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991.
Nevin Akpinar İlkden Talay Coşkun Ceylan Sultan Gündüz 《Environment, Development and Sustainability》2004,6(4):473-486
As in many developing countries also in Turkey, agriculture is on the center of rural development and rural women are on the center of agriculture. Although they are main part as a major labor force at every stage of agricultural activity and undertake responsibilities such as domestic task and childcare, women do not profit from social and economic benefits proportionate to the responsibilities they have undertaken. Agrotourism is an alternative activity in the rural development process, which combines agriculture and tourism, improves natural resources, contributes the rural area socially and economically. The aim of this study is to examine the participation conditions of rural women to the agrotourism activities, which is considered as an option in the context of sustainable rural development, and to identify the possible social and economic implications of agrotourism on the rural women’s life, after determining the situation and importance of rural women in the agricultural activity. This research was carried out in three villages of Kalecik district of Ankara and data gathered from group meetings and surveys. 相似文献
992.
Rainer Brüggemann Gerhard Ginzel Christian Steinberg 《Environmental Sciences Europe》1997,9(6):339-343
Conflict are frequently observed when drinking water protection areas are to be defined and when many variants of how to protect these area are to be found. Using ten potential scenarios, a method is presented here which shows how such conflicts concerning these variants may be handled in a systematic manner. The technique is derived from the use of partially ordered sets and their visualization by Hasse diagrams. The first step is to define rankings of different variants according to each aim of protection. A further step is to define an appropriate relationship of order. It is then possible to visualize the extent of consensus and of dissension through the use of a Hasse diagram. The final step is to quantify the importance of each protection aim and the initialization of an iteration. Should a complete consensus be found, this would result in a chain of (connected) variants. Should a complete dissension be found on the other hand, an antichain would then result (i.e. where all variants are isolated). 相似文献
993.
994.
995.
Sesbania rostrata in pure and amended Pb/Zn tailings. About 90% of seeds of S. rostrata germinated in pure Pb/Zn tailings, which contained high concentrations of Pb, Zn, Cu, and Cd. Although seedling growth suffered
from the adverse environment of Pb/Zn tailings, they became established on tailings stands, in the greenhouse, as well as
on the actual tailings dam, and completed their life cycle in 4 months. Dry matter production and nitrogen accumulation was
3200 kg/ha and 69.4 kg/ha, respectively in the actual tailings dam. Applying inorganic fertilizer to Pb/Zn tailings led to
no obvious improvement in growth and nodulation of S. rostrata, while tailings amended by river sediment or domestic refuse rich in organic matter improved the growth and nodulation of
the species. Azorhizobium caulinodans survived and formed N-fixing stem and root nodules in S. rostrata grown in pure Pb/Zn tailings with a nodule biomass exceeding 300 mg fresh matter per plant. 相似文献
996.
997.
T.I. Khan 《The Environmentalist》1997,17(4):283-287
Director of environmental studies at the Indira Gandhi Centre for Human Ecology, Environmental and Population Studies at the University of Rajasthan. This paper describes the biodiversity in the north-western Indian State of Rajasthan, its relationship with the environment and the existing human and livestock populations. As the biodiversity is depleting in this area due to zoogenic and anthropogenic reasons, certain pragmatic conservation strategies are advocated. The north-western part of India is occupied by a desert ecosystem, the Thar Desert. Animal husbandry is the major livelihood in the region, followed by agriculture. The vegetation, which is predominantly xerophytic and quite sparse, occurs in great variety. Six hundred and eighty-two plant species and 390 animal species have been identified from the Thar Desert. Many plant and animal species have become endangered due to zoogenic and anthropogenic activities. Plants such as Calligonum polygonoides, Tecomella undulata and Prosopis cineraria urgently require conservation. 相似文献
998.
The pH on the frustule of individual cells of the marine centric diatoms Coscinodiscus granii and Coscinodiscus wailesii (Bacillariophyceae) was measured with pH microsensors in culture media with increasing pH values of 8.04, 8.14, and 8.22,
respectively. In 85–96% of the C.
granii cells the pH on the frustule was up to 0.4 units higher than that of the medium, reaching a maximum pH 8.95. Only in 2–3%
the surface pH exceeded that of the medium by up to 0.7 pH units. These results strongly suggest that diatoms in batch cultures
differ, at least temporarily, in their individual photosynthetic activities. Infection experiments with the parasitoid nanoflagellate
Pirsonia diadema (Stramenopile) showed that flagellates failed to infect when the culture pH was 8.8 and above. pH measurements on freshly
infected C. granii showed that the prevalence of infection was higher in tendency on diatoms with low surface pH. Application of these results
to parasitoid-diatom interactions in natural waters suggests that within phytoplankton populations a strong photosynthetic
activity might prevent diatom cells temporarily from infection by pH-sensitive parasitoids. 相似文献
999.
We investigated the benefits of larval cannibalism in the Neotropical mosquito Trichoprosopon digitatum. The clutch size of the mosquito in the field was strongly correlated with adult female size, indicating a fitness advantage
to being large. In controlled laboratory experiments, we compared the survivorship and eventual adult sizes of larvae that
were given the opportunity to cannibalise conspecifics throughout their lifetimes with the survivorship and adult sizes of
larvae that were prevented from cannibalising. Since the benefits of cannibalism are likely to depend on the context in which
it occurs, the experiment was conducted at two levels of alternative food availability. When food availability was high most
larvae survived to adulthood, females cannibalised more than males and there was no measurable advantage to cannibalism in
terms of survival rate, emergence time or adult size. Larvae were significantly more cannibalistic when food availability
was lower, although under these conditions no larvae survived to adulthood. Nevertheless, under low food an important fitness
benefit to cannibalism was revealed: individuals which had the opportunity to cannibalise survived significantly longer as
larvae than those which did not. This increased longevity is likely to provide an important advantage to mosquito larvae when
they wait for the input of unpredictable food sources.
Received: 7 October 1995/Accepted after revision: 13 April 1996 相似文献
1000.
Reinhold Rühl 《Environmental Sciences Europe》2003,15(1):48-54
The data situation to chemical substances is unsatisfactory— in spite of in part considerable efforts in the last decades. One knows still very little on the subject of the dangerous characteristics of chemical substances. The consequences of this ignorance have primarily the employees to carry. They get sick due to a dealing with substances whose characteristics were not completely enlightened. But as well the enterprises have to suffer under it, after all, lose her experienced staff member and have to pay the costs about the Berufsgenossenschaften for these knowledge deficits. In the EU, the future European chemical policy is therefore discussed. The contribution explains the range of the sicknesses through dealing with substances with unknown characteristics. 相似文献