全文获取类型
收费全文 | 278篇 |
免费 | 0篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 25篇 |
环保管理 | 19篇 |
综合类 | 62篇 |
基础理论 | 48篇 |
环境理论 | 1篇 |
污染及防治 | 104篇 |
评价与监测 | 10篇 |
社会与环境 | 21篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 14篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 35篇 |
2012年 | 20篇 |
2011年 | 20篇 |
2010年 | 10篇 |
2009年 | 23篇 |
2008年 | 22篇 |
2007年 | 29篇 |
2006年 | 18篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 11篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有296条查询结果,搜索用时 291 毫秒
41.
42.
43.
The present study reports on the mercury concentrations of the vestimentiferan worm, Lamellibrachia satsuma, (Annelida: Pogonophora) found near hydrothermal vents at a depth of 80-100 m in the northern parts of Kagoshima Bay. The vestimentiferan worms had total mercury concentrations of 238 ng/g in the anterior muscle of the body and 164 ng/g in the posterior trophosome. Methylmercury constituted only 7.6% of total mercury detected anteriorly and 16.3% posteriorly. The mean total mercury concentration in filtrated ambient seawater of the worm habitat was 1.1 ng/l. The worm should accumulate mercury in seawater by a one-step into the anterior and posterior parts as 2.2 x 10(%) and 1.5 x 10(5) times those of the filtered ambient seawater, respectively. The bioaccumulation factor of mercury by the worms with only their respiration would be actually larger than that by other marine animals through food webs. The high bioaccumulation factor of mercury in the worms suggest the following two possibilities: (i) the biological half-life of organomercury in the worm could be exceptionally long; or (ii) the lifetime of vestimentiferan worms examined in the present study could be extremely long. Various metals in one specimen of the worm were analyzed by using ICP-MS, and then gold as well as silver were detected in the worm. Gold was detected for the first time from marine animals. 相似文献
44.
In the previous study, a new process concept for the thermal remediation of particulate/powder materials contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) has been verified. It leads to removal efficiencies of more than 99.9% in the soil contaminated by PCDD/Fs in terms of toxicity equivalent quantity (TEQ). However, details of the reactions and phenomena during the process, i.e., decomposition, vaporization, reformation and trap of PCDD/Fs and their relating compounds, have not sufficiently been clarified yet. The present study aims to examine experimentally the transport and fate of PCDD/Fs in the process. In the experiment, a laboratory-scale process simulator and a soil sample preliminary mixed with octachlorinated dibenzo-p-dioxin spiked by carbon-13 isotope (13C-OCDD) were used. The distribution of 13C-OCDD in the soil bed during the process was measured by applying a quench technique that rapidly cools-down the bed. Further, the total amount of 13C-OCDD discharged with outlet gas was measured. Using the obtained data, mass balance of 13C-OCDD in the process was estimated. The results show that about 99% of 13C-OCDD preliminary admixed with the soil was decomposed rather than released to the outlet gas. Only a trace amount of 13C-OCDD remained in the treated soil. In addition, a very small amount of other congeners having the 13C-cycles was detected in the treated soil and outlet gas although its TEQ values are not significant. These were probably formed by dechlorination reactions occurring in the process. 相似文献
45.
Formation and decomposition behaviors of PCDD/Fs during pyrolysis of polyvinyl chloride (PVC) with CuO have been investigated. These reactions proceed simultaneously, and the rate of decomposition exceeds that of formation with further retention. More 2,3,7,8-TCDD is formed when the dechlorination of PCDD/Fs proceeds significantly. Homologue profile patterns of PCDD/Fs show that the fractions of O8CDD and H6CDFs are relatively larger within PCDDs and PCDFs, respectively. Extremely large amounts of PCDD/Fs are obtained with the long retention time at 200 degrees C. The formation of PCDD/Fs decreases drastically with increase in the molar ratio of CuO/PVC. The acceptability of thermodynamic calculations on the formation of PCDD/Fs is also investigated. The thermodynamic calculated tendency of the effect of oxygen on the formation of PCDD/Fs agrees well with the experimental results, although absolute values of the amount of PCDD/Fs are much different. 相似文献
46.
Matsuyama T Tamaoki M Nakajima N Aono M Kubo A Moriya S Ichihara T Suzuki O Saji H 《Environmental pollution (Barking, Essex : 1987)》2002,117(2):191-194
Various detrimental factors in the environment damage plants, resulting in growth inhibition or withering. However, it is not easy to identify causal factors by visually inspecting the damaged plants. Therefore, we have developed a sensitive and reliable method for plant diagnosis, based on measuring changes in expression of a set of genes in a DNA microarray. With this method, we have been able to detect and discriminate between plants stressed by ozone, drought, or wounding. 相似文献
47.
Biofilm fermentation is a newly developed promising technique in fermentation technology. In this study no.3 and no.3S media have been used for the lipopeptide antibiotic iturin A production by Bacillus subtilis RB14. The main component of no.3 and no.3S media is Polypepton and Polypepton S, respectively. B. subtilis RB14 produces thick stable biofilm and high amount of iturin A in no.3S medium. Whereas, impaired biofilm formation and lower iturin A production was observed in no.3 medium. From the analytical information it was observed that the amounts of metal ions, such as K+, Ca2+ and Mn2+, cysteine and cellulose are lower in Polypepton compared to the Polypepton S. To investigate their effect on biofilm formation and iturin A production cysteine, cellulose, K+, Ca2+ and Mn2+ were added respectively into the no.3 medium at similar amount that Polypepton S contains. It was observed that individual addition of K+, Ca2+, cysteine and cellulose had no effect on biofilm formation, cellular growth induction or iturin A production. However, when Mn2+ was supplemented in no.3 medium, biofilm development was restored with an improved production of iturin A. Finally, combined addition of investigated substances into the no.3 medium resulted with highly folded, thick biofilm with high cellular growth and iturin A production compared to the original no.3 medium. 相似文献
48.
Ken Sasaki Kazuhisa Yamasaki Koji Tsuchida Takashi Nagao 《Die Naturwissenschaften》2009,96(5):625-629
In social insects, biogenic amines are thought to play regulatory roles in the transition between reproductive states in females.
To determine the effect of dopamine on the reproductive development of workers in primitively eusocial societies, isolated
workers of the paper wasp Polistes chinensis were supplied with oral dopamine. Ovarian development was accelerated in dopamine-fed workers as compared to control workers
of the same age fed only sucrose solution. Oral dopamine increased brain levels of dopamine and its metabolite (N-acetyldopamine). Brain levels of tyramine or octopamine were also increased by dopamine application in one of two colonies;
levels of the tyramine metabolite N-acetyltyramine were unchanged. These results indicate that dopamine plays a gonadotropic role in isolated workers in the
primitively eusocial wasp, similar to the gonadotropic role previously reported for juvenile hormone. This is the first study
to report effects of dopamine on ovarian development in workers of the paper wasp. 相似文献
49.
Takashi A. Inoue Kiyoshi Asaoka Kazuaki Seta Daisuke Imaeda Mamiko Ozaki 《Die Naturwissenschaften》2009,96(3):355-363
The feeding behavior in nectar-feeding insects is triggered by a sugar-receptor response in contact chemosensilla. The contact
chemosensilla are distributed not only on tarsi and the outside of the proboscis but also on the inside of the food canal
in Lepidoptera. Although the chemosensilla inside the food canal are assumed to detect sweet taste during the passage of nectar
through the food canal, their electrophysiological function has received little attention. In the nectar-feeding Asian swallowtail
butterfly, Papilio xuthus (Lepidoptera: Papilionidae), we found 15- to 30-μm-long sensilla neatly lined up along the inside galea wall, which forms
the food canal in the proboscis. The receptor neurons of these sensilla responded to sucrose. We hypothesized that starch
and sucrose compete with each other for a taste receptor site on the sensilla. When we added starch and sucrose to the food-canal
sensilla, the electrophysiological responses of food-canal sensilla were inhibited in parallel with the food-sucking behavior
of the butterflies. These results suggest that the food-canal sensilla are involved in the behavioral control of nectar-sucking
in this butterfly species. 相似文献
50.
Pharmacophagous acquisition of clerodendrins by the turnip sawfly (Athalia rosae ruficornis) and their role in the mating behavior 总被引:3,自引:0,他引:3
Summary. Adults of the turnip sawfly, Athalia rosae ruficornis (Tenthredinidae: Hymenoptera), frequently visit a plant, Clerodendron trichotomum (Verbenaceae), and feed pharmacophagously on the glandular trichomes on the leaf surface. A series of neo-clerodane diterpenoids (e.g. clerodendrins B and D) contained in glandular organs on the leaf surface stimulate feeding of the sawflies (both males and
females). The adults fed selectively on the trichomes were found to sequester a series of the bitter-tasting diterpenes (clerodendrin
D, ajugachin A, athaliadiol) in the body tissues, which suggested their primary role as defense substances against predators.
Females fed on Clerodendron leaves or on clerodendrin B or D were more successful in mating than unfed females. Thus, females seem to obtain an advantage
in mating success through the acquisition of the defensive principles from the Clerodendron plant.
Received 20 April 1999; accepted 29 June 1999 相似文献