非球面光学元件的面形检测技术

介绍了非球面各加工阶段的面形检测技术及其最新进展,重点介绍了非球面精密抛光期的面形检测技术,并对其中的非零位子孔径拼接干涉检测法和部分补偿法进行了详细阐述,提出了适用于大口径、深度非球面面形检测的组合干涉法的概念。概述了近年来受到关注的自由曲面非球面的发展和检测技术现状,展望了非球面检测技术的发展趋势。     

完备化Witt代数中自然出现的一些非有限阶化李代数的表示

讨论了完备化Witt代数的三类非有限阶化子代数的不可约非权模的实现,并利用它们的表示得到一些有趣的组合恒等式.     

梅特勒-托利多荣获“2010年度最佳售后服务厂商”大奖

2011年4月26日,中国科学仪器行业峰会"2011中国科学仪器发展年会(ACCSI 2011)"在北京京仪大酒店隆重召开。200多位仪器企业负责人、200多位实验室负责人和仪器应用研发专家及百位来自相关政府部门、相关学会商会和投资机构的嘉宾出席了本届年会。     

组合催化剂上丙烷选择氧化制丙烯酸

考察了在C3H8氧化脱氢的NiZrO催化剂和C3H6选择氧化的Mo基催化剂组成的组合催化剂上C3H8选择氧化制取丙烯酸的反应性能.结果表明,两个催化剂比例适当时,反应的丙烯酸收率可达最大.优化温度、烷氧比、空速以及N2含量等反应条件的结果发现,反应体系中O2的匮乏会严重影响反应性能.在有氧分布器的反应装置中对所选组合催化剂在优化的反应条件下进行了30h稳定性测试,结果表明,在340oC,反应性能基本稳定,C3H8转化率和丙烯酸选择性可分别维持在～20%和～74%.     

Synthesis of Star-like Polybutadienes by a Combination of Living Anionic Polymerization and “Click” Coupling Method

Three-arm and four-arm star-like polybutadienes(PBds) were synthesized via the combination of living anionic polymerization and the click coupling method. Kinetic study showed that the click reaction between the azido group terminated PBd-t-N3 and the alkyne-containing multifunctional linking reagent was fast and highly efficient. All coupling reactions were fully accomplished within 40 min at 50 °C in toluene in the presence of the reducing agent Cu(0), proven by 1H-NMR, FTIR and GPC measurements. For the coupling reactions between the PBd-t-N3 polymer and dialkyne-containing compound, the final conversion of the coupled PBd-PBd polymer was ca. 97.0%. When a PBd-t-N3 polymer was reacted with trialkyne-containing or tetraalkyne-containing compound, the conversion of three-arm or four-arm PBd was around 95.5% or 87.0%, respectively. Several factors influencing the coupling efficiency were studied, including the molecular weight of the initial PBd-t-N3, arm numbers and the molar ratio of the azido group to the alkynyl group. The results indicated that the conversion of the target products would be promoted when the molecular weight of the PBd-t-N3 was low and the molar ratio of the azido to alkynyl groups was close to 1.     

惯性/天文组合导航中的时空坐标转换及其误差分析

针对惯性/天文组合导航中将天文传感器测量信息从天球坐标系到地球坐标系转换的问题,研究了其转换过程中涉及到的时间系统和坐标转换关系,前者包括世界时、地球时、太阳系质心力学时、原子时和协调世界时等时间概念,后者包括岁差、章动、视恒星时和极移等旋转变换。对坐标转换过程中小于0.1″的因素进行了忽略和近似简化,误差分析表明,除地球自转角的计算需要比较精确的UT1时间外,其他天文参数计算中的时间输入均可直接使用UTC时间代替。仿真结果显示,所提简化算法的转换精度达到了0.2″,满足角秒级的天文传感器测姿精度需求。     

带交易费用的最优投资和比例再保险

研究了保险公司的最优投资和再保险问题.保险公司的盈余通过跳-扩散风险模型来模拟,可以把盈余的一部分投资到金融市场,金融市场由一个无风险资产和n个风险资产组成,并且保险公司还可以购买比例再保险;在买卖风险资产时,考虑了交易费用.通过随机控制的理论,获得了最优策略和值函数的显示解.     

Optimal investment with transaction costs based on exponential utility function: a parabolic double obstacle problem

This paper concerns optimal investment problem with proportional transaction costs and finite time horizon based on exponential utility function. Using a partial differential equation approach, we reveal that the problem is equivalent to a parabolic double obstacle problem involving two free boundaries that correspond to the optimal buying and selling policies. Numerical examples are obtained by the binomial method.     

基于两时段的WCVaR风险分析及其应用

针对随机变量的分布信息不完全的情况下,提出了两时段的Worst-Case Conditional Valueat-Risk(WCVaR)指标,并建立了两时段的风险-利润投资组合优化模型,该模型是一高维问题,具有复杂的优化结构.在损失函数为线性以及随机变量为离散界约束分布的假设下,运用最优化对偶理论将具有多层min-ma...