Fabrication of a TiO2-P25/(TiO2-P25+TiO2 nanotubes) junction for dye sensitized solar cells

The dye sensitized solar cell（DSSC）, which converts solar light into electric energy, is expected to be a promising renewable energy source for today’s world. In this work, dye sensitized solar cells, one containing a single layer and one containing a double layer, were fabricated. In the double layer DSSC structure, the under-layer was TiO₂-P25 film, and the top layer consisted of a mixture of TiO₂-P25 and TiO₂ nanotubes. The results indicated that the efficiency of the DSSC with the double layer structure was a significant improvement in comparison to the DSSC consisting of only a single film layer. The addition of TiO₂-P25 in the top layer caused an improvement in the adsorption of dye molecules on the film rather than on the TiO₂ nanotubes only. The presence of the TiO₂ nanotubes together with TiO₂-P25 in the top layer revealed the enhancement in harvesting the incident light and an improvement of electron transport through the film.     

周期素依赖蛋白激酶5在脑缺血中作用机制的研究

周期素依赖蛋白激酶5(Cyclin-dependent kinase5,Cdk5)属于小丝氨酸/苏氨酸周期素依赖性蛋白激酶家族成员,虽与其成员序列具有同源性,但与细胞周期的关系不大,却在神经元正常功能的维持以及神经细胞死亡等方面发挥重要作用[1]。Cdk5是神经系统中重要的蛋白激酶之一,它通过磷酸化不同的底物发挥神经调节功能。现已鉴定出Cdk5的底物近20种,就Cdk5的诸多功能而言,其底物远不止如此。近年来文献报道,Cdk5的过度激活与脑缺血/再灌注损伤时半影区细胞凋亡有关[2],引起了学术界的极大兴趣。Cdk5与特异性活化因子p25结合,通过磷酸化各种凋亡相关…     

Design and implementation of highway distress and preventive measures decision support system based on WebGIS

A highway distress and preventive measures decision support system based on WebGIS and J2EE architecture were studied, and the key issues for the system are presented. Such issues as spatial data and attribute data organization, technology of enhancing user experience, database connection pool were investigated. The feasibility of the theories and methods were tested through the system.     

黑曲霉As 3.3883菌种的诱变及其发酵条件探索

本文报导了黑曲霉As 3.3883经诱变可得一高产果胶酶的变异株JB513.该变异株经液体发酵制取果胶酶的最适条件是:起始pH 4.0,接种量2×10~4个/mL,通气量为培养基占摇瓶体积的1/5,发酵温度为30℃,发酵时间84h.其时,发酵液的果胶酶活力达11.9μmol·min~(-1)/mL(小试250mL),及12.0μmol·min~(-1)/mL(中试500L).同时发现该发酵液具有纤维素酶的活性.     

Aberrant CFTR-dependent HCO3- transport in mutations associated with cystic fibrosis

Cystic fibrosis (CF) is a disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). Initially, Cl- conductance in the sweat duct was discovered to be impaired in CF, a finding that has been extended to all CFTR-expressing cells. Subsequent cloning of the gene showed that CFTR functions as a cyclic-AMP-regulated Cl- channel; and some CF-causing mutations inhibit CFTR Cl- channel activity. The identification of additional CF-causing mutants with normal Cl- channel activity indicates, however, that other CFTR-dependent processes contribute to the disease. Indeed, CFTR regulates other transporters, including Cl(-)-coupled HCO3- transport. Alkaline fluids are secreted by normal tissues, whereas acidic fluids are secreted by mutant CFTR-expressing tissues, indicating the importance of this activity. HCO3- and pH affect mucin viscosity and bacterial binding. We have examined Cl(-)-coupled HCO3- transport by CFTR mutants that retain substantial or normal Cl- channel activity. Here we show that mutants reported to be associated with CF with pancreatic insufficiency do not support HCO3- transport, and those associated with pancreatic sufficiency show reduced HCO3- transport. Our findings demonstrate the importance of HCO3- transport in the function of secretory epithelia and in CF.     

离散裂隙网络模拟在地下硐室稳定性中的应用——以甘肃北山地下实验室为例

以甘肃北山地下实验室为研究对象,开展了离散裂隙网络-离散元（DFN-DEM）耦合方法在花岗岩地下硐室围岩稳定性分析方面的探索研究。选取地下实验室工程勘察范围内代表性勘察钻孔和地表露头裂隙数据进行统计分析,利用三维离散单元软件3DEC构建离散裂隙网络（DFN）和等效岩体模型,模拟分析了地下实验室-560 m水平试验巷道的硐室的稳定性。结果表明：硐室开挖引起硐室围岩应力重分布,裂隙与硐室开挖面相交部位发生应力集中现象,硐室围岩出现位移变形;在现有条件下,硐室围岩变形量较小,应力集中程度不高,地下硐室稳定性较好。     

Effect of SiO2 addition on the dielectric properties and microstructure of BaTiO3-based ceramics in reducing sintering

The effect of SiO₂ doping on the sintering behavior, microstructure, and dielectric properties of BaTiO₃-based ceramics has been investigated. Silica was added to the BaTiO₃-based powder prepared by the solid state method with 0.075mol%, 0.15mol%, and 0.3mol%, respectively. The SiO₂-doped BaTiO₃-based ceramic with high density and uniform grain size were obtained, which were sintered in reducing atmosphere. A scanning electron microscope, X-ray diffraction, and LCR meter were used to determine the microstructure as well as the dielectric properties. SiO₂ can form a liquid phase belonging to the ternary system of BaO-TiO₂-SiO₂, leading to the formation of BaTiO₃ ceramics with high density at a lower sintering temperature. The SiO₂-doped BaTiO₃-based ceramics can be sintered to a theoretical density higher than 95% at 1220℃ with a soaking time of 2 h. The dielectric constants of the sample with 0.15mol% SiO₂ addition sintered at 1220℃ is about 9000. Doping with a small amount of silica can improve the sintering and dielectric properties of BaTiO₃-based ceramics.     

服装结构设计CAD系统开发

本文对计算机辅助服装结构设计系统的设计思想与实现方法进行了探讨.提出将结构设计过程分作结构线设计和外形线设计两步完成,用导出关键参量计算模型的方法解决结构线设计中的经验估值问题;用图形变换的方法解决外形线设计中的"临摹"手法,从而较好地处理了设计师进行结构设计时所表现出的"活"的方面.以此为基础,在IBM PC/XT机上研制初步的服装结构设计系统.     

定积分在梯形面积逆向问题中的应用

应用定积分得到了梯形面积逆向计算问题的计算公式,并将该公式推广在三角形中.     

防污涂料/海水界面的原生动物初探

【目的】探讨利用微型生物作为防污涂料防污性能的"生物标示"的可行性。【方法】在总结近几年来海港微型生物试验的基础上,针对在海洋中广泛存在的原生动物纤毛虫进行初步探讨,试图开发原生动物作为防污鉴定的"生物标示"。【结果】在青岛中港进行初步调查,发现在涂有环氧系底漆、有机硅系低表面能防污涂料和亚铜系自抛光防污涂料的试片上共有9类纤毛虫,其中侧口类、管口类和游仆类3类纤毛虫显示出较大活性。从纤毛虫数量及其变化可明显得出3类涂层的防污性能的优劣。【结论】侧口类、管口类和游仆类3类纤毛虫有望开发为"生物标示"。