线段二维裁剪的新算法

本文提出了一种参数线段对矩形窗口裁剪的新算法,并且证明了算法的正确性.这种算法用参数表示线段上的点,根据文中提出的两个准则即可迅速判断线段是否有可见部份及可见部份的端点位置.本算法的主要优点是简化了现行方法中的繁琐计算与判断过程、性能可靠,可适用于对任何状态的线段的裁剪.     

赝功能原理

主要讨论赝功能原理的意义;重点讨论赝功的意义;对“赝功不是真实功”的常论,提出了新的观点,并做了分析探讨。     

Slater函数的双中心交换积分

采用复型Ｓｌａｔｅｒ轨道，推导了双中心交换积分公式，讨论了交换积分的一种特殊情形．对实际计算中的一些问题进行了讨论，给出了一部分计算结果．     

Eu~(3+)激活的La_2Na_2Sr_6(PO_4)_6Br_2和Y_2Na_2Ca_6(PO_4)_6F_2晶体中的发光中心

采用高温固相法合成了La_2Na_2Sr_6(PO_4)_6Br_2和Y_2Na_2Ca_6(PO_4)_6F_2。X射线衍射分析证明它们都为单一物相。用Sr_(10)(PO_4)_6Br_2和Ca_(10)(PO_4)_6F_2同晶指标化法进行指标化,结果表明:它们都属六方晶系的磷灰石结构,空间群为P6_3/m。计算了它们的晶胞参数。以Eu~(3+)做结构探针,研究了Eu~(3+)所处晶格的点对称性。研究表明:在La_2Na_2Sr_6(PO_4)_6Br_2中Eu~(3+)占据4f格位,为C_3点群,而在Y_2Na_2Ca_6(PO_4)_6F_2中Eu~(3+)处于6h格位,为C_6点群。     

New structure model of oxygen-evolving center and mechanism for oxygen evolution in photosynthesis

So far, many important questions and problems concerning the structure and mechanism of photosynthetic oxygen evolution are still unsolved. On the basis of recent achievements in this field, a new structure model is proposed whereby two H2O molecules bind asymmetrically to two manganese ions (Mn1Ⅱ and Mn4Ⅲ) at the open end of "C" shaped cluster and keep rather large distance. Two histidine residues coordinate to the other two manganese ions in higher oxidation state (Mn2Ⅳ and Mn3Ⅳ ) through their nitrogen atoms of the imidazole. Cl bound as terminal ligand to Mn4Ⅲl is connected to Ca, and the latter is needed to maintain the special configuration of two Mn2O2 units by bridged-oxo and bridged-carboxylate ligands. The whole structure of oxygen evolution center is asymmetry. A new mechanism for oxygen evolution invokes predictions of asymmetric oxidation of two H2O molecules, dynamic structural changes of oxygen e-volving center and indirect proton transport, etc. Only in S2 state, could Mn1Ⅳ = O. intermediate with high oxidation potential be formed. The S2→S3 process occurs with significant structural changes, as well as intramolecular and intermolecular hydrogen transfer. The S3 state corresponds to intermediate of Mn1Ⅳ-O… H… O-Mn4Ⅳ . During S3→ [S4] →S0, the O-O bond is formed only in S4 state. The change of nucleophilic interaction between Cl and manganese ions different oxidation states has consequence for the significant structural changes in H2O oxidation process.     

刚体平衡问题再研究

以刚体的平衡方程为理论依据推断出刚体在各种运动状态下能否处于平衡状态，并导出处于平衡状态所满足的运动学条件；同时对刚体在平面力系作用下平衡条件的等价条件作了证明。     

试谈以学生为中心的化学教学设计

对以学生为中心的化学教学设计的内涵和特征作了初步的探讨，并分析盐类水解的化学程序启发教学设计，是如何充分体现了以学生为中心。     

A Shortest Path Problem

ＡＳｈｏｒｔｅｓｔＰａｔｈＰｒｏｂｌｅｍ￥ＪＩＡＺｈｅｎｇｓｈｅｎｇ（ＭａｔｈｅｍａｔｉｃｓａｎｄＭｅｃｈａｎｉｃｓＤｅｐａｒｔｍｅｎｔｏｆＴａｉｙｕａｎＵｎｉｖｅｒｓｉｔｙｏｆｔｅｃｈｎｏｌｏｇｙＴａｉｙｕａｎ０３００２４）ＦＡＮＨｕｉ（Ｆｏｕｎｄ...     

基于绿色设计准则的塑料门窗铣削机设计

介绍了绿色设计在技术先进性,环境、材料和结构等方面的准则,并运用于塑窗锯铣加工中心的铣削机设计中,表明绿色设计可从技术上保证安全,可靠,经济地实现产品的各项功能和性能,同时只有在设计阶段将产品的“绿色度”作为设计目标,才能取得理想的设计结果。