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61.
考虑浓度扩散和扩散流随时间的变化,得到低浓度三分子反应模型的双曲型反应-扩散方程;讨论了方程的稳定性及存在行波解的条件,得到了化学振荡的色散关系和相速度.  相似文献   
62.
对普通野生稻和药用野生稻种子休眠的原因进行了探讨,表明野生稻种的遗传特性、形态性状、颖壳的透性和种子的生理特性与种子休眠有关。研究结果为打破野生稻种子休眠、提高其发茅力提供了依据和适宜的方法。  相似文献   
63.
本文介绍了杭州汽轮机厂计算机集成制造系统HTW-CIMS的总体方案以及开发和应用该系统时遵循的技术路线。  相似文献   
64.
Impacts of complex emergencies or relief interventions have often been evaluated by absolute mortality compared to international standardized mortality rates. A better evaluation would be to compare with local baseline mortality of the affected populations. A projection of population-based survival data into time of emergency or intervention based on information from before the emergency may create a local baseline reference. We find a log-transformed Gaussian time series model where standard errors of the estimated rates are included in the variance to have the best forecasting capacity. However, if time-at-risk during the forecasted period is known then forecasting might be done using a Poisson time series model with overdispersion. Whatever, the standard error of the estimated rates must be included in the variance of the model either in an additive form in a Gaussian model or in a multiplicative form by overdispersion in a Poisson model. Data on which the forecasting is based must be modelled carefully concerning not only calendar-time trends but also periods with excessive frequency of events (epidemics) and seasonal variations to eliminate residual autocorrelation and to make a proper reference for comparison, reflecting changes over time during the emergency. Hence, when modelled properly it is possible to predict a reference to an emergency-affected population based on local conditions. We predicted childhood mortality during the war in Guinea-Bissau 1998-1999. We found an increased mortality in the first half-year of the war and a mortality corresponding to the expected one in the last half-year of the war.  相似文献   
65.
协同运输管理运行机制研究   总被引:2,自引:0,他引:2  
协同运输管理是在CPFR基础上发展起来的一种供应链管理方法。它通过降低供应链中的运输成本、缩短商品交付时间和提高准时交货率,实现供应链价值的最大化。协同运输管理的有效实施,需要建立完善的运行机制,包括动力机制、约束机制、实际行为和惩罚机制,并配备相应的软硬件条件。  相似文献   
66.
Liberia has gone through civil crisis for over a decade which has resulted in the destruction of infrastructure and disruption of basic services delivery particularly in Monrovia, the capital city. Most of the 1.3 million people living in Monrovia are without adequate environmental sanitation and waste management services which situation poses a serious health risk to the residents. The current waste management service coverage is less than 20% and disposal is by indiscriminate open dumping. In 2003, there were series of outbreaks of cholera epidemics in the city during which time a total of 26,651 cases were reported with many dying.The waste management plan was initiated as an exit strategy of UNICEF following an intervention response programme to assist the Monrovia City Corporation (MCC) whose capacity in this area had been crippled as a result of years of war, through the provision of support in solid waste collection and disposal.The objectives of the plan were to:
(a) Improve waste management services delivery in the city.
(b) Strengthen the ability of the MCC to plan and manage the waste services delivery.
(c) Enhance cooperation of service beneficiaries through comprehensive and effective health education and service promotional campaign.
(d) Enhance revenue generation and community participation through the promotion of private sector and CBOs/NGOs active involvement in the waste management service delivery.
The general methodology adopted for the assignment entailed the following:Desk study and review of existing reports on Water and Environmental Sanitation (WES) in Monrovia and other relevant literature, consultation with stakeholders, site visits and participatory planning which aimed at soliciting the opinions of the various stakeholders involved with the respective components to capture their aspirations and experiences. It also covered collection and analysis of available information and data to facilitate the plan preparation and facilities design.The three-phased strategy (short, medium and long term) covering a period of 10 years (August 2004–December 2014), recommended a combination of technical options for collection based on the pursuit of staged development to allow for the adoption of realistically attainable standards within a framework of continuous and systematic improvements as economic conditions improved and new knowledge gained through practice. The plan sought to blend the capacity within the City Corporation with that of the private sector and NGOs/CBOs to respond to the diverse service demands of the city taking into consideration housing and infrastructural conditions, service costs and cost recovery to ensure sustainability. It also identified sources of financing and allocated financing responsibilities to facilitate effective plan implementation.  相似文献   
67.
网络时代馆际互借模式之研究   总被引:13,自引:0,他引:13  
馆际互借、资源共享的观念在我国已推行多年 ,由于图书馆自动化系统及网络系统的不断发展 ,网络时代的资源共享和馆际互借成了当前一个非常重要的课题。现代图书馆必须利用各种信息资源 ,达成馆际互借资源共享的目的。世界各国图书馆都在探讨馆际互借的模式 ,并且提出了各种方案 ,加以实践和探索。由于各国或地区情况的多样性 ,各种馆际互借的方式也不相同。本文主要探讨了美国、英国、德国、日本及中国香港、台湾地区馆际互借的模式 ,建设性地提出了我国馆际互借资源共享发展的趋势  相似文献   
68.
建设学习型教师队伍   总被引:2,自引:0,他引:2  
在知识经济时代,学习的重要性不言而喻。教师作为一个传播文化知识的职业群体,自觉学习乃至终身学习是他们的职业需要。构建学习型教师队伍不仅可以帮助教师个体成长和发展,而且还能使教师个体和教师群体以及学校组织同步发展。本文简要论述了建设学习型教师队伍的意义,提出构建学习型教师队伍和学习型组织的具体策略。  相似文献   
69.
Low dose risk estimation via simultaneous statistical inferences   总被引:2,自引:0,他引:2  
Summary.  The paper develops and studies simultaneous confidence bounds that are useful for making low dose inferences in quantitative risk analysis. Application is intended for risk assessment studies where human, animal or ecological data are used to set safe low dose levels of a toxic agent, but where study information is limited to high dose levels of the agent. Methods are derived for estimating simultaneous, one-sided, upper confidence limits on risk for end points measured on a continuous scale. From the simultaneous confidence bounds, lower confidence limits on the dose that is associated with a particular risk (often referred to as a bench-mark dose ) are calculated. An important feature of the simultaneous construction is that any inferences that are based on inverting the simultaneous confidence bounds apply automatically to inverse bounds on the bench-mark dose.  相似文献   
70.
两极交汇的张力——论中国第六代电影的叙事风格   总被引:1,自引:0,他引:1  
岳晓英 《唐都学刊》2006,22(6):99-103
中国第六代电影在叙事风格上呈现为诗意而又残酷、纪实而又魔幻、客观而又热情的两极交汇,这种撕裂感和矛盾性根源于第六代电影人自身文化定位的两难,也反映了当下中国文化深层次的紧张和选择的艰难。  相似文献   
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