排序方式: 共有38条查询结果,搜索用时 0 毫秒
31.
32.
Jha SK Acharya RN Reddy AV Manohar SB Nair AG Chavan SB Sadasivan S 《Journal of environmental monitoring : JEM》2002,4(1):131-137
The concentrations and distribution of the elements, including heavy metals such as As, Ba, Br, Co, Cr, Cs, Fe, Ga, K, Mn, Na, Rb, Sc, Sr, Th and Zn, were investigated in dated sediment cores of Nainital Lake located in the Himalayan region, in Uttar Pradesh state of India, which is considered as a remote background area. The concentrations of the elements were measured by instrumental neutron activation analysis using the k0 method. The International Atomic Energy Agency certified reference material SL-3 was used to evaluate the accuracy of the method. The normalized data for a series of elements were used to understand the source of loading. Elements like Br, Co, Cr, Fe, K, Mn and Zn show a negative correlation with increasing depth whereas elements like As, Ba, Cs, Na and Rb show a positive correlation with increasing depth. By considering the concentration for the bottom segments of the core as close to the baseline concentration, recent flux values for different elements were calculated. An increase in the flux value was observed for Br, Cr, Fe, K, Mn and Zn, which can be attributed to anthropogenic contribution in recent years. 相似文献
33.
Environmental contamination by pesticides has been documented in biotic and abiotic components. These persistent organic pollutants are lipid soluble, nonbiodegradable, and endocrine disrupters. The present study was therefore planned to determine whether the levels of these pesticides like DDT and its metabolites DDD and DDE, dieldrin, heptachlor, and HCH and its isomers (alpha, beta, and gamma) were higher in blood of breast cancer patients when compared with normal women who did not suffer from major diseases like blood pressure, tuberculosis, diabetes, thyroid dysfunction, arthritis, cancer, etc. and had not undergone any major surgery. The results indicated that organochlorine pesticides taken for analysis were found significantly high in breast cancer patients irrespective of age, diet, and geographic distribution. 相似文献
34.
以我国典型的大型浅水湖泊太湖为研究区域,采用国内外常用的环境流体动力学模型(EFDC),结合拉丁超立方取样(LHS)方法,研究湖泊水动力模型中4个重要的外部输入条件,即3个边界输入条件(出入湖流量、风速、风向)和1个初始输入条件(初始水位),对模型水动力模拟结果(水位、水龄以及流场)的影响与贡献.结果表明,初始水位的设定对模拟全湖水位和水龄产生决定性影响,不确定性的贡献率分别达到85.73%和66.125%,对垂向平均流速影响的贡献率只有3%;风速对表面流速模拟结果影响较大,贡献率达到58.70%,而对水位和水龄的贡献率分别为5.25%和3.00%.在垂向上,各层流速受外部输入条件不确定性的影响规律相似,贡献率排序为风速(55%~60%)>风向(10%~15%)>初始水位≈出入湖流量(1%~5%).因此在模拟大型浅水湖泊水动力过程时,可以根据不同的输出目标能够有针对性地提高外部输入条件的准确度,为提高模型精确度提供有效信息. 相似文献
35.
36.
Chopade Rushikesh L. Pandit Pritam P. Nagar Varad Aseri Vinay Mavry Badal Sharma Anuj Singh Apoorva Verma Rohit Kumar Awasthi Garima Awasthi Kumud Kant Sankhla Mahipal Singh 《Environmental science and pollution research international》2023,30(5):11199-11209
Environmental Science and Pollution Research - The identification of harmful metal ions in aquatic environments is a global concern since these contaminants can have serious consequences for... 相似文献
37.
Acharya Shantanu 《Environmental science and pollution research international》2022,29(20):29704-29718
Environmental Science and Pollution Research - The need for electricity all over the world is enhancing significantly. A major portion of this demand is met by fossil fuels leading to substantial... 相似文献
38.
Shrivastava Rupali Rajaura Rajveer Singh Srivastava Subodh Awasthi Kumud Kant 《Environmental science and pollution research international》2021,28(4):3864-3865
Environmental Science and Pollution Research - 相似文献