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Online since: March 2020
Authors: Liang Zhao, Qun Hu Xue, Hao Wang, Qian Huang, Shuang Yao
Table 2 Sample formula Serial Number Electrofusion Chemical MgO PVA M0 100 - 2.8 10 M25 75 25 2.8 10 M50 50 50 2.8 10 M75 25 75 2.8 10 M100 - 100 2.8 10 Following the formula in Table 2, after precise weighting, the raw materials were mix-ground for 12 h in an omnidirectional planetary ball mill.
Table 3 Physical properties of different samples Serial number Apparent porosity /% Volume density / (g·cm-3 ) Compressive strength /MPa M0 21.26 4.53 245 M25 12.04 4.99 289 M50 7.97 5.33 295 M75 6.26 5.39 264 M100 5.69 5.46 64 According to Fig. 2 and Table 3, the volume shrinking percentage of the electrofusion-made ZrO2 sample M0 was 5.66% after a 1710℃ × 2-h calcination.
(a) Sample M0 (b) Sample M50 (c) Sample M100 Figure 4 SEM microscopic structure pictures of M0, M50, and M100 As shown in Fig. 4, the grain size was uniform in the electrofusion-made ZrO2.
The grain boundaries were clear, and the structure was dense.
On the contrary, in the chemical-made ZrO2, grains yielded various shapes and sizes, and the number of cavities was also high.
Online since: December 2022
Authors: Hui Jun Yu, Hai Bin Yao, Shou Ji Si, Cheng Liang Zhao, Chang Ye Li, Hua Zhang, Hao Bin Sun, Xin Wu Wang, Chuan Zhong Chen
Thirdly, we can put a number of targets at random in vessel, because the cathodic arc evaporation source produces plasma instead of molten pool.
Firstly, increased negative bias intensifies the kinetic energy of the ions, which increases the number of ions that deposited to the coating, and polishes the surface of coating.
When arc current continues to increase, high kinetic energy ions are deposited on the substrate continuously, which increases the denseness of the coating, enhances the grain boundary strengthening effect as well.
At the same time, the higher the bombardment energy of ions is, the finer grain is.
However, when the arc current is higher, electric field intensity increases and arc spots gather more heat, it results in a number of melt pools and more larger particles, which are then deposited on the coating surface, affecting the surface quality [23].
Online since: November 2012
Authors: Surasing Arayangkun, Chawalit Thinvongpituk
The experiment was conducted with a number of steel rods of 10 mm. diameter.
Figure 5 Microstructure composition and G number at heat affected zone [13].
It is observed from Fig 5 that in heat affected zone, the composition of microstructure as well as number of grain (G number) are changed.
In addition, the G Number at heat affected zone is increasing, resulting in higher value of tensile strength.
Online since: November 2012
Authors: Ming Yin
Conclusion the surface roughness of part, can be further reduced the number of nano and from the original-level smooth surface can get receive better experiment.
Using 100°C water is to reduce the alveolar number in polishing desk and shorten time interval that ice desk turn from liquid state into solid state.
Fig. 1 Structure of mould The material of work piece is LY12 aluminum alloy, 45steel and YG6 hard alloy: mm (dia.thickness) Work pieces are fixed symmetrically in nylon mould by 502 glue, as showed in fig.2 The number can be 1~4 according to requirement and surface of work pieces should overtop mould surface 0.5mm.
Adherence produced by the surface energy between metal work pieces surface and ice surface which have conquered the interfacial energy make the metal crystal, especially the disorder lattices and relaxed lattices, glide through the boundary of grain or sub-boundary of grain.
Online since: May 2012
Authors: Chang Wu Liu, Shu Xin Liu, Yaming Kang, Duo Yang
Fillers in the various bioclastic are microcrystalline and fine-grained calcite, and there is a small amount of organic matter and iron distributing in calcite, the limestone contains a large number of biological debris(figure 1).
Fig.1 Microscopic characteristics of limestone flakes Table.1 Component identification of limestone field name Limestone Identification name Bioclastic limestone Structure Grain crumbs structure composition calcite 95%, organic matter 5%, iron rare Structural components bioclastic 75%,main dragonflies debris60%, chip5%, spine chip>5%,brachiopod <5%,Organic matter and iron5% 2.2 Limestone micro-structural analysis In this test analytical instruments is a Hitachi S-4800 scanning electron microscope,All samples were taken in the same rock in order to ensure the comparability of test results, and the samples were divided into two groups, one of groups is pressure saturated water 24 hours under room temperature and atmospheric pressure, respectively slice from the two sets of samples, Using scanning electron microscopy to analyze the microstructure of different moisture content limestone.
Fig.2 Hole topography of slices in Fig. 3 Hole topography of slices Natural moisture after Saturated 24 hours A large number of dissolution pores and micro-holes in the limestone calcite were found from the scanning electron micrograph in  natural water content, as shown in figure 2, most dissolved pores are about 20μm in diameter, maximum diameter is 100μm.
There are a large number of native and secondary bedding joints and micro-cracks according to slice morphology, enlarged figure shows that the dissolution pores in calcite intragranular and intergranular is developed, the diameter of most holes is about 20μm, maximum diameter is 100μm, after the water-saturated 24 hours, small corrosion holes in the limestone has increased, which is mainly caused by the solubility of calcite. 2.3Experimental study of limestone mechanics The experimental samples are processed into standard test pieces.
Online since: December 2006
Authors: Sun Ig Hong, Y.G. Park, M.Y. Wey, M. Ikenaga
Recently, CrN has beening popularity as a viable alternative to TiN in a number of important structural applications [4].
Results and Discussion The as received Ti-6Al-4V alloy shows a microstructure, consisting of acicular α and β-Ti formed in the prior β grain of about 600 µm in size, called the Widmanstatten structure [5].
After duplex coating, the depth of the carburized subsurface region was approximately 150 µm; the thickness of Cr thin film with fine microstructure of equiaxial grains was about 7.5 µm.
The plots of the peak stress versus the number of cycles to failure for the as-received (a) and duplex-coated (b) Ti-6Al-4V at 500 o C are shown in Fig. 3.
The peak stress versus the number of cycles to failure in the matrix and presence of unsheared β phase after creep.
Online since: January 2010
Authors: Shui Sheng Xie, Hai Bo Zhao, Jin Hua Xu, Hong Min Guo, Mao Peng Geng, Ying Zhang
In this method, the metal slurry was poured into slope when the temperature was a little higher than liquidus, by the cooling effect of slope, the core of thin grain grew up on wall of slop, and then the core was scoured into container from slope wall by metal slurry.
A: A1 expresses 650 C ° A2 expresses 640 C ° A3 expresses630 C ° B: B1 expresses 60° B2 expresses 45 ° B3 expresses 30° C: C1 expresses 630mm C2 expresses 600mm C3 expresses 570mm number factor 4 Calculate result and Experimental Research 4.1 Mesh and Calculation The 3D-Model of slope was built by Pro/E, and then meshes were generated, the length between two nodes was 7.000mm, the units number was 107602 and the nodes number was 20790 in all, it cost about 3 minutes and the final tetrahedron meshes are shown as Fig.1: Fig.1 The distribution of mesh in calculating region Fig.2 The temperature Field of Metal Liquid in Slope After Pouring a: The 0.5 Secs, b: the 0.96 Secs, c: The 1.5 Secs, d: The 3.4 Secs, e: The 5.9 Secs, f : The 7.3 Secs The simulation result of test 4 is shown in Fig.2. it could be seen that it cost about 7.3 seconds for the metal melts flew from the entrance to export, and the temperature gradient was obvious, temperature
Fig.8 Microstructure of Sample After Casting-Rolling Fig.8 shows the microstructure of the strip made according to the optimized parameters of slope technology obtained by simulative experiment, the solid grains in the metallographic structure of semi-solid magnesium alloy strips produced by the technology test were well distributed, mellow and tiny, the result was gratifying, which proves that the simulation coincides well with the practice. 5 Conclusion 1) Optimal parameters of slope technology was obtained (slope length 570 mm ,slope angle60o , pouring temperature 630 C o ) by the numerical simulation of rheocasting-rolling for semi-solid magnesium alloy used by slope, and these are verified by experiments. 2) The length of the slope was the main parameter which affects the temperature of semi-solid slurry, proper lean angle can be chosen for different equipment so as to benefit the technological process, and enhance the efficiency. 3) The change of lean angle
Online since: February 2014
Authors: Zhao Ru Guo, Zi Feng Yang
Plane and Body In addition to a number of high profile constructions and high pagodas , Chinese ancient architecture groups and more gentle to the ground and rolled around ...... as ordered .
Much greater than the strength of the wood along the grain stripes another important strength is its mechanical properties, the vertical force component as the main pillar of its use is parallel to grain strength , transverse beam wood components use the strength of its stripes , this is precisely the thinking " strong column weak beam " seismic design requirements are consistent.
Dougong ancient Chinese architecture unique to the support member , square pieces of wood called bucket, a short wooden bow called bracketing , oblique Longwood called Ang, bucket -shaped by a number of short pieces of wood and arched wooden Fang combination of mutual transfer member , collectively Dougong ( see Figure 4 ) .
Is also one of the most prominent ancient Chinese traditional architectural image features a large roof, the whole roof ( especially Dianding veranda , Shanding , etc. ) require a large number of complex structures and components , with its self- weight frame column online at strengthening the overall timber frame stability , to improve the seismic capacity of the building also made ​​no small contribution.
Online since: January 2013
Authors: Betty Martin, Vimala Juliet
Number of efforts have been made to identify hidden infestations, but only a few victorious methods have emerged.[7].
Many studies demonstrate that Piezoelectric microphone is used to spot stored product insects in grain.
A portable acoustic device demonstrates that irrespective of the number of larvae present in infested palms, the highest amplitude of acoustic sound was found in the frequency band of 500-1000 Hz[4].
Figure 3: Measure of codebook against sound sources Conclusion Results obtained from this work confirm that acoustic monitoring techniques can be used for rapid and easy detection of the presence of RPW in huge number inside the trunks of palms in various farms.
[2] F.Fleurat-Lessard, B.Tomasini, B.Fuzeau Acoustic detection and automatic identification of insect stages activity in grain bulks by noise spectra processing through classification algorithm 9th International Working Conference on Stored Product Protection 476 PS5-13 – 6304 [3] Ilyas Potamitis, Todor Ganchev, Nikos Fakotakis Automatic Bioacoustic Detection Of Rhynchophorus Ferrugineus [4] K.A.P.
Online since: May 2012
Authors: Wen Jin, Jin Hui Peng, Xin Hui Duan, Wen Wen Qu
From the XRD patterns of the samples, the grain diameter, was calculated using Scherrer’s equation[13] (Eq.2): D= (2) where D is the crystallite size of the catalyst, λ is the wavelength of X-ray diffraction, βc and βs are the FWHM of the catalyst and the standard, respectively. θ is the Bragg’s angle and k is coefficient.
Fig.1 shows the influence of activation time on iodine number and the yield of the ZnO/AC composites.
It can be seen from the figure that in both cases an increase in activation time results in higher iodine numbers and lower yields.
Therefore, some of the blocked pores reopen, and the iodine adsorption capacity of the final composites increases gradually, which is in agreement with the relationship between the pore size distribution and the iodine number previously reported [14].
The average grain diameter of ZnO was measured by Scherrer’s equation and it was found that their size increased from 32.9nm to 59.1nm with the increase of activating time.
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