矮壮素对非洲菊转基因苗生长的促进作用

转基因非洲菊幼苗经过多代抗生素筛选,生长受到很大的影响．为了更好地利用珍贵的转基因苗,采用了矮壮素结合其他生长调节因子来促进转基因苗的生长和生根的试验研究,发现添加0．2 mg／L矮壮素能大大提高转基因苗的生根能力和移栽成活率．     

物理化学实验中运用原理分析的教学模式探索

在指导学生进行物理化学实验的过程中,探索性地运用了原理分析进行实验教学.实践表明,此教学模式的实施能够显著激发学生的兴趣与求知欲,促进对物理化学课程理论知识的理解和掌握,培养了学生的独立操作能力,提高了学生的综合素质,是一种值得推广的新型实验教学改革模式.     

比较视野下的未来齐鲁民间体育游戏展望

齐鲁民间体育游戏独特的健身、娱乐及文化价值已被世人充分肯定。但并不代表游戏具有永恒的生命力,现实中齐鲁民间传统体育游戏的生存环境堪忧,许多游戏在逐渐消亡。只有良好而健全的文化传承机制,才能使齐鲁民间体育游戏能够屹立在文化之林,得以顺利延续和传承。本文通过对中西方体育的比较,展望未来齐鲁民间传统体育游戏。     

基于全局PID模糊滑模算法的机器人跟踪控制仿真

为了解决机器人跟踪控制过程中采用PID控制算法会出现抖动和误差的问题,提出一种机器人全局PID模糊滑模跟踪控制算法.通过将PID滑模控制和模糊控制相结合,设计了全局PID模糊滑模控制;基于模糊规则,对滑模控制增益进行自适应调整,从而消除建模误差和干扰,削弱了控制时产生的抖振、在线调整控制器参数和估计误差,并通过积分来消除外界干扰,因此提高了控制精度.仿真结果表明,与常规的PID算法相比,该方法在处理控制抖动和消除误差和干扰方面具有极高的鲁棒性.     

环形Hartmann势的Schrdinger方程束缚态的精确解

将环形Hartmann势的Schrdinger方程在球坐标系中进行变量分离,然后求解角向方程和径向方程,得出了精确的能谱方程,获得了归一化的角向和径向波函数,并给出了Hartmann势的径向矩阵元和径向平均值的通项表示式.     

Chronic quercetin exposure affects fatty acid catabolism in rat lung

Dietary quercetin intake is suggested to be health promoting, but this assumption is mainly based on mechanistic studies performed in vitro. Previously, we identified rat lung as a quercetin target tissue. To assess relevant in vivo health effects of quercetin, we analyzed mechanisms of effect in rat lungs of a chronic (41 weeks) 1% quercetin diet using whole genome microarrays. We show here that fatty acid catabolism pathways, like beta-oxidation and ketogenesis, are up-regulated by the long-term quercetin intervention. Up-regulation of genes (Hmgcs2, Ech1, Acox1, Pcca, Lpl and Acaa2) was verified and confirmed by quantitative real time PCR. In addition, free fatty acid levels were decreased in rats fed the quercetin diet, confirming that quercetin affects fatty acid catabolism. This in vivo study demonstrates for the first time that fatty acid catabolism is a relevant process that is affected in rats by chronic dietary quercetin. Received 6 July 2006; received after revision 29 August 2006; accepted 28 September 2006     

Allergic contact dermatitis: epidemiology, molecular mechanisms, in vitro methods and regulatory aspects

Contact allergies are complex diseases, and one of the important challenges for public health and immunology. The German 'Federal Institute for Risk Assessment' hosted an 'International Workshop on Contact Dermatitis'. The scope of the workshop was to discuss new discoveries and developments in the field of contact dermatitis. This included the epidemiology and molecular biology of contact allergy, as well as the development of new in vitro methods. Furthermore, it considered regulatory aspects aiming to reduce exposure to contact sensitisers. An estimated 15-20% of the general population suffers from contact allergy. Workplace exposure, age, sex, use of consumer products and genetic predispositions were identified as the most important risk factors. Research highlights included: advances in understanding of immune responses to contact sensitisers, the importance of autoxidation or enzyme-mediated oxidation for the activation of chemicals, the mechanisms through which hapten-protein conjugates are formed and the development of novel in vitro strategies for the identification of skin-sensitising chemicals. Dendritic cell cultures and structure-activity relationships are being developed to identify potential contact allergens. However, the local lymph node assay (LLNA) presently remains the validated method of choice for hazard identification and characterisation. At the workshop the use of the LLNA for regulatory purposes and for quantitative risk assessment was also discussed.     

Method of Stabilizing the Surface Energy of Fabrics Coated with Silicone

Silicone coatings have been used in this study. The method adopted was the liquid drop analysis on the coated fabrics. The contact angle between a liquid drop and the fabric surface was measured with two liquids continuously and recorded by a computer. The surface energy was calculated by means of Owens method. Kinetic measurement was adopted. The contact angle of liquids on the fabric coated silicone decreased with time was found. A compound solution DX has been found, so that the contact angle of the liquids on the fabric washed with DX becomes constant, and the surface energy of the fabric can be reduced to below 15 mJ/m2.     

Pd-Pt团簇升温过程中Pd原子偏析的分子动力学模拟研究

采用分子动力学模拟初始结构为二十面体Pd13Pt134,Pd55Pt92升温过程,研究发现团簇升温过程中内层Pd原子向外偏析,且原子分布位置和数量对升温过程中的热力学性质有影响.Pd55Pt92团簇的势能曲线在720~880K之间向下跃变,而Pd13Pt134团簇的势能曲线异常波动出现在980K附近.对Pd13Pt134的进一步研究表明Pd原子的位置是导致势能曲线异常的主要原因,Pt原子掺在核心层时势能曲线在升温过程中上升,而Pt原子掺在第二层时势能曲线出现异常变化,在900K处出现向下跃变.分析发现Pt原子在不同位置层的势能差别是导致势能曲线异常变化的主要原因.     

古典园林的虚拟仿真建模和动态效果研究

高真实感的动态仿真技术一直是古典园林虚拟研究的重点和热点,针对如何实现园林景观的数字化平台设计,本文提出了一种依托高真实感虚幻引擎开发工具包(Unreal Development Kit,UDK)与强大植物建模软件SpeedTree相结合的完整制作方案,它使园林虚拟仿真交互更加真实.该方案从基础建模、贴图处理、植被添加、户外光影和动效制作等方面提升了古典园林的虚拟仿真表现;模型的流线性表面及后期不透明贴图处理解决了古典园林中复杂模型的渲染时间长和真实感差的问题;根据UDK引擎和SpeedTree插件完成了植被的真实还原及复杂的光影问题,解决了日夜交替、光影浮动的动态逼真效果;最后探讨了虚拟技术与古典园林设计相结合的技术优势和发展前景.