医学电子显微镜室的运行与管理对策

电子显微镜室是一类有代表性的大型医学科研仪器实验室,此类实验室的运行管理有其特殊性.本文以某医学电子显微镜室四十年的运行管理为案例,分析总结了其在科研管理体制、人才制度、仪器维护管理等方面的成功经验,为拥有类似大型仪器实验室的医学科研机构的管理提供参考.

原位液体室透射电子显微镜技术的发展及应用

原位液体室透射电子显微镜技术的发展,极大地扩展了透射电子显微镜的使用范围,使之能够以纳米尺度的成像分辨率对液体环境中的样品进行实时动态分析.本文基于本课题组近年来参与和开展的研究,综述了原位液体室电子显微镜的研究进展,包括原位液体室透射电子显微镜实验装置的研制,及其在纳米材料制备与表征、电化学反应过程、新能源材料与器件、生命科学等领域的应用.最后,对原位液体室透射电子显微镜领域的未来发展趋势进行了展望.

我们是怎样建设实验中心的

广西农学院实验中心是1985年利用农业部的世界银行第二期贷款建立起来的。五年来,实验中心在教学、科研和对外的分析测试、开发新产品工作中发挥了积极作用,现已成为广西农学院教学和科研的重要基地。实验中心包括基础生化教研室、分子遗传研究室、组织培养研究室、发酵工程研究室、分析测试室、电子显微镜室。其有教学、科研人员62人。1985—1991年。

Fracture behavior of high strength Mg-Gd-Y-Zr magnesium alloy

The fracture behavior of a permanent mould casting Mg-8.57Gd-3.72Y-0.54Zr(mass fraction,%)(GW94) alloy was investigated under different thermal conditions,including as-cast,solution-treated,peak-aged,and over-aged states.Scanning electron microscopy(SEM) and optical microscopy(OM) were employed to examine the crack nucleation and fracture model.The results indicate that the GW94 alloy shows different behaviors of crack initiation and fracture under different thermal conditions. During tensile test at room temperature,the fracture model of the as-cast GW94 alloy is quasi-cleavage,while that of the solution-treated alloy is transgranular cleavage.It is a mixed pattern of transgranular and intergranular fracture for both the aged conditions.Large cavities formed at grain boundaries are observed in the peak-aged sample tested at 300℃,corresponding to the intergranular fracture.Localized plastic deformation at grain boundaries is also observed and corresponds to the high elongation at 300℃.

Improvement of anticorrosion and adhesion to magnesium alloy by phosphate coating formed at room temperature

A new surface protection process was developed to magnesium alloy against corrosion in aggressive environments.Firstly,a phosphate coating was formed on rinsed magnesium alloy.Then,powder painting was carried out on the phosphated magnesium alloy.Surface morphologies and phase compositions of the phosphate coating were investigated by X-ray diffraction(XRD) and scanning electron microscope(SEM) .The results show that the phosphate coatings formed in bath containing earth additives at room temperature have dense and fine microstructure.The phosphate coating provides excellent paint adhesion to the magnesium alloy. Salt spray tests indicate that the corrosion resistance of the phosphate coating plus paint could meet the demand of magnesium alloy automobile components in aggressive environments.

Volumetric Variation and Rheology of Cement Based Mineral Additions （Blast Furnace Slag and Silica Fume）

The partial substitution of clinker by mineral additions offers very significant, both economical and environmental benefits. This adds value to industrial waste, and contributes also in the preservation of natural resources, like clay and limestone, as well as the reduction of greenhouse gas emissions （CO2）. This study is interested in the simultaneous effect of BFS （blast furnace slag） and SF （silica fume） on setting time and water requirement of cement paste. The volumetric variations are tested in mortars, prepared in the same mixture of pastes, and the tests indicate that the addition of slag increase the fluidity, reduce the water demand, shrinkage and expansion, compared to the mortar, containing ten percent （10%） of Silica Fume only. The images of pastes obtained by SEM （scanning electron microscopy）, are indicated an improvement of the microstructure of the paste with a large amount of slag, which leads to improve durability.

In Situ TEM Observation of the Gasification and Growth of Carbon Nanotubes Using Iron Catalysts

We report the in situ transmission electron microscope (TEM) observation of the catalytic gasification and growth of carbon nanotubes (CNTs). It was found that iron catalysts can consume the CNTs when pumping out the precursor gas, acetylene, at the growth temperature, and reinitiate the growth when acetylene is re-introduced. The switching between gasification and growth of CNTs can be repeated many times with the same catalyst. To understand the phenomenon, thermogravimetric analysis (TGA) coupled with mass spectroscopy was used to study the mechanism involved. It was shown that the residual water molecules in the growth chamber of the TEM react with and remove carbon atoms of CNTs as carbon monoxide vapor under the action of the catalyst, when the precursor gas is pumped out. This result contributes to a better understanding of the water-assisted and oxygen-assisted synthesis of CNT arrays, and provides useful clues on how to extend the lifetime and improve the activity of the catalysts.

Study of lanthanide doped zinc oxide nanoparticles synthesized via a sonochemical method

In this work, lanthanide doped zinc oxide nanoparticles synthesized in room-temperature ionic liquid via a sonochemical method have been studied. Firstly, the cavitation bubble temperatures in 1-butyl-3-methylimidazolium hexafluorophosphate (ImPF6) have been estimated by the methyl radical recombination method. The temperatures measured in ImPF6 are in the range of 3000-4000 K. Secondly, a facile method has been proposed to prepare lanthanide (Ⅲ) doped zinc oxide nanoparticles in ImPF6 via an ultrasonic irradiation. The nanomaterials are studied by transmission electron microscopy, X-ray diffraction, photoacoustic and luminescence techniques. The results show that the relaxation processes of the samples depend strongly on the lanthanide doping. Moreover, a mechanism is proposed to interpret the formation of lanthanide (Ⅲ) doped zinc oxide nanoparticles in the ImPF6 upon ultrasonic irradiation.