测定半导体扩散层表面浓度、p-n结深度及扩散系数的霍耳效应法

本文叙述测定半导体扩散层表面浓度、P-n结深度及扩散系数的霍耳效应法。导出了求算半导体扩散层表面浓度、P-n结深度及扩散系数的一组积分公式。对砷由气相扩散入锗这一情况进行了详细研究:对上述公式进行数值积分并给出一系列图线,利用这些图线从实验值求得表面浓度等上述参数。实验表明:此法所测得的结深度和表面浓度分别与光干涉法直接测得的结深度和平均电导法测得的表面浓度,在误差范围内很好符合;而且此法所测得的扩散系数与B?senberg用电容法测得的也极为接近。扩散系数与温度的关系为D=2.3exp(-2.36/(kT)),当N₀=10¹⁴厘米^-3;D=1.7exp(-2.36/(kT)),当N₀=10¹⁶厘米^-3。     

1-(4-安替比林)-3-(8-喹啉)-三氮烯的合成及其分析应用

报道了新试剂1-(4-安替比林)-3-(8-喹啉)-三氮烯(APQT)的合成及其与镉(Ⅱ)的显色反应研究.在Triton X-100存在下,pH 10.5的Na2B4O7-NaOH的缓冲溶液中,试剂与镉(Ⅱ)形成2:1型的橙红色络合物,最大吸收波长为525nm,表观摩尔吸光系数为2.25×105L·mol-1·cm-1,镉含量在0-15μg/25mL范围内遵守比耳定律.     

Hidden 467-1467-1467-1

Letn be an integer. Denote byA _n one of the following two graded vector spaces: (a) the space of all multilinear Poisson polynomials of degreen (with a grading described below), or (b) the cohomology of the space of alln-uples of complex numbersz ₁,..., z_n withz _iz_j forij. We prove that the natural action of _n on each homogeneous component ofA _n can be extented to an hidden _n+1 -action and we compute the corresponding character (the _n -character being already given by Klyaschko and Lehrer-Solomon formulas).     

The IR absorption spectrum of 2 - aminothiazolid - 4 - one

A mechanical model has been used to calculate the frequencies in the vibrational spectrum of the imine and amine tautomeric structures for this compound; the IR spectrum for the crystalline state has been deduced for the range 80–3500 cm^–1, and a discussion is given for the effect of the tautomeric prototropic forms on the vibrational spectrum.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 9, pp. 76–82, September, 1971.     

5-(2-苯并噻唑偶氮)-8-氨基喹啉作为钴的光度分析试剂及应用研究

在阳离子表面活性剂溴化十六烷基三甲基铵存在下 ,于 p H=9.2的硼砂缓冲介质中 ,5 - (2 -苯并噻唑偶氮 ) - 8-氨基喹啉与钴 ( )形成 2∶ 1的蓝色配合物 ,其最大吸收波长位于 6 5 0 nm处 ,表观摩尔吸光系数为 1.2 4× 10 5L· mol-1· cm-1。钴浓度在 0— 10 .0μg/2 5 m L范围内 ,符合比耳定律。应用于维生素 B12 和水系沉积物中微量钴的测定 ,获得了满意的结果。     

X波段宽带极低噪声低温放大器

介绍了8～9GHz极低噪声低温放大器的研制。在≤15K的工作温度下,实测放大器的主要性能指标如下:等效噪声温度≤7.9K;增益>31dB,带内起伏≤1dB;输入反射损耗<-21dB;输出反射损耗<-23dB。它的研制成功,实现了深空探测、天文观测等X波段宽带低温接收机的核心器件国产化。     

预载条件下Y-Ba-Cu-O块材的悬浮力弛豫特性

文中以实验技术为手段,研究了不同工况下预载抑制悬浮力弛豫衰减的作用规律.实验以Halbach永磁轨道和三籽晶方形Y -Ba-Cu-O块材组成的系统为主要研究对象,通过改变块材的场冷方式、工作高度、预载高度等,研究这些因素对块材悬浮力弛豫的影响规律.选取30mm场冷高度、15mm工作高度,改变永磁轨道和块材,研究了轨道磁...     

1—(4—吡啶甲酰)—4—芳基氨基硫脲类和3—(4—吡啶基)—4—芳基—1,2,4—三唑啉—5—硫酮类化合物~(13)C—NMR谱研究

本文测定了新合成的,具有生理活性的1-(4-吡啶甲酰)-4 -苯基氨基硫脲,1-(4-吡啶甲酰)-4-对氯苯基氨基硫脲,1-(4 -吡啶甲酰)-4-对溴苯基氨基硫脲3-(4-吡啶基)-4-苯基-1,2,4,-三唑啉-5-硫酮,3-(4-吡啶基)-4-对氯苯基-1,2,4,-三唑啉-5-硫酮,3-(4-吡啶基)-4-对溴苯基-1,2,4-三唑啉-5-硫酮六个新化合物的~(13)C-NMR谱,并通过~(13)C-NMR谱中的宽带去偶,偏共振及APT技术,模型化合物对照,讯号强度对比及芳基取代基常数计算等方法,进行了上述化合物~(13)C-NMR谱峰的归属,并得到了甲酰肼基在吡啶环4位取代后对吡啶环各碳所产生的取代基效应.     

Unification of 3-3-1 models

A 3-3-1 model is constructed for three families that can be embedded into a single SU(8) unified model. Assuming appropriate branching rules and symmetry-breaking pattern, a complete fermion content is found within irreducible representations of SU(8), where light Standard Model fermions, heavy 3-3-1 fermions and superheavy fermions may be distinguished.     

Energy - dispersive X - ray diffraction of the ammonium - halides under pressure

Abstract

The structure of the ammonium halides NH₄X (X = Cl, Br, I) has been studied under pressure up to 40 GPa by energy dispersive X-ray diffraction using synchrotron radiation. Equations of state and a discussion on the possible structure of phase V will be presented.     

Identification ofμ +-sites in the 1-2-3 compoundin the 1-2-3 compound

Possibleμ ⁺ sites have been identified by a comparison of measured spontaneous internal fields in YBa₂Cu₃O_6+δ and REBa₂Cu₃O_7−δ and of measured second moments and width of transverse field powder spectra with the corresponding calculated quantities. In the YBa₂Cu₃O₇ system only one possibleμ ⁺ site emerges at a distance of ∼1.05 A from a chain oxygen O(4) at the position (0.15(1), 0.44(1), 0.071(1)). In the system YBa₂Cu₃O₆ the only possibleμ ⁺ sites are near to an oxygen O(1) with z/c=0.133 and the same distance as above. The analysis leads also to improved valuesμ _Ho = 2.2(1)μ _B andμ _Cu = 0.67(4)μ _B and to a determination of the latters direction:μ _Cu ‖〈110〉.     

Magnetic phase transitions in 187-01187-01187-01

We report SR measurements of Pr₂CuO_4– and (Pr_2–xCe_x)CuO_4– single crystals in the temperature range 4.2K300K. Two spin reorientation phase transitions were observed, although neutron scattering experiment could not detect these phase transitions. These allow us to conclude that magnetic moments of the Cu atoms order in an antiferromagnetic noncollinear cross like structure including a hidden canting spin arrangement.     

Mössbauer study of tin-doped 1-2-3 and 2-1-4 highT c superconductors

Samples of YBa₂(Cu_0.85Sn_0.15)₃O_7–y (1-2-3), La₂(Cu_0.95Sn_0.05)O4_4–x, and La_1.85Ba_0.15(Cu_0.95Sn_0.05)O_4–x (2-1-4), with different oxygen stoichiometry, have been studied by Mössbauer spectroscopy. These measurements reveal the existence of two inequivalent sites for Sn in the (1-2-3) compounds. The (1-2-3) spectra display two quadrupole doublets which we associate with Sn in Cu(1) and Cu(2) sites, respectively. La compounds show a single quadrupole doublet.     

137-01137-01137-01-deformed extended Galilei algebra

We apply the pseudoextension mechanism, which in the undeformed case gives the centrally extended Galilei group {ie137-02} as a contraction of a trivial extensionP×U(1) of the Poincaré group, to the case of the-Poincaré algebra. As a result, the four-dimensional {ie137-03}-deformed extended Galilei algebra is obtained.Presented at the 4th Colloquium Quantum Groups and Integrable Systems, Prague, 22–24 June 1995.     

Instanton contribution to 431-1431-1431-1decay

We study instanton effects on inclusive semileptonicb→u decay using the heavy quark effective field theory and the operator product expansion. The effect contributes not only to the hadronic matrix element but also to the coefficient functions in the operator product expansion. We find that the coefficient function is singular near the boundaries of the phase space. In order to use perturbative QCD reliably, it is necessary to introduce smearing near the boundary. However the instanton contribution tob→c decay seems negligibly small.     

Superconductivity in the Bi - Sr - Cu - O system

During the investigation of the system Bi–Sr–Cu–O a novel family of superconducting oxides, close to the composition Sr₂Bi₂Cu₂O₇₊ has been isolated, with a midpoint critical temperature ranging from 7 K to 22 K. The X-ray diffraction and high-resolution electron microscopy studies have shown its relationships with perovskite and demonstrated its bidimensional character. The possible relationships of this lamellar oxide with Aurivillius phases is discussed.     

Fe40—45Cr30—35Co20—25Mo0—4Zr0—2合金微观结构对矫顽力的影响

研究了高矫顽力型FeCrCo合金的磁性和微观结构.实验结果表明，适当的合金成分及热处理 条件可以明显提高FeCrCo合金的矫顽力.通过透射电镜、x射线衍射等手段得出结论：主体元 素含量的提高和微量元素的掺杂可以有效地控制相的组成，磁场热处理导致强磁性相和弱磁 性相的分离，回火后形成起磁硬化作用的调幅结构.该调幅结构中较大的两相成分差有利于 提高FeCrCo合金的矫顽力. 关键词： 矫顽力 调幅分解 磁场热处理 两相结构 成分差     

Analysis of the 33-133-133-1final state in photon-photon collisions

The reactione ⁺ e ^- e ⁺ e ^{- 00}e ⁺ e ^- 6 has been analysed using the full data sample taken with the Crystal Ball detector at the DORIS II storage ring at DESY. The ⁰⁰ invariant mass spectrum is dominated by the ', for which we determine the radiative width (') to be (4.5±0.3±0.5)keV. Near 1.9 GeV/c² we observe a second enhancement in the ⁰⁰ mass distribution. Assuming that these events are created by the production and subsequent decay of a wide resonanceX(1900), we have investigated the decay modes, the invariant mass distributions of the ⁰ and ⁰⁰ subsystems and the angular distributions of the final state mesons. We find that the data is best described byJ ^PC=2. For thisJ ^P assignment the resonance parameters are (X) BR(X)=(0.95±0.27±0.20) keV _tot (X)=(221±92±44)MeV, andM(X)=(1881±32±40) MeV/c².Deceased     

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Elementveruninigungen auch im Spurenbereich (ppm, ppb) becinflussen die Qualität von Halbleiterselen. Bei der Bestimmung interssierender Elemente (Ag, As, Au, Cd, Ga, Sb, Tl) mittles NAA ist mich der Neutronenbestrahlung im Kernreaktor wegen der Störung dutch die entstehende hohe Matrixaktiviät, der Anwesenheit reiner Betastrahler oder infolge Linienüberlagerung im Gammaspektrum im allgemeinen Keine instrumente NAA möglich. Daher müssen nache Zugabe inaktiver Träger und der Matrixabtrennung die interessierenden E-emente durch konventionel-e chemisch-analytische Trennverfahren (Extraktion, Fällung, Ionenaustausch) isoliert warden.     

2,4—二氨基—6—(取代苄基)—5—甲基吡啶(2,3d)并嘧啶类化合物的~(13)C NMR研究

2,4-二氨基-6-(取代苄基)-5-甲基吡啶(2,3d)并嘧啶类化合物是一类很有前途的抗癌新药。本文研究了24种7位氯代和氧代的该类化合物的碳谱,归属了母核及取代苄基上各碳的化学位移,并对两种取代对母核碳上的化学位移的影响规律进行了探讨,文中所有数据迄今未见文献报道。