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Microwave-assisted synthesis,crystal structure and toxicity of L-aspartic acid zinc spiral linear supramolecular polymer

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Science China Chemistry 2004年第4期47卷 295-300页

作者： ZHANG Youming lin Qi wei Taibao College of Chemistry and Chemical Engineering Gansu Key Laboratory of Polymer Materials Northwest Normal University Lanzhou730070China College of Chemistry and Chemical Engineering Gansu Key Laboratory of Polymer Materials Northwest Normal University Lanzhou730070China College of Chemistry and Chemical Engineering Gansu Key Laboratory of Polymer Materials Northwest Normal University Lanzhou730070China

L-aspartic acid zinc was synthesized by a rapid and convenient method in high yield under microwave conditions, and its single crystal structure was analyzed by X-ray diffraction. The structure unit of the title compound is [Zn(L-Asp)(H2O)2]·H2O, which is a bicyclo-complex forming a spiral linear polymer via coordination bonds. The spiral linear polymers are assembled as a three-dimensional supramolecule by intermolecular hydrogen bonds. The crystal belongs to the orthorhombic crystal system, P2(1)2(1)2(1) space group, a=0.7830(3) nm, b=0.9369(4) nm, c=11.599(5) nm, α=β=γ=90.00°, V=0.8509(6) nm3, Z=4, Dc=1.955 g/cm3, F(000)=512, μ=2.289. The toxicity of the title compound is lower than that of glutamic acid zinc and zinc sulfate. Keywords L-aspartic acid - zinc - microwave - supramolecule - toxicity

关键词： L-aspartic acid zinc microwave supramolecule toxicity

Markov game for autonomic joint radio resource management in a multi-operator scenario

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 48-55页

作者： ZHANG Yong-jing lin Yue-wei School of Telecommunication Engineering Beijing University of Posts andTelecommunications Beijing 100876 China

This article addresses the autonomy of joint radio resource management （JRRM） between heterogeneous radio access technologies（RATs） owned by multiple operators. By modeling the inter-operator competition as a general-sum Markov game, correlated-Q learning（CE-Q） is introduced to generate the operators＇ pricing and admission policies at the correlated equilibrium autonomically. The heterogeneity in terms of coverage, service suitability, and cell capacity amongst different RATs are considered in the input state space, which is generalized using multi-layer feed-forward neural networks for less memory requirement. Simulation results indicate that the proposed algorithm can produce rational JRRM polices for each network under different load conditions through the autonomic learning process. Such policies guide the traffic toward an optimized distribution and improved resource utilization, which results in the highest network profits and lowest blocking probability compared to other self-learning algorithms.

关键词： autonomic JRRM multi-operator reinforcement learning (RL) Markov game

Carboniferous-Permian rugose coral Cyathaxonia faunas in China

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Science China Earth Sciences 2010年第12期53卷 1864-1872页

作者： WANG XiangDong ZHANG YiQiang lin wei LPS Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Graduate University of Chinese Academy of Sciences Beijing 100049China

The Cyathaxonia faunas are widely distributed in the Carboniferous and Permian strata in *** fauna in China contains 12 families and 40 genera,and can be recognized as three episodes from Early Carboniferous to the end-Permian in terms of their occurrence and composition:1) Mississippian;2) Pennsylvanian-Early Permian;3) Middle Permian-Late *** were relatively abundant in episodes 1 and 2.A decrease of family Antiphyllidae and an increase of family Hapsiphyllidae can be observed from Early Carboniferous to the *** case studies are given to illustrate the bio-facies of the Cyathaxonia faunas,which are from the Mississippian of Baoshan,West Yunnan and the Mississippian of Chaohu,South *** both areas,Cyathaxonia faunas occur just below the large dissepimented solitary and compound coral assemblages in a continuous sequence in a single section,which implies that the occurrence of these small,non-dissepimented solitary corals is not strictly related with Gondwanan or Peri-gondwanan cold water environment,but might be controlled by such benthic conditions as deeper,mud-rich,quieter,and darker sedimentary environments.

关键词： Cyathaxonia fauna Carboniferous Permian paleoecology China Gondwana

The Hong Kong-Zhuhai-Macao Island and Tunnel Project

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Engineering 2017年第6期3卷 783-784页

作者： Ming lin wei lin Hang Kong-Zhuhai-Macao Island and Tunnel Project General Management Office China

The Hong Kong-Zhuhai-Macao （HZM） Bridge is located at the Pearl River estuary and has a total length of 55 km. The HZM Bridge＇s main navigational crossing is by way of two 100 000 m2 artificial islands and a 6.7 km...

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A study on the changes of dynamic feature code when fixing bugs: towards the benefits and costs of Python dynamic features

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Science China(Information Sciences) 2018年第1期61卷 169-186页

作者： Zhifei CHEN Wanwangying MA wei lin lin CHEN Yanhui LI Baowen XU State Key Laboratory for Novel Software Technology Nanjing University

Dynamic features in programming languages support the modification of the execution status at runtime, which is often considered helpful in rapid development and prototyping. However, it was also reported that some dynamic feature code tends to be change-prone or error-prone. We present the first study that analyzes the changes of dynamic feature code and the roles of dynamic features in bug-fix activities for the Python language. We used an AST-based differencing tool to capture fine-grained source code changes from 17926 bug-fix commits in 17 Python projects. Using this data, we conducted an empirical study on the changes of dynamic feature code when fixing bugs in Python. First, we investigated the characteristics of dynamic feature code changes, by comparing the changes between dynamic feature code and non-dynamic feature code when fixing bugs, and comparing dynamic feature changes between bug-fix and non-bugfix activities. Second, we explored 226 bug-fix commits to investigate the motivation and behaviors of dynamic feature changes when fixing bugs. The study results reveal that(1) the changes of dynamic feature code are significantly related to bug-fix activities rather than non-bugfix activities;(2) compared with non-dynamic feature code, dynamic feature code is inserted or updated more frequently when fixing bugs;(3) developers often insert dynamic feature code as type checks or attribute checks to fix type errors and attribute errors;(4) the misuse of dynamic features introduces bugs in dynamic feature code, and the bugs are often fixed by adding a check or adding an exception handling. As a benefit of this paper, we gain insights into the manner in which developers and researchers handle the changes of dynamic feature code when fixing bugs.

关键词： Python fine-grained code changes change behaviors dynamic features bug fixing

Correlation analysis between the occurrence of epidemic in ancient China and solar activity

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Science China Earth Sciences 2023年第1期66卷 161-168页

作者： Si CHEN Yong wei Xin’an YUE Kaihua XU Mingkun LI wei lin Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing Institute of Genomics Chinese Academy of Sciencesand China National Center for BioinformationBeijing 100101China Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunming 650223China

As the globe has witnessed the pandemic,epidemic diseases exert a strong impact on human beings and *** the Sun is the primary energy source of the Earth,some scientific pioneers attempted to search for the discernible relation between solar activity and the incidence of *** this study,the periodic changes and trends of ancient Chinese epidemic data were analyzed in comparison with those of sunspot numbers,a solar activity *** results show that the epidemic and solar activity changes are in good agreement to a certain extent,especially during the Gleissberg and the de Vries *** wavelet coherence shows that the frequency of the epidemic data and sunspot numbers are highly *** addition,results from the ensemble empirical mode decomposition illustrate consistent variations in low-frequency *** study has important implications for further understanding of the potential impact of solar activity on Earth’s biosphere,the underlying mechanism of which needs further exploration.

关键词： Epidemic Ancient China Solar activity Spectrum analysis

Buckling response of offshore pipelines under combined tension, bending, and external pressure

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第8期12卷 627-636页

作者： Shun-feng GONG lin YUAN wei-liang JIN Institute of Structural Engineering Zhejiang University Hangzhou 310058 China

The buckle and collapse of offshore pipeline subjected to combined actions of tension, bending, and external pressure during deepwater installation has drawn a great deal of attention. Extended from the model initially proposed by Kyriakides and his co-workers, a 2D theoretical model which can successfully account for the case of simultaneous tension, bending, and external pressure is further developed. To confirm the accuracy of this theoretical method, numerical simulations are conducted using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. The model is then used to study the effects of several important factors such as load path, material prop-erties, and diameter-to-thickness ratio, etc., on buckling behaviors of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which aims to provide the design guidelines for deepwater pipeline with solid theoretical basis.

关键词： Deepwater Offshore pipeline Buckle External pressure

The new multistage water adsorption model of Longmaxi Formation shale considering the spatial configuration relationship between organic matter and clay minerals

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Petroleum Science 2022年第5期19卷 1950-1963页

作者： Zhi-Ye Gao Shu-ling Xiong lin wei State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China Unconventional Petroleum Research Institute China University of PetroleumBeijing102249China School of Energy Resources China University of GeosciencesBeijing100083China

The water adsorption by shale significantly affects shale gas content and its seepage ***,the mechanism of water adsorption by shale is still unclear due to its strong heterogeneity and complicated pore *** relationship between the adsorbed water content at different relative humidities(RHs)and shale compositions,as well as shale pore structure and the spatial configuration relationship between organic matter(OM)and clay minerals,was investigated to clarify the controlling factors and mechanisms of water adsorption by Longmaxi Formation shale from the Southern Sichuan Basin in ***,the water adsorption process could be generally divided into three different stages from 0%RH to 99%***,the Johnston’s clay mine ral interlayer pore structure model(JCM),the Freundlich model(FM)and the Dubinin-Astakhov model(DAM)were tested to fit the three water adsorption stages from low RH to high RH,*** fitting results of the JCM and FM at lower RHs were far from good,while the fitting results of DAM at higher RHs were ***,two revised models(LRHM and MRHM)considering the spatial configuration relationship between OM and clay minerals were proposed for the two stages with lower RHs,and performed better fitting results indicating the pronounced effect of the spatial configuration relationship between OM and clay minerals on the water adsorption process of Longmaxi Formation *** outcomes of this study will contribute to clarifying the water distribution characteristics in the pore network of shale samples with variable water contents.

关键词： Longmaxi formation shale Water content OM-clay complexes Spatial occurrence relationship

Intent Pattern Recognition of Lower-limb Motion Based on Mechanical Sensors

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 651-660页

作者： Zuojun Liu wei lin Yanli Geng Peng Yang School of Control Science and Engineering Hebei University of Technology Engineering Research Center of Intelligent Rehabilitation Ministry of Education Department of Electrical Engineering and Computer Science Case Western Reserve University Hebei University of Technology

Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.

关键词： Above-knee prosthesis hidden Markov model(HMM) intra-class correlation coefficient(ICC) intent pattern recognition sensor fusion