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Fuzzy adaptive robust control for space robot considering the effect of the gravity

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Chinese Journal of Aeronautics 2014年第6期27卷 1562-1570页

作者： Qin Li Liu Fucai Liang Lihuan Gao Jingfang Key Lab of Industrial Computer Control Engineering of Hebei Province Yanshan University

Space robot is assembled and tested in gravity environment, and completes on-orbit service（OOS） in microgravity environment. The kinematic and dynamic characteristic of the robot will change with the variations of gravity in different working condition. Fully considering the change of kinematic and dynamic models caused by the change of gravity environment, a fuzzy adaptive robust control（FARC） strategy which is adaptive to these model variations is put forward for trajectory tracking control of space robot. A fuzzy algorithm is employed to approximate the nonlinear uncertainties in the model, adaptive laws of the parameters are constructed, and the approximation error is compensated by using a robust control algorithm. The stability of the control system is guaranteed based on the Lyapunov theory and the trajectory tracking control simulation is performed. The simulation results are compared with the proportional plus derivative（PD） controller, and the effectiveness to achieve better trajectory tracking performance under different gravity environment without changing the control parameters and the advantage of the proposed controller are verified.

关键词： Fuzzy adaptive Microgravity Robustness Space robot Trajectory tracking control

Tranylcypromine upregulates Sestrin 2 expression to ameliorate NLRP3-related noise-induced hearing loss

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Neural Regeneration research 2025年第5期20卷 1483-1494页

作者： Xihang Chen Zhifeng Chen Menghua Li Weiwei Guo Shuolong Yuan Liangwei Xu Chang Lin Xi Shi Wei Chen Shiming Yang Senior Department of Otolaryngology Head and Neck Surgery Chinese PLA General HospitalChinese PLA Medical SchoolBeijingChina State Key Laboratory of Hearing and Balance Science BeijingChina national Clinical research Center for Otolaryngologic Diseases BeijingChina Key Laboratory of Hearing Science Ministry of EducationBeijingChina Beijing Key Laboratory of Hearing Impairment Prevention and Treatment BeijingChina Department of Otorhinolaryngology Head and Neck Surgery The First Affiliated Hospital of Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Otolaryngology Head and Neck Surgery The 940th Hospital of Joint Logistics Support Force of Chinese PLALanzhouGansu ProvinceChina Key Laboratory of Tropical Biological Resources of Ministry of Education School of Pharmaceutical SciencesHainan UniversityHaikouHainan ProvinceChina Academician Workstation of Hainan University School of Pharmaceutical SciencesYazhou BaySanyaHainan ProvinceChina

Noise-induced hearing loss is the primary non-genetic factor contributing to auditory ***,there are currently no effective pharmacological interventions for patients with noise-induced hearing ***,we present evidence suggesting that the lysine-specific demethylase 1 inhibitor–tranylcypromine is an otoprotective agent that could be used to treat noise-induced hearing loss,and elucidate its underlying regulatory *** established a mouse model of permanent threshold shift hearing loss by exposing the mice to white broadband noise at a sound pressure level of 120 d B for 4 *** found that tranylcypromine treatment led to the upregulation of Sestrin2(SESN2)and activation of the autophagy markers light chain 3B and lysosome-associated membrane glycoprotein 1 in the cochleae of mice treated with *** noise exposure group treated with tranylcypromine showed significantly lower average auditory brainstem response hearing thresholds at click,4,8,and 16 k Hz frequencies compared with the noise exposure group treated with *** findings indicate that tranylcypromine treatment resulted in increased SESN2,light chain 3B,and lysosome-associated membrane glycoprotein 1 expression after noise exposure,leading to a reduction in levels of 4-hydroxynonenal and cleaved caspase-3,thereby reducing noise-induced hair cell ***,immunoblot analysis demonstrated that treatment with tranylcypromine upregulated SESN2 expression via the autophagy *** treatment also reduced the production of NOD-like receptor family pyrin domaincontaining 3(NLRP3)*** conclusion,our results showed that tranylcypromine treatment ameliorated cochlear inflammation by promoting the expression of SESN2,which induced autophagy,thereby restricting NLRP3-related inflammasome signaling,alleviating cochlear hair cell loss,and protecting hearing *** findings suggest that inhibiting lysine-specific demethylase 1 is a

关键词： 4-hydroxynonenal apoptosis autophagy cleaved caspase-3 inflammation NOD-like receptor family pyrin domain-containing 3(NLRP3) noise-induced hearing loss oxidative stress Sestrin2 tranylcypromine

Densification,microstructure,and fracture behavior of TiC/Si_3N_4 composites by spark plasma sintering

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Rare Metals 2008年第3期27卷 315-319页

作者： BAI Ling GE Changchun SHEN Weiping MAO Xiaodong ZHANG Ke Laboratory of Special Ceramics and Powder Metallurgy University of Science and Technology Beijing Beijing 100083 China

TiC/Si3N4 composites were prepared using the β-Si3N4 powder synthesized by self-propagating high-temperature synthesis （SHS） and 35 wt.% TiC by spark plasma sintering. Y2O3 and Al2O3 were added as sintering additives. The almost full sintered density and the highest fracture toughness （8.48 MPa·m1/2） values of Si3N4-based ceramics could be achieved at 1550℃. No interfacial interactions were noticeable between TiC and Si3N4. The toughening mechanisms in TiC/Si3N4 composites were attributed to crack deflection, microcrack toughening, and crack impedance by the periodic compressive stress in the Si3N4 matrix. However, increasing microcracks easily led to excessive connection of microcracks, which would not be beneficial to the strength.

关键词： silicon nitride titanium carbide spark plasma sintering (SPS) microstructure fracture behavior

Interlayer engineering for titanium clad steel by hot roll bonding

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Journal of Iron and Steel research International 2018年第7期25卷 739-745页

作者： Xi-yang Chai Tao Pan Feng Chai Xiao-bing Luo Hang Su Zhi-gang Yang Cai-fu Yang Department of Structural Steels Central Iron and Steel Research Institute Beijing 100081 China School of Materials Science and Engineering Tsinghua University Beijing 100084 China

Hot roll bonding was carried out between commercially pure titanium TA2 and high-strength low-alloy steel Q390 using pure Nb or Mo interlayer at 950 ~C with a total reduction ratio of 86.7%. Interfacial microstructure and bonding properties of titanium clad steel plates were investigated by electron microscopy and mechanical tests. The results showed β-Ti, TiC and Fe2Ti reaction phases were generated at Ti/steel interface for the clad plates with no interlayer. Inserting Nb or Mo interlayer can effectively suppress the formation of brittle phases, while the weak bonding joint transferred to Nb/steel or Mo/steel interface. And some micro-voids were found at the interface of Nb/steel and Mo/steel. The improved shear strength of clad plates with Nb interlayer might be attributed to the elimination of brittle phases at bonding interface. The small size and little quantities of the micro-voids at Nb/steel interface had a relatively weak effect on shear strength. However, the large number and big size of micro-voids were responsible for the degradation of shear strength for the clad plates with Mo interlayer.

关键词： Titanium clad steel Interlayer - Interfacial microstructure Brittle phase Micro-void

Influence of crystal structure and formation energies of impurities (Mg, Zn and Ca) in zinc blende GaN

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中国有色金属学会会刊：英文版 2006年第B2期16卷 854-857页

作者：熊志华江风益万齐欣饶建平 research Center for Luminescence Materials and Devices of Education MinistryNanchang University Nanchang 330047China

First-principles calculations on neutral metal impurities (Mg, Zn and Ca) in zinc blende GaN were studied. Formation energies were calculated for substitution on the gallium site, the nitrogen site and incorporation in the octahedral interstitial site and the tetrahedral interstitial sites. The calculated results show that the major defects studied have a high formation energy in excess of 5 eV, and the gallium substitutional site is favorable for incorporation. MgGa has particularly low formation energy 1.19 eV and can be expected to incorporate readily into GaN. The local crystal structural changes around the impurity in the lattice were studied after metal atoms occupying the gallium substitutional site. It shows that the lattice constant becomes bigger and the tetrahedral angle between impurities and its nearest N atom becomes smaller mainly due to the extended M-N bond length and big size of impurities atoms, which results in a local lattice distortion. The Zn-N (2.04 A) bond strength is the smallest among the three impurities which raises the formation energy. CaGa is unfavorable due to a large size mismatch in spite of a large bond strength (2.25 A). The calculated results identify the two key factors determining impurities incorporation in zinc blende GaN: the atomic size of impurities comparing to that of host atoms and the bond strength between the impurities and its neighbors. The results are in well agreement with other calculated and experimental results.

关键词：闪锌矿型氮化镓杂质晶体结构晶体缺陷形成能

A Retrieval Algorithm of Sheet Metal Parts Based on Relationships of Features

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Chinese Journal of Aeronautics 2012年第3期25卷 453-472页

作者： WANG Dawei YAN Guangrong LEI Yi ZHANG Jiaying School of Mechanical Engineering and Automation Beihang University Beijing 100191. China Modern Education Center. Shandong University of Science and technology. Ta ian 271019. china

With the rapid increase in the number of three-dimensional （3D） models each year, to quickly and easily find the part desired has become a big challenge of enterprises. Meanwhile, many methods and algorithms have been proposed for part retrieval. However, most of the existing methods are designed lbr mechanical parts, and can not be well worked for sheet metal part re- trieval. An approach to feature-based retrieval of sheet metal parts is presented. Firstly, the features frequently used in sheet metal part design are chosen as the ＂＇key words＂ in retrieval. Based on those features, a relative position model is built to express the different relationships of the features in 3D space. Secondly, a description method of the model is studied. With the descrip- tion method the relative position of features in sheet metal parts can be expressed by four location description matrices. Thirdly, based on the relative position model and location description matrices, the equivalent definition of relationships of two feature groups is given which is the basis to calculate the similarity of two sheet metal parts. Next, the tbrmula of retrieval algorithm for sheet metal parts is given. Finally, a prototype system is developed to test and verify the effectiveness of the retrieval method suggested. Experiments verify that the new method is able to meet the requirements of searching sheet metal parts and possesses potentials in practical application.

关键词： CAD sheet metal retrieval algorithm features search 3D model

Vapor pressure and thermochemical properties of ZrCl4 for ZrC coating of coated fuel particles

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中国有色金属学会会刊：英文版 2008年第3期18卷 728-732页

作者：刘超刘兵邵友林李自强唐春和 Institute of Nuclear and New Energy technology Tsinghua University

Vapor pressure of zirconium tetrachloride(ZrCl4) under vacuum and an argon pressure of 1×105 Pa was measured. The thermochemical changes of ZrCl4 during evaporation were studied by thermogravimetry-differential thermal analysis(TG-DTA), X-ray diffractometry(XRD), scanning electron microscopy(SEM) and energy-dispersive X-ray(EDX) analysis. At the same temperature, vapor pressures of ZrCl4 under vacuum and an argon pressure of 1×105 Pa are approximately the same. The vapor pressure exceeds 1×105 Pa at 340 ℃, which is high enough for ZrC coating of coated fuel particles. ZrCl4 sample is hydrolyzed to some extent to give ZrO2 and HCl, which however, has little influence on vapor pressure of ZrCl4 at high temperature. No ZrCl3 and Cl2 are produced by decomposition of ZrCl4 during evaporation, which is confirmed by thermodynamic calculation.

关键词：汽压热化学转变 ZrC敷料燃烧颗粒

Effects of the two-step ageing treatment on the microstructure and properties of 7B04 alloy pre-stretched thick plates

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Rare Metals 2007年第3期26卷 193-199页

作者： LI Zhihui XIONG Baiqing ZHANG Yong ＇an ZHU Baohong WANG Feng LIU Hongwei State Key Laboratory for Fabrication and Processing of Nonferrous Metals General Research Institute for Nonferrous Metals Beijing 100088 China

The effects of the two-step ageing parameters （temperature and time） on the mechanical properties and electrical conductivity of 7B04 （A1-Zn-Mg-Cu） pre-stretched thick plates were studied. The results reveal that the initial T1 ageing contributes a major increase of the tensile strength, and the 0.2% proof stress value reaches 482 MPa after ageing for 7 h at 115℃. Behavioral differences in the tensile properties of the alloy after the two-step ageing treatment were less with the first-step ageing at 115~C for different time periods （7, 14, and 21 h）. The effects of the second ageing parameters on the properties and microstructure of the 7B04 alloy were remarkable. TEM analysis of the samples aged at Temper I （7 h at 115℃ ＋ 12 h at 160℃） and Temper II （7 h at 115℃ ＋ 16 h at 165℃） indicates that two kinds of phases, i.e. 11＇ and 11 phases, precipitate from the matrix and efficiently improve the tensile strength of the alloy, and the grain boundary precipitates are coarse and discrete. There are obvious precipitate free zones （PFZs） along the grain boundary in the microstructure of the alloy after the two-step ageing treatment.

关键词： 7B04 alloy two-step ageing mechanical properties electrical conductivity microstructure

Steam effects over Pd/Ce_(0.67)Zr_(0.33)O_2 three-way catalyst

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Journal of Rare Earths 2011年第3期29卷 217-224页

作者：王建强沈美庆王军王务林 Key Laboratory for Green Chemical technology of State Education Ministry School of Chemical Engineering&TechnologyTianjin University china Automotive technology&research Center State Key Laboratory of Engines Tianjin University

In the purification process of automobile exhaust,existing water plays an important role as an oxidant,which converts CO and hydrocarbons（HCs） by the water-gas shift（WGS） and the steam reforming（SR） reactions,respectively,especially at high *** it is major component of the exhaust which can affect significantly the thermal stability of the three-way *** experiments were carried out close to the real operation conditions（GHSV,concentration,etc.） with a Pd/Ce0.67Zr0.33O2 catalyst supplying information on the CO and C3H8 oxidation reactions in feedstream formed by different reactant *** obtained results showed that the activity of the CO and C3H8 oxidation was promoted by the addition of steam due to the WGS and SR *** WGS and SR reaction were competitive under oxygen-lean *** kinetic analysis was considered for WGS and SR reactions.

关键词： three-way catalysts water-gas shift steam reforming turnover frequency compensation effect rare earths