首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1783篇
  免费   157篇
  国内免费   506篇
安全科学   268篇
废物处理   27篇
环保管理   145篇
综合类   1367篇
基础理论   350篇
污染及防治   137篇
评价与监测   115篇
社会与环境   19篇
灾害及防治   18篇
  2024年   18篇
  2023年   62篇
  2022年   84篇
  2021年   81篇
  2020年   62篇
  2019年   71篇
  2018年   50篇
  2017年   70篇
  2016年   69篇
  2015年   118篇
  2014年   166篇
  2013年   107篇
  2012年   127篇
  2011年   130篇
  2010年   88篇
  2009年   122篇
  2008年   131篇
  2007年   103篇
  2006年   99篇
  2005年   81篇
  2004年   56篇
  2003年   47篇
  2002年   45篇
  2001年   41篇
  2000年   41篇
  1999年   42篇
  1998年   34篇
  1997年   38篇
  1996年   38篇
  1995年   45篇
  1994年   40篇
  1993年   37篇
  1992年   36篇
  1991年   31篇
  1990年   25篇
  1989年   10篇
  1988年   1篇
排序方式: 共有2446条查询结果,搜索用时 15 毫秒
101.
李丽坤 《环境》2011,(9):60-63
俗话说有披着羊皮的狼,现在有一些垃圾食品也披上了健康食品的外衣,一定要小心鉴别哦!生活中,我们总是容易被各种美食诱惑,有一些是因为它们的味道确实鲜美,还有一些则因为在通常印象中,它们极富营养。其实,我们还真需留个心眼,因为有些食物非但没有想象中的对身体有益,过多食用,还可能产生负面影响。  相似文献   
102.
Aged refuse from waste landfills closed for eight years was examined and found to contain rich methanotrophs capable of biooxidation for methane. Specially, community structure and methane oxidation capability of methanotrophs in the aged refuse were studied. The amount of methanotrophs ranged 61.97 103–632.91 103 cells/g (in dry basis) in aged refuse from Shanghai Laogang Landfill. Type I and II methanotrophs were found in the aged refuse in the presence of sterilized sewage sludge and only Type I methanotrophs were detected in the presence of nitrate minimal salt medium (NMS). The clone sequences of the pmoA gene obtained from the aged refuse were similar to the pmoA gene of Methylobacter, Methylocaldum, and Methylocystis, and two clones were distinct with known genera of Type I methanotrophs according to phylogenetic analysis. Aged refuse enriched with NMS was used for methane biological oxidation and over 93% conversions were obtained.  相似文献   
103.
The study investigated the effects of ethanol on the adsorption properties of bentonite and kaolin for benzene and toluene removal.  相似文献   
104.
Considerable variations may exist in CH4 emissions from the Three Gorges Reservoir.  相似文献   
105.
论文以中国南海筛选的一株塔玛亚历山大藻Alexandrium tamarense C101为研究对象,研究了两种抗生素,氨苄青霉素(ampicillin,Amp)和新霉素(neomycin,Nm)对A.tamarense C101细胞生长、形态以及毒素含量的影响.结果表明:和空白对照组相比,经1 500μg/mL Nm...  相似文献   
106.
为研究丙烯气体最小点火能随温度的变化规律,首先采用最小点火能测试系对甲烷气体进行了测试和评估,得到了不同温度下的最小点火能及其随温度的变化趋势。结果表明,可燃气体(或液体蒸气)敏感浓度均略高于其当量浓度。气体最小点火能随温度升高而增大。  相似文献   
107.
Arbuscular mycorrhizal fungi(AMF) are important components of soil microbial communities,and play important role in plant growth. However, the effects of AMF phylogenetic groups(Glomeraceae and non-Glomeraceae) on host plant under various heavy metal levels are not clear. Here we conducted a meta-analysis to compare symbiotic relationship between AMF phylogenetic groups(Glomeraceae and non-Glomeraceae) and host plant functional groups(herbs vs. trees, and non-legumes vs. legumes) at three heavy metal levels. In the meta-analysis, we calculate the effect size(ln(RR)) by taking the natural logarithm of the response ratio of inoculated to non-inoculated shoot biomass from each study. We found that the effect size of Glomeraceae increased, but the effect size of non-Glomeraceae decreased under high level of heavy metal compared to low level. According to the effect size, both Glomeraceae and non-Glomeraceae promoted host plant growth, but had different effects under various heavy metal levels. Glomeraceae provided more benefit to host plants than non-Glomeraceae did under heavy metal condition, while non-Glomeraceae provided more benefit to host plants than Glomeraceae did under no heavy metal. AMF phylogenetic groups also differed in promoting plant functional groups under various heavy metal levels.Interacting with Glomeraceae, herbs and legumes grew better than trees and non-legumes did under high heavy metal level, while trees and legumes grew better than herbs and non-legumes did under medium heavy metal level. Interacting with non-Glomeraceae, herbs and legumes grew better than trees and non-legumes did under no heavy metal. We suggested that the combination of legume with Glomeraceae could be a useful way in the remediation of heavy metal polluted environment.  相似文献   
108.
A high strength chemical industry wastewater was assessed for its impact on anaerobic microbial com- munity dynamics and consequently mesophilic methane generation. Cumulative methane production was 251 mL/g total chemical oxygen demand removed at standard temperature and pressure at the end of 30 days experimental period with a highest recorded methane percentage of 80.6% of total biogas volume. Volatile fatty acids (VFAs) analysis revealed that acetic acid was the major intermediate VFAs produced with propionic acid accumulating over the experimental period. Quantitative analysis of microbial communities in the test and control groups with quantitative real time polymerase chain reaction highlighted that in the test group, Eubacteria (96.3%) was dominant in comparison with methanogens (3.7%). The latter were dominated by Methanomicrobiales and Methanobacteriales while in test groups increased over the experimental period, reaching a maximum on day 30. Denaturing gradient gel electrophoresis profile was performed, targeting the 16S rRNA gene of Eubacteria and Archaea, with the DNA samples extracted at 3 different time points from the test groups. A phylogenetic tree was constructed for the sequences using the neighborhood joining method. The analysis revealed that the presence of organisms resembling Syntrophomonadaceae could have contributed to increased production of acetic and propionic acid intermediates while decrease of organisms resembling Pelotomaculum sp. could have most likely contributed to accumulation of propionic acid. This study suggested that the degradation of organic components within the high strength industrial wastewater is closely linked with the activity of certain niche microbial communities within eubacteria and methanogens.  相似文献   
109.
高芳 《世界环境》2014,(6):76-77
<正>日本是垃圾能源化利用最发达的国家之一,垃圾分类很严格,原生垃圾是不能直接处理的。城市生活垃圾分类后,可燃组分由垃圾转运车收集送入垃圾焚烧厂,再经过机械筛选和人工分选,在焚烧炉内焚烧,产生的热能发电供给城市电网,部分余热用于一个城市公共游泳池;对于可生物降解的有机垃圾,如厨余垃圾等,进行甲烷发酵,发酵产生的沼气可以制备家用和车用燃气,也可用于发电。焚烧处理厂同时也是资源回收中心,家庭的大件垃圾如家具等,必须送回该厂处理,并交处理费。一些损  相似文献   
110.
ENN精粹     
徐芳  夏威 《世界环境》2014,(6):94-95
<正>有前景的埃博拉疫苗处于研发状态ENN环境新闻网新闻2014年10月27日并不是每个染上埃博拉病毒的人都会死亡,埃博拉病毒感染的存活率大约30%左右,这表明用疫苗来应对埃博拉病毒是完全有可能的。虽然目前已经有了应对埃博拉病毒的实验和疫苗,但是都尚未进行安全性和有效性的大规模的测试(2期临床试验)。国际免疫学会联盟(IUIS)日前在其官方杂志上发表了一份声明,前沿免疫学迫切需要有足够的资金用于临床试验的候选疫苗和疫苗试验者,并且还得尽快  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号