Excited-state dynamics in light-harvesting complex of Rhodobacter sphaeroides

Photodynamics of peripheral antenna complexes, light-harvesting complex （LH2） of Rhodobacter （Rb） Sphaeroides 601, was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results reveal dramatic dynamical evolutions within B800 and B850 absorption bands of antenna complexes LH2. At excitation wavelength around 835 nm, a sharp photobleaching signal was observed which was assigned to the contribution of the two-exciton state, which was further confirmed by the power dependence measurement. Rate equations with eight-level scheme were used to calculate the population evolution in LH2 and the transient dynamics under femtosecond pulse excitation. The research results prove that not only the transition from ground state to one-exciton state but also that from one-exciton state to two-exciton state contribute to the photodynamics of B850.     

Complicated phenomena of the Beichuan-Yingxiu surface fracture zone during Wenchuan <Emphasis Type="Italic">M</Emphasis>s8.0 earthquake in Sichuan Province,China

After Wenchuan Ms8.0 earthquake, the surface fractures have been investigated in Beichuan City and Yingxiu Town. It was found that the Beichuan-Yingxiu earthquake fracture zone trends northeastward, dipping to northwest. The earthquake fracture zone is mainly characterized by thrust faulting with small amounts of strike-slip movement, and demonstrating various complexities for different areas. The phenomena related to dextral strike-slip displacement are found in Beichuan City and those related to left-lateral strike-slip movement in Yingxiu Town. The compressive shortening of the two surface fracture zones in Beichuan City is 2.8-3.9 m and the left-lateral strike-slip displacement of the surface fractures in Yingxiu Town is 0.52 m.     

Optical nonlinearity and ultrafast dynamics of ion exchanged silver nanoparticles embedded in soda-lime silicate glass

Ag nanoparticles embedded in soda-lime silicate glass were fabricated by ion-exchange and subse-quently annealing method. Z-scan technique, femtosecond time-resolved optical Kerr effect （OKE） technique and femtosecond pump-probe experiment were used to investigate the effects of laser wavelength and laser pulse duration as well as annealing temperature on the third-order optical nonlinearity and ultrafast dynamics of the composites. It was found that the third-order susceptibility of Ag nanoparticles composite glass measured by 400 nm pulse source is larger than that measured by 800 nm pulse source due to an enhancement effect of local field near surface plasmon resonance of Ag nanoparticles in silicate glass. The third-order optical nonlinearity measured by ns laser source is about two orders of magnitude larger than that measured from fs pulse. The annealing temperature has an important effect on the third-order optical nonlinearity and ultrafast dynamics of the composites. Third-order nonlinear susceptibility up to 10^-l0 esu and fast relaxation process up to 0.2 ps have been obtained in Ag nanoparticles doped glass.     

遗传算法在AGV全局路径优化中的应用

采用改进的链路可视图进行建模,使用遗传算法对AGV静态已知环境进行路径规划,并结合在AGV中的具体应用对其进行了改进.在建模过程中,对障碍物做了边界扩展,将障碍物顶点作为行走节点,达到AGV行走过程中避撞的目的.在路径搜索过程中,借鉴蚁群算法的基于可行表的路径搜索方式到初始种群的产生过程,避免了AGV实际问题中无效路径的产生,提高了搜索效率.在初始种群的搜索过程中,对死路情况做了处理,避免了搜索停滞.交叉过程中,采用重复点交叉的几种处理方式,既避免了AGV搜索到断路的情况,也较大提高了产生最优路径的效率.交叉变异过程中人为产生环路的做法,有利于优良个体的产生.将蚁群算法的正反馈优化策略引入遗传算法的多次迭代中的改进中,加快了算法向最优解收敛的速度.MATLAB仿真结果表明,改进后的遗传算法能够快速准确地搜索到AGV的全局最优路径.     

粗糙脉孢菌BenR基因在哈茨木霉中的定点转化

以β2-微管蛋白基因为定点整合位点,通过原生质体法将多菌灵抗性基因转化到哈茨木霉中,获得了具有多菌灵抗性的生物防治工程菌株．多菌灵抑制抗性转化子菌丝生长的ECso值达471．26μg／mL,比哈茨木霉原菌株提高1200倍以上;转化子对多菌灵的抗性具有遗传稳定性,且在无选择压力下菌丝生长速度及菌落形态与原菌株无显著差别;抑菌活性检测结果表明,3个转化子对立枯丝核菌均具有较强的抑菌活性,对菌丝生长的抑制率分别为87．5％、86．3％和85％．     

云南少数民族茶祭祀研究

云南少数民族常常以茶作为祭天祀祖的物品。作为祭品的茶,往往寄托祭祀者的深深的祝愿。文章从宗教学的角度阐述了中国茶文化和宗教仪式——祭祀之间的关系,介绍我国民间传统茶祭祀的由来以及云南少数民族茶祭祀的渊源、形式和特点,通过探讨茶祭祀这种我国独有宗教礼仪活动的理论意义、实践效应和学术价值,进而把已经和正在消失的茶叶祭祀内容挖掘出来,为的是从她曾走过的历史道路中发掘存在其中尚未实现的思想文化潜力。     

伪狂犬病病毒主要毒力基因缺失后的免疫原性研究

本试验研究伪狂犬病病毒（PRV）基因缺失疫苗株D1、D2和D3的免疫原性．对4周龄仔猪按不同剂量分别肌注接种D1、D2、D3后,于7、14d后采血：14d后用10^7pFU强毒株PRVFa滴鼻攻毒所有试验猪,攻毒7d后检查PRV在猪体内器官的分布．基因缺失毒株接种后试验组仔猪体温略有升高,接种部位未发生炎性反应,不向外散毒．PRVFa攻毒后试验组的仔猪体温稍有升高但不超过40℃,对照接毒组连续4d均超过40℃、有1头出现明显神经症状并死亡．强毒攻毒后,各剂量免疫组散毒均为2～3d,而对照组、同居猪散毒均为5d．对照组10个器官组织（大脑、小脑、三叉神经、心、肺、肝、肾、淋巴结、脾和扁桃体）均检测出PRV;D1组除大脑、小脑、肺脏外均检测出PRV;D2、D3组除大脑、小脑外,其它均检出PRV．免疫组的保护率均为100％,对照组为75％．试验结果表明D1、D2和D3能对接种猪提供充分的保护;攻毒后疫苗接种猪都向外排毒,但散毒天数均远低于对照组且未从同居感染猪中分离出病毒;D1、D2和D3是具有高度免疫原性且接种安全的基因缺失疫苗株．     

科技型中小企业发展的金融支持问题研究

科技型中小企业的发展离不开金融的支持。针对科技型中小企业的融资特点和我国科技型中小企业的融资现状,通过借鉴国际经验,从加强政府支持、完善风险投资机制、加大商业银行支持和建立多层次资本市场这四个方面论述了如何构建科技型中小企业的金融支持体系。     

坐标教学法在足球脚背内侧踢球教学中的实验研究

根据运动技能形成的生理规律和足球技术的特点,针对体育系足球课脚背内侧踢球技术教学进行实验研究;在教学实验中采用坐标教学法来防止和纠正学生在初学踢球时易犯错误。研究结果表明,坐标教学法简便易行,既丰富了学生学习活动的情境;又体验了足球运动的乐趣,能帮助学生在有限课时中较快掌握足球脚背内侧踢球技术,提高足球课教学效果,对其它足球踢球技术教学起到举一反三的作用。     

干湿循环-硫酸盐作用的混凝土中硫酸根离子分布预测

以影响混凝土中硫酸根离子分布的混凝土水灰比、环境中硫酸根离子浓度、侵蚀龄期和侵蚀深度4种影响因素为参数,以试验数据为训练样本,基于BP神经网络算法,建立了干湿循环-硫酸盐侵蚀作用下混凝土中硫酸根离子分布拟合及预测模型.经验证,该模型对硫酸盐侵蚀作用下混凝土中硫酸根离子分布具有良好的拟合及预测效果.