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Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation

Science China Chemistry 2006年第2期49卷 186-192页

作者： HU Jun1, WANG Jianlong1,2 & CHEN Rong1 1. laboratory of Environmental Technology, Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China 2. state key Joint laboratory of Environmental simulation and Pollution control, Tsinghua University, Beijing 100084, China Correspondence should be addressed to Wang Jianlong 1. Laboratory of Environmental Technology Institute of Nuclear Energy Technology Tsinghua University Beijing 100084 China 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control Tsinghua University Beijing 100084 China

The degradation of 4-chlorophenol (4-CP) by using gamma rays generated by a 60Co source in the presence of O3 was investigated. The radiolysis of 4-CP and the kinetics of 4-CP min-eralization were analyzed based on the determination of total organic carbon (TOC). The influence of initial 4-CP concentration and the free radicals scavengers (such as NaHCO3 and t-butanol) on the 4-CP degradation was also studied. The results showed that when the radiation rate was 336 Gy·min?1, 4-chlorophenol at concentration of 10 mg·L?1 could be completely degraded at the radiation dose of 2 kGy. The degradation of 4-chlorophenol could be described by a first-order reaction model, the rate constant of 4-CP degradation by combined ozonation and radiation was 0.1016 min?1, which was 2.4 times higher than the sum of radiation (0.0294 min?1) and ozonation (0.0137 min?1). It re-vealed that the combination of radiation and ozonation resulted in synergistic effect, which can re-markably increase the degradation efficiency of 4-CP.

关键词： radiolysis, 4-chlorophenol, priority pollutant, degradation, O3, synergistic effect, kinetics.

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Effects of Micronutrient Niacin on Treatment Efficiency of Textile Wastewater

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Wuhan University Journal of Natural Sciences 2006年第3期11卷 737-741页

作者： LIANG Wei HU Hongying GU Xin CHE Yuling WANG Hui GUO Yufeng SONG Yudong State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 Hubei China Environment Simulation and Pollution Control State Key Joint Laboratory Department of Environmental Science and EngineeringTsinghua University Beijing 100084 China

Textile wastewater is well known as one of the wastewaters to be most difficultly treated. The effects of niacin on textile wastewater treatment efficiency were studied by continuous addition of 1.0 mg·L^-1 niacin, the physical and chemical indexes of the water samples, such as COD, ammonia and dehydrogenase activities, were analyzed every day with standard methods, and obvious improvement in wastewater treatment performance was achieved. The exact results showed that：① Niacin could improve the COD removal efficiency signifcantly with removal rates being 1.31 times as to those of the control system; ② under this experimental condition, addition of niacin had almost no effect on the removal of ammonia;③ Addition of niacin could improve the activity of dehydrogenase by 130 %. It proved that the biological treatment performance of textile wastewater treatment system probably could be optimized through micronutrient niacin supplement.

关键词： textile wastewater biological treatment niacin, COD dehydrogenase activities

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Hydroxyl radicals induced by quartz particles in lung alveolar macrophages: the role of surface iron

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Progress in Natural Science:Materials International 2006年第10期16卷 1038-1044页

作者： LI Yi, ZHU Tong, GUO Xinbiao and SHANG Yu ( state key Joint laboratory for Environmental simulation & Pollution control, Peking University, Beijing 100871, China Occupational & Environmental Health Sciences, School of Public Health, Peking University Health Science Center, Beijing 100083, China) [a]State Key Joint Laboratory for Environmental Simulation & Pollution Control Peking University Beijing China [b]Occupational & Environmental Health Sciences School of Public Health Peking University Health Science Center Beijing China

Previous studies have shown that hydroxyl radical generation is a key step in the mechanism of pathogenic process caused by airborne particles to the lung. However, there is no direct evidence for dose-response relationship between airborne particles and hydroxyl radical generation. In this study, hydroxyl radicals generated in lung alveolar macrophages exposed to quartz particles were measured using a highly sensitive capillary electrophoresis-fluorescence detection method. The results demonstrated that quartz particles induced the generation of hydroxyl radical in a dose-dependent manner, and the amount of the hydroxyl radicals was 10-10 mol/10 cells. The viability of alveolar macrophages exposed to quartz particles decreased with the increase of quartz concentration, showing a clear dose-response relationship. Hydroxyl radical scavenger mannitol could increase the viability of quartz-treated cells, suggesting that hydroxyl radical contributed directly to cell death. In this study this contribution accounted for about 5%-20% of cell death. The hydroxyl radical generating potential was found to be related to surface iron content of the quartz particles.

关键词： inhalable quartz hydroxyl radical capillary electrophoresis dose-response relationship iron.

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Pollution characteristics of atmospheric fine particles and their secondary components in the atmosphere of Shenzhen in summer and in winter

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Science China Chemistry 2006年第5期49卷 466-474页

作者： NIU Yuwen1,2,HE Lingyan1,2,HU Min2,ZHANG Jing2 & ZHAO Yunliang2 1. Shenzhen Graduate School of Peking University,Shenzhen 518055,China 2. state Joint key laboratory of Environmental simulation and Pollution control,College of Environmental Sciences,Peking University,Beijing 100871,China 1. Shenzhen Graduate School of Peking University Shenzhen 518055 China 2. State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing 100871 China

Two field measurements for atmospheric fine particles were conducted in Baoan district of Shenzhen during the summer and winter in 2004. Totally 30 sets of 24 h samples were collected, and then the mass concentrations and chemical compositions were determined. The seasonal varia- tions and secondary pollution characteristics of fine particles during the sampling periods were dis-cussed with meteorological factors. The results show that seasonal variations of atmospheric particles are significant in Shenzhen. The average mass concentrations of PM2.5 and PM10 in summer were 35 μg·m-3 and 57 μg·m-3, respectively, and those in winter were 99 μg·m-3 and 135 μg·m-3, respec-tively. The concentrations of both PM2.5 and PM10 in winter increased 184% and 137%, respectively, compared to those in summer. PM2.5 accounted for 61% and 75% of PM10 in summer and in winter, respectively, indicating severe fine particle pollution in Shenzhen. During the summer and winter sampling periods, the mean OC/EC ratios were 3.4 and 1.6, respectively. The estimated secondary organic carbon (SOC) averagely accounted for 56% and 6% of the total OC in summer and in winter, respectively, which implies a major contribution of SOC to OC in summer. During the continuous high temperature period in summer, both the concentrations and fractions of secondary aerosol compo-nents in PM2.5 were highly elevated, suggesting severe secondary pollution again. The prevailing wind was from South China Sea in summer, and the air quality was good. The prevailing wind in winter was from China's Mainland to the north, and the polluted air mass led to poor air quality.

关键词： PM2.5, mass concentration, secondary pollution, seasonal variation, Shenzhen.

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Method based on finite element mesh for CAD surface data repair

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Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics 2006年第2期23卷 142-145+174页

作者： Hu, Ping Gong, Ke-Jia Yang, Guang State Key Laboratory of Automobile Dynamic Simulation Institute of Automobile Body and Die Engineering Jilin University Changchun 130025 China

As a result of diverse precision adopted by different data format, approximation changes with the conversion in different data format will result in apertures or overlaps among the curved surface in the process of auto body CAD modeling or mesh generation, a method based on finite element mesh for CAD surface data repair is presented in this paper. The approach also can repair some defects of the mesh on curved surface. It can expand the range of the acceptable finite element mesh and is helpful to reduce the difficulty in high quality mesh generation of auto body CAD. The validity of the method is confirmed by the results of the complex industry-forming product.

关键词： automobiles

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Quantitative relationship between visibility and mass concentration of PM2.5 in Beijing

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Journal of Environmental Sciences 2006年第3期18卷 475-481页

作者： WANG Jing-li ZHANG Yuan-hang SHAO Min LIU Xu-lin ZENG Li-min CHENG Cong-lan XU Xiao-feng Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing 100871 China Beijing Meteorological Information and Network Center Beijing 100089 China

The pollution of particulate matter less than 2.5μm （PM2.5） is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that of the U,S, national ambient air quality standards proposed by U.S. EPA. The major contributors to mass of PM2.5 were organics, crustal elements and sulfate. The chemical composition of PM2.5 varied largely with season, but was similar at different monitor stations in the same season. The fine particles （PM2.5） cause atmospheric visibility deterioration through light extinction, The mass concentrations of PM2.5 were anti-correlated to the visibility, the best fits between atmospheric visibility and the mass concentrations of PM2.5 were somehow different： power in spring, exponential in summer, logarithmic in autumn, power or exponential in winter. As in each season the meteorological parameters such as air temperature and relative humidity change from day to day, probably the reason of above correlations between PM2.5 and visibility obtained at different seasons come from the differences in chemical compositions of PM2.5.

关键词： PM2.5 atmospheric urban aerosol air pollution meteorological factor visibility

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Research of driver optimal preview acceleration integrated decision model

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Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition) 2006年第SUPPL. 1期36卷 172-176页

作者： Guan, Hsin Zhang, Li-Cun Gao, Zhen-Hai State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130022 China

Research of driver model is not only important to the study of vehicle handling and stability, but also turns to be a key technology to the study of vehicle intelligent assistant driving systems and intelligent vehicle. Both driver's behavior and characters of vehicles move are analyzed in this paper to make the decision of lateral and longitudinal acceleration for its changing scale and bring out its increment network. Simple method with transform of reference frame is used to preview vehicle future course. Integrated decision of vehicle preview course is made by the index of efficiency with index of safety and handling. simulation on typical road verified the rationality and validity of the model.

关键词： automobile drivers

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Numerical simulation by using high-strength steel blanks in the multi-stage stamping process

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Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition) 2006年第SUPPL. 1期36卷 97-101页

作者： Zhao, Dong-Xu Tang, Yu-Jia Chen, Xiao-Bin Han, Ying-Chun Hu, Ping State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130022 China

High-strength steel blanks have been widely used in the automotive industry. The high-strength steel blanks with high yield strength have introduced many challenges to the formability in stamping process. However, in some situations the multi-stage process is a very effective solution for the stamping of high-strength blanks with a relatively lower formability than that of common steel blanks. Manufacturing defects often occure in the flange region during forming. In this paper, we demonstrate that these defects can be eliminated by modifying technical condition and technical procedure. In the multistage process, the change of strain path will be beneficial to the reduction of strain peaks and the utilization of the potential plasticity.

关键词： Metal forming

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simulation of vehicle TCS control logic

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Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition) 2006年第SUPPL. 1期36卷 187-190页

作者： Chen, Lin Lu, Ji-Ming Li, Yan Hu, Ping State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130022 China State Key Laboratory of Automobile Dynamic Simulation Institute of Auto-body and Die Engineering Jilin University Changchun 130022 China

Traction control System (TCS) is a typical active vehicle control technique. This paper focuses on the application of TCS, and a vehicle model was established. A control logic which was applied to start vehicles on the low adhesion and 'μ-split' road surface was proposed and simulated on the vehicle model. The results of these simulations indicate that the traction control logic can work well.

关键词： Vehicles

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Local surface shape recognition algorithm

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Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition) 2006年第SUPPL. 1期36卷 130-133+152页

作者： Guo, Wei Hou, Wen-Bin Hu, Ping Guo, Shu-Hua Liu, Da-You College of Materials Science and Engineering Jilin University Changchun 130022 China College of Computer Science and Technology Jilin University Changchun 130022 China State Key Laboratory of Automobile Dynamic Simulation Institute of Auto-body and Die Engineering Jilin University Changchun 130022 China

To improve the design automatism and make the design more independent of design specialist, it is necessary to develop the intelligent CAD systems based on CBR (Case-based Reasoning). In the case-based intelligent computer aided stamping processing design system, it needs retrieve the former useful case by the local shape of the automobile panel surface. So auto recognition of the local shape of the automobile panel surface is the key issue. To quickly recognize the surface local shape, an improved method based on spin-images is presented. Then, in order to recognize the local shape more accurately, an altitude-image method is proposed and introduced into independently developed intelligent die-face CAD system based on CBR. By these two methods, the local 3D surface shape would be recognized quickly and accurately. The results show that the algorithm is effectual.

关键词： automobile manufacture

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