具有控制系数的高阶线性微分方程复振荡的一个结果

该文考虑具有控制系数 A\-0 和系数仅有有限个极点的高阶线性齐次微分方程（1.1）。得到了一个复振荡结果，该结果是J. K. Langley［11］等作者在整系数下相应结果的推广。     

水平均匀大气中多束光在接收面上的相关性及其对光强起伏的影响

在科尔莫戈罗夫理论的基础上，推广了光束在接收面上相关函数的物理含义。分析了多光束在接收面上的相关性。并在此基础上形成多光束光强起伏方差的解析表达式。分析结果表明，随着信道间距的增加，信道相关性下降。到达接收面的光强起伏方差降低；当信道完全重合，即相关系数变为1时，叠加后的光强起伏方差没有明显降低。与单光束时没有区别；在允许范围内增加光束数目可降低光强起伏。     

用毛细管测量纯水表面张力系数的误差讨论

通过用毛细管测量纯水表面张力系数实验，得到管内径d与接触角θ的相对误差之间的关系曲线，由此说明实验测得的表面张力系数α和理论公式相比呈现一定的偏差，并简单地讨论了实验的理想状态与实际情况的差别．     

用PM3量化参数预测多氯代二苯并呋喃的logKow

从现有的PCDFs分子的正辛醇 /水分配系数 (logKow)实验数据出发 ,建立定量结构 性质关系方程(QSPR) .采用G98W程序包中的PM3方法对 13 5个多氯代二苯并呋喃 (PCDFs)分子和二苯并呋喃进行了优化计算 ,作业命令为 #pPM3optfreqscf(conver =9) ,以计算所得的分子轨道能量、碳原子电荷作为PCDFs分子结构描述符 ,运用多元线性回归技术建立了PCDFs的logKow与分子结构描述符的四元方程 ,最优相关系数为 0 .95 0 7,标准偏差为 0 .173 7,经检验该模型的稳健性好 ,并对未有实验数据的 85个PCDFs的logKow进行预测     

Reference values for drag and lift of a two‐dimensional time‐dependent flow around a cylinder

This paper presents a numerical study of a two‐dimensional time‐dependent flow around a cylinder. Its main objective is to provide accurate reference values for the maximal drag and lift coefficient at the cylinder and for the pressure difference between the front and the back of the cylinder at the final time. In addition, the accuracy of these values obtained with different time stepping schemes and different finite element methods is studied. Copyright © 2004 John Wiley & Sons, Ltd.     

The interfacial conformation of polypropylene glycols and foam behaviour

The foam behaviour of low molecular weight polypropylene glycols (PPG) was investigated as a function of concentration and molecular weight (190–2000 g mol⁻¹). For each polypropylene glycol, foam stability increases with concentration and passes through a maximum, beyond which foamability is suppressed as the solubility limit of the glycol is exceeded and droplets of glycol form. Light-scattering data as well as static and dynamic surface tension results provide the key information leading to these interpretations. A maximum in foamability was observed for the PPG molecules with increasing molecular weight (caused by a change in molecular conformation at the interface). This suppresses the Marangoni effect and leads to a decrease in foam stability.     

离子束增强沉积VO2多晶薄膜的温度系数

用改进的离子束增强沉积方法和恰当的退火从V2O5粉末直接制备了VO2多晶薄膜.实验测试表明，薄膜的取向单一、相变特性显著、结构致密、界面结合牢固、工艺性能良好，薄膜的电阻温度系数（TCR）最高可达4.23%/K.从成膜机理出发，较详细地讨论了离子束增强沉积 VO2多晶薄膜的TCR高于VOx薄膜的TCR的原因.分析认为，单一取向的VO2结构使薄膜晶粒具有较高的电导激活能，致密的薄膜结构减少了氧空位和晶界宽度，使离子束增强沉积 VO2多晶薄膜结构比其他方法制备的VOx薄膜更接近于单晶VO2是其具有高TCR的原 关键词： VO2多晶薄膜 离子束增强沉积 热电阻温度系数     

行波管内不连续性的简易模型分析

 根据行波管内微波信号在输能装置和切断衰减器处两个不连续性之间来回反射的物理现象，建立行波管输出段的简易网络串模型，并对行波管输出段传输特性参数的幅频特性、相频特性进行计算分析。结果表明：输能装置和切断衰减器的不连续性是造成幅相一致性行波管相位不可补偿的重要因素之一。     

Maintenance of Soft Calibration Models in the Determination of Zinc,Cadmium, Lead and Copper by Differential Pulse Anodic Stripping Voltammetry

A strategy for constructing a global multivariate calibration model that includes calibration samples measured over time on different days is developed and applied in electroanalysis. Both synthetic and real samples (tap, extracted and river water) are analyzed by differential‐pulse anodic stripping voltammetry, showing the suitability of the global model constructed that provides successful results similar to those of the usual multivariate calibration. In addition the capability of discrimination of this model is evaluated in prediction for the mean of three replicates with estimation of probability of false noncompliance, α, and false compliance, β, being found 3.1, 11.2, 6.7 and 64.7 nM for nominal concentrations of zinc, cadmium, lead and copper of 96.0, 40.4, 37.3 and 328.0 nM respectively when α=β=0.05. It has been proven that the use of the global calibration does not imply a loss of multivariate analytical sensitivity, using this parameter as quality index of the analytical procedure. The viability of using calibration maintenance strategies with electroanalytical techniques is shown, providing a way to save time and experimental effort when these techniques are used in routine analysis.