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741.
The widespread usage of antibiotics in agriculture leads to releases into the environment, but there is insufficient knowledge of the side-effects on non-target organisms. Therefore, we investigated the effects of the sulfonamide-antibiotic sulfamethoxazole (SMX) on Caenorhabditis elegans at phenotypic, biochemical and molecular biological levels. Multiple endpoints, including life history traits, thermal stress resistance and lipid peroxidation, as well as gene expression profiles, were determined after exposure of the nematodes to SMX. In contrast to expectations, SMX prolonged the lifespan and increased both the body size and pharynx pumping rate. On the other hand, SMX delayed reproductive timing and caused lipid peroxidation. The total number of offspring and thermal stress resistance were unaffected. The up-regulation of hsp-16.1 indicated stress in general and the increased lipid peroxidation oxidative stress in particular. This oxidative stress indicated that mitohormesis was the likely cause of the longevity and that enhanced pumping frequency was probably the reason for the increased growth. The sole adverse effect was delayed initial reproduction. This delay, however, can be crucial for r-strategists, such as the bacterivorous model animal used, in sustaining their populations in the environment in the presence of predators. Bacterivorous animals, in turn, are essential to maintaining nutrient recycling via the microbial loop. 相似文献
742.
ABSTRACTComparing and evaluating the Nationally Determined Contribution (NDC) is an important element in global stocktake in the post-Paris climate negotiations, aimed at closing the emissions gap with the Paris Agreement goals. To date, however, there has still been no explicit guideline or method. By applying emissions allowance allocated by 16 schemes as benchmarks, this paper tries to compare and evaluate the NDCs of the top six emitters, which jointly account for about 70% of the world’s CO2 emissions. Results show that the four developed countries’ NDCs lack ambition with respect to most allocations under 2°C and all under 1.5°C, indicating they need to substantially ratchet up their NDCs and lead elevating mitigation. Evaluating cumulative emissions is more likely to clarify the ambition and fairness of China’s NDC. If considering cumulative emissions, China’s NDC is aligned with the median of cumulative allowances under 2°C and within the 1.5°C range. The Paris Agreement invited the Parties to communicate the mid-century low emissions strategies. This paper also tries to explore the mid-century mitigation in the perspective of allocations, which might provide decision-makers with some useful information when envisaging the post-NDC mitigation. 相似文献
743.
There are many uncertain factors,such as stochastic,fuzzy and gray information in the risk analysis on natural hazard.The set pair analysis(SPA)deals effectively with the various uncertain factors contributing to evaluation of the risk level of natural disasters.The evaluation indicators and standards of natural disasters risk are analyzed by identity-discrepancycontrary(IDC).The result,the connection numbers,still has uncertainty information.Thus,yielding the risk evaluation model of natural disasters based on connection function,which construct a set pair relation between the indicators of connection numbers and comprehensive evaluation standards,and describe uncertainty of the connection numbers by using connection function.The study showed that the proposed model takes into account only the uncertainty of risk evaluation indicator identification on natural disasters,also the uncertainty of result connection numbers.This approach gives full consideration to the uncertainty of systematic evaluation process along with the actual meaning of comprehensive evaluation functions.Therefore,this means it is able to reduce the uncertainty of final evaluation results and improve the accuracy and reasonability of evaluation results.This model is capable of reflecting actual situation of the risk evaluation on natural disaster affected by various uncertain factors and has a promotional value in the natural disaster risk assessment. 相似文献
744.
Abstract Reservoir water environment is a grey system. The grey clustering method is applied to assessing the reservoir water environment to establish a relatively complete model suitable for the reservoir eutrophication evaluation and appropriately evaluate the quality of reservoir water, providing evidence for reservoir management. According to China’s lakes and reservoir eutrophication criteria and the characteristics of China’s eutrophication, as well as certain evaluation indices, the degree of eutrophication is classified into six categories with the utilization of grey classified whitening weight function to represent the boundaries of classification, to determine the clustering weight and clustering coefficient of each index in grey classifications, and the classification of each clustering object. The comprehensive evaluation of reservoir eutrophication is established on such a foundation, with Sichuan Shengzhong Reservoir as the survey object and the analysis of the data attained by several typical monitoring points there in 2006. It is found that eutrophication of Tiebian Power Generation Station, Guoyuanchang and Dashiqiao Bridge is the heaviest, Tielusi and Qinggangya the second, and Lijiaba the least. The eutrophication of this reservoir is closely relevant to the irrational exploitation in its surrounding areas, especially to the aggravation of the non-point source pollution and the increase of net-culture fishing. Therefore, it is feasible to use grey clustering in environment quality evaluation, and the point lies in the correct division of grey whitening function 相似文献
745.
Pan Jiahua 《中国人口.资源与环境(英文版)》2013,11(2):39-53
Abstract Climate change has become a hot topic in international environmental negotiations. For post-Kyoto international climate regime negotiations, many countries have proposed a variety of frameworks to share the emission reduction responsibilities and allocate carbon emission rights, and have tried to quantify the emission reduction obligations of all countries based on the perspectives of international equity and individual equity. In this paper, the authors have distinguished the concepts of carbon emissions rights based on these two perspectives respectively, have analyzed the relationship between carbon emissions per capita and economic development, and have calculated and compared the proportion of cumulative emissions per capita of different countries in history and future, and then authors conclude that emission reduction obligations should be allocated based on each country’s conditions, including historical emissions, development stage, and future demands. Developed countries should take the initiative to significantly reduce their emissions because they have already accomplished their industrialization process. However, developing countries are still in the process of industrialization, which requires more emission rights to meet their development needs. For China, the concept of carbon emissions based on individual equity can be used as a theoretical tool for the allocating the international carbon emissions rights. 相似文献
746.
747.
采用等体积浸渍法,制备了一系列含有相同含量活性组分(MoO3、CoO和NiO)不同USL沸石含量的加氢脱硫催化剂。通过X-射线衍射(XRD)、氮气吸附脱附、吡啶红外(Py-FTIR)和氨气程序升温脱附(NH3-TPD)等分析方法对样品进行了表征。结果表明:与Cat.0(参比剂,仅以γ-Al2O3为载体)相比,添加USL沸石催化剂所得加氢油的烯烃含量、芳烃含量和研究法辛烷值(RON)均增加;仅当催化剂载体中USL沸石加量在0~40m%之间变化时,加氢油的异构烷烃含量呈上升趋势;而当载体中USL沸石添加量在0~20m%之间变化时,催化剂的脱硫率有所升高。综合对比,当载体中USL沸石添加量约为40m%,催化剂具有最佳的综合性能指标,脱硫率达90%,RON损失仅为1.5左右。 相似文献
748.
Journal of Polymers and the Environment - In this research, bio-based polyamide (bio-PA) was synthesized from dimethyl furan-2,5-dicarboxylate and 1,3-cyclohexanedimethanamine by melt... 相似文献
749.
Qiong Guo Zhichao Yang Bingliang Zhang Ming Hua Changhong Liu Bingcai Pan 《Frontiers of Environmental Science & Engineering》2022,16(6):71
750.
In this study, three different hull-less barley varieties were used to prepare steamed cakes, and their nutritional value, sensory qualities, textural properties, and in vitro starch hydrolysis were evaluated. The results showed that the contents of total dietary fiber (4.50%-5.12%), β-glucan (2.96%-3.96%), total flavonoids (12.56-38.73 mg/100 g), and γ-aminobutyric acid (5.08-9.53 mg/100 g) in the steamed hull-less barley cakes were significantly higher than that in the steamed wheat cake, which were 0.65%, 0.23%, 3.93 mg/(100 g), and 2.63 mg/(100 g), respectively. The sensory properties of steamed ordinary hull-less barley and wheat cakes were not significantly different, but the steamed 08-1127 (waxy hull-less barley) cake was softer and out of shape. The springiness, resilience, cohesiveness, gumminess, and adhesiveness of steamed ordinary hull-less barley cakes were similar to those of steamed wheat cake, while those of steamed 08-1127 cakes were significantly lower than those of steamed ordinary hull-less barley cakes. Steamed hull-less barley cake also showed a maximum starch hydrolysis rate (38.76%-42.74%) that was lower than that of steamed wheat cake (49.92%), and the contents of rapidly (11.58%-13.16%) and slowly digested starch (5.34%-7.56%) were lower than that of steamed wheat cake (17.21% and 15.97%, respectively). In addition, the glycemic (59.37-61.67) and hydrolysis indexes (35.82-40.00) were lower than those of steamed wheat cake (76.66 and 67.30, respectively), and the contents of resistant starch (2.74%-3.55%) were higher than those of wheat steamed cake (1.68%). Therefore, the steamed cakes of ordinary hull-less barley had a higher content of nutritional components than the steamed cake of wheat, and the in vitro starch hydrolysis parameters were better than those of steamed wheat cake. When it is necessary to consider both nutritional and sensory qualities, ordinary hull-less barley can be selected as the raw material for steamed cakes, but waxy hull-less barley is not suitable for making steamed cakes. © 2022 Science Press. All rights reserved. 相似文献