全文获取类型
收费全文 | 452篇 |
免费 | 29篇 |
国内免费 | 46篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 2篇 |
环保管理 | 127篇 |
综合类 | 133篇 |
基础理论 | 199篇 |
污染及防治 | 18篇 |
评价与监测 | 14篇 |
社会与环境 | 24篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 18篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 15篇 |
2013年 | 32篇 |
2012年 | 19篇 |
2011年 | 22篇 |
2010年 | 13篇 |
2009年 | 21篇 |
2008年 | 20篇 |
2007年 | 21篇 |
2006年 | 40篇 |
2005年 | 29篇 |
2004年 | 28篇 |
2003年 | 25篇 |
2002年 | 11篇 |
2001年 | 28篇 |
2000年 | 17篇 |
1999年 | 21篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有527条查询结果,搜索用时 343 毫秒
161.
不同栽培基质对石山珍稀濒危植物苗期生长的影响 总被引:6,自引:0,他引:6
对 6种石山珍稀濒危植物在石灰岩土壤和酸性红壤上的苗期生长状况及体内化学元素含量进行了对比研究 ,结果表明 :(1 )每种植物在 2种土壤上的物候学特征基本一致 ;(2 )小花异裂菊和青檀在石灰岩土壤上生长量比酸性土壤上高 ,海南椴在酸性土壤上生长量比石灰岩土壤上高 ;(3 ) 6种植物体内Ca、B 2种化学元素的含量是石灰岩土上比酸性土上高 ;除小花异裂菊外 ,Al在其它 5种植物中的含量都是酸性土上高于石灰岩土上 ,小花异裂菊则是石灰岩土上高于酸性土上 ;(4 )K、Zn、B的生物吸收系数是石灰岩土高于酸性土 ,而N、P、Ca、Mg、Fe、Al、Mn则是酸性土高于石灰岩土。 相似文献
162.
基于气候变化下部分珍稀濒危物种脆弱性分析,初步提出了适应对策,探讨了部分物种适应措施。气候变化下,珍稀濒危物种脆弱性表现在物种分布范围减少、破碎化和失去原分布范围、丰富度下降、种群数量减少、物种灭绝、栖息地退化或消失等。珍稀濒危物种适应气候变化需要分析物种自然适应机制,加强就地保护,增加种群数量,开展迁地和遗传保护,减少其它干扰,保护和恢复栖息地,建立自然保护区适应对策等。每个物种需要分析目前濒危程度和气候变化下的脆弱性来提出适应对策。 相似文献
163.
桐庐县富春江、分水江库区漂浮物主要由水葫芦、生活垃圾、动物尸体三部分构成,结合桐庐县垃圾处理处置设施建设现状及规划,对水葫芦及生活垃圾采用机械打捞-压缩中转-烘干(仅水葫芦)-焚烧工艺,对动物尸体采用人工打捞-冷藏车运输-冷库储存-焚烧工艺。为确保水葫芦焚烧可行性,比较了烟气直接烘干和蒸汽间接烘干两种工艺,推荐采用蒸汽间接烘干。 相似文献
164.
Pär Segerdahl 《Journal of Agricultural and Environmental Ethics》2007,20(2):167-193
Although the notion of natural behavior occurs in many policy-making and legal documents on animal welfare, no consensus has
been reached concerning its definition. This paper argues that one reason why the notion resists unanimously accepted definition
is that natural behavior is not properly a biological concept, although it aspires to be one, but rather a philosophical tendency
to perceive animal behavior in accordance with certain dichotomies between nature and culture, animal and human, original
orders and invented artifacts. The paper scrutinizes the philosophy of natural behavior as it developed in the organic movement
in response to a perceived contrast between industrialized and traditional agriculture. There are two reasons for focusing
on the organic movement: (i) the emphasis on “the natural” is most accentuated there and has a long history, (ii) everyday
life on organic farms presupposes human/animal interplay, which conflicts with the philosophical tendency to separate nature
from culture. This mismatch between theory and practice helps us see why, and how, the philosophy of natural behavior needs
to be reconsidered. The paper proposes that we understand farms as local human/animal cultures, and asks what we can mean
my natural behavior in such contexts. Since domestic animals adapt to agricultural environments via interaction with caretakers,
such interplay is analyzed as “hub” in these animals’ natural behavior. 相似文献
165.
Craig A. Peters 《黑龙江环境通报》2001,21(11):917-923
Fetal models of urinary tract disease have been used for many years and have provided unique and important insights into the pathophysiology of these conditions. This review will summarize the principal model systems used and the current directions of investigation. These models (including rabbit, opossum, sheep and recently swine) have demonstrated that in utero obstruction of the urinary tract alters renal growth, differentiation and produces stereotypical patterns of tissue response, particularly fibrosis. New molecular understanding of these processes has identified specific mechanisms that may be key elements in the development of renal dysfunction due to obstruction. These factors include the renin–angiotensin system (RAS) and its interaction with TGF-β in altering growth regulation and tissue fibrosis. These factors offer the prospect of clinical utility as markers of disease progression as well as pharmacologic therapy. Gene knockout systems have opened a new horizon of molecular models of congenital obstructive uropathy with insights into the role of the RAS in particular. It remains to be defined how closely these knockouts represent the human conditions they resemble. Continued application of fetal models of urinary obstruction, integrating large animal and knockout systems offers promise for improved diagnosis and treatment in these challenging conditions. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
166.
Kate M. Millar 《Journal of Agricultural and Environmental Ethics》2000,12(1):41-50
An analysis of the ethical impacts of the use of anAutomatic Milking System (AMS) is employed as a casestudy to illustrate the use of a form of bioethicalanalysis in technology assessment. The approach isbased on the Ethical Matrix, where `impacts' areassessed in terms of (lack of) respect for threeethical principles as applied to interest groups. Inthis case, only impacts on dairy cows are examined,and principally in terms of their behaviouralfreedom.In contrast to traditional milking systems, AMS, inprinciple, allow cows to present for milkingvoluntarily. So with AMS, it is claimed that dairymanagement relies on the autonomous interaction of thecow with her environment.One of the roles of bioethical analysis is to identifythe influence of rhetoric and symbolism in technologyassessment, e.g., with respect to the claimed`voluntariness' of cows' presentation. The AMS can beinstalled to allow cows three types of access, viz., i)free choice ii) rewarded access (RA) iii) obligatoryaccess (OA). Studies suggest the desire for milkremoval per se is not critical in the cow'sattendance at the AMS. Continued motivation to bemilked, required for the system to function,principally relies on RA and OA. Both RA and OA aresubject to numerous factors, such as: design of theAMS, location, etc. In turn, these can affect thecows' behavioural freedom and welfare.One of the aims of this approach is to illustrate theethical basis on which public policy is or can beformulated. 相似文献
167.
168.
169.
DENA R. SPATZ KELLY M. NEWTON REINA HEINZ BERNIE TERSHY NICK D. HOLMES STUART H. M. BUTCHART DONALD A. CROLL 《Conservation biology》2014,28(5):1282-1290
Seabirds are the most threatened group of marine animals; 29% of species are at some risk of extinction. Significant threats to seabirds occur on islands where they breed, but in many cases, effective island conservation can mitigate these threats. To guide island‐based seabird conservation actions, we identified all islands with extant or extirpated populations of the 98 globally threatened seabird species, as recognized on the International Union for Conservation of Nature Red List, and quantified the presence of threatening invasive species, protected areas, and human populations. We matched these results with island attributes to highlight feasible island conservation opportunities. We identified 1362 threatened breeding seabird populations on 968 islands. On 803 (83%) of these islands, we identified threatening invasive species (20%), incomplete protected area coverage (23%), or both (40%). Most islands with threatened seabirds are amenable to island‐wide conservation action because they are small (57% were <1 km2), uninhabited (74%), and occur in high‐ or middle‐income countries (96%). Collectively these attributes make islands with threatened seabirds a rare opportunity for effective conservation at scale. La Biogeografía de Aves Marinas Amenazadas Globalmente y las Oportunidades de Conservación en Islas 相似文献
170.
准确评价甲烷(CH4)的温室效应是制定有效减排路径的基础.首次采用新提出的、针对短寿命气候污染物(SLCP)设计的气候指标GWP-star (GWP*)对中国畜牧业CH4排放的温室效应进行定量评价,并与常用的GWP指标评价结果相比较.结果表明,GWP的视角下我国畜牧业CH4排放的温室效应持续增加.因此,畜牧业实现碳中和需要完全消除排放,或以增加碳汇、增加资源化利用的形式抵消每年稳定的CH4排放.在GWP*的视角下,2015~2019年间畜牧业CH4排放的温室效应较20年前有所减少,降低的热量相当于从20年前的大气中减少2.1×104万t CO2的热量,畜牧业只需每年有效降低0.3%的CH4排放则可在短期内实现自身碳中和.在中国畜牧业持续采取有效减排措施的情况下,采用GWP*的标准制定减排目标比用GWP制定的减排目标更早达到,但选择GWP还是GWP*需要综合考虑评价的目的、评价的时间尺度和实际可操作性. 相似文献