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81.
The purpose of this study was to determine certain blood biochemical parameters in hens of Isa Brown breed (n = 20) after nickel administration. Animals were divided into four groups (K, P1, P2, P3). Experimental hens (n = 5; in each group) received nickel (NiCl2) as peroral administration in drinking water in various doses (P1 – 0.02 g NiCl2/L; P2 – 0.2 g NiCl2/L; P3 – 2.0 g NiCl2/L of drinking water) for 28 days. The last group – K (n = 5) was the control, receiving no nickel. Biochemical parameters of mineral profile (calcium; phosphorus; magnesium; sodium; potassium) and of energy and enzymatic profile [(glucose; total cholesterol; total proteins; triglycerides; alanine aminotransferase (ALT) aspartate aminotransferase (AST) gamma glutamyl transferase (GGT) and glutamatdehydrogenase (GLDH)] were analyzed in blood serum on Day 0, 7, 14, 21 and 28 of the experiment. Average levels of mineral metabolism parameters were relatively stable apart from calcium. The evaluation registered a significant decrease in calcium during the experiment mainly in the group with highest nickel concentration in drinking water. No significant differences were detected between groups in energy and enzymatic profile apart from the concentrations of ALT on Day 7. In conclusion, there were significant associations between nickel levels and calcium and ALT in blood serum of the hens. No significant differences were detected in other biochemical parameters of mineral profile (P, Mg, Na, K) and energy and enzymatic profile (glucose, total cholesterol, total proteins, triglycerides, AST, GGT and GLDH) after nickel administration. Our results may contribute to an evaluation of reference levels of analyzed parameters, to monitor the health and nutritional status of hens. In this study also the negative effect of nickel mainly on calcium metabolism was detected.  相似文献   
82.
We investigated PCDDs and related compounds in the blood of young Japanese women, approximately 20 years of age, who had not yet had children, and discussed how the TEQ level of PCDDs and related compounds in their blood may affect the next generation. Means of total TEQ levels were 0.063 pg/g for whole blood basis and 21 pg/g for lipid basis. TEQ of PCDDs, PCDFs and coplanar PCBs accounted for about 43, 34 and 23% of the total TEQ in the whole blood basis, respectively. In the lipid basis, their values were about 44, 34 and 22%, respectively. Previously, we investigated PCDDs and related compounds levels in mother's breast milk, lymphocyte subpopulation and thyroid function of their children, and found negative correlations between the TEQ level of PCDDs and related compounds and CD4+/CD8+, and/or the TEQ level of PCDDs and related compounds and the T4 level in 36 mothers and children. Of these cases, the average age was approximately 28 years. PCDDs and related compounds may be related to immunopathy, such as atopic dermatitis. The effects of PCDDs and related compounds on babies of young Japanese women are important and must be further evaluated.  相似文献   
83.
Abstract

The presence of pesticides, both persistent and biodegradable, in the environment is a problem which is both significant and potentially dangerous to humans. An index of biodegradability is presented which is based on the correlation between environmental stability and fat solubility. Halogenated pesticides are, therefore, both more fat soluable and more resistant to biodegradation, while methylated pesticides are more water soluable and, therefore, more biodegradable. Three methods for detecting low‐levels of halogenated pesticides are presented: the Macro, the Micro “Florisil,”; and the Micro “Silica.”; A method is also presented to detect these chemicals in blood. Two methods for the detection of nonpersistent, organophosphorus and carbamate insecticides, Cholinesterase inhibition and urinary metabolites, are described. Finally, methods of monitoring human exposure through the detection of phenols, phenoxy acids, alkyl phophates, and anilines are presented.  相似文献   
84.
Workers at an electronics recycling plant have previously been shown to have elevated serum levels of polybrominated diphenyl ethers (PBDEs) compared to referents without occupational PBDE exposure. Subsequent structural changes and industrial hygiene measures at the plant were applied to improve the work environment. The present study aims to assess the impact of these work environment changes on the occupational exposure to PBDEs.

Blood were drawn from the workers and analyzed at two different laboratories, and serum concentrations of several PBDE congeners were determined by GC/MS or GC/HRMS. Cross-sectional studies were performed prior to (in 1997; N = 19) and after (in 2000; N = 27) workplace improvements. Longitudinal studies were performed on twelve of the workers that were sampled at both occasions.

Even though the amount of processed goods had doubled in 2000 as compared to 1997, there was a significant decrease in the serum levels of BDE-183 and BDE-209. For BDE-209 the levels observed in year 2000 were even lower than in referents with no occupational exposure. In contrast to the decrease of higher brominated diphenyl ethers, the concentrations of BDE-47 did not significantly change. For BDE-153, the cross-sectional study indicated no change, whereas the longitudinal follow up indicated a significant increase.

This study shows that the industrial hygiene improvements clearly reduced the occupational exposure to BDE-183 and BDE-209 at the plant. Still, the levels of hexa- to nonaBDEs but not BDE-209 were elevated, compared to referents with no occupational exposure.  相似文献   

85.
2,4-二硝基酚厌氧生物降解动力学研究   总被引:2,自引:2,他引:0  
研究了间歇试验条件下,2,4-二硝基酚(2,4-DNP)与葡萄糖共基质时的厌氧降解动力学.结果表明:2,4-DNP与葡萄糖能同时被微生物降解;葡萄糖浓度高低对2,4-DNP的降解影响不大,而2,4-DNP的存在明显影响COD的降解.当2,4-DNP浓度<225 mg/L时,其比降解速率随浓度增大而增大,浓度为225 mg/L时比降解速率达到最大;由于底物抑制,当2,4-DNP浓度>225 mg/L时,其比降解速率呈下降趋势.选用Andrews非竞争性抑制模型描述2,4-DNP厌氧降解动力学,对实验数据进行非线性拟合,求得模型参数qmaxKsKi分别为3.24 mg/(h·g)、196.23 mg/L和165.91mg/L,实验数据与该动力学方程拟合较好.  相似文献   
86.
利用莱茵衣藻(Chlamydomonasreinhardtii CC-125)与凝结芽孢杆菌(Bacilluscoagulans BS32)构建藻菌共生系统,通过Biolog EcoPlateTM微孔板筛选系统可利用碳源,进而研究葡萄糖和L-丙氨酸对藻菌共生系统中微藻和细菌生长的影响,并考察其对养殖废水的净化能力.结果...  相似文献   
87.
Fetal blood samples collected at 14–22 weeks' gestation by fetoscopy have been analysed for 25 different red cell antigens and anti-A antibodies. The results obtained demonstrate that the technique can be used to determine fetal blood groups during mid-pregnancy and also to provide the opportunity to study the physiological and pathological developments of blood groups and their antibodies and to manage more rationally those pregnancies threatened by erythroblastosis fetalis.  相似文献   
88.
PROBLEM: A prior study indicated that zero tolerance laws differ in their enforceability and likelihood of enforcement, with California's law being easier to enforce than New York's, and New Mexico's being the hardest of all. The question is, do these differences in enforcement affect teenagers' knowledge and perception of these laws? METHOD: A telephone survey was conducted to investigate awareness of the laws among 17-20 year olds in these three states and perceptions of enforcement. RESULTS: Estimated percentages of teenagers who knew of the laws were much higher in New York and California (71% and 65%, respectively) than in New Mexico (34%). Perceptions that police were enforcing the law, that licenses could be suspended, and that penalties were often applied were also lowest in New Mexico. IMPACT ON INDUSTRY: The potential of zero tolerance laws will not be realized without better awareness among young people. Full enforcement of the laws accompanied by publicity about the enforcement is recommended. Changes to the laws and their application may encourage enforcement efforts.  相似文献   
89.
The final clean-up of residential lead abatement projects in federally-supported housing, as well as in other housing in a number of states, must meet surface dust lead clearance levels expressed as g of lead per square foot. These clearance levels were established because hand-to-mouth ingestion of lead-contaminated dust is recognised as a major pathway through which many children are exposed. A dilemma exists because many floors in housing undergoing abatement are carpeted and the established clearance levels are generally not recommended for use on carpets. These clearance levels are also used as 'action levels' to determine whether exposure reduction activities are needed. The US Environmental Protection Agency is currently in the process of issuing standards for hazardous levels of lead in interior dust and bare soil under Title X of the Housing and Community Development Act of 1992, The Residential Lead-Based Paint Hazard Reduction Act of 1992. An effort to develop a potential surface dust lead clearance level for carpets was made using an existing vacuum dust collection method that has previously been shown to be a reliable indicator of childhood lead exposure. This method was designed for use on carpeted and non-carpeted surfaces. Using data from the Cincinnati Soil Lead Abatement Demonstration Project, the suggested floor-dust lead level where an estimated 95% of the population of children would be expected to have blood lead values below the national goal of 10 g dL–1, was more than an order of magnitude lower than the current floor-dust lead clearance level of 1080 g m–2 (100 g ft–2). Further comparisons of blood lead and carpet lead levels in other parts of the country should be performed before a risk-based lead loading clearance level is established.  相似文献   
90.
营养和环境条件对光滑球拟酵母葡萄糖代谢速度的影响   总被引:1,自引:0,他引:1  
增加培养基中Mg2 浓度,使磷酸果糖激酶和3-磷酸甘油醛脱氢酶活性提高22.2%和23.4%,葡萄糖消耗速率从1.94g L-1h-1提高到2.43g L-1h-1,提高了25%.较低kLa(200h-1)导致胞内ATP处于较低的水平,变构激活糖酵解关键酶活性,与高kLa(450h-1)比较,葡萄糖消耗速率(2.31g L-1h-1)提高了35%,低kLa虽能加快葡萄糖消耗,但不利于丙酮酸产量的提高.烟酸(NA)是细胞合成NAD 的前体,培养基中缺乏NA导致细胞生长微弱,葡萄糖消耗缓慢;NA质量浓度从4mg/L增加到8mg/L时,葡萄糖消耗速度(2.01g L-1h-1)和丙酮酸产量(46.4g/L)分别提高了48.4%和29%,高NA浓度有利于高葡萄糖消耗速度的提高,但降低了丙酮酸对葡萄糖的产率.一定浓度的(0~10mg/L)的外源电子受体乙醛提高了光滑球拟酵母中醇脱氢酶活性(提高8.6%),加速NAD 再生,降低NADH/NAD 比率,从而促进细胞生长和提高葡萄糖消耗速度.以上结果表明,营养和环境条件通过改变细胞胞内辅因子水平,影响糖酵解关键酶活性而改变葡萄糖代谢速度.图3表4参18  相似文献   
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