计算旋转螺旋面三维边界层的一种积分方法

本文将计算二维层流边界层的Thwaites方法和计算二维湍流边界层的Truckenbrodt方法推广,用以求解旋转系统的“准三维”边界层方程,得到了计算旋转螺旋面上三维边界层的一种可迭代求解的积分方法.应用此方法进行了两例计算.计算结果与理论精确解或实验测量的对比表明,本文方法是有效的.     

Direct analysis of thin-layer chromatographic spots of narcotics by means of diffuse reflectance Fourier transform infrared spectroscopy

The technique of diffuse reflectance Fourier transform infrared spectrometry (DRIFT) as an in situ detection method was used for the qualitative and quantitative analysis of drugs (heroin, cocaine and codeine) separated by thin layer chromatography.It was found that at a given interferometer throughput and detector sensitivity the quality of the spectrum depends strongly in the type of the chromatographic thin layer used. A detection limit of approx. 2 g was attained on a microcrystalline cellulose thin layer with a dynamically aligned Bio-Rad Digilab FTS 60A/896 type interferometer and room temperature DTGS detector. A reliable qualitative analysis can be made with as little as 10 to 15 g drug per spot.     

Lyotropic effect in surface charge,electrokinetics, and coagulation of a rutile dispersion

Potentiometric, electrokinetic, and coagulation experiments with a rutile dispersion in the pH region above the point of zero charge exhibit an inverse lyotropic sequence for counterions: Li⁺>K⁺>Cs⁺. The potentiometric and electrokinetic data were interpreted by a surface complexation model assuming the Stern-Gouy-Chapman structure of the interfacial layer, which yielded the values of inner layer capacitances,C, and the intrinsic equilibrium constants,K _ass ⁰ , characterizing the specificity of each counterion. These parameters were used to explain the order of lyotropic sequences in the adsorption, coagulation, and electrokinetic phenomena.     

Characterization of the organization in shear layers via the Proper Orthogonal Decomposition

Experiments are performed in an incompressible plane turbulent mixing layer, using various hot wire rake configurations. From these experiments, the Proper Orthogonal Decomposition is applied for kernels where the space-time correlation tensor is evaluated over different spatial meshes and velocity components configurations. The resulting decompositions are then discussed in terms of characterization of the organization of the flow for various scalar or vectorial approaches of the POD. An incrtial range law is evidenced. The instantaneous contribution of the first modes of the POD to the organization of the flow is analyzed. A dynamical behavior for the organization of the flow is observed from the correlation between the first two modes contribution.     

秦淮河流域典型排涝泵站前池水质与降雨特征响应关系

为分析排涝泵站前池水质与降雨特征的响应关系,对南京市城区秦淮河沿线2个排涝泵站前池水质以及降水量开展高频在线自动监测,结合回归树方法分析了不同降雨强度、前期干旱时间条件下排涝泵站前池水质变化规律,探讨了不同类型排涝泵站前池水质的主要影响因素。结果表明:晴雨天均有生活污水汇入的A泵站前池氨氮质量浓度在大雨强下降低,中雨强下先升高后降低,小雨强下平缓上升,A泵站前池污染物质量浓度主要受降雨强度和次降水量影响;主要接收降雨径流,雨量大时有生活污水溢流汇入的B泵站,前池污染物质量浓度在大雨强下先升高后逐渐降低,中雨强下降低,小雨强下变化不大,B泵站前池水质主要受次降水量、前期干旱时间和降雨强度影响;2个泵站前池CODMn质量浓度变化与降雨的响应规律相似,但更多受到与前期干旱时间关联的地表径流冲刷作用影响;连续降雨均导致泵站前池氨氮质量浓度和CODMn质量浓度波动变化较大,而前期干旱时间越长,降雨发生后泵站前池水质越差。     

面向对象的二叉树装配模型研究

文章研究可装配性设计中的产品装配建模,提出一种以装配体为对象并能充分反映装配过程特点的二叉树装配模型。应用面向对象技术,建立了相应的数据结构及应用框架,为可装配性评价奠定了基础,也可做为通用的产品装配模型应用于ＣＡＰＰ等领域。     

苦丁茶树扦插繁殖的研究

采用不同种类和不同浓度的植物生长调节剂、不同苗段、插穗不同节数以及插穗不同剪叶量等几种处理方法,对苦丁茶树插穗生根的影响进行了试验,结果表明：在试验的几种促根药剂中,以浓度２００ｍｇ／Ｌ的ＮＡＡ对苦丁茶树插穗生根的效果最佳;在同样条件下,二段苗的发根能力是强;随着插穗节数的增多,其发根能力就增强,但综合考虑到成活率、扦插苗的长势、繁殖系数以及经济效益等因素,笔者认为以每插穗具两个节为宜;在相同条件下,每张叶剪去１／３再插穗的,其发根能力最强．     

电化学原子层外延及Te,CD元素欠电势沉积研究

阐述了一种处延沉积化合物半导体的新方法－电化学原子层外延（ＥＣＡＬＥ）并对其基础欠电势沉积（ＵＰＤ）进行了讨论,着重研究了Ⅱ,Ⅳ族元素Ｃｄ,Ｔｅ的电化学欠电势沉积,根据电化学循环伏安曲线,研究了Ｔｅ和Ｃｄ在Ｓｉ－Ａｕ（１１１）基片上以及交替生长过程中ＵＰＤ沉积电位及相应覆盖度值,由此确定了在Ｓｉ－Ａｕ（１１１）衬底上交替沉积Ｔｅ,Ｃｄ原子层的方法,在此基础上,初步进行了多次交替沉积,并用ＡＦＭ与Ａ     

BP神经网络用于函数逼近的最佳隐层结构

研究采用反向传播算法的人工神经网络用于函数逼近时的支结构。方法,以典型的ｎ输入、单输出的多层ＢＰ网为例,在几种不同的网络隐层结构下对典的连续函数进行逼近训练。,分析各网络输出的全局误差。     

SrGa2S4:Ce blue TFEL in new structure

SrGa₂S₄: Ce blue TFEL device with a novel structure was prepared by electron beam evaporation. The dielectric constant of insulator layer in this structure is far less than that in the conventional structure, so the hot-electrons can be accelerated in SiO₂ layers. The stable TFEL with good chromaticity was achieved and the basic characteristics were investigated.