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71.
文中对计算电子结构的集团Bethe晶格方法进行了改进。简化了原子集团的选取方式,提出了求解复数Dyson方程组的矩阵解方法和平均集团Bethe晶格方法。研究了Penrose tiling的局部、整体和平均电子状态密度。发现了Penrose tiling的局部电子状态密度对准周期点阵的长程有序性特别敏感的性质。提出了计算Penrose tiling局部及整体电子状态密度应遵循的原则.得出了某些合金的准晶相可能是电子化合物的结论。 相似文献
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Fiona Q. Wood 《高等教育研究与发展》1989,8(2):237-250
Under the federal government's current policy on funding university research, institutions which can best identify and encourage the higher performers amongst their academic staff will fare better than others. However, in order to secure a strong position in competing for these government funds universities will need to know more about the research activity of their academic staff and how staff in different disciplines are likely to respond to the increased use of performance indicators. This paper reports the views of staff from one Australian university on such issues. One of the main findings is that potential research output is influenced by a range of factors including the differences in research styles, methods and strategies and the degree of dependence on funds. Such findings favour the differential use of performance measures depending on the nature of the research undertaken rather than the use of measures which are intended to standardise research output within or across disciplines. 相似文献
74.
Plexiform lesions (PLs), which are often accompanied by perivascular infiltrates of mononuclear cells, represent the hallmark lesions of pulmonary arteries in humans suffering from severe pulmonary arterial hypertension (PAH). Endothelial progenitor cells (EPCs) have been recently implicated in the formation of PLs in human patients. PLs rarely develop in rodent animal models of PAH but can develop spontaneously in broiler chickens. The aim of the present study was to confirm the presence of EPCs in the PLs in broilers. The immune mechanisms involved in EPC dysfunction were also evaluated. Lungs were collected from commercial broilers at 1 to 4 weeks of age. The right/total ventricle ratios indicated normal pulmonary arterial pressures for all sampled birds. Immunohistochemistry was performed to determine the expressions of EPC markers (CD133 and VEGFR-2) and proangiogenic molecule hepatocyte growth factor (HGF) in the lung samples. An EPC/lymphocyte co-culture system was used to investigate the functional changes of EPCs under the challenge of immune cells. PLs with different cellular composition were detected in the lungs of broilers regardless of age, and they were commonly surrounded by moderate to dense perivascular mononuclear cell infiltrates. Immunohistochemical analyses revealed the presence of CD133+ and VEGFR-2+ cells in PLs. These structures also exhibited a strong expression of HGF. Lymphocyte co-culture enhanced EPC apoptosis and completely blocked HGF-stimulated EPC survival and in vitro tube formation. Taken together, this work provides evidence for the involvement of EPCs in the development of PLs in broilers. It is suggested that the local immune cell infiltrate might serve as a contributor to EPC dysfunction by inducing EPC death and limiting their response to angiogenic stimuli. Broiler chickens may be valuable for investigating reversibility of plexogenic arteriopathy using genemodified inflammation-resistant EPCs. 相似文献
75.
Hao Tian Jinhui Zhao Xinyao Wang Lizhuo Wang Hao Liu Guoxiu Wang Jun Huang Jian Liu G Q Lu 《国家科学评论(英文版)》2020,7(11):1647
It is highly desirable to design hollow structures with multi-scale functions by mimicking cells for the construction of micro/nanoreactors. Herein, we report the construction of hollow-structured submicrometer-photoreactors with bimetallic catalysts loaded within mesoporous silicas. The synthesis parameters are optimized to study the evolution of hollow structure through hydrothermal treatment and an ‘adhesive-contraction’ formation mechanism is proposed. AuPt@HMZS catalysts exhibited a broader absorbance region under visible light and the adsorption edge displayed a red-shift, indicating the strong metal–metal interactions at the alloy interface. The reaction performance of the coupled Au-Pt catalysts can be tuned to achieve excellent catalytic activity in cinnamyl alcohol oxidation to cinnamic acid for 3.1 mmol g−1 with 99% selectivity. The proposed strategy to build hollow structures as multifunctional micro/nanoreactors is promising for the design of high-performance and sustainable catalysts for chemical synthesis. 相似文献
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Reading and Writing - Writing is essential for communication in literate societies, and its successful acquisition and development is central to academic achievement. Beginning in early childhood,... 相似文献
78.
Tonia J. Land Tonya G. Bartell Corey Drake Mary Q. Foote Amy Roth McDuffie Erin E. Turner 《课程研究杂志》2019,51(4):471-493
Elementary mathematics curriculum materials can serve as a lever for instructional change. In this paper, we promote a particular kind of instructional change: supporting teachers in learning to integrate children’s multiple mathematical knowledge bases (MMKB), including children’s mathematical thinking and children’s home and community-based mathematical funds of knowledge, in instruction. A powerful means of supporting pre-service teachers in integrating children’s MMKB in instruction may be to scaffold teachers’ noticing of potential spaces in elementary mathematics curriculum materials for connecting to children’s MMKB and then developing practices for leveraging these spaces during instruction. We focus on existing and potential spaces in written curriculum materials, or curriculum spaces, so as to better support teachers in enacting curriculum that opens spaces for connecting to children’s MMKB. 相似文献
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曹文强 《武汉工程职业技术学院学报》2004,16(1):10-14
本文将由非线性量子动力学方程同时导出薛定锷方程和牛顿方程.这样就不仅证明了经典力学与量子力学已被统一了起来,且证明了薛定锷场(波函数)不是非物质性的几率波.而是刻出物质性背景空间性质的物质性场. 相似文献