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A novel fractional wavelet transform and its applications

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Science china(Information Sciences) 2012年第6期55卷 1270-1279页

作者： shi Jun,ZHANG NaiTong & LIU XiaoPing Communication Research center,{2. Institute of technology,harbin 150001,china 1. Communication Research center Harbin Institute of Technology Harbin 150001 China

The wavelet transform (WT) and the fractional Fourier transform (FRFT) are powerful tools for many applications in the field of signal ***,the signal analysis capability of the former is limited in the time-frequency *** the latter has overcome such limitation and can provide signal representations in the fractional domain,it fails in obtaining local structures of the *** this paper,a novel fractional wavelet transform (FRWT) is proposed in order to rectify the limitations of the WT and the *** proposed transform not only inherits the advantages of multiresolution analysis of the WT,but also has the capability of signal representations in the fractional domain which is similar to the *** with the existing FRWT,the novel FRWT can offer signal representations in the time-fractional-frequency ***,it has explicit physical interpretation,low computational complexity and usefulness for practical *** validity of the theoretical derivations is demonstrated via simulations.

关键词： time-frequency analysis wavelet transform multiresolution analysis fractional Fourier transform time-fractional-frquency analysis

Synthesis and magnetic properties of CdS/α-Fe_2._3 hierarchical nanostructures

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 997-1002页

作者： CHEN YuJin1,2.3, shi XiaoLing1, CAO MaoSheng1 & ZHU ChunLing4 1 School of Materials Science and Engineering, Beijing Institute of technology, Beijing 100081,{2. 2.Micro-Nano Technologies Research center, Hunan University, Changsha 410082.{2. 3 College of Science, harbin Engineering University, harbin 150001,{2. 4 College of Material Science and Chemical Engineering, harbin Engineering University, harbin 150001,{2. 1. School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China 2. Micro-Nano Technologies Research center Hunan University Changsha 410082 China 3. College of Science Harbin Engineering University Harbin 150001 China 4. College of Material Science and Chemical Engineering Harbin Engineering University Harbin 150001 China

CdS/α-Fe2.3 hierarchical nanostructures, where the CdS nanorods grow irregularly on the side surface of α-Fe2.3 nanorods, were synthesized via a three-step process. The diameters and lengths of CdS nanorods can be tuned by changing the ethylenediamine (EDA) and Cd ion concentrations. The magnetic investigations by superconducting quantum interference device indicate that the hierarchical nanostructures have an Morin transition at lower temperature (2.0 K) than that of the single bulk α-Fe2.3 materials (2.3 K). Importantly, the hierarchical nanostructures exhibit weakly ferromagnetic characteristics at 300 K. A sharp peak assigned to the surface trap induced emission are observed in room temperature PL spectra. Combining with the optoelectronic properties of CdS, the CdS/ α-Fe2.3 hierarchical nanostructures may be used as multi-functional materials for optoelectronic and magnetic devices.

关键词： α-Fe2.3 CdS hierarchical nanostructures magnetic properties

Study on Environmental Multi-parameter Sensor Based on MEMS

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稀有金属材料与工程 2006年第S3期 377-380页

作者： Hongquan Zhang~(1,3) Tong Zhang~2.Likai Sun~3 Yunbo shi~3 Jianying Guo~1 (1.harbin University of Science and {2.,harbin 150080,china) (2.Automobile Electronic Engineering {2. Research and Development center,harbin 150001,china) (3.Northeast Transducer {2. Research Institute,harbin 150001,china)

A new membrane type Al2.3micromachining material is *** develop an environmental multi-parameter detection micro-system,which implements the detection to temperature,humidity,wind speed,and *** test results illustrate that the heat-release unit in micro-system intercross greatly affects other sensing units on the *** study the method of etching process,which formed cavity to reduce the heat exchange efficiency and decrease temperature intercross effect.

关键词： Al2.3 membrane sensing unit environmental multi-parameter microsystem

Integrated Gas Sensor Based on MEMS

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稀有金属材料与工程 2006年第S3期 173-175页

作者： Hongquan Zhang~(1,3) Tong Zhang~2.Likai Sun~3 Yunbo shi~1 Jianying Guo~1 (1.harbin University of Science and {2.,harbin 150080,china) (2.Automobile Electronic Engineering {2. Research and Development center,harbin 150001,china) (3.Northeast Transducer {2. Research Institute,harbin 150001,china)

Integrated gas sensor suspending bridge style micro-structure has been developed on Al2.3new type membrane based on ***4gas sensing unit and CO gas sensing unit were fabricated separately on 4 unit array style suspending bridge *** have studied on time-sequence modulation form voltage pulse heating method which forms different work temperature conditions

关键词： Al2.3 membrane micro-structure gas sensor

Arylamine N-acetyltransferases: a new inhibitor of apoptosis in HepG2.cells

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第9期9卷 701-706页

作者： Yu-bin JI1,2. shi-yong GAO1,2.(1Postdoctoral Research Station of the Institute of Materia Medica, center for Life Sciences and Environmental Sciences, {2. University of Commerce, {2. 150076, china) (2.OE Engineering Research center of Natural Anticancer Drugs, {2. University of Commerce, {2. 150076, china) Postdoctoral Research Station of the Institute of Materia Medica Center for Life Sciences and Environmental Sciences Harbin University of Commerce Harbin 150076 China MOE Engineering Research center of Natural Anticancer Drugs Harbin University

Objective: To explore how arylamine N-acetyltransferases (NATs) is related to cell apoptosis. Methods: NAT activity in apoptotic HepG2.cells was measured using high performance liquid chromatography (HPLC); the apoptosis rate of HepG2.cells acted upon by an NAT inhibitor was measured using flow cytometry. Results: NAT activity was lowered in apoptotic HepG2.cells; apoptosis rate induced by camptothecin (CAM) increased after inhibition of NAT activity in HepG2.cells. Conclusion: NAT can inhibit apoptosis in HepG2.cells.

关键词： Arylamine N-acetyltransferases (NATs) Apoptosis HepG2 Camptothecin (CAM)

Study on Multi-enterprise Collaborative Resource Planning Based Process-oriented Decision Model

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武汉理工大学学报 2006年第S2期28卷 600-606页

作者： shi Jinhua~1 HE Yingying~2.LIU Jianmin~3 1.School of Management,harbin Institute of {2.,harbin 150001,china 2.Weihai Nongyou Software Company,Weihai 2.42.9,china 3.Weihai High-tech Pioneering Service center,Weihai 2.42.9,china School of Management Harbin Institute of TechnologyHarbin 150001China Weihai Nongyou Software Company Weihai 264209China Weihai High-tech Pioneering Service center Weihai 264209China

Aiming to share the information,knowledge and optimizing resource via collaborating with multiple external partners across their supply chains,the concept model and system framework of multi-enterprises collaborative resource planning (MECORP) are put *** there is Considerable pressure to improve the operation of MECORP system,their inherent complexity can make modelling a MECORP system a difficult *** there could be considerable benefits in designing MECORP taking into account the operation of the *** order to address the central research issue of developing of a methodology that can assist a manager in making decisions by modelling the operation of MECORP *** methodology called process-oriented deci- sion model (PODM) is presented in the *** uses an abstracted network to model MECORP *** MECORP system supported by PODM,can effective optimize the manifold resource,coordinate the relationship of multiple partners and assist deci- ***,an industry excample of MECORP system is described to illustrate the application of PODM.

关键词： collaboration decision multi-enterprises operation process resource planning

EXPERIMENTS AND SIMULATIONS OF A NEW DEVELOPED FORMING technology-SHEAR-EXTRUSION PROCESS OF COMPONENTS WITH BRANCHES

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Acta Metallurgica Sinica(English Letters) 2001年第3期14卷 212-218页

作者： H.L. Yang, D.C. Kang, Z.L. Zhang, X.H. Piao and Z.D. shi (National Die and Mold CAD Engineering Research center, Shanghai Jiaotong University, Shanghai 2.0030,{2.) (School of Materials Sci. & Eng., harbin Institute of technology, harbin 150001,{2.) National Die and Mold CAD Engineering Research center Shanghai Jiaotong University School of Materials Sci. & Eng. Harbin Institute of Technology

Shear-extrusion process and its forming parameters are proposed, whilst its laborsaving characteristic is utilized to forge large-size shutoff valve bodies on the middle-due press. This new process is intended for the manufacture of large-size forged tubular components with branches on the middle-due press. Experiments are carried out and processing parameters are obtained regarding the shear- extrusion process of a large-size shutoff valve body. Deformation and metal flow in the shear- extrusion process are investigated. In order to verify the laborsaving characteristic of this new process, some contrast experiments of extrusion force are performed between shear-extrusion and upsetting-extrusion for forming tubular components with branches. Based on rigid-plastic FEM, a plane-strain model is established to analyze shear-extrusion process of tubular components with branches. The analysis results by 2.dimensions FEM are comparatively well consistent with experimental results. Both simulated and experimental results show that this new forming process is feasible for forging large-size tubular components with branches on the middle-due press.

关键词： Metal extrusion Shearing Simulation Tubular steel structures

Effect of Modulus Heterogeneity on the Equilibrium Shape and Stress Field ofαPrecipitate in Ti-6Al-4V

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 1017-1028页

作者： Di Qiu Rongpei shi Materials Genome Institute Shanghai UniversityShanghai200444China School of Materials Science and Engineering Harbin Institute of TechnologyShenzhen518055China Shanghai Frontier Science center of Mechanoinformatics Shanghai UniversityShanghai200444China Zhejiang Laboratory Hangzhou311100China

For media with inclusions(e.g.,precipitates,voids,reinforcements,and others),the difference in lattice parameter and the elastic modulus between the matrix and inclusions cause stress concentration at the *** stress fields depend on the inclusions’size,shape,and distribution and will respond instantly to the evolving *** study develops a phase-field model concerningmodulus *** effect of modulus heterogeneity on the growth process and equilibrium state of theαplate in Ti-6Al-4V during precipitation is ***αprecipitate exhibits strong anisotropy in shape upon cooling due to the interplay of the elastic strain and interfacial *** calculated orientation of the habit plane using the homogeneous modulus ofαphase shows the smallest deviation fromthat of the habit plane observed in the experiment,compared to the case where the homogeneous modulus ofβphase is *** addition,the equilibrium volume ofαphase within the systemusing homogeneousβmodulus exhibits the largest dependency on the applied *** stress fields across theα/βinterface are further calculated under the assumption of modulus heterogeneity and compared to those using homogeneous modulus of eitherαorβ*** study provides an essential theoretical basis for developing mechanics models concerning systems with heterogeneous structures.

关键词： Elastic heterogeneity habit plane stress field titanium phase-field simulation

Neural Network Robust Control Based on Computed Torque for Lower Limb Exoskeleton

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 83-99页

作者： Yibo Han Hongtao Ma Yapeng Wang Di shi Yanggang Feng Xianzhong Li Yanjun shi Xilun Ding Wuxiang Zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beihang Goer(WeiFang)Intelligent Robot Co. Ltd.Beihang UniversityWeifangChina Research center of Satellite technology Harbin Institute of TechnologyHarbinChina Beijing Xinfeng Aerospace Equipment Co. LtdBeijingChina

The lower limb exoskeletons are used to assist wearers in various scenarios such as medical and industrial *** modeling errors of the exoskeleton in different application scenarios pose challenges to the robustness and stability of its control *** Radial Basis Function(RBF)neural network is used widely to compensate for modeling *** order to solve the problem that the current RBF neural network controllers cannot guarantee the asymptotic stability,a neural network robust control algorithm based on computed torque method is proposed in this paper,focusing on trajectory *** innovatively incorporates the robust adaptive term while introducing the RBF neural network term,improving the compensation ability for modeling *** stability of the algorithm is proved by Lyapunov method,and the effectiveness of the robust adaptive term is verified by the *** wearing the exoskeleton under different walking speeds and scenarios were carried out,and the results show that the absolute value of tracking errors of the hip and knee joints of the exoskeleton are consistently less than 1.5°and 2.5°,*** proposed control algorithm effectively compensates for modeling errors and exhibits high robustness.

关键词： Lower limb exoskeleton Model compensation RBF neural network Computed torque method