全文获取类型
收费全文 | 3028篇 |
免费 | 278篇 |
国内免费 | 839篇 |
专业分类
安全科学 | 315篇 |
废物处理 | 147篇 |
环保管理 | 234篇 |
综合类 | 1922篇 |
基础理论 | 415篇 |
污染及防治 | 485篇 |
评价与监测 | 206篇 |
社会与环境 | 238篇 |
灾害及防治 | 183篇 |
出版年
2024年 | 17篇 |
2023年 | 55篇 |
2022年 | 194篇 |
2021年 | 164篇 |
2020年 | 171篇 |
2019年 | 128篇 |
2018年 | 166篇 |
2017年 | 141篇 |
2016年 | 127篇 |
2015年 | 180篇 |
2014年 | 240篇 |
2013年 | 236篇 |
2012年 | 243篇 |
2011年 | 220篇 |
2010年 | 204篇 |
2009年 | 207篇 |
2008年 | 174篇 |
2007年 | 183篇 |
2006年 | 158篇 |
2005年 | 100篇 |
2004年 | 117篇 |
2003年 | 110篇 |
2002年 | 135篇 |
2001年 | 125篇 |
2000年 | 91篇 |
1999年 | 76篇 |
1998年 | 43篇 |
1997年 | 29篇 |
1996年 | 31篇 |
1995年 | 24篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有4145条查询结果,搜索用时 468 毫秒
941.
942.
对采自盐城北部潮间带的241个表层沉积物样进行测试分析,探讨了沉积物中重金属(Cu、Pb、Zn、Cr、Cd、As、Hg)空间分布特征及各元素相关关系,并采用Hakanson潜在生态风险指数法进行了污染评估。结果表明:1)研究区重金属Zn、Pb、Hg含量均符合国家规定的一类沉积物标准,Cr、Cd、Cu、As含量在大部分站位也都低于一类沉积物标准,其中Cr仅在个别站位处达到二类沉积物标准,Cd、Cu、As在少数站位达到二类沉积物标准。2)研究区Cu、Pb、Zn、As四种元素在物源或迁移累积特征上具有相似性,Cd元素不受元素粒度控制律控制。3)研究区重金属总体污染和潜在生态危害处于低风险级别,重金属潜在生态危害系数由大到小依次为:CdAsCuPbCrZnHg。 相似文献
943.
运用探地雷达进行加油站埋地罐区油品泄漏检测,先后对8座加油站进行了埋地罐区泄漏测试,发现某加油站埋地罐区的疑似泄漏区域,并对疑似泄漏区域进行了验证确认。 相似文献
944.
Yi H. Liu Jian Chen Chun M. Wang Yi R. Guo Xiao Liang Guo N. Zhu 《Journal of environmental science and health. Part. B》2013,48(6):540-546
A new method for specific antibody production was developed using antibody (Ab)-pesticide complex as a unique immunogen. Parathion (PA) was the targeted pesticide, and rabbit polyclonal antibody (Pab) and mouse monoclonal antibody (Mab) were used as carrier proteins. The Ab-PA complexes were generated by conjugating the two antibodies with an excessive dosage of PA. It was shown that the sensitivity of homologous enzyme-linked immunosorbent assay (ELISA) using the new antibodies was similar to that using original antibodies. However, the new mouse Pab had not only similar positive recognizing spectrum as the original Mab, but also a significantly improved sensitivity in heterologous ELISA when some recognizable competitors were applied. IC50 value of ELISA based on a combination of the new mouse Pab and hapten 9 was 0.24 ng/mL, which was 445.54 times as that of the homologous ELISA. An Ab-pesticide complex may be a suitable alternative immunogen for producing highly specific antibody to improve the immunoassay sensitivity. 相似文献
945.
<正>地处祖国西南边陲的云南省,气候变幻异常,自然灾害频发。特别是每年进入汛期以来,全省大部分地区都会出现持续性的强降雨,导致严重的洪涝、泥石流、山体滑坡等重大自然灾害发生,造成重大人员伤亡和财产损失。其中,德宏、怒江、保山、临沧、红河、版纳六个州市灾情尤为严重。据有关资料记载:灾情最严重的2004年,全省3800万人口,就有1400多万受灾,占全省 相似文献
946.
Shiliang Su Rui Xiao Xiangyang Xu Zhonghao Zhang Xiaoya Mi Jiaping Wu 《Regional Environmental Change》2013,13(1):77-89
This study employed spatial regression to analyze the determinants of dissolved oxygen (DO) and nutrients in the Qiantang River, China. Determinants of their spatial patterns in 1996 and 2003 as well as their dynamics during this time period were characterized at sub-basin and 500-m riparian buffer scales. Results indicated that the determinants differed by variable and by scale. Built-ups, farmland, water body, population density and gross domestic product were positive indicators for nutrient pollution and hypoxia, while distance to river source and forest were negative indicators. Higher slope variability indicates more DO and nutrients. In addition, built-up increases that were accelerated by population growth and economic development accounted for DO and nutrients dynamics to a large extent. This study highlighted that incorporation of spatial autocorrelation into regression was not only a methodological advantage but also a promising management tool. 相似文献
947.
基于现有竹炭、竹醋生产工艺流程及工业技术水平,设计了一套具有创新性的竹炭、竹醋生产设备,并给出了设备完整的结构以及包括微波源功率在内的关键制造参数.该设备首次引入微波热解技术代替传统的燃烧加热方法,同时窑炉整体设计遵循节约生产空间、原料充分转化、废气废渣循环处理、热量多级利用、全封闭式生产、自动化控制等节能、环保、高效的思想.此外,在对微波源的设计上依据多源溃能理论,采用以小功率磁控管组合代替大功率磁控管设计,从而大幅降低设备的制造成本,提高微波源的使用寿命及工作稳定性. 相似文献
948.
Population genetics of Crassostrea ariakensis in Asia inferred from microsatellite markers 总被引:1,自引:0,他引:1
Jie Xiao Jan F. Cordes Haiyan Wang Ximing Guo Kimberly S. Reece 《Marine Biology》2010,157(8):1767-1781
Crassostrea ariakensis is an important aquacultured oyster species in Asia, its native region. During the past decade, consideration was given to
introducing C. ariakensis into Chesapeake Bay, in the United States, to help revive the declining native oyster industry and bolster the local ecosystem.
Little is known about the ecology and biology of this species in Asia due to confusion with nomenclature and difficulty in
accurately identifying the species of wild populations in their natural environment. Even less research has been done on the
population genetics of native populations of C. ariakensis in Asia. We examined the magnitude and pattern of genetic differentiation among 10 wild populations of C. ariakensis from its confirmed distribution range using eight polymorphic microsatellite markers. Results showed a small but significant
global θ
ST (0.018), indicating genetic heterogeneity among populations. Eight genetically distinct populations were further distinguished
based on population pairwise θ
ST comparisons, including one in Japan, four in China, and three populations along the coast of South Korea. A significant positive
association was detected between genetic and geographic distances among populations, suggesting a genetic pattern of isolation
by distance. This research represents a novel observation on wild genetic population structuring in a coastal bivalve species
along the coast of the northwest Pacific. 相似文献
949.
Xue-Yan Liu Hua-Yun Xiao You-Yi Li Hong-Wei Xiao Yan-Li Wang 《Environmental pollution (Barking, Essex : 1987)》2010,158(6):2273-2281
Epilithic mosses are characterized by insulation from substratum N and hence meet their N demand only by deposited N. This study investigated tissue C, total Chl and δ13C of epilithic mosses along 2 transects across Guiyang urban (SW China), aiming at testing their responses to N deposition. Tissue C and total Chl decreased from the urban to rural, but δ13Cmoss became less negative. With measurements of atmospheric CO2 and δ13CO2, elevated N deposition was inferred as a primary factor for changes in moss C and isotopic signatures. Correlations between total Chl, tissue C and N signals indicated a nutritional effect on C fixation of epilithic mosses, but the response of δ13Cmoss to N deposition could not be clearly differentiated from effects of other factors. Collective evidences suggest that C signals of epilithic mosses are useful proxies for N deposition but further works on physiological mechanisms are still needed. 相似文献
950.
Disasters produce winners and losers. This paper evaluates such winners and losers in a spatial context. The hypothesis is that, because of severe damage to the core disaster area and the constraints associated with the cost of transportation, economic demand would shift to the immediate edge of the disaster zone where either minor or no damage is observed. Empirical analysis of growth patterns in counties/parishes in the states of Alabama, Louisiana, and Mississippi in the United States after Hurricane Katrina (August 2005) verified the spatial demand shift hypothesis. The study found that the post‐Katrina core disaster area became a ‘doughnut hole’ of low income and employment growth, surrounded by a ring of high growth counties/parishes on the edge of the hole. The short‐run adjustment in growth rates may have altered permanently the spatial distribution of employment and income both at the core and in the areas at the edge. 相似文献