血管入口区域长度问题

根据入口区域长度的定义，应用解析法研究了一个界定血管入口长度的方法．分析了刚性的及弹性的等截面圆直血管和圆锥形直血管的定常流动、非定常振荡流动等多种流动情况下的入口区域长度     

血管流动模拟实验的计算机控制及数据处理系统

对血管脉动流模拟实验提出了一种新型的计算机控制系统和数据处理系统．着重论述了这一系统的原理、功能和实施控制的各种软件处理方法．     

用挤出物胀大等方法测量聚合物熔体的第一法向应力差

在挤出机上安装自行设计的毛细管口模,对PP,HDPE和PS熔体采用挤出物胀大法在较高剪切速率下测量第一法向应力差N_1,发现:由于N_1受胀大比B和剪切应力τ_W的双重影响,因此弹性测试比粘性测试所需的毛细管口模长径比要大;将挤出物胀大法与其他测量N_1的方法进行综合的分析比较,结果表明,挤出物胀大法所测N_1值比较合理,并可满足一般工程计算的要求。     

烯丙基苯并噁嗪及其中间体的合成工艺研究

以3-氯丙烯、苯酚、甲醛和苯胺为原料,制备了烯丙基苯并噁嗪及其中间体烯丙基苯基醚、邻烯丙基苯酚.探讨了原料比、反应温度、反应时间对产物收率的影响.结果表明,邻烯丙基苯酚与苯胺、甲醛反应物质的量之比为1∶1∶2、反应温度为80℃、反应6 h时,烯丙基苯并噁嗪的收率可达到98.8%.     

A family study of endophenotypes for psychosis within an early intervention programme in Hong Kong: Rationale and preliminary findings

The study of endophenotypes may be a viable strategy to tackle the genetic complexity and phenotypic heterogeneity of psychosis, but this research direction is relatively under-developed in China as compared to Western countries. We have recently initiated one of the first family studies of endophenotypes for psychosis in China. Patients entering an established early psychosis intervention service are recruited into this research project for phenotyping, endophenotyping and genotyping. At the endophenotypic...     

The approximation of long‐memory processes by an ARMA model

A mean square error criterion is proposed in this paper to provide a systematic approach to approximate a long‐memory time series by a short‐memory ARMA(1, 1) process. Analytic expressions are derived to assess the effect of such an approximation. These results are established not only for the pure fractional noise case, but also for a general autoregressive fractional moving average long‐memory time series. Performances of the ARMA(1,1) approximation as compared to using an ARFIMA model are illustrated by both computations and an application to the Nile river series. Results derived in this paper shed light on the forecasting issue of a long‐memory process. Copyright © 2001 John Wiley & Sons, Ltd.     

Detection of Design Fault in Dart Placement - intersecting Dart

It is easy to apply lines in design drawings to create different styles, however, there is no guarantee that all the style lines drawn are able to be manufactured. In this paper, we focus on one undeliverable style to enhance our understanding of the relationship between the design sketch and the pattern design process. In order to evidence that such style is unworkable, a systematic display of pattern development, and to be reinforced by mathematical evaluation, will be introduced and addressed. When one can easily detect design fault, waste of product development time can be minimized.     

左思《蜀都赋》的创作观及资料来源初探

左思,既非蜀人,又未曾涉足蜀地,其《蜀都赋》却成就了＂洛阳纸贵＂的千古文章盛事。从史料中还原左思潜心十年的写作情形,结合历来评论,考辩他重本实的创作观。进而以文本为依据探讨左思既从史书方志、前人诗赋作品,以及寻访人物等广泛的资料来源。     

Plant genetics: increased outcrossing in hothead mutants

Arising from: S. J. Lolle, J. L. Victor, J. M. Young & R. E. Pruitt 434, 505-509 (2005); Lolle et al. reply. Lolle et al. report that loss-of-function alleles of the HOTHEAD (HTH) gene in Arabidopsis thaliana are genetically unstable, giving rise to wild-type revertants. On the basis of the reversion of many other genetic markers in hth plants, they suggested a model in which a cache of extragenomic information could cause genes to revert to the genotype of previous generations. In our attempts to reproduce this phenomenon, we discovered that hth mutants show a marked tendency to outcross (unlike wild-type A. thaliana, which is almost exclusively self-fertilizing). Moreover, when hth plants are grown in isolation, their genetic inheritance is completely stable. These results may provide an alternative explanation for the genome wide non-mendelian inheritance reported by Lolle et al.     

苏州城市竞争力的理性思考

城市是一个相对独立的利益主体,在发展和竞争中追求自身利益的最大化,由城市所具有的竞争优势、比较优势、领先优势、绝对优势等因素综合形成的力量即是城市竞争力。城市竞争是关于其价值增长以及地位提升的竞争,研究城市竞争力的主要目的在于制定竞争战略。