全文获取类型
收费全文 | 445篇 |
免费 | 38篇 |
国内免费 | 68篇 |
专业分类
化学 | 37篇 |
晶体学 | 1篇 |
力学 | 24篇 |
综合类 | 1篇 |
数学 | 415篇 |
物理学 | 73篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 19篇 |
2013年 | 37篇 |
2012年 | 13篇 |
2011年 | 18篇 |
2010年 | 20篇 |
2009年 | 37篇 |
2008年 | 32篇 |
2007年 | 41篇 |
2006年 | 18篇 |
2005年 | 27篇 |
2004年 | 35篇 |
2003年 | 37篇 |
2002年 | 26篇 |
2001年 | 21篇 |
2000年 | 33篇 |
1999年 | 19篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 19篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有551条查询结果,搜索用时 15 毫秒
71.
Martin Bohner 《Mathematische Nachrichten》1996,182(1):67-72
We consider a certain Sturm - Liouville eigenvalue problem with self- adjoint and non -separated boundary conditions. We derive an explicit formula for the oscillation number of any given eigenfunction. 相似文献
72.
Changes in vocal fold oscillation threshold pressure were induced in excised canine larynges by experimentally causing fluid movement into and out of the vocal folds. The transport was facilitated by exposing the vocal folds to various osmotic solutions, and it was assumed that changes in hydration caused changes in the internal tissue viscosity. A range of oscillation threshold pressures was measured for each condition of hydration by varying length and glottal width. The oscillation threshold pressure shifted as predicted. Decreased hydration (increased viscosity) raised the threshold of oscillation, and increased hydration (decreased viscosity) lowered the threshold of oscillation. This apparently represents the first in vitro model for the study of the effect of viscosity changes of the internal environment of the vocal folds on phonation. 相似文献
73.
一阶变系数滞后型微分方程解的振动性积分条件与渐近性 总被引:2,自引:0,他引:2
计国君 《数学的实践与认识》1998,(2)
本文给出了一阶变系数滞后型微分方程振动解存在的积分条件,同时利用Banach不动点定理讨论了该类方程解的渐近性。 相似文献
74.
Acoustic analysis was performed on recordings of 10 early music singers producing examples of vibrato, exaggerated vibrato, whole-tone trill, and trillo to obtain measures of oscillation rate, frequency extent, and jitter. Oscillation rates for vibrato, exaggerated vibrato, and trill were similar, but trillo rate was much faster. Average frequency extent of oscillation was 1 semitone (st) for vibrato, 2.21 st for exaggerated vibrato, 2.71 st for whole-tone trill, and 1.64 st for trillo. Jitter measures indicated that exaggerated vibrato had the most stable oscillations and trillo the least. 相似文献
75.
We use the Radial Baryon Acoustic Oscillation (RBAO) measurements, distant type Ia supernovae (SNe Ia), the observational H(z) data (OHD) and the Cosmic Microwave Background (CMB) shift parameter data to constrain cosmological parameters of ΛCDM and XCDM cosmologies and further examine the role of OHD and SNe Ia data in cosmological constraints. We marginalize the likelihood function over h by integrating the probability density P∝e−χ2/2 to obtain the best fitting results and the confidence regions in the Ωm–ΩΛ plane. With the combination analysis for both of the ΛCDM and XCDM models, we find that the confidence regions of 68.3%, 95.4% and 99.7% levels using OHD+RBAO+CMB data are in good agreement with that of SNe Ia+RBAO+CMB data which is consistent with the result of Lin et al.'s (2009) [24] work. With more data of OHD, we can probably constrain the cosmological parameters using OHD data instead of SNe Ia data in the future. 相似文献
76.
Oscillatory and asymptotic criteria of third order nonlinear delay dynamic equations with damping term on time scales
下载免费PDF全文
![点击此处可从《Journal of Applied Analysis & Computation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Qinghua Feng 《Journal of Applied Analysis & Computation》2018,8(4):1260-1281
In this paper, we are concerned with oscillatory and asymptotic behavior of third order nonlinear delay dynamic equations with damping term on time scales. By using a generalized Riccati function and inequality technique, we establish some new oscillatory and asymptotic criteria. The established results on one hand extend some known results in the literature, on the other hand unify continuous and discrete analysis as two special cases of an arbitrary time scale. We also present some applications for the established results. 相似文献
77.
Oscillation of second order nonlinear dynamic equations with a nonlinear neutral term on time scales
下载免费PDF全文
![点击此处可从《Journal of Applied Analysis & Computation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this article, we consider the oscillation of second order nonlinear dynamic equations with a nonlinear neutral term on time scales. Some new sufficient conditions which insure that any solution of the equation oscillates are established by means of an inequality technique and Riccati transformation. This paper improves and generalizes some known results. Several illustrative examples are given throughout. 相似文献
78.
Weinian Li Weihong Sheng Pingping Zhang 《Journal of Applied Analysis & Computation》2018,8(6):1910-1918
In this paper, we investigate the oscillation of a class of nonlinear fractional nabla difference equations. Some oscillation criteria are established. 相似文献
79.
In this paper, a fractional partial differential equation subject to the Robin boundary condition is considered. Based on the properties of Riemann-Liouville fractional derivative and a generalized Riccati technique, we obtained sufficient conditions for oscillation of the solutions of such equation. Examples are given to illustrate the main results. 相似文献
80.
Oscillation Criteria For A Class Of First Order Neutral Impulsive Differential-Difference Equations
下载免费PDF全文
![点击此处可从《Journal of Applied Analysis & Computation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Arun Kumar Tripathy 《Journal of Applied Analysis & Computation》2014,4(1):89-101
Sufficient conditions areestablished for oscillation of all solutions of a class ofnonlinear neutral impulsive differential-difference equations offirst order with deviating argument and fixed moments of impulse effect. 相似文献