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Cooperative Optimization of Reconfigurable Machine Tool Configurations and Production Process Plan

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 982-989页

作者： xie Nan li Aiping XUE Wei Sino-German College of Applied Science Tongji University Shanghai 201804 China Institute of AdvancedManufacturing Technology Tong/i University Shanghai 201804 China College of Mechanical & Electrical Engineering Wenzhou University Wenzhou 325000 China

The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and reduce production cost. Therefore, a cooperative strategy is needed to concurrently solve the above issue. In this paper, the cooperative optimization model for RMT configurations and production process plan is presented. Its objectives take into account both impacts of process and configuration. Moreover, a novel genetic algorithm is also developed to provide optimal or near-optimal solutions： firstly, its chromosome is redesigned which is composed of three parts, operations, process plan and configurations of RMTs, respectively; secondly, its new selection, crossover and mutation operators are also developed to deal with the process constraints from operation processes （OP） graph, otherwise these operators could generate illegal solutions violating the limits; eventually the optimal configurations for RMT under optimal process plan design can be obtained. At last, a manufacturing line case is applied which is composed of three RMTs. It is shown from the case that the optimal process plan and configurations of RMT are concurrently obtained, and the production cost decreases 6.28% and nonmonetary performance increases 22%. The proposed method can figure out both RMT configurations and production process, improve production capacity, functions and equipment utilization for RMT.

关键词： reconfigurable manufacturing system reconfigurable machine tool configuration process plan cooperative optimization model

Estimating emissions from crop residue open burning in China based on statistics and MODIS fire products

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Journal of Environmental Sciences 2016年第6期28卷 158-170页

作者： Jing li Yu Bo Shaodong xie College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution ControlPeking University

With the objective of reducing the large uncertainties in the estimations of emissions from crop residue open burning, an improved method for establishing emission inventories of crop residue open burning at a high spatial resolution of 0.25°× 0.25° and a temporal resolution of1 month was established based on the moderate resolution imaging spectroradiometer（MODIS） Thermal Anomalies/Fire Daily Level3 Global Product（MOD/MYD14A1）. Agriculture mechanization ratios and regional crop-specific grain-to-straw ratios were introduced to improve the accuracy of related activity data. Locally observed emission factors were used to calculate the primary pollutant emissions. MODIS satellite data were modified by combining them with county-level agricultural statistical data, which reduced the influence of missing fire counts caused by their small size and cloud cover. The annual emissions of CO2, CO, CH4,nonmethane volatile organic compounds（NMVOCs）, N2O, NOx, NH3, SO2, fine particles（PM2.5）,organic carbon（OC）, and black carbon（BC） were 150.40, 6.70, 0.51, 0.88, 0.01, 0.13, 0.07, 0.43,1.09, 0.34, and 0.06 Tg, respectively, in 2012. Crop residue open burning emissions displayed typical seasonal and spatial variation. The highest emission regions were the Yellow-Huai River and Yangtse-Huai River areas, and the monthly emissions were highest in June（37%）.Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of within ±126% for N2O to a high of within ± 169% for NH3.

关键词： Crop residue open burning Air quality Emission inventory Moderate resolution imaging spectroradiometer(MODIS)

Type Synthesis of 4-DOF Parallel Kinematic Mechanisms Based on Grassmann line Geometry and Atlas Method

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1073-1081页

作者： xie Fugui li Tiemin liU Xinjun Department of Mechanical Engineering Tsinghua University Department of Precision Instruments Tsinghua University Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control Tsinghua University

Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms（PKMs）, but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method for engineering application is a very challenging issue, which should be further studied in the field. Grassmann line geometry, which can investigate the dimensions of spatial line-clusters in a concise way, is taken as the mathematic foundation. Atlas method is introduced to visually describe the degrees of freedom（DOFs） and constraints of a mechanism, and the dual rule is brought in to realize the mutual conversion of the freedom-space and constraint-space. Consequently, a systematic method based on Grassmann line geometry and Atlas method is generated and the entire type synthesis process is presented. Three type 4-DOF PKMs, i.e., 1T3R, 2T2R and 3T1R（T： translational DOF; R： rotational DOF）, are classified according to the different combinations of the translational DOFs and rotational DOFs. The type synthesis of 4-DOF PKMs is carried out and the possible configurations are thoroughly investigated. Some new PKMs with useful functions are generated during this procedure. The type synthesis method based on Grassmann line geometry and Atlas method is intuitive and concise, and can reduce the complexity of the PKMs＇ type synthesis. Moreover, this method can provide theoretical guidance for other PKMs＇ type synthesis and engineering application. A novel type synthesis method is proposed, which solves the existing methods＇ problems in terms of complicated, not intuitive and unsuitable for practical application.

关键词： type synthesis parallel kinematic mechanism Grassmann line geometry atlas method

Constitutive parameters identification of thermal barrier coatings using the virtual fields method

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Acta Mechanica Sinica 2019年第1期35卷 78-87,I0003页

作者： Mengmeng Zhou Huimin xie Luming li School of Aerospace Engineering Tsinghua UniversityBeijing 100084China

Thermal barrier coatings (TBCs) are widely applied in thermal components to protect metallic components. Owing to the complex layered structure of TBCs and difficult preparation of coating, the mechanical characterization of TBCs should be of primary importance. With regard to TBCs, this study deals with the constitutive parameters identification of bi-material. Considering the complex construction and boundary of bi material, the virtual fields method (VFM) was employed in this study. A methodology based on the optimized virtual fields method combined with moire interferometry was proposed for the constitutive parameters identification of bi-material. The feasibility of this method is verified using simulated deformation fields of a two-layer material subjected to three point ben ding loading. As an application, the deformation fields of the TBC specimens were measured by moire interferometry. Then, lhe mechanical parameters of the coating were identified by the proposed method. The identification results indicate that Young's modulus of the TBC top coating is 89.91 GPa, and its Poisson's ratio is 0.23.

关键词： Virtual Fields Method Thermal barrier coatings Mechanical parameters identification Moiré interferometry

Mutual authenticated quantum no-key encryption scheme over private quantum channel

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Science China(Information Sciences) 2018年第2期61卷 216-223页

作者： li YANG Chenmiao WU Huiqin xie State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences Data Assurance and Communication Security Research Center Chinese Academy of Sciences School of Cyber Security University of Chinese Academy of Sciences

In this paper, we realize Shamir’s no-key protocol via quantum computation of Boolean functions and a private quantum channel. The proposed quantum no-key protocol has three rounds and provides mutual data origin authentication. Random Boolean functions are used to create entanglement and guarantee that any adversary without keys cannot pass the authentication. Thus, our protocol can resist the manin-the-middle attack. A security analysis has shown that pieces of ciphertexts of the three rounds are completely mixed state. This property ensures no adversary can get any information about the sent message or authentication keys. Therefore, our protocol is unconditionally secure and its authentication keys can be reused.

关键词： quantum cryptography no-key protocol quantum entanglement information-theoretical security private quantum channel

Red tetrazolium as an effective inhibitor for the corrosion of cold rolled steel in 7.0 mol·L^(-1) H_2SO_4 solution

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Chinese Journal of Chemical Engineering 2018年第12期26卷 2641-2653页

作者： Xianghong li Shuduan Deng Xiaoguang xie Faculty of Chemical Engineering Southwest Forestry University Faculty of Materials Science and Engineering Southwest Forestry University School of Chemical Science and Technology Yunnan University

The corrosion inhibition of cold rolled steel(CRS) in 7.0 mol·L^(-1) H_2 SO_4 solution by red tetrazolium(RTZ) was carefully investigated using both experimental procedures and theoretical techniques. The results show that RTZ acts as an effective inhibitor for the corrosion of CRS in 7.0 mol·L^(-1) H_2SO_4, and the maximum inhibition efficiency is higher than 95% with a RTZ concentration of 2.0 mmol·L^(-1). The adsorption of RTZ on CRS surface follows Langmuir isotherm. RTZ effectively retards both cathodic and anodic reactions, and acts as a mixed-type inhibitor. EIS exhibits two capacitive loops, and their resistances increase drastically in the presence of RTZ. SEM and AFM confirm that the addition of RTZ could significantly retard the corrosion of CRS surface. A series of characterizations like FTIR, RS, XRD and XPS reveal that the corrosion CRS surface is composed of the corrosion products of iron sulfates, iron oxides and iron hydroxide, as well as inhibitor. Theoretical results of quantum chemical calculation and molecular dynamics(MD) indicate that the adsorption center of RTZ+(organic cationic part of RTZ) mainly relies on its tetrazole ring,and the adsorption of RTZ+on Fe(001) surface is in a nearly flat orientation mode.

关键词： Steel Sulfuric acid Red tetrazolium Corrosion inhibitor Adsorption

Kinetics mechanism of microwave sintering in ceramic materials

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Science China(Technological Sciences) 2009年第9期52卷 2727-2731页

作者： HAO HongShun XU lihua HUANG Yong ZHANG XiaoMeng xie ZhiPeng Department of Inorganic Non-metallic Materials University of Science and Technology BeijingBeijing 100083China Department of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Based on the traditional sintering model incorporating the characteristic of microwave sintering, the ionic conductance diffusion mechanism in microwave sintering was studied. A flat-ball model was presented to describe the kinetics process in microwave sintering, and was applied to the sintering process of TZP and ZrO2-Al2O3 ceramics. The results indicate that the shrinkage rate of materials in microwave sintering is proportional to t2/3 and r-4/3, respectively, where t is the sintering time and r is the particle radius. Whereas, the shrinkage rate of materials in conventional sintering is proportional to sintering time t2/5. Our model suggests that microwave sintering is faster than conventional sintering, which shows a good agreement with the experimental observation in sintering process of TZP and ZrO2-Al2O3.

关键词： microwave sintering ionic conductance kinetics sintering mechanism

Numerical simulation of the preparation of semi-solid metal slurry with damper cooling tube method

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Journal of University of Science and Technology Beijing 2007年第5期14卷 443-448页

作者： Haoqiang Yang Shuisheng xie Lei li State Key Laboratory for Fabrication and Processing of Nonferrous Metals Beijing General Research Institute for Nonferrous Metals Beijing 100088 China

In semi-solid forming process, preparing the slurry with rosette or globular microstructure is very important. A new approach named the damper cooling tube method （DCT）, to produce the semi-solid metal slurry, has been introduced. To optimize the technical parameters in designing the apparatus, the finite volume method was adopted to simulate the flow process. The temperature effects on the rheological properties of the slurries were also considered. The effects of the technical parameters on the slurry properties were studied in detail.

关键词： semi-solid forming rheology damper cooling tube method finite volume method

Rehabilitative training effects of severe mixed-type cerebral palsy in children One case report

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Neural Regeneration Research 2008年第5期3卷 573-576页

作者： Chuyang li Minda xie Guangzhou Rehabilitation Research Center for Children Cerebral Palsy Guangzhou 510630 Guangdong Province China

It has often been thought that severe spastic and athetoid cerebral palsy children respond poorly to rehabilitative training effects and have a poor prognosis after school age. The present study included a nine-year-old severe spastic and athetoid cerebral palsy boy, who received 2 years of physical therapy, supplemented with drugs and orthotic devices and who acquired good therapeutic effects. The beneficial rehabilitative effects were as follows： After discharge, primitive reflex disappeared, and both vertical reflex and parachute reflex were found; In the establishment of balance reflex, sitting position was rated as level III, and standing position was rated as level II. The boy could independently walk for 30-50 meters. In the assessment of muscle tone, the level was rated according to the Modified Ashworth Scale and was decreased from three, four to one, two, and the level rated according to the Clonus Scale decreased from V to II. Motor function was noticeably improved. The level was rated according to the Gross Motor Function Classification System and was decreased from V to II. The total score of 88 items of the Gross Motor Function Measure was increased from 6.1% to 72.2%. The Berg Balance Scale score increased from 0 to 42. The Holden Walking Functional Classification level increased from 0 to 3. The score of activities of daily living increased from 9.5 to 70. The symptoms of dysarthria were alleviated from severe to moderate, and those of salivation were alleviated from level V to level I. These results demonstrated that after systemic and scientific treatment and training, the spastic and athetoid cerebral palsy boy had the ability to walk independently and to care for himself.

关键词： spastic and athetoid cerebral palsy effect evaluation case report