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Palaeorunoff estimations achieved from palaeoclimatic information for the southwest part of the North china Plain: an attempt to apply a climatological approach to palaeohydrology

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Journal of environmental sciences 2000年第3期12卷 330-336页

作者： WANG Hong\|ya, XIE Qiang (Department of Urban and environmental sciences,{2.,beijing 100871, china) 北京大学北京 1 0 0 871

Palaeoclimatic scenario projecting annual temperature and annual precipitation is firstly formalized with data available and speculations for the southwest part of the North china Plain (35— 37°N, 115—119°E) during the last 2.000 years. Then, with three regression equations relating annual runoff to annual precipitation and derived with data of modern hydrological and meteorological records, values of annual runoff are calculated in terms of the corresponding values of annual precipitation from this palaeoclimatic scenario for this region during this temporal interval. These results indicate that runoff is the most during 8000—3000 a B.P. and the least during 2.000—12.00 a B.P.; runoff occurring during 12.00—8000 a B.P. and during 3000—0 a B.P. is less than the one occurring during 8000—3000 a B.P. and more than the one occurring during 2.000—12.00 a B.P.; and the runoff occurring during 2.000—12.00 a B.P., 12.00—8000 a B.P., and 3000—0 a B.P. is respectively 43, 46 and 66 percent of the one occurring during 8000—3000 a B.P. Values of bankfull discharge for palaeochannels of the Yellow River flowing in this region during the same interval are calculated from available estimates of slope of stream bed of these palaeochannels with a regression equation relating bankfull discharge to slope of stream bed and ratios of bankfull discharge are further calculated from these values for different groups of palaeochannel formed during different time spans embraced in this interval. To conduct a cross check, these values and ratios of bankfull discharge are compared to the corresponding values and ratios of runoff occurring during roughly the same time spans. The same direction and similar relative magnitude of changes of the surface water occurring in this region during the last 2.000 years are indicated by these comparisons.

关键词： palaeorunoff the southwest part of the North china Plain palaeoclimate

Adjoint method for the optimum planning of industrial pollutant sources

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Science china Earth sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2. HU Fei2.& ZHU Jiang2.1. College of environmental sciences,{2., beijing 100871, china 2. LAPC, Institute of Atmospheric Physics, Chinese Academy of sciences, beijing 10002., china 1. College of environmental sciences Peking University 100871 Beijing China 2. LAPC Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

Biogenic Isoprene Emission Mechanism from ^(13)CO_2.Exposure Experiments

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Chinese Chemical Letters 2002年第9期13卷 897-900页

作者： Min SHAO State Joint Key Laboratory of environmental Simulation and Pollution Control, center for environmental sciences, peking university, beijing 100871 State Joint Key Laboratory of environmental Simulation and Pollution Control Center for Environmental Sciences Peking University Beijing 100871 China

Biogenic isoprene emissions have been believed to be from only photosynthesis processes in plant. However nocturnal isoprene emission from pine is detected. And by feeding 13CO2.to plants, it is found that both photos... 详细信息

关键词： Emissions volatile organic compounds (VOCs) 13C labeling isoprene.

Influence of fuel quality on vehicular NOx emissions

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Journal of environmental sciences 2001年第3期13卷 265-271页

作者： WANG Shao xia, SHAO Min, ZHANG Yuan hang (State Joint Key Laboratory of environmental Simulation and Pollution Control, center for environmental sciences, peking university, beijing 100871, china. State Joint Key Laboratory of environmental Simulation and Pollution Control Center for Environmental Sciences Peking University Beijing 100871 China.

The quality of gasoline and diesel fuel affects pollutant emissions from vehicles. By applying the COMPLEX model, developed by the US EPA and industry to relate fuel composition to vehicle emissions, this paper estimates the influence of improvements in gasoline quality to lower vehicular NOx emissions. A case study is performed for Guangzhou City that has NOx concentrations significantly above the national ambient air quality standards (NAAQS). The paper discusses the potential for reducing NOx in Guangzhou by improving the quality of gasoline.

关键词： Air quality Automotive fuels Gasoline

Flux of dimethylsulfide in the Jiaozhou Bay,china

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Journal of environmental sciences 1997年第1期9卷 80-85页

作者： Hu Min Tang Xiaoyan center of environmental {2.,peking university,beijing 100871,chinaLi Jinlong Yu Zhongju Department of Technical Physics,peking university,beijing 100871,china center of environmental {2. Peking University Beijing 100871 China Department of Technical Physics Peking University Beijing 100871 China

Seasonal measurements of dimethylsulfide(DMS)in surface waters were carried out during 1993-1994 in the Jiaozhou Bay.A seasonal variation is observed for DMS concentrations in seawater,ranging from 0.6 to 8.97 nmol S/L with the highest values in spring.A factor of 4 was measured for DMS concentrations with mean concentrations of 5.85 nmol S/L or 6.58 nmol S/L in spring and 1.40nmol S/L in winter.A sea-to-air flux of DMS also showed a seasonal variation.

关键词： dimethyl sulfide flux seawater atmosphere.

A SYSTEM DYNAMICS APPROACH FOR SUSTAINABLE DEVELOPMENT IN THE MIYUN RESERVOIR AREA, china

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Chinese Geographical Science 2002年第2期12卷 157-165页

作者： SUN Yan feng,GUO Huai cheng,QU Guang yi(center for environmental {2.,peking university,beijing 100871,P. R. china) center for environmental {2. Peking University Beijing 100871 P. R. China

Miyun Reservoir was designated as the water source of beijing City in 1982. Since that time, socio economic development in Miyun Area has been slowing due to the restriction of severe environmental standards. More and more attention from the public and government has been paid to the regional sustainable development. And an effective planning for the local society management system is urgently desired. In this study, a regional sustainable development system dynamics model, named MiyunSD, is developed for supporting this planning task. MiyunSD consists of dynamic simulation models that explicitly consider information feedback that governs interactions in the system. Such models are capable of simulating the system′s behavior and predicting its developing situation of the future. For the study case, interactions among a number of system components within a time frame of fifteen years are examined dynamically. Three planning alternatives are carefully considered. The base run is based on an assumption that the existing pattern of human activities will prevail in the entire planning horizon, and the other alternatives are based on previous and present planning studies. The different alternatives will get different system′s environmental and socio economic results. Through analyzing these dynamic results, local authorities may find an optimal way to realize the objectives that the regional environment will be well protected and at the same time the economy will be rapidly developed.

关键词： Miyun reservoir sustainable development model policy management system dynamics

Effect of CH3OOH on the atmospheric concentration of OH radicals

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Progress in Natural Science:Materials International 2006年第11期16卷 1141-1149页

作者： WANG Caixia and CHEN Zhongming**(The State Key Laboratory of environmental Simulation and Pollution Control, College of environmental {2., peking university, beijing 100871, china) [a]The state key Laboratory of environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing China

Methyl hydroperoxide （CH3OOH, MHP） is known to be a significant sink and reservoir of HOx and ROx radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 2.3±2.K and total pressure of 1.01×105 Pa, using the long path Fourier transform infrared （LP-FTIR） spectrometry. OH radicals are generated by the photolysis of O3 in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be （3.99±0.15）×10 -12.cm3·molecule -1 ·s -1 , and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91±0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.

关键词： OH radicals methyl hydroperoxide rate coefficient UV photolysis gas-phase reaction LP-FTIR.

Mixed uncertainty analysis of polycyclic aromatic hydrocarbon inhalation and risk assessment in ambient air of beijing

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Journal of environmental sciences 2008年第4期20卷 505-512页

作者： College of environmental sciences and Engineering,{2., beijing 100871, china GUO Huaicheng LIU Yong HUANG Kai WANG Zhen ZHAN Xinye 不详 School of Natural Resources and Environment University of Michigan Ann Arbor 48109 USA Department of Civil and Resource Engineering Dalhousie University Halifax NS B3JIZ1 Canada

This article presents the application of an integrated method that estimates the dispersion of polycyclic aromatic hydrocarbons （PAHs） in air, and assesses the human health risk associated with PAHs inhalation. An uncertainty analysis method consisting of three components were applied in this study, where the three components include a bootstrapping method for analyzing the whole process associated uncertainty, an inhalation rate （IR） representation for evaluating the total PAH inhalation risk for human health, and a normally distributed absorption fraction （AF） ranging from 0% to 100% to represent the absorption capability of PAHs in human body. Using this method, an integrated process was employed to assess the health risk of the residents in beijing, china, from inhaling PAHs in the air. The results indicate that the ambient air PAHs in beijing is an important contributor to human health impairment, although over 68% of residents seem to be safe from daily PAH carcinogenic inhalation. In general, the accumulated daily inhalation amount is relatively higher for male and children at 10 years old of age than for female and children at 6 years old. In 1997, about 1.73% cancer sufferers in beijing were more or less related to ambient air PAHs inhalation. At 95% confidence interval, approximately 2.2.309 individual cancer incidences can be attributed to PAHs pollution in the air. The probability of greater than 500 cancer occurrence is 15.3%. While the inhalation of ambient air PAHs was shown to be an important factor responsible for higher cancer occurrence in beijing, while the contribution might not be the most significant one.

关键词： polycyclic aromatic hydrocarbons (PAHs) uncertainty analysis human health risk

Reinvestigation of the Henry's law constant for hydrogen peroxide with temperature and acidity variation

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Journal of environmental sciences 2010年第4期22卷 570-574页

作者： Daoming Huang,Zhongming Chen The State Key Laboratory of environmental Simulation and Pollution Control,College of environmental {2. and Engineering,peking university,beijing 100871,china. [a] The State Key Laboratory of environmental Simulation Pollution Control College of Environmental Sciences Engineering Peking University Beijing 100871 China

Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx （OH and HO2. radicals and O3 in the atmosphere. Its partitioning between gas and aqueous phases in the atmosphere, usually described by its Henry＇s law constant （KH）, significantly influences its role in atmospheric processes. Large discrepancies between the KH values reported in previous work, however, have created uncertainty for atmospheric modelers. Based on our newly developed online instrumentation, we have re-determined the temperature and acidity dependence of KH for hydrogen peroxide at an air pressure of （0.960 ± 0.013） atm （1 atm = 1.0132. × 10^5 Pa）. The results indicated that the temperature dependence of KH for hydrogen peroxide fits to the Van＇t Hoff equation form, expressed as lnKH = a/T - b, and a = -△H/R, where KH is in M/atm （M is mol/L）, T is in degrees Kelvin, R is the ideal gas constant, and AH is the standard heat of solution. For acidity dependence, results demonstrated that the KH value of hydrogen peroxide appeared to have no obvious dependence on decreasing pH level （from pH 7 to pH 1）. Combining the dependence of both temperature and acidity, the obtained a and b were 702. ± 138 and 11.97 ± 0.48, respectively, AH was （58.40 ± 1.15） kJ/（***）, and the uncertainties represent σ. Our determined KH values for hydrogen peroxide will therefore be of great use in atmospheric models.

关键词： hydrogen peroxide Henry's law constant atmosphere acidity