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EFFECT OF MATRIX STRENGTHENING ON SLIDING WEAR PROPERTIES OF SiCp/2024Al COMPOSITES

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中国有色金属学会会刊：英文版 1998年第4期8卷 25-30页

作者： Ma, Zongyi Liang, Yan'an Lu, Yuxiong bi, jing Inst of Metal Research Chinese Acad of Sciences Shenyang China

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关键词： composite aluminum SiC wear particulate

A NEW UNSTEADY THREE DIMENSIONAL MODEL FOR MACROMOLECULAR TRANSPORT AND WATER FILTRATION ACROSS THE ARTERIAL WALL

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Applied Mathematics and Mechanics(English Edition) 2001年第10期22卷 1155-1172页

作者： HUANG Hao(黄浩) wen Gong-bi(温功碧) Department of Mechanics and Engineering Science State Key Laboratory for Turbulence and Complicated System Research Peking University Beijing 100871 P R China Department of Mechanics and Engineering Science State Key Laboratory for Turbulence and Complicated System Research Peking University Beijing 100871 P R China

A new unsteady three-dimensional convective-diffusive mathematical model for the transportation of macromolecules and water across the arterial wall was proposed . After the formation of leaky junctions due to the mitosis of endothelial cell of the arterial wall, the macromolecular transport happens surrounding the leaky cells. The arterial wall was divided into four layers: the endothelial layer, the subendothelial intima, the internal elastic lamina and the media for the convenience of research. The time-dependent concentration growth,the effect of the shape of endothelial cell and the effect of physiological parameters were analyzed. The analytical solution of velocity field and pressure field of water flow across the arterial wall were obtained; and concentration distribution of three macromolecules ; LDL,HRP and Albumin, were calculated with numerical simulation method. The new theory predicts, the maximum and distribution areas of time dependent concentration with round shape endothelial cell are both larger than that with ellipse-shape endothelial cell. The model also predicts the concentration growth is much alike that of a two-dimensional model and it shows that the concentration reaches its peak at the leaky junction where atherosclerotic formation frequently occurs and falls down rapidly in a limited area beginning from its earlier time growth to the state when macromolecular transfer approaches steadily. These predictions of the new model are in agreement with the experimental observation for the growth and concentration distribution of LDL and Albumin.

关键词： unsteady three-dimensional model flow across the arterial wall macromolecular transportation atherosclerosis concentration distribution

An unexpected approach to enhance specific surface area and mesopore amount of polyaniline by Zn doping

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Rare Metals 2024年第9期43卷 4585-4594页

作者： Zhi-Da Zhu Yu-Zhe Han Xiao-bi jing School of Mechanical Engineering Yangzhou UniversityYangzhou 225127China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Poly-p-anisidine could be easily fabricated via the oxidative polymerization reaction of p-anisidine using H_(2)O_(2)as the green *** was unexpectedly found that zinc doping could significantly improve the adsorption ability of the material versus heavy metals such as Pb,Cu,Pd,Ag and *** of nitrogen adsorption–desorption experiments demonstrated that Zn doping could enhance the specific surface area and mesopore amount of the prepared material,which might facilitate its absorption to *** work not only provides a novel material for the treatment of heavy metal-polluted water but also leads to a nice mesoporous catalyst support for environment protection and organic synthesis,*** Zn-doped poly-panisidine can be employed as the catalyst support to prepare Cu@PANI-OMe/Zn or Pd@PANI-OMe/Zn for the oxidative degradation reaction of phenol or Suzuki–Miyaura coupling reactions,*** discloses a new strategy for fabricating the mesoporous polyaniline materials with profound application potential.

关键词： Surfaces Porous materials Rare metal concentration Adsorption Catalysis

Baseline distribution optimization and missing data completion in wavelet-based CS-Tomo SAR

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Science China(Information Sciences) 2018年第4期61卷 164-172页

作者： Hui bi Jianguo LIU bingchen ZHANG wen HONG Science and Technology on Microwave Imaging Laboratory Institute of ElectronicsChinese Academy of Sciences University of Chinese Academy of Sciences Department of Earth Science and Engineering Imperial College London

In this paper, we propose a coherence of measurement matrix-based baseline distribution optimization criterion, together with an L1 regularization missing data completion method for unobserved baselines(not belonging to the actual baseline distribution), to facilitate wavelet-based compressive sensingtomographic synthetic aperture radar imaging(CS-Tomo SAR) in forested areas. Using M actual baselines,we first estimate the optimal baseline distribution with N baselines(N > M), including N-M unobserved baselines, via the proposed coherence criterion. We then use the geometric relationship between the actual and unobserved baseline distributions to reconstruct the transformation matrix by solving an L1 regularization problem, and calculate the unobserved baseline data using the measurements of actual baselines and the estimated transformation matrix. Finally, we exploit the wavelet-based CS technique to reconstruct the elevation via the completed data of N baselines. Compared to results obtained using only the data of actual baselines, the recovered image based on the dataset obtained by our proposed method shows higher elevation recovery accuracy and better super-resolution ability. Experimental results based on simulated and real data validated the effectiveness of the proposed method.

关键词： tomographic synthetic aperture radar imaging(Tomo SAR) compressive sensing(CS) baseline distribution optimization coherence of measurement matrix

Operator-Based Robust Nonlinear Control for SISO and MIMO Nonlinear Systems With PI Hysteresis

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IEEE/CAA Journal of Automatica Sinica 2018年第2期5卷 523-530页

作者： Shuhui bi Lei Wang Shengjun wen Mingcong Deng School of Electrical Engineering University of Jinan Jinan 250022 China Shandong Provincial Key Laboratory of Automotive Electronics Technology Institute of Automation Shandong Academy of Sciences Qilu University of Technology (Shandong Academy of Sciences) Jinan 250014 China Department of Electronic and Information Engineering Zhongyuan University of Technology Zhengzhou 450007 China Department of Electrical and Electronic Engineering Tokyo University of Agriculture and Technology 2-24-16 Nakacho KoganeiTokyo 184-8588 Japan IEEE

In this paper, operator based robust nonlinear control for single-input single-output(SISO) and multi-input multi-output(MIMO) nonlinear uncertain systems preceded by generalized Prandtl-Ishlinskii(PI) hysteresis is considered respectively. In detail, by using operator based robust right coprime factorization approach, the control system design structures including feedforward and feedback controllers for both SISO and MIMO nonlinear uncertain systems are given, *** which, the controller design includes the information of PI hysteresis and its inverse, and some sufficient conditions for the controllers in both SISO and MIMO systems should be satisfied are also derived respectively. Based on the proposed conditions, influence from hysteresis is rejected, the systems are robustly stable and output tracking performance can be ***, the effectiveness of the proposed method is confirmed by numerical simulations.

关键词： Index Terms-Generalized PI hysteresis operator based robustright coprime factorization robust nonlinear control.

Fault Feature Extraction of Diesel Engine Based on bispectrum Image Fractal Dimension

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 216-226页

作者： Jian Zhang Chang-wen Liu Feng-Rong bi Xiao-Bo bi Xiao Yang State Key Laboratory of Engines Tianjin University

Fault feature extraction has a positive effect on accurate diagnosis of diesel engine. Currently, studies of fault feature extraction have focused on the time domain or the frequency domain of signals. However, early fault signals are mostly weak energy signals, and time domain or frequency domain features will be overwhelmed by strong back?ground noise. In order consistent features to be extracted that accurately represent the state of the engine, bispectrum estimation is used to analyze the nonlinearity, non?Gaussianity and quadratic phase coupling(QPC) information of the engine vibration signals under different conditions. Digital image processing and fractal theory is used to extract the fractal features of the bispectrum pictures. The outcomes demonstrate that the diesel engine vibration signal bispectrum under different working conditions shows an obvious differences and the most complicated bispectrum is in the normal state. The fractal dimension of various invalid signs is novel and diverse fractal parameters were utilized to separate and characterize them. The value of the fractal dimension is consistent with the non?Gaussian intensity of the signal, so it can be used as an eigenvalue of fault diagnosis, and also be used as a non?Gaussian signal strength indicator. Consequently, a symptomatic approach in view of the hypothetical outcome is inferred and checked by the examination of vibration signals from the diesel motor. The proposed research provides the basis for on?line monitoring and diagnosis of valve train faults.

关键词： Engine fault diagnosis bispectrum image processing Fractal Signal processing

Design of Tough, yet Strong, Heat-resistant PLA/PBAT Blends with Reconfigurable Shape Memory Behavior by Engineering Exchangeable Covalent Crosslinks

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Chinese Journal of Polymer Science 2023年第12期41卷 1868-1878,I0007页

作者： Xiao-wen Zhou jing Huang Xu-Hui Zhang Ting Li Yang Wang Shi-Bo Wang bi-Hua Xia Wei-Fu Dong The Key Laboratory of Synthetic and biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China

Polylactide(PLA)has often been blended with biodegradable poly(butylene adipate-co-terephthalate)(PBAT)to improve its ***,the strength and heat resistance of PLA are always ***,exchangeable hydroxyl-ester crosslinks are constructed in PLA/PBAT blends by successively introducing a tertiary amine-containing polyol,bis-(2-hydroxyethyl)amino-tris(hydroxymethyl)methane(BTM)and 4,4’-diphenylmethane diisocyanate(MDI)via reactive *** can react with both PLA and PBAT by transesterification,generating PLA or PBAT chains with terminal or pendant hydroxyl groups,which can then react with MDI to form *** internal catalysis of tertiary amine moiety in BTM,transesterification between the residual hydroxyl groups and ester bonds can occur at high temperatures,endowing the PLA/PBAT network with vitrimeric *** to the transesterification and chain extension reactions with MDI between PLA and PBAT,the interfacial adhesion is greatly *** a result of the excellent interfacial adhesion and the network structure,the prepared PLA/PBAT blends show greatly enhanced heat resistance and toughness(more than 40 times that of PLA)while maintaining high stiffness comparable to ***,the prepared PLA/PBAT blends exhibit promising reconfigurable shape memory *** present work provides a new and facile way to achieve high-performance and functional biodegradable polymeric materials.

关键词： Polylactide Dynamic covalent bonds Strengthening and toughening Heat resistance Shape memory

Particulate organic carbon export flux by ^(234)Th/^(238)U disequilibrium in the continental slope of the East China Sea

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Acta Oceanologica Sinica 2013年第10期32卷 67-73页

作者： bi Qianqian DU Jinzhou WU Ying ZHOU jing ZHANG jing State Key Laboratory of Estuarine and Coastal Research East China Normal University

234Th is widely used to quantify the magnitude of upper ocean particulate organic carbon （POC） export in oceans. In the present work, the rates of particulate organic carbon export were measured based on the distribution patterns of 234Th/238U disequilibrium in the water column within the continental slope of the East China Sea （ECS） during May 2011. The profiles of particulate and dissolved 234Th activities at all three stations showed a relative deficit with respect to 238U in the upper 100 m of the water column. The dissolved 234Th scavenging rates and the particulate 234Th removal rates and their residence times were calculated by a one-dimensional steady state model. The results showed that the dissolved a34Th scavenging rates and the particulate 234Th removal rates ranged from 12.4-61.4 dpm/（m3.d） and from 3.8-21.8 dpm/（m3.d）, respectively. The residence times of dissolved and particulate 234Th were in the range of 3.4-158 d and 63.7- 96.5 d, respectively. Combined with the measurement of POC/Z34Th ratios of suspended particles, POC export flux （calculated by carbon） from the euphotic zone was estimated in the study region, which ranged from 4.14-14.7 mmol/（m2 .d）, with an average of 8.21 mmol/（m3.d）, occupying 35% of the prime productivity in the study area. The results of this study can provide new information for better understanding the carbon biogeochemical cycle within the continental slope of the ECS.

关键词： 234Th/238U disequilibrium residence time POC export East China Sea (ECS)

Mutation of Residue Arginine^18 of Cytochrome b559 α-Subunit and its Effects on Photosystem Ⅱ Activities in Chlamydomonas reinhardtii

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Journal of Integrative Plant biology 2007年第7期49卷 1054-1061页

作者： jing-jing Ma Liang-bi Li Yu-Xiang jing Ting-Yun Kuang Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of Sciences Beijing 100093 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

It has been known that arginine is used as the basic amino acid in the α-subunit of cytochrome bsss （Cyt bsss） except histidine. However, previous studies have focused on the function of histidine in the activities of photosystem （PS） Ⅱ and there are no reports regarding the structural and/or functional roles of arginine in PSll complexes. In the present study, two arginine18 （R18） mutants of Chlamydomonas reinhardtii were constructed using site-directed mutagenesis, in which R18 was replaced by glutamic acid （E） and glycine （G）. The results show that the oxygen evolution of the PSII complex in the R18G and R18E mutants was approximately 60% of wild-type （WT） levels and that, after irradiation at high light intensity, oxygen evolution for the PSll of mutants was reduced to zero compared with 40% in WT cells. The efficiency of light capture by PSll （Fv/Fm） of R18G and R18E mutants was approximately 42%-46% that of WT cells. Furthermore, levels of the α-subunit of Cyt bsss and PsbO proteins were reduced in thylakoid membranes compared with WT. Overall, these data suggest that R18 plays a significant role in helping Cyt bss9 maintain the structure of the PSll complex and its activity, although it is not directly bound to the heme group.

关键词： Chlamydomonas reinhardtii chloroplast transformation cytochrome b559 mutation photosystem Ⅱ.