温度计标定中曲线拟合的应用及研究

文章从曲线拟合的基本原理出发,介绍了在无变量与自变量函数关系的情况下,如何对温度计标定的实验数据进行合理的曲线拟合,从而实现温度计标定;并介绍了编程实现对数学解析式进行求解的具体流程。     

Influence of intra-cavity loss on transmission characteristics of fiber Bragg grating Fabry–Perot cavity

A theoretical model of the fiber Bragg grating Fabry–Perot(FBG-FP) transmission spectrum considering loss of FBG and intra-cavity fiber is presented. Several types of FBG-FPs are inscribed experimentally, and their spectra are measured.The results confirm that weak intra-cavity loss is enhanced at the resonance transmission peak, that is, loss of transmission peaks is observably larger than other wavelengths. For FBG-FPs with multi resonance peaks, when the resonance peak wavelength is closer to the Bragg wavelength, the more significant loss effect of resonance transmission peak is exhibited.The measured spectra are fitted with the presented theoretical model. The fitted coefficient of determinations are near 1,which proves the validity of the theoretical model. This study can be applied to measure FBG loss more accurately, without a reference light. It can play an important role in FBG and FBG-FP writing process optimization and application parameter optimization.     

一种基于OpenFlow光接入网的轻量级安全身份认证加密机制

为满足互联网多业务背景下各方对于安全性的更高要求,平衡因引入安全机制造成的高代价问题,通过分析软件定义光接入网(SDOAN)所面临的通信安全挑战,提出了一种基于加密生成地址(CGA)算法与哈希生成地址(HGA)算法相结合的轻量级安全身份认证加密机制(CH-CNA)。该机制遵循OpenFlow协议的信息交互方式,通过引入无第三方参与的CGA算法和HGA算法,以此分别完成通信节点之间的首次认证绑定和非首次认证绑定。在认证绑定过程中可有效防止攻击者伪造、篡改认证交互消息,从而建立起面向接入网的端到端可信连接。采用OMNeT++网络仿真软件对提出的CH-CNA机制进行了测试,实验结果表明,该机制在保证通信节点之间安全性交互的同时,降低了平均计算开销和因恶意攻击引起的阻塞率,符合轻量级的定义要求。     

Characteristics of a PLZT electro-optical deflector

A beam deflector was designed and fabricated by using a lead lanthanum zirconate titanate(PLZT)ceramic with high quadratic electro-optic(EO)effect,based on refraction at an interface between areas with and without applied voltage.Its EO coefficients of R33=2.1×10~(-16)V2/m~2 and R_(13)=-0.37×10~(-16)V~2/m~2 were obtained.Moreover,the hysteresis characteristics of the EO deflection were observed,and the effects of temperature on the characteristics of beam deflector were also investigated in detail.     

Wavelength dependence of soft tissue ablation by using pulsed lasers

Pulsed laser ablation of soft biological tissue was studied at 10.6-,2.94-,and 2.08-μm wavelengths.The ablation effects were assessed by means of optical microscope,the ablation crater depths were measured with reading microscope.It was shown that Er:YAG laser produced the highest quality ablation with clear, sharp cuts following closely the spatial contour of the incident beam and the lowest fluence threshold.The pulsed CO_2 laser presented the moderate quality ablation with the highest ablation efficiency.The craters drilled with Ho:YAG laser were generally larger than the incident laser beam spot,irregular in shape,and clearly dependent on the local morphology of biotissue.The ablation characteristics,including fluence threshold and ablation efficiency,varied substantially with wavelength.It is not evident that water is the only dominant chromophore in tissue.     

微波消解-EDTA微量滴定法测定葛根中钙和镁

葛根是一种医疗保健价值和经济价值均极高的豆科藤本植物,常用于传统中药、药食方面,含有多种人体必需微量元素,尤其是钙和镁的含量较高,葛根中钙和镁的测定常采用原子吸收光谱法和原子发射光谱法[1-3].     

Fenestration operation in middle ear bone with pulsed infrared lasers: an in-vivo study

The feasibility of fenestration operation in middle ear bone with pulsed infrared laser is evaluated. Healthy male New Zealand rabbits in vivo are used in the experiment. Middle ear mastoid bone of animal model is completely exposed with conventional methods, and then a pulsed CO2 laser （10.6 μm） and an Er：YAG laser （2.94 μm） are used to perform the fenestration operation. Diamond drill is also used as a control group. The total operation time and light irradiation time are recorded and the opening efficiency is assessed. The morphological changes and thermal damage around the opening window on the middle ear bone are examined. It is shown that both laser systems are suitable for the fenestration operation in middle ear bone, and this no-touch technique has a lot of benefits compared with traditional methods. The bleeding during operation has an important effect on operation time and thermal injury and needs to be controlled efficiently in further study.     

在平方晶格上自旋-1模型的一种近似解

本文通过decoration变换和decimation变换把在平方晶格上的自旋-1模型等价于一个checkerboard晶格上具有次近邻和四体相互作用的伊辛模型,并得到自旋-1模型的近似临界条件。该近似临界条件在极限情况下与Onsager的严格解一致。 关键词：