全文获取类型
收费全文 | 492篇 |
免费 | 37篇 |
国内免费 | 126篇 |
专业分类
安全科学 | 35篇 |
废物处理 | 36篇 |
环保管理 | 30篇 |
综合类 | 263篇 |
基础理论 | 94篇 |
污染及防治 | 116篇 |
评价与监测 | 39篇 |
社会与环境 | 13篇 |
灾害及防治 | 29篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 30篇 |
2021年 | 36篇 |
2020年 | 29篇 |
2019年 | 21篇 |
2018年 | 30篇 |
2017年 | 25篇 |
2016年 | 23篇 |
2015年 | 46篇 |
2014年 | 30篇 |
2013年 | 51篇 |
2012年 | 57篇 |
2011年 | 40篇 |
2010年 | 42篇 |
2009年 | 34篇 |
2008年 | 31篇 |
2007年 | 16篇 |
2006年 | 27篇 |
2005年 | 22篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有655条查询结果,搜索用时 609 毫秒
601.
洪水作为复杂的时间序列,仅从时域角度分析其特征,无法全面反映洪水时间序列的特性。文章采用Morlet小波分析方法,从频域角度解读洪水时间序列的特性。研究表明:洪水时间序列不论是洪峰时间序列,还是各场洪水的演进过程,其频域信息均能更完整地反映出洪水特性。通过Morlet小波的时–频域转化,洪水演进过程在频域上所占的频域带宽窄程度,反映出洪水演进过程的不同信息,能有效地提取洪峰流量过程。洪峰流量过程的频域信息更加直观、有效地反映出洪水的洪峰流量过程涨、落特性。 相似文献
602.
603.
604.
The cytotoxic effects of seven carbamate pesticides, aldicarb, aldicarb sulfone, aldicarb sulfoxide, benfuracarb, pirimicarb, propoxur and thiobencarb, were compared in Chinese hamster ovary (CHO-K1) cell line of Circetulus griseus. The endpoints evaluated were lysosomal function by neutral red assay and mitochondrial integrity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay). The carbamates tested were evaluated in both serum-free medium and in serum-containing medium. Results demonstrate that CHO-K1 lysosomes appeared more susceptible to propoxur, aldicarb and its metabolites than mitochondria. Aldicarb was the most toxic carbamate pesticide tested on CHO-K1 cells and aldicarb sulfoxide the least. The presence of foetal calf serum (FCS) diminished significantly the cytotoxicity of tested carbamates. 相似文献
605.
重污染河道钝化底泥对紫花苜蓿生长及重金属吸收的影响 总被引:1,自引:0,他引:1
河道底泥重金属污染是限制底泥资源化利用的主要因素。采用盆栽实验研究了沈阳细河重污染河道底泥与碱性炉渣和锯木屑配比后养分含量变化及对紫花苜蓿(Medicago sativa L.)生长的影响。结果表明:钝化底泥基质中有机质和养分含量较高,能满足植物初期生长所需养分,但相对保肥能力较低。将底泥采用碱性炉煤渣钝化处理后,钝化底泥基质上紫花苜蓿生物量及株高均显著高于纯底泥处理,其中SD4处理(河道底泥∶燃煤炉渣∶锯木屑=1.0∶1.0∶0.5)中的植株长势最好。所有钝化底泥基质上紫花苜蓿地上部和根部重金属含量极显著降低,而且根部重金属含量显著高于地上部含量。与纯底泥对照相比,钝化底泥基质上紫花苜蓿地上部和根部对重金属Cd、Cu、Pb、Zn的富集系数(BCF)和转移系数(TF)均小于1.0。 相似文献
606.
Alba Pineda-Solano Lina R. Saenz Victor Carreto Maria Papadaki M. Sam Mannan 《Journal of Loss Prevention in the Process Industries》2012,25(5):797-802
This work shows an application of inherent safety principles to a reaction widely used in the pharmaceutical industry. More specifically, it incorporates the teachings of Trevor Kletz into the design of an inherently safer process for the N-oxidation of alkylpyridines. This reaction is of interest because of the hazards resulting from the undesired, gas-generating decomposition of hydrogen peroxide, the oxidizing agent. The generation of oxygen, combined with the flammability of the alkylpyridines, represents a serious fire and explosion hazard for this process. The purpose of this paper is to demonstrate how an inherently safer process can be potentially achieved by designing improved reactors and by assessing conditions that reduce or eliminate the hazards. Furthermore, it is shown that such improvement in safety increases the efficiency of the process and results in a cost reduction. 相似文献
607.
Sludge as dioxins suppressant in hospital waste incineration 总被引:1,自引:0,他引:1
Yan M Li X Yang J Chen T Lu S Buekens AG Olie K Yan J 《Waste management (New York, N.Y.)》2012,32(7):1453-1458
Nitrogen containing compounds such as ammonia, urea and amines can effectively inhibit the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Sewage sludge accumulates both sulfur and nitrogen during wastewater treatment so it could be used to reduce PCDD/Fs formation. Indeed, it is observed in this study that the gas evolving from the sludge drying process can significantly suppress chlorobenzene (CBz) and PCDD/Fs formation from fly ash collected from a hospital waste incinerator. For instance, the reduction of hexachlorobenzene (HxCBz) and PCDD/Fs amount was 92.1% and 78.7%, respectively, when the drying gas evolving from 2g sludge flew through 2g fly ash. These tests were conducted in the frame of projects devoted to hospital waste incineration. The disposal technology for hospital waste (HW), developed in this institute, features rotary kiln pyrolysis combined with post-combustion followed by flue gas cleaning. Hence, some preliminary tests were devoted to investigate dioxins suppression by co-pyrolysis and co-combustion of polyvinyl chloride (PVC) and sludge in lab scale. More experimental research will be conducted to appropriately assess these effects of sludge on PCDD/Fs emissions during co-pyrolysis/combustion of HW and sludge. 相似文献
608.
建立了固相萃取—微波衍生化—气相色谱-质谱联用法快速同时测定水中雌酮(E1)、17α-雌二醇(α-E2)、17β-雌二醇(β-E2)、雌三醇(E3)、17α-乙炔基雌二醇(EE2)、双酚A(BPA)等6种雌激素物质的分析方法,对色谱柱升温程序、固相萃取及衍生化条件进行了优化。色谱柱最佳升温程序为:初始温度50 ℃,保持2 min;以20 ℃/min速率升至260 ℃,保持5 min;最后以10 ℃/min速率升至280 ℃,保持5 min。实验结果表明,在选取 HC-C18萃取小柱、添加双(三甲基硅烷基)三氟乙酰胺(BSTFA)+1%三甲基氯硅烷(TMCS)+吡啶作为衍生化试剂、微波315 W衍生化加热4 min的条件下,6种目标物标准曲线的相关系数均大于0.999,BPA、E1、EE2及E3的线性范围为3~300 ng/L,17α-E2及17β-E2的线性范围为5~300 ng/L,方法检出限为2.0~5.0 ng/L,加标回收率为76.45%~96.24%。 相似文献
609.
Yi KW Lee MY 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(1):17-22
Effects of various environmental stresses such as heavy metals, salts and low (high) temperature on the secretion of peroxidase isozyme into the medium were examined in rice (Oryza sativa cv. Nak-Dong) suspension culture. The major extracellular peroxidases secreted into the medium by various stresses were cationic isoperoxidases. A far migrating cationic isoperoxidase RC3 was isolated from the medium after application of CaCl2, the effective stimulator for peroxidase secretion. Isolation of extracellular isoperoxidase RC3 was accomplished by ammonium sulfate fractionation, CM-cellulose cation-exchange chromatography, and Sephacryl S-100 gel filtration. The enzyme was a glycoprotein having molecular weight of approximately 34 KDa as determined by SDS-PAGE and 38 KDa by Sephacryl S-100 gel filtration. The pI value of the enzyme was 8.9. Kinetic studies revealed that the optimum pH of the enzyme was 6.0 for guaiacol and H2O2, and the Km values for guaiacol and H2O2 were 10.5 mM and 3.2 mM, respectively. 相似文献
610.
Calculation of clothing insulation by serial and parallel methods: effects on clothing choice by IREQ and thermal responses in the cold. 总被引:1,自引:0,他引:1
Kalev Kuklane Chuansi Gao Ingvar Holmér Lina Giedraityte Peter Br?de Victor Candas Emiel den Hartog Harriet Meinander Mark Richards George Havenith 《International journal of occupational safety and ergonomics》2007,13(2):103-116
Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values. Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted. 相似文献