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International Journal of Mining Science and Technology 2017年第6期27卷 1065-1071页

作者： Zha Zhengao Ma Li Li Kemin Ding Xiaohua Xiao Shuangshuang School of Mines China University of Mining and Technology Xuzhou 221116 China School of Energy Engineering Xi’an University of Science and Technology Xi’an 710054 China State Key Laboratory for Geomechanics & Deep Underground Engineering China University of Mining and Technology Xuzhou 221116 China

The paper aims to identify a reasonable method for mining ultra-thick coal seams in an end-slope in surface mine, With a case study of Heidaigou surface coal mine(HSCM), the paper conducted a comparative research on three mining methods, namely Underground Mining Method(UMM), Highwall Mining System(HMS) and Local Steep Slope Mining Method(LSSMM). A model was firstly established to simulate the impact that UMM and HMS exert on monitoring points and surface deformation. The way that stripping and excavation amount varies with different slope angle, and the corresponding end slope stability were analyzed in the mode of LSSMM. Then a TOPSIS model was established by taking into account six indicators such as recovery ratio, technical complexity and adaptability, the impact on surface mining production, production safety and economic benefits. Finally, LSSMM was determined as the best mining method for mining ultra-thick coal seams in end slope in HSCM.

关键词： Ultra-thick coal seam end wall in surface mine Highwall Mining System Local steep slope Resource exploitation

Case-based reasoning model based on attribute w&ghts optimized by genetic algorithm for predicting end temperature of molten steel in RH

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Journal of Iron and Steel Research International 2019年第6期26卷 585-592页

作者： Kai Feng An-jun Xu Peng-fei Wu Dong-feng He Hong-bing Wang School of Metallurgy and Ecology Engineering University of Science and Technology Beijing 100083 China Beijing Key Laboratory of Knowledge Engineering for Materials Science University of Science and Technology Beijing 100083 China China Minmetals Corporation Beijing 100010 China School of Computer and Communication Engineering University of Science and Technology Beijing 100083 China

Temperature control is the key of Ruhrstahl-Heraeus (RH) process in steelmaking plant. The accuracy of RH control model greatly affects the molten steel temperature fluctuation. To obtain RH control model with higher accuracy, an improved case-based reasoning (CBR) model based on attribute weights optimized by genetic algorithm (GA) was proposed. The fitness function in GA was determined according to the prediction accuracy of end temperature of molten steel in RH;then, GA is used to optimize all the attribute weights based on known case base. An improved CBR model that contains the optimized attribute weights was applied to predict end temperature of molten steel in RH, and the prediction accuracy wascalculated. Four methods, CBR based on attribute weights optimized by GA (CBR-GA), ordinary CBR, back propagation neural network (BPNN) and multiple linear regression (MLR) method were employed for comparison. The results show that in the error range of [- 3 ℃, 3 ℃],[- 5 ℃, 5 ℃],[- 7 ℃, 7 ℃] and [- 10 ℃, 10 ℃], the prediction accuracy of CBR-GA was improved by 19.99%, 28.19%, 27.11% and 16.3%, respectively, than that of MLR. Compared with BPNN, the prediction accuracy increased by 3.22%, 7.44%, 5.29% and 2.40%, respectively. Compared with ordinary CBR, the accuracy increased by 5.43%, 5.80%, 4.66% and 2.27%, respectively.

关键词： Case-based reasoning Genetic algorithm end temperature prediction RH process Molten steel

Working Mechanism of a Kind of Non-resonant Linear Piezoelectric Motor with Flexible Driving end

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第5期35卷 749-759页

作者： Chen Xifu Huang Weiqing Lu Qian Li Ming Ren Yaoqing School of Mechanical Engineering Yancheng Institute of Technology State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

A non-resonant piezoelectric linear motor with a flexible driving end,which has an extensive working frequency range and good operation stability,is studied theoretically and *** on the microscopic vibration characteristics of the motor stator,the longitudinal vibration model is established for the whole motor *** to the Coulomb friction model and the motor vibration model,the friction mechanism of the nonresonant piezoelectric linear motor is investigated by dynamical analysis of the whole motor ***,the vibration characteristics and mechanical output characteristics of the stator are simulated and experimentally studied on the basis of the friction drive mechanism ***,both the simulation and experimental results show that this kind of motor remain stable in the frequency domain from 2.2 kHz to 3.5 kHz and that when the pre-stress is 4 Nand the driving voltage is 90 V,the maximum velocity of the motor is above 4 mm/s and the maximum thrust is nearly 0.5 N.

关键词： piezoelectric motor non-resonance friction drive principle flexible drive end

Size variation of the end Permian conodont Neogondolella at Meishan Section,Changxing,Zhejiang and its significance

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Science China Earth Sciences 2006年第4期49卷 337-347页

作者： LUO Genming LAI Xulong JIANG Haishui ZHANG Kexin Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

This study is based on both a generic and species level investigation of the individual size of the latest Permian conodont Neogondolella Pa elements collected from Meishan Section A, Changxing, Zhejiang Province. In this study, an obvious size reduction of Neogondolella Pa elements within bed 24e of the upper Changxing Limestone is recognized. The size variation of the Neogon- dolella occurs simultaneously with some important events including the negative shift of δ 13C, change in the ratio of the abundance of cyanobacterial biomarkers versus that of other general bacterial biomarkers and the shallowing of the sea water. Through the investigation of the paleoenvironmental changes and the analysis of the paleoecology of the conodont genus Neogondolella, the authors propose that the major factors for the size reduction of species of the conodont genus Neogondolella are food shortages caused by the mass extinction, the shallowing of the sea water as well as the in- crease in opacity of the sea water during the end Permian. The same phenomenon of Neogondolella size reduction is also observed in preliminary research from the same horizon at Shangsi Section, Sichuan Province. All the evidence suggests that there was a mass extinction that occurred at the horizon of bed 24e, and the evidence supports the viewpoint of a multi-phase mass extinction during the Permian and Triassic transition in South China.

关键词： Meishan Section, end Permian, conodont, Neogondolella, size reduction.

FINITE ELEMENT ANALYSES OF THE EXTRUSION FLOWS OF BOGER FLUIDS WITH end-DRAWING AND GRAVITY-DRAWING

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Chinese Journal of Chemical Engineering 1995年第2期3卷 50-59页

作者：范毓润范西俊路甬祥浙江大学力学系浙江杭州

The spinning flow of Boger fluids and the gravity-drawing extrusion flow of a Newtonianas well as a Boger fluid have been simulated by using the stream-line finite element method and thetechnique of matching the finite element solutions with those of one-dimensional spinning *** recoverable shear strain is proved not to be a basic parameter in characterising thespinning flow of Boger *** Newtonian fluids this technique predicts the experimental jetshape *** Boger fluids,the numerical simulation agrees with the experimental data of spin-ning flow reported by Sridhar et al.,but seems to give an insufficient swelling and over contractionof the jets when drawn by its own weight,compared with the experimental results of Trang *** implies that the Oldroyd-B model fitting the viscometric-flow data fails to describeaccurately the elasticity and extensional viscosity in the extrusion flow of Boger fluids with gravi-ty-drawing.

关键词： finite element method spinning flow extrusion flow end drawing gravity drawing

Research on end-force Output of 8-cable Driven Parallel Manipulator

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International Journal of Automation and computing 2020年第3期17卷 378-389页

作者： Sen-Hao Hou Xiao-Qiang Tang Ling Cao Zhi-Wei Cui Hai-Ning Sun Ying-Wei Yan State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control Tsinghua UniversityBeijing 100084China Postal Scientific Research and Planning Academy Beijing 100096China

The return capsule needs to be launched to the moon and return back to earth in the third stage of the Chinese lunar exploration ***,it is necessary to perform simulations on the *** paper presents an 8-cable-driven parallel manipulator to achieve end-force output in a low-gravity ***-force output refers to the vector sum of the external force on the end-effector.A model of end-force output is established based on a kinematics model,a dynamic model,and a force analysis of an 8-cable driven parallel *** obtain end-force output in a low-gravity environment,the cable force has to be controlled to counteract *** addition,a force-position mix control strategy is proposed to proactively control the cable force according to the force optimal distribution given by the closed-form force distribution ***,a suitable choice for an end-force output is obtained by modeling the effect of cable force on end-force *** results show that the actual cable force agrees well with the calculated force distribution,indicating that it is feasible to realize end-force output in a low gravity environment.

关键词： Cable driven parallel manipulators low gravity environment end force output cable force control mix control strategy

Stress singularity near the end of a cylindrical interface and the linear elasticity of push-in tests

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Science China(Technological Sciences) 1998年第5期41卷 471-481页

作者：王清嵇醒王远功 Department of Engineering Mechanics and Technology Tongji University Shanghai China

Investigated is the push-in test used to determine the interfacial strength of fiber-reinforced composites via the method of singular integral equation. Singularity analysis shows that stresses near the end for an intact interface have a power singularity, and the singularity index is only dependent on the material constants of the fiber and the matrix. In order to describe the interfacial strength at the initial debonding of the push-in test, critical interfacial shear stress intensity factor and the related singularity index are adopted. This interfacial strength characteristic parameter is applied to analysis of the push-in test results of carbon fiber reinforced epoxy resin composites.

关键词： interfacial strength cylindrical interface interface end stress singularity stress intensity factor singular integral equation push-in test.

Research on polyfluorene derivatives end-capped by N-hexyl-carbazole and benzene

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Science China(Technological Sciences) 2009年第8期52卷 2190-2194页

作者： Yang Xu Hua Wang FangFang Wei JianXin Hou HeFeng Zhou BingShe Xu College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Interface Science and Engineering in Advanced Materials Taiyuan University of Technology Taiyuan 030024 China

Copolymers of 9,9-dioctylfluorene (DOF) and 2-thienyl-benzothiadiazole (DBT) were synthesized by Suzuki reaction and end-capped by N-hexyl-carbazole and benzene, which were abbreviated as PDOF-DBT-Cz and PDOF-DBT-B, respectively. The photophysical, electrochemical and thermal properties of the copolymers were studied. The results indicated that replacement of N-hexyl-carbazole as end-capping group of PDOF-DBT can vary light color and improve luminescence efficiency.

关键词： fluorene carbazole end capping material

A-π-D-π-A small-molecule donors with different end alkyl chains obtain different morphologies in organic solar cells

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Chinese Chemical Letters 2019年第4期30卷 906-910页

作者： Yanan Shi Chen Yang Huan Li Lixuan Liu Ruimin Zhou Wenjun Zou Zhen Wang Qiong Wu Dan Deng Jianqi Zhang Kun Lu Zhixiang Wei CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology University of Chinese Academy of Sciences Sino-Danish College University of Chinese Academy of Sciences

For bulk-heterojunction organic solar cells, the morphology of the blend films highly influence the exciton dissociation and charge transport process. In this work, two novel A-π-D-π-A(A represents the acceptor unit and D represents the donor unit) backbone structure small molecular electron donors based on two dimensional conjugated naphtho[1,2-b:5,6-b']dithiophene(NDT) with different end alkyl chains, named as NDT-3T-EH and NDT-3T-O, have been designed and synthesized. The photovoltaic property of NDT-3T-O-based device is better than that of the NDT-3T-EH and the best efficiency reaches 7.06%, and the photovoltaic property of NDT-3T-EH reaches 6.11%. The difference in the performance should be attributed to the different morphology and phase separation resulted from the different crystallinity and aggregation ability of two donors. The results demonstrate that the optimized end alkyl chains can be used to design A-π-D-π-A backbone structure small molecular electron donors for smallmolecule organic solar cells.

关键词： Organic solar cells All-small-molecule A-π-D-π-A small molecular donor end alkyl chain Morphology of active layer

Cloning and characterization of vernalization-related gene (ver203F) cDNA 3'end

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Chinese Science Bulletin 1999年第14期44卷 1289-1294页

作者： YONG Weidong, CHONG Kang , LIANG Tiebing, XU Zhihong , TAN Kehui and ZHU Zhiqing Research Center for Molecular and Developmental Biology, Institute of Botany, Chinese Academy of Sciences , Beijing 100093, China Shanghai Institute of Plant Physiology , Chinese Academy of Sciences , Shanghai 200032, China Corresponding authors Research Center for Molecular and Developmental Biology Institute of Botany Chinese Academy of Sciences Beijing China Shanghai Institute of Plant Physiology Chinese Academy of Sciences Shanghai China

Based on the cDNA fragment sequence of vernalization-related gene verc203 cloned by differential screening in our lab, the 5′primer has been designed. The cDNA 3′end of ver203 gene (1 197 bp) has been cloned by the RACE method. And it is identified by Northern blotting that its expression is special in vernalization treatment. After comparing the sequence in the nucleotide sequence databases of Genbank, EMBL and DDBJ, the gene has homology with Hordeum vulgare jesmonate-induced protein gene. It is suggested that this gene might be related to the signal transduction mediated by jamonate.

关键词： wheat vernalization-related gene cDNA 3’ end RACE.