摘要：As a special type of novel flexible structures, tensegrity holds promise for many potential applications in such fields as materials science, biomechanics, civil and aerospace engineering. Rhombic systems are an important class of tensegrity structures, in which each bar constitutes the longest diagonal of a rhombus of four strings. In this paper, we address the design methods of rhombic structures based on the idea that many tensegrity structures can be constructed by assembling one-bar elementary cells. By analyzing the properties of rhombic cells, we first develop two novel schemes, namely, direct enumeration scheme and cell-substitution scheme. In addition, a facile and efficient method is presented to integrate several rhombic systems into a larger tensegrity structure. To illustrate the applications of these methods, some novel rhombic tensegrity structures are constructed.

摘要：针对雨洪模型结构应与实际物理现象较好吻合,以保障内涝防治规划中雨洪模拟结果的准确性,提出了一套提升复杂联围雨洪模拟精度的方法。通过剖析复杂联围的排涝模式,揭示复杂联围的排涝特点及联围内部片区涝水排除特点,分析片区不同地形的产汇流特性及其适宜的模拟方法,并提出了复杂联围的雨洪模型构建方法和建模步骤。以粤港澳大湾区的中(山)珠(海)联围为例,开展复杂联围雨洪模型构建的实证研究。结果表明:构建的模型结构与实际雨洪过程相吻合,模型精度较高,并在率定测试中表现稳定,平均纳什效率系数比其他未遵循联围排涝过程的模型结构高出0.05~0.61。

摘要：Compared to the current eddy braking patterns using a single magnetic source,hybrid excitation rail eddy brakes have many advantages,such as controllability,energy saving,and various operating *** the large braking power consumption of the high-speed train,a hybrid excitation rail eddy brake system,which is based on the principle of electromagnetic field,is proposed to fulfill the needs of safety and *** the working processes of the mechanical lifting system and electromagnetic system are *** the electromagnetic system analyzed using the finite element method,the factors such as speed,air gap,and exciting current have influences on the braking force and attractive *** last,the structure optimization of the brake system is discussed.

摘要：为了研究大径厚比薄壁铝管冷推弯成形工艺参数,基于ABAQUS/Explicit平台建立了LF2M-Φ75 mm×1.5 mm导管1D弯曲半径有限元模型。通过有限元模拟优化得到管坯长度L=250 mm。设计了正交试验,对管坯与凹模间隙、顶推压力、管坯与凹模间摩擦因数3个工艺参数进行研究。基于虚拟正交试验结果,分析了典型位置的外侧壁厚、内侧壁厚、截面椭圆度变化规律。采用极差分析法得到了最优工艺参数:管坯与凹模间隙0.1 mm、顶推压力25 MPa、管坯与凹模间摩擦因数0.1。完成了试验件的制造、测量,验证了管坯尺寸和工艺参数的可靠性;通过爆破性能试验,得到了推弯导管最大耐压力,能够满足设计及服役要求。

摘要：目的:水平起降空天飞行器需兼顾高速巡航和低速起降性能。本文旨在构建一种面向控制的空天飞行器低速段动力学建模与迭代分析流程,探究质心位置对空天飞行器稳定性及控制性能的影响,并在保证空天飞行器水平起降能力的约束下,迭代获得合理的飞行器质心位置。创新点:1.结合几何外形参数化方法、势流理论和0维混合排气涡扇发动机建模方法实现空天飞行器低速段气动/推进性能数据的快速获取;2.基于所获得的气动/推进性能数据,开展代理建模研究,获得适用于性能分析及控制器设计需要的气动力/力矩系数代理模型;3.基于可变质心的气动力/力矩系数代理模型进行空天飞行器水平起降性能分析及质心位置迭代设计。方法:1.通过形状/类型函数法建立空天飞行器几何参数化模型;2.基于势流理论和0维涡扇发动机理论快速获取空天飞行器低速段气动/推进性能数据;3.通过代理模型技术,获得不同质心位置下的飞行器气动力/力矩系数拟合表达式,并基于该表达式确定符合水平起降约束的质心位置。结论:1.空天飞行器研究中,需综合考虑高低速性能,并协调水平起降、稳定性和控制性能等多方面指标;2.本文所提出的空天飞行器概念方案,满足抬头、触地约束的质心范围在距机头65%机身长度处;3.本文所提出的面向控制建模与性能分析流程可以满足空天飞行器概念方案阶段数据快速获取、方案快速迭代优化的要求。

摘要：Energetic particle radiation diagnoses mainly detect the particles(such as neutrons,gamma rays,hard X-rays,and escaping electrons)that are radiated in the discharge process of the experimental advanced superconducting tokamak device to characterize the operating state of the plasma in real *** upgrading of these diagnoses requires new instruments based on national(here,“national”means developed and produced by a Chinese company)core chips and open-source software with advanced digitization,a high sampling rate,and a high time *** new spectroscopy system designed in this study adopts the national field-programmable gate array(FPGA)and an analog-to-digital converter as the core chip,and it is developed using Qt on *** communication between the FPGA and embedded controller occurs via a high-speed peripheral component interconnect eXtension for instrument express protocol with a direct memory access *** this basis,the time resolution of the system is improved from 2 to 1 ms,the maximum channel address is increased to 4096,and the sampling rate is increased from 10 to 80 *** experiments of the spectroscopy system with 152Eu and 137Cs sources demonstrate that the best energy resolution is 0.27%and the measurement error is less than±0.5 keV.

摘要：Antimicrobial peptides may be regarded as a potential source of future antibiotics, and the modes of action have implicated the cationic and hydrophobic nature of their interaction with bacterial membranes. In the present study, a 16-residue peptide (LGR16) was developed with the aim of examining the feasibility of designing an antimicrobial peptide by segregating hydrophobic residues in the nonpolar side and positively charged residues in the polar side, based on the helical wheel projections. Antimicrobial activity, hemolytic activity, cytotoxicity against mammalian cells and bactericidal kinetics were investigated to fully evaluate the biological function of the peptide. The results showed that the peptide LGR16 had strong antimicrobial activity, and its MICs against Gram-negative and Gram-positive bacteria were 8 and 4 μg/mL, respectively. LGR16 also exhibited rapid bactericidal action and had totally eradicated the bacteria at 10 min. LGR16 showed only weak hemolysis against chicken red blood cells and cytotoxicity aginst Vero cells at its MICs, and the concentration that caused 50% hemolysis exceeded its MICs 8-fold. Overall, antimicrobial peptides can be designed by assembling hydrophobic residues in the hydrophobic side and basic residues in the opposite side. The peptide LGR16 may be developed as a prospective candidate for an antimicrobial drug.

摘要：建立锤片式粉碎机转子组振动的力学模型及数学模型,分析了其固有频率及在额定转速下的振幅与其它参数的关系,为锤片式粉碎机在设计、制造、安装3个环节减少设备振动提供理论依据.

摘要：创业型广告设计人才培养的理念可以概括为"重创新、厚功底、强合作、大实践"。承担着培养新一代广告设计人才的本科教育,既要重视创新与合作意识教育,也要为学生树立基于实践基础之上的积极乐观的心态与信心。

摘要：In the one-gravity environment on the ground, the simulation of the contact process of two flying objects in the zero-gravity environment of space has been a challenging issue since humans first explored space by flying objects. Hardware-in-the-loop （HIL） simulation is an important and effective method to test the usability, reliability, and safety of real docking mechanisms in space. There are four main issues for HIL simulation systems： Design of simulators capable of high frequency response, high motion precision, high velocity, and rapid acceleration; compensation for simulation distortion; design of a control model for the HIL simulation process; and experimental verification. Here, we propose a novel HIL simulator system with a 6-DOF 3-3 perpendicular parallel mechanism and a 3-DOF 3-PRS parallel mechanism; discover the principle of simulation distortion; present distortion compensation models for the force measurement system, dynamic response, and structural dynamics of the simulator; and provide a control model for the HIL simulation process. Two kinds of experiments were performed on the pas- sive-undamped elastic rod and the docking mechanisms to test their performances and to verify the effectiveness and usability of the HIL simulator. The HIL simulation system proposed in this paper is useful for developing space docking, berthing, refu- eling, repairing, upgrading, transporting, and rescuing technologies.