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On-machine Precision Preparation and Dressing of Ball-headed Diamond Wheel for the Grinding of Fused Silica

Chinese Journal of Mechanical Engineering 2013年第5期26卷 982-987页

作者： CHEN Mingjun LI Ziang YU Bo PENG Hui FANG Zhen Center for Precision Engineering Harbin Institute of technology The 26th Research Institute China Electronics Technology Group Corporation

In the grinding of high quality fused silica parts with complex surface or structure using ball-headed metal bonded diamond wheel with small diameter,the existing dressing methods are not suitable to dress the ball-headed diamond wheel precisely due to that they are either on-line in process dressing which may causes collision problem or without consideration for the effects of the tool setting error and electrode *** on-machine precision preparation and dressing method is proposed for ball-headed diamond wheel based on electrical discharge *** using this method the cylindrical diamond wheel with small diameter is manufactured to hemispherical-headed *** obtained ball-headed diamond wheel is dressed after several grinding passes to recover geometrical accuracy and sharpness which is lost due to the wheel wear.A tool setting method based on high precision optical system is presented to reduce the wheel center setting error and dimension *** effect of electrode tool wear is investigated by electrical dressing experiments,and the electrode tool wear compensation model is established based on the experimental results which show that the value of wear ratio coefficient K’ tends to be constant with the increasing of the feed length of electrode and the mean value of K’ is *** experiments of fused silica are carried out on a test bench to evaluate the performance of the preparation and dressing *** experimental results show that the surface roughness of the finished workpiece is 0.03 μ*** effect of the grinding parameter and dressing frequency on the surface roughness is investigated based on the measurement results of the surface *** research provides an on-machine preparation and dressing method for ball-headed metal bonded diamond wheel used in the grinding of fused silica,which provides a solution to the tool setting method and the effect of electrode tool wear.

关键词： precision preparation electrical discharge dressing ball-headed diamond wheel fused silica

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Extraction of indium from indium-zinc concentrates

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Transactions of Nonferrous Metals Society of China 2006年第6期7卷 1448-1454页

作者：李仕庆唐谟堂何静杨声海唐朝波陈永明 School of Metallurgical Science and Engineering Central South University 2.Liuzhou Huaxi Group corporation Liuzhou 545006China

A new process for extracting indium from indium-zinc concentrates was *** process can directly extract indium from removed copper solution by D2EHPA,and cancel the stage of removing iron in the traditional process because of using iron and part of zinc in the In-Zn concentrates for direct preparing high quality Mn-Zn soft magnetic *** technologies in the processes,such as leaching the neutral leached residues with high concentrated acid at high temperature,reduction ferric and removing copper,and extracting indium,were *** results show that total recovery ratio of indium is increased from less than 70% in the traditional process to more than 95%.This process has the advantages of largely simplifying the procedure of indium extraction,zero draining off of iron residue and zero emitting of *** this is a clean production process.

关键词： indium extraction hot acid leaching zinc neutral leached residue

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Fusion of Gaussian Mixture Models for Maneuvering Target Tracking in the Presence of Unknown Cross-correlation

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Chinese Journal of Electronics 2016年第2期25卷 270-276页

作者： ZHU Hongyan GUO Kai CHEN Shuo School of Electronic and Information Engineering Xi'an Jiaotong University China Electronics Technology Group corporation No.28 Research Institute

The paper addresses the problem of estimation fusion for maneuvering target tracking in the presence of unknown cross-correlation. To improve the fusion accuracy, two major points are concerned. Firstly, the Interacting multiple model(IMM) estimator is performed for each sensor, and the local estimate is represented by a Gaussian mixture model instead of a Gaussian density to keep more details of the local tracker. Next, a close-formed solution of fusing two Gaussian mixtures in the Covariance intersection(CI) framework is derived to cope with the unknown cross-correlation of local estimation errors. Experimental results demonstrate that the proposed approach provides some improvements in the fusion accuracy over the competitive methods.

关键词： Gaussian mixture model(GMM) Estimation fusion Interacting multiple model(IMM) Covariance intersection(CI) Cross-correlation

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Simulation of Control and Guidance System for the Spinning Missile

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Journal of Systems Engineering and Electronics 1994年第3期5卷 49-56页

作者： Meng Daikui (China Changfeng System Engineering corporation, P.O.Box 142-30, Beiging 100854, China) China Changfeng System Engineering corporation P.O. Box 142-30 Beiging 100854 China

Adopted for some small-size short range surface-to-air missiles and antitank guided missiles is a single-channel control method of making missile rotating around its longitudinal axis. In hardware-in-the-loop simulations of the guidance and control system for these kinds of spinning missiles, improper use of special simulation equipment and test method will cause significant errors, even lead to failure of the simulation. In this article, the author gives an analysis of the causes of significant errors and failure of the simulation, and puts forward a solution, which is improved workable in making the hardward-in-the-loop simulation successful.

关键词： Computer simulation Error analysis Computer system recovery Missiles

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Ammonium Metavanadate Fabricated by Selective Precipitation of Impurity Chemicals on Inorganic Flocculants

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Journal of Renewable Materials 2023年第4期11卷 1951-1961页

作者： Bo Shi Dandan Zhu Pengxiang Lei Ximin Li Hengbo Xiao Lihua Qian Shandong Aluminum Industry corporation Limited ZiboChina Petroleam&Natural Gas Transport corporation of China WuhanChina School of Chemistry and Chemical Engineering Hubei University of TechnologyWuhanChina School of Physics Huazhong University of Science and TechnologyWuhanChina

High purity ammonium metavanadate(NH_(4)VO_(3))is the most vital chemical to produce V2O5,VO2,VN alloy,VFe alloy and VOSO4,which have some prospective applications for high strength steel,smart window,infrared detector and imaging,large scale energy storage ***_(4)VO_(3)is usually produced by spontaneous crystallization from the aqueous solution due to its sharp dependence of solubility on the ***,hazardous chemicals in industrial effluent,include phosphorate,silicate and arsenate,causing severe damage to the *** this work,these impurities are selectively precipitated onto inorganic flocculants,while the vanadate dissolved in an aqueous solution keeps almost ***,high purity NH_(4)VO_(3)is produced by the crystallization from the purified *** screening various flocculants and precipitating parameters,polyaluminum sulfate with an optimal amount of 50 g/L,is demonstrated to selectively remove phosphorate,silicate and arsenate,corresponding to the removing efficiency of 93.39%,97.11%and 88.31%,***_(4)VO_(3)from the purified solution holds a purity of 99.21%,in comparison with 98.33%in the product from the crude *** purifying technology cannot only produce NH_(4)VO_(3)with high added value,but also reduce the environmental pollution of waste liquid.

关键词： Ammonium metavanadate flocculating agent phosphate arsenate cooling precipitation vanadium slag bayer alumina liquor

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A strategic flight conflict avoidance approach based on a memetic algorithm

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Chinese Journal of Aeronautics 2014年第1期27卷 93-101页

作者： Guan Xiangmin Zhang Xuejun Han Dong Zhu Yanbo Lv Ji Su Jing School of Electronic and Information Engineering Beihang University National Key Laboratory of CNS/ATM Beihang University Aviation Data Communication corporation

Conflict avoidance （CA） plays a crucial role in guaranteeing the airspace safety. The cur- rent approaches, mostly focusing on a short-term situation which eliminates conflicts via local adjust- ment, cannot provide a global solution. Recently, long-term conflict avoidance approaches, which are proposed to provide solutions via strategically planning traffic flow from a global view, have attracted more attentions. With consideration of the situation in China, there are thousands of flights per day and the air route network is large and complex, which makes the long-term problem to be a large-scale combinatorial optimization problem with complex constraints. To minimize the risk of premature convergence being faced by current approaches and obtain higher quality solutions, in this work, we present an effective strategic framework based on a memetic algorithm （MA）, which can markedly improve search capability via a combination of population-based global search and local improve- ments made by individuals. In addition, a specially designed local search operator and an adaptive local search frequency strategy are proposed to improve the solution quality. Furthermore, a fast genetic algorithm （GA） is presented as the global optimization method. Empirical studies using real traffic data of the Chinese air route network and daily flight plans show that our approach outper- formed the existing approaches including the GA .based approach and the cooperative coevolution based approach as well as some well-known memetic algorithm based approaches.

关键词： Air traffic control Combinatorial optimization Conflict avoidance Genetic algorithm Memetic algorithm

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Extraction and separation of nickel and cobalt from saprolite laterite ore by microwave-assisted hydrothermal leaching and chemical deposition

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International Journal of Minerals,Metallurgy and Materials 2013年第7期20卷 612-619页

作者： Yan Zhao Jian-ming Gao Yi Yue Ben Peng Zai-qing Que Min Guo Mei Zhang State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological Engineering University of Science and Technology Beijing China Metallurgical Group corporation

Extraction and separation of nickel and cobalt from saprolite laterite ore were studied by using a method of microwave-assisted hydrothermal leaching and chemical deposition. The effects of leaching temperature and time on the extraction efficiencies of Ni2＋ and Co2＋ were investigated in detail under microwave conditions. It is shown that the extraction efficiencies of Ni2＋ and Co2＋ from the ore pre-roasted at 300℃ for 5 h were 89.19% and 61.89% when the leaching temperature and time were about 70℃ and 60 min, respectively. For the separation process of Ni and Co, the separation of main chemical components was performed by adjusting the pH values of sulfuric leaching solutions using a NaOH solution based on the different pH values of precipitation for metal hydroxides. The final separation efficiencies of Ni and Co were 77.29% and 65.87%, respectively. Furthermore, the separation efficiencies of Fe of 95.36% and Mg of 92.2% were also achieved at the same time.

关键词： laterites hydrometallurgy nickel metallurgy cobalt metallurgy microwave heating leaching chemicaldeposition

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Study on dispersion characteristics of terahertz waves in helical waveguides

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Chinese Physics B 2020年第11期29卷 386-390页

作者： Jin-Hai Sun Shao-Hua Zhang Xu-Tao Zhang He Cai Yong-Qiang Liu Zeng-Ming Chao Science and Technology on Electromagnetic Scattering Laboratory Beijing 100854China China Aerospace System Engineering corporation Beijing 100070China

Corresponding to the atmospheric transmission windows of the electromagnetic spectrum in the low terahertz range,the mode coupling and dispersion characteristics of two helically corrugated waveguides(HCW)in the frequency ranges of 90 GHz-100 GHz and 260 GHz-265 GHz are *** analytic calculations and numerical simulations,dispersion curves and structural parameters of the two frequency ranges waveguides are obtained.A novel method was proposed to obtain the dispersion of the HCW from the eigenwave solution using a periodic boundary *** HCW in a frequency range of 90 GHz-100 GHz was fabricated and its dispersion performance was *** comparing the measured results with the theoretical and the simulated results,the validity of the analytical and simulation method is *** to our machining capability,the dispersion of the 260 GHz-265 GHz HCW was only simulated and calculated and it was found that the results agree well with each other.

关键词： coupling coefficient dispersion curves gyrotron traveling wave tube(gyro-TWT) helical waveguide

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Comparison between dynamic programming and genetic algorithm for hydro unit economic load dispatch

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Water Science and Engineering 2014年第4期7卷 420-432页

作者： Bin XU Ping-an ZHONG Yun-fa ZHAO Yu-zuo ZHU Gao-qi ZHANG College of Hydrology and Water Resources Hohai University National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University China Three Gorges corporation Datang Yantan Hydropower corporation Yellow River Engineering Consulting Co. Ltd.

The hydro unit economic load dispatch （ELD） is of great importance in energy conservation and emission reduction. Dynamic programming （DP） and genetic algorithm （GA） are two representative algorithms for solving ELD problems. The goal of this study was to examine the performance of DP and GA while they were applied to ELD. We established numerical experiments to conduct performance comparisons between DP and GA with two given schemes. The schemes included comparing the CPU time of the algorithms when they had the same solution quality, and comparing the solution quality when they had the same CPU time. The numerical experiments were applied to the Three Gorges Reservoir in China, which is equipped with 26 hydro generation units. We found the relation between the performance of algorithms and the number of units through experiments. Results show that GA is adept at searching for optimal solutions in low-dimensional cases. In some cases, such as with a number of units of less than 10, GA＇s performance is superior to that of a coarse-grid DP. However, GA loses its superiority in high-dimensional cases. DP is powerful in obtaining stable and high-quality solutions. Its performance can be maintained even while searching over a large solution space. Nevertheless, due to its exhaustive enumerating nature, it costs excess time in low-dimensional cases.

关键词： hydro unit economic load dispatch dynamic programming genetic algorithm numerical experiment

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High Oxygen Nanocomposite Barrier Films Based on Xylan and Nanocrystalline Cellulose

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Nano-Micro Letters 2010年第4期2卷 235-241页

作者： Amit Saxena Thomas J.Elder Jeffrey Kenvin Arthur J.Ragauskas School of Chemistry and Biochemistry Georgia Institute of Technology USDA-Forest Service Southern Research Station Micromeritics Instrument corporation

The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan,sorbitol and nanocrystalline *** morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more open structure as compared to xylan-sorbitol films containing sulfonated nanocrystalline *** average pore diameter,bulk density,porosity and tortuosity factor measurements of control xylan films and nanocomposite xylan films were examined by mercury intrusion porosimetry *** films reinforced with nanocrystalline cellulose were denser and exhibited higher tortuosity factor than the control xylan *** xylan films had average pore diameter,bulk density,porosity and tortuosity factor of 0.1730 μm,0.6165 g/ml,53.0161% and 1.258,respectively as compared to xylan films reinforced with 50% nanocrystalline cellulose with average pore diameter of 0.0581 μm,bulk density of 1.1513 g/ml,porosity of 22.8906% and tortuosity factor of *** transmission rate tests demonstrated that films prepared with xylan,sorbitol and 5%,10%,25% and 50% sulfonated nanocrystalline cellulose exhibited a significantly reduced oxygen permeability of 1.1387,1.0933,0.8986 and 0.1799 cm^3×μm/m^2×d×k Pa respectively with respect to films prepared solely from xylan and sorbitol with a oxygen permeability of 189.1665 cm^3×μm/m^2×d×k *** properties suggested these nanocomposite films have promising barrier properties.

关键词： Nanocomposites Xylan Nanocrystalline cellulose Oxygen barrier

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