不同年龄自发性高血压大鼠血管平滑肌Ca2+/CaM-PP活性变化

目的研究不同年龄自发性高血压大鼠血管平滑肌Ca2+/CaM-PP活性变化.方法应用酶活性测定方法,对12周、16周SHR大鼠和Wistar大鼠的A、MA、CA血管平滑肌Ca2+/CaM-PP进行活性比较.结果Wistar大鼠随年龄增长,Ca2+/CaM-PP活性呈上升趋势,而SHR鼠其阻力血管该酶活性降低,但随年龄变化不明显.结论①自发性高血压使阻力血管平滑肌Ca2+/CaM-PP下降,但12周与16周间无显著差异.②不同种鼠血管平滑肌该酶活性变化不同.     

一种测量钛酸钡/聚氨酯材料电致伸缩性能的新方法

提出利用数字散斑相关方法测量材料的电致伸缩性能的新方法.通过数字散斑相关方法得到面内位移,从而由几何三角关系得到离面位移,实现电致伸缩应变的测量.采用该方法对高电场作用下钛酸钡/聚氨酯复合高分子材料的电致伸缩性能进行了测量.在高电场作用下,对重复加电放电过程进行分析,得到电致伸缩应变,从而获取材料的电致伸缩系数.实验中采用双线性插值方法获取亚象素灰度值,以提高测量精度,并将结果与曲面拟合算法的计算结果进行了比较.结果表明:钛酸钡的加入提高了聚氨酯材料的电致伸缩性能;数字散斑相关方法可以有效地实现材料的电致伸缩系数的测量.该方法为电致伸缩性能的研究提供了一种有效的工具.     

光纤通信系统中2/8转换单元的设计

提出了以2／8转换芯片为核心的2／8转换单元的一种设计方案，将CPLD／FPGA技术与光纤通信技术结合，其技术指标符合ITU—T建议G．703的要求，使产品外围电路简单，成本低，可靠性高。     

Toronto multiagency child abuse research project: The abused and the abuser

Information from 422 cases of child mistreatment in Toronto was gathered from the files of a child welfare agency and a children's hospital. These data were compared to patterns reported in previous studies and clinical writings on child mistreatment to investigate similarities and differences in families whose children have been abused in Canada, England, and the United States. Findings from the present study were similar to others in many respects. The differences were primarily in the area of lower incidences of such problems as perinatal difficulties in the children and intellectual limitations and social isolation in the parents; however, there was a higher incidence of single-parent families. The results suggest that clinicians should bear in mind that child mistreatment cannot be ruled out on the grounds that no serious problems have been noted for the child or the family.     

“Students Get What Flows Downward”: District Leaders’ Rationalizations of the Standardized Testing of Children

What do students stand to gain from high-stakes, standardized testing? We consider answers to this question from the perspective of urban district leaders tasked with designing and overseeing the implementation of standardized testing policies. Results revealed variation in leaders’ framing of and rationale for standardized testing with respect to benefits for students and whether/why students should strive for high test scores. Implications for both approaches to standardized testing and broader improvement initiatives are discussed.     

试说"-V/V"式

本考察了“-V／V”式的各个构成成分的句法和语义特点;探讨了该句式在语法分布上的特点,即该句式一般只出现于肯定句和表示肯定的反问句中而不出现于否定句中;研究了该句式在语用表达上的作用,着力解释了动词后成分所具有的超乎寻常性及其形成的原因。     

Delphi7.0下多层分布式数据库管理系统的实现

介绍了两层的Client/Server结构模式和多层的Client/Server结构的优缺点以及在Delphi7.0下多层Client/Server结构的设计方法和关键技术。     

Differences in Graduation Rates Between Young Black and White College Students: Effect of Entry into Parenthood and Historically Black Universities

Black and White students who enrolled in college by age 20 were selected from a national probability sample, in order to estimate the prevalence of having children and the effect of having a child on probability of graduation with a bachelors degree. Black students reported significantly higher rates of having children than White students, but rates for Black students at historically Black universities were similar to those of Black students at predominantly White universities. After controlling for family background, achievement, and other student characteristics, having a child within 5 years of starting college generally reduced the probability of graduating with a bachelors degree for Black women and White women and men. The independent effect of attending a historically Black college was significantly positive for Black women but not statistically significant for Black men.     

基于SSL协议的Web信息安全研究与实现

目前校园网中学校的管理和教学工作大部分是基于B／S模式的，由于Browser和Web Server之间通信时所使用的HTTP协议存在安全隐患，因此本文从信息安全的角度，分析讨论了数据加密、SSL协议的基本原理，并为校园网的Web信息安全给出了完整的解决方案。     

基于SPKI/SDSI证书的Web服务访问控制模型

文中概述了SPKI/SDSI,分析了Web服务的特点和对其访问的安全需求,提出了一种基于SPKI/SDSI证书的Web服务的访问控制模型,给出了保证其安全性的解决方法,并对SPKI/SDSI证书进行了扩展。