c轴定向氮化铝薄膜的制备

利用电子回旋共振 (ECR)微波增强化学气相沉积法 (PECVD)并使用氮气 (N2 ) ,氩气 (Ar)和AlCl3蒸气作为气源在直径为 6 .35cm的 (10 0 )单晶硅片表面制备了c轴定向氮化铝 (AlN)薄膜 ,并使用X射线衍射仪及其X射线特征能谱和扫描电镜 (SEM)分析了薄膜特征 ,研究了微波功率、基板温度和N2 流量对薄膜c轴定向的影响 ,得到了c轴偏差角小于 5°的高质量大面积AlN薄膜。     

Analysis of saltation characteristics of bed-load transport in flowing water

The study of bed-load transport is of great significance both in theory and in practice. This paper discusses the saltation of bed-load solid grains in flowing water. Experiments and theoretic analysis have been made by means of high-speed photographing and advanced data processing technique with a combined method based on mechanical and statistical theories. It indicates that the saltation is the main form of the bed-load transport under ordinary flowing conditions. In the meantime, taking successive saltation as the model of bed-load transport, systematic analysis has been made with regard to the kinematic properties and mechanism of saltation. The statistical analysis shows that the probability density functions of the relative height and length of saltation are in conformity with Γ-type distribution, while the probability density functions of the relative velocities of saltation are in conformity with the Gaussian distribution. The project supported by National Natural Science Foundation of China     

1，4－二氟四苯基苯的合成、结构与构象

借助电子转移催化反应的方法，用电子给予体１，４－二锂四苯基丁二烯将惰性的三溴氟甲烷活化，并与之发生反应，产物１，４－二氟四苯基苯的结构经ＭＳ、ＮＭＲ和Ｘ射线单晶衍射确证，并以分子力学的方法对其进行了构象分析。     

A novel fermentation process for calcium magnesium acetate (CMA) production from cheese whey

Applied Biochemistry and Biotechnology - A novel, anaerobic fermentation process is developed to produce calcium magnesium acetate (CMA) from cheese whey. CMA can be used as a noncorrosive road...     

离子束引起的在Al／Cr双层薄膜界面处的原子混合

用600keV的Kr~ 离子轰击Al/Cr双层薄膜样品进行界面原子反应及相互混合的研究。实验样品是在单晶硅上蒸镀约500nm厚的铝膜,相继再蒸上所需厚度的铬膜而制成的。轰击剂量为2.0×10~(15)-2.5×10~(16)Kr~ /cm~2。用2.0MeVa粒子对轰击前后的样品进行了卢瑟福背散射(RBS)分析,发现界面处有明显的原子混合存在;当轰击剂量≥1.0×10~(16)Kr~ /cm~2时,RBS谱出现有明显的坪台,经拟合计算和x射线衍射(XRD)测量证实确有化合物Al_(13)Cr_2存在;还分别得到了原子混合量及混合效率与轰击剂量的关系;最后对界面处的原子混合机制进行了讨论。     

Heterolytic and Homolytic N-NO Bond Dissociation Energies of N-Nitroso-benzenesulfonylmethylamines in Acetonitrile

Great interests have been accumulated in recent years in the chemistry and biochemistry of nitric oxide (NO) since the remarkable discoveries of its key roles in a wide range of human physiological processes. To elucidate the mechanistic details of NO migration from its donor to its acceptor, it is necessary to determine the Y-NO bind energy that registers the thermodynamic driving force for NO release and capture. In this paper the heterolytic and homolytic N-NO bond dissociation energies [ i. e., △Hhet(N-NO) and △Hhomo(N-NO)] for ten N-nitroso-p-substituted-benzensulfonyl methylamines in acetonitrile are offered, which were obtained from titration calorimetry and thermodynamic cycles, respectively (Scheme 1).     

Rapid magnetization reversal in magnetic small particles induced by non-static bias field

Magnetization reversal processes by a switching field in single-domain nano-sized magnetic particles in the presence of a small transverse non-static bias field are studied. Applying an oscillating bias field instead of a static field, the reversal time becomes much shorter when the switching field is slightly stronger than the effective anisotropy field. A pulsed bias field of a suitably chosen duration in the nanosecond scale is found to induce a rapid switching, even when the switching field is smaller than the anisotropy field. The dependence of the reversal time on the frequency of an oscillating bias field and the duration of a pulsed bias field are studied. The present work thus complement the earlier studies on switching in the presence of a static bias field.     

系列类立方烷型Fe4S4簇合物的XPS分析

对7种类立方烷型Fe_4S_4簇合物进行了XPS分析,得到了中心离子Fe的价态,给出了系列Fe_4S_4中骨架硫的结合能,由峰合成结果给出各种S、N的比例与按结构式计算的结果相同。     

青岛港货运吞吐量的时间序列模型

运用时间序列分析方法对时间序列建立ARMA,ARIMA模型.搜集了青岛港1999年1月～2003年5月的货运吞吐量数据,对进行分析,建立了青岛港货运吞吐量的模型.通过预留的部分数据对模型进行检验,并对模型的残差进行检验,得出模型比较合理.     

无花果多糖的分离、纯化和鉴定

经脱脂、沸水抽提、乙醇沉淀、酶-Sevag法脱蛋白得到粗多糖,再经DEAE-Sepharose fast flow阴离子交换层析和Sephadex G-200葡聚糖凝胶柱层析得到纯化的无花果多糖(FCPS),用红外光谱和紫外光谱分析鉴定该多糖.红外光谱分析具有典型的多糖特征吸收峰,紫外光谱分析未见蛋白质(280 nm)与核酸(260 nm)的特征吸收峰.结果表明,所提取的无花果多糖为单一组分的多糖.