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141.
Examining the impacts of disaster resettlement from a livelihood perspective: a case study of Qinling Mountains,China
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Disaster resettlement, as a mitigation and preparedness measure, entails significant economic, physical, and social impacts, which continue to challenge understanding of recovery from major events, especially regarding the extent of the context and environmental efforts to rebuild livelihoods. Based on a case study of Qinling Mountains, China, this research investigates the effects of disaster resettlement from a livelihoods perspective. Methodologically, it proposes a framework that combines the pressure–state–response framework and the sustainable livelihoods approach, and it employs a structural equation model to examine how specific factors affect disaster resettlement. The results indicate that conflicts may occur during and after resettlement owing to the difference or disparity between the concerns of resettled peasants and those of the government. Consequently, the risks related to livelihoods need to be taken seriously. Effective risk communication is critical to bridge the gap between different stakeholders. The paper concludes with some practical and policy recommendations. 相似文献
142.
Smallholder Agroforestry Systems For Carbon Storage 总被引:3,自引:0,他引:3
James M. Roshetko Rodel D. Lasco Marian S. Delos Angeles 《Mitigation and Adaptation Strategies for Global Change》2007,12(2):219-242
Most smallholder agroforestry systems in Southeast Asia are tree- and species-rich systems producing non-wood and wood products
for both home use and market sale. Due to their high biomass, these systems contain large carbon (C) stocks. While the systems
of individual farmers are of limited size, on a per area basis smallholder systems accumulate significant amounts of C, equaling
the amount of C stored in some secondary forests of similar age. Their ability to simultaneously address smallholders’ livelihood
needs and store large amounts of C makes smallholder systems viable project types under the Clean Development Mechanism (CDM)
of the Kyoto Protocol, with its dual objective of emissions reduction and sustainable development. Smallholder systems have
not developed in areas where enabling conditions do not exist. A CDM project that facilitates a minimum threshold of enabling
conditions that make smallholder agroforestation possible should qualify for C credits. To secure smallholder confidence,
the agroforestry systems promoted through a CDM project must be socially and economically viable independent of C payments.
To assure system productivity and profitability, projects should provide farmers with technical and marketing assistance.
Additionally, project sites should meet the following preconditions: areas of underutilized low-biomass landuse systems available
for rehabilitation; smallholders interested in tree farming; accessible markets for tree products; supportive local governments;
sufficient infrastructure; and transparent and equitable relationships between project partners. Questions of leakage and
additionality should not be problematic and can be addressed through the project design, establishment of quantifiable baseline
data and facilitating enabling conditions. However, smallholder-focused CDM projects would have high transaction costs. The
subsequent challenge is thus to develop mechanisms that reduce the costs of: (a) making information (e.g., technology, markets)
more accessible to multiple clients; (b) facilitating and enforcing smallholder agreements and (c) designing feasible monitoring
systems. 相似文献
143.
汽车代用燃料及应用前景 总被引:4,自引:0,他引:4
介绍了已经开发使用的代用燃料氢气,甲醇,乙醇,新配方汽油,天然气,液化石油气,电动汽车等,并对代用燃料车和汽油车的环境安全性,成本,能耗消耗等方面作了比较,指出天然气,液化石油气是当前最有前途的代用燃料。 相似文献
144.
Population frequencies of alternative male phenotypes in tree lizards: geographic variation and common-garden rearing studies 总被引:2,自引:0,他引:2
Diana K. Hews Christopher W. Thompson Ignacio T. Moore Michael C. Moore 《Behavioral ecology and sociobiology》1997,41(6):371-380
Tree lizards (Urosaurus ornatus) vary in throat fan (dewlap) color. Earlier, we described five dewlap types (Orange, Orange-Blue, Yellow, Yellow-Blue, and
Blue), and reported that only males had blue in the dewlap and that presence or absence of a discrete blue patch was correlated
with male alternative reproductive phenotypes in a central Arizona population. Here, with a modified scheme characterizing
two dewlap elements, background color (orange, yellow, blue) and blue patch occurrence, we assessed: (1) sexual, annual, and
geographic variation in the frequencies of dewlap elements; (2) simple habitat correlates; and (3) the effects of laboratory
rearing regime on dewlap type. Within a population, frequencies of males and females expressing orange or yellow backgrounds
did not differ, suggesting that control of background is similar in the sexes. Within several populations, frequencies of
the dewlap elements did not differ across years (and probably generations), indicating that phenotype frequencies are relatively
stable. Among five populations frequencies of background colors varied, as did frequencies of male types (blue patch present
or absent). Dewlap frequencies did not correlate with habitat (boulders or mesquite trees), although few populations were
sampled. In male and female offspring reared from eggs to sexual maturity in a common-garden laboratory study, background
color frequencies in both sexes and blue patch frequencies in males differed among offspring from different populations. Offspring
frequencies matched respective parental population frequencies. Results suggest that among-population variation in frequencies
of the two dewlap elements are mediated by differences in genetics, in maternal effects, or both. Thus, differences in male
behavior functionally linked to the blue patch also may be controlled by genetic or maternal effects.
Received: 17 January 1997 / Accepted after revision: 30 August 1997 相似文献
145.
Yoshihito Hongo 《Behavioral ecology and sociobiology》2007,62(2):245-253
I conducted a detailed morphological analysis of the Japanese horned beetle Trypoxylus dichotomus septentrionalis to clarify the allometric relationship between horn length and body size and examined its mating success and reproductive
behaviour in the field. The relationship between horn and body size was not discontinuous at the switch point body size, but
the slope of the linear relationship changed at the switch point. Shape of the allometric relationship was initially steep
and became flatten around the switch point in both linear and log scales; that is, minor males showed a positive relationship
and major males showed a negative one. Major males gained more mating success than minor males. Within major males, individuals
with larger horn or body size had higher mating success than individuals with smaller ones. Within minor males there were
no differences in horn and body size between mated and unmated individuals. Although sneak-like behaviours were exhibited
by both morphs, it is likely that these behaviours rarely lead to direct benefit. These results suggest that dimorphic allometry
of T. dichotomus is consistent with the hypothesis of a continuous reaction norm that meets a ceiling, which restrains further allometric
growth. 相似文献
146.
Alternative reproductive tactics and male-dimorphism in the horned beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae) 总被引:6,自引:0,他引:6
Douglas J. Emlen 《Behavioral ecology and sociobiology》1997,41(5):335-341
Adult dung beetles (Onthophagus acuminatus) exhibit continuous variation in body size resulting from differential nutritional conditions experienced during larval development.
Males of this species have a pair of horns that protrude from the base of the head, and the lengths of these horns are bimodally
distributed in natural populations. Males growing larger than a threshold body size develop long horns, and males that do
not achieve this size grow only rudimentary horns or no horns at all. Previous studies of other horned beetle species have
shown that horned and hornless males often have different types of reproductive behavior. Here I describe the mating behaviors
of the two male morphs of O. acuminatus during encounters with females. Females excavate tunnels beneath dung, where they feed, mate and provision eggs. Large, horned
males were found to guard entrances to tunnels containing females. These males fought with all other males that attempted
to enter these tunnels. In contrast, small, hornless males encountered females by sneaking into tunnels guarded by other males.
In many instances, this was accomplished by digging new tunnels that intercepted the guarded tunnels below ground. Side-tunneling
behavior allowed sneaking males to enter tunnels beneath the guarding male, and mate with females undetected. Both overall
body size and relative horn length significantly affected the outcome of fights over tunnel ownership. These results suggest
that alternative reproductive tactics may favor divergence in male horn morphology, with long horns favored in males large
enough to guard tunnels, and hornlessness favored in smaller males that adopt the “sneaking” behavioral alternative.
Received: 12 October 1996 / Accepted after revision: 8 August 1997 相似文献
147.
Organic synthesis is usually performed in solution to dissolve both reactants and catalysts and to deliver heat. Here, we
show that glycerol, which is a non-toxic, biodegradable, and recyclable liquid manufactured from renewable sources, has a
high potential to serve as alternative green solvent for organic reactions. Several catalytic and non-catalytic reactions
were successfully performed in glycerol. High products yields and selectivities were achieved. Besides solubility of the reactants
and the catalysts and easy separation of the product, glycerol offers several other benefits such as catalyst recycling, microwave
assisting reaction, and biphasic and emulsion modes. 相似文献
148.
Sperm traits often show extreme variation both between and within species. Between-species variation may often be interpreted
in the context of a sperm competition theory, but within-species variation has remained unexplained. Previous studies on intraspecific
variation in sperm traits have focused on a limited set of variables and may have failed to explain observed variation because
of potential trade-offs between different sperm traits. We report on variation in number, size, motility and longevity of
sperm in the frog Crinia georgiana, a species where sperm competition is common. We found intrapopulation variation in sperm size and motility and interpopulation
variation in relative sperm number and size. When we combined relative sperm number and size into one variable, and motility
and longevity into another, we found significant interpopulation variation in these variables as well. We also detected considerable
intra- and significant interpopulation variation in cumulative sperm quality, a combination of all four sperm traits. Furthermore,
a significant effect of the interaction between population origin and male size on sperm characteristics indicated interpopulation
variation in the strength of selection acting on sperm traits of males adopting different mating strategies. We discuss heterogeneity
in the reproductive environment, a complex genetic background in the determination of sperm characteristics and varying levels
of developmental noise as potential contributors to the observed variation in sperm traits. 相似文献
149.
A. M. Starik A. M. Savel’ev O. N. Favorskii N. S. Titova 《International Journal of Green Energy》2018,15(3):161-168
The paper concerns the comparative analysis of combustion characteristics of different alternative fuels such as Fischer-Tropsch Synthetic Paraffinic Kerosene (FT-SPK), cryogenic methane, bioethanol, biomethanol, biobutanol, dimethyl ether, biodiesel and conventional aviation kerosene Jet-A as well as analysis of emissions of NOx, CO, CO2, H2O, HNOy (y = 2,3) and organics for gas turbine engine operating on these fuels. The analysis has shown that the usage of all considered alternative fuels results in the increase of H2O emission, compared to kerosene-fueled combustor, and, as consequence, in the growth of water vapor supersaturation that can increase the rate of the H2O vapor condensation and enhance the formation of contrails and cirrus clouds in the atmosphere. The usage of all considered alternative fuels except FT-SPK, cryogenic methane and dimethyl can increase the CO2 emission compared to using of kerosene. Emission of N-containing species can be reduced upon the usage of considered alternative fuels, except dimethyl ether, for which one can expect the increase in the emissions of HNO2 and HNO3 approximately by 10%. The emission of CO decreases for all fuels except biodiesel. The major decrease can be achieved upon the replacement of kerosene to bioethanol. 相似文献
150.
The October 2005 earthquake in northern Pakistan severely affected the livelihoods of 1.5 million people. With the destruction of material assets and communications infrastructure, the quake had a devastating impact on people's way of life in this remote mountainous region. This paper explores livelihood revival interventions undertaken during the earthquake response, and considers how differentiated livelihood outcomes were achieved. In addressing this objective the paper examines livelihood rehabilitation schemes in terms of structural aspects, working strategies, key factors, strengths of interventions and the role of human agency in influencing livelihood trajectories of quake‐affected communities. Primary data for this study was gathered in northern Pakistan between October 2008 and January 2009. The study identifies structural shortcomings and strengths of the programmes attempting to revive the livelihoods of poor and vulnerable households. It identifies how households in two villages made the most of opportunities to improve their lives and move towards favourable outcomes. 相似文献