Synchronization for IR‐UWB System Using a Switching Phase Detector‐Based Impulse Phase‐Locked Loop

Conventional synchronization algorithms for impulse radio require high‐speed sampling and a precise local clock. Here, a phase‐locked loop (PLL) scheme is introduced to acquire and track periodical impulses. The proposed impulse PLL (iPLL) is analyzed under an ideal Gaussian noise channel and multipath environment. The timing synchronization can be recovered directly from the locked frequency and phase. To make full use of the high harmonics of the received impulses efficiently in synchronization, the switching phase detector is applied in iPLL. It is capable of obtaining higher loop gain without a rise in timing errors. In different environments, simulations verify our analysis and show about one‐tenth of the root mean square errors of conventional impulse synchronizations. The developed iPLL prototype applied in a high‐speed ultra‐wideband transceiver shows its feasibility, low complexity, and high precision.     

Synchrotrons radiation stability measurement and improvement

In the 3rd generation synchrotron light source,beside the orbit,air disturbance and ground vibration also could affect the position stability of photon beam in synchrotrons radiation measurement.In the condition of implementation of orbit feedback system at SSRF,the measured position stability of photon beam in synchrotrons radiation measurement station was presented in this paper.And then the improvement methods of position stability of photon beam were discussed.Finally the measured result was shown when the designed feedback system is implemented to improve the position stability of photon beam.     

水基气雾剂中右旋炔丙菊酯、右旋苯醚菊酯、氯菊酯气相色谱法测定

目的:建立水基气雾剂中右旋炔丙菊酯、右旋苯醚菊酯、氯菊酯的气相检测方法。方法:采用邻苯二甲酸二戊酯和邻苯二甲酸二丁酯两种物质作内标进行对比,丙酮作为溶剂,用HP-5的毛细管柱为分离柱,采用程序升温的方法进行分离,FID检测器,进样口温度300℃,检测器温度300℃,柱温初始180℃以20℃/min升温至280℃,保留5 min。结果:3种物质在标样与内标质量比1∶5~5∶1范围内呈良好线性关系,相关系数大于0.999,回收率为92.34%~105.12%,RSD为0.182%~0.649%。结论:此方法准确可靠,并且检测快速、高效,对原有方法进行补充。     

Lifetime extension of in‐core self‐powered neutron detector using new emitter materials

In this paper, new in‐core self‐powered neutron detector emitter candidate materials, ie, vanadium, cobalt, and silver, have been examined in their lifetimes compared with the commonly used rhodium emitter. Using a new quantitative lifetime evaluation model, the lifetimes of vanadium and cobalt were determined to be longer than that of rhodium, but these materials were also shown to have the disadvantage of low signal intensities. Under normal operating conditions, we showed that rhodium emitter can be used for 2 cycles of pressurized water reactors (PWRs) with lifetime of 4.35 years, whereas silver can be used for 5 cycles of PWRs with lifetime of 8.04 years. Three sensitivity tests were performed for rhodium and silver about (1) the emitter size, (2) the fuel assembly burnup, and (3) the emitter temperature variations. From the test results, we observed that the lifetimes of rhodium and silver emitters remained 2 and 5 cycles long, respectively. We concluded that silver can significantly extend the in‐core detector's lifetime in PWR operation.     

有机液体吸光度检测仪的开发应用

湿法冶金生产工艺中,有机萃取是常见的工艺,生产过程中有机液体的颜色及色深(吸光度),是工艺指标性参数,但是对于有机液体的在线测量,因缺乏成熟的仪器,目前大多靠人眼目测和实验室比对的方式。我们以比尔-朗伯定律为理论依据,通过对有机液体吸光度变化与光电吸收关系的研究,开发了有机液体吸光度检测仪,并投入了现场应用,取得了良好的效果。     

基于EJ299-33A探测器的核材料时间关联测量系统的时间分辨

n-γ的时间关联测量可提取核材料的质量、增殖因数，其中时间分辨是表征关联精度的1个重要指标。本文基于数字化数据获取与处理方法，对具有n-γ甄别能力的塑料闪烁体EJ299-33A探测器组成的核材料时间关联测量系统的时间分辨进行研究，采用⁶⁰Co与²²Na γ源进行了对比测量，分析了源对本征时间分辨的影响，进一步通过离线的条件加载反演，给出时间分辨的等效电子能量阈值依赖关系。通过对²⁵²Cf自发裂变时间关联谱的测量和解耦，讨论了时间分辨对不同符合事件的影响。结果表明：系统时间分辨随阈值增加而减少，在阈值为230 keVee时采用⁶⁰Co测量的结果约为560 ps，可满足核材料快时间符合测量的精度要求，而在相同条件下，由于正电子湮没位置的不确定性和延迟符合的影响，²²Na源测量的时间分辨展宽至816 ps；裂变事件时间关联测量中n-n符合受时间分辨的相对影响小于γ-γ符合。     

Accuracy improvement of a 3D passive laser tracker for the calibration of industrial robots

The laser tracker has been used as the mainstream instrument for the position accuracy calibration of industrial robots for quite a long time. However, due to the complexity of the built-in dual-axis active servo tracking system, its cost is high and the target reflector has to adjust its pose frequently, so it cannot be popularized in the production and application sites of industrial robots. Based on this drawback, a 3D passive laser tracker (3DPLT) with high precision, simple structure, easy operation and low cost is proposed in this paper. Firstly, the overall structure of the system is designed, and its position error model based on the principle of spherical coordinate measurement and vector transfer method is established. Then, the error parameters are identified by experiments to formulate the error compensation model. Finally, the multi-pose and large-range spatial error compensation verification experiments of the system are carried out on a commercial coordinate measuring machine. The results show that the spatial volumetric errors of the 3DPLT can achieve within 40 μm after compensation with a good repeatability of ±4 μm. A comparison contouring test with a commercial ballbar is also carried out to validate its applicability of robot calibration.     

基于63Ni辐伏同位素电池原型封装可靠性研究

以加载有63Ni源片的GD3217Y型探测器为处理件，在完成对封装材料的配方选择、灌注工艺、流程的制定并得到具有较好工艺性的灌注条件的基础上，分别对原件、加载不锈钢圆片器件、加载电镀814×107Bq63Ni不锈钢圆片器件进行非放、放射灌注封装。在对灌件可靠性进行检测的基础上，着重考察了原件、无/加载不锈钢圆片灌件、加载电镀814×107Bq63Ni不锈钢圆片灌件封装前后、自然老化及人工加速老化后电学输出特性，即考察在63Ni源持续辐照下，灌料、63Ni源、不锈钢片、芯片以及其他部件构成的体系内部之间相互作用关系，即封装件特殊要求——屏蔽性、时效性。研究结果表明，对以上结构的GD3217Y型探测器组件采用该种封装方式后除改善探测器组件的环境适应性，特别是在保证放射源使用安全性的基础上具有较为稳定的电学输出性能，这为辐伏效应同位素电池封装提供了参考。     

Separation Using Foaming Techniques

Abstract

Separation of various chemical components from each other is often the most difficult step in analytical procedures. The problems attached to separation become further magnified when the species concentations are extremely low. A group of techniques that has proven useful especially in dilute solutions for separating and concentrating metallic as well as nonmetallic ions and complexes, proteins, microorganisms, particulates, etc. is the adsorptive bubble separation techniques. Minerals have indeed been treated using some of these techniques for decades. The success of these processes is primarily dependent upon differences in the natural surface activity of various species or particulates in the system or in their tendency to associate with surfactants. The efficiency of the process is determined by such variables as solution pH, ionic strength, concentration of various activating and depressing agents, and temperature. A proper control of variables offers an opportunity to separate a variety of metallic and nonmetallic species and particulates. In this paper the principles governing various foam separation techniques, particularly froth flotation, are presented along with the recent results on the role of variables that can be controlled to achieve complete removal of species and particulates for analytical purposes.     

空气轴承式板形仪测力系统动态响应性能分析

空气轴承式板形仪用于对在线轧制板带材进行板形的实时检测,故对板形仪的动态性能要有一定的要求.分析了板形仪测力系统组成,并推导出测力系统的总传递函数.分析了板形仪测力系统在单位脉冲和单位阶跃信号下的动态响应,得出了对板形仪设计有益的结论,为空气轴承式板形仪的结构设计和性能特性分析提供充分的理论依据.