同步辐射真空紫外（VUV）区中的团簇物理

本文概述了同步辐射在团簇物理研究中的应用,讨论主要集中在真空紫外(VUV)区。重点说明其实验方法、研究进展状况和实验设计的一般考虑;并选择介绍德国DESY的团簇物理实验站CLULU;最后,对未来的发展方向提出作者的一些观点。     

自大气中氮合成氨的演示实驗

在教学法的文献中,会提到一些演示合成氨的裝置。類似裝置的結構实質在於將純制後的自銨鹽得到的氮和由啟普裝置發生的氫通入气体混合點,从这裹再將氮氫混合气通入裝有接觸剂的管子。讓生成的氨通过酚酞的酒精溶液,数分鐘後,溶液变成深紅色。应該指出,所有这些類似的裝置仍然是笨     

侵犯前颅底的筛窦肿瘤切除

探讨侵犯前颅底筛窦肿瘤的手术方式及前颅底重建的方法。方法：对１９９４－１９９８年间的４例侵犯前颅底的筛窦肿瘤采用额骨硬脑膜外进路颅面联合手术,分别用带蒂额骨膜瓣或帽状腱膜瓣及颅骨内板结合耳脑胶重建前颅底。结果：４例创口一期愈合,均未见脑脊液鼻漏及脑膜脑膨出,１例术后出现一过性尿崩症,１例术后视力提高,术后随访半年至５年,４例均存活,结论：额骨硬脑膜外入路颅面联合手术是切除侵犯前颅底筛窦肿瘤的有效方     

Multiple-Pulse Operation in Passively Mode-Locked Fibre Laser with Positive Dispersion Cavity

We report the observation of rectangular shape spectrum in passively mode-locked fibre laser with positive dispersion cavity. The spectrum is broad and flat, and 3dB bandwidth can be up to 17.61 nm. Multiple-pulse operation is observed in our laser system. The spectrum width, pulse energy, pulse width and peak power of the mode-locked laser output change with the appearance of multiple-pulse operation.     

Temperature Dependence of the Fluorescence Emission Intensity of Eu/TiO2 Nanocrystals

The samples of europium ions doped titanium dioxide （Eu^3＋/TiO2） nanocrystals are synthesized by a modified sol-gel method with hydrothermal treatment. The x-ray diffraction and scanning electron microscopy are used to characterize the sample. The temperature-dependent fluorescence emission effect of Eu^3＋-doped samples is investigated. It is found that under the excitation of 514.5nm light, the emission intensity of Eu^3＋ reaches a maximum value at 450K among various Eu^3＋ dopant concentrations in Eu^3＋ /TiO2 nanocrystals. The variation of the emission intensity may be attributed to the photon-assist absorption and the temperature-quenching effect.     

我国工科大学物理教学大纲和教学基本要求的制订概况(1954-1995年)

《非物理类理工学科大学物理课程教学基本要求》（正式报告稿）和《非物理类理工科大学物理实验课程教学基本要求》（正式报告稿）已分别在本刊2006年第5期和第6期刊登．本刊将继续刊登有关文章． 为让广大读者了解我国工科物理教学大纲和教学基本要求修订的历史概况，本刊特请上海交通大学胡盘新教授（原工科物理课程教学指导委员会委员）回忆整理撰写了这篇文章，并请原工科物理课程教学指导委员会主任委员夏学江教授、原副主任委员吴百诗教授、原委员恽瑛教授、汤毓骏教授以及课程教学指导委员会联络员汤发宇同志对该文进行了修正补充． 几十年的物理教学改革的历程，与时俱进，稳步发展，充溢着我国物理教学老前辈的睿智和敬业精神，我们今天的物理教学工作都是基于前人打下的良好基础．我们要永远记住这些老前辈和他们的业绩，并不断学习他们严谨、科学的作风及无私奉献的精神．[编者按]     

Evolutionary Prisoner's Dilemma Game Based on Pursuing Higher Average Payoff

We investigate the prisoner＇s dilemma game based on a new rule： players will change their current strategies to opposite strategies with some probability if their neighbours＇ average payoffs are higher than theirs. Compared with the cases on regular lattices （RL） and Newman-Watts small world network （NW）, cooperation can be best enhanced on the scale-free Barabasi-Albert network （BA）. It is found that cooperators are dispersive on RL network, which is different from previously reported results that cooperators will form large clusters to resist the invasion of defectors. Cooperative behaviours on the BA network are discussed in detail. It is found that large-degree individuals have lower cooperation level and gain higher average payoffs than that of small-degree individuals. In addition, we find that small-degree individuals more frequently change strategies than do large- degree individuals.     

三光束飞秒激光干涉在GaP,ZnSe表面诱导二维复合纳米-微米周期结构

报道了三光束飞秒激光干涉在GaP和ZnSe晶体表面诱导二维复合纳米-微米周期结构.改变三束光的偏振组合方式,可以得到不同的纳米-微米复合结构.理论计算了相应偏振条件下光场强度分布、椭偏度分布和偏振方向分布.实验和理论计算结果表明,烧蚀斑上的微米长周期结构是由三光束干涉的强度花样决定,短周期纳米结构是由光场的偏振干涉花样决定.这些研究在纳米材料制备、超高密度光存储以及材料特性周期性调制等方面有很大的应用前景.     

Evolutionary prisoner’s dilemma on Newman-Watts social networks with an asymmetric payoff distribution mechanism

In this paper, we introduce an asymmetric payoff distribution mechanism into the evolutionary prisoner's dilemma game (PDG) on Newman--Watts social networks, and study its effects on the evolution of cooperation. The asymmetric payoff distribution mechanism can be adjusted by the parameter α: if α>0, the rich will exploit the poor to get richer; if α<0, the rich are forced to offer part of their income to the poor. Numerical results show that the cooperator frequency monotonously increases with α and is remarkably promoted when α>0. The effects of updating order and self-interaction are also investigated. The co-action of random updating and self-interaction can induce the highest cooperation level. Moreover, we employ the Gini coefficient to investigate the effect of asymmetric payoff distribution on the the system's wealth distribution. This work may be helpful for understanding cooperative behaviour and wealth inequality in society.     

动态超高压微射流对卵清蛋白微观结构的影响

采用圆二色谱(CD)、X射线衍射(XRD)、ANS荧光探针和紫外(UV)光谱研究了动态超高压微射流对卵清蛋白微观结构的影响。结果表明：卵清蛋白的微观结构的变化与处理压力有关,CD显示不同压力处理的卵清蛋白二级结构中的α-螺旋,β-折叠,β-转角和无规卷曲之间发生相互转化,二级结构的有序性提高;X射线衍射图谱直观显示不同压力处理的卵清蛋白晶体结构增加,160 MPa处理下结晶区最大,说明蛋白结构的有序性提高,与CD分析结果相似;ANS荧光探针光谱显示卵清蛋白的表面疏水性随着处理压力的增大而提高,120 MPa处理下达到最大;紫外光谱显示随着处理压力的增大,卵清蛋白最大紫外吸光值下降,卵清蛋白分子表面的具有紫外吸收的芳香氨基酸残基被包埋于分子内部,卵清蛋白的三维结构发生改变。