检索结果-南通市图书馆

The symmetric space,strong isotropy irreducibility and equigeodesic properties

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

Science China Mathematics 2024年第1期67卷 129-148页

作者： Ming xu Ju Tan School of Mathematical Sciences Capital Normal UniversityBeijing 100048China School of Microelectronics and Data Science Anhui University of TechnologyMa'anshan 243032China

A smooth curve on a homogeneous manifold g/H is called a Riemannian equigeodesic if it is a homogeneous geodesic for any g-invariant Riemannian *** homogeneous manifold g/H is called Riemannian equigeodesic,if for any x∈g/H and any nonzero y∈Tx(g/H),there exists a Riemannian equigeodesic c(t) with c(0)=x and ■(0)=*** two notions can be naturally transferred to the Finsler setting,which provides the definitions for Finsler equigeodesics and Finsler equigeodesic *** prove two classification theorems for Riemannian equigeodesic spaces and Finsler equigeodesic spaces,***,a homogeneous manifold g/H with a connected simply connected quasi compact g and a connected H is Riemannian equigeodesic if and only if it can be decomposed as a product of Euclidean factors and compact strongly isotropy irreducible ***,a homogeneous manifold g/H with a compact semisimple g is Finsler equigeodesic if and only if it can be locally decomposed as a product,in which each factor is Spin(7)/g2,g2/SU (3) or a symmetric space of compact *** results imply that the symmetric space and the strongly isotropy irreducible space of compact type can be interpreted by equigeodesic *** an application,we classify the homogeneous manifold g/H with a compact semisimple g such that all the g-invariant Finsler metrics on g/H are *** suggests a new project in homogeneous Finsler geometry,i.e.,to systematically study the homogeneous manifold g/H on which all the g-invariant Finsler metrics satisfy a certain geometric property.

关键词： equigeodesic equigeodesic space flag manifold orbit type stratification symmetric space strongly isotropy irreducible space

A Mendelian randomisation,propensity score matching study to investigate causal association between serum homocysteine and intracranial aneurysm

在线全文

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2024年第3期9卷 202-211,I0104-I0109页

作者： Zhuohua Wen Xin Feng Xin Tong Chao Peng Anqi xu Haiyan fan Yiming Bi Wenchao Liu Zhenjun Li Shenquan guo fa Jin Ran Li Yanchao Liu Shixing Su Xin Zhang Xifeng Li xuying He Aihua Liu Chuanzhi Duan Neurosurgery Center Department of Cerebrovascular SurgeryEngineering Technology Research Center of Education Ministry of China on Diagnosis and Treatment of Cerebrovascular DiseaseZhujiang HospitalSouthern Medical UniversityGuangzhouChina Beijing Neurosurgical Institute Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Department of Neurosurgery Guangdong Provincial People's Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouChina

Background and purpose Recent observational studies have reported that serum total homocysteine(tHcy)is associated with intracranial aneurysms(IAs).However,the causal effect of tHcy on IAs is *** leveraged large-scale genetic association and real-world data to investigate the causal effect of tHcy on IA *** We performed a two-sample Mendelian randomisation(MR)using publicly available genome-wide association studies summary statistics to investigate the causal relationship between tHcy and IAs,following the recommendations of the Strengthening the Reporting of Observational Studies in Epidemiology-MR ***,a propensity score matching(PSM)analysis was conducted to evaluate the detailed effects of tHcy on risk of IA formation by utilizing real-world multicentre data,including 9902 patients with and without IAs(1:1 matched).Further interaction and subgroup analyses were performed to elucidate how tHcy affects risk of IA *** MR analyses indicated that genetically determined tHcy was causally associated with IA risk(OR,1.38,95%CI 1.07 to 1.79;p=0.018).This is consistent with the more conservative weighted median analysis(OR,1.41,95%CI 1.03 to 1.93;p=0.039).Further sensitivity analyses showed no evidence of horizontal pleiotropy or heterogeneity of single nucleotide polymorphisms in causal *** to the PSM study,we found that,compared with low tHcy(≤15μmol/L),moderate tHcy(>15-30μmol/L)(OR 2.13,95%CI 1.93 to 2.36)and high tHcy(>30μmol/L)(OR 3.66,95%CI 2.71 to 4.95)were associated with a higher IA risk(p trendgroup analyses demonstrated significant ORs of tHcy in each subgroup when stratified by traditional cardiovascular risk ***,there was also a synergistic effect of tHcy and hypertension on IA risk(p interactionge-scale genetic evidence and multicentre real-world data support a causal as

关键词： matching random centre

Strong hetero-interface interaction in 2D/2D WSe_(2)/ZnIn_(2)S_(4) heterostructures for highly-efficient photocatalytic hydrogen generation

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

Journal of Energy Chemistry 2024年第10期97卷 379-387,I0008页

作者： xu guo Xing Liu jing Shan Zhuo xu Zhiming fa.g Lu Wang Shengzhong Liu School of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China Shaanxi Key Laboratory for Advanced Energy Devices School of Materials Science and EngineeringShanxi Normal UniversityXi'an 710119ShanxiChina Qinghai Advanced Energy Storage Laboratory SPIC Qinghai Photovoltaic Industry Innovation Center Co.Ltd.State Power Investment CorporationXining 810oo7QinghaiChina Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

green hydrogen is urgently required for sustainable development of human beings and rational construction of heterostructures holds great promising for photocatalytic hydrogen ***,2D/2D WSe_(2)/ZnIn_(2)S_(4) heterostructures with strong hetero-interface interaction and abundant contact were constructed via an impregnation-annealing *** charge transfer from ZnIn_(2)S_(4) to WSe_(2)was evidenced by transient absorption spectroscopy in crafted heterostructures owing to the tight and2D face-to-face *** a result,the prepared WSe_(2)/ZnIn_(2)S_(4) heterostructures exhibited boosted photocatalytic performance and a highest hydrogen evolution rate of 3.377 mmol/(g h)was achieved with an apparent quantum yield of 45.7%at 420 *** work not only provides new strategies to achieve efficient 2D/2D heterostructures but also paves the way for the development of green hydrogen in the future.

关键词： Strong hetero-interface interaction in 2D/2D WSe_(2)/ZnIn_(2)S_(4) heterostructures for highly-efficient photocatalytic hydrogen generation

Even-odd layer-dependent multiferroic in freestanding rare-earth orthorhombic perovskite

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 151-157页

作者： Shaowen xu fanhao Jia Ning Dai School of Physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Department of Physics College of ScienceHangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

Freestanding oxide perovskites possess strong interlayer coupling between adjacent atomic layers,thus exerting a determinative effect on the magnetism and ferroelectricity of these atomic-scale ***,we propose an effective strategy to manipulate magnetism and ferroelectricity in freestanding rare-earth orthorhombic perovskite via modulation of layer *** performing first-principles calculations,an even-odd oscillation is demonstrated in few-layer gdAlO_(3)perovskite(gAP).Specifically,odd-layer systems with charged atomic layers are ferromagnetic polar metals,while even-layer systems are antiferromagnetic ferroelectric *** thickness-dependent magnetic phase transition originates from carrier doping,as rationalized by the Stoner ***,we demonstrate the promotion of in-plane ferroelectricity via the concurrent application of two distinct antiferrodistortive displacements,each driven by formation and breaking of *** multiferroic phases may emerge in other transition metal oxide perovskites supporting multiple valence states,e.g.,few-layer gd MO_(3)(M=V,Cr,Mn,and Ni).This work puts forward a strategy for layer thickness engineering of magnetism and ferroelectricity in 2D oxide perovskite multiferroic materials.

关键词： few-layer rare-earth perovskite multiferroicity size effect first principles calculations

Analysis of fatty Acid in Biological Samples Using Liquid Chromatography–Quadrupole-Orbitrap Mass Spectrometry Under Parallel Reaction Monitoring Mode

在线全文

学校读者我要写书评

暂无评论

Journal of Analysis and Testing 2024年第2期8卷 210-217页

作者： Jingxuan Yang Wenjun guo Xiaohang xu Liang Zhao Yajuan xu Yang Wang School of Pharmaceutical Sciences Changchun University of Chinese MedicineChangchun130117China Key Laboratory of Medicinal Materials Jilin Academy of Chinese Medicine SciencesChangchun130021China Jilin ginseng Academy Changchun University of Chinese MedicineChangchun130117China

fatty acids(fas)are an important class of functional small molecules and participate in a variety of life biological *** experiment proposed a liquid chromatography–quadrupole-Qrbitrap mass spectrometry(LC–Q-Orbitrap MS)method to perform fa profiling under parallel reaction monitoring(PRM)acquisition *** fa was derivatized by 2-dimethylaminoethylamine(DMED)to increase the ionization e fficiency and provide the characterized fragment *** mass spectra obtained from full scan,multiple ion monitoring(MIM),and PRM were *** results showed that the protonated ion of fa+DMED–H2O was detected and the neutral loss of 45.06 Da was observed in the tandem mass *** PRM method provided the highest selectivity and sensitivity for fa detection with the help of accurate mass weight and specific neutral loss-based *** method validation was performed using the fa standards and pooled quality control serum sample,which showed that the established method had good repeatability,stability,and ***,the developed method was successfully applied to analyze the rat serum and brain tissue samples for the drug e ffi-cacy evaluation of gross saponin of Tribulus terrestris ***(gSTTF)against middle cerebral artery occlusion(MCAO)-induced ischemic *** method has extensive practicability and great potential in the detection of fa,especially for the analysis of samples with complex matrices.

关键词： fatty acid Derivatization LC-Q-Orbitrap MS Parallel reaction monitoring Biological sample

Multiple conductive network for KTi_(2)(PO_(4))_(3)anode based on MXene as a binder for high-performance potassium storage

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 539-544页

作者： Tong Su Yue Wang Qizhen Zhu Mengyao xu Ning Qiao Bin xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China

KTi_(2)(PO_(4))_(3)is a promising anode material for potassium storage,but suffers from low conductivity and difficult balance between high capacity and good structural ***,the Ti_(3)C_(2)T_(x)MXene is used as a multifunctional binder to fabricate the KTi_(2)(PO_(4))_(3)electrode by the traditional homogenizing-coating *** MXene nanosheets,together with the conductive agent super P nanoparticles,construct a multiple conductive network for fast electron/ion transfer and high electrochemical ***,the network ensures the structural stability of the KTi_(2)(PO_(4))_(3)electrode during the de-intercalation/intercalation of 4 K^(+)ions,which is beneficial for simultaneously achieving high capacity and good cycle ***,the MXene-bonded KTi_(2)(PO_(4))_(3)electrode delivers a reversible capacity of 255.2 mAh/g at 50 mA/g,outstanding rate capability with 132.3 mAh/g at 2 A/g,and ex-cellent cycle performance with 151.6 mAh/g at 1 A/g after 2000 *** work not only suggests a high-performance anode material for potassium-ion batteries,but also demonstrates that the MXene is a promising binder material for constructing conductive electrodes in rechargeable batteries.

关键词： MXene Ti_(3)C_(2)T_(x) KTi_(2)(PO_(4))_(3) Anode Conductive network Potassium storage

Design and Implementation of a High-Sensitivity Magnetic Sensing System Based on gMI Effect

在线全文

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2024年第3期33卷 237-247页

作者： Wenzhu Wu Ming xu Changlin Han Junquan Tang Jia xu Lin xu Mingxin Qin Department of Electronic Engineering Army Medical UniversityChongqing 400038China Chongqing Medical and Pharmaceutical College Chongqing 401331China Department of Intelligence Science and Technology National University of Defense TechnologyChangshaChangsha 410073China Intelligent game and Decision Lab Beijing 100091China

A high-sensitivity magnetic sensing system based on giant magneto-impedance(gMI)effect is designed and *** system comprises a gMI sensor equipped with a gradient probe and an signal acquisition and processing module.A segmented superposition algorithm is used to increase target signal and reduce the random *** results show that under unshielded,room temperature conditions,the system achieves successful detection of weak magnetic fields down to 2 pT with a notable sensitivity of 1.84×10^(8)V/T(g=1000).By applying 17 overlays,the segmented superposition algorithm increases the power proportion of the target signal at 31 Hz from6.89%to 45.91%,surpassing the power proportion of the 2 Hz low-frequency interference ***,it reduces the power proportion of the 20 Hz random *** segmented superposition process effectively cancels out certain random noise elements,leading to a reduction in their respective power *** high-sensitivity magnetic sensing system features a simple structure,and is easy to operate,making it highly valuable for both practical applications and broader dissemination.

关键词： high-sensitivity magnetic field sensing system gMI effect segmented superposition algorithm

Comprehension-driven design of advanced multi-block single-ion conducting polymer electrolytes for high-performance lithium-metal batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 357-359页

作者： xu Dong Dominic Bresser Helmholtz Institute Ulm(HIU) Helmholtzstrasse 1189081 UlmGermany Karlsruhe Institute of Technology(KIT) P.O.Box 364076021 KarlsruheGermany

The continuously growing importance of batteries for powering(hybrid)electric vehicles and storing renewable energy has prompted a renewed focus on lithium-metal batteries(LMBs)in recent years,as its high theoretical specific capacity of about 3860 mA h g^(-1) and very low redox potential(-3.04 V *** standard hydrogen electrode)promise substantially higher energy densities compared to current lithium-ion batteries(LIBs)[1].However,lithium metal electrodes face severe challenges associated with the risk of dendritic lithium deposition and the high reactivity with traditional organic liquid electrolytes,resulting in a continuous loss of electrochemically active lithium and a relatively low Coulombic efficiency[2].To address these challenges,solid inorganic and polymer electrolytes have emerged as a potentially saferalternative.

关键词： lithium polymer prompt

Dynamic Routing of Multiple QoS-Required Flows in Cloud-Edge Autonomous Multi-Domain Data Center Networks

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 2287-2308页

作者： Shiyan Zhang Ruohan xu Zhangbo xu Cenhua Yu Yuyang Jiang Yuting Zhao School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing100876China College of Computer Science and Technology Tianjin UniversityTianjin300072China Institute of Artificial Intelligence Nankai UniversityTianjin300071China College of Information Science and Engineering East China University of Science and TechnologyShanghai200237China

The 6th generation mobile networks(6g)network is a kind of multi-network interconnection and multi-scenario coexistence network,where multiple network domains break the original fixed boundaries to form connections and *** this paper,with the optimization objective of maximizing network utility while ensuring flows performance-centric weighted fairness,this paper designs a reinforcement learning-based cloud-edge autonomous multi-domain data center network architecture that achieves single-domain autonomy and multi-domain *** to the conflict between the utility of different flows,the bandwidth fairness allocation problem for various types of flows is formulated by considering different defined reward *** the tradeoff between fairness and utility,this paper deals with the corresponding reward functions for the cases where the flows undergo abrupt changes and smooth changes in the *** addition,to accommodate the Quality of Service(QoS)requirements for multiple types of flows,this paper proposes a multi-domain autonomous routing algorithm called LSTM+*** a Long Short-Term Memory(LSTM)layer in the actor and critic networks,more information about temporal continuity is added,further enhancing the adaptive ability changes in the dynamic network *** LSTM+MADDPg algorithm is compared with the latest reinforcement learning algorithm by conducting experiments on real network topology and traffic traces,and the experimental results show that LSTM+MADDPg improves the delay convergence speed by 14.6%and delays the start moment of packet loss by 18.2%compared with other algorithms.

关键词： Multi-Domain data center networks autonomous routing