微纳卫星释放分离参数的测试方法

采用自由落体的试验方法,在地面模拟卫星在轨释放过程,测试某微纳卫星在轨释放速度、姿态以及对卫星星上设备的冲击,卫星的释放速度通过高速摄影的测量方法,卫星的释放姿态和星上设备的冲击响应通过集成在试验卫星上的测试系统测量。该试验方法可以一次测量出卫星的释放姿态、释放速度以及释放分离对卫星星上设备的冲击响应。

贵州大湾煤矿复杂地层井下定向钻进施工技术

针对大湾煤矿地区复杂煤层地质构造,采用前进式开分支孔布孔方法,用于探测煤层顶底板位置,精确探明煤层走向,为抽掘采提供依据,为后续工作做好前期准备。贵州大湾煤矿在历年瓦斯鉴定中均被定为瓦斯矿井,瓦斯孔施工采取普通钻进工艺时,会遇到钻进工作量大、孔深达不到要求、施钻轨迹无法精准控制、钻孔瓦斯浓度抽采率低等问题。采取顺层定向孔方法在已探明的煤层中施工长距离钻孔,可实现对复杂煤层远距离瓦斯抽采。现场试验表明:采用前进式开分支孔工艺,能够实现复杂煤层地质构造精确探顶,探明钻孔见煤段高达75%;通过优化钻孔设计与高精度控制钻孔轨迹大大增加了顺层定向孔在复杂煤层中的覆盖率,钻孔见煤段达63.7%,提高了瓦斯抽采效率,为巷道的抽掘采工作打好了基础。

一个新的锌(Ⅱ)配位聚合物的合成、结构及其可调节荧光性能

以4,4′-双(1H-咪唑基)联苯,5-苯基间苯二甲酸和Zn(OAc)_(2)·2H_(2)O为原料,在水热条件下合成了一个新的Zn(Ⅱ)配合物[Zn(L)(dib)]_(n)·3nH_(2)O[(1,H_(2)L=5-苯基间苯二甲酸,dib=4,4′-双(1H-咪唑基)]联苯,其结构经IR,元素分析和X-射线单晶衍射表征。

Influence of Boron Content in Iron Oxide on Performance of Mn-Zn Ferrites

The ferrites of PC30 （Mn-Zn ferrites） were prepared by using a dry processing route. The effect of Mn-Zn ferrites doped with H3BO3 was investigated on the basis of microstructure analysis. The results of the samples doped with H3BO3 less than 5 × 10^-5 showed that the doping had no significant effect on power loss, initial permeability, fine grain microstructure, and density of Mn-Zn ferrites. With the further increase in H3BO3 doping （up to 1 × 10 ^-4 ）, the microstructure of Mn-Zn ferrites is in the critical state between fine grain and ＂sandwich＂, and the initial permeability and density of Mn-Zn ferrites begin falling quickly; the increased H3BO3 doping also results in deteriorated power loss properties. Thus, the control of the boron content in iron oxide is of utmost importance for the quality of Mn-Zn ferrites in producing process.