Sort by:
Publication Type:
Open access:
Publication Date:
Periodicals:
Search results
Online since: September 2013
Authors: Xing Rong Liu, Dao Chen Zhu, Yuan Mei Chen
., grained puerarin MEKC standard equation: Y=36.522X-471.9, R2=0.9994(N=5), the puerarin concentration in 550 μg/mL to 750 μg/mL range comes out a good relationship.
One was internal factors that including isoflavonoids molecular size, the number and location of the free hydroxyl groups on the skeleton, connected with the skeleton of the number of glycosylation, type and location, ionizable site (e.g., a sulfonic acid group).Another was the external factors, including the buffer solution, and additives, etc.
One was internal factors that including isoflavonoids molecular size, the number and location of the free hydroxyl groups on the skeleton, connected with the skeleton of the number of glycosylation, type and location, ionizable site (e.g., a sulfonic acid group).Another was the external factors, including the buffer solution, and additives, etc.
Online since: July 2014
Authors: Yuan Lou Gao, Lei Wang, Li Zhou
Simplified Physical Model
The extruded object between solid particles at the entrance is very poor, in the process of enter the extruder it mixed with grain, it mixed with air in the extruder after entering the extruder will melt in extrusion machine under the action of fluid pressure, thence fluid physical model can be simplified into gas and molten fluid two phase flow model, namely, continuous flow discrete bubbles in the liquid materials [3].
Low Reynolds number method need to have corresponding large number of nodes near wall area and fine grid.
CFX make wall function method and the low Reynolds number method gradually switch between grid, and without accuracy loss.
Low Reynolds number method need to have corresponding large number of nodes near wall area and fine grid.
CFX make wall function method and the low Reynolds number method gradually switch between grid, and without accuracy loss.
Online since: July 2012
Authors: Leonid Afremov, Yury Kirienko
For example, consider a system of N magnetic grains of
size a, uniformly distributed in a nonmagnetic matrix.
According to [1, 4], N1 is the number of particles, whose magnetic moments of both phases are parallel to the external field H; N2 is the number of particles with the magnetic moments of the first phase that are parallel to H and the magnetic moments of the second phase are antiparallel to H.
The corresponding numbers of particles in each of these states we denote as N1, N2, N3 and N4.)
According to [1, 4], N1 is the number of particles, whose magnetic moments of both phases are parallel to the external field H; N2 is the number of particles with the magnetic moments of the first phase that are parallel to H and the magnetic moments of the second phase are antiparallel to H.
The corresponding numbers of particles in each of these states we denote as N1, N2, N3 and N4.)
Online since: August 2011
Authors: Ji Lin Xu, Jun Ming Luo, Li Ping Deng
Therefore, it will form Kekendaer effect [13], leading to form a large number of pores on the surface layer and an uneven workpiece surface.
Furthermore, a large number of rare earth elements are adsorbed on the aluminized coating surface, and the corresponding activity aluminum atoms concentration decreases, where the diffusion of chemical potential of aluminum atoms greatly weakens, leading to the decrease of aluminized coating thickness and the defect of non-uniform aluminized coating thickness.
During the high-temperature oxidation process, with the number of cycles increased and time extended, the linear the cavity bands in the aluminized coating/substrate interface of the aluminized sample without added Y2O3 gradually gathered into linear cracks parallel with the surface.
At the same time, the microstructure of aluminized coating added rare earth Y2O3 presents smaller grains, due to grain refinement, increasing the aluminizing channel and slightly higher aluminum content in the aluminized coating, which not only increases the strength and hardness, but also improve the plastic, better resistance to cracking and spalling.
However, the aluminized coating of the sample prepared in high Y2O3 content (6% Y2O3) presents loose, and forms a large number of cavities on the surface, leading to an uneven surface of the workpiece.
Furthermore, a large number of rare earth elements are adsorbed on the aluminized coating surface, and the corresponding activity aluminum atoms concentration decreases, where the diffusion of chemical potential of aluminum atoms greatly weakens, leading to the decrease of aluminized coating thickness and the defect of non-uniform aluminized coating thickness.
During the high-temperature oxidation process, with the number of cycles increased and time extended, the linear the cavity bands in the aluminized coating/substrate interface of the aluminized sample without added Y2O3 gradually gathered into linear cracks parallel with the surface.
At the same time, the microstructure of aluminized coating added rare earth Y2O3 presents smaller grains, due to grain refinement, increasing the aluminizing channel and slightly higher aluminum content in the aluminized coating, which not only increases the strength and hardness, but also improve the plastic, better resistance to cracking and spalling.
However, the aluminized coating of the sample prepared in high Y2O3 content (6% Y2O3) presents loose, and forms a large number of cavities on the surface, leading to an uneven surface of the workpiece.
Design of 2D Wave Booster Ultrasonic Vibration-Assisted Cutting Tool in Small Size Surface Machining
Online since: June 2022
Authors: Hai Nam Tran, Nguyen Thanh Hai, Anh Son Tran, Nguyen Tan Phuoc
(2)
The cutting tool selected is a diamond coated multi-point grinding tools with a grain size about 150 Grit according to ANSI (or P150 according to FEPA) [6].
Each abrasive grain corresponding to a cutting point has rake angle cutting edge γ < 0, so we can convert the abrasive particle diameter 2r ~ 100 μm and roughness height Rtmax approximately as shown in Fig. 4b and c.
The mode number is 10 and the range for searching the mode frequency is from 35 to 45 kHz.
The modified parameters are the number of slits and width.
Acknowledgement The research is funded by the Vietnam National University, Ho Chi Minh City (VNU-HCM) under grant number C2020-20-05”.
Each abrasive grain corresponding to a cutting point has rake angle cutting edge γ < 0, so we can convert the abrasive particle diameter 2r ~ 100 μm and roughness height Rtmax approximately as shown in Fig. 4b and c.
The mode number is 10 and the range for searching the mode frequency is from 35 to 45 kHz.
The modified parameters are the number of slits and width.
Acknowledgement The research is funded by the Vietnam National University, Ho Chi Minh City (VNU-HCM) under grant number C2020-20-05”.
Online since: December 2025
Authors: Noureddine El Hasbaoui, Abdelouahab Elhadrami, Rachid Brahmi
To do this, the required quantity of NH4VO3 precursor is dissolved in a mixture of 0.3M oxalic acid and water (H2C2O4/H2O= 1/5 by weight ratio). 1g of treated catalyst is immersed in the precursor salt solution, then left under mechanical agitation overnight, allowing perfect distribution of the precursor salt over all the grains of the treated catalyst.
The mixture is then left to stir mechanically overnight, to ensure perfect distribution of the precursor salt on all the grains of the treated catalyst.
Numbered lists can be added as follows:Color figures are welcome for the online version of the journal.
The excess I2 solution is back-assayed with a thiosulfate solution and the volume of thi-osulfate spent to determine the number of moles of unreacted SO2 after the back-assay, the rate of conversion of SO2 to SO3 at a given temperature is expressed by the following formula: TC%=n0-ntn0*100 With: nt=Qt*tVM no: Number of moles of SO2 at reactor inlet, nt: Number of moles of unreacted SO2; Q(t): Start (L/min) of SO2 gas entering furnace; t: Reaction time in min.
The mixture is then left to stir mechanically overnight, to ensure perfect distribution of the precursor salt on all the grains of the treated catalyst.
Numbered lists can be added as follows:Color figures are welcome for the online version of the journal.
The excess I2 solution is back-assayed with a thiosulfate solution and the volume of thi-osulfate spent to determine the number of moles of unreacted SO2 after the back-assay, the rate of conversion of SO2 to SO3 at a given temperature is expressed by the following formula: TC%=n0-ntn0*100 With: nt=Qt*tVM no: Number of moles of SO2 at reactor inlet, nt: Number of moles of unreacted SO2; Q(t): Start (L/min) of SO2 gas entering furnace; t: Reaction time in min.
Online since: March 2006
Authors: Shunichi Kuba, Yoshitaka Kojima, Hideto Suzuki
The number of reports
[1]~[8]on TBC has recently increased with attention to
TBC.
A- A tm tc w t 45 R10 R30 A A 8.5 Fig. 2 Specimen geometry 50 100 150 200 250 300 350 400 450 500 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 Nf [cycle] Stress Amplitude : S [MPa] HIP Specimen HIP Specimen HIP Specimen HIP Specimen ● IN738LC ▲ IN738LC+NiCoCrAlY+Porous YSZ ◆ IN738LC+NiCoCrAlY+Dense YSZ ■ IN738LC+NiCoCrAlY NON HIP Specimen NON HIP Specimen NON HIP Specimen NON HIP Specimen ○ IN738LC △ IN738LC+NiCoCrAlY+Porous YSZ ◇ IN738LC+NiCoCrAlY+Dense YSZ Fig.3 Number of cycle to failure : N [cycle] Fig.4 shows the photos of fracture process.
The crack propagates intergranualarly first, and then finally it fractured at grain boundary because of cross section reduction.
The crack initiates from the surface corner and propagate intergranularly and finally fractured at the grain boundary.
Considering small number of data in their experiment, there is a possibility of micro-shrinkage effect.
A- A tm tc w t 45 R10 R30 A A 8.5 Fig. 2 Specimen geometry 50 100 150 200 250 300 350 400 450 500 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 Nf [cycle] Stress Amplitude : S [MPa] HIP Specimen HIP Specimen HIP Specimen HIP Specimen ● IN738LC ▲ IN738LC+NiCoCrAlY+Porous YSZ ◆ IN738LC+NiCoCrAlY+Dense YSZ ■ IN738LC+NiCoCrAlY NON HIP Specimen NON HIP Specimen NON HIP Specimen NON HIP Specimen ○ IN738LC △ IN738LC+NiCoCrAlY+Porous YSZ ◇ IN738LC+NiCoCrAlY+Dense YSZ Fig.3 Number of cycle to failure : N [cycle] Fig.4 shows the photos of fracture process.
The crack propagates intergranualarly first, and then finally it fractured at grain boundary because of cross section reduction.
The crack initiates from the surface corner and propagate intergranularly and finally fractured at the grain boundary.
Considering small number of data in their experiment, there is a possibility of micro-shrinkage effect.
Online since: January 2013
Authors: Jian Yin, Xian Chao Zhang, Yi Chi, Qi Ling Pang
Fixed gelled material total amount for 370 Kg/m3, sand rate 44% constant, change water-binder ratio of 0.35, 0.45 and 0.55, the aggregate limiting grain size is less than 26.5 mm, The slump for 160±20mm by cement materials control, different proportion (0, 40%, 50%, 60% and 70%) FASG composite powder to selected and the mixed quantity of proportion (FA: SG = 1:4) isometric substitute cement concrete C40 preparation, hope to achieve good workability and uniformity , Meet the rules about C40 intensity level requirements and and to mix C40 preparation high performance concrete, see table 3 and table 4.
Kg/cm3 Serial number C FASG W/B S G Water reducing agent /% B0 370 0 0.45 810 1030 1 B7 111 259 0.45 810 1030 1 Erosion simulation test.
At present, a large number of the theoretical and experimental research about the carbonization of concrete have been carried out by the experts and scholars being at home and abroad, the conclusion was same in principle, which concrete neuter problems, which is caused by the carbonation, acid rain contribution is not serious.
Concrete samples were cured for 28d on the standard curing (ST0), and sampling at ST1, ST3, ST6 mode (where, 0, 1, 3and 6 represent cycle number), there are 8 samples in all, four specimens are C40 high performance concrete and the other four are benchmark concrete, after surface treatment, microscope were observed by electron microscope, which were shown in figure 2, figure 3.
The interfacial Ca(OH)2 grain got smaller, which improved the microstructure of the cement base material, at the same time, due to micro aggregate effect of fly ash and slag, clearance of cement particle was filled, structure was improved, the aperture size and porosity reduced.
Kg/cm3 Serial number C FASG W/B S G Water reducing agent /% B0 370 0 0.45 810 1030 1 B7 111 259 0.45 810 1030 1 Erosion simulation test.
At present, a large number of the theoretical and experimental research about the carbonization of concrete have been carried out by the experts and scholars being at home and abroad, the conclusion was same in principle, which concrete neuter problems, which is caused by the carbonation, acid rain contribution is not serious.
Concrete samples were cured for 28d on the standard curing (ST0), and sampling at ST1, ST3, ST6 mode (where, 0, 1, 3and 6 represent cycle number), there are 8 samples in all, four specimens are C40 high performance concrete and the other four are benchmark concrete, after surface treatment, microscope were observed by electron microscope, which were shown in figure 2, figure 3.
The interfacial Ca(OH)2 grain got smaller, which improved the microstructure of the cement base material, at the same time, due to micro aggregate effect of fly ash and slag, clearance of cement particle was filled, structure was improved, the aperture size and porosity reduced.
Online since: September 2014
Authors: Guo Qiang Guo, Ming Chen, Ying Juan Mu, Chang Qi Yang, Ying Tian, Zhong Quan Li
Comparison of the microstructure from sample 1 to 4, it indicates cryogenic treatment had certain influence on the metallurgical structure, such as grain size of acicular martensite and carbides, content of residual austenite.
In the matrix of martensite, the number of primary carbides have decreased greatly in sample 3 which using shallow cryogenic treatment (-70℃) and tempered treatment (SCT) in one time.
The number of secondary carbides increased and their distribution was more homogeneously as shown in Fig. 1 (4), these was obtained after cryogenic treatment and tempered treatment in two times.
A number of key factors contribute to these results including: slender needle-shaped martensite which is obtained by quench, cryogenic and temper treatment has high hardness, and it also has better abrasion resistance.
Cryogenic treatment had positive influence on the metallurgical structure, such as grain size of acicular martensite and carbides, content of residual austenite, macrohardness of material and abrasion resistance. 2.
In the matrix of martensite, the number of primary carbides have decreased greatly in sample 3 which using shallow cryogenic treatment (-70℃) and tempered treatment (SCT) in one time.
The number of secondary carbides increased and their distribution was more homogeneously as shown in Fig. 1 (4), these was obtained after cryogenic treatment and tempered treatment in two times.
A number of key factors contribute to these results including: slender needle-shaped martensite which is obtained by quench, cryogenic and temper treatment has high hardness, and it also has better abrasion resistance.
Cryogenic treatment had positive influence on the metallurgical structure, such as grain size of acicular martensite and carbides, content of residual austenite, macrohardness of material and abrasion resistance. 2.
Online since: December 2013
Authors: Alexander Kovancev, Vladimir Vereshchagin, Alexander Zakutaev, Andrey Klishin
The investigations and modeling of crystalline structures of oxides and their physical properties stand out in this direction, which are closely connected with the detailed study of microstructures at the molecular level: differentiation between surface and bulk effects given the grain sizes and boundaries, determination of conditions of the evolution and stabilization of a crystalline structure at different scale levels of the structural organization [1-3].
Step 2.To one of those ions (to what ion it is selected in a random manner), the third is attached, and so forth up to a predetermined number of built clusters; and a defined cluster must not overlap any previous one.
The density is computed as the ratio of the current number of ions N in a cluster to the volume of a sphere circumscribed about a system from its center of mass: ρ=N43πR3-1, (3) where R is the distance from the cluster’s center to the most distant atom.
The first parameter–the vertex-connectivity–shows the number of clusters having a common vertex with the initial cluster (l1), the second parameter–the edge-connectivity–the number of clusters having a common edge with the initial cluster (l2).
Numerical simulation of Al2O3 crystalline structures allows controlling the structures on multiple length scales and creating brand new materials with an ultrafine-grained structure as well as materials with unique properties and heightened operational characteristics [11-14].
Step 2.To one of those ions (to what ion it is selected in a random manner), the third is attached, and so forth up to a predetermined number of built clusters; and a defined cluster must not overlap any previous one.
The density is computed as the ratio of the current number of ions N in a cluster to the volume of a sphere circumscribed about a system from its center of mass: ρ=N43πR3-1, (3) where R is the distance from the cluster’s center to the most distant atom.
The first parameter–the vertex-connectivity–shows the number of clusters having a common vertex with the initial cluster (l1), the second parameter–the edge-connectivity–the number of clusters having a common edge with the initial cluster (l2).
Numerical simulation of Al2O3 crystalline structures allows controlling the structures on multiple length scales and creating brand new materials with an ultrafine-grained structure as well as materials with unique properties and heightened operational characteristics [11-14].