精密丝杠匀速校正系统上位机设计与实现

该文针对丝杆的螺距受到机械加工等物理条件的限制,在一定精度要求下,不可能完全均匀。加载在丝杆上移动的物体,在单位时间上,其速率可以认为是变速运动。该文主要提出了一种精密丝杠校正系统设计方法,提出在一定精度要求下,能够使移动物体匀速运动的电机控制算法,并给出了上位机设计过程。校正算法由C++实现,上位机由MFC实现,采用Matlab与VC混编的方法绘制控制曲线。     

供应链失效风险识别与评估*

供应链风险是影响供应链实践应用的关键因素之一,供应链风险管理是供应链管理的重要内容。采用故障树理论和模糊理论对供应链风险进行了分析,构造了供应链失效风险故障树,该故障树由供应商、制造商、分销商三部分组成;分析了各个部分的失效原因,设计了正态模糊算子,阐述了供应链风险概率计算方法。针对一个供应链实例,采用上述方法对各个要素失效风险进行了定量计算,确定了供应链失效风险等级。     

杂环类双光子材料的研究进展

双光子吸收材料在诸多领域如光限幅、双光子上转换激射、双光子荧光显微术、三维光存储以及三维微加工等方面有潜在的应用前景.近年来,对有机双光子吸收材料的研究正成为材料领域研究的热点之一.杂环化合物由于具有优良的双光子性质,高的光学稳定性,因而成为研究的重点.对杂环简单的化学修饰,就可以实现对材料的最大吸收波长和发射波长大范围的调节.同时杂环化合物一般具有较强的推拉电子能力,能有效的提高双光子上转换激射效率,是一类很有发展潜力的双光子材料.     

多维超几何分布的最可能成功数

超几何分布是一种重要的离散型概率分布,本文利用反证法以及比较法求出了三维超几何分布的最可能成功次数,并在此基础上,求出了多维超几何分布的最可能成功次数.     

正交曲线坐标系中单位基矢对时间的导数

不同正交曲线坐标系的单位基矢之间的变化矩阵是复数域的幺正矩阵,在实数域是正交矩阵.由此,推导出不同正交曲线坐标系的单位基矢之间的变化规律,进而推导出正交曲线坐标系的单位基矢对本身坐标的求导和对时间的求导规律.再将中间过程的另一正交曲线坐标系的单位基矢选取为单位常矢量,得出普适公式.最后以球坐标系与柱坐标系的单位基矢的本身空间坐标求导为例进行讨论,分别得出球坐标系与柱坐标系中单位基矢对时间的一阶、二阶导数的变化规律.     

Monotone Set-Valued Function Defined by Set-Valued Choquet Integral

Structural characteristics and absolute continuities of monotone set-valued function defined by set-valued Choquet integral are discussed. Similar to the single-valued monotone set function,several important structural characteristics of set-valued function are defined and have been proven the same as those in the original set functions,such as null-additivity,weakly null-additivity,order continuity,strong order continuity and property(S). A counterexample shows that order continuity and strong order contin...     

Catalysis of Active Carbon Supporting Transition Metal Oxides for Pyrotechnical Reagent with Potassium Perchlorate

In order to improve the pyrotechnical reagent with potassium perchlorate,composite catalyst of active carbon supporting transition metal oxides (TMO),Fe2O3 and CuO,were prepared and added into pyrotechnical reagent with potassium perchlorate.Accelerating rate calorimeter (ARC) was used to study the catalysis of pyrotechnical reagent which is consisted of potassium perchlorate and composite catalyst.Composite catalyst of both Fe2O3 and CuO supported by active carbon can catalyze pyrotechnical reagent with potassium perchlorate.Furthermore,it can lower the apparent activation energy and accelerate the reaction with a smaller quantity than that with Fe2O3 and CuO.The maximal reaction rate of pyrotechnical reagent with potassium perchlorate mixed with Fe2O3/active carbon and CuO/active carbon is 8.31 min-1 and 9.13 min-1,which is 1.74 times and 1.91 times of pyrotechnical reagent mixed with no catalyst;time to maximal rate was 18.99 min and 1.96 min respectively,which is lower than pyrotechnical reagent mixed with no catalyst by 86.46% and 98.67% ;the apparent activation energy is 368.10 kJ·mol-1 and 325.29 kJ·mol-1,which is lower than pyrotechnical reagent mixed with no catalyst by 31.89% and 39.81% respectively.     

Surface chemical study of the selective separation of chalcopyrite and marmatite

FCLS (Ferric Chromium Lignin Sulfonate) was used to aid the separation of chalcopyrite from marmatite. Flotation, adsorption and zeta-potential tests of treated marmatite and chalcopyrite were performed. The flotation of marmatite was strongly depressed, while that of chalcopyrite was only slightly depressed, over a wide range of pH values when FCLS was used as depressant in the presence of Butyl Xanthate (BX). The adsorption of BX onto chalcopyrite or marmatite takes place over a wide pH range. The adsorption density of BX on chalcopyrite and marmatite decreases as the pH increases. The adsorption density of FCLS onto marmatite is greater than the adsorption density onto chalcopyrite. The zeta potentials of chalcopyrite and marmatite become more negative due to the addition of xanthate and FCLS.     

浅谈图书馆管理与服务创新

适应创新国家决策需要,图书馆管理服务需要不断创新发展思路。本文从经费来源、服务理念、服务方式和队伍管理等四个方面,对这个问题进行了探讨。     

基于改进粒子群算法鸡西电网无功优化规划

应用传统粒子群算法于电力系统无功优化问题存在收敛精度不高、陷入局部最优的缺点,而利用粒子群群体每次迭代的最优值取代其本次迭代的最差值,可提高粒子群算法的寻优特性。在鸡西电网的无功优化规划中,先对鸡西电网的每个节点进行灵敏度分析,选择部分节点做为无功补偿的候选节点,之后将所提算法应用于鸡西电网进行实际计算和分析,经过此方法对鸡西电网进行优化规划计算后,较好的改善了鸡西电网的电压水平和无功分布,提高了供电质量,大大降低了线损,有良好的理论价值和实用价值。