全文获取类型
收费全文 | 99篇 |
免费 | 9篇 |
专业分类
化学 | 7篇 |
力学 | 11篇 |
数学 | 27篇 |
物理学 | 63篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2017年 | 7篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 6篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有108条查询结果,搜索用时 31 毫秒
91.
92.
In the present work a numerical study was carried out to investigate the inclusion behaviour in a four strand asymmetric billet caster tundish. A parameter called separation efficiency was used to compare inclusion behaviour quantitatively. An open source CFD code called OpenFOAM was used to model the inclusions through Lagrangian Particle Tracking approach. First, the Lagrangian particle class was defined in the existing simpleFoam solver of the OpenFOAM and the same customized solver was used to track particles in the already obtained velocity field. Inclusions were modelled as spheres and various forces acting were also considered. Present numerical results were validated using available experimental results and found to be in good agreement. Further, such inclusion behaviour was also extended for a real industrial case tundish. Inclusion flotation characteristics in thermally induced flow was analyzed in detail. This is, perhaps, for the first time such an exhaustive study on inclusion analysis being reported considering the forces acting on the inclusions particles and with OpenFOAM. 相似文献
93.
94.
本文介绍一种用于电视跟踪系统的全视场捕获模块,在背景较为单调的情况下,它可以在一个电视场的时间内,在全视场范围内自动捕获目标,该模块还具有波门跟踪功能。文中给出了模块的具体实现及外场试验结果。 相似文献
95.
96.
A two-beam laser triangulation method has been proposed to measure the position of a moving object. The method uses two parallel laser beams to judge the moving direction of an object, allowing us to track it and measure its positions. An uncertainty of 0.2 mm for a measurement range of 50 mm has been obtained. This tracking measurement capability is useful in the calibration of the position of a moving robot arm. 相似文献
97.
光电经纬仪的跟踪误差及其检测 总被引:2,自引:2,他引:0
本文开头指出了跟踪性能是光电经纬仪第一重要技术指标,接着叙述了跟踪原理和跟踪误差的检测方法,并对跟踪误差进行了较深入的分析讨论文章最后,将跟踪误差分门别类,介绍了降低跟踪误差,提高跟踪性能的途径。 相似文献
98.
Vinod B Johri 《Pramana》2002,59(3):L553-L561
We present a realistic scenario of tracking of scalar fields with varying equation of state. The astrophysical constraints
on the evolution of scalar fields in the physical universe are discussed. The nucleosynthesis and the galaxy formation constraints
have been used to put limits on Ωφ and estimate ɛ during cosmic evolution. Interpolation techniques have been applied to estimate ɛ ⋍0.772 at the present epoch.
The epoch of transition from matter to quintessence dominated era and consequent onset of acceleration in cosmic expansion
is calculated and taking the lower limit Θ
n
/0
=0.2 as estimated from SN
e
I
a
data, it is shown that the supernova observations beyond redshift z=1 would reveal deceleration in cosmic expansion. 相似文献
99.
Multiresolutional signal processing has been employed in image processing and computer vision to achieve improved performance that cannot be achieved using conventional signal processing techniques at only one resolution level[1,2,5,6]. In this paper,we have associated the thought of multiresolutional analysis with traditional Kalman filtering and proposed A new fusion algorithm based on singular Sensor and Multipale Models for maneuvering target tracking. 相似文献
100.
针对登月过程严酷的力学条件、月球表面复杂的环境特征以及严格的重量要求,设计了一种可适用于月基观测的跟踪转台.该转台主要由水平轴系及驱动机构和竖直轴系及驱动机构组成,采用霍耳元件作为位置检测元件,其综合指向准确度≤0.1°.基于有限元分析方法确定转台结构方案、优化主要支撑件结构及合理选材,并对驱动机构与轴系对转台刚度、温度适应性和指向准确度的影响做了深入分析与计算.同时进行了整机的力学模拟试验和运动机构的高低温试验,一阶谐振频率为49 Hz,在-40 ℃ ~+80 ℃温度范围内工作正常.结果表明转台各项性能指标满足工程任务要求,具有结构紧凑、可靠性高、重量轻的特点. 相似文献