摘要：分段线性表示(PLR)技术目前已在多个领域被广泛用于重新表征高维的时间序列数据,以实现数据维度降低、波动过滤和整体趋势提取的目的。然而,该技术目前尚未在高速列车的隧道压力波数据的相关分析处理中得到应用。因此,本研究首次引入PLR技术对典型的高维列车压力波数据序列进行重新表征,并针对高速列车的压力波数据专门设计了一种基于感知重要点(PIP)且性能表现较好的PLR算法。研究结果表明,数据点重要性的度量方法和分段误差评估方法,特别是前者,对压力波序列的PIP的识别优先级甚至最终结果都会产生影响。与欧氏距离(ED)和正交距离(OD)相比,当将垂直距离(VD)作为数据点重要性的度量方法时,PLR_PIP算法(PLR_PIP_VD)获得了更合理的高速列车压力波的PLR结果。通过累积误差、平均误差和最大误差三种分段误差评估方法之间的对比,当将累积误差作为分段误差评估方法时,PLR_PIP_VD算法得到了相对较好的高速列车压力波的PLR结果。提出的适用于高速列车压力波PLR分析的PLR_PIP算法,为高速列车的压力波数据序列的分析处理提供了一种新的方法。

摘要：The multidisciplinary design optimization(MDO)approach is very crucial for the conceptual design of the aircraft,and this is due to the complex interaction between different disciplines, especially for the hypersonic vehicle. In the hypersonic vehicle, the airframe and the engine are highly integrated. In the current survey, the research progress in the MDO approach has been reviewed comprehensively from four primary techniques, namely the design of experiments, the surrogate modeling, the optimization method and the MDO framework, and its application to the aerospace engineering has been summarized from its category as well. The concurrent subspace optimization approach is the most popular method in the aerospace engineering for its easy implementation, and following is the collaborative optimization approach. The multi-level optimization approach has attracted a growing attention due to its high efficiency. In conclusion, some promising research recommendations have been put forward, namely the combination of the low- and high-fidelity optimization approaches, the consideration of the uncertainty analysis and the MDO approach coupled with the data mining techniques.

摘要：In view of the probability dilution problem of the existing quantitative indexes of rendezvous trajectory safety performance using collision probability,this paper proposes a new quantitative index of rendezvous trajectory safety performance by well combining collision probability with warning *** proposed new index increases monotonously as the position errors of the chaser spacecraft increase,therefore it can effectively overcome the problems of the reduction in the largest performance value and the advancement in the most dangerous time induced by the probability *** proposed new index is applied to the safety design of close range rendezvous *** mission’s safety requirements for initial navigation precision and the safe region of initial and final keeping points’positions with a certain navigation precision are analyzed,and several valuable conclusions about the relation between position navigation precision and velocity navigation precision as well as the relation between keeping points’positions and navigation precision are obtained.

摘要：制备低成本的高效电催化剂是缓解目前面临的环境能源危机的重要方式.通过无定型化和构建异质结构可以有效地改变催化剂的电子结构,从而实现电催化性能的稳步提升.但是对于两者之间协同作用的研究则相对较少.在本文中,我们构建了富含异质结构的无定型FeMo基(a-FeMo)电催化剂,并系统评估了该催化剂的氮气还原和析氧反应性能.得益于无定型结构引起的活性位点数目的增多和异质结构引发的电子的重新分布,a-FeMo催化剂表现出优异的电化学催化性能.在-0.1 V ***的电势下,a-FeMo催化剂表现出29.15%的法拉第效率和71.78μg_(NH_(3)) mg_(cat.)^(-1) h^(-1)的氨气产率.这为合理设计具有低成本优势、高活性和长时间稳定性的优异催化剂提供了有益的参考.

摘要：A novel layout has been proposed to reduce the single event upset(SEU) vulnerability of SRAM *** 3-D technology computer-aided design(TCAD) simulation analyses show that the proposed layout can recover the upset-state much easier than conventional layout for larger space of PMOS *** the angle incidence,the proposed layout is immune from ion hit in two plans,and is more robust against SEU in other two plans than the conventional *** ability of anti-SEU is enhanced by at least 33% while the area cost reduced by 47%.Consequently,the layout strategy proposed can gain both reliability and area cost benefit simultaneously.

摘要：由于日益严重的环境和能源危机,可见光催化剂的开发已成为当今最具挑战和紧迫的任务之一.将TiO_2和其它窄禁带半导体复合,已被证明是一种有效的可提高其可见光光催化性能的策略.Cu_2O是一种禁带宽度为2.0 eV的p型窄禁带半导体,InVO_4则是一种禁带宽度为2.0 eV的n型半导体,因它们可用于可见光光解水产氢和有机污染物的可见光降解而在过去的数年中引起了人们广泛的关注.但是纯的Cu_2O和InVO_4由于光生电子空穴对在其内部快速地复合,光催化活性通常都比较低.基于能带工程的策略本文设计了一种新型的可见光响应的InVO_4-Cu_2O-TiO_2三元纳米异质结,并通过普通的湿化学法进行制备:先通过水热法制备InVO_4,再通过溶胶-凝胶法制备InVO_4-TiO_2二元复合物,最后通过沉淀和还原过程制备得到InVO_4-Cu_2O-TiO_2三元纳米异质结.在10%InVO_4-40%Cu_2O-50%TiO_2三元纳米异质结的X-射线衍射谱中没有观察到明显的杂质峰;通过透射电子显微技术和高分辨透射电子显微技术观察到了它们之间异质结的形成,纳米颗粒的尺寸范围在5-20 nm;经紫外可见漫反射光谱估算得到10%InVO_4-40%Cu_2O-50%TiO_2的禁带宽度为2.78 e V,在可见光区域具有较强的吸收.以普通的9 W节能灯作为可见光光源光照甲基橙5 h后,纯的InVO_4,TiO_2和Cu_2O几乎没有光催化活性;10%InVO_4-90%TiO_2的光催化活性也很低,甲基橙降解率为8%;70%Cu_2O-30%TiO_2对甲基橙降解率达84%,但初始活性较低;10%InVO_4-40%Cu_2O-50%TiO_2对甲基橙降解率接近90%,并且循环使用6次后,其光催化活性的保持率还维持在90%以上,而50%Cu_2O-50%TiO_2光催化活性的保持率只有74%.经对使用过的10%InVO_4-40%Cu_2O-50%TiO_2进行X射线光电子能谱表征发现,存在一弱小的Cu(II)震动卫星峰,表明在InVO_4-Cu_2O-TiO_2的光催化过程中Cu_2O的光蚀并不严重.从能带工程的角度分析,InVO_4-Cu_2O-TiO_2三元纳米异质结具有优异的可见光催化性能的主要原因为:InVO_4的导带电极电位约为-0.5 e V(***,下同),价带电位约为+1.5 e V,Cu_2O的分别约为-1.6和+0.4 e V,与TiO_2(导带和价带电极电位分别约为-0.23和+2.97 e V)相比,它们的导带位置更负,将它们组装成三元复合结构,可见光激发的导带电子就可能从InVO_4和Cu_2O的导带迁移到TiO_2的导带上去.同时,n型的TiO_2和InVO_4都与p型的Cu_2O形成p-n异质结,n型的TiO_2和InVO_4之间形成n-n异质结,由于p-n异质结中内电场的存在以及不同能级相互耦合,可进一步促进可见光激发的导带电子从InV O4和Cu_2O的导带迁移到TiO_2的导带上去,以及可见光激发的价带空穴从InVO_4的价带迁移到Cu_2O的价带上去,从而实现光生载流子空间上的有效分离.本文有望为新型可见光响应的半导体复合催化剂的设计和制备提供新的思路.

摘要：目的:针对高超声速飞行过程中机体前缘和进气道之间相互影响的问题,本文从头部进气的角度出发,利用内转式进气道高总压恢复系数和高压缩效率的特性,探索前体与进气道的一体化设计。创新点:1.提出一种内转式轴对称基准流场的构建方法,并设计生成内转式进气道;2.设计内转式乘波前体/进气道一体化构型,并提出将进气道进口型线划分为前体前缘型线(FCC)和进气道唇口型线(LCC)。方法:1.构建内转式轴对称基准流场(图9);2.在基准流场中生成内转式进气道并设计构造进气道外表面(图13);3.通过仿真模拟,验证所提方法及原理的正确性和有效性(图15~20)。结论:1.基于特征线理论,设计并求解内转式乘波前体/进气道轴对称基准流模型(IARFM),同时设计并生成了内转式进气道和外壁面;提出将进气道进口型线划分为前体前缘型线(FCC)和进气道唇口型线(LCC)。2.提出了内转式乘波前体/进气道(ITWF)的一体化设计方法,并通过对无粘数值模拟结果与理论设计值的比较,验证了设计方法的正确性和有效性。3.经过分析可知,激波形状和位置的数值模拟结果与基准流模型吻合较好。这些结果验证了无粘流设计条件下的一体化设计过程的正确性,且该一体化结构具有较高的总压恢复系数和气流捕获效率。

摘要：一(n， n ) 多党的量秘密分享的阀值计划古典或量消息基于分离的量 Fourier 变换被建议。在我们的建议计划，仅当所有参加者在音乐会工作，秘密消息，被使用前面的量 Fourier 变换编码并且由使用颠倒译码，以如此的一个方法被切开并且分享，它能在他们之中被重建。而且，我们也讨论这个协议怎么必须小心地为改正错误或一个不诚实的参加者被设计。安全分析证明我们的计划是安全的。另外，这个计划有它与量计算完全兼容的一个优点并且更容易在分布式的量认识到安全计算。

摘要：As two promising biomaterials for bone implants,biomedical metals have favorable mechanical properties and good machinability but lack of bioactivity;while bioceramics are known for good biocompatibility or even bioactivity but limited by their high ***,a kind of composites composing of bioceramics and biomedical metals,have been developed as an effective solution by combining their complementary *** paper focused on the recently studied biocermets for bone implant ***,biocermets were divided into ceramic-based biocermets and metal-based biocermets according to the phase *** characteristics were systematically summarized,and the fabrication methods for biocermets were reviewed and *** were put on the interactions between bioceramics and biomedical metals,as well as the performance improvement *** importantly,the main methods for the interfacial reinforcing were summarized,and the corresponding interfacial reinforcing mechanisms were *** addition,the in vitro and in vivo biological performances of biocermets were also ***,future research directions were proposed on the advancement in component design,interfacial reinforcing and forming mechanisms for the fabrication of high-performance biocermets.

摘要：Metal organic chemical vapor deposition(MOCVD) is a key equipment in the manufacturing of semiconductor optoelectronic devices and microwave devices in industry. Heating system is a vital part of MOCVD. Specific heating device and thermal control technology are needed for each new reactor design. By using resistance-wire heating MOCVD reaction chamber model, thermal analysis and structure optimization of the reactor were developed from the vertical position and the distance between coils of the resistance-wire heater. It is indicated that, within a certain range, the average temperature of the graphite susceptor varies linearly with the vertical distance of heater to susceptor, and with the changed distances between the coils; furthermore, single resistance-wire heater should be placed loosely in the internal and tightly in the external. The modulate accuracy of the temperature field approximately equals the change of the average temperature corresponding to the change of the coil position.