摘要：The electrospinning process was applied to fabricate the nanofibers of biodegradable poly(ε-caprolactone)(PCL) in which different contents of multiwalled carbon nanotubes(MWCNTs) were embedded. Afterward,the electrospun nanofibers were successfully decorated with shish-kebab structure via a self-induced crystallization technique. The topographical features and the mechanical properties of the composite scaffolds were characterized,and the biocompatibility of the material was assessed by using human osteogenic sarcoma osteoblasts(MG-63 cells). The carbon nanotube(CNT) concentration is found to affect the fiber diameter and mechanical properties of electrospun nanofibers and the periodic distance of the shish-kebab architecture. Cellular attachment and proliferation assays reveal that 0.5 wt% CNT-embedded PCL scaffold shows enhanced biocompatibility with MG-63 cells than their counterparts made of neat PCL, and the collagen-like nanotopology provided by the shish-kebab structure further facilitates the cell adhesion and proliferation. The superior interactions between cells and scaffolds demonstrate that the shish-kebab-structured CNTs/PCL nanofibers may be promising candidate for tissue engineering scaffold application.

摘要：在线性回归模型的理论研究中,参数的点估计是一个重要的研究方向。针对设计矩阵的近似复共线性,考虑回归系数的椭球约束,推广了广义岭型估计在均方误差阵意义下优于广义最小二乘估计的有关结论;针对广义岭型估计是一种自适应非线性估计,提出了采用线性Minimax估计和平衡损失函数确定广义岭型估计岭参数的具体方法,并应用R软件作了算例分析和比较。

摘要：变压器状态检修是一个设计多台变压器及庞大数据的复杂问题,在分析现有方法的基础上,提出了一种基于三角模糊数层次分析的决策方法,该方法利用模糊数学和三角模糊数合理反应了专家经验的模糊性和因素两两比较结果的区间性,并提出了一种利用平均优势度的排序方法解决三角模糊数层次分析排序上的不足。同时给出了三角模糊数层次分析的分析步骤。最后,利用实际算例证明了此方法具有较高的实用意义。

摘要：本文基于Kinect深度摄像头,结合2D SLAM算法设计出了一套精确的轮式移动机器人导航系统。该系统主要包括底盘驱动、数据采集、PC三大部分。通过机器人自身携带的Kinect深度摄像头对室内环境扫描,利用Gmapping算法构建出环境地图,在已构建出的栅格地图基础上,结合A*算法和动态窗口法,实现机器人的自主定位与导航。

摘要：The instability of soil bank slopes induced by freeze-thaw cycles at the northern foot of Tianshan Mountain is very *** failure not only caused a large amount of soil erosion,but also led to serious reservoir sedimentation and water quality degradation,which exerted a lot of adverse effects on agricultural production in the local irrigation *** on field investigations on dozens of irrigation reservoirs there,laboratory tests were carried out to quantitatively analyze the freeze-thaw effect on the soil engineering characteristics to reveal the facilitation on the bank slope *** results show that the softening characteristics of the stressstrain curves gradually weaken,the effective cohesions decline exponentially,the seepage coefficients enlarge,and the thermal conductivities decrease after 7 freeze-thaw *** freeze-thaw effect on the specimens with low confining pressures,low dry densities and high water contents is more *** water migration and the phase transition between water and ice result in the variations of the soil internal microstructures,which is the main factor affecting the soil engineering *** water supply and the alternation of positive and negative temperatures at the reservoir bank slopes in cold regions make the water migration and phase transition in the soil very *** is easy to form a large number of pores and micro cracks in the soil freezing and thawing *** volume changes of the soil and the water migration are difficult to reach a dynamic balance in the open ***-term freeze-thaw cycles will bring out the fragmentation of the soil particles,resulting in that the micro cracks on the soil surfaces are developing *** soil of the bank slopes will fall or collapse when these cracks penetrate,which often happens in winter there.

摘要：为了研究桥梁常用Q345C结构钢锈蚀损伤后的疲劳性能,开展了Q345C钢材电化学加速锈蚀试验和拉伸疲劳试验,得到了不同锈蚀损伤程度下Q345C钢材的蚀坑深度分布特征和疲劳寿命,给出了50%和97.7%存活率下的S-N曲线,并对不同锈蚀率试件的疲劳断口特征进行了对比分析,通过3D扫描逆向建模并结合ABAQUS/FE-SAFE进行疲劳寿命仿真分析。结果表明:随着锈蚀率的增大,锈蚀区域由点蚀为主向均匀锈蚀为主转变;锈蚀对疲劳性能降低与应力水平有关,低应力水平下锈蚀对疲劳性能的降低尤为显著;未锈蚀试件97.7%存活率的S-N曲线与BS 7608规范接近且略大于钢结构设计规范GB 50017-2003,而锈蚀损伤试件97.7%存活率S-N曲线均低于常用疲劳规范曲线,且200万次等效疲劳强度明显降低;锈蚀试件断口存在明显的疲劳台阶且断裂后塑性变形小,试件的断口裂纹扩展面积比与应力水平和锈蚀率均呈反比;锈蚀试件疲劳寿命仿真结果与试验相比误差最大仅为6.32%。

摘要：为研究不同固结方式下土体不排水抗剪强度的差异,基于应力控制式三轴仪对饱和细粒土进行了k_(0)固结和等向固结三轴不排水压缩试验,结果表明:k_(0)固结三轴不排水抗剪强度为等向固结不排水强度的0.87倍,后者高估了土体实际强度,实际应用中可在比对试验基础上,通过等向固结三轴试验结果换算k_(0)固结不排水抗剪强度;等向固结、k_(0)固结三轴不排水标准强度随塑性指数增大呈减小趋势,分布于0.27~1.15之间。标准强度随着超固结比的增大而增大,正常固结或接近正常固结的黏土,其标准强度介于0.27~0.47之间,OCR大于2.2的超固结黏土,其标准强度大于0.50。

摘要：结合象山港跨海大桥工程实例,采用快速氯离子电迁移法(RCM)法测试了不同水胶比情况下,复掺粉煤灰和矿粉海工混凝土的氯离子扩散系数;用差热分析法(DTA)和扫描电镜(SEM)分析了复掺粉煤灰和矿粉对海工混凝土氯离子抗渗性的影响机理;并运用Fick第二定律对海工混凝土结构抗氯离子侵蚀耐久寿命进行预测。试验结果显示,降低水胶比及复掺粉煤灰和矿粉能有效提高混凝土的氯离子抗渗性,使混凝土的设计寿命得到延长。

摘要：针对传统道钉缺乏感知能力和交互能力差的问题,设计了一种基于LoRa的智能道钉系统,详细介绍了智能道钉和道钉网关的软硬件设计。智能道钉通过周期性采集道路温度信息,实现道路养护提示和冰冻预警,以提高道路安全性。搭建了LoRa网络环境,满足了公路环境广域覆盖、高可靠性、低功耗的网络传输需求。自定义网络通信协议,实现智能道钉与道钉网关之间的数据传输和远程控制。实验结果表明,智能道钉通信距离为500 m,实现了高效稳定的远程控制;太阳能电池供电方案满足道钉长期工作需求;智能道钉发光性能良好,适合夜间指引防护。

摘要：TiO_(2)-based materials have been considered as one of most promising alternatives for high-performance Li(Na)-ion batteries because of the low cost,simple composition,easy synthesis,good environmental protection,excellent safety and relatively high specific ***,the inferior electronic conductivity and poor ion diffusion coefficients are the biggest bottlenecks that restrict the popular *** effort has been focused on resolving these problems toward large-scale applications,and numerous significant advances have been *** the present work,a comprehensive overview of structure characteristics,electrochemical reaction mechanism and modification strategies of TiO_(2)-based materials was *** recent advances of various efficient ways for improving conductivity,Li(Na)storage capacity,rate capability and cycle stability are systematically summarized,including surface engineering,constructing composite and element doping,*** TiO_(2)-based materials with novel porous heterogeneous core-shell structures have been regarded as one of the most effective ways to resolve these ***,the future research directions and development prospects of TiO_(2)-based anode materials used in the manufacture of high-performance Li(Na)-ion batteries are *** review can provide important comprehension for the construction and optimization of highperformance of TiO_(2)-based anode materials.