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Seismic performance evaluation of dam-reservoir-foundation systems to near-fault ground motions

NATURAL HAZARDS 2014年第2期72卷 651-674页

作者： Wang, Gaohui Zhang, Sherong Wang, Chao Yu, Mao Tianjin Univ State Key Lab Hydraul Engn Simulat & Safety Tianjin 300072 Peoples R China

Ground motion records obtained in recent major strong earthquakes have provided evidence that ground motions recorded near the near-fault regions differ in many cases from those observed further away from the seismic source. As the forward directivity and fling effect characteristics of the near-fault ground motions, they have the potential to cause more considerable damage to structures during an earthquake. Therefore, understanding the influence of near-fault ground motions on the performance of structures is critical to mitigate damage and perform effective response. This paper presents results of a study aimed at evaluating the effects of near-fault and far-fault ground motions on seismic performance of concrete gravity dams including dam-reservoir-foundation interaction. Koyna gravity dam is selected as a numerical application. Four different near-fault ground motion records with an apparent velocity pulse are used in the analyses. The earthquake ground motions recorded at the same site from other events that the epicenter far away from the site are employed as the far-fault ground motions. The seismic performance evaluation method based on the demand-capacity ratio, the cumulative overstress duration and the spatial extent of overstressed regions is presented. The concrete damaged plasticity model including the strain hardening or softening behavior is employed in nonlinear analyses. Nonlinear seismic damage analyses of the selected concrete dam subjected to both near-fault and far-fault ground motions are performed. The results obtained from the analyses show the effects of near-fault ground motions on seismic performance of concrete gravity dams and demonstrate the importance of considering the near-fault ground excitations.

关键词： Concrete gravity dams Seismic performance Near-fault ground motions Demand-capacity ratio (DCR) Seismic damage Concrete damaged plasticity (CDP) model Dam-reservoir-foundation interaction

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The benzoyl peroxide-promoted functionalization of simple alkanes with 2-aryl phenyl isonitrile

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CHEMICAL COMMUNICATIONS 2014年第65期50卷 9179-9181页

作者： Sha, Wanxing Yu, Jin-Tao Jiang, Yan Yang, Haitao Cheng, Jiang Changzhou Univ Jiangsu Key Lab Adv Catalyt Mat & Technol Sch Petrochem Engn Changzhou 213164 Peoples R China Changzhou Univ Jiangsu Prov Key Lab Fine Petrochem Engn Changzhou 213164 Peoples R China Nanjing Univ State Key Lab Coordinat Chem Nanjing 210093 Jiangsu Peoples R China

The benzoyl peroxide (BPO)-promoted phenanthridinylation of simple alkanes with isonitrile is developed via C(sp(3))-H and C(sp(2))-H bond cleavage. This procedure is featured by dual C-C bond formation proceeding wit... 详细信息

关键词： CARBON-HYDROGEN-BONDS METAL-FREE PHENANTHRIDINE DERIVATIVES OXIDATIVE CYCLIZATION CATALYZED ARYLATION ACTIVATION PALLADIUM 2-ISOCYANOBIPHENYLS COPPER COMPLEXES

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Performance study of ZrO₂ ceramic micro-filtration membranes used in pretreatment of DMF wastewater

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DESALINATION 2014年 346卷 1-8页

作者： Zhang, Qi Xu, Rong Xu, Pengwei Chen, Ruoyu He, Qiang Zhong, Jing Gu, Xuehong Changzhou Univ Sch Petrochem Engn Jiangsu Key Lab Adv Catalyt Mat & Technol Changzhou 213164 Jiangsu Peoples R China Nanjing Univ Technol State Key Lab Mat Oriented Chem Engn Nanjing 210009 Jiangsu Peoples R China

Three kinds of 19-channel ZrO2 micro-filtration membranes with different pore size were used for pretreatment of dimethylformamide (DMF) wastewater from the polyurethane (PU) synthetic leather factories, which would enter the distillation column for further purification. The effects of membrane pore size, tross flow velocity (CFV) and transmembrane pressure (TMP) on ceramic membrane filtration performances were investigated. Experimental results indicated that the optimum membrane pore size, CFV and TMP were 0.2 mu m, 3 m center dot s(-1) and 0.2 MPa, respectively, with the corresponding liquid turbidity removal rate of 99.62% and suspended solid content retention rate of 99.99%. The membrane fouling mechanism was analyzed by resistance in series model. The main resistance derived from the particle adsorption and sedimentation on the membrane surface. The ratio of particle adsorption and sedimentation resistance to total resistance was above 70% for the 0.2 mu m membrane. The backflushing technology was applied and the effect of backflushing on the permeate flux was studied. The permeate flux eventually increased by 50% with the optimum backflushing pressure of 0.6 MPa, backflushing time of 5 s and backflushing interval of 20 min. A combination cleaning method was used to regenerate the ZrO2 micro-filtration membrane. The pure water flux recovered to 608.2 L center dot m(-2) center dot h(-1) and flux recovery rate was 96.8% which indicated that the combination cleaning method was effective. (C) 2014 Elsevier B.V. All rights reserved.

关键词： DMF wastewater ZrO2 micro-filtration membrane Pretreatment Backflushing process Membrane fouling

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A copper-mediated oxidative N-cyanation reaction

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CHEMICAL COMMUNICATIONS 2014年第61期50卷 8412-8415页

作者： Teng, Fan Yu, Jin-Tao Jiang, Yan Yang, Haitao Cheng, Jiang Changzhou Univ Sch Petrochem Engn Jiangsu Prov Key Lab Fine Petrochem Engn Changzhou 213164 Peoples R China Changzhou Univ Dept Chem Changzhou 213164 Peoples R China

Copper-promoted N-cyanation of aliphatic sec-amine by CuCN is achieved via oxidative coupling. This procedure employs O-2 as a clean oxidant. Notably, sulfoximines and 1,1,3,3-tetramethylguanidine also worked well in this procedure. Thus, it represents a key progress in the C-N bond formation reaction as well as in the cyanation reaction.

关键词： COPPER CYANIDES OXIDATIVE coupling SULFOXIMINES CHEMICAL research

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Risk assessment of earth dam overtopping and its application research

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NATURAL HAZARDS 2014年第2期74卷 717-736页

作者： Zhang, Sherong Tan, Yaosheng Tianjin Univ Sch Civil Engn Dept Hydraul Engn State Key Lab Hydraul Engn Simulat & Safety Tianjin 300072 Peoples R China

The problem of dam safety is one of the most important research topics of water conservancy projects, and many researchers pay much attention to study the risk of earth dam overtopping. This paper synthesizes in the definition of risk the probabilities of dam failure and the corresponding losses, including the probability estimation, losses evaluation and criteria exploring risk approaches. Then, a comprehensive risk assessment system of dam flood overtopping is established, which is widely applicable. Gate failure, randomness of flood, initial water level and time-varying effects are incorporated in the failure probability model. Many complex factors are simplified in losses estimation. In addition, thresholds of various types of losses are proposed and are adapted to the national conditions. The methodology is applied to the Lianghekou hydropower station in China to illustrate the assessment process of flood overtopping risk and to evaluate its safe loophole with a view to the failure of spillway gates. Monte Carlo simulation and JC method programs are adopted to solve the model based on MATLAB tools and DELPHI. The results show that the losses pose significant impact on the risk assessment and should be considered in the assessment of risk. Probability calculation and loss estimation could be well combined with standards, providing a basis for risk management and decision-making.

关键词： Earth dam Risk assessment Flood overtopping Failure probability Losses evaluation Risk thresholds

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Copper-catalyzed cyanation of disulfides by azobisisobutyronitrile leading to thiocyanates

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CHEMICAL COMMUNICATIONS 2014年第81期50卷 12139-12141页

作者： Teng, Fan Yu, Jin-Tao Yang, Haitao Jiang, Yan Cheng, Jiang Changzhou Univ Jiangsu Prov Key Lab Fine Petrochem Engn Jiangsu Key Lab Adv Catalyt Mat & Technol Sch Petrochem Engn Changzhou 213164 Peoples R China Nanjing Univ State Key Lab Coordinat Chem Nanjing 210093 Jiangsu Peoples R China

The copper-catalyzed cyanation of disulfides by azobisisobutyronitrile (AIBN) was developed, leading to thiocyanates in moderate to good yields. This procedure tolerates a series of functional groups, such as chloro, nitro, methyl and methoxycarbonyl in the phenyl ring of disulfides. Notably, it enables the use of two ArS units in (ArS)(2). CuI was found to be essential for the in situ formation of cyanide anions.

关键词： CN BOND-CLEAVAGE CYANIDE SOURCE ORGANIC THIOCYANATES ARYL THIOCYANATES FACILE SYNTHESIS H CYANATION INDOLES N,N-DIMETHYLFORMAMIDE ARYLTHIOCYANATES ACETONITRILE

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Sensitive detection of multiple mycotoxins by SPRi with gold nanoparticles as signal amplification tags

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JOURNAL OF COLLOID AND INTERFACE SCIENCE 2014年 431卷 71-76页

作者： Hu, Weihua Chen, Hongming Zhang, Hilanhuan He, Guangli Li, Xin Zhang, Xiaoxing Liu, Yang Li, Chang Ming Southwest Univ Inst Clean Energy & Adv Mat Chongqing 400715 Peoples R China Chongqing Key Lab Adv Mat & Technol Clean Energie Chongqing 400715 Peoples R China Southwest Univ Fac Mat & Energy Chongqing 400715 Peoples R China Chongqing Univ State Key Lab Power Transmiss Equipment & Syst Se Chongqing 400044 Peoples R China Chinese Acad Agr Sci Inst Agroprod Proc Sci & Technol Key Lab Agroprod Proc Minist Agr Beijing 100193 Peoples R China

Detection of multiple toxic mycotoxins is of importance in food quality control. Surface plasmon resonance imaging (SPRi) is an advanced tool for simultaneously multiple detections with accuracy;however, it suffers from limited sensitivity due to the instrumental constraint and small sizes of mycotoxins with only one epitope for an insensitive competitive immunoassay. In this work a gold nanoparticle (AuNP)-enhanced SPRi chip *** to sensitively detect multiple mycotoxins using a competitive immunoassay format. The sensing surface is constructed by uniformly attaching dense mycotoxin antigens on poly[oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA) brush modified SPRi gold chip. After competitive binding in a sample solution containing respective monoclonal antibodies, secondary antibody-conjugated AuNPs are employed to bind with the captured monoclonal antibodies for further amplification of the SPRi signal. Highly specific and sensitive simultaneous detection is achieved for three typical mycotoxins including Aflatoxin B1 (AFB1), Ochratoxin A (OTA) and Zearalenone (ZEN) with low detection limits of 8, 30 and 15 pg mL(-1) and dynamic ranges covering three orders of magnitude. (C) 2014 Elsevier Inc. All rights reserved.

关键词： Surface plasmon resonance imaging Immunoassay Mycotoxin Gold nanoparticles Signal amplification

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Investigate on the Reliability of Electronic Voltage Transformer Based on Capacitive Voltage Dividing with Low Capacity Under the Transient Impulse Voltage

Investigate on the Reliability of Electronic Voltage Transfo...

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The 5th International Conference on Reliability of Electrical Products and Electrical Contacts

作者： XiXiu Wu Ge Yan Yu Feng Benjin Wang Shipu Wu School of Automation Wuhan University of TechnologyWHUT China Electric Power Research Institute EPRI

Transfer overvoltage can be easily generated in the low voltage side of EVT（Electronic Voltage Transformer）based on capacitive voltage dividing under the transient impulse voltage of power *** overvoltage may damage the secondary equipment which connects with the voltage divider of EVT,resulting in the reliability of the whole EVT being reduced *** typical impulse voltages are chosen,which are standard lighting voltage and VFTO（Very Fast Transient Overvoltage caused by disconnect or operation）,to study the capacitance value of voltage divider influencing on the transient characteristic of the overvoltage at the low voltage side due to the transient impulse voltage *** amplitude value and the dominant frequency distribution of overvoltage in the low-voltage side are calculated with different main capacitance value（C=500pF and C=75pF）.Factors,such as the front time,the voltage rise rate and the voltage polarity of the transient voltage and the parameters of grounding network effecting on the low-voltage side overvoltage are analyzed as *** research results show that① As the value of the main capacitance C is smaller,the overvoltage generated at the low voltage side is lower.②The shorter front time and the faster voltage rise rate of transient impulse voltage lead to higher low-voltage side overvoltage;③The grounding network parameter inductance L has significant effect on the characteristics of low voltage side *** the value of L is larger,the overvoltage of low-voltage side is higher.④The value of the overvoltage caused by VFTO is always higher than that caused by the standard lighting voltage no matter how to change the parameters of grounding network under the condition of C=75pF;If C=500pF and L<10μH,low-voltage side overvoltage caused by VFTO is higher than that caused by standard lighting voltage,but when L>20μH,the result is inversed.

关键词： impulse voltage electronic voltage transformer capacitive voltage dividing reliability grounding network

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Bimetallic PdCu nanoparticle decorated three-dimensional graphene hydrogel for non-enzymatic amperometric glucose sensor

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SENSORS AND ACTUATORS B-CHEMICAL 2014年 190卷 707-714页

作者： Yuan, Ming Liu, Aiping Zhao, Ming Dong, Wenjun Zhao, Tingyu Wang, Jiajun Tang, Weihua Zhejiang Sci Tech Univ Key Lab Adv Text Mat & Mfg Technol Minist Educ Ctr Optoelect Mat & Devices Hangzhou 310018 Zhejiang Peoples R China Zhejiang Univ Technol Minist Educ & Zhejiang Prov Key Lab E&M Hangzhou 310032 Zhejiang Peoples R China Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China

A bimetallic PdCu nanoparticle (NP) decorated three-dimensional graphene hydrogel (PdCu/ GE) was developed by a simple one-step hydrothermal method. The PdCu/GE hybrids exhibited an interconnected microporous framework with PdCu NPs dispersed and encapsulated within the GE layers. The PdCu/GE hybrids showed significant electrocatalytic activity toward glucose oxidation due to the synergistic effect of PdCu NPs and GE sheets in the alkaline solution containing chloride ions, presenting a substantial increase in the oxidation current and decrease in the onset potential of oxidation compared to the monometallic modified GE hybrids. At an applied potential of -0.4 V, the PdCu/ GE modified electrode with optimized bimetallic ratio presented quick respond to glucose oxidation with a wide linear range up to 18 mM and a reproducible sensitivity of 48 mu A (mg mM)(-1) in the presence of chloride ions. Furthermore, the PdCu/ GE modified electrode exhibited high selectivity to glucose and resistance against poisoning by commonly interfering species such as dopamine, ascorbic acid, uric acid, acetamidophenol and some monosaccharides. The PdCu/ GE hybrid hydrogels with 3D micropores were therefore promising for the future development of non-enzymatic amperometric glucose sensors with improved electrochemical performances. (c) 2013 Elsevier B. V. All rights reserved.

关键词： Graphene hydrogel Microporous structure Bimetallic nanoparticle Non-enzymatic glucose sensor

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Bayesian-Based Hybrid Simulation Approach to Project Completion Forecasting for Underground Construction

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JOURNAL OF CONSTRUCTION engineering AND MANAGEMENT 2014年第1期140卷

作者： Zhang, Sherong Du, Chengbo Sa, Wenqi Wang, Chao Wang, Gaohui Tianjin Univ State Key Lab Hydraul Engn Simulat & Safety Tianjin 300072 Peoples R China

Real-time simulation is powerful in forecasting the completion probability of long-term projects with repetitive tasks but fails to consider the time-varying uncertainty of inputs caused by construction process variabilities. In this paper, an improved method is introduced for predicting the time-varying probability of project completion of ongoing underground cavern group projects using Bayesian updating techniques. Within a tailor-made hierarchical simulation model, the Bayesian approach is adopted to constantly update duration distributions of unfinished project activities according to onsite data. The probability of project completion can therefore be increasingly refined during the process. The methodology is further explained in a case study where its feasibility and advantage over traditional approaches are verified. The success may also be replicated in addressing other similar time-varying uncertainty issues inherently present in almost all construction projects.

关键词： Forecasting Simulation Bayesian analysis Underground construction Excavation Hybrid methods Forecasting Simulation Bayesian analysis Underground construction Excavation Cost and schedule

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