全文获取类型
收费全文 | 2304篇 |
免费 | 23篇 |
国内免费 | 35篇 |
专业分类
安全科学 | 88篇 |
废物处理 | 173篇 |
环保管理 | 201篇 |
综合类 | 331篇 |
基础理论 | 399篇 |
污染及防治 | 778篇 |
评价与监测 | 233篇 |
社会与环境 | 148篇 |
灾害及防治 | 11篇 |
出版年
2024年 | 2篇 |
2023年 | 38篇 |
2022年 | 87篇 |
2021年 | 95篇 |
2020年 | 44篇 |
2019年 | 37篇 |
2018年 | 93篇 |
2017年 | 88篇 |
2016年 | 136篇 |
2015年 | 74篇 |
2014年 | 128篇 |
2013年 | 228篇 |
2012年 | 162篇 |
2011年 | 176篇 |
2010年 | 119篇 |
2009年 | 100篇 |
2008年 | 137篇 |
2007年 | 124篇 |
2006年 | 116篇 |
2005年 | 95篇 |
2004年 | 76篇 |
2003年 | 45篇 |
2002年 | 39篇 |
2001年 | 14篇 |
2000年 | 7篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1979年 | 2篇 |
1966年 | 2篇 |
1962年 | 2篇 |
1961年 | 2篇 |
1960年 | 2篇 |
1959年 | 2篇 |
1953年 | 2篇 |
1929年 | 1篇 |
1928年 | 2篇 |
排序方式: 共有2362条查询结果,搜索用时 15 毫秒
941.
Diogo Rúben Neves Sara Rodrigues Concei??o Juana Fortes Maria Teresa Reis Jo?o Alfredo Santos Rui Capit?o 《Journal of Coastal Conservation》2012,16(4):489-501
This paper describes a first approach on the risk assessment in port navigation using GUIOMAR, an integrated system for port and coastal engineering modelling developed at the National Civil Engineering Laboratory (LNEC), Portugal, using a GIS software environment. A set of automatic procedures was designed to include a new methodology based on the amplitude of the wave-induced vertical movement of a ship along its trajectory. In this methodology, the risk in port navigation is assessed on the basis of a combination of the probability of exceedance of a pre-set threshold for the ship??s vertical movements and its consequences. To test the new procedures, a set of sea wave records obtained at the Sines wave-buoy from 1988 to 2002 was transferred into Sines Port using two numerical models of sea wave propagation and deformation (SWAN and DREAMS), included in the GUIOMAR system. The numerical model WAMIT was used for estimating the wave-induced ship??s vertical movements inside the port. By applying the new procedures, automatic generation of risk maps was carried out for navigation in the vicinity of the West breakwater of the Port of Sines. The recent developments contribute towards a more versatile and efficient GUIOMAR system, which results in a more adequate tool to support decision-making processes in port and coastal management. 相似文献
942.
Hipólito Amanda Caretta Talita de Oliveira Silveira Victória Akemi Itakura Bersaneti Gabrielly Terassi Mali Suzana Celligoi Maria Antonia Pedrine Colabone 《Journal of Polymers and the Environment》2021,29(10):3199-3209
Journal of Polymers and the Environment - Sophorolipids are glycolipid biosurfactants produced by the yeast Starmerella bombicola. They have great potential for application in the food industry due... 相似文献
943.
Maria Grazia Gnoni Gianni Lettera 《Journal of Loss Prevention in the Process Industries》2012,25(3):609-616
A close relationship between near-miss events and major accidents has been demonstrated in major hazard facilities: a near-miss and an accident have often common causes. A near-miss could be defined as a hazardous condition where the event sequence could lead to an accident if it had not been interrupted. An effective Near-miss Management System (NMS) aims to quickly recognize signals from the operational fields in order to apply prevention strategies. As a standard reference model has not yet been developed, the NMS design represents a complex issue. The present paper proposes a critical comparison between two methodologies which could be applied for a near-miss event assessment: a matrix and an index based method. The purpose is to evaluate potentiality and pitfalls of their application as their global efficiency could influence the whole performance of the whole NMS design. An application in a test case of a chemical plant is proposed: results obtained have proved useful in supporting safety management in an effective design of a NMS. 相似文献
944.
微型、小型和中型企业创造了巴西的主要财富.但是这些企业却难以遵守环境法律.在这种情况下,清洁生产意义重大;它使得应用简便、廉价、持续的解决方案帮助小企业减少其环境影响、降低雇员的健康和安全风险成为可能.清洁生产战略通过把中心放在减少浪费和损耗上而改善环境条件.在实施清洁生产措施的同时,对一些措施的环境效率和经济可行性进行评估.采用最多的是良好的内务管理等简便措施.良好的内务管理包括业务参数的最优化、程序的标准化、改进买卖系统以及维护、信息和培训程序的最优化.巴西良好的内务管理战略所占的优势表明了对低成本解决方案的优先选择. 相似文献
945.
Within a species, ontogenetic and genetic variation in defensive chemistry can provide the basis for natural selection from
different predator types. The osmeterial chemistry of fifth (last) instar Papilio glaucus caterpillars is known to differ qualitatively from the composition of early instar caterpillars. However, the osmeterial
chemistry of early instar caterpillars has not been thoroughly characterized and may change as the caterpillars undergo their
first three molts. We have used GC/MS to identify a suite of about 50 different terpene compounds in the osmeterial secretions
of P. glaucus caterpillars, and found the relative amounts of these compounds changed significantly with each molt. These quantitative
changes preceded the more dramatic qualitative switch to the production of 2-methylbutyric and isobutyric acids after the
molt to the fifth instar. We also examined the effects of diet and genetic background on the relative quantities of 15 terpenes
present in the secretions of third instar caterpillars. Parentage was found to affect the percentages of many more of the
individual components than did diet, although both exerted an effect. The ontogenetic and genetic variations in the composition
of the osmeterial secretions appear to have an effect on would-be predators. In the laboratory, terpene secretion was found
to discourage attack by ants, whereas the switch from terpene to acid production rendered the caterpillars less palatable
to a larger predator, the green anole. In the field, the presence of functional osmeteria did not seem to dramatically increase
survival in a field study, and only a small, non-significant advantage was seen. Similarly, field data was suggestive that
parentage might affect the likelihood of survival in a natural setting, but the stage of the caterpillar and the field site
significantly affected survivorship. Further studies with greater replicates will be needed to determine whether and to what
extent chemical differences in osmeterial components as well as behavior contribute to differences in outcomes in the field. 相似文献
946.
Marcel Clusa Carlos Carreras Marta Pascual Stephen J. Gaughran Susanna Piovano Cristina Giacoma Gloria Fernández Yaniv Levy Jesús Tomás Juan Antonio Raga Fulvio Maffucci Sandra Hochscheid Alex Aguilar Luis Cardona 《Marine Biology》2014,161(3):509-519
Loggerhead turtles nesting in the Mediterranean Sea exhibit remarkable genetic structuring. This paper tests the hypothesis that young loggerhead turtles from different rookeries do not distribute homogeneously among the major Mediterranean foraging grounds, due to a complex pattern of surface currents. We extracted long fragments of mitochondrial DNA from 275 stranded or bycaught juvenile turtles from six foraging grounds (Catalano-Balearic Sea, Algerian basin, Tyrrhenian Sea, Adriatic Sea, northern Ionian Sea and southern Levantine Sea). We used a Bayesian mixed-stock analysis to estimate the contributions from rookeries in the Mediterranean, the North-west Atlantic and Cape Verde to the studied foraging grounds. Differences were found in the relative contribution of juvenile turtles of Atlantic and Mediterranean origin to each foraging ground. A decreasing proportion of Atlantic juveniles was detected along the main surface current entering the Mediterranean, with a high prevalence of turtles from eastern Florida in the Algerian basin and lower numbers elsewhere. In regard to the turtles of Mediterranean origin, juveniles from Libya prevailed in central and western Mediterranean foraging grounds other than the Algerian basin. Conversely, the Adriatic Sea was characterised by a large presence of individuals from western Greece, while the southern Levantine Sea was inhabited by a heterogeneous mix of turtles from the eastern Mediterranean rookeries (Turkey, Lebanon and Israel). Overall, the distribution of juveniles may be related to surface circulation patterns in the Mediterranean and suggests that fisheries might have differential effects on each population depending on the overlap degree between foraging and fishing grounds. 相似文献
947.
Maria D. Kamitsou Varvara Sygouni Dimitra G. Kanellopoulou Konstantinos Gardikis Petros G. Koutsoukos 《Environmental geochemistry and health》2018,40(4):1449-1464
Clays and muds have been used for centuries as cosmetics or pharmaceutical products for various therapies. The suitability of muds and clays for health- and beauty-related applications depends on their physicochemical properties, mineralogical composition, particle characteristics and toxicity. In this work, the physicochemical characterization of 12 mud specimens from different natural spa resorts in Greece and one from Israel (Dead Sea) is presented. All specimens were sterilized at 121 °C for 20 min, because of their intended use. The Greek mud specimens were collected from various locations in Macedonia, Western Greece and Northeast Aegean. All muds were characterized concerning their mineralogical, chemical components as well as their morphological characteristics using appropriate methods [powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), nitrogen absorption specific surface area measurements (BET), scanning electron microscopy and energy dispersive X-ray spectroscopy]. The concentrations of F?, Cl?, NO3? and SO42? anions at equilibrium with the mud specimens were measured by ion chromatography. Total calcium concentration was measured using atomic absorption spectroscopy, and the concentration of total N, C, H and S in the solids was measured using elemental analysis. Moreover, total phenolic concentration (TPC) in distilled water equilibrated with the mud specimens was measured as an index for their antioxidant properties. Several muds were found to present high TPC. Several of the examined mud specimens were found to have the potential use as pharmaceuticals or cosmetics. Based on the physicochemical characteristics of the mud specimens examined, possible improvement in their use and applicability has been suggested. 相似文献
948.
Maria Byrne Natalie A. Soars Melanie A. Ho Eunice Wong David McElroy Paulina Selvakumaraswamy Symon A. Dworjanyn Andrew R. Davis 《Marine Biology》2010,157(9):2061-2069
Climate change driven ocean acidification and hypercapnia may have a negative impact on fertilization in marine organisms
because of the narcotic effect these stressors exert on sperm. In contrast, warmer, less viscous water may have a positive
influence on sperm swimming speed and so ocean warming may enhance fertilization. To address questions on future vulnerabilities
we examined the interactive effects of near-future ocean warming and ocean acidification/hypercapnia on fertilization in intertidal
and shallow subtidal echinoids (Heliocidaris erythrogramma, H. tuberculata, Tripneustes gratilla, Centrostephanus rodgersii), an asteroid (Patiriella regularis) and an abalone (Haliotis coccoradiata). Batches of eggs from multiple females were fertilized by sperm from multiple males in all combinations of three temperature
and three
\textpH/P\textCO2 {\text{pH}}/P_{{{\text{CO}}_{2} }} treatments. Experiments were placed in the setting of projected near-future conditions for southeast Australia, an ocean
change hot spot. There was no significant effect of warming and acidification on the percentage of fertilization. These results
indicate that fertilization in these species is robust to temperature and
\textpH/P\textCO2 {\text{pH}}/P_{{{\text{CO}}_{2} }} fluctuation. This may reflect adaptation to the marked fluctuation in temperature and pH that characterises their shallow
water coastal habitats. Efforts to identify potential impacts of ocean change to the life histories of coastal marine invertebrates
are best to focus on more vulnerable embryonic and larval stages because of their long time in the water column where seawater
chemistry and temperature have a major impact on development. 相似文献
949.
Pacific lion-paw scallops were collected from natural aggregations in Laguna Ojo de Liebre (Pacific Ocean), the Gulf of California,
and from aquaculture facilities for genetic diversity analyses. Mitochondrial DNA sequencing uncovered two highly supported
clades separated by 2.5% divergence. Data from ten microsatellite markers suggest individuals from these mitogroups are introgressed,
raising questions about the mitotype origin. Some evidence suggests gene flow between La Paz and Ojo de Liebre; otherwise
the Gulf of California and Ojo de Liebre are acting as two distinct populations. It is unclear whether translocations between
sites have influenced the observed genetic structure or whether gene flow has been facilitated by past geologic events. Finally,
scallops spawned for aquaculture are unique from the wild and have significantly less diversity. These results warrant the
attention of managers and producers who should work to monitor and conserve genetic diversity in both wild and aquaculture
populations. 相似文献
950.
Kurt Paschke Juan Pablo Cumillaf Sergio Loyola Paulina Gebauer Mauricio Urbina María Eugenia Chimal Cristina Pascual Carlos Rosas 《Marine Biology》2010,157(1):7-18
Episodes of hypoxia are common in the marine environment, and their ecological effects depend, in part, on their severity
and duration. Many species of decapod crustaceans reside in areas with fluctuating oxygen regimens. Physiological mechanisms
enhance the ability of these crustaceans to cope with acute episodes of hypoxia. Southern king crab, Lithodes santolla, fishery is important in the south of South America, and some data describe fishing zones with low dissolved oxygen (DO) levels
(3.5 mgO2 l−1, i.e., 8.3 kPa). Our main objective was to evaluate the effect of dissolved oxygen level on respiratory metabolism, nutritional
physiology, and immunological condition of L. santolla juveniles. Individual animals were exposed for 10 days to different oxygen tensions (2.1, 4.2, 8.5, 12.7, and 21.1 kPa) to
quantify the oxygen consumption rate; thereafter, blood oxyhemocyanin (Hc), protein concentration, as well as hemocytes, were
sampled. Freeze-dried animals were dissected, and digestive gland metabolites (glycogen, protein, glucose, cholesterol, acylglycerol,
and lactate) and digestive enzyme activity (general protease, trypsin, and chymotrypsin), as well as gill lactate dehydrogenase
(LDH) activity, were quantified. In the present study, Lithodes santolla showed a critical oxygen tension between 4 and 9 kPa, indicating that this crab species is more sensitive to DO than other
crustacean species. Protein and Hc concentrations followed a similar pattern to that of oxygen consumption. Digestive gland
glycogen and protein concentration did not change after 10 days at different oxygen exposures, but glucose, cholesterol, and
acylglycerol concentrations decreased linearly and proportionally to the available oxygen in the water. As in other decapods,
chymotrypsin showed over 90% of the total quantified proteases activity. Chymotrypsin activity together with total proteases
and trypsin was not affected by the environmental oxygen tension. Gill LDH and digestive gland lactate followed a similar
increase at lower environmental oxygen tension but dropped sharply at the lowest tension (2.1 kPa). Dissolved oxygen affected
also the immune system through reduction of hemocytes. This could provide a critical window for opportunistic pathogens to
become established when crabs are exposed to hypoxic conditions. L. santolla juveniles show a moderate tolerance to low oxygen availability by modifying the concentration of hemolymph proteins, mainly
OxyHc, some digestive gland metabolites, and by activating the anaerobic metabolism. This allows L. santolla juveniles to inhabit temporarily low oxygen zones in the deep ocean and suggests an advantage for culture conditions. 相似文献