A PHRAGMEN－LINDELOF ALTERNATIVE FOR A CLASS OF SECOND ORDER QUASILINEAR EQUATIONS IN R~3

ＡＰＨＲＡＧＭＥＮ－ＬＩＮＤＥＬＯＦＡＬＴＥＲＮＡＴＩＶＥＦＯＲＡＣＬＡＳＳＯＦＳＥＣＯＮＤＯＲＤＥＲＱＵＡＳＩＬＩＮＥＡＲＥＱＵＡＴＩＯＮＳＩＮＲ￣３￥ＬｉｎＣｈａｎｇｈａｏ（林长好）（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＳｏｕｔｈＣｈｉｎａＮｏｒｍａｌＵｎ...     

三元相图及坐标变换的单纯形优化法测定铜(Ⅱ)-邻菲啰啉-铬天菁S三元络合物组成

本文用三元相图及坐标变换的单纯形优化法安排实验,测定铜(Ⅱ)-邻菲啰啉(Phen)-铬天菁S(CAS)三元络合物组成。通过两种方法,不同途径所得结果一致,络合比为3:3:2。     

Absolute value programming

We investigate equations, inequalities and mathematical programs involving absolute values of variables such as the equation Ax+B|x| = b, where A and B are arbitrary m× n real matrices. We show that this absolute value equation is NP-hard to solve, and that solving it with B = I solves the general linear complementarity problem. We give sufficient optimality conditions and duality results for absolute value programs as well as theorems of the alternative for absolute value inequalities. We also propose concave minimization formulations for absolute value equations that are solved by a finite succession of linear programs. These algorithms terminate at a local minimum that solves the absolute value equation in almost all solvable random problems tried.     

The coradical of a Jordan (alternative) coalgebra and the quasiregular radical of its dual algebra

It is proved that the orthogonal complement to the coradical of a Jordan (alternative) coalgebra coincides with the quasiregular radical of the dual algebra.     

Testing the Gumbel Hypothesis Via the Pot-Method

We consider an i.i.d. sample, generated by some distribution function, which belongs to the domain of attraction of an extreme value distribution with unknown shape and scale parameters. We treat the scale parameter as a nuisance parameter and establish for the hypothesis of Gumbel domain of attraction an asymptotically optimal test based on those observations among the sample, which exceed a given threshold sequence. Asymptotic optimality is achieved along certain contiguous extreme value alternatives within the concept of local asymptotic normality (LAN). Adaptive test procedures exist under restrictive assumptions. The finite sample size behavior of the proposed test is studied by simulations and it is compared to that of a test based on the sample coefficient of variation.     

化学概念理解水平的确定与测查研究——以酸碱反应概念理解测查工具的开发为例

为测量学生酸碱反应概念的理解水平,并诊断学生的相异构想,基于RASCH模型开发了酸碱反应概念理解的测查工具。使用该测查工具对752名高中生进行测试,分析显示测试结果有一定的信度和效度。研究还表明,中学生对酸碱反应概念的理解水平随年级升高而提高,但在不同的理解水平上学生均存在较多的相异构想。     

Determination of potassium in fatty acid methyl esters applying an ion-selective potassium electrode

An easy and inexpensive method of potassium determination in fatty acid methyl esters (FAME) applying an ion-selective potassium electrode (ISE-K) is presented. FAME are considered alternative fuel for diesel engines. Simple apparatus and procedure were developed to avoid contact of ester samples with the sensitive ISE-K membrane, which can damage the ISE membrane surface in long time operation. Using different FAME samples with a wide range of known potassium content a calibration curve was constructed. Among all samples, ISE-K satisfactory predicted potassium content in FAME as identified by the AAS reference method.     

ALTERNATE PREDOMINANCE IN COMPETITION FOR CONJUGATION IN NITROGEN BRIDGE COMPOUND

It is demonstrated quantitatively that the serial number N is not m + n + 4 in the nitrogen bridge conjugated system (Ⅸ), so the lone pair of electrons on the nitrogen cannot conjugate with acenyl branch and formyl polyenic branch simultaneously. The character of UV spectra and substituent equivalents (△Ns) show that acenyl branch competes for the lone pair of electrons with formyl polyenic branch. If the length m of acenyl branch is lengthened while n keeps constant, a point where the acenyl branch is predominant over formyl polyenic branch in competition, will eventually be reached. On the other hand, the effect of the latter will become greater than the former. The effect of the two branches predominates each other alternately with the alternate increase in m and n values.     

化学学习中记忆的7种缺陷

记忆是学生进行其他认知活动的基础,因记忆容量以及保持时间等限制具有一些缺陷,表现为分心、暗示、健忘、纠缠、空白、错认、偏颇等7种类型。记忆缺陷影响着学生的化学学习,了解化学学习中学生记忆的7种缺陷,可以精准地把握学生化学学习产生困难的原因,并采取一定的教学方法改进教学。