公元6世纪前地中海周边地区扁壶发展脉络——兼论北朝胡风扁壶来源

最早的扁壶起源于地中海地区，从埃及的“新年瓶”到科普特人的“朝圣者瓶”，其间有着较为清晰的继承与发展序列，且两类扁壶都随着殖民、贸易或朝圣等活动辐射到地中海东部地区。公元6世纪，伴随丝绸之路的东西方交往，朝圣者瓶极有可能传播到了中原地区。中原工匠选取当时流行的胡人乐舞为主题，结合中国传统扁壶与佛教造像的装饰细节，创新出了用于陪葬的精美胡风扁壶。     

聚焦强度可调的高数值孔径的双焦点超透镜

基于超表面对光波的振幅、相位和偏振进行调控来实现聚焦与成像的超透镜受到广泛关注。设计了一种聚焦强度可调的高数值孔径的双焦点超透镜，并进行了理论分析和仿真验证。仿真结果表明，该超透镜能有效地将圆偏振入射光聚焦到半高宽为0.44λ的光斑上，对应的数值孔径高达0.95。此外，通过改变入射光的偏振态，可以灵活地调制两个焦点的相对强度，而不同于以往的双焦点超透镜需要对光强进行重新组合。更重要的是，当圆偏振光入射时，它的聚焦效率可达65%，可适用在0.8~1.2 THz的较宽频率范围和0°~20°的入射角内，同时该工作为多焦点超透镜的设计提供了重要思路，也将在多成像系统、光学层析成像技术等许多领域具有较高的应用价值。     

基于分数阶微分的金属橡胶迟滞非线性动力学模型

金属橡胶元件的应力应变关系为非线性滞回曲线,现有的金属橡胶动力学模型大多采用多参数、分段函数进行描述,增加了系统的复杂性。通过分析金属橡胶的弹性恢复力和阻尼力的组成,利用分数阶微分能够描述各种材料及过程记忆性的特点,提出一种含有分数阶微分的金属橡胶黏弹性本构模型,在此模型基础上建立了金属橡胶非线性动力学系统模型;通过正弦位移加载实验获取了典型金属橡胶隔振系统在多种激励幅值、频率作用下的恢复力;采用遗传算法对实验数据进行曲线拟合,识别出模型中所有参数;通过分析推导出系统模型中各参数与振幅及频率的函数关系。结果表明,所提出的含分数阶微分项的金属橡胶非线性动力学系统模型,具有连续的数学表达式,能够较准确地反映金属橡胶非线性系统的完整动力学性能,而且与现有金属橡胶动力学系统模型相比,参数较少,结构简单,为金属橡胶动力学系统的研究提供了新的思路。     

A novel radial basis function method for 3D linear and nonlinear advection diffusion reaction equations with variable coefficients

The radial basis function method for 3D advection diffusion reaction equations with variable coefficients is presented. The proposed method implements the linear combination of radial basis functions which impose boundary conditions in advance, and thus such a combination with weighted parameters can be used to construct the final approximation. Furthermore, the weighted parameters are solved by substituting the approximation into governing equations. This method leads to crucial improvements in the feasibility and accuracy which can now be easily applied to general 3D nonlinear problems through linearized techniques. Finally, accuracy and efficiency of the proposed method are verified by several examples.

     

基于石墨烯的光缆监测和追踪方案研究

本文介绍了一种基于石墨烯监测、追踪的新型光缆接头盒,在传统光缆接头盒中仅增加了由光耦合部分和电处理部分组成的集成芯片：光耦合部分通过石墨烯与D形光纤的强相互作用实现每根光纤的信号耦合与转换,电处理部分通过电信号接收模块、中心控制模块、信息处理与存储模块、鉴权模块、收发天线模块和传感模块等对电信号进行处理和监控,最终达到对传输线路(包括管道、杆塔等)光缆中光纤的精细监测、上报和追踪。     

Fiber optic displacement sensor used in railway turnout contact monitoring system

Railway turnout contact monitoring is very important in high-speed rail operation systems. In order to measure the distance between the sharp rail and the basic rail in a switch system, a wide-range, high-precision fiber Bragg grating (FBG) displacement sensor was designed. Because the distance between the sharp and basic rails is always greater than 14 cm, the measurement range width and accuracy of the proposed sensor system are ensured through the use of a long spring and a beam of constant strength. A differential compensation method is used to eliminate temperature effects. Test results show that the resolution of the proposed sensor is 0.040 mm and the measuring range is 0—170 mm. A field test was also carried out to evaluate the performance of the sensors.     

乡村电商人才培养教学内容及路径研究

通过高校设计教育专业输出课程,培养有技术、重内容、懂品牌、善营销的乡村电商人才。以抖音平台为例,通过检索     

Modeling and Analysis the Effects of EMP on the Balise System

Balise system is one kind of high-rate point-mode data transmission equipment. It plays an indispensable role in Chinese Train Control System (CTCS), and it has been immigrated and widely used for passenger dedicated lines and high-speed lines. Thus, its working conditions directly affect train operation safety. However, the balise information transmission system (BITS) is based on the principle of electromagnetic induction, and the communication process is susceptible to external electromagnetic interference. Therefore, it is vital to study the influence of transient signal interference on the balise system. This paper builds the up-link model between the vehicle antena and the balise, and verifies the model’s correctness using finite-difference time-domain method and electromagnetic field theory. This paper analyzes the effect of electromagnetic pulses on the transponder's uplink and simulates the coupled current under irradiation. The spectral distribution of the three types of pulse interference is analyzed according to relevant standards. Strong electromagnetic pulses have a strong energy distribution in the working frequency band of the up-link, which will generate in-band interference and bit errors. It will affect the balise communication and threaten the safety of train operation. As we know we are the first to analyze the effects of EMP on Chinese BITS, which will lay a foundation for the research of electromagnetic anti-interference or protection to high-speed railway.     

Effect of the local defects induced by bending strain on the quench properties for YBCO tapes

The effect of local defects on the quench properties for YBCO tapes after applying bending strain was investigated at self-field in 77 K. The minimum quench energy (MQE) was related to the position of defects in the tape and the smallest MQE appears where the region of the defects existed in the position of the heater at the same transport current. The normal zone propagation velocity (NZPV) was related to the size and quantity of the regions of defects. The more defects were in the tape, the faster the normal-zone propagation velocity.