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排序方式: 共有311条查询结果,搜索用时 15 毫秒
91.
文章阐述变电站低压并联电抗器隐性环流和涡流现象,并对此进行分析,提出应对措施,对避免和消除不利因素具有现实的指导作用。 相似文献
92.
不同温度下异波折板反应器处理生活污水的研究 总被引:2,自引:0,他引:2
本实验采用64.8L的厌氧异波折流板反应器处理生活污水,研究了低温对异波折流板反应器运行效能的影响。结果表明,温度从30℃降至20℃反应器运行15d达到稳定后,COD去除率仅从83.6%下降至76.9%。各隔室的VFA浓度均有所上升,前面隔室升幅较大,比甲烷活性略有下降;当温度从20℃下降至10℃时,产氢产乙酸菌和产甲烷菌等受到较大影响,在反应器运行达到稳定后COD去除率从76.9%下降至45%~55%,出水水质受影响较大,比甲烷活性下降幅度较大。 相似文献
93.
应用广义Bethe树上奇偶马尔可夫链场上的一个强极限定理,得到了状态出现频率的若干强极限定理,作为推论得到了状态出现频率的粗略估计,从而推广了齐次树上马尔可夫链场和二进树上奇偶马尔可夫链场中的部分结论。 相似文献
94.
Edgar G. Hertwich 《Economic Systems Research》2011,23(1):27-47
This paper reviews assessments of environmental impacts arising from consumption, taking into account the production and disposal of goods consumed. Assessments have mostly focused on understanding household consumption, but there is an increasing interest in understanding government consumption, as well as in the treatment of gross capital formation and trade. National economic and environmental accounts are the most frequently used data source for such studies and input–output techniques are usually applied. For many OECD countries and a few developing countries, assessments address only energy or greenhouse gas emissions. Few studies address a broader range of emissions-related environmental impacts. There is a lack of consideration for important pressures on ecosystems such as habitat change and overexploitation of fisheries and forests. In all countries, housing and food are important. In poor countries, public services can contribute substantially, while in rich countries, mobility and the consumption of manufactured goods is important. In rapidly developing economies, investments, especially in infrastructure and buildings, are important causes of environmental pressure as well. Differences in production conditions and pollution intensities across countries are substantial, so explicitly modelling the production of internationally traded goods using multi-regional input–output analysis is necessary to account correctly for the environmental impacts arising from the consumption of imported goods. 相似文献
95.
Diane P. Dupont 《Environmental and Resource Economics》2003,25(3):319-341
Embedding is said to occur when thewillingness-to-pay (WTP) values for a gooddiffer according to whether the good is valuedon its own or as part of a package of goods. Itcan manifest itself as a question order orsequencing effect whereby the WTP for a gooddepends upon the order in which contingentvaluation questions are asked. Usingsplit-sample data from different questionorderings of a survey administered to a generalpopulation, the willingness-to-pay values forimprovements to three recreational activities(swimming, fishing, and boating in HamiltonHarbour, Ontario, Canada) are estimated. Respondents are divided into three types ofuser groups: active users, potentially activeusers, and passive users. The paper thenexamines the extent to which embedding in theform of different question sequences affectseach of these three user types. Severalarguments are put forward to suggest whypassive users might be more susceptible toquestion order than active users. The resultssupport the hypothesis that order effects arelikely to be larger for passive users and alsoshow that potentially active users may beaffected by question order to a greater extentthan active users. This highlights theimportance of considering context when usingmultiple-question CVM to value passive usegoods. 相似文献
96.
短程硝化反硝化生物脱氮工艺及影响因子 总被引:5,自引:0,他引:5
介绍了传统生物脱氮工艺和短程硝化一反硝化工艺原理,提出了短程硝化反硝化的关键是如何控制硝化过程中NO2^--N的积累。分析了影响NO2^--N积累的主要因素为温度、游离氨、pH值、溶解氧、有害物质和泥龄,提出了实现短程反硝化的控制条件。 相似文献
97.
针对传统项目管理所存在的局限性,以遗传性项目管理知识领域为基础,提出了一种组织结构优化的新方法——基因组方法。系统地阐述了基因组方法实施的前提条件和实施步骤,为企业提高项目管理水平,进行项目管理方法的创新打开了一个新的思路。 相似文献
98.
Wayne W. Smith Jeremy C. Clement Robert E. Pitts 《Journal of Teaching in Travel & Tourism》2018,18(2):109-122
ABSTRACTThis research adds to the overall literature and academic understanding of early career progression of hospitality professionals. The results of an analysis of the career profiles of graduates of an undergraduate business school majoring in Hospitality and Tourism Management indicate that there are five potential career paths for hospitality professionals graduating from this program. The groups are (1) Traditional Hospitality; (2) Stallers; (3) Nonhospitality; (4) Loyalists; and (5) Entrepreneurs. The findings indicate that there is substantial job movement in the first three years after graduation. Further, if promotion happens within the first 6 months to a year, graduates are more likely to stay with the organization. Finally, those that leave hospitality are likely to go into highly related fields such as health care and real estate. 相似文献
99.
Shannon Hebblethwaite 《Leisure Sciences: An Interdisciplinary Journal》2017,39(5):415-425
ABSTRACTThe continued focus on the individual as a unit of analysis, along with the privileging of the nuclear family over the past two decades of family leisure scholarship, has rendered grandparents virtually invisible in family leisure scholarship. In this commentary, I examine the position of grandparents in leisure research and suggest that the implicit acceptance of the status quo has been detrimental to the state of family leisure research. Drawing on literature from both leisure studies and family relations, I assert a more nuanced understanding of the complexities of diverse family forms is vital to the progression of family leisure scholarship. 相似文献
100.
郑春华 《石油化工技术经济》2007,23(3):50-53
通过现场拍摄的PD-201加氢反应器腐蚀照片,依据氢腐蚀及孔蚀的原理,探讨了加氢反应器腐蚀原因,提出并实施了修复方案,修复后的PD-201加氢反应器运行1年,未发现修复处有异常腐蚀。 相似文献