摘要：分析了生物质致密成型单孔试验装置的受力状况,推导了成型模具内壁法向应力与外壁周向应变的关系式。结合有限元法对成型过程进行了数值模拟,以木屑为对象分析了压制速度和含水率对模孔内壁法向应力的影响,并进行了试验验证。结果表明,压缩速度和含水率都对模孔受力影响显著,压缩速度为80mm/min,含水率为10%时,模孔内壁法向应力最小。通过测量模具外壁周向应变来获得对应内壁法向应力这一方法是可行的,增大压缩速度、减小含水率均能使模孔内压减小。提出的方法对研究成型过程中物料与模具的接触、模具的应力场分布有重要价值。

摘要：Four types of seismic design details were tested using 11 transfer column specimens and one comparison specimen of RC under low cyclic reversed loading. Test results show that diagonal cracks control the failure pattern and damage occurs mainly in the RC section with weak shear capacity in the transfer columns. There is a large difference in the bearing capacity and ductility of the transfer columns according to the test results, which indicates that the strengthening effect of diverse structural measures is quite different. The section ratio of I-section-encased steel and the axial compression ratio also have a great influence on the bearing capacity and ductility. Although the bearing capacity of transfer columns with additional longitudinal bars and additional X bars is relatively large, they have poor deformation capacity. Setting more stirrups along the columns is the best structural measure to enhance the seismic performance. The studs on the I-sectionencased steel by welding can help to complete the stress transfer between the steel and concrete, and avoid performance degradation of the two materials due to bonding failure.

摘要：现有单侧六自由度、七自由度的双臂机器人的冗余自由度过多,致使制造成本高昂、控制复杂,难以实现批量生产应用。文章设计了一款单侧五自由度的双臂协作机器人,首先构建机械臂结构,并基于D-H参数法建立数学模型,完成了正逆运动学分析,然后运用MATLAB与蒙特卡洛法进行工作空间分析,发现机器人工作空间广、适应性强,且参数合理,最后利用Adams进行仿真验证实验,证实了双臂协作的可能性与结构设计的合理性。

摘要：The studies of British Marxism can be divided into two periods: the upsurge period (1980s-1990s) and thedeepening development period (the beginning of 21st century to now). The studies mainly feature expansions ofresearch scopes, disputes in its definition and boundaries, and transformations from case studies to comprehensiveresearch. There are reasons to expect its future prosperity, if research work can fulfill the following three tasks:strengthening basic studies with literature collections and material analyses, changing logical perspectives byadhering to a holistically structured system, and with an orientation to the practical issues in China, conductingBritish Marxism studies under the context of the socialism with Chinese characteristics.

摘要：针对超磁致伸缩致动器(Giant Magnetostrictive Actuator,GMA)动力学中存在混沌现象,降低系统输出稳定性的问题,这里设计了一种位移时滞反馈控制器用于抑制系统中存在的混沌运动。首先基于安培电路定律、非线性二次畴转模型和结构动力学方程,建立了GMA的电-磁耦合动态数学模型;其次通过MATLAB数值模拟研究无量纲激振力对GMA系统的影响规律,从定性和定量的角度分析GMA系统的分岔和混沌现象;最后利用位移时滞反馈控制器抑制GMA系统的混沌运动。研究结果表明:GAM系统在一定参数条件下具有混沌特性;增大位移反馈增益系数能够有效消除GMA系统中的混沌现象,对提高系统的输出稳定性具有一定的指导作用。

摘要：研究了抗分散剂掺量对硫铝酸盐水泥砂浆性能的影响。结果表明:随着抗分散剂掺量的增加,水泥浆体的流动性降低,凝结时间缩短,剪切应力与塑性黏度增加,但增幅降低;当抗分散剂掺量为2.0%时,砂浆的水样悬浊物含量、浊度、pH值显著降低,抗分散性能提高;加入抗分散剂后,砂浆的水陆强度比超过70%;抗分散剂的掺入提高了水泥浆体的累计放热量,提高了水泥的水化程度,且对水泥的水化产物组成没有影响;综合来看,当抗分散剂掺量为2.0%时,砂浆的综合性能最佳。

摘要：　　每周我们只有3个小时的字体设计课,但课上我们几乎不再工作了.那时老师会一对一地来看我们的作品.……

摘要：通过分析基于加权最小均方误差准则的全通型分数延时滤波器(APFDF)的设计和求解,针对目前APFDF迭代求解在收敛性和数值稳定性方面存在的问题,提出基于改进遗传算法的APFDF求解方法.通过精英策略,保证遗传算法的收敛.采用混合遗传算子,在加快遗传算法向全局最优解收敛的同时,防止其在最优解附近徘徊.仿真结果表明,新设计的APFDF具有低阶数和高精度的特点,将其应用于宽带数字波数形成,孔径渡越问题得以解决,形成波束几乎完全逼近理想波束.

摘要：设计了一种可用于加密的块结构低密度生成矩阵Block-LDGM码.该码的生成矩阵由一组交织子矩阵组成,且这些交织子矩阵可以用二次交织多项式来描述.以这些二次交织多项式的系数作为密钥,可实现对交织子矩阵的随机化,从而实现对Block-LDGM码的加密.基于三分图,提出多边缘置信度传播算法和滤波衰减消解方法,实现基于Block-LDGM码的低复杂度信息压缩编码.仿真结果表明:设计的可加密BlockLDGM码,具有近香农限的压缩性能,同时具有较高的保密能力.

摘要：手性分子组装是化学、材料、生命科学等领域研究的重要课题之一。研究分子组装过程的手性诱导和控制，对手性组装结构及材料的设计构筑及其在分子识别、分离、催化、不对称光学等领域的应用具有指导意义，也有助于对自然界中手性起源这一基本科学问题的认识。