Characteristic Functions over C*-Probability Spaces

Various properties of the characteristic functions of random variables in a non- commutative C*-probability space are studied in this paper. It turns out that the distributions of random variables are uniquely determined by their characteristic functions. By using the properties of characteristic functions, a central limit theorem for a sequence of independent identically distributed random variables in a C*-probability space is established as well.     

湘中晚泥盆世早期的两个古群落分析

利用生态地层工作方法对湘中晚泥盆世早期的化石群落进行了研究,并划分出两个古群落,较详细地分析了各群落的生物组成、分异度、相对丰富度、生物的生活方式、基底物质性质等。群落总是与其生存的特定空间环境相联系,每个群落有其自身的生物组成和发展过程。     

Developmental exposure to organic lead causes permanent hippocampal damage in Fischer-344 rats

Summary The long-term consequences of neonatal exposure to triethyl lead, the putative neurotoxic metabolite of the anti-knock gasoline additive tetraethyl lead, were examined with respect to central nervous system (CNS) development. We presently report a series of studies in which exposure of neonatal rats to organic lead produces profound CNS damage in adulthood as indicated by dose-dependent, persistent behavioral hyperreactivity as well as dose-dependent, preferential, and permanent damage to the hippocampus. General morphological parameters of brain development were not altered. Pharmacological probes of neurotransmitter system integrity suggested a functional and dose-dependent relationship between this behavioral hyperreactivity and hippocampal damage via cholinergic, but not dopaminergic, pathways. Furthermore, these alterations were not accompanied by long-term alterations in motor activity and were not attributable to the presence of lead in adult neural tissue. Finally, these behavioral, anatomical, and pharmacological indices of developmental exposure to organic lead were dissociable from any effects of early undernutrition. These data collectively indicate that organolead compounds may pose a potent neurotoxic threat to the developing CNS.     

随机利润的集中数

假设需求量ξ是随机变量，销售利润为其中Ｐ＞０是产品单价，ａ≥０是产品单位可变成本，ｂ≥０是固定成本，ｃ＞０是企业最大生产能力．本文对这类随机利润的集中数：数学期望、中数和众数进行了研究，得到了许多重要结果．本文结果对企业的经营管理和决策有一定理论参考价值．     

Neuronal and glial markers of the central nervous system

Summary This brief review evaluates the expression of cell-specific markers on differentiated neural cells and, where necessary, on their developing precursors. Within these limitations only the commonly used markers are discussed and those deemed unequivocal are only briefly appraised.     

对ZF～1仪评定体育考生灵敏素质的可行性分析

本文提出一种评定体育考生灵敏素质的新方法(ZF～1仪测试法),通过与经验法的比较,证明新方法是一种简便、精确、客观可行的评定方法。     

两栖类发声与发声中枢的研究——回顾、现状、展望

近年来,动物发声与发声机制的研究取得了长足的进展,在两栖类动物中,发声行为的中枢调控以及听觉、激素的作川机制已经有了较深入的认识。本文试图对这方面的研究历史、现状以及未来进行综合性论述和评价。     

中原城市群的职能分类探讨

运用区位商和统计分析的方法,对中原城市群九个城市进行了统一的职能分类,发现了存在的问题,并提出了优化对策．     

滇中城市群景观格局及生态环境效应研究

滇中城市发展面临资源环境人均拥有不足、资源分配不均以及生态环境脆弱等各种压力。选取1990年、2000年、2010年、2018年四期美国4～5号陆地卫星专题制图仪扫描影像(thematic mapper, TM)所获取的多波段。影像,研究滇中城市群土地利用时空变化及其景观格局演变特征和生态环境效应。结果表明：除建设用地外其他用地破碎度逐步增加,形状变得复杂,随着城市的发展,除建设用地景观类型连接度增加,其余用地降低且破碎化程度增加;滇中城市群地均生态系统服务价值整体表现为降低、空间上表现为东低西高,区县间差异大,生态环境整体趋于恶化趋势,引起生态环境改善的因素是林地、水域与耕地转为建设用地;当坡度小于3度时,水文调节废物处理值较大,当坡度大于3度时,生物多样性保护与土壤形成与保护值较高,而食物生产与美学景观值较低。林地、水域聚集的地区集聚类型表现为高-高聚类,建设用地聚集的地区集聚类型表现为低-低聚类;滇中城市群内有约59%的区县生态环境质量下降,有32%的地区上升。滇中城市群的发展要侧重改善用地结构和效能,加大环境保护力度。     

Central limit theorem for the occupation time of catalytic super-Brownian motion

The catalytic super_Brownian motion has been considered. If both the catalytic medium process Q and CSBM started with Lebesgue measure λ, the central limit theorem for occupation time of CSBM has been obtained in dimension 3 for P-λ_a.s.Q.