全文获取类型
收费全文 | 3463篇 |
免费 | 88篇 |
国内免费 | 184篇 |
专业分类
安全科学 | 212篇 |
废物处理 | 36篇 |
环保管理 | 793篇 |
综合类 | 1347篇 |
基础理论 | 303篇 |
环境理论 | 7篇 |
污染及防治 | 286篇 |
评价与监测 | 582篇 |
社会与环境 | 132篇 |
灾害及防治 | 37篇 |
出版年
2024年 | 4篇 |
2023年 | 53篇 |
2022年 | 48篇 |
2021年 | 86篇 |
2020年 | 114篇 |
2019年 | 61篇 |
2018年 | 64篇 |
2017年 | 119篇 |
2016年 | 137篇 |
2015年 | 149篇 |
2014年 | 180篇 |
2013年 | 233篇 |
2012年 | 128篇 |
2011年 | 239篇 |
2010年 | 88篇 |
2009年 | 230篇 |
2008年 | 197篇 |
2007年 | 201篇 |
2006年 | 154篇 |
2005年 | 134篇 |
2004年 | 127篇 |
2003年 | 123篇 |
2002年 | 108篇 |
2001年 | 90篇 |
2000年 | 83篇 |
1999年 | 79篇 |
1998年 | 78篇 |
1997年 | 59篇 |
1996年 | 42篇 |
1995年 | 60篇 |
1994年 | 64篇 |
1993年 | 38篇 |
1992年 | 25篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1973年 | 5篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有3735条查询结果,搜索用时 31 毫秒
1.
Crop damage is the most common impact of negative interactions between people and elephants and poses a significant threat to rural livelihoods and conservation efforts. Numerous approaches to mitigate and prevent crop damage have been implemented throughout Africa and Asia. Despite the documented high efficacy of many approaches, losses remain common, and in many areas, damage is intensifying. We examined the literature on effectiveness of crop-damage-mitigation strategies and identified key gaps in evaluations. We determined there is a need to better understand existing solutions within affected communities and to extend evaluations of effectiveness beyond measurement of efficacy to include rates of and barriers to adoption. We devised a conceptual framework for evaluating effectiveness that incorporates the need for increased emphasis on adoption and can be used to inform the design of future crop-damage mitigation assessments for elephants and conflict species more widely. The ability to prevent crop loss in practice is affected by both the efficacy of a given approach and rates of uptake among target users. We identified the primary factors that influence uptake as local attitudes, sustainability, and scalability and examined each of these factors in detail. We argue that even moderately efficacious interventions may make significant progress in preventing damage if widely employed and recommend that wherever possible scientists and practitioners engage with communities to build on and strengthen existing solutions and expertise. When new approaches are required, they should align with local attitudes and fit within limitations on labor, financial requirements, and technical capacity. 相似文献
2.
Tibor Hartel Ben C. Scheele Abi Tamim Vanak Laurențiu Rozylowicz John D. C. Linnell Euan G. Ritchie 《Conservation biology》2019,33(6):1256-1265
Achieving coexistence between large carnivores and humans in human-dominated landscapes (HDLs) is a key challenge for societies globally. This challenge cannot be adequately met with the current sectoral approaches to HDL governance and an academic community largely dominated by disciplinary sectors. Academia (universities and other research institutions and organizations) should take a more active role in embracing societal challenges around conservation of large carnivores in HDLs by facilitating cross-sectoral cooperation to mainstream coexistence of humans and large carnivores. Drawing on lessons from populated regions of Europe, Asia, and South America with substantial densities of large carnivores, we suggest academia should better embrace the principles and methods of sustainability sciences and create institutional spaces for the implementation of transdisciplinary curricula and projects; reflect on research approaches (i.e., disciplinary, interdisciplinary, or transdisciplinary) they apply and how their outcomes could aid leveraging institutional transformations for mainstreaming; and engage with various institutions and stakeholder groups to create novel institutional structures that can respond to multiple challenges of HDL management and human–large carnivore coexistence. Success in mainstreaming this coexistence in HDL will rest on the ability to think and act cooperatively. Such a conservation achievement, if realized, stands to have far-reaching benefits for people and biodiversity. 相似文献
3.
Dario Paladini Maria Giovanna Russo Antonio Tartaglione Annamaria Loffredo Pasquale Martinelli 《黑龙江环境通报》2002,22(13):1185-1187
Toriello–Carey syndrome is a rare malformative complex, described for the first time in 1988, characterized by agenesis of the corpus callosum, facial anomalies, cardiac defects and hypotonia. Relatively few neonatal cases have been reported. We describe here the first prenatal ultrasound diagnosis of the syndrome based on the detection of agenesis of the corpus callosum and spongious cardiomyopathy in a 22-week-old fetus of a couple with positive family history. The first sib of the couple was diagnosed with Toriello–Carey syndrome at 1 year of age, and had, in addition to the typical facial anomalies not detectable by ultrasound, agenesis of the corpus callosum and the same heart lesion (spongious cardiomyopathy). This report demonstrates that prenatal diagnosis of Toriello–Carey syndrome is feasible in the second trimester of pregnancy. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
4.
针对某乡镇企业十分发达地区的跨行政(市县)区域水污染死鱼事故的剖析,本文提出了处理解决跨行政区域水污染纠纷事故的若干对策建议。 相似文献
5.
南水北调的资源、环境和社会效应 总被引:6,自引:0,他引:6
俞澄生 《长江流域资源与环境》1994,3(3):265-270
建设南水北调工程,对中国的水资源在地区间进行合理调配,将带动其他资源的合理配置与利用,还可改善环境,是社会发展的需要,又受社会条件制约,一旦突破建成,将促使社会生产力发生新的飞跃并持续发展。 相似文献
6.
7.
8.
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
9.
A. Coulomb L'Herminé A. Aboura S. Brisset L. Cuisset V. Castaigne P. Labrune R. Frydman Dr G. Tachdjian 《黑龙江环境通报》2003,23(11):938-943
Prader–Willi syndrome (PWS) results from either paternal deletion of 15q11–q13, or maternal uniparental disomy (UPD) of chromosome 15 or imprinting center mutation. Prenatal diagnosis of PWS is currently indicated for chromosomal parental translocation involving chromosome 15 and for decreased fetal movements during the third trimester of gestation. Here we present the prenatal diagnosis of PWS during the first trimester of gestation and autopsy findings. Chorionic villus sampling (CVS) was performed for advanced maternal age at 13 weeks' gestation. CVS showed mosaicism including cells with a normal karyotype and cells with trisomy 15. Amniocentesis showed cells with a normal karyotype. Molecular analysis demonstrated that the fetus had a typical PWS abnormal methylation profile and maternal disomy for chromosome 15. Fetal ultrasound examination showed slightly enlarged lateral ventricles and hypoplasic male external genitalia without intra-uterine growth retardation. The autopsy showed a eutrophic male fetus with facial dysmorphy, hypoplasic genitalia, abnormal position of both feet and posterior hypoplasia of the corpus callosum. This report points out that in a karyotypically normal fetus with ambiguous male external genitalia and cerebral anomalies, extensive cytogenetic and molecular biology studies are strongly recommended because of risk of PWS. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
10.
Linden F Vincent 《Natural resources forum》2003,27(2):108-116
Situations of water scarcity challenge sustainability and threaten small users' access to water. In response to this problem, there has been a search for a method of hydrological analysis that can better represent the needs of small water users. While this search is rooted in the debate favouring a more participatory and inclusive allocation of the resource, it also requires a new focus on smallholder hydrology that can confront the gaps and biases found in current hydrological practices in many countries. This article looks at past hydrological practices and also at results of recent studies, highlighting the perspective of smallholder irrigators in surface water planning in Zimbabwe, and groundwater planning in India. These case studies show that wider social forces, not always best science, drive hydrological practices. However, new frameworks focusing on the water user can emerge for more equitable and sustainable water management. 相似文献