文化软实力之时尚产业（美国简介）

本条目为“厦门大学美洲校友会2018年双年会（2018.9.29，旧金山）”的演示文稿。 贺俐，厦大校友，重庆人，纽约时尚买手，美国康奈尔大学MBA学位，中美时尚行业的青年创业领袖。2012年协助时尚女王靳羽西女士和环球小姐中国区组委会筹办了宋庆龄基金会中国美基金的慈善晚宴。2014年带领团队在美国成立摩根时尚有限责任公司，著有《当时尚预见跨境电商》一书

小型感性耦合射频等离子体中和器的实验研究

为了研究适用于百瓦级电推力器的离子束流中和技术,基于电子鞘层模型、射频等离子体最优放电技术和通过插入探针实现快速点火的方法,设计了一套小型感性耦合射频等离子体中和器(RF plasma neutralizer,RPN).实验研究了RPN中和器的稳定工作条件和电子引出特性,实现了RPN中和器稳定工作和电子有效引出.实验结果表明:电子引出特性主要取决于发射孔附近阳极斑的形成与否,而阳极斑的形成又主要受结构设计、工质流量和偏置电压等运行条件的影响;通过对RPN运行条件的优化试验,获得了55~150mA可调电子束流范围和较高的工质利用系数(3.9~10.5),满足离子束流中和需求;另外,实验中还观察到了电子束流随工质流量或偏置电压的迟滞现象

基于扩张状态观测器的无拖曳系统参数辨识

分析了卫星无拖曳控制系统的在轨参数辨识问题,由于无拖曳系统的不稳定性质,需要设计控制器使其稳定,在此基础上进行闭环辨识.根据自抗扰控制原理,设计了扩张状态观测器以估计系统不同控制回路的扰动和状态,基于状态和扰动估计值设计控制器使系统稳定.提出了基于扩张状态观测器(ESO)的多输入多输出系统闭环参数辨识方法.为提高实际应用中的辨识效果,引入积分型滤波器对观测状态中的噪声进行抑制.将这种方法应用于类似LISA Pathfinder的单轴无拖曳模型,对系统动力学参数进行估计,通过数值仿真实验验证了该辨识方法的有效性和实用性

Ground performance tests and evaluation of RF ion microthrusters for Taiji-1 satellite

The Taiji-1 satellite is a test satellite for the verification of those key technologies involved in the Taiji Program in Space, China's space gravitational wave detection project; and the spacecraft drag-free control technology is one of its key technologies used to improve the microgravity level of spacecraft. Thus, a demand for a high-precision and continuously adjustable micronewton-level thrust has been proposed on the spacecraft micro-propulsion system. In allusion to such a task, a set of micronewton-level RF ion propulsion system was designed based on the principle of self-sustained discharge of RF plasma so as to conduct studies on the parameter optimization and engineering of RF ion thruster, and an engineering prototype of the micronewton-level continuously adjustable RF ion thruster was successfully developed to meet the design index requirements. The operating parameters have been solidified through further studies on the extreme operating conditions of the engineering prototype, and a series of ground simulation tests of space environment were successfully passed. The ground test and calibration experiment results of the micro-propulsion engineering prototype show that the engineering prototype has fully met the requirements of the Taiji-1 mission, thus having laid a solid foundation for the successful space verification of the key technologies for the Taiji-1 satellite

构建pomc:Egfp作为新型环境内分泌干扰效应评估平台的研究

<正>环境内分泌干扰物包括各类可以改变、模仿、拮抗生物体内的内分泌调节系统,从而通过对体内激素的产生及发生效应的各个步骤发生干扰作用的化合物。鱼类等环境监测模式生物的运用,以及较为成熟的雌激素生物标记物研究,使得过去大多数对污染物的内分泌干扰效应几乎都局限于对其的性激素干扰效应

A torsional thrust stand for measuring the thrust response time of micro-Newton thrusters

Drag-free technology functions as the keystone for space-based gravitational wave detection satellites moving along a geodesic path, like the Laser Interferometer Space Antenna (LISA) Pathfinder, to achieve ultra-high microgravity level. Several prerequisites for micro-thrusters operated under the drag-free technique include constantly adjustable thrust, high resolution, low noise and fast response time. Accordingly, a torsional thrust measurement system was methodically devised to measure the thrust response time of such micro-thrusters on the ground. The characteristics of the dynamic thrust change with time are inverted by the angular displacement of the torsional pendulum, established by the dynamic equation of the same, thus, measuring the rise/fall time of the thrust applied to the torsional pendulum. Calibration of the torsional pendulum thrust measurement system is carried out by the standard electrostatic force generated by the electrostatic comb-drive or microelectromechanical actuator, facilitating the suitable identification of the pendulum parameters. Afterwards, the electrostatic and electromagnetic forces generated by the actuator are applied to validate the measurable thrust response time of the torsional thrust stand. The experimental results show that the above-mentioned thrust stand can effectively measure the thrust response time up to 10 ms for a thrust step in 10 s of micronewtons, which qualifies as the thrust response time required by micro-thrusters for space-based gravitational wave detection

亚微牛级推力测量系统设计及实验研究

空间引力波探测任务需要具有亚微牛级推力分辨率和推力噪声的微推力器来实现卫星平台高精度无拖曳控制任务,为了在地面对所需微推力器的推力进行标定,设计并研制了一套基于扭摆的亚微牛级推力测量系统。该系统选用高精度、高分辨率电容式位移传感器作为扭摆角位移传感装置,利用高精度电子天平对静电梳进行标定,再利用该静电梳标定扭摆,得到推力与角位移的关系。此外,研究了高精度弱力标定技术和亚微牛级微推力在线测量技术,分析了测量误差来源以及控制方案,最后利用静电梳产生标准弱力测量扭摆推力分辨能力和范围等。实验结果表明:该系统可测推力范围为0～400μN,分辨率达到0.1μN,背景噪声功率谱密度优于0.1μN/((Hz)~(1/2))(10 mHz～1 Hz),满足空间引力波探测在10 mHz～1 Hz频段推力测量需求

Experimental Study on the Effects of Discharge Chamber Length on 5 cm Radio-Frequency Ion Thruster

For keeping microgravity level of microgravity and space science satellites, a kind of electric thruster, the radio-frequency ion thruster (RIT) has been designed and applied. The RIT produces thrust through ionizing neutral particles in the discharge chamber and extracting ions by the ion optics system. The length of discharge chamber affects the ionization of neutral particles as well as the performance of RIT. In this paper, an experimental study has been carried out for analyzing the influence of discharge chamber length. In the experiment, the RIT-5 with various discharge chamber lengths, 27.6 mm, 30.0 mm, 31.9 mm, 35.5 mm, 40.0 mm, has different performances under the same condition. With the same radio frequency power and propellant flow rate, the RIT-5 has the optimal performance in beam current and efficiency when the discharge chamber length is 30.0 mm or 31.9 mm

基于扭摆的微冲量测量方法及实验研究

超高微重力水平的卫星平台在空间引力波探测、地球重力场测量中发挥着重要的作用,脉冲微推力器可以帮助微重力卫星实现姿态控制.微冲量是评价脉冲微推力器性能的重要指标之一,常用的基于扭摆的微冲量测量方法有两种,方法一是根据单个冲量元瞬间作用于无阻尼扭摆后,扭摆转动最大角位移计算冲量,方法二是根据高固定频率的连续脉冲作用于有阻尼扭摆后,扭摆转动的平均角位移计算冲量.为了在地面实现对脉冲微推力器的微冲量测量,利用已有的基于扭摆的亚微牛级推力测量系统,进行了实验研究.利用静电梳齿产生的标准静电力标定已有的扭摆推力测量系统,通过电容式位移传感器测量扭摆角位移,进而得到推力与角位移的关系,以及其他扭摆系统参数;然后,根据两种冲量测量方法,再以电磁螺线圈与永磁体分别产生瞬时磁力与固定频率的磁力作用于扭摆,研究推力测量系统微冲量测量性能.实验结果表明:使用方法一时,推力测量系统冲量测量范围为0.05～220μN·s,分辨力可达到0.02μN·s;而利用方法二测量微冲量相比于方法一而言,能够扩大冲量测量范围,提高冲量分辨能力