W型永磁电机转矩脉动分析与抑制方法

针对永磁同步电机转矩脉动偏大时电机输出性能较差的问题,对W型永磁同步电机的转矩脉动进行详细分析并研究其抑制方法.首先利用等效磁路法与洛伦兹力定律,推导出电机转矩脉动解析式,基于解析式对W型磁极的位置参数进行优化,并利用有限元软件仿真验证;然后利用转子极面偏心的方法进一步削弱电机转矩脉动,并分析最优偏心距.研究表明,当W...     

电动汽车驱动用永磁同步电机数字控制系统

为提高电动汽车的动力性和行驶里程,提出了车用永磁同步电动机数字化控制策略。该策略采用具有参数自调整功能的模糊P1速度控制器来提高系统的动力性和鲁棒性,采用基于空间电压矢量脉宽调制方法设计电流控制器来提高车载电源电压利用率,从而提高电动汽车的行驶里程。基于该策略开发的车用永磁同步电动机数字化控制系统实验结果证明了该策略的有效性。     

2′-脱氧胞苷探针测定血清样品中蛋白质含量

白蛋白在血浆总蛋白中占有很大的比例,高达40%~60%,它在人体内起着至关重要的作用,可以通过分析蛋白质的含量来反映人体的健康状况.人血清白蛋白表面具有多样化的结合位点,2′-脱氧胞苷能够与人血清白蛋白(HSA)相结合,但由于这种结合改变了HSA的结构,其荧光性质也就随之发生了改变.发明了一种新的测定蛋白质的方法,用2′-脱氧胞苷作荧光探针分子结合固定波长同步荧光光谱法对蛋白质的含量进行分析.在一定的条件下,当HSA的浓度满足在1.38~276μg·mL-1这一条件时,溶液的同步荧光强度(ISF)与HSA的浓度具有确定的线性关系.通过测定11份空白溶液发现检出限为0.024μg·mL-1(n=11).对实验条件进行了探究,发现溶液的pH值、扫描波长的变化量(Δλ)、试剂的加入顺序以及溶液的离子强度等因素都会影响体系荧光光谱特征及强度.还测量了人血清中的蛋白含量,回收率在98.4%~104.3%范围内.     

Motion of Enzyme‐Powered Microshell Motors

Microshells are attractive in constructing bubble‐propelled micromotors due to the lower energy consumption for bubbles forming on a concave surface. In this work, enzyme‐powered microshell motors were fabricated on multimetallic (Au/Ag/Au) microshells along with the modification of catalase on its concave surface. The catalase triggered the decomposition of hydrogen peroxide to oxygen gas, hence propelling the autonomous motion of microshell motors. A size‐dependent motion behaviour was observed for the microshell motors in the form of slow tremble and fast translation motion for a size smaller and larger than 5 μm, respectively, according to the size, generation efficiency and ejection mechanism of bubbles and the intensity of Brownian motion. In addition, the effect of fuel concentration on the motion speed of microshells was dependent on whether the bubble generation was affected by the limited mass transfer in the microshell space. These findings play an important role for the design of microshell motors.     

Application of solvent extraction and synchronous spectrofluorimetry to the determination of the formation constant for a 1:1 complex of carbazole withβ-cyclodextrin in water-dimethyl sulfoxide medium

Extraction of carbazole in heptane was performed at 25±1°C with an aqueous dimethyl sulfoxide (DMSO) medium containing -cyclodextrin (CD) at consecutive concentrations in the range of 0–10 mM. The fluorescence intensity of carbazole remaining in the heptane phase was measured by synchronous scanning fluorimetry. The apparent formation constant (K _f) for a 1:1 carbazole: CD inclusion complex in water-DMSO medium was determined by using a linear plot of the distribution ratio calculated from the fluorescence intensities vs. the -CD concentration. The values thus obtained ranged from 477 M^–1 in a 10% v/v DMSO medium to 12.1 M^–1 in a 60% v/v medium. Good linear relationships were observed between logK _f and the DMSO concentration ([DMSO]), and also between logK _f and the logarithm of the distribution coefficient (K _d) for carbazole. The formation constant in 100% water was estimated to be approximately 1.0×10³ M^–1 on the basis of the logK _f vs. [DMSO] and the logK _f vs. logK _d correlations.     

数字喷墨印刷关键技术及其实现

经过20多年的完善与发展，喷墨技术已经成为大幅面广告印刷行业的主要印刷技术。随着图书按需印刷需求的快速扩张以及国家环保政策的迅速落地，喷墨印刷技术作为一项高效环保的数字化印刷技术，得到越来越高的关注，业内普遍认为喷墨印刷技术将是数字化印刷的必然发展趋势。然而与已经成熟的多Pass喷墨印刷设备不同，单Pass喷墨印刷设备在数据带宽、数据在线重构、高精度同步控制、喷嘴在线补偿等方面有着极高的技术要求。本文首先简要介绍了喷墨技术，然后针对单Pass喷墨印刷设备需要解决的技术问题提出了相应的解决方案。依据本文技术设计的单Pass书刊喷墨印刷机已经投放市场，并且获得了用户的普遍认可。     

胶束增敏导数—可变角同步荧光法同时测定两种羟基联苯

本文建立了２，２’－二羟基联苯（ＤＨＰ）和４－羟基联苯（ＨＰ）的胶束增敏导数－可变角同步荧光同时分析方法，可变角同步扫描所得到的ＤＨＰ和ＨＰ的谱峰位置均对应于常规光谱中的最佳激发－发射位置，经二阶求导后，消除分析谱带干扰，所得的二阶导数－可变角同步光谱即可用于两物质的同时测定，方法快速灵敏，ＤＨＰ测定范围为０．０５～０．５ｍｇ／Ｌ，ＨＰ测定范围为０．０７～２ｍｇ／Ｌ。     

咔唑、蒽和苝的同时恒能量同步荧光法分析

建立了咔唑、蒽和苝的同时恒能量同步荧光分析法。对方法的优越性进行了比较说明。实验是在自制带恒能量扫描多功能荧光分光计上进行的。咔唑、蒽和苝的检测限分别为1ng/ml、0.8ng/ml和0.5ng/ml,相对标准偏差不大于4.4％。     

溶解态菲及其中间代谢产物1-羟基-2-萘甲酸的同时测定

运用导数-同步荧光光谱建立了快速同时测定溶解态菲(Phenanthrene,Phe)及其中间代谢产物1-羟基-2-萘甲酸(1-Hydroxy-2-naphthoic acid,1H2NA)的分析方法。所建方法同时测定Phe与1H2NA的线性范围分别为4.0~1.0×103μg/L和4.0~1.2×103μg/L,检出限分别为0.08μg/L和0.07μg/L,加标回收率分别为96.5%~105.3%和99.2%~106.5%,相对标准偏差均小于1.0%。该方法可应用于实验室条件下溶解态Phe微生物降解过程中Phe和1H2NA的测定,具备原位研究Phe降解过程中间代谢产物1H2NA的应用潜力。