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Influence of backfilling rate on the stability of the"backfilling bodyimmediate roof"cooperative bearing structure

International Journal of mining Science and Technology 2022年第6期32卷 1197-1206页

作者： Xianjie Du Guorui Feng min zhang Zehua Wang Wenhao Liu College of mining Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030024China Key Laboratory of Shanxi Province for mine Rock Strata Control and Disaster Prevention Taiyuan 030024China State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China Zhengzhou Coal Industry(Group)Co LtdZhengzhou 450007China College of Civil Engineering Taiyuan University of TechnologyTaiyuan 030024China

To reduce the cost of backfilling coal mining and utilize the underground space of coal mines,a new backfilling mining method with low backfilling rate called constructional backfilling coal mining(CBCM)is *** "backfilling body-immediate roof" cooperative bearing structure of CBCM is analyzed by establishing the model of the medium thick plate on an elastic *** influence of the backfilling rate on the stability of overlying strata is analyzed by the numerical simulation *** control effect of CBCM is verified by a physic similar simulation *** economic benefit of CBCM is *** conclusions are:the deformation characteristics of the immediate roof and critical backfilling spacing in CBCM can be analyzed based on the Hu Haichang’s *** the bearing capacity of the immediate roof is beneficial to the stability of the overlying *** CBCM has a good control effect on the overburden in Xinyang mine when the backfilling rate is lower than 25%.The backfilling cost of per ton coal is 37.39 yuan/t when the backfilling rate is 13.7%,with a decrease rate of 56.63%than the *** research results can provide theoretical support for the application of CBCM in coal mining.

关键词： Constructional backfilling coal mining Immediate roof Cooperative bearing structure Medium thick plate on elastic foundation Backfilling rate Overlying strata

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Research on the environmental capacity of a reservoir by using the conceptual net method

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Chinese Journal Of Geochemistry 2009年第2期28卷 227-230页

作者： ZHOUFuchun HUANG min zhang Longhui Key Laboratory of Hydraulic and Water Transport Engineering under the ministry of Education Chongqing Jiaotong University Chongqing 400074 China

The aquatic environment capacity possesses the largest tolerance to pollutants. We can improve the calculating precision using the conceptual net method. Its basic ways involved in calculation include the following aspects: first, to establish the flow continuity equation, flow motion equation, water quality equation and other mathematical models; at the same time, to conceptualize the reservoir studied, divide the reservoir into several functional areas, and use the one-dimensional section-beginning calculation model to calculate all cross-sections of each functional area; then, to superimpose the environmental capacity of each functional section to get the aquatic environment capacity of the entire two-dimensional space; and finally, to introduce how to make use of the conceptual net to calculate the aquatic environment capacity in terms of the actual reservoir's situation.

关键词：水环境容量水库运用方式概念网计算精度储层划分功能区域连续性方程运动方程

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Hierarchical LSTM with char-subword-word tree-structure representation for Chinese named entity recognition

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Science China(Information Sciences) 2020年第10期63卷 74-88页

作者： Chen GONG Zhenghua LI Qingrong XIA Wenliang CHEN min zhang School of Computer Science and Technology Soochow University

Chinese named entity recognition(CNER) aims to identify entity names such as person names and organization names from Chinese raw text and thus can quickly extract the entity information that people are concerned about from large-scale texts. Recent studies attempt to improve performance by integrating lexicon words into char-based CNER models. These existing studies, however, usually focus on leveraging the context-free words in lexicon without considering the contextual information of words and subwords in the sentences. To address this issue, in addition to utilizing the lexicon words, we further propose to construct a hierarchical tree structure representation composed of characters, subwords and context-aware predicted words from segmentor to represent each sentence for CNER. Based on the tree-structure representation, we propose a hierarchical long short-term memory(HiLSTM) framework, which consists of hierarchical encoding layer, fusion layer and CRF layer, to capture linguistic knowledge at different levels. On the one hand, the interactions within each level help to obtain the contextual information. On the other hand, the propagations from the lower-levels to the upper-levels can provide additional semantic knowledge for CNER. Experimental results on three widely used CNER datasets show that our proposed HiLSTM model achieves significant improvement over several strong benchmark methods.

关键词： natural language processing named entity recognition representation learning neural networks

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Vibration reduction for a new-type maglev vehicle with mid-mounted suspension under levitation failure

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Science China(Technological Sciences) 2023年第12期66卷 3475-3487页

作者： zhang min LIU Jing CAO Yi CHEN XianFa MA WeiHua State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Levitation failure occasionally occurs when a maglev vehicle runs on a track. At the moment of levitation failure, the levitation module falls and hits the track, and there is a violent impact on the maglev vehicle-bridge coupled system. In this paper, the response of the maglev vehicle-bridge coupled system at the moment of and after levitation failure is analyzed, and three methods of reducing the vibration are proposed. First, a dynamics model of the maglev vehicle-bridge coupled system, which considers the control system, five flexible bridges, and track irregularity, is established, and the correctness of the model is verified using test data. The system response for different failure cases is then analyzed. Finally, the three methods of reducing vibration under levitation failure are proposed, and their effectiveness is evaluated. The results show that the failure position and speed barely affect the response, whereas the maximum impact forces due to levitation failure reduced by 13%, 63%, and 50% by adopting the three methods, namely connecting the first and third coils in series, coupling the ends of the levitation module vertically, and adopting two sets of anti-roll devices, respectively. When the latter two schemes are combined, the maximum impact force reduced from 133 kN(without vibration-reduction measures) to 9 kN, and the vibration-reduction measure is also effective for failures of the levitation units at the ends of the vehicle.

关键词： mid-and low-speed maglev vehicle maglev vehicle with mid-mounted suspension coupled vibration levitation failure vibration reduction

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Microstructure and properties of Ag–Ti_3SiC_2 contact materials prepared by pressureless sintering

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International Journal of minerals,Metallurgy and Materials 2018年第7期25卷 810-816页

作者： min zhang wu-bian tian pei-gen zhang jian-xiang ding ya-mei zhang zheng-ming sun jiangsu key laboratory of advanced metallic materials school of materials science and engineeringsoutheast UniversityNanjing 211189China jiangsu key laboratory of construction materials school of materials science and engineeringsoutheast universityNanjing 211189China

Ti3SiC2-reintbrced Ag-maJxix composites are expected to serve as eleclrical contacts. In this study, the wettability of Ag on a Ti3SiC2 subslxate was measured by the sessile drop melkod. The Ag-Ti3SiC2 composites were prepared from Ag mad Ti3SiC2 powder mix- tures by pressureless sintering. The effects of compacting pressure （100-800 MPa）, sintering temperature （850-950~C）, mad soaking time （0.5-2 h） on the microslxucture mad properties of the Ag-Ti3SiC2 composites were investigated. The experimental results indicated that Ti3SiC2 paxticulates were uniformly distxibuted in flae Ag matrix, wiflaout reactions at the interthces between flae two phases. The prepared Ag-10wt%Ti3SiC2 had a relative density of 95% mad an electrical resistivity of 2.76 x 10 3 m~）＇cm when compacted at 800 MPa mad sintered at 950~C for 1 h. The incorporation of Ti3SiC2 into Ag was found to improve its hardness without substantially compromising its electrical conductivity; INs behavior was attxibuted to the combination of ceramic and metallic properties of the Ti3SiC2 reinforcement, suggesting its potential application in electrical contacts.

关键词： MAX phase Ag-Ti3SiC2 contact materials wettability pressureless sintering

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An excellent deep-ultraviolet birefringent material based on[BO2]∞ infinite chains

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Light(Science & Applications) 2022年第9期11卷 2217-2224页

作者： FANGFANG zhang XINGLONG CHEN min zhang WENQI JIN SHUJUAN HAN ZHIHUA YANG SHILIE PAN Research Center for Crystal Materials CAS Key Laboratory of Functional Materials and Devices for Special EnvironmentsXinjiang Technical Institute of Physics and ChemistryCAS40-1 South Beijing RoadUrumqi 830011China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049 BeijingChina

Birefringent materials play indispensable roles in modulating the polarization of light and are vital in the laser science and ***,the design of birefringent materials operating in the deep-ultraviolet region(DUV,λ≤200 nm)is still a great *** this work,we developed a new DUV birefringent crystal LiBO_(2) based on[BO2]∞infinite chains in the Li-B-O system,which simultaneously achieves the shortest UV cutoff edge(164 nm)and the largest birefringence(≥0.168 at 266 nm)among all the reported borate-based DUV birefringent *** crystals of LiBO_(2) with dimensions up to Ø55×34 mm^(3) were grown by the Czochralski method,providing access to large-sized single crystal with low ***,it has a high laser damage threshold and stable physicochemical *** outstanding characters unambiguously support that LiBO_(2) can be an excellent birefringent material for DUV application.

关键词： birefringent polarization ultraviolet

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High-resolution short time interval measurement system implemented in a single FPGA chip

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Chinese Science Bulletin 2011年第12期56卷 1285-1290页

作者： WANG Hai zhang min LIU Jie Department of Measurement and Control Xidian University Xi' an 710071 China

This study proposes a high-resolution short time interval measurement system based on the Vernier delay line (VDL) method. It should be noted that the programmable delay elements (PDEs) in the Xilinx field programmable gate arrays (FPGAs) provide a novel realization of delay lines. The delay lines can provide an accurate delay difference of 50 ps, which is process, voltage and temperature (PVT) invariant. An excellent consistency for the delay lines can be achieved by adjusting the timing and layout to minimize the measurement errors. The resolution achieved was 58 ps. Experimental results indicate a measurement standard deviation of 36 ps, a differential nonlinearity (DNL) of 36 ps and integral nonlinearity (INL) of 14 ps. The system features high accuracy, easy implementation and low cost.

关键词： FPGA芯片测量系统时间间隔高分辨率现场可编程门阵列 Xilinx 延迟线积分非线性

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Adaptive Iterative Learning Control for Nonlinear Time-delay Systems with Periodic Disturbances Using FSE-neural Network

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International Journal of Automation and computing 2011年第4期8卷 403-410页

作者： Chun-Li zhang Jun-min Li Department of Applied Mathematics Xidian University Xi＇an 710071 PRC

An adaptive iterative learning control scheme is presented for a class of strict-feedback nonlinear time-delay systems, with unknown nonlinearly parameterised and time-varying disturbed functions of known periods. Radial basis function neural network and Fourier series expansion （FSE） are combined into a new function approximator to model each suitable disturbed function in systems. The requirement of the traditional iterative learning control algorithm on the nonlinear functions （such as global Lipschitz condition） is relaxed. Furthermore, by using appropriate Lyapunov-Krasovskii functionals, all signs in the closed loop system are guaranteed to be semiglobally uniformly ultimately bounded, and the output of the system is proved to converge to the desired trajectory. A simulation example is provided to illustrate the effectiveness of the control scheme.

关键词： Adaptive control iterative learning control (ILC) time-delay systems Fourier series expansion-neural network periodic disturbances.

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Geochemical characteristics, forming conditions and resource evaluation of oil-cracking gas as ex-emplified by the platform area of the Tarim Basin

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Chinese Journal Of Geochemistry 2011年第3期30卷 346-352页

作者： zhang min CHEN Xiaohui HUANG Guanghui Department of Geochemistry Yangtze University Jingzhou 434023 China The Key Laboratory of Exploration Technology for Oil & Gas Resources Ministry of Education Yangtze University Jingzhou 434023 China

Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs, two kinds of natural gases with different relationships between C2/C3 and C1/C2, C2/C3 and C1/C3, C2/C3 and 100×C1/(C1-C5) were identified in the Tarim Basin, and proposed further by the authors. The relationship charts of C2/C3 and C1/C2, C2/C3 and C1/C3, C2/C3 and 100×C1/(C1-C5) can be used to effectively distinguish oil-cracking gas from kerogen-cracking gas. Petro-leum geological analysis of the oil-cracking gas reservoirs showed that the distribution of oil-cracking gas is mostly related with deep-seated faults or faults with a large fault throw, and the burial depth of paleo-oil reservoir is rela-tively high; crude oil-cracking gas resources have been evaluated by using both forward and inversion methods. The plots of C2/C3 vs. C1/C2, C2/C3 vs. C1/C3, and C2/C3 vs. 100×C1/(C1-C5) were used to distinguish between oil-crack-ing gas and kerogen-cracking gas, and estimate the mixed ratios of the two kinds of natural gases in the main gas reservoirs of the platform area.

关键词：原油裂解气地球化学特征塔里木盆地资源评价面积平台干酪根裂解气成条

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Geochemical characteristics and possible origin of natural gas in the Taibei Depression,Turpan-Hami Basin,China

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Chinese Journal Of Geochemistry 2010年第3期29卷 307-312页

作者： ZHAO Hongjing zhang min WANG Zhiyong China University of Geosciences Wuhan 430074 China Geochemical Department of Yangtze University Jingzhou 434023 China The Key Laboratory of Exploration Technologies for Oil and Gas Resources （Yangtze University） Ministry of Education Jingzhou 434023 China Research Institute of Petroleum Exploration and Development TuHa Oilfield Homi 839009 China

292 chemical composition data and 82 isotopic composition data of gas samples collected from the Taibei Depression of the Turpan-Hami Basin, West China, were used in the study of their origin. Non-hydrocarbon gas is poor in most samples whereas abundant nitrogen in some samples is positively correlated with δ13C1. Although methane is the main constituent, higher molecular gaseous hydrocarbons, from ethane to pentane, are detected in most samples, in accordance with the distribution of oil reservoirs. The stable carbon isotope ratios of methane, eth-ane and propane are defined as δ13C1: -45.5‰ to -33.5‰, δ13C2: -30.2‰ to -10.5‰, and δ13C3: 27.6‰ to -11.2‰, respectively. According to the distribution of carbon isotope ratios, 2 families of gas can be grouped, most showing normal distribution of carbon isotopes, and others having obvious heavier carbon isotopes and being of abnormal distribution. Based on the isotopic composition, the disagreement between the relationship of △(δ13C1-δ13C2) and δ13C2 and that of △(δ13C1-δ13C2) and δ13C2, and the calculated Ro, there are oil-associated gas, coal-derived gas and mixture of them. Other samples with obviously heavier isotopic compositions from the Yanmuxi oilfield of the Taibei Depression have been degraded by organisms.

关键词：地球化学特征伴生天然气台北凹陷吐哈盆地起源中国碳同位素比值同位素组成

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