全文获取类型
收费全文 | 482篇 |
免费 | 5篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 38篇 |
废物处理 | 17篇 |
环保管理 | 134篇 |
综合类 | 45篇 |
基础理论 | 94篇 |
污染及防治 | 118篇 |
评价与监测 | 29篇 |
社会与环境 | 15篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 14篇 |
2013年 | 41篇 |
2012年 | 14篇 |
2011年 | 28篇 |
2010年 | 15篇 |
2009年 | 18篇 |
2008年 | 21篇 |
2007年 | 21篇 |
2006年 | 22篇 |
2005年 | 14篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 20篇 |
2001年 | 16篇 |
2000年 | 12篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 15篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 13篇 |
1990年 | 4篇 |
1989年 | 9篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1972年 | 1篇 |
1971年 | 3篇 |
排序方式: 共有493条查询结果,搜索用时 109 毫秒
311.
George O. Rogers 《Journal of Environmental Planning and Management》1997,40(1):59-80
This paper examines the relationship between perceived risk and hazard events in two communities in terms of the perception and acceptability of risk. One community experienced an acute risk event comprised of a fire at a chemical plant that resulted in a large-scale evacuation (an acute hazard). The other community was involved in a seven-year controversy over the siting of a hazardous waste incinerator (a chronic risk). While the results are broadly consistent with a learning model of perceived risk, the support is more limited than envisioned; hence, the static forces of risk perception are stronger than anticipated. 相似文献
312.
Nancy Steinberg Warren Shirley Soukup Jennifer L. King Peter St. J. Dignan 《黑龙江环境通报》2001,21(13):1111-1113
A case of prenatally diagnosed non-mosaic trisomy 20 in cells cultured from a chorionic villus sample (CVS)is presented. The term placental karyotype was also non-mosaic trisomy 20. The karyotype of thenewborn was 46,XY/47,XY,+20 in foreskin cultures and in a second skin culture; blood lymphocyte culture was 46,XY. Aside from diffuse, hypopigmentary swirls along the lines of Blaschko observed on hisextremities and trunk, referred to as hypomelanosis of Ito, the patient is clinically normal at 8¾ years ofage. In addition, he is one of the oldest reported cases of mosaic trisomy 20 confirmed after birth forwhich the clinical outcome has been monitored. This case demonstrates that these trisomy 20 findings are compatible with normal psychomotor development and phenotype. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
313.
Seiffert ER Nasir S Al-Harthy A Groenke JR Kraatz BP Stevens NJ Al-Sayigh AR 《Die Naturwissenschaften》2012,99(2):133-141
Despite significant recent improvements to our understanding of the early evolution of the Order Proboscidea (elephants and
their extinct relatives), geographic sampling of the group’s Paleogene fossil record remains strongly biased, with the first
~30 million years of proboscidean evolution documented solely in near-coastal deposits of northern Africa. The considerable
morphological disparity that is observable among the late Eocene and early Oligocene proboscideans of northern Africa suggests
that other, as yet unsampled, parts of Afro-Arabia might have served as important centers for the early diversification of
major proboscidean clades. Here we describe the oldest taxonomically diagnostic remains of a fossil proboscidean from the
Arabian Peninsula, a partial mandible of Omanitherium dhofarensis (new genus and species), from near the base of the early Oligocene Shizar Member of the Ashawq Formation, in the Dhofar Governorate
of the Sultanate of Oman. The molars and premolars of Omanitherium are morphologically intermediate between those of Arcanotherium and Barytherium from northern Africa, but its specialized lower incisors are unlike those of other known Paleogene proboscideans in being
greatly enlarged, high-crowned, conical, and tusk-like. Omanitherium is consistently placed close to late Eocene Barytherium in our phylogenetic analyses, and we place the new genus in the Family Barytheriidae. Some features of Omanitherium, such as tusk-like lower second incisors, the possible loss of the lower central incisors, an enlarged anterior mental foramen,
and inferred elongate mandibular symphysis and diminutive P2, suggest a possible phylogenetic link with Deinotheriidae, an extinct family of proboscideans whose origins have long been
mysterious. 相似文献
314.
The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) and its metabolites 1,1-dichloro-2,2-bis(4-chlorophenyl) ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE) were monitored during an 8-week remediation process. Physicochemical characterization of the treated soil was performed before and after the bioremediation process. The isolation and identification of predominant microorganisms during the remediation process were also carried out. The efficiency of detoxification was evaluated after each bioremediation protocol. Humidity and pH and the heterotrophic microorganism count were monitored weekly. The DDT concentration was reduced by 79% after 8 weeks via biostimulation with surfactant addition (B + S) and 94.3% via biostimulation alone (B). Likewise, the concentrations of the metabolites DDE and DDD were reduced to levels below the quantification limits. The microorganisms isolated during bioremediation were identified as Bacillus thuringiensis, Flavobacterium sp., Cuprivadius sp., Variovorax soli, Phenylobacterium sp. and Lysobacter sp., among others. Analysis with scanning electron microscopy (SEM) allowed visualization of the colonization patterns of soil particles. The toxicity of the soil before and after bioremediation was evaluated using Vibrio fischeri as a bioluminescent sensor. A decrease in the toxic potential of the soil was verified by the increase of the concentration/effect relationship EC50 to 26.9% and 27.2% for B + S and B, respectively, compared to 0.4% obtained for the soil before treatment and 2.5% by natural attenuation after 8 weeks of treatment. 相似文献
315.
南茜 《中国个体防护装备》2006,(4):41
经国家安全生产监督管理总局批准,个体防护装备现行12项行业标准被废止,其中部分行业标准将由国家标准代替。具体情况如下:序号123456789101112替代标准GB/T2626-1992防尘口罩GB/T12624-1990劳动保护手套通用技术条件GB17622-1998带电作业用绝缘手套通用技术条件GB2811-1989安全帽GB2811-1989安全帽GB/T13641-1992劳动护肤剂通用技术条件GB/T14272-2002羽绒服装GB12011-2000电绝缘鞋通用技术条件废止标准LD3-1991防振鞋一般技术条件LD5-1991防砸背甲LD29-1992防尘口罩LD30-1992劳动防护雨衣LD34-1992劳动防护手套LD34.1-1992带… 相似文献
316.
317.
318.
Directional selection by fisheries and the timing of sockeye salmon (Oncorhynchus nerka) migrations.
Thomas P Quinn Sayre Hodgson Lucy Flynn Ray Hilborn Donald E Rogers 《Ecological applications》2007,17(3):731-739
The timing of migration from feeding to breeding areas is a critical link between the growth and survival of adult animals, their reproduction, and the fitness of their progeny. Commercial fisheries often catch a large fraction of the migrants (e.g., salmon), and exploitation rates can vary systematically over the fishing season. We examined daily records of sockeye salmon (Oncorhynchus nerka) in the Egegik and Ugashik management districts in Bristol Bay, Alaska (USA), for evidence of such temporally selective fishing. In recent years, the early migrants have experienced lower fishing rates than later migrants, especially in the Egegik district, and the median migration date of the fish escaping the fisheries has been getting progressively earlier in both districts. Moreover, the overall runs (catch and escapement) in the Egegik district and, to a lesser extent the Ugashik district, have been getting earlier, as predicted in response to the selection on timing. The trends in timing were not correlated with sea surface temperature in the region of the North Pacific Ocean where the salmon tend to concentrate, but the trends in the two districts were correlated with each other, indicating that there may be some common environmental influence in addition to the effect of selection. Despite the selection, both groups of salmon have remained productive. We hypothesize that this resilience may result from representation of all component populations among the early and late migrants, so that the fisheries have not eliminated entire populations, and from density-dependent processes that may have helped maintain the productivity of these salmon populations. 相似文献
319.
Nancy L. Douglas Kerri M. Mullen Stephanie C. Talmage C. Drew Harvell 《Marine Biology》2007,150(6):1137-1144
Chitinases are involved in defense against chitinaceous pathogens in both invertebrates and vertebrates. This study investigated
whether sea fan corals, Gorgonia ventalina (Linnaeus) collected from the Florida Keys between the summer of 2002 and the summer of 2005 contain chitinases, and whether
these enzymes could serve an analogous protective role against the fungal pathogen, Aspergillus sydowii (Thom et Church). Crude extracts of healthy sea fans contained detectible levels of exochitinase activity in an in vitro
microplate assay using fluorogenic substrates. The exochitinase levels decreased upon injury, agitation, or manipulation of
the tissue. A concurrent, transient increase of exochitinase in the surrounding water suggests that sea fans release chitinases
as a response to these stresses. By contrast, endochitinase was detected in only 2 of 15 sea fans (13%), suggesting a high
degree of variation for this enzyme. Sea fan chitinase-containing seawater and anion exchange chromatography fractions were
both active against A. sydowii in an absorbance-based antifungal assay. The presence of chitinases in sea fan extracts, their release into the surrounding
water upon stress, and their activity against A. sydowii suggests that further study of these enzymes in coral stress responses is warranted. 相似文献
320.
Regional Environmental Change - Scenario planning is a flexible tool used to assess a broad range of plausible, relevant, divergent, and challenging futures, for short-term responses and long-term... 相似文献