Racial similarity as a moderator variable in the perception of leader behavior and control     

M.Peter Scontrino  James R Larson  Fred E Fiedler 《Int J Intercult Relat》1977,1(2):111-117

This study compared leader behavior ratings of black and white Army infantry squad members serving in squads led either by black or white leaders. One black and one white squad member, chosen at random from each of 34 racially mixed squads, rated their leader's Consideration and Initiation of Structure behaviors (Stogdill, 1963), and their leader's behavior relevant to French and Raven's (1959) five bases of social power. In general, it was found that members who were of the same race as their leader rated him as significantly less likely to use punishment-related behaviors than did members who were of a different race than their leader. However, same-race members did not rate their leader's considerate or structuring behavior differently than did different-race members. The overall pattern of findings were discussed in terms of the leaders' implicit reliance on their punishment power to obtain compliance from different-race subordinates.  相似文献   

基于PIC单片机及阵列电路方式控制大量外设的研究     

陈征  王剑 《科技广场》2012,(10):94-97

本文介绍了PIC单片机的特点,以及利用该芯片、移位寄存器74LS164和阵列电路控制继电器的开关闭合,来实现对大量外部设备的控制。该方法的实现可以有效地节省大量的单片机I/O引脚的使用个数,特别是在一些要实现的功能较多的工程中,效果更为显著。  相似文献   

游泳训练对Ⅱ型糖尿病Wistar大鼠肠系膜动脉舒张功能改善作用的研究     

崔贺成 《山东体育学院学报》2012,28(1):57-61,66

目的:通过建立wistar大鼠Ⅱ型糖尿病动物模型,观察Ⅱ型糖尿病(T2DM)模型大鼠,经游泳训练后肠系膜动脉舒张功能的变化,并探讨其内在影响机制。方法:实验材料wistar大鼠60只,造模完成后随机分成3组:正常对照组(CON),Diabetes模型组(DI),游泳运动组(SEX),每组15只。进行游泳训练共计8周。结果:T2DM可造成肠系膜动脉血管舒张功能降低(P<0.05),且存在内皮依赖性。舒张功能的降低与eNOS-NO系统活性降低直接相关。游泳训练可有效维持内皮依赖性舒张功能(P<0.05),其上调eNOS-NO系统。另外,T2DM造成的eNOS-NO系统活性降低与该系统上游蛋白PI-3K,Akt降低有关,且在加入上游蛋白抑制剂(PI-3K)LY294002及eNOS阻断剂L-NAME后保护效应消失。结论:游泳训练能改善T2DM wistar大鼠肠系膜舒动脉舒张功。其内在保护作用可能是通过部分激活PI-3K-Akt-eNOS信号通路而实现。  相似文献   

F4方程式摩托艇比赛电子计时系统的设计     

高鹏  王敏 《湖北体育科技》2012,31(5):543-545,499

为了提高摩托艇比赛计时系统的精确性和高效性,设计了一种电子计时系统,系统以单片机AT89C51为微控制单元,通过激光传感器,对激光进行感知,并将激光信号转化成电信号传递给单片机,系统设计了两种模式,一种是排位赛模式,第二种是竞速赛模式,分别编写了两套程序,单片机根据程序可以准确执行指令,实验表明,次电子计时系统大大提高了裁判的准确度,以及成绩编排效率,而且完全可以符合现有摩托艇的比赛规则。  相似文献   

一种基于C8051F060的声波信号采集系统的设计     

曾维 《科技通报》2012,28(4):63-64

为了监测某区域某频率段内声波信号的强弱,提出一种以C8051F060为控制核心的声波信号采集系统的设计方案。采用压力场声波传感器将可识别的声波信号转换为适当幅度的电信号,该信号经过由程控滤波器地处理后直接送至带高速ADC的单片机进行处理,最后以SYG2401281图形点阵液晶为显示器件实现声波信号的实时显示。  相似文献   

基于TMS320F2812的CANopen协议的通信实现     

张文勇 《兰州石化职业技术学院学报》2010,10(4):31-33

CANopen是一种开放的现场总线协议,是欧洲嵌入式工业控制网络的主要标准协议.在分析CANopen协议的对象字典、设备模型和通信对象等的基础上,采用CANopen协议的子协议DS301实现了基于CAN总线的TMS320F2812与主控模拟调试软件之间的通讯,并通过测试验证了通讯过程中信息传递的正确性和可靠性.  相似文献   

9,10-二苯乙炔基蒽的合成及光谱性质研究     

李智勇  崔书亚 《绵阳师范学院学报》2010,29(5):54-56

本研究以二溴蒽和苯乙酮为原料,通过Sonogashira钯催化偶联反应,四氢呋喃和二乙胺混合溶剂作为偶联反应溶剂,以较高的收率获得了标题化合物,且运用IR,UV,熔点等手段进行了结构鉴定,并通过紫外光谱和荧光光谱研究了其光谱性质。  相似文献   

基于VPC3+C的Profibus-DP智能从站设计   总被引：1，自引：0，他引：1  

姜日新  宋延民  张平  雷贵亮 《天津工程师范学院学报》2010,20(4)

从开发的角度介绍了VPC3+C芯片的主要功能和单片机C8051F020以及软硬件设计的主要思想,分析了Profibus-DP从站的状态机,并介绍了从站与主站通讯所需的GSD文件.  相似文献   

Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways     

Feng Gao  Xin-yang Hu  Xiao-jie Xie  Qi-yuan Xu  Ya-ping Wang  Xian-bao Liu  Mei-xiang Xiang  Yong Sun  Jian-an Wang 《Journal of Zhejiang University. Science. B》2010,11(8):608-617

Mesenchymal stem cell(MSC)transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90)against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Apoptosis was assessed by Hoechst 33258nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4)and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2)was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,totaI-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.  相似文献   

基于PIC18F4550和DirectDraw技术的廉价高速虚拟示波器     

邢文生  张宏 《焦作大学学报》2010,24(1):100-102

因价格原因,廉价虚拟示波器存在数据采集速度慢、数据传输到计算机的速度慢、波形显示反应慢等瓶颈等问题。文章使用A／D转换芯片MAX1002实现模拟量的高速采集,使用USB单片机PIC18F4550实现数据的高速传输,使用DirectDraw技术解决显示速度慢问题。文章详细论述了系统的硬件与软件设计。  相似文献