T路计数问题的推广

本文将二维直交空间中的 T路计数问题推广到 n维直 (斜 )交空间中 k( n)向 T路计数问题 ,并给出 n=3,k=2 ,3时的一些具体计数公式 ,同时给出了 Catalan数的几个新的几何 (组合 )解释     

Mechanistic Insights into the Synthesis of [Rh(acac)(CO)(NHC)] (NHC=N-heterocyclic carbene) Complexes Using a Weak Base

A simple synthetic method to access a wide range of [Rh(acac)(CO)(NHC)] complexes is described. In situ infra-red monitoring provides insights into the mechanism of the reaction, including the identification of a key intermediate. An understanding of the reaction mechanism leads to the discovery of novel pathways to commonly used congeners.     

A facile, microwave-assisted synthesis of novel optically active polyamides derived from 5-(3-methyl-2-phthalimidylpentanoylamino)isophthalic acid and different diisocyanates

5-(3-Methyl-2-phthalimidylpentanoylamino)isophthalic acid as a novel aromatic diacid monomer was prepared in three steps. In the first step, phthalic anhydride was reacted with l-isoleucine in acetic acid solution, and the resulting imide acid was obtained in high yield. In the second step, treatment of this imide acid with excess thionyl chloride gave aliphatic acid chloride in good yield. In the last step, this acid chloride was reacted with 5-aminoisophthalic acid to provide novel bulky chiral aromatic diacid monomer. The direct polycondensation reactions of this diacid with several aromatic and aliphatic diisocyanates such as 4,4′-methylenebis(phenyl isocyanate), toluylene-2,4-diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate were carried out under microwave irradiation. In order to compare this method with classical heating, the polymerization reactions were also performed under solution polycondensation conditions. The polymerization reactions occurred rapidly under microwave conditions and produced a series of novel optically active polyamides (PA)s containing pendent phthalimide group, with good yields and moderate inherent viscosities of 0.17-0.60 dL/g. Some of the new PAs showed good solubility and are readily soluble in organic solvents. The resulting macromolecules were characterized by FT-IR, specific rotation, and representative ones by ¹H NMR, elemental and thermogravimetric analyses (TGA).     

军事行动避空侦察的时机和路线选择

介绍了军事行动中侦察卫星运动轨迹的预测方法,并规划了最优行军路线.首先根据雷达探测俯仰角与探测距离的几何关系,确定雷达探测经度范围,并对卫星周期及卫星被探测到的初始位置进行求解,从而建立卫星进出雷达探测范围时刻的预测模型,对几种卫星的过顶情况进行预测·最后,在此基础上建立简化的行军路线模型,选择最优行军路线,躲避卫星侦察.     

Aliphatic thermoplastic poly(ether urethane)s having long PEG sequences synthesized through a non-isocyanate route

A non-isocyanate route for synthesizing thermoplastic polyurethanes with excellent thermal and mechanical properties was described. Melt transurethane polycondensation of 1,6-bis(hydroxyethyloxy carbonyl amino)hexane with four poly(ethylene glycol)s(PEGs), i.e. PEG400, PEG600, PEG1000, or PEG1500, was conducted at different molar ratios. A series of thermoplastic poly(ether urethane)s(TPEUs) with long PEG sequences were prepared. The TPEUs were characterized via gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray scattering, and tensile tests. The TPEUs exhibit Tg between 12.4 °C and-40.4 °C, Tm of up to 149.8 °C, and initial decomposition temperature over 239.4 °C. The tensile strength of the TPEUs reaches 38.39 MPa with a strain at break of 852.92%.     

溶剂热合成球形Cu2ZnSnS4 （CZTS）微粉的研究

本文采用高压溶剂热法合成了铜锌锡硫(CZTS)粉体,采用XRD、SEM测试方法对合成产物的物相、形貌进行了表征。探讨了温度,时间以及表面活性剂等因素对溶剂热合成CZTS粉体形貌、物相和性能的影响。结果表明:高压溶剂热法制备的CZTS目标粉体纯度高,制备周期短,产物形貌为球形的片状集合体。反应进程随着反应温度的升高而加快,随着保温时间的延长而趋于完全。加入部分表面活性剂对团聚现象改善并不明显。     

基于两阶段混合动态规划算法的龙门吊路径优化

产业界已出现利用多台轨道式龙门吊同时作业以提升集装箱码头装船效率的情况,由于需要确定每台龙门吊的取箱作业集合以及增加了“避免碰撞”、“顺次移动”等现实约束,故其移动路径规划问题在模型建立与求解上比单台轨道式龙门吊更为复杂。本文针对两台轨道式龙门吊同时作业的情形,建立了龙门吊移动路径网络模型,并开发了基于贪婪算法与动态规划的两阶段混合算法,并通过仿真算例,借助与基于实际调度规则所得到的调度方案的对比,验证了模型及优化算法的有效性与实用性。     

Multi-step Reaction Route Developed for Improving Crystallinity of Boron Nitride Nanoparticles

A multi-step reaction route was developed to synthesize boron nitride(BN) nanoparticles via the reaction between NaN₃ and BCl₃ in a benzene-thermal solution. By means of this route, the crystallinity of BN nanoparticles was improved via increasing the reaction steps. Meanwhile, a phase transformation from hexagonal BN(hBN) or turbostratic BN(tBN) to cubic BN(cBN) occurred, resulting in the increase of cBN content. Moreover, the content of cBN also slightly increased when the temperature was elevated from 265 ℃ to 280 ℃.     

利用瑞利干涉仪测定不同浓度液体的折射率

本从测定不同压强下气体折射率的瑞利干涉仪的基本工作原理出发,扩展其内部补偿板的补偿能力,使其达到能精确测定浓度变化范围很大的均匀液体的目的。     

用函数求根法解系统控制问题

提供了一大类系统控制问题的求解路线.当所考察的问题可转化为参数估计时,可以把问题进一步转化为未知回归函数求根(根即待估参数)的问题,而扩展截尾的随机逼近算法是解决这类求根问题的恰当工具.给出了算法的一般收敛定理,它已在一系列系统控制问题中得到应用.以ARMA过程的辨识,Hammerstein系统的适应调节为例,展示了上述求解路线的具体实现,并附有相应的模拟计算实例.这种方法提供的估计是递推的,并且以概率1收敛到真值.