钢-混凝土组合楼盖空间作用的试验研究

为了研究钢混凝土组合楼盖的空间作用,采用伪静力试验方法对按1/4比例缩小的单跨、4层、4柱距的钢框架、带水平支撑钢框架、组合框架以及带水平支撑组合框架模型进行了弹性比较试验,并对组合框架结构模型进行了破坏试验。试验结果表明,钢混凝土组合楼板能够满足水平荷载作用下协同框架结构整体受力的要求。在弹塑性阶段,混凝土楼板和钢梁之间仍然能够通过栓钉共同工作,有效地减小水平荷载作用下框架结构的侧向位移。试验验证了组合楼盖传递水平荷载的有效性,为进一步的理论研究提供了参考。     

以创新能力培养为目标,创建具有“产、学”结合特色的实践教学体系

本文叙述了“产、学”结合的实践教学新体系。阐明了具有地方专科、“产、学”结合以及工程研发为特色的实践教学环节。取得的成果包括优化整合基础实验室、强化电工电子实习、增设技术岗位工程实践教学环节、自研自制大型自动控制设备 ,以及培养和造就一批务实的能打硬仗的师资队伍     

Characteristics of decadal-centennial-scale changes in East Asian summer monsoon circulation and precipitation during the Medieval Warm Period and Little Ice Age and in the present day

Using meteorological observations, proxies of precipitation and temperature, and climate simulation outputs, we synthetically analyzed the regularities of decadal-centennial-scale changes in the summer thermal contrast between land and ocean and summer precipitation over the East Asian monsoon region during the past millennium; compared the basic characteristics of the East Asian summer monsoon (EASM) circulation and precipitation in the present day, the Little Ice Age (LIA) and the Medieval Warm Period (MWP); and explored their links with solar irradiance and global climate change. The results indicate that over the last 150 years, the EASM circulation and precipitation, indicated by the temperature contrast between the East Asian mainland and adjacent oceans, had a significant decadal perturbation and have been weaker during the period of rapid global warming over the past 50 years. On the centennial time scale, the EASM in the MWP was strongest over the past 1000 years. Over the past 1000 years, the EASM was weakest in 1450?C1570. When the EASM circulation was weaker, the monsoon rain belt over eastern China was generally located more southward, with there being less precipitation in North China and more precipitation in the Yangtze River valley; therefore, there was an anomalous pattern of southern flood/northern drought. From the 1900s to 1920s, precipitation had a pattern opposite to that of the southern flood/northern drought, with there being less precipitation in the Yangtze River valley and more precipitation in North China. Compared with the case for the MWP, there was a longer-time-scale southern flood/northern drought phenomenon in 1400?C1600. Moreover, the EASM circulation and precipitation did not synchronously vary with the trend of global temperature. During the last 150 years, although the annual mean surface temperature around the world and in China has increased, the EASM circulation and precipitation did not have strengthening or weakening trends. Over the past 1000 years, the weakest EASM occurred ahead of the lowest Northern Hemispheric temperature and corresponded to the weakest solar irradiance.     

虚拟企业中多媒体信息的混沌加密方法

论述了混沌加密原理,设计了混沌加密算法,混沌加密算法是对称加密算法·分析了混沌加密的效率及安全性·给出了对多媒体信息的加密结果,指出混沌加密是非常有效的加密方法·对使用Java实现虚拟企业中多媒体信息的混沌加密的一些技术问题做了讨论和处理·     

窄带钢卷取张力的探讨

通过对某厂３５０－３００冷轧机组的测试，分析了其张力制度，并应用恒张力控制原理分析了卷取张力不恒定的原因，提出了改进措施。文中还结合现场实际情况，分析了带钢板形、厚差与张力的关系，找出了产品质量不佳的主要原因。     

一些常数的几何性质

设X是巴拿赫空间,研究高继的几个常数E(t,X),e(t,X),F(t,X),f(t,X)的几何性质,其中包括它的上下界和它与其它一些经典常数的关系.最后给出了蕴含正规结构的一些充分条件.     

基于核心-边缘理论的区域结构及其演化研究

从就业人口的比重和密度切入,以全国第五次人口普查和2000年到2005年的中国城市统计年鉴为基础,运用定量方法和GIS表现手段,分析了江苏省静态的区域经济结构及其演化,力求反映其区域经济分布的时空规律性.     

靶场内外场一体化仿真体系结构及时间管理

靶场内外场一体化仿真试验可以有效利用靶场内、外场现有的资源和系统,将内场中的各种仿真试验资源和外场各种实装系统联合起来,为虚拟靶场提供综合试验能力,使得内、外场试验有机地融为一体。首先针对靶场内外场一体化仿真试验的应用需求,提出了基于数据分发服务(data distribution service,DDS)的层次化仿真体系结构；然后设计并实现了针对该体系结构的基于网关的时间管理方法,并提出了一种基于全球定位系统(global positioning system,GPS)的时间同步方法；最后通过在实际靶场中进行测试评估,验证了该体系结构、时间管理方法的有效性。     

准Z源升压变换器的软开关技术仿真研究

在具有相同输入电压、开关管占空比相等的条件下,准Z源升压变换器拓扑可以提供比传统升压变换器拓扑更高的输出电压,具有效率高、实用输出电压范围广的优点。在准Z源升压变换器的基础上设计了一种软开关电路,用辅助开关管代替原拓扑中的二极管,实现了主开关管的零电压开通。在MATLAB/Simulink环境下对该软开关电路进行了仿真。仿真结果表明,改进后的准Z源升压变换器能降低主开关管的开关应力与续流二极管的通态损耗,增强了系统的稳定性,可以提高开关器件的使用寿命。     

滚动轴承内圈滚道表层残余应力分布实验研究

以B7008C/P4滚动轴承内圈滚道为例,将剥层与X射线衍射法相结合,测量了轴承内圈滚道表层残余应力分布状态,并采用有限元法分析了剥层造成的应力释放,修正了残余应力测量值.研究结果表明:当滚道表层剥除厚度为微米级时,残余应力测量值与修正值之间的最大相对误差为3.9%,并且随着剥除厚度的增大,应力释放效果愈加明显.国内外同型号(B7008C/P4)轴承对比分析表明:国外轴承内圈滚道表面残余压应力更大,近表层残余压应力的剧烈变化深度更大,更有利于提高轴承的疲劳寿命.