高频大功率GXN—50型霓虹灯电子电源的研制

ＧＸＮ－５０型霓虹灯电子电源是为负载提供高频交流电压电流的电源设备，是一种专用大功率霓虹灯电源。该产品采用先进的电子技术，节能效率高，带负载能力强（比传统电源高４倍以上），并采用超音技术，用特制的电子开关代替价格昂贵的机械继电器，因而无任何噪声，灯光变化采用程序控制，变换方式灵活，工作稳定可靠。该电源体积小、重量轻，并设计了过压过流保护电路，具有抗干扰能力强等特点。     

用定标块准确确定圆度仪的放大倍数

用定标块校准圆度仪的放大倍数时，一般是将定标块在圆度仪上测量的圆记录放大轮廓图用同心圆模板对线，找出凹下轮廓的径向放大值，然后除以定标块小平面弦高的实际值，其商即为放大倍数。但是，这种方法的缺点是测量准确度不高，不适用于圆度仪自动化程度日益提高带来的快速数字采样自动化校准放大倍数的要求。根据未抑制的定标块圆记录放大轮廓的凹下部分为一弦线的特点，推导了式（８）～（１３）。按要求的采样相邻点的夹角在弦线中点附近的直线上找出三个连续采样值，代入式（８）～（１３），可准确计算出圆度仪的放大倍数。用实例验证了这种新方法的准确性和可行性。     

误差修正技术在电子经纬仪中的应用

分析了经纬仪三轴误差及其性质并采用误差分离方法将其求出，给出了水平角和垂直角的误差修正公式，讨论了电子经纬仪采用误差修正技术以提高水平角和垂直角的测量精度。     

载波相位DGPS快速定位算法

介绍ＤＧＰＳ系统原理，分析讨论了载波相位ＤＧＰＳ定位中主要残差在中、低动态下的影响，提出了载波相位ＤＧＰＳ接收机中一种不需要解算整周模糊度而快速解算定位的一种算法。     

误差分离法测圆柱度误差的不确定度估计

阐述五测头误差分离法在普通机床上实现圆柱度误差在位测量的原理和方法，并对测量不确定度进行了全面的分析和估计，明确了测量精度范围。此不确定度分析有助于机床误差的修正和补偿，对其它形状误差的精密测量和误差分离技术的实际应用具有普遍意义。     

一种大轴同轴度测量方法的研究

介绍了一种测量大轴同轴度误差的方法。用误差分离技术有效地分离掉测量过程中的偏心误差，从而可得到精度较高的同轴度误差。     

PSD线性误差的无基准校正

叙述了一种自律校正方法。它不用其它高精度基准，仅以一对ＰＳＤ与计算机组成的自律校正系统，精确检定其线性误差。本方法可简单地推广应用于其它传感器和测量仪器的校正。     

现代误差理论及其基本问题

简述误差理论的产生与发展过程，指出了经典误差理论存在的问题，并进一步论述了现代误差理论的特征及其基本内容。     

测量不确定度应用中的几个问题

就ＩＳＯ１９９３（Ｅ）测量不确定度表示指南，指出一些使用不当的问题，并就两类评定方法、不确定度的传播与合成、扩展不确定度的包含因子以及规范表示方式等问题阐述了作者的一些见解。     

“敏感点法”检测凸轮升程的误差分析

从“敏感点法”原理入手，通过对方法原理误差、被测凸轮偏心误差、检测系统的误差、测头制造和安装误差以及不符合阿贝原理等引起的升程误差的讨论，对“敏感点法”检测凸轮升程的误差进行了比较全面的分析。     

Learning in an immersive digital theater

The Houston Museum of Natural Science, in collaboration with Rice University has an outreach program taking portable digital theaters to schools and community sites for over five years and has conducted research on student learning in this immersive environment. By using an external independent evaluator, the effectiveness of NASA-funded Education and Public Outreach (EPO) projects can be assessed. This paper documents interactive techniques and learning strategies in full-dome digital theaters. The presentation is divided into Evaluation Strategies and Results and Interactivity Strategies and Results. All learners from grades 3–12 showed statistically significant short-term increase in knowledge of basic Earth science concepts after a single 22-min show. Improvements were more significant on items that were taught using more than one modality of instruction: hearing, seeing, discussion, and immersion. Thus immersive theater can be an effective as well as engaging teaching method for Earth and Space science concepts, particularly those that are intrinsically three-dimensional and thus most effectively taught in an immersive environment. The portable system allows taking the educational experience to rural and tribal sites where the underserved students could not afford the time or expense to travel to museums.     

Stochastic particle acceleration by the forced interaction of relativistic current sheets

We address the problem of interacting relativistic current sheets in self-consistent kinetic plasma simulations within the framework of the Particle-In-Cell model. The interaction is enforced in head-on collisions of up to 10 current sheets at relativistic bulk speeds. The simulations are motivated by the general problem of Poynting flux dissipation in ‘striped wind’ configurations presumably governing the relativistic outflows pervasive in pulsar winds and gamma-ray bursts. We identify the generation of non-thermal particles and formation of a stable power-law shape in the particle energy distributions f(γ) dγ ∝ γ^−s dγ. In 1D, a spectral index s ∼ 2 is observed and attributed to a stochastic Fermi-type acceleration mechanism. In 2D, the generic index of s ∼ 3–4 is retained as in previous simulations of individual current sheets. Whereas in 2D the high energy cut-off is constrained by the limited dissipation of magnetic energy, in 1D the process converts the bulk motion of current sheets towards directed particle momentum of an exclusive class of non-thermal particles.     

Concept options for the aerial survey of Titan

Various aerial platforms intended for long endurance survey of the Titan surface are presented. A few novel concepts are introduced, including a heated methane balloon and a balloon with a tethered wind turbine. All the concept options are predicted to have lower scientific payload fractions than the Huygens probe. It is concluded that the selection of the best aerial platform option depends on more accurate mass estimates and a clear decision on whether, or not, in situ surface composition measurements are required in conjunction with aerial remote sensing.     

Heterogeneous solid/gas chemistry of organic compounds related to comets,meteorites, Titan,and Mars: Laboratory and in lower Earth orbit experiments

To understand the evolution of organic molecules involved in extraterrestrial environments and with exobiological implications, many experimental programs in the laboratory are devoted to photochemical studies in the gaseous phase as well as in the solid state. The validity of such studies and their applications to extraterrestrial environments can be questioned as long as experiments conducted in space conditions, with the full solar spectrum, especially in the short wavelength domain, have not been implemented. The experiments that are described here will be carried out on a FOTON capsule, using the BIOPAN facility, and on the International Space Station, using the EXPOSE facility. Vented and sealed exposition cells will be used, which will allow us to study the chemical evolution in the gaseous phase as well as heterogeneous processes, such as the degradation of solid compounds and the release of gaseous fragments.     

基于LuGre模型的电液加载系统摩擦补偿

为了提高电液加载系统控制精度,针对摩擦问题提出了基于LuGre摩擦模型的前馈补偿方法.建立了用于摩擦仿真分析和补偿器设计的电液加载系统数学模型;通过实验获取并分析了相关的摩擦数据;基于实验数据进行LuGre模型参数辨识,把LuGre模型和辨识结果引入电液加载系统数学模型,并进行仿真结果与实际摩擦数据的对照,证明了LuGre摩擦模型的准确性.设计前馈补偿器,进行了实验对比,实验结果表明前馈补偿器可将摩擦产生的控制误差有效地降至未补偿时的30%左右.      

CoRoT and Kepler results: Solar-like oscillators

The space-borne observatories CoRoT (Convection Rotation and planetary Transits) and Kepler have provided photometric time series data of unprecedented precision for large numbers of stars. These data have revolutionized the fields of transiting exoplanets and asteroseismology. In this review some important asteroseismic results obtained using data from the CoRoT and Kepler space missions concerning stars that show solar-like oscillations are discussed. These results comprise, among others, measurements of the location of the base of the convection zone and helium second-ionization zone in main-sequence stars, the presence (or not) of core-helium burning in red-giant stars, as well as differential rotation in these stars.     

The ESA scientific programme

The ESA scientific programme has, so far, provided several significant astrophysics experiments and further important missions are scheduled for execution during the next decade. These missions are briefly summarised together with several astrophysics investigations presently under study.     

HELIO: The Heliophysics Integrated Observatory

Heliophysics is a new research field that explores the Sun–Solar System Connection; it requires the joint exploitation of solar, heliospheric, magnetospheric and ionospheric observations.     

Radioactivity of the Moon and planets

In this report the main results of the study of radioactivity of the solar sistem bodies are considered. The radioactivity of the Moon and planets was measured by means of vehicles in situ. The radioactivity of the lunar samples, brought to the Earth was studied with laboratory equipment.     

应用于毫米波反射计的多项式校准方法

为了在毫米波波段准确测量波导器件的反射系数,提出了一种应用在反射系数测试前端(反射计)中的校准方法.该校准方法采用基于多项式的误差模型,使得每一个误差项的求解都转化成一个求解轨迹圆圆心的问题,同时不影响求解精度.采用一个滑动负载、一个滑动短路和一个短路器,在毫米波波段降低了对标准件理想程度的要求.实验中搭建了一个Ka波段的反射计,图解误差项的求解过程,分析了误差项的物理意义.把校准后的测量结果与商用矢量网络分析仪(VNA,Vector Network Analyzer)进行比较,吻合较好.同样比较了一组W波段反射计对波纹喇叭的测量结果,进一步验证了方法的合理性.