三氯化锑和二氧杂环己烷配合物[SbCl3·{(CH2)4O2}1.5]的合成与晶体结构

New solid complex of the antimony trichloride and dioxane was obtained th rough a reaction of the dioxane and the absolute methanol solution of the antimony trichloride.The formula of the complex is[SbCl₃·{(CH₂)₄O₂}_1.5].The crystal structure of the complex belongs to cubic system,space group I-43d,a=17.1417(5)Å,Z =16.The trivalent antimony ion n ot only bonds directly to three chlorine anions,but also is coordinated by three oxygen atoms of th e dioxane molecules.Two oxygen atoms in a dioxane molecule will coordinate to different antimony ions,respectively.     

概率论与数理统计教学案例研究

给出了概率论与数理统计课程中的两个教学案例.案例一是针对新冠筛查中逐一检验和分组检验的问题,结合概率论与数理统计中离散型随机变量的分布列及其数学期望的知识点给出的,并进行了问题的引申研究.案例二是针对图像加密的安全性问题,结合概率论与数理统计中相关系数定义以及基于概率的信息熵的概念,给出了一个适用于信息安全专业的专业案...     

夹管电磁阀定量-流动注射分析系统测定海水中亚硝酸盐和硝酸盐氮

采用3个夹管电磁阀联用代替传统六通阀的样品定量方法,自制一套多通道流动注射分析仪,并优化了仪器的最佳测试条件,实现了海水中硝酸盐氮和亚硝酸盐氮含量的测定。本分析系统结构简单,性能可靠,测定频率为28个/h。测试结果表明,亚硝酸盐氮和硝酸盐氮的线性范围(以氮含量计)分别为25～1000μg/L和50～1000μg/L(R≥0.999),检出限分别为1.8和4.8μg/L;加标回收率在94.5%～105.3%之间;加标200.0μg/L的回收实验的相对标准差在1.3%～4.5%之间(n=6)。经t检验分析,本方法与国标方法测定数据无显著性差异,可适用于海水中微量亚硝酸盐氮和硝酸盐中氮的快速测定分析。     

甘氨酸溶液导电性质的研究

测量了不同浓度的甘氨酸溶液的电导率，发现测得的电导率与导电离子浓度的关系与理论有很大的偏差，提出了氨基酸溶液的介电理论和“偶极子氛”模型，都成功地解释了氨基酸溶液的导电性与其中的导电离子及兼性离子浓度的关系，深刻提示了甘氨酸独特的兼性离子性。     

数学教学中的稚化艺术

日本数学教育家米山国藏认为：“无论是对于科学工作者、技术人员、还是数学教育工作者，最重要的就是数学的精神、思想和方法，而数学知识是第二位的”．这个看法是正确的，因为从某种意义上讲，数学思维与数学方法是数学知识体系的灵魂．然而，当前数学教学中普遍存在教...     

Quantitative Single-Ion Irradiation by ASIPP Microbeam

A single-ion microbeam facility has been constructed by the microbeam research group in ASIPP (Institute of Plasma Physics, Chinese Academy of Science). The system was designed to deliver defined numbers of hydrogen ions produced by a van de Graaff accelerator, covering an energy range from 200 keV to 3 MeV, into living cells (5μm-20μm diameter) growing in culture on thin plastic films. The beam is collimated by a 1-μm inner diameter HPLC (high performance liquid chromatograph) capillary, which forms the micron-dimensional beam-line exit. A microbeam collimator, a scintillation ion counting system and a fast beam shutter, which constitute a precise dosage measuring and controlling system, jointly perform quantitative single-ion irradiation. With this facility, we can presently acquire ion-hitting efficiency close to 95%.     

LD-pumped high repetition rate Q-switched Nd:YVO_4 laser by using La_3Ga_5SiO_(14) single crystal electro-optic modulator

A diode-end-pumped electro-optic (EO) Q-switched Nd:YVO4 laser operating at repetition rate of 10 kpps (pulses per second) was reported. A block of La3Ga5SiO14 (LGS) single crystal was used as a Q-switch and the driver was a metal oxide semiconductor field effect transistor (MOS-FET) pulser of high repetition rate and high voltage. At continuous wave (CW) operation, the slope efficiency of the laser was 46%, and maximum optical-to-optical efficiency was 38.5%. Using an output coupler with transmission of 70%, a 10-kpps Q-switched pulse train with 0.4-mJ monopulse energy and 8.2-ns pulse width was achieved, the optical conversion efficiency was around 15%, and the beam quality M2 factor was less than 1.2.