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61.
王雨 《南都学坛》2001,21(3):57-59
通过研究不同浓度Na2 CO3、KPS存在的条件下复合驱油体系的相行为变化 ,找到了形成中相最佳区的条件 ,揭示了相行为与油水界面张力及表面活性剂在不同相间分配量大小的相关性 ,从临界胶束浓度变化对相态转变机理给予合理解释。  相似文献   
62.
以系统理论、协同理论为理论依据,在分析物流企业资源的概念和物流企业的自组织演化过程的基础上,介绍了物流企业资源并购整合动因和模式,并从微观角度入手,阐述物流企业在资源并购整合各个相变过程中协同管理内容和层次,为中国本土物流企业进行物流资源并购整合活动提供相应的理论依据。  相似文献   
63.
主要阐述最简方案下存活式句法理论的主要内容,并对其优势和不足做出评价。从理论构建以及语言事实分析两个视角来看,与语段理论相比,存活理论更加符合最简句法的基本理念和要求,其理论设计更为合理,语料应用范围更为宽广。除此之外,以存活理论为基础,从核心句法操作、句法特征以及句法与其他语言模块的接口等角度反思最简方案下构建句法推导理论应该注意的问题。  相似文献   
64.
Two-stage designs offer substantial advantages for early phase II studies. The interim analysis following the first stage allows the study to be stopped for futility, or more positively, it might lead to early progression to the trials needed for late phase II and phase III. If the study is to continue to its second stage, then there is an opportunity for a revision of the total sample size. Two-stage designs have been implemented widely in oncology studies in which there is a single treatment arm and patient responses are binary. In this paper the case of two-arm comparative studies in which responses are quantitative is considered. This setting is common in therapeutic areas other than oncology. It will be assumed that observations are normally distributed, but that there is some doubt concerning their standard deviation, motivating the need for sample size review. The work reported has been motivated by a study in diabetic neuropathic pain, and the development of the design for that trial is described in detail.  相似文献   
65.
For a dose finding study in cancer, the most successful dose (MSD), among a group of available doses, is that dose at which the overall success rate is the highest. This rate is the product of the rate of seeing non-toxicities together with the rate of tumor response. A successful dose finding trial in this context is one where we manage to identify the MSD in an efficient manner. In practice we may also need to consider algorithms for identifying the MSD which can incorporate certain restrictions, the most common restriction maintaining the estimated toxicity rate alone below some maximum rate. In this case the MSD may correspond to a different level than that for the unconstrained MSD and, in providing a final recommendation, it is important to underline that it is subject to the given constraint. We work with the approach described in O'Quigley et al. [Biometrics 2001; 57(4):1018-1029]. The focus of that work was dose finding in HIV where both information on toxicity and efficacy were almost immediately available. Recent cancer studies are beginning to fall under this same heading where, as before, toxicity can be quickly evaluated and, in addition, we can rely on biological markers or other measures of tumor response. Mindful of the particular context of cancer, our purpose here is to consider the methodology developed by O'Quigley et al. and its practical implementation. We also carry out a study on the doubly under-parameterized model, developed by O'Quigley et al. but not  相似文献   
66.
文章在一个内生经济增长的OLG模型框架下研究现收现付制养老保险计划的挤出效应。具体考察公共养老金税率变动对家庭的消费与储蓄、生育选择以及经济增长的长期影响。结果表明,存在向上利他动机的情况下,挤出效应的大小取决于养老基金的规模,适度规模的公共养老金计划不会挤出私人储蓄。而有利于消费增加与经济增长;较大规模的公共养老金计划会对私人自愿储蓄与消费产生负面影响,并且对储蓄的挤出作用要大于对消费的挤出。人口老龄化进程在一定程度上缓解挤出效应,促进资本积累与经济增长。  相似文献   
67.
本文结合青海民族地区实际 ,对世界贸易组织情况及其与中国谈判所涉及的领域作了简要介绍 ,分析了加入世贸组织后给青海民族地区经济建设带来契机与严峻考验 ,并有针对性地提出了对策。  相似文献   
68.
A significant proportion (4%, Australian Institute of Health and Welfare, 2008) of children and young people in Australia live in some form of residential care, usually in small group‐homes staffed by residential care workers in shifts. However, as Hawkins‐Rodgers (2007) points out, these placements are often not resourced to heal the effects of trauma and multiple attachment disruptions in their residents. The lack of an archetypal ‘family’ has led in the past to family therapists considering that there is little work to be done with such clients. This leaves such placements to be supported most frequently by clinicians who specialise in behaviour management and other linearly founded models of practice. The Alternate Care Clinic (ACC) is the first mental health service in New South Wales dedicated entirely to children and young people in out of home care with a high level of complex needs. This article examines the systemic therapeutic model the clinic has developed in the last two years. In particular, the article seeks to explore the importance of ‘meaning making’ in a diffuse parental system, particularly with regards to the term ‘family’. The complexities of working in this area and possible ways forward are illustrated with a closely worked case study.  相似文献   
69.
Using a grounded theory approach, this study evaluated narratives from a sample of 170 emancipated foster youth (66.5% female; 84.6% non-white) as they reflected on their experiences between the ages of 18 and 25 across three data waves. Corbin and Strauss’ (1990) three-phase coding process revealed five overarching themes: adult values and characteristics, nature of the transition process, material needs and resources, relationship concerns, and affective experiences. Although some elements of Arnett’s (2000) model of emerging adulthood were evident in this sample of emancipated foster youth, such as individualistic qualities and instability, other core features were rarely discussed, such as self-focus and optimism, or were expressed in unique ways, such as exploration and feeling in-between. There were significant age-related changes, but not gender differences, in youth’s discussion of varied themes. These findings suggest promising avenues for intervention during the sensitive period of developmental reorganization that characterizes the transition from adolescence to young adulthood.  相似文献   
70.
On the basis of simple rational-choice theory, it is argued that Christian religious involvement influences the divorce, abortion, non-payment, and children-born-out-of-wedlock rates negatively. This influence stems from an expectation that a god punishes certain forms of action and from social reprimands of devotees. Regression analysis is then used to test the theory in the case of Sweden in the year 1990, and the importance of religion, in its negative effect on all of these rates, is strongly confirmed. A particularly interesting result: the marginal effect on three of these rates of increasing the fraction of people active in the Church of Sweden is clearly larger than the marginal effect of increasing the fraction of more conservative free-church members.  相似文献   
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