Helmholtz potentiality conditions for systems of difference-differential equations

For operators corresponding to systems ofμth-order difference-differential equations of neutral type, necessary and sufficient conditions for potentiality with respect to the classical bilinear form are obtained. These results are applied to first-order quasilinear systems. Translated fromMatematicheskie Zametki, Vol. 64, No. 3, pp. 437–442, September, 1998. The author wishes to express his thanks to V. M. Savchin for fruitful discussions and useful remarks.     

Constructive and Destructive Two-Pulse Excitation Investigated with a White-Light Michelson Interferometer

Linear propagation of two pulses through methanol solution of aluminum phthalocyanine chloride is investigated using a modified white-light Michelson interferometer. The observed coherence time of the white light is 6 fs, and the separation between the two-excitation pulses is set to about 10 fs. The excitation is dependent on the phase-relation between the two pulses. We have observed an enhancement of the excitation when the two pulses are in-phase and strong suppression of the excitation when the two pulses are out of phase by π.     

Approximate controllability for trajectories of semilinear control systems

We treat an abstract semilinear control system and study the controllability problem for its trajectories. Assuming a range condition of the control action operator and an inequality condition on the system parameters, we can show that the reachable trajectory set of the semilinear system is equivalent to that of its corresponding linear system.The author wishes to express his deep appreciation to Prof. T. I. Seidman for his many helpful suggestions and to Prof. W. Takahashi for many stimulating conversations.     

Photorefractive shearing interferometer

A novel method of obtaining shearing interferogram by slightly moving the crystal in a photorefractive interferometer is proposed. This method can measure the phase of an object itself instead of its diffraction field, and it is easy to realize continuously changeable shearing distance in any lateral direction and introduce carrier fringes at the same time. Both the theoretical analysis and experimental verification are given.     

高光通量短波红外静止干涉成像光谱仪研究

讨论高光通量静止干涉（傅里叶变换）成像光谱仪的基本原理及结构特点，建立了短波红外的高光通量静止傅里叶变换光谱仪的实验系统，给出了实验结果。     

A complete active-space self-consistent-field study on cubic N8

Summary Complete Active-Space Self-Consistent-Field (CAS-SCF) calculations for cubic N₈ are presented. We studied the N₈↔4N₂ reaction inD _4h symmetry and found its energy release and activation barrier with three different atomic basis sets. The energy release for this reaction is predicted to be around 526 kcal/mol, while the energy barrier to dissociation is estimated about 159 kcal/mol. These results are in substantial agreement with previousab initio estimates. The authors of this paper have agreed to not receive the proofs for correction.     

Weber electrodynamics: part III. mechanics,gravitation

Weber electrodynamics predicts the Kaufmann-Bucherer experiments and the fine structure energy level splitting of the H-atom (neglecting spin) without mass change with velocity (i.e., mass ). The Weber potential for the gravitational case yields Newtonian mechanics, confirming Mach's principle. It provides a cosmological condition yielding an estimated radius of the universe of 8 × 10⁹ light years. Despite these successes, the independent evidence for Kaufmann mechanics, where mass changes with velocity (i.e., mass ) is convincing. Perhaps a slight alteration may make the Weber theory compatible with Kaufmann mechanics.     

冲击波处理的结晶MgO的化学分析正电子谱研究

冲击波处理的结晶ＭｇＯ的化学分析正电子谱研究＊张菊郑小明（杭州大学催化研究所，杭州３１００２８）常志向（抚顺石油化工研究院，抚顺１１３００１）关键词冲击波，化学分析正电子谱，结晶氧化镁，丁烯，脱氢冲击波是在介质中以超音速传播的压力脉冲．气体中的冲击波...     

Ar—Kr溶液扩散系数的分子动力学模拟及其与温度的关系

用分子动力学模拟方法研究确定Ａｒ－Ｋｒ溶液的自扩散系数Ｄ１、Ｄ２和互扩散系数Ｄ１２以及它们随温度变化的规律。结果表明，分别用Ｇｒｅｅｎ－Ｋｕｂｏ法和Ｅｉｎｓｔｅｉｎ法得到的扩散系数在数值上一致；该溶液的３种扩散系数均满足Ｄ＝Ｄ０ｅ＾Ｅ／ＲＴ关系。     

FTS-20E富里叶红外光谱仪数据系统改造

报道了ＦＴＳ－２０Ｆ富里叶红外光谱仪数据系统改造的工作采用ＩＢＭ４８６计算机及新的数据接口取代了陈旧的ＮＯＶＡ４数据系统，文章详细描述了其硬件设计和软件编辑，改造不仅更新了ＦＴＳ－２０Ｅ里叶红外光谱仪，而且还使其达到９０年代的水平。