检索结果-南通市图书馆

Syntheses and Crystal Structures of Sm(OAr)+2(THF)+3·THF and Sm(OAr)_2(DME)_2 (Ar =C_6H_2-tert-Bu_3-2,4,6)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2005年第10期24卷 1152-1156页

作者： YUAN fu-Gen ZHU Xue-Hua wenG Lin-Hong Department of Chemistry University of Science and Technology ofSuzhou Suzhou 215009 China Department of Chemistry Fudan University Shanghai 200433 China

Reaction of SmI2（THF）x with 2 equivalents of NaOAr （Ar = C6H2-tert-Bu3-2,4,6） in THF affords a divalent complex of Sm（OAr）2（THF）yTHF 1 in 90.8% yield. Treatment of 1 with 1,2-dimethoxyethane （DME） leads to the ligand-exchange reaction, and a DME-solvated complex of Sm（OAr）2（DME）2 2 was obtained. Complex 1 crystallizes in monoclinic, space group P21/c with a = 10.366（5）, b = 33.024（15）, c = 16.123（7） A, β = 93.197（8）°, V = 5511 （4） A^3, Z = 4, C52H90O6Sm, Mr = 961.59, Dc = 1.159 g/cm^3, F（000） = 2048,μ（MoKα） = 1.107 mm^-1, R = 0.0844 and wR = 0.1401 for 4694 observed reflections. Complex 2 crystallizes in monoclinic, space group C2/c with a = 27.222（5）, b = 10.6140（19）, c = 17.398（4） A, β = 110.245（3）°, V = 4716.4（16） A^3, Z = 4, C44H78O6Sm, Mr = 853.41, Dc = 1.202 g/cm^3, F（000） = 1808,μ（MoKα） = 1.285 mm^-1, R = 0.0361 and wR = 0.0830 for 5210 observed reflections.

关键词： divalent samarium aryloxide azobenzene

Fast counting the cardinality of flows for big traffic over sliding windows

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2017年第1期11卷 119-129页

作者： jingsong SHAN Yinjin fu Guiqiang NI Jianxin LUO Zhaofeng WU College of Command Information Systems PLA University of Science and Technology Nanjing 223002 China Huaiyin Institute of Technology Huaian 221002 China

Counting the cardinality of flows for massive high-speed traffic over sliding windows is still a challenging work under time and space constrains, but plays a key role in many network applications, such as traffic management and routing optimization in software defined network. In this pa- per, we propose a novel data structure （called LRU-Sketch） to address the problem. The significant contributions are as follows. 1） The proposed data structure adapts a well-known probabilistic sketch to sliding window model; 2） By using the least-recently used （LRU） replacement policy, we design a highly time-efficient algorithm for timely forgetting stale information, which takes constant （O（1）） time per time slot; 3） Moreover, a further memory-reducing schema is given at a cost of very little loss of accuracy; 4） Comprehensive ex- periments, performed on two real IP trace files, confirm that the proposed schema attains high accuracy and high time *** including IEEE TPDS, ACM ToS, JCST, MIDDLEWARE, CLUSTER, NAS, etc. Currently, his research interests include big data management, cloud storage, and distributed file systems.

关键词： probabilistic data structure sketch streaming data cardinality flow

Effect of Monolithic LaB_6 on the Ablation Resistance of ZrC/SiC Coating Prepared by Supersonic Plasma Spraying for C/C Composites

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 Materials Science & Technology 2016年第10期32卷 996-1002页

作者： Yujun Jia Hejun Li Lu Li Qiangang fu Kezhi Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University

Ablation resistance of monolithic LaB-doped ZrC coating for SiC-coated carbon/carbon composites by supersonic atmospheric plasma spray was investigated under an oxyacetylene torch with a heat flux of 4.18 MW/m~2. Result shows that ZrC coating with 10 vol.% LaBhas a good ablation resistance compared with pure ZrC, ZrC with 20 vol.% LaBand SiC-doped ZrC coating. After ablation for 15 s, the weight is increased by 1.12 mg/s. The good ablation resistance is ascribed to the formation of a stabilized scale which consists of protective LaZrO-containing molten phase and ZrOparticles keeping the integrity of the coating.

关键词： Ceramic coating C/C composites Ablation performance

Effect of Chinese propolis on PC-PLC activity and TLR4 expression in LPS-treated vascular endothelial cells

在线全文

学校读者我要写书评

暂无评论

中国病理生理杂志 2011年第7期27卷 1257-1263页

作者： XUAN Hong - zhun SANG Qing LI Ya - jing HU fu - liang College of Animal Sciences Zhejiang University Hangzhou 310029 China School of Life Science. Liaocheng UniversityLiaocheng 252059 China Zhejiang Economic and Trade Polytechnic Hangzhou 310018 China

AIM:To investigate the effect of Chinese propolis on the activity of phosphatidylcholine-specific phospholipase C (PC-PLC)and the expression of Toll-like receptor 4 (TLR4)in LPS-treated vascular endothelial cells (VECs).METHODS:Confluent VECs were stimulated with LPS at the concentration of 100 μg/L in the presence of 0.5% fetal bovine *** cells were treated with Chinese propolis at the concentration of 12.5 mg/L for 12 h and 24 *** viability of VECs 'and the level of nitric oxide (NO)were detected by sulforhodamine B (SRB)assay and chemical method,*** activity of PC-PLC was measured using L-a-phosphatidylcholine as *** protein levels of TLR4,nuclear factor-KB p65 (NF-KB p65)and p53 were determined by Western *** level of intracellular reactive oxygen species (ROS)was examined using a fluorescent probe,2',7'-dichlorodihydrofluorescin (DCHF).For the measurement of mitochondrial membrane potential,the fluorescent dye JC-1 was ***:Treatment with Chinese propolis for 24 h had no effect on the viability of ***,the levels of NO and ROS were significantly decreased by Chinese ***-PLC activity and NF-KB p65 expression were significantly depressed by Chinese propolis treated for 12 h,and the expression of TLR4 and p53 were dramatically decreased by Chinese propolis treated for 12 and 24 *** effect of Chinese propolis on mitochondrial membrane potential was ***:Chinese propolis depresses the activity of PC-PLC and the expression of TLR4,and then inhibits the downstream signal molecules such as NF-KB p65,p53,ROS and NO in VECs.

关键词：病理学医学临床生理

Improved Differential Evolution with Shrinking Space Technique for Constrained Optimization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2017年第3期30卷 553-565页

作者： Chunming fu Yadong XU Chao JIANG Xu HAN Zhiliang HUANG State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University School of Mechanical Engineering Nanjing University of Science and Technology

Most of the current evolutionary algorithms for constrained optimization algorithm are low computational efficiency. In order to improve efficiency, an improved differential evolution with shrinking space technique and adaptive trade-off model, named ATMDE, is proposed to solve constrained optimization problems. The proposed ATMDE algorithm employs an improved differential evolution as the search optimizer to generate new offspring individuals into evolutionary population. For the con- straints, the adaptive trade-off model as one of the most important constraint-handling techniques is employed to select better individuals to retain into the next population, which could effectively handle multiple constraints. Then the shrinking space technique is designed to shrink the search region according to feedback information in order to improve computational efficiency without losing accuracy. The improved DE algorithm introduces three different mutant strategies to generate different offspring into evo- lutionary population. Moreover, a new mutant strategy called ＂DE/rand/best/l＂ is constructed to generate new individuals according to the feasibility proportion ofcurrent population. Finally, the effectiveness of the pro- posed method is verified by a suite of benchmark functions and practical engineering problems. This research presents a constrained evolutionary algorithm with high efficiency and accuracy for constrained optimization problems.

关键词： Constrained optimization - Differentialevolution Adaptive trade-off model Shrinking spacetechnique

Epidemiological-survey-based multidimensional modeling for understanding daily mobility during the COVID-19 pandemic across urban-rural gradient in the Chinese mainland

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2023年第4期26卷 603-615页

作者： Feng Zhao Zixuan Dai wenyu Zhang Yiting Shan Cheng fu Key Laboratory of Geographical Process Analysis&Simulation of Hubei Province Central China Normal UniversityWuhanChina College of Urban and Environmental Sciences Central China Normal UniversityWuhanChina Department of Geography University of ZurichZurichSwitzerland

Human mobility survey data usually suffer from a lack of resources for *** survey records,which are released to the public as a containment measure by local authorities,provide place visitation details validated by the *** study collected and analyzed the epidemiological survey reports published by local governments in the Chinese mainland,between January 2020 and November *** reveal the mobility patterns during the COVID-19 pandemic across the urban-rural gradient in China’s mainland,we derived key mobility indicators from the epidemiological survey data from rural to *** then applied exploratory factor analysis to identify latent factors that affected people’s *** found that the pandemic poses varying impacts across the urban-rural gradient in the Chinese mainland,and the mobility patterns of middle and small cities are more *** results also showed that the pandemic did not enlarge gender gap in people’s mobility,as gender was not a significant driving factor for explaining people’s quantity of out-of-home activities as well as extent of life space,while age group and city levels were ***,we argue that the epidemiological survey data are valuable data sources for daily mobility modeling,especially for relevant studies to understand human mobility patterns during the pandemic.

关键词： Human mobility epidemiological survey exploratory factor analysis gender gap urban-rural gap COVID-19 pandemic

Secure cooperative output regulation for linear parameter-varying systems under DoS attacks: a resilient observer approach

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(Information Sciences) 2023年第9期66卷 35-49页

作者： Chengcheng fu Hao ZHANG Chao HUANG Zhuping WANG Huaicheng YAN School of Electronic and Information Engineering Tongji University School of Information Science and Engineering East China University of Science and Technology

This paper investigates the cooperative output regulation problem of heterogeneous linear parameter-varying multi-agent systems under denial-of-service(DoS) attacks. The matrix and state of the exosystem are taken to be unknown to the followers. Moreover, with the assumption that only a directed spanning tree exists in the communication topology, a resilient observer is proposed to exponentially estimate the global information, which can also be effective under DoS attacks with a certain intensity. Afterward,to avoid using the exact value of the exosystem matrix, a distributed online algorithm is proposed, through which the linear parameter-varying output regulation equation is asymptotically solved. Based on the resilient observer and the solution of the output regulation equation, a distributed regulator is proposed to achieve asymptotic cooperative output regulation for all agents. Some numerical simulations are conducted to verify the effectiveness of the proposed observer, algorithm, and controller.

关键词： cooperative output regulation heterogeneous multi-agent systems DoS attacks linear parameter-varying systems

Simultaneously Enhanced Cryogenic Tensile Strength,Ductility and Impact Resistance of Epoxy Resins by Polyethylene Glycol

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 Materials Science & Technology 2014年第1期30卷 90-96页

作者： Qingping Feng Jiaoping Yang Yu Liu Hongmei Xiao Shaoyun fu Technical Institute of Physics and Chemistry Chinese Academy of Sciences

Rubbers have been well accepted for modifying brittle epoxies but rubber modified epoxies usually posses lowered tensile strength though enhanced ductility and fracture resistance. In this work, a polyethylene glycol （PEG-4000） is used to modify diglycidyl ether of bisphenol A/methyltetrahydrophthalic anhydride system for enhancing cryogenic tensile strength, ductility and impact resistance. The results display that the cryogenic tensile strength, ductility （failure strain） and fracture resistance （impact strength） are all enhanced for the modified epoxy system at proper PEG contents. The maximum tensile strength （127.8 MPa） at the cryogenic temperature （77 K） with an improvement of 30.1% is observed for the modified system with the 15 wt% PEG content. The ductility and impact resistance at both room temperature and cryogenic temperature are all improved for the modified epoxy system with proper PEG-4000 contents. These observations are explained by the positron annihilation lifetime spectroscopy results and scanning electron microscopy results. Moreover, the glass transition temperature decreases slightly with increasing PEG content.

关键词： Epoxy resin Modification Polymer composite Tensile strength

Reshaping Li–Mg hybrid batteries:Epitaxial electrodeposition and spatial confinement on MgMOF substrates via the lattice‐matching strategy

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第8期6卷 248-261页

作者： Yongqin Wang fulin Cheng Jiawen Ji Chenyang Cai Yu fu School of Materials Science and Engineering Co‐Innovation Center of Efficient Processing and Utilization of Forest ResourceNanjing Forestry UniversityNanjingJiangsuChina

The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced ***,the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical ***,we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF *** chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg,establishing the crucial prerequisites for successful heteroepitaxial ***,the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular *** inspiration from the“blockchain”concept prevalent in the realm of big data,we seamlessly integrated a conductive polypyrrole framework,acting as a connecting“chain,”to interlink the“blocks”comprising the MgMOF *** innovative design significantly amplified charge‐transfer efficiency,thereby increasing overall electrochemical *** resulting architecture(MgMOF@PPy@CC)served as an exceptional host for heteroepitaxial Mg electrodeposition,showcasing remarkable electrostripping/plating kinetics and excellent cycling ***,a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions(10mAcm^(–2)),maintaining operation for an extended 1200 h,surpassing previously reported ***,on coupling the MgMOF@PPy@CC anode with a Mo_(6)S_(8) cathode,the assembled battery showed an extended lifespan of 10,000 cycles at 70 C,with an outstanding capacity retention of 96.23%.This study provides a fresh perspective on the rational design of epitaxial electrocrystalli

关键词： epitaxial electrodeposition lattice‐matching strategy Li-Mg hybrid batteries MOF substrate spatial confinement