全文获取类型
收费全文 | 120篇 |
免费 | 2篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 3篇 |
环保管理 | 15篇 |
综合类 | 16篇 |
基础理论 | 29篇 |
污染及防治 | 41篇 |
评价与监测 | 15篇 |
社会与环境 | 2篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 14篇 |
2008年 | 14篇 |
2007年 | 10篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有127条查询结果,搜索用时 46 毫秒
91.
David J. Schulz Zhi-Yong Huang Gene E. Robinson 《Behavioral ecology and sociobiology》1998,42(5):295-303
Three experiments were conducted to explore the effects of severe food shortage on the control of two important and interrelated
aspects of temporal division of labor in colonies of the honey bee (Apis mellifera): the size and age distribution of a colony's foraging force. The experiments were conducted with single-cohort colonies,
composed entirely of young bees, allowing us to quickly distinguish the development of new (precocious) foragers from increases
in activity of bees already competent to forage. In experiment 1, colony food shortage caused an acceleration of behavioral
development; a significantly greater proportion of bees from starved colonies than from fed colonies became precocious foragers,
and at significantly younger ages. Temporal aspects of this starvation effect were further explored in experiment 2 by feeding
colonies that we initially starved, and starving colonies that we initially fed. There was a significant decrease in the number
of new foragers in starved colonies that were fed, detected 1 day after feeding. There also was a significant increase in
the number of new foragers in fed colonies that were starved, but only after a 2-day lag. These results suggest that colony
nutritional status does affect long-term behavioral development, rather than only modulate the activity of bees already competent
to forage. In experiment 3, we uncoupled the nutritional status of a colony from that of the individual colony members. The
behavior of fed individuals in starved colonies was indistinguishable from that of bees in fed colonies, but significantly
different from that of bees in starved colonies, in terms of both the number and age distribution of foragers. These results
demonstrate that effects of starvation on temporal polyethism are not mediated by the most obvious possible worker-nest interaction:
a direct interaction with colony food stores. This is consistent with previous findings suggesting the importance of worker-worker
interactions in the regulation of temporal polyethism in honey bees as well as other social insects.
Received: 17 April 1997 / Accepted after revision: 26 December 1997 相似文献
92.
Urban littering is considered an important environmental and public issue globally. This problem is growing considerably within coastal communities of the southern region of South America. The goals of this study were to assess (1) the abundance and composition of urban litter; (2) the spatial and temporal variations of its abundance; and (3) the relationship between the abundance of litter and three anthropogenic variables (i.e. abundance of pedestrians, of parked vehicles, and of trash bins) in Mar del Plata, the most populated coastal city in Argentina. Eighty-eight transects, each covering 1425 m2, were sampled along four sites from April 2008 to March 2009. Results showed 20,336 items (ca. 14 items per m2) of which cigarette butts (33%), papers (31%), and plastics (22%) were the most commonly littered items. Higher amounts of litter were found in an industrial area (city’s harbor), while the abundance of litter appeared relatively even throughout the year. Redundancy analysis techniques indicated a high abundance of all three anthropogenic variables associated with the central business district area of the city and an area in close proximity to a major seaside resort, where cigarette butts and papers dominated. This is the first study that has examined spatial and temporal variations of urban litter in a high-density coastal city in Argentina. Our results showed that addressing the problems associated with urban litter must include intensive educational and advertising campaigns directed at pedestrians and owners of parked vehicles, but waste reduction, clean-up operations and law enforcement should be also considered. 相似文献
93.
植物病原细菌的BIOLOG系统鉴定及其多元统计初析 总被引:1,自引:0,他引:1
Biolog细菌鉴定系统已广泛应用于细菌快速鉴定 ,通过比较菌株碳源利用的代谢指纹 ,还可用于细菌分类研究[1~ 4 \〗.该系统具有自动化和标准化程度高、结果快速准确和操作简便等优点 ,它主要根据细菌对 95种碳源的利用情况 ,以四唑紫 (Tetrazolium)为指示剂 ,Biolog代谢指纹经计算机处理并与数据库内已知细菌比较 ,实现对待测菌的快速鉴定 .Biolog系统用于细菌分类研究中 ,除已广泛采用聚类分析并以树状图表示菌株间的相似关系外 ,近年来 ,国外许多学者已应用多元统计方法 (主成分分析、因子分析和方差分析 )… 相似文献
94.
Landscape connectivity, as an important indicator of regional landscape functional pattern measured by cost–distances model,
could both reveal evidence of, and act as an indicator, for desertification. Using Minqin county as a case study, this study
was further to test cost–distance connectivity for indicating desertification, and to analyze temporal changes of connectivity
in the county from 1977 to 1997. The results further indicate the connectivity interpreted as lower cost–distance and higher
risk of desertification. The temporal change analysis of connectivity provides more detail supplement of desertification processes.
Landscape connectivity changes in the county had three distinctive phases, the strongest decline of log cost–distance with
overwhelming decrease area and decrease amount in the period 1977–1984, and its slight decline with the relative balance between
the high decrease amount and high increase amount in the period 1984–1992, then its the slight decline with the relative balance
between the low decrease amount and low increase amount in the period 1992–1997. The frequent temporal and spatial transition
in source class, grassland, alkali–saline land and irrigated cultivated land caused negative effects on the oasis environment. 相似文献
95.
Temporal trends and sources of PCDD/Fs, pentachlorophenol and chlornitrofen in paddy field soils along the Yoneshiro River basin, Japan 总被引:1,自引:0,他引:1
Kobayashi J Sakai M Kajihara H Takahashi Y 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1233-1242
In order to understand the long-term behaviors of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), pentachlorophenol (PCP), and 2,4,6-trichlorophenyl-4′-nitrophenyl ether (chlornitrofen, CNP) in paddy soil, we measured their concentrations in paddy soil samples collected in 1982 and 1984 (1980s) and in 2000 and 2002 (2000s) from the Yoneshiro River basin, Japan. The concentrations of PCP and CNP decreased from the 1980s to the 2000s, whereas the concentrations of PCDD/Fs and their toxic equivalency (WHO2006-TEQ) remained. The major sources of PCDD/Fs in the paddy soil samples were attributed to impurities in PCP and CNP as a result of comparisons of homologue and congener profiles and principal component analysis. Based on the results of comparison of total input and remaining amount, it is estimated that more than 99% of PCP and CNP applied to the paddy fields had disappeared, whereas most of the applied PCDD/Fs and TEQ remained. 相似文献
96.
This study examined the spatial-temporal variations and factors influencing the management of groundwater along a section of the Bagmati river corridor in the Kathmandu valley (Nepal). The results showed that rural areas were less polluted than urban areas. In urban areas, the biochemical oxygen demand (BOD), total nitrogen (TN) and total phosphorus (TP) concentrations ranged from 8.41 to 29.74 mg/L, 6.7 to 128.96 mg/L and 0.06 to 1.5 mg/L, respectively. In rural areas, the BOD, TN and TP concentrations ranged from 0.78 to 18.25 mg/L, 4.8 to 11.56 mg/L and 0.07 to 0.65 mg/L, respectively. The level of organics was higher in the pre-monsoon season, while the level of nutrients was higher in post-monsoon season. A comparison of the groundwater and surface water in the upstream rural areas revealed that the TP concentration was higher in the groundwater than in the surface water, which was attributed to the sorption of phosphorus on iron, aluminum or calcium compounds contained in the surface water, which depends upon the temperature, pH and dissolved oxygen. In urban areas, a few wells were found at groundwater levels lower than the corresponding surface water levels and were subjected to a high risk of pollution. Overall, these findings reinforce the notion that the management of surface and ground waters in an integrated approach is essential for attaining sustainable development of groundwater systems. 相似文献
97.
Aivo Lepland Reidulv Be Aave Lepland Oddbjrn Totland 《Journal of environmental management》2009,90(11):3589-3598
Acoustic equipment, including interferometric sonar and parametric sub-bottom profiler, have been used to determine the volume and lateral spread of dredged sediments disposed in the natural submarine depression in the Bekkelag Basin, inner Oslofjord since the beginning of the Oslo Harbor remediation project in 2006. This natural depression is used as a subaqueous confined disposal facility (CDF). Calculation of the volume of disposed sediments in the CDF is based on elevation change, derived from two high-resolution bathymetric datasets obtained in 2004, i.e. before the onset of the remediation project, and in April 2008. Seismic profiles across the CDF have been used to estimate the settlement of the original seabed, caused by loading-induced dewatering and compaction of the seabed sediments under the disposed masses.Detailed bathymetry and backscatter data demonstrate the lateral spread of disposed sediments within a well-confined area covering ca. 195,000 m2. The sea bottom within this area is distinctly softer than the surrounding seabed as shown by very low acoustic backscatter amplitude, signifying a very loose surface character of the disposed sediments. The thickness of the disposed sediments reaches 6 m the deepest part of the original depression. The volume calculation of the disposed sediments in the CDF, based solely on bathymetry data, gives a value of ca. 310,000–320,000 m3. Settlement of the original seabed as a result of loading has been estimated to be 30 cm at 5 m thickness of the disposed sediments. Under the condition that the settlement rate is linearly correlated to the thickness of disposed sediments, the settlement corrected volume of disposed sediments is ca. 330,000–340,000 m3. Presented results demonstrate high accuracy and good reproducibility of acoustic seafloor data, and indicate a great potential of such methods as monitoring tools in environmental projects that involve dredging and subaqueous disposal. 相似文献
98.
Temporal changes in the distribution of exogenous HCB and DDT among different soil organic matter fractions were studied under sterile and non-sterile conditions, different soil water contents, and different concentrations of added Cu(2+). The residence time was 311days. Soil organic matter was fractionated into fulvic acid (FA), humic acid (HA), bound-humic acid (BHA), lipid, and insoluble residue (IR) fractions by a methyl isobutyl ketone (MIBK) method. Results revealed that there is a mass transfer tendency of DDT and HCB from FA, HA and BHA to IR and lipid fractions with increasing residence time. Microbial activity accelerated the mass transfer, while the addition of Cu(2+) slowed it down. The HCB and DDT transfer rate decreased as the soil moisture increased from 1.9% to 60%, but increased when soil moisture increased further to 90%. A two-compartment first order kinetic model was used to describe the mass transfer from FA, HA and BHA. 相似文献
99.
Mobility of metals and metalloids in a multi-element contaminated soil 20 years after cessation of the pollution source activity 总被引:5,自引:0,他引:5
Clemente R Dickinson NM Lepp NW 《Environmental pollution (Barking, Essex : 1987)》2008,155(2):254-261
Knowledge of trace element concentrations and mobility is important in the ecotoxicological assessment of contaminated soils. We analysed soil pore water under field conditions to provide new insights into the mobility of residual contaminants in the surface 50cm of a highly contaminated woodland soil. Cadmium and Zn were highly mobile in the acidic soil, concentrations increasing with depth in soil pore water, showing considerable downward mobility. High levels of surface organic matter restricted the solubility of Cu, Pb and Sb, with highest concentrations being found close to the surface. Dissolved organic carbon in pore water had a strong influence on mobility of Cu, Zn, Pb and Sb. Elevated As had moved from the organic surface horizons but was largely immobilised in deeper layers and associated with Fe and Al oxides. The measured differential mobility of pollutants in the present study is highly relevant to protection of groundwater and other receptors. 相似文献
100.
Levels and temporal trends (1983-2003) of persistent organic pollutants (POPs) and mercury (Hg) in seabird eggs from Northern Norway 总被引:1,自引:0,他引:1
Helgason LB Barrett R Lie E Polder A Skaare JU Gabrielsen GW 《Environmental pollution (Barking, Essex : 1987)》2008,155(1):190-198
The main objective of this study was to investigate possible temporal trends of persistent organic pollutants (POPs) and mercury in eggs of herring gulls (Larus argentatus), black-legged kittiwakes (Rissa tridactyla), common guillemots (Uria aalge) and Atlantic puffins (Fratercula arctica) in Northern Norway. Eggs were collected in 1983, 1993 and 2003. Egg concentrations of POPs (PCB congeners IUPAC numbers: CB-28, 74, 66, 101, 99, 110, 149, 118, 153, 105, 141, 138, 187, 128, 156, 157, 180, 170, 194, 206, HCB, alpha-HCH, beta-HCH, gamma-HCH, oxychlordane, trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT) and mercury were quantified. Generally, POP levels decreased between 1983 and 2003 in all species. No significant temporal trend in mercury levels was found between 1983 and 2003. 相似文献