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Risk analysis for a cascade reservoir system using the brittle risk entropy method

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Science China(Technological Sciences) 2016年第6期59卷 882-887页

作者： YANG Yin ren qing Wen TIAN Ying XIONG Yao College of Hydraulic Conservation and Hydropower Engineering Hohai University department of Engineering Mechanics Hohai University

The principal means of conserving water and utilizing hydropower in China is to exploit the use of a series of reservoirs in a cascade. This method and its inherent engineering safety problems are receiving increasing attention nowadays. In the field of engineering safety analysis, much work has focused on single reservoir projects in the past few years, but there is little research available on the safety risk analysis of cascade reservoirs, either within China or internationally. Therefore, a framework for risk analysis on the cascade reservoir system based on the theory of system engineering is constructed in this article. A cascading failure model is established and the connection degree factor discussed. In addition, the importance degree of the subsystem, which can be calculated by combining the analytical hierarchy process and the entropy weight method, is explained. According to brittleness theory of a complex system, brittle risk entropy is proposed as a performance index for measuring the collapse uncertainty of the cascade reservoir system. In addition, the brittle risk of the cascade reservoir system is predicted, which provides a reference for safety analysis in water conservation and hydropower construction projects in China.

关键词： cascading failure model safety analysis risk assessment complex system brittle risk entropy

Reliability of the Ultimate Strength of Ship Stiffened Panel Subjected to Random Corrosion degradation

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China Ocean Engineering 2017年第1期31卷 11-18页

作者： FENG Guo-qing HU Bing-nan ren Hui-long College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

Attentions have been increasingly paid to the influence of the corrosion on the ultimate strength of ship structures. In consideration of the random characteristics of the corrosion of ship structures, the method for the ultimate strength analysis of the ship stiffened panel structure subjected to random corrosion degradation is presented. According to the measured corrosion data of the bulk carriers, the distribution characteristics of the corrosion data for the stiffened panel on the midship deck are analyzed, and a random corrosion model is established. The ultimate strength of the corroded stiffened panel is calculated by lhe nonlinear finite element analysis. The statistical descriptions of the ultimate strength of the corroded stiffened panel are defined through the Monte Carlo simulations. A formula is proposed on the ultimate strength reduction of the stiffened panel as a function of the corrosion volume. The reliability analysis of the ultimate strength of the corroded deck stiffened panel is performed. It shows that both the corrosion data of the deck stiffened panel and the ultimate strength of the random corroded deck stiffened panel follow the log-normal distribution. The ultimate stress ratio of the stiffened panel is inversely proportional to the corrosion volume ratio.

关键词： stiffened panel corrosion ultimate strength time variant reliability corrosion volume /:~no- ~T (~ ~11 R NI R^n l-I I. 9017 Rollnhilltvnftho.ltlmnto ~trontrth nf^hl

Effect of methyl tert-butyl ether on adipogenesis and glucose metabolism in vitro and in vivo

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Journal of Environmental Sciences 2019年第11期31卷 208-219页

作者： Yue Tang Qidong ren qing Wen Caixia Yu Xinni Xie qing Hu Yuguo Du State Key Laboratory of Environmental Chemistry and Eco-toxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China School of Chemical Sciences University of Chinese Academy of Sciences Beijing 100049 China School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen 518055 China

Methyl tert-butyl ether (MTBE),as a widely used gasoline additive,is suspected of being environmentally *** accumulates mainly in adipose tissue,but its effect on obesity or obesity-related metabolic disorders has not been well understood ***,we examined the effect of MTBE on the adipose function and the related metabolic processes with both 3T3-L1 cell line and C57BL/6J mice *** found that exposure to MTBE at the environmental relevant concentration (100 μmol/L) could significantly induce differentiation of preadipocyte and disturb insulin-stimulated glucose uptake of mature *** in vivo observation in male mice showed a positive correlation of visceral white adipose tissue (vWAT) expansion and cell size increase with MTBE treatment in 14 *** tolerance and insulin sensitivity tests demonstrated that MTBE at 1000 μg/(kg·day) disturbed the systemic glucose metabolism in a gender-specific manner,which might be partly attributed to the alterations of gut microbiota community at genus level with respect to Akkermansia,Clostridium XIVb,and *** summary,our study characterized the effect of MTBE on adipose tissue function and glucose homeostasis in vitro and in vivo,and revealed that systemic disorders of the glucose metabolism might be modulated by the related gut microbiota.

关键词： MTBE Adipogenesis Glucose metabolism Metabolic disorder Gut microbiota

Smoke suppressant in flame retarded thermoplastic polyurethane composites: Synergistic effect and mechanism study

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Nano Research 2021年第11期14卷 3926-3934页

作者： Hongyuan ren Kelan qing Ying Chen Yanjun Lin Xue Duan State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China

Considerable smoke and toxic volatiles generation has compromised the application of thermoplastic polyurethane (TPU) and caused a great threat to human life. Here, nano-MgFe layered double hydroxide (MgFe-LDH) with uniform particle size was synthesized to reduce smoke density and toxic gases of TPU composites using ammonium polyphosphate (APP) as a flame retardant agent. The results show that the combination of 16 wt.% APP and 4 wt.% MgFe-LDH greatly decreased the smoke density (D20min and Ds, max), smoke production rate (SPR) and heat release rate (HRR) of TPU composites. Furthermore, the MgFe-LDH synergist demonstrated high efficiency in decreasing total volatiled products and toxic volatiles evolved, such as the CO, HCN and isocyanates. The reason was mainly attributed to the chemical reaction between MgFe-LDH and APP, which can promote the compactness of char layers with fine microstructure formed in the decomposition process of MgFe-LDH/APP/TPU composites. The protective char layers could act as barriers between combustion zone and matrix to protect the unburned substrate and promote smoke suppression effect.

关键词： layered double hydroxide thermoplastic polyurethane smoke suppression synergistic effect

Methyl tertiary-butyl ether inhibits THP-1 macrophage cholesterol efflux in vitro and accelerates atherosclerosis in ApoE-deficient mice in vivo

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Journal of Environmental Sciences 2021年第3期33卷 236-247页

作者： Qidong ren Xinni Xie Yue Tang qing Hu Yuguo Du State Key Laboratory of Environmental Chemistry and Eco-Toxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

The biosafety of methyl tertiary-butyl ether(MTBE),mainly used as a gasoline additive,has long been a contentious *** addition to its routine toxicities,MTBE has been demonstrated to disrupt glucose and lipid metabolism and contribute to the development of type2 diabetes as well as *** one of the morbidities related to dyslipidemia,atherosclerosis is worthy of being investigated under MTBE *** foam cells derived from macrophages play pivotal roles during atherosclerosis development,we studied the effects of MTBE on macrophages in vitro and assessed the effect of MTBE on atherosclerosis plaque formation with the ApoE^(-/-)mouse model in uiuo for the first *** results demonstrated that exposure to MTBE at environmentally relevant concentrations decreased the expression of ABCA1 and ABCG1,which are responsible for macrophage cholesterol efflux,at both mRNA and protein levels in THP-1 ***,treatment with MTBE inhibited the transport of cholesterol from macrophages to High-density ***^(-/-)mice exposed to MTBE at environmentally relevant concentrations(100,1000μg/kg)displayed significant increases in lesion area in the aorta and aortic root compared to vehicletreated *** analysis indicated that MTBE exposure enhanced the macrophagespecific marker Mac-2 contents within plaques in the aortic root,implying that MTBE could promote macrophage-derived foam cell formation and thus accelerate atherosclerosis plaque *** for the first time demonstrated the pro-atherogenic effect of MTBE via eliciting disruption of macrophage cholesterol efflux and accelerating foam cell formation and atherosclerosis plaque development.

关键词： Methyl tertiary–butyl ether(MTBE) macrophage cholesterol efflux ApoE^(-/-)mouse Atherosclerosis

Integral precession calibration method of PIGA on linear vibration table

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Chinese Journal of Aeronautics 2024年第3期37卷 219-236页

作者： Chuang SUN Shun-qing ren Jun-wei CAO Ru HUO department of Automation Tsinghua UniversityBeijing 100084China School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China Faculty of Information technology Beijing University of TechnologyBeijing 100124China

Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a linear vibration table in this *** on the precise expressions of PIGA’s inputs,the error calibration model of PIGA is *** angular velocity errors of PIGA are suppressed by integer periodic precession and the errors caused by non-integer periods vibrating are *** complete calibration process,including planning,preparation,PIGA testing,and coefficient identification,is designed to optimize the test operations and evaluate the calibration *** effect of the main errors on calibration uncertainty is analyzed and the relative sensitivity function is proposed to further optimize the test *** and simulation results verify that the proposed 10-position calibration method can improve calibration uncertainties after compensating for the related *** order of calibration uncertainties of the second-and third-order coefficients are decreased to 10^(-8)(rad.s^(-1))/g^(2)and 10^(-8)(rad.s^(-1))/g3,*** with the other two classical calibration methods,the calibration uncertainties of PIGA’s nonlinear error coefficients can be effectively reduced and the proportional residual errors are decreased less than 3×10-6(rad.s^(-1))/g by using the proposed calibration method.

关键词： PIGA Linear vibration table Vibration measurement Calibration Error analysis Uncertainty analysis

Semisolid die forging process,microstructures and properties of AZ31 magnesium alloy mobile telephone shells

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 665-670页

作者： ren-guo Guan Li-qing Chen Fu-rong Cao Zhan-yong Zhao Yong ren College of Materials and Metallurgy Northeastern University Shenyang 110004 China State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 China

A semisolid slurry of AZ31 magnesium alloy was prepared by vibrating wavelike sloping plate process,and the semisolid die forging process,microstructures,and properties of the magnesium alloy mobile telephone shell were *** semisolid forging process was performed on a YA32-315 four-column universal hydraulic *** microstructures were observed by optical microscopy,the hardness was analyzed with a model 450SVD Vickers hardometer,the mechanical properties was measured with a CMT5105 tensile test machine,and the fractograph of elongated specimens was observed by scanning electron microscopy （SEM）.The results reveal that with the increase of die forging force,the microstructures of the product become fine and dense.A lower preheating temperature and a longer dwell time are favorable to the formation of fine and dense *** optimum process conditions of preparing mobile telephone shells with excellent surface quality and microstructures are a die forging force of 2000 kN,a die preheating temperature of 250℃,and a dwell time of 240 *** solution treatment at 430℃ and aging at 220℃ for 8 h,the Vickers hardness is 61.7 and the ultimate tensile strength of the product is *** fractographs show the mixing mechanisms of quasi-cleavage fracture and ductile fracture.

关键词： magnesium alloys semisolid forging microstructure mechanical properties fracture

Moderate electron–spin interaction in Fe-intercalated NbSe_(2)

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Chinese Physics B 2025年第1期34卷 451-456页

作者： Qiao-Yu Liu Jian-Li Bai qing-Xin Dong Li-Bo Zhang Jing-Wen Cheng Pin-Yu Liu Cun-Dong Li Yu Huang Ying-Rui Sun Zhi-An ren Gen-Fu Chen Institute of Physics and Beijing National Laboratory for Condensed Matter Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China

The interaction between charge and spin degrees of freedom has always been the central issue of condensed matter physics,and transition metal dichalcogenides(TMDs)provide an ideal platform to study it benefiting from their highly tunable *** this article,the influence of Fe intercalation in NbSe_(2)was elaborately investigated using a combination of *** studies have shown that the insertion of Fe atoms induces an antiferromagnetic state in which the easy axis aligns out of the *** sign reversal of the magnetoresistance across the Neel temperature can be satisfactorily explained by the moderate interaction between electrons and local *** Hall and Seebeck measurements reveal a multi-band nature,and the contribution of various phonon scattering processes is discussed based on the thermal conductivity and specific heat data.

关键词： transition metal dichalcogenide intercalation spin-electron interaction

Working Principle and Error Analysis for Hemispherical Resonator Gyro under Force-rebalance Mode

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 75-80页

作者： Hong-Bo Zhao Shun-qing ren Space Control and Inertial Technology Research Center Harbin Institute of Technology

The two control methods, namely the general-control and the quadrature-control modes for HRG under force-rebalance mode were introduced firstly. Then the azimuth of antinode on the hemispherical resonator was deduced. The dynamics equations of resonator under the nonuniformity of density distribution were established by way of Bubonov-Galerkin method which is commonly used for solution of differential equations, and the state equation was established through the dynamics equations. The analytic solutions of the vibration displacement and the velocity were achieved by solving the state equation, and then the ratio of rebalance excitation to primary excitation was derived under the two working modes, thus the estimation of input angular rate of HRG were obtained. By comparing and calculating these two modes, the error caused by resonator's machining defects can be greatly inhibited under quadrature-control, and the fourth harmonic density error's tolerance were calculated to ensure the accuracy of HRG under these two modes.

关键词： hemispherical resonator gyro force-rebalance mode quadrature-control density distribution nonuniformity