摘要：电磁波在无线通信等领域的广泛应用导致了严重的电磁污染,迫切需要研发高性能电磁波吸收材料.本文针对吸波材料阻抗不匹配等关键问题,设计并成功制备了新型核壳LaOCl/LaFeO_(3)纳米纤维电磁波吸收剂.这种独特的一维多级结构由导电LaFeO_(3)磁性壳层和离子化合物LaOCl核层组成.基于介电-磁损耗耦合和阻抗匹配的协同作用,LaOCl/LaFeO_(3)纳米纤维在超低负载条件下(4 w t%),表现出-40.1 d B(2.0 mm)的反射损耗和6.4 GHz(2.4 mm)的有效吸收带宽.该工作提出了一种新型LaOCl/LaFeO_(3)纳米纤维吸波材料,并为阻抗匹配调控和电磁吸波性能优化开辟了新策略.

摘要：热防护系统设计需要高空间分辨率的热流密度场测 量 方法来获取热流密度峰值及其对应的空间位 置 然而, 燃烧产生的背景 辐射严重阻碍了现有热流密度场测 量 方法的应用. 为了解决该难题, 提出了一种适用于强辐射燃烧环境的热流密度场测 量 方法, 基本 思想是利用温敏漆测 量 燃烧室外壁面温度的变化历程结合三维瞬态热传导反问题的求解确定内壁面热流密度场分布. 文中详细介绍 了测量系统构成、 数据处理方法及温敏漆涂层厚度对测 量 结果的影响, 最后给出了数值和实验结果验证了该方法的可行性.

摘要：A high-performance, low cost inverse integer transform architecture for advanced video standard (AVS) video coding standard was presented. An 8×8 inverse integer transform is required in AVS video system which is compute-intensive. A hardware transform is inevitable to compute the transform for the real-time application. Compared with the 4×4 transform for H.264/AVC, the 8×8 integer transform is much more complex and the coefficient in the inverse transform matrix T8 is not inerratic as that in H.264/AVC. Dividing the T8 into matrix S8 and R8, the proposed architecture is implemented with the adders and the specific CSA-trees instead of multipliers, which are area and time consuming. The architecture obtains the data processing rate up to 8 pixels per-cycle at a low cost of area. Synthesized to TSMC 0.18μm COMS process, the architecture attains the operating frequency of 300 MHz at cost of 34 252 gates with a 2-stage pipeline scheme. A reusable scheme is also introduced for the area optimization, which results in the operating frequency of 143 MHz at cost of only 19 758 gates.

摘要：水系金属空气电池具有理论能量密度高、安全性高等优点,但受限于金属阳极(如锌、铁、铝、镁)的电化学不可逆性以及碱性电解质对大气中二氧化碳的化学不稳定性.本工作首次设计了一种可充电的铋-空气电池,该电池使用了非碱性的三氟甲磺酸铋(Bi(OTf)_(3))水系电解质.得益于三电子反应和相对于标准氢电极+0.32 V的高电位,铋金属负极具有383 mA h g^(−1)的高比容量和1000次循环的良好稳定性,以及99.6%高库仑效率.铋金属负极在Bi(OTf)_(3)电解液中无腐蚀、钝化和析氢等副反应.此外,非碱性的铋-空气电池通过三氧化二铋(Bi_(2)O_(3))的可逆形成/分解,在环境空气中实现了长期运行稳定性(>200 h).这项工作为探索新型水系金属空气电池作为安全稳定的电源系统提供了新思路.

摘要：表面聚合物涂层作为保护层广泛应用于表面防腐、防渗透和抗冲击等各种领域,如何在已有材料体系和工艺条件下提高涂层机械力学性能,是一个重要但具有挑战性的问题.受自下而上的制造工艺和生物体的层级结构的能量耗散机制的启发,本文开发了一种具有自褶皱表面形态和梯度交联结构的光固化涂层.理论模拟和实验结果表明,表面自褶皱的独特形貌和体系内梯度交联结构有助于提升涂层的力学性能及抗冲击性.这种光固化自褶皱涂层为设计功能抗冲击聚合物涂层材料开辟了新的途径.

摘要：基于有机共轭聚合物的电致变色器件(ECD)在数字和彩色显示器中具有广阔的应用前景.然而,制备兼具优异电致变色性能、柔韧性和定制化图案的ECD仍然是一个挑战.本文报道了利用喷墨打印技术制备二维层状聚苯胺(PANI)基柔性图案化ECD的方法.层状PANI均匀分散在甲酸中,能够实现高精度、稳定的喷墨打印.同时,层状PANI的纳米级厚度、适当的掺杂比例,以及无添加剂的墨水成分,使得打印后的PANI电极和器件保持较高的电致变色性能和电化学特性.喷墨打印所得电极不仅表现出优异的光学对比度(76%,750 nm波长)、良好的着色效率(259.1 cm^(2)C^(-1))、较短的着色/褪色时间(1.8/2.4 s),而且具有赝电容特性与机械柔韧性.此外,本文所开发的二维层状PANI墨水可以定制化设计并打印成各种图案,并以此制备电化学控制的可寻址电致变色显示器.这种二维层状PANI电致变色材料可进一步用于柔性和图案化ECD,在新型光电显示领域具有较好的应用前景.

摘要：实体识别消歧是知识库扩充和信息抽取的重要技术之一。近些年该领域诞生了很多研究成果,提出了许多实体识别消歧系统。但由于缺乏对这些系统的完善评测对比,该领域依然处于良莠淆杂的状态。因此很有必要设计一个评测框架对各个系统进行统一评测。本文提出一个实体识别消歧系统的统一评测框架,用于公平地比较各个实体识别消歧系统的效果。该框架代码开源,可以采用新的系统、数据集、评测机制扩展。通过该框架评测实体系统,可以分析得到系统各个模块的优劣之处。本文分析对比了几个公开的实体识别消歧系统,并总结出了一些有用的结论。

摘要：锂硫电池固有的缓慢转化动力学和严重的穿梭效应导致其可逆容量和循环寿命差,严重阻碍了其实际应用.为了解决这些问题,我们设计并构建了一种Ni/Ni_(2)P异质结嵌入介孔碳纳米球的复合材料(Ni/Ni_(2)P-MCN),将其用于锂硫电池隔膜改性以促进多硫化物的催化转化.研究发现,Ni/Ni_(2)P-MCN改性隔膜可以通过丰富的异质结化学吸附位点吸附多硫化物、抑制穿梭效应,而且对多硫化物的转化具有优异的催化活性.此外,具有暴露介孔结构的导电碳球可以作为物理屏障,容纳沉积的不溶性Li_(2)S.因此,使用Ni/Ni_(2)P-MCN改性隔膜的电池显示出优异的倍率性能(5 C下431 mA h g^(-1))和循环稳定性(1500次循环下平均容量衰减约0.031%).在4.2 mg cm^(-2)的高载硫下,输出面积比容量约3.5 mA h cm^(-2).我们认为,这种独特的Ni/Ni_(2)P异质结/多孔碳复合材料在高性能、可持续储能器件中具备巨大的应用潜力.

摘要：Decentralized and unstructured peer-to-peer applications such as Gnutella are attractive because they require no centralized directories and no precise control over network topology or data placement. Search algorithm is the major component of the distributed system and its efficiency also does influence the systems performance. However the flooding-based query algorithm used in Gnutella produces huge traffic and does not scale well. Gnutella-like P2P topology has power-law characteristic, so a search algorithm was proposed based on high degree nodes of power-law network, High Degree Nodes-Based Search (HDNBS). Extensive simulation results show that this algorithm performs on power-law networks very well, achieves almost 100% success rates, produces O(logN) messages per query and can locate target file within O(logN) hops.

摘要：The conceptual design of mechatronic systems is addressed under the thrust of concurrent engineering and an enhanced conceptual design methodology describing the early design stage of mechatronic systems is presented through an example illustration of a pick and place *** methodology treats each feasible solution as a solution *** the methodology,Quality Function Deployment(QFD)is used as a baseline for the analysis of the mapping from customers to engineering requirements,Axiomatic Design(AD)is adopted as a guideline to generate feasible,good design solution alternatives,and Theory of Inventive Problem Solving(TRIZ)is applied to deal with domain conflicts in design.