首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   121篇
  免费   3篇
  国内免费   2篇
  2021年   3篇
  2020年   2篇
  2019年   2篇
  2018年   1篇
  2017年   3篇
  2016年   1篇
  2015年   1篇
  2014年   5篇
  2013年   6篇
  2011年   13篇
  2010年   6篇
  2009年   8篇
  2008年   13篇
  2007年   5篇
  2006年   8篇
  2005年   5篇
  2004年   3篇
  2003年   7篇
  2002年   2篇
  2001年   5篇
  2000年   2篇
  1999年   3篇
  1997年   1篇
  1996年   5篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1987年   2篇
  1986年   1篇
  1984年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1973年   1篇
排序方式: 共有126条查询结果,搜索用时 31 毫秒
101.
The effect of Phanerochaete chrysosporium and Pleurotus ostreatus whole cells and their ligninolytic enzymes on models of colored industrial wastewaters was evaluated. Models of acid, direct and reactive dye wastewaters from textile industry have been defined on the basis of discharged amounts, economic relevance and representativeness of chemical structures of the contained dyes. Phanerochaete chrysosporium provided an effective decolourization of direct dye wastewater model, reaching about 45% decolourization in only 1 day of treatment, and about 90% decolourization within 7 days, whilst P. ostreatus was able to decolorize and detoxify acid dye wastewater model providing 40% decolourization in only 1 day, and 60% in 7 days. P. ostreatus growth conditions that induce laccase production (up to 130,000 U/l) were identified, and extra-cellular enzyme mixtures, with known laccase isoenzyme composition, were produced and used in wastewater models decolourization. The mixtures decolorized and detoxified the acid dye wastewater model, suggesting laccases as the main agents of wastewater decolourization by P. ostreatus. A laccase mixture was immobilized by entrapment in Cu-alginate beads, and the immobilized enzymes were shown to be effective in batch decolourization, even after 15 stepwise additions of dye for a total exposure of about 1 month.  相似文献   
102.
Background, aim, and scope  Life cycle analyses (LCA) approaches require adaptation to reflect the increasing delocalization of production to emerging countries. This work addresses this challenge by establishing a country-level, spatially explicit life cycle inventory (LCI). This study comprises three separate dimensions. The first dimension is spatial: processes and emissions are allocated to the country in which they take place and modeled to take into account local factors. Emerging economies China and India are the location of production, the consumption occurs in Germany, an Organisation for Economic Cooperation and Development country. The second dimension is the product level: we consider two distinct textile garments, a cotton T-shirt and a polyester jacket, in order to highlight potential differences in the production and use phases. The third dimension is the inventory composition: we track CO2, SO2, NO x , and particulates, four major atmospheric pollutants, as well as energy use. This third dimension enriches the analysis of the spatial differentiation (first dimension) and distinct products (second dimension). Materials and methods  We describe the textile production and use processes and define a functional unit for a garment. We then model important processes using a hierarchy of preferential data sources. We place special emphasis on the modeling of the principal local energy processes: electricity and transport in emerging countries. Results  The spatially explicit inventory is disaggregated by country of location of the emissions and analyzed according to the dimensions of the study: location, product, and pollutant. The inventory shows striking differences between the two products considered as well as between the different pollutants considered. For the T-shirt, over 70% of the energy use and CO2 emissions occur in the consuming country, whereas for the jacket, more than 70% occur in the producing country. This reversal of proportions is due to differences in the use phase of the garments. For SO2, in contrast, over two thirds of the emissions occur in the country of production for both T-shirt and jacket. The difference in emission patterns between CO2 and SO2 is due to local electricity processes, justifying our emphasis on local energy infrastructure. Discussion  The complexity of considering differences in location, product, and pollutant is rewarded by a much richer understanding of a global production–consumption chain. The inclusion of two different products in the LCI highlights the importance of the definition of a product's functional unit in the analysis and implications of results. Several use-phase scenarios demonstrate the importance of consumer behavior over equipment efficiency. The spatial emission patterns of the different pollutants allow us to understand the role of various energy infrastructure elements. The emission patterns furthermore inform the debate on the Environmental Kuznets Curve, which applies only to pollutants which can be easily filtered and does not take into account the effects of production displacement. We also discuss the appropriateness and limitations of applying the LCA methodology in a global context, especially in developing countries. Conclusions  Our spatial LCI method yields important insights in the quantity and pattern of emissions due to different product life cycle stages, dependent on the local technology, emphasizing the importance of consumer behavior. From a life cycle perspective, consumer education promoting air-drying and cool washing is more important than efficient appliances. Recommendations and perspectives  Spatial LCI with country-specific data is a promising method, necessary for the challenges of globalized production–consumption chains. We recommend inventory reporting of final energy forms, such as electricity, and modular LCA databases, which would allow the easy modification of underlying energy infrastructure. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
103.
Four different types of cotton-based fabrics, namely, loom-state cotton, cotton/polyester (50/50), cotton/polyester (35/65) and grey mercerized fabrics were bioscoured and bleached. The four substrates are given enzymatic treatment using cellulase enzyme to affect bio-polishing followed by crosslinking using N,N-dimethylol 4,5-dihydroxyethylene urea (DMDHEU) to affect easy care finishing. In another series of experiments the said bioscoured–bleached substrates were similarly crosslinked followed by bio-polishing. Technical properties of the treated fabric that were monitored include: nitrogen content, loss in fabric weight, tensile strength, elongation at break, tear strength, whiteness index, surface roughness and wrinkle recovery angle. Scanning electron micrograph was also examined. Conclusions arrived at from these studies indicated that: post-crosslinking and pre-crosslinking revealed marginal differences in N%, wrinkle recovery angle and whiteness index, a point which validates the argument that cellulase enzyme could not break down the DMDHEU crosslinks within the molecular structure of cotton-containing fabrics. Meanwhile the surface roughness obtained with pre-crosslinking is a bit higher than those of post-crosslinking. Moreover, post-crosslinking caused higher losses in strength properties than pre-crosslinking. Scanning electron micrograph shows that cotton sample pre-crosslinked is almost smooth than those post-crosslinked.  相似文献   
104.
105.
Cyanidase, an immobilized enzyme preparation for hydrolyzing cyanide to ammonia and formate, was applied for the treatment of cyanide-containing waste waters from the food industry. Apricot seed extract was chosen as a model effluent. The enzymatic hydrolysis of pure amygdalin, the main cyanogenic glycoside in the extract, and the degradation of the cyanide formed was investigated and compared with the behavior of the real extract in a batch slurry reactor. A diffusional-type, flat-membrane reactor with immobilized cyanidase was developed, where the enzyme is effectively protected from adverse effects of high molecular components contained in the extract. For monitoring continuous-membrane reactor operation, a new unsegmented ammonia measurement system was developed and applied. In continuous operation the cyanidase retained its original activity for more than 400 hours on steam. (c) 1993 John Wiley & Sons, Inc.  相似文献   
106.
The feasibility of using fish farm effluents was evaluated as a source of inorganic nutrients for mass production of marine diatoms. Batch cultures were conducted from May to July 1995 in 16-L outdoor rectangular tanks, homogenized by gentle aeration (0.2 L air L–1 h–1). The effluents from the two fish farms studied were both characterized by high concentrations of inorganic materials (NH4-N, PO4-;P, Si(OH)4-Si) and were shown to support production of marine diatoms. Moreover, periodic measurements of inorganic matter levels in the cultures showed that clearance was efficacious (90% in 3–5 days). Water purification efficiency and culture productivity were further increased through appropriate nutrient balancing. When effluents were limited in silicate, addition of Na2SiO3 induced a significant increase in both diatom biomass and nutrient removal efficiency. In this case, up to 720 000 cell mL–1 were produced dominated bySkeletonema costatum. By contrast, in effluents loaded with silicate, adjustment of the N:P:Si ratio by NH4-N and PO4-P supplementation then gave increased biomass production. In this case, the maximum cell density found was 450 000 cell mL–1, dominated byChaetoceros spp.Author for correspondence  相似文献   
107.
Archived data from a long-term (1973–1988) monitoring study were used to assess the impacts of kraft mill effluents (KME) on fish community dynamics in Elevenmile Creek, a small blackwater stream located in Cantonment, Florida, compared to a neighboring stream, Black Creek, that did not receive KME. The fish community in Elevenmile Creek was generally lower in species richness and diversity than the reference stream. The exception was the mill outfall site, which had similar species richness and diversity to the reference stream. Neither species richness nor diversity changed substantially during the survey period in either stream. Throughout the survey, Elevenmile Creek was numerically dominated by bluegill, Lepomis macrochirus, and eastern mosquitofish, Gambusia affinis. Black Creek had greater abundances of minnows, suckers, and darters. Time series analysis of L. macrochirus for Elevenmile Creek showed that this species was more abundant during winter than summer, but no overall long-term trend was found. Although data used in this study may not be representative of the fish community in Elevenmile Creek as it exists today, results suggest that Elevenmile Creek was highly disturbed during the survey and that species diversity did not increase following mill treatment upgrades.  相似文献   
108.
A family of five strictly related glycoconjugated azo dyes (GADs), characterized by the presence of the same chromophore and a variable number (1-4) of deprotected hexose units, has been prepared by employing succinate bridges for connecting the azo dye and the sugar portions. The modulation of the hydrophilic portion determines the appreciable changes in the water solubility of GADs. In all the cases, however, hydrophobic fibres (polyester) were homogeneously dyed with GADs at temperatures lower than that used for original azo dyes, at atmospheric pressure, and avoiding the use of surfactants. Furthermore, GADs show an interesting multipurpose character leading to dyeing well also the natural fibres as, for instance, wool. The presence of a variable number of hexose units in the different GADs determines some changes in the colour intensity of dyed fabrics, but in all the cases an appreciable rubbing and water fastness were maintained.  相似文献   
109.
110.
城市生活污水浇灌对金盏菊生长的影响   总被引:1,自引:0,他引:1  
用三种稀释倍数的城市生活污水[污水:清水(v/v)为1:0、1:0.5、1:1]处理金盏菊种子及盆花,结果表明,污灌处理不仅显著地降低种子的萌发率,还增加萌发后幼苗病害的发生率;未经稀释的原生污水显著抑制金盏菊幼苗的生长,而稀释后抑制作用降低,当稀释至适当浓度时,则对幼苗生长起促进作用;对于金盏菊成年植株,污灌处理(不论稀释与否)显著地增加其茎、叶和根的鲜重,分别较对照增加161.63%~215.12%、86.77%~109.23%和23.89%~34.13%。综合分析表明,原生污水经过适当稀释后用于草花污灌,可以使污水中的营养盐得到回用,提高草花的观赏性。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号