均质球体在半圆形凹槽中的运动分析——一维方向可自由移动的半圆形凹槽的情形

用动力学的方法,建立均质球体与一维方向可自由移动的半圆形凹槽组成的系统的运动微分方程,进一步分析均质球体在半圆形凹槽内做无滑滚动的临界角,并求出均质球体大角度振动周期的精确公式和近似公式.     

New experimental measurement of natSe(n, γ) cross section between 1 eV to 1 keV at the CSNS Back-n facility

The ⁷⁴Se is one of 35 p-nuclei, and ⁸²Se is a r-process only nucleus, and their (n, γ) cross sections are vital input parameters for nuclear astrophysics reaction network calculations. The neutron capture cross section in the resonance range of isotopes and even natural selenium samples has not been measured. Prompt γ-rays originating from neutron-induced capture events were detected by four C₆D₆ liquid scintillator detectors at the Back-n facility of China Spallation Neutron Source (CSNS). The pulse height weighting technique (PHWT) was used to analyze the data in the 1 eV to 100 keV region. The deduced neutron capture cross section was compared with ENDF/B-VIII.0, JEFF-3.2, and JENDL-4.0, and some differences were found. Resonance parameters were extracted by the R-matrix code SAMMY in the 1 eV-1 keV region. All the cross sections of ^natSe and resonance parameters are given in the datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00019.     

非晶(Fe0.99Mo0.01)78Si9B13,Fe78Si9B13合金激波晶化主相α-Fe变化研究

研究激波对非晶FeBSi,FeMoBSi合金的影响,经X射线衍射分析,测定主晶化相α-Fe(Mo,B,Si)晶格常量.结果表明：晶格常量比正常值偏小,用双势模型计算晶格常量,理论值与实验符合得很好.从而肯定晶格常量变小是形成B的替代式固溶体和缺位式固溶体所致. 关键词：     

Fe73.5Cu1Nb3B9Si13.5非晶态合金的激波纳米晶化研究

实验表明,非晶态合金在激波影响下会转变为纳米晶.最近的实验进一步发现,Fe_73.5Cu₁Nb₃B₉Si_13.5非晶态合金中的Cu,Nb在激波晶化中的细化作用被抑制,且样品在这种转变之后作进一步的退火处理,其晶粒度变大而晶格常数变小.在激波晶化机理分析中提出了“激波流体晶化”构想. 关键词：     

非晶、纳米晶材料的历史与现状

 一、非晶金属的发现人类使用了八千多年的金属(从青铜开始)且一直都是多晶态金属,1934年,克拉默在真空中把金属蒸发到冷基底(玻璃)上,经X射线测定,发现这种金属膜中原子的周期性消失了,这是人们第一次发现非晶金属.此后不久,布伦纳(1937)用电解沉积法得到了Ni-P非晶合金.     

Influence of defect states on band gaps two-dimensional phononic crystal in the of4340 steel in an epoxy

The band structures of a new two-dimensional triangle-shaped array geometry of 4340 steel cylinders of square cross section in an epoxy resin were studied by the plane-wave expansion and supercell calculation method. The band gaps of this type of phononic crystals with different defects were calculated such as defect-free, 60 crystal linear defect states, 120 crystal linear defect states, and 180 crystal linear defect states. It was found that the band gap will emerge in different linear defects of the phononic crystals and the bandwidth of linear defect states is larger than that of the free-defect crystal by about 2.14 times within the filling fraction F = 0.1-0.85. In addition, the influence of the filling fraction on the relative width of the minimum band gap is discussed.     

范德瓦耳斯气体直线过程的若干讨论

首先对各种范德瓦耳斯气体在同一条确定直线过程中的温度转换点和吸放热转换点进行求解,随后绘制出温度以及吸放热特性对斜率和体积的依赖关系三维图,最终找到了影响温度和吸放热转换点的因素.     

用数值计算的方法研究面光源的牛顿环干涉及干涉条纹的可视化

运用MATLAB软件模拟了平行光垂直照射时的牛顿环,平行光非垂直照射时的牛顿环以及面光源情况下的牛顿环。     

4×n阶网络的等效电阻理论及实验研究

应用矩阵变换方法研究了4×n阶电阻网络侧端等效电阻,求解了差分方程组,并计算出n取有限值和趋于无穷大时,4×n阶电阻网络的等效电阻.用NI Multisim 10模拟软件对4×n阶电阻网络进行模拟实验测量,实验结果与理论值相符.