气体分子碰撞的模型无关分析

本文纯粹基于统计平均的思想,模型无关分析导出了气体分子的碰壁数和平均碰撞频率.     

Decay of correlations for the Rauzy-Veech-Zorich induction map on the space of interval exchange transformations and the central limit theorem for the Teichmüller flow on the moduli space of Abelian differentials

The aim of this paper is to prove a stretched-exponential bound for the decay of correlations for the Rauzy-Veech-Zorich induction map on the space of interval exchange transformations. A corollary is the Central Limit Theorem for the Teichmüller flow on the moduli space of abelian differentials with prescribed singularities.

     

Effect of bias in ferroelectric-antiferroelectric relaxation

The ferroelectric-antiferroelectric transition in greyscale generation of antiferroelectric liquid crystal displays (AFLC) is a heterogeneous process. The process has been described as the growth of finger-like domains [1]. We have previously studied the ferroelectric-antiferroelectric phase transition, relaxation that follows the data pulse in surface stabilized asymmetric antiferroelectric liquid crystal displays using biasless video frequency waveforms [2]. This relaxation involves an intensity decay of the light transmitted by a pixel and depends on several parameters such as surface stabilization, rotational viscosity of the AFLC, magnitude of the data pulse, and bias voltage. The usual multiplexed driving of AFLC displays leads to long-term stabilisation of the grey levels induced by the data pulses within the selection time. However, depending on the bias level, alternative greyscale mechanisms may be obtained by allowing the grey levels to decay during the frametime. These greyscales may be advantageous in some instances since they improve the dynamic response of the AFLC device and reduce the reset time of the waveform. In this study we extend the previous work to include the effect of bias. We present the measured data, in terms of growth pattern and speed and present an extension of the previously model on order to explain the results.     

啁啾脉冲堆积及其放大特性

根据啁啾脉冲堆积的原理以及模型介绍了两路脉冲堆积时脉冲的时间与频谱特性,分析了堆积脉冲产生时间与频谱调制,以及交叠区产生非线性频率啁啾的原因。通过非线性薛定谔方程,分析了堆积脉冲的放大特性,介绍了啁啾参量对放大结果的影响以及放大后堆积脉冲的频率啁啾的变化。研究表明,在堆积脉冲的放大过程中自相位调制效应非常明显,严重影响了脉冲的频谱与频率啁啾。     

Centrality of the collision and random matrix theory

I discuss the results from a study of the central 12CC collisions at 4.2 A GeV/c.The data have been analyzed using a new method based on the Random Matrix Theory.The simulation data coming from the Ultra Relativistic Quantum Molecular Dynamics code were used in the analyses.I found that the behavior of the nearest neighbor spacing distribution for the protons,neutrons and neutral pions depends critically on the multiplicity of secondary particles for simulated data.I conclude that the obtained results offer the possibility of fixing the centrality using the critical values of the multiplicity.     

Study of Hopficity in Certain Classes of Rings

The main results proved in this paper are:

1. For any non-zero vector space V _Dover a division ring D, the ring R= End(V _D) is hopfian as a ring

2. Let Rbe a reduced π-regular ring &; B(R) the boolean ring of idempotents of R. If B(R) is hopfian so is R.The converse is not true even when Ris strongly regular.

3. Let Xbe a completely regular spaceC(X) (resp. C ^?(X)) the ring of real valued (resp. bounded real valued) continuous functions on X. Let Rbe any one of C(X) or C ^?(X). Then Ris an exchange ring if &; only if Xis zero dimensional in the sense of Katetov. for any infinite compact totally disconnected space X C(X) is an exchange ring which is not von Neumann regular.

4. Let Rbe a reduced commutative exchange ring. If Ris hopfian so is the polynomial ring R[T ₁,…,T _n] in ncommuting indeterminates over Rwhere nis any integer ≥ 1.

5. Let Rbe a reduced exchange ring. If Ris hopfian so is the polynomial ring R[T].     

1.2 MV重复频率脉冲电源的测试诊断系统

为了更好分析系统的放电特性和工作状态,优化脉冲功率源系统的设计,研制了一套1.2 MV重复频率高功率微波驱动电源测试诊断系统。通过研究高电压、大电流测试技术和数据采集、信号处理、故障诊断技术,同时运用虚拟仪器和电磁兼容等技术,探索开发了一套重复频率脉冲电压电流测试诊断系统。结合系统的研制需求,通过分析各种数据采集设备的优缺点,硬件选用了凌华公司的PXI数据采集系统,软件采用LabVIEW,设计开发了重复频率快信号的采集诊断程序,研制出实时诊断系统,并在1.2 MV重复频率脉冲电源系统中应用,实现了对重复频率电源关键点电压电流的测试以及数据的诊断、处理和远程在线监测,出现故障时报警、存储数据并自动断电等功能。     

弹光晶体频率温度系数对弹光调制系统的影响

分析了（xyt）φ1切型长度伸缩振动模式下硒化锌晶体谐振器的频率温度特性。推导了温度与硒化锌晶体的密度、杨氏模量和膨胀等材料性质的关系,计算了硒化锌晶体的频率温度系数。结果表明,相对于硒化锌的一级频率温度系数而言,硒化锌的高级频率温度系数可以忽略。弹光调制系统工作时所产生的热量会引起温度变化,从而导致谐振频率改变。当弹光调制系统工作在50kHz的谐振频率位置时,硒化锌晶体温度每改变1℃,晶体本征频率改变2.5Hz,相对于弹光调制系统16Hz的谐振半峰宽而言,该频率温度漂移不可忽略。     

通用快速RS编译码的设计

提出一种针对通用伽罗华域的快速RS编译码技术。该编译码技术利用了时域编码、频域译码,适用于通用的RS码本原生成表达式。分析表明,该技术与传统的时域编译码相比,复杂度明显降低,但仍具有相同的编译码能力,同时b=1本原生成表达式的RS编译码整系统的复杂度最低,仿真结果与理论分析一致。     

运动平台上多基地雷达接收机中频率误差对测距的影响

针对运动平台上的多基地雷达,定量分析了接收机中频综与发射机工作频率之间的误差对测距的影响。