全文获取类型
收费全文 | 203篇 |
免费 | 0篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 34篇 |
环保管理 | 6篇 |
综合类 | 29篇 |
基础理论 | 36篇 |
环境理论 | 1篇 |
污染及防治 | 79篇 |
评价与监测 | 11篇 |
社会与环境 | 12篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 18篇 |
2012年 | 5篇 |
2011年 | 15篇 |
2010年 | 12篇 |
2009年 | 14篇 |
2008年 | 6篇 |
2007年 | 14篇 |
2006年 | 19篇 |
2005年 | 18篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有213条查询结果,搜索用时 671 毫秒
171.
The relationship between somatic growth and incremental growth of otoliths of Pacific saury, Cololabis saira (Brevoort), larvae under different temperature conditions was studied in the laboratory for three age groups (0 to 9, 10
to 20 and 20 to 30 d posthatch). Larvae were incubated from hatching to 9 d at 24, 20, and 16 °C. Further, larvae initially
reared at an ambient temperature of 21.7 °C were transferred to experimental temperatures of 22, 18, and 14 °C on Day 10 and
reared to Day 20 and similarly from Day 20 and reared to Day 30 posthatch. Growth trajectories of larvae sampled at the end
of the three experiments were back-calculated using the biological intercept method and compared to the measured values 0
and 5 d after the start of each experiment. Back-calculated knob length at the different temperatures indicated no significant
difference to the measured knob lengths except for the cases at 20 °C from hatching to 9-d-old larvae and at 14 °C from 20-
to 30-d-old larvae. The close correlation between somatic and otolith growth shown in this study indicated the feasibility
of estimating the growth history of Pacific saury larvae using otolith readings.
Received: 14 April 1999 / Accepted: 27 October 1999 相似文献
172.
Groundwater flow at Kharga Oasis, located in the western desert of Egypt, was previously analyzed using numerical models; however, the lack of basic data often limits the implementation of these models, as well as introducing a problem for model calibration and validation. The Grey Model (GM) was used to overcome these difficulties of data limitation and uncertainty of hydrogeological conditions. However, no clear theories exist for selecting the number of input model trends and the most suitable values of input parameters. Therefore, in the current study, a modification of the GM is newly proposed and called the Modified Grey Model (MGM) in an attempt to determine a process for selecting the best input models' trends with the appropriate values of input parameters to achieve acceptable fitting to observations. The sensitivity analysis results showed that the MGM produced more stable results than the GM using a wide range of values for input parameters. Moreover, the MGM reduced the calculation time required for fitting the measured piezometric level trends by 99.8 %. Three development scenarios of groundwater withdrawal were proposed that involved either expanding the present extraction rate or redistributing the groundwater withdrawal over the recent working production wells (RWPWs). The results concluded that the groundwater table in the northern part of the oasis could be temporally recovered to an economical piezometric level; however, the table in the southern part is severely decreased. Therefore, new production wells are recommended to be constructed in the southern part far enough from the RWPWs. 相似文献
173.
Xunde Li Naoko Watanabe Chengling Xiao Thomas Harter Brenda McCowan Yingjia Liu Edward R. Atwill 《Environmental monitoring and assessment》2014,186(2):1253-1260
Generic Escherichia coli was isolated from surface water and groundwater samples from two dairies in Northern California and tested for susceptibility to antibiotics. Surface samples were collected from flush water, lagoon water, and manure solids, and groundwater samples were collected from monitoring wells. Although E. coli was ubiquitous in surface samples with concentrations ranging from several hundred thousand to over a million colony-forming units per 100 mL of surface water or per gram of surface solids, groundwater under the influence of these high surface microbial loadings had substantially fewer bacteria (3- to 7-log10 reduction). Among 80 isolates of E. coli tested, 34 (42.5 %) were resistant to one or more antibiotics and 22 (27.5 %) were multi-antibiotic resistant (resistant to ≥3 antibiotics), with resistance to tetracycline, cefoxitin, amoxicillin/clavulanic acid, and ampicillin being the most common. E. coli isolates from the calf hutch area exhibited the highest levels of multi-antibiotic resistance, much higher than isolates in surface soil solids from heifer and cow pens, flush alleys, manure storage lagoons, and irrigated fields. Among E. coli isolates from four groundwater samples, only one sample exhibited resistance to ceftriaxone, chloramphenicol, and tetracycline, indicating the potential of groundwater contamination with antibiotic-resistant bacteria from dairy operations. 相似文献
174.
Akio Kamimura Yugo Akinari Takeru Watanabe Kazuo Yamada Fumiaki Tomonaga 《Journal of Material Cycles and Waste Management》2010,12(2):93-97
We have achieved major improvements in the efficient chemical recycling of waste fiber-reinforced plastics (FRPs). The effects
of reduction in the amounts of dimethylaminopyridine (DMAP) used for depolymerization were examined. The treatment of waste
FRP in the presence of 1 or 2 wt% DMAP resulted in the successful recovery of monomeric materials that could be employed in
the polymerization process to produce recycled plastic. The separation of linker units from glass fiber, however, was unsuccessful.
The purity of the recovered monomeric material, when treated with activated charcoal, was improved to about 70%. This resulted
in effective decoloration of the recovered monomer. Finally, the purified material, after undergoing repolymerization, provided
high-quality recycled plastic comparable to new plastics produced from new monomers. 相似文献
175.
Fuma S Watanabe Y Kawaguchi I Takata T Kubota Y Ban-Nai T Yoshida S 《Journal of environmental radioactivity》2012,103(1):15-19
Derivation of effect benchmark values for each taxonomic group, which has been difficult due to lack of experimental effects data, is required for more adequate protection of the environment from ionising radiation. Estimation of effects doses from nuclear DNA mass and subsequent species sensitivity distribution (SSD) analysis were proposed as a method for such a derivation in acute irradiation situations for assumed nuclear accident scenarios. As a case study, 5% hazardous doses (HD5s), at which only 5% of species are acutely affected at 50% or higher lethality, were estimated on a global scale. After nuclear DNA mass data were obtained from a database, 50% lethal doses (LD50s) for 4.8 and 36% of the global Anura and Caudata species, respectively, were estimated by correlative equations between nuclear DNA mass and LD50s. Differences between estimated and experimental LD50s were within a factor of three. The HD5s obtained by the SSD analysis of these estimated LD50s data were 5.0 and 3.1 Gy for Anura and Caudata, respectively. This approach was also applied to the derivation of regional HD5s. The respective HD5s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan. This HD5 value for the Japanese Anura was significantly higher than the global value, while Caudata had no significant difference in global and Japanese HD5s. These results suggest that this approach is also useful for derivation of regional benchmark values, some of which are likely different from the global values. 相似文献
176.
Measuring Water Storage Fluctuations in Lake Dongting, China, by Topex/Poseidon Satellite Altimetry 总被引:1,自引:0,他引:1
Zhang J Xu K Yang Y Qi L Hayashi S Watanabe M 《Environmental monitoring and assessment》2006,115(1-3):23-37
Although satellite radar altimetry was developed and optimized for open oceans, it has been used to monitor variations in the level of inland water-bodies such as lakes and rivers. Here, for the first time, we have further used the altimetry-derived variation of water level for estimating the fluctuation of water storage as an addition to the present in situ water storage estimation systems to be used in remote areas and in emergency situation such as in the events flooding monitoring and for studying the effect of climate change. Lake Dongting, the second largest lake in China, influenced frequently by flooding, was, therefore, chosen to demonstrate the potential of the technique. By using the concept of an “assumed reference point”, we converted Topex/Poseidon satellite altimetry data on water level variations in Lake Dongting to “water level” data. The “water level” time-series data and in situ water storage were used to establish a rating curve. From the rating curve, we converted data on “water level” derived from seven years (1993–1999) of Topex/Poseidon data to actual water storage in Lake Dongting. The result reveals that the seasonal and annual fluctuations of water storage occurred during the 1990s with a more frequent flooding at the late 1990s' especially the flooding in whole catchment level in 1998 and 1999. The study supports the usefulness of satellite altimetry for dense and continuous monitoring of the temporal variations in water dynamic in moderate to large lakes. 相似文献
177.
Iida T Todaka T Hirakawa H Hori T Tobiishi K Matsueda T Watanabe S Yamada T 《Chemosphere》2007,67(9):S263-S271
Polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran and dioxin-like polychlorinated biphenyl concentrations in human blood, lung, liver, bile, pancreas, spleen, kidney and mesentery fat were determined to assess the concentrations and distribution of these chemicals in human tissues from 20 donors. The mean TEQ concentrations in blood, lung, liver, bile, spleen, pancreas, kidney and mesentery fat were 119, 178, 228, 50, 113, 163, 138 and 139 pg TEQ/g lipid, respectively. Parallel levels were seen in the blood, spleen, kidney and mesentery fat; in the lungs and pancreas, the levels were somewhat higher. Among the organ tissues samples, the highest concentration was observed in the liver and the lowest in the bile. Mean total-TEQ concentration of the liver was about 4.5 times higher than that of bile. Positive correlations were observed among the concentrations of dioxins in various tissues. However, the concentrations in bile were not correlated with any tissues. It is suggested that the distribution behavior of dioxin-like congeners in human tissues varies among tissues and the kinds of congeners ingested. To evaluate the relationship between the accumulation levels of dioxins and their pathophysiological significance or risk, data must be accumulated from a more extensive group of human samples. 相似文献
178.
Fresh municipal solid waste incineration residues (MSWIR) and a drilling core of 2-10 years old landfilled MSWIR were investigated to determine the alterations due to weathering in a landfill. Physical and geochemical properties and transformations of major components and heavy metals were analyzed for fresh and landfilled residues. Carbonates and hydroxides (10-12vol%) as major mineralogical compositions in the 8-10 years weathered MSWIR were observed by modal analysis of thin sections. Three step sequential extractions indicated that reducible phases, mainly the Fe, Al and Mn hydroxides increased with depth in the landfill. A pH controlled leaching test (including availability test and pH dependent leaching test) was then conducted. Results indicated lower concentrations of leachable contents at pH values from 6 to 10 for the four elements (Pb, Zn, Al and Fe) in the 8-10 years landfilled residues than in the fresh and 1-2 years landfilled residues. This means that 8-10 years weathered MSWIR became more stable than fresh landfilled residues. The reasons for the stabilization of these elements might be the hydration of Al and Fe during weathering in the landfill, which then results in the heavy metals adsorptions of these minerals. 相似文献
179.
Suzuki Y Watanabe I Oshida T Chen YJ Lin LK Wang YH Yang KC Kuno K 《Chemosphere》2007,68(7):1270-1279
Concentrations of 17 trace elements were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) in Formosan squirrels (Callosciurus erythraeus) of Taiwan and Japan to document trace element pollution in Taiwan. High concentrations of elements used to produce semiconductors - Ga, As, Cd, In and Tl - were found in animals captured in Miaoli County, which is the nearest site to Hsinchu City, a chief city of Taiwan's semiconductor industry. Significant correlations between Ga, As, In and Tl were found in the kidney, liver, lung and muscle tissues of Taiwanese squirrels. Hierarchical cluster analysis indicated that Ga, As, In and Tl were of the same clade, indicating that Ga, As, In and Tl were discharged from an identical origin. Molar ratios of Ga/As concentration in lungs of animals captured in Miaoli resembled those of animals after intratracheal administration of particulate gallium arsenide (GaAs). This result might indicate that the higher concentrations of Ga and As in the specimens in Miaoli resulted from atmospheric exposure to GaAs. 相似文献
180.
Kenji Karino Takatsugu Ishiwatari Hiromi Kudo Aya Sato 《Behavioral ecology and sociobiology》2011,65(6):1305-1315
Female mate preference for dorsal fin length in male guppies (Poecilia reticulata) was investigated. In a dichotomous choice experiment using live males, females preferred males with longer dorsal fins to
those with shorter dorsal fins. When the dorsal fin lengths of the two males were reversed by surgical manipulation, the females
reversed their preference. To further examine this preference behaviour, a second dichotomous choice experiment was conducted
using digitally modified male images that differed only in dorsal fin lengths. In this next experiment, females preferred
male images with a longer dorsal fin than those with a shorter dorsal fin. In order to clarify the cost of possessing a long
dorsal fin for males, the effect of dorsal fin length on swimming performance of males was also examined with a flow chamber.
Male swimming performance was enhanced by surgically shortening the dorsal fin. The result of this study suggests that the
long dorsal fin of male guppies is a costly handicap that may have evolved due to female mate choice. 相似文献