全文获取类型
收费全文 | 511篇 |
免费 | 13篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 526篇 |
出版年
2022年 | 6篇 |
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 22篇 |
2017年 | 25篇 |
2016年 | 34篇 |
2015年 | 14篇 |
2014年 | 22篇 |
2013年 | 29篇 |
2012年 | 22篇 |
2011年 | 19篇 |
2010年 | 21篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 18篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1998年 | 14篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 14篇 |
1994年 | 5篇 |
1993年 | 16篇 |
1992年 | 7篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1972年 | 6篇 |
1970年 | 4篇 |
1968年 | 2篇 |
1967年 | 4篇 |
1966年 | 3篇 |
1965年 | 3篇 |
1962年 | 2篇 |
1957年 | 2篇 |
排序方式: 共有526条查询结果,搜索用时 15 毫秒
1.
2.
O. N. Zavrazhnaya I. N. Oleinikov E. D. Naumov V. V. Petrov 《Chemical and Petroleum Engineering》1993,29(11):555-559
Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 11, pp. 28–30, November, 1993. 相似文献
3.
A. V. Naumov 《Russian Journal of Non-Ferrous Metals》2007,48(1):10-16
Based on the publications of recent years, a review of the modern state of the world and Russian markets of bismuth is made and an attempt of prognosing the further development and perspectives in this field is given. 相似文献
4.
A. V. Naumov 《Russian Journal of Non-Ferrous Metals》2007,48(4):265-272
Based on publications of recent years, the modern state of the world market of germanium and germanium-containing products after the depression of 1999–2000 years is reviewed. 相似文献
5.
The concentration fields of disperse impurity are calculated on the basis of a k- model of turbulence in a wide range of Stokes numbers.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 4, pp. 548–555, October, 1985. 相似文献
6.
Various CaCO3-based products are often used in the form of concentrated aqueous dispersions. This study investigates the stabilization of PCC dispersions prepared directly in the mother-liquid after the carbonation of (hydrated) lime through the adsorption of a commercial sodium polyacrylate dispersant. The results demonstrate that the composition of the mother-liquid, particularly the Ca2+ activity, profoundly influences virtually all processes pertinent to dispersion stabilization—from the initial charging of the CaCO3 surface in base PCC dispersions, to the surface charge regulation and dispersion stabilization efficiency of the polyacrylate dispersing agent. Rising prominence of the counterion condensation effects in Ca2+ rich solutions limits the conditions conducive to the surface charge regulation through dispersant adsorption to an optimum pH range of about 8-11. Furthermore, dispersion stability analysis, based on the classical DLVO theory of colloid stability, and corroborated by experimental evidence in the form of particle size distribution analyses, also indicates that optimum stability conditions for such PCC dispersions are established with small dispersant doses (0.25-0.5% per dry weight) in the pH range of about 9-11. 相似文献
7.
We consider two-stage stochastic programming models with quantile criterion as well as models with a probabilistic constraint on the random values of the objective function of the second stage. These models allow us to formalize the requirements for the reliability and safety of the system being optimized and to optimize system’s performance under extreme conditions. We propose a method of equivalent transformation of these models under discrete distribution of random parameters to mixed-integer programming problems. The number of additional integer (Boolean) variables in these problems equals to the number of possible values of the vector of random parameters. The obtained mixed optimization problems can be solved by powerful standard discrete optimization software. To illustrate the approach, the results of numerical experiment for the problem of small dimension are presented. 相似文献
8.
Scientific-Production Union "VNIITMASh." Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 21–24, May, 1990. 相似文献
9.
V. A. Naumov 《Journal of Engineering Physics and Thermophysics》1995,68(5):683-686
The article is concerned with the study of the effect of E. S. Asmolov's corrections to Saffman's lift force for the wall vicinity and a nonzero ratio of Reynolds numbers. It is shown in what way these corrections change the particle paths in a Couette layer and the conditions of deposition.Notation
x=X/D, y=Y/D
dimensionless longitudinal and transverse coordinates
-
u=U
p
/U
, =V
p
/U
dimensionless projections of particle velocity on the longitudinal and transverse axes
- =tU
/D
dimensionless time
-
U
2/(18D)
Stokes number
- =
g
/
p
,
coefficient of the gas kinematic viscosity
-
particle diameter
-
/D
-
g
,
p
densities of the gas and particle material
-
du/d
-
dv/d
-
P
s
Saffman's force
-
C
coefficient in the formula for Saffman's force
-
yRe
d
1/2
-
A
v
r
Re
d
1/2
-
3.08
- Re
V
r
/
- Re
k
2/)U
g
/Y
-
A
Re/Re
k
1/2
- Re
d
U
D/
-
V
r
((U
g
–U
p
)2+V
p
2
)1/2
Indices
g
refers to gas parameters
-
p
refers to the parameters of particles
- 0
at the time momentt=0
-
S
Saffman's force
-
k
Reynolds number based on the velocity gradient
-
based on velocity
-
r
relative velocity
-
x
projection on thex axis 相似文献