软件控制实现高速摄影机的收片启动特性

对棱镜补偿式高速摄影机的收片启动特性进行了定量分析 ,根据分析给出了在工程中实现这一运动特性的步骤和方法 ,该方法的核心思想是从试验中得到控制运行所需要的参数 ,然后用软件控制实现摄影机的收片启动特性。实际的工程使用证明该方法简便且行之有效 ,方便了摄影机调试     

On the Extension of a TCFT to the Boundary of the Moduli Space

The purpose of this paper is to describe an analogue of a construction of Costello in the context of finite-dimensional differential graded Frobenius algebras which produces closed forms on the decorated moduli space of Riemann surfaces. We show that this construction extends to a certain natural compactification of the moduli space which is associated with the modular closure of the associative operad, due to the absence of ultra-violet divergences in the finite-dimensional case. We demonstrate that this construction is equivalent to the “dual construction” of Kontsevich.     

On the Possibility of the Implicit Renormalization of the Casimir Energy

We propose a procedure for renormalizing the Casimir energy that makes the steps that are used in the standard renormalization procedure, that is, regularization, subtraction, and deregularization, implicit. The proposed procedure is based on the calculation of a set of convergent sums, each of which is related to the initial divergent sum of the non-renormalized Casimir energy. Next, we construct a system of linear equations that relates this set of convergent sums to the renormalized Casimir energy. The unknown renormalized Casimir energy is obtained as a result of solving this system of equations. In this case, both the calculations of the convergent sums and the subsequent solution of the system of linear equations are performed with a certain (generally speaking, arbitrary) ordered accuracy; thus, the result is also approximate. The proposed procedure is, first, more computationally effective than the standard one, and, second, applicable not only to the problems where a transcendental equation for the spectrum can be written, but also to the problems where the spectrum is known only numerically.     

Note on the solution of the master equation in the exciton model of pre-equilibrium theory

In a number of publications the master equation of the exciton model of pre-equilibrium theory for nuclear reactions is solved by iterative means. It is shown in this note that an exact and analytical solution of this particular type of master equation exists and can be calculated. The time integral over the solution of this master equation can be obtained by a simple method, from which the summed pre-equilibrium and equilibrium emission spectra can be calculated very easily.     

Effect of the fluid in the inclusions of cement paste on the ultrasonic velocity

The durability of cement composites significantly depends on the movement of the fluids into the material through the porous system. The aqueous phase contained in the pores can cause irreversible damage from the dimensional stability viewpoint. In this sense, methods for non-destructive characterization of both, the porous structure and water content should be investigated. In this work, the effect of the fluid in the inclusions of the cement paste on the ultrasonic velocity is studied. Firstly, a theoretical analysis based on the micromechanical model, considering the microstructural information of the matrix and the fluid filling the pores, is presented. Some experimental work is made later using cement paste samples, whose porous structure is maintained dry or saturate with water. In both cases, the ultrasonic velocity is measured and compared to the one predicted by the micromechanical model. Using this technique, the ultrasonic velocity can be predicted with errors below 2% in the cases of dry or water saturated cement paste.     

Universal form of the power spectrum of the aero-optical aberration caused by the supersonic turbulent boundary layer

Based on the measurement of one-dimensional （1D） optical path difference （OPD） of the supersonic turbulent bound- ary layer, an analytical form for the power spectrum of the two-dimensional （2D） OPD is obtained with its structure function and under the locally homogeneous isotropic assumption. The universality of this spectrum is argued, and its validity is checked by the comparison with experimental result. The potential applications of this model in theoretical and numerical studies are emphasized. Another contribution of this work is around the application of correlation function to analyzing the statistics of OPD. Based on our results and other results published elsewhere, we show that the OPD is often not stationary, and one should be cautious about using this tool.     

Dependence of the anomalous fading of the TL and blue-OSL of fluorapatite on the occupancy of the tunnelling recombination sites

The anomalous fading (AF) of thermoluminescence (TL) and optically stimulated luminescence (OSL) signals in Durango apatite is attributed to tunnelling effects. Electrons from the TL and OSL traps in this material are transferred, via a tunnelling effect, to the recombination sites. The availability of recombination sites for tunnelled electrons is of major importance for the degree of AF rate observed in this material. It is expected that a variation of the number of the electron recombination sites will be reflected in the experimentally measured AF rate. In the present work an investigation of the recombination sites for the tunnelled electrons is attempted by studying the AF effect using a special technique, in which the anomalously faded TL (OSL) is replaced by an equal amount of TL (OSL) induced by a beta dose.     

The principle of the Internet evolving and the conjecture of the optimal structure of Internet

In this paper we will give the statistical characteristics and general principles of an optimal structure of the Internet, which is a scale-free network. Since the purpose of the Internet is to allow fast and easy communication, the average path length is used to measure the performance of the network, and the number of edges of the network is used as a metric of its cost. Based on this, the goal of this Internet optimization problem is to obtain the highest performance with the lowest cost. A multi goal optimization problem is proposed to model this problem. By using two empirical formulas of and , we are able to find the statistical characteristics of the optimal structure. There is a critical power law exponent α _c for the Internet with power law degree distribution, at which the Internet can obtain a relatively good performance with a low cost. We find that this α _c is approximately 2.1.     

Origin of the usefulness of the natural-time representation of complex time series

The concept of natural time turned out to be useful in revealing dynamical features behind complex time series including electrocardiograms, ionic current fluctuations of membrane channels, seismic electric signals, and seismic event correlation. However, the origin of this empirical usefulness is yet to be clarified. Here, it is shown that this time domain is in fact optimal for enhancing the signals in time-frequency space by employing the Wigner function and measuring its localization property.     

高效透明导电膜荧光屏的研究

介绍了一种新型荧光屏结构,采用透明导电膜代替传统荧光屏中的铝膜作电极.分别测试了新型荧光屏和传统荧光屏的加电特性.实验结果表明新型荧光屏具有较高的耐压性能,对提高X射线变像管的空间分辨率有重要作用,而且能延长变像管的寿命.采用透明导电膜制作荧光屏还具有工艺简单,成本低和成品率高的优点.     

Construction of the minimal superspace-translation tensor and the derivation of the supercurrent

The superspace analogue of the improved energy-momentum tensor is analysed. The supercurrent of Ferrara and Zumino is derived from the superspace-translation tensor in its minimal form. The additional freedom in this tensor, as compared to the supercurrent, is exhibited.     

Study of the behaviour of the fibre Bragg grating fabricated with cladding mode suppression fibre

One effective method for suppression of coupling from guided optical modes into cladding modes in an optical fibre Bragg grating is to use cladding mode suppression fibre. In this specially engineered fibre, the grating is written into the core and the inner cladding, both of which are photosensitive. A theory is presented in this paper to analyse the spectral characteristics of this kind of gratings. A fibre Bragg grating was experimentally fabricated with this kind of photosensitive fibre (PS-RMS-50 from StockerYale). It is shown both theoretically and experimentally that such gratings exhibit strong suppression of the coupling between core mode and cladding mode. The experimental result is in good agreement with the theoretical analysis.     

Considering the effectiveness of 3rd order aberration theory from the view point of sine condition in the presence of spherical aberration

Even though the level of computer simulation for optical designing is becoming powerful, the 3rd order aberration theory is still useful for prospecting optical characteristics and developing optics. Therefore, it is important to confirm its validity even now. Considering the physical meaning of imaging, pupil coordinates should be defined by the direction cosine of the ray. The sine condition in the presence of spherical aberration has been derived by using this coordinate and its validity was later confirmed by practical lens designing. On the other hand, in order to deal with object imaging and pupil imaging equivalently, conventional aberration theory uses the pupil coordinate defined by the slope of the ray. By applying this theory, it had been deduced that no spherical aberration exists when the isoplanatic condition is fulfilled and it was then concluded that the sine condition in the presence of spherical aberration is meaningless. Therefore, one might think that this conventional aberration theory is less useful. However, this time I found that the 3rd order spherical aberration can exist with no 3rd order coma aberration under this aberration theory. As a result, the conventional aberration theory is meaningful at least in the 3rd order region.     

On the utility of momentum space in the density functional theory description of the steric effect

This paper assesses the utility of momentum space in the density-based quantification of the steric effect proposed by Liu [J. Chem. Phys. 126, 244103 (2007)], which is based on a new energy partition scheme where the total electronic energy is decomposed into contributions from three independent effects: steric, electrostatic, and the fermionic quantum. The steric energy defined in this way is repulsive, exclusive, and extensive and intrinsically linked to Bader's quantum theory of atoms in molecules. In this work, the plausibility of defining and computing steric energies using momentum densities according to this scheme is confirmed from numerical tests. Moreover, we found that the correlation between the experimental scales of the steric energies and theoretical values computed from momentum densities is even better than the same correlation with theoretical estimations obtained from position densities.     

On the structure of the quantum-mechanical probability models

In this paper the role of the mathematical probability models in the classical and quantum physics is shortly analyzed. In particular the formal structure of the quantum probability spaces (QPS) is contrasted with the usual Kolmogorovian models of probability by putting in evidence the connections between this structure and the fundamental principles of the quantum mechanics. The fact that there is no unique Kolmogorovian model reproducing a QPS is recognized as one of the main reasons of the paradoxical behaviors pointed out in the quantum theory from its early days.Paper written in honor of L. de Broglie.     

Effect of the isovector coupling channel on the macroscopic part of the nuclear binding energy

The effect of isovector coupling channel on the macroscopic part of the nuclear binding energy is studied using the relativistic density-dependent Thomas–Fermi approach. The dependency of this effect on the number of neutrons and protons is also studied. The isovector coupling channel leads to increased nuclear binding energy, and this effect increases with the increasing neutron number in the nucleus.     

基于动力学同步的复杂网络结构识别速度研究

基于动力学同步的复杂网络结构识别是探测复杂网络拓扑性质的重要方面, 其中识别速度是一个重要但鲜有讨论问题. 首先对弱耦合条件下耦合非线性振子网络结构识别速度的问题进行了研究. 发现识别速度随耦合强度成正比增长. 通过解析讨论, 肯定了这一关系是普适的. 之后基于我们最近提出的反复驱动识别方法, 将处于同步稳定态的耦合区域也纳入研究范围. 在这种情形下存在一个最佳的时间片段的长度使识别速度达到极值. 这些结论加深了对时间序列中蕴含的拓扑结构信息量的理解.     

休伦法在观测溶液浓度分布中的应用

休伦法 (Schlierenmethod)在观察物质流的折射率梯度方面的应用已有相当长的历史。对该方法进行改进 ,将其引入晶体生长的监控领域。介绍了该方法的原理及测量公式 ,并进行了实验观察 ,取得了比较理想的定性结果。结果表明 ,用这一方法可以很方便地观测透明物质或溶液中的折射率梯度或浓度的分布情况 ,特别是在晶体生长检测领域中有着广泛的应用前景。