考虑渗透系数变化的地下结构温度-渗流耦合分析

地下岩体的温度随着深度的增加呈逐渐上升的趋势，在地下水的作用下，岩体温度-渗流耦合作用明显。分析了地下岩体温度场与渗流场间的相互作用效应，考虑流体渗流和岩体骨架本身的热传导作用以及温度梯度所产生的渗流作用，并计入温度对水体运动粘滞系数及岩体渗透率的影响，给出了完整的基于连续介质模型的地下岩体温度-渗流耦合数学模型。借助...     

一类多输出函数研究

本文研究和讨论了作为多输出函数的N级模2~M背包变换平衡特性,给出了N级模2~M平衡背包变换的结构、计数和函数性质,指出了N级模2~M平衡背包变换本身作为密码变换函数存在着除了第M路外,所有各路的输出函数都是不完全函数的弱点,从而得出了背包变换是密码学弱函数的结论.     

Broadband Convergence of 40 GHz-ROF and 10-Gb/s WDM-PON Systems in the Duplex Access Network

A broadly converged 40G-ROF and 10-Gb/s WDM-PON multi-service access system is proposed and exper- imentally demonstrated. This scheme consists of an integrated system of 40G-ROF and 10-Gb/s WDM-PON simultaneously transmitting independent 2.5-Gb/s wireless and 10-Gb/s wire signal. At the base station, it employs a remodulation scheme, which is achieved by remodulating the upstream OOK signal on the DPSK downstream signal, to reduce the cost of the base station. The transmission experiment is carried out over a 25-km-long single mode fiber （SMF-28）. The results show that the sensitivities of downstream PON and ROF signal are -14.5 dBm and -21.5 dBm, respectively, and the sensitivity of upstream signal is -25.3 dBm.     

In Situ Tests of Multiwalled Carbon Nanotubes with Strength Close to Theoretical Predictions

Using MEMS technology and transmission electron microscopy we show experimentally multiwalled carbon nanotubes with a mean fracture strength of larger than 100 GPa, which exceeds the earlier observations by a factor of approximately 3. These results are in excellent agreement with quantum-mechanical estimations. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging is used to directly determine the number of fractured shells and the ehirality of the outer shell. Electron irradiation at 200keV for 10, 100 and 1800s lead to improvements of the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. This procedure is a cost effective way of customizing the properties of multiwall nanotubes for many applications of interest ranging from nanocomposites to nanodevices.     

飞秒激光制作铌酸锂光波导的研究

针对Z切割铌酸锂晶体在中心波长为800 nm、重复频率为76 MHz的飞秒脉冲激光下,利用放大倍数为40、数值孔径为0.65的会聚透镜聚焦,研究了扫描速度和扫描次数的变化时刻写光波导结构的影响,分析了波导结构变化的原因,并测试了1×2光波导功分器的通光性能.实验结果表明:在采用横向扫描、聚焦深度为350～400tm、扫...     

决策者具有(严格)凸性偏好结构下的一类交互式多目标决策方法

为了更好地解决决策者具有(严格)凸性偏好结构下的多目标决策问题,一般目标空间为有界凸域的情形常常可以转化为目标空间为有界闭凸区域的情形,首先分析了切割平面及该平面上偏好最优点与被切割平面分割成的为有界闭凸区域的目标空间或目标空间的子集的两个部分之间的关系;然后分析并指出了对于包含全局偏好最优目标方案点的为有界闭凸域的目标空间及其子集(准最优目标集),在确定了切割平面上的偏好最优点后,通过适当地选取供决策者与切割平面的偏好最优点进行比较判断的目标方案点,经过一次比较就可以确定一个新的范围更小的包含全局偏好最优目标方案点的目标空间的有界闭凸子区域(准最优目标集).为获取切割平面上的偏好最优点,提出了改进的坐标轮换法.在这些结论和方法的基础上,提出了决策者具有(严格)凸性偏好结构下的一类交互式多目标决策方法,要求决策者提供较易的偏好性息,决策效能较好.     

Purification and Characterization of Protein Tyrosine Phosphatase MEG1 and Preparation of Anti-PTPMEG1 Antibody

<正>PTPMEG1 is an intracellular protein tyrosine phosphatase(PTP),which contains FERM and PDZ domains. This study focuses our attention on the expression,purification and characterization of catalytic domain of PTPMEG1(△MEG1) and preparation of its polyclonal antibody.A cDNA fragment encoding△MEG1 protein(amino acid residues 643—926) was amplified by PCR and then cloned into the pT7-7 vector.Both soluble and insoluble recombinant△MEG1 proteins were observed after induction by IPTG.Soluble△MEG1 was purified via two chromatographic steps,and the purified enzyme was characterized.With para-nitrophenylphosphate(pNPP) as a substrate,△MEG1 exhibited typical enzymatic characteristics of classic PTPs and classical Michaelis-Menten kinetics.Insoluble△MEG1,which was mainly distributed in the inclusion body of E.coli cells extracts,was purified by preparative electrophoresis gel for the preparation of the polyclonal antibody.A rabbit was immunized with△MEG1 purified by preparative electrophoresis to generate anti-△MEG1 antibody.Anti-serum was collected on 28th day after initial injection and purified via affinity chromatography.The purified polyconal antibody displayed a satisfactory titer and sensitivity.     

基于极化-空间模超纠缠的量子网络多跳纠缠交换方法研究

基于纠缠交换方法进行多跳量子信息传输,是实现远距离量子网络通信的基本方式之一.传统的多跳量子网络通常使用单自由度极化光子纠缠态作为量子信道,信息传输容量较低且容易受到噪声的干扰.本文提出一种基于超纠缠的高效量子网络多跳纠缠交换方法,利用极化-空间模式两自由度的纠缠光子,建立超纠缠量子多跳信息传输通道.以远程超纠缠隐形传态的信道建立需求为例,首先给出了基础的逐跳超纠缠交换方案,为降低该方案的端到端超纠缠建立时延,提出在中间量子节点进行同时测量的并行超纠缠交换方案.在此基础上,为降低并行超纠缠交换的经典信息开销,进一步提出一种分级并行超纠缠交换方案.理论分析及仿真结果表明该方案的纠缠建立时延接近于并行超纠缠交换方案,但可以减少经典信息传输量,在一定程度上实现两者的平衡.相比传统的纠缠交换方法,本文方案有利于解决远程超纠缠通信的需求,对未来构建更高效率的量子网络有积极意义.     

一类差分系统边值问题在渐近线性下的多解存在性

应用临界点理论,获得了一类差分系统边值问题在渐近线性下存在多个非平凡解的条件.     

Wavelet-fractional Fourier transforms

This paper extends the definition of fractional Fourier transform （FRFT） proposed by Namias V by using other orthonormal bases for L^2（R） instead of Hermite-Gaussian functions. The new orthonormal basis is gained indirectly from multiresolution analysis and orthonormal wavelets. The so defined FRFT is called wavelets-fractional Fourier transform.