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141.
In-line particle holography is a well-known method used for visualization and measurement of small objects such as sizes, 3-D positions and velocities. However, this method suffers from a major drawback that is conventional analysis of its reconstructed images is very tedious and time consuming. In this paper, we review recent progress in holographic particle tracking and sizing by using wavelet transform. Recent experimental results of spherical object measurement are noted. 相似文献
142.
143.
朱明高 《宁波大学学报(理工版)》1988,(2)
本文就纤维材料、浆料工艺特性、环境因素、竞聚率及聚合工艺等方面对聚合物经纱浆料的分子设计作了较为详尽的分析,提出了经纱浆料聚合物分子设计的一些依据。 相似文献
144.
桂祖华 《应用数学和力学(英文版)》1996,17(7):659-663
NEWTON'STHEOREMWITHRESPECTTOALOTOFCENTERSANDTHEIRAPPLICATIONS¥(桂祖华)GutZuhua(DepartmentofAppliedMathematicsofShanghaiJiaotongUn... 相似文献
145.
The physical properties of materials are critical to their functionality, and the ability to control these properties using external forces is a significant challenge. In this study, we investigate the effect of three high frequency acoustic wave vibration patterns on the structure and morphology of MOF particles. Our results indicate that while regular vibration patterns generated by SAW can alter particle morphology, hybrid waves and Lamb waves with irregular vibration patterns can synthesise MOF crystals with multi-level pores. The vibration pattern of acoustic waves is shown to be a critical factor in controlling the particle morphology process. These results provide new insights into the precise control of crystal structure and the theory of crystallisation by particle attachment (CPA). 相似文献
146.
非独立模式算法下粒径分布反演及分类的研究 总被引:1,自引:0,他引:1
在光全散射法颗粒粒径测量中,提出一种非独立模式算法下粒径分布反演及分类的方法。对被测颗粒系分别按照不同的粒径分布函数同时进行反演,并依据反演误差大小判断被测颗粒系符合哪种分布函数。仿真实验结果表明,在非独立模式下,完全可以利用已知的不同分布函数的反演误差作为分类依据,从而更准确地确定被测颗粒系的粒径分布。采用的遗传反演算法能够在3个可见光波长下得到较准确的粒径分布,反演结果稳定可靠,最大限度地减少了多个波长的使用,从而对光源有更大的选择余地。对透射消光测量结果加入5%随机噪声时,单峰分布颗粒系的反演误差小于5%,多峰分布颗粒系的反演误差小于10%。整个算法运行时间小于2 s。该方法具有原理简单,计算速度快等优点,能够满足颗粒粒径在线测量的要求。 相似文献
147.
C. Theodosiou 《International Journal of Non》2009,44(4):371-3457
Fast and accurate simulation of mechanical structures with complex geometry requires application of the finite element method. This leads frequently to models with a relatively large number of degrees of freedom, which may also possess non-linear properties. Things become more complicated for systems involving unilateral contact and friction. In classical structural dynamics approaches, such constraints are usually modeled by special contact elements. The characteristics of these elements must be selected in a delicate way, but even so the success of these methods cannot be guaranteed. This study presents a numerical methodology, which is suitable for determining dynamic response of large scale finite element models of mechanical systems with multiple unilateral constraints. The method developed is based on a proper combination of results from two classes of direct integration methodologies. The first one includes standard methods employed in determining dynamic response of structural models possessing smooth non-linearities. The second class of methods includes specialized methodologies that simulate the response of dynamical systems with unilateral constraints. The validity and effectiveness of the methodology developed is illustrated by numerical results. 相似文献
148.
149.
APPLICATION OF GENETIC ALGORITHM IN PARTICLE SIZE ANALYSIS BY MULTISPECTRAL EXTINCTION MEASUREMENTS 总被引:1,自引:0,他引:1
Gerard Grhan 《中国颗粒学报》2004,2(6):235-240
Both dependent and independent model algorithms are designed with genetic algorithm (GA) to retrieve aerosol size data from multispectral extinction measurements. Compared with the traditional dependent model algorithm, e.g., simplex, GA can locate the global optimized solution instead of local ones. As an independent model algonthm, when combined with B-splines, GA gives consistent results with Chahine and Phillip-Twomey-NNLS algorithms. Numerical simulations also show that GA has high stability and good resistance to relatively higher error levels. For a population size of 50 in the present paper, the feasible ranges for genetic operators Pc and pm are found to be [0.01, 0.5] and [0.01, 0.15], respectively, and the generation number Gen_Max should be larger than 250. 相似文献
150.