关于县际公路建设项目若干问题的思考及探讨

县际公路建设,是一项惠及广大农民群众的伟大工程,是建设小康社会的重要基础设施。以县际公路建设的亲身经历,从政策、资金、设计、管理、养护五个方面揭示县际公路建设过程中存在地一些问题,以期在今后类似工程建设中能得到参建各方的高度关注与改进。     

ArHF和ArFH异构体系的理论研究

应用RHF/6-311 G（d）、MP2/6-311 G（d）量子化学理论计算方法，对ArHF和ArFH异构体系进行了理论探讨，结果表明在OK时，ArHF分子比ArFH分子稳定；MP2（full）/6-311 G(d) 计算得到的ArHF和ArFH体系的电子相关能相差不大，并且发现此类范德华分子络合物的电子相关能可以从其组成的Ar原子和HF分子的电子相关能之和来近似计算。     

发展教育,新闻界义不容辞

拉丁美洲教育事业落后。那里的新闻工作者认为,报纸应当动员舆论,敦促政府为教育做实事。阿根廷《12点钟报》副社长马丁·格拉诺夫斯基有言:"教育的重要性,并不取决于新闻单位如何报道它。"他是在联合国教科文组织召开的传播媒体与教育研讨会上说这番话的。这次研讨会是上半年在布宜诺斯艾利斯召开的,来自拉丁美洲各文字媒体的十多位新闻工作者与会。拉丁美洲传播媒体为何很少报道教育?联合国教科文组织设在布宜诺斯艾利斯的国际教育规划院院长胡安·     

线性码的重量分布

本文给出线性码重量分布之间很有用的一个关系,并给出一个应用。     

Preparation of Silver—Coated Polystyrene Composite Particles

We report a feasible approach to the preparation of monodispersed metal-shell composite microspheres based on a combination of surface reaction and surface seeding techniques. The method was implemented for coating polystyrene (PS) spheres with silver shell having a variable thickness by controlling the amount of reagents in the reaction procedure. These composite spherical particles in dimensions of the submicrometer range may become attractive building blocks for the creation of metallo-dielectric photonic band gap materials when they are organized into crystals.     

Oeffner展宽器高倍率展宽脉冲的理论与实验研究

在理论上分析了Oeffner展宽器的色散特性，给出了展宽脉冲随Oeffner展宽器系统参数变化的关系．据此在实验上建立了一台Oeffner飞秒展宽器系统，将19fs的种子脉冲无色差展宽至605ps，测量结果与理论计算一致．     

带鳍通道性能的遗传算法优化

与光滑通道相比,带鳍通道有更高的传热系数,附加的鳍,极大地增强了通道的传热.然而,传热的增强又与压降的升高相关联,这又导致泵动力需求的增加,因此应该寻求对该系统的优化设计.该文的主要目的是,通过如下方式来精确地确定鳍的位置和尺寸:利用遗传算法实现最小压降时达到最优传热.鳍的每种布局作为问题(遗传算法中的一个个体)的一个解.通常,首先随机地产生一个初始种群,然后该算法在所有这些解中搜索,利用布局函数迭代出新解,最后得到鳍的优化设计.     

Two Typical Examples of Scaling Ionic Partition Scheme for Estimating Correlation Energy of A2 Type Molecules

Based on the calculation results of pair correlation energy contributions of the various electron pairs in Na2 and H2NNH2 systems and the application of the scaling ionic partition scheme for symmetrical A2 type systems, the total correlation energies of Na2 and H2NNH2 have been reproduced by using this simple scheme. The two results show that the absolute deviations are within an acceptable range of error, however, in this way, more than 90% of computational work can be saved. The most attractive result in present paper is that, in these two molecules the coefficients c1 and c2 in the estimation equation can be obtained by the proportion of correlation energy of A^- to that of A^ singlet system. Therefore, it is believed that the proposed ionic partition scheme for symmetrical A2 molecules would be very useful to estimate the correlation energies of large symmetrical molecules.