共查询到18条相似文献，搜索用时 187 毫秒
1.
2.
基于α-远域族的推广形式α-相关远域族的概念,给出了L-拓扑空间的Ⅲ超仿紧性,研究了其与Ⅲ强F仿紧性和Ⅱ超仿紧性之间的关系,并得出Ⅲ超仿紧性是闭遗传的结论. 相似文献
3.
在L-拓扑空间中借助于θ-开L-集和它们的不等式给出了θ-紧性的新定义,这里L是完备的DeMorgan代数．它也能够借助于θ-闭L-集和它们的不等式刻画、当L是完全分配的DeMorgan代数时,讨论了θ-紧性的更深层特征. 相似文献
4.
5.
7.
Meso紧空间、Hausdorff空间的映射性质 总被引：2，自引：0，他引：2
完备映射是拓扑映射中一种简单而重要的映射.通过研究完备映射的性质以及Hausdorff 空间、Meso紧空间的结构,证明了完备映射下Hausdorff 空间的性质及 Meso紧空间被完备映射逆象保持,从而完善了这几种拓扑空间的性质刻画. 相似文献
8.
以L-fuzzy拓扑空间中的几乎可数层仿紧集为背景,介绍了L-fuzzy双拓扑空间中的几乎可数层仿紧集的定义,并刻画了其基本特征.深入研究了L-fuzzy双拓扑空间中几乎可数层仿紧集的性质,并证明了它是"L-好的推广". 相似文献
9.
孙军娜 《渭南师范学院学报》2010,25(5):13-15
以＊超仿紧性为背景,介绍了可数＊超仿紧性的定义,并刻画了其基本特征.深入研究了L-fuzzy可数＊超仿紧性的性质,并证明了可数＊超仿紧性是＂L-好的推广＂. 相似文献
10.
本文给出了LF集的超紧性的网式、滤子式等几种刻划,剖析了超紧集的层次结构,得出了在导出分明拓扑满足T_2分离性的前提下子集的超紧性与其任—α—集的紧性等价等一系列结果。 相似文献
11.
陈月红 《广东技术师范学院学报》2005,27(4):6-8
利用已有的集值映射的C-上半连续与C-下半连续的概念,推广了文献[3]中的某些结论.本文还引进了集台一种弱的紧性概念:C-上紧、C-下紧的性质,并在F(x0)分别是C-上紧、C-下紧的较弱条件下,给出了集值映射的C-上半连续与C-下半连续的一个刻划. 相似文献
12.
当前,我们国家教育发展战略主题明确,开放教育发展势头良好,依托地方电大建成有中国特色的开放大学将成为远程教育创新发展的一个新趋势。本文从湖州广播电视大学教学和管理实践出发,对于区域开放大学体系的构建及其良好的运行机制进行初步的探讨。 相似文献
13.
The relation between composition operators on the Dirichlet spaces in the open unit disk and derivative weighted composition operators on the Bergman spaces in the open unit disk is investigated firstly,and for a combination of several derivative weighted composition operators which acts on classic Bergman space,the lower bound of its essential norm is estimated in terms of the boundary data of the symbols of d-composition operators.Some similar results about composition operators on the Dirichlet space are also presented.A necessary condition is given to determine the compactness of the combination of several derivative weighted composition operators on Bergman spaces. 相似文献
14.
Studies of synergetic irradiation effects and liquid lead-bismuth eutectic （LBE） corrosion/embrittlement effects on ferritic/martensitic （F/M） steels are of great importance for developing high power spallation neutron targets （〉1 MW） such as the European Spallation Source （ESS） and Accelerator Driven System （ADS） facilities that can be used for transmuting long-lifetime radioactive wastes. Liquid LBE （45Pb-55Bi, in terms of mass fraction） has been selected as the candidate target material in high power spallation neutron targets due to its favourable thermal, physical ＆ chemical properties, and to its high spallation neutron yield. 9Cr F/M steels such as T91 （9CrlMoVNb, in terms of mass fraction） have been chosen as the structural material for the targets due to their good mechanical properties and good resistance to irradiation induced swelling in fission neutron irradiation environments. For developing high power spallation neutron targets, behaviors of F/M steels in spallation neutron target irradiation environments and LBE corrosion/embrittlement effects have been extensively studied. However, many open questions have not been answered. The aim of this paper is to describe the present research situation on this topic. The obtained experimental data about LBE embrittlement effects on F/M steels is summarized and the influence of different parameters involved is analyzed to understand the influence effect on LBE embrittlement effect of F/M s. 相似文献
15.
宋瑞丽 《南阳师范学院学报》2010,9(3):4-7
用Galerkin方法和紧性原理及嵌入定理,在分数次Sobolev空间中,证明一类非线性双曲型方程局部广义解和局部古典解的存在唯一性． 相似文献
16.
低分子有机酸对土壤氟吸附的影响 总被引：1，自引：0，他引：1
用平衡吸附法研究了柠檬酸、草酸对土壤氟吸附的影响,并提出有机酸影响氟吸附的可能机理.实验结果表明:有机酸对土壤氟吸附有较大的影响:(1)当有机酸处于低浓度时,土壤氟吸附量随浓度升高而增加;高浓度时,土壤氟吸附量随浓度升高而降低;(2)在有机酸存在条件下,土壤氟的吸附量与平衡氟浓度间呈极显著的直线正相关或负相关. 相似文献
17.
H. Rashed Shaker 《Open Learning》2013,28(1):57-70
In Bahrain, 36 international universities from 10 different countries provide distance education services through 21 local agencies to more than 800 students. Results from a survey suggest that the majority of the distance education students are working, married, of middle income class, and studying for a Bachelor's degree. The students find the distance education option attractive because: (1) there are a limited number of places in the conventional Bahrainian universities and on particular courses, and limited scholarships and financial support available for conventional students; (2) the distance system is more open and flexible in respect of their regulatory requirements; and (3) the students find it caters better for those with poor secondary school scores, low income, family and job responsibilities. 相似文献
18.
练泓 《安顺师范高等专科学校学报》2014,(2):36-37
地方高校青年教师在政府主导培养和学校主导培养两种模式中获得成长机会,但这两种模式自身的局限性,使得青年教师在成长过程中面临着瓶颈.针对这种状况,需要地方高校与时俱进地改进现有模式,尊重青年教师的个性特长,发掘青年教师成长源泉,统一管理职能,成立专门机构,形成系统化的培养机制,并不断拓宽培训渠道,开展多元化的培养培训活动. 相似文献