthotopic glioma tumor growth in *** results demonstrate that the integration of Dtype neuropeptide,AIE photosensitizers and RENPs could be promising candidates for in vivo NIR-II fluorescence image-guided through-skull PDt treatments of brain tumors.

关键词： aggregation-induced emission D-type neuropeptide glioma photodynamic therapy rare-earth doping nanoparticles

the Role of Adipose tissue-derived Exosomes in Chronic Metabolic Disorders

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Medical Science 2024年第3期44卷 463-474页

作者： Rui he Yong CheN Division of Endocrinology Department of Internal MedicineTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Laboratory of Endocrinology & Metabolism Key Laboratory of Vascular Aging of the Ministry of EducationTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Branch of National Clinical Research Center for Metabolic Diseases Wuhan430030China

Excessive fat deposition in obese subjects promotes the occurrence of metabolic diseases,such as type 2 diabetes mellitus(t2DM),cardiovascular diseases,and non-alcoholic fatty liver disease(NAFLD).Adipose tissue is not only the main form of energy storage but also an endocrine organ that not only secretes adipocytokines but also releases many extracellular vesicles(EVs)that play a role in the regulation of whole-body *** are a subtype of EVs,and accumulating evidence indicates that adipose tissue exosomes(At Exos)mediate crosstalk between adipose tissue and multiple organs by being transferred to targeted cells or tissues through paracrine or endocrine ***,the roles of At Exos in crosstalk with metabolic organs remain to be fully *** this review,we summarize the latest research progress on the role of At Exos in the regulation of metabolic ***,we discuss the potential role of At Exos as biomarkers in metabolic diseases and their clinical application.

关键词： exosome adipose tissue obesity diabetes chronic metabolic disorder miRNA

Double-confined nanoheterostructure Sb/Sb_(2)S_(3)@ti_(3)C_(2)t_(x)@C toward ultra-stable Li-/Na-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2067-2079页

作者： Dan Wang Qun Ma Huan he Zhi-Yuan Wang Run-Guo Zheng Hong-Yu Sun Yan-Guo Liu Chun-Li Liu School of Materials Science and Engineering Northeastern UniversityShenyang110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China Key Laboratory of Dielectric and Electrolyte Functional Material hebei Province Qinhuangdao 066004China Department of Physics and Oxide Research Center Hankuk University of Foreign StudiesYongin 17035Korea

Antimony-based materials with high capacities and moderate potentials are promising anodes for lithium-/-sodium-ion ***,their tremendous volume expansion and inferior conductivity lead to poor structural stability and sluggish reaction ***,a doubleconfined nanoheterostructure Sb/Sb_(2)S_(3)@ti_(3)C_(2)t_(x)@C has been fabricated through a solvothermal method followed by low-temperature heat *** dual protection of“MXene”and“carbon”can better accommodate the volume expansion of Sb/Sb_(2)S_(3).the strong covalent bond(ti-S,ti-O-Sb,C-O-Sb)can firmly integrate Sb-based material with ti_(3)C_(2)t_(x)and carbon,which significantly improves the structure *** addition,the carbon layer can restrain the oxidation of MXenes,and the nano-Sb/Sb_(2)S_(3)can facilitate electron/ion transport and suppress the restacking of *** heterogeneous interface between Sb and Sb_(2)S_(3)can further promote interfacial charge *** MXene-Sb/Sb_(2)S_(3)@C-1 with the optimal Sb content shows high specific capacities,comparable rate properties and ultra-stable cycling performances(250 m Ah·g^(-1)after 2500 cycles at 1 A·g^(-1)for sodium-ion batteries).Ex situ X-ray diffractometer(XRD)test reveals the storage mechanism including the conversion and alloying process of MXene-Sb/Sb_(2)S_(3)@*** voltammetry(CV)test results demonstrate that the pseudocapacitance behavior is dominant in MXene-Sb/Sb_(2)S_(3)@C-1,especially at large *** design paves the way for exploring high-performance alloy-based/conversion-type anode for energy storage devices.

关键词： Sb/Sb_(2)S_(3) MXene Carbon Anode Lithium-ion batteries Sodium-ion batteries

Experimental study on reactions between alkaline basaltic melt and orthopyroxenes: constraints on the evolution of lithospheric mantle in the North China Craton

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第2期43卷 354-365页

作者： Hanqi he Mingliang Wang Hongfeng tang Key Laboratory for High temperature and High Pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China University of Chinese Academy of Sciences Beijing 100049China School of Resource and Civil Engineering Suzhou UniversitySuzhou 234000AnhuiChina

the experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus are reported in this *** reactions are proposed to simulate the interactions between melts from the asthenospheric mantle and the lithospheric *** starting melt in the experiments was made from the alkaline basalt occurring in Fuxin,Liaoning Province,and the orthopyroxenes were separated from the mantle xenoliths in Damaping,hebei *** results show that clinopyroxenes were formed in all the reactions between the alkaline basaltic melt and orthopyroxenes under the studied P–t *** formation of clinopyroxene in the reaction zone is mainly controlled by dissolution–crystallization,and the chemical compositions of the reacted melt are primarily infl uenced by the diff usion eff *** is the most important parameter controlling the reactions between the melt and orthopyroxenes,which has a direct impact on the melting of orthopyroxenes and the diff usion of chemical components in the *** also directly controls the chemical compositions of the newly formed clinopyroxenes in the reaction zone and the reacted *** formation of clinopyroxenes from the reactions between the alkaline basaltic melt and orthopyroxenes can result in an increase of CaO and Al_(2)O_(3) contents in the rocks containing this ***,the reactions between the alkaline basaltic melt from the asthenospheric mantle and orthopyroxenes from the lithospheric mantle can lead to the evolution of lithospheric mantle in the North China Craton from refractory to fertile with relatively high CaO and Al 2 O 3 *** addition,the reacted melts in some runs were transformed from the starting alkaline basaltic into tholeiitic after reactions,indicating that tholeiitic magma could be generated from alkaline basaltic one via reactions betwe

关键词： Alkaline basaltic melt Orthopyroxene Melt–mineral reaction High-temperature and high-pressure experiment Genesis of basalt Evolution of lithospheric mantle in the North China Craton

Comparison of CWSI and t_(s)-t_(a)-VIs in moisture monitoring of dryland crops(sorghum and maize)based on UAV remote sensing

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第7期23卷 2458-2475页

作者： Hui Chen Hongxing Chen Song Zhang Shengxi Chen Fulang Cen Quanzhi Zhao Xiaoyun Huang tengbing he Zhenran Gao College of Agriculture Guizhou UniversityGuiyang 550025China Institute of New Rural Development Guizhou UniversityGuiyang 550025China Institute of Rice Industry technology Research College of Agricultural SciencesGuizhou UniversityGuiyang 550025China

Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern *** unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical crop water stress index(CWSI)based on canopy temperature and three-dimensional drought indices(tDDI)constructed from surface temperature(t_(s)),air temperature(t_(a))and five vegetation indices(VIs)for monitoring the moisture status of dryland *** machine learning algorithms(random forest regression(RFR),support vector regression,and partial least squares regression)were used to compare the performance of the drought indices for vegetation moisture content(VMC)estimation in sorghum and *** main results of the study were as follows:(1)Comparative analysis of the drought indices revealed that t_(s)-t_(a)-normalized difference vegetation index(tDDIn)and t_(s)-t_(a)-enhanced vegetation index(tDDIe)were more strongly correlated with VMC compared with the other *** indices exhibited varying sensitivities to VMC under different irrigation regimes;the strongest correlation observed was for the tDDIe index with maize under the fully irrigated treatment(r=-0.93).(2)Regarding spatial and temporal characteristics,the tDDIn,tDDIe and CWSI indices showed minimal differences Over the experimental period,with coefficients of variation were 0.25,0.18 and 0.24,*** three indices were capable of effectively characterizing the moisture distribution in dryland maize and sorghum crops,but the tDDI indices more accurately monitored the spatial distribution of crop moisture after a rainfall or irrigation event.(3)For prediction of the moisture content of single crops,RFR models based on tDDIn and tDDIe estimated VMC most accurately(R^(2)>0.7),and the tDDIn-based model predicted VMC with the highest accuracy when considering multiple-crop samples,with R^(2)and RMSE of 0.62 and 14.26%,***,tDDI proved more effective than the CWSI in e

关键词： maize sorghum t_(s)-t_(a)-VIs CWSI UAV machine learning crop moisture monitoring