全文获取类型
收费全文 | 536篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 16篇 |
废物处理 | 15篇 |
环保管理 | 63篇 |
综合类 | 294篇 |
基础理论 | 48篇 |
污染及防治 | 82篇 |
评价与监测 | 16篇 |
社会与环境 | 8篇 |
出版年
2018年 | 6篇 |
2017年 | 7篇 |
2015年 | 15篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 9篇 |
2011年 | 14篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1995年 | 7篇 |
1984年 | 5篇 |
1982年 | 4篇 |
1967年 | 7篇 |
1966年 | 6篇 |
1965年 | 5篇 |
1963年 | 9篇 |
1962年 | 4篇 |
1961年 | 7篇 |
1959年 | 6篇 |
1958年 | 8篇 |
1957年 | 5篇 |
1956年 | 10篇 |
1955年 | 12篇 |
1954年 | 10篇 |
1947年 | 4篇 |
1942年 | 4篇 |
1939年 | 10篇 |
1938年 | 8篇 |
1937年 | 5篇 |
1936年 | 4篇 |
1934年 | 4篇 |
1933年 | 6篇 |
1932年 | 6篇 |
1929年 | 5篇 |
1928年 | 4篇 |
1927年 | 4篇 |
1926年 | 5篇 |
1925年 | 4篇 |
1914年 | 5篇 |
1913年 | 4篇 |
排序方式: 共有542条查询结果,搜索用时 15 毫秒
441.
Karl F. Nordstrom Ulrike Gamper Giorgio Fontolan Annelore Bezzi Nancy L. Jackson 《Environmental management》2009,44(6):1121-1135
Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments
will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to
projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes
in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation
on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after
beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available
for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation.
Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally
functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they
interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding
shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required
if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush. 相似文献
442.
/ Since 1975, the European Union (EU) has developed an impressive body of waste management legislation, although, according to the principle of subsidiarity, responsibilities belong to the most local level at which the tasks can be carried out effectively. Using economic theory, this paper examines several factors that influence the efficient distribution of regulatory authority among the EU and the member states. We specifically analyze the role of harmonization that, in our opinion, will often lead to an overcentralization. Within this context, a second issue is becoming more important, as ongoing discussions show. If no consensus can be reached about harmonization, should member states be allowed to stop cross-border shipments of waste, or should the EU strive for a common market for waste? We take the position that most objections against waste shipments are not convincing, especially if the member states implement minimum standards for landfills and waste processing facilities and common information and control systems. Competition between different national regulations within adequate constraints that, e.g., control transboundary externalities leads to more efficient waste management structures in Europe than national self-sufficiency or centralized decision-making at the EU level. KEY WORDS: Waste management; European Union; Subsidiarity; Institutional competition; Harmonization; Cross-border shipments of waste 相似文献
443.
444.
Some flame retardants and the antimicrobials triclosan and triclocarban enhance the androgenic activity in vitro 总被引:1,自引:0,他引:1
Contaminants including flame retardants, antimicrobial agents and phthalates, occurring as residues in human tissues were associated with altered endocrine function. In our study we analysed the flame retardants tetrabromobisphenol A (TBBPA), hexabromocyclodecane (HBCD), penta-bromodiphenylether (BDE-100) and hexa-BDE (BDE-155), the antimicrobial compounds triclosan (TCS) and triclocarban (TCC) and eight phthalates for their androgenic and antiandrogenic activity in vitro in the MDA-kb2 cell line. No or only weak androgenic activity was observed for all the tested compounds. TBBPA showed weak antiandrogenic activity, which was demonstrated for the first time. The flame retardants HBCD, BDE-100 and BDE-155 enhanced the dihydrotestosterone-dependent activation of androgen receptor-responsive gene expression but exhibited little or no agonistic activity. The enhancement reached 150%, which was similar to the antimicrobials (TCS up to 180%, and TCC up to 130%). This enhancement of androgenic activity represents a novel mode of action of the endocrine activity of flame retardants. In contrast, most phthalates showed antiandrogenic activity. Butylbenzyl phthalate (BBP), dibutyl phthalate (DBP) and diethyl phthalate (DEP) showed strong antiandrogenicity, whereas the action of diethylhexyl phthalate (DEHP), dipentyl phthalate (DPP), dimethyl phthalate (DMP), and the DEHP metabolite monoethylhexyl phthalate (MEHP) was lower. Our in vitro study demonstrates for the first time a weak antiandrogenic activity of TBBPA, and a significant enhancement of the androgenic activity of HBCD, BDE-100 and BDE-155, which represents a novel mechanism of hormonal activity of flame retardants. 相似文献
445.
Dilution-based emissions sampling from stationary sources: Part 1--Compact sampler methodology and performance 总被引:4,自引:0,他引:4
England GC Watson JG Chow JC Zielinska B Chang MC Loos KR Hidy GM 《Journal of the Air & Waste Management Association (1995)》2007,57(1):65-78
This paper presents the design and performance of a compact dilution sampler (CDS) for characterizing fine particle emissions from stationary sources. The sampler is described, along with the methodology adopted for its use. Dilution sampling has a number of advantages, including source emissions that are measured under conditions simulating stack gas entry and mixing in the ambient atmosphere. This is particularly important for characterizing the semivolatile species in effluents as a part of particulate emissions. The CDS characteristics and performance are given, along with sampling methodology. The CDS was compared with a reference dilution sampler. The results indicate that the two designs are comparable for tests on gas-fired units and a diesel electrical generator. The performance data indicate that lower detection limits can be achieved relative to current regulatory methods for particulate emissions. Test data for the fine particulate matter (PM2.5) emissions are provided for comparison with U.S. Environment Protection Agency (EPA) Conditional Test Method 040 for filterable particulate matter (FPM) and the EPA Method 202 for condensable particulate matter. This comparison showed important differences between methods, depending on whether a comparison is done between in situ FPM determinations or the sum of such values with condensable PM from liquid filled impingers chilled in an ice bath. These differences are interpretable in the light of semivolatile material present in the stack effluent and, in some cases, differences in detection and quantification limits. Determination of emissions from combustors using liquid fuels can be readily achieved using 1-hr sampling with the CDS. Emissions from gasfired combustors are very low, requiring careful attention to sample volumes. Sampling volumes corresponding with 6-hr operation were used for the combined mass and broad chemical speciation. Particular attention to dilution sampler operation with clean dilution air also is essential for gas-fired sources. 相似文献
446.
Niu J Chen J Martens D Quan X Yang F Kettrup A Schramm KW 《Environmental pollution (Barking, Essex : 1987)》2003,123(1):39-45
Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment. 相似文献
447.
Beat Meyer Karl Hermanns 《Journal of the Air & Waste Management Association (1995)》2013,63(8):816-821
Urea-formaldehyde resin bonded partlcleboard, medium density fiberboard and plywood paneling are used as flooring, wall paneling, for cabinet work and in furniture, and are present In almost every office, home and public building. If large quantities of these products are used In poorly ventilated spaces, high manufacturing quality control is necessary to avoid problems of latent formaldehyde release. Indoor air formaldehyde concentrations depend on the nature of the product, the product surface to air volume (loading) factor, temperature, humidity, age and product emission rates. Standard test methods are now available for measuring product emission rates that make It possible to predict the performance of UF-bonded pressed wood materials If use conditions and environmental parameters are known. Recent modifications In adhesive and board manufacturing parameters have made It possible to reduce formaldehyde emission significantly, and UF-bonded wood products are now capable of meeting indoor air quality standard levels of 0.1 ppm under almost all customary loading conditions. 相似文献
448.
Lutz W.D. Weber Bernhard U. Stahl Margitta Lebofsky Richard H. Alper Laszlo Kerecsen Karl Rozman 《Chemosphere》1991,23(11-12)
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exerts its acute toxicity by inducing a gradually increasing voluntary feed refusal. However, this seems not to be caused by a direct effect on the central nervous system, as far higher concentrations of TCDD were found in the brain after intracerebroventricular (i.c.v.) than after lethal intravenous (i.v.) injections, but were not accompanied by a wasting syndrome. TCDD causes inhibition of several key enzymes of gluconeogenesis, with phosphoenolpyruvate carboxykinase (PEPCK) responding earliest and strongest to the insult. Responses of pyruvate carboxylase (PC) and glucose-6-phosphatase (G-6-Pase) are less pronounced and begin at later time points. Blood and brain levels of tryptophan increase following TCDD treatment with a lag period of about three days, shortly after the decrease of PEPCK activity becomes apparent. Since thi samino acid is the precursor of the appetite suppressant neurotransmitter serotonin, and since it is normally degraded via gluconeogenesis, a series of events can be suggested to explain the TCDD-induced wasting syndrome. By an as yet unrevealed mechanism TCDD decreases the activity of PEPCK to about 40 percent of normal, leading to a back-up of gluconeogenic substrates, among them tryptophan, which in turn can further inhibit PEPCK activity in vivo. This causes an increase in serotonin turnover in brain and possibly in other tissues. Increased serotonergic activity in turn is likely to play an important role in the increasing feed refusal of TCDD-treated rats which eventually leads to death. 相似文献
449.
450.
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs), including 2378-substituted isomers were present in samples of shellfish and fish, and ambient air collected from Masan Bay, and Masan City, South Korea. Total concentrations of PCDDs/DFs in mussel and clam were 750 pg g(-1), lipid weight (lw), and 3418 pg g(-1), lw, respectively. Total concentrations of PCDDs/DFs in mullet, gizzard and flounder were 52, 82, and 122 pg g(-1), lw, respectively. Shellfish tissues contained a greater number of PCDD/DF isomers, contributing greater total concentrations of PCDDs/DFs compared to fish collected from the same locations. The predominance of 2378-substituted PCDDs/DFs in fish is represented in greater total concentrations of 2378-TeCDD equivalents (TEQs), whereas there was very limited occurrence of 2378-substituted isomers in shellfish. TEQ concentrations in samples of mussel and clam were 0.97 and 12 pg g(-1), lw, respectively. Total TEQs in mullet, gizzard and flounder were 12, 22 and 18 pg g(-1), lw, respectively. In fish 2378-substituted PCDDs accounted for 100% of the total concentrations of PCDDs, and 2378-substituted PCDFs accounted from 59% to 73% of the total PCDFs. The 2378-substituted isomers accounted for only 3% of the total PCDDs/DFs in shellfish. Ambient air collected from two sites contained a wide range of isomers of tetra- through heptachlorinated PCDDs/DFs. Even though the total concentration of PCDDs/DFs in ambient air (12.8 pgm(-3)) collected from an industrial area was 2-fold greater than that in air samples (6.3 pgm(-3)) collected from an urban/rural area, total TEQs (0.07 and 0.08 pgm(-3)) there was no statistical difference between the two samples. 相似文献