高性能混凝土粉体颗粒群分形密集效应的评价

目的 在水泥基复合材料颗粒群分形几何密集效应模型的基础上，评价高性能混凝土粉体颗粒群的密集效应．方法 用分形模型通过数值解析的方法，根据已知最大、最小粒径，根据调整相应的分形维数，模拟传统的密实填充理论方程．并与高性能混凝土超细粉体常用颗粒群粒径范围比较，分析评价其密集效应．结果 研究表明，采用分形模型评价水泥基粉体材料（1～120μm）颗粒群，发现Andreasen最紧密堆积模型中指数为1／2和1／3时，对应分形模型的10～1000nm之间的颗粒群质量分数应在8．85％～18．72％，这与目前高性能混凝土中超细粉体材料如硅灰等常用掺量相吻合．适当提高粗颗粒含量对最紧密堆积有利．结论 要实现最紧密堆积，仅用超细矿渣和粉煤灰是不够的，必须降低中等颗粒含量，掺入硅灰，并适量增加粗颗粒的含量，分形模型对进一步探索超细粉体对高性能混凝土材料密集效应的内在规律提供了重要的理论依据．     

大面积光学多层膜玻璃

随着磁控溅射技术的不断进步,大面积光学多层膜玻璃也日渐发展,广泛地应用于建筑、汽车、平板显示等行业。对几种大面积光学多层膜玻璃的原理、应用以及制备技术分别作了简要介绍及评述。     

PLC在断路器控制中的应用

提出了由 PL C构成的断路器控制装置 ,由于 PL C内部有大量的辅助继电器 ,可充分发挥其互锁功能 ,大大提高了控制装置的可靠性 ,通过编程和改变外部接线 ,可使控制装置具有多种功能 ,若配置适当的接口 ,与上位计算机进行通讯 ,实现电力系统的“四遥”。     

Comparison of clay mineral stratigraphy to other proxy palaeoclimate indicators in the Mesozoic of NW Europe

This paper reviews the opportunities and pitfalls associated with using clay mineralogical analysis in palaeoclimatic reconstructions. Following this, conjunctive methods of improving the reliability of clay mineralogical analysis are reviewed. The Mesozoic succession of NW Europe is employed as a case study. This demonstrates the relationship between clay mineralogy and palaeoclimate. Proxy analyses may be integrated with clay mineralogical analysis to provide an assessment of aridity-humidity contrasts in the hinterland climate. As an example, the abundance of kaolinite through the Mesozoic shows that, while interpretations may be difficult, the Mesozoic climate of NW Europe was subject to great changes in rates of continental precipitation. We may compare sedimentological (facies, mineralogy, geochemistry) indicators of palaeoprecipitation with palaeotemperature estimates. The integration of clay mineralogical analyses with other sedimentological proxy indicators of palaeoclimate allows differentiation of palaeoclimatic effects from those of sea-level and tectonic change. We may also observe how widespread palaeoclimate changes were; whether they were diachronous or synchronous; how climate, sea level and tectonics interact to control sedimentary facies and what palaeoclimate indicators are reliable.     

Predictors of subjective fatigue among individuals with rheumatoid arthritis

OBJECTIVE: To examine a range of variables potentially associated with rheumatoid arthritis (RA)-related fatigue and to determine which variables best predict subjective fatigue. METHODS: Measures of fatigue, disease activity, pain, and various psychosocial factors were gathered from 73 individuals with RA. Correlations between fatigue and other variables were examined, and the "best" predictors of fatigue were determined with multiple regression analyses. RESULTS: Many of the variables that were significantly correlated with fatigue had a psychosocial character. Moreover, the "best" predictors of increased fatigue were higher levels of pain, more depressive symptoms, and female sex. Longer symptom duration, less perceived adequacy of social support, and less disease activity were significant predictors of fatigue, over and above the "best" model. CONCLUSION: RA-related fatigue appears to be strongly associated with psychosocial variables, apart from disease activity per se. Correspondingly, treatment of fatigue may be enhanced by interventions that address relevant cognitive and behavioral dimensions.     

The art of survival: unleashing the talents of end stage renal disease patients to increase their wellness

Patients with end stage renal disease (ESRD) often suffer compromised self-esteem and lowered self-confidence, isolation from the larger community and increased dependence on the health care system. Despite improved technology and medical care, such concepts as "quality of life" and "feeling well" still elude these patients. There is a growing realization in the health care field that other interventions and approaches are needed. This article will describe how the creative arts can activate, motivate and promote wellness for ESRD patients. The focus is on the use of professional artists, dancers and writers to help restore a sense of wholeness, health, and happiness to patients' lives. This preliminary work which explores the belief that art and artistic experiences have healing properties, will hopefully result in a more comprehensive research project in the near future.     

Mental health and psychic structure: an empirical study

Psychodynamic clinicians cite psychic structure and structural changes observed in treatment as sources of important information about unconscious psychological processes and configurations. Empirical studies have had difficulty demonstrating that psychic structure measures something different from psychiatric symptoms and everyday functioning. This study examined the relationship between psychic structure and mental health using the Health-Sickness Rating Scale (HSRS) to measure mental health and two different measures to assess psychic structure: Kernberg's personality organization (PO) and Wallerstein's Scales of Psychological Capacities (PSYCAP). Bivariate correlations and multiple regression analyses were computed based on ratings for 124 psychiatric inpatients and psychotherapy clients. Correlations showed that mental health and psychic structure are substantially interrelated, and multiple regression analyses indicated that 44% of the variance of HSRS is explained by psychic structure measured with the two methods taken together. The findings provide some support for a general factor of mental health and psychic structure and a "pure" component of psychic structure that is independent from mental health. Different factor-analytic models for understanding the relationship between mental health and psychic structure are discussed.     

Trends in cigarette consumption cannot fully explain trends in British lung cancer rates

STUDY OBJECTIVES: To determine whether British lung cancer (LC) trends are adequately explained by cigarette smoking trends, and whether modelling using aggregated smoking prevalence estimates can validly replace modelling using individual smoking histories. METHODS: Observed LC trends for 1955-1985 for both sexes and three age groups were compared with multistage model predictions using smoking history data from two surveys (HALS, AHIP). The modelling used the individual smoking data directly or aggregated prevalence estimates. It allowed for variation in age of starting and stopping smoking, amount smoked, tar levels, and environmental tobacco smoke (ETS) exposure. RESULTS: Observed male LC rates fell faster than predicted by a model (with the first and penultimate stages assumed affected by smoking) that allowed for variation in amount smoked and in tar level (with some provision for "compensation"), and was based on aggregated smoking data from HALS. The discrepancy equated to an annual change unexplained by smoking of -2.4%, -2.8%, and -1.9% for ages 35-44, 45-54, and 55-64. The annual unexplained changes were less in women, and reversed at age 55-64; -1.7%, -0.8%, and +0.8% for the three ages. They were similar using individual smoking histories (-2.6%, -1.8%, and -1.6%; women, -0.9%, -0.5%, and +0.2%). The discrepancies were unexplained by plausible alternative multistage parameters, full allowance for tar reduction, alternative estimates of amount smoked, or ETS. CONCLUSIONS: British LC trends cannot be fully explained by cigarette consumption trends, implying factors other than cigarette smoking contribute importantly to overall risk. Predictions using aggregated prevalence estimates provide useful information.     

Cdkn2a, the cyclin-dependent kinase inhibitor encoding p16INK4a and p19ARF, is a candidate for the plasmacytoma susceptibility locus, Pctr1

Plasma cell tumor induction in mice by pristane is under multigenic control. BALB/c mice are susceptible to tumor development; whereas DBA/2 mice are resistant. Restriction fragment length polymorphisms between BALB/c and DBA/2 for Cdkn2a(p16) and Cdkn2b(p15), and between BALB/c and Mus spretus for Cdkn2c(p18(INK4c)) were used to position these loci with respect to the Pctr1 locus. These cyclin-dependent kinase (CDK) inhibitors mapped to a 6 cM interval of chromosome 4 between Ifna and Tal1. C.D2-Chr 4 congenic strains harboring DBA/2 alleles associated with the Pctr1 locus contained DBA/2 "resistant" alleles of the CDK4/CDK6 inhibitors p16 and p15. On sequencing p16 and p18 cDNAs, two different allelic variants within ankyrin repeat regions of p16 were found between BALB/c and DBA/2 mice. By using an assay involving PCR amplification and restriction enzyme digestion, allelic variants were typed among several inbred strains of mice. One of the variants, G232A, was specific to two inbred strains, BALB/cAn and ABP/Le, of mice and occurred in a highly conserved amino acid in both human and rat p16. When tested with wild-type (DBA/2) p16, both A134C and G232A BALB/c-specific variants of p16 were inefficient in their ability to inhibit the activity of cyclin D2/CDK4 in kinase assays with retinoblastoma protein, suggesting this defective, inherited allele plays an important role in the genetic susceptibility of BALB/c mice for plasmacytoma induction and that p16(INK4a) is a strong candidate for the Pctr1 locus.     

When implicit learning fails: amnesia and the problem of error elimination

We propose that one of the major functions of explicit memory is the elimination of learning errors. The hypothesis is explored by means of a stem completion task in which subjects are presented with stems having many potential completions, and in the initial phase are either encouraged to guess, the "errorful" procedure, or are provided with the correct completion, the "errorless" condition. Learning is then tested over a sequence of nine trials. The performance of amnesic subjects who are assumed to have good implicit but bad explicit learning is compared with that of normal elderly subjects, who are assumed to have an intermediate level of explicit learning skill, and young controls who are expected to be high in both implicit and explicit learning capacity. As predicted, errorless learning is beneficial, with the effect being particularly marked for the amnesic group. A detailed analysis of the intrusion errors supports an interpretation of the results in terms of the relative contribution to the three groups of implicit learning, which is assumed to be particularly vulnerable to interference. Implications for the analysis of normal learning, and for the rehabilitation of brain damaged patients are discussed.