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Robust signal recovery algorithm for structured perturbation compressive sensing

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Journal of Systems engineering and Electronics 2016年第2期27卷 319-325页

作者： Youhua Wang Jianqiu Zhang school of Information science and technology Fudan UniversityShanghai 200433China science and technology on Analog integrated circuit Laboratory Chongqing 400060China

It is understood that the sparse signal recovery with a standard compressive sensing（CS） strategy requires the measurement matrix known as a priori. The measurement matrix is, however, often perturbed in a practical *** order to handle such a case, an optimization problem by exploiting the sparsity characteristics of both the perturbations and signals is formulated. An algorithm named as the sparse perturbation signal recovery algorithm（SPSRA） is then proposed to solve the formulated optimization problem. The analytical results show that our SPSRA can simultaneously recover the signal and perturbation vectors by an alternative iteration way, while the convergence of the SPSRA is also analytically given and guaranteed. Moreover, the support patterns of the sparse signal and structured perturbation shown are the same and can be exploited to improve the estimation accuracy and reduce the computation complexity of the algorithm. The numerical simulation results verify the effectiveness of analytical ones.

关键词： sparse signal recovery compressive sensing(CS) structured matrix perturbation

Precipitation behavior and martensite lath coarsening during tempering of T/P92 ferritic heat-resistant steel

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International Journal of Minerals,Metallurgy and Materials 2014年第5期21卷 438-447页

作者： Lin-qing Xu Dan-tian Zhang Yong-chang Liu Bao-qun Ning Zhi-xia Qiao Ze-sheng Yan Hui-jun Li State Key Lab of Hydaulic engineering Simulation and Safety School of Material Science and EngineeringTianjin University school of Materials science and engineering Tianjin University of Technology school of Mechanical engineering Tianjin University of Commerce

Tempering is an important process for T/P92 ferritic heat-resistant steel from the viewpoint of microstructure control, as it facili- tates the formation of final tempered martensite under serving conditions. In this study, we have gained deeper insights on the mechanism underlying the microstructural evolution during tempering treatment, including the precipitation of carbides and the coarsening of martensite laths, as systematically analyzed by optical microscopy, transmission electron microscopy, and high-resolution transmission electron mi- croscopy. The chemical composition of the precipitates was analyzed using energy dispersive X-ray spectroscopy. Results indicate the for- mation of M3C （cementite） precipitates under normalized conditions. However, they tend to dissolve within a short time of tempering, owing to their low thermal stability. This phenomenon was substantiated by X-ray diffraction analysis. Besides, we could observe the precipitation of fine carbonitrides （MX） along the dislocations. The mechanism of carbon diffusion controlled growth of M23C6 can be expressed by the Zener＇s equation. The movement of Y-junctions was determined to be the fundamental mechanism underlying the martensite lath coarsening process. Vickers hardness was estimated to determine their mechanical properties. Based on the comprehensive analysis of both the micro- structural evolution and hardness variation, the process of tempering can be separated into three steps.

关键词： ferritic steel heat resisting tempering precipitation martensite coarsening

A high sensitivity localized surface plasmon resonance sensor based on D-shaped photonic crystal fiber for low refractive index detection

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Optoelectronics Letters 2022年第7期18卷 425-429页

作者： PAN Honggang CAO Chuanbo ZHANG Ailing PAN Fei SUI Pengxia LIU Xinbo engineering Research Center of Optoelectronic Devices and Communication technology Ministry of EducationTianjin Key Laboratory of Thin Film Electronics and Communication DevicesSchool of Integrated Circuit Science and EngineeringTianjin University of TechnologyTianjin 300384China

In this paper,a localized surface plasmon resonance(LSPR)refractive index sensor based on photonic crystal fiber(PCF)is proposed to solve the problem of low refractive index analyte detection.31 silver nanowires are placed on the surface of the D-shaped PCF,which increases the contact area between the plasma material and the *** simulation results indicate that the maximum sensitivity of the sensor reaches 16400 nm/RIU,and the refractive index detection range is 1.26—*** is proved that the sensor has a good prospect in low refractive index detection.

关键词： fiber refractive shaped

Micro-displacement sensor based on an asymmetric wavy multimode fiber interferometer

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Optoelectronics Letters 2023年第3期19卷 134-138页

作者： LI Yuanzheng LI Yi MIAO Yinping WANG Fang HU Kai ZHANG Kailiang tianjin Key Laboratory of Film Electronic and Communication Devices School of Integrated Circuit Science and EngineeringEngineering Research Center of Optoelectronic Devices&Communication TechnologyMinistry of EducationTianjin University of TechnologyTianjin 300384China

We proposed a compact and tunable multimode interferometer(MMI)based on an asymmetric wavy fiber(AMWF),which has axial offset,off-center taper waist,and *** fabrication process only contains non-axis pulling processes of single-mode fiber on two close *** qualitative analyses and experiments verify the tunable multimode propagation of the *** results show a nonlinear wavelength response with increasing axis displacement from 0 to 120μ*** the range of 0—10μm,the sensitivity reaches the highest value of-1.33 nm/μ*** to its cost-effective,high-compact and tunable multimode propagation properties,the AMWF provides a promising platform for micro-nano photonic devices and optical sensing applications.

关键词： interferometer fiber multimode

Simultaneous synthesis of heat-integrated water networks by a nonlinear program:Considering the wastewater regeneration reuse

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Chinese Journal of Chemical engineering 2022年第4期35卷 402-411页

作者： Fangyou Yan Wei Li Jinli Zhang school of Chemical engineering and Material science Tianjin University of Science and TechnologyTianjin 300457China Key Laboratory for Green Chemical technology MOE School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Key Laboratory of Systems Bioengineering MOE School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Heat-integrated water network synthesis(HIWNS)has received considerable attention for the advantages of reducing water and energy *** is effective in water and energy *** integer non-linear programming(MINLP)is usually applied in *** this work,a novel nonlinear programming(NLP)was proposed for HIWNS by considering wastewater reuse and wastewater regeneration *** variables are changed to non-linear equation by the methods for identifying stream roles and denoting the existence of process *** model is tested by examples with single and multiple regeneration unit *** testing results showed that the NLP is an alternative method for HIWNS with wastewater reuse and regeneration reuse.

关键词： None-linear programming Heat-integrated water network synthesis Wastewater regeneration reuse

Magnetic entropy change and magnetic properties of LaFe_(11.5)Si_(1.5) after controlling the Curie temperature by partial substitution of Mn and hydrogenation

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Chinese Physics B 2016年第2期25卷 459-462页

作者：傅斌韩洁 school of Materials science and engineering Tianjin University of Technology Tianjin 300384 China College of science Tianjin University of Technology Tianjin 300384 China

Magnetic properties and magnetic entropy changes of La（Fe_（1-x）Mn_x）_（11.5）Si_（1.5）H_y compounds are investigated. Their Curie temperatures are adjusted to room temperature by partial Mn substitution for Fe and hydrogen absorption in 1-atm（1 atm = 1.01325×10~5Pa） hydrogen gas. Under a field change from 0 T to 2 T, the maximum magnetic entropy change for La（Fe_（0.99）Mn_（0.01））_（11.5）Si_（1.5）H_（1.61）is-11.5 J/kg. The suitable Curie temperature and large value of ？S_m make it an attractive potential candidate for the room temperature magnetic refrigeration application.

关键词： magnetic refrigeration Curie temperature (Tc) hydrogen absorption magnetocaloric effect(MCE)

Controlling the size of fragrance microcapsules using designed agitator paddles: Experiment and CFD simulation

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Particuology 2019年第2期17卷 38-45页

作者： Hongbin Zhao Xuening Fei Baolian Zhang Shuxing Zhao Guangmin Li Lingyun Cao school of Chemical engineering and technology Tianjin University Tianjin 300350 China school of science Tianjin Chengjian University Tianjin 300384 China school of Materials science and engineering Tianjin Chengjian University Tianjin 300384 China school of Energy and Safety engineering Tianjin Chengjian University Tianjin 300384 China

Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales, and agitator paddle design, and the effects of each on particle size and distribution of prepared microcapsules were determined. The experimental results showed that the pattern design of orifices in the plate paddles control the flow field well. Narrow particle-size distributio ns of the microcapsules were obtained. The fluid flow characteristics including fluid velocity field, turbulent kinetic energy field, and shear stress distribution for thedifferent agitator paddle types in different reaction kettles were simulated using CFD tech no logy. The correlations between simulated data and experime ntal results were an alyzed. Significantly, the simulated average flow velocity was found to show good negative linear correlation w让h the average particle size of prepared microcapsules, with a correlation of y =-2.166x + 42.626.

关键词： Fragrance microcapsule Melamine-formaldehyde Particle size Orifice stirring paddle CFD simulation

Selective hydrogenation of acetylene on SiO_2-supported Ni-Ga alloy and intermetallic compound

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Journal of Energy Chemistry 2019年第2期28卷 40-49页

作者： Lei Wang Fengxu Li Yanjun Chen Jixiang Chen tianjin Key Laboratory of Applied Catalysis science and technology Department of Catalysis Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin University

Ni/Si O_2 and bimetallic Ni_xGa/SiO_2 catalysts with different Ni/Ga atomic ratios(x = 10～2) were investigated for the selective hydrogenation of *** was found that Ni_xGa/SiO_2 showed higher selectivity to ethylene than Ni/Si O_*** is attributed to the formation Ni-Ga alloy and Ni3 Ga intermetallic compound(IMC) where there was a charge transfer from Ga to Ni,which is favorable for reducing the adsorption strength and amount of ethylene on Ni *** a result,the over-hydrogenation,the C–C bond hydrogenolysis and the polymerization were suppressed,and subsequently the selectivity to ethylene was *** the decrease of Ni/Ga atomic ratio,the activity and stability of the Ni_xGa/SiO_2 catalysts increased first and then decreased,while the ethylene selectivity tended to ***_5 Ga/SiO_2 exhibited the best *** the conditions of 180 °C,0.1 MPa,and a reactant(1.0 vol% acetylene,5.0 vol% H_2 and 94 vol% N_2) with the space velocity of 36,000 m L h^(-1) g^(-1),the acetylene conversion maintained at 100% on Ni_5 Ga/SiO_2 during 120 h time on stream and the selectivity to ethylene was 75%～81%after reaction for 68 *** was also found that the formation of Ni-Ga alloy and Ni_3 Ga IMC suppressed the incorporation of carbon to form NiCx,subsequently enhancing the catalyst ***,with increasing the Ga content,the catalyst acid amount and strength tended to increase,which promoted the polymerization and carbon deposition and so the catalyst deactivation.

关键词： Selective hydrogenation Acetylene Ni-Ga alloy Ni3Ga intermetallic compound

Ceria modified three-dimensionally ordered macro-porous Pt/TiO_2 catalysts for water-gas shift reaction

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Journal of Rare Earths 2009年第3期27卷 425-430页

作者：梁皓张媛刘源 tianjin Key Laboratory of Applied Catalysis science and engineering Department of Catalysis Science and TechnologySchool of Chemical Engineering and TechnologyTianjin University

Three-dimensionally ordered macro-porous （3DOM） TiO2 and ceria-modified 3DOM TiO2 supported platinum catalysts were prepared with template and impregnation methods, and the resultant samples were characterized by scanning electron microscopy（SEM）, X-ray diffractometer（XRD）, high-resolution transmission electron microscopy（HRTEM） and temperature programmed reducfion（TPR） techniques. The catalytic performances over the platinum-based catalysts were investigated for water-gas shift （WGS） reaction in a wide temperature range （180-360 ℃）. The results showed that 3DOM Pt/TiO2 catalyst exhibited obviously better catalytic performance than the corresponding non macro-porous catalyst, owing to the macro-porous structure favoring mass transfer. Addition of celia into 3DOM Pt/TiO2 led to improvement of catalytic activity. TPR and HRTEM results showed that the interaction existed between ceria and titanium oxide and addition of ceria promoted the reducibility of platinum oxide and TiO2 on the interface of platinum and TiO2 particles, which contributed to high activity of the celia modified catalysts. The results indicated that ceria-modified 3DOM Pt/TiO2 was a promising candidate of fuel cell oriented WGS catalyst.

关键词： three dimensionally ordered ceria macro-porous water gas shift platinum rare earths