P TYPE GRADIENT ENHANCED DQF COSY EXPERIMENTS SHOW LOWER t 1 NOISE THAN N TYPE *

脉冲相位的不稳定性是导致二维谱中的T1噪声的原因之一.本文从理论上和实验上对脉冲相位不稳定性所引起的T1噪声进行了研究.从角动量算符IX，Iy和Iz推导中发现，由于磁化矢量在P型和n型dQfCOSy实验的脉冲梯度场中进动方向的内在差异，一部分脉冲相位误差在P型dQfCOSy实验会被重聚掉，在n型dQfCOSy实验中却会被加重.因此P型dQfCOSy实验的T1噪声比n型小.理论推导还得到T1噪声在P型和n型中的理论比值为3∶11.以上理论结果得到我们实验结果的支持t 1 noise, stemming from the instabilities of pulse phases in 2D spectroscopy, has been investigated theoretically as well as experimentally.Based on the angular momentum operator I x,I y,I z formalism, our deductions show that the different precessing directions of the magnetization between P type and N type gradient enhanced DQF COSY experiments result in that P type gradient enhanced DQF COSY experiments refocus the phase errors of pulses, while N type gradient enhanced DQF COSY experiments strengthen the effect of the phase errors of pulses.Therefore, t 1 noise in P type gradient enhanced DQF COSY experiments is lower than that in N type.In addition, the theoretical ratio of P type to N type is 3∶11, which is supported by our experimental results

ER-200D-SRC型EPR谱仪微机系统的研制

本文详细叙述了用于西德Bruker分析仪百公司ER-200D-SRC型EPR谱仪的自动控制、数据采集累加、数据处理分析的软硬件系统。该系统硬件由两大块组成，一块为北京祥云数据设备公司的A/D、D/A接口卡，另一块为我们自己设计的数字量控制接口卡，可分别独立地插入PC机的扩展槽中。该系梵软件采用TurboC2.0编写，具有菜单式、结构化、模块化、汉字实时工作提示、数据实时屏幕显示、实验参数实时显示等特在，用户界面良好，它可实现对ER-200D-SRC型EPR谱仪中心磁场、扫描磁场宽度的设置、绘图仪自动控制、数据采集累加及实验数据的分析和处理等各项功能。学位：理学硕士院系专业：物理与机电工程学院物理学系_无线电物理学号：xy00012

Determination of Humidity of Particulate Materials by the Method of Coaxial Cavity Perturbation

导出开路端外导体加长的λ/4同轴腔受颗粒状介质微扰的频偏近似计算公式，并在实验上测出不同湿度不同颗粒大小黄豆的频偏值.理论计算及实验均表明，如用上述腔体的过极限圆波导段做容器，由于过极限圆波导中电磁场沿纵向按指数率衰减，当选择合适的衰减系数α，在通常的黄豆等粮食颗粒的线度变化范围内，填充一层颗粒状介质所产生的频偏值随颗粒半径r的变化不大.应用此种腔体测量颗粒状介质湿度，可以在一定范围内消除粒度大小和形状的影响.The approximate Formula For calculating Frequency shiFt by the perturbation method of coaxial cavity ,which has a extended outer conductor,is deduced ,and the experimental results For Frequency shiFt measurement of soybeans with diFFerent radii under with diFFerent levels of humidity are presented.IF the section of cut ofF circular waveguide above mentioned is used as a vessel,the electromagnetic Field in it would attenuate exponentially along the longitudinal direction.When the attenuation constant is selected suitably ,the Frequency shiFt caused by Filling a layer of particulate material in it has little to do with the measured object′s radius R iF soybeans,peanuts and so on were used as sample.For this reason,such a cavity can be used For measuring humidity of some particulate material ,which can eliminate the inFluence of its size and shape to some extent.福建省自然科学基

THE OPTIMIZATION OF EXPERIMENTAL PARAMETER AND PROCESSING METHOD OF EXPERIMENTAL DATA FOR MEASUREMENT OF TRANSVERSE RELAXATION TIME (AND SELF-DIFFUSION COEFFICIENT) OF INTERMOLECULAR MULTIPLE QUANTUM COHERENCES IN NMR

针对测量横向弛豫时间T2 的CPMG脉冲序列和我们所设计的可同时测量高极化单组份单峰核自旋体系n阶分子间多量子相干横向弛豫时间T2 ,n和自扩散系数Dn 的改进的CRAZED脉冲序列 ,分析了影响测量T2 、T2 ,n(或Dn)的各种因素 ,并着重从技术方面讨论了准确测量T2 ,n和Dn 的实验参数优化和实验数据处理方法In light of the CPMG pulse sequence , which is used to measure the transverse relaxation time T\-2, and of modified CRAZED pulse sequence, which is designed to simultaneously measure the transverse relaxation time, T\-\{2,n\}, and self diffusion coefficient, D\-n, of intermolecular multiple quantum coherences (iMQCs) for a highly polarized spin system with only one type of spin species, all kinds of factors, which will affect the measurement of T\-2? T\-\{2,n\} (or D\-n), are analyzed. The processing method of the experimental data and the optimization of the experimental parameter for the accurate measurement of \%T\-\{2,n\}\% and \%D\-n\% of iMQCs are discussed from the point of view of technique.国家自然科学基金资助项目 (1 0 0 0 5 0 0 6和 1 9975 0 3 8);; 福建省自然科学基金资助项目 (C991 0 0 0 1

TM-128电脑多功能涡流探伤仪微机系统的改造

本文叙述TM-128多功能涡流探伤仪与IbMPC/386微机联机的软硬件系统。该系统具有如下功能,仪器工作频率检测与显示,平衡电桥调整显示,阻抗平面图显示,阻抗时间分量图显示,缺陷报警,图形存储及打印等。其接口硬件由两路A/d模数转换电路及InIEl8253可编程定时计数电路组成,可插入PC机的扩展槽中。其软件采用TurbOC语言编写,具有菜单式、结构化、模块化等特点,由于采用无需CCdOS支持的汉字显示技术,使得操作极其方便,用户界面良好

THE IMPROVEMENT of MICROCOMPUTER SYSTEM FRO A BRUKER ER-200D-SRC SPECTROMETER

详细叙述了德国brukEr分析仪器公司Er-200d-SrC型EPr谱仪与IbMPC/386微机联机的软硬件系统，该系统综合了仪器的自动磁场扫描控制，数据采集累加和数据分析处理及数据绘图、打印等各项功能。其硬件由IbMPC/386微机及二大接口模块组成。一块为商品化的12位A/d、d/A接口卡，另一块为自行设计的以InTEl-8255可编程通用接口电路为主体的数字量输入输出控制接口卡，可分别独立地插入PC机的扩展槽中，其软件采用C语言编写，具有菜单式、结构化、模块化、汉字工作提示、实验数据实时屏幕绘图、实验参数实时显示等特点，用户界面良好，该系统恢复并提高了原谱仪的整体性能，具有一定的推广价值。The software and hardware system was developed For use with the GermanBRUKER ANALYTISCHE MESSTECHNIK COMPANY'S EPR Spectrometer model ER-200D-SRC.The system was used to control spectrometer during magneticsweeping，collect data From spectral scans in single-scan and multiscan modes， dataanalysis and manipulation， output data to the spectrometer x-y recorder and printdata to printer，The hardware is based on IBM PC/386 computer and two interFacemodules， one of which is commercialized 12-bit A/D and D/A interFaced， and theother a designed digital I/O control card with a general programable interFace ICINTEL 8255 being it’s main body．The two cards can be inserted into PC's extensionsocket respectively.The software，written in C language， is characterized by chinesecharacter menu display,structured and modularized program and real-time working.It has good user’s interFace and easy operation， The system has recovered and im-proved the whole Funtion of the original spectrometer and has certain value Fordevelopment

Simultaneous Measurements of Transverse Relaxation Time and Self-diffusion Coefficient of Intermolecular Multiple Quantum Coherences in NMR

提出一种可同时直接测量高极化核自旋体系分子间 n阶多量子相干横向弛豫时间 T2 ,n 和自扩散系数 Dn的一维核磁共振方法 .实验结果表明 :对于单组份单峰的高极化核自旋体系 ,分子间 n(n≥ 1)阶多量子相干横向弛豫时间 T2 ,n 和自扩散系数 Dn 分别具有如下关系 :T2 ,n ≈ T2 ,1/ n和 Dn ≈n D1,这里 T2 ,1和 D1分别为该峰的单量子相干横向弛豫时间和自扩散系数 .这些结果有助于揭示分子间多量子相干横向弛豫和自扩散的性质和机理 .Simultaneous measurements of transverse relaxation time, T_(2,n), and self-diffusion coefficient, D_n, of intermolecular multiple quantum coherences (iMQCs) were presented for a highly polarized single-component spin system. The pulse sequence proposed herein effectively suppresses the effects of radiation damping, inhomogeneity of magnetic field and variation of dipolar correlation distance, all of which may affect quantitation of T_(2,n) and D_n. Experimental results demonstrate that the quantitative relationship between T_(2,n)(n≥1) and T_(2,1) is T_(2,n)≈T_(2,1)/n and the quantitative relationship between D_n(n≥1) and D_1 is D_n≈nD_1. These results will be helpful for understanding fundamental properties and mechanisms of the transverse relaxation times and self-diffusion coefficients of iMQCs.国家自然科学基金 (10 0 0 5 0 0 6和 19975 0 38);; 福建省自然科学基金 (C9910 0 0 1)资助项

Application of Microwave Method to Measurement of Nonequilibrium Carrier Lifetime

介绍用有哑铃状孔-缝端盖的微波谐振腔测量片状半导体材料非平衡载流子寿命的一种方法.腔体用圆柱TE011模高Q腔，易于更换端盖，可以达到较高的测量精度.实验表明，对同一半导体材料测量得到的有效寿命不因端盖孔-缝的改变而变化，所以可以通过选用孔-缝尺寸不同的端盖，来测量不同电导率的材料，以提高信号幅度，从而提高精度.测量是无接触的，因此无需对样品进行加工.用小的孔-缝端盖还可以用来对半导体材料有效寿命的二维分布进行研究.A method for measurement of nonequilibrium charge carrier lifetime by the TE 011 mode cylindrical cavity with dumbbell shape slots is presented. The measurement is non contact and the sample processing is not required. Moreover, the quality factor Q of cylindrical cavity is high, and high measurement sensitivity can be achieved.For the same sample, the carrier lifetime is not changed with the variation of the coverplate of the cavity with different size of the slots. In order to get high measurement sensitivity, the appropriate size of the slots should be chosen to measure the samples of different conductivity. Meanwhile, the planar distribution of carrier lifetime in semiconductor can be analyzed by such method.福建省自然科学基

The Characteristics and Application of the TE 011 mode Cylindrical Cavity with Dumbbell shape Slots on Its Plate

介绍用微波谐振腔测量片状介质材料的电导率、介电常数和半导体非平衡载流子寿命的方法.对圆柱腔TE011模端盖上的哑铃状孔-缝的特性进行了研究，指出单个哑铃状孔-缝与TE011模耦合很弱，两个对称的哑铃状孔-缝与TE011模具有较强的耦合，后者可用于小损耗片状介质材料介电常数、半导体材料非平衡载流子寿命等参数的测量.因为测量是无接触的，所以无需对样品进行特殊加工.TE011模品质因数Q值高，因而测量具有较高的精度.A method For measurement of the relative permittivity, conductivity of the medium as well as unbalanced carrier liFetime of semiconductor by the TE 011 mode cylindrical cavity with dumbbell shape slot is proposed. We made a study of the characteristics of the TE 011 mode cylindrical cavity with dumbbell shape slots on its plate, pointed out that the coupling between single dumbbell shape slot with TE 011 mode was low, but it was high iF a couple of symmetry dumbbell shape slots were used, and that the latter can be used conveniently For measurement of the permittivity of low loss platelike sample and the unbalanced carrier liFetime τ of semiconductor.The measurement is non contact and the sample processing is not required. The quality Factor Q of TE 011 mode is highs, so that higher measurement sensitivity can be achieved.福建省自然科学基

APPLICATIONSTUDYONSOLVENTSIGNALSUPPRESSION WITHSELECTIVEEXCITATIONTECHNIQUE INCOMBINATION WITHPFG

对结合脉冲梯度场的选择激发技术在溶剂峰抑制中的四种可行序列进行比较，实验表明非对称的双梯度自旋回波序列在谱图的相位特性和溶剂峰抑制效果两方面均是最佳的方案，并将其推广应用到溶剂峰抑制的gCOSy 实验中，获得较理想的溶剂峰抑制效果Theschemesforsolventsignalsuppression using selectiveexcitation techniquein combi nation with PFGhas been studied comparatively.Four practicable pulsesequences have been investigated.The results show that non sym metric selective double PFG spin echo (DPFGSE) isthe mostefficientsolventsignalsuppression schemein both phase property and solventsuppression effect.This scheme has been introduced for solvent signal suppression purposesin 2DgCOSYexperimentand a satisfied result has been achieved .福建省自然科学基