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731.
上海大气超细颗粒物和工业纳米颗粒的表征及细胞毒性的比较研究 总被引:3,自引:2,他引:1
采集了上海市石洞口地区2010年春季不同粒径大气颗粒物样品,使用ICP-AES和FESEM技术分析了颗粒物的化学组成和微观特征,比较了不同粒径的大气颗粒物与3种工业纳米颗粒物的生物活性.结果表明,在染毒剂量为25、50、100和200μg.mL-1时,大气颗粒物水溶组分和不溶组分及工业纳米颗粒均可以抑制A549细胞生长活性并能诱导细胞产生活性氧(ROS),且大气细颗粒水溶组分生物活性最强,在上述染毒剂量下对细胞生长活性的抑制率分别达到13.31%、18.15%、20.43%和23.78%.在纳米尺度的颗粒物染毒组分中,纳米NiO的生物活性最强,在上述染毒剂量下对细胞生长活性的抑制率分别达到11.81%、15.12%、17.62%和19.44%.因此,大气细颗粒物水溶组分是最主要的毒性成分. 相似文献
732.
锌金属硫蛋白对PM2.5暴露的运动大鼠血清抗氧化酶及免疫指标的影响 总被引:1,自引:1,他引:0
为了探讨锌-金属硫蛋白(Zn-Metallothionein,Zn-MT)对细颗粒污染运动大鼠血清抗氧化酶及免疫指标的影响.选取雄性SD大鼠56只,随机分为安静对照组、运动对照组、Zn-MT+运动组、低剂量PM2.5+运动组、Zn-MT+低剂量PM2.5+运动组、高剂量PM2.5+运动组、Zn-MT+高剂量PM2.5+运动组,采用递增负荷跑台训练后即刻处死,取血测定大鼠血清CAT、T-SOD、GSH、GSH-Px、白细胞介素IL-2、IL-6、IL-8、MCP-1、MCP-R1α、并进行有关统计学检验.结果表明,与安静组相比,运动组抗氧化酶下降,白细胞介素及免疫因子升高;与运动对照组相比,PM2.5染毒组大鼠血清SOD、GSH、GSH-Px活性下降且有剂量相同趋势变化;IL-2、IL-6、IL-8、MCP-1、MIP-1α显著性上升;补充Zn-MT后,血清抗氧化酶呈回升趋势;IL-2、IL-6、IL-8、MCP-1、MIP-1α有所下降.补充Zn-MT在一定程度上可以减轻由于运动产生自由基而对机体造成氧化应激损伤,保护机体的免疫系统,增强机体的运动能力. 相似文献
733.
734.
735.
珠江口水体组分的吸收特性分析 总被引:3,自引:1,他引:2
水体组分吸收特性是水下光场和水面光谱的主要影响因子,对其进行研究有助于提高对水体光学特性的认识和水质参数的遥感反演.基于2013年7月珠江口水体30个样本的实测数据,对珠江口水体总颗粒物、非藻类颗粒物、浮游藻类和CDOM的吸收特征进行了分析,结果表明:1总颗粒物吸收特征为非藻类颗粒物主导类型;2非藻类颗粒物的吸收系数遵循指数衰减规律,主要来源是陆源性输入,指数斜率Sd均值与空间变化幅度高于内陆二类水体;3多项式关系能较好地表达aph(440)与叶绿素a浓度的关系,而aph(675)与叶绿素a浓度存在很好的线性相关,辅助色素对浮游藻类吸收系数的影响主要在短波波段,长波波段叶绿素a的影响占主导地位,比吸收系数随叶绿素a浓度的增加而减小,呈现幂指数衰减规律;4CDOM输入以陆源为主,光谱曲线在紫外波段250~290 nm之间存在一个吸收肩,按光谱特征分段拟合Sg值能够更好地表达CDOM吸收特性,M值与A段(240~260 nm)的斜率Sg值呈现较强的正相关,珠江口水体的M值较小,CDOM中腐殖酸含量较高;5珠江口水体非色素颗粒物吸收在总吸收中占主导地位,浮游藻类吸收对总吸收的贡献远小于非色素颗粒物,CDOM吸收对总吸收的贡献最小,当CDOM中腐殖酸含量较高时,CDOM对水体总吸收的贡献大,腐殖酸含量较低时,CDOM对水体总吸收的贡献小. 相似文献
736.
Atmospheric particles(total suspended particles(TSPs); particulate matter(PM) with particle size below 10 μm, PM10; particulate matter with particle size below 2.5 μm, PM2.5)were collected and analyzed during heating and non-heating periods in Harbin. The sources of PM10 and PM2.5were identified by the chemical mass balance(CMB) receptor model.Results indicated that PM2.5/TSP was the most prevalent and PM2.5was the main component of PM210, while the presence of PM10–100was relatively weak. SO-4and NO-3concentrations were more significant than other ions during the heating period. As compared with the non-heating period, Mn, Ni, Pb, S, Si, Ti, Zn, As, Ba, Cd, Cr, Fe and K were relatively higher during the heating period. In particular, Mn, Ni, S, Si, Ti, Zn and As in PM2.5were obviously higher during the heating period. Organic carbon(OC) in the heating period was 2–5 times higher than in the non-heating period. Elemental carbon(EC) did not change much. OC/EC ratios were 8–11 during the heating period, which was much higher than in other Chinese cities(OC/EC: 4–6). Results from the CMB indicated that 11 pollution sources were identified, of which traffic, coal combustion, secondary sulfate, secondary nitrate, and secondary organic carbon made the greatest contribution. Before the heating period, dust and petrochemical industry made a larger contribution. In the heating period, coal combustion and secondary sulfate were higher. After the heating period, dust and petrochemical industry were higher. Some hazardous components in PM2.5were higher than in PM10, because PM2.5has a higher ability to absorb toxic substances. Thus PM2.5pollution is more significant regarding human health effects in the heating period. 相似文献
737.
Lifeng Zhang Jiangtian Hou Xiaotao Bi 《Journal of Loss Prevention in the Process Industries》2013,26(6):1328-1334
Electrostatic charges accumulated on wood particles through triboelectrification during their transportation and handling processes can cause hazardous electrical discharge which may further trigger dust explosion. In this work, tribo-charging behavior of different kinds of wood particles was investigated by a vibrating plate charging method. It was found that reduction in the work function difference between contact bodies might contribute to the reduction of tribo-charge generation, while the reduction of electrical resistivity of wood pellets could effectively accelerate the charge dissipation. As the particle size decreases, accumulated charges increase significantly. In contrast, higher moisture content of wood particles leads to lower charge accumulation due to an accelerated charge dissipation rate. Tribo-charging behaviors of white pellets, torrefied pellet, steam treated pellets and dark pellets have also been investigated. Compared to the white pellets, they all have shown a reduction on charge accumulation to some extent. However, results suggested that all of them have nearly equivalent tribo-charge density as coal and wheat grains used as references in this study. 相似文献
738.
Tomasz Ciach Tomasz R. Sosnowski 《International journal of occupational safety and ergonomics》2013,19(3):321-333
The paper presents results of investigations of a novel method for diesel exhaust filtration in a fibrous filter supplemented by the external electrostatic field (FEF), which may be used to eliminate the occupational hazard near sources of diesel emission. The reported research follows the preliminary basic study of soot removal in such systems (Ciach, Sosnowski, & Podgórski, 1995), and is focused on the construction and testing of a prototype technical-scale FEF device. The results suggest a strong relation between applied voltage and filtration efficiency of the system and demonstrate the influence of aerosol precharging on the efficiency, which can be more than 95%. 相似文献
739.
以广州市楼顶降尘为研究对象,在分析其粒度分布和重金属总量的基础上,采用单一化学提取法(DWLP、TCLP)和多级化学提取法(SEP)研究了大气颗粒物中4种重金属元素的生物有效性。结果表明:样品中96%以上颗粒小于100μm,其中10μm和2.5μm以下颗粒分别占33%和11%。大气颗粒物中重金属含量很高,Cu、Pb、Zn和Cd的平均含量分别为362.43、1033.81、830.32和5.80mg/kg,是广东省环境土壤背景值的17~64倍。单一提取法中,TCLP的提取效率明显高于DWLP,表明pH值是影响大气颗粒物中重金属释放的主要因素。SEP法结果显示,Zn和Cd的生物可利用态比例远高于Cu和Pb。经DWLP和TCLP法提取后,颗粒物中重金属的总含量有不同程度的降低,生物可利用态所占比例明显增加。通过综合分析,发现SEP此其他两种方法更适用于评价大气颗粒物中重金属的生物有效性。 相似文献
740.
Radioactive particles present a novel exposure pathway for members of the public. For typical assessments of potential doses received by members of the public, habit surveys and environmental monitoring combine to allow the assessment to occur. In these circumstances it is believed that the probability of encounter/consumption is certain. The potential detriment is assessed through sampling the use of environmental monitoring data and dose coefficients such as that in ICRP 60 [ICRP, 1990. 1990 Recommendations of the international commission on radiological protection. Publication 60. Annals of the ICRP 21 (1-3)]. However, radioactive particles often represent a hazard that is difficult to quantify and where the probability of encounter is less than certain as are the potential effects on health. Normal assessment methodologies through sampling and analysis are not appropriate for assessing the impact of radioactive particles either prospectively or retrospectively. This paper details many of the issues that should be considered when undertaking an assessment of the risk to health posed by radioactive particles. 相似文献