高校开设体育教学基础班浅议

本文针对我院教学改革，二年级体育教学进行分项授课，通过实践，教学效果良好，但对“三差”生在教学中也存在一定困难，放建议开设基础班的教学.     

水泥中Mg含量准确测定的探讨

本文就水泥中Mg含量的EDTA满定法测定进行探讨．改进后的方法与原子吸收光谱分析法比较，结果令人满意．     

用稻壳、稻草制取水玻璃过程中金属杂质的去除及其机理分析

对用稻壳、稻草制备水玻璃所剩余的炭渣进行了分析，给出实验结果．结果表明：金属成分在水玻璃的制备过程中以难溶化合物的形式被除去；难溶化合物能与酸反应，转化为可溶化合物；新技术制取的水玻璃溶液与传统方法相比，纯度相同，甚至更高．     

人民币汇率走势探析

主要分析了人民币汇率近几年的走势及其成因，阐述了人民币不贬值的意义，论述了人民币今后的走势及其主要依据．     

自控八方向逐点比较法差补程序设计

采用差值原理，刀架进给由四方向变为八方向，扩大了加工范围；采用微观逼近法解决了曲线加工问题；采用平移原理解决加工切线不过圆心的问题；另外，采用坐标判别法解决曲线加工中的顺时针、逆时针加工问题．     

Photoluminescence from Ge-SiO2 thin films and its mechanism

Ge-SiO₂ thin films were deposited on p-type Si substrates using the radio frequency (rf) magnetron sputtering technique with a Ge-SiO₂ composite target. Films were annealed in N₂ ambience for 30 min at 300℃—1000℃ with an interval of 100℃. Through the X-ray diffraction, the average size of Ge nanocrystals (nc-Ge) was determined. They increased from 3.9 to 6.1 nm with increasing annealing temperature in the range of 600℃—1000℃. Under ultraviolet excitation, all samples emit a strong violet band centered at 396 nm. With the formation of nc-Ge, the samples exhibit another emission of orange band with the peak at 580 nm and its intensity increases with the increasing size of nc-Ge. The peak positions of two bands do not shift obviously. Experimental data indicate that the violet band comes from GeO defect and the orange band originates mainly from the luminescence centers at the interface between the nc-Ge and SiO₂ matrix.     

基于三参数区间数的灰色模糊综合评判

综合灰色数学和模糊数学的优点,提出使用三参数区间数来表示灰色模糊数,并将其应用到综合评判问题中,给出了相应的灰色模糊综合评判的方法和步骤.最后讨论了三参数区间数的排序方法.该方法适合于解决工程实际中同时具有灰色性和模糊性的评判问题,所举算例也证明了这一点.     

Role of self-peptides in positively selecting the T-cell repertoire

The fate of an immature thymocyte is determined by the specificity of its alpha beta T-cell receptor. Only cells expressing receptors that interact with sufficient affinity with major histocompatibility complex (MHC) molecules expressed on thymus epithelial cells are positively selected and go on to mature and seed the peripheral lymphoid organs. The H-2Kb class-I MHC molecule positively selects for the maturation of cytotoxic T lymphocytes that will respond in the periphery to H-2Kb cells presenting a foreign peptide. We have now analysed the ability of variant H-2Kb molecules to positively select T-cells that respond to H-2Kb with ovalbumin. Our results indicate that self-peptides, presented in the groove of the class-I molecule on thymus epithelial cells, are critically involved in positive selection of the T-cell repertoire. Furthermore, the ability of four different H-2Kb variants to select this response in the thymus correlates with their ability to present the ovalbumin peptide, indicating that a self-peptide mimic of the foreign peptide could be involved in positive selection.     

Plasmid-related anaerobic autotrophy of the novel archaebacterium Sulfolobus ambivalens

Three different species of the genus Sulfolobus, S. acidocaldarius, S. solfataricus (= Caldariella) and S. brierleyi, have been distinguished by the conditions required for optimal growth, by the component patterns of their DNA-dependent RNA polymerases and by DNA sequence data. Many isolates of these species are able to grow chemolithoautotrophically using CO2 as the sole carbon source and the oxidation of S(0) with O2 yielding sulphuric acid, as the energy source, though a few others grow only heterotrophically. We show here that a strain of a novel Sulfolobus species, S. ambivalens, is alternatively able to live by an anaerobic mode of chemolithoautotrophy, also using CO2 as the sole carbon source, but using reduction of S(0) with H2, yielding H2S as the energy source. This mode of growth is correlated with the amplification of a plasmid, pSL10.