全文获取类型
收费全文 | 10245篇 |
免费 | 10篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 37篇 |
废物处理 | 795篇 |
环保管理 | 1303篇 |
综合类 | 1026篇 |
基础理论 | 3234篇 |
污染及防治 | 1890篇 |
评价与监测 | 1051篇 |
社会与环境 | 918篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 5篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 1481篇 |
2017年 | 1385篇 |
2016年 | 1203篇 |
2015年 | 146篇 |
2014年 | 38篇 |
2013年 | 55篇 |
2012年 | 481篇 |
2011年 | 1372篇 |
2010年 | 715篇 |
2009年 | 626篇 |
2008年 | 905篇 |
2007年 | 1258篇 |
2006年 | 41篇 |
2005年 | 48篇 |
2004年 | 55篇 |
2003年 | 85篇 |
2002年 | 120篇 |
2001年 | 24篇 |
2000年 | 30篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 14篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 20篇 |
1983年 | 15篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1961年 | 2篇 |
1959年 | 2篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1953年 | 1篇 |
1935年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
31.
Dr. Linda A. Cannizzaro Barbara K. Hecht Helen A. Bixenman Stephen Pazdziorko Robert Tamis Frederick Hecht 《黑龙江环境通报》1988,8(4):297-301
We report herein a de novo unbalanced chromosome translocation in a fetus resulting from in vitro fertilization technology. Prenatal diagnostic analysis of an amniotic fluid revealed a 46,XX,4p+ karyotype. The origin of the extra material on the short arm of chromosome 4 could not be identified by a variety of banding techniques. However, examination of fetal parts did reveal some dysmorphic features. 相似文献
32.
Gamergates (i.e. mated reproductive workers) are mostly known from ant species within the Ponerinae. We report here the discovery of gamergates in two species of the subfamily Myrmicinae. Until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. However, in two species of the myrmicine Metapone (Metapone madagascarica and a newly discovered, not yet described Metapone species) all workers have six ovarioles and a spermatheca; and some of them are mated. There are no morphological differences between mated and non-mated workers. Field observations and laboratory studies indicate that colonies of the Metapone species can reproduce with gamergates only. 相似文献
33.
Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x. 相似文献
34.
Aysen Müezzinoğlu Tolga Elbir Abdurrahman Bayram 《Environmental Engineering and Policy》1998,1(2):109-116
In this study, an inventory of air pollutant emission estimates from major air polluting sources in Turkey for period between 1985 and 2005 with 5-year intervals were estimated. Inventory covers anthropogenic sources of five major air pollutants of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides and non-methane volatile organic compounds. Their break-down with respect to main activity sectors were shown and their distribution by the largest industrial source categories were worked out as annual estimates. This inventory and its analysis point to serious environmental implications of air pollutants and a need to develop a policy plan for reducing these emissions. 相似文献
35.
Dr. O. W. Jones Nolan E. Penn Stephen Shuchter Claire A. Stafford Teri Richards Colleen Kernahan Jennifer Gutierrez Patricia Cherkin Sylvia Reinsch Barbara Dixson 《黑龙江环境通报》1984,4(4):249-256
This article reports the results of a retrospective study designed to examine the responses of couples to genetic amniocentesis and subsequent therapeutic abortions due to birth defects. Fourteen women and 12 men were interviewed by experienced interviewers using a structured format designed by the authors, and each interview was audiotaped for later rating. The 5 raters (all women) were instructed to independently rate each interview using forms designed by the authors to elicit information about many aspects of the participant's individual responses as well as perceptions of spouse's responses to the process of pregnancy, amniocentesis, therapeutic abortion, and sequelae. Ratings of all 5 raters were conjoined and an homogeneous narrative was constructed for each interview. Results indicate, in general, that the respondent couples coped well with this experience. In fact 70 per cent of the respondent couples described their marital relationships as becoming closer as a result of their experience. Only a few participants reported long-term deleterious effects. Most couples coped by relying on relatives, friends, and occasionally, professional counsellors. In addition, most participants in this study suggested ways to improve the medical and psychological aspects of this experience. 相似文献
36.
Amniocyte clones from a mid-trimester pregnancy disclosed 45,X/46,XY sex chromosome mosaicism. Because of the uncertainty concerning the phenotype of the fetus, the parents elected to terminate the pregnancy. Mixed (asymmetrical) gonadal dysgenesis was not found. The fetus appeared to have a normal male uro-genital system. No malformations of any type were detected, although as expected, the fetus did have 45,X/46,XY mosaicism. 相似文献
37.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach. 相似文献
38.
A case of fatal generalized dystrophic epidermolysis bullosa is described in a prematurely born female whose mother had strikingly elevated mid-trimester serum and amniotic fluid alpha-fetoprotein concentrations, a positive amniotic fluid acetylcholinesterase band, and negative serial ultrasound studies. This case lends further support to an association between autosomal recessive generalized dystrophic epidermolysis bullosa and increased levels of alpha-fetoprotein, positive amniotic fluid acetylcholines'terase, and normal ultrasound findings. 相似文献
39.
Andreas Züttel 《Mitigation and Adaptation Strategies for Global Change》2007,12(3):343-365
Hydrogen storage and transportation or distribution is closely linked together. Hydrogen can be distributed continuously in
pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system but also
pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels.
Furthermore, hydrogen is regenerative and environment friendly. There are two reasons why hydrogen is not the major fuel of
toady’s energy consumption: First of all, hydrogen is just an energy carrier. And, although it is the most abundant element
in the universe, it has to be produced, since on earth it only occurs in the form of water. This implies that we have to pay
for this energy, which results in a difficult economic task, because since the industrialization we are used to consuming
energy for free. The second difficulty with hydrogen as an energy carrier is the low critical temperature of 33 K, i.e. hydrogen
is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric
density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure
gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific
surface area (at T < 100 K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent
and ionic compounds (at ambient pressure), oxidation of reactive metals e.g. Li, Na, Mg, Al, Zn with water. These metals easily
react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can
be thermally reduced to the metals in a solar furnace. 相似文献
40.
FUENSANTA CARAVACA DINO FIGUEROA ANTONIO ROLDÁn CONCEPCIÓN AZCÓN-AGUILAR 《Environmental management》2003,31(3):0412-0420
The reestablisment of autochthonous plant species is an essential strategy for recovering degraded areas under semiarid conditions.
A field experiment was carried out to assess the short-term effect of two reafforestation methods involving mycorrhizal inoculation
and compost addition on soil quality parameters and Rhamnus lycioides seedling growth. The nutrient content (NPK) and enzymatic activities (dehydrogenase, urease, protease-BAA, acid phosphatase
and β-glucosidase) increased and bulk density decreased in the rhizosphere soil with the organic amendment. Biomass C of rhizosphere
soil increased by at least 240% with respect to the control soil after mycorrhizal inoculation and the combination of compost
addition + mycorrhizal inoculation. Both mycorrhizal inoculation and composted organic residue addition increased R. lycioides seedling growth in the same proportion. In the short term, we conclude that the application of both reafforestation methods
not only enhances the establishment of R. lycioides seedlings, but also improves soil quality. 相似文献