检索结果-内蒙古大学图书馆

NO_x Release from Snow and Ice Covered Surface in Polar Regions and the Tibetan Plateau

Advances in Climate Change Research 2011年第3期000卷

作者： Feng Wang Weili Lin Junxia Wang Tong Zhu Centre for Atmosphere Watch & Services Meteorological Observation CentreChina Meteorological Administration Beijing 100081 China China Quality Certification Center Beijing 100070 China State Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China

The exchanges of NOx between snow and air have significant impact on the atmospheric components and photochemical processes in the overlying boundary *** exchanges increase the oxidizing capacity of the atmosphere and may have a crucial impact on the air signals that are retrieved from ice *** the recent years,sunlit snow and ice have been demonstrated to be important NOx sources in the polar atmospheric boundary *** paper makes a thorough review on the release of NOx from snow and ice,including field observations and experimental evidences,release mechanisms and influential parameters that affect such a release process,polar NOx concentrations and fluxes,and environmental impacts of the chemical processes of NOx in the polar atmospheric boundary *** the Tibetan Plateau,the released NOx observed recently in the sunlit snow/ice-cover is 1-order magnitude more than that in polar regions,but further scientific research is still needed to reveal its impact on the atmospheric oxidizing capacity.

关键词： NOx exchange between snow and air polar area atmospheric oxidizing capacity Tibetan Plateau

来源：评论

学校读者我要写书评

暂无评论

An Input-output Model to Analyze Sector Linkages and CO2 Emissions

引用

Procedia Environmental Sciences 2010年 2卷 1841-1845页

作者： Ju Liping Chen Bin State Key Laboratory of Water Environment Simulation and Pollution Control School of Environment Beijing Normal University Beijing China 100875 State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

International negotiations of reducing CO2 emissions address the question of how to account annual CO2 emissions of each sector of one city. The aim of this study is to establish the CO2 inventories focused on the supply chain emissions of CO2 emissions form each sector, e.g. agriculture, industry, transportation and tertiary industry. And to categorize upstream emission sources to identify the significant sectors that contribute the most to climate change. Moreover, IO-LCA method is chosen to evaluate the upstream carbon footprint and carbon dioxide emissions intensity of 28 economic sectors of Chongqing from 2002 to 2007. CO2 emissions the top-3 of which includes Transportation Equipment, Smelting and Pressing of Metals, Electricity, Steam Production and Supply, and CO2 emissions density the top-3 of which includes Coal Mining and Dressing, Nonmetal Minerals Mining and Dressing, Petroleum, Coking and Nuclear Fuel Processing.

关键词： input-output models CO2 emissions CO2 emission density Chongqing

来源：评论

学校读者我要写书评

暂无评论

Output feedback control of electronic throttle based on observer

Output feedback control of electronic throttle based on obse...

引用

作者： Hu, Yunfeng Chen, Hong Guo, Hongyan State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun Jilin 130025 China Department of Control Science and Engineering Jilin University Changchun Jilin 130025 China

ISBN: (纸本)9787894631046

The structure of the automotive electronic throttle control system is introduced in this paper. For the better tracking performance, a nonlinear electronic throttle model is setup for designing the controller. A observer is designed to estimate the unmeasured state variable. Backstepping technique is used to design the nonlinear output feedback controller. Finally, The simulation results are provided to demonstrate the effectiveness of the proposed controller.

关键词： controllers

来源：评论

学校读者我要写书评

暂无评论

Ecological network model analysis of China's endosomatic and exosomatic societal metabolism

引用

Procedia Environmental Sciences 2010年 2卷 1400-1406页

作者： Yating Li Yan Zhang Naijin Yang State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University 19 Xinjiekou Wai Street Beijing 100875 China

The uncontrolled development of socio-economy is at the great expense of ecological environment and resource consumption, bringing great obstacle to the sustainable development of the society. Analysis of the societal metabolic system is important to promote social sustainability. We analyzed the basic metabolic process and used ecological network analysis to study network structure and the functions of the societal metabolic system, as well as the complex ecological relationships. Based on the results of the utility relationship analysis, we can clarify the trophic levels of components by utility analysis, quantify the contribution of each component to the system by throughflow analysis, and determine the role and position of each component in the system. Taking China as an example, the ecological network model of the societal metabolic system has been defined to analyze the China's endosomatic and exosomatic societal metabolism. The basic components of the system consists of the internal environment, the agriculture sector, the mining sector, the manufacturing sector, the domestic sector, the possessing recycling sector and the external environment. It can be concluded that China is in the extensive style of economic development mode. For the exosomatic societal metabolism, it is necessary to advocate advanced products and technology import and control primary products export; for the endosomatic societal metabolism, it is necessary to reduce the primary industries, to encourage high-efficiency industries, and to expand the scale of the possessing recycling industries, so as to improve the self-repairing ability of the societal metabolic system, further we can make the development of our society much more healthier.

关键词： Endosomatic and exosomatic societal metabolisms ecological network analysis metabolic processes metabolic pathway structure metabolic relationship metabolic trophic level China

来源：评论

学校读者我要写书评

暂无评论

Assessment of river water quality in Pearl River Delta using multivariate statistical techniques

引用

Procedia Environmental Sciences 2010年 2卷 1220-1234页

作者： Xiaoyun Fan Baoshan Cui Hui Zhao Zhiming Zhang Honggang Zhang School of Environment Beijing Normal University State Key Joint Laboratory of Environmental Simulation and Pollution Control No. 19 Xinjiekouwai Street Beijing 100875 China

The Pearl River Delta (PRD) region is one of the most industrialized areas in China, and the river water is increasingly deteriorated due to anthropogenic pollution from the rapid economic development. Principal component analysis (PCA) and cluster analysis (CA) were used to identify characteristics of water quality and to assess water quality spatial pattern in this region. The results of PCA for three regions showed that the first four components of PCA analysis showed 85.52% and 89.25% of the total variance in the data sets of North River region and West River region, respectively, the first three components showed 84.63% of variance for data set of East River region. Results of CA based on the station score of PCA were that stations of North River region, East River region and West River region were grouped into four, three and four clusters, respectively corresponding to severe pollution, moderate pollution, light pollution (except for East River region) and good water quality, which indicated the similarity and dissimilarity of the river water quality. Since, the results suggest that PCA and CA techniques are useful tools for assessment of water quality and management of water resources.

关键词： Water quality principal component analysis cluster analysis Pearl River Delta

来源：评论

学校读者我要写书评

暂无评论

Study on Risk Zoning Technology of Major Environmental Risk Sources in Urban Scale and Its Application in Shanghai, China

引用

Procedia Environmental Sciences 2010年 2卷 1050-1062页

作者： Ya Yang Junwei Ma Beijing Normal University State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing 100875 P. R. China

Because of the inherent characteristics of the cities, such as high population density, complicated traffic, numerous pollution sources, etc., it has become very important to conduct environmental risk zoning in urban scale. Based on analyzing the current research situation of the regional environmental risk assessment and regional environmental risk zoning, this paper constructed the index system and the quantitative model of environmental risk zoning which are fit for urban scale, applies AHP to weight index and comprehensive evaluation method to calculate comprehensive risk index value. Then applying the method to Shanghai, and with the clustering function of SPSS and the visualization of GIS, the quantitative risk zoning map of Shanghai was obtained. The result can provide reference for environmental risk management of Shanghai.

关键词： Urban scale major environmental risk sources quantitative zoning technology Shanghai

来源：评论

学校读者我要写书评

暂无评论

Characteristics analysis of first flush effect on runoff pollutants from different urban underlying surfaces

Characteristics analysis of first flush effect on runoff pol...

引用

2010 International Conference on Mechanic Automation and control Engineering, MACE2010

作者： Wang, Wei Ouyang, Wei Hao, Fanghua School of Environment State Key Joint Laboratory of Environmental Simulation and Pollution Control Beijing Normal University Beijing China

ISBN: (纸本)9781424477388

Surface water quality is negatively influenced by the urbanization process to pollutant loads in stormwater runoff and increases in runoff peaks and volumes. The first flush effect is the main impetus for pollutants transportations. This study compared the characteristics of first flush effect on stormwater runoff from blacktop driveway, concrete roof, and roof with grassland. The first flush effects of chemical oxygen demand (COD), Ammonium-Nitrogen (NH3-N), Nitrate-Nitrogen (NO3-N) and Total Phosphorous (TP) were studied through monitoring of rainfall runoff on three different kinds of underlying surface, including bituminous roof, green roof and asphalt road. And four linear relationships for these pollutants were stimulated. The results demonstrated that the first flush effects of these four pollutants on three different kinds of underlying surface presented significantly. Over 80% of pollution load was delivered within the first 40% of the whole runoff period. Thus, retaining the initial runoff could effectively reduce runoff pollution. The linear relationships of four pollutants were presented significantly as well. Most of the correlation coefficients were more than 0.9, which showed that controlling pollution source could significantly diminish pollutants for the similarity of these four pollutants. ©2010 IEEE.

关键词： Roofs

来源：评论

学校读者我要写书评

暂无评论

control and simulation of two manipulators handling a flexible payload

Control and simulation of two manipulators handling a flexib...

引用

Chinese control Conference (CCC)

作者： Peng Zhang Yuanchun Li State key laboratory of automobile dynamic simulation Jilin University Changchun 130025 China Department of Communication Engineering Jilin University Changchun 130025 China

The traditional studies about two manipulators handling a flexible payload are mainly focused on configuration analysis and stability. In this paper, the control problem based on observer is studied. With the characteristic of flexible payload, the relations of the vibration states are got from the contact points between the end of manipulators and flexible payload. A new observer is designed based on the available states. In order to make the system easy to control, the model is divided into a slow subsystem and a fast subsystem. The controllers are designed for each subsystem, respectively. The stability of the whole system can be guaranteed with the observer and the control method. The simulation validates the observer and controller.

关键词： Observers Vibrations Equations Mathematical model Manipulators Payloads Cooperative systems

来源：评论

学校读者我要写书评

暂无评论

Method of Road Traffic Accidents Causes Analysis Based on Data Mining

Method of Road Traffic Accidents Causes Analysis Based on Da...

引用

International Conference on Computational Intelligence and Software Engineering (CiSE)

作者： Rui Tian Zhaosheng Yang Maolei Zhang College of Traffic and Transportation & State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun Jilin China Department of Traffic Info Engineering & Control Nanling Campus of Jilin University Changchun Jilin China

Aiming at the phenomenon of road traffic accident frequency, a method of road traffic accidents causes analysis based on data mining was put forward. First analyzed the related attributes and causes of road traffic accidents. Then introduced two kinds of basic theory of data mining : rough sets theory and the theory of association rules. Finally proposed the method of road traffic accidents causes analysis based on data mining. Using the method of traffic data analysis, can improve the road traffic safety management level effectively.

关键词： Accidents Roads Association rules Safety Vehicles Data analysis

来源：评论

学校读者我要写书评

暂无评论

Discharge-salinity relationships in Modaomen waterway, Pearl River estuary

引用

Procedia Environmental Sciences 2010年 2卷 1235-1245页

作者： Zhiming Zhang Baoshan Cui Hui Zhao Xiaoyun Fan Honggang Zhang School of Environment Beijing Normal University State Key Joint Laboratory of Environmental Simulation and Pollution Control No. 19 Xinjiekouwai Street Beijing 100875 China

There are many parameters determining salt intrusion in alluvial estuaries, including river discharge, channel shape, tidal forcing. In this paper, according to a well-tested theory for the calculation of salt intrusion in estuary regions, the salt intrusion length can be computed by the model that drives from this well-tested theory. There is an analytical method that presented for the salt intrusion in a funnel-shaped estuary. The method is tested against monitoring data from 6 stations during dry season in 2005 in the Modaomen water way. The average value of salt intrusion length to the point where the salinity on the cross section is 0.5‰ is 37.0 km. When the projects of the water transfer to meet the emergency stemming from salty tide put into effect, the salt intrusion length is decreased, which is 20.7 km on average. According to the length which is predicted by the model, we establish two optimal regression equations for the discharge-salt intrusion relationship at slack after flood tide during dry season (using the calculated length and measured length to discharge, respectively), one is an exponential regression equation, xL0 = 104.13 e-0.0007Q (R2=0.8276); the other is a power-law regression equation, xL0 = 106 Q-1.401 (R2=0.8007). Our results suggest that the salt intrusion length is dependent on the river discharge. The two regression equations used to determine discharge in the Modaomen water way which can explain river discharge-salt relationships, and offer a useful tool for predicting the relationships between estuarine salinity and river freshwater discharge.

关键词： Salt intrusion Freshwater discharge Modaomen waterway Pearl River estuary

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：