高层框架-核心筒及衍生结构体系主要抗侧组件分析

为更加深入和系统地了解高层建筑中应用最广的框架-核心筒结构,基于构件的受力特点,首次提出了抗侧组件的概念,指出核心筒、腹板框架和翼缘框架为该种结构体系的三个主要抗侧组件。基于6栋普通框架-核心筒结构及衍生结构体系的高层塔楼,计算了主要抗侧组件所承担的倾覆力矩比例来衡量其抗侧能力,详尽剖析了抗侧组件的工作原理。通过量化各抗侧组件的抗侧效能,使框架-核心筒结构的抗侧体系设计更加明晰。结果表明:在普通框架-核心筒、筒中筒、带环桁架的框架-核心筒结构中,核心筒为关键抗侧组件;单独带巨撑或伸臂的框架-核心筒结构中,关键抗侧组件分别是腹板框架和翼缘框架。     

The lethal giant larvae Gene in Tribolium castaneum: Molecular Properties and Roles in Larval and Pupal Development as Revealed by RNA Interference

We identified and characterized the TcLgl gene putatively encoding lethal giant larvae (Lgl) protein from the red flour beetle (Tribolium castaneum). Analyses of developmental stage and tissue-specific expression patterns revealed that TcLgl was constitutively expressed. To examine the role of TcLgl in insect development, RNA interference was performed in early (1-day) larvae, late (20-day) larvae, and early (1-day) pupae. The early larvae injected with double-stranded RNA of TcLgl (dsTcLgl) at 100, 200, and 400 ng/larva failed to pupate, and 100% mortality was achieved within 20 days after the injection or before the pupation. The late larvae injected with dsTcLgl at these doses reduced the pupation rates to only 50.3%, 36.0%, and 18.2%, respectively. The un-pupated larvae gradually died after one week, and visually unaffected pupae failed to emerge into adults and died during the pupal stage. Similarly, when early pupae were injected with dsTcLgl at these doses, the normal eclosion rates were reduced to only 22.5%, 18.0%, and 11.2%, respectively, on day 7 after the injection, and all the adults with abnormal eclosion died in two days after the eclosion. These results indicate that TcLgl plays an essential role in insect development, especially during their metamorphosis.     

复合陶瓷BaTiO_3/Ni_(0.5)Zn_(0.5)Fe_2O_4的常温巨介电特性研究

采用传统的固相反应法和氧化物陶瓷工艺制备了无铅磁电复合陶瓷(1–x)BaTiO3/x Ni0.5Zn0.5Fe2O4(质量配比,x=0,0.2,0.5,0.8)(BTO/NZF),研究了NZF含量对复合陶瓷的物相组成、微观形貌、致密度和介电性能的影响。结果表明:当NZF含量较低(x=0,0.2,0.5)时,NZF对复合陶瓷有介电稀释效应;当NZF含量较高(x=0.8)时,复合陶瓷晶粒尺寸、致密度及两相间接触面积增大,其NZF含量达到复合陶瓷渗流阈值,产生Maxwell-Wagner(M-W)表面极化效应,使得复合陶瓷在低频(f=40 Hz)下具有高的巨介电常数(ε′=312 238)和较低的介电损耗(tanθ=0.40)。     

Recalcitrant tumor of the fifth metacarpal bone in a hemodialyzed patient

The article presents a case report about a 38‐year‐old hemodialyzed woman who presented to our department with a painful, expansile, lytic bone lesion of the fifth metacarpal epiphysis. The lesion was resected and replaced by corticocancellous bone graft. At 3 months, imaging suggested signs of graft resorption and local recurrence which necessitated repeat excision and grafting. Because of secondary parathyroidism subsequent subtotal parathyroidectomy was performed. This procedure leads to appropriate bone remodeling by 8 weeks postoperatively, and recurrence has not been observed at 2 years of follow up.     

超磁致伸缩力传感器及其实验研究

超磁致伸缩材料具有相对磁导率高、磁机转换率高等优良特性,对于传感器装置是一种很好的材料.文中基于维拉里效应原理完成了超磁致伸缩力传感器的设计,并利用有限元分析方法验证了所设计传感器磁场分布的合理性.提出了基于电感测童力传感器输出特性的方法,并进行了实验,确定了该传感器的灵敏度最高状态的最佳偏置磁场强度;并测量了0～10(3)作用力下传感器的输出特性,实验结果表明该传感器输出特性良好,可用于高精度要求的场合.     

三峡工程特大型混凝土施工系统模糊可靠性集成分析研究

针对三峡工程特大型混凝土施工系统可靠性研究,采用模糊可靠性集成分析的相关理论与方法,给出了特大型混凝土施工系统可靠性描述,提出并设计了适合于三峡工程应用的特大型混凝土施工系统可靠性模糊分析集成系统。     

Mn_2Sb_(0.95)Bi_(0.05)化合物的磁性和电输运性能

通过首先熔炼Sb0.95Bi0.05固溶体,然后再把该固溶体和Mn一起熔炼的多步骤熔炼法,成功地制备了Mn2Sb0.95Bi0.05化合物。样品的热磁曲线测量表明在亚铁磁的Mn2Sb基体中,通过Bi对Sb的替代可以在90K附近诱发亚铁磁到反铁磁转变。与这个一级变磁转变相对应,随着温度的降低,该化合物的电阻曲线在90K附近呈现异常的向上跳跃。电阻异常变化的机理可以被归结为反铁磁态下的超级布里渊区带隙的形成。     

脉冲电流对超磁致伸缩换能器影响实验研究

在分析超磁致伸缩换能器结构和工作原理的基础上,利用设计好的驱动电源激励超磁致伸缩换能器,研究了输入不同脉宽脉冲电流与换能器振幅输出之间的关系.研究结果表明,当脉宽为75 μs时,换能器的余震波最小,其首波振幅达到82μm,比输入脉冲电流滞后25 μs,主振频率为46 kHz并不随着脉宽的变化而变化.     

基于可控性柱面网壳结构主动控制作动器布置的优化研究

利用磁致伸缩材料的磁控特性制作的作动器可以对结构进行主动控制。首先分析了这种作动器的工作原理和设计方法,并通过实验对其进行了输出性能测试。接着在对作动器进行动力学建模的基础上,推导出整个柱面网壳结构的作动控制方程,同时基于作动效率,提出了不依赖于控制方法的位置优化准则,并且在综合考虑控制效果系数、硬件成本和系统复杂性等因素的基础上,初步确定了作动器的数量,然后采用遗传算法,对作动器的布置位置进行了优化。最后利用LQR主动控制算法,对一柱面网壳模型结构进行了主动控制分析。结果表明,通过优化布置的作动器能够有效地减小结构的动力反应,是一种较好的主动控制方法。此外,主动控制模拟结果也验证了应用遗传算法优化此类问题的优越性和可靠性。     

Cu层和Mo层对NiFe多层膜巨磁电阻（GMR）的影响

采用磁控溅射方法制备了ＮｉＦｅ／Ｃｕ和ＮｉＦｅ／Ｍｏ两个系列的多层膜，进行了结构，磁性和磁电阻测量，并对部分ＮｉＦｅ／Ｃｕ多层膜样品作了电镜分析，对于ＮｉＦｅ／Ｃｕ多层膜，在室温下的测量到巨磁电阻随Ｃｕ层厚度振荡的第一，二三峰。在ＮｉＦｅ／Ｍｏ多层膜样品中未发现巨磁电阻效应，讨论了非磁性 多层膜的磁性，界面结构和巨磁电阻效应。