一种稳定的自由空间量子密钥分配实验系统

基于量子密钥分配的基本原理,采用B92方案,以单光子作为信息载体,使用极化编码,搭建了一个简单易行的实验装置,实现了自由空间传输的量子密钥分配,平均每脉冲光子数为0．1,粗码率12．7kbits／s,误码率4％左右。     

Luminescent Tb3+ complex with pendant crown ether showing dual-component recognition of H+ and K+ at multiple pH windows

[structure: see text] A lanthanide luminescent probe that was functionalized with quinoline-alkylated diaza-18-crown-6 showed dual-component recognition of concentrations of H+ and K+ at four independent pH ranges, including in the physiological pH window. Moreover, it exhibited pH- and [K+]-independent long-lived lanthanide luminescent lifetimes in aqueous solution.     

Invariant Mean—Value Property and M—Harmonicity in the Unit Ball of R^n

In 1993,Ahern,Flores and Rudin showed that,if f is integrable over the unit ball BC^n of C^n and satisfies∫BC^nfoφdv=f（φ（0)) for every φ∈Aut(BC^n),then f is M-harmonic if and only if n≤11.The present paper is about an analogous question in the context of the unit ball Bn of R^n as well as in the weighted setting.     

微波消解-原子吸收光谱法测定桑叶中微量元素

用微波消解及火焰原子吸收法测定5月,6月,8月,9月及10月等5个时期的桑叶中Fe,Mn,Cu,Zn,Ca 5种元素的含量,同时做精密度和加标回收试验,并对其含量进行比较,以期为临床,药物及食用含量研究开发利用提供参考.测定结果表明,各元素总体含量Ca>Fe>Mn>Zn>Cu,不同时期桑叶中微量元素各不相同,9月的桑叶中,各元素的含量均较高.     

在第23届全国中学生物理竞赛决赛颁奖大会上的发言

今年（2006年）6月我国科技界开了一次重要的会议，就是中国科学院第13次院士大会和中国工程院第8次院士大会，这次两院院士大会特别强调了创新型人才的需要和培养创新型人才的重要性．在这次大会上，胡锦涛主席发表了重要讲话，讲到三个问题，一是目前的形势和我国科技战线的任务；二是建设宏大的创新型科技人才队伍；三是两院院士要在建设创新型国家中大显身手．在第二个问题中，他讲到创新型人才的重要性，特别提到“千军易得，一将难求”，并归纳了这种领军人才的素质和特点．这些，应该是同学们的努力方向，希望同学们去认真学习．     

部分耗尽SOI MOSFET总剂量效应与偏置状态的关系

实验表明SOI MOSFET掩埋氧化层中的总剂量辐射效应与辐射过程中的偏置状态有关. 对诱发背沟道泄漏电流的陷阱电荷进行了研究. 建立一个数值模型来模拟不同偏置下陷进电荷的建立, 它包括辐射产生的载流子复合和俘获的过程. 模拟结果与实验结果相符, 解释了总剂量辐射效应受偏置状态影响的机理.     

Thermal Performance of Laser Diode Array under Constant Convective Heat Transfer Boundary Condition

Three-dimensional heat transfer model of laser diode array under constant convective heat transfer coefficient boundary condition is established and analytical temperature profiles within its heat sink are obtained by separation of variables. The influences on thermal resistance and maximum temperature variation among emitters from heat sink structure parameters and convective heat transfer coefficient are brought forward. The derived formula enables the thermal optimization of laser diode array.     

Long lasting phosphorescent properties of Ti doped ZrO2

A novel long-lasting afterglow phosphor ZrO₂:Ti is prepared by the conventional solid-stated method and their luminescent properties are investigated. A bluish white strong and broad emissive band, which is attributed to originate from the recombination of electrons trapped by F⁺ centers and the holes created in Valence band, is observed under 254 nm UV irradiation. The identical color long afterglow, which lasts about 1 h, is found in the ZrO₂:Ti phosphor after removing the 254 nm UV light. The mechanism of the long lasting phosphorescence (LLP) has been discussed based on the thermoluminescence (TL) results. The replacement of Zr by Ti produces more anion vacancies, resulting in the enhanced photoluminescence (PL) and LLP of ZrO₂:Ti sample. These results indicate that ZrO₂:Ti phosphor has potential promising applications.     

Circuit simulation for synchronization of a fractional-order and integer-order chaotic system

We design a new three-dimensional double-wing fractional-order chaotic system with three quadratic terms, confirmed by numerical simulation and circuit implementation. We then study the synchronization between the new double-wing fractional-order chaotic system and different Lorenz systems with different structures. In the process of the synchronization, the definition of ‘the simplest response system’ and the practical method of designing the circuit have been originally proposed. The circuit of ‘the simplest response system’ (even the simplest incommensurate-order response system), holding different structures with the drive system, of any one integral or fractional drive system now can be designed effectively and sufficiently. Our results are supported by numerical simulation and circuit implementation.     

Synthesis of Novel Isoxazole-contained Analogues of Losartan

Losartan 1 (Dup-753) is a nonpeptide angiotensin II receptor (type AT1) antagonist discovered by Duncia, J.V. et al. 1 in 1990 and its potassium salt (cozaar) has been marketed as an antihypertensive since 1995 2. 1 2 Starting from Dup-753, a great number of structural related compounds have been prepared by several laboratories and several antihypertensive drugs have been developed3. In order to find new and more active compounds, a novel type of Losartan analogues 2 was designed and syn…