加强实验室物品管理的新举措

为加强对实验室内所有物品的管理,并且解决在“双基”实验室评估工作中对“低值耐用品”概念的不同解释,我们物理实验中心创新设计出了一种“实验室管理卡”,通过它实现了对各种物品的规范化管理,所有物品都有帐可查。     

Ru(II)–DMSO complexes containing aromatic and heterocyclic acid hydrazides: Structure,electrochemistry and biological activity

The reaction of cis-[RuCl₂(DMSO)₄] with a family of aromatic and heterocyclic acid hydrazides yielded new complexes of the general formula trans-[RuCl₂(DMSO)₂(hydrazide)] · nH₂O (n = 0; 1–6; n = 1; 7). The new complexes have been characterized by IR, UV–Vis and ¹H NMR spectroscopic methods. In addition, the structure of one of the complexes, [RuCl₂(DMSO)₂(tcah)] · H₂O (tcah = thiophene-2-carboxylic acid hydrazide), has been determined by single crystal X-ray diffraction. All the studies reveal the neutral bidentate coordination of the hydrazide ligands through the acyl oxygen and amine nitrogen atoms. The electron transfer properties of the complexes were studied by cyclic voltammetry and all the complexes except one show an irreversible/quasi-reversible reduction wave (Ru^II/Ru^I) and an uncoupled oxidation peak (Ru^III/ Ru^II). The preliminary DNA-binding ability of the complexes, studied with herring sperm DNA, shows the binding of the complexes with DNA with a lesser affinity than classical intercalators. The complexes have also been screened for their antibacterial activity against five pathogenic bacteria.     

非化学专业无机及分析化学理论与实验教学的一致性

在"讲一练二考三"新型教学理念的指导下,结合多年非化学专业无机及分析化学课程理论教学和实验教学的经验,针对无机及分析化学理论课和实验课教学的特点和存在的一些问题,阐述了在无机及分析化学课程教学中理论课教学内容和实验课教学内容相结合的实践探索和体会,以及取得的效果。     

大空腔探测系统主动中子多重性反应系数模拟研究

为确定主动中子多重性反应系数对测量精度的影响,对大空腔探测系统主动中子多重性方法测量铀部件质量的全过程进行了直接模拟,基于MCNPX对28组相同浓缩度、相同密度、不同质量的内径1.2 cm的半球壳型铀部件进行了模拟研究,获得了反应系数与样品增殖的关系曲线。对半球型、内径1.2 cm的半球壳型铀部件的模拟测量质量偏差都在1.5%以内,对内径3.2 cm的半球壳型、半径6 cm和8 cm的圆柱型等形状差异较大的铀部件质量也仅偏小5%~10%。     

Study on the efficiency of the digging process using the model of excavator bucket

In the first part of the paper, an experimental program is presented investigating the soil cutting problem, with the application of vertical rigid walls at various widths as the working tools. It was found that when the tool width equalled the width of the soil bin, the soil cutting problems might be treated as plane strain processes. For the tools for which no interaction with the sidewalls of the bin was observed, the zone of the plane strain deformations occurred in the central part of the tools. In the second part of this paper a new experimental program of laboratory tests is presented, for a tool model in the shape of an excavator’s bucket equipped with teeth. The experimental verification of the influence of teeth (number of teeth and the position of teeth on the bucket’s inside lip) on the efficiency of the digging cycle is the aim of this paper. For high values of teeth spacing, the superposition of the plane strain deformation mechanism with three-dimensional failure modes within the soil was observed. For the low values of teeth spacing, the teeth did not act as separate three-dimensional objects but as one wide tool built up from several modules. As a consequence, the deformation pattern in front of such an assembly of teeth was again the plane strain deformation pattern.     

北京大学实验室危险化学废弃物暂存研究

北京大学作为争创世界一流大学的中国高校,教学科研工作量突飞猛进,随之实验室危险废弃物(以下简称:危废)产量大幅增长。如何保证这些危废在校期间的安全暂存,成为全校实验室安全管理和环保工作的重要内容。北京大学根据性质的不同对危废进行了分类管理,优化改进了实验室危险化学废弃物暂存柜结构;对暂存环境中挥发的VOCs进行了监测,并利用二氧化钛纳米线光催化剂对污染气体进行了净化测试研究。结果发现所有检测到的污染成分都能被光催化技术净化消除,显示出光催化技术是一种很有潜力的VOCs净化手段,可用于解决校园危废的复杂VOCs污染问题。