支持22个轨道角动量模式的低平坦色散微结构光纤

设计了一种可支持22个轨道角动量(OAM)模式传输的新型微结构光纤,该光纤具有低平坦色散、低损耗等优点,光纤中可支持的各个矢量模式之间有效折射率差值均大于10-4,对应的22个OAM模式都能够在纤芯中稳定传输。在1500~1600nm波段范围内,通过优化包层最内圈两层空气孔的物理参数,该光纤中可支持传输的模式色散均能控制在0~50ps·(nm·km)~(-1)范围内,HE71和EH51模式的色散变化值低于12.8ps·(nm·km)~(-1),其余模式的色散变化范围低于5ps·(nm·km)~(-1)。在1550nm波段处,该光纤所支持的所有模式损耗均低于1.35×10~(-9) dB/m。     

具有荧光响应功能的分子四边形的组装(英文)

由缩氨基脲和2-喹啉醛合成了席夫碱配体H2L,并与过渡金属离子Cd2+组装得到了四边形配合物CQ。用X射线衍射对配合物的晶体结构进行了测定,发现其具有I41/a空间群。通过荧光测试发现该配合物在CH3CN溶液中具有较强的荧光,加入间苯二甲酸、对苯二甲酸阴离子后荧光发生淬灭,而加入邻苯二甲酸阴离子荧光无变化,可以将邻苯二甲酸阴离子从其他2种二酸阴离子中区分出来。     

变中求新——2010年高考上海试卷的分析和思考

2010年高考上海试卷,是上海自单独命题以来和以往试卷相比变化最多的一份试卷,本文将就试卷变化的背景、试卷本身的特点作简单的介绍和评析.     

一种基于音频应用的∑△power DAC研究和实现

介绍了一种应用在音频系统的∑△power DAC。对整个∑△power DAC的设计进行了详细的介绍，实际的硬件用Synopsys工具进行了完整的电路设计、仿真和版图设计。在MP3中得到实际应用，音质效果良好。     

基于上海交通车管业务浅谈多网络多业务系统的网络安全措施

上海交通车管业务经过这几年的努力,已逐步打造出一个较为完整的信息化平台,该信息化平台包括了多类型的网络和多类型的业务系统;因此对于上海交通车管信息安全防范工作除了各个网络的安全,还包括各个网络的系统的信息交互的安全。本文就该信息化平台采用的几项网络安全防范措施作简要的介绍以供探讨。     

Dual-demodulation large-scope high-sensitivity refractive index sensor based on twin-core PCF

In this paper, a refractive index (RI) sensor based on the twin-core photonic crystal fiber (TC-PCF) is presented. Introducing the rectangular array in the core area makes the PCF possible to obtain high birefringence and low confinement loss over the wavelength range from 0.6 μm to 1.7 μm. Therefore, the core region can enhance the interaction between the core mode and the filling material. We studied theoretically the evolution characteristics of the birefringence and operating wavelength corresponding to the strongest polarization point under the condition of filling the rectangular array with RI matching fluid range from 1.33 to 1.41. Simulation results reveal that the proposed TC-PCF has opposite evolutions of change rates between the B and wavelength, and the maximum RI sensing sensitivities of 1.809×10-2 B/RIU and 8 700 nm/RIU at low and high RI infill are obtained respectively, which means that the TC-PCF features of dual-parameter demodulation for the RI sensing can maintain a high refractive index sensing sensitivity within a large scope of RI ranging from 1.33 to 1.41. Compared with the results of single-parameter demodulation, it is an optimized method to improve the sensitivity of low refractive index sensors, which has great application potency in the field of biochemical sensing and detection.     

空间因特网的移动管理

从航天器到地面最终用户的完整路径采用 IP 技术时需解决移动管理问题。当进行互 支持时，应引入微观移动协议进行移动管理。在参考移动因特网研究领域的几种典型微观移动协议基 础上，根据空间任务网络拓扑结构和操作特点，并考虑可实现性等问题，最终选择分层移动 IP 协议作为 解决方案。仿真结果表明，在互支持的情况下，使用微观移动协议明显改进了切换性能。     

菲罗啉大环双核Fe3+配合物的合成及其荧光性质

根据文献方法合成大环配体L,通过溶剂法与金属盐Fe(ClO₄)₂·6H₂O反应合成了两个新的菲罗琳大环双核Fe₃₊配合物[Fe₂(L)(μ-O)(DMF)₄]·4ClO₄(1, CCDC： 1834054）和[Fe₂(L)(μ-O)(SCN)₄]·4ClO₄(2, CCDC： 1834055）,其结构经IR和元素分析表征。晶体结构解析表明：1属三斜晶系,2属单斜晶系。配合物中两个铁原子通过一个氧桥进行连接,由于氧桥的连接使得配体发生折叠进而产生了π-π堆积。配体荧光滴定实验显示,配体L对过渡金属存在响应,随着过渡金属离子的加入,配体的荧光强度不断减弱。     

Intermodal interference based refractive index sensor employing elliptical core photonic crystal fiber

A refractive index (RI) sensor based on elliptical core photonic crystal fiber (EC-PCF) has been proposed. The asymmetric elliptical core introduces the polarization-dependent characteristics of the fiber core modes. The performances of intermodal interference between the intrinsic polarization fiber core modes are investigated by contrast in two interferometers based on the Mach-Zehnder (M-Z) and Sagnac interference model. In addition, the RI sensing characteristics of the two interferometers are studied by successively filling the three layers air holes closest to the elliptical core in the cladding. The results show that the M-Z interference between LP01 and LP11 mode in the same polarized direction is featured with the incremental RI sensing sensitivity as the decreasing interference length, and the infilled scope around the elliptical core has a weak correlation with the RI sensing sensitivity. Due to the high birefringence of LP11 mode, the Sagnac interferometer has better RI sensing performance, the maximum RI sensing sensitivity of 12 000 nm/RIU is achieved under the innermost one layer air holes infilled with RI matching liquid of RI=1.39 at the pre-setting EC-PCF length of 12 cm, which is two orders of magnitude higher than the M-Z interferometer with the same fiber length. The series of theoretical optimized analysis would provide guidance for the applications in the field of biochemical sensing.     

肿瘤细胞中长春新碱的高效液相色谱法测定

长春新碱（ＶＣＲ）为重要和常用抗肿瘤药物之一。肿瘤细胞耐药性是导致化疗失败的主要原因。为了筛选耐药细胞的逆转剂,建立了测定肿瘤细胞内ＶＣＲ浓度的高效液相色谱法,色谱条件为：Ｚｏｒｂａｘ－ＯＤＳ反相柱２５ｃｍ×４．６ｍｍｉ．ｄ．,流动相：０．０２ｍｏｌ／ＬＫ２ＨＰＯ４（ｐＨ６．６）∶ＣＨ３ＯＨ（２０∶８０,Ｖ／Ｖ）,流速：１．０ｍＬ／ｍｉｎ,检测波长：２６７ｎｍ。方法简单、快速、选择性好,在１０～２００ｍｇ／Ｌ范围内ＶＣＲ浓度－峰高呈良好的线性关系（ｒ＝０．９９９８）,仪器灵敏度为４ｎｇ。