电感耦合等离子体原子发射光谱法测定8种蔬菜中微量元素

将电感耦合等离子体原子发射光谱法(ICP-AES)应用于 8 种蔬菜中钙、铝、铜、铁、锰、锌、铬、汞、磷、硒、镁、砷、镉、铅、钾、钠等16种微量元素的测定.方法中给出了仪器的工作条件,并叙述了分析谱线的选择,采用微波加热方法对试样进行消解.16 种微量元素的检出限在 0.3～30.0 μg·L-1之间,经试验得出各元素的回收率在 94.3%～104.8%之间.     

氢化物发生-电热原子吸收光谱法测定人发中铅

经清洗并干燥的人发样用硝酸-高氯酸混合酸溶解,试样溶液中铅(Ⅱ)转化成铅烷(PbH4)及试样中铅量的测定采用WHG-102A2型流动注射氢化物发生器及GGX-9型原子吸收光谱仪的联用而自动完成.方法的最佳测定条件,包括铁氰化钾的加入量、原子化温度、高氯酸的影响及干扰试验等作了试验和选择.方法的检出限为0.25μg·L-1,在8μg·g-1的水平上进行精密度试验,测得结果的相对标准偏差(n=10)为3.0%.     

Synthesis and Evaluation of Optical 2‐Benzyl‐5‐bromo‐4‐oxopentanoic Acids as Transition‐state Analog Inhibitors against Carboxypeptidase A

Both enantiomers of 2‐benzyl‐5‐bromo‐4‐oxopentanoic acid were prepared utilizing the diazo ketones as the key intermediates. The compounds were assayed for inhibitory activity against carboxypeptidase A (CPA, EC 3.4.17.1). The (R)‐form is 260‐fold more potent than the corresponding (S)‐form. The finding that (R)‐form, which belongs to the L‐series, is mostly responsible for the inhibitory activity accords with the substrate specificity of CPA. For comparison, both the optical forms of 2‐benzyl‐4‐oxopentanoic acid were also synthesized and evaluated as the inhibitors against CPA. These results reveal that the introduction of a bromo group at the α‐position of ketones can significantly enhance the electrophilicity of the carbonyl group. Further molecular docking study suggested that the gem‐diol form of the α‐bromo ketone, which mimics the transition state in the CPA catalytic process, could chelate the zinc ion in the active site of CPA and thus result in the strong inhibition.     

新颖、无金属、高效分子碘催化的苯乙烯氢化芳基化反应

本文通过使用单质碘作为催化剂,在室温无溶剂的条件下研究了各种芳烃和不同苯乙烯衍生物的氢化芳基化反应,并能以较高的收率得到一系列1,1－二芳基甲烷衍生物。本合成策略避免了重金属的使用,提供了对环境友好的高效合成方法。     

基于最优化教学设计理论的多媒体课件的设计与制作

首先介绍了最优化教学设计理念和思想.然后以Flash MX作为开发平台,〈计算机文化基础〉为主要内容,探索并制作了以学生为本的交互式、情景化计算机辅助教学（CAI）课件.重点阐述了多媒体课件的功能模块设计思想和交互式教学过程所涉及的主要技术,并探讨了计算机多媒体辅助教学课件优化设计的模式及理论方法,使多媒体教学课件的知识结构更加符合学生课堂求知心理.     

Study on Quantum Trust Model Based on Node Trust Evaluation

Trust is the premise and foundation of se-cure communication, no matter in the quantum commu-nication or classical communication. In fact, the existing quantum secure communication protocols and technolo-gies are implicitly related to trust; or assume some trust premise in advance; or create or obtain a trust relationship. This paper studies on quantum trust model using node trust evaluation based on author's own research achieve-ments. We introduce the trust management into quantum communication network to build secure trusted quantum communication network based on evaluating the trust val-ues of nodes, which are used to evaluate the reliability of each user. We put forward a scheme of quantum trust model based on node trust evaluation, and describe the thought and process of trust evaluation in detail based on the principles of quantum entanglement and quantum teleportation. We analyze the feasibility and safety of this scheme, which provides a new thinking and method for es-tablishing a credible secure quantum communication net-work.     

基于量测预测联合估计的单站只测角跟踪

提出用于单站只测角系统的修正最佳线性无偏估计(BLUE)滤波器。针对BLUE 滤波器用于雷达目标跟踪时需要完备的非线性观测集合来构建转换量测及单站只测角系统只提供方位观测,无法直接应用普通BLUE滤波器跟踪目标的问题,构造了基于目标状态预测的预测斜距,并在分析预测斜距误差统计特性后,用斜距预测和方位观测组成转换量测,推导出可应用于单站只测角系统的BLUE滤波模型。所提改进算法在性能和运算量上有明显优势,有很好的应用潜力。     

“自动控制原理”实验设计与教学改革思考

“自动控制原理”课程作为自动化专业重要的基础课程,它对实验教学提出了很高要求.本文针对“自动控制原理”实验教学现状,结合典型的伺服实验平台,从实验设计和实验教学改革两方面探讨提升实验教学质量的措施,以深化学生对控制理论的理解,提升学生的实践能力.     

硅基片上刻蚀衍射光栅及其平坦化设计

刻蚀衍射光栅（EDG）作为实现波分复用功能的关键器件,对于片上光互连的实现至关重要。为了实现1310nm波段通道间隔为20nm的硅基EDG,采用了基尔霍夫标量衍射理论仿真方法进行理论设计和仿真验证,通过在闪耀光栅反射面引入布喇格反射光栅来提高反射效率、降低器件插入损耗,并在入射波导处引入多模干涉耦合器以实现通道频谱平坦化设计。结果表明,闪耀光栅反射面的反射效率由35%提高到了85%,1dB带宽达到12nm。这对于提高系统稳定性、增大传输距离和容量、降低系统成本具有显著作用,能够满足光互连系统的实际应用需求。