全文获取类型
收费全文 | 84篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 26篇 |
晶体学 | 1篇 |
力学 | 4篇 |
数学 | 9篇 |
物理学 | 46篇 |
出版年
2021年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2013年 | 7篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2003年 | 1篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1982年 | 3篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1937年 | 1篇 |
1931年 | 1篇 |
1923年 | 1篇 |
1898年 | 1篇 |
1889年 | 1篇 |
1883年 | 1篇 |
排序方式: 共有86条查询结果,搜索用时 15 毫秒
21.
Orit Hazzan E. Paul Goldenberg 《International Journal of Computers for Mathematical Learning》1996,1(3):263-291
To make optimal use of computational environments, one must understand how students interact with the environments and how students' mathematical thinking is reflected and affected by their use of the environments. Similarly, to make sense of research on students' thinking and learning, one must understand how the environments and contexts used in the research may affect the conclusions one derives.The research on students' learning of functions has approached the topic in terms of symbols and graphs (see, for example, Leinhardt et al. (1990) for a review of work up to that point; Harel and Dubinsky (1992) for a collection of research; and Dugdale et. al. (1995), for some recent thinking about implications for curriculum reform using technology). Dynamic geometry environments (DGEs) like Cabri Geometry or Geometer's Sketchpad, offer us an opportunity to get a new perspective on these old and important issues. DGEs let students build geometrical constructions and then drag certain objects around the screen in a continuous manner while observing how the entire construction responds dynamically. In this way DGEs model functional relationships that are not specified by symbols or represented by graphs.Based on interviews with undergraduate mathematics majors, this paper presents preliminary observations that confirm some old results and raise some new questions about students' notions of function. 相似文献
22.
B. G. Goldenberg T. N. Goryachkovskaya V. S. Eliseev N. A. Kolchanov V. I. Kondrat’ev G. N. Kulipanov V. M. Popik S. E. Pel’tek E. V. Petrova V. F. Pindyurin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(4):637-640
Preliminary results of fabrication and testing of LIGA mask samples for deep x-ray lithography in the spectral range of 3.5–13.5 keV are presented. The mask fabrication method is based on direct mask patterning with minimum element sizes of ≥ 10 μm by a synchrotron radiation x-ray microbeam. Such a method does not require an intermediate mask, which significantly simplifies fabrication and reduces the laboriousness and cost of LIGA masks. 相似文献
23.
Glyavin M.Yu. Goldenberg A.L. Kuftin A.N. Lygin V.K. Postnikova A.S. Zapevalov V.E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(2):474-483
In order to provide electron beams of powerful gyrotrons, magnetron-injection guns operating in the regime of the temperature limited current are used. The electron beam quality and gyrotron performances are defined both by the cathode emission processes and the processes occurring in the electron beam during its formation and transportation. The results of measurements of the energy spectrum and velocity spread of the gyrotron electron beam in different regimes are given. Experimental data on the parameter of efficient emission inhomogeneity for different regimes are presented, as well as the dependencies of electron beam parameters on efficient inhomogeneity of the cathode 相似文献
24.
Real-world networks are characterized by common features, including among others a scale-free degree distribution, a high clustering coefficient and a short typical distance between nodes. These properties are usually explained by the dynamics of edge and node addition and deletion. 相似文献
25.
26.
Ohne Zusammenfassung 相似文献
27.
28.
29.
30.
It is demonstrated, by numerical simulations of a 2D assembly of polydisperse disks, that there exists a range (plateau) of coarse-graining scales for which the stress tensor field in a granular solid is nearly resolution independent, thereby enabling an "objective" definition of this field. Expectedly, it is not the mere size of the system but the (related) magnitudes of the gradients that determine the widths of the plateaus. Ensemble averaging (even over "small" ensembles) extends the widths of the plateaus to subparticle scales. The fluctuations within the ensemble are studied as well. Both the response to homogeneous forcing and to an external compressive localized load (and gravity) are studied. Implications to small solid systems and constitutive relations are briefly discussed. 相似文献