摘要：对QCr0.8/TC4进行电子束焊接,研究焊缝中金属间化合物层(即IMC-layer)对接头力学性能的不利影响,提出利用电子束二次叠加焊接方式来改善接头性能的思路。结果表明,对中焊时在铜侧熔合线处形成的金属间化合物层,偏铜侧焊接时在钛侧熔合线处形成的金属间化合物层,是接头中的薄弱环节。利用电子束叠加焊接方式,须合理设计焊接顺序。先进行对中焊,再利用偏铜侧焊接,可将第一道焊缝形成的金属间化合物层破碎重熔,形成组织较好的化合物层,改善接头的力学性能。接头的抗拉强度为276.0MPa,达到了母材强度的76.7%。

摘要：这份报纸对一个调遣的目标考虑多重导弹的同时的攻击问题。与大多数同时的攻击问题在被提出的存在文学不同当导弹 time-to-go 的一个一致问题估计，这份报纸作为导弹 ranges-to-go 的一致问题提出它。基于这策略，新奇分布式的指导法律被建议与未知可操作性的目标解决同时的攻击问题。适应控制方法被介绍估计目标加速的上面的界限。建议指导法律的有效性理论上并且数字地被验证。

摘要：硬磁软材料因其灵活的可编程性、非接触驱动和快速响应等优点,近年来在软体机器人、生物医疗器件和柔性电子等领域引起了广泛关注.这种多功能复合材料通常是由硬磁性粒子嵌入柔性基质构成,能够在外部磁场激励下产生较大的变形.本文提出一种三维柔性杆模型来定量预测细长形硬磁弹性体的空间大变形行为.模型采用基于中心线的基尔霍夫描述,将三维磁-弹性能量函数简化为一维形式.通过使用共旋坐标公式描述刚体运动,并用显式时间积分进行非线性求解,研究了在不同方向和大小的外加磁场作用下,硬磁弹性体的大变形弯曲、后屈曲和扭转行为.代表性算例分析表明该模型与传统的实体单元相比具有更高的效率和精度(只需要少量单元即可保证1%以内误差).研究结果可用于指导硬磁细长柔性结构可编程形貌的理性设计与调控.

摘要：This paper presents a basis for the space of hyperbolic polynomials Γm=span{1, sht, cht, sh2t, ch2t, …, shmt, chmt} on the interval [0,α] from an extended Tchebyshev system, which is analogous to the Bernstein basis for the space of polynomial used as a kind of well-known tool for free-form curves and surfaces in Computer Aided Geometry Design. Then from this basis, we construct quasi Bézier curves and discuss some of their properties. At last, we give an example and extend the range of the pa- rameter variable t to arbitrary close interval [r, s] (r<s).

摘要：基于Deform-3D数值模拟技术和物理模拟技术,对大尺寸粉末冶金TiAl合金坯的热锻过程进行模拟分析,研究锻坯的热力学性能与温度场的相关性,获得应力、应变和温度场的分布规律以及载荷随行程和时间的变化规律等一系列高温塑变特征。在此基础上,设计新型的锻造包覆机构,并进行工程实验验证。结果表明:1150～1200°C是热包覆锻造的最优热加工温度区间,最终获得外观良好的大尺寸钛铝合金锻饼,其直径大于150mm。

摘要：采用改进的固定电导池常数法研究 NaF-AlF3-CaF2-Al2O3-ZrO2熔盐体系的电导率。结果表明， NaF-AlF3-3%Al2O3-3%CaF2-ZrO2熔盐体系的电导率随着ZrO2含量（0~5%）的增加呈降低趋势。每增加1%氧化锆，电导率相应地降低约0.02 S/cm。温度每增加1°C时电导率相应降低约0.004 S/cm。随着NaF与AlF3摩尔比的增加，体系的电导率随之增加。最后采用二次回归正交设计方法，建立分子比相同时电解质的电导率与温度和氧化锆浓度关系的回归方程。

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：The problem of computing a piecewise linear approximation to a surface from its sample has been a focus of research in geometry modeling and graphics due to its widespread applications in computer aided design. In this paper, we give a new algorithm, to be called offset surface filtering (OSF) algorithm, which computes a piecewise-linear approximation of a smooth surface from a finite set of cloud points. The algorithm has two main stages. First, the surface normal on every point is estimated by the least squares best fitting plane method. Second, we construct a restricted Delaunay triangulation, which is a tubular neighborhood of the surface defined by two offset surfaces. The algorithm is simple and robust. We describe an implementation of it and show example outputs.

摘要：本文设计、开发了两种新型高温近共沸混合工质M1和M2。实验研究了不同工况下M1和M2两种工质的性能并进行对比分析。测试结果验证了M1和M2作为新型高温工质的可行性和可靠性。此外,本文还应用支持向量机及BP人工神经网络模型对高温热泵性能进行预测。预测结果表明:对于制热量和输入功率的预测,SVM-RBF、SVM-LF和BP三种模型均具有较高的预测精度,对于性能系数的预测,SVM-RBF模型具有较好的预测精度。最后,本文使用支持向量机模型对M1和M2两种工质的潜力进行评估。评估结果表明,M1的高温热泵在产热温度为130℃时仍具有良好的性能。

摘要：设计了新型Ti44Al6Nb1.0Cr2.0V合金,并采用真空自耗法熔炼制备尺寸为d225 mm×320 mm的合金锭。结果表明,其层片厚度在780~1830μm范围。此合金表现为一种改进的近片层(M-NL)微观结构,主要由(α2+γ)层片结构和较多的(B2+等轴γ)小块状结构组成。合金的室温拉伸性能适中,在选取的12个研究位置中,5#位置其平均性能达到UTS=499 MPa和σ=0.53%。合金表现出明显的脆性断裂特征,其中穿晶穿片层断裂模式较为普遍。室温拉伸实验后,在γ相中可以观察到<101]和1/2<112]超位错。大量Nb、Cr、V等元素的加入造成了合金较低的堆垛层错能,这对合金塑性的提升是有益的,但铸造微裂纹导致了合金提早断裂,对性能造成很大影响。