关于不定方程组a2x^2—a1y^2=a2—a1,a3y^3—a2z^2=a3—a2的非平凡解

给出了不定方程组a2x^2-a1y^2=a2-a1,a3y^3-a2z^2=a3-a2有正整数解的一个充分必要条件以及当系数（a1,a2,a3）满足条件（a1,a2,a3）＝1且a1a2＋1∈N^2或a2-a1＝1时求该不定方程组的非平凡正整数解的一个方法，该方法可以在计算机上用“迭代”算法实现。     

Modeling of a Cooperation Environment in a Virtual Enterprise

IntroductionIn1 991 ,the agile manufacturing concept was firstproposed in the Iacocca Institute report“2 1 stCentury Manufacturing Enterprise Strategy”[1] .Now many organizations and countries are engagedin agile manufacturing research and technology,fo…     

Simulation of a compartment fire using a zone model

This paper presents the zone modeling analysis of a single compartment flashover fire. Two criteria are applied in the model to judge the onset of ignition for different combustibles. By calculating the total received energy through radiation or the surface temperature of the combustible, the fire growth can be quantitatively determined. The improved zone fire model shows the influence of different combustibles upon the fire growth. This model is better than the traditional zone model because the common criteria of flashover, i.e. an upper layer temperature of 600℃ and the heat radiation intensity received by the floor of 20 kW/m^2, have not been applied in it.     

Development of a Measurement System Far-IR Using a MCT Sensor

The far-infrared radiation （Far-IR） has good effects on us, promoting the circulation of the blood and metabolic. So textile products including far-IR have been developed. But it is very difficult to measure the amount of far-IR in the textile quicHy and correctly. Newly developed Mercury Cadmium Telluride （MCT） sensor system could solve this problem.     

How a membrane agent buys goods in a membrane store

In this paper we consider a specific model of membrane systems, i. e. membrane systems with attributes. In these systems, the information is placed at the membranes in form of attributes, no objects are considered inside the membranes except for other membranes. The membrane system with attributes evolves according to rules that compute new values for the attributes from the attributes assigned to the membranes involved in the rule. The model of membrane systems with attributes allows us to specify business transactions in a precise way and to simulate different models for such transactions with a suitable tool for membrane systems with attributes.     

How a membrane agent buys goods in a membrane store

In this paper we consider a specific model of membrane systems, i. e. membrane systems with attributes. In these systems, the information is placed at the membranes in form of attributes, no objects are considered inside the membranes except for other membranes. The membrane system with attributes evolves according to rules that compute new values for the attributes from the attributes assigned to the membranes involved in the rule. The model of membrane systems with attributes allows us to specify business transactions in a precise way and to simulate different models for such transactions with a suitable tool for membrane systems with attributes.     

形如a…a0…0的完全方幂

设l是适合l≥3的正整数,a是适合1≤a≤9的正整数,设ak…a1a0表示十进制正整数a0+10a1+…+10kak,其中ai(i=0,1,…,k)是适合0≤ai≤9的整数,运用初等方法证明了当l=3时,形如a…a0…0的三次方幂仅有103m和8.103m;当l>3时形如a…a0…0的l次方幂仅有10lm,其中m是正整数。     

Quasi-cardinality of a Fuzzy Set on a Measurable Universe of Discourse

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃａｒｄｉｎａｌｉｔｙｏｆａｆｕｚｚｙｓｅｔｉｓｏｎｅｏｆｔｈｅｐｒｏｂｌｅｍｓｔｈａｔｈａｖｅｂｅｅｎｉｎｔｅｒｅｓｔｅｄｉｎｆｕｚｚｙｓｔａｔｉｓｔｉｃｓｄｕｅｔｏｉｔｓｖａｒｉｅｔｙｏｆａｐｐｌｉｃａｔｉｏｎ .Ｆｏｒｅｘａｍｐｌｅｉｎｉｎｓｕｒａｎｃｅａｃｔｕａｒｙ ,ｔｈｅｆｕｚｚｙｓｅｔｏｆｐｅｏｐｌｅｉｎｔｈｅｔｈｉｒｄｓｔａｔｅｉｓｒｅｌａｔｅｄｔｏｔｈｅｃａｒｄｉｎａｌｉｔｙ[1] .Ａｌｓｏｔｈｅｃａｒｄｉｎａｌｉｔｙｉｓｃｌｏｓｅｌｙｒｅｌａｔｅｄｔｏ…     

叶绿素a的光谱分析

叶绿素ａ的光谱分析周武（山东师范大学化学系，２５００１４，济南；３６岁，男，实验师）地球上一切生命活动都需要能量．能量最主要来源是太阳光．只有绿色植物（以及某些细菌）能转化和贮存太阳能，这一过程就是光合作用．光合作用时，叶绿素吸收太阳能转变为化学能，...     

Characterization of a nitrogenase CrFe protein from a mutant UW3 of Azotobacter vinelandii grown on a Cr-containing medium

Biological nitrogen fixation is one of the most im-portant biochemical reactions in nature. It is catalyzed by an anaerobic metalloenzyme complex-nitrogenase. Three genetically distinct nitrogenase systems exist in Azotobacter vinelandii (A. vinelandii): Mo-containing nitrogenase, V-containing one and “Fe only” nitro-genase[1―4]. They are composed of two separable com-ponent proteins. For example, conventional Mo-con- taining nitrogenase is composed of component I (MoFe protein) and com…     

Soil Erosion on a Slope without Vegetation： a Simulating Experiment on a Bare Land in Mt. Tanakami

0　IntroductionManystudieshavebeendoneonthesedimentdischargeinMt.Tanakami .Thosestudiesconcerntheamountofsedi mentsandfewdiscussionsabouttheprocessonly .Andthesedi mentyieldmechanismindevastatedslopeinMt.Tanakamiisnotfullyunderstood.Inordertorecordthewholeprocessofsoilero sionfromthebeginningofprecipitation ,totheendofsedimentmovement,asimulatingexperimentbyusingartificialrainiscon ducted .Basedonthisexperiment,andbyfurthercomparingwiththepreviousdataofsedimentsinthisarea,somebasicdataaboutc…     

R600a、R134a环保型制冷剂维修工艺探讨

R600a、R134a作为CFC制冷剂的替代物,越来越被广泛使用。本文从R600a、R134a的特性来对其维修工艺进行探讨。     

叶绿素a的柱层析分离

引言叶绿素在绿色植物的光合作用中起着重要的作用。利用叶绿素a作为光敏剂进行太阳能的转换和光电池的研究已有很多报导。叶绿素a一般是从叶绿体色素中用蔗糖柱层析分离得到的。在植物生理学和有机化学实验中也列有叶绿体色素分离的实验。如果能用食用白糖代替分析纯蔗糖或硅胶作吸附剂,将会节省开支,具有一定的经济效益。本文将食用白糖作吸附剂和分析纯蔗糖作吸附剂分离叶绿素a的效果进行了对比实验。     

TNF ligands: is TALL-1 a trimer or a virus-like cluster?

Native TALL-1 (B-cell activation factor, BAFF; also known as BlyS) was initially described as a homotrimer, but Liu and colleagues claim that it is a 60-subunit complex on the basis of their results from X-ray crystallography and size-exclusion chromatography. They consider TALL-1 60-mers to be the biologically active form, and the arrangement of the 60-mers resembles that of the capsid of satellite tobacco necrosis virus. Here we show that active TALL-1 is trimeric under normal physiological conditions and that formation of higher-order oligomers is an artefact of tagging the amino terminus of the protein with a histidine tag.