A novel design approach for a high-current, very-wide-band transconductance amplifier is described. The approach is based on paralleling the input and output of complementary unipolar current-mirror cells. Each cell has a fixed current gain determined by the ratio of two resistors. A differential input voltage-to-current circuit drives the cell array. The design avoids the need for a single low-resistance current-sensing resistor and the attendant problems inherent in such resistors. A prototype of the cell-based transconductance amplifier was implemented with ten positive and ten negative current cells to gain some experimental familiarity with the approach and provide verification of computer simulation results. The prototype transconductance amplifier is DC coupled, has a 3-dB bandwidth of about 750 kHz, and can deliver up to 35 A RMS (root mean square) at 100 kHz with an output voltage of 5 V RMS. Other important characteristics such as output-load regulation and DC offsets are discussed.<>
介绍了一种新型的大电流、超宽带跨导放大器的设计方法。该方法基于并联互补单极电流镜像单元的输入和输出。每个电池有一个固定的电流增益，由两个电阻的比值决定。差分输入电压-电流电路驱动单元阵列。该设计避免了对单个低阻电流感测电阻的需求以及此类电阻固有的随之而来的问题。为了对该方法有一定的实验了解，并对计算机仿真结果进行了验证，设计了具有10个正、负电流电池的跨导放大器原型。原型跨导放大器是直流耦合的，具有约750 kHz的3db带宽，并且可以在100 kHz时提供高达35 a的均方根(均方根)，输出电压为5 V RMS。讨论了输出负载调节和直流偏置等其他重要特性。
{"title":"A high-current, very-wide-band transconductance amplifier","authors":"O.B. Laug","doi":"10.1109/IMTC.1989.36858","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36858","url":null,"abstract":"A novel design approach for a high-current, very-wide-band transconductance amplifier is described. The approach is based on paralleling the input and output of complementary unipolar current-mirror cells. Each cell has a fixed current gain determined by the ratio of two resistors. A differential input voltage-to-current circuit drives the cell array. The design avoids the need for a single low-resistance current-sensing resistor and the attendant problems inherent in such resistors. A prototype of the cell-based transconductance amplifier was implemented with ten positive and ten negative current cells to gain some experimental familiarity with the approach and provide verification of computer simulation results. The prototype transconductance amplifier is DC coupled, has a 3-dB bandwidth of about 750 kHz, and can deliver up to 35 A RMS (root mean square) at 100 kHz with an output voltage of 5 V RMS. Other important characteristics such as output-load regulation and DC offsets are discussed.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"360 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122774184","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}
IEEE 488.2 defines standard formats, protocols, and common commands for IEEE 488 programmable instrumentation. Conventional software techniques can be used to write a parser that implements the formats and common commands. Such a parser requires a simple data stream interface, where data are simply gotten (commands) or placed (responses). The author describes a software driver for an IEEE 488 interface. This driver provides a simple data stream interface to the parser while conforming to the protocol requirements of IEEE 488.2. The crux of this implementation is the isolation of the message exchange control protocol, which is implemented with a simple state machine, from the parser. The protocol requirements of IEEE 488.2 have been converted to a state machine where each transition is the result of an external signal. In this process some anomalies in IEEE 488.2 have been identified and corrected.<>
{"title":"Efficient instrument design using IEEE 488.2","authors":"J.E. Mueller","doi":"10.1109/IMTC.1989.36822","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36822","url":null,"abstract":"IEEE 488.2 defines standard formats, protocols, and common commands for IEEE 488 programmable instrumentation. Conventional software techniques can be used to write a parser that implements the formats and common commands. Such a parser requires a simple data stream interface, where data are simply gotten (commands) or placed (responses). The author describes a software driver for an IEEE 488 interface. This driver provides a simple data stream interface to the parser while conforming to the protocol requirements of IEEE 488.2. The crux of this implementation is the isolation of the message exchange control protocol, which is implemented with a simple state machine, from the parser. The protocol requirements of IEEE 488.2 have been converted to a state machine where each transition is the result of an external signal. In this process some anomalies in IEEE 488.2 have been identified and corrected.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115473980","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}
An ASYST-based real-time data-acquisition system for measurement of the depolarization properties of various materials on the Earth's surface is described. The ALPS system is flown in a NASA P3 and uses an Nd:YAG laser pulsed at 20 Hz to irradiate the Earth's surface. The ALPS data-acquisition system measures the multispectral reflected energy of the laser with 12 photomultiplier tubes, whose outputs are digitized with a charge-integrating A/D (analog/digital) converter. An IBM PC/AT configured with an Intel Inboard 386 and a Kinetic Systems 2926 PC interface with direct memory access card serves as the system controller. Between each pair of laser pulses (50 ms) the software must read the reflected laser signal, the dark current background level, and various items of housekeeping information and these store this data in a RAM disk. The data are displayed for analysis and permanently stored in the AT's hard disk when the aircraft is turning for its next acquisition pass. The ALPS ASYST software is completely menu-driven and controls all data-acquisition, processing, analysis, and database functions.<>
描述了一种基于asyst的实时数据采集系统，用于测量地球表面各种材料的退极化特性。ALPS系统搭载在NASA的P3飞机上，使用脉冲频率为20赫兹的Nd:YAG激光照射地球表面。ALPS数据采集系统使用12个光电倍增管测量激光器的多光谱反射能量，其输出通过电荷积分a /D(模拟/数字)转换器进行数字化。配置了Intel Inboard 386和带直接存储器访问卡的Kinetic Systems 2926 PC接口的IBM PC/AT作为系统控制器。在每对激光脉冲之间(50毫秒)，软件必须读取反射的激光信号、暗电流背景电平和各种管家信息，并将这些数据存储在RAM磁盘中。当飞机转向下一个采集通道时，这些数据将被显示供分析，并永久存储在空中交通管制处的硬盘中。ALPS ASYST软件完全由菜单驱动，控制所有数据采集、处理、分析和数据库功能
{"title":"A real-time data acquisition system for the NASA Airborne Laser Polarimeter Sensor (ALPS)","authors":"G.C. Elman, J.E. Kalishoven, P. Dabney","doi":"10.1109/IMTC.1989.36825","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36825","url":null,"abstract":"An ASYST-based real-time data-acquisition system for measurement of the depolarization properties of various materials on the Earth's surface is described. The ALPS system is flown in a NASA P3 and uses an Nd:YAG laser pulsed at 20 Hz to irradiate the Earth's surface. The ALPS data-acquisition system measures the multispectral reflected energy of the laser with 12 photomultiplier tubes, whose outputs are digitized with a charge-integrating A/D (analog/digital) converter. An IBM PC/AT configured with an Intel Inboard 386 and a Kinetic Systems 2926 PC interface with direct memory access card serves as the system controller. Between each pair of laser pulses (50 ms) the software must read the reflected laser signal, the dark current background level, and various items of housekeeping information and these store this data in a RAM disk. The data are displayed for analysis and permanently stored in the AT's hard disk when the aircraft is turning for its next acquisition pass. The ALPS ASYST software is completely menu-driven and controls all data-acquisition, processing, analysis, and database functions.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127479198","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}
The authors describe iRALPH, an interpreter for stack-oriented DSP (digital signal processing) programs that provides both a batch-processing language and a command-driven user interface. Using either of these two modes, the user can read and write data files, generate sample data, perform arithmetic functions on the data, generate digital filters, filter the sampled data, and create presentation-quality plots of the results of the analysis. Other operations that can be performed on data include finding the discrete Fourier transform, estimating the power spectral density, and the correlation, and obtaining the histogram. To minimize its complexity, the interpreter was written using yacc and lex, and the primitives have been carefully structured to allow extensions. The extensions can be made by writing procedures in the interpreted language or by writing primitives in the C programming language.<>
{"title":"An extensible digital-signal-processing interpreter for use with computer-assisted instrumentation","authors":"T. A. Hull, S. Dyer","doi":"10.1109/IMTC.1989.36821","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36821","url":null,"abstract":"The authors describe iRALPH, an interpreter for stack-oriented DSP (digital signal processing) programs that provides both a batch-processing language and a command-driven user interface. Using either of these two modes, the user can read and write data files, generate sample data, perform arithmetic functions on the data, generate digital filters, filter the sampled data, and create presentation-quality plots of the results of the analysis. Other operations that can be performed on data include finding the discrete Fourier transform, estimating the power spectral density, and the correlation, and obtaining the histogram. To minimize its complexity, the interpreter was written using yacc and lex, and the primitives have been carefully structured to allow extensions. The extensions can be made by writing procedures in the interpreted language or by writing primitives in the C programming language.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124552796","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}
The Asyst programming environment for the IBM PC, which greatly simplifies software development for both data acquisition and data analysis, is described. Asyst communicates with numerous data acquisition and GPIB cards, making data acquisition and control of laboratory instruments a straightforward and easy task. Asyst contains a wide variety of analytical routines for data manipulation and theoretical modeling. Data acquisition, graphics, and advanced mathematical routines are integrated into a single programming environment to facilitate development of user-specific software. An automatic code generator has been added to the latest available version of Asyst to provide a novice user with easy access to advanced acquisition, graphics, and analysis routines. A menu generator allows easy development of menu-driven programs. A language interface can be used to incorporate routines written in other languages directly into Asyst programs.<>
{"title":"Integrated software: the use of the Asyst programming environment in science and engineering","authors":"R.W. Kreilick","doi":"10.1109/IMTC.1989.36866","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36866","url":null,"abstract":"The Asyst programming environment for the IBM PC, which greatly simplifies software development for both data acquisition and data analysis, is described. Asyst communicates with numerous data acquisition and GPIB cards, making data acquisition and control of laboratory instruments a straightforward and easy task. Asyst contains a wide variety of analytical routines for data manipulation and theoretical modeling. Data acquisition, graphics, and advanced mathematical routines are integrated into a single programming environment to facilitate development of user-specific software. An automatic code generator has been added to the latest available version of Asyst to provide a novice user with easy access to advanced acquisition, graphics, and analysis routines. A menu generator allows easy development of menu-driven programs. A language interface can be used to incorporate routines written in other languages directly into Asyst programs.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132249654","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}
The authors describe a 30-megasamples/s 12-bit analog-to-digital converter (ADC) using a subranging conversion technique. The key circuits for obtaining high accuracy at a 30-MHz conversion rate are a pipelined track-and-hold circuit and a high-speed 5-bit digital-to-analog converter. These circuit design features are presented. The ADC was fabricated on a printed-circuit board with about 500 surface mounting devices, and utilized for a precision digital oscilloscope. In a curve-fit test, effective bits of better than 10.0 were obtained with up to a 10-MHz input frequency.<>
{"title":"A 30 Ms/s 12-bit analog-to-digital converter","authors":"M. Imamura, N. Kusayanagi","doi":"10.1109/IMTC.1989.36811","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36811","url":null,"abstract":"The authors describe a 30-megasamples/s 12-bit analog-to-digital converter (ADC) using a subranging conversion technique. The key circuits for obtaining high accuracy at a 30-MHz conversion rate are a pipelined track-and-hold circuit and a high-speed 5-bit digital-to-analog converter. These circuit design features are presented. The ADC was fabricated on a printed-circuit board with about 500 surface mounting devices, and utilized for a precision digital oscilloscope. In a curve-fit test, effective bits of better than 10.0 were obtained with up to a 10-MHz input frequency.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132527761","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}
A novel method of measuring standing-wave distributions, using a modulated scatterer and a microwave homodyne receiver, has been developed, analyzed, tested, and shown to yield accurate results. Because the modulated scatterer can take the form of a small photoconductive dipole on the end of an optical fiber, access to the field to be measured from a contiguous shielded region, as in slotted transmission line instruments, is not necessary. With the availability of relatively inexpensive computer-controlled micropositioners, the mechanical translation of such a scatterer along a microstrip transmission line designed for operation at millimeter wavelengths can be readily automated and combined with scatterer microwave signal measurements. Analysis shows that the modulated scattered microwave signal is proportional to the cube of the standing-wave pattern of microwave signal variation on the microwave guiding structure, assuming that a single mode of propagation is involved. This has been verified experimentally.<>
{"title":"A new method of measuring standing wave distributions on electromagnetic waveguiding structures","authors":"D. Griffin","doi":"10.1109/IMTC.1989.36881","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36881","url":null,"abstract":"A novel method of measuring standing-wave distributions, using a modulated scatterer and a microwave homodyne receiver, has been developed, analyzed, tested, and shown to yield accurate results. Because the modulated scatterer can take the form of a small photoconductive dipole on the end of an optical fiber, access to the field to be measured from a contiguous shielded region, as in slotted transmission line instruments, is not necessary. With the availability of relatively inexpensive computer-controlled micropositioners, the mechanical translation of such a scatterer along a microstrip transmission line designed for operation at millimeter wavelengths can be readily automated and combined with scatterer microwave signal measurements. Analysis shows that the modulated scattered microwave signal is proportional to the cube of the standing-wave pattern of microwave signal variation on the microwave guiding structure, assuming that a single mode of propagation is involved. This has been verified experimentally.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131445453","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}
The authors present a novel method of calibrating the diode detectors used in six-port network analyzers, without disconnecting the diodes. The method uses only a precision variable attenuator or a power meter with no additional directional coupler. The important feature of this method is that no actual measurement of power is required to calibrate the diode detectors for six-port operation. It is very well suited to in-situ calibration of the diode detection circuits for operation of the six-port with pulse signals when the average power detected by the power meter drops to very low levels for low duty cycles. In these cases, the precision variable attenuator method is required. Measurement results are presented.<>
{"title":"New in-situ calibration of diode detectors used in six-port network analyzers","authors":"G. Colef, P. Karmel, M. Ettenberg","doi":"10.1109/IMTC.1989.36917","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36917","url":null,"abstract":"The authors present a novel method of calibrating the diode detectors used in six-port network analyzers, without disconnecting the diodes. The method uses only a precision variable attenuator or a power meter with no additional directional coupler. The important feature of this method is that no actual measurement of power is required to calibrate the diode detectors for six-port operation. It is very well suited to in-situ calibration of the diode detection circuits for operation of the six-port with pulse signals when the average power detected by the power meter drops to very low levels for low duty cycles. In these cases, the precision variable attenuator method is required. Measurement results are presented.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114409873","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}
An optical alarm for large industrial vacuum systems has been developed to prevent overflow of vacuum filters and traps. The alarm prevents two problems: (1) nuclear reactions when the dirt contains both radioactive materials and water and (2) overload of the vacuum system. The level of dirt in the trap is detected by the attenuation of light across the trap. Water in the trap is detected by light refraction at large angles of incidence to the water surface. To minimize sensitivity to dirty trap walls, a second detector measures light attenuation across the empty section of the trap, and the results are used to normalize the first detector output. Logic circuits minimize sensitivity to large chunks of dirt moving in the trap.<>
{"title":"An optical alarm for vacuum traps","authors":"M. G. Duncan, J. J. Henry","doi":"10.1109/IMTC.1989.36910","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36910","url":null,"abstract":"An optical alarm for large industrial vacuum systems has been developed to prevent overflow of vacuum filters and traps. The alarm prevents two problems: (1) nuclear reactions when the dirt contains both radioactive materials and water and (2) overload of the vacuum system. The level of dirt in the trap is detected by the attenuation of light across the trap. Water in the trap is detected by light refraction at large angles of incidence to the water surface. To minimize sensitivity to dirty trap walls, a second detector measures light attenuation across the empty section of the trap, and the results are used to normalize the first detector output. Logic circuits minimize sensitivity to large chunks of dirt moving in the trap.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117033344","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}
The RF-DC differences (d) of primary voltage standards were determined by experimental and theoretical procedures. The voltage standards, with different operating principles and designs, have been compared with CTVCs (coaxial thermal voltage converters) at frequencies from 1 to 100 MHz. The method recommended for determining the d values is to derive an empirical formula and then to correct if from measured data. The uncertainty of primary voltage standards established by this method is +or-0.007% at 1 MHz, +or-0.01% at 3 MHz, +or-0.02% at 10 MHz, 0.07% at 30 MHz, +or-0.15% at 50 MHz, and +or-0.2% at 100 MHz. This specification is shown to be reliable while leaving sufficient margin for error.<>
{"title":"Experimental studies of the RF-DC differences of voltage standards","authors":"D. Huang, Shui-Zhi He","doi":"10.1109/IMTC.1989.36845","DOIUrl":"https://doi.org/10.1109/IMTC.1989.36845","url":null,"abstract":"The RF-DC differences (d) of primary voltage standards were determined by experimental and theoretical procedures. The voltage standards, with different operating principles and designs, have been compared with CTVCs (coaxial thermal voltage converters) at frequencies from 1 to 100 MHz. The method recommended for determining the d values is to derive an empirical formula and then to correct if from measured data. The uncertainty of primary voltage standards established by this method is +or-0.007% at 1 MHz, +or-0.01% at 3 MHz, +or-0.02% at 10 MHz, 0.07% at 30 MHz, +or-0.15% at 50 MHz, and +or-0.2% at 100 MHz. This specification is shown to be reliable while leaving sufficient margin for error.<<ETX>>","PeriodicalId":298343,"journal":{"name":"6th IEEE Conference Record., Instrumentation and Measurement Technology Conference","volume":"561 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123520178","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}
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