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Zuo Z.,China Academy of Safety Science and Technology
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2015

In order to research evolutionary laws of unconfined vapor cloud explosion (UVCE) induced by combustible gas leak in long-distance oil and gas pipelines, Bayesian networks on buried pipelines corrosion leak fire were built by analyzing event nodes on inner and outer wall corrosion failure, combustible gas leak, the gas cloud diffusion and UVCE. The state ranges and discrete methods of node variables were studied. Priori probability and conditional probability distribution of the node variables were set by analyzing on accident statistics data and expert judgements. Bayesian network inference strategy was developed, the sensitivities of each network node variable on inference results were analyzed by researching on evolution mechanism of corrosion leak fire, and the rationality of the model was verified. The results show that there are greater uncertainty in the process of pipeline corrosion leaks and secondary disaster. The uncertainty presents in diverse intermediate event status value and probability of accident evolutionary path is influenced by the model input conditions. Bayesian network approach has a greater advantage to describe the dependency relations of accident intermediate nodes, and it can be used to measure uncertainties of accidents risk quantitatively. ©, 2015, Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science). All right reserved. Source

A comprehensive analytical method based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for measuring 6 exogenous endocrine disruptors--bisphenol diglycidyl ethers, including bisphenol A diglycidyl ether (BADGE), bisphenol A glycidyl (2,3-dihydroxypropyl) ether (BADGE x H2O), bisphenol A glycidyl (3-chloro-2-hydroxypropyl) ether ( BADGE x HCl), bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) ether (BADGE x H2O x HCl), bisphenol F diglycidyl ether (BFDGE) and bisphenol F bis (3-chloro-2-hydroxypropyl) ether (BFDGE x 2HCl). The samples were extracted with methyl tert-butyl ether (MTBE) by ultrasonic wave assistant extraction. The extracts were cleaned up and concentrated on multi-walled carbon nanotubes (MWCNTs). The target compounds were analyzed by HPLC-MS/MS under positive ion mode using a COSMOSIL C18 column as analytical column. Under the optimal conditions, the calibration curves showed a good linearity in the concentration range of 1.0-100.0 microg/L for 6 target compounds. The correlation coefficients (r2) were higher than 0.999 1. Recoveries of 6 analytes at three spiked levels ranged from 78.6% to 89.9%, with relative standard deviations (RSDs) less than 10%. The detection limits of the method ranged from 0.5 to 1.5 microg/L. The method is sensitive and simple, and is suitable for the rapid determination of the migration of bisphenol diglycidyl ethers from food contact materials. Source

Wang F.,Nanjing University of Technology | Liu J.-H.,Nanjing Normal University | Li W.-M.,China Academy of Safety Science and Technology
Journal of Molecular Catalysis | Year: 2013

Epoxides being very useful and versatile intermediates for the synthesis of many commodities and fine chemicals, and many problems, such as high energy consumption and environmental pollution, existed in industrial production, which makes studies on styrene epoxidation by environmentally friendly methods is a subject of great interest from both academic and industrial points of view. A series of Au-silica (nanosphere) catalysts were prepared by in situ synthesis; highly dispersed gold nanoparticles (GNPs, 6.4 nm) were obtained, and catalytic tests showed good catalytic activity and epoxidation selectivity. The catalysts were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and other instruments, combining with the investigation on the reactivities of styrene epoxidation, the preparation conditions of Au-silica catalysts were optimized. Source

Wang Y.-M.,China Academy of Safety Science and Technology | Wang Y.-M.,University of Science and Technology Beijing
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2010

Traffic incidents will reduce the traffic capacity, and even cause the traffic congestion. So building an effective simulation model is necessary to study the rules of congestion's propagating. The behavioral characteristics of individual vehicles in the traffic jam are different from others, but the current traffic CA (cellular automaton) models neglect those differences. The differences were taken into account by introducing some new rules into the old CA model. With the new CA model, the process of traffic congestion's propagating could be simulated correctly. Lastly, the relationships between congestion's propagating and some traffic parameters were explored by this model. Source

Liu X.,China Academy of Safety Science and Technology
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2010

A simple and sensitive method for the determination of six synthetic sweeteners (sodium cyclamate, saccharin sodium, acesulfame-K, aspartame, alitame and neotame) in food was developed. The synthetic sweeteners were extracted by methanol-water (1 : 1, v/v). The extract was separated on a C18 column using 0.1% (v/v) formic acid-5 mmol/L ammonium formate/acetonitrile as mobile phase, and then detected by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) using multiple reaction monitoring (MRM) mode. The good linearities (r > 0.998) were achieved for all the analytes over the range of 20-500 microg/L. The recoveries obtained ranged from 81.3% to 106.0% at three spiked concentrations, with the relative standard deviations lower than 11%. The established method has been successfully applied to the determination of synthetic sweeteners in food. Source

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