摘要：Synchrotron radiation X-ray micro-computed tomography(SR-μCT)is a 3D imaging technique that is widely employed for the characterization of defects in advanced materials and *** this study,we characterize several typical defects in octettruss and re-entrant 3D lattice structures by using SR-μ*** 3D micro-lattice structures are manufactured using projection micro litho stereo exposure(PμLSE)additive manufacturing *** as-fabricated 3D lattice samples are characterized using optical microscopy,and subsequently,by SR-μ*** more,a statistical analysis is performed to characterize the surface roughness and internal defects qualitatively,whereby the statistical geometrical parameters of struts along different directions and strut joints are analyzed and ***,several typical defects are identified:(1)holes at the joints of the strut and irregular diameter deviations of the strut in the octet-truss lattice structure;(2)irregular diameter variations,bulges,dislocations,grooves,accumulations,and torsion in the re-entrant lattice *** of these defects are related to the building direction,the weight of the structure,bubbles,dust,and impurities during the PμLSE additive manufacturing process.

摘要：Kirigami arts have provided a more promising method for building multiscale structures,which can shape two-dimensional(2D)sheets into three-dimensional(3D)configurations by cutting and ***,we first carried out a theoretical analysis of the mechanical properties of 2D honeycomb lattice structures and experimental verification combined with finite element(FE)***,a series of thick-walled 3D kirigami-inspired honeycomb(TW3KH)structures with different mechanical properties were designed and fabricated on the exploration and optimization of geometric parameters of 2D honeycomb *** investigations of folding feasibility,self-expansion,and self-folding performance experimentally showed that our designed four-dimensional(4D)printing structure had good programmability and shape memory capability and a large volume change ratio during shape ***,research on its compression deformation behavior found that the TW3KH structures can recover load-bearing capacity very well when the angle is ***,these TW3KH structures have great advantages in space-saving smart load-bearing equipment.

摘要：近年来,古镇盲目追求发展而导致滨水空间被挤占和破坏的案例层出不穷,空间特色消失。本文拟从“双修”的视角切入,与“特色小镇”的空间景观特色要求相契合,针对古镇滨水空间的普遍特征和存在问题,提出滨水空间营造的分段策略以及与之匹配的“穿、缝、浮、凸、叠”五式方法,修复古镇滨水岸线生态,修补古镇滨水空间环境,探索研究其规划方法并进行规划实践。

摘要：为了解决白桦容器育苗中的基质底肥问题,采用正交试验设计方法,通过増施不同剂量的尿素(N)、过磷酸钙(P)和硫酸钾(K)基肥试验,筛选适宜的白桦容器育苗基质增施基肥方案。当年生白桦播种苗苗高(H)、地径(D)和地上生物量(B)对増施N、P和K的反应均不相同。随着N和K的增加,H表现出初始增加随后降低的抛物线式变化趋势,而随着P增加,H表现出初始增加随后稳定的S型曲线变化趋势;适宜H增长的N、P、K配方分别为1.310 4、0.329 4、0.760 4 g/株。随着N、P和K的增加,D均表现出初始增加随后稳定的S型曲线变化趋势;适宜D增长的N、P和K配方分别为1.965 6、0.847 0和0.760 4 g/株。随着N增加,B表现出初始增加随后稳定的S型曲线变化趋势,而随着P和K增加,B表现出初始增加随后降低的抛物线式变化趋势;适宜B增长的N、P、K配方为1.9656、0.3294和0.7604g/株。综合来看,白桦容器育苗时可在育苗基质中添加N、P和K分别为1.310 4、0.329 4和0.760 4 g/株。

摘要：随着现代导弹技术的发展,对发动机性能要求越来越高,装填比要求也更高,采用常规装药结构已经满足不了总体需求。为了满足总体要求,开展了基于形状记忆聚合物固体发动机装药芯模试验研究,利用形状记忆聚合物的形状记忆效应,把形状记忆芯模固化为容易脱模的形状。然后,将其加工成需要固化的形状,涂上合适的脱模剂以后作为推进剂芯模使用,推进剂固化完成后,对芯模进行热刺激,则芯模会回复成之前容易脱模的形状,从而自行脱模。采用变形量50%和100%形状记忆聚合物芯模进行了假药和真药装药试验与点火实验,芯模成功脱模,装药内型面良好,并进行了∅118 mm试验发动机点火。试验结果表明,采用形状记忆聚合物芯模可以实现复杂异性药形设计,从而拓宽了发动机装药形式,提高了装填比,为药形设计提供了一种新的制备工艺。

摘要：高层建筑中钢结构屋面结构外挑出下部结构范围会导致结构下部悬空,变化的造型则会导致悬挂式施工平台无法按统一模数设计受力支座。基于此,文章通过研究外挑钢结构造型特点,构思一种利用外挑钢梁作为锚固点的悬挂式钢结构平台,同时使锚固支座可调,有效解决了施工平台设计难题;还进一步分析了渐变造型的外挑钢屋面施工平台加工要点,包括型材选择加工、焊接成型、试吊、验收等。该施工平台设计提供了一种新的施工平台搭设思路,同时操作简单、材料易得,值得推广应用。

摘要：国家火星探测任务是建设航天强国进程中的重大标志性工程,是中国航天走向更远深空的里程碑工程.智能材料这种集材料、结构和功能于一体的先进材料将会对火星探测任务有所助力.形状记忆聚合物及其复合材料作为一种典型的智能材料,可在有效减轻载荷的同时实现自主变形,已经在地球同步轨道航天器的应用中崭露头角.因此有必要研究这种新型环氧基形状记忆聚合物复合材料应用于火星探测工程的可能性.首先,针对“天问一号”火星探测器的任务需求,设计了一个具有自释放功能的着陆平台国旗装置.其中的锁紧释放装置由碳纤维增强的形状记忆聚合物复合材料制成,分别从静态拉伸力学性能、动态热机械性能和形状记忆性能三个角度评估了空间辐照和长期存储对形状记忆聚合物复合材料的影响.其中,空间辐照包括γ射线和紫外射线,辐照剂量分别为5×10^(5)rad和23.6 kCal.长期存储分为低温-196℃、室温25℃和高温85℃存储30天,和低温-196℃存储457天两组实验.最后,从“祝融号”火星车所携带相机拍摄的照片可以看到五星红旗被成功释放,旗面平整、图案清晰.这说明所研究的环氧基形状记忆聚合物复合材料可成功应用于火星探测任务,未来有望以多种结构形式助力我国的火星采样返回乃至其它深空探测任务.

摘要：针对外场大场景视频监控需求,分析研究了单台全景摄像机全景图像缺点,多台全景摄像机多路全景图像拼接融合难点和拼接融合算法原理,设计了一种多路全景图像拼接融合算法。研究结果认为,该算法设计合理,可有效拼接融合多路全景图像,具有良好的视觉观感和图像质量,可对提升外场全景监控能力提供借鉴。

摘要：The deployable structures based on shape memory polymer com-posites(SMPCs)have been developed for its unique properties,such as high reliability,low-cost,lightweight,and self-deployment without complex mechanical devices compared with traditional deployable *** order to increase the inflatable structure system’s robustness and light the weight of it,a cubic deployable support structure based on SMPC is designed and analyzed *** cubic deployable support structure based on SMPC consists of four dependent spatial cages,each spatial cage is composed of 12 three-longeron SMPC truss booms and end *** shape recovery of arc-shaped deployable laminates drive the three-longeron SMPC truss booms to unfold,thus realize the expansion of the deployable support *** concept and operation of the cubic deployable support structure are described in detail.A series of experiments are performed on the three-longeron deployable laminates unit and the simplified cubic deployable support structure to investigate the shape recovery behavior in the deployment *** indicate that the cubic deployable support structure has a high deployment-tgo-stowage volume ratio and can achieve self-deployment,package,and deploy without complex mechanical devices.

摘要：本文采用文献资料法、逻辑分析法等研究方法,分析当前体育教育专业学生教学实践能力培养存在的问题,探讨师范专业认证背景下体育教育专业学生教学实践能力培养问题。研究认为,体育教育专业学生教学实践能力培养存在的问题主要有:(1)体育教师对新时代体育教学改革举措掌握不充分;(2)体育教师教学设计一体化不足;(3)学生学科教学知识(PCK)未能有效形成;(4)课程内容设置深度不够;(5)教育见习、实习、研习安排与基层体育教学实践关联深度不够等。针对存在的问题,基于师范专业认证背景,提出体育教育专业学生教学实践能力培养策略:(1)高校体育教师要深入学习和全面把握新时代教育理论;(2)完善教学设计一体化,明确课程教学主线;(3)注重学生教学实践,促进学生学科教学知识(PCK)形成;(4)根据实际需要安排课程学时学分和优化教学内容;(5)高度重视“三习”活动质量等。