scholarly journals Quantitative measurement and mechanism analysis of the high-efficiency laser propulsion of a graphene sponge

2020 ◽  
Vol 28 (23) ◽  
pp. 33869
Author(s):  
Lei Wang ◽  
Wing Yim Tam ◽  
Qiuling Zhao ◽  
Xia Wang
Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1389
Author(s):  
Wei Gao ◽  
Zifu Li ◽  
Siqi Zhang ◽  
Yuying Zhang ◽  
Pingfeng Fu ◽  
...  

To dispose of arsenic-containing tailings with low carbon and high efficiency, sodium sulphate (Na2SO4), sodium hydroxide (NaOH), calcium nitrate Ca(NO3)2 and calcium hydroxide Ca(OH)2 were independently added to metallurgical slag-based binder (MSB) solidification/stabilisation (S/S)-treated tailings (MSTs) to enhance the MST arsenic S/S performance. Results showed that only Ca(OH)2 could increase the unconfined compressive strength of MST from 16.3 to 20.49 MPa and decrease the leachate As concentration from 31 μg/L to below 10 μg/L. Na3AsO4·12H2O and NaAsO2 were used to prepare pure MSB paste for mechanism analysis. The results of microstructure analyses showed the high specific surface area and amorphous properties of calcium–sodium aluminosilicate hydrate facilitated the adsorption or solid-solution formation of As(V) and As(III). As(V) formed an inner-sphere complex in ettringite, whereas As(III) formed an outer-sphere complex, and the relatively larger size and charge of As(V) compared with SO42− restrict substitution inside channels without affecting the ettringite structure under high loading of As(V). The added Ca(OH)2 promoted the hydration reaction of MSBs and facilitated the formation of a Ca–As(V) precipitate with low solubility, from Ca4(OH)2(AsO4)2·4H2O (Ksp = 10−27.49) to Ca5(AsO4)3(OH) (Ksp = 10−40.12). This work is beneficial for the application of cement-free MSB in the S/S process.


2012 ◽  
Vol 535-537 ◽  
pp. 2483-2487 ◽  
Author(s):  
Ming Sheng Zhang

High-efficiency early strength agents were obtained which included triethanolamine, glycol and calcium nitrate. Then it was tested for concrete. Though text, we find that the compressive strength and flexural strength of the specimen, use of the high-efficiency early strength agent is greatly improved than with its much better not to use high-efficiency early strength agent. With time go on, high-efficiency early strength agent added does not make the strength of concrete worse, but better. Using SEM and XRD analysis technology text high-efficiency early strength agent by adding performances of concrete, including the degree of cement hydration, the morphology of hydration products and the composition of mineral formation. Analysis of the role of high-efficiency early strength agents from the perspective of the mechanism. Identified high-efficiency early strength agent impact on the cement hydration, for the further development of early strength agent to provide a theoretical basis.


2011 ◽  
Vol 487 ◽  
pp. 376-380 ◽  
Author(s):  
Xin Li Tian ◽  
Fang Guo ◽  
Ya Tao Mao ◽  
Bao Guo Zhang ◽  
Jian Quan Wang ◽  
...  

Axial turn-grinding is a method to cut the cylindrical work piece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip as the main cutting edge to remove materials and the abrasives in the inside or outside surface of tool as a minor cutting edge to sharpen the processed surface. Through analysis the simplified model, a slightly stress concentration was found at the junction surface of processed surface and machined surface, which had little damage to the workpiece because of happening in the part to be removed or precision machining allowance, and both cracks propagation caused by material rupture were effective removal after material removal mechanism analysis because the extension of the median/radial crack and lateral crack were both happening in the part to be removed.


2014 ◽  
Vol 53 (7) ◽  
pp. 076501 ◽  
Author(s):  
Daiji Kanematsu ◽  
Shigeo Yata ◽  
Yoichiro Aya ◽  
Akira Terakawa ◽  
Masahiro Iseki

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 947
Author(s):  
Anyu Li ◽  
Hua Deng ◽  
Yanhong Jiang ◽  
Chenghui Ye

Biochars were produced with magnesium chloride as an additive for the sorption of hexavalent chromium dissolved in water using five types of straw (from taro, corn, cassava, Chinese fir, and banana) and one type of shell (Camellia oleifera) as the raw materials. The removal of hexavalent chromium by the six biochars mainly occurred within 60 min and then gradually stabilized. The kinetics of the adsorption process were second order, the Langmuir model was followed, and the adsorption of Cr(VI) by the six biochars was characterized by Langmuir monolayer chemisorption on a heterogeneous surface. Banana straw biochar (BSB) had the best performance, which perhaps benefitted from its special structure and best adsorption effect on Cr(VI), and the theoretical adsorption capacity was calculated as 125.00 mg/g. For the mechanism analysis, Mg-loaded biochars were characterized before and after adsorption by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS). The adsorption mechanism differed from the adsorption process of conventional magnetic biochar, and biochar interactions with Cr(VI) were controlled mainly by electrostatic attraction, complexation, and functional group bonding. In summary, the six Mg-loaded biochars exhibit great potential advantages in removing Cr(VI) from wastewater and have promising potential for practical use, especially BSB, which shows super-high adsorption performance.


2012 ◽  
Vol 152-154 ◽  
pp. 1779-1784
Author(s):  
Hong Bing Xin ◽  
Qiang Huang ◽  
Yue Qing Yu

Mechanism analysis and synthesis commonly used analytic method and graphical method, etc., but the homotopy method has high efficiency in nonlinear analysis of mechanism. This paper applies the homotopy continuation method PHCpack solver to solve mechanism position and orientation, and draws the mechanism configuration according to the results obtained, the relative error of numerical results to exact solutions shows that the homotopy continuation method PHCpack solver can provide sufficient accuracy of mechanism position and orientation analysis, and meet the engineering needs.


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