山水之旅的四种审美境界

自然山水作为审美对象,为人们赞叹吟咏.然而思想境界、人生阅历不同者在山水面前各得其所.有的写山河之美,有的抒内心之情,有的感人生之悟,有的体物我相融,有的四种境界皆备,留下了无数篇隽永优美的画卷.阅读这些山水游记,欣赏他们独特的审美视角和心灵感受,从而培养我们对山水的热爱和审美情趣.     

The competition between two polarization states in two-dimensional random medium

In a two-dimensional random medium, when the transverse magnetic (TM) polarization state and the transverse electric (TE) polarization state share the same population inversion, there is a competition in the population inversion between the two states. Such competition is analyzed by using the finite difference time domain method to numerically solve Maxwell equations with a set of system parameters. The results indicate that TM state has a larger lasing threshold than TE state does so that TM state is strongly suppressed by TE state in the competition. The larger the size of the medium, the easier the lasing modes in TM state appears.     

重论汤显祖《牡丹亭》之音律及"汤沈之争"的曲学背景

《牡丹亭》的音律问题直接引发了明代戏剧史上所谓的“汤、沈之争”。由于忽视对该剧音律的探讨,导致人们对这场争论至今尚无合理的解释。汤显祖在《牡丹亭》的用韵、格律、宫调等方面,既有合理的运用规则,也有随意的破坏成例。“汤沈之争”暴露了明清戏曲家对戏曲音律认识的不足。     

Crystallographic symmetry effect on the nucleation in non-equilibrium aggregation pattern

Some non-equilibrium patterns formed in different systems are composed by crystallites with correlations in their crystallographic orientation. This reflects the fact that crystallographic symmetry controls the successive nucleation in the crystallite aggregating process. Based on the crystallographic symmetry, a new classification to describe the different kinds of anisotropy for non-equilibrium aggregation pattern has been proposed: parallel aggregation, twin aggregation and radial (random) aggregation. This new classification can clarify the different anisotropy related to the crystal point group, which the previous classifications cannot. The nucleation mechanisms for these three kinds of patterns are also discussed based on the symmetric relationship among the crystallites. It is shown that the crystallographic symmetry plays an important role not only on the crystal polyhedral shape formed by growth, but also on the aggregation pattern formed by nucleation.     

2(1H)-吡啶酮互变异构体系取代效应的理论计算

取代的2（1H）-吡啶酮团类化合物常具有诱人的生物活性[1，2]．由于其酮式和醇式结构的互变异构化性质，确定互变异构平衡体系中的优势结构及研究取代基对平衡体系的影响，对阐明该类化合物的构效关系有着重要的意义．实验发现2（1H）-吡啶酮的6-位H被取代后对其互变异构平衡有     

From 2D hyperbolic forests to 3D Euclidean entangled thickets

A method is developed to construct and analyse a wide class of graphs embedded in Euclidean 3D space, including multiply-connected and entangled examples. The graphs are derived via embeddings of infinite families of trees (forests) in the hyperbolic plane, and subsequent folding into triply periodic minimal surfaces, including the P, D, gyroid and H surfaces. Some of these graphs are natural generalisations of bicontinuous topologies to bi-, tri-, quadra- and octa-continuous forms. Interwoven layer graphs and periodic sets of finite clusters also emerge from the algorithm. Many of the graphs are chiral. The generated graphs are compared with some organo-metallic molecular crystals with multiple frameworks and molecular mesophases found in copolymer melts. Received 10 December 1999     

Photon statistics of a bad-cavity laser near threshold

A simple model of a bad-cavity laser is presented based on Haken's master equation for N pumped two-level atoms in a cavity. Via adiabatic elimination of fast variables the whole photon statistics is solved analytically near threshold. It is shown that the second order coherence function g ⁽²⁾ (0) has a very different behavior near threshold for a bad-cavity laser compared to a good-cavity laser. The power spectrum illustrates nicely the different time scales involved in the dynamics. Received: 13 November 1998 / Revised: 19 May 1998 / Accepted: 6 July 1998     

菠菜PSII核心复合物激发能传递与温度的关系

采用基于延时分次扫描单光子计数器为探测装置的皮秒时间分辨荧光光谱测试系统研究了菠菜光系统 (PSⅡ )核心复合物光能传递与温度的关系。分别对PSII核心复合物样品在 2 0℃、42℃、48℃下做温浴处理 ,然后以脉宽为 1 2 0 ps,重复率为 4MHz ,波长为 5 1 4nm的Ar+激光作为光源分别激发处理后样品的荧光。通过对测量结果进行数据处理 ,分析比较发现 :同一温度下 ,呈荧光带的激发能传递速度比副荧光带处的快 ;同一波长下 ,慢组分的时间常量随温度升高而变慢 ,而快速组分的时间常数则变化不大 ;做 42℃温浴处理的样品接近于蛋白质解体的临界状态     

Electromagnetic transition in waveguide with application to lasers

The electromagnetic transition of two-level atomic systems in a waveguide is calculated. Compared with the result in free space, the spontaneous emission rate decrease because the phase space is smaller, and meanwhile, some resonance appears in some cases. Moreover, the influence of non-uniform electromagnetic field in a waveguide on absorption and stimulated emission is considered. Applying the results to lasers, a method to enhance the laser power is proposed. Received 29 May 2001 and Received in final form 25 October 2001     

苏轼--词体的最初终结者

苏轼是词坛上贡献至伟的一位重要人物，然而，就其创作实践产生的流弊来看，他又算得上词体终结的初始者。他的以诗为词，最终导致了词体特点的丧失；他的不协音律，导致了词与音乐关系的疏远，并最终使词丧失了和音乐结合的条件；还有他追求雅化的倾向，又造成了后人变本加厉地去求博求雅，以至于词体让人难以看慢。让词成为少数文人雅士把玩的工艺品，并使最终走向枯萎、衰亡。