全文获取类型
收费全文 | 555篇 |
免费 | 113篇 |
国内免费 | 43篇 |
专业分类
化学 | 236篇 |
晶体学 | 5篇 |
力学 | 163篇 |
综合类 | 1篇 |
数学 | 14篇 |
物理学 | 292篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 27篇 |
2021年 | 49篇 |
2020年 | 32篇 |
2019年 | 22篇 |
2018年 | 21篇 |
2017年 | 36篇 |
2016年 | 45篇 |
2015年 | 39篇 |
2014年 | 34篇 |
2013年 | 71篇 |
2012年 | 24篇 |
2011年 | 33篇 |
2010年 | 22篇 |
2009年 | 31篇 |
2008年 | 17篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 16篇 |
2004年 | 15篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 7篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 12篇 |
1996年 | 10篇 |
1995年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1957年 | 1篇 |
排序方式: 共有711条查询结果,搜索用时 0 毫秒
101.
This paper investigates the nonequilibrium dynamics of two-dimensional Ising spin glass by dynamical Monte Carlo simulations. A new method is developed to quantitatively measure the age of domain growth. Using this method it investigates how temperature shift affects the effective age of domain growth. It finds that the T -shift dependence of the effective age follows the prediction of the droplet model quite well. It also investigates the overlap length between the spin glass states as well as the correlated flips of spins,which are not consistent with the theoretical predictions. The possible reasons are discussed. 相似文献
102.
103.
理论分析了射流抛光的紊动冲击射流特点,构建了射流抛光的垂直冲击射流模型和斜冲击射流模型。根据射流抛光冲击射流的特点,比较各种流体模型后,采用RNG k-e 模型应用于射流抛光模型的计算。利用计算流体力学理论的二阶迎风格式对抛光模型方程离散,用SIMPLEC数值计算方法对射流抛光过程的紊动冲击射流和离散相磨粒分布进行数值模拟,得到了射流抛光过程的连续流场和离散相磨粒与水溶液的耦合流场,同时计算出了抛光液射流在工件壁面上的压力、速度、紊动强度、剪切力分布和磨粒体积质量分布,分析了垂直射流抛光模型和斜冲击射流抛光模型紊流流场的特点。 相似文献
104.
105.
106.
Determination of four acidic nonsteroidal anti‐inflammatory drugs in wastewater samples by dispersive liquid–liquid microextraction based on solidification of floating organic droplet and high‐performance liquid chromatography 下载免费PDF全文
Mihail Simion Beldean‐Galea Virginia Coman Didier Thiébaut Jérome Vial 《Journal of separation science》2015,38(4):641-648
A simple, environmentally friendly, and sensitive dispersive liquid–liquid microextraction based on solidification of floating organic droplet for the extraction of four acidic nonsteroidal anti‐inflammatory drugs (ketoprofen, naproxen, ibuprofen, and diclofenac) from wastewater samples subsequent by high‐performance liquid chromatography analysis was developed. The influence of extraction parameters such as pH, the effect of solution ionic strength, type of extraction solvent, disperser solvent, and extraction solvent volume were studied. High enrichment factors (283–302) were obtained through the developed method. The method provides good linearity (r > 0.999) in a concentration range of 1–100 μg/L, good intra‐ and inter‐day precision (relative standard deviation < 7%) and low limits of quantification. The relative recoveries of the selected compounds were situated over 80% both in synthetic and real water samples. The developed method has been successfully applied for the analysis of the selected compounds in wastewater samples. 相似文献
107.
利用三维分子动力学模拟方法,研究了纳米尺度水滴撞击冷壁面的结冰过程.数值模拟中,统计系统采用微正则系综,势能函数选用TIP4P/ice模型,温度校正使用速度定标法,牛顿运动方程的求解采用文莱特算法,水滴内部结冰过程则通过统计垂直方向水分子温度分布来判定.研究发现,当冷壁面温度降低时,水滴完全结冰的时间减小,但水滴降至壁面温度的时间却增大;同时随着壁面亲水性降低,水滴内部热传递速度减慢(尤其是冷壁面与水滴底端分子层间),水滴内部温度趋于均匀,但水滴完全结冰时间延长. 相似文献
108.
The dynamics of two-phase flows depend crucially on interfacial effects like surface tension and phase transition. A numerical method for compressible inviscid flows is proposed that accounts in particular for these two effects. The approach relies on the solution of Riemann-like problems across the interface that separates the liquid and the vapour phase. Since the analytical solutions of the Riemann problems are only known in particular cases an approximative Riemann solver for arbitrary settings is constructed. The approximative solutions rely on the relaxation technique.The local well-posedness of the approximative solver is proven. Finally we present numerical experiments for radially symmetric configurations that underline the reliability and efficiency of the numerical scheme. 相似文献
109.
Zhongyu Shi 《中国物理 B》2022,31(5):54701-054701
The phenomenon of droplet impact on an immiscible liquid is encountered in a variety of scenarios in nature and industrial production. Despite exhaustive research, it is not fully clear how the immiscibility of the liquid on which a droplet impacts affects the crown evolution. The present work experimentally investigates the evolution kinematics of a crown formed by the normal impact of a camellia oil droplet on an immiscible water layer. Based on discussion of dynamic impact behaviors for three critical Weber numbers (We), the radius of the crown and its average spreading velocity are compared with those of previous theoretical models to discuss their applicability to the immiscible liquid. The evolution kinematics (morphology and velocity) are analyzed by considering the effects of the We and layer thickness. Furthermore, the ability of crown expansion in radial and vertical directions is characterized by a velocity ratio. The results show that our experimental crown radius still follows a square-root function of evolution time, which agrees with the theoretical predictions. The dimensionless average spreading velocity decreases with We and follows a multivariate power law, while the dimensionless average rising velocity remains constant. The velocity ratio is shown to linearly increase with We, demonstrating that the rising movement in crown evolution gradually enhances with We. These results are helpful for further investigation on the droplet impact on an immiscible liquid layer. 相似文献
110.
排烟增湿脱硫活化反应器内液滴──脱硫剂颗粒碰撞的数值模拟 总被引:5,自引:0,他引:5
排烟增湿脱硫活化反应器内液滴──脱硫剂颗粒碰撞的数值模拟唐庆,徐旭常(清华大学热能工程系北京100084)关键词液滴-颗粒碰撞,脱硫,数值模拟要有效的控制SOZ的污染,降低燃煤电厂排烟中SOZ的浓度显得尤为重要。在众多的烟气脱硫技术中,排烟增湿活化脱... 相似文献