浅谈立体化学中易混淆的几个概念

本文就高等职业院校有机化学教学中的立体化学部分，cis—trans、Z—E、R—S、D—L、d—l等易混淆的概念及命名进行了区分和讲解，为立体化学的学习打下坚实的基础。     

Optical computing

Researchers are using new conducting polymers to make transistor-like switches that are smaller and thousand times faster than the silicon transistors. Electricity-conducting organic molecules that are much thinner than semiconductor wires, are being teased into self-assembling. These advances promise super-tiny all-optical chips. In fact, progress in optical storage devices can now shrink an entire Library’s book collection down to sugar-cube size. Optical computers could be leaving silicon number crunchers choking in the dust by decade’s end.     

含Ni~(2 )离子晶体的光吸收谱分析

本文利用C_i点群对称下的晶场势表达式,推算出C_i对称下的晶场微扰矩阵元;并利用点荷模型对(NH_4)_2Ni(BeF_4)_2·6H_2O晶体的光谱进行计算。计算结果与实验较为符合。对在解释这类物质的光吸收谱分裂方面所流行的观点,即用简化的O_h点群对称晶场上加上自旋—轨道耦合的观点进行了讨论,提出了不同的看法。     

How to realize a negative refractive index material at the atomic level in an optical frequency range?

INTRODUCTION Recently, a new type of artificial compositematerials (so-called left-handed media or negativerefractive index media) whose electric permittivityand magnetic permeability are simultaneouslynegative (corresponding to a negative refractiveindex) over a certain frequency band has attractedconsiderable attention due to its extraordinaryelectromagnetic properties (Pendry, 2000; Shelbyet al., 2001; Grbic and Eleftheriades, 2004; Chen eal., 2004). The negative refractive inde…     

Diagnostic value of optic disc retinal nerve fiber layer thickness for diabetic peripheral neuropathy

Journal of Zhejiang University-SCIENCE B - To investigate the value of optic disc retinal nerve fiber layer (RNFL) thickness in the diagnosis of diabetic peripheral neuropathy (DPN). Ninety...     

无源光接入网可靠性研究

论文对无源光接入网的可靠性进行了研究。通过对网络可靠性模型的分析,研究并给出了采用树形拓扑结构的无源光接入网的可靠性和可用性模型。在分析和比较了无源光接入网保护和恢复措施基础上,对无源光接入网的可靠性机制进行了分析。     

Image Distortion of Optical Coherence Tomography

A kind of image distortion in Optical Coherence Tomography (OCT) resulted from average refractive index changes between structures of bio-tissue is discussed for the first time. Analysis is given on following situations:1) Exact refraction index changes between mierostruetures;2)The gradient of average refractive index change between different tissue layers is parallel to the probe beam;3) The gradient of average refractive index change is vertical to the probe beam. The results show that the image distortion of situation 1) is usually negligible ;in situation 2) there is a spread or shrink effect without relative location error; however, in situation 3)there is a significant image error inducing relative location displacement between different structures. Preliminary design to eliminate the distortion is presented, the method of which mainly based on the image classification and pixel array re-arrangement.     

Automatic separation system for marine meiobenthos based on laser-induced fluorescence technology

An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence technology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluoresce ncesystem was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.     

草席编织机颜色图案编织装置的研制

本文介绍普通草席编织机颜色图案编织控制电路和机械结构的设计和制造。采用光机电一体技术,提高了草席编织机颜色图案编织的定位准确性、图案可变性和可调性,实现良好的经济效益。     

How to realize a negative refractive index material at the atomic level in an optical frequency range?

The theoretical mechanism for realizing a negative refractive index material in an optical frequency range with an atomic gas system of electromagnetically induced transparency(EIT)is studied. It is shown that under certain conditions such a dense gas can exhibit simultaneously negative permittivity and negative permeability,and negligibly small loss.