一阶非线性差分方程边值问题解的存在性

研究一类非线性差分方程边值问题,建立了该类问题至少存在一个解的充分条件．     

一类超二次Hamilton系统的无穷多周期解

利用喷泉定理研究一类超二次Hamilton系统,在不需假设Ambrosetti-Rabinowitz条件的情形下,可得到无穷多周期解的存在性.     

Solving traveling salesman problems using generalized chromosome genetic algorithm

Generalized chromosome genetic algorithm （GCGA） was proposed for solving generalized traveling salesman problems （GTSP） as reported in the authors＇ earlier work. Theoretically, the GCGA could also be used to solve the classical traveling salesman problem （CTSP）, which has not been reported by others. In this paper, the generalized chromosome characteristics are analyzed and the feasibility for consistently solving the GTSP and CTSP is verified. Numerical experiments show the advantages of the GCGA for solving a largescale CTSP.     

高校设备管理中存在的问题及对策分析

通过对高校仪器设备使用中存在的普遍现象进行综合分析研究,指出了高校仪器设备中存在重购置、轻使用、低利用率及管理不规范等现象,提出了相应的解决对策.     

基于新疆工科中职学校学分制应用模式研究现存问题分析

中职学校学分制应用一直是我国职业教育领域关注的焦点。本文以新疆水利水电学校部分专业在试行学分制过程中所存在的问题为例,提出了相应的改进意见。     

Microstructural evolution in the surface of Ti-10V-2Fe-3Al alloy by solution treatments

By solution treatments in vacuum and in air,the surface region of Ti-10V-2Fe-3Al exhibits different microstructures from the interior region of the alloy.When solution treated in vacuum,the microstructure of the specimen is composed of dominant β phase and a few of α " martensite in surface region,with a large amount of α" martensite and a little of β phase in interior.When solution treated in air,the specimen is characterized by dominant surficial a phase and interior β phase.In addition,the lattice parameter evolutions of a and β phases were observed in the surface region of the specimens by solution treatment in air.The mechanism for the surface effects is discussed in light of the structural stability and phase evolution in Ti-10V-2Fe-3Al alloy with solution treatments.     

关于高职学生高等数学教与学中若干问题的调查与分析

通过10个问题的调查问卷,摸清了高职学生对于高等数学教与学中若干问题的太度和看法,并探讨了解决问题的方法和途径。     

新时期科技期刊编辑的压力与应对策略

现代科技期刊对编辑提出了更高的要求,文章就编辑业务和科技期刊体制改革两方面逐一分析说明,提出新时期科技期刊编辑应加强信息甄别和提炼能力,通过继续教育更新业务技能,实现编辑工作现代化、网络化,争当行内“专家”和“外交官”,以从容应对新时代压力。     

Recent advances in multistep solution nanosynthesis of nanostructured three-dimensional complexes of semiconductive materials

Constructing simply nanostructured zero-,one-,and two-dimensional crystallites into threedimensional multifunctional assemblies and systems at low-cost is essential and highly challenging in materials science and engineering.Compared to the simply nanostructured components,a three-dimensional(3D) complex made with a precisely controlled spatial organization of all structural nanocomponents can enable us to concert functionalities from all the nanocomponents.Methodologically,so doing in nm-scales via a solution chemistry route may be much easier and less expensive than via other mechanisms.Hence,we discuss herein some recent advances in multistep solution syntheses of nanostructured 3D complexes of semiconductors with a focus mainly on their synthetic strategies and detailed mechanisms.     

分形介质中球向渗流模型解的相似结构

本文针对分形介质储层中球面径向渗流模型,利用Laplace变换,获得了在考虑井筒储集和表皮系数的井底条件和各种外边界条件下的无量纲储层压力和井底压力的Laplace空间解;并通过深入地分析,发现并研究了解的相似结构和相似核函数的特征.本研究给编制试井分析软件带来了极大的方便,也是渗流力学理论的新进展.