New strategies of photoprotection

Adequate photoprotection is essential to control UV-related disorders, including sunburn, photoaging and photocarcinogenisis. Sun avoidance, protection of skin with clothing, and sunscreens are presently the best way of photoprotection, assuming that they are used properly. However, new strategies, which are based on or make use of the endogenous protective response to UV light, may further improve currently used photoprotective means. The addition of repair enzymes and/or antioxidants has a positive effect on skin's recovery from UV-induced DNA-damage. Several botanical agents, mainly vitamins and polyphenols, have shown to influence signal transduction pathways leading to photoprotective effects. Also stimulation of endogenous UV-response pathways via irradiation with a low UV dose or via simulation of UV-induced DNA-damage results in photoprotective effects. Future research in this field and combination of different photoprotective strategies will hopefully lead to improved photoprotection.     

肾脏冷灌注过程中的生物传热实验研究

在保护液亚临界相变温度范围进行肾脏器官的低温延时保存,是一个不同于传统低温保存的新方法。为保持细胞活性必须从器官摘取的第一步展开研究,用保护液对离体肾脏进行冷灌注是移植器官保存的重要环节,研究冷灌注过程中器官温度随时间变化的传热特征,探求提供与传统生物保存方法所不同的传热传质条件非常重要。用高倍率红外热象仪、热电偶探针、超声血流计等,对猪整体肾脏冷灌注过程进行了实时测试,得出动脉血管作为冷源时的肾脏温度动态变化曲线。实验结果表明,在1℃冷却液匀速灌注过程中肾脏温度的降低表现为非均匀变化,究其原因是由于肾脏内特定的组织结构引起。实验研究将对肾脏器官的三维温度场数值计算提供宝贵的实验依据。     

Stochastic utility-efficient programming of organic dairy farms

Opportunities to make sequential decisions and adjust activities as a season progresses and more information becomes available characterise the farm management process. In this paper, we present a discrete stochastic two-stage utility-efficient programming model of organic dairy farms, which includes risk aversion in the decision maker’s objective function as well as both embedded risk (stochastic programming with recourse) and non-embedded risk (stochastic programming without recourse). Historical farm accountancy data and subjective judgements were combined to assess the nature of the uncertainty that affects the possible consequences of the decisions. The programming model was used within a stochastic dominance framework to examine optimal strategies in organic dairy systems in Norway.     

对一系列具有共轭发色团的有机硼喹啉配合物的基态和激发态性质的理论研究

文献合成并研究了一系列发光材料(Ph2Bq-x2) [x2=5,7-dibromo(1); 5,7-diphenyl(2); 5,7-bis(biphenyl-4-yl); 5,7-bis(9,9-dihexylfluoren); q=8-quinolinelate]。结果显示，在强吸收峰处，随着配体共轭链的增长，光谱发生明显红移。这里，用di(p-nitrostyryl) (3) 和 distyryl (4) 来分别取代bis(biphenyl-4-yl) 和 bis(9,9-dihexylfluorenyl)。用密度泛函理论和含时密度泛函理论来研究并比较了四个分子的电子结构和光谱性质。计算结果表明简单的取代基仍然可以产生从1到4的红移。此外，3和4 在吸收峰的位置具有比1和2大的振子强度，这将增加电子从基态到激发态的跃迁几率，较高的向激发态的跃迁几率意味这强的发射强度。     

Synthesis of Dendritic-Linear Block Copolymers by Atom Transfer Radical Polymerization

Polymers and copolymers with complex, yet well-defined architectures are drawing significant attentions in the search for materials with excellent properties. Of these macromolecular structures, dendritic-linear block copolymers consisting of covalently bound linear and dendritic segments have shown interesting solution, solid-state, and interfacial properties. As a novel polymerization approach, atom transfer radical polymerization (ATRP) has been attracting increasing interest recently, sin…     

等离子体的振荡及流体效应的解释

在普通物理层次内对等离子体的主要基本特性进行分析并简单介绍有关应用。     

高阶非线性Schr(o)dinger方程的自相似解

研究非线性项的形式为|u|pu,p>0的2m阶非线性Schr(o)dinger方程的自相似解.利用scaling和压缩映象原理证明了当初值满足一定条件时Cauchy问题解的整体存在性,据此给出了当初值的形式为U(x/|x|)|x|-2m/p时,自相似解的存在性.     

Bi-Lipschitz maps in <Emphasis Type="Italic">Q</Emphasis>-regular Loewner spaces

By applying the theory of quasiconformal maps in measure metric spaces that was introduced by Heinonen-Koskela, we characterize bi-Lipschitz maps by modulus inequalities of rings and maximal, minimal derivatives in Q-regular Loewner spaces. Meanwhile the sufficient and necessary conditions for quasiconformal maps to become bi-Lipschitz maps are also obtained. These results generalize Rohde’s theorem in ℝ ⁿ and improve Balogh’s corresponding results in Carnot groups. This research is supported by China NSF (Grant No. 10271077)     

与相变潜热有关的铁电-顺电相界动力学及其尺寸效应

对于铁电-顺电相界的快移动，提出了相变潜热释放传导机理进行解释，并对其尺寸效应做了进一步研究.研究表明相界移动速率随体系厚度的减小而增加.理论结果与实验符合. 关键词： 铁电相变 相界动力学 相变潜热 尺寸效应     

FS水声遥控系统

本文介绍一种可实用的ＦＳ式编码的水声遥控系统，该系统采用９个频率点进行移频编码，可有效抗多途对译码的影响，编码设计能使遥控指令的码间距做得较大，通过自适应滤波器有效译码，可将误码率控制在希望值以下。理论分析和试验结果均表明，本系统误码率接近０，解码率１５００ｍ以内大于０．９，近距离大于０．９６本系统已应用于水下物理场测量系统中。