摘要：Electronic absorption bands of conjugated linear carbon chain molecules, namely polyynes H(C≡C)nH (n=5-7), are exploited to devise light-polarizing films applicable to the UV. Laser ablated polyynes are separated in size and dispersed in a film of polyvinyl alcohol (PVA), which is stretched to align the trapped linear polyyne molecules inside. As a nature of the structural anisotropy, transition dipole of the UV absorption for polyyne molecules is in parallel with the molecular axis and the absorption occurs only for the electromagnetic wave having the amplitude of its electric vector along the molecular axis. Aligned and fixed orientationally in the solid PVA film, polyyne molecules act as selective absorbers of one of the polarization components of incident light at particular wavelength. Using a light source of linearly polarized UV light, whose direction of polarization is rotatable, angular dependence of the absorption intensity is investigated for the stretched PVA film containing aligned polyyne molecules and analyzed in terms of an order parameter in the theory of linear dichroism.

摘要：锌表面自然形成的非均匀氧化层(ZnO)会与电解液发生反应形成Zn_(4)(OH)_(6)SO_(4)·xH_(2)O(ZSH)副产物,导致锌负极表面非均匀沉积,从而阻碍水性锌离子电池实际应用.为了排除氧化层分布形式的影响,本文利用表面终止化学设计策略在锌负极表面制备了一层完全氧化的ZnO层,研究发现锌负极均匀分布的ZnO层会原位演化形成致密的ZSH功能层.均匀且致密的ZSH能够有效隔绝电解液的腐蚀,从而有效提高锌负极界面的稳定性.此外,ZSH(002)晶面边缘的不饱和悬空键(如-O)更容易和Zn(H_(2)O)_(6)^(2+)结构中的锌离子形成强Zn-O键,可以促进Zn(H_(2)O)_(6)^(2+)的脱溶剂化和锌离子沿边扩散,实现了高度可逆的锌沉积行为并限制了副反应.基于此,本文提出与“表面脱水-晶体通道转移”机制明显不同的“边缘脱水-沿边缘转移”锌离子输运新机制.更重要的是,基于此组装的全电池显示出高循环稳定性(超过1000次循环)和高库仑效率(99.07%),验证了其潜在的实际应用价值.

摘要：增材制造作为一种先进成形方法备受关注,然而,增材制造过程的开发通常需要进行高成本且费时的试错实验,这大大限制了增材制造技术的发展。机器学习作为一种新型人工智能技术,可以加快增材制造各环节的研发进程,因而受到了学术界和工业界的广泛关注。本文综述了基于机器学习的增材制造过程优化和新型金属材料研发进展。首先,对应用于增材制造中的机器学习技术进行了简述;其次,对机器学习在金属材料增材制造过程控制与优化中的应用展开论述,包括成形过程监测与质量控制、工艺窗口预测和沉积路径优化等;然后,介绍了机器学习在基于增材制造研发新型合金材料的研究与应用现状,包括合金成分设计和组织性能预测等;最后,总结并展望了机器学习在该领域未来的发展趋势。

摘要：TLS(transport layer security)协议的基本设计目标是为两个通信实体之间提供数据的保密性和完整性.由于在传输层安全握手协议中最耗费计算资源的步骤是服务器RSA解密运算,优化的批处理的RSA方法提出可以用于加速 TLS 会话的初始化.首先指出了以前的批处理方法由于要求多证书实现而实用性不强.然后提出了单一证书策略的方法,从而克服了这一问题.还提出结合用户对于因特网服务质量的要求优化了批处理参数.为了选择优化的批处理的参数,不仅考虑了服务器的性能,而且还考虑了客户可容忍的等待时间.通过分析并在阐述平均排队时间、批处理服务时间和系统稳定性的基础上提出了一种新颖的优化批处理调度算法,已部署在服务器上.最后通过分析和模拟两种方法验证了所提出方案的实用性和有效性.

摘要：Custom-made esthetic finger prostheses, which are used for rehabilitation of patients with missing or impaired fingers, have been fabricated manually. However, such fabrication is time-consuming and requires manual skill. Here we propose a computer-aided method for fabricating finger pros-theses to save time and allow fabrications that do not require considerable manual skill. In this method, the dimensions of a patient’s healthy finger on the contralateral hand are first measured using a caliper. Using these dimensions, a three-dimensional model is constructed for fabricating a prosthesis for the patient’s impaired finger. Using the 3D model, a mold is designed using 3D modeling tools and a computer-aided design system. The resulting mold is then fabricated using a 3D printer. A finger prosthesis is fabricated by pouring silicone resin into the mold. A finger prosthesis for a volunteer was experimentally fabricated according to the proposed method. To evaluate the size and shape of the finger prosthesis, the difference between the finger prosthesis and the original finger of the volunteer was analyzed. Because the average difference between them was 0.25 mm, it was concluded that the proposed method could be used to fabricate a finger prosthesis of adequate size and shape.

摘要：目的 探讨糖尿病与非糖尿病成人致死性冠心病的患病趋势。设计 队列研究。地点 Nord-Trondelag健康研究（HUNT）的两次调查，以挪威人群为基础的研究。参试者 参加第一次（1984—1986）和第二次（1995—1997）调查的人员分别有74914和64829名，包括男性和女性。主要结局评估指标 9年连续随访期间，两次糖尿病与非糖尿病成人的年龄关联冠心病死亡率。结果 共计2623名男性和1583名女性死于冠心病。最近随访期中的死亡率显著降低：70～79岁非糖尿病组中，每1000人年死亡男性从16．38下降到8．79（减少48％，95％可信区间为39％～55％），女性从6．84下降到2．68（减少62％，52％～70％）。而同年龄组糖尿病患者中，每1000人年死亡男性从38．97下降到17．89（减少54％，32％～69％），女性从28．15下降到11．83（减少59％，37％～73％）。在基线年龄小于70岁组中减少更为显著，而在80岁及以上组中减少则较小。糖尿病患者其冠心病死亡率比非糖尿病者高2倍多，女性更为显著。在两次调查中，糖尿病状态导致的死亡率基本无差异。结论 从第一次到第二次调查中，冠心病死亡率的普遍明显降低对糖尿病患者有益；但糖尿病相关的冠心病死亡率较一般人群高2倍多这一事实并没有随着时间的推移而改变。