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Conception and Design of Active Balancer for Planar Mechanisms

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Chinese Journal of Mechanical Engineering 2009年第6期22卷 822-832页

作者： ZHANG ying yao Yan-An CHA Jianzhong School of Mechanical and Electronic Control Engineering Beijing Jiaotong University Beijing 100044 China

The dynamic balancing is an important issue in mechanism design. For the existing balancing methods, both passive and active ones, there is still room for improvement in adaplability and independency. In view of this, a concept of active balancer is developed as a new solution for the dynamic balancing with more flexibility. The proposed balancer is an independent additional device with a control system inside, which consists of a two-degree-of-freedom （DOF） linkage and a controllable motor, and can be attached to a machine expediently with little change to its original structure and motion. One of the two inputs of the two-DOF linkage shares the same shaft with its output, which is connected to the input shaft of a machine to be balanced and driven by the original actuator. The other input is driven by the control motor. By properly selecting the speed trajectories of the control motor and link parameters of the two-DOF linkage, one or more dynamic effects of the mechanisms can be minimized or eliminated adaptively. The design procedure of the active balancer is put forward and a two-step optimization is developed to find out optimal design parameters of the balancer for various design requirements and constraints. Taking a force-balanced crank-rocker mechanism as the reference mechanism, numerical examples are given to illustrate the design procedure. The balancing effects of the proposed balancer are compared with those of the existing adding dyads （DYAD） method. The results show that the introduction of the control system provides the active balancer with better balancing effect and more flexibility than the DYAD method. A considerable reduction in the dynamic effects （input torque, shaking moment and shaking force） can be achieved for different balancing object by designing the structural and control parameters of the balancer, and the deterioration of dynamic performance caused by alterative working conditions can be compensated effectively by redesigning the

关键词： active balancing shaking moment input torque shaking force optimum balancing two-degree-of-freedom linkage

Dechlorination of carbon tetrachloride by the catalyzed Fe-Cu process

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Journal of Environmental Sciences 2007年第7期19卷 792-799页

作者： XU Wen-ying GAO Ting-yao The National Engineering Research Center for Urban Pollution Control Tongji University Shanghai 200092 China.

The dectrochemical reduction characteristics of carbon tetrachlofide （CT） were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders＇ iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders＇ iron. The entire CT in 350 ml aqueous solution with 320 mg/L was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with Fe/Cu ratio of 10：1 （w/w） were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were different. The degradation rate was not significantly influenced by pH in the catalyzed Fe-Cu process; in Master Builders＇ iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders＇ iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode （Cu） and anode （Fe） compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value.

关键词： carbon tetrachloride electrochemical reduction characteristics catalyzed Fe-Cu process reduction mechanisms

A novel posture alignment system for aircraft wing assembly

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第11期10卷 1624-1630页

作者： Bin ZHANG Bao-guo yao ying-lin KE College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China

A novel 6-degree of freedom (DOF) posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive half-ball shaped end-effector, and the positioners together with the wing are considered as a 3-PPPS (P denotes a prismatic joint and S denotes a spherical joint) redundantly actuated parallel mechanism. The kinematic model of this system is established and a trajectory planning method is introduced. A complete analysis of inverse dynamics is carried out with the Newton-Euler algorithm, which is used to find the desired actuating torque in the design and path planning phase. Simulation analysis of the displacement and actuating torque of each joint of the positioners based on inverse kinematics and dynamics is conducted, and the results show that the system is feasible for the posture alignment of aircraft wings.

关键词： Aircraft wings Three-coordinate positioner Posture alignment Kinematics Dynamics

Cooperative Beamforming for Multi-Relay Networks with Limited Feedback

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China Communications 2019年第10期16卷 56-64页

作者： Jia Zhu ying yao Yulong Zou Tong Wu School of Telecommunications and Information Engineering Nanjing University of Posts and Telecommunications

In this paper, we consider a multi-relay cooperative communication network that consists of a source node transmitting to its destination with the help of multiple decode-and- forward (DF) relays. Specifically, the DF relays that succeed in decoding the source signal are allowed to re-transmit their decoded results simultaneously to the destination in a cooperative beamforming manner. In order to carry out the cooperative beamforming, the destination needs to send the quantized channel state information (CSI) to the relays through a limited feedback channel in the face of channel quantization errors (CQE). We propose a CQE oriented multi-relay beamforming (MRB) scheme, denoted CQE-MRB for short, for the sake of improving the throughput of relay-destination transmissions. An effective throughput defined as the difference between the transmission rate and the feedback rate is used to measure an outage probability of the source-destination transmission. Simulation results demonstrate that the outage performance of proposed CQEMRB scheme is improved substantially with an increasing number of relays. Moreover, it is shown that the number of channel quantization bits can be further optimized to minimize the outage probability of proposed CQE-MRB scheme.

关键词： cooperative beamforming relay selection effective throughout limited feedback quantization error

The extraction of potassium from K-feldspar ore by low temperature molten salt method

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Chinese Journal of Chemical Engineering 2018年第4期26卷 845-851页

作者： Zhao Wang Quanyou Zhang ying yao Yongzhong Jia Bingjun Xie Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining 810008 China Qinghai Engineering and Technology Research Center of Comprehensive Utilization of Salt Lake Resources Xining 810008 China University of Chinese Academy of Sciences Beijing 100049 China Mangya Xingyuan Potash Corporation Ltd. Haixi 817500 China

The low temperature molten salt method was used to extract potassium from K-feldspar ore, and some related factors including mass ratio between NaNO_3, NaOH, H_2O and K-feldspar ore, particle size of K-feldspar ore,reaction temperature and time were investigated, respectively. In addition, the optimum condition for this method was determined by a series of condition experiments. What was more, the K-feldspar ore and the leach residue after reaction based on the above optimum condition were analyzed by XRD, SEM and EDS,separately. The results of which indicated that the mechanism of extraction of potassium for this method was according to the ion exchange reaction between sodium ion and potassium ion, and the extraction ratio of potassium had an obvious improvement than that of traditional methods, which could reach up to 96.25%.Therefore, this method can be a feasible solution to extract potassium from K-feldspar ore for its low energy consumption and high efficiency.

关键词： Low temperature molten salt K-feldspar Mechanism Extraction ratio

The role of time preferences in contract breach:Evidence from Chinese poultry farmers participating in contract farming

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Journal of Integrative Agriculture 2023年第2期22卷 623-641页

作者： HOU Jing ZHOU Li Jennifer IFFT ying Rui-yao Business School Jiangsu Normal UniversityXuzhou 221116P.R.China College of Economics and Management Nanjing Agricultural UniversityNanjing 210095P.R.China Department of Agricultural Economics Kansas State UniversityManhattanKansas 66506USA

Farmers’contract breach behavior is cited as one of the major stumbling blocks in the sustainable expansion of contract farming in many developing *** paper examines farmers’contract breach decisions from the perspective of time *** empirical analysis is based on a household survey and economic field experiments of poultry households participating in contract farming conducted in Jiangsu Province,China.A discounted utility model and a maximum likelihood technique are applied to estimate farmers’time preferences and the effect of time preferences on contract breach in the production and sales phases are explored with a bivariate probit *** results show that,on average,the poultry farmers in the sample are generally present biased and impatient regarding future *** regression results show that farmers with a higher preference for the present and a higher discount rate are more likely to breach contracts,and time preferences play a greater role in the production phase than in the sales *** considering heterogeneity,specific investments and transaction costs promote contract stability only for farmers with a low degree of ***,compared with large-scale farmers,small-scale farmers’contract breach decisions are more significantly affected by their time *** results have implications for contract stability policies and other issues that are impacted by the linking of behavioral preferences to agricultural decisions.

关键词： time preferences contract breach contract farming economic field experiments China

Characterizations of Additive Jordan Left *-Derivations on C*-Algebras

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Journal of Mathematical Research with Applications 2021年第5期41卷 531-536页

作者： ying yao Guangyu AN Department of Mathematics Shaanxi University of Science and Technology

An additive mapping δ from a *-algebra A into a left A-module M is called an additive Jordan left *-derivation if δ（A） = Aδ（A） + Aδ（A） for every A in A. In this paper,we prove that every additive Jordan left *-derivation from a complex unital C-algebra into its unital Banach left module is equal to zero. An additive mapping δ from a *-algebra A into a left A-module M is called left *-derivable at G in A if δ（AB） = Aδ（B） + Bδ（A） for each A, B in A with AB = G. We prove that every continuous additive left *-derivable mapping at the unit element I from a complex unital C-algebra into its unital Banach left module is equal to zero.

关键词： additive mapping Jordan left *-derivation left *-derivable mapping C*-algebra

Structural Evolution in Flowing Immiscible Blends in the Presence of Rough Particles:Dependence of Shear Rate and Blend Ratio

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Chinese Journal of Polymer Science 2021年第8期39卷 1059-1068,I0008页

作者： Si-ying Xiang ying-Chun yao Miao-Miao Lu Ya-Jiang Huang Mi-Qiu Kong Guang-Xian Li College of polymer science and engineering State key laboratory of polymer materials engineering of ChinaSichuan UniversityChengdu 670065China

The influence of polystyrene particles with different nanoscale roughnesses on the morphology of polyisobutylene/poly-dimethylsiloxane blends was studied under shear flow by using confocal laser scanning *** was found that the surface roughness of particles strongly affected their diffusion and distribution behaviors,thereby determining the size and spatial arrangement of droplets in the *** roughness effect of particles was found to possess a strong dependence on both the blend ratio and the shear *** result suggested that the particle roughness can serve as a new parameter to control the structure-property correlation in particle-filled polymer blends,especially under slow flow.

关键词： Rough particles Immiscible polymer blends Shear flow

Preliminary investigation of phosphorus adsorption onto two types of iron oxide-organic matter complexes

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Journal of Environmental Sciences 2016年第4期28卷 152-162页

作者： Jinlong Yan Tao Jiang ying yao Song Lu Qilei Wang Shiqiang Wei Key Laboratory of Eco-environments in Three Gorges Reservoir Region Ministry of EducationChongqing Key Laboratory of Agricultural Resources and EnvironmentCollege of Resources and EnvironmentDepartment of Environmental Science and EngineeringSouthwest University Department of Forest Ecology and Management Swedish University of Agricultural Sciences School of Material Science & Engineering Beijing Institute of Technology

Iron oxide（FeO）coated by natural organic matter（NOM）is *** associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients（e.g.,phosphorus（P））.In this study,ferrihydrite/goethite-humic acid（FH/GE–HA）complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were *** results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe *** maximum adsorption capacity（Q（max））decreased in the order of FH（22.17 mg/g）〉FH-HA（5.43 mg/g）〉GE（4.67 mg/g）〉GE-HA（3.27 mg/g）.After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA *** decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM *** dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption *** P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and ***,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.

关键词： Phosphorus Ferrihydrite–humic acid complex Goethite–humic acid complex Adsorption