Security of the traditional quantum key distribution protocols with finite-key lengths

Quantum key distribution(QKD) in principle can provide unconditional secure communication between distant parts.However, when finite-key length is taken into account, the security can only be ensured within certain security level. In this paper, we adopt the Chernoff bound analysis method to deal with finite-key-size effects, carrying out corresponding investigations on the relationship between the key generation rate and security parameters for different protocols, including BB84,measurement-de...     

一个修正HS共轭梯度法及其收敛性

It is well-known that the direction generated by Hestenes-Stiefel (HS) conjugate gradient method may not be a descent direction for the objective function. In this paper, we take a little modification to the HS method, then the generated direction always satisfies the sufficient descent condition. An advantage of the modified Hestenes-Stiefel (MHS) method is that the scalar βkH Sffikeeps nonnegative under the weak Wolfe-Powell line search. The global convergence result of the MHS method is established under some mild conditions. Preliminary numerical results show that the MHS method is a little more efficient than PRP and HS methods.     

氯化钙/三赞胶微胶囊的制备及其对核黄素的控制释放

为实现核黄素在肠道中的可控释放，本研究利用三赞胶的pH响应性，使用滴球法制备三赞胶水凝胶微胶囊，以核黄素为负载药物，氯化钙为调控因子，研究了微胶囊的物性与释放特性。结果表明：0.3%三赞胶在0.06 mol/L盐酸固定液中可以形成稳定的凝胶结构，添加氯化钙后微胶囊的硬度增加但弹性降低。氯化钙添加量由0逐渐增加至10%,三赞胶微胶囊在十二指肠中的释放率无显著变化，空肠释放率由42.5%逐渐降低至24.1%,在氯化钙添加量2%及以上时可在回肠释放，且释放率由21.6%逐渐降低至14.9%。粘度特性与SEM图像分析表明，添加氯化钙提高三赞胶溶液的粘度，降低微胶囊的孔隙度是控制核黄素释放的主要原因。本研究通过调整三赞胶微胶囊中的氯化钙添加量，实现了核黄素在肠道中的可控释放，表明可控释三赞胶微胶囊在口服递送领域具有广阔的应用前景。