全文获取类型
收费全文 | 86篇 |
免费 | 14篇 |
国内免费 | 43篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 3篇 |
环保管理 | 15篇 |
综合类 | 84篇 |
基础理论 | 20篇 |
污染及防治 | 13篇 |
评价与监测 | 2篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 3篇 |
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 6篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1992年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
排序方式: 共有143条查询结果,搜索用时 437 毫秒
81.
永定县典型地质灾害成因分析与防治建议 总被引:1,自引:0,他引:1
本文针对福建省永定县地质灾害详细调查中典型地质灾害点--滑坡的发育特征和形成因素进行了研究,并提出了相应的防治建议,以期为类似地质灾害的调查和治理提供一定的依据和借鉴. 相似文献
82.
北运河武清段水污染时空变异特征 总被引:14,自引:6,他引:8
通过对北运河武清段水系(主河道——北运河和龙凤河,北运河支流——柳河、灌溉沟渠)的水质进行监测,采用灰色关联法对水质状况进行评价,并利用多元统计法对污染的时空变异特征进行了分析.结果表明,北运河武清段水系17个观测点中有23.8%的观测点的水质为Ⅲ类水,12.7%为Ⅳ类水,63.5%为Ⅴ类水.水质存在时空变异,夏、冬季节各河道水质差异不显著,春、秋季节差异显著.沟渠水质最差,其总磷(TP)含量和BOD5值明显高于其他河道;TP、硝态氮(NO3--N)、COD、总有机碳(TOC)、温度(T)、溶解氧(DO)和总氮(TN)解释了全部的季节性变异,BOD5、pH、溶解性总固体(TDS)和叶绿素a(Chl-a)的季节变异主要受人为因素影响,氧化还原电位(ORP)、氨氮(NH4+-N)和亚硝态氮(NO2--N)次之.NH4+-N和TN解释了51%的空间变异,主河道的氮污染是由上游工厂和企业排放污水造成的;北运河武清段的主要污染物依次为:有机污染物、氨氮、硝态氮、酸碱废水和磷,污染表现为复合污染,点源仍是最主要的污染源. 相似文献
83.
84.
Xi Cheng Hong Li Yujie Zhang Yuping Li Weiqi Zhang Xuezhong Wang Fang Bi Hao Zhang Jian Gao Fahe Chai Xiaoxiu Lun Yizhen Chen Jian Gao Junyi Lv 《环境科学学报(英文版)》2018,30(9):150-167
Continuous observation of isoprene, α-pinene and β-pinene was carried out in a typical urban area of Beijing from March 2014 to February 2015, using an AirmoV OC online analyzer. Based on the analysis of the ambient level and variation characteristics of isoprene, α-pinene and β-pinene, the chemical reactivity was studied, and their sources were identified. Results showed that the concentrations of isoprene, α-pinene and β-pinene in the urban area of Beijing were lower than those in richly vegetated areas; the concentrations of isoprene were at a moderate level compared with those of previous studies of Beijing. Concentrations of isoprene, α-pinene and β-pinene showed different seasonal, monthly, daily and diurnal variations, and all of the three species showed higher level at night than those in the daytime as a whole, the variations of isoprene, α-pinene and β-pinene mainly influenced by emission of sources, photochemical reaction, and meteorological parameters. Isoprene was the largest contributor to the total OFP values than α-pinene and β-pinene. α-Pinene was the largest contributor to the total SOAFP values than isoprene and β-pinene in autumn, while isoprene was the largest one in other seasons. Isoprene, α-pinene and β-pinene were derived mainly from biological sources; and α-pinene level were also affected by industrial sources. To reduce the concentrations of isoprene, α-pinene and β-pinene, it is necessary to scientifically select urban green plant species, and more strict control measures should be taken to reduce the emission of α-pinene from industrial sources, such as artificial flavors and resins synthesis processes. 相似文献
85.
在摇瓶条件下,首先对A.eutrophus生产PHB的一步法和二步法进行了比较研究,然后探讨了A.eutrophus对不同碳源的利用情况,提出了较佳的PHB发酵条件,并分析了PHB的发酵过程曲线.研究结果表明,本研究采用的A.eutrophus以一步法生产PHB较为适宜,其对3种不同碳源的利用能力为:果糖>丁酸>葡萄糖;培养基中的丁酸浓度和pH值对PHB发酵的生产指标和动力学参数有较大影响,其最佳值为1.8%和pH为0.8;最终发酵过程达到细胞于重ρ=7.2g·L-1,胞内PHB含量ρ=5.0g·L-1,ω(PHB)占细胞干重72.2%. 相似文献
86.
87.
Furberg AS Sandanger T Thune I Burkow IC Lun E 《Journal of environmental monitoring : JEM》2002,4(1):175-181
Increased cancer incidence and mortality have been found among humans exposed to high levels of organochlorines (OCs), either accidentally or as industrial workers. In order to assess levels of OCs in Norwegian women north of the Arctic Circle and validate self-reported fish consumption as a surrogate measure of organochlorine body burden, concentrations of seven polychlorinated biphenyl (PCB) congeners [IUPAC Nos. CB-105, CB-118, CB-138 (+ CB-163), CB-153, CB-180, CB-183, CB-187], beta-hexachlorocyclohexane (beta-HCH), 2,2'-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) and cis- and trains-chlordane (c-CD and t-CD) were examined in plasma samples of middle-aged women attending for health screening. Altogether, 47 of those invited (81%) completed a questionnaire and donated a suitable blood sample. The ability of questionnaire data to predict plasma levels of OCs was tested in linear and logistic regression analyses. Measured plasma concentrations were in the range reported for the general female population of other Western countries and the relative amounts of PCBs were similar to the circumpolar pattern. Intake of seagulls' eggs was a predictor of PCB congeners CB-138 (+CB-163) (p<0.05) and CB-153 (p<0.01). No other food category was positively associated with any compound. In contrast, duration of residence in the study municipality, body mass index (BMI) and lifetime lactation (months) were the best univariate predictors. There was an increase in beta-HCH, p,p'-DDE and most of the PCBs (p<0.05 for all) with increasing length of time a subject had lived in the municipality. BMI was a positive predictor for beta-HCH (OR=3.10, 95% CI 1.50-6.43, per 5 kgm(-2)), chlordane (OR=2.13, 95% CI 1.12-4.05, per 5 kgm(-2)) and CB-105 and CB-153 (p<0.05 for both). Lactation was negatively associated with all OCs (p<0.05), except chlordane and two of the PCB congeners. Time living in the municipality and lactation explained 34%, of the variance in concentration of total PCB in a multivariate model (p<0.001). The results indicate that regular consumption of fish (mostly lean species) from the Norwegian waters is not associated with an increased body burden of OCs (e.g., of importance to cancer development), although they confirm that lactation is the most important elimination route of these contaminants in women. 相似文献
88.
采用高通量测序-分子鉴定分级技术于2018年对大长山岛临近海域微藻粒级结构进行了研究,同时探讨了叶绿素a分级法测算微藻粒级结构的误差.结果发现,叶绿素a分级法测算微微型藻类(< 3μm)误差高达82%,严重低估了小粒径微藻的组成,分子鉴定分级法测算春季小粒径微藻生物量组成平均为86%,夏季平均为52%,秋季平均为20%.春季优势种抑食金球藻生物量占41%,夏季优势种金牛微球藻生物量占21%,这2种微微型藻类会严重影响滤食性贝类正常摄食生长,养殖风险较高.总氮、总磷、溶解硅等环境因子和贝类摄食的下行效应影响着该海域微藻粒级结构的变化. 相似文献
89.
养殖场沼液中雌激素排放特征及去除效果研究 总被引:1,自引:0,他引:1
为探究典型奶牛养殖场沼液中类固醇雌激素的排放特征,采用固相萃取-高效液相色谱串联质谱(SPE-HPLC-MS/MS)分析方法,对重庆市某奶牛养殖场厌氧池和好氧池出水中类固醇雌激素进行夏、秋、冬3季连续监测.结果表明:类固醇雌激素(含雌酮;17α-雌二醇;17β-雌二醇;雌三醇;硫酸雌酮)在厌氧池和好氧池出水中总浓度分别在347.28~2117.65ng/L和10.75~1070.00ng/L之间,其中厌氧池出水以雌酮(E1)、17α-雌二醇(17α-E2)和17β-雌二醇(17β-E2)为主,好氧池出水以E1和17β-E2为主.研究显示:好氧处理对E1、17β-E2、17α-E2的平均去除率达85.70%、56.82%、57.32%,厌氧处理可有效去除硫酸雌酮(E1-3S).在微生物作用下,厌氧和好氧处理均存在E1、17α-E2和17β-E2的相互转化,但雌三醇(E3)的低检出率则显示体系中雌激素转化为E3的比例较低.对雌激素活性(EEQ95th)的评估显示厌氧-好氧处理后雌激素活性平均降低70.34%,但沼液的雌激素生态环境风险仍不可忽视,需持续观察及研究. 相似文献
90.
以低COD/TN的实际生活污水为研究对象,采用SBR反应器,对短程硝化的启动条件进行了优化.结果表明,温度30℃、溶解氧(DO) 2.0mg/L、污泥龄为7d时,系统在实时控制条件下运行32周期,可以成功启动短程硝化.在总氮(TN)去除率>95%的情况下,亚硝酸盐积累率(NO2--N /NOx--N)>90%,随后的64d,温度恢复到常温(20~24℃),系统仍稳定运行.荧光原位杂交技术(FISH)检测表明,经过32个周期种群优化,污泥中氨氧化菌(AOB)的含量提高了38.9%,亚硝酸盐氧化菌(NOB)的含量降低了53.2%.在线动态控制DO浓度和曝气时间可以逐渐淘汰系统中的NOB,从而获得稳定的短程硝化,提高系统脱氮效率. 相似文献