EXISTENCE AND UNIQUENESS OF SOLUTIONS FOR HIGHER ORDER NONLINEAR THREE-POINT BOUNDARY VALUE PROBLEMS

In this paper,by using Leray-Schauder degree theory,we establish the exi- stence and uniqueness theorems for some higher order nonlinear three-point boundary value problems.     

Application of the digital matched-filter technique to ultrasonic non-destructive testing

Acoustic-pulse compression is obtained in systems with differenttimebandwidth products by applying the digital matched-filter technique toultrasonic non-destructive testing.The signal is linearly frequency-modulated(LFM)pulse and the digitized electrical-excitation signalitself is used as a digita1 matched filter.Experimental results are in goodagreement with theory.Suppressions of side lobes achieve -41.9 dB and-41.5 dB for the Hamming and Gaussian weighted signals respectively.It shows that the application of the digital matched-filter technique im-proves the performances of a ultrasonic testing system explicitly.     

THE ESTIMATION OF PRIOR FROM FISHER INFORMATION

ＴＨＥＥＳＴＩＭＡＴＩＯＮＯＦＰＲＩＯＲＦＲＯＭＦＩＳＨＥＲＩＮＦＯＲＭＡＴＩＯＮ￥ＬＩＹＵＡＮＺＨＡＮＧ；Ｋ．Ｍ．ＬＡＬＳＡＸＥＮＡＡＮＤＱＩＡＮＧＷＥＮＪＩＵＡｂｓｔｒａｃｔ：ＩｎＢａｙｅｓｉａｎａｎａｌｙｓｉｓ，ｔｈｅｍａｘｉｍｕｍｅｎｔｒｏｐ...     

THE THREE-DIMENSIONAL STRESS INTENSITY FACTOR UNDER MOVING LOADS ON THE CRACK FACES

The dynamic stress intensity factor history for a half plane crack in anotherwise unbounded elastic body,with the crack faces subjected to a tractiondistribution consisting of two pairs of combined mode point loads that move in adirection perpendicular to the crack edge is considered.The analytic expression for thecombined mode stress intensity factors as a function of time for any point along thecrack edge is obtained.The method of solution is based on the application of integraltransform together with the Wiener-Hopf technique and the Cagniard-de Hoop method.Some features of the solution are discussed and graphical results for various point loadspeeds are presented.     

人原发性肝癌中的转甲状腺素蛋白(Transthyretin)基因

本文从人正常肝对原发性肝癌的递减式cDNA文库(Subtracting cDNA libra-ry)中筛选出pG8cDNA克隆.Northem杂交证明它在正常肝中高度转录,而在9例肝癌中转录严重受阻遏.9例肝癌DNA MspI酶切杂交信号提示,4例肝癌中该基因存在部分DNA片段的丢失.在另7对肝癌及癌旁组织样本中,有4例肝癌中该基因同样存在部分片段丢失.cDNA序列分析证明它与转甲状腺素蛋白(Transthyretin,TTR)基因的编码区全部同源.本文首次报道了在人肝癌中TTR基因转录严重受阻遏及在基因结构上可能存在丢失或缺陷,提示TTR基因可能是人肝癌中基因缺陷的一个标记或抗癌基因之一.     

高能重离子碰撞中粒子源密度分布和强度干涉学

强度干涉学的分析结果与粒子源的平均半径有关;利用小相对动量差区域的关联函数可以估计粒子源的均方半径2>;由比值2>/2>可以获得源密度细致分布的信息.对Bevalac流光室1.8A GeV Ar+Pb中心碰撞实验数据的分析,得到了该反应π源的平均半径,提出了π源膨胀的一种可能模式;指明在目前的实验精度内,先验的高斯模型是合理的.     

A NOTE ON REGULARITY AND EXISTENCE OF SOLUTIONS FOR A CLASS OF NON－UNIFORMLY DEGENERATE ELLIPTIC EQUATIONS

ＡＮＯＴＥＯＮＲＥＧＵＬＡＲＩＴＹＡＮＤＥＸＩＳＴＥＮＣＥＯＦＳＯＬＵＴＩＯＮＳＦＯＲＡＣＬＡＳＳＯＦＮＯＮ－ＵＮＩＦＯＲＭＬＹＤＥＧＥＮＥＲＡＴＥＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＳ￥ＬＩＪＵＮＪＩＥ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＺｈｅｊｉａｎｇＵｎｉ...     

FRANCIS QL ALGORITHM FOR FINDING THE EIGENVALUES OF ANTI-SYMMETRIC MATRICES

In this paper,we demonstrate that the double-shift QL algorithm for an irreducible anti-symmetric iridiagonal matrix with the shifts being two eigenvalues of the 2×2 matrix in the left upper corner of this matrix is convergent and the convergence rale of Ms kind of algorithm is generally cubic.     

A NEW ENGINEERING CALCULATING MODEL FOR A LINEAR INCLUSION AND ITS APPLICATIONS

By using the hypothesis of the deformation of the straight bar and beamin mechanics of materials,a new engineering calculating model for a linear inclusion inplane is presented.Through the Kelvin's solution of a concentrated force,the inclusionproblem is reduced to solving a set of uncoupled singular integral equations which canbe solved by the numerical method of singular integral equation.Based on theseresults,several applicable examples including an inclusion-crack problem are calculatedand the results are quite satisfactory.     

La0.67Pb0.33MnO3的磁性及输运特性

利用固相反应烧结法制备了La067Pb033MnO3单相多晶样品.研究了其结构、磁性及输运特性.结果表明，样品呈菱面相晶体结构，空间群为R3C，居里温度TC(=353K)非常接近TMI(=360K).在居里温度附近，发生铁磁-顺磁转变，导电特性由金属特征向半导体特征过渡.磁电阻在居里点达到极大值.当H=16T时，磁电阻的极大值为145%；当H=08T时，磁电阻的极大值为9%.输运性质表明，TTMI时 关键词： 磁电阻 输运特性 磁极化子 钙钛石