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排序方式： 共有93条查询结果，搜索用时 15 毫秒
1.
2.
In this paper, Cu52Zr37Ti8In3 bulk metallic glass has been studied by nanoindentation. Three different ways for nanoindentation tests were employed. Load-control nanoindentation was used to investigate the effect of the loading rate on the hardness and Young’s modulus. Young’s modulus of the specimen shows a loading rate dependence. The constant-load indentation creep measurement was performed. The creep data were fitted with the generalized Kelvin model, and the compliance spectrum and retardation spectrum were derived. Furthermore, the storage compliance and loss compliance were also discussed. For characterizing the change of the hardness and Young’s modulus with increasing indentation depth, depth-control nanoindentation analysis was conducted. The results show that both the hardness and Young’s modulus decrease with nanoindentation depth. 相似文献
3.
Small-target detection in infrared imagery with a complex background is always an important task in remote sensing fields. It is important to improve the detection capabilities such as detection rate, false alarm rate, and speed. However, current algorithms usually improve one or two of the detection capabilities while sacrificing the other. In this letter, an Infrared (IR) small target detection algorithm with two layers inspired by Human Visual System (HVS) is proposed to balance those detection capabilities. The first layer uses high speed simplified local contrast method to select significant information. And the second layer uses machine learning classifier to separate targets from background clutters. Experimental results show the proposed algorithm pursue good performance in detection rate, false alarm rate and speed simultaneously. 相似文献
4.
介绍了通过运用网络平台构建物理实验中心的管理系统,以实现学生选课、成绩管理、教学信息管理和发布、教学资料的上网及仪器管理等一系列的功能,使物理实验中心的各项工作有序而高效. 相似文献
5.
《Wave Motion》1987,9(4):323-332
Surface waves moving at a speed near some critical value on a viscous fluid flow down an incline are studied. An inhomogeneous equation of the Burgers type is derived as a model equation for the long time evolution of the surface waves, when the shear stress on the free surface and the deviation of the uneven bottom from an inclined plane are prescribed. A soliton-like wave and a shock-like front generated ahead of or behind a moving source on the free surface are discovered. 相似文献
6.
The stacks of multi-layer Ti3C2Tx and other types of MXene materials limit their electrochemical performance. Herein, we report a facile exfoliation technique to improve the exfoliation efficiency through Li-intercalation into Ti3C2Tx interlayers in isopropyl alcohol (IPA) with LiOH as intercalant. This de-intercalation method presented here not only effectively delaminates the stacked Ti3C2Tx multi-layers into separate few-layer MXene sheets, but also achieves high-rate supercapacitive performance of Ti3C2Tx electrode. The as-produced delaminated Ti3C2Tx shows highly improved electrochemical capacitive properties from 47 to 115 F g− 1 at 200 mV s− 1. Even at extremely high scan rate of 1000 mV s− 1, a specific capacitance of 82 F g− 1 is still obtained. The high-rate capability can be attributed to improved ions accessibility into the few-layer structures. This study offers a new and simple exfoliation pathway for MXenes materials to exploit their full potential in energy storage applications. 相似文献
7.
Using Bi2（SO4）3 as the catalyst and TMSCl as the additive, a wide variety of aldehydes, ketones, and acetals were smoothly condensed with aryl ethers at room temperature to provide the corresponding diarylmethanes and triarylmethanes selectively in good to excellent yields. 相似文献
8.
《The Journal of chemical thermodynamics》2003,35(11):1861-1895
Relative densities and massic heat capacities have been measured for acidified aqueous solutions of YCl3(aq), YbCl3(aq), DyCl3(aq), SmCl3(aq), and GdCl3(aq) at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa. These measurements have been used to calculate experimental apparent molar volumes and heat capacities which, when used in conjunction with Young’s rule, were used to calculate the apparent molar properties of the aqueous chloride salt solutions. The latter calculations required the use of volumetric and thermochemical data for aqueous solutions of hydrochloric acid that have been previously reported in the literature. The concentration dependences of the apparent molar properties have been modeled using Pitzer ion interaction equations to yield apparent molar volumes and heat capacities at infinite dilution. The temperature and concentration dependences of the apparent molar volumes and heat capacities of each trivalent salt system were modeled using modified Pitzer ion interaction equations. These equations utilized the revised Helgeson, Kirkham, and Flowers equations of state to model the temperature dependences of apparent molar volumes and heat capacities at infinite dilution. Calculated apparent molar volumes and heat capacities at infinite dilution have been used to calculate single ion properties for the investigated trivalent metal cations. These values have been compared to those previously reported in the literature. The differences between single ion values calculated in this study and those values calculated from thermodynamic data for aqueous perchlorate salts are also discussed. 相似文献
9.
10.
《Colloids and Surfaces》1987,22(1):51-76
Cationic polyacrylamides of varying molar masses but of similar charge density were tested as flocculants for kaolin suspensions. Flocculant performance was assessed by determining the extent of polymer adsorption, the subsidence rates of the flocculated suspensions and the residual turbidities of the resulting supernatants. The sol concentration was kept constant at 20 g kaolin dm−3 in 10−3 mol dm−3 NaCl solution; pH was varied from 3 to 10. It was found that the subsidence rates did not reflect the trends of polymer adsorption. Polymer adsorption decreased while subsidence rates increased as the molar mass of the polymers increased. Increased adsorption of polymer with pH did not result in higher rates of subsidence. The principal effect of the quaternary cationic charge is to produce a partially extended polymer molecule at all values of the pH. The positive polymeric charge is of secondary importance to the length of the molecule in determining the efficacy of flocculation by polymer bridging and does not counteract the increasing self-repulsion of the clay particles with increasing pH which produced poor floc formation. 相似文献