全文获取类型
收费全文 | 50篇 |
免费 | 4篇 |
国内免费 | 4篇 |
专业分类
化学 | 13篇 |
力学 | 23篇 |
数学 | 9篇 |
物理学 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 2篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有58条查询结果,搜索用时 17 毫秒
1.
2.
Abstract In his communication on the detection limits for thermal emission spectroscopy of metallic species in flame media, Fassel (1) attacks our previous statement that detection limits for Al, Be and Mo were available only for turbulent oxygen-supported hydrogen or acetylene flames. It should be borne in mind that he was referring to a preliminary communication (2) which naturally does not carry an extensive bibliography. It should also be noted that we were concerned, in context, with a comparison of the separated flame with conventional flames, not with highly unconventional flames such as those to which he refers. Whilst the point with which he takes issue was a very minor one, incorporated in our preliminary communication mainly as an “aside”, we firmly disagree with his observation. The flame he refers to (3) (4) is, in fact, a diluted oxy-acetylene flame which is supported by venting some air (and therefore nitrogen) to dilute the fuel-oxygen mixture. Fassel's communication (1) erroneously refers to this as a 'premixed oxy-acetylene flame', whereas elsewhere (5) it is described more correctly as an oxygen-nitrogen-acetylene flame. The burner he long-pathlength carbonaceous flames (10). They also allow more sensitive molecular emission spectroscopy of sulphur in an air-hydrogen flame (11), etc. We hope that this unfortunate correspondence will not distract attention from the main issue of our previous or previous preliminary communication on the separated nitrous oxide-acetylene flime. 相似文献
3.
Non-linear dynamic intertwining of rods with self-contact 总被引:1,自引:0,他引:1
Twisted marine cables on the sea floor can form highly contorted three-dimensional loops that resemble tangles. Such tangles or ‘hockles’ are topologically equivalent to the plectomenes that form in supercoiled DNA molecules. The dynamic evolution of these intertwined loops is studied herein using a computational rod model that explicitly accounts for dynamic self-contact. Numerical solutions are presented for an illustrative example of a long rod subjected to increasing twist at one end. The solutions reveal the dynamic evolution of the rod from an initially straight state, through a buckled state in the approximate form of a helix, through the dynamic collapse of this helix into a near-planar loop with one site of self-contact, and the subsequent intertwining of this loop with multiple sites of self-contact. This evolution is controlled by the dynamic conversion of torsional strain energy to bending strain energy or, alternatively, by the dynamic conversion of twist (Tw) to writhe (Wr). 相似文献
4.
5.
G. Cardone A. Corbo Esposito G.P. Panasenko 《Nonlinear Analysis: Theory, Methods & Applications》2006
The method of partial asymptotic decomposition of a domain is applied to a model non-linear equation set in a rod structure. The estimates of error are provided. An asymptotic expansion of solution is constructed and justified. 相似文献
6.
Maria Giovanna Mora Stefan Müller 《Calculus of Variations and Partial Differential Equations》2007,28(2):161-178
A rigorous derivation is given of a rod theory for a multiphase material, starting from three-dimensional nonlinear elasticity. The stored energy density is supposed to be nonnegative and to vanish exactly on a set consisting of two copies of the group of rotations SO(3). The two potential wells correspond to the two crystalline configurations preferred by the material. We find the optimal scaling of the energy in terms of the diameter of the rod and we identify the limit, as the diameter goes to zero, in the sense of Γ-convergence. 相似文献
7.
The compound [K(18‐crown‐6)]8[Ge9=Ge9=Ge9=Ge9] ˙ 8en ( 1 ) featuring a [Ge9=Ge9=Ge9=Ge9]8‐cluster anion was synthesized from K4Ge9 for the first time. The X‐ray single crystal analysis shows that, in many respects such as bond connection and packing style, compound 1 is quite different from the previously reported compounds [Rb(18‐crown‐6)]8[Ge9=Ge9=Ge9=Ge9] ˙ 2en ( 2 ) and [Rb(18‐crown‐6)]8[Ge9=Ge9=Ge9=Ge9] ˙ 6en ( 3 ). Crystal packing of 1 gives strong indications that the highly charged nano‐rods self assembly in a hexagonal rod packing. 相似文献
8.
A. Larsson 《Colloid and polymer science》1999,277(7):680-686
Negatively charged silica particles were investigated at pH 10.0. They were found to be rod-shaped (cylinder) with a diameter
of 5–5.5 nm and a full length of 44–67 nm depending on the rod model used. Moreover, the particles were found to be stable
against aggregation in the region 0.4–50 mM NaCl.
Received: 2 December 1998 Accepted in revised form: 2 February 1999 相似文献
9.
Rods and plates with weakenings are studied using homogenization approach. For rods, two limiting cases amenable to asymptotic integration are considered. It is shown, among other things, that plates with periodic weakenings can be reduced to rods. 相似文献
10.
J. N. Lillington 《国际流体数值方法杂志》1981,1(1):3-16
This paper considers a finite difference scheme for modelling the convection/diffusion equation in strongly convective flow regimes including circumstances in which significant source terms are present. The main objective is to provide an alternative approach to central and/or upwind difference methods which for various reasons are unsatisfactory. To illustrate the main features of the scheme, an assessment of its accuracy is made by means of a Taylor expansion analysis and a study of its performance in two model problems. As a demonstration of its generality for use in large-scale practical problems, some numerical results are presented for the prediction of the temperature distribution in a flow through a partially blocked heated rod bundle. The main conclusions are that in almost all practical circumstances results obtained using the scheme are not susceptible to false diffusion or spatial oscillations, which are, respectively, the inherent weaknesses in many upwind and central difference scheme formulations, and in general its use results in improved overall accuracy. 相似文献