Low Temperature Specific Heat of Amorphous Alloys

A low temperature specific heat model for amorphous alloys was proposed by comprehensive applications of Debye model, two-lever scattering model, and energy band theory. In this model, the low temperature specific heat was considered to be composed of the parts contributed from the lattice as well as that from electrons, and the former part is resulted from the atoms periodically arranged besides those disorderly distributed, and a specific heat formula, which is suitable for amorphous alloys at low temperature, C _p =α T ³+β T, was derived by theoretical analysis. Results show that there is a perfect linear relationship between C _p /T and T ², and many experiment results can be explained satisfactorily by using this model.     

超声波传感器在料位测量中的应用

简要介绍超声波传感器的料位测量原理,从换能器材料结构、电路和回波处理软件两方面提出改进意见和方法,并探讨在探头安装方面应注意的几个问题,达到提高超声波传感器在固态料位测量中应用水平的目的。     

电影与建筑设计

我爱看电影，但工作后就很少有机会去影院了（对我来说那是一种很遥远、很奢侈的事情了）。因此，我买了很多的影碟，无论大片小品，不分类型、国家，只要觉得有意思就留下，先堆在家里。只要一有机会，我就会打开电脑，将影碟放入机器中，然后便陶醉于电影的世界中。为此，我家中的影碟堆积如山，曾经粗相的统计过，至少在几千张以上。     

TiB2／Al自润滑复合材料在动压马达零件上的应用研究

复合材料组织致密，颗粒分布均匀．与基体结合紧密．具有较高的弹性模量和抗弯强度。室温下与GCr15轴承钢对磨时其摩擦系数在0．2左右．自磨时摩擦系数在0．08左右．摩擦表面没有明显的粘着或犁削痕连．磨损率明显低于SiCr／Al复合材料和GT35合金．呈现出较好的自润滑性能。     

MnO_x/rGO复合材料的水热合成及电容性能

以氧化石墨(GO)为载体,KMnO_4为Mn源,水合肼为还原剂,采用水热法一步合成MnO_x/rGO复合材料,探索KMnO_4与GO质量配比(w)对复合材料结构和电容性能的影响。实验结果表明,w对MnO_x/rGO复合材料的组成和形貌影响显著,当w为1∶3时复合材料主要由大量的Mn_3O_4和rGO(还原氧化石墨)组成,同时含有少量Mn OOH杂相,当w增大至1∶1时新出现少量MnCO_3杂相。随着w增大,rGO表面的MnO_x负载量逐渐增多,颗粒也逐渐长大变粗。MnO_x与rGO两者复合兼具了良好的导电性和高的电容量,当w为1∶1时,MnO_x/rGO复合材料在电流密度为0.05 m A/cm~2条件下的电容量为257 F/g,经过500次循环后容量保持达90.7%。     

从文献计量角度看国际天然气水合物研发态势

以ISI Web of Know ledge信息平台提供的SC I(网络版)数据库、IN SPEC数据库和D II数据库为数据源,以Derwent Analytics软件为分析手段,对1995―2005年期间发表/申请的国际天然气水合物研究论文/创新专利的年度分布、国家分布、机构分布、期刊分布和作者分布情况作了分析与比较,从文献计量角度指出了国际天然气水合物的研发主要集中在美、日、俄、加、英、德、法、中、挪等国的国立科研机构、政府部门和大学。同时分析了中国天然气水合物的研究概况。     

一种塔式起重机自动倍率转换装置的设计

阐述了塔式起重机现有的倍率转换方式,分析了现有方式的优缺点.提出了一种结构简单的新型自动倍率转换方法,并建立倍率转换结构关键部位的接触曲线模型,保证了此倍率转换的平稳性.     

In-Plane and Out-of-Plane Magnetoresistance in Bi2Sr2CaCu2O8+x with Various Carrier Densities

The in-plane and out-of-plane magnetoresistance of Bi ₂ Sr ₂ CaCu ₂ O _8+x single crystals was investigated in magnetic fields of 12 T, oriented parallel to the c axes. Crystals with different carrier concentrations, corresponding to the underdoped, optimally doped, and overdoped region of the phase diagram of high-temperature superconductors, were prepared by variation of the oxygen content. Above the critical temperature, the magnetoresistance is positive for in-plane and negative for out-of-plane currents in all samples. With recent theories for superconducting order-parameter fluctuations, the in-plane magnetoresistance can be described well for all samples. Only the out-of-plane magnetoresistance of the underdoped crystal shows distinct deviations from the theoretical predictions and appears to be influenced by the pseudo-gap.