检索结果-内蒙古大学图书馆

The effect of regeneration on the received signal strength

PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS 1929年第2期17卷 0339-0346页

作者： van der Pol, B Philips Glowlamp Works Ltd Phys Lab Eindhoven Netherlands

It is the purpose of this paper to give a theory of the effect of regeneration using the solution of a non-linear differential equation, and to present experimental verification of the theory. It is shown that: (a) as a first approximation, detection has no effect on the radio-frequency grid voltage developed under the influence of an incoming signal, (b) the amplification obtained through regeneration equals the two-thirds power of the ratio of the " grid space" to the amplitude obtained with zero regeneration. It is apparent from (b) that much greater gain is obtained through regeneration with weak signals than with strong signals. The verification of the theory is made with a circuit arrangement operating at 500 cycles per second. Application is made to radio frequencies using this as a model of a high-frequency system, following a theorem for model systems which is stated.

关键词： Anodes Radio frequency Voltage density estimation robust algorithm Laboratories Differential equations RF signals RLC circuits Tuned circuits Silicon compounds

来源：评论

学校读者我要写书评

暂无评论

IRREVERSIBLE-PROCESSES IN SOFT-FERROMAGNETIC THIN-FILMS

引用

IEEE TRANSACTIONS ON MAGNETICS 1987年第1期23卷 250-258页

作者： VANDERVOORT, FAN VANDENBERG, HAM Department of Electrical Engineering Delft University of Technnology Delft Netherlands

By means of Bitter observations, irreversible magnetization transformations have been studied in rectangular Permalloy bars of various sizes which were exposed to a uniform external field. Samples prepared by the lift-off technique showed a remarkable deviation in the domain structure conversions compared with samples prepared by RF-sputter etching. This can be attributed to edge defects. Besides the impact of edge imperfections on the hysteresis of the object, it is shown that even without defects a response of the volume-average magnetization to the external field exhibits hysteresis as soon as one single irreversible transformation has taken place. The functional dependence of the value of the external field at which the irreversible transformations reveal themselves on the dimensions of the rectangular bars is derived by using a surface-charge model. The predictions agree very well with the observations. The irreversible behavior of these particular transformations is explained by considering the free energy of the object, which involves magnetostatic and exchange energy.

关键词： Transistors Magnetostatics Bars Magnetic domains Magnetic hysteresis density estimation robust algorithm Magnetic confinement Magnetization Strips Torque

来源：评论

学校读者我要写书评

暂无评论

The interaction between the Drosophila secreted protein Argos and the epidermal growth factor receptor inhibits dimerization of the receptor and binding of secreted Spitz to the receptor

引用

MOLECULAR AND CELLULAR BIOLOGY 2000年第6期20卷 2098-2107页

作者： Jin, MH Sawamoto, K Ito, M Okano, H Osaka Univ Grad Sch Med Div NeuroanatDept Neurosci Biomed Res Ctr Osaka 5650871 Japan Japan Technol Corp Core Res Evolut Sci & Technol Osaka 5650871 Japan Sci & Technol Agcy Japan Strateg Promot Syst Brain Sci Osaka 5650871 Japan

Drosophila Argos (Aos), a secreted protein with an epidermal growth factor (EGF)-like domain, has been shown to inhibit the activation of the Drosophila EGF receptor (DER), However, it has not been determined whether Aos binds directly to DER or whether regulation of the DER activation occurs through some other mechanism, Using DER-expressing cells (DER/S2) and a recombinant DER extracellular domain-Fc fusion protein (DER-Fc), we have shown that Aos binds directly to the extracellular domain of DER with its carboxyl-terminal region, including the EGF-like domain. Furthermore, Aos can block the binding of secreted Spitz (sSpi), a transforming growth factor cr-like ligand of DER, to the extracellular domain of DER, We observed that sSpi stimulates the dimerization of both the soluble DER extracellular domain (sDER) and the intact DER in the DER/S2 cells and that Aos can block the sSpi-induced dimerization of both sDER and intact DER, Moreover, we have shown that, by directly interacting with DER, Aos and SpiAos (a chimeric protein that is composed of the N-terminal region of Spi and the C-terminal region of Aos) inhibit the dimerization and phosphorylation of DER that are induced by DER's overexpression in the absence of sSpi, These results indicate that Aos exerts its inhibitory function through dual molecular mechanisms: by blocking both the receptor dimerization and the binding of activating ligand to the receptor. This is the first description of this novel inhibitory mechanism for receptor tyrosine kinases.

关键词： Eye Proteins Membrane Proteins Nerve Tissue Proteins Receptor Epidermal Growth Factor metabolism 眼蛋白质类膜蛋白质类神经组织蛋白质类信号传递 Membrane Proteins dimerization Eye Proteins Extracellular Domain density estimation robust algorithm AUXILIARY ORIFICES Receptor Nerve Tissue Proteins ErbB Receptors Drosophila

来源：评论

学校读者我要写书评

暂无评论

AN 8-BIT VIDEO ADC INCORPORATING FOLDING AND INTERPOLATION TECHNIQUES

引用

IEEE JOURNAL OF SOLID-STATE CIRCUITS 1987年第6期22卷 944-953页

作者： VANDEGRIFT, REJ RUTTEN, IWJM VANDERVEEN, M Philips Research Laboratories Eindhoven Netherlands

A flash-type analog-to-digital converter that operates without a sample-and-hold circuit and incorporates folding and interpolation techniques is presented. It achieves an excellent performance while dissipating only 300 mW from a single 5-V power supply. The folding and interpolation system and the corresponding block diagram are explained. Implementation of folding and interpolation circuitry and the design of the reference resistor are discussed in detail. Several advantages of the system are investigated. The effective resolution of the converter is given as a function of analog input frequency. An 8-bit resolution bandwidth of 8 MHz is achieved. Up to an analog input frequency of 5 MHz, every distortion component stays below -60 dB. The maximum sample rate is 55 MHz. The circuit occupies 6 mm/SUP 2/ of silicon area, bonding pads included. It is realized in a 2.5-/spl mu/m bipolar process with an f/SUB T/ of 7.5 GHz.

关键词： Interpolation Circuits Frequency conversion Silicon Consumer products Harmonic distortion Power harmonic filters density estimation robust algorithm Power supplies Resistors

来源：评论

学校读者我要写书评

暂无评论

ANALYTICAL AND EXPERIMENTAL APPROACHES FOR THE DESIGN OF LOW-DISTORTION WIEN BRIDGE OSCILLATORS

引用

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 1981年第2期30卷 147-151页

作者： KAPLAN, BZ SAARONI, R ZUCKERT, B Department of Electrical Engineering Ben-Gurion University of the Negev Beersheva Israel

Although Wien bridge oscillators are commonly used as fixed-frequency generators of low distortion there has apparently not been suggested a simple systematic method based on nonlinear theory for reducing their distortions. This paper attempts at filling the gap. This is achieved by suggesting a network which is on the one hand a Wien bridge oscillator and it can be also regarded as a Van der Pol oscillator. Van der Pol oscillators, however, are well known and as a result the task of systematically reducing the distortion becomes a straightforward procedure which is demonstrated by a series of experiments. Additional improvements (in the economy of design and with regard to a further reduction of distortions) are attained by slightly modifying the basic Van der Pol type system. The small level of distortion achieved in the present work systems is explained as partly due to the deliberate generation of harmonic components which are then subtracted from the output signal to remove the distortion components which are added by the amplifier circuit.

关键词： Oscillators Bridge circuits Low pass filters density estimation robust algorithm Equations Harmonic analysis Distortion measurement

来源：评论

学校读者我要写书评

暂无评论

EQUIVALENT CIRCUIT FOR A LUMPED-ELEMENT Y CIRCULATOR

引用

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1968年第5期MT16卷 308-+页

作者： BERGMAN, JO CHRISTENSEN, C

New symbol for ideal circulator with given impedance matrix is proposed;symbol is used in derivation of equivalent circuits for lumped-element three-port circulator where loss resistances are excluded.

关键词： Equivalent circuits Solid state circuits Physics Frequency dependence Germanium Silicon Signal to noise ratio Microwave devices density estimation robust algorithm Diodes

来源：评论

学校读者我要写书评

暂无评论

AXIAL-MODE SELECTIVITIES FOR VARIOUS TYPES OF INTEGRATED TWIN-GUIDE LASERS

引用

IEEE JOURNAL OF QUANTUM ELECTRONICS 1977年第8期13卷 619-622页

作者： SUEMATSU, Y KISHINO, K KAMBAYASHI, T TOKYO INST TECHNOL DEPT PHYS ELECTRMEGURO KUTOKYO 152JAPAN

Wavelength dependencies of the gains, namely the axial-mode selectivities, of various types of integrated twin-guide (ITG) injection lasers are given theoretically. The double-resonator type, the distributed Bragg reflector (DBR), and the two tandem-connection types of ITG lasers are considered. The axial-mode selectivities are also discussed briefly in relation to the efficiencies.

关键词： Laser modes Laser theory Fiber lasers Chemical lasers Distributed Bragg reflectors Mirrors Optical resonators density estimation robust algorithm Optical fibers

来源：评论

学校读者我要写书评

暂无评论

LOW-FREQUENCY DIFFUSION NOISE IN GAAS-MESFETS

IEEE ELECTRON DEVICE LETTERS

引用

IEEE ELECTRON DEVICE LETTERS 1984年第6期5卷 202-204页

作者： DUH, KH ZHU, XC VANDERZIEL, A Electrical Engineering Department University of Minnesota Minneapolis MN USA

We report here on low-frequency diffusion noise of GaAS MESFET's. The Poole-Frenkel effect gives a shift of the corner frequency (f = D/πL 2 ). From the measurements the activation energy of the diffusing ions is... 详细信息

关键词： Low-frequency noise Gallium arsenide MESFETs Noise generators Frequency Voltage Diffusion processes Permittivity Noise measurement density estimation robust algorithm

来源：评论

学校读者我要写书评

暂无评论

APPLICATION OF THE QUANTIZED HALL-EFFECT TO A NEW RESISTANCE STANDARD AT VSL

引用

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 1985年第2期34卷 314-316页

作者： VANDERWEL, W HARMANS, KJPM KAARLS, R MOOIJ, JE VANSWINDEN LAB 2600 AR DELFTNETHERLANDS

A description is given of the setup for quantized Hall effect measurements. Preliminary results, obtained with MOCVD grown GaAs-AIGaAs heterojunctions, are presented. These include temperature dependence of the quanti... 详细信息

关键词： Hall effect Magnetic field measurement Circuits Electrical resistance measurement Laboratories Noise level density estimation robust algorithm MOCVD Heterojunctions Temperature dependence

来源：评论

学校读者我要写书评

暂无评论

EQUIPARTITION LAWS OF THERMAL NOISE

引用

IEEE JOURNAL OF QUANTUM ELECTRONICS 1981年第8期17卷 1324-1325页

作者： VANDERZIEL, A Department of Electrical Engineering University of Minnesota Minneapolis MN USA

Classically, the thermal noise in electricalRCcircuits andLCRseries circuits is governed by the equipartition lawfrac{1}{2}overline{CV{2}} = frac{1}{2}kT, whereV(t)is the noise voltage developed acrossC. When quantum effects are taken into account, the equipartition law no longer holds forRCcircuits, although an equipartition law can be deemed for the measured mean square noise voltage under certain conditions. InLCRseries circuits the equipartition lawfrac{1}{2}overline{CV{2}} = frac{1}{2}kT, changes intofrac{1}{2}overline{CV{2}} = frac{1}{2}bar{E}(fUL{0})for high-Qtuned circuits, wherebar{E}(fUL{0})is the average energy of a harmonic oscillator tuned at the tuning frequency of the tuned circuit.

关键词： RLC circuits Circuit noise Hafnium Voltage Tuned circuits Quantum mechanics Frequency measurement Gain measurement Noise measurement density estimation robust algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：