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Journal of Physics E: Scientific Instruments最新文献

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Single-pulse two-dimensional CO2 laser beam profiling 单脉冲二维CO2激光束剖面
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/016
N. C. Kerr, S. Clark, D. C. Emmony
{"title":"Single-pulse two-dimensional CO2 laser beam profiling","authors":"N. C. Kerr, S. Clark, D. C. Emmony","doi":"10.1088/0022-3735/22/12/016","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/016","url":null,"abstract":"The construction and performance of a system for the spatial characterisation of a CO2 pulsed laser beam is described. A CCD video camera and framestore interfaced to a personal computer are used to image the spatial intensity distribution produced by a CO2 pulse incident upon a temperature-dependent luminescent screen.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"1 1","pages":"1034-1036"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83115261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Improvements to a system of computer-controlled voltage supplies 计算机控制电压供应系统的改进
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/006
S. K. Howell, T. D. S. Hamilton, B. Turton
{"title":"Improvements to a system of computer-controlled voltage supplies","authors":"S. K. Howell, T. D. S. Hamilton, B. Turton","doi":"10.1088/0022-3735/22/12/006","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/006","url":null,"abstract":"New modules are described that allow a single computer to control large systems of floating voltage supplies, which are programmed by providing serial RS232 data according to a specified protocol. This information is decoded to provide data for one or more DAC modules, each of which generate isolated, bipolar voltages which are then amplified to provide up to +or-300 V.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"24 1","pages":"994-997"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90785602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Temperature resistant and vacuum tight LiF connections 耐温和真空紧密的liff连接
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/005
R. Horne, L. As, E. D. Kuyper, L. Hermans, B. Mulder
{"title":"Temperature resistant and vacuum tight LiF connections","authors":"R. Horne, L. As, E. D. Kuyper, L. Hermans, B. Mulder","doi":"10.1088/0022-3735/22/12/005","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/005","url":null,"abstract":"A method is described for making LiF constructions involving LiF-LiF and LiF-metal seals which are vacuum tight over a wide temperature range. As an application, rectangular LiF (001) surfaces have been assembled to form a flat channel which is connected to a copper vacuum flange. LiF machining was done using an ultrasonic technique. Mixtures of LiF and PbF2 were used as sealing agents throughout. The entire construction has been proved vacuum tight in the temperature range 78 K to 700 K.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"29 1","pages":"992-993"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76093514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
DESIGN NOTE: Simple oven design for highly reactive metal beam applications 设计说明:简单的烘箱设计，适用于高活性金属梁应用
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/020
L. Bañares, Á. G. Ureña
{"title":"DESIGN NOTE: Simple oven design for highly reactive metal beam applications","authors":"L. Bañares, Á. G. Ureña","doi":"10.1088/0022-3735/22/12/020","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/020","url":null,"abstract":"An oven design suitable for producing stable beams of highly reactive metals is reported. Its attraction is in its simplicity, low cost and versatility in molecular beam and atomic/molecular physics experiments involving highly reactive metals such as rubidium, caesium, etc. An application is described for the case of atomic caesium, where the metal is produced by the chemical reaction Ba(s)+CsCl(s) to BaCl(s)+Cs(v). One of the main advantages of the present design is the use of a thin-walled, stainless steel pipe, as crucible and heater simultaneously, which considerably simplifies its design. With respect to the experimental method, the simplicity in the loading, working and cleaning procedures compared with the use of pure metal should be noted.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74537545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Apparatus for the measurement of electro-optical rotation changes in polymer solutions 测量聚合物溶液中电光旋光度变化的装置
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/017
K. Weir, B. Jennings
{"title":"Apparatus for the measurement of electro-optical rotation changes in polymer solutions","authors":"K. Weir, B. Jennings","doi":"10.1088/0022-3735/22/12/017","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/017","url":null,"abstract":"With highly asymmetric macromolecules, the observed optical activity depends upon the orientation of the molecules relative to the propagation direction of incident, linearly polarised light. Application of a pulsed electric field is accompanied by transient changes in the optical rotation. A laser-based apparatus has been assembled to measure these small changes with high precision. Details of the system are described along with the theoretical considerations upon which the design was established. The performance of the apparatus is demonstrated by measurements on solutions of the alpha -helical polypeptide poly- gamma -benzyl-L-glutamate in dichlorethane. The sensitivity of the measurements far exceeds all previous estimations of the rotatory powers associated with the alpha -helical axial directions.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"23 1","pages":"1037-1042"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74037546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Measurement of the electroplastic effect in Nb Nb中电塑性效应的测量
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/015
W. Cao, A. Sprecher, H. Conrad
{"title":"Measurement of the electroplastic effect in Nb","authors":"W. Cao, A. Sprecher, H. Conrad","doi":"10.1088/0022-3735/22/12/015","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/015","url":null,"abstract":"The procedures employed to measure the electroplastic effect resulting from the application of a high-density ( approximately 105 A cm-2) electric current pulse of 120 mu s duration during the plastic deformation of Nb in a uniaxial tension test are described in detail. Special attention is focused on eliminating the side effects of the current, such as result from Joule heating and the pinch effect. Thermally activated plastic-flow theory is employed to calculate the side contributions of thermal softening and load oscillations resulting from inertia effects. The electron-dislocation interaction contribution is derived for Nb and found to be about four times that for the FCC metals Al and Cu, and to increase with an increase in the plastic deformation rate just before the application of the current pulse.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"1 1","pages":"1026-1034"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87916388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
Ratio transformer bridge for the measurement of dielectric constant of lossy liquids 测量有耗液体介电常数的比率变压器桥
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/008
M. Gunasekaran, Y. Jayalakshmi
{"title":"Ratio transformer bridge for the measurement of dielectric constant of lossy liquids","authors":"M. Gunasekaran, Y. Jayalakshmi","doi":"10.1088/0022-3735/22/12/008","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/008","url":null,"abstract":"A three-terminal capacitance bridge is developed for the measurement of the dielectric constant of lossy liquids. Using this modified ratio transformer bridge, the capacitance shunted by a resistance as low as 50 Omega is measured at 10 kHz. The capacitance error associated with the inductance of the connecting wire is compensated using the novel method of introducing an additional transformer to the existing ratio transformer bridge. Other sources of capacitance errors, such as the non-zero output impedence of the ratio transformer and the shield capacitances of the cables, are discussed.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"22 1","pages":"1000-1004"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74698187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Accounting for the effects of gas species on piston gauge calculated area: absolute mode 考虑气体种类对活塞计计算面积的影响:绝对模式
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/002
F. Jones, B. E. Welch
{"title":"Accounting for the effects of gas species on piston gauge calculated area: absolute mode","authors":"F. Jones, B. E. Welch","doi":"10.1088/0022-3735/22/12/002","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/002","url":null,"abstract":"A model has been developed, and tested experimentally, to account for the apparent dependence of the effective cross-sectional area of pistons in gas-piston-gauge pressure standards on the particular gas with which the gauge is operated, in the absolute mode. The model treats a pressure drop or loss that depends on the pressure difference across the gauge (P1-P2), the fall rate of the piston, the density of the gas and the viscosity of the gas. The model was tested using helium, neon, argon, nitrogen and krypton, and several values of (P1-P2). An algorithm was developed for calculating the piston cross-sectional area. The experimental results confirmed the model and resulted in a reduction in measurement uncertainty arising from this effect by approximately one order of magnitude.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"97 1","pages":"981-985"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76097673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
A microprocessor-based method for the measurement of speed and speed variation of low-speed drives 一种基于微处理器的低速驱动器速度和速度变化测量方法
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/019
R. Koul, H. S. Vora, M. N. Kumbhare, Y. Tyagi
{"title":"A microprocessor-based method for the measurement of speed and speed variation of low-speed drives","authors":"R. Koul, H. S. Vora, M. N. Kumbhare, Y. Tyagi","doi":"10.1088/0022-3735/22/12/019","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/019","url":null,"abstract":"A digital method for the accurate measurement and display of speed and speed variation of low-speed drives is described. The method is based on the use of an incremental shaft encoder in association with an accurate crystal oscillator. The speed variations can be detected to within one thousandth of the time taken for one revolution of the drive shaft. The speed variation, along with its time of occurrence, is stored on the RAM and can be printed by a serial printer or can be stored on the hard disc of a personal computer.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"4 1","pages":"1044-1045"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84903832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A pulsed crossed supersonic molecular beam apparatus to study the dynamics of refractory atom reactions 一种用于研究难熔原子反应动力学的脉冲交叉超音速分子束装置
Journal of Physics E: Scientific Instruments Pub Date : 1989-12-01 DOI: 10.1088/0022-3735/22/12/013
M. Costes, C. Naulin, G. Dorthe, G. Daleau, J. Joussot‐Dubien, C. Lalaude, M. Vinckert, A. Destor, C. Vaucamps, G. Nouchi
{"title":"A pulsed crossed supersonic molecular beam apparatus to study the dynamics of refractory atom reactions","authors":"M. Costes, C. Naulin, G. Dorthe, G. Daleau, J. Joussot‐Dubien, C. Lalaude, M. Vinckert, A. Destor, C. Vaucamps, G. Nouchi","doi":"10.1088/0022-3735/22/12/013","DOIUrl":"https://doi.org/10.1088/0022-3735/22/12/013","url":null,"abstract":"A pulsed crossed supersonic molecular beam apparatus is described which is suitable for the determination of state-to-state reactive cross sections of ground state refractory atoms with oxidant molecules. The unique aspect of the instrument is its metal-atom beam, in which the atoms are generated by laser ablation of the corresponding solid and are entrained in neutral gases which expand supersonically at the exit of a pulsed nozzle. The peak intensities from this source can exceed the intensities obtainable with a conventional metal-oven effusive source by orders of magnitude for the more refractory elements. Other characteristics, such as a truly tunable velocity range from 600 to 3400 m s-1 associated with a velocity spread between 20 and 10% FWHM, constitute improvements over such conventional sources. Evidence of this superiority is given by comparative experiments on the reaction dynamics of carbon and aluminium. The versatility of the pulsed metal beam, which can accommodate metals, including the most refractory elements, is of great promise for future experiments in this area.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"16 1","pages":"1017-1023"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83455128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 20
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