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11.
1.引言 随着企业的不断变革。信息技术(IT)管理问题也变得越来越棘手了。在IT管理中,今天是非常重要的因素,明天可能就变得无足轻重了。另外,各类企业中的商务和IT领域持续以惊人的速度相结合。在这种复杂的环境中,IT的管理已经不再仅仅是IT经理的工作了。许多关于信息技术的决策显然也超出了IT经理的工作范围。有一些关于企业存亡与竞争的关键 相似文献
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Terry K 《Medical economics》1998,75(19):125-6, 131-3
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Terry K 《Medical economics》1996,73(10):109-10, 113-4, 117-23
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The paper focuses on the evaluation of membrane filtration for the treatment of liquid radioactive streams generated in area decontamination operations. In this work, semi-permeable membranes were demonstrated to be effective reducing the volume of wastewater containing cesium and cobalt by two orders of a magnitude. The efficiency of membrane separation was enhanced by employing additives that enlarged the size of target radionuclide species and improved their rejection by the membranes. This was achieved by chelation with synthetic water-soluble polymers and by adsorption on micro particles of adsorbent coupled with micelle formation. The effect of wastewater composition and that of the radionuclide-binding additives on the volume reduction was investigated. Membrane treatment is expected to help simplify further processing and decrease disposal costs. 相似文献
17.
Zhai J Xiao HW Kujawa-Roeleveld K He Q Kerstens SM 《Water science and technology》2011,64(11):2177-2184
A new type of hybrid constructed wetland (CW), consisting of both vertical-baffled flow wetland (VBFW) and horizontal subsurface flow wetland (HSFW), has been deployed in Southern China to naturally accelerate the removal of organic matter and nitrogen. The hybrid CW system is characterised by a combination of continuous baffled flow vertical wetland and 'S' pattern horizontal subsurface flow wetland with natural aeration ditches to increase the concentration of dissolved oxygen in the HSFW bed. An internal circulatory system from the HSFW effluent back to the VBFW may optionally be operated to enhance the biological denitrification effect. Cyperus alternifolius is the main macrophyte in the wetland bed. The performance of the hybrid CW was studied with a pilot-scale system and three full-scale systems for municipal sewage treatment in Southern China. The results suggest that this new hybrid CW can achieve removal efficiencies of chemical oxygen demand, suspended solids, ammonia nitrogen, total nitrogen, and total phosphorus of better than 83.6, 95.0, 71.7, 64.5 and 68.1% respectively, with a specific wetland bed area of 0.70-0.93 m(2) PE(-1). The mean effluent concentrations of these parameters would meet the regulatory discharge limits for wastewater treatment systems (GB18918, 2002) and reuse in the context of agricultural irrigation solutions in China. 相似文献
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Upflow anaerobic sludge bed reactors fed on glucose were used to investigate the effects of Ce(3+) on soluble microbial products (SMP) production, which is the majority of the residual chemical oxygen demand present in the effluent. It was found that Ce(3+) concentration of 0.05 mg/L had no significant effect on the amount of SMP production, whereas that of 1 mg/L led to the increase in SMP production. The molecular-weight distribution and carbohydrate analysis indicated that an increase in SMP production may be partly attributed to the release of extracellular polymeric substances (EPS) into the bulk solution resulted from cerium toxicity, and the nucleic acids analysis suggested that increased cell lysis also contributed to SMP accumulation in the presence of Ce(3+). The increase in SMP production in the presence of Ce(3+) is possibly a consequence of the release of EPS and increased cell lysis due to cerium toxicity. 相似文献
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A major fraction of nutrients emitted from households are originally present in only 1% of total wastewater volume. New sanitation concepts enable the recovery and reuse of these nutrients from feces and urine. Two possible sanitation concepts are presented, with varying degree of source separation leading to various recovery products. Separate vacuum collection and transport followed by anaerobic treatment of concentrated black water (BW) demonstrated on a scale of 32 houses preserve 7.6 g/N/p/d and 0.63 gP/p/d amounting to respectively 69 and 48% of the theoretically produced N and P in the household, and 95% of the retained P was shown to be recoverable via struvite precipitation. Reuse of the anaerobic sludge in agriculture can substantially increase the P recovery. Energy recovery in the form of biogas from anaerobic digestion of concentrated BW, fits well in new concepts of sustainable, zero energy buildings. Nutrient recovery from separately collected urine lowers the percentage of nutrient recovery in comparison with BW but can, on the other hand, often be implemented in existing sanitation concepts. Theoretically 11gN/p/d and 1.0 g P/p/d are produced with urine, of which 38-63 and 34-61% were recovered in practice on a scale of 8-160 inhabitants in Sweden. New sanitation concepts with resource recovery and reuse are being demonstrated worldwide and more and more experience is being gained. 相似文献
20.
Yoochatchaval W Kumakura S Tanikawa D Yamaguchi T Yunus MF Chen SS Kubota K Harada H Syutsubo K 《Water science and technology》2011,64(10):2001-2008
The biodegradation characteristics of palm oil mill effluent (POME) and the related microbial community were studied in both actual sequential anaerobic ponds in Malaysia and enrichment cultures. The significant degradation of the POME was observed in the second pond, in which the temperature was 35-37 °C. In this pond, biodegradation of major long chain fatty acids (LCFA), such as palmitic acid (C16:0) and oleic acid (C18:1), was also confirmed. The enrichment culture experiment was conducted with different feeding substrates, i.e. POME, C16:0 and C18:1, at 35 °C. Good recovery of methane indicated biodegradation of feeds in the POME and C16:0 enrichments. The methane production rate of the C18:1 enrichment was slower than other substrates and inhibition of methanogenesis was frequently observed. Denaturing gradient gel electrophoresis (DGGE) analyses indicated the existence of LCFA-degrading bacteria, such as the genus Syntrophus and Syntorophomonas, in all enrichment cultures operated at 35 °C. Anaerobic degradation of the POME under mesophilic conditions was stably processed as compared with thermophilic conditions. 相似文献