PRODUCT GENE REPRESENTATION AND ACQUISITION METHOD BASED ON POPULATION OF PRODUCT CASES

The representation and acquisition of a product gene is a crucial problem in product evolutionary design. A new methodology of product gene representation and acquisition from a population of product cases is proposed, and the methodology for product evolutionary design based on a population of product cases is realized. By properly classifying product cases according to its product species, the populations of product cases are divided and a model is established. Knowledge of the scheme design is extracted and formulated as the function base, principle base, and structure base, which are then combined to form a product gene. Subsequently, the product gene tree is created and represented by object-oriented method. Then combining this method with the evolutionary reasoning technology, an intelligent and automatic evolutionary scheme design of product based on the population of product cases is realized. This design method will be helpful in the processing of knowledge formulation, accumulation, and reuse, and in addressing the difficulty of acquiring design knowledge in traditional design. In addition, the disadvantages of manual case adaptation and update in case-based reasoning can be eliminated. Moreover, by optimizing the design scheme in multiple levels and aspects of product function, principle, and structure etc., the level of creativity in the scheme design can be improved.     

单模光子增加双模压缩真空态的量子特性

将一模产生算符作用在双模压缩真空态上,构建 了单模光子增加双模压缩真空态。 研究了该量子态另一模的压缩效应、反聚束效应、统计分布和Wigner函数。采用数值计算 方法,讨论了产生算符作用次数和双模压缩参数对其量子特性的影响。研究结果表明:b模 光场没有呈现压缩效应;随产生算符作用次数的增大,b模的反聚束效应减弱,但其亚泊 松分布性质增强;随双模压缩参数的增大,b模的反聚束效应和亚泊松分布性质都减弱。另 一方面,随产生算符作用次数增大,Wigner函数的负性减弱。     

Photoinduced Plasticity in Cross‐Linked Liquid Crystalline Networks

Photoactivated reversible addition fragmentation chain transfer (RAFT)‐based dynamic covalent chemistry is incorporated into liquid crystalline networks (LCNs) to facilitate spatiotemporal control of alignment, domain structure, and birefringence. The RAFT‐based bond exchange process, which leads to stress relaxation, is used in a variety of conditions, to enable the LCN to achieve a near‐equilibrium structure and orientation upon irradiation. Once formed, and in the absence of subsequent triggering of the RAFT process, the (dis)order in the LCN and its associated birefringence are evidenced at all temperatures. Using this approach, the birefringence, including the formation of spatially patterned birefringent elements and surface‐active topographical features, is selectively tuned by adjusting the light dose, temperature, and cross‐linking density.     

Effect of tin addition on corrosion behavior of a low-alloy steel in simulated costal-industrial atmosphere

The effect of tin addition on the atmospheric corrosion behavior of a low-alloy steel in simulated coastal-industrial atmosphere has been investigated by indoor wet/dry cyclic corrosion test (CCT). The results indicate that tin addition can obviously make the steel substrate more resistant to atmospheric corrosion by suppressing the cathodic H⁺ reduction reaction, and but tin addition is not of obvious beneficial effect when the steel is covered with a thicker rust layer during long-term corrosion process. The reason lies in the fact that the presence of un-reduced H⁺ can lower the electrolyte pH value and lead to a loose and porous rust layer on tin-containing steel sample than that on tin-free steel sample. In addition, the 120 CCT cycles corrosion process of the two steels can be divided into three stages. Both the tin-free and tin-containing steels show an increasing corrosion rate during the initial corrosion stage and then exhibit a decreasing corrosion rate during the second and third corrosion stages. Moreover, tin addition makes the tin-containing steel rust layer have a higher amount of α-FeOOH and lower amount of γ-FeOOH and Fe₃O₄ than the tin-free steel rust layer.     

Microstructure and soft-magnetic properties of FeCoPCCu nanocrystalline alloys

Fe_83.2-xCo_xP₁₀C₆Cu_0.8 (x = 0, 4, 6, 8 and 10) alloys with a high amorphous-forming ability and good soft-magnetic properties were successfully synthesized. Saturation magnetic flux density (B_s) is effectively enhanced from 1.53 T to 1.61 T for as-quenched alloy by minor Co addition, which is consistent well with the result of the linear relationship between average magnetic moment and magnetic valence. For Co-contained alloys, the value of corecivity (H_c) is mainly determined by magneto-crystalline anisotropy, while effective permeability (μ_e) is dominated by grain size and average saturation polarization. After proper heat treatment, the Fe_79.2Co₄P₁₀C₆Cu_0.8 nanocrystalline alloy exhibited excellent soft-magnetic properties including a high B_s of 1.8 T, a low H_c of 6.6 A/m and a high μ_e of 15,510, which is closely related to the high volume fraction of α-(Fe, Co) grains and refined uniform nanocrystalline microstructure.     

Distinct beneficial effect of Sn on the corrosion resistance of Cr-Mo low alloy steel

In this work,the beneficial effect of Sn addition on the corrosion resistance mechanism of Cr-Mo low alloy steel was studied.Results demonstrated that Sn improves the corrosion resistance of the steel matrix mainly by influencing the microstructural transformation.Sn addition and the synergistic effect of Sn,Cr,and Mo promote the formation of α-FeOOH,SnO2,SnO,Cr(OH)3,and molybdates,lead to the improved protection and stability of the rust layer.This synergistic effect also endows the inner rust layer with cation selectivity,preventing the further penetration of Cl-and inhibiting the localized corrosion of steel.     

素数域椭圆曲线密码系统算法实现研究

针对素数域椭圆曲线密码系统的算法高速实现，分别讨论了对椭圆曲线上的点的加法和倍点运算。以及对点的标量乘法运算进行优化的技术，同时给出了测试比较结果，说明了所讨论的优化技术可以大大提高整个椭圆曲线密码系统的算法实现性能。     

影响烧结Nd-Fe-B磁体退磁曲线方形度的因素

通过分析具有不同退磁曲线方形度的磁体发现，烧结体的显微组织对磁体的方形度有很大影响，磁体中晶粒的异常长大会严重恶化磁体的方形度，晶粒的形状及晶界相等影响到退磁场的大小，进而影响到磁体的方形度，添加元素影响到磁体中的相结构和相分布，对反磁化场的均匀性有所影响。     

Symmetry Measure Computation for Convex Polyhedra

The paper discusses measures and indices of different kind of symmetry (central, reflection, rotation, mirror rotation) for 3D convex shapes. The measures are based on Minkowski addition and inequalities for volume and mixed volume and are valid for convex shapes only. Symmetry index computation in 3D case is a complicated optimization problem. Taking advantage of convex polyhedra we investigate the situations when these indices can be computed efficiently.