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101.
魏晋南北朝是中国古代动乱最多、人民生活最悲惨的时代。战争、动乱使汉王朝“独尊儒术”的旧思想体制大崩溃 ,导致魏晋南北朝时期的古代中国思想最解放、最自由。美学思想和精神的自由 ,酿就了艺术创造精神的勃发 ,因而新的艺术形式、艺术规律应运而生并相互融会贯通。此时的盆景艺术正是在绘画、园林、盆栽、赏石等艺术形式的影响下孕育了自己最初的表现形式和美学规律 ,因此可以说该时期是盆景发展史上的一个重要阶段 相似文献
102.
Jan C. H. van Eijkeren 《Risk analysis》2002,22(1):159-173
A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori. 相似文献
103.
Ian H. Langford 《Risk analysis》2002,22(1):101-120
Existential, or existential-phenomenological philosophical approaches to the social psychology of risk perception provide a novel framework for understanding issues that are common to all humanity, such as fear of death, freedom and responsibility, isolation and meaninglessness, as these anxieties are a function of existing, or being-in-the-world. These fundamental anxieties can be related theoretically to the ways people perceive risks within social and cultural milieus, and can also be used practically within case studies, as demonstrated in the three examples presented, which examine perceptions of climate change, food-related risks, and environmental awareness via a mixture of quantitative and qualitative techniques. The discussion focuses on the possible insights that can be gained from taking an existential perspective on risk perception, and relates notions of contemporary technologically-oriented societies to the existential challenges faced by individuals and societies in the contemporary world. 相似文献
104.
105.
Blaine J. Fowers Kelly H. Montel David H. Olson 《Journal of marital and family therapy》1996,22(1):103-119
Recent studies have shown that group differences in marital stability and satisfaction can be predicted based on premarital relationship quality. There is also a growing literature indicating that there are distinct types of relationships, both premaritally and developmentally over time. This study examined the relationship between the four premarital types (Vitalized, Harmonious, Traditional, and Conflicted) identified by Fowers and Olson (1992) and relationship outcome over a 3-year period with 393 couples. A substantial relationship was found, with conflicted couples being the most likely to separate or divorce. Vitalized couples had the highest levels of satisfaction, followed by Harmonious, Traditional, and Conflicted couples. Traditional couples were less likely to have divorced than Harmonious couples, even though Harmonious couples had higher premarital relationship satisfaction scores. 相似文献
106.
William R. Shadish Kevin Ragsdale Renita R. Glaser Linda M. Montgomery 《Journal of marital and family therapy》1995,21(4):345-360
This article reviews the major findings from a multiproject meta-analysis of the effects of marital and family therapy (MFT). Across 163 randomized trials, MFT demonstrates moderate, statistically significant, and often clinically significant effects. No orientation is yet demonstrably superior to any other, nor is MFT superior to individual therapy. Cost effectiveness information is scant in these 163 studies, but supportive. Randomized experiments yield very different answers from nonrandomized experimental studies of the effects of MFT, calling into question whether we should mix the two in reviews. We have also found several new differences in the ways that marital therapy (MT) and family therapy (FT) studies are conducted, making them harder to compare. Finally, important questions still exist about whether any psychotherapy, including MFT, yet has sufficient information about how well research generalizes to everyday clinical practice. 相似文献
107.
Scheduling Updates of Probabilistic Risk Assessments: The Arkansas Nuclear One-Unit 1 Experience 总被引:1,自引:0,他引:1
This paper presents the results of a study that identified how often a probabilistic risk assessment (PRA)should be updated to accommodate the changes that take place at nuclear power plants. Based on a 7-year analysis of design and procedural changes at one plant, we consider 5 years to be the maximum interval for updating PRAs. This conclusion is preliminary because it is based on the review of changes that occurred at a single plant, and it addresses only PRAs that involve a Level 1 analysis (i.e., a PRA including calculation of core damage frequency only). Nevertheless, this conclusion indicates that maintaining a useful PRA requires periodic updating efforts. However, the need for this periodic update stems only partly from the number of changes that can be expected to take place at nuclear power plants–changes that individually have only a moderate to minor impact on the PRA, but whose combined impact is substantial and necessitates a PRA update. Additionally, a comparison of two generations of PRAs performed about 5 years apart indicates that PRAs must be periodically updated to reflect the evolution of PRA methods. The most desirable updating interval depends on these two technical considerations as well as the cost of updating the PRA. (Cost considerations, however, were beyond the scope of this study.) 相似文献
108.
D. R. Wingo 《Statistical Papers》1993,34(1):271-276
In a recent paper in this journal, Lee, Kapadia and Brock (1980) developed maximum likelihood (ML) methods for estimating the scale parameter of the Rayleigh distribution from doubly censored samples. They reported convergence difficulties in attempting to solve numerically the nonlinear likelihood equation (LE). To mitigate these difficulties, they employed approximations to simplify the LE, but found that the solution of the resulting simplified equation can give rise to parameter estimates of erratic accuracy. We show that the use of approximations to simplify the LE is unnecessary. In fact, under suitable parametric transformation, the log-likelihood function is strictly concave, the ML estimate always exists, is unique and finite. Furthermore, the LE is easy to solve numerically. A numerical example is given to illustrate the computations involved. 相似文献
109.
A table is presented for the construction and selection of tightened-normal-tightened sampling scheme of type TNT-(n1, n2;c). Efficiency of TNT-(n1, n2;c) scheme over conventional single and double sampling plans is discussed. 相似文献
110.