基于欧氏距离及向量内积的骨架提取算法

对骨架算法进行研究,提出一种骨架提取算法.通过对图像内部像素点进行距离变换得到其最近边界点的位置,将内部像素点到最近边界点的向量定义为边界向量,根据物体内部相邻边界向量的方向,计算每个像素点的内积值和其8邻域的最小内积值,得到的最小内积点,以确定的阈值从最小内积点中选取骨架种子点,再对骨架种子点进行处理,得到连通的骨架.试验证明这种算法能保证骨架具的完整性和连通性,正确反映物体的拓扑结构.     

反应注射充模特性及模具浇口结构设计的研究

本文对反应注射充模过程中的铺展流、射流、绕流和气泡的特性进行了分析研究，并讨论了模具浇口结构及位置对充模的影响，给出了制品的设计方法。     

The Torque Transmission Capabilities of the Adhesively-Bonded Tubular Single Lap Joint and the Double Lap Joint

With the wide application of fiber-reinforced composite materials in aircraft, space structures and robot arms, the design and manufacture of composite joints have become a very important research area because they are often the weakest areas in composite structures.

In this paper, the stress and torque transmission capabilities of the adhesively-bonded tubular single lap joint and the double lap joint were experimentally tested. In order to compare the experimental results with the calculated results, the stress and torque transmission capabilities were analyzed by the 3-dimensional finite element method taking into consideration the nonlinear properties of the adhesive.

From the experiments it was found that the torque transmission capabilities of the adhesively-bonded double lap joint was 2.7 times as large as that of the single lap joint. Also, it was found that the fatigue limit of the double lap joint was 16 times as large as that of the single lap joint.     

基于动态优先级策略的多AGV无冲突路径规划

自动导引运输车(AGV)路径规划影响柔性制造车间的高效、平稳生产.分析了多AGV在车间执行运输任务时常见的冲突类型,提出了一种基于动态优先级策略的多AGV无冲突路径规划方法.该方法通过时间窗检测冲突类型,并将等待时间、行驶距离、任务紧急程度作为量化动态优先级的考虑因素,进而利用动态优先级作为等待、二次路径规划两种冲突消减方法的选择依据.案例研究表明,在已知各AGV可行路径时,运用所提方法不仅能够实现多AGV的无冲突路径规划,而且能够提升多AGV完成运输任务的整体效率.     

基于动态优先级策略的多AGV无冲突路径规划

自动导引运输车(AGV)路径规划影响柔性制造车间的高效、平稳生产.分析了多AGV在车间执行运输任务时常见的冲突类型,提出了一种基于动态优先级策略的多AGV无冲突路径规划方法.该方法通过时间窗检测冲突类型,并将等待时间、行驶距离、任务紧急程度作为量化动态优先级的考虑因素,进而利用动态优先级作为等待、二次路径规划两种冲突消减方法的选择依据.案例研究表明,在已知各AGV可行路径时,运用所提方法不仅能够实现多AGV的无冲突路径规划,而且能够提升多AGV完成运输任务的整体效率.     

Generic Adaptive Sliding Mode Control for a Quadrotor UAV System Subject to Severe Parametric Uncertainties and Fully Unknown External Disturbance

International Journal of Control, Automation and Systems - This paper aims to provide a generic robust controller that is able to manipulate all kinds of quadrotor unmanned aerial vehicle (UAV)...     

A novel ADRC‑based design for a kind of fexible aerocraft

The paper presents a novel control design, which is based on the idea of active disturbance rejection control (ADRC), for a kind of fexible aerocraft whose controlled variable cannot be measured directly. Since the original frame of ADRC cannot be directly applied, the paper puts forward a new extended state observer (ESO) and the corresponding ADRC law. In order to assign the poles of the closed-loop system to ideal positions such that the vibration can be quickly suppressed, an elastic damping term is added into feedback law. The advantages of the new ESO for efectively estimating both the rigid mode and elastic mode from the measurements are discussed. Moreover, the analysis on the stability, the relative stability and the steady state of the closed-loop system is given. Finally, the efectiveness and robustness of the proposed ADRC are verifed by simulations.     

Noncovalent Functionalized Graphene-Filled Polyimides with Improved Thermal,Mechanical, and Wear Resistance Properties

A facile method is proposed to prepare poly-o-phenylenediamine (PoPD) noncovalent functionalized graphene (G)-reinforced polyimide (PI) nanocomposites. PoPD-G exhibited excellent dispersibility in various organic solvents. The structures of PoPD-G were characterized by Raman and UV spectrum, which verified the π–π interactions between PoPD and G. The effective exfoliation of graphene nanosheets was investigated by observation of the morphology of PoPD-G with SEM, SPM, and TEM. Compared to PI/G composites, the interfacial adhesion between graphene nanosheets and PI matrices promoted efficient stress transfer from PI chains to PoPD-G nanofillers. Polyimide nanocomposites with different incorporations of PoPD-G exhibited outstanding thermal properties. It is interesting to note that only 0.5 wt% PoPD-G-reinforced PI composites increased by 20.8% in hardness, enhanced by 84.0% in storage modulus, and reduced by 72.8% in wear rate compared with neat PI. The eminent enhancement was attributed to the facile dispersion of graphene nanosheets and strong interface adhesion between PI and PoPD-G.     

基岩型富氦气藏形成条件

氦气是一种广泛应用于军工、航天、医疗等高新技术产业的稀缺战略资源,但其在世界分布极其不均,中国是贫氦国家面临着严峻的氦气供给安全问题。在系统总结前人研究成果基础上,结合本次实验分析对比了世界上最成熟的氦气生产气田（美国潘汉德—胡果顿气田）与中国氦气生产潜力较大的东坪气田,探讨两者的成藏要素及富氦机理。结果发现：两者均是以天然气作为载体气的基岩型富氦气藏,储层物性好,均发育以膏岩为主的低渗致密的良好盖层。两者的差异性在于,前者花岗岩形成年代更为古老,尤其是碳酸盐岩地层中富含的花岗岩碎屑,其年龄集中在元古宙,平均比东坪气田花岗岩的形成年代早400 Ma;前者氦气运移模式偏向于单一的饱和地下水脱溶释放,而后者存在“过路”古老花岗岩储层的天然气“萃取”释放。两者对比之下,提出形成年代久远的高U、Th氦源岩、充足的载体气、良好的基岩风化壳储层与致密的盖层,和充足的地下水（边底水）作为媒介参与氦气运移,是形成基岩型富氦气藏的必要条件。     

Degradability and biocompatibility of bioglass/poly(amino acid) composites with different surface bioactivity as bone repair materials

Bioglass (BG) possesses excellent bioactivity and has been widely used in the manufacture of biomaterials. In this study, a composite with different surface bioactivity was fabricated via in situ melting polymerization by incorporating BG and poly(amino acid) (PAA) at a suitable ratio. The structure of the composite was characterized by Fourier transform infrared spectroscopy and XRD. The compressive strength of the BG/PAA composites was 139 MPa (BG:PAA = 30:70). The BG/PAA composites were degradable, and higher BG in composite showed higher weight loss after 4 weeks of incubation in simulated body fluid. In addition, the BG/PAA composite maintained adequate residual compressive strength during the degradation period. The SEM results showed the differences in surface bioactivities of the composites directly, and 30BG/PAA composite showed thicker apatite layer and higher Ca/p than 15BG/PAA. in vitro MG-63 cell culture experiments showed that the composite was noncytotoxic and thus allows cells to adhere, proliferate, and differentiate. This indicates that the composite has good biocompatibility. The implantations in the bone defects of rabbits for 4 and 12 weeks were studied. The composites had good biocompatibility and were capable of guiding new bone formation without causing any inflammation. The composite may be successfully used in the development of bone implants.