摘要：The size effects of microstructure of lattice materials on structural analysis and minimum weight design are studied with extented multiscale finite element method（EMsFEM） in the paper. With the same volume of base material and configuration, the structural displacement and maximum axial stress of micro-rod of lattice structures with different sizes of microstructure are analyzed and *** is pointed out that different from the traditional mathematical homogenization method, EMsFEM is suitable for analyzing the structures which is constituted with lattice materials and composed of quantities of finite-sized *** minimum weight design of structures composed of lattice material is studied with downscaling calculation of EMsFEM under stress constraints of micro-rods. The optimal design results show that the weight of the structure increases with the decrease of the size of basic sub-unit cells. The paper presents a new approach for analysis and optimization of lattice materials in complex engineering constructions.

摘要：为解决低光照条件下的图像噪声多、亮度低、细节模糊等问题,提出了一种融合零参考深度曲线的低照度图像增强与去噪算法(UMDCEAD-NET)。该算法首先设计了一个特征提取网络,以u-net为主干网络,并在主干U-Net的下采样过程融入mobile-net,以提高算法特征提取能力,保留更多图像细节信息。其次,为解决图像像素级光照不足、网络的退化的问题,利用深度曲线估计(LE-曲线)对提取特征进行迭代,结合深度可分离卷积降低网络模型的参数量,并设计了5个非参考损失函数,提高算法在不同光照条件下的泛化能力和细节保留能力。最后,结合AD-NET(attentional denoising network)对增强后的图像进行降噪处理,以减少增强图像的噪声,使得图像更符合人眼的视觉感知。实验结果显示,本文算法在公开数据集Zero-DCE平均峰值信噪比(peak signal-to-noise ratio,PSNR)达到22.29,相比Zero-DCE++算法提高了32%,在公开数据集LOL的PSNR达到21.15,相比SGZ算法提高了3%。可见,该算法能够有效地解决增强后图像的噪声问题,使得增强后的图像暗部和亮部区域的细节信息更加丰富,与其他主流算法相比本文算法图像质量有明显提升。

摘要：发展可再生、可降解的脂肪族聚酯材料有望部分替代目前广泛使用的聚烯烃类材料,对于解决塑料污染问题具有重要意义.本文工作以商业化α-氨基酸作为初始原料,设计合成了一类结构上类似于丙交酯(LA)的取代乙交酯单体(substituted-glycolide,sGA),研究了单体的开环聚合(ROP)反应过程以及侧链结构对聚合物热性能、力学性能以及回收性能的影响.结果表明,使用辛酸亚锡(Sn(Oct)2)/苯甲醇(BnOH)催化体系可以实现sGAs单体的高效可控ROP,并且所得聚合物保持高的立构规整度.通过对聚合反应条件的控制,所有的单体都可以聚合得到高分子量聚合物.此外,含有较长碳链的聚合物具有最低的玻璃化转变温度(T_(g)),同时,这些聚合物热稳定性与聚乳酸(PLA)相似.力学性能方面,侧链为乙基的聚合物链可以通过折叠排列形成规整的晶体结构,表现出兼具柔韧性与强度的特性.最后,这些聚合物都可以在Sn(Oct)_(2)催化下解聚回收为单体而不影响再次聚合.

摘要：为探究冷冻-微波法净化污水水质效果,研究设计室内污水冻结成冰,结合微波快速解冻,按T1~T5时间段收集融出水试验。结果表明:(1)17 min的微波解冻可取代传统14.5 h的污水冰解冻。(2)T1+T2的微波处理,去除污水中59.18%和64.57%以上的理化指标含量和离子含量,同时色度、浑浊度、絮状沉淀也显著减少。(3)微波解冻17 min后的水产品中,TDS与总硬度浓度比最大仅0.16,总碱度、HPO_(3)、PO_(4)^(3-)、COD_(Mn)、SiO_(2)、H_2SiO_(3)的浓度在0.20~0.41之间;K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)、Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)-、NO_(3)^(-)浓度比仅在0.05~0.20之间;As的浓度接近0。(4)主成分分析结果显示,冷冻-微波法净化TDS及总阴离子净化效果最好,主成分综合得分Y分别为4.55和3.65。总体而言,结合冻融过程与微波快速解冻,可快速、高效地实现污水处理。

摘要：To evaluate the therapeutic efficiency of tissue-engineered human corneal endothelia (TE-HCEs) on rabbit primary corneal endotheliopathy (PCEP),TE-HCEs reconstructed with monoclonal human corneal endothelial cells (mcHCECs) and modified denuded amniotic membranes (mdAMs) were transplanted into PCEP models of New Zealand white rabbits using penetrating *** TE-HCEs were examined using diverse techniques including slit-lamp biomicroscopy observation and pachymeter and tonometer measurements in vivo,and fluorescent microscopy,alizarin red staining,paraffin sectioning,scanning and transmission electron microscopy observations in *** corneas of transplanted eyes maintained transparency for as long as 200 d without obvious edema or immune *** corneal thickness of transplanted eyes decreased gradually after transplanting,reaching almost the thickness of normal eyes after 156 d,while the TE-HCE non-transplanted eyes were turbid and showed obvious corneal *** polygonal corneal endothelial cells in the transplanted area originated from the TE-HCE *** intact monolayer corneal endothelium had been reconstructed with the morphology,cell density and structure similar to those of normal rabbit corneal *** conclusion,the transplanted TE-HCE can reconstruct the integrality of corneal endothelium and restore corneal transparency and thickness in PCEP *** TE-HCE functions normally as an endothelial barrier and pump and promises to be an equivalent of HCE for clinical therapy of human PCEP.

摘要：Three kinds of 4-hydroxyl azobenzene compouds with different substituents varied as -NO2, -H, -OCH3 in the para-position were synthesized and characterized. Their nonlinearoptical properties in tetrahydrofuran (THF) and chloroform (CHCl3) solution were determined using Z-scan technique. The results revealed that the nonlinear absorption (β) and nonlinear refraction (γ) values of three azobenzene compounds in THF solution were larger than those in CHCl3 solution. It was mainly due to the regular arrangement and effective π-conjugation of azobenzene molecules caused by the formation of hydrogen bonds between the hydroxyl groups of azobenzene molecules and the oxygen atom of the THF molecules. Among three kinds of azobenzene compounds, the 4-nitro-4′-hydroxyazobenzene (NAzoOH) had the largest coefficients of β and γ values in both THF and CHCl3 solution. It was mainly because that a push-pull (D-π-A) electron system was formed by the electron withdrawing nitro-substituent with electron donating hydroxyl-group in both extremities of azobenzene, resulting in a higher electron delocalization.

摘要：从广告的特点出发,总结了广告设计传统教学模式中的不足之处,探讨了"提案式"教学方法在广告设计课程中的积极作用。对完善广告设计教学提出自己的思考。从"提案式"教学的课程设计、教学实施和教师角色3个方面表述了"提案式"教学的实际应用过程。

摘要：连续混沌调频雷达的发射信号采用连续混沌信号实现信号调频,其性能逼近噪声调频信号,避免了离散调频设计中存在的前提限制(如:脉冲持续时间长、频率跳变等).基于混沌动力学理论,提出了连续混沌调频雷达的波形设计方法.该方法根据连续混沌调频信号的动力学模型,设定时间尺度变换函数,调制处于正弦振荡的Colpitts电路频率,可实现任意频谱结构的目标波形输出.该文结合设计实例给出了具体的设计步骤,并分析了设计性能,仿真结果表明该方法是有效可行的.

摘要：提出了基于连续混沌时间尺度变换的连续混沌调频信号动力学设计理论,并以Colpitts电路为例给出了具体的实现模型.通过吸引子重构和Lyapunov指数分析,阐述了连续混沌调频信号的动力学特性.结果显示连续混沌调频信号的最大Lyapunov指数与混沌信号的最大Lyapunov指数相同;连续混沌调频信号的动力学设计实现方式简单且系统参数易于控制,同时信号形式与数学意义上的连续混沌调频信号保持一致.

摘要：在卫星的服役周期中,发射阶段的动力学环境最为恶劣,期间受到多种复杂载荷的作用。传统的星箭连接适配器由于刚度较大,给航天器的参数设计及生产带来了极大的困难。为了达到多轴隔振的目的,基于粘弹性材料受到剪切力作用时产生较大阻尼损耗的原理设计了一种新型整星隔振器。针对该隔振系统进行了简化,以质量刚度阻尼耦合的形式来模拟卫星和隔振器之间的关系,对其进行了隔振效果的分析。其中,重点对仿真中出现的隔振系统的一阶模态结构阻尼系数的饱和现象提供了详尽的理论和数值分析。最后,针对新型整星隔振器的工程具体应用提出了两点参考准则。