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531.
基于区域大气环境模拟系统RegAEMS开发了大气污染物来源解析模块APSA,以京津冀及周边"2+26"城市为研究对象,模拟2017年12月26日~2018年1月2日该地区一次PM2.5重污染过程,对PM2.5进行区域和行业来源解析.结果表明:本次污染持续时间长、影响范围广、污染程度重,"2+26"城市PM2.5小时最大值为201~507μg/m3,RegAEMS可较好模拟出PM2.5时空分布;区域来源解析表现为外围区域对"2+26"边界城市影响较大,贡献为15.3%~57.5%,"2+26"中部城市受外围区域影响较小,贡献为0.3%~8.4%,区域传输特征明显,受近地面风场影响较大;行业来源表现为区域内生活源、工业源贡献较大,分别为26.6%~45.8%、16.4%~37.8%,交通源占比13.0%~35.9%.本文研究表明RegAEMS可以实现重污染过程PM2.5的数值模拟和来源解析,在大气污染精准管控方面具有较好应用前景. 相似文献
532.
533.
Paul Chiou Wei Tang Che-Jen Lin Hsing-Wei Chu Rafael Tadmor T. C. Ho 《Environmental Modeling and Assessment》2009,14(5):645-659
Speciated samples of PM2.5 were collected at the Big Bend site from July of 2003 to June 2006 and the McDonald Observatory site from July of 2003 to
August of 2005 in southwestern Texas, respectively, by the US Environmental Protection Agency. A total of 175 samples for
the Big Bend site and 105 samples for the McDonald Observatory site with 52 species were measured; however, 30 and 32 species
from the Big Bend and McDonald Observatory sites, respectively, were excluded because of too much below-detection-limit data.
Due to the laboratory change about November 1 of 2004 and possible analytical artifacts, phosphorous was excluded as well.
Among the species excluded, 31 species are common to both sites. The two data sets were analyzed by positive matrix factorization
to infer the sources of PM observed at the two sites. The analysis resolved five source-related factors for Big Bend and four
for McDonald Observatory. Sulfate-rich secondary aerosol, coal burning, motor vehicle/road dust, and a mixed factor were identified
as common sources to both sites. The other factor identified for Big Bend is related to soil. Sulfate mainly exists as ammonium
salts. The sulfate-rich secondary aerosols account for about 62% and 66% of the PM2.5 mass concentration at the two sites, respectively. The highest concentration of Si associated with Ca, Fe,
\textSO42 - {\text{SO}}_4^{2 - } , and organic carbon at the two sites was possibly attributed to the coal-fired power plants in the region. Basically, the
factor of sulfate and coal burning at the two sites showed similar chemical composition profiles and seasonal variation that
reflect the regional characteristics of these sources. The regional factors of sulfate, coal burning, and soil showed predominantly
low-frequency variations; however, the area-related and/or local factors showed both high and low frequency variations. The
motor vehicle/road dust and the mixed factors were likely to be area-related and/or local source. 相似文献
534.
为研究全氟辛烷磺酸盐(PFOS)暴露对胎鼠肺部损伤的诱导作用,孕期SD大鼠在5~20mg·kg-1剂量范围内的PFOS中处理7d,取胎鼠全肺并分析其发育所受的影响。通过形态学比较,发现随着PFOS浓度的增加,胎鼠体长和体重均显著降低,高剂量暴露会导致胎鼠死亡。通过组织学检测,发现胎鼠肺的发育受到PFOS暴露的抑制。通过WesternBlot检测肺泡Ⅰ/Ⅱ型细胞的发育,发现肺泡Ⅰ型细胞特异蛋白Podoplanin表达显著减少(p<0.05),肺泡Ⅱ型细胞特异蛋白SP-C表达减少但未出现显著差异,此外,与对照组相比高剂量暴露会引起血管内皮生长因子(VEGF)表达显著减少(p<0.01)。实验结果说明,PFOS暴露会导致胎鼠肺部发育出现损伤,这种损伤可能是肺泡Ⅰ型细胞及肺部血管发育受抑制引起胎鼠肺部气体交换功能破坏。 相似文献
535.
Fu-Lin Evelyn Chu Eric D. Lund Paul R. Littreal Kate E. Ruck Ellen Harvey Jean-René Le Coz Yanic Marty Jeanne Moal Philippe Soudant 《Marine Biology》2009,156(2):155-169
The kinetics and efficiency of sterol production and bioconversion of phytosterols in two heterotrophic protists Oxyrrhis marina and Gyrodinium dominans were examined by feeding them two different algal species (Rhodomonas salina and Dunaliella tertiolecta) differing in sterol profiles. R. salina contains predominantly brassicasterol (≅99%) and <2% cholesterol. The major sterols in D. tertiolecta are ergosterol (45–49%), 7-dehydroporiferasterol (29–31%) and fungisterol (21–26%). O. marina fed R. salina metabolized dietary brassicasterol to produce 22-dehydrocholesterol and cholesterol. O. marina fed D. tertiolecta metabolized dietary sterols to produce cholesterol, 22-dehydrocholesterol, brassicasterol and stigmasterol. G. dominans fed either R. salina or D. tertiolecta metabolized dietary sterols to make cholesterol, brassicasterol and a series of unknown sterols. When protists were fed R. salina, which contains cholesterol, the levels of cholesterol were increased to a magnitude of nearly 5- to 30-fold at the phytoplankton-heterotrophic
protist interface, equivalent to a production of 172.5 ± 16.2 and 987.7 ± 377.7 ng cholesterol per mg R. salina carbon consumed by O. marina and G. dominans, respectively. When protists were fed D. tertiolecta, which contains no cholesterol, a net production of cholesterol by the protists ranged from 123.2 ± 30.6 to 871.8 ± 130.8 ng
per mg algal C consumed. Cholesterol is not only the dominant sterol, but a critical precursor for many physiologically functional
biochemicals in higher animal. As intermediates, these heterotrophic protists increase the amount of cholesterol at the phytoplankton–zooplankton
interface available to higher trophic levels relative to zooplankton feeding on algae directly. 相似文献
536.
Abstract The coastal water of northeast Taiwan island, called ‘Yin-Yang Hai’ for its distinct yellow colour compared with blue offshore water, was investigated from 1989 to 1990 by the authors. Biological study showed the dominant species of plankton to be Copepoda, Cladocera, planktonic eggs and Diatoma. Dominant species of benthos were young crabs, Amphipoda and Annelida, with Amphipoda usually occurring in heavily polluted areas. Heavy metal data showed that the concentration of copper was high. the copper and iron concentration in algae of the intertidal zone was also high. the concentrations of iron and copper in inshore water were also higher than in offshore water. By comparison of the pH and salinity distribution of this area, we conclude that this coastal water has been polluted by acid waste water from coastal industry. the suspended solids concentration in sea water is high. Flocculation occurring at the boundary of fresh and saline water might be a reason for the distinct yellow colour of the water of this area. Further study is required. 相似文献
537.
Liver alterations were stereologically determined in five groups, each of 10 male and female Sprague–Dawley weanling rats fed PCB 105 (2,3,3′,4,4′-pentachlorobiphenyl) for 13 weeks at concentrations of 0.05, 0.5, 5, and 50?ppm mixed with corn oil. Animals from two groups receiving the oil in diets served as controls for each gender. A significant increase in mean volume fraction (VF) of smooth endoplasmic reticulum (SER) profiles was estimated in hepatocytes of female rats in 0.5, 5, and 50?ppm groups. A significant decrease in VF of mitochondria in female rats at 50?ppm was detected. In addition, a decrease in VF of lipid droplets was measured in female rats at 0.5, 5, and 50?ppm groups. No difference was found in VF of rough endoplasmic reticulum (RER) cisternae, and peroxisome profiles at any concentration of the PCB in either male or female animals as compared to baseline values from controls. A significant elevation of baseline VF for RER in female rats was detected in comparison with males. In the present study, no observable adverse effect level (NOAEL) for PCB 105 was estimated at <0.5?ppm for hepatocyte alterations in female Sprague–Dawley rats. 相似文献
538.
Guor‐Cheng Fang Cheng‐Nan Chang Yuh‐Shen Wu Ding‐Guor Yang Chia‐Chium Chu 《毒物与环境化学》2013,95(3-4):341-355
Aerosol samples of particulate and chemical species for PM10 (particulate matter with aerodynamic diameters less than 10 μm) collected by Universal sampler were studied from June to August 1998 in the suburban area of central Taiwan. The ratios of PM2.5/PM2.5–10 displayed that the fine particles (particle size < 2.5 μm) are prevailing in the suburban site. Ion Chromatography was used to analyze for the water‐soluble ions: sulphate and nitrate in the Universal samples. Also, the collected samples were analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Cu and Cr. The results indicated that the crustal elements (Ca and Fe) and resuspended matters were dominated in the coarse particulate mode while the anthropogenic elements (Cr, Pb, Cu) and sulphate components are mainly in the fine particle fraction. The results also showed that the sulphate and nitrate make the largest portion of the chemical species collected by Universal sampler (PMio). The concentrations of heavy metals in THU are generally high, owing to the higher motor vehicle and industrial density nearby. The degree of pollution from this source differs from day to day, depending on the motor vehicle density. 相似文献
539.
Experimental research on inhibition performances of the sand-suspended colloid for coal spontaneous combustion 总被引:1,自引:0,他引:1
Yong-liang Xu De-ming WangLan-yun Wang Xiao-xing ZhongTing-xiang Chu 《Safety Science》2012,50(4):822-827
Serious mine fire disasters have occurred in Northwest China where there are abundant coal resources. For the shortage of water and loess, a large cost of conventional grouting slurry is needed. However, plenty of sand and fly ash resources have been found there. In order to improve the quality of sand injection and reduce the wastage of water during grouting, a kind of new compound material of sand-suspended colloid, which is composed of mineral inorganic gel and organic polymer, was developed in this paper. And the inhibition performance experiments of the sand-suspended colloid were carried out. The results show that the sand-suspended colloid efficaciously affected the oxidation characteristics above the critical temperature during the acceleration oxidation of the lignite and fat-gas coal samples and restrained the oxidation course by increasing the activation energy, so that it reduced the contents of CO and C2H4 and depressed the oxidation rate during the coal spontaneous combustion, and finally inhibited the coal spontaneous combustion. 相似文献
540.
Lan-yun Wang Yong-liang Xu Shu-guang Jiang Ming-gao Yu Ting-xiang Chu Wei-qing Zhang Zheng-yan Wu Li-wen Kou 《Safety Science》2012,50(7):1528-1534
Low temperature oxidation of coal will result in coal spontaneous combustion in mined-out areas. We proposed to use ionic liquids to inhibit the coal spontaneous combustion in this paper. In order to study the inhibiting effect of ionic liquid (IL) on coal oxidation, we successfully dissolved bituminous coal samples in six kinds of imidazolium based ionic liquids, [AOEmim][BF4], [HOEmim][BF4], [Amim][Cl], [Emim][AC], [Bmim][AC] and [Bmim][OTf]. The functional groups in the coal samples pre-treated by different ILs were detected by Fourier Transform Infrared Spectroscopy (FTIR) in detail. It is found that the ILs are capable of breaking the associated hydroxyls into dissociated hydroxyls. And during the interaction between coal and ILs, the carboxyl groups have been created. Thermo Gravimetric experiment results show that the weight loss ratios of the IL-treated coals were less during 20–400 °C stage, compared with the IL-untreated coal, which indicates that most of the easily reductive groups effectively dissolved in the ionic liquids. According to the exothermic rate curves and the computed activation energy values, it is demonstrated that the [Bmim][OTf] and [Bmim][AC] make better effect than the other ILs for depressing the oxidation rate of bituminous coal. 相似文献