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331.
332.
总结了绿色建材的基本概念与评价方法,介绍了绿色混凝土、绿色墙体材料、绿色涂料、相变储能建筑材料,认为绿色建材和绿色建筑技术将成为未来建筑行业的主要研究方向之一,今后我国绿色建材发展的主要前提首先是提高政府、设计人员的环保意识,其次要健全评价体系。 相似文献
333.
Seidel B Alm M Peters R Kördel W Schäffer A 《Environmental science and pollution research international》2006,13(2):125-130
Background Due to the bovine spongiform encephalopathy (BSE), specified risk material (SRM) as well as animal meat and bone meal (MBM)
are banned from the food and feed chain because of a possible infection with pathogenic prions (PrPSc). Nowadays, prions are
widely accepted to be responsible for TSE(transmissible spongiform encephalopathies)-caused illnesses like BSE and scrapie,
and especially for the occurrence of the new variant of CJD in humans. Presently, SRM and MBM are burnt under high temperatures
to avoid any hazards for humans, animals or the environment. The aim of this study was to evaluate a method using animal fat
separated from Category I material which includes SRM and the carcasses of TSE-infected animals, or animals suspected of being
infected with TSE, as a source for producing biodiesel by transesterification, analogous to the biodiesel process using vegetable
oil.
Methods For this purpose, animal fat was spiked with scrapie-infected hamster brain equivalents – as representative for a TSE-infected
animal – and the biodiesel manufacturing process was downscaled and performed under lab-scale conditions.
Results and Discussion The results analysed by Western blotting showed clearly that almost each single step of the process leads to a significant
reduction of the concentration of the pathogenic prion protein (PrPSc) in the main and side-products.
Conclusion The data revealed that the biodiesel production, even from material with a high concentration of pathogenic prions, can be
considered as safe.
Recommendations and Outlook The obtained results indicated that biodiesel produced from prion-contaminated fat was safe under the tested process conditions.
However, it has to be pointed out that the results cannot be generalized because a different process control using other conditions
may lead to different results and then has to be analysed independently. It is clear that the production of biodiesel from
high risk material represents a more economic usage than the combustion of such material. 相似文献
334.
Burchard H. Heede 《Journal of the American Water Resources Association》1972,8(3):523-530
ABSTRACT The influence of a forest on the formation of steps in two small streams of the Colorado Rocky Mountains was studied. Steps provided by logs fallen across the channel added to flow energy reduction. The streams required additional gravel bars to adjust to slope. Average step length between logs and gravel bars was strongly related to channel gradient and median bed material size. Based on the average number of log steps per 50 feet of channel, an average of 116 percent of gravel bars were added at Fool Creek and 60 percent at Deadhorse Creek. The latter had 52 percent more logs in the channel and therefore required less bed material movement than the former. Although these are “rushing mountain streams,” most flow velocities ranged between 0.5 and 2.5 f.p.s. Exponents of a function relating rate of change of depth or velocity to discharge indicated that dynamic stream equilibrium was attained. Implications for forest management are that sanitation cuts (removal of dead and dying trees) would not be permissible where a stream is in dynamic equilibrium and bed material movement should be minimized. 相似文献
335.
温凤梅 《中国环境管理干部学院学报》2005,15(3):129-130
"物质的量"是国际单位制中七个基本物理量之一,其概念抽象、理论性强,学生掌握难度较大.因此,用通俗易懂的类比法探讨了"物质的量"的概念,又用类比法推出了"物质的量"的单位--摩尔,指出了摩尔的适用范围,易于学生理解和掌握,提高了学生学习化学的兴趣,提高了教学质量. 相似文献
336.
337.
A novel paper-based material containing titanium dioxide (TiO2) photocatalyst was successfully prepared by a papermaking technique with the internal addition of inorganic fibers on which TiO2 particles were supported. Photodegradation performance of acetaldehyde gas, an indoor pollutant, and the durability of the TiO2-containing papers were investigated under UV irradiation. Ceramic fiber suspension and polydiallyldimethylammonium chloride as a cationic flocculant were mixed, followed by the addition of TiO2 suspension and anionic polyacrylamide. Subsequently, the inorganic mixture was poured into a pulp suspension, and TiO2 handsheets then prepared by a papermaking method. The tensile strength of TiO2-containing paper without a ceramic carrier decreased by more than 30% after 240-h UV irradiation (2 mW/cm2), although the strength of the TiO2 sheet with ceramic fibers remained reasonably stable. The efficiency of acetaldehyde decomposition by the TiO2 paper containing an inorganic carrier was nearly equal to that of the carrier-free TiO2 paper. Scanning electron microscopic observation suggested that most TiO2 particles were predominantly supported on the inorganic fiber matrix, and were mostly out of contact with organic pulp fibers. The TiO2 paper with an inorganic carrier demonstrated both excellent photocatalytic performance and durability, which before had been mutually incompatible for organic materials containing TiO2 photocatalyst. The two-stage mixing procedure for TiO2 sheet-making is promising for the simple manufacture of high performance paper with photocatalytic ability. 相似文献
338.
Richard F. Hadley William W. Emmett 《Journal of the American Water Resources Association》1998,34(3):629-637
ABSTRACT: A flood-control dam was completed during 1979 on Bear Creek, a small tributary stream to the South Platte River in the Denver, Colorado, area. Before and after dam closure, repetitive surveys between 1977 and 1992 at five cross sections downstream of the dam documented changes in channel morphology. During this 15-year period, channel width increased slightly, but channel depth increased by more than 40 percent. Within the study reach, stream gradient decreased and median bed material sizes coarsened from sand in the pools and fine gravel on the rime to a median coarse gravel throughout the reach. The most striking visual change was from a sparse growth of streamside grasses to a dense growth of riparian woody vegetation. 相似文献
339.
磨料水射流除鳞技术在钢厂的应用 总被引:2,自引:0,他引:2
为了暴露各种钢材在热轧过程中产生的表面缺陷,需清除附于其上的氧化铁皮,称之为“除鳞”。传统的除鳞方法有酸洗、表面剥皮、喷丸处理等,这些方法存在很多缺点。本文介绍已在湖南涟钢用于生产的磨料水射流除鳞生产线,用磨料水射流除鳞具有速度快、质量高、成本低、操作简便等独特的优点。 相似文献
340.
炭黑厂焦油脱水过程中产生的尾气(苯、甲苯等苯系物)用冷却法能用效冷凝其中大量有机物,且冷却水温度愈低冷却效果愈好,当水温降至5℃左右时,尾气中的有机物基本能全部冷凝除去,冷凝油相中除苯系物外还萘,冷凝水相的BOD5/CODCR比值大于0.5,具有很好的可生化性。 相似文献