基于多反应通道的高产额激光中子源实验研究

基于超短超强激光的短脉冲中子源是实现超快中子探测的理想中子源。如何提升中子产额是目前短脉冲激光中子源实现应用需求亟需解决的关键问题。提出基于靶背鞘场加速机制和束靶反应方案,采用LiD复合组分靶作为中子转换体,可以有效提升激光中子产额。与常规的LiF转换体相比,除了p-Li和d-Li两个反应道之外,LiD转换体可以多出p-D和d-D两个反应道,因此可充分利用激光加速的质子和氘离子的多反应通道优势来提升中子产生概率。实验结果表明,相比于LiF转换体,LiD转换体可带来中子产额2～3倍的提升,达到5.2×10⁸ n/sr的最高中子产额,并具备更好的前冲性。实验还区分了多反应通道的贡献,证明中子产额提升主要来自于p-D反应。     

Lipschitz曲线上Besov-Triebel-Lizorkin空间的嵌入定理

本文用离散的Calderón型再生公式。证明了Lipschitz曲线上Beasov空间与Triebel-Lizorkin空间的嵌入定理。     

Fractional integration associated with second order divergence operators on R~n

The classical Hardy-Littlewood-Sobolev theorems for Riesz potentials (-Δ) -α/2 are extended to the generalised fractional integrals L-α/2 for 0 < α < n, where L =-div A is a uniformly complex elliptic operator with bounded measurable coefficients in Rn.     

Lipschitz曲线上的Besov空间和Triebel-Lizorkin空间(Ⅰ)定义与基本性质

本文把 Caldero'n 表示定理推广到 Lipschitz 曲线上的一类分布,从而在Lipschitz 曲线上定义了 Besov 空间 (?)(Γ)与 Triebel-Lizorkin 空间(?)(Γ),其中 -1<α<1,1≤p,q≤∞.文中还讨论了这些空间的基本性质.     

恒温器径向温度不均匀性对低温温度计精密校验影响的估计

在分析低温温度计的校验误差时,需要估计温度不均匀性的影响.本文提出一个估计这种影响的方法.若使用同一型号的两支电阻温度计进行测试,则径向温度理想均匀的必要条件是两温度计的电阻比不因温度起伏而变化,充分条件是两温度计所处部位之间无同步温差.分析测试数据对这两个条件的偏离,就可以估计出温度不均匀性的影响.文中给出方法应用实例,并对实验条件进行讨论.     

高压液封直拉法生长GaP单晶

利用国产ZFL 018型高压单晶炉和液封直拉(LEC)法生长了掺碲(硫)GaP单晶,其常温电学参数为;nTe,s～(2～15)×1017cm-3;μn～(86～134)cm2/sv;位错密度(1～4)×104cm-2。     

TiO_2/Ag composite nanowires for a recyclable surface enhanced Raman scattering substrate

Multifunctional TiO2/Ag composite nanowires are fabricated with a hydrothermal method by precipitating Ag nanoparticles （NPs） on the surfaces of TiO2 nanowires. This hierarchical one-dimensional （1D） nanostructure can be used as a surface enhanced Raman scattering （SERS） substrate with high sensitivity, for detecting the rhodamine 6G （R6G） in a wide range of low concentrations （from 1 × 10 6 M to 1 × 10-12 M）. In addition, the substrate can be self-cleaned under the irradiation of ultraviolet （UV） light due to the superior photocatalytic capacity of the TiO2/Ag composite nanostructure, making the recycled use of SERS substrates closer to reality. With both the evident SERS performance and high efficiency of photocatalytic capacity, such TiOz/Ag composite nanowires demonstrate considerable potential in the chemical sensing of organic pollutants.     

异戊二烯分子10a′轨道的电子动量谱

首次获得了异戊二烯分子10a′轨道的电子动量谱的实验结果，并与用Hatree-Fock方法和密度泛函理论计算得到的结果作了比较，实验结果和理论结果符合较好。     

Secure Quantum Key Distribution Network with Bell States and Local Unitary Operations

We propose a theoretical scheme for secure quantum key distribution network following the ideas m quantum aense coding. In this scheme, the server of the network provides the service for preparing and measuring the Bell states,and the users encode the states with local unitary operations. For preventing the server from eavesdropping, we design a decoy when the particle is transmitted between the users. The scheme has high capacity as one particle carries two bits of information and its efficiency for qubits approaches 100%. Moreover, it is unnecessary for the users to store the quantum states, which makes this scheme more convenient in applications than others.     

原子吸收光谱法测定钨精矿中的铅

用盐酸、硝酸分解样品,高氯酸冒烟析出钨酸分离钨,在硝酸、高氯酸介质中采用原子吸收光谱仪测定钨精矿中铅,方法简便快速,干扰少,准确度、精密度均好,测定下限可达到0.005%,适用于钨精矿中铅的测定.