Structural optimization of precision instruments through modal analysis

In order to improve the dynamic stability of precision instruments during the design process, a compositive design method based on modal analysis of structure is proposed. With uniform boundary conditions and material characters, the results of Finite Element Analysis (FEA) vary with models. It should be checked whether the model is correctly simplified. Modal experiments can be used for such purpose. The method combines the high efficiency and agility of FEA with the reliability and accuracy of experiments, and avoids the drawbacks of FEA or experiments, such as uncertainty of FEA and high cost of experiments. Taking rotor frame structure as an example, this method is applied as follows: First the modal characters of structure are analyzed with FEA, and then the natural frequencies of the structure are tested by experiments to check the reliability of FEA method, and finally the design scheme is optimized by modifying structure parameters with confirmed FEA.

Precision photonic integration for future large-scale photonic integrated circuits

Since the proposal of the concept of photonic integratedcircuits (PICs), tremendous progress has been made. In2005, Infinera Corp. rolled out the first commercial PICs, inwhich hundreds of optical functions were integrated onto asmall form factor chip for wavelength division multiplexing(WDM) systems[1], then a monolithically integrated 10 ×10 Gb/s WDM chip has been demonstrated, the channelnumber is ten[2]. Like ICs, large-scale PICs (LS-PICs) will besure to be pursued. However, there are still some generalchallenges associated with LS-PICs. The challenges for III–V(mainly InP) PICs is the semiconductor process, which is notmature for LS-PICs. Up to now, the channel number in commercialIII–V WDM PICs by Infinera is still about ten or less.For silicon photonics, the challenge is the silicon based lightsource. The low cost and mature solution for silicon lasers isstill unavailable and only 4 × 25 Gb/s PICs are deployed byIntel Corp. after 18-year R&D investment. Thus it is still unavailablefor practical LS-PICs in the present times.

A Study of Precision Factors of Large-scale Object Surface Profile Laser Scanning Measurement

In this paper, we presented a method of using the l as er scanning triangulation for the non-contact 3D surface profile measurement of large-scale object. The characteristic of large-scale object non-contact mea surement is analyzed and the measuring method is proposed. Main factors influenc ing measurement precision such as image distortion and accurate designation of s peckle center are analyzed and methods of solving these problems are proposed. W e designed a combined filter by which the pulse noise and the Gaussian noise of speckle image can be eliminated efficiently. Using the characteristic of intensi ty distribution of laser speckle image we proposed a new approximating method th at could locate the center of laser speckle image at sub-pixel. The auxiliary v ariables are set to linearize the relationship between the image displacement an d the distance, the accurate values of laser triangulation system parameters cou ld be calibrated accurately and the measuring precision is increased remarkabl y. Using the above techniques we designed a measuring system based on laser sc anning triangulation. The results of the experiment show that these methods can raise the measuring precision of large-scale 3D surface profile effectively.

Design of High Precision Horizontal Control Network for Large-Scale Hydropower Project

A new solution of combination network of GPS and high precise distance measurements with EDM is proposed. Meanwhile, it’s inadvisable only using GPS network without distance measurements. Three schemes: terrestrial network, GPS network and combination network are discussed for horizontal control network design of Xiangjiaba Dam in view of precision, reliability, coordinate and outlay in detail.

Opening and Sharing of Large-scale Instruments and Equipment in Agricultural Research Institutes:A Case Study of Environment and Plant Protection Institute of Chinese Academy of Tropical Agricultural Sciences

The article introduces the main practices and achievements of the Environment and Plant Protection Institute of Chinese Academy of Tropical Agricultural Sciences in promoting the sharing of large-scale instruments and equipment in recent years,analyzes the existing problems in the management system,management team,assessment incentives and maintenance guarantee,and proposes improvement measures and suggestions from aspects of improving the sharing management system,strengthening management team building,strengthening sharing assessment and incentives,improving maintenance capabilities and expanding external publicity,to further improve the sharing management of large-scale instruments and equipment.

Preliminary Application of Combinatorial Measurement and Regression Analysis Method to High Precision Instrumental Analysis

With determination micro-Fe by 1, 10-phenanthroline spectrophotometry for example, they are systematically introduced the combinatorial measurement and regression analysis method application about metheodic principle, operation step and data processing in the instrumental analysis, including: calibration curve best linear equation is set up, measurand best linear equation is set up, and calculation of best value of a concentration. The results showed that mean of thrice determination , s = 0 μg/mL, RSD = 0. Results of preliminary application are simply introduced in the basic instrumental analysis for atomic absorption spectrophotometry, ion-selective electrodes, coulometry and polarographic analysis and are contrasted to results of normal measurements.

A novel wide-range precision instrument for measuring three-dimensional surface topography

We developed a measuring instrument that had wide range, high precision, small measuring touch force. The instrument for three-dimensional (3D) surface topography measurement was composed of a high precision displacement sensor based on the Michelson interference principle, a 3D platform based on vertical scanning, a measuring and control circuit, and an industrial control computer. It was a closed loop control system, which changed the traditional moving stylus scanning style into a moving platform scanning style. When the workpiece was measured, the lever of the displacement sensor returned to the balanced position in every sample interval according to the zero offset of the displacement sensor. The non-linear error caused by the rotation of the lever was, therefore, very small even if the measuring range was wide. The instrument can measure the roughness and the profile size of a curved surface.

Research on the Large Precision Instrument Error Correction Model under the Perspectives of Stability and Robustness

In this paper, we conduct research on the large precision instrument error correction model under the perspectives of stability androbustness. It is one of the effective methods to improve the instruments accuracy using error correction technology, but at present, a lot of errorcorrection is limited to the system error modifi cation, only a small number of the instruments to an error in the dynamic error correction timely,device on the instrument precision sensors, apparently complicate the instrument structure. To fully system error correction that will affect theprecision of instrument mainly random error. Instrument is the main task of error correction is to use a certain method to compensate separableinstruments each component part of a deterministic system error, so the key problems of error correction as is the requirement of equipmentstructure stability is good, with this to ensure that the instrument error of the uncertainty, so that the fundamental fl aw. Under this basis, this paperproposes the novel countermeasure of the issues that is innovative.

Research on the Precision Instrument Reliability and Antiinterference Mode from the Intrusion Detection Angle based on Rough Set

In this paper, we conduct research on precision instrument reliability and anti-interference mode from the intrusion detectionangle based on rough set. Ultra-precision machining applications range from soft metal to hardened steel, stainless steel, high speed steel,cemented carbide and some other hard processing material, to the semiconductor, glass, ceramics and the other hard brittle non-metallic materials,almost all materials available ultra-precision machining technology for the processing. To enhance the robustness of the mentioned equipment,we consider the integration of the rough set and intrusion detection to modify the corresponding issues that will optimize the traditional methodsfrom systematical level which holds special signifi cance.

Design of Signal Lamp Filament Monitoring Alarm Instrument

To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.

Discussion of the process control of large-scale instruments and equipment procurement in State Key Laboratory

In recent years,the usage,management and benefit of large-scale scientific research instruments and equipment in scientific research institutes have been a leading issue in the management of scientific research institutes.Within the scope of equipment budget,it is necessary for each equipment acquisition team to conduct a round of communication,coordination and negotiation with suppliers in order to improve the cost performance of equipment procurement and maximize the performance index to meet the needs of scientific research.By introducing the practical experience of the State Key Laboratory in purchasing imported equipment and managing large-scale instruments,this paper probes into the management process of the imported large-scale scientific research tax-free equipment of scientific research institutes,and explores the system and methods to guarantee and improve the efficiency of large-scale instruments in scientific research institutes from the aspects of policy,funds and technology.

一种基于自适应时钟和波纹减少环路的高精度电流反馈仪表放大器

电流反馈仪表放大器芯片因其高精度、高共模抑制比等优势,广泛应用于微弱信号检测。传统CFIA利用斩波技术降低1/f噪声和失调电压以提升放大器精度,但额外引入斩波波纹会显著限制其精度提升。为此,本文提出一种基于自适应时钟和波纹减小环路的新型电流反馈仪表放大器ARCFIA,该放大器针对传统斩波放大器波纹,采用波纹减少环路RRL对其抑制,并借助自适应时钟ACLK,将斩波开关的输入参考噪声谱密度降低。实验结果表明,ARCFIA实现了低于1.4μV的低失调电压和17.2 nV/√Hz的输入参考噪声,同时波纹被减少到ARCFIA噪声基底以下,通过减小失调、噪声和波纹,实现了精度的进一步提升。此外,ARCFIA还具有一定潜力应用于复杂环境下的高精度测量系统。

不同测试方法在精密手术器械功能质量检查中的比较效果研究

目的:分析对比不同测试方法在精密手术器械功能质量检查中的测试效果,保障手术器械额安全使用。方法:通过查询相关文献及专业书籍,选定精密手术剪和持针器,选用不同的测试材料及方法。精密手术剪依次采用纱布、棉毛布及Interlock手术器械测试套装内的硅胶薄膜方法测试器械切割性能;精密持针器依次采用光照、夹针和Interlock手术器械测试套装内的夹线方法测试器械夹持性能。选取医院清洗消毒合格的100件精密手术剪和100件持针器进行测试效果研究,自制满意度问卷调查手术医生对器械使用的满意度。结果:100件精密手术剪经纱布、棉毛布和硅胶薄膜3种方法测试后,切割性能合格数量分别为94件、76件和58件,其差异有统计学意义(χ^(2)=36.526,P<0.05);手术医生对采用硅胶薄膜测试合格的精密手术剪使用满意率最高,为100%,棉毛布和纱布法分别为82.0%和67.0%,其差异有统计学意义(χ^(2)=48.439,P<0.05)。100件精密持针器经光照、夹针和夹线3种方法测试后,夹持性能合格数量分别为96件、78件和62件,其差异有统计学意义(χ^(2)=38.160,P<0.05);手术医生对采用夹线测试合格的精密持针器使用满意率最高,为100.0%、夹针和光照分别为79.0%和62.0%,医生使用满意率比较,差异有统计学意义(χ^(2)=57.705,P<0.05)。结论:采用Interlock手术器械测试套装内的测试物检查精密手术剪及持针器功能质量,能客观精准地反映器械功能状态,为器械定期维护与保养提供参考,确保器械安全使用。

多中心产业共治的区域现代产业集群建设策略——以广东省精密仪器设备产业集群为例

在国际高端技术封锁日益严峻的新形势下,从任务解构的角度将区域现代产业集群建设进行分层任务细化尤为重要,且需要从目标需求导向的角度出发,针对具体分层任务明确多元治理主体的结构关系及对应主体的治理举措。基于现代产业体系的内涵特征提出区域现代产业集群建设逻辑,并基于多中心治理理论构建多中心产业共治建设区域现代产业集群的理论框架。研究认为,面向区域现代产业集群建设的战略层、发展层、支撑层等五大分层建设任务,政府部门、企业、科研机构、行业协会与服务机构等多元主体通过自发互动博弈,形成分类主导的多中心产业共治模式。为进一步阐述及试验理论,以广东省精密仪器设备产业集群主导咨询机构的集群治理为实践案例,认为其存在多中心联动的积极性和共治模式均有待加强的问题,且关键核心技术短缺问题较为突出。针对此,提出健全多中心联动协调工作机制、政企双中心共治提升产业安全度、多维支撑中心有序推进关键核心技术攻关、政府牵引多中心集聚融通、数字治理创新助推区域产业集群智慧建设等共治效能提升的建议。

基于机器视觉技术的高精度光学仪器表面动态变形测量研究

伴随着光学仪器精度的逐渐提高,其表面动态变形事件发生频率也呈现急剧增加的趋势,是影响与制约光学仪器发展与应用的主要因素之一。为了满足光学仪器的应用需求,提出基于机器视觉技术的高精度光学仪器表面动态变形测量方法。采用机器视觉设备获取高精度光学仪器表面图像,对表面图像进行灰度化处理、去噪处理与增强处理,以此为基础,应用SURF特征检测算法提取表面图像的特征点,通过FLANN算法匹配相邻图像的特征点,利用Delaunay三角化在表面图像区域形成三角网格,进一步计算表面图像特征点的位移与应变,从而实现高精度光学仪器表面动态变形的测量。实验数据显示:在横坐标为1μm时,应用提出方法获得的表面动态变形位移纵坐标为1.8μm,与实际位移基本保持一致,在实验组别为6时,应用提出方法获得的光学仪器表面动态变形应变数值为3μm,与实际应变数值保持一致,充分证实了提出方法具备较好的应用性能。

服务一流学科的大型仪器设备精准化开放管理体系探索与实践

随着一流学科建设的深入,越来越多的大型仪器被投入高校使用,然而当前众多高校的院级大型仪器平台具有一定的局限性。文章结合江南大学生物工程学院仪器管理现状,通过完善管理制度,创新仪器分类方式,构建用户分级体系和规范分层培训流程,落实大仪助理的遴选机制以及安全监管体系,协同形成一套标准化、可执行的适用于生物工程学院的大型仪器设备精准化开放管理体系,更好地服务于一流学科建设。

振动响应传递率及其在光学精密设备中的应用

基于振动响应传递率的工作模态分析方法(operational modal analysis,OMA)相比于传统的试验模态分析方法(experimental modal analysis,EMA)不需要激励被测系统,因此具有测试步骤简单,应用场景广泛的优点。但当前基于振动响应传递率的工作模态分析方法还处于起步阶段,暂未形成统一的理论体系。为此,梳理和总结了基于传递率的工作模态分析方法的有关研究成果,并将其应用于光学精密设备的模态测试之中。

The Jiao Tong University Spectroscopic Telescope Project

The Jiao Tong University Spectroscopic Telescope(JUST)is a 4.4-meter f/6.0 segmented-mirror telescope dedicated to spectroscopic observations.The JUST primary mirror is composed of 18 hexagonal segments,each with a diameter of 1.1 m.JUST provides two Nasmyth platforms for placing science instruments.One Nasmyth focus fits a field of view of 10′and the other has an extended field of view of 1.2°with correction optics.A tertiary mirror is used to switch between the two Nasmyth foci.JUST will be installed at a site at Lenghu in Qinghai Province,China,and will conduct spectroscopic observations with three types of instruments to explore the dark universe,trace the dynamic universe,and search for exoplanets:(1)a multi-fiber(2000 fibers)medium-resolution spectrometer(R=4000-5000)to spectroscopically map galaxies and large-scale structure;(2)an integral field unit(IFU)array of 500 optical fibers and/or a long-slit spectrograph dedicated to fast follow-ups of transient sources for multi-messenger astronomy;(3)a high-resolution spectrometer(R~100000)designed to identify Jupiter analogs and Earth-like planets,with the capability to characterize the atmospheres of hot exoplanets.

影响惯性仪表精度长期稳定的材料学问题与对策

陀螺仪和加速度计等惯性仪表的精度对零组件的尺寸变化有着极其敏感的反应。随着对惯性仪表精度及其稳定性研究的深入,发现材料的尺寸不稳定是导致精度稳定性差的主要原因之一。以多种惯性仪表构件的常用材料为例,从材料学角度系统综述了微观缺陷、第二相、晶粒和织构、内应力以及环境因素对材料尺寸稳定性的影响规律,并提出了如何从材料内禀特性出发改善惯性仪表精度长期稳定性,展望了惯性仪表材料与工艺的未来发展方向。