Relative position determination of a lunar rover using high-accuracy multi-frequency same-beam VLBI

Multi-frequency same-beam VLBI means that two explorers with a small separation angle are simultaneously observed with the main beam of receiving antennas. In the same-beam VLBI, the differential phase delay between two explorers and two receiving telescopes can be obtained with a small error of several picoseconds. The differential phase delay, as the observable of the same-beam VLBI, gives the separation angular information of the two explorers in the celestial sphere. The two-dimensional relative position on the plane-of-sky can thus be precisely determined with an error of less than 1 m for a distance of 3.8×105 km far away from the earth, by using the differential phase delay obtained with the four Chinese VLBI stations. The relative position of a lunar rover on the lunar surface can be determined with an error of 10 m by using the differential phase delay data and the range data for the lander when the lunar topography near the rover and the lander can be determined with an error of 10 m.     

二次曲面和平面位置关系的判式

在解析几何中有二次曲线与直线位置关系的讨论、二次曲面与直线位置关系的讨论,而二次曲面与平面相关位置关系的探讨较少.本文给出二次曲面a11x2+a22y2+a33z2+2a12xy+2a13xz+2a23yz+2a14x+2a24y+2a34z+a44=0(1)和平面Ax+By+Cz+D=0(2)的相对位置的判别式Δ=a11a12a13a14Aa21a22a23a24Ba31a32a33a34Ca41a42a43a44DA B C D0(aij=aji).(3)并证明了:若Δ>0,则二次曲面(1)与平面(2)相交;若Δ=0,则(1)和(2)相切;若Δ<0,则(1)和(2)相离.     

限位排序的若干结果

In this paper,we first consider the position restriction scheduling problems on a single machine.The problems have been solved in certain special cases,especially for those obtained by restricting the processing time pj=1.We introduce the bipartite matching algorithm to provide some polynomial-time algorithms to solve them.Then we further consider a problem on unrelated processors.     

Dynamic stability of nonlinear barge-towing system

A method for predicting the dynamic stability of a nonlinear barge-towing system is presented in which the equations of motion of the dynamic system are first transformed into a six-dimensional state-space equation. The governing equation is then linearized by using the Taylor series expanding with respect to the equilibrium configurations of the towed barge. It is found that the stability conditions of a towing system are determined by the signs of the real part of some associated eigenvalues: Positive and negative 1's will result in unstable and stable dynamic responses, respectively, and 0 corresponds to the marginally stable condition. The reliability of the foregoing criteria is confirmed by the time histories (simulations) of the nonlinear barge-towing system. The effects of the stabilizing skegs and significantly improve the course stability of the towed barge and that the length and material of the towrope are also key factors affecting the dynamic stability of the barge-towing system.     

Numerical techniques for finding equilibrium in von Neumann’s model

Numerical methods for finding an equilibrium position in von Neumann’s multisector economy model are proposed. They can be implemented using computers with floating-point arithmetic. The proposed methods are based on reducing the problem to solving the corresponding matrix games.     

长焦距宽波段光学系统二级光谱及畸变——波差法参数求解(续)

本文论述了用波差法求解星模拟器上的光学系统各透镜光焦度和曲率半径的方法。为了校正长焦距、宽谱段光学系统二级光谱与畸变，系统的前后组分别在正逆光路下，各自保留约同值反号的位置色差及球差，用波像差法能较准确的解出其解。     

HLS新研制的束流位置探测器定标和误差分析

介绍了NSRL二期工程中,为存储环上注入段真空盒改造而新研制的8组束流位置探测器的定标和数据处理过程及其探头定标电场的拟合和误差计算结果.介绍了专门用于BPM信号处理模块的电子学系统以及它的运行性能.     

N-乙基吡咯S1态超快动力学：飞秒时间分辨光电子成像研究

N-乙基吡咯是吡咯分子的一个乙基取代衍生物,它的激发态衰变动力学目前为止很少被研究. 本文利用飞秒时间分辨光电子成像的实验方法研究N-乙基吡咯分子S₁态的衰变动力学. 实验采用241.9和237.7 nm的泵浦激发波长. 在241.9 nm激发下,得到5.0±0.7 ps,66.4±15.6 ps和1.3±0.1 ns三个寿命常数. 在237.7 nm激发下,得到2.1±0.1 ps和13.1±1.2 ps两个寿命常数. 所有寿命常数都归属为S₁态的振动态. 本文并对不同S₁振动态的弛豫机理进行了讨论.     

First- and second-order sensitivities of beams with respect to cross-sectional cracks

This paper deals with a variational formulation for the sensitivity problem of beam systems in the context of deformable solids with cracks. Natural frequencies are defined as state variables involved in the energy functional of the system, while the cracks length and position are treated as system parameters. The hierarchical equation system is formed and solved for the first and second derivatives of the natural frequency functions with respect to the cracks length and position. An analytical procedure for calculations of the second-order sensitivities of natural frequencies is proposed for the non-symmetrical equation system operator. Numerical algorithms are worked out and implemented computationally. Analytical and numerical aspects of the problem are discussed in detail through a number of illustrative results.The support of this work by the State Committee for Scientific Research (KBN) under Grant No. 4-050-0148/17-98-00 is gratefully acknowledged.     

基于质谱技术识别脂质双键位置的研究进展

脂质在能量贮存和信号传递方面发挥着巨大作用,同时还是生物膜的主要组成成分。不饱和脂质双键位置不同,生理学意义和生物学功能会有很大差异,因此脂质双键位置的识别至关重要。质谱具有灵敏快速、准确度高等优势,已成为脂质结构研究的重要方法。近年来,不同原理的电离技术与选择性衍生反应迅速发展起来,与质谱相结合已广泛应用于多种脂质双键位置的识别。本文主要对这些新型质谱技术进行总结,并展望了其未来发展趋势。