Cathodoluminescence Depth Profiling in SiO2:Ge Layers

 For investigation of the luminescent center profile cathodoluminescence measurements are used under variation of the primary electron energy E ₀ = 2…30 keV. Applying a constant incident power regime (E ₀·I ₀ = const), the depth profiles of luminescent centers are deduced from the range of the electron energy transfer profiles dE/dx. Thermally grown SiO₂ layers of thickness d = 500 nm have been implanted by Ge⁺-ions of energy 350 keV and doses (0.5–5)10¹⁶ ions/cm². Thus Ge profiles with a concentration maximum of (0.4 – 4) at% at the depth of d_m≅240 nm are expected. Afterwards the layers have been partially annealed up to T _a = 1100 °C for one hour in dry nitrogen. After thermal annealing, not only the typical violet luminescence (λ = 400 nm) of the Ge centers is strongly increased but also the luminescent center profiles are shifted from about 250 nm to 170 nm depth towards the surface. This process should be described by Ge diffusion processes, precipitation and finally Ge nanocluster formation. Additionally, a Ge surface layer is piled-up extending to a depth of roughly 25 nm.     

Multiple polypeptide forms observed in two-dimensional gels of Methylococcus capsulatus (Bath) polypeptides are generated during the separation procedure

We have examined two-dimensional electrophoresis (2-DE) gel maps of polypeptides from the Gram-negative bacterium Methylococcus capsulatus (Bath) and found the same widespread trains of spots as often reported in 2-DE gels of polypeptides of other Gram-negative bacteria. Some of the trains of polypeptides, both from the outer membrane and soluble protein fraction, were shown to be generated during the separation procedure of 2-DE, and not by covalent post-translational modifications. The trains were found to be regenerated when rerunning individual polypeptide spots. The polypeptides analysed giving this type of trains were all found to be classified as stable polypeptides according to the instability index of Guruprasad et al. (Protein Eng. 1990, 4, 155-161). The phenomenon most likely reflects conformational equilibria of polypeptides arising from the experimental conditions used, and is a clear drawback of the standard 2-DE procedure, making the gel picture unnecessarily complex to analyse.     

蒙特卡洛模拟退火与距离限制相结合的方法在多肽溶液构象分析中的应用

多维核磁共振技术的飞速发展议得其在生物大分子结构测定方面的应用已经达到可以与【射线晶体学并驾齐驱的地步．蛋白质结构堆积紧密，较适合于用核磁共振方法给出确定的结构．与蛋白质不同的是多肽的柔性较大，在溶液中可能存在多种构象，核磁共振实验给出的只是平均信息＊．利用核磁，（振数据构建分子结构模型常用的方法有距离几何、分子动力学等，在由核磁共振NOESZ得到的距离信息足够多时可以给出较好的结果问．由于多肽本身的特点：柔性较大，由核磁共振得到的距离信息较少等，利用距离几何、分子动力学方法进行构象搜索时容易陷入…     

烟碱型乙酰胆碱受体吡啶基胺类配体的构效关系研究

采用分子动力学模拟退火技术寻找了一类新型烟碱型乙酰胆碱受体吡啶基胺类配体分子的优势构象，用分子力学方法进行了结构优化，再用半经验量子化学方法中的AM1方法进一步优化，并做了电子结构计算.用计算所得物化参数对配体亲和性进行多元线性回归分析，回归结果表明：化合物pKi值与分子最低空轨道能量(ELUMO)、吡啶基所带总电荷(Qp)及分子构象相关.根据计算结果对该类化合物与受体的作用机制和作用位点进行了讨论.     

Singular perturbed Markov chains and exact behaviors of simulated annealing processes

We study asymptotic properties of discrete and continuous time generalized simulated annealing processesX(·) by considering a class of singular perturbed Markov chains which are closely related to the large deviation of perturbed diffusion processes. Convergence ofX(t) in probability to a setS ₀ of desired states, e.g., the set of global minima, and in distribution to a probability concentrated onS ₀ are studied. The corresponding two critical constants denoted byd and withd are given explicitly. When the cooling schedule is of the formc/logt, X(t) converges weakly forc>0. Whether the weak limit depends onX(0) or concentrates onS ₀ is determined by the relation betweenc, d, and . Whenc>, the expression for the rate of convergence for each state is also derived.     

带残损原材料的二维优化下料问题的研究

本文将遗传算法和模拟退火算法相结合来求解二雏优化下料问题，下料件为不规则形状，原材料上带有残损，问题具有一般性。并在Windows2000平台下，用Matlab实现上述算法。通过实例验证了该算法的有效性。     

用磁控溅射和退火方法制备AlSb多晶薄膜

采用磁控溅射法在玻璃衬底上制备Al/Sb预制多层薄膜,然后将Al/Sb预制多层薄膜在退火炉中退火得到AlSb多晶薄膜.用X射线衍射(XRD)法测薄膜结构;用扫描电镜(SEM)测薄膜Al/Sb成分比,结果表明AlSb多晶薄膜具有单一的晶相、均匀的结构,以及粒径大约20nm的晶粒.根据电导率(lnσ)与温度(T)的关系得到电导激活能为0.21和0.321eV,为制备出适用于太阳电池的AlSb多晶薄膜奠定了一定的技术基础.     

退火温度对KDP晶体光学均匀性的影响研究

 研究了磷酸二氢钾（KDP）晶体热退火前后光学均匀性的变化，发现适当温度下退火可以降低KDP晶体的内应力，提高晶体的消光比，从而提高晶体的光学均匀性。实验证明，50℃下退火即可消除部分内应力，110℃下退火可以消除生长鬼影和鬼线。但是,退火温度太高（如170℃）,也可能使晶体的均匀性降低。     

An efficient nonfullerene acceptor for all-small-molecule solar cells with versatile processability in environmentally benign solvents

A new structure of dicyanodistyrylbenzene-naphthalimide-based nonfullerene acceptor NIDCSN was synthesized and characterized to have a favorable electron accepting property and versatile processability in various organic solvents. The nonfullerene all-small-molecule solar cells comprising p-DTS(FBTTh₂)₂ as the donor and NIDCSN as the acceptor exhibited a maximum power conversion efficiency of 3.45% with a remarkable open-circuit voltage of 1.04 V, together with similar device performances when fabricated in five different solvents including environmentally benign non-halogenated ones.     

Study of the purifying affects of thermal annealing for polymer‐wall liquid crystal cells

The thermal annealing process was proposed to purify the pixel regions of a liquid crystal (LC) cell with polymer walls. This technique, based on thermal‐induced phase separation, successfully evicts the residual monomers from the LC volume and significantly improves electro‐optical properties of the polymer‐wall LC devices. The influence of the annealing process on the purity of LC‐rich domain and the electro‐optic properties of a LC cell was explored with a series of experiments. According to the experimental results, the annealing technique is extremely prospective for constructing flexible polymer‐wall LC display applications.