全文获取类型
收费全文 | 11956篇 |
免费 | 194篇 |
国内免费 | 765篇 |
专业分类
安全科学 | 222篇 |
废物处理 | 917篇 |
环保管理 | 1388篇 |
综合类 | 2390篇 |
基础理论 | 3416篇 |
环境理论 | 1篇 |
污染及防治 | 2329篇 |
评价与监测 | 1105篇 |
社会与环境 | 1055篇 |
灾害及防治 | 92篇 |
出版年
2024年 | 6篇 |
2023年 | 42篇 |
2022年 | 137篇 |
2021年 | 140篇 |
2020年 | 115篇 |
2019年 | 97篇 |
2018年 | 1580篇 |
2017年 | 1485篇 |
2016年 | 1297篇 |
2015年 | 260篇 |
2014年 | 197篇 |
2013年 | 246篇 |
2012年 | 661篇 |
2011年 | 1546篇 |
2010年 | 868篇 |
2009年 | 770篇 |
2008年 | 1045篇 |
2007年 | 1346篇 |
2006年 | 166篇 |
2005年 | 124篇 |
2004年 | 107篇 |
2003年 | 123篇 |
2002年 | 158篇 |
2001年 | 66篇 |
2000年 | 67篇 |
1999年 | 43篇 |
1998年 | 46篇 |
1997年 | 26篇 |
1996年 | 22篇 |
1995年 | 32篇 |
1994年 | 14篇 |
1993年 | 13篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
162.
Adaptive maritime spatial planning (MSP) uses monitoring and evaluation of the effectiveness of spatial and temporal management
measures to promote understanding and improve planning and decision-making. An adaptive approach to MSP involves exploring
alternative ways to meet management objectives, predicting the outcomes of alternative management measures, implementing one
or more of these alternative management measures, monitoring to learn about the effects of management measures, and then using
the results to update knowledge and adjust management actions. A monitoring and evaluation plan should be designed to be both
cost effective and comprehensive. The process of setting and assessing performance metrics requires that the ecological and
socio-economic objectives of the spatial management plan must be clearly stated up front for management actions to reflect
those objectives accurately. To evaluate the effectiveness of a MSP plan, a range of ecological, socio-economic and institutional
indicators need to be developed and monitored. 相似文献
163.
In this paper, we explore a range of concerns that arise in measuring short-term effects of ozone on health. In particular,
we tackle the problem of measuring exposure using alternative daily measures of ozone derived from hourly concentrations.
We adopt the exposure paradigm of Chiogna and Bellini (Environmetrics 13:55–69, 2002) extending it to ozone concentrations,
and we compare its performances with respect to traditional exposure measures by exploiting model selection. To investigate
the stability of model selection, we then apply the idea of bootstrapping the modelling process. 相似文献
164.
Salinity levels vary spatially in coastal areas, depending on proximity to freshwater sources, and may also be slowly decreasing
as a result of anthropogenic climatic changes. The impact of salinity on host–parasite interactions is potentially a key regulator
of transmission processes in intertidal areas, where trematodes are extremely common parasites of invertebrates and vertebrates.
We investigated experimentally the effects of long-term exposure to decreased salinity levels on output of infective stages
(cercariae) and their transmission success in the trematode Philophthalmus sp. This parasite uses the snail Zeacumantus subcarinatus as intermediate host, in which it asexually produces cercariae. After leaving the snail, cercariae encyst externally on hard
substrates to await accidental ingestion by shorebirds, which serve as definitive hosts. We found that at reduced salinities
(25 or 30 psu), the cercarial output of the parasite was lower, the time taken by cercariae to encyst was longer, fewer cercariae
successfully encysted and encysted parasites had lower long-term survival than at normal seawater salinity (35 psu). The strong
effect of salinity on the replication and transmission of this parasite suggests that there may be sources and sinks of transmission
to birds along coastal areas, depending on local salinity conditions. Also, unless it evolves to adapt to changing conditions,
the predicted reduction in salinity as a consequence of climate change may have negative impact on the parasite’s abundance. 相似文献
165.
Loss of zooxanthellae (dinoflagellate Symbiodinium) from corals will sometimes lead to mass mortality of corals. To detect and quantify Symbiodinium released from corals, we developed a zooxanthellae “trap” and a quantitative PCR (qPCR) system with Symbiodinium clades A–F-specific primer sets. The trap was attached to a branch or the surface of several wild stony corals, and the water
samples within the traps, including released Symbiodinium, were subjected to qPCR. All tested corals released clade C Symbiodinium at estimates of ~5,900 cells h−1 cm−2 of coral surface. Although all tested Pocillopora eydouxi harboured both clades C and D, some of these colonies released only clade C or released a lesser amount of clade D than that
in the tissues. Our Symbiodinium quantification system revealed that wild hermatypic corals constantly release Symbiodinium to the environment. Our result suggests that some corals may discharge certain clades of Symbiodinium alternatively. 相似文献
166.
167.
Liu Yajie Dong Feng 《Environmental science and pollution research international》2021,28(11):13536-13551
Environmental Science and Pollution Research - In the face of the global haze crisis, exploring the driving force of political factors for controlling minute atmospheric particles has become... 相似文献
168.
169.
Luo Yinfei Xiao Yong Hao Qichen Zhang Yunhui Zhao Zhen Wang Shengbin Dong Gaofeng 《Environmental science and pollution research international》2021,28(35):48312-48329
Environmental Science and Pollution Research - Groundwater resource is significantly important for sustainable development of the world, especially for arid endorheic watersheds. A total of 28... 相似文献
170.
利用高效液相色谱法分析了长江口-浙闽沿岸表层沉积物中的色素组成和含量,探讨了海洋初级生产力、浮游植物功能类群和浮游植物色素保存效率的空间分布特征及其影响因素.结果表明,沉积物中的色素类型主要为沉积绿素(chloropigments,Chlorins)[包括叶绿素a(chlorophyll-a,Chl-a)及其降解产物(pheopigments,Pheo-a),如脱镁叶绿素a(pheophytin-a,PHtin-a)、脱镁叶绿酸a(pheophorbide-a,PHide-a)、焦脱镁叶绿素a(p Pheophytin-a,p PHtin-a)、甾醇绿素酯(sterol chlorin esters,SCEs)和胡萝卜醇绿素酯(carotenol chlorin esters,CCEs)].Chlorins高值区呈南北两大斑块状分布,可能主要是受到长江冲淡水及浙闽沿岸泥质区上升流输运的营养盐的影响.研究区域内类胡萝卜素整体上无明显趋势性变化,在长江口以及浙闽沿岸各呈现一个高值区.基于沉积物中特征类胡萝卜素比例估算得到的浮游植物功能类群中硅藻、甲藻、定鞭藻、青绿藻、隐藻和蓝藻的相对贡献分别为48.8%±17.4%、10.7%±11.5%、8.1%±7.2%、18.6%±8.2%、9.4%±6.4%和4.3%±3.2%.对营养盐水平、水体盐度等外界环境的偏好导致硅藻和甲藻比例离岸降低,青绿藻、隐藻和蓝藻比例离岸增加.Chl-a/Pheo-a比值的分布表明,较高的沉积速率以及季节性的底层水体缺氧事件导致了近岸海域(长江口最大浑浊带外缘、杭州湾湾口以及浙闽沿岸上升流区)具有较高的沉积色素保存效率,这些沉积色素保存效率较高的区域可能是进行海洋生态环境历史重建的理想区域,而杭州湾水体通过舟山群岛与外部海水进行水体交换时造成的较差沉积环境可能是导致杭州湾外海具有较低沉积色素含量和较低保存效率的主要原因. 相似文献