全文获取类型
收费全文 | 89篇 |
免费 | 10篇 |
国内免费 | 3篇 |
专业分类
化学 | 5篇 |
力学 | 8篇 |
综合类 | 3篇 |
数学 | 10篇 |
物理学 | 76篇 |
出版年
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1984年 | 2篇 |
排序方式: 共有102条查询结果,搜索用时 15 毫秒
61.
黑龙江电视塔设计中的温度效应研究 总被引:6,自引:0,他引:6
本文通过对高寒地区建筑结构的调查研究,提出了多功能钢结构电视塔中温度效应较为显著的几个方面的问题。同时结合筹建中的黑龙江电视塔,通过计算就温度效应对钢塔的影响作一定性分析,得出一系列结论和建议供参考。 相似文献
62.
63.
针对欧拉方程三种流行的对流-压力通量分裂方法(Liou-Steffen,Zha-Bilgen和Toro-Vázquez)进行特征分析,进而提出一种新的对流-压力通量分裂格式。采用Zha-Bilgen分裂方法将欧拉方程的通量分裂成对流项和压力项两部分,使用TV格式来计算这两部分的数值通量。利用压力比构造激波探测函数,并且在强激波附近的亚声速区域增加TV格式的剪切粘性来克服数值模拟中的激波不稳定性。数值算例的计算结果表明,新的对流-压力通量分裂格式不仅保留了原始TV格式精确分辨接触间断的优点,而且具有更好的鲁棒性,在数值模拟多维强激波问题时不会出现不稳定现象。因此,该格式是一种精确并且具有强鲁棒性的数值方法,可以广泛地应用于可压缩流体的数值计算中。 相似文献
64.
一种数字微镜阵列分区控制和超分辨重建的压缩感知成像法 总被引:1,自引:0,他引:1
提出一种压缩感知成像框架结构.该结构采样端用新建的采样矩阵实现数字微镜阵列分区控制,可增强信息获取的准确性,测量得到与新数字微镜阵列对应的压缩采样值;重构端由采样值优化重构出低分辨率图像后,根据分区控制过程建立压缩感知理论框架下的超分辨重建模型,利用梯度稀疏约束优化算法进行求解,恢复出原高分辨率图像.实验结果表明:数字微镜阵列分区控制与超分辨重建相结合的方法可以明显降低压缩感知成像系统的计算量,缩短成像时间,并且具有较高的图像重构质量. 相似文献
65.
Abstract This article reports a numerical investigation on the transmission performance of multilevel systems operating in building links encompassing step-index plastic optical fibers. For such an aim, a simplified model for the multimode fiber propagation is introduced. A sub-carrier multiplexing technique is also simulated to demonstrate the distribution of broadcasting television channels by adopting such fibers. The reported results show that a unique building network based on step-index plastic optical fibers is suitable to carry both Ethernet and broadcast TV signals in all rooms. 相似文献
66.
The usage of rapid heat cycle molding (RHCM) has gained increasing attention in overcoming the limits of conventional injection molding (CIM) and improving the surface quality and mechanical properties of molded plastic products. In RHCM, the vario‐thermal mold temperature control system is the key technique because it directly affects the molding cycle time and the final part quality. In this study, a new RHCM technology with electric heating and coolant cooling was studied in detail. Two different RHCM mold structures for a large LCD TV panel were proposed and designed. The numerical simulation method was used to analyze the thermal response of the mold cavity surface at the heating stage and the thermal response of the resin melt at the cooling stage. The heating/cooling efficiency of the proposed electric heating RHCM system was evaluated. The thermal expansion analysis of mold cavity was implemented and the fixation of the cavity in molds was also optimized. The results showed that the electric‐heating mold with a separate cooling plate can efficiently enhance the heating efficiency. The thermal expansion of the cavity surface can be reduced by increasing the alleviating‐gap between the cavity and the cavity‐retainer plate. Then, the service lifetime of the electric‐heating mold can be improved. A RHCM production line with electric heating for the large LCD TV panel was constructed. Both the simulation and test production results indicate that the proposed electric heating RHCM technique can realize high‐temperature injection molding without increasing the molding cycle time. The surface appearance of the LCD TV panels was dramatically improved and the surface marks that usually occur in CIM process were eliminated completely. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
67.
68.
69.
利用微光像增强器的图像增强功能,将微光像增强管耦合到电荷耦合器件(CCD)上即构成微光图像增强CCD(简称ICCD)。它具有两个重要的特性:一是通过选择适当的像管输入窗及光电阴极,使ICCD光谱响应范围由可见光扩展到X射线、紫外、近红外区域,从而使该器件能适用于各种用途;二是使ICCD的灵敏度达到10-4lx以下,实现了ICCD摄像器件在黎明或黄昏的照度下(102lx)在1/4月光下(10-2lx)、在星光下(10-4lx)都能有效的工作。微光ICCD电视摄像系统可应用在天文、医疗、火控、制导、飞机紫外预警等方面。重点阐述了微光ICCD电视摄像技术的发展与性能评价。 相似文献
70.
Bending and acoustic waves in a water-filled box studied by pulsed TV holography and LDV 总被引:1,自引:0,他引:1
Pulsed TV holography and laser Doppler vibrometry (LDV) are non-destructive and non-contacting methods useful in the testing of mechanical properties in a wall separating two media. This paper presents comparative studies of transient, propagating bending waves in an impact-loaded thin aluminium wall of a box, and acoustic waves generated in the water inside the box using the two mentioned methods. Besides being evaluated and compared, the results were used to investigate qualities of the methods for the specific applications. The measured wave propagations obtained from the two methods are consistent regarding both amplitude and phase. Further, transient pressure fields in the water have been computed from the pulsed TV holography measurements. Since none of the two methods are capable of providing both temporal and spatial information simultaneously, they complement each other. 相似文献