核磁共振波谱仪的管理与维护

介绍了核磁共振仪主要由超导磁体、谱仪和工作站组成,同时我校核磁共振仪还配有自动进样器、UPS等辅助设备。工作中需要定期对磁体和探头等重要部件进行维护,对常见问题的处理和解决办法主要从进样取样、锁场和匀场、样品旋转等方面讨论。为了使仪器处于良好的运行状态,更好地完成样品的测试,仪器管理人员和使用人员均应掌握核磁共振仪的管理和维护,保证学校的教学和科研。     

Q 800动态机械热分析仪的维护及常见问题探讨

介绍了DM A Q800动态机械热分析仪的维护,对常见问题进行了探讨。维护主要涉及低温冷却附件（GCA）、空压机（ACA）以及Q800本身,常见问题主要是如何通过合理的制样以及装载样品来获得更准确的测试结果,掌握维护及如何制样装载样品既能得到准确的测试结果,同时也能延长仪器使用的寿命和降低仪器使用不当对操作者造成的伤害。     

核磁共振成像超导磁体设计方法研究

核磁共振成像是一种先进的影像检查方式,其广泛用于医学检查和化学检查领域。核磁共振系统主要由磁体部分、磁共振波谱仪部分及数据处理部分组成,而磁体部分主要是通过主磁体提供磁场进行工作。本文对核磁共振成像超导磁体设计方法进行了分析研究。     

新型太阳模拟器性能测试

文章介绍了一种新型太阳辐射模拟器的整体构造和技术指标;详细阐述了其性能测试方法,包括光源的光谱分布、辐照度范围、均匀性和稳定性等性能;同时对测试仪器、测试方法、测试结果以及常见问题的解决方法进行了分析和总结。     

智能化测试仪器的特点及发展趋势研究

测试技术的智能化发展主要靠测试仪器、测试系统和测试生态的智能化,而测试仪器的智能化是整个测试技术智能化的核心。基于此,介绍了智能化测试仪器的主要特点,并对这些特点进行了分析,进而提出了一些对智能化测试仪器在信息处理、通用化、集约化、无线通信、虚拟化、智能生态等方面的发展及趋势的看法。     

流动注射仪QC8500测定水中酚含量重复性差的原因分析

针对流动注射仪重复性差的问题,经过一系列标准液分析、仪器处理、实验测试,找出原因。强调标准操作以及仪器日常维护的重要性,希望可供相关从业者参考借鉴。     

高能所研制成功1.5T核磁共振成像超导磁体

<正>近日,中国科学院高能物理研究所研制成功场强为1.5特斯拉的核磁共振成像超导磁体,为实现该产品国产化奠定了基础。超导磁体是核磁共振成像设备的核心关键部件,长期以来,国内核磁共振成像产业的发展受制于国外     

风电齿轮箱噪声测试系统的设计简介

风电齿轮箱作为风机的重要组成部分，是机组的核心部件之一，故加强对其的维护和保养十分必要。但是，由于风机工作环境恶劣，在运转的过程中常常会受到多种因素的影响，造成运转问题出现。考虑到齿轮箱的维护和更换成本，在事故发生之前对问题进行解决十分必要。而通过噪声监测来达到“以噪带震”检测齿轮箱的方法是一种可选的途径。本文针对风电机组的齿轮箱噪声测试系统设计问题进行简要分析，探究噪声检测构成以及设计原理，以此提升相关工作效能。     

美开发出高强度医用核磁共振成像仪

美国伊利诺伊大学芝加哥分校2007年12月4日宣布，该校研制的高强度的核磁共振成像仪已经完成了安全测试，即将投入临床使用。测试证明，这种强度高达9．4特斯拉的扫描仪对人体是安全的。与目前核磁共振成像仪利用水分子追踪扫描不同，这一高强度的仪器借助的是钠离子。     

中科院电工研究所研制出无须补充液氦的超导磁体系统

正中科院电工研究所王秋良研究组在国家支撑计划支持下,采用多级振动隔离制冷机振动与分离小腔液氦液化回流技术,研制出国际上首台商业化主动冷却零挥发液氦400 MHz核磁共振谱仪磁体系统和10~12T/100mm高稳定度超导磁体系统。图为400MHz核磁共振谱仪现场测试高场及高均匀度超导磁体系统对磁场均匀度和振动有着较高要求,一般需要在中心区域产生达     

低温杜瓦装置的结构设计与传热分析

为了获得有效的超导磁体运行的低温环境,文中介绍了低温超导磁体杜瓦装置的结构设计和传热分析,研制了一套采用真空多层绝热、铜辐射冷屏、蛇形排气管结构形式的绝热系统.通过传热理论计算表明,液氦的损耗量小于技术要求的0.9L/h指标,能够保证超导磁体系统能够在一定的低温环境下长日时间的运行.     

基于超声的圆筒件焊缝检测系统

圆简件是电站锅炉广泛应用的一种部件,其焊接质量关系到产品的安全运行.对其焊接质量的内部检测主要依赖于无损检测技术.分析了圆简件超声波检测的困难,提出了解决这些困难的方法,制订了有针对性的检测工艺,较好地满足了检测要求.     

钢丝绳无损检测技术研究进展

针对钢丝绳应用及检测过程中安全性能、利用率、检测精度等问题,综合分析了现阶段钢丝绳无损检测国内外相关研究成果,总结并提出了今后的研究方向。首先,介绍了无损检测技术当前在实际工程中的应用,具体对比分析了两种主流探伤仪技术特点,以及在桥梁建筑等行业中的应用;接着,介绍了现在无损检测技术发展状况,着重论述了钢丝绳磁检测技术和非磁检测技术研究和应用现状,其中磁检测技术主要包括电磁法和永磁法,非磁检测主要包括电流法、声发射法和声-超声检测法;最后,在对比当前无损检测研究方法的基础上提出了集中钢丝绳无损检测的可行方法,指出了发展声-超声检测技术的研究趋势。     

核磁共振仪的开放共享与维护

核磁共振仪是高等院校重要的大型科研测试设备。科学管理与维护,对于提高其使用质量、确保设备性能完好、降低设备维修成本具有重要现实意义。根据作者近三年来在400兆超导核磁共振仪的开放共享、实际管理和维护工作中的经验,就如何做好核磁共振仪的开放共享、使用管理与维护问题进行探讨,旨在提高仪器设备的完好率和使用率,保障教学和科研工作的顺利进行。     

Design and investigations of the superconducting magnet system for the multipurpose superconducting electron cyclotron resonance ion source

The production of intense beams of heavy ions with electron cyclotron resonance ion sources (ECRIS) is an important request at many accelerators. According to the ECR condition and considering semi-empirical scaling laws, it is essential to increase the microwave frequency together with the magnetic flux density of the ECRIS magnet system. A useful frequency of 28 GHz, therefore, requires magnetic flux densities above 2.2 T implying the use of superconducting magnets. A cooperation of European institutions initiated a project to build a multipurpose superconducting ECRIS (MS-ECRIS) in order to achieve an increase of the performances in the order of a factor of ten. After a first design of the superconducting magnet system for the MS-ECRIS, the respective cold testing of the built magnet system reveals a lack of mechanical performance due to the strong interaction of the magnetic field of the three solenoids with the sextupole field and the magnetization of the magnetic iron collar. Comprehensive structural analysis, magnetic field calculations, and calculations of the force pattern confirm thereafter these strong interactions, especially of the iron collar with the solenoidal fields. The investigations on the structural analysis as well as suggestions for a possible mechanical design solution are given.     

Construction and calibration of a 12 T pulsed magnet integrated with a 4 K closed-cycle refrigerator

A low cost 12 T pulsed magnet system has been integrated with a closed-cycle helium refrigerator for performing magnetotransport measurements. Minimal delay between pulses and ac current excitation with software lock-in to reduce noise enables quick but accurate measurements to be performed at temperatures of 4-300 K up to 12 T. An additional pulsed magnet operating with a liquid nitrogen cryostat extends the range up to 19 T. The instrument has been calibrated against a commercial superconducting magnet by comparing quantum Hall effect data in a p-channel SiGe/Si heterostructure, and common issues arising out of pulsed magnet usage have been addressed. The versatility of the system is demonstrated through magnetotransport measurements in a variety of samples such as heterostructures, narrow gap semiconductors, and those exhibiting giant magnetoresistance.     

Structure elucidation capabilities on typical pharmaceutical drugs by new nuclear magnetic resonance technology: a 400 MHz high-temperature superconducting power-driven magnet NMR system

Nuclear magnetic resonance (NMR) is a powerful technique for the structure elucidation of organic molecules and significantly important in the pharmaceutical industry supporting the discovery and development of drug substances or active pharmaceutical ingredients (APIs). Following an initial study and assessment of a prototype NMR instrument with a high-temperature superconducting (HTS) power-driven magnet of 9.4?T (400?MHz for ¹H observation) operating with standard commercial electronics and probes, we tested the instrument with three compounds representing typical pharmaceutical drugs. We compared results from two probes and shimstacks with different geometries (broadband fluorine observe (BBFO) with Bruker orthogonal shim system-3 (BOSS3) and Bruker quattro nucleus probe (QNP) with BOSS1 shims) testing standard one-dimensional (1D) NMR experiments including selective excitation experiments, and two-dimensional (2D) homonuclear and heteronuclear experiments for the purposes of evaluating the equipment for structure elucidation capabilities. In our initial study on cinacalcet HCl, only the 1D ¹H experiment showed a loss of resolution when using the longer coiled BBFO probe with the BOSS3 shims compared to the shorter coiled QNP probe with BOSS1 shims. The selective excitation experiments using the cinacalcet HCl were successful. Our characterization of 1D (¹H, ¹³C, ¹⁹F) and 2D (¹H-¹H and ¹H-¹³C) NMR experiments for compounds I and II with the two probes and shimstacks indicated no significance differences. Overall, these results are satisfactory with the HTS magnet at the field of 9.4?T for the structural elucidation work of standard pharmaceutical compounds. This new technology has the advantage of being able to locate the HTS NMR magnet system in any chemistry or analytical laboratory where the samples are produced, facilitating rapid analysis with minor needs from the facilities and without cryogenic liquids.     

A prototype of a superconducting magnet for a 170-GHz gyrotron

Within the framework of the “International Thermonuclear Experimental Reactor” (ITER) program, a prototype of a superconducting magnet for a 170-GHz gyrotron has been developed, manufactured, and tested. The operating induction value (7.1 T at the center of a 219-mm-diameter cold hole and 8.1 T on the winding) is reached at a current of 185.2 A. In the final version of the magnet, the required induction value was reached without aging. Special requirements are imposed on the distribution of the magnetic field along the axis, including an abrupt field decrease on both sides of the magnet. Axial forces are additionally taken by a special device. The magnet’s sections are wound with multifiber conductors based on niobium-tin and niobium-titanium alloys. Seventeen resistive shunts are provided for protecting sections during their transition to the normal state. The magnet is equipped with a device for removing a part of energy from the sections. Mechanical stresses in the magnet’s sections and the structure’s power elements have been measured during tests.     

永磁低场核磁共振分析仪原理和应用

近年来随着核磁共振技术不断进步,国内许多公司和科研机构成功研制出永磁低场磁共振分析仪,本文以NM120-Analyst型核磁共振分析仪作为这类仪器的代表,简单介绍永磁低场磁共振分析仪的结构原理,再分类讨论永磁低场磁共振分析仪在相关领域的基本应用。实践证明,该类仪器已分别在医学磁共振成像设备教学和培训、食品研究、石油勘探、新能源开发等领域中得到广泛应用。     

磁石玩具耐久性测试的标准化与实现

为了解决磁石玩具耐久性测试中存在的耗时长、效率低、外部干扰多等问题,研制一套基于PLC控制技术的自动测试装置,以实现磁石玩具耐久测试的标准化。介绍了测试标准化的要素及其实现过程,对磁石玩具耐久性测试自动测试装置的结构组成、工作原理、工作过程进行了详细阐述,指出该装置可满足中国、美国、欧盟等玩具安全标准关于磁石玩具测试要求。