首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34篇
  免费   1篇
  国内免费   3篇
安全科学   2篇
废物处理   3篇
环保管理   1篇
综合类   13篇
基础理论   7篇
污染及防治   5篇
评价与监测   4篇
社会与环境   2篇
灾害及防治   1篇
  2022年   1篇
  2018年   1篇
  2017年   2篇
  2016年   1篇
  2013年   5篇
  2012年   3篇
  2011年   5篇
  2010年   2篇
  2009年   2篇
  2005年   4篇
  2004年   2篇
  2003年   1篇
  2002年   4篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
排序方式: 共有38条查询结果,搜索用时 312 毫秒
31.
以开源GIS软件GRASS为平台,首次通过辐射过程模型r.sun和编程语言Shell实现长江流域500 m分辨率的晴日辐射反演(包括直接辐射、散射辐射和反射辐射),为了解长江流域辐射时空分布规律和相关宏观气候、生态建模奠定基础。结论如下:(1)精度验证表明,晴日辐射反演结果较理想;相关晴日指数的误差指标MPE、MAPE和RMSE分别为37%、75%和64%,r.sun模型可进一步用于中国其它区域;(2)长江流域晴日辐射年均日值为2424±245 MJ/(m2·d),其各组分差异显著,直接、散射、反射辐射分别占总辐射的842%、156%和02%;(3)晴日辐射空间分布梯度明显,沿三级地形阶梯向东辐射值及变异逐渐减小,海拔变化引起的大气衰减因素在决定晴日辐射分布时起重要作用;(4)晴日辐射季节分布不对称,月际变化总体呈倒“U”形分布;直接辐射和散射辐射变化趋势基本一致,但二者比例随大气浑浊度的变化波动剧烈。  相似文献   
32.
Abstract

The immunosuppressive effect of lindane was assessed in weanling rats over a period of 5 weeks. Agglutinin titres against S. typhi ‘O’ and ‘H’, S. paratyphi ‘AH’ and ‘BR’ antigens were determined following TAB vaccination in control and lindane‐fed animals. The titres attained in non‐treated controls were higher significantly than those in treated animals indicating a suppressive effect of lindane on humoral immune responses.  相似文献   
33.
XHAN-90B型氨氮在线自动监测仪在环境分析中的应用   总被引:3,自引:0,他引:3  
XHAN-90B型氨氮在线自动监测仪各项性能指标优越,可以准确地在线自动监测环境中不同种类的地表水和工业废水.  相似文献   
34.
The resistance pattern and mechanisms of bacterial isolates obtained from clinical origin, soil, industrial effluent, orange juice products and drinking water were studied using commonly used antibiotics. The microbial load of the water samples, industrial effluent and orange juice products were 1.0 × 101–2.25 × 106, 2.15 × 105, and 3.5 × 104–2.15 × 105 cfu mL–1, respectively. The faecal coliform test revealed that only two out of twenty orange juice products had MPN of 2 and 20, the MPN of water ranged from 1–rc="/content/r701696m91q111g6/xxlarge8805.gif" alt="ge" align="MIDDLE" BORDER="0">1800, while the effluent had MPN of rc="/content/r701696m91q111g6/xxlarge8805.gif" alt="ge" align="MIDDLE" BORDER="0">1800. The bacterial isolates that were isolated include E. coli, S. aureus, P. vulgaris, S. marcescens, S. pyogenes, B. cereus, B. subtilis, Micrococcus sp., Klebsiella sp., P. aeruginosa, and Enterobacter sp. Also, clinical and soil isolates of P. aeruginosa were used in the study. Among the eight antibiotics tested for resistance on five strains of each bacterium, seven different resistance patterns were observed among the bacterial isolates obtained from water, effluent and orange juice products. Among the clinical and soil isolates of P. aeruginosa, four multiple-drug resistance patterns were obtained. Thirty strains of E. coli and S. aureus were tested for rc="/content/r701696m91q111g6/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-lactamase production and fourteen strains, seven each of E. coli and S. aureus that had high Minimum Inhibitory Concentration values (MIC) for both Amoxycillin and Cloxacillin were positive.  相似文献   
35.
核辐射技术在环境污染治理中的应用   总被引:11,自引:0,他引:11  
以γ射线或电子束为基本手段的核辐射技术,在环境污染治理中的应用日益广泛,除了其优良的消毒性能外,还可用于废气、废水、固体废物以及环境难降解有毒有机物的处理,该文阐述了电子束辐照烟气脱硫、辐照处理工业废水、辐射降解,难降解有机污染物等方面的研究应用,以及利用气溶胶强化电子束脱硫硝和对石油进行辐射脱硫的设想,并展望了这类技术的应用前景。  相似文献   
36.
A simple method was developed for the preparation of an autoclavable, long-side-chain poly (rc="/content/r684424264857477/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxyalkanoate) (LSC-PHA) colloidal suspension, which was used as a substrate for enzymatic degradation and to prepare agar overlay plates for the isolation of microorganisms producing extracellular LSC-PHA depolymerase. Six cultures producing extracellular LSC-PHA depolymerase were isolated from a composted hydrocarbon-contaminated soil. All were pseudomonads or related bacteria. All (with the possible exception ofXanthomonas maltophilia) could produce LSC PHA. Except forX. maltophilia none could hydrolyze poly (rc="/content/r684424264857477/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxybutyrate). Screening of sevenPseudomonas strains known to accumulate LSC PHA showed that all were negative for extracellular LSC-PHA depolymerase production. It was concluded that extracellular LSC-PHA depolymerase producers are found mostly in the genusPseudomonas but that they are relatively uncommon.  相似文献   
37.
Summary Feeding by the homopteranPsylla pyricola on leaves of pear trees induces the production of volatile compounds, such as (E,E)-rc="/content/r26g4585p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene and methyl-salicylate, as well as the production of polyphenols. The inference on induction is based on GC-MS and HPLC chromatograms from the same samples ofPsylla infested leaves, leaves from the same pear tree beforePsylla infestation and uninfested leaves from other pear trees.Psylla infestation greatly enhanced the production of volatiles ((E,E)-rc="/content/r26g4585p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene, methyl-salicylate and others) and triggered the production of new polyphenols, characterized by much longer retention times.However, the responses to infestation depend critically on leaf age (defined by leaf distance to apex). With respect to the leaf volatiles it appears that infested, old leaves produce fewer compounds and lower amounts of the volatiles than infested, young leaves. Moreover, there seem to be differences in pattern. Relative to (E,E)-rc="/content/r26g4585p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene, methyl-salicylate was found in much lower amounts in heavily infested, old leaves. With respect to polyphenols it was found that infested old leaves collected in August have polyphenols with the same retention times, but more or less equal amounts as uninfested young leaves collected in May. This shows thatPsylla infestation causes the induced response mostly in young leaves.The induced leaf volatiles may act as synomones to heteropteran bugs. As shown elsewhere,Anthocoris nemoralis responds significantly to (E,E)-rc="/content/r26g4585p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene and methyl-salicylate when offered in pure form against clean air in a Y-tube olfactometer. The effect of polyphenols on the performance ofP. pyricola is not yet known. Hence, a role in direct defence is still to be investigated.  相似文献   
38.
Zusammenfassung Ziel und Schwerpunkte  Um das Verhalten des künstlichen Radionuklids137Cs im Landschaftshaushalt der Saar-Lor-Lux Region zu klaren, wurdend die r?umliche Verteilung sowie das deszendente Migrationsverhalten und die Tiefenfunktionen des Radioisotops in den wichtigsten Bodensubstraten saarl?ndischer Wald?kosysteme untersucht. Ergebnisse  Demnach finden sich die h?chsten137Cs-Aktivit?ten im Norden des Landes, w?hrend die Gebiete im Süden und Südosten deutlich geringere Konzentrationen aufweisen. Es konnten deszendente Migrationsraten zwischen 0,25 cm/a und 1,0 cm/a festgestellt werden. Durchschnittlich treten die h?chsten Migrationsraten in den tonig-schluffigen Substraten des Muschelkalks auf (0,66 cm/a), gefolgt von den lehmig ausgepr?gten Substraten des Unterrotliegenden (0,53 cm/a) und den sandigen Substraten des Buntsandsteins (0,41 cm/a). In den tonarmen Bodensubstraten des Unterrotliegenden und des Buntsandsteins lassen sich 90–95% der Aktivit?ten in den oberen 10 cm der humusreichen Oberb?den nachweisen, wohingegen in den tonreichen Substraten des Muschelkalks bis zur gleichen Tiefe nur etwa 70–76% zu finden sind. Schlussfolgerungen  Mit einem Abnehmen der als Leitbahnen fungierenden Prim?r-und Sekund?rporen in zunehmender Tiefe ist künftig mit einer deutlichen Reduzierung der Verlagerungsgeschwindigkeit von137Cs in den Substraten des Muschelkalks zu rechnen. Insbesondere bei geringm?chtigen B?den auf kluftreichem Ausgangsgestein impliziert die maximale Eindringtiefe des Isorops von 40 cm in den Unterboden jedoch eine m?gliche Kontamination des oberfl?chennahen Grundwassers, ebenso wie an Standorten mit hohem Grundwasserstand. Ausblick  Aufgrund der hier vorgestellten Ergebnisse wurde ein137Cs-Monitoring in das Boden-Dauerbeobachtungsprogramm des Landesamts für Umweltschutz des Saarlandes aufgenommen Online-First: 25. April 2000  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号