应用于空间惯性传感器的压电驱动器的性能测试

为保证空间惯性传感器的正常在轨运行,在发射阶段需保证测试质量固定以避免与周围电容极板的接触碰撞;到达预定轨道后再重新捕获并以最小残余线速度将测试质量释放至精确位置,保持自由悬浮状态。测试质量的捕获定位对驱动器提出高精度的要求。本文针对在太空中捕获定位释放测试质量所用的压电直线驱动器进行了设计定制与性能测试。试验结果表明:该定制的压电驱动器最小步长小于1 nm,但步长稳定性误差较大;150 V工作电压条件最大驱动力达72 N;单步行进驱动力稳定;夹持测试质量过程中,驱动力稳定,稳定性偏差为0.16%。满足捕获、定位、释放机构的使用需求。     

基于社会性科学议题促进核心素养发展的元素化合物教学*——以“论证重雾霾天气‘汽车限行’的合理性”为例

在“氮及其化合物”教学中,利用社会性科学议题“论证重雾霾天气‘汽车限行’的合理性”,通过直面议题激发原始想法、探讨汽车尾气与雾霾是否存在关系、探讨汽车尾气是不是导致雾霾的主要原因、面对议题的科学决策的具体教学环节,促进学生掌握氮及其化合物的主要性质,建立从物质类别、元素价态视角研究物质性质及转化的思路方法,促进多个维度核心素养的融合发展。经过多轮次教学改进,结合教学实践过程及其教学效果抽提出真实情境的创设、驱动性问题的设计、课前、课上和课后3个阶段统筹安排等教学策略。     

Synthesis of tetrahydroisoquinolines through TiCl4-mediated cyclization and Et3SiH reduction

A versatile and efficient telescoped reaction sequence for the synthesis of tetrahydroisoquinolines(THIQs)is reported that uses TiCl4 to promote cyclization of a benzylaminoacetal derivative and Et3SiH for reduction of the intermediate 4-hydroxy-THIQ.This method is complimentary to the classical Pomeranz-Fritsch and related reactions since it tolerates electron-withdrawing substituents and allows access to 8-substituted THIQs.     

A set of novel multi-allelic SNPs for forensic application developed through massively parallel sequencing and its examples of population genetic studies

Massively parallel sequencing (MPS) technology allows to simultaneously type multitudinous molecular genetic markers for many samples in one run with the feature of high detection resolution, and thereby arouses the increasing attention from forensic science. Herein, multiple allelic single nucleotide polymorphisms (multi-allelic SNPs) were screened for personal identification and parentage testing, and then were genotyped using MPS platform. Unrelated individuals of Chinese Mongolian and Kazakh groups were investigated to further estimate forensic effectiveness and applicability of these multi-allelic SNPs. The results of sequencing efficiency estimations and forensic genetic statistical parameters demonstrated that this MPS panel of multi-allelic SNPs was expected to be work for forensic applications. Subsequently, the exploration of population genetic variation patterns among the two investigated groups and other 26 reference populations revealed that these Chinese Mongolian and Kazakh groups had the similar population genetic patterns with the populations from East Asian, but European ancestral composition in the Kazakh group was higher than that in the Mongolian group. Currently, the present results were the preliminary research to scrutinize genetic information of these two ethnic minority groups employing multi-allelic SNPs.     

理论设计ZnTiS3化合物光电性能的第一性原理计算

根据实验上合成LiNbO₃(LN)构型的ZnTiO₃铁电化合物,基于第一性原理的方法设计研究了化合物LN-ZnTiS₃(LN构型)的特性。计算结果表明LN-ZnTiS₃化合物满足力学稳定条件。根据化学势平衡相图分析,LN-ZnTiS₃在常压下不会形成稳定结构,但施加外部压力可以形成稳定结构。电子态密度和带隙的计算结果表明,LN-ZnTiS₃的价带顶(VBM)主要由S-p轨道组成,导带底(CBM)则由Ti-d轨道组成,硫原子的替代可以促进体系费米能级以上的电子状态大幅度下降到较低的能级,从而减小LN-ZnTiS₃的带隙。LN-ZnTiS₃的带隙计算值为1.04 eV,可以促进可见光的吸收,可以看出LN-ZnTiS₃是一种潜在的高效率光伏材料。     

Multilinear target-based decision analysis with hybrid-information targets and performance levels

Fuzzy Optimization and Decision Making - For several classes of decisions, the use of target-based decision analysis (TBDA) is more appropriate than utility analysis. Recent literature on TBDA...     

一种基于矢量水听器阵的归一化加权Capon波束形成方法

矢量水听器同时拾取声场的标量信息声压和矢量信息振速。本文在分析了各向同性噪声场下矢量水听器阵Capon波束形成方位谱的基础上，提出了一种归一化加权Capon波束形成的改进算法，并给出了方位谱的表达式。本方法不需要特征分解，并且得到的是通常意义上的功率谱(可用于估计信号的能量)。仿真计算表明，此方法的性能优于Capon法，可大大提高方位估计的精度。     

强碰撞下的漂移波稳定性

在碰撞存在时,考虑到在扰动电场作用下电子沿磁力线的宏观运动,用迴旋动力技术导出了强碰撞的积分本征方程。随后用LCN方法严格解析地证明了在平板剪切磁场的作用下,漂移波是绝对稳定的。 关键词：