检索结果-南通市图书馆

Distance Between α-Orientations of Plane Graphs by Facial Cycle Reversals

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2019年第4期35卷 569-576页

作者： wei juan zhang Jian Guo QIAN Fu Ji zhang School of Mathematical Sciences Xiamen University School of Mathematical Sciences Xinjiang Normal University

Cycle reversal had been shown as a powerful method to deal with the relation among orientations of a graph since it preserves the out-degree of each vertex and the connectivity of the orientations. A facial cycle reversal on an orientation of a plane graph is an operation that reverses all the directions of the edges of a directed facial cycle. An orientation of a graph is called an α-orientation if each vertex admits a prescribed out-degree. In this paper, we give an explicit formula for the minimum number of the facial cycle reversals needed to transform one α-orientation into another for plane graphs.

关键词： α-Orientation facial cycle reversal distance plane graph

Distributions of Neutron Exposures in AGB Stars and the Galaxy

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2007年第2期7卷 224-234页

作者： Wen-Yuan Cui Feng-Hua zhang wei-juan zhang Lu zhang Bo zhang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Physics Hebei Normal University Shijiazhuang 050016 Department of Modern Physics University of Science and Technology of China Hefei 230026 Graduate School of Chinese Academy of Sciences Bejing 100049

Based on the s-process nucleosynthesis model with the 13C（α, n）16O reaction occurring under radiative conditions in the interpulse phases, we investigate the characteristics of the distribution of neutron exposure in low-mass Asymptotic Giant Branch （AGB） stars. We introduce a new concept, the distribution of neutron exposures of the Galaxy （NEG）, to study the chemical evolution characteristics of the Galaxy for s-process elements. Using a chemical evolution model of the Galaxy, we develop a model for the NEG and obtain the evolution results of the NEG in different epochs. The present results appear to reasonably reproduce the distribution of neutron exposures of the solar system （hereafter NES）. The main component and the strong component in the NES are built up in different epochs. The strong component of the s-process is mainly synthesised in the low-mass and metal-poor AGB stars, and the main component is produced by the s-process in the low-mass AGB stars with higher metallicities.

关键词： Galaxy evolution- stars AGB and post-AGB- stars abundances

Cubic vertex-transitive non-Cayley graphs of order 12p

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2018年第6期61卷 1153-1162页

作者： wei-juan zhang Yan-Quan Feng Jin-Xin Zhou Department of Mathematics Beijing Jiaotong University Beijing 100044 China

A graph is said to be vertex-transitive non-Cayley if its full automorphism group acts transitively on its vertices and contains no subgroups acting regularly on its vertices. In this paper, a complete classification of cubic vertex-transitive non-Cayley graphs of order 12 p, where p is a prime, is given. As a result, there are 11 sporadic and one infinite family of such graphs, of which the sporadic ones occur when p equals 5, 7 or 17, and the infinite family exists if and only if p ≡ 1(mod 4), and in this family there is a unique graph for a given order.

关键词： Cayley graphs vertex-transitive graphs automorphism groups

Sequence-activated chemiluminescence probes: programmable illumination for high-contrast in vivo sensing and imaging

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 26-34页

作者： Yutao zhang juan Li wei-Hong Zhu Zhiqian Guo Shanghai Key Laboratory of Functional Materials Chemistry Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Institute of Fine Chemicals School of Chemistry and Molecular Engineering East China University of Science and Technology State Key Laboratory of Bioreactor Engineering Shanghai Frontier Science Research Base of Optogenetic Techniques for Cell MetabolismEast China University of Science & Technology

Sequence-activated chemiluminescence(CL) technique offers a unique approach to detecting specific biomolecules or cellular events with high sensitivity and spatial resolution. The fundamental principle behind sequence-activated CL probes involves tailoring highly-controllable CL signals in response to specific sequences or events of interest, thus enabling high-contrast signals under complex physiological conditions. This sequential activation could be triggered by enzymes, reactive oxygen species(ROS), biothiols or changes in the microenvironment. These unique sequence-activated CL probes bestow several advantages, including minimal background, deep-tissue penetration, and the ability of non-invasive or minimally invasive detection. The sequence-activated CL techniques represent a significant advancement in molecular imaging and diagnostics. In this mini-review, we focus on the latest developments in sequential CL probes, addressing the technical challenges and discussing the future trajectory by harnessing CL signaling and molecular recognition.

关键词： chemiluminescnece sequence-activation in-vivo bioimaging cyclic peroxide

Privacy-Preserving Trust Negotiation with Hidden Credentials and Hidden Policies in a Multi-Party Environment

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2008年第5期13卷 553-556页

作者： GUO Shanqing wei juan zhang Chunhua XU Qiuliang School of Computer Science and Technology ShandongUniversity Jinan 250101 Shandong China

Until now, there are numerous protocols that can achieve privacy-preserving trust negotiation between two parties involved, but there is no effective privacy-preserving trust negotiation schemes proposed between multi-users. In this paper, a privacy-preserving trust negotiation scheme with multi-parties is proposed, which can protect their credentials and access control policies during the procedure for establishing the trust between multi-strangers, and its privacy-preserving ability also is proved. These works extend the trust negotiation mechanism to multi-users, which can be thought as a substantial extension of the state-of-the-art in privacy-preserving trust negotiations between two parties involved.

关键词： trust negotiation credential policy privacy-preserving

Melting Evaluation of Phase Change Materials Impregnated into Cascaded Metal Foams with Regionalized Enhancement

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 223-241页

作者： wei Xinyi zhang Nan zhang Zhaoli CAO Xiaoling YUAN Yanping School of Mechanical Engineering Southwest Jiaotong University

Metal foam promotes the heat transfer of phase change materials(PCMs) in the penalty of reducing the energy storage density of the composite *** this work,the effects of constant porosity(0.96,0.94,0.92,or 0.90) and pore density(PPI) of metal foam on heat transfer of composite PCMs are *** rate could be enhanced by employing with low porosity copper ***,aiming to the right bottom phase changing "dead region",a regionalized enhancement strategy of cascaded metal foams is *** dynamic melting performances of all the composite PCMs are comprehensively *** results reveal that the cascaded configuration is beneficial for *** show that the horizontal strategy enhances melting performance:a maximum of 17.98% reduction in total melting time could be reached when the rear part porosity is 90%.The energy storage density rate could be raised by 5.48%.Besides,the vertical strategy performs with a better average temperature uniformity of 0.441 and brings a lower temperature in the heated *** sum up,the regionalized enhancement of copper foam provides better performance in the phase change *** shows significant potential for solar heat storage and thermal protection.

关键词： copper metal foam heat transfer enhancement phase change materials regionalized enhancement

Aerodynamic Optimization and Flow Mechanism for a Compressor Cascade at Low Reynolds Number

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 92-109页

作者： LI Lin zhang Jianshe CHEN Caiyan TAN wei zhang Yanfeng Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of Sciences University of Chinese Academy of Sciences National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine

Low-Reynolds-number effect is an important factor affecting the performance of compressors and other main components of high-altitude long-endurance unmanned aerial *** improve the flow condition and reduce flow loss under the condition of high altitude and low Reynolds number(Re),this paper proposes an optimization process based on a surrogate model,which combines the class-shape transformation method(CST),the Latin hypercube sampling(LHS) method,the light gradient-boosting machine algorithm(LightGBM),and a genetic algorithm(GA) to optimize a high-subsonic compressor *** surrogate model is verified to be accurate and can be used in the optimization *** accuracy of the GA is higher than the other algorithms under common test *** optimization results are verified by numerical simulation,and the flow differences before and after optimization are compared,especially the flow within the boundary *** changing the blade shape,the optimization process adjusts the loading distribution to delay the transition of the optimized blade on the suction surface,which changes the turbulent reattachment in the laminar separation bubble(LSB) into laminar ***,the mixing loss induced by the turbulent reattachment of the LSB and the wake loss of turbulent separation at the trailing edge are significantly reduced,and the performance of the compressor profile is finally *** addition,turbulent separation of the optimized profile is delayed reducing the range of the wake region on the suction *** this optimization process,the reduction of total pressure loss coefficient at Re of 2.5×10～5,3.5×10～5,and 4.5×10～5 are 16.32%,20.76%,and 22.16%,respectively.

关键词： Reynolds number

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

公平感对供应链成员定价决策影响的研究

管理科学学报 2017年第7期20卷 115-126页

作者：刘威志李娟张迪陈炜南京大学工程管理学院南京210093

本文研究公平感对由一个供应商和一个零售商组成的二级供应链中的定价决策的影响,其中供应商决定批发价格,零售商在接受供应商批发价格合同之后决定零售价格,市场需求受到零售价格的线性影响.采用管理实验方法得出,首先,供应商的批发价... 详细信息

本文研究公平感对由一个供应商和一个零售商组成的二级供应链中的定价决策的影响,其中供应商决定批发价格,零售商在接受供应商批发价格合同之后决定零售价格,市场需求受到零售价格的线性影响.采用管理实验方法得出,首先,供应商的批发价格和零售商的零售价格均分别低于完全理性假设下的均衡解;供应商是利他性的,即,乐于看到零售商收益的增加,并且,供应商认为零售商是完全理性的,即零售商的决策目标是最大化自身收益;然而,零售商却是刻毒性的,即乐于看到供应商收益的减少.其次,批发价格的变异度大于零售价格的,即供应商决策的难度大于零售商的.给管理者的启示是:供应商应考虑零售商的刻毒性的特征,降低批发价格,以提高零售商接受供应商所提批发价格的概率;此外,还应该为供应商提供辅助决策手段,以降低批发价格的变异度。

关键词：公平感变异度管理实验

Joint Estimation of SOH and RUL for Lithium-Ion Batteries Based on Improved Twin Support Vector Machineh

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2025年第1期122卷 243-264页

作者： Liyao Yang HongyanMa Yingda zhang wei He School of Electrical and Information Engineering Beijing University of Civil Engineering and ArchitectureBeijing100044China Institute of Distributed Energy Storage Safety Big Data Beijing100044China Beijing Key Laboratory of Intelligent Processing for Building Big Data Beijing100044China

Accurately estimating the State of Health(SOH)and Remaining Useful Life(RUL)of lithium-ion batteries(LIBs)is crucial for the continuous and stable operation of battery management ***,due to the complex internal chemical systems of LIBs and the nonlinear degradation of their performance,direct measurement of SOH and RUL is *** address these issues,the Twin Support Vector Machine(TWSVM)method is proposed to predict SOH and ***,the constant current charging time of the lithium battery is extracted as a health indicator(HI),decomposed using Variational Modal Decomposition(VMD),and feature correlations are computed using Importance of Random Forest Features(RF)to maximize the extraction of critical factors influencing battery performance ***,to enhance the global search capability of the Convolution Optimization Algorithm(COA),improvements are made using Good Point Set theory and the Differential Evolution *** Improved Convolution Optimization Algorithm(ICOA)is employed to optimize TWSVM parameters for constructing SOH and RUL prediction ***,the proposed models are validated using NASA and CALCE lithium-ion battery *** results demonstrate that the proposed models achieve an RMSE not exceeding 0.007 and an MAPE not exceeding 0.0082 for SOH and RUL prediction,with a relative error in RUL prediction within the range of[-1.8%,2%].Compared to other models,the proposed model not only exhibits superior fitting capability but also demonstrates robust performance.

关键词： State of health remaining useful life variational modal decomposition random forest twin support vector machine convolutional optimization algorithm