浙江近海海鳗食性的分析研究

海鳗是我国沿海重要的海产经济鱼类之一。本文根据1988～1990年采集的224尾标本的解剖观察,对海鳗的消化器、饵料生物组成、摄食强度变化、不同海区饵料生物组成进行了分析研究。     

GPS技术用于高等级公路勘测的若干问题

介绍了近年来全球定位系统技术用于线路控制测得的具体做法，结合在若干条高等公路上的应用实例，分析研究了应引起注意的若干问题。实证明，在高等级公路勘测中采用ＧＰＳ技术，将从根本上改进勘测技术，更好地为线路设计和施工放线服务。     

地下水系统稳定性判断研究

本文从地下水系统的角度出发,分析了矿井涌水量预测难以得到理想结果的原因,指出地下水系统的稳定性判断是其关键,并从系统理论和统计理论两方面探讨了进行地下水稳定性判断的依据,提出了从系统状态估计入手进行地下水系统稳定性判断的方法。参7。     

三维形体消隐和相贯线的一种新算法

利用棱线的图示规律和凸体、凹体的遮挡特性,给出消隐和相贯线的一种新算法。主要技术途径为对体的棱和面进行分类处理,引入了边界线、准轮廓线和轮廓线等概念,使得对凹体可以作与凸体相同的消隐处理,而无需将其分成若干个凸体。引入了“广义面”的概念,将体对棱线的遮挡转化为“广义面”对棱线的遮挡。同时提出了判断相贯线“真伪性”的四条原则和寻找“有效”交点的方法,从而大大降低了算法的时间复杂度,提高了计算精度和可靠性。     

掺杂纳米半导体超微粒ZnS:Mn2+光学特性研究

九十年代对纳米尺寸(nanoscale)材料的光物理性质的深入研究,导致了介于微观与宏观物理间的新的学科一介观物理(mesoscopic physics)的产生.其科学义在于建立和发展介于原子分子和固体之间所谓介观系统(mesoscopic system)的量子理论,揭示介观物质特性及其相互作用本质,并利用介观特性探索新型结构和功能材料.以往对纳米半导体超微粒材料的研究主要集中于与本征特性相关的量子尺寸效应,或缺陷对超微粒本征特性的影响[1,2].超微粒中过渡金属离子中心发光性质研究首次报道于1993年[3,4]并指出这可能成为崭新的一类发光材料.     

Effect of an impurity on 3-electron quantum dots in magnetic fields

1 Introduction Quantum dots (QDs), often referred to as artificial atoms, are currently under in-tense study because they provide ideal structures used in optical-electronic microdevices, so they are essential in developing microtechniques. They are also essential in the aca-demic aspect, because rich information on microstructures can be extracted both theo-retically and experimentally. Since the early fabrication of the QDs, external magnetic field has been used to control their propertie…     

Energetic instability unjams sand and suspension

Jamming is a phenomenon occurring in systems as diverse as traffic, colloidal suspensions, and granular materials. A theory on the reversible elastic deformation of jammed states is presented. First, an explicit granular stress-strain relation is derived that captures many relevant features of sand, including especially the Coulomb yield surface and a third-order jamming transition. Then this approach is generalized, and employed to consider jammed magnetorheological and electrorheological fluids, again producing results that compare well to experiments and simulations.     

Ultrahigh-resolution optical coherence tomography by broadband continuum generation from a photonic crystal fiber

We have developed an ultrahigh-resolution optical coherence tomographic system in which broadband continuum generation from a photonic crystal fiber is used to produce high longitudinal resolution. Longitudinal resolution of 1.3-microm has been achieved in a biological tissue by use of continuum light from 800 to 1400 nm. The system employed a dynamic-focusing tracking method to maintain high lateral resolution over a large imaging depth. Subcellular imaging is demonstrated.     

基于MATLAB频分多址接入模型的仿真研究

介绍了频分多址模型,对模型进行了理论分析,采用Matlab编程模拟了其通信过程,并对实验结果进行了分析,实验表明该方法实用可行。