摘要：Biophysical restrictions regulate protein diffusion,nucleus deformation,and cell migration,which are all universal and important processes for cells to perform their biological ***,current technologies addressing these multiscale questions are extremely ***,through two-photon polymerization(TPP),we present the precise,low-cost,and multiscale microstructures(micro-fences)as a versatile investigating *** nanometer-scale printing resolution and multiscale scanning capacity,TPP is capable of generating micro-fences with sizes of 0.5-1000μ*** micro-fences are utilized as biophysical restrictions to determine the fluidity of supported lipid bilayers(SLB),to investigate the restricted diffusion of Src family kinase protein Lck on SLB,and also to reveal the mechanical bending of cell nucleus and T cell climbing *** together,the proposed versatile and low-cost micro-fences have great potential in probing the restricted dynamics of molecules,organelles,and cells to understand the basics of physical biology.

摘要：Utilizing density functional theory(DFT)and non-equilibrium Green's function,we systematically studied the electrical transport and rectification properties of thiol-and amino-terminated molecules embedded in graphene *** firstly found the thiol-terminated moleculesshowbetterelectron transport properties compared to the amino-terminated,which can be attributed to the strong electronwithdrawing ability and favorable coupling ***,the symmetrical molecules show almost symmetrical current-voltage(-V)curves and exhibit negligible rectification *** the other hand,the asymmetrical molecules exhibit asymmetrical I-V curves and better rectification *** rectification effect is closely related to molecular asymmetry *** example,the rectification ratio of asymmetric N6((E)-N1-(3-aminopropyl)-but-2-ene-1,4-diamine)molecule is much smaller than the N4(5-phenylthiazole-2,4-diamine)and N5(2,6-diaminohexane-1,1,5-triol)***,we found the rectification ratio of the asymmetrical amino-terminated molecules can reach 400,while the biggest rectification ratio of the thiol-terminated molecule can only reach *** findings offer crucial insights for future graphene molecular electronic device design.

摘要：Time, cost, and quality are three key control factors in rockfill dam construction, and the tradeoff among them is important. Research has focused on the construction time-cost-quality tradeoff for the planning or design phase, built on static empirical data. However, due to its intrinsic uncertainties, rockfill dam construction is a dynamic process which requires the tradeoffto adjust dynamically to changes in construction conditions. In this study, a dynamic time-cost-quality tradeoff （DTCQT） method is proposed to balance time, cost, and quality at any stage of the construction process. A time-cost-quality tradeoff model is established that considers time cost and quality cost. Time, cost, and quality are dynamically estimated based on real-time monitoring. The analytic hierarchy process （AHP） method is applied to quantify the decision preferences among time, cost, and quality as objective weights. In addition, an improved non-dominated sorting genetic algorithm （NSGA-II） coupled with the technique for order preference by similarity to ideal solution （TOPSIS） method is used to search for the optimal compromise solution. A case study project is analyzed to demonstrate the applicability of the method, and the efficiency of the proposed optimization method is compared with that of the linear weighted sum （LWS） and NSGA-II.

摘要：无人机在现代战争中已发挥重要作用,为夺取海域制空权,航母配备无人机是必然趋势.面向无人机着舰的高精度控制要求,本文针对存在建模误差与外部干扰的无人机,在动态面控制框架下提出一种基于干扰区间观测器的无人机预设性能着舰飞行控制策略.该策略能够对未知项提供区间估计,在前馈补偿未知项的同时,控制律将根据区间估计的宽度动态调节控制器增益,从而保证无人机的轨迹始终处在着舰轨迹约束范围内.同时,在干扰区间观测器与飞行控制律设计过程中,引入非线性增益,有效地处理了着舰机动中的状态非线性耦合.最后,基于Lyapunov函数方法与不变集理论,给出着舰飞行控制策略的参数设计条件,数值仿真也进一步表明该策略的有效性.

摘要：为有效检测三角网格曲面上的角点特征,提出一种基于最小主曲率的角点检测算法.首先通过计算网格顶点处的最小主曲率,利用加权最小主曲率定义角点特征函数,并计算角点特征值;然后利用迭代阈值法自动产生检测阈值,以去除噪声和特征不明显的角点;最后采用非极大值抑制法消除局部邻域内的角点聚簇获取特征明显的角点.在此基础上,在多个尺度下分别计算每个网格顶点处的角点特征值,并通过加权将其合并成多尺度角点特征值,新的角点特征值使得角点检测算法具有较高的稳定性和鲁棒性.通过重复检测率实验和部分重叠曲面的配准实验,验证了文中算法的有效性与实用性.

摘要：日常巡检是500m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行和维护中的重要工作. FAST部件众多,巡检过程中存在工作量大、寻找部件费时费力的问题.实现巡检定位,可以引导维护人员快速到达故障点,对提高巡检效率,保障望远镜正常运行有重要意义.考虑到反射面对卫星信号存在遮挡,采用惯性导航的方式,基于双足脚绑IMU(Inertial Measurement Unit),设计了1套步行导航算法.算法沿用零速修正框架,融合双足信息,并结合磁场信息修正航向误差.在规则轨迹中测试了算法有效性,水平定位误差在行走距离的3%以内.在巡检现场的不规则轨迹中,结合沿途标志点,水平定位误差小于11 m,能够满足日常巡检定位的需要和支撑后续巡检定位系统的实用化.

摘要：针对机器人的目标人跟踪问题,提出一种利用目标人腿部信息自适应跟踪的方法。该方法利用激光雷达作为环境感知传感器,实时获取环境的二维激光扫描数据;然后采用设计的激光相邻点聚类算法对激光扫描数据进行分割和聚类;再利用人腿圆弧状特征设计的类圆弧人腿形状识别算法从分割的数据中识别腿部数据,获得目标人腿部相对于机器人的位置信息;最后利用Kalman滤波算法对目标人的位置和速度进行跟踪,使机器人能够平稳地跟踪目标人运动。该算法在iRobot机器人平台上进行实验,实验结果验证了算法的有效性。

摘要：【目的】高功率半导体激光器的光学灾变损伤是限制其可靠性和寿命的主要因素,因此,有效的缺陷检测对于优化激光器芯片的制造工艺和结构设计至关重要。提出了一种基于改进YOLOv7-Tiny的轻量化激光器芯片缺陷检测算法,旨在解决深度学习应用于缺陷检测时面临的高计算量和参数量问题。【方法】利用轻量化卷积神经网络替换特征提取主干有效减少对计算资源消耗,有效提取电致发光图像中缺陷特征。为从上下文特征获取更丰富的信息,引入多分支重参数化卷积块重构聚合模块,通过多路径分支丰富特征表示,训练与推理的解耦保证检测效率。此外,结合坐标注意力,提升定位精度。进行了剪枝实验和模型部署,验证算法的初步应用。【结果】在电致发光缺陷数据集上的实验结果显示,本文方法能在较低的参数和计算量下准确地检测出芯片缺陷,展现出良好的性能。

摘要：为准确获取船体开孔板的焊接初始缺陷,借助有限元软件Abaqus先对船体开孔板焊接过程进行焊接模拟,继而对其极限强度开展了非线性有限元分析。结果表明,将基于热弹塑性有限元法获得船体开孔板焊接初始缺陷,运用于船体开孔板极限强度的分析可行。通过与已有经验公式进行对比,所选船体开孔板算例极限强度与经验公式计算值之间的误差均在10%以内。

摘要：铜离子在不同细胞生理过程中作为催化辅助因子起着很重要的作用,但是体内铜离子浓度出现异常也会导致疾病甚至死亡。与铜离子相比,汞离子是各种重金属污染物中最普遍、最危险的一种。因此,对它们高灵敏度、高选择性检测具有非常重要的意义。荧光探针法由于具有灵敏度高、快速便捷、可视化和原位无损检测等优点而成为Cu^(2+)与Hg^(2+)离子重要的检测手段之一。本文总结了近几年基于小分子Cu^(2+)和Hg^(2+)离子双识别荧光探针的设计合成、性能及其在分析方面的研究与最新进展,并展望了此类荧光探针未来的研究与发展方向。