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排序方式: 共有1110条查询结果,搜索用时 31 毫秒
951.
当前我国的区域发展不平衡问题日益凸显,国家“十一五”规划中出台的主体功能区战略试图根据一些理想的条件和标准对我国区域空间进行合理的重新划分和建构,从而达到促进我国区域协调发展的目的.决策层对区域协调发展的关注从早期狭义上更多地单纯强调经济发展的人民生活水平差距的逐渐缩小,后来逐渐扩展到广义上的区际实际收入水平和公共服务的均等化过程.根据中国2001-2009年的数据,我们发现无论是狭义上还是广义上,我国区际发展不协调程度都呈现扩大趋势,并且广义的区域不协调程度远超过狭义的区域不协调程度.主体功能区战略是逻辑意义上的以地为本,同时也是对区域过去发展水平的一个事后承认或被动承认,中国区域经济的发展水平与主体功能区的开发顺序和开发重点形成了相互促进的同向递增关系.主体功能区的划分标准有着较大随意性和不严谨性,加上相关配套政策和措施的不完善,主体功能区建设短时期内不会缩小反而可能会加大我国本已不小的区际发展差距. 相似文献
952.
Strumińska-Parulska DI Skwarzec B Fabisiak J 《Journal of environmental radioactivity》2011,102(12):1105-1111
The aim of the paper was plutonium (238Pu and 239+240Pu) determination in seabirds, permanently or temporarily living in northern Poland at the Baltic Sea coast. Together 11 marine birds species were examined: 3 species permanently residing in the southern Baltic, 4 species of wintering birds and 3 species of migrating birds. The obtained results indicated plutonium is non-uniformly distributed in organs and tissues of analyzed seabirds. The highest plutonium content was found in the digestion organs and feathers, the smallest in skin and muscles. The plutonium concentration was lower in analyzed species which feed on fish and much higher in herbivorous species. The main source of plutonium in analyzed marine birds was global atmospheric fallout. 相似文献
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954.
Accidental Versus Operational Oil Spills from Shipping in the Baltic Sea: Risk Governance and Management Strategies 总被引:2,自引:0,他引:2
Marine governance of oil transportation is complex. Due to difficulties in effectively monitoring procedures on vessels en
voyage, incentives to save costs by not following established regulations on issues such as cleaning of tanks, crew size,
and safe navigation may be substantial. The issue of problem structure is placed in focus, that is, to what degree the specific
characteristics and complexity of intentional versus accidental oil spill risks affect institutional responses. It is shown
that whereas the risk of accidental oil spills primarily has been met by technical requirements on the vessels in combination
with Port State control, attempts have been made to curb intentional pollution by for example increased surveillance and smart
governance mechanisms such as the No-Special-Fee system. It is suggested that environmental safety could be improved by increased
use of smart governance mechanisms tightly adapted to key actors’ incentives to alter behavior in preferable directions. 相似文献
955.
Naomi Clark-Shen Andrew Chin Sirachai Arunrugstichai Jessica Labaja Meira Mizrahi Benaya Simeon Neil Hutchinson 《Conservation biology》2023,37(1):e13962
In Southeast Asia, elasmobranchs are particularly threatened. We synthesized knowledge from the peer-reviewed and gray literature on elasmobranchs in the region, including their fisheries, status, trade, biology, and management. We found that 59% of assessed species are threatened with extinction and 72.5% are in decline; rays were more threatened than sharks. Research and conservation is complicated by the socioeconomic contexts of the countries, geopolitical issues in the South China Sea, and the overcapacity and multispecies nature of fisheries that incidentally capture elasmobranchs. The general paucity of data, funds, personnel, and enforcement hinders management. Reduced capacity in the general fishery sector and marine protected areas of sufficient size (for elasmobranchs and local enforcement capabilities) are among recommendations to strengthen conservation. 相似文献
956.
2005年夏季环渤海16条主要入海河流的污染状况 总被引:3,自引:1,他引:2
2005-07-01~2005-07-05对环渤海的黄河等16条主要河流的入海污染同步调查显示,13条河流断面的水质属于Ⅳ类以上,其中子牙新河等8条河流水质属于劣Ⅴ类,通过污染分担率分析,环渤海河流的首要污染物为石油类(11条河流),其次为营养盐,高锰酸盐指数仅位居第3.采用综合营养状态指数法评价,大辽河、黄河等7条河流处于富营养状态,而小清河、蓟运河等7条河流处于重度富营养状态,可见环渤海河流的富营养化现象非常严重.有机污染物的调查显示,16条河流断面采样点TOC的平均值为16 .41 mg/L,高锰酸盐指数的平均值为6 .04 mg/L,其中易降解有机物所占比例平均为15 .61%,表明虽然环渤海16条河流中的化学需氧有机物质的污染严重,但总有机物的入海通量更大,这一点必须引起足够的重视. 相似文献
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959.
The growing diversity of image scenes brings a great challenge to human activity recognition in practice. Traditional activity recognition methods cannot satisfy the demand of precise action recognition in complex scenes. In this work, we build a training set of worker's activities on offshore drilling platform by collecting data from offshore drilling monitor, and then an improved multi-level convolutional pose machine (MCPM) method is proposed and trained to recognize activities of workers on the platforms. In human object detection, a multi-rule region proposal marker algorithm is developed to separate the seawater area, and the ducts of similar personnel is pre-discriminated by support vector machine. We use the characteristics of the human body key-points not affected by complex background noise to assist the detection of the human target. As results, it shown that our method performs better than Faster-RCNN, MobileNet-SSD and SSD algorithms in detecting human target on the offshore drilling platform, and achieves well accuracy in recognizing many key activities. To our best acknowledge, it is the first attempt of using deep model to recognize worker's activities on offshore drilling platform. 相似文献
960.
Pike DA 《Environmental management》2008,41(4):461-464
Individual sea turtle nests have an extremely low probability of producting adult turtles; thus the practice of moving nests
away from the ocean (where they will not be inundated by seawater) is a questionable conservation strategy. Recently in Environmental Management, Mrosovosky used the repeatability of nesting female turtles to place their eggs in certain locations to infer that some
females may consistently nest in areas which will be flooded, lowering the chance that any eggs will hatch. This information
was used to hypothesize that saving “doomed” sea turtle nests may then alter the genetic composition of the population, ultimately
resulting in turtles that nest in poor habitats. Here I question Mrosovosky’s argument by focusing on several weaknesses inherent
in the original article, namely that at present there is no evidence to suggest that nest-site selection is a heritable trait
with an underlying genetic basis. 相似文献