Galileo and the problem of infinity

During the period before the Greek revolution of 1821, and especially during the years between 1750 and 1821, there were two ways in which European scientific thought was propagated in Greece. The first is traditional. It comes from ancient Greece and, through Byzantium, reaches the period before the Greek revolution. It makes known the thought of Aristotle, Democrititus, and others on ‘natural philosophy’. The second way comes from Europe. The Greek scholars of the period before the Greek revolution, and especially at the end of the eighteenth century, tried to bring to and propagate in Greece the spirit ofthe European Enlightenment, They tried to make known to the Greek people the scientific achievements of Newton, Descartes, Lavoisier, and Laplace. Scientific knowledge is an important weapon against superstition, and Greek students had to learn about science to become free persons in an independent Greek state.     

三个新大环草酰胺Ni(Ⅱ)配合物配体的合成、结构和DNA切割活性研究

合成了3个新的大环草酰胺Ni(Ⅱ)单核配合物NiL1(1),NiL2·CH3CH2OH(2)和NiL3·1.25H2O(3).由于羟基和草酰胺基团的氧原子都能够与金属离子配位,因此,NiL1-3可以用作构筑同多核和异多核配位化合物的配合物配体.X-射线单晶结构分析表明,每个大环配体的4个N原子与Ni(Ⅱ)配位,构成变形的平面正方形配位环境;Ni-N键的长度都非常短,表明3个大环配体中所有氮原子的配位能力都很强.1~3中的醇羟基使羟自由基淬灭,从而抑制了配合物切割DNA的活性.     

Galileo and the problem of concentric circles

In 1892, Eliakim Hastings Moore accepted the task of building a mathematics department at the University of Chicago. Working in close conjuction with the other original department members, Oskar Bolza and Heinrich Maschke, Moore established a stimulating mathematical environment not only at the University of Chicago, but also in the Midwest region and in the United States in general. In 1893, he helped organize an international congress of mathematicians. He followed this in 1896 with the organization of the Midwest Section of the New York City-based American Mathematical Society. He became the first editor-in-chief of the Society's Transactions in 1899, and rose to the presidency of the Society in 1901.     

Semantic-Oriented Knowledge Transfer for Review Rating

With the rapid development of Web 2.0, more and more people are sharing their opinions about online products, so there is much product review data. However, it is difficult to compare products directly using ratings because many ratings are based on different scales or ratings are even missing. This paper addresses the following question: given textual reviews, how can we automatically determine the semantic orientations of reviewers and then rank different items? Due to the absence of ratings in many reviews, it is difficult to collect sufficient rating data for certain specific categories of products (e.g., movies), but it is easier to find rating data in another different but related category (e.g., books). We refer to this problem as transfer rating, and try to train a better ranking model for items in the interested category with the help of rating data from another related category. Specifically, we developed a ranking-oriented method called TRate for determining the semantic orientations and for ranking different items and formulated it in a regularized algorithm for rating knowledge transfer by bridging the two related categories via a shared latent semantic space. Tests on the Epinion dataset verified its effectiveness.     

用不同靶材制备B-C-N薄膜及其红外表征

采用射频磁控溅射方法,分别利用六方氮化硼(h-BN)、硼(B)和石墨(C)靶,在氩气和氮气的氛围中,沉积B-C-N薄膜.傅里叶变换红外光谱(FTIR)分析表明:在1200～1800cm-1和1000～1750cm-1处出现了较宽的吸收峰;在2200cm-1处出现了CN键的特征吸收峰.表明在沉积的薄膜中,C原子与N原子相结合.分别溅射C和h-BN靶,红外光谱分析表明,B—C键在1100cm-1处未产生吸收峰,即利用h-BN和C靶沉积的B-C-N薄膜倾向于相分离,利用B和C靶沉积的B-C-N薄膜中的原子实现了原子量级的化合.     

槲皮素制备分离条件的优化

为了快速、准确地寻求制备分离槲皮素的最佳操作条件,在非线性多组分色谱模型的基础上,通过人工补偿逆方法及二组分近似拟合确定多组分的非线性吸附等温线,以槲皮素的生产能力为优化目标函数,一定纯度和回收率为限制条件,结合板高的影响确定工作参数的初值与变化区间,进一步应用"二分法"优化进样质量浓度和进样体积。该方法减少了试验数量及目标样品的使用量,可以作为确定天然药物最佳制备分离条件的一种精确、高效方法。     

煤矿通风安全控制中的影响因素分析

煤炭是我国的第一能源,在一次性能源结构上所占比例达70%以上。在煤炭矿井的生产过程中,由于复杂的地形及通风不良等因素,容易发生瓦斯爆炸等事故。详细探讨了煤矿通风安全控制中的影响因素及安全对策。     

谈混凝土灌注桩的施工工艺

在现代建筑工程施工中,采取桩基础,既节省了施工工期,又保证了工程质量,并取得了相应的经济效益和社会效益.在工业与民用建筑中,地下水位高、地下土层结构比较复杂的情况下常采用混凝土灌注桩施工.混凝土灌注桩是现场浇筑,施工大部分在水下进行,施工过程不易目测,施工质量很难控制和检查.所以在施工过程中,严格按照施工工艺规范和设计要求进行控制,就尤为重要.     

关于dW=-pdV的微观解释

应用简单物理模型,从微观上分析和计算了外界对理想气体系统作功的公式dw=-pdV.     

浅议法律移植的局限性

在市场经济及法治思想日益成型的现代中国,各种学术观点的争鸣,让我们看到了法治中国的希望.在中西法律资源的比较中,大多数法学家主张把西方发达国家的法治理念、制度作为中国法制建设的模本.本文认为,我们应当全面认识法律移植在法制现代化进程中的作用,在看到法律移植对我国法制进步的积极性的同时也要看到其局限性.