全文获取类型
收费全文 | 1124篇 |
免费 | 42篇 |
国内免费 | 103篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 39篇 |
环保管理 | 48篇 |
综合类 | 398篇 |
基础理论 | 171篇 |
污染及防治 | 170篇 |
评价与监测 | 418篇 |
社会与环境 | 1篇 |
出版年
2024年 | 11篇 |
2023年 | 13篇 |
2022年 | 17篇 |
2021年 | 13篇 |
2020年 | 27篇 |
2019年 | 26篇 |
2018年 | 19篇 |
2017年 | 35篇 |
2016年 | 44篇 |
2015年 | 46篇 |
2014年 | 80篇 |
2013年 | 147篇 |
2012年 | 84篇 |
2011年 | 98篇 |
2010年 | 48篇 |
2009年 | 59篇 |
2008年 | 41篇 |
2007年 | 58篇 |
2006年 | 61篇 |
2005年 | 24篇 |
2004年 | 29篇 |
2003年 | 33篇 |
2002年 | 24篇 |
2001年 | 22篇 |
2000年 | 34篇 |
1999年 | 15篇 |
1998年 | 30篇 |
1997年 | 22篇 |
1996年 | 26篇 |
1995年 | 25篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 17篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
排序方式: 共有1269条查询结果,搜索用时 31 毫秒
801.
为比较气相色谱法和高效液相色谱法测定废水中N,N-二甲基甲酰胺是否存在显著性差异,分别使用这两种方法测定N,N-二甲基甲酰胺含量。结果显示,两种方法的精密度、准确度和测定结果无显著性差异,均可作为测定废水中N,N-二甲基甲酰胺的方法。 相似文献
802.
采用高效液相色谱三重质谱联用直接进样法测定地表水中的阿特拉津,样品经0.2μm滤膜过滤后直接上机测定,前处理无需消耗有机溶剂。选用SunFire C18(5μm*4.6 mm*150 mm)色谱柱,流动相为0.1%甲酸乙腈∶0.1%甲酸水=7∶3,流速为0.5 ml/min;质谱条件为电喷雾离子源(ESI+)电离,采用串联质谱多反应监测方式(MRM)检测。该法测定饮用水水源中阿特拉津的最低检出限为0.018μg/L,精密度为0.4%~1.0%,准确度为-0.2%~-6.6%,线性范围为0.5μg/L~100.0μg/L,相关系数为0.999 8,线性良好,能满足环境监测工作的实际应用。 相似文献
803.
根据测量不确定度评定与表示理论,对吹扫捕集气相色谱-质谱法测定水中挥发性有机物的不确定度进行了评定,以水中氯仿为例进行分析,通过对测量重复性、使用注射器、标准曲线拟合等影响测量结果的不确定度分量的分析和量化,求得水中挥发性有机物测定结果的相对合成标准不确定度。目的是建立吹扫捕集气相色谱-质谱法测定水中挥发性有机物的不确定度评定方法,以评定测量结果的质量。该不确定度评定方法在实际工作中具有较强的实用价值。 相似文献
804.
805.
806.
建立了鱼体中多氯联苯残留量的气相色谱分析方法。结果表明,7种指示性多氯联苯的线性范围为0.001μg/mL-0.20μg/mL。标准添加浓度为1.0μg/kg-10.0μg/kg时,PCB28、PCB52、PCB101、PCB118、PCB138、PCB153和PCB180的回收率均为80%-105%。方法检出限为0.3μg/kg。该方法前处理简便快捷,净化效果好,准确性高。 相似文献
807.
采用高温操作,对六味地黄丸的有效成分进行了分析。当柱温提高到60℃时,采用黏度大而洗脱能力强的异丙醇混合物为流动相,分离时间比升温前缩短30 min;总峰数目为83,其中紫外检测器可识别峰个数为65,蒸发光散射检测器可识别峰个数为59。 相似文献
808.
A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron (Fe) and humic acid (HA) in a water environment. The factors affecting the complexation of Fe and HA, such as ionic strength, pH, temperature and UV radiation, were investigated. The Fe-HA complex residence time was also studied. Experimental results showed that pH could influence the deprotonation of HA and hydrolysis of Fe, and thus affected the complexation of Fe and HA. The complexation was greatly disrupted by the presence of NaCl. Temperature had some influence on the complexation. The yield of Fe-HA complexes showed a small decrease at high levels of UV radiation, but the effect of UV radiation on Fe-HA complex formation at natural levels could be neglected. It took about 10 hr for the complexation to reach equilibrium, and the Fe-HA complex residence time was about 20 hr. Complexation of Fe and HA reached a maximum level under the conditions of pH 6, very low ionic strength, in the dark and at a water temperature of about 25°C, for 10 hr. It was suggested that the Fe-HA complex could form mainly in freshwater bodies and reach high levels in the warm season with mild sunlight radiation. With changing environmental parameters, such as at lower temperature in winter or higher pH and ionic strength in an estuary, the concentration of the Fe-HA complex would decrease. 相似文献
809.
In this study,graphene oxide was covalently immobilized on silica-coated magnetite and then modified with 2-phenylethylamine to give a nanocomposite of type Fe_3O_4@SiO_2@GO-PEA that can be applied to the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons(PAHs) from water samples.The resulting microspheres(Fe_3O_4@SiO_2@GO-PEA) were characterized by Fourier transform-infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),CHNS elemental analysis,and vibrating sample magnetometry(VSM) techniques.The adsorbent possesses the magnetic properties of Fe_3O_4 nanoparticles that allow them easily to be separated by an external magnetic field.They also have the high specific surface area of graphene oxide which improves adsorption capacity.Desorption conditions,extraction time,amount of adsorbent,salt concentration,and pH were investigated and optimized.Following desorption,the PAHs were quantified by gas chromatography with flame ionization detection(GC-FID).The limits of detection(at an S/N ratio of 3) were achieved from 0.005 to0.1 μg/L with regression coefficients(R~2) higher than 0.9954.The relative standard deviations(RSDs) were below 5.8%(intraday) and 6.2%(inter-day),respectively.The method was successfully applied to the analysis of PAHs in environmental water samples where it showed recoveries in the range between 71.7%and 106.7%(with RSDs of 1.6%to 8.4%,for n = 3).The results indicated that the Fe_3O_4@SiO_2@GO-PEA microspheres had a great promise to extraction of PAHs from different water samples. 相似文献
810.