The compensability between the longitudinal andtransverse mismachining tolerance of gratingin the optical pick-up head

In this paper numeric analysis is made to the influence of the longitudinal mismachining tolerance (LMT) and the transverse mismachining tolerance (TMT) of the grating in the optical pick-up head (GOPH) of VCD, DVD, and CD-ROM on the transmissivity and the intensity ratio of the auxiliary light beam to the main read-write light beam (IRAM) by using the general expression of diffraction efficiency obtained from the scalar diffraction theory. On solving GOPH problem, the scalar diffraction theory and the vector diffraction theory are coincident, and the scalar diffraction theory is reliable. The result shows that LMT and TMT can compensate for the inverse effect of IRAM, however, at the expense of reducing transmissivity. As far as GOPH is concerned, the goodness that LMT and TMT can be effectively compensated for is very advantageous in manufacturing of the grating.     

应用介孔分子印迹聚合物萃取粮食中的乙酰甲胺磷

以乙酰甲胺磷为模板分子,3-氨基丙基三乙氧基硅烷(APTES)为功能单体,表面活性剂正十二烷胺(DDA)为介孔模板剂,正硅酸乙酯为交联剂,采用溶胶凝胶技术制备乙酰甲胺磷介孔分子印迹聚合物(MIP),并对其进行了表征。Scatchard分析表明,该聚合物对乙酰甲胺磷有两种结合方式,最大表观结合量Q_(max1)=47.03 mg/g,Q_(max2)=90.31 mg/g;平衡解离常数k_(d1)=57.14 mg/L,k_(d2)=188.68 mg/L。吸附动力学测定结果显示,其对乙酰甲胺磷的吸附符合准二级动力学模型;吸附热力学测定结果显示其吸附为放热过程。将该聚合物用于基质固相分散萃取(MSPD)粮食中乙酰甲胺磷,最佳条件为:聚合物与样品的质量比为1∶1,研磨时间为8 min,淋洗剂为乙醇-水(2∶1,体积比),洗脱剂为乙腈-乙酸溶液(19∶1,体积比)。所得洗脱液采用高效液相色谱法检测,测得乙酰甲胺磷的线性范围为0.03～0.3μg/g,检出限为0.015μg/g,回收率为92.5%～97.1%,相对标准偏差为2.9%～3.7%。该方法兼具介孔分子印迹技术的高选择性如和MSPD技术的快速分离性,为乙酰甲胺磷残留分析提供了新思路。     

溶剂和链长对木犀草素抗氧化活性影响的理论研究

基于木犀草素的结构特点,采用量子化学的密度泛函理论(DFT)方法研究了溶剂和酯基对木犀草素抗氧化活性的影响.首先,研究了化合物中分子内氢键的性质.其次,从热力学角度通过抽氢反应(HAT)、逐步电子转移质子转移(SET-PT)和质子优先损失电子转移(SPLET)机制分析了化合物的抗氧化能力.氢键性质分析发现,木犀草素及其...     

条纹管激光成像系统空间分辨力实验研究

简要分析了非扫描激光成像的技术优势,介绍了利用条纹管实现非扫描激光成像的工作原理,说明了图像空间分辨力与系统距离精度的对应关系。对影响图像空间分辨力的主要因素进行了理论分析,得到了系统总空间分辨力与各单元器件空间分辨力和放大倍率的对应关系,在此基础上,对现有条纹管成像系统进行了相应的计算,得到了空间分辨力的理论预期值;最后,提出了一种基于分辨力板成像的系统空间分辨力测试方法,设计了相应的验证实验,对实测图像进行了去噪处理和数据分析,得到了图像的衬比度传递函数(CTF)曲线,通过衬比度传递函数分析,计算出了成像系统的实际空间分辨力,并将实测的分辨力数据与理论值进行了对比分析。     

利用偏钛酸浆料制备大比表面纳米管钛酸工艺的研究

以偏钛酸浆料为原料通过水热法合成了纳米管钛酸,并采用TEM,比表面积测定仪等分析手段观察其形貌和管径大小,测定了其比表面积和孔体积.同时运用正交实验法考察了反应温度、反应时间对纳米管钛酸比表面积和孔体积的影响.实验结果表明,所制备的纳米管钛酸平均比表面积高达 340m2 /g,最佳的制备工艺是:工业碱NaOH的质量分数为 25. 7 %、偏钛酸浆料的质量分数为 17. 1 %、后处理酸度为pH=1、反应温度为 120℃、反应时间为 20h.     

二硫化钼粘结固体润滑涂层的径向和切向微动损伤的比较研究

通过径向和切向微动试验考察了二硫化钼粘结固体润滑涂层的微动摩擦学特性 ,并利用扫描电子显微镜、能量色散谱和X射线光电子能谱等分析了两类微动损伤区的微观特征 .结果表明 :二硫化钼粘结固体润滑涂层具有良好的抗径向微动损伤性能 ;切向微动条件下无混合区存在 ,涂层损伤强烈依赖于位移幅值 ,并伴随MoS2 的氧化 ;径向微动损伤呈现切向微动部分滑移区的特征     

An efficient deterministic secure quantum communication scheme based on cluster states and identity authentication

A novel efficient deterministic secure quantum communication scheme based on four-qubit cluster states and single-photon identity authentication is proposed. In this scheme, the two authenticated users can transmit two bits of classical information per cluster state, and its efficiency of the quantum communication is 1/3, which is approximately 1.67 times that of the previous protocol presented by Wang et al [Chin. Phys. Lett. 23 (2006) 2658]. Security analysis shows the present scheme is secure against intercept-resend attack and the impersonator's attack. Furthermore, it is more economic with present-day techniques and easily processed by a one-way quantum computer.     

Analysis of identification methods of key nodes in transportation network

The identification of key nodes plays an important role in improving the robustness of the transportation network. For different types of transportation networks, the effect of the same identification method may be different. It is of practical significance to study the key nodes identification methods corresponding to various types of transportation networks. Based on the knowledge of complex networks, the metro networks and the bus networks are selected as the objects, and the key nodes are identified by the node degree identification method, the neighbor node degree identification method, the weighted k-shell degree neighborhood identification method (KSD), the degree k-shell identification method (DKS), and the degree k-shell neighborhood identification method (DKSN). Take the network efficiency and the largest connected subgraph as the effective indicators. The results show that the KSD identification method that comprehensively considers the elements has the best recognition effect and has certain practical significance.     

平场全息凹面光栅结构参量误差之间的补偿作用

平场全息凹面光栅的制作和使用中不可避免地存在结构参量误差,包括曲率半径误差、制作结构误差以及使用结构误差.利用光线追迹方法研究了像宽随波长的变化曲线与子午焦线的对应变化关系,有助于光谱仪的设计和装调.通过分析各种结构参量误差对像宽曲线的影响发现,在较大误差范围内,光栅参量误差对子午焦线的影响作用为平移作用和倾斜作用.数...