全文获取类型
收费全文 | 2798篇 |
免费 | 307篇 |
国内免费 | 965篇 |
专业分类
安全科学 | 392篇 |
废物处理 | 101篇 |
环保管理 | 243篇 |
综合类 | 2083篇 |
基础理论 | 385篇 |
污染及防治 | 424篇 |
评价与监测 | 154篇 |
社会与环境 | 150篇 |
灾害及防治 | 138篇 |
出版年
2024年 | 14篇 |
2023年 | 41篇 |
2022年 | 157篇 |
2021年 | 152篇 |
2020年 | 161篇 |
2019年 | 108篇 |
2018年 | 114篇 |
2017年 | 138篇 |
2016年 | 103篇 |
2015年 | 145篇 |
2014年 | 170篇 |
2013年 | 231篇 |
2012年 | 247篇 |
2011年 | 247篇 |
2010年 | 203篇 |
2009年 | 220篇 |
2008年 | 229篇 |
2007年 | 228篇 |
2006年 | 239篇 |
2005年 | 192篇 |
2004年 | 135篇 |
2003年 | 93篇 |
2002年 | 96篇 |
2001年 | 92篇 |
2000年 | 83篇 |
1999年 | 61篇 |
1998年 | 33篇 |
1997年 | 29篇 |
1996年 | 33篇 |
1995年 | 28篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1984年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有4070条查询结果,搜索用时 15 毫秒
191.
Rui Xu Peter E. Mortimer Rong Ping Kuang Jun He Wu Di Zhang Fang Yin 《Journal of environmental science and health. Part. B》2013,48(8):651-657
This study focuses on assessing the impact of sublethal doses of paraquat on the survival, the emergence, the life span and the parasitic behavior of Diaeretiella rapae M’Intosh (Hymenoptera: Braconidae). The impact of sublethal doses was measured at room temperature using different densities of the cabbage aphid Brevicoryne brassicae. The results reveal that the field dose of paraquat caused 100% mortality in D. rapae. The percentage emergence of D. rapae decreased from 80.5% in the control group to 71.5% when treated with the lowest concentration of paraquat. Similarly, the life span of parasitoids that emerged from the mummy treated with paraquat also decreased significantly. Oviposition capability and ovipositor thrusting frequency of D. rapae also treated with sublethal dose paraquat decreased significantly along with a shortened patch residence time in the foraging area. 相似文献
192.
193.
194.
2001年10-12月国内环境事件数据 总被引:4,自引:18,他引:4
简要统计了201年10-12月国内发生的各种污染事件和自然灾害.包括大气污染、水体污染、放射性物质污染以及地震、病虫害、山体滑坡、泥石流等灾害. 相似文献
195.
2002年7-10月国内安全事故数据 总被引:3,自引:41,他引:3
统计了2002年7-10月国内发生的各种安全事故1231起,包括矿业事故、交通事故、爆炸事故、火灾、毒物泄露和中毒及其他事故.统计表明,在这些事故中,矿业事故最多,占63.1%,平均每天6.5起事故,其次是交通事故(18.6%)、其他事故(6.0%)、爆炸事故(4.8%)、毒物泄露和中毒(4.1%)、火灾(3.3%).1231起事故共死亡2 773人,伤3 206人,死亡人数的百分比分别为矿业事故48.9%、交通事故34.5%、其他事故8.3%、爆炸事故3.8%、泄露中毒2.8%、火灾1.7%;受伤人数的百分比分别为交通事故51.7%、泄露中毒19.1%、矿业事故12.2%、其他事故8.1%、爆炸事故7.0%、火灾1.9%. 相似文献
196.
1 深入学习邓小平理论,努力维护林业改革与发展的安全环境和林区社会稳定 深入学习邓小平理论是当前重大而紧迫的任务。当前,林业各项改革正稳步推进,但改革不可能一帆风顺,已经出现了这样那样的问题,也还会出现其它的问题。要解决这些问题,就要求我们深入学习邓小平理论,坚持解放思想、实事求是的思想路线,从改革、发展、稳定的大局出发,做好各项工作。1.1 讲学习,用理论指导实践 “讲学习、讲政治、讲正气”是今年全党、全国的一项重要工作,是进一步深刻领会邓小平理论的重要举措。“讲学习”冠以“三讲”之首,说… 相似文献
197.
用蒽醌生产中的废硫酸制备硫酸钾 总被引:2,自引:0,他引:2
研究了以蒽醌生产中的废硫酸为原料,通过缔合,置换,解缔等步骤,制备硫酸钾的最佳工艺条件。在最佳条件下,可使废硫酸中H2SO4的质量分数从23%降至0.60%,废硫酸成盐率为89.01%,硫酸钾纯度为95.85%。 相似文献
198.
揭开武汉东湖蓝藻水华消失之谜 总被引:115,自引:3,他引:112
水华(亦称湖靛)是湖泊富营养化最恶劣的表征之一。武汉东湖70年代至1984年间每年夏季出现蓝藻水华,1985年起突然消失,至今已有14年没有重现,原因何在?通过三次设在湖里的围隔试验,证明鲢鳙的大量放养,是水华消失的决定性因素。 相似文献
199.
A new energetic substance hexanitrohexaazaisowurtzitane (or CL-20) was tested for its toxicities to various ecological receptors. CL-20 (epsilon-polymorph) was amended to soil or deionized water to construct concentration gradients. Results of Microtox (15-min contact) and 96-h algae growth inhibition tests indicate that CL-20 showed no adverse effects on the bioluminescence of marine bacteria Vibrio fischeri and the cell density of freshwater green algae Selenastrum capricornutum respectively, up to its water solubility (ca. 3.6 mg l(-1)). CL-20 and its possible biotransformation products did not inhibit seed germination and early seedling (16-19 d) growth of alfalfa (Medicago sativa) and perennial ryegrass (Lolium perenne) up to 10,000 mg kg(-1) in a Sassafras sandy loam soil (SSL). Indigenous soil microorganisms in SSL and a garden soil were exposed to CL-20 for one or two weeks before dehydrogenase activity (DHA) or potential nitrification activity (PNA) were assayed. Results indicate that up to 10,000 mg kg(-1) soil of CL-20 had no statistically significant effects on microbial communities measured as DHA or on the ammonium oxidizing bacteria determined as PNA in both soils. Data indicates that CL-20 was not acutely toxic to the species or microbial communities tested and that further studies are required to address the potential long-term environmental impact of CL-20 and its possible degradation products. 相似文献
200.
Odor and gas release from anaerobic lagoons for treating swine waste affect air quality in neighboring communities but rates of release are not well documented. A buoyant convective flux chamber (BCFC) was used to determine the effect of lagoon loading rate on measured odor and gas releases from two primary lagoons at a simulated wind speed of 1.0 m s(-1). Concentrations of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) in 50-L air samples were measured. A panel of human subjects, whose sensitivity was verified with a certified reference odorant, evaluated odor concentration, intensity, and hedonic tone. Geometric mean odor concentrations of BCFC inlet and outlet samples and of downwind berm samples were 168 +/- 44 (mean +/- 95% confidence interval), 262 +/- 60, and 114 +/- 38 OU(E) m(-3) (OU(E), European odor unit, equivalent to 123 microg n-butanol), respectively. The overall geometric mean odor release was 2.3 +/- 1.5 OU(E) s(-1) m(-2) (1.5 +/- 0.9 OU s(-1) m(-2)). The live mass specific geometric mean odor release was 13.5 OU(E) s(-1) AU(-1) (animal unit = 500 kg live body mass). Overall mean NH3, H2S, CO2 and SO2 releases were 101 +/- 24, 5.7 +/- 2.0, 852 +/- 307, and 0.5 +/- 0.4 microg s(-1) m(-2), respectively. Nitric oxide was not detected. Odor concentrations were directly proportional to H2S and CO2 concentrations and odor intensity, and inversely proportional to hedonic tone and SO2 concentration (P < 0.05). Releases of NH3, H2S, and CO2 were directly proportional (P < 0.05) to volatile solids loading rate (VSLR). 相似文献