全文获取类型
收费全文 | 36844篇 |
免费 | 405篇 |
国内免费 | 309篇 |
专业分类
安全科学 | 1087篇 |
废物处理 | 1416篇 |
环保管理 | 5049篇 |
综合类 | 5564篇 |
基础理论 | 10483篇 |
环境理论 | 22篇 |
污染及防治 | 9659篇 |
评价与监测 | 2269篇 |
社会与环境 | 1771篇 |
灾害及防治 | 238篇 |
出版年
2022年 | 267篇 |
2021年 | 241篇 |
2019年 | 269篇 |
2018年 | 516篇 |
2017年 | 487篇 |
2016年 | 727篇 |
2015年 | 605篇 |
2014年 | 858篇 |
2013年 | 2739篇 |
2012年 | 1082篇 |
2011年 | 1591篇 |
2010年 | 1308篇 |
2009年 | 1331篇 |
2008年 | 1588篇 |
2007年 | 1691篇 |
2006年 | 1488篇 |
2005年 | 1278篇 |
2004年 | 1229篇 |
2003年 | 1218篇 |
2002年 | 1174篇 |
2001年 | 1566篇 |
2000年 | 1094篇 |
1999年 | 674篇 |
1998年 | 530篇 |
1997年 | 534篇 |
1996年 | 544篇 |
1995年 | 594篇 |
1994年 | 533篇 |
1993年 | 473篇 |
1992年 | 499篇 |
1991年 | 456篇 |
1990年 | 478篇 |
1989年 | 501篇 |
1988年 | 419篇 |
1987年 | 356篇 |
1986年 | 321篇 |
1985年 | 370篇 |
1984年 | 352篇 |
1983年 | 393篇 |
1982年 | 382篇 |
1981年 | 327篇 |
1980年 | 290篇 |
1979年 | 325篇 |
1978年 | 263篇 |
1977年 | 233篇 |
1976年 | 238篇 |
1975年 | 235篇 |
1974年 | 216篇 |
1973年 | 213篇 |
1972年 | 229篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
82.
In a 1981 survey of 436 Florida citrus growers, 27 pesticide related poisoning incidents were reported that were to have taken place within one year of the interview date. From these reports it is possible to estimate that there are 376 citrus fieldworker related poisonings per year in Florida. This number of estimated poisonings may be developed into an incidence rate of 113 fieldworker poisonings per 10,000 fieldworkers. 相似文献
83.
84.
Global change, i.e. the mega-process radically transforming the relationship between nature and human civilization since
the end of World War II, is investigated from the point of view of systems analysis. It is argued that this unbridled process
should rather be domesticated by planetary control strategies transpiring from a new science called “geocybernetics”. The
formal aspects of geocybernetic theory are sketched and illustrated in a tutorial theatre world reflecting the overall environment
and development problematic. Within this setting a straightforward operationalization of the sweeping “sustainable development”
ideal through a set of concise paradigms can be achieved. Evidence is provided that geocybernetics is actually feasible on
the basis of earth system modelling and fuzzy-control techniques. 相似文献
85.
86.
H. T. Schreuder 《Environmental monitoring and assessment》1994,33(3):237-245
Simplicity and efficiency in design and estimation are all important in deciding on sampling strategies. A simple model is given and illustrated for four practical situations to show how a good sampling strategy should be selected.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
87.
The effectiveness of inorganic alumino-silicate sorbents (alumina and kaolinite) to adsorb airborne lead and cadmium from the effluent stream of a simulated waste incinerator was studied. A 20 kW (68,000 BTU/h) flow reactor was used to achieve the temperature and residence times typical of a waste incinerator. Solutions containing lead or cadmium were introduced yielding airborne metals concentrations between 15 and 150 ppm. Gas samples were drawn into a particle impactor that collected the airborne particles and condensed phase metal aerosols, separating them into ten size ranges from 0.2 μm to greater than 10 μm. Metals to sorbent mass ratios between 0.03 and 1.56 were investigated. Scavenging efficiency increased as the ratio of sorbent to injected metal mass was increased. The scavenging efficiencies were as high as 76% for lead scavenged by kaolinite to as low as 14% for cadmium scavenged by alumina. 相似文献
88.
T. Antoniadi C. Yapijakis P. Kaminopetros C. Makatsoris V. Velissariou D. Vassilopoulos M. B. Petersen 《黑龙江环境通报》2002,22(5):425-429
The presence of maternal cells in fetal samples constitutes a serious potential source for prenatal misdiagnosis. Here we present our approach for detecting maternal cell contamination (MCC) at prenatal diagnosis for eight monogenic disorders (autosomal recessive: β-thalassaemia, sickle-cell anaemia, cystic fibrosis, prelingual deafness; autosomal dominant: achondroplasia, Huntington disease, myotonic dystrophy, neurofibromatosis type I; X-linked: spinobulbar muscular atrophy). Our aim was to apply a simple and low-cost approach, which would easily and accurately provide information on the fetal tissue MCC status. MCC testing was applied to cases of recessive inheritance where the primary mutation screening of the fetus revealed the presence of the maternal mutation, to cases concerning dominant inheritance and to cases of multiple gestation. The potential presence of maternal cells was determined by the amplification of the 3′-HVR/APO B, D1S80, THO1 and VNTRI of vWf polymorphic loci, which have previously demonstrated high heterozygosity in Caucasians. Among 135 prenatal diagnoses, 44 finally needed to be tested for MCC (32.6%). MCC was detected in four cases, where DNA was isolated directly from chorionic villi samples (CVS), and in one case with DNA isolated directly from amniotic fluid (AF). In almost 90% of cases a simple test of one polymorphic locus provided sufficient information about MCC. The choice of the appropriate locus is therefore essential, while the simultaneous screening of both parents provides the means for distinguishing non-informative sites about MCC. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
89.
Abstract: Broadly conceived and considered in its many usages, sustainability has grave defects as a planning goal, particularly when used by conservationists: it confuses means and ends; it is vague about what is being sustained and who or what is doing the sustaining; it is uninspiring; it is little more than Pinchot-era conservation (and thus ignores the many lessons learned since then); it need not be linked to land, to the land's functioning, or to any ecological science; it need not include a moral component; it is consistent with the view of humans as all-powerful manipulators of the planet; and, in general, it is such a malleable term that its popularity provides only a facade of consensus. When sustainability is defined broadly to include the full range of economic and social aspirations, it poses the particular risk that ecological and biodiversity concerns will be cast aside in favor of more pressing human wants. Given these many defects, the conservation movement should discard the term in favor of a more alluring goal, attentive to nature and its ecological functioning. A sound goal would incorporate and distill the considerable ecological and moral wisdom accumulated since Pinchot's day while giving conservationists the rhetorical tools needed to defend the land against competing pressures. In our view, conservation would be well served by an updated variant of "land health," Aldo Leopold's ecologically grounded goal from the 1940s. Land health as an independent understanding should set the essential terms of how we live and enjoy the earth, providing the framework within which we pursue our many social and economic aims. 相似文献
90.
5p deletion syndrome commonly known as cri du chat is well described in affected neonates with catlike cry and hypotonia. Karyotyping will usually show a deletion of the short arm of one chromosome 5 with variable breakpoints. Only a few cases have been reported prenatally, and the fetal form of the syndrome has not been clearly individualised. We report a new case of 5p deletion syndrome diagnosed prenatally in association with Dandy–Walker syndrome and agenesis of the corpus callosum. Other brain anomalies have been reported previously, but this unusual association suggests the use of a specific probe in the investigation of these malformations. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献