非局部反应扩散方程的临界爆破指标

本文证明了一类来源于燃烧理论的非局部反应扩散方程的临界爆破指标的存在性，而且临界指标属于爆破情形     

用参数正交选优神经网络算法解货郎问题

本文发现了货郎问题(TSP)能量函数的参数空间中的吸引域与全局性优化解之间存在着确定的对应关系，并找到了许多参数空间中的吸引域．在此基础上提出了一种新算法——参数正交选优神经网络算法求解TSP，30城市、31城市(中国)和300城市TSP的求解结果都十分满意，表明这种新算法的有效性．     

Pretreatment procedure for selenium speciation in shellfish using high‐performance liquid chromatography–microwave‐assisted digestion–hydride generation‐atomic fluorescence spectrometry

A pretreatment procedure based on an enzymatic hydrolysis extraction followed by a two‐step clean‐up has been performed for selenium speciation in shellfish samples. Bivalve samples were extracted with protease XIV, lipase VII and protease VIII. By using a protease VIII–lipase VII mixture, quantitative recoveries were obtained for all the selenium species, except for selenocystine (59%). Owing to the complexity of the matrix, clean‐up procedures were required to remove interferents that affected the chromatographic separation. The extracts were first partitioned in dichloromethane and then passed through a column with aminopropylsilane. Speciation of selenocystine, selenomethionine, selenoethionine, selenite and selenate was obtained using a high‐performance liquid chromatography–microwave‐assisted digestion–hydride generation‐atomic fluorescence spectrometry coupling. The chromatographic system consisted of an anion exchange and a reversed‐phase column, both connected through a six‐port switching valve. On‐line microwave‐assisted digestion and hydride generation steps were performed prior to atomic fluorescence detection. The method was applied to clam and prawn samples collected from the southwest coast of Spain. Copyright­© 2002 John Wiley & Sons, Ltd.     

Bounded truth table does not reduce the one-query tautologies to a random oracle

The relativized propositional calculus is a system of Boolean formulas with query symbols. A formula in this system is called a one-query formula if the number of occurrences of query symbols is just one. If a one-query formula is a tautology with respect to a given oracle A then it is called a one-query tautology with respect to A. By extending works of Ambos-Spies (1986) and us (2002), we investigate the measure of the class of all oracles A such that the set of all one-query tautologies with respect to A does not p-btt-reduce to A, where p-btt denotes polynomial-time bounded-truth-table. We show that certain Dowd-type generic oracles all belong to the class, and hence measure of the class is one.The author was partially supported by Grant-in-Aid for Scientific Research (No. 14740082), Japan Society for the Promotion of Science.     

一类带有非线性边界条件的拟线性抛物型方程解的大时间性态

本文讨论一类带有非线性边界条件的拟线性抛物型方程解的大时间性态，给出了解整体存在的充分必要条件．     

A multi NaI(Tl) detector array for medium energyγ-ray spectroscopy

An array of seven hexagonal NaI(Tl) detectors has been set up for measuringγ-ray spectra in the energy region 5 MeV ≤E _γ ≤ 40 MeV with good accuracy. This is in contrast to earlier set ups which mostly used one large sized (about 10 inchesφ × 15 inches long)NaI(Tl) detector. This set up has been made for the study ofγ decay of GDR based on high spin states and ultra-dipole radiations. The array has been provided with the following features: a) TOF discrimination against neutrons, b) pile up detection and elimination, c) active and passive shielding to cut down background and d) an array of trigger counters for multiplicity dependence measurements. The well known program EGS4 has been used to determine the response of the array forγ-rays in the energy region 5–40 MeV and several test measurements have been carried out to confirm the validity of the calculated response functions. Some typicalγ-ray spectra fromα and¹⁶O induced reactions measured at VECC, Calcutta and Pelletron accelerator at TIFR are also shown.     

Free resolutions of the defining ideal of certain rational surfaces

We consider the surface obtained from the projective plane by blowing up the points of intersection of two plane curves of same degree meeting transversely. We find minimal free resolutions of the defining ideals of these surfaces embedded in projective space by the sections of a very ample divisor class. All of the results are proven over an algebraically closed field of arbitrary characteristic.     

一类半线性抛物方程组的爆破临界指标

本文考察一类半线性抛物方程组的Cauchy问题，计算出了该问题的爆破临界指标。     

IGBT闩锁现象的解析模拟

本文从ＩＧＢＴ发生闩锁的机理出发，推导出ＩＧＢＴ结构中两个寄生双极晶体管的共基极电流放大系数 及ＮＰＮ管基区横向电阻随电流密度变化的解析模型，并据此对条形和矩形元胞结构的ＩＧＢＴ器件编制了闩锁电流分析计算程序，取得了与国外报道相一致的结果。