全文获取类型
收费全文 | 156篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 2篇 |
环保管理 | 20篇 |
综合类 | 38篇 |
基础理论 | 64篇 |
污染及防治 | 20篇 |
评价与监测 | 6篇 |
社会与环境 | 2篇 |
出版年
2022年 | 4篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2013年 | 10篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 15篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1981年 | 2篇 |
1978年 | 3篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1963年 | 2篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1959年 | 1篇 |
1958年 | 4篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1955年 | 3篇 |
1954年 | 1篇 |
1953年 | 1篇 |
1950年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 31 毫秒
101.
Katarzyna Wojczulanis-Jakubas Dariusz Jakubas Julien Foucher Joanna Dziarska-Pałac Hubert Dugué 《Die Naturwissenschaften》2013,100(11):1095-1098
Relatively little attention has been paid to sex differences in the migration of birds in autumn. We studied the autumn migration strategy of molecularly sexed males and females in the globally threatened aquatic warbler Acrocephalus paludicola. We captured 176 birds at a stopover site in the Loire estuary at Donges, France. The median date for the passage of adults was 8 days earlier in males than females, although the timing of migration in first-year males and females was similar. This indicates that males, who are without parental duties, can start their migration earlier than females and first-year birds. Adults were significantly heavier than immature birds but did not have higher fat scores. In both age categories, more males (two to three times more) were captured. However, various factors (including tape-luring) can affect observed sex ratio. 相似文献
102.
103.
104.
Turbulence and turbulent flux events in a small estuary 总被引:2,自引:0,他引:2
Relatively little systematic research has been conducted on the turbulence characteristics of small estuaries. In the present
study, detailed measurements were conducted in a small subtropical estuary with a focus on turbulent flux events. Acoustic
Doppler velocimeters were installed in the mid-estuary at fixed locations and sampled simultaneously and continuously for
50 h. A turbulent flux event analysis was performed for the entire data sets extending the technique of Narasimha et al. (Phil
Trans R Soc Ser A 365:841–858, 2007) to the unsteady open channel flow motion and to turbulent sub-events. Turbulent bursting
events were defined in terms of the instantaneous turbulent flux. The data showed close results for all ADV units. The very-large
majority of turbulent events lasted between 0.04 and 0.3 s with an average of 1 to 4 turbulent events observed per second.
A number of turbulent bursting events consisted of consecutive turbulent sub-events, with between 1 and 3 sub-events per main
event on average. For all ADV systems, the number of events, event duration and event amplitude showed some tidal trends,
with basic differences between high- and low-water periods. A comparison between the present estuary data and the atmospheric
boundary layer results of Narasimha et al. (Phil Trans R Soc Ser A 365:841–858, 2007) showed a number of similarities and
demonstrated the significance of turbulent events in environmental flows. A burstiness index of 0.85 was found for the present
data. 相似文献
105.
Hubert Trzaska 《The Environmentalist》2005,25(2-4):181-185
Summary The paper discusses several aspects of the practical application of the SAR. It is shown that the unit is an ideal solution
for basic research and laboratory experiments. SAR is directly nonmeasurable unit. Although methods and devices based upon
indirect SAR measurements may widen our knowledge about EM energy distribution and absorption within a body. It is shown that
for practical applications the temperature SAR measurement methods are not sensitive enough while methods based upon E(H) measurement are less accurate than traditional approaches. As a result of assumption SAR = 4 W/kg as a basic restriction
the present protection standards are illogical and nonrealiazable. A return to traditional units (E, H, S) in the standards
and surveying metrology is suggested. 相似文献
106.
107.
Wanzenböck Josef Gassner Hubert Lahnsteiner Barbara Hassan Yasmin Hauseder Gudrun Doblander Christine Köck Günter 《Water, Air, & Soil Pollution: Focus》2002,2(4):227-248
In order to analyse potential influences of soda industryeffluents on the ecological integrity of Traunsee (TS) weinvestigated the fish community of the lake in comparison witha reference lake (Hallstättersee HS) and used a reconstructionfrom the (older) literature concerning the original speciescomposition of Traunsee. Published `Index of Biotic Integrity(IBI)' metrics were considered to be of limited value due tothe relatively low species number in the oligotrophic, Alpinelake. Therefore we included, in addition to speciescomposition, studies on egg distribution, larval fishdensities, life-history parameters (i.e. growth, maturity,fecundity, age and size composition), stress levels and heavymetal content of the dominant whitefish (Coregonuslavaretus), as well as overall fish density and biomass (usinghydroacoustics) to assess the ecological status of the fishcommunity. Two of the original 18 species have disappearedfrom the lake, presumably in connection with the introductionof non-native eel (Anguilla anguilla) and theconstruction of a power plant in the outflow. Silt from grindedlimestone together with highly alkaline pore waters is emittedvia industrial wastewater from Sodaworks and covers part of thelake bottom. We observed that eggs of whitefish were spawnedmainly in the main inflowing river and close to the shore, thusavoiding the silty areas and making the anticipated damage tothe reproductive potential of whitefish neglectable. This wascorroborated by larval surveys done weekly on both lakes fromJanuary to May, which showed halve the density of whitefishlarvae in TS compared to HS. Estimates of potentially spawningfish from hydroacoustic surveys resulted in a ratio of 1(TS) :3 (HS). Analysis of whitefish revealed that they are growingfaster in TS and have higher fecundity leading to somecompensation of lower abundance. High levels of fishing in TSmight have led to this pattern and to depressed yields asindicated by the age composition. Level of oxidative stress andheavy metal content were not discernible from the referencelake. Therefore we concluded that negative impacts on theecological status of the fish community resulted from fisheriesmismanagement and a power plant situated in the outflow of thelake, considered to have damaged spawning places for somespecies, but not from soda industry effluents. 相似文献
108.
Gas-liquid interface measurements were conducted in a strongly turbulent free-surface flow (i.e., stepped cascade). Local void fractions, bubble count rates, bubble size distributions and gas-liquid interface areas were measured simultaneously in the air-water flow region using resistivity probes. The results highlight the air-water mass transfer potential of a stepped cascade with measured specific interface area over 650 m–1 and depth-average specific area up to 310 m–1. A comparison between single-tip and double-tip resistivity probes suggests that simple robust single-tip probes may provide accurate, although conservative, gas-liquid interfacial properties. The latter device may be used in the field and in prototype plants.
Notation
a = specific interface area (m–1); a
mean = depth-average specific interface area (m–1): a
mean=frac1Y
90limits
sup>
Y
90
sup
0(1–C)dy; C = local void fraction; C
gas = dissolved gas concentration (kg m–3); C
mean = depth-average mean air concentration defined as: C
mean=1–d/Y
90; C
s = saturation concentration (kg m–3); D = dimensionless air bubble diffusivity (defined by [1]); d = equivalent clear-water flow depth (m): d=limits
sup>
Y
90
sup
0(1–C) dy; dab = air bubble diameter (m); dc = critical flow depth (m); for a rectangular channel: d
c=sqrt[3]q
w
2/g; F = air bubble count rate (Hz); F
max = maximum bubble count rate (Hz), often observed for C=50%; g = gravity acceleration (m s–2); h = step height (m); K
L = liquid film coefficient (m s–1); K = integration constant defined as: K=tanh
–1
sqrt0.1)+(2D)–1 [1]; L = chute length (m); N = velocity distribution exponent; ———– *Corresponding author, E-mail: h.chanson@mailbox.uq.edu.au
Q
w = water discharge (m3 s–1); q
w = water discharge per unit width m2 s–1); t = time (s); V = local velocity (m s–1); V
c = critical flow velocity (m s–1); for a rectangular channel: V
c=sqrt[3]q
w
g
V
max = maximum air-water velocity (m s–1); V
90 = characteristic air-water velocity (m s–1) where C = 90%; W = channel width (m); x = longitudinal distance (m) measured along the flow direction (i.e., parallel to the pseudo-bottom formed by the step edges); y = distance (m) normal to the pseudo-bottom formed by the step edges; Y90 = characteristic distance (m) where C=0.90; Y
98 = characteristic distance (m) where C=0.98; = slope of pseudo-bottom by the step edges; = diameter (m). 相似文献
109.
Hubert Baratin 《生态毒理学报》1998,20(3):30-33
处在工业发展背后的正是科学,而且人们习惯于假设纯科学的风险分析就足以使事故的频率和严重性下降到接近零的数值.这已经差不多实现了.但是,社会仍然认为剩余的风险不是太高.因此,需要考虑可以从最近和不久前发生的事故和准事故中提取的反馈数据的实体.信息技术和通讯的发展,国际合作的普及以及公益意识的提高,已经使得有可能编制和不断更新有关工业事故的数据库.本文叙述了法国ARIA数据库及其应用. 相似文献
110.