两元

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

Using properties of idempotents,we show several necessary and sufficient conditions for the invertibility of the difference of two idempotents, and exhibit some applications to matrix ring s.

本文研究在一个有单位元的环中两个幂等元之差的可逆性问题，利用幂等元的性质，得到了两个幂等元之差可逆的几个充分必要条件，并给出了在矩阵环中的几个应用。

In this paper, the conventional isopiestic technique have been modified and extended to multicomponent unsaturated mixed solvent solutions, each containing two or three volatile solvents and two unsaturated solutes, and multicomponent saturated aqueous solutions, each containing two unsaturated solutes and one or two saturated solutes. Isopiestic measurements have been conducted systematically for the first time for two mixed solvent electrolyte solutions, two quaternary saturated aqueous solutions and three quinary saturated aqueous solutions and the experimental results have been compared with the ideal-like solution model.

本文将传统的等压技术，经过改进后，进一步应用于含有两种或三种挥发性溶剂和两种非饱和溶质的多元混合溶剂溶液以及含有一种或两种饱和溶质和两种非饱和溶质的多元饱和水溶液，首次系统地测定了两例混合溶剂电解质溶液、两例四元饱和水溶液和三例五元饱和水溶液的等压平衡，并将实验结果与类理想溶液模型进行了比较。

Data show that the trading volume on the main hot money did not show a marked decline, and on December 3, 4 significantly enlarge the volume, Shanghai and Jiangsu Guotai Junan the most obvious way to enlarge transactions, 3 amounted to 419,000,000 yuan transactions, 4 more Is 7.5 billion, two-day net buying 204 million, on the 5th of the main transactions are as follows: Chinese iron 110,000,000 yuan to buy, sell 112 million Tebian Electric 031,000,000 yuan to buy, sell 018,000,000 yuan, CITIC Securities 031,000,000 yuan to buy, sell 039,000,000 yuan, the Industrial and Commercial Bank bought 110,000,000 yuan; and as the "suicide squad leader," the Soochow Hangzhou Wenhui Road in the near future on the relatively slow growth in the volume of transactions, mainly trade: CITIC Securities 049,000,000 yuan to buy, sell 125 million, in the Second Railway Board 110,000,000 yuan to buy, sell 027,000,000 yuan, Haitong Securities 036,000,000 yuan to buy, sell 051,000,000 yuan, China Ping An bought 158,000,000 yuan .

数据显示，在主热钱交易量没有出现明显下降，12月3日，4体积显着扩大，上海，江苏国泰君安的最明显的方法扩大交易，三达4.19亿元的交易，4更多的75亿美元，为期两天的净买入2.04亿，在主要交易第五如下：中铁一一〇〇〇〇〇〇〇元购买，出售1.12亿特变电工0.31亿元购买，销售0.18亿元，中信证券0.31亿元的购买，出售0.39亿元，工商银行收购了1.1亿元，并作为"自杀班长"，东吴杭州文晖路在不久的将来，主要是贸易上的交易量增长相对缓慢：中信证券0.49亿人民币购买，出售1.25亿美元，在第二次铁路局1.10亿元购买，销售0.27亿元，海通证券0.36亿元购买，销售0.51亿元，中国平安购买一点五八零亿元。

At the same time, This part elaborate detailedly his transformation of his poems style, from simulate to mature, which relates to his vagabondage .

同时，这一部分对其各个时期诗风的转变进行了详细的阐述，从最初的模拟之作到最终走向成熟，无不与其漂泊的人生有着密切的联系；第三部分对汪元量诗歌创作进行成因分析，揭示出蒙元统治是汪元量诗歌创作的政治动因，宽松的文化环境是他诗歌创作的契机，而"宗唐得古"风尚，则是汪元量诗歌创作的温床；第四部分对汪元量研究中存在的"宋旧宫人诗词真伪"和汪元量仕元两个问题进行了更加全面、更加科学的论述，揭示出王国维先生提出的宋旧宫人诗词为伪作这一观点不能成立。

The equilibrium geometries of squaraines substituted by heteropentacyclic, benzo fuzed heteropentacyclic, heterohexacyclic, benzo fuzed heterohexacyclic, heptacyclic, benzo fuzed heteroheptacyclic and zwitterionic squaraines were obtained with ab initio calculation at HF/6-31G* level and the electronic spectra were examined using CIS/6-31G* method.

用从头算6-31G~*方法优化了多种五元杂环、苯并五元杂环、六元杂环、苯并六元杂环、七元环和苯并七元杂环取代的方酸分子以及方酸两性离子分子的几何结构；用CIS／6-31G~*方法计算了其电子光谱；通过TDHF／6-31G~*方法计算其线性极化率、一阶和二阶超极化率来研究分子结构和非线性光学性质之间的关系，同时用两态模型解释了部分分子的一阶超极化率。

The first idea to deal with the packet loss is the new proposal of multitask ATM cells and the required new ADPCM encoder. This scheme combines three tasks together, namely, reducing cell packeting delay, avoiding breakdown of speech decoders due to one lost cell, compensating or replacing the lost information segment, by dividing the cell payload field into two parts——main and additional information fields, the latter again consists of synchronization information and the coded speech information contained in the last cell.

首先以ATM网络为例，提出了新的信息分组多任务装配法，以及对应此方法的新型ADPCM语音编码系统，这种方法中，利用特殊设计的编码器，使ATM信元负载信息域，由主要和附加用户信息两部分组成，后者又由同步信息和前一个信元语音段信息组成，通过选择和调节信元中两部分信息域的比例，实现了小的分组装配时延、高的分组丢失补偿质量、强的阻断误差传递功能三者的结合。

The main technique applied in our method is derived from the features of the eight bit-planes of a gray image. The XOR bit-wise operation is used for two bit pixels among the neighboring bit-planes from the most significant bit to the least significant bit.

本提出方法是将欲隐藏之灰阶影像分解成八张位元平面，并利用其影像前几个位元平面0与1分布会有群聚现象，将两两位元平面间作XOR (Exclusive-or)运算，再使用线性四元树的观念将运算后的资料进行有效BFS编码，之后再隐藏於伪装图之像素最低位元，使最后藏入资料的伪装图影像仍呈现高度清晰的图像显示，也就是说PSNR的测度皆能远大於30dB。

It is an important route to increase efficiency and reduce pollutants on coal using for resident that clean coal technologies suitable for resident is to be chosen and used. In this paper, a quantitative assessing method on clean coal technologies us is used to assess and screen clean coal technologies suitable for resident . Integrated cost for unit energy production on various clean coal technologies suitable for resident is coal cleaning 48.37 yuan/GJ,coal molding for resident 45.37 yuan /GJ,coking 28.53 yuan/GJ,coal pressurized gasification combined with methanol 54.73 yuan /GJ,coal pressurized gasification combined with oil and 50.71 yuan/GJ,coal two-segment stove gasification 88.66 yuan/GJ,erection stove gasification 38.84 yuan /GJ. Integrated cost for unit energy production on coking is the least.

选用合适的民用清洁煤技术是提高居民生活用煤能源利用效率、减少环境污染的重要途径之一，本文利用笔者提出的清洁煤技术定量评价方法对民用清洁煤技术进行了定量评价与筛选，评价结果表明，在标准状态下各种民用适用清洁煤技术的单位综合成本分别为选煤48元/GJ，民用型煤45.73元/GJ，炼焦制气28.53元/GJ，加压气化联产甲醇54.73元/GJ，加压气化联产油蜡50.71元/GJ，两段炉气化88.66元/GJ，直立炉气化38.84元/GJ，其中炼焦制气是单位综合成本最小的民用清洁煤技术。

Several main results on the evolutions of the life and environment on early earth are summarized as follows:(1) the oxygenation of surface environment didn''t cease until a stable stage for 0.4Ga appeared after 1.6Ga;(2) compared to the isotopic compositions of kerogens and coexisted carbonates, the differences between two can effectively carrier the signals from local environments and bio-assemblages;(3) multiple isotopic relationships between kerogens and individual alkanes in Proterozoic samples were observed, which would depend on the specific biogeochemical processes;(4) repeated biogeochemical changes were observed accompanying Neoproerozoic glaciations, which suggesting that environmental rather than evolutionary forces were driving the biogeochemical changes;(5) the bio-radiations after Neoproterozoic glaciations were definitely suggested by molecular and isotopic data to be at the early Cambrian and after the middle of Doushantuo deposition with different triggers for them.

研究获得以下重要认识：（1）古元古代地表环境的氧化可能一直持续到中元古代早期(约1.6Ga)，而在此之后的4亿年里则保持相对稳定；（2）相对于传统的干酪根和碳酸盐的碳同位素组成，二者之差则能更好反映区域环境的演化特征；（3）在元古代干酪根与单体烷烃类之间存在多种碳同位素组成关系；而其与不同的生物地球化学过程有关；（4）全球海洋生物地球化学特征随新元古代多次冰期出现循环波动，这显然为环境因子的驱动；（5）在新元古代大冰期之后，分子与同位素数据显示地球生命在陡山沱中后期和早前寒武纪出现两次大辐射，然而两次生命辐射的本质却是不同的。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。