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991.
英国学者Fred Pearce认为:一个绝对干净的海岸是毫无生机的,他把这样的海滨称为"漂洗的海岸",意思是人们过度地追求海滨的清洁和干净,将海草、浮屑和一些可以为海滨微生物提供营养的生活污水完全除净,使这些海洋微生物长期处于"饥饿"状态,这样的海岸似乎干净,但却破坏了生态平衡。他发现海滨地区的海草、 相似文献
992.
春季大亚湾海域沉积物-海水界面营养盐的交换速率 总被引:2,自引:1,他引:1
2007年4月应用实验室培养法研究了大亚湾海域沉积物-海水界面营养盐的交换速率(ν)和交换通量(F),并与间隙水分子扩散模型计算结果进行了对比。结果表明,νDIN变化范围为304.21~441.92μmol/m2.d,平均为368.05μmol/m2.d,νPO4-P变化范围为27.08~110.21μmol/m2.d,平均为48.64μmol/m2.d,νSiO3-Si变化范围为1878.10~6024.40μmol/m2.d,平均为3653.84μmol/m2.d。与间隙水分子扩散模型计算结果相比较,两者之间存在数量级的差异。产生差异的原因在于,间隙水分子扩散模型在浅水海湾中应用时没有考虑到沉积物底栖生物活动以及风浪扰动等因素的影响。大亚湾海域春季FDIN/SE为2.03×107mol,FPO4-Pi/SE为2.68×106mol,FSiO3-Si/SE为2.02×108mol,为维持大亚湾春季的初级生产力,沉积物交换过程可提供约10%的DIN、21%的PO4-P和98%的SiO3-Si。 相似文献
993.
Dezhen Chen Zhenzhen Guan Guangyu Liu Gongming Zhou Tong Zhu 《Frontiers of Environmental Science & Engineering in China》2010,4(2):235-243
Aged municipal solid wastes (MSW) excavated from landfills and dumpsites were characterized to analyze their fraction composition,
moisture content, and lower heat value (LHV). The necessity and feasibility of recycling combustibles from aged MSW to improve
the incineration of fresh MSW were investigated. The results showed that combustibles in aged MSW were easily separated from
other components and than LHV of the separated combustibles are higher than 11000 kJ/kg. The fresh MSW are of high moisture
contents with average LHV below 6500 kJ/kg, making their stable combustion difficult to maintain in MSW incinerators. For
both fresh MSW and aged MSW, plastics are the main contributor to their LHV. To improve incineration of fresh MSW that are
characterized with low LHV, combustibles separated from aged MSW were made into refuse derived fuel (RDF) pellets and were
then added to fresh MSW by 2% wt.–5% wt. LHV variation and air supply resistance change of the MSW layer on the incinerator
grate caused by the addition of RDF was checked, and no significant changes were found. No obvious difference was observed
for the ‘burn-out time’ between RDF pellets and fresh MSW either. RDF made from aged MSW combustibles is found to be a promising
auxiliary fuel to improve the incineration of fresh MSW, and aged MSW from old landfill cells and dumpsites can be finally
disposed of jointly with fresh MSW by recycling combustible from the former to be coincinerated with the latter in the incineration
plants. 相似文献
994.
防雷技术在湖南地震台站的应用 总被引:1,自引:0,他引:1
本文从讨论雷电对地震台站产生的危害出发,为了确保台站仪器设备的正常运行,根据台站的不同情况,进行了防雷方案分类设计和分类实施,使防雷技术在地震台站取得了良好效果。 相似文献
995.
Urban road network development (RND) plays an important role in social and economic evolution. However, the unlimited expansion of roads leads to great changes in urban landscape patterns, which further affect ecosystems. To better characterize the urban ecological risk (UER) of RND, in this study, RND was considered the stressor and habitat provision the assessment endpoint in a UER assessment. According to the theory of landscape ecology, habitat quality disturbance intensity (HQDI) is used to quantify the negative effect of RND on an urban ecosystem. In particular, we aimed to explore the exposure-response function between road density and HQDI under RND stress. A case study was carried out in Xiamen City to examine this association. In terms of spatial distribution, this study showed that developed areas had the highest HQDI values, whereas low HQDI values were mostly associated with suburban areas. In addition, the probability distribution of HQDIs was uneven and the urban ecosystem showed unequal sensitivities to different types of roads. Based on a multilevel characterization of UER, results of this provide a framework to predict UER under RND stress and may enhance the ability of risk managers to develop scientifically based control measures. 相似文献
996.
Zhang Boling Wang Yiran Zhao Xu Cao Lanxin Tong Ruipeng 《Environmental geochemistry and health》2021,43(10):4139-4162
Environmental Geochemistry and Health - Although dust suppressants are widely applied to control road dust pollution, a consensus on their effectiveness has not been reached. To evaluate the... 相似文献
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不同产地麻疯树种仁的含油量及脱油种仁的佛波酯含量 总被引:1,自引:0,他引:1
选用国内4种不同产地的麻疯树种仁,对其含油量以及脱油后的佛波酯含量进行了研究.采用GB/T 5512-85粮食、油料检验粗脂肪测定法进行麻疯树种仁含油量的测定;脱油后种仁经二氯甲烷超声提取佛波酯,采用高效液相色谱(HPLC)对其含量进行检测.结果表明,小金河、攀枝花、仁里、片角乡麻疯树种仁的含油量分别为58.29%、60.84%、58.83%和56.12%,脱油后种仁中佛波酯含量分别为2.43 mg g-1、2.25 mg g-1h、2.03 mg g-1和1.21 mg g-1.不同产地的麻疯树种仁含油量均有差异,在深入开发麻疯树资源时,种仁含油量的高低可作为其选种依据之一.4种不同产地的麻疯树种仁脱油后的佛波酯含最均高于无毒麻疯树品种,要利用麻疯树的脱油种仁这一潜在饲料资源,对其进行进一步脱毒处理是必要的.图3表3参10 相似文献