A Compact Atom Interferometer for Future Space Missions

Atom interferometry represents a quantum leap in the technology for the ultra-precise monitoring of accelerations and rotations and, therefore, for the science that relies on these quantities. These sensors evolved from a new kind of optics based on matter-waves rather than light-waves and might result in an advancement of the fundamental detection limits by several orders of magnitude. This paper describes the current status of the Space Atom Interferometer project (SAI), funded by the European Space Agency. In a multi-pronged approach, SAI aims to investigate both experimentally and theoretically the various aspects of placing atom interferometers in space: the equipment needs, the realistically expected performance limits and potential scientific applications in a micro-gravity environment considering all aspects of quantum, relativistic and metrological sciences. A drop-tower compatible atom interferometry acceleration sensor prototype has been designed, and the manufacturing of its subsystems has been started. A compact modular laser system for cooling and trapping rubidium atoms has been assembled. A compact Raman laser module, featuring outstandingly low phase noise, has been realized. Possible schemes to implement coherent atomic sources in the atom interferometer have been experimentally demonstrated.     

Adaptation of a 2-D Clinostat for Simulated Microgravity Experiments with Adherent Cells

The fast-rotating 2-D clinostat, a ground-based facility for investigations in simulated microgravity, is mainly used for experiments with cell suspensions. Here, we describe the adaptation of a 2-D clinostat for adherent cell investigations using commercially available slide flasks. As a gradient of residual accelerations is present in the slide flasks during clinorotation, the range of maximal g-values has to be adjusted to the investigated cells and type of analysis. For gene expression analysis, a harvesting slide chamber was constructed, allowing collection of cells exposed to defined g-values. Using this slide chamber, human 1F6 melanoma cell line, exposed in the ranges of ≤0.012 g, ≤0.024 g, or ≤0.036 g for 24 h, was harvested and the respective mRNA levels of guanylyl cyclase A (GC-A), an enzyme catalyzing cyclic GMP synthesis, were determined by real-time quantitative PCR analysis. Our results show that the down-regulation of GC-A mRNA levels in 1F6 melanoma cells depends on the residual acceleration values with a maximal reduction at ≤0.012 g. We further used the slide flasks by the clinorotation of murine RAW 264.7 macrophage cell line for f-actin analysis. The laser scanning microscopy images of cells exposed to g-values of ≤0.006 g for 1 h show an increase in the cell size of clinorotated cells, but no rearrangement in the f-actin filament system compared to static 1-g controls. Thus, 2-D clinostats equipped with slide flasks can be used for adherent cell experiments, however, the maximal g-values have to be carefully considered.     

原子系统的光发射量子理论

根据电磁辐射场的量子化理论,结合SU(1,1)Lie代数理论和SO(3)Lie代数理论,得到原子系统光发射的量子论。作为例子,结出了氢原子发射时原子的跃迁寿命。     

用于原子干涉仪的光学锁相环系统

研制了一种用于原子干涉仪的外差式光学锁相环系统,实现了两台外腔半导体激光器频率和相位的同步,锁相后的激光拍频线宽低于1 Hz,10 MHz积分带宽内的残余相位噪音为0.002 rad2,频偏1~100 kHz范围内的相位噪音达到-100 dBc/Hz。研究了闭环相位噪音对原子干涉仪的影响,当自由演化时间为200 ms、拉曼π脉冲时间为30 μs、单次循环时间为1 s时,锁相后相位噪音对重力测量灵敏度的贡献为10μGal?Hz-1/2     

原子系统的光吸收量子理论

根据电磁辐射场的量子化理论,结合SU(1,1)Lie代数理论和SO(3)Lie代数理论,得到原子系统光吸收的量子论。作为例子,给出氢原子的光吸收截面。     

Ultrasonic High-Temperature Sensors: Past Experiments and Prospects for Future Use

Ultrasonic thermometry sensors (UTS) have been intensively studied in the past to measure temperatures from 2080 K to 3380 K. This sensor, which uses the temperature dependence of the acoustic velocity in materials, was developed for experiments in extreme environments. Its major advantages, which are (a) capability of measuring a temperature profile from multiple sensors on a single probe and (b) measurement near the sensor material melting point, can be of great interest when dealing with on-line monitoring of high-temperature safety tests. Ultrasonic techniques were successfully applied in several severe accident related experiments. With new developments of alternative materials, this instrument may be used in a wide range of experimental areas where robustness and compactness are required. Long-term irradiation experiments of nuclear fuel to extremely high burn-ups could benefit from this previous experience. After an overview of UTS technology, this article summarizes experimental work performed to improve the reliability of these sensors. The various designs, advantages, and drawbacks are outlined and future prospects for long-term high-temperature irradiation experiments are discussed.     

Report on Microgravity Experiments of Dynamic Surface Deformation Effects on Marangoni Instability in High-Prandtl-Number Liquid Bridges

This paper reports an overview and some important results of microgravity experiments called Dynamic Surf, which have been conducted on board the International Space Station from 2013 to 2016. The present project mainly focuses on the relations between the Marangoni instability in a high-Prandtl-number (Pr=?67 and 112) liquid bridge and the dynamic free surface deformation (DSD) as well as the interfacial heat transfer. The dynamic free surface deformations of large-scale liquid bridges (say, for diameters greater than 10 mm) are measured with good accuracy by an optical imaging technique. It is found that there are two causes of the dynamic free surface deformation in the present study: the first is the time-dependent flow behavior inside the liquid bridge due to the Marangoni instability, and the second is the external disturbance due to the residual acceleration of gravity, i.e., g-jitter. The axial distributions of DSD along the free surface are measured for several conditions. The critical parameters for the onset of oscillatory Marangoni convection are also measured for various aspect ratios (i.e., relative height to the diameter) of the liquid bridge and various thermal boundary conditions. The characteristics of DSD and the onset conditions of instability are discussed in this paper.     

A Semi-automated Electrophysiology System for Recording from Xenopus Oocytes Under Microgravity Conditions

We describe a custom-made two electrode voltage clamp (TEVC) system suitable for real-time recording from Xenopus laevis oocytes in microgravity research applications. This miniaturized version of a standard laboratory TEVC, has proven to be reliable and robust. It allows the recording of membrane currents of comparable quality to ground-based TEVC measurements. The data presented were obtained during an ESA parabolic flight campaign (Bordeaux, France) and suggests that differing gravity conditions can reversibly modulate transmembrane ionic current in Xenopus laevis oocytes.     

Large Bolometer Arrays with Superconducting NbSi Sensors for Future Space Experiments

New techniques in microelectronics allow to build large arrays of bolometers filling the focal plane of submillimeter and millimeter telescopes. The expected sensitivity increase is the key for the next generation of space experiments in this wavelength range. Superconducting bolometers offer currently the best prospects in terms of sensitivity and multiplexed readout. We present here the developments led in France based on NbSi alloy thermometers. The manufacturing process of a 23 pixel array and the test setup are described.      

基于LabVIEW的自动条码数据采集系统

基于LabVIEW平台通过串口实现了条码扫描器的控制与条码数据的读取,开发了自动条码数据采集系统,可快速采集和管理现场的条码数据,并利用条码数据进行数据库访问.     

Dynamics for Droplets in Normal Gravity and Microgravity

A numerical study has been carried out to investigate the deformation dynamics of droplets under normal gravity and the thermocapillary migration of droplets under microgravity. The Navier–Stokes equations coupled with the energy conservation equation are solved on a staggered grid by the method of lines, and the mass conserving level set method is used to predict the surface deformation of the droplet. The simulation for the falling droplet in the air under normal gravity shows that the value of Weber number affects mainly the deformation of the droplet, while the value of Reynolds number has direct impact on the falling velocity of the droplet. From the simulation for the droplet thermocapillary migration and lateral oscillation under microgravity, it is found that the value of Marangoni number has obvious effects on the moving velocity and temperature distribution of the droplet.     

冷原子吸收分光光度法测定化妆品中汞的不确定度分析

采用冷原子吸收分光光度法测定化妆品中的汞，其不确定度来源于称样、消化、定容、稀释标准溶液及由标准溶液浓度—吸收率拟合的直线。通过对各个不确定度分量的计算合成得出被测量样品中汞含量的标准不确定度和扩展不确定度。     

Use of Dynamic Scaling for Trajectory Planning of Floating Pedestal and Manipulator System in a Microgravity Environment

In this paper, motion planning and coordination is investigated for a space robot composed of a floating pedestal and manipulator. In some cases, such as a manipulator grasping a higher quality target, the dynamic coupling can occur leading to under-actuation of the floating pedestal (that is, the required control force of the pedestal exceeds the thrust limit). As a result, the desired operation may not be achieved due to large control error. Therefore, we propose an innovative planning method, termed dynamic scaling planning method, to avoid pedestal under-actuation and guarantee accuracy of manipulator operations. Furthermore, to validate the proposed method, an experimental model of a space robot operating in a magnetic-liquid hybrid suspension microgravity simulation environment was developed. Results of the experimental simulations demonstrate that the proposed method can effectively avoid under-actuation of the pedestal. Moreover, the end-effector of the manipulator follows a desired path to successfully reach its target location.     

Miniaturized Optical Fiber Sensor Interrogation System Employing Echelle Diffractive Gratings Demultiplexer for Potential Aerospace Applications

To enable the application of optical fiber sensors to aerospace vehicles, the sensor interrogation or data acquisition system has to meet small size and low weight requirements. This paper presents the developmental work of an echelle diffractive gratings (EDGs) demultiplexer-based optical fiber sensor interrogation system. The operation principle of this system and its application to fiber Bragg grating (FBG) sensor interrogation are presented. The experimental results have shown that the developed interrogator (not including the electronic controller) weighs less than 60 g and provides better than 1 pm measurement resolution and better than plusmn10 pm measurement accuracy.     

通风管道中颗粒沉积的实验研究

通风与空调系统中的风管系统（简称：通风系统）内的颗粒沉积会对室内人员造成严重影响,同时还会降低通风与空调系统的性能,甚至导致室内二次污染。如果清楚了通风管内何处沉积着或易于沉积有害气溶胶,就能在最初设计通风系统时多加注意,在设计阶段就应该尽量减少它们的沉积,同时还可以提高建筑补救效率以及降低相关费用。掌握通风管道中颗粒沉积的知识不仅对模拟建筑内颗粒情况有帮助,还可以更加充分地了解颗粒运动情况。     

应用VRML技术的脉冲爆震发动机虚拟实验系统开发

在脉冲爆震发动机的教学科研中,迫切需要开发一个演示系统结构与运行过程的虚拟实验室系统。以VRML虚拟现实技术为平台和UG三维实体建模为单元,构建了具有交互功能的脉冲爆震发动机虚拟动态实验系统,实现了脉冲爆震发动机的虚拟拆卸与装配以及脉冲爆震发动机系统的虚拟运行。该虚拟实验系统避免了实际试验过程的危险性和涉密性等问题,具备远程教学科研的演示功能。     

Facilities for Simulation of Microgravity in the ESA Ground-Based Facility Programme

Knowledge of the role of gravity in fundamental biological processes and, consequently, the impact of exposure to microgravity conditions provide insight into the basics of the development of life as well as enabling long-term space exploration missions. However, experimentation in real microgravity is expensive and scarcely available; thus, a variety of platforms have been developed to provide, on Earth, an experimental condition comparable to real microgravity. With the aim of simulating microgravity conditions, different ground-based facilities (GBF) have been constructed such as clinostats and random positioning machines as well as magnets for magnetic levitation. Here, we give an overview of ground-based facilities for the simulation of microgravity which were used in the frame of an ESA ground-based research programme dedicated to providing scientists access to these experimental capabilities in order to prepare their space experiments.     

CO_2制冷剂在食品冷冻冷藏中的应用前景

CO2制冷剂在制冷与空调中的应用主要有三方面：热泵热水器、汽车空调和食品冷冻冷藏。本文论述了CO2制冷剂在食品冷冻冷藏中的应用前景。在国外超市已取得了成功的经验,由于我国正在加速R22的淘汰进程,相信在不久的将来会在我国超市中出现。     

杭州国电机械设计研究院科研综合楼低温送风变风量空调系统设计

介绍了杭州国电机械设计研究院科研综合楼低温送风变风量空调系统的设计方案及产品选型特点,对工程实际运行数据进行了分析,指出该系统具有节能、舒适和运行可靠等优点,值得应用和推广。