一种激光像亮度增强的显微高速摄影系统

首次在显微高速摄影中成功地引入溴化亚铜蒸汽激光器作为像亮度增强器,动态分辨率接近物镜的衍射分辨极限,并对布朗运动,浮游生物的动态情况进行观察、记录。     

人工晶体前移与人眼屈光调节关系的研究

基于Hwey-Lan Liou眼模型,采用ZEMAX光学设计软件实现光线追迹的方法研究了人工晶体在眼内的前移与人眼屈光调节之间的关系.结果表明：人工晶体每前移一定的距离,人眼所获得的屈光调节量不恒定;调节量大小依赖于眼轴长度和所需植入的人工晶体,特别是眼轴长度;对于不同眼轴长度术眼中的人工晶体前移,人眼所获得的屈光调节量与眼轴长度呈负相关.     

二模振荡激励下水槽中的孤立波

在狭而长的水槽中,垂直方向用两个频率进行参量激励下,研究了水波的运动。假定水的运动是不可压缩流体的无粘无旋运动,依运动的变分表示和有限空间内简正波表象得出流体的Lagrange密度和表面自由位移的方程。用多重尺度和平均变分法计算得到流体复位移应满足的非线性偏微分方程——(40)式。在稳态条件下,讨论了激励条件和流体参数间应满足的关系。在一定条件下,方程可解它是呈双曲正割函数外形的孤立波。 关键词：     

Time-Domain Mapping of Electromagnetic Ray Movement Inside 2D Anisotropic Region

The paper presents the extension of the time-domain mapping method applied to 2D billiard problem inside an anisotropic region bounded by ellipse [1]. In this paper, it has been considered the ray movement inside 2D anisotropic region bounded by arbitrary differentiable curve. It has been proved that the problem can be one-to-one mapped onto 2D mathemeatical billiard problem inside the region possessing isotropic properties by linear transformation of group velocity hodograph and boundary with the same coefficient, which is equal to anisotropy of the ray group velocity, simultaneously. The main features of the ray movement inside 2D anistropic region are discussed.     

Mapping ear canal movement using area-based surface matching

Movement of the external ear canal, associated with jaw motion, relative to the concha region of the pinna has been studied. Pairs of open-jaw and closed-jaw impressions were taken of 14 ears from 10 subjects. Three-dimensional coordinate data were obtained from the concha and the anterior surface of the canal using a reflex microscope. Proprietary area-based matching software was used to evaluate distortion of the two surfaces between the two jaw positions. The canal data from each pair were placed into the same coordinate system with their respective concha regions aligned. Difference maps of the canal data were used to demonstrate the amount of anterior-posterior (A-P), superior-inferior (S-I), and medial-lateral (M-L) movement, relative to the concha, that occurred between the open- and closed-jaw impressions. The concha regions did not undergo significant deformation. The canal regions underwent varying amounts of deformation with all canals conforming within an rms of 136 microm across the entire surface. The majority of canals underwent significant movement relative to the concha. M-L movement ranged from +2.0 to -3.8 mm; eight canals moved laterally, five moved medially, and two showed no movement. S-I movement ranged from +3.7 to -2.7 mm; nine canals moved inferiorly, two moved superiorly, and three showed no movement. A-P movement ranged between +7.5 and -8.5 mm, with five canals moving anteriorly, three posteriorly, and four in a mixed fashion. This study has shown the variability of canal movement relative to the concha and does not support previous reports that suggest that the ear canal only widens with jaw opening.     

硫化物矿床断层微粒的红外光谱分析

前人的研究着重于断层活动对矿体空间位置的改造或成矿方面,忽视了硫化物矿石及其围岩在断层活动过程中形成微粒的研究。文章采用傅里叶变换红外光谱和扫描电镜分析硫化物矿床断层微粒,结果表明,样品主要由含水硫酸钙、含水硫碳酸钙、石英、绢云母和有机质组成。其中含水硫碳酸钙是新发现的矿物。这反映在断层活动过程中,硫化物矿物中的S2-发生了氧化转变为S6+,形成含水硫酸钙,或者含水硫碳酸钙矿物。研究结果不仅可应用于该类型矿床找矿勘探,而且对于矿石利用等方面也是有意义的。另外,文章还讨论了含水硫酸钙、含水硫碳酸钙的红外光谱鉴定特征,提出红外光谱分析技术十分适合断层活动形成的含水硫酸钙和含水硫碳酸钙微粒的分析。     

Quantitative analysis of asymmetrical cortical activity in motor areas during sequential finger movement

Brain asymmetry is a phenomenon well known for handedness and has been studied in motor cortices. However, few quantitative studies on asymmetrical cortical activity in motor areas have been conducted. In this study, we systematically investigated asymmetrical cortical activity in motor areas during sequential finger movement by quantitatively analyzing functional magnetic resonance imaging (fMRI) blood oxygenation level-dependent (BOLD) responses. The norm of BOLD signal percentage of change was introduced to quantitatively measure the BOLD signal intensity change difference between the left and right motor areas. The results of the data collected from six subjects show that the norm of BOLD signal percentage of change in the right motor area is higher than that in the left motor area for two-hand movement (P=.0059) and single-hand movement (P=.0279) with right-handedness. These results from fMRI show the asymmetry of motor areas and may suggest that the left hemisphere motor area comes into being as an adaptation system that needs few neuron cells only to finish any movement task for right-handedness. The activation intensity in the left motor area is reduced with normal right finger movement. The activation intensity in the right motor area is obviously higher than that in the left motor area.     

A new understanding of the resistive state and the V-I characteristic of high-Tc superconductors

Bardeen-Stephen dissipation in the regime of thermally activated flux flow (TAFF) and flux creep has been considered with respect to its contribution to the activation energy for thermally initiated flux movement. The inclusion of this flux flow dissipation term leads to a new expression for the voltage-current (V-I, or E-J) characteristics. The extended model describes the flux dynamics in the three regimes of flux movement: TAFF, creep, and flux flow, in a satisfactory way and explains the main experimental observations.     

The activation of the cortical hand area by toe tapping in two bilateral upper-extremities amputees with extraordinary foot movement skill

Functional reorganization of the human brain after an arm amputation has been documented in several investigations, but as far as we know, there has been no report on amputees with skilled foot movement ability. To further assess the power of functional reorganization of the brain after an amputation, we investigated two bilateral upper-extremities amputees who were professional sculptors and painters with their feet. Performance tests showed that they possessed high foot movement ability. Functional MRI data indicated that toe tapping of the amputees not only activated the classical foot primary motor cortex, but also activated the hand area. In the T1-weighted MRI, the central sulci of both amputees kept their characteristic shape. Our study suggests that there is a remarkable power of neural plasticity in the motor cortex, and the maturation of the cortex develops in response to daily practice. The possible mechanisms of the reorganization are tentatively discussed.     

Separation of metals in a rotating plasma II

The movement of two types of metallic atoms that were introduced into a rotating argon plasma has been followed using the hook method.     

城市道路U形转向交通流特性模拟分析

以NaSch模型为基础建立设置U形转向的路段交通流模型,对其特性进行模拟分析. 结果表明,U形转向路口对交通流影响显著,会导致在较小进车概率时发生自由流状态到拥挤状态的相变,相应的临界流量也随之降低. 设置双U形转向系统的相变、临界流量等交通流特性与单转向系统具有明显差异,其系统效率较高. 在实际交通规划与管理时应避免设置单转向系统,以减小U形转向的负面影响. 关键词： 交通流 元胞自动机 U形转向 相变     

One-dimensional reflective diffuser for line beam shaper with microlens array homogenizer

A laser beam shaping architecture based on a microlens array homogenizer has been exploited, in which the interference effect due to the coherency of the laser source deteriorates the uniformity. Moving diffusers have been considered as an effective way of averaging out the interference pattern. Because the uniformity is required in the line direction only, a one-dimensional reflective-type diffuser with a well-controlled diffusion angle has been proposed and prototyped. The diffuser is attached onto a rotating cylinder for movement in operation. The experiment demonstrates the effectiveness of the scheme, and a line beam with a uniformity of up to 92% has been achieved.     

Radiotracer Investigations of the Shaft Processes in Polish Zine and Lead Metallurgy Part. I. Investigation of Charge Materials Movement

The principal phenomena and processes occurring in the ISP furnace as well as the radiotracer methods for the investigation of charge flow dynamics have been discussed. The ⁶⁵Zn radioisotope was applied for investigations of the batch movement dynamics. The tracer was obtained on the way of direct neutron activation of the zincflead sinter in the nuclear reactor. The activity distribution measurements were performed by taking-out the samples. Three series of experiments were carried out in order to examine the batch material movement and its dependence on the furnace charging manner. The influence of the process parameters on the batch movement has also been discussed. The shortest descent time of the charge material is strongly favoured by the joint system of charging the furnace (i.e. coke and sinter together).     

An automated ac-magnetic susceptibility apparatus

We report here both hardware and software for an ac susceptibility measurement system, namely the design and construction of the cryostat, coil system, sample rod assembly and also the automation of the sample rod movement, bridge control and nulling etc with the help of an inexpensive Z-80A microprocessor via a home-made IEEE-488 interface. The variable parameters are temperature, magnitude of the rms field and frequency. An entirely new dynamic bridge nulling algorithm with continuous sample movement, which eliminates to a large extent problems related to time-dependent drifts, has been developed. We also present some experimental data collected with this system.     

Plasma-chemical reactor based on a low-pressure pulsed arc discharge for synthesis of nanopowders

A reactor for producing nanopowders in the plasma of a low-pressure arc discharge has been developed. As a plasma source, a pulsed cold-cathode arc evaporator has been applied. The design and operating principle of the reactor have been described. Experimental data on how the movement of a gaseous mixture in the reactor influences the properties of nanopowders have been presented.

     

无人水下航行器势场航路规划方法研究

对运动障碍威胁环境下UUV航路规划问题进行了研究。首先分别对规划过程中固定障碍、运动障碍建立了排斥势场,对目标点建立了吸引势场,将航路规划问题转变为寻找最优势场点问题;然后提出一种改进的粒子群算法(NPSO),在UUV航路规划过程中,寻找距离当前路径点固定步长范围内的最优势场点,将其作为下一路径点,最终实现UUV在运动障碍威胁环境中的航路规划;最后对所提方法进行了仿真验证,UUV可以有效躲避固定障碍与运动障碍威胁,寻找到较优航路,取得了较好的仿真效果。     

Energy parameters of activation processes in the area of phase transformations in a nanocluster of superionic conductor LaF<Subscript>3</Subscript>

The results of quantum chemical calculations of the profiles of intracell potential relief at the elementary disordering act in various parts of the lattice of a crystallite LaF₃ of the size 3.5 × 2.0 × 2.2 nm containing 1200 ions have been presented. For dielectric and highly conductive (HC) phases it has been established that the potential barriers, which limit the movement in the anion sublattice, in the central part of the nanocluster are about 1.5?2.0 times higher than the potential barriers on its faces. It has been shown that for this reason, the efficiency of thermally stimulated motion in the anion sublattice on the faces of a crystallite is several orders of magnitude greater than the efficiency of the movement of fluorine ions in its central regions.     

SUMS: synchronous undulator–monochromator scans at Synchrotron Soleil

A strategy for performing synchronous undulator–monochromator scans (SUMS) compatible with the control system of Synchrotron Soleil has been developed. The implementation of the acquisition scheme has required the development of an electronic interface between the undulator and the beamline. The characterization of delays and jitters in the synchronous movement of various motor axes has motivated the development of a new electronic synchronization scheme among various axes, including the case when one of the axes is electronically accessible in `read‐only' mode. A software prototype has been developed to allow the existing hard continuous software to work in user units. The complete strategy has been implemented and successfully tested at the TEMPO beamline.     

Domain wall dynamics near the limit velocity in a cubic ferromagnet with induced magnetic anisotropy

A research has been conducted into the dynamics of the 180° domain wall in a cubic ferromagnet with induced magnetic anisotropy, this domain wall moving at a velocity close to the limit one. The Landau–Lifshits equation has been reduced to a modified double Sine–Gordon equation with the highest dispersion. A solution has been found which corresponds to the moving 180° domain wall. This paper has determined the dependencies of the velocity of the domain wall's stationary movement on the quality factor and on the ratio of the induced and the cubic magnetic anisotropy constants in slabs with the developed (0 0 1) and (0 1 1) surfaces.     

The effect of Guinier–Preston zones on the dynamic yield stress of alloys under the shock-wave load

Technical Physics - The movement of an ensemble of edge dislocations under shock-wave action on an alloy that contains the Guinier–Preston zones has been theoretically studied. The analytical...