全文获取类型
收费全文 | 70篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 5篇 |
环保管理 | 6篇 |
综合类 | 18篇 |
基础理论 | 22篇 |
环境理论 | 1篇 |
污染及防治 | 14篇 |
评价与监测 | 2篇 |
社会与环境 | 1篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 6篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有74条查询结果,搜索用时 359 毫秒
61.
The carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido-[4,3-b]indole (Trp-P-2), have been measured in condensate of cigarette mainstream smoke by high-performance liquid chromatography. These carcinogens have been detected in indoor air as well as in the air of the outdoor environment. Levels of these carcinogens in indoor air were much higher than those in outdoor air. The source of these carcinogens in indoor air was determined to be cigarette smoke by the application of smoking machine studies. Concentrations of these carcinogens in indoor air increased markedly with an increase in cigarettes smoked. The results in this investigation suggest that cigarette smoking is a source of carcinogenic tryptophan pyrolysis products in the indoor environment. Our data also suggest that smokers are persistently exposed to the carcinogenic heterocyclic amines together with potent carcinogens such as polynuclear aromatic hydrocarbons and N-nitroso compounds. 相似文献
62.
Manabe S Kurihara N Wada O Izumikawa S Asakuno K Morita M 《Environmental pollution (Barking, Essex : 1987)》1993,80(3):281-286
A carcinogen, 2-amino-1-methyl-6-phenylimidazo [4,5-b]-pyridine (PhIP), has been measured in airborne particles, diesel-exhaust particles, and incineration ash from garbage-burning plants. PhIP was found in all kinds of samples. In the light of the present results, together with the previous findings that PhIP was present in cooked foods and cigarette smoke, PhIP is likely to be an ubiquitous environmental pollutant. These observations also suggest that PhIP may be formed through the combustion process. 相似文献
63.
Vertical distribution, chlorophylla (chla) and phaeopigment concentrations in the gut, and natural nitrogen isotope ratio (
15N) were investigated for pelagic amphipodsThemisto japonica (Bovallius) collected from the Sea of Japan in July 1987. Differences in diel vertical migration behavior were clearly observed between small and largeT. japonica. Many small (<5 mm body length) amphipods appeared in the phytoplankton-rich shallow layers. Their gut pigment concentrations were higher (mean 0.52 ± 0.15µg chla g–1 amphipod) than those of large amphipods (mean 0.33±0.14µg g–1); this implies that the amphipods fed on a large amount of phytoplankton during the early stage of life. The
15N values of small amphipods were lower (5.7 to 6.3) than those of large amphipods (6.8 to 11.7), reflecting the lower trophic level of small amphipods compared to large ones. The
15N values for small amphipods were similar to those of herbivorous zooplankton. The amphipods' feeding behavior thus changes from herbivorous to carnivorous as they grow. 相似文献
64.
Manabe S Izumikawa S Asakuno K Wada O Kanai Y 《Environmental pollution (Barking, Essex : 1987)》1991,70(3):255-265
Diesel-exhaust particles are known to contain mutagenic and carcinogenic chemicals. The aim of this study was to determine whether carcinogenic amino-alpha-carbolines and amino-gamma-carbolines are present in diesel-exhaust particles. These carcinogens which were originally isolated from pyrolysates of proteins and amino acids have been detected in diesel-exhaust particles obtained from two test vehicles as well as in standard materials of automobile-exhaust particles obtained from National Institute for Environmental studies. The levels of these carcinogens were far less than those of polycyclic aromatic hydrocarbons such as benzo[a]pyrene. However, the presence of these amino-alpha-carbolines and amino-gamma-carbolines in diesel-exhaust particles suggests that these compounds are environmental pollutants and also that diesel-exhaust is one of the sources of these carcinogens in the outdoor environment. 相似文献
65.
The dry-wet cycle is a common climatic phenomenon in the tropical regions of monsoon-affected Asia. An intermittent increase
in N2O was clearly observed in the Bang Nara River, with a tropical swamp catchment at the beginning of rainy season of November
1997. The intramolecular distribution of isotopes clearly demonstrated that nitrification is the major process for the production
of N2O. Using stable isotope data, the production mechanism of N2O in the study areas was found to vary in time and space with changes in the redox boundary along the water flow.
Received: 2 November 1999 / Accepted in revised form: 19 January 2000 相似文献
66.
67.
68.
Genetic population structures along the Japanese coast, analyzed by sequence data from the mitochondrial DNA COI region, were
determined for four intertidal brachyuran species in the superfamily Thoracotremata (Ocypode ceratophthalma, Gaetice depressus, Chiromantes dehaani and Deiratonotus japonicus), which were characterized by different habitat requirements. O. ceratophthalma (seashore; supratidal sand) and C. dehaani (estuarine; supratidal marsh) showed no significant genetic differentiation among Japanese populations. The Japanese populations
of O. ceratophthalma, however, were found to genetically differentiated from the Philippine population. G. depressus (seashore; intertidal cobbles) exhibited significant genetic differentiation between the Amami-Ohshima population and other
local populations. D. japonicus (estuarine; intertidal cobbles) showed significant genetic differentiation among many local populations separated by about
30–1,200 km. The different patterns of genetic population structure recorded for the four species, thus, do not simply correspond
to habitat type.
An erratum to this article can be found at 相似文献
69.
Microbial activity and accumulation of organic matter in the burrow of the thalassinidean mud shrimp, Upogebia major, were studied on a tidal flat along the northern coast of Tokyo Bay, Japan. The burrow of U. major is Y-shaped with an upper U-shaped part plus a lower I-shaped part. Its lower part can extend to a depth of 2 m. In the present
study, we compare electron transport system activity (ETSA), bacterial abundance and organic matter content [total organic
carbon (TOC), total nitrogen (TN) and chlorophyll a (chl. a)] of the burrow wall sediment with the tidal flat surface and non-burrow sediments. We also compared the U- and I-shaped
part in terms of these parameters. ETSA in the burrow wall was higher than at the tidal flat surface in the warmer season,
and was always higher than at surrounding non-burrow sediments. Bacterial abundance in the burrow wall was higher than at
the tidal flat surface and surrounding sediment. TOC and TN contents in the burrow wall were two to three times higher than
those at the tidal flat surface and non-burrow sediments, regardless of season. However, there was no significant difference
in chl. a content between burrow wall and tidal flat surface. These results suggest that organic enrichment of the burrow wall is a
result of organic matter particles such as phytodebris accumulation along the burrow wall. For all parameters of the burrow
walls, no statistical differences were found between the two parts. Present results indicate that U. major actively transports the water containing suspended organic particles not only through the U-part but also into the deeper
I-part. These indicate that burrow of the mud shrimp provides a dynamic environment for microbial community in tidal flat
sediment. 相似文献
70.
Interval between reproductive events is an important factor for iteroparous animals because it determines the number of clutches
throughout life. This study examined whether female size, clutch size, shell size and prenuptial molting affected the clutch
interval in the hermit crab Pagurus nigrivittatus. Precopulatory guarding pairs of P. nigrivittatus were sampled in the field and kept in the laboratory until the female extruded eggs. The clutch interval of each female was
assessed as one of two types of relatively “short” and “long” intervals by checking whether the guarded female had eggs and/or
egg cases from the preceding brood or not when the guarding pair was collected. The clutch interval was longer in females
with prenuptial molting than those without molting and these females usually grew larger at the prenuptial molt. This suggests
that female P. nigrivittatus with a long interval might allocate energy into growth at the expense of the number of clutches during the current reproductive
season. The allocation to growth is theoretically predicted to decrease with female size. Gastropod shell size is also known
to affect the reproductive activity in hermit crabs. However, female size did not significantly affect the clutch interval
in P. nigrivittatus, and the effect of gastropod shell size on clutch interval was not consistent with previous empirical studies. These results
may be caused by differences in the gastropod species of shell occupied by the females of P. nigrivittatus. 相似文献