期刊文献+
共找到13,336篇文章
< 1 2 250 >
每页显示 20 50 100
Novel Mobility Formula for Parallel Mechanisms Expressed with Mobility of General Link Group 被引量:14
1
作者 ZHANG Yitong LU Wenjuan +3 位作者 MU Dejun YANG Yandong ZHANG Lijie ZENG Daxing 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第6期1082-1090,共9页
The determination of virtual constraints is always one of the key and difficult problems in traditional mobility calculation. To make mobility calculation simple, considering avoiding virtual constraints, some new for... The determination of virtual constraints is always one of the key and difficult problems in traditional mobility calculation. To make mobility calculation simple, considering avoiding virtual constraints, some new formulae have been presented, however these formulae can hardly intuitively reflect general link group's restrictions on output member and its influences on independence of output parameters, which is premise to the judgment of the properties of mobility. Towards the problem to reveal the intrinsic relationship between the degree of freedom(DOF) of a mechanism, the link group, and the dimension of output parameters, also to avoid determination of virtual constraint, based on the new concepts of the "DOF of general link group" and "node parameters", a new formula in the calculation of the mobility of mechanisms is presented that is expressed with DOFs of the general link groups and rank of motion parameters of base point of the output link. It is named GOM(mobility of groups and output parameter) formula. On the basis of new concepts of"effective parameters" and "invalid parameters", a rule is put forward for solving the DOF of mechanisms with invalid parameters by GOM formula, that is, the base point parameters are the subset of effective parameters of link group. Thereafter, several examples are enumerated and the results coincide with the prototype data, which proves the validity of the proposed formula. Meanwhile, it is obtained that the necessary and sufficient condition for the judgment of output parameters independence is that each of the DOF of the link group is not less than zero. The proposed formula which is simple in calculation provides theoretical basis for the judgment of independence of output parameters and provides references for type synthesis of novel parallel mechanisms with independence requirements of their output parameters. 展开更多
关键词 parallel mechanism degree of freedom general link group output parameters
下载PDF
Mechanical mechanism of overlying strata breaking and development of fractured zone during close-distance coal seam group mining 被引量:26
2
作者 Jianguo Ning Jun Wang +1 位作者 Yunliang Tan Qiang Xu 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2020年第2期207-215,共9页
This study mainly investigates the mechanical mechanism of overlying strata breaking and the development of fractured zones during close-distance coal seam group mining in the Gaojialiang coal mine.First,a mechanical ... This study mainly investigates the mechanical mechanism of overlying strata breaking and the development of fractured zones during close-distance coal seam group mining in the Gaojialiang coal mine.First,a mechanical model for the second"activation"of broken overlying strata is established,and the related mechanical"activation"conditions are obtained.A recursive formula for calculating the separation distance of overlying strata is deduced.Second,a height determining method for predicting the height of fractured zones during close-distance coal seam group mining is proposed based on two values,namely,the separation distance and ultimate subsidence value of overlying strata.This method is applied to calculate the fractured zone heights in nos.20107 and 20307 mining faces.The calculated results are almost equal to the field observation results.Third,a modified formula for calculating the height of a waterflowing fractured zone is proposed.A comparison of the calculated and observed results shows that the errors are small.The height determining method and modified formula not only build a theoretical foundation for water conservation mining at the Gaojialiang coal mine,but also provide a reference for estimating the height of water-flowing fractured zones in other coal mines with similar conditions. 展开更多
关键词 Coal SEAM group Activation mechanism Separation Water-flowing fractured ZONE Modified FORMULA
下载PDF
THE METAMORPHIC FEATURE,AGE AND MECHANISM OF AMUGANG GROUP IN NORTHERN TIBET 被引量:3
3
作者 He Zhonghua,Li Cai,Wang Tianwu,Yang Deming(Changchun University of Science and Technology,Changchun 130026,China) 《地学前缘》 EI CAS CSCD 2000年第S1期195-195,共1页
Amugang Group is distributed mainly over Amugang, Jiangai Mountain, Mayigangri,Gemuri and Qiagela,etc. lt includes Gemuri Formation and Qiagela Formation. They had even been thought of the crystalline basement of Qian... Amugang Group is distributed mainly over Amugang, Jiangai Mountain, Mayigangri,Gemuri and Qiagela,etc. lt includes Gemuri Formation and Qiagela Formation. They had even been thought of the crystalline basement of Qiangtang terrain. However, Gemuri Formation and Qiagela Formation are not alike in the protolithes, metamorphism and deformation, rock association,etc.In fact, they are different in mechanism.Gemuri Formation is composed of high\|Pressure, low\|temperature glaucophane greenschist\|faci metamorphic rocks. The petrolithes of the blueschists are glaciomarine conglomerates and basalts from the Southern Qiagtang area. The typical mineralogy include: glaucophane+ epidote + calcite +stilpnomelane and stilpnomelane+chlorite+sericite+ quartz+ glaucophane. P.T conditions for the metamorphism of blueschist are estimated to be 0 6~0 7GPa and 320~400℃.The 40 Ar/ 39 Ar dating of the crossite has yielded good plateau age of (222 5±3 7)Ma,which represents the formation of Gemuri Formation.Qiagela Formation comprises schist series, marbles, Gneisses and plagioamphiboles. The protolithes of them are a suit of argillaceous sandstones, arkoses, carbonates and mafic volcanic rocks. The Sm\|Nd isochron age of the metamorphic mafic volcanic rocks is (268 0±5 6)Ma, which shows that The age of the protolithes is early Dias. The typical mineralogy include: Muscovite+biotite+plagioclase+quartz; garnet+kyanite+ staurolite+ biotite+ muscovite+plagioclase+quartz; amphibole+ plagioclase±garnet+ quartz. They are meos\|pressure,meso\|temperature low amphibole\|faci metamorphic rocks. Qiagela Formation is coexistent with the late Triassic and the early Jurassic volcano\|magmatic arc in space and overlapped by the triassic limestones of Xiaocaka Formation. So,it is suggested that the formation of Qiagela Formation be between the late Dias and the late Triassic period. Its genesis is relative to the thermal current provided by magmatic activity. 展开更多
关键词 Amuggang group METAMORPHIC FEATURE age mechanism NORTHERN TIBET
下载PDF
A notary group-based cross-chain mechanism 被引量:3
4
作者 Anping Xiong Guihua Liu +2 位作者 Qingyi Zhu Ankui Jing Seng W.Loke 《Digital Communications and Networks》 SCIE CSCD 2022年第6期1059-1067,共9页
As an emerging distributed technology, blockchain has begun to penetrate into many fields such as finance, healthcare, supply chain, intelligent transportation. However, the interoperability and value exchange between... As an emerging distributed technology, blockchain has begun to penetrate into many fields such as finance, healthcare, supply chain, intelligent transportation. However, the interoperability and value exchange between different independent blockchain systems is restricting the expansion of blockchain. In this paper, a notary group-based cross-chain interaction model is proposed to achieve the interoperability between different blockchains. Firstly, a notary election mechanism is proposed to choose one notary from the notary group to act as a bridge for cross-chain transactions. Secondly, a margin pool is introduced to limit the misconduct of the elected notary and ensure the value transfer between the involved blockchains. Moreover, a reputation based incentive mechanism is used to encourage members of the notary group to participate in cross-chain transactions. Ethereum-based experiments demonstrate that the proposed mechanism can provide an acceptable performance for cross-chain transactions and provide a higher security level than ordinary cross-chain mechanisms. 展开更多
关键词 Blockchain Cross-chain Notary group Reputation ranking Incentive mechanisms
下载PDF
Generalized Kinematics Analysis of Hybrid Mechanisms Based on Screw Theory and Lie Groups Lie Algebras 被引量:2
5
作者 Peng Sun Yanbiao Li +3 位作者 Ke Chen Wentao Zhu Qi Zhong Bo Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第5期171-184,共14页
Advanced mathematical tools are used to conduct research on the kinematics analysis of hybrid mechanisms,and the generalized analysis method and concise kinematics transfer matrix are obtained.In this study,first,acco... Advanced mathematical tools are used to conduct research on the kinematics analysis of hybrid mechanisms,and the generalized analysis method and concise kinematics transfer matrix are obtained.In this study,first,according to the kinematics analysis of serial mechanisms,the basic principles of Lie groups and Lie algebras are briefly explained in dealing with the spatial switching and differential operations of screw vectors.Then,based on the standard ideas of Lie operations,the method for kinematics analysis of parallel mechanisms is derived,and Jacobian matrix and Hessian matrix are formulated recursively and in a closed form.Then,according to the mapping relationship between the parallel joints and corresponding equivalent series joints,a forward kinematics analysis method and two inverse kinematics analysis methods of hybrid mechanisms are examined.A case study is performed to verify the calculated matrices wherein a humanoid hybrid robotic arm with a parallel-series-parallel configuration is considered as an example.The results of a simulation experiment indicate that the obtained formulas are exact and the proposed method for kinematics analysis of hybrid mechanisms is practically feasible. 展开更多
关键词 Hybrid mechanism Screw theory Lie groups Lie algebras Kinematics analysis Humanoid robotic arm
下载PDF
Study on the Formation Mechanism of Oxygen-containing Groups on the Surfaces of Hypercrosslinked Polystyrenes
6
作者 Guan Hua MENG Ai Min LI +2 位作者 Lin WU Fu Qiang LIU Quan Xing ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第1期121-124,共4页
The synthetic parameters were changed to explore the formation mechanism of the oxygen-containing groups on the surfaces of the hypercrosslinked polymers. The FT-IR spectra and the Boehm titration were used to charact... The synthetic parameters were changed to explore the formation mechanism of the oxygen-containing groups on the surfaces of the hypercrosslinked polymers. The FT-IR spectra and the Boehm titration were used to characterize the surface chemistry of the synthesized polymers. The GC-MS was applied to analyze nitrobenzene which was the solvent in the reaction. The functionalities such as carbonyls and phenols were formed through the oxidation of residual chloromethyl groups by nitrobenzene and the carboxylic groups were formed through further oxidation by oxygen. The nitrobenzene was deoxidized to nitrosobenzene and further to aniline. 展开更多
关键词 SYNTHESIS oxygen-containing groups mechanism.
下载PDF
Effect of high mobility group box-1 protein on immune cells and its regulatory mechanism 被引量:1
7
作者 Ying-yi LUAN Feng-hua YAO +3 位作者 Qing-hong ZHANG Xiao-mei ZHU Ning DONG Yong-ming YAO 《中国应用生理学杂志》 CAS CSCD 2012年第6期548-554,共7页
High mobility group box-1 protein(HMGB1),which is a nuclear protein,participates in chromatin architecture and transcriptional regulation.When released from cells,HMGB1 also plays a well-established role as a pro-infl... High mobility group box-1 protein(HMGB1),which is a nuclear protein,participates in chromatin architecture and transcriptional regulation.When released from cells,HMGB1 also plays a well-established role as a pro-inflammatory mediator during innate immune responses to injury.In the initial stage of injury,there is a release of large quantities of early pro-inflammatory mediators to initiate or perpetuate immune responses against pathogens,but this pro-inflammatory period is transient,and it is followed by a prolonged period of immune suppression.At present,several lines of evidences have suggested that HMGB1 is a late cytokine provoking delayed endotoxin morbidity,which may enhance the production of early proinflammatory mediators,and it can contribute potently to the activation of different immune cells and play a role in the development of host cell-mediated immunity.The biology of HMGB1 has been extensively studied as a pro-inflammatory cytokine of systemic inflammation,however,this review will attempt to provide a summary of the effects of HMGB1 on different immune cells and its regulatory mechanism in acute insults. 展开更多
关键词 免疫细胞 调控机制 核蛋白 迁移率 HMGB1 炎症介质 基因转录调控 免疫反应
下载PDF
Mechanism and experiment of substituting high drainage roadway with directional long drilling group to extract pressure-relief gas
8
作者 谢生荣 赵耀江 +3 位作者 张守宝 杨洪增 肖殿才 田春阳 《Journal of Central South University》 SCIE EI CAS 2012年第9期2591-2597,共7页
By establishing the numerical model in the vertical plane and the similar model in the horizontal plane of gas flow in goaf, the influence of high drainage roadway or drilling on the gas seepage field was analyzed, an... By establishing the numerical model in the vertical plane and the similar model in the horizontal plane of gas flow in goaf, the influence of high drainage roadway or drilling on the gas seepage field was analyzed, and the extraction mechanism was clarified. On this basis, the academic thought of directional long drilling group instead of high drainage roadway was put forward. And then using complex function theory, the permeation mechanical model of drilling group with circle distribution in the mining-induced fracture zone was established to explore the coupling relationship between the drilling quantity, extraction volume and the equivalent extraction rate of single drilling. Finally, combined with the concrete geological production conditions, the main parameters of directional long drilling group were determined. The distance between the drilling group center and the air-return roadway is 24 m, the height is 18 m, and the three drillings are in an approximate equilateral triangle distribution with a space of 8 m. The equivalent extraction square is 4.15 m2. It is shown that the effect of directional long drilling group is evident. The gas content in the upper comer is controlled below 0.95%, the content in the tail roadway is kept below the alarm value, and the content is over 50% in the drill, realizing the secure and effective extraction of coal and gas. 展开更多
关键词 high position fracture ring drilling group extraction seepage field complex function permeation mechanical model extraction disturbance
下载PDF
Application of Specialized Group Management in the Quality Control of Perioperative Nursing 被引量:2
9
作者 Cong Fu Xuefei Li +4 位作者 Li Wang Yuanyuan Jiang Xinrong Qi Chen Ding Shanshan Tang 《Journal of Clinical and Nursing Research》 2024年第2期70-75,共6页
Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating r... Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating room management was adopted from July 2019 to June 2020,and specialized group management was adopted from July 2020 to June 2021.The surgeon’s satisfaction,surgical nurses’core professional competence,and surgical patients’satisfaction were obtained through surveys and the results were analyzed.Results:Surgeon satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Besides,surgical nurses’core professional competency scores before the implementation of specialized group management were significantly lower than after its implementation(P<0.05).Lastly,surgical patients’satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Conclusion:Specialized group management helps to improve the quality of perioperative care and should be applied in clinical practice. 展开更多
关键词 Specialized group management operating room Quality of care CONTROL
下载PDF
基于Group-Res2Block的智能合成语音说话人确认方法
10
作者 李菲 苏兆品 +2 位作者 王年松 杨波 张国富 《应用科学学报》 CAS CSCD 北大核心 2024年第4期709-722,共14页
针对现有说话人确认任务基于自然语音条件下并不适用于智能合成语音的问题,提出一种基于Group-Res2Block的智能合成语音说话人确认方法。首先,设计了Group-Res2Block结构,在Res2Block的基础上将当前分组与相邻前后分组进行合并形成新的... 针对现有说话人确认任务基于自然语音条件下并不适用于智能合成语音的问题,提出一种基于Group-Res2Block的智能合成语音说话人确认方法。首先,设计了Group-Res2Block结构,在Res2Block的基础上将当前分组与相邻前后分组进行合并形成新的分组,以增强说话人局部特征的上下文联系;其次,设计了并行结构的多尺度通道注意力特征融合机制,利用不同大小卷积核实现同一层级的特征在通道维度的特征选择,以获取更具表现力的说话人特征,避免信息冗余;最后,设计了串行结构的多尺度层注意力特征融合机制,构建层结构,将深浅层特征整体进行融合并赋予不同权重,以获取最优的特征表达。为验证所提出特征提取网络的有效性,构建了中英文两种智能合成语音数据集进行消融实验和对比实验。结果表明本文方法在该任务的评价指标精确度(accuracy,ACC)、等错误率(equal error rate,EER)和最小检测代价函数(minimum detection cost function,minDCF)上是最优的。此外,通过对模型泛化性能进行测试,验证了本文方法对未知智能语音算法的适用性。 展开更多
关键词 说话人确认 智能合成语音 group-Res2Block深度神经网络 多尺度特征 注意力机制
下载PDF
Study on Value Added Mechanism of Human Capital of Innovative Group
11
作者 Hong Qing 《学术界》 CSSCI 北大核心 2016年第5期286-290,共5页
Innovation group is the subject of innovation activities,to promote the increment of human capital group innovation,contribute to more,better innovation,create more benefits and wealth for enterprises,organizations an... Innovation group is the subject of innovation activities,to promote the increment of human capital group innovation,contribute to more,better innovation,create more benefits and wealth for enterprises,organizations and the whole society.In the value-added mechanism,human capital value from an accretion and symbiotic value.Establish training mechanism and incentive mechanism to promote a health and value based human capital value,improve the communication mechanism and operation mechanism to promote symbiosis value-added based human capital value,is to strengthen the team effect,an important way to promote the increment of human capital group innovation. 展开更多
关键词 人力资本 激励机制 创新型 资本增值 资本价值 运行机制 新活动 共生
下载PDF
A Large-Scale Group Decision Making Model Based on Trust Relationship and Social Network Updating
12
作者 Rongrong Ren Luyang Su +2 位作者 Xinyu Meng Jianfang Wang Meng Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期429-458,共30页
With the development of big data and social computing,large-scale group decisionmaking(LGDM)is nowmerging with social networks.Using social network analysis(SNA),this study proposes an LGDM consensus model that consid... With the development of big data and social computing,large-scale group decisionmaking(LGDM)is nowmerging with social networks.Using social network analysis(SNA),this study proposes an LGDM consensus model that considers the trust relationship among decisionmakers(DMs).In the process of consensusmeasurement:the social network is constructed according to the social relationship among DMs,and the Louvain method is introduced to classify social networks to form subgroups.In this study,the weights of each decision maker and each subgroup are computed by comprehensive network weights and trust weights.In the process of consensus improvement:A feedback mechanism with four identification and two direction rules is designed to guide the consensus of the improvement process.Based on the trust relationship among DMs,the preferences are modified,and the corresponding social network is updated to accelerate the consensus.Compared with the previous research,the proposedmodel not only allows the subgroups to be reconstructed and updated during the adjustment process,but also improves the accuracy of the adjustment by the feedbackmechanism.Finally,an example analysis is conducted to verify the effectiveness and flexibility of the proposed method.Moreover,compared with previous studies,the superiority of the proposed method in solving the LGDM problem is highlighted. 展开更多
关键词 Large-scale group decision making social network updating trust relationship group consensus feedback mechanism
下载PDF
Adaptive Event-Triggered Time-Varying Output Group Formation Containment Control of Heterogeneous Multiagent Systems
13
作者 Lihong Feng Bonan Huang +2 位作者 Jiayue Sun Qiuye Sun Xiangpeng Xie 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1398-1409,共12页
In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed topology.The MAS is composed of a number... In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed topology.The MAS is composed of a number of tracking leaders,formation leaders and followers,where two different types of leaders are used to provide reference trajectories for movement and to achieve certain formations,respectively.Firstly,compen-sators are designed whose states are estimations of tracking lead-ers,based on which,a controller is developed for each formation leader to accomplish the expected formation.Secondly,two event-triggered compensators are proposed for each follower to evalu-ate the state and formation information of the formation leaders in the same group,respectively.Subsequently,a control protocol is designed for each follower,utilizing the output information,to guide the output towards the convex hull generated by the forma-tion leaders within the group.Next,the triggering sequence in this paper is decomposed into two sequences,and the inter-event intervals of these two triggering conditions are provided to rule out the Zeno behavior.Finally,a numerical simulation is intro-duced to confirm the validity of the proposed results. 展开更多
关键词 Adaptive control event-triggered mechanisms for-mation containment(FC) heterogeneous multiagent systems time-varying group formation.
下载PDF
The tangential k-Cauchy-Fueter type operator and Penrose type integral formula on the generalized complex Heisenberg group
14
作者 REN Guang-zhen SHI Yun KANG Qian-qian 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第1期181-190,共10页
The tangential k-Cauchy-Fueter operator and k-CF functions are counterparts of the tangential Cauchy–Riemann operator and CR functions on the Heisenberg group in the theory of several complex variables,respectively.I... The tangential k-Cauchy-Fueter operator and k-CF functions are counterparts of the tangential Cauchy–Riemann operator and CR functions on the Heisenberg group in the theory of several complex variables,respectively.In this paper,we introduce a Lie group that the Heisenberg group can be imbedded into and call it generalized complex Heisenberg.We investigate quaternionic analysis on the generalized complex Heisenberg.We also give the Penrose integral formula for k-CF functions and construct the tangential k-Cauchy-Fueter complex. 展开更多
关键词 the generalized complex Heisenberg group the tangential k-Cauchy-Fueter type operator Penrose-type integral formula
下载PDF
Comparison of Group-Buying Online Auction and Posted Pricing Mechanism in an Uncertain Market
15
作者 CHEN Jian, LIU Yunhui, SONG Xiping (School of Economics and Management, Tsinghua University Beijing 100084 China Department of System Engineering and Engineering Management, The Chinese University of Hong Kong Shatin NT Hong Kong China) 《Journal of Electronic Science and Technology of China》 2004年第3期1-5,共5页
Demand uncertainty is a key factor for the seller's decision making, especially in the e-business environment, for the website to sell products through the online auction. In this paper, two kinds of demand uncert... Demand uncertainty is a key factor for the seller's decision making, especially in the e-business environment, for the website to sell products through the online auction. In this paper, two kinds of demand uncertainties are considered: the consumer regime uncertainty and the inherent randomness of the market environment. Then, how to use a novel business model and group-buying auction (GBA) is analyzed in such a market environment. Based on the comparison of the GBA and the posted price mechanism, some conditions that favor the GBA are provided. 展开更多
关键词 group-buying auction demand uncertainty posted pricing mechanism
下载PDF
The Operation Mechanism of Agricultural Products Supply Chain and Profit Allocation Model in the Context of Asymmetric Information 被引量:1
16
作者 齐天真 孙蕊 郭超坤 《Agricultural Science & Technology》 CAS 2016年第1期197-200,233,共5页
The research performed analysis on causes of asymmetric information of agricultural product supply chain and made conclusion on operation mechanism and characteristics of supply chain based on asymmetric information. ... The research performed analysis on causes of asymmetric information of agricultural product supply chain and made conclusion on operation mechanism and characteristics of supply chain based on asymmetric information. Finally, the research detailed profit sharing of agricultural product supply chain in the context of asymmetric information and proposed suggestions, providing references of pricing and profit sharing of supply chains of agricultural products. 展开更多
关键词 Information asymmetry The supply chain of agricultural products The operation mechanism Profit allocation model
下载PDF
“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate Lithium Storage
17
作者 Yan Zhao Qiang Yuan +5 位作者 Liting Yang Guisheng Liang Yifeng Cheng Limin Wu Chunfu Lin Renchao Che 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期348-360,共13页
Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(gen... Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term cyclability.Here,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical properties.During Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O movement.Such superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries. 展开更多
关键词 NiNb_(2)O_(6)porous fiber “Zero-strain”mechanism Electrochemical property Harsh-temperature operation Operando characterization
下载PDF
The configuration mechanism of English and Chinese double-object construction for verbs of creation
18
作者 许宁云 韩丹 《Sino-US English Teaching》 2010年第5期39-46,共8页
Verbs of creation in English and Chinese demonstrate asymmetries in its projection to double-object construction. But underling the projection process there is a uniform operation mechanism, namely that the configurat... Verbs of creation in English and Chinese demonstrate asymmetries in its projection to double-object construction. But underling the projection process there is a uniform operation mechanism, namely that the configuration is affected by the interaction between the Meaning Assignment Principle (MAP), the Distance Principle of Iconicity (DPI) and the Lexical Feature Constraints (LFC), among which MAP and DPI are inviolable due to its cross-linguistic universality. Once LFC is violated, there must be compensation on the part of DPI, otherwise, the verb of creation in question would be unacceptable to double-object construction. 展开更多
关键词 double-object construction verbs of creation DOC formation operation mechanism
下载PDF
Constraint Force Analysis of Metamorphic Joints Based on the Augmented Assur Groups 被引量:5
19
作者 LI Shujun WANG Hongguang YANG Qiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第4期747-755,共9页
In order to obtain a simple way for the force analysis of metamorphic mechanisms, the systematic method to unify the force analysis approach of metamorphic mechanisms as that of conventional planar mechanisms is propo... In order to obtain a simple way for the force analysis of metamorphic mechanisms, the systematic method to unify the force analysis approach of metamorphic mechanisms as that of conventional planar mechanisms is proposed. A force analysis method of metamorphic mechanisms is developed by transforming the augmented Assur groups into Assur groups, so that the force analysis problem of metamorphic mechanisms is converted into the force analysis problems of conventional planar mechanisms. The constraint force change rules and values of metamorphic joints are obtained by the proposed method, and the constraint force analysis equations of revolute metamorphic joints in augmented Assur group RRRR and prismatic metamorphic joints in augmented Assur group RRPR are deduced. The constraint force analysis is illustrated by the constrained spring force design of paper folding metamorphic mechanism, and its metamorphic working process is controlled by the spring force and geometric constraints of metamorphic joints. The results of spring force show that developped design method and approach are feasible and practical. By transforming augmented Assur groups into Assur groups, a new method for the constraint force analysis of metamorphic joints is proposed firstly to provide the basis for dynamic analysis of metamorphic mechanism. 展开更多
关键词 metamorphic joints constraint forces augmented Assur groups metamorphic mechanism
下载PDF
BOUNDEDNESS OF FRACTIONAL MAXIMAL OPERATOR AND THEIR HIGHER ORDER COMMUTATORS IN GENERALIZED MORREY SPACES ON CARNOT GROUPS 被引量:5
20
作者 Vagif GULIYEV Ali AKBULUT Yagub MAMMADOV 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1329-1346,共18页
In the article we consider the fractional maximal operator Mα, 0 ≤α 〈 Q on any Carnot group G (i.e., nilpotent stratified Lie group) in the generalized Morrey spaces Mp,φ(G), where Q is the homogeneous dimens... In the article we consider the fractional maximal operator Mα, 0 ≤α 〈 Q on any Carnot group G (i.e., nilpotent stratified Lie group) in the generalized Morrey spaces Mp,φ(G), where Q is the homogeneous dimension of G. We find the conditions on the pair (φ1, φ2) which ensures the boundedness of the operator Ms from one generalized Morrey space Mp,φ1 (G) to another Mq,φ2 (G), 1. 〈 p ≤q 〈 ∞. 1/p - 1/q = α/Q, and from the space M1,φ1 (G) to the weak space Wq,φ2 (G), 1 〈 q 〈 ∞, 1 - 1/q = α/Q. Also find conditions on the φ which ensure the Adams type boundedness of the Ms from M α (G) from Mp,φ^1/p(G)to Mq,φ^1/q(G) for 1 〈p〈q〈∞ and fromM1,φ(G) toWMq,φ^1/q(G)for 1〈q〈∞. In the case b ∈ BMO(G) and 1 〈 p 〈 q 〈 ∞, find the sufficient conditions on the pair (φ1, φ2) which ensures the boundedness of the kth-order commutator operator Mb,α,k from Mp,φ1 (G) to Mq,φ2(G) with 1/p - 1/q = α/Q. Also find the sufficient conditions on the φ which ensures the boundedness of the operator Mb,α,k from Mp,φ^1/p(G) tom Mp,φ^1/p (G) for 1 〈p〈q〈∞. In all the cases the conditions for the boundedness of Mα are given it terms of supremaltype inequalities on (φ1, φ2) and φ , which do not assume any assumption on monotonicity of (φ1, φ2) and φ in r. As applications we consider the SchrSdinger operator -△G + V on G, where the nonnegative potential V belongs to the reverse Holder class B∞(G). The MB,φ1 - Mq,φ2 estimates for the operators V^γ(-△G + V)^-β and V^γ△↓G(-△G + V)^-β are obtained. 展开更多
关键词 Carnot group fractional maximal function generalized Morrey space Schrodinger operator BMO space
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部