摘要：The strict avalanche criterion(SAC)is one of the most important cryptographic criteria for substitution boxes(S-boxes)used in many symmetric encryption ***,there are few constructive methods for S-boxes fulfilling the SAC until *** this paper,to construct S-boxes satisfying the SAC directly,we generalize the concatenation techniques of Boolean functions to *** the idea of concatenating small variable S-boxes,we present a simple yet effective construction method of S-boxes satisfying the ***,a simple example on how to construct SAC S-boxes with large input variables by small variables SAC S-boxes is given.

摘要：The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can obtain low friction and good wear resistance with evolving surface morphology. By analyzing the mechanism of the surface of a dung beetle for reducing soil wear and adherence, we design a cemented carbide drill bit with a bionic surface, which is expected to have superior anti-wearing and anti-sticking properties for drilling the soft coal seam. Inspired from the characteristics of the head and pronotum surface of the dung beetle, optimized non-smooth surface of the drill bit was constructed. The working performance of this innovative drill was experimentally tested. With comparative experiments under the identical drilling conditions, the wear rates, drilling times of conventional drills and bionic drills were measured. Compared with the conventional counterpart, the drill designed exhibits better performance in reducing wear and sticking drilling-breaks, therefore achieving higher levels of efficiency. The diameter of the dome and pit on the bit surface is in the range of 0.8–1.2 mm, and the bionic drill bits could get better performance with preferable drilling speeds and wear rates.

摘要：The paper studies the problem of fault detection filter design for uncertain linear continuous-time systems. A design procedure dealing with parameter uncertainties is proposed for residual generation, the sensitivity to fault and the robustness against disturbances are both enhanced on residual outputs through satisfying some performance indexes. By the aid of the generalized Kalman-Yakubovich-Popov(GKYP)lemma, the fault sensitivity performance index can be dealt with in the given frequency range directly, which avoids approximations associated with frequency weights of the existing techniques. An iterative algorithm based on linear matrix inequality(LMI)is given to obtain the solutions. A numerical example is given to illustrate the effectiveness of the proposed methods

摘要：Cardiovascular diseases are the leading cause of morbidity and mortality throughout the world underlining the importance of efficient treatments including disease modeling and drug discovery by cardiac tissue ***,the predictive power of these applications is currently limited by the immature state of the ***,we developed gelatin hydrogels chemically crosslinked by genipin,a biocompatible crosslinker,as cell culture *** rat cardiomyocytes appear synchronous beatingwithin 2 days after seeding on ***,we applied the electrical stimulation as a conditioning treatment to promote the maturation of cardiomyocytes cultured on the *** results show that electrical stimulation improves the organization of sarcomeres,establishment of gap junctions,calcium-handling capacity and propagation of pacing signals,thereby,increase the beating velocity of cardiomyocytes and responsiveness to external *** above system can be applied in promoting physiological function maturation of engineered cardiac tissues,exhibiting promising applications in cardiac tissue engineering and drug screening.

摘要：电离层频率调制导致地表面杂波的多谱勒展宽,极大地限制了高频天波雷达的目标探测性能。本文针对这种电离层频率调制,给出了一种级联的两步校正处理的方法。在第一步校正中,首先分析这种时变信号的时频分布,并设计了一种谱峰追踪方法从时频分布中获得粗糙的电离层频率调制估计。然后采用基于分段多项式相位模型的参数化方法作二次校正处理,消除残余调制污染。模拟结果表明,即使对Bragg峰发生混叠的重污染的情形,这种级联的校正方法都具有非常好的效果。

摘要：Lithium-sulfur(Li-S)batteries are promising next-generation high energy density batteries but their practical application is hindered by several key problems,such as the intermediate polysulfide shuttling and the electrode degradation caused by the sulfur volume *** acts as one of the most essential components to build the electrodes of Li-S batteries,playing vital roles in improving the performance and maintaining the integrity of the cathode structure during cycling,especially those with high sulfur *** date,tremendous efforts have been devoted to improving the properties of binders,in terms of the viscosity,elasticity,stability,toughness and conductivity,by optimizing the composition and structure of polymer ***,the binder modification endows them strong polysulfide trapping ability to suppress the shuttling and decreases the swelling to maintain the porous structure of *** this review,we summarize the recent progress on the binders for Li-S batteries and discuss the various routes,including the binder combination use,functionalization,in-situ polymerization and ion cross-linking,etc.,to enhance their performance in stabilizing the cathode,building the high sulfur loading electrode and improving the cyclic *** last,the design principles and the problems in further applications are also highlighted.

摘要：本文提出了一种考虑几何非线性的三维连续体结构显式拓扑优化方法.采用移动可变形孔洞(MMV)方法描述结构,具有设计变量少、可与CAD系统无缝集成的优点.此外,由于结构拓扑描述模型与有限元分析模型之间解耦,在有限元分析中可以直接删除孔洞区域的冗余自由度,从根本上解决有限变形拓扑优化因弱单元引起的收敛性问题,同时显著提高了有限元分析的计算效率.数值算例验证了该方法的有效性,结果表明:(1)无论单工况还是多工况载荷作用下,几何非线性对三维结构的最优拓扑构型均具有显著影响;(2)优化后的几何非线性结构可以充分利用大位移和小应变来降低结构柔顺度;(3)几何非线性拓扑优化应评估优化设计的临界失稳荷载,以保证结构服役的安全性.

摘要：为了结合等通道转角和分流挤压技术生产板材,研究了一种等通道转角分流（P-ECAP）挤压新技术.通过有限元方法研究了用于高速列车的6005A铝合金板材的挤压.在传统分流模具的分流通道内设计了等通道转角工艺.预测了不同通道转角对P-ECAP工艺挤出板材的废料长度变化的影响;研究了通道转角和挤压速度对最大工件温度和其他场变量的影响.结果表明：板材在通道转角为160＆#176;时具有最好的尺寸精度,而且废料的尺寸也最小;较为合理的挤压速度为3～5 mm/s.另外,当挤压速度从1mm/s增加到9mm/s时,挤压力的峰值上升了49％,工件的最高温度升高了70℃.在通道内的转角变形区,等效应变有上升趋势;挤出板材的焊合区和模具边缘最大主应力为张应力.

摘要：浮式平台概念的选择及其结构设计是深水工程项目的关键环节之一.它决定了平台在波浪载荷作用下的动力学响应、立管在深水条件下的运动以及进行平台建造与安装的技术难度等.结构强度、结构的抗疲劳性能以及结构的整体和局部稳定性能是浮式平台设计必须重点考虑的三个主要方面.总结了当前浮式平台设计的主要方法和它的主要任务以及技术要求,着重分析了设计过程中的主要技术难点及重点;最后,讨论了浮式平台结构设计的潜在发展趋势.

摘要：板料/模具间的摩擦润滑条件是影响薄壁钛合金产品成形质量、成形极限和模具寿命的关键因素。利用压缩扭转摩擦方法,结合正交试验设计,改变模具材料、润滑状态、温度和压力等参数,研究热成形CP-3钛板和模具间摩擦因素的变化规律及作用机理。结果表明:影响CP-3板料温成形摩擦因数显著因素为润滑剂、模具粗糙度、模具材料、转速、压力和温度;相对于干摩擦,石墨和Mo S2干膜润滑剂对板料/模具间摩擦的改善效果均很明显,摩擦因数最大降低了0.318;不同参数下Cr12Mo V/CP-3和铝青铜(QA110-3-1.5)/CP-3摩擦因数的变化趋势基本相同,即随模具表面粗糙度和转速的增大而增大,随温度和压力的增加先增大然后减小。