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Border-search and jump reduction method for size optimization of spatial truss structures

Babak DIZANGIAN, Mohammad Reza GHASEMI

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 123-134 doi: 10.1007/s11709-018-0478-2

摘要： This paper proposes a sensitivity-based border-search and jump reduction method for optimum design of spatial trusses. It is considered as a two-phase optimization approach, where at the first phase, the first local optimum is found by few analyses, after the whole searching space is limited employing an efficient random strategy, and the second phase involves finding a sequence of local optimum points using the variables sensitivity with respect to corresponding values of constraints violation. To reach the global solution at phase two, a sequence of two sensitivity-based operators of border-search operator and jump operator are introduced until convergence is occurred. Sensitivity analysis is performed using numerical finite difference method. To do structural analysis, a link between open source software of OpenSees and MATLAB was developed. Spatial truss problems were attempted for optimization in order to show the fastness and efficiency of proposed technique. Results were compared with those reported in the literature. It shows that the proposed method is competitive with the other optimization methods with a significant reduction in number of analyses carried.

关键词： optimum design     sensitivity analysis     reduction method     spatial trusses     OpenSees    

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Achieving air pollutant emission reduction targets with minimum abatement costs: An enterprise-levelallocation method with constraints of fairness and feasibility

《环境科学与工程前沿（英文）》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1459-6

摘要：

• Quantification of efficiency and fairness of abatement allocation are optimized.

关键词： Pollutant emission reduction allocation     Emission reduction measures     Total abatement cost     Economic efficiency     Abatement space    

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Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1807-1817 doi: 10.1007/s11705-022-2243-2

摘要： The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor. Under the same reduction conditions (300 °C in H2), the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y catalyst. Therefore, an in-situ H2 reduction and moderate oxidation method was developed to increase the catalyst activity. Moreover, the influence of oxidation temperature on the developed method was investigated. The catalysts were characterized by Brunauer–Emmett–Teller method, hydrogen temperature programmed reduction H2-TPR, hydrogen temperature-programmed dispersion (H2-TPD), X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, O2 chemisorption and oxygen temperature-programmed dispersion (O2-TPD) analyses. The results showed that there existed an optimal Ru/RuOx ratio for the catalyst, and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H2 reduction and moderate oxidation (oxidized at 100 °C). Excessive oxidation (200 °C) resulted in a significant decrease in the Ru/RuOx ratio of the in-situ H2 reduction and moderate oxidized Ru/C-i2 catalyst, the interaction between RuOx species and the support changed, and the hard-to-reduce RuOx species was formed, leading to a significant decrease in catalyst activity. The developed in-situ H2 reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.

关键词： Ru/C catalyst     in-situ H2 reduction and moderate oxidation     in-situ reduction     non-in-situ reduction     hydrogenation of 3     5-dimethylpyridine    

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underground structures in layered ground under inclined P-SV waves using stiffness matrix and domain reduction

《结构与土木工程前沿（英文）》 2023年 第17卷 第1期   页码 10-24 doi: 10.1007/s11709-022-0904-3

摘要： A numerical framework was proposed for the seismic analysis of underground structures in layered ground under inclined P-SV waves. The free-field responses are first obtained using the stiffness matrix method based on plane-wave assumptions. Then, the domain reduction method was employed to reproduce the wavefield in the numerical model of the soil–structure system. The proposed numerical framework was verified by providing comparisons with analytical solutions for cases involving free-field responses of homogeneous ground, layered ground, and pressure-dependent heterogeneous ground, as well as for an example of a soil–structure interaction simulation. Compared with the viscous and viscous-spring boundary methods adopted in previous studies, the proposed framework exhibits the advantage of incorporating oblique incident waves in a nonlinear heterogeneous ground. Numerical results show that SV-waves are more destructive to underground structures than P-waves, and the responses of underground structures are significantly affected by the incident angles.

关键词： underground structures     seismic response     stiffness matrix method     domain reduction method     P-SV waves    

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Model reduction of contact dynamics simulation using a modified Lyapunov balancing method

Jianxun LIANG, Ou MA, Caishan LIU

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 383-391 doi: 10.1007/s11465-011-0244-9

摘要：

Finite element models are often used to simulate impact and contact dynamics responses of multibody dynamical systems. However, such a simulation remains very inefficient because very small integration time step must be used when solving the involved differential equations, especially when the involved contact stiffness is high. Although many model reduction techniques have been available to improve the efficiency of finite element based simulations, these techniques cannot be readily applied to contact dynamics simulations due to the high nonlinearity of the contact dynamics models. This paper presents a model reduction approach for finite-element based multibody contact dynamics simulation, based on a modified Lyapunov balanced truncation method. An example is presented to demonstrate that, by applying the model reduction the simulation process is significantly speeded up and the resulting error is bounded within an acceptable level. The performance of the method with respect to some influential factors such as element size, shape and contact stiffness is also investigated.

关键词： contact dynamics     dynamic simulation     model reduction     finite element method    

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Efficient and selective electro-reduction of nitrobenzene by the nano-structured Cu catalyst preparedby an electrodeposited method via tuning applied voltage

Yali CHEN,Lu XIONG,Weikang WANG,Xing ZHANG,Hanqing YU

《环境科学与工程前沿（英文）》 2015年 第9卷 第5期   页码 897-904 doi: 10.1007/s11783-015-0782-1

摘要： Pollution caused by toxic nitrobenzene has been a widespread environmental concern. Selective reduction of nitrobenzene to aniline is beneficial to further efficient and cost-effective biologic treatment. Electrochemical reduction is a promising method and Cu-based catalysts have been found to be an efficient cathode material for this purpose. In this work, Cu catalysts with different morphologies were fabricated on Ti plate using a facile electrodepositon method via tuning the applied voltage. The dendritic nano-structured Cu catalysts obtained at high applied voltages exhibited an excellent efficiency and selectivity toward the reduction of nitrobenzene to aniline. Effects of the working potential and initial nitrobenzene concentration on the selective reduction of nitrobenzene to aniline using the Cu/Ti electrode were investigated. A high rate constant of 0.0251 min and 97.1% aniline selectivity were achieved. The fabricated nano-structured Cu catalysts also exhibited good stability. This work provides a facile way to prepare highly efficient, cost-effective, and stable nano-structured electrocatalysts for pollutant reduction.

关键词： nitrobenzene     nano-structured Cu     electro-reduction     voltage-dependent electrodeposition     high selectivity     high stability    

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The influencing factors of the WTP for the risk reduction of chemical industry accidents in China

Lei HUANG, Zhijuan SHAO, Weiliang BAO, Bailing DUAN, Jun BI, Zengwei YUAN

《环境科学与工程前沿（英文）》 2012年 第6卷 第6期   页码 860-868 doi: 10.1007/s11783-012-0467-y

摘要： To explore the factors that influence respondents’ willingness to pay (WTP) for the risk reduction of chemical industry accidents, a questionnaire survey combined with contingent valuation and psychometric paradigm methods were conducted in the city of Yancheng, Jiangsu Province, China. Both traditional socioeconomic variables and perceived characteristics of the hazards were considered in this study, and a Tobit model was used to find the factors influencing WTP under three risk reduction scenarios. The results showed that three demographic characteristics, , , and , significantly affected the WTP for chemical risk reduction. In addition, three extracted public risk perception factors, , , and , also strongly affected the WTP. The mean WTP value increased as the magnitude of the risk reduction increased. The number of factors influencing the WTP decreased as the reduction level improved, and only the factor had a significant influence on the WTP for a higher level (80%) of risk reduction. The cost for chemical safety management of Yancheng was calculated, and the optimized risk reduction level was determined. These findings can assist governments and policy makers to formulate suitable strategies for risk control, to reach target groups of people to develop effective communication, and to provide specific references for the best investment for the security of local residents.

关键词： risk perception     willingness to pay     contingent valuation method     risk management school of the environment    

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A MATLAB code for the material-field series-expansion topology optimization method

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 607-622 doi: 10.1007/s11465-021-0637-3

摘要： This paper presents a MATLAB implementation of the material-field series-expansion (MFSE) topo-logy optimization method. The MFSE method uses a bounded material field with specified spatial correlation to represent the structural topology. With the series-expansion method for bounded fields, this material field is described with the characteristic base functions and the corresponding coefficients. Compared with the conventional density-based method, the MFSE method decouples the topological description and the finite element discretization, and greatly reduces the number of design variables after dimensionality reduction. Other features of this method include inherent control on structural topological complexity, crisp structural boundary description, mesh independence, and being free from the checkerboard pattern. With the focus on the implementation of the MFSE method, the present MATLAB code uses the maximum stiffness optimization problems solved with a gradient-based optimizer as examples. The MATLAB code consists of three parts, namely, the main program and two subroutines (one for aggregating the optimization constraints and the other about the method of moving asymptotes optimizer). The implementation of the code and its extensions to topology optimization problems with multiple load cases and passive elements are discussed in detail. The code is intended for researchers who are interested in this method and want to get started with it quickly. It can also be used as a basis for handling complex engineering optimization problems by combining the MFSE topology optimization method with non-gradient optimization algorithms without sensitivity information because only a few design variables are required to describe relatively complex structural topology and smooth structural boundaries using the MFSE method.

关键词： MATLAB implementation     topology optimization     material-field series-expansion method     bounded material field     dimensionality reduction    

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Novel coprecipitation–oxidation method for recovering iron from steel waste pickling liquor

Shejiang Liu, Hongyang Yang, Yongkui Yang, Yupeng Guo, Yun Qi

《环境科学与工程前沿（英文）》 2017年 第11卷 第1期 doi: 10.1007/s11783-017-0902-1

摘要： Coprecipitation–oxidation method was developed to recover the iron from wastewater. Fe O nanoparticles were well synthesized from steel waste pickling liquor. Promoters greatly improved the properties of synthesized Fe O nanoparticle. Real-time control of the Fe /Fe molar ratio was achieved by ORP monitoring. Waste pickling liquors (WPLs) containing high concentrations of iron and acid are hazardous waste products from the steel pickling processes. A novel combined coprecipitation–oxidation method for iron recovery by Fe O nanoparticle production from the WPLs was developed in this study. An oxidation–reduction potential monitoring method was developed for real-time control of the Fe /Fe molar ratio. The key coprecipitation–oxidation parameters were determined using the orthogonal experimental design method. The use of promoters greatly improved the Fe O nanoparticle crystallinity, size, magnetization, and dispersion. X-ray diffraction patterns showed that the produced Fe O nanoparticles were single phase. The Fe O nanoparticles were approximately spherical and slightly agglomerated. Vibrating sample magnetometry showed that the Fe O nanoparticles produced from the WPLs had good magnetic properties, with a saturation magnetization of 80.206 emu·g and a remanence of 10.500 emu·g . The results show that this novel coprecipitation–oxidation method has great potential for recycling iron in WPLs.

关键词： Waste pickling liquor     Coprecipitation–oxidation     Fe3O4 nanoparticles     Oxidation–reduction potential     Promoter    

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Electrocatalytic reduction of NO to NH in ionic liquids by P-doped TiO nanotubes

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 726-734 doi: 10.1007/s11705-022-2274-8

摘要： Designing advanced and cost-effective electrocatalytic system for nitric oxide (NO) reduction reaction (NORR) is vital for sustainable NH3 production and NO removal, yet it is a challenging task. Herein, it is shown that phosphorus (P)-doped titania (TiO2) nanotubes can be adopted as highly efficient catalyst for NORR. The catalyst demonstrates impressive performance in ionic liquid (IL)-based electrolyte with a remarkable high Faradaic efficiency of 89% and NH3 yield rate of 425 μg·h−1·mgcat.−1, being close to the best-reported results. Noteworthy, the obtained performance metrics are significantly larger than those for N2 reduction reaction. It also shows good durability with negligible activity decay even after 10 cycles. Theoretical simulations reveal that the introduction of P dopants tunes the electronic structure of Ti active sites, thereby enhancing the NO adsorption and facilitating the desorption of *NH3. Moreover, the utilization of IL further suppresses the competitive hydrogen evolution reaction. This study highlights the advantage of the catalyst−electrolyte engineering strategy for producing NH3 at a high efficiency and rate.

关键词： nitric oxide reduction reaction     electrcatalysis     ammonia production     phosphorus-doped titania    

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Enhancement of extracellular Cr(VI) reduction for anammox recovery using hydrazine: performance, pathways

《环境科学与工程前沿（英文）》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1715-z

摘要：

● N2H4 addition enhanced and recovered anammox performance under Cr(VI) stress.

关键词： Extracellular Cr(VI) reduction     Electron transfer     Anammox     Hydrazine     Cr(VI) inhibition    

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Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

《能源前沿（英文）》 doi: 10.1007/s11708-023-0908-2

摘要： The Haber-Bosch process is the most widely used synthetic ammonia technology at present. Since its invention, it has provided an important guarantee for global food security. However, the traditional Haber-Bosch ammonia synthesis process consumes a lot of energy and causes serious environmental pollution. Under the serious pressure of energy and environment, a green, clean, and sustainable ammonia synthesis route is urgently needed. Electrochemical synthesis of ammonia is a green and mild new method for preparing ammonia, which can directly convert nitrogen or nitrate into ammonia using electricity driven by solar, wind, or water energy, without greenhouse gas and toxic gas emissions. Herein, the basic mechanism of the nitrogen reduction reaction (NRR) to ammonia and nitrate reduction reaction (NO3− RR) to ammonia were discussed. The representative approaches and major technologies, such as lithium mediated electrolysis and solid oxide electrolysis cell (SOEC) electrolysis for NRR, high activity catalyst and advanced electrochemical device fabrication for NO3 − RR and electrochemical ammonia synthesis were summarized. Based on the above discussion and analysis, the main challenges and development directions for electrochemical ammonia synthesis were further proposed.

关键词： electrochemical ammonia synthesis     nitrogen     nitrate     nitrogen reduction reaction (NRR) to ammonia     nitrate reduction reaction (NO–3 RR)    

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Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

《结构与土木工程前沿（英文）》 2014年 第8卷 第3期   页码 270-281 doi: 10.1007/s11709-014-0265-7

摘要： Many researches have been carried out to study the fresh and hardened properties of concrete containing crumb rubber as replacement to fine aggregate by volume, yet there is no specific guideline has been developed on the mix design of the rubbercrete. The experimental program, which has been developed and reported in this paper, is designed and executed to provide such mix design guidelines. A total of 45 concrete mixes with three different water to cement ratio (0.41, 0.57 and 0.68) were cast and tested for fresh and mechanical properties of rubbercrete such as slump, air content, unit weight, compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. Influence of mix design parameters such as percentage of crumb rubber replacement, cement content, water content, fine aggregate content, and coarse aggregate content were investigated. Three levels of slump value (for conventional concrete mixes) has been selected; low, medium and high slump. In each slump level, water content was kept constant. Equations for the reduction factors (RFs) for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity have been developed. These RFs can be used to design rubbercrete mixes based on the conventional mix (0% crumb rubber content)

关键词： crumb rubber     recycled tire     mix design     reduction factor     strength     modulus elasticity    

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A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

《能源前沿（英文）》 2017年 第11卷 第3期   页码 268-285 doi: 10.1007/s11708-017-0466-6

摘要： Development of active and durable electrocatalyst for oxygen reduction reaction (ORR) remains one challenge for the polymer electrolyte membrane fuel cell (PEMFC) technology. Pt-based nanomaterials show the greatest promise as electrocatalyst for this reaction among all current catalytic structures. This review focuses on Pt-based ORR catalyst material development and covers the past achievements, current research status and perspectives in this research field. In particular, several important categories of Pt-based catalytic structures and the research advances are summarized. Key factors affecting the catalyst activity and durability are discussed. An outlook of future research direction of ORR catalyst research is provided.

关键词： oxygen reduction reaction (ORR)     electrocatalysis     platinum catalyst     activity     durability    

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Reduction of CeO

Elena Yu. KONYSHEVA

《化学科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 249-261 doi: 10.1007/s11705-013-1333-6

摘要： Reduction behavior of pure and doped CeO , the multi-phase La Sr CoO ? CeO , La Sr MnO ? CeO , and La Ni Fe O ? CeO composites, was studied under hydrogen containing atmosphere to address issues related to the improvement of electrochemical and catalytic performance of electrodes in fuel cells. The enhanced reduction of cerium oxide was observed initially at 800°C in all composites in spite of the presence of highly reducible transition metal cations that could lead to the increase in surface concentration of oxygen vacancies and generation of the electron enriched surface. Due to continuous reduction of cerium oxide in La Sr CoO ? CeO and La Sr MnO ? CeO (up to 10 h) composites the redox activity of the Ce /Ce pair could be suppressed and additional measures are required for reversible spontaneous regeneration of Ce . After 3 h exposure to H -Ar at 800°C the reduction of cerium oxides and perovskite phases in La Ni Fe O ? CeO composites was diminished. The extent of cerium oxide involvement in the reduction process varies with time, and depends on its initial deviation from oxygen stoichiometry (that results in the larger lattice parameter and the longer pathway for O transport through the fluorite lattice), chemical origin of transition metal cations in the perovskite, and phase diversity in multi-phase composites.

关键词： reduction of cerium oxide     composites     perovskites     catalyst under hydrogen containing atmosphere    

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标题 作者 时间 类型 操作

Border-search and jump reduction method for size optimization of spatial truss structures

Babak DIZANGIAN, Mohammad Reza GHASEMI

期刊论文

Achieving air pollutant emission reduction targets with minimum abatement costs: An enterprise-levelallocation method with constraints of fairness and feasibility

期刊论文

Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in

期刊论文

underground structures in layered ground under inclined P-SV waves using stiffness matrix and domain reduction

期刊论文

Model reduction of contact dynamics simulation using a modified Lyapunov balancing method

Jianxun LIANG, Ou MA, Caishan LIU

期刊论文

Efficient and selective electro-reduction of nitrobenzene by the nano-structured Cu catalyst preparedby an electrodeposited method via tuning applied voltage

Yali CHEN,Lu XIONG,Weikang WANG,Xing ZHANG,Hanqing YU

期刊论文

The influencing factors of the WTP for the risk reduction of chemical industry accidents in China

Lei HUANG, Zhijuan SHAO, Weiliang BAO, Bailing DUAN, Jun BI, Zengwei YUAN

期刊论文

A MATLAB code for the material-field series-expansion topology optimization method

期刊论文

Novel coprecipitation–oxidation method for recovering iron from steel waste pickling liquor

Shejiang Liu, Hongyang Yang, Yongkui Yang, Yupeng Guo, Yun Qi

期刊论文

Electrocatalytic reduction of NO to NH in ionic liquids by P-doped TiO nanotubes

期刊论文

Enhancement of extracellular Cr(VI) reduction for anammox recovery using hydrazine: performance, pathways

期刊论文

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

期刊论文

Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

期刊论文

A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

期刊论文

Reduction of CeO

Elena Yu. KONYSHEVA

期刊论文