STUDY ON THE OXIDIZABILITY-RESISTANCE OF FLEXIBLE GRAPHITE BY USING ADDITIVE

Abstract: The oxidizability-resistance of graphite products havebeen studied with the addition of H_3PO_4 and H_3BO_3. A available way hasbeen found to increase the oxidizability-resistance of graphite products.The oxidizability-resistance of graphite products rises remarkably aftertreating with 1% H_3PO_4 and 3% H_3BO_3. Meanwhile, the relative princi-ple has been proposed also.     

STUDIES ON THE APPLICATION OF TOWER MILL IN THE PRODUCTION OF ULTRAFINE WOLLASTONITE

The feasibilities of ultrafine wollastonits powder have beenanalysed based on joint considerations of satisfying product size re-quiremet,preserving the needlelike wollastonite structure,maintaining aneasy operation,stable performance and simolified flowsheet,etc.Opti-mum operating conditions have been established through systematic reseach-es on the bases of product requirements.Modern analytical technique suchas light-transmission particle sizing and scanming electron spectroscopyhave been used to determine the size and morphology of the product.It isfound that the meedelelike structure can be preserved even down to the ul-trafine range by using the tower mill.The tower,mill is easy to operate,has stable performances,and can be used in open-circuit to produce re-quired products without needing for a classifier.     

A NEW MINERAL——FLUORBRITHOLITE-(CE)

The new mineral fluorbritholite-(Ce)occurs innepheline syenite,marble xenoliths,sodalite syenite xenoliths andpegmatite dikes at Mont St.Hilaire,Quebec.It is associatedmainly with analcine,microcline,aegirine,zircon,biotite,Pyro-phanite,astrophylite,ancylite,natrolite,monazite etc.The mineral is hexagonal,P6_3/m,with a 9.517 (5) (?),c 6.983(4)(?),c/a 0.7337,v 547.7(8)(?),Z=2.The strongest Xray powder diffraction lines and their relative intensities(visual)are:2.851(100),2.821(30),2.753(30),1.970(20),1.969(30)(for MSH-3).Fluorbritholite-(Ce) crystal is shown prismatic.Its colouris pale yellow,tan,reddish-brown.Streak colourless to palebrown;Lustre adamantine;OPaque to translucent;Hardness 5;Brittle;Cleavage{0001}distinct;Fracture even to conchoidal;Density 4.66(1)(meas) or 4.66g/cm~3(calc.);Non-fluorscent.Optically umaxial(-),ω 1.792 (5),ε1.786(5) in Na light;Nonpleochroic.Electron microprobe analyses correspond to ((Ce_(1.69) La_(1.02)Na_(0.82) Nd_(0.44) Sr_(0.30) Ca_(0.17) Mn_(0.17) Y_(0.09) Pr_(0.06)     

Damages of windings of a three-phase slip-ring induction machine having parallel paths in the stator or in the rotor

Contents The following damages of a three-phase slip-ring induction machine having parallel paths in the stator or in the rotor are analysed in the paper: break in a parallel path of the stator or the rotor winding, internal short-circuit in the stator winding, earth fault of the stator winding. The mathematical model of asymmetrical states is presented. For the case of existence of the parallel paths in the windings, specific action of the space harmonics of the magnetic field, deformed as a result of internal asymmetry, is described.

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Wicklungsschäden der Dreiphasen-Schleifringläufer-maschine mit parallelen Wicklungszweigen im Stator oder RotorTeil 1: Das mathematische Modell

Übersicht In dem Aufsatz werden die folgenden Schäden der Dreiphasen-Schleifringläufermaschine mit parallelen Wicklungszweigen im Stator oder Rotor analysiert: Unterbrechung von parallelen Wicklungszweigen, innerer Kurzschluß in der Statorwicklung, Erdschluß. Das mathematische Modell von unsymmetrischen Zuständen wird dargestellt. Die spezifische Wirkung der Raumharmonischen, des infolge der inneren Unsymmetrie deformierten magnetischen Feldes, wird für den Fall des Vorhandenseins von parallelen Wicklungszweigen beschrieben.

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Part 2: Arch. Elektrotech. 71 (1988) 269–274     

控制变量受约束的最优控制问题的求解与计算

庞氏最小原则P.M.P.(Pontryagins Minimum Principle)的发现,尽管揭示了最优控制u的一个重要性质,却没有对实际中能够遇到的各种情形,提供寻找u的具体方法。本文通过初等变换方法,将有界控制闭域化为元界开域,于是控制变量受约束的最优控制问题 O.C.P.B.C.(Optimal ControlProblem with Bounded Control)可转化为无约束问题,通过变分法来求解,从而克服了古典变分法的局限性,同时,对求解非线性两点边值问题的多重射击法(Multiple Shooting Method)作了改进,使之适合于计算带内点条件的两点边值问题,提高了O.C.P.B.C.数值计算的效率,最后给出了一个数值例子。     

显微组织和盐水介质对16Mn钢疲劳裂缝扩展速率的影响

本文研究了热轧供货状态和淬火回火状态的16Mn钢的疲劳裂缝扩展速率以及3.5％NaCl水介质的影响。对显微组织,应力比和载荷频率的影响规律以及腐蚀产物的作用进行了一定分析。最后对腐蚀疲劳裂纹扩展曲线在低△K范围出现突然转折的现象进行了扼要讨论。     

异弹模界面裂缝应力强度因子的计算

本文将分区混合有限元用于计算异弹模界面裂缝应力强度出子,扩大了分区混合有限元的应用范围。由实例说明,数字计算结果与试验值相当符合。     

球-矩形窗口在聚类趋势检验中的效

本文讨论Hopkins统计量在球-矩形窗口内应用时对聚类趋势检验的效。Monte-Carlo模拟结果和对IMOX数据的实际检验说明,如果聚内是致密的,聚间是良好分开的,那么以Hopkins统计量和球-矩形窗口为模型建立的聚类趋势检验是有效的。     

非局部弹性薄板侵彻问题的非线性分析

采用有限变形理论分析了非局部弹性薄板侵彻问题。利用张量分析、积分变换、微分方程和特殊函数的数学工具,求出相关问题的运动方程,得到不相关问题的解答。     

A robust formulation of SAW Green's functions for arbitrarily thick multilayers at high frequencies

This paper presents a robust formulation of SAW Green's functions for arbitrarily thick multilayers at high frequencies. The formulation is an alternative to that based on the transfer matrix method, which suffers from numerical instabilities when the frequency and/or thickness parameters become large. This numerical difficulty can be attributed to the mixture of exponentially growing and decaying terms during the transfer matrix calculations. To be more instructive, the numerical instability is delineated in terms of upward-bounded and downward-bounded waves within each layer. In accordance with such boundedness association, a recursive scheme not involving any growing terms is developed based on the scattering matrices to eliminate the instability. The resulting reflection matrix method is extremely concise and preserves the simplicity and convenience of the transfer matrix method. Using the reflection matrices, the generalized Green's functions that relate the particle velocity and the rate of electric potential change to the surface stress and charge are formulated succinctly. These Green's functions are useful for having incorporated the electrical properties of the vacuum above the surface. Numerical computations are exemplified to demonstrate the instabilities of the transfer matrix method and to justify the robustness of the reflection matrix formula