全文获取类型
收费全文 | 5231篇 |
免费 | 379篇 |
国内免费 | 1480篇 |
专业分类
安全科学 | 390篇 |
废物处理 | 242篇 |
环保管理 | 847篇 |
综合类 | 3297篇 |
基础理论 | 724篇 |
污染及防治 | 942篇 |
评价与监测 | 364篇 |
社会与环境 | 226篇 |
灾害及防治 | 58篇 |
出版年
2024年 | 5篇 |
2023年 | 58篇 |
2022年 | 120篇 |
2021年 | 141篇 |
2020年 | 133篇 |
2019年 | 153篇 |
2018年 | 167篇 |
2017年 | 183篇 |
2016年 | 254篇 |
2015年 | 228篇 |
2014年 | 362篇 |
2013年 | 501篇 |
2012年 | 491篇 |
2011年 | 454篇 |
2010年 | 377篇 |
2009年 | 459篇 |
2008年 | 325篇 |
2007年 | 442篇 |
2006年 | 391篇 |
2005年 | 322篇 |
2004年 | 198篇 |
2003年 | 195篇 |
2002年 | 167篇 |
2001年 | 146篇 |
2000年 | 131篇 |
1999年 | 154篇 |
1998年 | 97篇 |
1997年 | 60篇 |
1996年 | 63篇 |
1995年 | 87篇 |
1994年 | 43篇 |
1993年 | 39篇 |
1992年 | 38篇 |
1991年 | 21篇 |
1990年 | 16篇 |
1989年 | 6篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有7090条查询结果,搜索用时 281 毫秒
281.
对Ni/Fe二元金属表面特性、在氯代有机物还原脱氯中的应用以及还原机理的研究概况进行了综述,并讨论了实际应用中存在的问题和发展前景. 相似文献
282.
高层建筑的消防设计审核是消防执法中的重要环节.以规范为指导,根据我国国情和具体工程设计情况,对高层建筑临时高压消防水系统中有关消防水泵房的出水管的布置、高位消防水箱的容积以及增压设施的设置几方面的规定进行了探讨. 相似文献
283.
284.
285.
For phosphorus (P) recovery from wastewater, the effect of humic substances (HS) on the precipitation of calcium phosphate was studied. Batch experiments of calcium phosphate precipitation were undertaken with synthetic water that contained 20 mg/L phosphate (as P) and 20 mg/L HS (as dissolved organic carbon, DOC) at a constant pH value in the range of 8.0-10.0. The concentration variations of phosphate, calcium (Ca) and HS were measured in the precipitation process; the crystalline state and compositions of the precipitates were analysed by powder X-ray diffraction (XRD) and chemical methods, respectively. It showed that at solution pH 8.0, the precipitation rate and removal efficiency of phosphate were greatly reduced by HS, but at solution pH ≥9.0, the effect of HS was very small. The Ca consumption for the precipitation of phosphate increased when HS was added; HS was also removed from solution with the precipitation of calcium phosphate. At solution pH 8.0 and HS concentrations ≤3.5 mg/L, and at pH ≥ 9.0 and HS concentrations ≤ 10 mg/L, the final precipitates were proved to be hydroxyapatite (HAP) by XRD. The increases of solution pH value and initial Ca/P ratio helped reduce the influence of HS on the precipitation of phosphate. 相似文献
286.
287.
Yapeng Song Hui Gong Jianbing Wang Fengmin Chang Kaijun Wang 《Frontiers of Environmental Science & Engineering》2020,14(4):64
288.
通过建立直接进样-高效液相色谱串联质谱(HPLC-MS/MS)测定污水处理厂进出水中的10种全氟化合物的方法,了解污水厂进出水中全氟化合物污染情况。10种目标分析物在10~500 ng/L范围内具有良好的线性关系,方法检出限为2.3~8.3 ng/L,精密度为2.1%~7.1%,加标回收率为60.6%~91.7%。应用该方法测定某市典型污水厂进出水中的全氟化合物,进水中全氟化合物质量浓度为90.9~206 ng/L,主要污染物是PFOA、PFHxS和PFBS;出水中全氟化合物的质量浓度为67.4~158 ng/L,环境排放量为6.7~22.9 g/d,主要污染物是PFOA和PFHxS。结果表明,该方法能很好地适用于复杂基质中10种全氟化合物的检测。 相似文献
289.
建立了固相萃取(SPE)-超高效液相色谱/三重四极杆串联质谱(UPLC-MS/MS)同时测定地表水中8种亚硝胺类化合物的方法。水样中目标物经椰壳活性炭固相萃取小柱吸附富集,小柱经氮气吹干后采用二氯甲烷洗脱。待测样品采用Atlantis T3柱,以水-甲醇作为流动相进行梯度洗脱,大气压力化学电离源(APCI)正离子模式多反应监测方式(MRM)进行检测,内标法定量分析。8种目标物在相关线性范围内线性良好(r≥0.9950),地表水加标回收率为55.4%~90.4%,相对标准偏差为3.1%~14.3%,方法检出限为1.1 ~1.8 ng/L。本方法准确度和灵敏度高,适用于快速测定地表水中8种亚硝胺类化合物含量。 相似文献
290.
Steroid estrogens such as estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) have been suspected to be the main contaminants, which can affect the endocrine system of animals. Many authors have investigated these chemicals in the domestic wastewater treatment plants (WTP). However, wastewater from industries producing steroid contraceptives has not got ample attention. From the environmental point of view, the four steroids are very significant because even very low concentrations (ng/L) can cause reproductive disturbances in human, livestock and wildlife. The main purpose of the present investigation was to develop an analytical method for the determination of the four steroid estrogens present in WTP of a pharmacy factory, mainly producing contraceptive medicine in Beijing, China. Analysis was performed by solid-phase extraction (SPE) system and liquid chromatography combined with tandem mass spectrometry (LC/MS/MS). The average recoveries from effluent samples ranged from 88% to 103% and the precision of the method ranged from 9% to 4%. Based on 0.5-L wastewater samples, the limit of quantification (LOQ) was determined at 0.7 ng/L for E1, 0.8 for E2, 0.9 ng/L for E3, and 0.5 ng/L for EE2 in influent, and 1.0 ng/L for E2 and EE2, and 2.0 ng/L for E1 and E3 in effluent. In the influent samples, average concentrations of 80, 85, 73 and 155 ng/L were determined for E1, E2, E3 and EE2, respectively, showing that they were removed in this WTP to the extent of 79, 73, 85 and 67%, respectively. 相似文献