检索结果-南通市图书馆

中华病理学杂志 2000年第5期29卷 383-384页

作者：何韶衡李萍 MarkG.Buckley andrew f.walls ImmunopharmacologyGroup Mailpoint837SouthamptonGeneralHospital 华西医科大学附属第一医院检验科

应用BB1单克隆抗体检测嗜碱性粒细胞在支气管哮喘患者气道中的分布及其临床意义

在线全文

学校读者我要写书评

暂无评论

华中科技大学学报（医学版） 2006年第3期35卷 317-320页

作者：刘辉国 andrew f.walls Aki Mochizuki francis H.Y.Green 华中科技大学同济医学院附属同济医院呼吸内科武汉430030 英国南安普敦大学医学院免疫药理部加拿大卡尔加里大学病理学及实验医学部

目的采用一种新的针对嗜碱性粒细胞的单克隆抗体,对不同程度支气管哮喘患者支气管肺组织进行免疫组织化学检测,以明确嗜碱性粒细胞在不同组织结构中的分布及其临床意义。方法对10例致死性哮喘、9例非致死性哮喘和9例非哮喘对照组患者支... 详细信息

目的采用一种新的针对嗜碱性粒细胞的单克隆抗体,对不同程度支气管哮喘患者支气管肺组织进行免疫组织化学检测,以明确嗜碱性粒细胞在不同组织结构中的分布及其临床意义。方法对10例致死性哮喘、9例非致死性哮喘和9例非哮喘对照组患者支气管肺组织进行戊二醛固定、石蜡包埋制片后,采用BB1单克隆抗体进行免疫组织化学染色。结果致死性哮喘组与非致死性哮喘组、非哮喘对照组比较,其黏膜下层、平滑肌、黏液腺及肺泡中嗜碱性粒细胞均明显升高(均P<0.05)。而非致死性哮喘组与非哮喘对照组相比,其嗜碱性粒细胞的差异无显著性意义。结论BB1单克隆抗体可有效地用于支气管肺组织标本的嗜碱性粒细胞免疫组织化学检测,同时急性发作的致死性哮喘患者气道中嗜碱性粒细胞明显增加,可能与哮喘病情恶化、甚至死亡有关,而非致死性的慢性哮喘患者气道中嗜碱性粒细胞与对照组无异,说明嗜碱性粒细胞可能主要参与哮喘的急性病程。

关键词：哮喘嗜碱性粒细胞单克隆抗体

在线全文

学校读者我要写书评

暂无评论

甚低噪声fET输入放大器

宇航计测技术 1990年第6期9卷 73-75页

作者： StevenR.Jefferts f.L.walls 阎军长春大学

本文介绍了一种甚低噪声 fET 共源一共栅输入放大器的设计、原理和特性。这种放大器在频率为500Hz～500kHz 范围内的噪声指标小于1.2nV/Hz^(1/2)和0.25fA/Hz^(1/2)。适当加以变化,可用千1Hz～30MHz 频率范围的各种要求低噪声增益的场合。

关键词：放大器甚低器 fET 输入放大器

在线全文

学校读者我要写书评

暂无评论

光的压缩态

中国激光 1983年第Z1期 536-536页

作者： Daniel f.walls 新西兰怀卡托大学物理系汉密尔顿

压缩态是这样一种量子态,在此量子态中一个正交相中的偏离方差小于相干态时的值。所差的部分必需靠另一个正交相中的涨落之增大来补偿,以便满足海森堡测不准关系。压缩态有可能应用于受量子噪声限制的光通讯系统。本文将讨论各种产生和... 详细信息

压缩态是这样一种量子态,在此量子态中一个正交相中的偏离方差小于相干态时的值。所差的部分必需靠另一个正交相中的涨落之增大来补偿,以便满足海森堡测不准关系。压缩态有可能应用于受量子噪声限制的光通讯系统。本文将讨论各种产生和检测光的压缩态的方案。我们以二能级原子的共振荧光为例加以说明。如实验已证实的,从二能级原子产生的荧光表现出光子反聚束效应。对于那些不足以使原子饱和的驱动场强,荧光也是被压缩的。压

关键词：压缩态原子荧光光子二能级分子弱光玻色子反聚束共振模

Validation of a discrete element model using magnetic resonance measurements

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Particuology 2009年第4期7卷 297-306页

作者： Christoph R.Müller Stuart A.Scott Daniel J.Holland Belinda C.Clarke andrew J.Sederman John S.Dennis Lynn f.Gladden Department of Chemical Engineering and Biotechnology University of CambridgePembroke StreetCambridge CB2 3RAUnited Kingdom

The discrete element model （DEM） is a very promising modelling strategy for two-phase granular systems. However, owing to a lack of experimental measurements, validation of numerical simulations of two-phase granular systems is still an important issue. In this study, a small two-dimensional gas- fluidized bed was simulated using a discrete element model. The dimensions of the simulated bed were 44mm × 10mm × 120 mm and the fluidized particles had a diameter dp = 1.2 mm and density ρp = 1000 kg/m^3. The comparison between DEM simulations and experiments are performed on the basis of time-averaged voidage maps. The drag-law of Beetstra et al. [Beetstra, R., van der Hoef, M.A., ＆ Kuipers,J. A. M. （2007b）. Drag force of intermediate Reynolds number flow past mono- and bidispersed arrays of spheres. AIChE Journal, 53,489-501 ] seems to give the best results. The simulations are fairly insensitive to the coefficient of restitution and the coefficient of friction as long as some route of energy dissipation during particle-particle and particle-wall contact is provided. Changing the boundary condition of the gas phase at the side-walls from zero-slip to full-slip does not affect the simulation results. Care is to be taken that the cell sizes are chosen so that a reasonable number of particles can be found in a fluid cell.

关键词： Discrete element modelling Magnetic resonance imaging Voidage Gas-fluidized beds

在线全文

学校读者我要写书评

暂无评论

低噪声频率综合

现代雷达 1989年第6期11卷 47-54,16页

作者： f.L.walls C.M.felton 韦传安 Time and frequency Division Nat-ional Bureau of Standards felton Electronics Design 美国

本文综述了相位噪声的各种定义和经无噪声倍频、分频和变频后相位噪声的变化。其次综述了非致冷参考频率(rf)和微波振荡器的相位噪声。利用系统方法可以综合出一个微波信号,其近载频相位噪声受一个低频石英振荡器的控制,而高频相位噪声... 详细信息

本文综述了相位噪声的各种定义和经无噪声倍频、分频和变频后相位噪声的变化。其次综述了非致冷参考频率(rf)和微波振荡器的相位噪声。利用系统方法可以综合出一个微波信号,其近载频相位噪声受一个低频石英振荡器的控制,而高频相位噪声则受微波源的控制。用这种方法比用单个源可能得到的相位噪声性能优越。最后,比较了各种放大器、倍频器和分频器的相位噪声。虽然,分频器的相位噪声一般地比最好的倍频器要差,但是对大多数应用来说通常是足够了。应当特别指出两点,其一是对某些分频器,文献中引用的相位噪声或许悲观,其二是如果处于振动热应力条件下,系统的相位噪声常常会受到严重的影响。

关键词：低噪声频率综合相位噪声

Modeling of unidirectional blood flow in microvessels with effects of shear-induced dispersion and particle migration

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2022年第10期43卷 1585-1600页

作者： G.ROURE f.R.CUNHA Laboratory of Microhydrodynamics and Rheology Department of Mechanical EngineeringUniversity of BrasíliaBrasília70910900Brazil Department of Chemical and Biological Engineering University of Colorado BoulderBoulder803090596USA

A cell-free layer,adjacent to microvessel walls,is present in the blood flow in the microcirculation *** layer is of vital importance for the transport of oxygen-saturated red cells to unsaturated *** this work,we first discuss the physics of formation of this cell-free layer in terms of a balance between the shear-induced dispersion and particle *** this end,we use high-viscosity drops as prototypes for cells,and discuss our results in terms of physical parameters such as the viscosity ratio and the capillary *** also provide a short-time analysis of the transient drift-dispersion equation,which helps us better explain the formation process of the cell-free ***,we present models for investigating the blood flow in two different scales of *** investigating the blood flow in venules and arterioles,we consider a continuous core-flow model,where the core-flow solution is considered to be a Casson fluid,surrounded by a small annular gap of Newtonian plasma,corresponding to the cell-free *** also propose a simple model for smaller vessels,such as capillaries,whose diameters are of a few *** this lower-bound limit,we consider a periodic configuration of aligned,rigid,and axi-symmetric cells,moving in a Newtonian *** this regime,we approximate the fluid flow using the lubrication *** intrinsic viscosity of the blood is theoretically predicted,for both the lower and upper-bound regimes,as a function of the non-dimensional vessel diameter,in good agreement with the previous experimental *** compare our theoretical predictions with the experimental data,and obtain qualitatively good agreement with the well-known fåhræus-Lindqvist effect.A possible application of this work could be in illness diagnosis by evaluating changes in the intrinsic viscosity due to blood abnormalities.

关键词： theory flow dispersion

Exact Time-Dependent Wave functions of a Confined Time-Dependent Harmonic Oscillator with Two Moving Boundaries

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第11期52卷 820-824页

作者： C.f.Lo Institute of Theoretical Physics and Department of Physics The Chinese University of Hong Kong

By applying the standard analytical techniques of solving partial differential equations, we have obtained the exact solution in terms of the fourier sine series to the time-dependent Schrodinger equation describing a quantum one-dimensional harmonic oscillator of time-dependent frequency confined in an infinite square well with the two walls moving along some parametric trajectories. Based upon the orthonormal basis of quasi-stationary wave functions, the exact propagator of the system has also been analytically derived. Special eases like （i） a confined free particle, （ii） a confined time-independent harmonic oscillator, and （iii） an aging oscillator are examined, and the corresponding time- dependent wave functions are explicitly determined. Besides, the approach has been extended to solve the case of a confined generalized time-dependent harmonic oscillator for some parametric moving boundaries as well.

关键词： infinite square well harmonic oscillator moving boundaries fourier series

Prediction of boundary shear stress distribution in straight open channels using velocity distribution

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2021年第2期14卷 159-166页

作者： Behzad Malvandi Mahmoud f.Maghrebi Department of Civil Engineering Ferdowsi University of MashhadMashhad 91775-1111Iran

Conventional methods for measuring local shear stress on the wetted perimeter of open channels are related to the measurement of the very low velocity close to the *** near-zero velocity values with high fluctuations has always been a difficult task for fluid flow near solid *** solve the observation problems,a new model was developed to estimate the distribution of boundary shear stress from the velocity distribution in open channels with different cross-sectional *** estimate the shear stress at a point on the wetted perimeter by the model,the velocity must be measured at a point with a known normal distance to the *** experimental work of some other researchers on channels with various cross-sectional shapes,including rectangular,trapezoidal,partially full circular,and compound shapes,was used to evaluate the performance of the proposed *** exponent coefficients for the model were found using the multivariate Newton method with the minimum of the mean absolute percentage error(MAPE)between the model and experimental data as the objective ***,the calculated shear stress distributions along the wetted perimeter were compared with the experimental *** most important advantage of the proposed model is its inherent *** mean MAPE value for the seven selected cross-sections was 6.9%.The best results were found in the cross-sections with less discontinuity of the wetted perimeter,including the compound,trapezoidal,and partially full circular *** contrast,for the rectangular cross-section with an angle between the bed and walls of 90°,MAPE increased due to the large discontinuities.

关键词： Open channel Boundary shear stress Viscous shear stress Velocity distribution Velocity gradient

Edge-induced radiation force and torque on a cylindrically-radiating active acoustic source located near a rigid corner-space

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2019年第2期4卷 166-172页

作者： f.G.Mitri Santa fe NM 87508United States

This work examines the physical effect of the edge-induced acoustic radiation force and torque on an acoustically radiating infinitely-long circular cylindrical source,located near a rigid *** harmonic(linear)radiating waves of the source,vibrating in monopole or dipole radiation modes near a rigid corner-space in a non-viscous fluid,the modal series expansion method in cylindrical coordinates,the classical method of images and the translational addition theorem are applied to obtain the mathematical expressions for the radiation force and torque components in exact partial-wave *** results illustrate the theory,and examine some of the conditions where the radiation force and torque components vanish,which has the potential to achieve total motion suppression(i.e.,translation or rotation).furthermore,depending on the size parameter of the source and the distances from the rigid corner space,these physical observables take positive or negative values,anticipating the prediction of pulling/pushing motions toward the corner space,and possible spinning of the source clockwise or *** present analysis and its results may be useful in some applications related to underwater acoustical oceanographic engineering of submerged objects,cloaking and stealth technology development and the experimental design of elongated unmanned autonomous vehicles or submarines,as well as the manipulation of an active carrier or ultrasound contrast agents of elongated cylindrical shapes near a corner space or chamber walls at a right angle.

关键词： Edge-induced radiation force and torque Radiation of sound Rigid corner space Cylindrical source Monopole/dipole vibration Underwater acoustics.