小波相位分析测量成像径向畸变

为了测量光学成像像面各个像素的径向畸变大小,提出将小波变换载频条纹相位分析应用于径向畸变测量。采用正弦载波条纹作为测量模板,把径向畸变转化为径向调制相位。应用条纹相位分析导出径向调制相位和径向畸变的转化关系。采用小波频率估计和相位估计提取变形条纹的相位,由于变形条纹中心点是零畸变,中心点的瞬时频率和相位可以计算参考条纹的基频相位。两种基频相位之差就是与所有像素径向位置畸变分布对应的三维调制相位——称为径向畸变分布。利用校正公式和立方卷积插值算法对彩色畸变图像进行校正,给出详细的理论分析和实验结果。     

多酸掺杂Bi2O3-x/Bi光催化剂用于高效可见光催化降解四溴双酚A和NO去除

四溴双酚A(TBBPA)是一种重要的塑料添加剂和阻燃剂,广泛用于树脂、塑料、胶黏剂以及涂料中.它不仅是持久性的机污染物,还是一种内分泌干扰物,具有免疫毒性、神经毒性和细胞毒性.NOx,特别是NO,是主要的大气污染物之一,是形成PM2.5的重要前体,也容易引起酸雨,引发光化学烟雾、臭氧损耗、温室效应等,严重危害生态环境和...     

基于生存模型的上海F1赛事游客停留时间研究

采用生存模型中的Cox模型对2012年F1大奖赛中国站游客的停留时间及其影响因素进行实证研究.结果显示:2012年上海F1赛事游客停留时间均值为4.80天；受游客社会人口特征、赛事游客满意度、举办地形象和旅游出行特征等4个方面因素的影响.研究表明:F1大奖赛中国站的品牌效应已逐渐形成,为提高赛事游客停留时间,赛事主办方应加强赛前宣传,提升服务质量,针对高消费群体推出深度旅行产品,旅游部门要完善相关旅游产品结构.     

“东后魏尺”考

从贾思勰《齐民要术》中关于大、小亩的记载进行考证，结果表明东魏一北齐之际，至少在山东地区存在34cm以上的“东后魏尺”．     

SalenMn(Ⅲ)催化非活化烯烃的不对称溴胺化反应研究

对SalenMn(Ⅲ)催化的非活性烯烃溴胺化反应进行研究,考察催化剂、溶剂、溴化试剂、温度和时间对反应产率和对映体过量(ee)值的影响。研究发现,当Cat.1为催化剂、氯代苯为溶剂和次溴酸钠为溴化试剂在10°C下反应6h,反应产率最高为88%,ee(对映体过量值)最高为93%。此方法为构建手性氮杂环化合物提供了新选择。     

Ground State Properties for Bose-Condensed Gas in Anisotropic Traps

Based on the energy functional and variational method, we present a new method to investigate the ground state properties for a weakly interacting Bose-condensed gas in an anisotropic harmonic trap at zero temperature. With this method we are able to find the analytic expression of the ground-state wavefunction and to explore the relevant quantities, such as energy, chemical potential, and the aspect ratio of the velocity distribution. These results agree well with previous ground state numerical solutions of the Gross-Pitaevskii equation given by Dalfovo et al. [Phys. Rev. A 53 （1996） 2477] This new method is simple compared to other methods used to solve numerically the Gross-Pitaevskii equation, and one can obtain analytic and reliable results.     

Enhancement of charging performance of quantum battery via quantum coherence of bath

An open quantum battery (QB) model of a single qubit system charging in a coherent auxiliary bath (CAB) consisting of a series of independent coherent ancillae is considered. According to the collision charging protocol we derive a quantum master equation and obtain the analytical solution of QB in a steady state. We find that the full charging capacity (or the maximal extractable work (MEW)) of QB, in the weak QB-ancilla coupling limit, is positively correlated with the coherence magnitude of ancilla. Combining with the numerical simulations we compare with the charging properties of QB at finite coupling strength, such as the MEW, average charging power and the charging efficiency, when considering the bath to be a thermal auxiliary bath (TAB) and a CAB, respectively. We find that when the QB with CAB, in the weak coupling regime, is in fully charging, both its capacity and charging efficiency can go beyond its classical counterpart, and they increase with the increase of coherence magnitude of ancilla. In addition, the MEW of QB in the regime of relative strong coupling and strong coherent magnitude shows the oscillatory behavior with the charging time increasing, and the first peak value can even be larger than the full charging MEW of QB. This also leads to a much larger average charging power than that of QB with TAB in a short-time charging process. These features suggest that with the help of quantum coherence of CAB it becomes feasible to switch the charging schemes between the long-time slow charging protocol with large capacity and high efficiency and the short-time rapid charging protocol with highly charging power only by adjusting the coupling strength of QB-ancilla. This work clearly demonstrates that the quantum coherence of bath can not only serve as the role of "fuel" of QB to be utilized to improve the QB's charging performance but also provide an alternative way to integrate the different charging protocols into a single QB.     

钻具遇卡声波检测理论与实验研究*

石油钻探过程中,钻具经常发生陷入泥沙中不能自由活动进而卡在井下的事故。本文提出使用单发双收声系来检测钻具遇卡的方法,首先使用有限差分模拟了钻具外为自由流体和泥沙两种介质时的钻铤波响应,通过对比远近接收器的钻铤波衰减,发现泥沙卡钻情况下的钻铤波衰减要明显大于自由钻具情况。随后建立了实验模型对理论结果进行了验证。理论模拟与实验结果均表明声波方法可用以检测钻具遇卡事故,从而确定卡钻的深度位置,为解卡钻作业提供解释依据。     

高等数学CAI汉字技术

作者在多年从事ＣＡＩ软件研制工作的过程中，针对高等数学ＣＡＩ研制的难点——有关汉字的处理问题，潜心钻研，提出了一种非常方便、实用的小汉字库技术，圆满地解决了这一难题。本文给出了这种技术的构成原理，并提供了详细的Ｃ语言源程序．     

微型加速度传感器用于金属棒弹性模量测量

基于振动理论给出的悬臂梁弯曲自由振动的一阶固有频率与材料弹性模量的关系,提出用微型加速度传感器测量悬臂梁单端自由振动的频率,并在自行搭建的实验装置上对钢棒的弹性模量进行了测量,分析了影响测量结果准确性的因素.最终实验结果与手册查询到的对照值十分吻合,测量的相对不确定度为0.66%.本实验原理清晰、装置构成简单、操作简便、结果较精确,适于教学使用或工业现场检测之用.