全文获取类型
收费全文 | 12080篇 |
免费 | 132篇 |
国内免费 | 1073篇 |
专业分类
安全科学 | 156篇 |
废物处理 | 894篇 |
环保管理 | 1404篇 |
综合类 | 2475篇 |
基础理论 | 3470篇 |
环境理论 | 1篇 |
污染及防治 | 2659篇 |
评价与监测 | 1114篇 |
社会与环境 | 993篇 |
灾害及防治 | 119篇 |
出版年
2024年 | 6篇 |
2023年 | 62篇 |
2022年 | 158篇 |
2021年 | 115篇 |
2020年 | 105篇 |
2019年 | 98篇 |
2018年 | 1552篇 |
2017年 | 1476篇 |
2016年 | 1339篇 |
2015年 | 324篇 |
2014年 | 199篇 |
2013年 | 249篇 |
2012年 | 679篇 |
2011年 | 1567篇 |
2010年 | 878篇 |
2009年 | 772篇 |
2008年 | 1041篇 |
2007年 | 1385篇 |
2006年 | 150篇 |
2005年 | 88篇 |
2004年 | 100篇 |
2003年 | 149篇 |
2002年 | 171篇 |
2001年 | 72篇 |
2000年 | 80篇 |
1999年 | 75篇 |
1998年 | 71篇 |
1997年 | 56篇 |
1996年 | 55篇 |
1995年 | 45篇 |
1994年 | 39篇 |
1993年 | 35篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1972年 | 2篇 |
1935年 | 2篇 |
1918年 | 1篇 |
1917年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Monavari SM Omrani GA Karbassi A Raof FF 《Environmental monitoring and assessment》2012,184(4):1841-1846
Environment problems associated with the generation of waste are part of societal changes where households play an important
role. These societal changes influence the size, structure and characteristic of given households. For the effective planning
of solid-waste handling infrastructure, it is essential to know the quantity of waste generation and its composition. This
paper presents the findings of a study carried out in an urban municipal area in Iran to determine the household solid-waste
generation rate and waste composition based on field surveys and to determine the related socioeconomic parameters. The dependent
variables were waste generation and composition, and independent variables were family size, family employment, age, number
of room and education. Over 400 sample households were selected for the study using a stratified random sampling methodology
and from five different socioeconomic groups. Waste collected from all groups of households were segregated and weighted.
Waste generation rate was 5.4 kg/household/day. Household solid waste comprised of ten categories of wastes and with the largest
component (76.9%). The generation and composition of household solid waste were correlated with family size, education level
and households income. This paper adequately suggests new insights concerning the role of socioeconomic parameters in affecting
the generation of household waste. 相似文献
942.
Mehmet Cetin Ilknur Zeren Hakan Sevik Cansel Cakir Huseyin Akpinar 《Environmental monitoring and assessment》2018,190(3):167
The surface site of Yesilyuva Nature Park encompasses natural, social, economic, and cultural characteristics and has become a marker of the region’s natural and cultural heritage. To support the preservation of this site, promotional activities should be planned. In this study, because of tourism and related opinions of residents and visitors alike in terms of their natural determination, an important cultural and historical feature is aimed at evaluating the tourism potential of Yesilyuva Nature Park. This framework is designed to establish prospective tourism sustainability. As a result, Yesilyuva Nature Park’s natural and cultural properties have been determined to be suitable for sustainable tourism activities using geographic information systems (GIS). This protection in the field, which balances sustainability and landscape design, will provide for the development of tourism activities. In the Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis and survey, residents and visitors reported that the most important feature of the Yesilyuva Nature Park was its natural beauty. Visitors often come to observe traditional and natural life and to engage in tourism activities. All the data, which includes maps derived from GIS, represents landscape planning for sustainable tourism areas in Yesilyuva Nature Park. 相似文献
943.
总结了有限空间作业过程中常见的错误,并按照HSE管理体系的理念,针对这些错误提出了纠正措施。 相似文献
944.
This study seeks to expand empirical research on how municipalities have adapted and innovated (or not) their water systems as a result of climate change. We analyze characteristics of water governance at the municipal scale in Oklahoma, USA. ArcMap 10.3 was used to build a qualitative geographic information system (GIS) based on fieldwork, including interviews and site-observations, to compare dynamic capabilities that lead to innovation in 38 cities in the state. The GIS enables visualization of our digitalized research to understand the interconnections between drivers of innovativeness—the combination of dynamic capabilities and innovation rates—and state of water resource infrastructure in place specific and regional planning contexts. In particular, the GIS takes into consideration income level, the influence of state-level water policy (Water for 2060 Act), water manager certification levels, population, dynamic capabilities, and perceptions of risk and vulnerability to water system change. Digitizing this information provides a diverging perspective on the historical lack of innovation in the public sector, as different socio-cultural, socio-economic, and socio-political contexts occur throughout Oklahoma, a state notorious for its oil centered economy and its climate change deniers. The findings suggest that innovativeness is directly related to dynamic capabilities and indirectly related to population size, income level, and the educational backgrounds of water decision-makers. The visualizations also show that some cities have surplus capacity for adaptation, while others were able to more efficiently turn capacity into water management innovations. Seeing representations of water governance success and failure in communities affords the opportunity to educate citizens and decision-makers to adapt water infrastructures to the effects of climate change, showcasing the utility of digitalization in a quest for sustainable solutions. 相似文献
945.
We test the hypothesis that echolocation behavior can be used to find the border between bat habitats. Assuming that bats
react to background targets in “edge space” but not in “open space”, we determined the border between these two habitat types
for commuting individuals of the parti-colored bat Vespertilio murinus. We recorded sequences of bats’ echolocation signals while they flew parallel to the walls of large buildings and to the
ground and determined the signals’ average bandwidth, duration, and pulse interval. These parameters varied systematically
with the estimated horizontal and vertical distances between the bats and the background. A distinct effect of horizontal
distance to the background on echolocation behavior was found for horizontal distances of less than 6 m, thus indicating the
border between edge and open space. Only a few bats flew at vertical distances below 5 m. However, enough passages at vertical
distances of 5 m and above indicated that the vertical border is somewhere below a distance of 5 m. Within edge space, V. murinus reacted to the background by reducing signal duration, increasing bandwidth at closer distances, and often emitting one signal
per wing beat. In open space, signal parameters did not vary as a function of distance to the background. There, V. murinus emitted the longest signals with the narrowest bandwidth and often made one or two wing beats without emitting a pulse. With
our data we support with statistical methods the hypothesis that echolocation behavior reveals the border between the habitat
types “edge” and “open space”. 相似文献
946.
Summary. We report field and laboratory evidence indicating that the defensive compounds secreted by the millipedes Amplinus bitumidus (Diplopoda: Polydesmida) and Anadenobolus putealis (Diplopoda: Spirobolida) attract the carrion scarab Canthon morsei (Scarabaeidae: Scarabaeinae). In a Mexican tropical rain forest, C. morsei was mostly caught in pitfall traps baited with the carcasses of both millipede species. Only a few beetles were attracted
to fish carrion. Experimental evidence indicates that C. morsei is attracted to freshly dead millipedes. Benzaldehyde and HCN were identified from Amplinus bitumidus; but 2-methyl-1,4-benzoquinone (toluquinone) and 2-methoxy- 3-methyl-1,4-benzoquinone from Anadenobolus putealis. Benzaldehyde attracted significantly more C. morsei individuals than fish meat, or millipedes of both species did after rinsing in hexane. This is the first report of Polydesmida
attracting dung beetles. 相似文献
947.
Vinod Kumar Yata Bhupesh Chandra Tiwari Irfan Ahmad 《Environmental Chemistry Letters》2018,16(1):79-84
High population rise and climate changes are increasing issues of agricultural production and food safety. Nanotechnology is finding revolutionary applications to improve agricultural and food systems, notably for better crop production and food preservation. Here we review research, industrial and patent trends of nanoscience in food and agriculture. In a literature survey, we found 44.6% publications in the nano-food research area during the years 2013–2015 and 59.09% publications in the nano-agriculture research area during 2012–2015. USA is leading in the development of nanotechnology firms with a maximum share of 75.5% of the total firms, followed by Germany and France with 8.10 and 4.74%, respectively. USA is leading in the nano-food research with 22 granted patents, whereas China is placed first in nano-agriculture research with 28 granted patents during assessment years 2011–2015. Nano-food research focused mainly on nano-food packaging with 76.84% contributions, whereas in nano-agriculture research, focus has been on nano-fertilizers with 90% contributions. Germany, France, Korea, Italy, Czech Republic, Slovenia and Slovak republic have more than 20% of dedicated nanotechnology firms. A growth of about 45% in nano-food patents has been observed for USA during 2011–2015, and China is leading in the nano-agriculture patents with an increase of 60.7% during 2012–2015. 相似文献
948.
Ignacio J. Moncho-Esteve Frederik Folke Manuel García-Villalba Guillermo Palau-Salvador 《Environmental Fluid Mechanics》2017,17(4):695-714
This paper presents large eddy simulation of turbulent flow in a meandering open channel with smooth wall and rectangular cross-section. The Reynolds number based on the channel height is 40,000 and the aspect ratio of the cross-section is 4.48. The depth-averaged mean stream-wise velocity agree well to experimental measurements. In this specific case, two interacting cells are formed that swap from one bend to the other. Transport and mixing of a pollutant is analysed using three different positions of release, e.g. on the inner bank, on the outer bank and on the centre of the cross section. The obtained depth-average mean concentration profiles are reasonably consistent with available experimental data. The role of the secondary motions in the mixing processes is the main focus of the discussion. It is found that the mixing when the scalar is released on the centre of the cross-section is stronger and faster than the mixing of the scalar released on the sides. When the position of release is close to a bank side, the mixing is weaker and a clear concentration of scalar close to the corresponding side-wall can be observed in both cases. 相似文献
949.
We present a new system for microscopic multicolour variable chlorophyll fluorescence imaging of aquatic phototrophs. The
system is compact and portable and enables microscopic imaging of photosynthetic performance of individual cells and chloroplasts
using different combinations of blue, green, red or white light. Automated sequential exposure of microscopic samples to the
three excitation colours enables subsequent deconvolution of the resulting fluorescence signals and colour marking of cells
with different photopigmentation, i.e., cyanobacteria, green algae, red algae and diatoms. The photosynthetic activity in
complex mixtures of phototrophs and natural samples can thus be assigned to different types of phototrophs, which can be quantified
simultaneously. Here, we describe the composition and performance of the new imaging system and present applications with
both natural phytoplankton and microalgal culture samples. 相似文献
950.
Distribution and availability of potentially toxic metals in soil in central area of Belgrade,Serbia 总被引:1,自引:0,他引:1
Rabia Ahmed Ghariani Ivan Gržetić Mališa Antić Snežana Nikolić Mandić 《Environmental Chemistry Letters》2010,8(3):261-269
Belgrade, capital city of Serbia, has over 1,600,000 inhabitants and over 400,000 vehicles trafficking every day on its streets.
The investigation of soil pollution was performed by sequential extraction analysis to investigate the availability of potentially
toxic metals (Zn, Cd, Pb, Co, Ni, Cu, Cr and Mn) under different oxidation and pH conditions. All investigated metals were
mainly extracted from soils with neutral or acidic extractants. Serious pollution was observed along roads and streets with
high traffic frequency, but Pb and Ni pollution was the highest since their concentrations exceed both soil Serbian standard
and Canadian guidance values and is characteristic for all investigated sites. Cd, Cu, Cr and Zn concentrations are moderately
high since they are between Canadian guideline and Serbian standard. 相似文献