全文获取类型
收费全文 | 105篇 |
免费 | 11篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 2篇 |
环保管理 | 7篇 |
综合类 | 33篇 |
基础理论 | 38篇 |
污染及防治 | 20篇 |
评价与监测 | 5篇 |
社会与环境 | 3篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 4篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 11篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 11篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有126条查询结果,搜索用时 15 毫秒
1.
Jeffrey Barber 《Environment, Development and Sustainability》2003,5(1-2):63-93
At the World Summit on Sustainable Development (WSSD), world leaders agreed that eliminating unsustainable production and consumption is one of the three overriding objectives of sustainable development. Achieving that objective should have been a major priority for the WSSD Plan of Implementation. Increases in consumption and production over the past decade were largely responsible for the worsening environmental and social trends. Unfortunately, the negotiators of the Plan paid insufficient attention to the lessons from 10 years of discussions about the concepts, the available policies and tools and their effectiveness, the impacts of those policies on developing countries, and the political commitment of countries in an era of globalization. Despite a promising proposal for a new ten-year work programme aimed at bridging the gap implementing the Agenda 21 commitments from Rio, Summit negotiators produced barely more than a muted echo of recommendations from the past which have yet to be taken seriously enough by the world's leaders in a comprehensive intergovernmental strategy. In the ten-year review of progress to achieve sustainable production and consumption (SPAC), governments quickly skipped past the critical work of examining why things are getting worse, avoiding the task of identifying the obstacles (which in some cases were themselves) and in turn avoiding the commitment to time-bound measurable targets. If nothing else, the WSSD demonstrated that a global strategy to achieve SPAC will come not from a UN consensus of world leaders but from a strategic alliance of responsible governments, civil society and others with a vision beyond the next election cycle. 相似文献
2.
Evelien?M.?de OldeEmail author Henrik?Moller Fleur?Marchand Richard?W.?McDowell Catriona?J.?MacLeod Marion?Sautier Stephan?Halloy Andrew?Barber Jayson?Benge Christian?Bockstaller Eddie?A.?M.?Bokkers Imke?J.?M.?de Boer Katharine?A.?Legun Isabelle?Le Quellec Charles?Merfield Frank?W.?Oudshoorn John?Reid Christian?Schader Erika?Szymanski Claus?A.?G.?S?rensen Jay?Whitehead Jon?Manhire 《Environment, Development and Sustainability》2017,19(4):1327-1342
Sustainability indicators are well recognized for their potential to assess and monitor sustainable development of agricultural systems. A large number of indicators are proposed in various sustainability assessment frameworks, which raises concerns regarding the validity of approaches, usefulness and trust in such frameworks. Selecting indicators requires transparent and well-defined procedures to ensure the relevance and validity of sustainability assessments. The objective of this study, therefore, was to determine whether experts agree on which criteria are most important in the selection of indicators and indicator sets for robust sustainability assessments. Two groups of experts (Temperate Agriculture Research Network and New Zealand Sustainability Dashboard) were asked to rank the relative importance of eleven criteria for selecting individual indicators and of nine criteria for balancing a collective set of indicators. Both ranking surveys reveal a startling lack of consensus amongst experts about how best to measure agricultural sustainability and call for a radical rethink about how complementary approaches to sustainability assessments are used alongside each other to ensure a plurality of views and maximum collaboration and trust amongst stakeholders. To improve the transparency, relevance and robustness of sustainable assessments, the context of the sustainability assessment, including prioritizations of selection criteria for indicator selection, must be accounted for. A collaborative design process will enhance the acceptance of diverse values and prioritizations embedded in sustainability assessments. The process by which indicators and sustainability frameworks are established may be a much more important determinant of their success than the final shape of the assessment tools. Such an emphasis on process would make assessments more transparent, transformative and enduring. 相似文献
3.
高效液相色谱-串联质谱法测定海水中孔雀石绿及其代谢物 总被引:1,自引:0,他引:1
建立了海水中孔雀石绿及其代谢物的高效液相色谱-串联质谱检测方法,取500 mL海水样品,以二氯甲烷萃取,旋转蒸发浓缩后,以甲醇定溶,经0.45μm滤膜过滤后,应用高效液相色谱-串联质谱测定海水中孔雀石绿及其代谢物残留量.本方法MG和LMG线性范围为0.5~100μg/L,相关系数为0.9978和0.9970,仪器检出限为0.2μg/L,定量限为0.5μg/L,MG回收率为74.0%~95.0%,LMG回收率72.0~91.5%.该方法灵敏度高、准确性好,适用于海水中痕量孔雀石绿及其代谢物的检测. 相似文献
4.
5.
哈尔滨等几个城市气候变化的对比分析 总被引:4,自引:1,他引:4
应用距平分析和Morlet小波变换方法对哈尔滨、石家庄、武汉、广州等4个城市1951—2004年的年均气温和夏季降水进行了对比分析,结果发现,这4个城市:(1)近50多a来气温基本上都是呈逐渐升温趋势,升温幅度都在1℃以上,其中哈尔滨的气温年变化比其他3个城市剧烈;(2)气温年代际演变特征非常明显,存在10~25a尺度的变化,在20世纪80年代前期发生气候突变;(3)近50多a夏季降水变化趋势不太一致,在空间分布上表现为波列特征;(4)夏季降水年代际变化特征非常明显,都存在10a左右尺度变化;(5)降水变化趋势与气温变化趋势不一致。 相似文献
6.
Current issues and uncertainties in the measurement and modelling of air-vegetation exchange and within-plant processing of POPs 总被引:3,自引:0,他引:3
Barber JL Thomas GO Kerstiens G Jones KC 《Environmental pollution (Barking, Essex : 1987)》2004,128(1-2):99-138
Air-vegetation exchange of POPs is an important process controlling the entry of POPs into terrestrial food chains, and may also have a significant effect on the global movement of these compounds. Many factors affect the air-vegetation transfer including: the physicochemical properties of the compounds of interest; environmental factors such as temperature, wind speed, humidity and light conditions; and plant characteristics such as functional type, leaf surface area, cuticular structure, and leaf longevity. The purpose of this review is to quantify the effects these differences might have on air/plant exchange of POPs, and to point out the major gaps in the knowledge of this subject that require further research. Uptake mechanisms are complicated, with the role of each factor in controlling partitioning, fate and behaviour process still not fully understood. Consequently, current models of air-vegetation exchange do not incorporate variability in these factors, with the exception of temperature. These models instead rely on using average values for a number of environmental factors (e.g. plant lipid content, surface area), ignoring the large variations in these values. The available models suggest that boundary layer conductance is of key importance in the uptake of POPs, although large uncertainties in the cuticular pathway prevents confirmation of this with any degree of certainty, and experimental data seems to show plant-side resistance to be important. Models are usually based on the assumption that POP uptake occurs through the lipophilic cuticle which covers aerial surfaces of plants. However, some authors have recently attached greater importance to the stomatal route of entry into the leaf for gas phase compounds. There is a need for greater mechanistic understanding of air-plant exchange and the 'scaling' of factors affecting it. The review also suggests a number of key variables that researchers should measure in their experiments to allow comparisons to be made between studies in order to improve our understanding of what causes any differences in measured data between sites. 相似文献
7.
以半知菌属疣孢漆斑菌Myrothecium verrucaria NF-08为供试菌,采用响应面方法优化菌株产漆酶条件,并以其漆酶粗酶进行3种结构类型6种染料的脱色试验,考察了粗酶浓度、温度和p H值对脱色率的影响.两水平析因设计、中心组合设计和验证试验结果表明:葡萄糖浓度为15.4 g·L~(-1)、蛋白胨浓度为43.3 g·L~(-1)和培养基初始p H值为6.68时,漆酶活性达到最大值(25.58±1.60)U·m L~(-1),是单因素试验(16.82 U·m L~(-1))的1.52倍,提高了52.1%.以上述发酵条件获得的M.verrucaria NF-08漆酶粗酶对3种结构类型染料均有脱色效果,排序为偶氮类优于芳甲烷类优于蒽醌类.脱色率随粗酶浓度增大(2~8 U·m L~(-1))、反应温度升高(15~35℃)而上升,随p H值上升(4~10)而下降.粗酶浓度为5 U·m L~(-1),反应温度为25℃,p H值为4时,偶氮类染料铬黑T和芳甲烷类染料碱性品红即可几乎完全脱色,脱色率分别为99.2%和94.6%. 相似文献
8.
Mahlon Craig Barber 《Ecological modelling》1978,5(2):125-135
Historic ecosystem resource flow is modeled as a retrospective discrete Markov chain to obtain the expected values and variances of compartmental residence times and numbers of intercompartmental transfers that compartmental standing crops have experienced since their latest entry into the ecosystem. The transition probabilities of the proposed retrospective Markovian model are either stationary or time inhomogeneous according to whether a steady state or non-steady state ecosystem, respectively, is analyzed. 相似文献
9.
The high frequency of extra-pair paternity in tree swallows is not an artifact of nestboxes 总被引:6,自引:0,他引:6
C. A. Barber Raleigh J. Robertson Peter T. Boag 《Behavioral ecology and sociobiology》1996,38(6):425-430
A common criticism of nestbox studies is one of creating artificial nesting conditions and breeding behavior different from
what would be seen under natural conditions. We assessed the frequency of extra-pair paternity (percentage of broods with
at least one extra-pair young) in 25 families of tree swallows (Tachycineta bicolor) nesting in natural cavities and compared it to that in a nestbox population. We found that 84% of females nesting in natural
cavities obtained fertilizations from extra-pair males. These extra-pair males fathered 69% of all nestlings. Studies of tree
swallows breeding in nestboxes have shown that 50–87% of broods contained extra-pair young, with extra-pair males fathering
38–53% of all the young. In broods with extra-pair paternity, natural cavities contained a significantly greater proportion
of extra-pair young than did nestboxes. Despite differences in nesting habitat and female age structure, the frequency of
extra-pair paternity did not differ significantly between the natural-cavity and nestbox populations. Therefore, the presence
of extra-pair paternity in tree swallows is not an artifact of nestboxes or of artificial nesting conditions.
Received: 2 May 1995/Accepted after revision: 14 January 1996 相似文献
10.
P. H. Wiebe A. W. Morton A. M. Bradley R. H. Backus J. E. Craddock V. Barber T. J. Cowles G. R. Flierl 《Marine Biology》1985,87(3):313-323
Four variants of the Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) have been constructed to sample a broad size spectrum of oceanic animals from microzooplankton to micronekton. The systems differ in mouth opening dimensions (ranging from 1/4 to 20 m2), the number of nets carried (from 5 to 20), and the mesh size of the netting (from 64 m to 3.0 mm). A new electronics package enables an operator to send commands down a single conductor, armored cable to open/close the nets and provides 12-bit resolution for the environmental (temperature, depth, conductivity) and net operation data (flow, net-frame angle, net-bar release), which are transmitted up the cable to the deck unit at 2-s intervals. A microcomputer system, interfaced to the deck unit, calculates salinity, volume filtered by a net, net trajectory velocity, and vertical velocity. The data are printed out and stored on disc, and profiles of temperature and salinity versus depth are plotted during the course of the tow. Analysis of the relationship between the geometry of the MOCNESS under tow and the past and present methods used to estimate the water filtered by a net revealed that significant bias is introduced when the ascent or descent angle of a net is disregarded. The bias is a function of the ratio of vertical velocity to net trajectory velocity and results in an underestimate of volume filtered while shooting a net and an overestimate while hauling. 相似文献