Economical quantum secure direct communication network with single photons

In this paper a scheme for quantum secure direct communication (QSDC) network is proposed with a sequence of polarized single photons. The single photons are prepared originally in the same state $\vert 0\rangle$ by the servers on the network, which will reduce the difficulty for the legitimate users to check eavesdropping largely. The users code the information on the single photons with two unitary operations which do not change their measuring bases. Some decoy photons, which are produced by operating the sample photons with a Hadamard, are used for preventing a potentially dishonest server from eavesdropping the quantum lines freely. This scheme is an economical one as it is the easiest way for QSDC network communication securely.     

奇异核特性及相关反应研究

论述了晕核,尤其是质子晕核的特性及实验研究．探讨了放射性核引起的转移反应以及晕核的近库仑位垒熔合反应． The properties of halo nuclei, especially proton halo nuclei and their experimental researches have been reviewed. The transfer reactions induced by radioactive beams and near barrier fusion with halo nucleus are discussed.     

晕核及弱束缚核的近垒熔合

阐述了晕核近垒熔合反应研究的意义;叙述了理论上关于晕核破裂与入射道相对运动的耦合使熔合截面增强还是阻禁了晕核熔合两种相反观点的争论,以及晕核熔合反应实验研究的现状;探讨了用弱束缚核代替晕核进行实验研究以求对理论上的争论作出判断的构想．     

稀土核区三轴超形变全同带

系统地考察了稀土核区三轴超形变带的跃迁能量、角动量增量顺排和动力学转动惯量.研究表明这些三轴超形变带为全同带.     

Development of large-area quadrant silicon detector for charged particles

The quadrant silicon detector, a kind of passivated implanted planar silicon detector with quadrant structure on the junction side, gained its wide application in charged particle detection. In this paper, the manufacturing procedure, performance test and results of the quadrant silicon detector developed recently at the China Institute of Atomic Energy are presented. The detector is about 300 μm thick with a 48 mm×48 mm active area. The leakage current under the full depletion bias voltage of -16 V is about 2.5 nA, and the rise time is better than 160 ns. The energy resolution for a 5.157 MeV α-particle is around the level of 1%. Charge sharing effects between the neighboring quads, leading to complicated correlations between two quads, were observed when α particles illuminated on the junction side. It is explained as a result of distortion of the electric field of the inter-quad region. Such an event is only about 0.6% of all events and can be neglected in an actual application.     

16O+152Sm、184W准弹和弹性散射的位垒分布

利用¹⁶O束流轰击稳定形变靶¹⁵²Sm和¹⁸⁴W,在背角测量准弹散射和弹性散射激发函数,分别定出准弹和弹性位垒分布D^qel(E)和D^el(E).将结果与从已有的熔合激发函数、自旋分布及其相邻同位素¹⁵⁴Sm和¹⁸⁴W实验得出的位垒分布进行比较,得到相互自洽的结果,同时也用ECIS79程序作了耦合道理论计算.实验表明,靶的变形效应导致位垒分布是非对称的.     

核ANC的激发态中子晕

利用转移反应^11B(d,p)^12 B和^12C(d,p)^13C 抽取^12B→^11B n和^13C←^12C n重叠函数的核渐归一化常数，计算了^12Ｂ和^13C核中子密度分布的均方根半径及其在核外的几率。实验结果表明，^12B的第二（J^π=2^-），第三（J^π=1^-）激发态和^13C的第一（J^π=1/2^ ）激发态为中子晕态，而^13C的第三（J^ π=5/2^ )激发态是中子皮态。考察了库仑势和角动量对晕形成的阻碍效应.提出了均方根半径对于有效核子分离的统一的标度定律。     

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.     

形变区超重核的合成和衰变研究

理论预言超重核²⁷⁰Hs是形变双幻数核. 利用二参量Smoluchowski方程计算了不同弹靶组合下合成^266—270Hs反应的形成截面, 提出了最佳弹靶组合和轰击能量, 预言了α衰变半衰期.     

垒下熔合裂变中观察到的异常

测量了¹⁶O+²³²Th、²³⁸U和¹⁹F+²³²Th近垒和垒下熔合裂变截面以及碎片角分布.包含靶核静态形变的耦合道理论解释了垒下熔合截面增强,预言了复合核系统自旋分布展宽.而实验上观察到的碎片角分布各向异性明显与裂变统计理论的预言不一致.