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321.
外源钙对两种价态锑胁迫下水稻幼苗吸收积累锑和钙的影响 总被引:1,自引:0,他引:1
通过溶液培养试验,研究外源钙对两种价态锑[Sb(III)和Sb(Ⅴ)]胁迫下水稻吸收积累锑和钙的影响。结果表明,这两种价态的Sb对水稻生长均有抑制作用,Sb(III)比Sb(Ⅴ)对水稻毒害更明显,施Ca可缓解Sb对水稻的毒害。Sb(III)和Sb(Ⅴ)的添加对水稻根系和茎叶吸收积累Ca影响不一致。当溶液中的Ca浓度为5.0 mmol·L-1时,添加三价Sb 10和30μmol·L-1均可以显著地降低水稻茎叶中的Ca含量15.7%和49.4%,但是添加Sb(Ⅴ)浓度为30μmol·L-1时,却分别提高水稻茎叶和根系Ca含量26.2%和50.4%。Ca的添加可以显著地降低水稻根系和茎叶对两个价态Sb的吸收积累。在30μmol·L-1Sb(III)处理下,添加5.0和20 mmol·L-1的Ca可导致水稻根系和水稻茎叶Sb浓度分别比对照处理降低19.0%-79.4%和42.6%-71.8%;在30μmol·L-1Sb(Ⅴ)处理下,添加5.0和20 mmol·L-1的Ca可导致水稻根系和水稻茎叶Sb浓度分别比对照处理降低34.3%-70.6%和74.1%-84.6%。Ca的添加对Sb在水稻根系和茎叶中的富集系数和分配比率也有显著影响。综上所述,可以通过施用Ca肥来防治农田Sb污染,降低Sb对人体健康的危害。 相似文献
322.
本文根据笔者多年的实际工作经验,分析和讨论了亚甲基蓝分光光度法在测定污染源废气中硫化氢时的一些见解,并提出了相应的措施。 相似文献
323.
Guoqing Wang Jianyun Zhang Junliang Jin Josh Weinberg Zhenxin Bao Cuishan Liu Yanli Liu Xiaolin Yan Xiaomeng Song Ran Zhai 《Mitigation and Adaptation Strategies for Global Change》2017,22(1):67-83
Climate change is a global environmental issue, which is challenging water resources management and practices. This study investigates the impact of climate change on water resources of the Yellow River basin, a major grain-producing area in China, and provides recommendations on strategies to increase adaptive capacity and resilience in the basin region. Results show that the recorded stream flows of the Yellow River declined from 1951 to 2010 and have decreased significantly in the middle and lower reaches. The variable infiltration capacity (VIC) model performs well as a tool to simulate monthly discharge of both the tributary catchments and the whole Yellow River basin. Temperature across the Yellow River basin over 2021–2050 is expected to continue to rise with an average rates of approximately 0.039–0.056 °C/annum. The average annual precipitation in the basin is projected to increase by 1.28–3.29 % compared with the 1991–2010 baseline. Runoff during 2021–2050 is projected to decrease by 0.53–9.67 % relative to 1991–2010 with high decadal and spatial variability. This is likely due to the model’s projections of a significant rise in temperature and changes in precipitation patterns. Climate change will likely aggravate the severity and frequency of both water shortages and flooding in the basin region. It is therefore essential to devote sufficient attention on structural and non-structural measures for the Yellow River basin to cope with climate change. At the global level, strategies to increase adaptive capacity and build resilience to climate change focus on public education to improve awareness of climate risks, implementing the integrated water resources management and planning based on impact assessments. 相似文献
324.
Road dust is one of the most common pollutants and causes a series of negative effects on plant physiology. Dust's impacts on plants can be regarded as a combination of load,composition and grain size impacts on plants; however, there is a lack of integrated dust effect studies involving these three aspects. In our study, Sophora japonica seedlings were artificially dusted with road dust collected from the road surface of Beijing so that we could study the impacts of this dust on nitrogen/carbon allocation, biomass allocation and photosynthetic pigments from the three aspects of composition, load and grain size. The results showed that the growth characteristics of S. japonica seedlings were mostly influenced by dust composition and load. Leaf N, root–shoot ratio and chlorophyll a/b were significantly affected by dust composition and load; leaf C/N, shoot biomass, total chlorophyll and carotenoid were significantly affected by dust load; stem N and stem C/N were significantly affected by dust composition; while the dust grain size alone did not affect any of the growth characteristics. Road dust did influence the growth characteristics more extensively than loam. Therefore, a higher dust load could increase the differences between road dust and loam treatments. The elements in dust are well correlated to the shoot N, shoot C/N, and root–shoot ratio of S. japonica seedlings. This knowledge could benefit the management of urban green spaces. 相似文献
325.
326.
三江平原湿地的生态保护与修复 总被引:2,自引:0,他引:2
三江平原是中国最大的平原沼泽分布区,从二十世纪七十年代中后期国家开始对三江平原进行多次大规模的开垦,这些开垦基本上是天然湿地,从而导致了土地退化和生态环境恶化,使湿地的面积不但减少,其功能不断退化,引起一系列生态环境问题。因此,积极采取措施保护现有的湿地,开展受损湿地的生态恢复,战缓和消除导致温地退化因素的影响,实现三江平原湿地资源的可持续利用、人与自然和谐相处,是湿地生态保护和修复的目标。 相似文献
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329.
龙王江锑砷金矿带位于湘西雪峰弧形构造带中段西南侧,赋存于板溪群浅变质岩系中,主要为与剪切带有关的破碎蚀变岩型金矿。矿床的某些地球化学标志可作为成矿预测和找矿评价的依据。 相似文献
330.
对大庆测井公司放射源库及周围环境的放射性水平进行了调查,调查内容分为环境空气气溶胶辐射水平、水环境辐射水平、环境地表γ辐射空气吸收剂量率及土壤环境辐射水平四个方面.监测调查结果表明:源库内和源库外总α、总β监测值与对照点比较,均没有显著性差异,说明空气中的环境是安全的;放射源库周围水环境总α、总β监测值符合相应标准规定,说明水环境未受到放射性污染;γ辐射空气吸收剂量率监测值范围均在黑龙江省室外天然本底值21.6×10-9~196.9×10-9 Cy/h范围内,说明放射源库室外地区未受到放射性污染;土壤监测值与黑龙江省土壤放射性水平进行了对比,也未发现放射源库周围土壤环境受到放射性污染.总之,大庆石油管理局测井公司放射源库未形成对周围环境及人群健康的不良影响. 相似文献