检索结果-南通市图书馆

A COUPLED MODEL OF HYDRODYNAMICS AND water quality FOR YUQIAO RESERVOIR IN HAIHE RIVER BASIN

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2008年第5期20卷 574-582页

作者： LIU Xiao-bo PENG Wen-qi HE Guo-jian LIU Jing-ling WANG Yu-chun School of Environment Beijing Normal University Beijing 100875 China Department of water Environment China Institute of Water Resources and Hydropower Research Beijing100038 China Department of Hydraulic Engineering State Key Laboratory of Hydroscience and Engineering TsinghuaUniversity Beijing 100084 China

In order to simulate the characteristics of hydrodynamic field and mass transport processes in the Yuqiao Reservoir （YQR）, a 2-D coupled model of hydrodynamics and water quality was developed, and the water-quality related state variables in this model included CODMn, TN and TP. The hydrodynamic model was driven by employing observed winds and daily measured flow data to simulate the seasonal water cycle of the reservoir. The simulation of the mass transport and transformation processes of CODMn, TN and TP was based on the unsteady diffusion equations, driven by observed meteorological forcing and external loadings, with the fluxes form the bottom of reservoir and the plant photosynthesis and respiration as internal sources and sinks. A finite volume method and Alternating Direction Implicit （ADI） scheme were used to solve these equations. The model was calibrated and verified by using the data observed from YQR in two different years. The results showed that in YQR, the wind-driven current was an important style of lake current, while the concentration of water quality item was decreasing from east to west because of the external pollutant loadings. There was a good agreement between the simulated and measured values, with the minimal calculation error percent of 0.1% and 2.6% and the mean error percent of 44.0% and 51.2% for TN and TP separately. The simulation also showed that, in YQR, the convection was the main process in estuaries of inflow river, and diffusion and biochemical processes dominate in center of reservoir. So it was necessary to build a pre-pond to reduce the external loadings into the reservoir.

关键词： model simulation Yuqiao Reservoir (YQR) wind driven current water quality

EVALUATION OF water AND SEDIMENT QUALITIES AT RIVER MOUTHS IN THE HAIHE RIVER SYSTEM

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2007年第4期22卷 318-326页

作者： Cheng LIU1, Zhao-Yin WANG1,2, Yun HE3, and Dongsheng CHENG3 1 Prof., Dr., International Research and Training center on Erosion and Sedimentation, Beijing, 100044, china 2 Prof., Dr., Dept. of Hydraulic Engineering, Tsinghua University & International Research and Training center on Erosion and Sedimentation, Beijing, 100084, china 3 Dr., Senior Engineer, china Institute of water Resources and Hydropower Research, Beijing, 100044, china Int Res & Training Ctr Eros & Sedimentat Beijing 100044 Peoples R China Tsinghua Univ Dept Hydraul Engn Beijing 100084 Peoples R China Int Res & Training Ctr Eros & Sedimentat Beijing 100084 Peoples R China china Inst water Resources & Hydropower Res Beijing 100044 Peoples R China

water and sediment qualities are studied by analyzing samples taking from the mouths of the Haihe, Duliujian, New Ziya and Beipai rivers in the Haihe river basin in north china in 2005 and 2001, in order to find the changes of water and sediment pollutions. The concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP) are analyzed and results have been compared for the two times. The in-situ measurement for Dissolved Oxygen (DO) and Sediment Oxygen Demand (SOD) rates were carried at the Haihe and Duliujian river mouths in 2006. The results show that the waters of the 4 river mouths are still seriously polluted, though much improved in the case of the Haihe and Duliujian rivers. The main pollutants are TP and TN in the New Ziya and Beipai rivers and mercury (Hg) at all 4 river mouths. Compared with those in 2001, the concentrations of almost all metals and arsenic in the 4 river mouths have decreased. water quality at Haihe and Duliujian shows an improving trend, while the water quality at Beipai is similar to that of 2001. In contrast, water at the New Ziya river mouth is more severely polluted. The sediments in the 4 river mouths are not seriously polluted by heavy metals but are polluted by nitrogen and phosphorus. Most of the pollutant contents in the sediments show little change between 2001 and 2005. The in-situ DO and SOD measurement shows that the waters at the Haihe river mouth is in the state of oxygen depletion, and SOD is important consumer of DO at the river mouths. The overall analysis shows that increasing water pollution and eutrophication in waters far from cities are ongoing causes of concern.

关键词： River mouth water quality Sediment quality Eutrophication Sediment oxygen demand

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

太阳集热器性能测试试验系统

太阳能学报 2004年第3期25卷 278-282页

作者：郑小年黄巧燕张晓黎辛礼华中科技大学数控工程中心武汉430074 湖北省产品质量监督检验所武汉430061

在太阳跟踪精度,流量测量控制精度和温度测量控制精度满足条件的情况下,通过压力降落试验,时间常数试验,稳态效率试验以及入射角修正系数试验,测试太阳集热器的综合性能。

关键词：试验太阳集热器综合性能

Research on water Resources Conservation of Mountain River Based on the Concept of Region Partition

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第4期8卷 582-591页

作者： LIU Yubang TAO Qingyu LIANG Chuan WU Yong State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 61o059 China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource & Hydropower Sichuan University Chengdu 61oo65 China Academic Journal center of Chengdu University of Technology Chengdu 61oo59 China

Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient,and its level is far from being adaptable to the development of a harmonious *** mountain ecosystems play a key role in water resources conservation of mountain rivers,and the characteristics of mountain ecosystems and hydrologic features of mountain river follow strong temporal and spatial distribution,partition theory can be applied to the water resources conservation of mountain *** theory observes the following partition principles:regional relativity,spatial continuity,integralcounty,meeting management needs,hierarchical principle,and comparability *** it lays equal emphasis on both water resources conservation and environmental protection,on both water quality conservation and water quantity protection,on the combination of water features,water cycle and water *** the partition methods,index method and map superposition method will be applied in region *** example of region partition of water resources conservation in the upper reaches of the Yangtze River shows that the partition theory is practicable in water resources conservation of mountain rivers,and it provides a platform for future study in water resources conservation.

关键词： water resources conservation Mountain river Region partition Mountain ecosystems

在线全文

学校读者我要写书评

暂无评论

油脂中成分的气相色谱-质谱分析

分析测试学报 2007年第S1期26卷 275-277页

作者：许华刘晓毅曹红北京市海淀区产品质量监督检验所/国家食品质量安全监督检验中心北京市海淀区产品质量监督检验所/国家食品质量安全监督检验中心北京100083 北京市理化分析测试中心北京100089

A method that components were extracted by hydrodistillation and analyzed by purge and trap-gas chromatography-mass spectrometry was developed;And a method that fats and oils were esterfied by BF3-CH3OH,and analyzed by gas chromatography-mass spectrometry were developed *** and oils samples were analyzed with these developed methods.

关键词： Fats and oils Components Gas chromatography-mass spectrometry

Cadmium Bioaccumulation by Three Varieties of Lentinula edodes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

食用菌学报 2006年第4期 93-94页

作者： XU Li-hong 1*, WU Ying-miao 2, YE Chang-wen 2, CHEN Qiao-biao 2, WANG Gang-jiu 1 1Farm Products quality Supervision and inspection center of the Chinese Agricultural Department, Hangzhou, Zhejiang 310021, china and Institute for quality and Standard of Farm Products, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang 310021, china 2Qingyuan Science and Research center of Edible Fungi, Qingyuan, Zhejiang 323800, china

Three strains of Lentinula edodes, the largest category of edible mushrooms exported from china, were selected for a comparative study of cadmium (Cd) bioaccumulation capacity. L. edodes strain qingke-20 exhibited the highest Cd bioaccumulation capacity from growth substrates containing both high and low concentrations of the heavy metal. Lower levels of Cd bioaccumulation were observed with strain 241-1, whereas strain 9015 exhibited the lowest bioaccumulation capacity. This latter strain appeared to be relatively resistant to Cd uptake and may be suitable for commercial production purposes.

关键词： Bioaccumulation Cadmium Heavy metal Lentinula edodes

A discussion on typhoon occurred in the Haikou Bay and impact mechanism on seawater quality

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2001年第3期20卷 355-362页

作者： Chen Chunhua, Li Qiaoxiang 1.Marine Exploitation Plan & Design Research Institute of Hainan Province, Haikou 570203, china 2.Marine Monitoring center of Hainan Province, Haikou 570011, china Marine Exploitation Plan/Design Res. Institute of Hainan Province Haikou 570203 China Marine Monitoring Ctr. Hainan Prov. Haikou 570011 China

water quality parameters such as pH, DO, COD, PQ4 - P, SiO3 - Si, NO2 - N, NO3 -N in the Haikou Bay were monitored respectively before and after Typhoon 9618 occurring on Sep. 18, 1996. Based on the statistics of typhoon in the Haikou Bay and numerical calculation of stormy current, the mechanism of water quality variation caused by typhoon is discussed. The typhoon impact on the Haikou Bay usually appears between July and November, most usually between August and October. The monitoring results before a typhoon were different from that. The stormy wave and windstorm cur-rent stir up the sediment in near-shore bottom and make the bottom water mix with the surface water strongly, specially windstorm current with strong velocity at the head of the bay stirs up higher pollutants sediment near sea area of sewage outfall, and heavy rain with typhoon carries the pollutants from land through the Nandu River to the Haikou Bay, so the contents of COD, PO4 - P, NO4 - N, NO3 ~N, SiO3 after a typhoon are higher than those before. Windstorm current is violent, which makes offshore high DO water exchange more frequently with inner bay water and oxygen in the air dissolves in sea water faster, so DO content after typhoon is higher than that before typhoon. This strong action of water exchange also causes lower pH change before and after the typhoon.

关键词： The Haikou Bay typhoon seawater quality impact mechanism