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Online since: March 2013
Authors: You Wang, Xiao Guang Sun, Liang Wang
While the EB-PVD TBCs often exhibit columnar grain characteristic, the inner finer sub-grains are arranged in the coarse columnar grains.
The major axis of the columnar grain is often parallel to the thermal flux direction which is not beneficial to decrease the effective thermal conductivity of the TBCs.
The number of the micro-pores of DCL LZ/YSZ TBCs did not exhibit evident decrease tendency which is attributed to its excellent sintering resistance ability of the LZ layer at high temperature.
The number of the micro-pores of the DCL LZ/YSZ TBCs still did not show evident decrease tendency which is attributed to its super sintering resistance ability at high temperature[35].
The major axis of the columnar grain is often parallel to the thermal flux direction which is not beneficial to decrease the effective thermal conductivity of the TBCs.
The number of the micro-pores of DCL LZ/YSZ TBCs did not exhibit evident decrease tendency which is attributed to its excellent sintering resistance ability of the LZ layer at high temperature.
The number of the micro-pores of the DCL LZ/YSZ TBCs still did not show evident decrease tendency which is attributed to its super sintering resistance ability at high temperature[35].
Online since: October 2008
Authors: X. Zhao, Ping Xiao
Both a small increase in the yttria concentration and coatings based on other stabilisers
all fail at smaller numbers of thermal cycles, whether they are deposited by EBPVD or APS [16].
Clarke has developed an approximate method to describe the thermal conduction by lattice vibrations at high temperature [42]: 32 216132 32 AB p M Em �k870 ρ κ .→ (2) where kB is the Boltzmann's constant, NA the Avogadro's number, M the molecular weight, m the number of atoms per molecule, ρ the material density, and E the elastic modulus.
Structural modification: one efficient way to decrease the thermal conductivity of the TBC is to introduce microstructural defects such as pores, voids, grain/interface boundaries that constitute obstacles against the through-thickness heat transfer propagation.
In addition, the interface disorder can scatter phonons at grain boundaries or interfaces between similar materials [51].
These ions are usually contained in the oxides formed on a number of Al2O3-forming bond coat alloys.
Clarke has developed an approximate method to describe the thermal conduction by lattice vibrations at high temperature [42]: 32 216132 32 AB p M Em �k870 ρ κ .→ (2) where kB is the Boltzmann's constant, NA the Avogadro's number, M the molecular weight, m the number of atoms per molecule, ρ the material density, and E the elastic modulus.
Structural modification: one efficient way to decrease the thermal conductivity of the TBC is to introduce microstructural defects such as pores, voids, grain/interface boundaries that constitute obstacles against the through-thickness heat transfer propagation.
In addition, the interface disorder can scatter phonons at grain boundaries or interfaces between similar materials [51].
These ions are usually contained in the oxides formed on a number of Al2O3-forming bond coat alloys.
Online since: October 2010
Authors: Xin Gong Li, Nan Hu, Yi Qiang Wu
Bamboo belongs to one of fast growing plants,it has the advantages of straight grain, beautiful color, high strength and toughness, and excellent processing property.
(1) Due to factor number m=3, taking zero level number m0=9, obtained the length of asterisk arm γ=1.682, the upper limit of is =70, the lower limit of is=50, zero level =60.According to =(xjr-xj0)/γ, obtained =6.
Table 1 The number of factors and levels (s/mm) () (%) Upper Asterisk Arm(γ) 70 170 12 Upper Level(1) 66 166 11.6 Zero Level(0) 60 160 11 Lower Level(1) 54 154 10.4 Lower Asterisk Arm(-γ) 50 150 10 6 6 0.6 Table 2 Test result of mechanical properties Test Number MOR[MPa] MOE[MPa] TS[%] IB[MPa] 1 45.97 5171 13.1 1.624 2 49.14 5481 12.6 2.246 3 54.72 5815 11.8 2.942 4 50.2 5603 12.6 2.779 5 54.77 5962 10.8 3.097 6 46.79 5405 12.8 2.027 7 55.17 6171 10.8 3.31 8 47.72 5499 12.8 2.155 9 51.30 5906 12.3 2.849 Variance and Regression Analysis Static Bending Strength (MOR) Table 3 MOR variance analysis Source of Variance Square of Deviance Degrees of Freedom Average of Square of Deviance Value of F Critical Value of F Significance A 3.184 2 1.592 8.040 =19 =99 No B 0.406 2 0.203 1.026 No C 98.275 2 49.138 248.170 Yes Error 0.396 2 0.198 Sum 102.261 8 Regression equation: (2) Modulus of Elastic (MOE) Table 4 MOE variance analysis Source
(1) Due to factor number m=3, taking zero level number m0=9, obtained the length of asterisk arm γ=1.682, the upper limit of is =70, the lower limit of is=50, zero level =60.According to =(xjr-xj0)/γ, obtained =6.
Table 1 The number of factors and levels (s/mm) () (%) Upper Asterisk Arm(γ) 70 170 12 Upper Level(1) 66 166 11.6 Zero Level(0) 60 160 11 Lower Level(1) 54 154 10.4 Lower Asterisk Arm(-γ) 50 150 10 6 6 0.6 Table 2 Test result of mechanical properties Test Number MOR[MPa] MOE[MPa] TS[%] IB[MPa] 1 45.97 5171 13.1 1.624 2 49.14 5481 12.6 2.246 3 54.72 5815 11.8 2.942 4 50.2 5603 12.6 2.779 5 54.77 5962 10.8 3.097 6 46.79 5405 12.8 2.027 7 55.17 6171 10.8 3.31 8 47.72 5499 12.8 2.155 9 51.30 5906 12.3 2.849 Variance and Regression Analysis Static Bending Strength (MOR) Table 3 MOR variance analysis Source of Variance Square of Deviance Degrees of Freedom Average of Square of Deviance Value of F Critical Value of F Significance A 3.184 2 1.592 8.040 =19 =99 No B 0.406 2 0.203 1.026 No C 98.275 2 49.138 248.170 Yes Error 0.396 2 0.198 Sum 102.261 8 Regression equation: (2) Modulus of Elastic (MOE) Table 4 MOE variance analysis Source
Online since: November 2012
Authors: Lei Lei Hou, Yu Qi Wang, Tie Gao, Jia Jing Jiang
Due to NWMO contains a large number of polydentate ligands, so it can be used as chelating agents, and with a variety of metal ion the reaction of chelates with the ring structure and a more stable.
For example Fe2+, the molecular structure of NWMO present in a large number of polydentate ligands, when Fe2+ in contact with NWMO, the NWMO is very easy to provide a large number of lone pair of electrons, and fast reaction to generate a macromolecular chelate of ring structure.
Probably because NWMO contains a large number of ligands is able to quickly react, but the production of chelates is not very stable.
Visible coexistence of ions on metal removal has played a catalytic role, may be caused due to surface adsorption, and concealed, to generate mixed grain and other reasons.
For example Fe2+, the molecular structure of NWMO present in a large number of polydentate ligands, when Fe2+ in contact with NWMO, the NWMO is very easy to provide a large number of lone pair of electrons, and fast reaction to generate a macromolecular chelate of ring structure.
Probably because NWMO contains a large number of ligands is able to quickly react, but the production of chelates is not very stable.
Visible coexistence of ions on metal removal has played a catalytic role, may be caused due to surface adsorption, and concealed, to generate mixed grain and other reasons.
Online since: December 2010
Authors: Jian Chao Dou, Jian Sen Yang
Crushed stone, grain size of 5~25 mm, silt content of 0.4%, Mud content of 0.2%. (4) Silica fume.
Table 3 Design of orthogonal experiment Number Column number 1 2 3 4 Factor Water-cement ratio air conten Silica fume Sand ratio Unit % % % % 1 2 3 4 5 6 7 8 9 A B C D E F G H I 0.40 0.40 0.40 0.47 0.47 0.47 0.55 0.55 0.55 1.0 3.5 6.0 1.0 3.5 6.0 1.0 3.5 6.0 0 5 10 5 10 0 10 0 5 30 34 38 38 30 34 34 38 30 Mix Proportion.
Table 4 Concrete mix proportion and the 28d compressive strength Number Parameters The material consumption in Unit volume / (kg/m3) Water Reducer /kg Air- entraining agent /kg Compressive strength /MPa Water- cement ratio Sand ratio /% air content /% C SF W S G A 0.4 30 1.0 400 0 160 566 1321 2.60 0.0000 55.10 B 0.4 34 3.5 380 20 160 614 1192 3.60 0.6400 52.28 C 0.4 38 6.0 360 40 160 648 1057 4.00 1.6000 46.73 D 0.47 38 1.0 380 20 188 688 1122 2.40 0.0000 50.86 E 0.47 30 3.5 360 40 188 513 1196 3.20 0.3200 45.80 F 0.47 34 6.0 400 0 188 554 1076 0.80 0.3200 34.86 G 0.55 34 1.0 360 40 220 588 1141 0.60 0.0000 56.13 H 0.55 38 3.5 400 0 220 631 1029 0 0.0680 35.93 I 0.55 30 6.0 360 20 220 480 1120 0 0.1786 32.51 Experiment method.
Table 5 60d CLE of concrete and orthogonal analysis Number Water-cement ratio Air content Silica fume Sand ratio CLE/ (unit:10-6.
Table 3 Design of orthogonal experiment Number Column number 1 2 3 4 Factor Water-cement ratio air conten Silica fume Sand ratio Unit % % % % 1 2 3 4 5 6 7 8 9 A B C D E F G H I 0.40 0.40 0.40 0.47 0.47 0.47 0.55 0.55 0.55 1.0 3.5 6.0 1.0 3.5 6.0 1.0 3.5 6.0 0 5 10 5 10 0 10 0 5 30 34 38 38 30 34 34 38 30 Mix Proportion.
Table 4 Concrete mix proportion and the 28d compressive strength Number Parameters The material consumption in Unit volume / (kg/m3) Water Reducer /kg Air- entraining agent /kg Compressive strength /MPa Water- cement ratio Sand ratio /% air content /% C SF W S G A 0.4 30 1.0 400 0 160 566 1321 2.60 0.0000 55.10 B 0.4 34 3.5 380 20 160 614 1192 3.60 0.6400 52.28 C 0.4 38 6.0 360 40 160 648 1057 4.00 1.6000 46.73 D 0.47 38 1.0 380 20 188 688 1122 2.40 0.0000 50.86 E 0.47 30 3.5 360 40 188 513 1196 3.20 0.3200 45.80 F 0.47 34 6.0 400 0 188 554 1076 0.80 0.3200 34.86 G 0.55 34 1.0 360 40 220 588 1141 0.60 0.0000 56.13 H 0.55 38 3.5 400 0 220 631 1029 0 0.0680 35.93 I 0.55 30 6.0 360 20 220 480 1120 0 0.1786 32.51 Experiment method.
Table 5 60d CLE of concrete and orthogonal analysis Number Water-cement ratio Air content Silica fume Sand ratio CLE/ (unit:10-6.
Online since: May 2013
Authors: Guang Yong Pan
(6)Test factors
Inspection standard is not reasonable, terms of inspection is not reasonable, inspection instruments is not reasonable.
2.2 Mechanism analysis of cracking and wrinkled
Automobile stamping produce crack and wrinkle as the table 1:
Table 1 The cause of the cracking and wrinkle
the cause of cracking
the cause of wrinkling
①The blank-holder force is too large or uneven
①Pressure material force is too small or uneven
②Convex and concave die clearance is too small
②The number of draw bead too little or improper arrangement
③Draw bead layout is not uniform
③Balance block the clearance is too large
④Concave die or draw bead groove fillet is too small
④Air pressure is too small
⑤Pressure side face is bright and clean
⑤Concave die fillet radius is too big
⑥Process notch too little, air pressure is too great
⑥Pressure side surface is rough, loose in the tight
⑦Work surface lubricate insufficient or improper
⑦Work Surface lubricate too much, and daub improper position
⑧Blank
(2)Influence factors of plastic deformation and deforming resistance ①Metal organization Metal plastic main influencing factors include the composition metal lattice type, the nature of the impurities, the quantity and distribution, grain size, shape and boundary strength, etc.
The state of stress of metal plastic has a great influence, the number of compressive stress and numerical is larger, and the number of the tensile stress and numerical is smaller, metal plastic is the better. ②Plastic condition The elastic deformation transition to the plastic deformation of metal, mainly depends on in a certain degeneration conditions (deformation temperature and strain rate) the metal's physical mechanics performance and its stress state.
Table 4 Wrinkling causes and corresponding measures Stamping parts produced the cause of wrinkling Wrinkling improvement measures ①Pressure material force is too small or uneven ①Adjust the slider bolt, increase the blank-holder force ②The number of draw bead too little or improper arrangement ②Add DORA draw bead quantity, change the position and elastic ③Balance block the clearance is too large ③Reduce balance piece clearance, change balance block position ④Air pressure is too small ④Increase air pressure ⑤Concave die fillet radius is too big ⑤Reduce the concave die fillet radius ⑥Pressure side surface is rough, loose in the tight ⑥Grinding blank holder surface, the tight in the pine ⑦Work Surface lubricate too much, and daub improper position ⑦According to the regulation parts and dosage used lubricating oil, apply uniform properly ⑧Blank size is too small, shape is not reasonable ⑧Increase the blank size, change the blank shape ⑨Material is too soft ⑨Transform hard a qualified raw
(2)Influence factors of plastic deformation and deforming resistance ①Metal organization Metal plastic main influencing factors include the composition metal lattice type, the nature of the impurities, the quantity and distribution, grain size, shape and boundary strength, etc.
The state of stress of metal plastic has a great influence, the number of compressive stress and numerical is larger, and the number of the tensile stress and numerical is smaller, metal plastic is the better. ②Plastic condition The elastic deformation transition to the plastic deformation of metal, mainly depends on in a certain degeneration conditions (deformation temperature and strain rate) the metal's physical mechanics performance and its stress state.
Table 4 Wrinkling causes and corresponding measures Stamping parts produced the cause of wrinkling Wrinkling improvement measures ①Pressure material force is too small or uneven ①Adjust the slider bolt, increase the blank-holder force ②The number of draw bead too little or improper arrangement ②Add DORA draw bead quantity, change the position and elastic ③Balance block the clearance is too large ③Reduce balance piece clearance, change balance block position ④Air pressure is too small ④Increase air pressure ⑤Concave die fillet radius is too big ⑤Reduce the concave die fillet radius ⑥Pressure side surface is rough, loose in the tight ⑥Grinding blank holder surface, the tight in the pine ⑦Work Surface lubricate too much, and daub improper position ⑦According to the regulation parts and dosage used lubricating oil, apply uniform properly ⑧Blank size is too small, shape is not reasonable ⑧Increase the blank size, change the blank shape ⑨Material is too soft ⑨Transform hard a qualified raw
Online since: August 2012
Authors: Gui Tang Wang, Jian Zhe Chen, Jian Qiang Chen, Xin Liang Yin
Median filter applies to impulse noise or grain noise, and can protect effectively the details of the edge outline of the image.
(3) m and n are the ranks number of the window.
(4) k and l are the ranks number of the image, k>m, l>n.
Then the visual system calculates the number of bordered gear tooth based on the identified center coordinates of current gear.
Finally the visual system determines whether external gear tooth arise circumstance of missing tooth or collapsed tooth according to the number of marginal gear tooth.
(3) m and n are the ranks number of the window.
(4) k and l are the ranks number of the image, k>m, l>n.
Then the visual system calculates the number of bordered gear tooth based on the identified center coordinates of current gear.
Finally the visual system determines whether external gear tooth arise circumstance of missing tooth or collapsed tooth according to the number of marginal gear tooth.
Online since: January 2012
Authors: Nian Liu, Su Qi, Wei Wu, Jin Xing He
Their number, expansive content and other parameters can be seen in Table 1.Steel is a self-made straight seam steel pipe.
Table. 1 Specimen condition Number Size(mm) Expansive agent dosage (%) Quantity Remark A Φ180x3x630 0 3 common reinforced concrete B Φ180x3x630 8 3 micro-expansive concrete filled steel tube C Φ180x3x630 10 3 micro-expansive concrete filled steel tube D Φ180x3x630 12 3 micro-expansive concrete filled steel tube E Φ180x3x630 20 3 micro-expansive concrete filled steel tube Pouring and curing of concrete and top cover welding.
Table. 2 Different concrete mix proportion (kg/m3) Number Water Cement Fly ash Expansive Sand Pebble A 182 470 70 —— 615 1093 B 182 470 70 38 577 1093 C 182 470 70 47 568 1093 D 182 470 70 56 559 1093 E 182 470 70 94 521 1093 Table. 3 Concrete strain in specimen E Stain Age(d) Concrete Normal Vertical Circumferential 2 -15 2590 2956 4 -37 2572 3025 6 -47 2558 3087 8 -54 2554 3118 10 -64 2552 3142 13 -75 2534 3156 16 -83 2521 3164 22 -94 2501 3177 27 -101 1988 3185 Fig. 1 Curves of different hydration Fig. 2 Curve between longitudinal strain and heat of concrete time of the outer wall of a steel pipe of each specimen Fig. 3 Curve between ring strain and Fig. 4 Stress distribution of the inner time of the outer wall of a steel pipe surface
Load reach more than 300 kN, strain rate of increase is less than the rate of increase stress, at this time, the top of the steel tube individual local appear the bulking phenomenon, produce the situation are the main reasons why here is the lack of concrete watered close-grained.
Table. 4 Measured value of failure limit load of specimens in each group Number A B C D E Failure load 1740 1890 1850 1860 1700 Fig. 7 Curve of load-displacement of A, D, E Fig. 8 Curve of load-pipe wall ring strain of A, specimens B, C specimens Fig. 9 Curve of load-pipe wall ring strain of A, D, E specimens It can be seen from table 4: B, C, D load of the specimens are damaged is close, and they are larger than A, E group destructive load, group E destructive load less than group A destructive load, which indicates that the mixed with moderate expansion agent specimens of damage to the limit load increases; But the mixed quantity of expansive agent will affect their own strength of the concrete too much, and make its limit fracture load oppositely lower.
Table. 1 Specimen condition Number Size(mm) Expansive agent dosage (%) Quantity Remark A Φ180x3x630 0 3 common reinforced concrete B Φ180x3x630 8 3 micro-expansive concrete filled steel tube C Φ180x3x630 10 3 micro-expansive concrete filled steel tube D Φ180x3x630 12 3 micro-expansive concrete filled steel tube E Φ180x3x630 20 3 micro-expansive concrete filled steel tube Pouring and curing of concrete and top cover welding.
Table. 2 Different concrete mix proportion (kg/m3) Number Water Cement Fly ash Expansive Sand Pebble A 182 470 70 —— 615 1093 B 182 470 70 38 577 1093 C 182 470 70 47 568 1093 D 182 470 70 56 559 1093 E 182 470 70 94 521 1093 Table. 3 Concrete strain in specimen E Stain Age(d) Concrete Normal Vertical Circumferential 2 -15 2590 2956 4 -37 2572 3025 6 -47 2558 3087 8 -54 2554 3118 10 -64 2552 3142 13 -75 2534 3156 16 -83 2521 3164 22 -94 2501 3177 27 -101 1988 3185 Fig. 1 Curves of different hydration Fig. 2 Curve between longitudinal strain and heat of concrete time of the outer wall of a steel pipe of each specimen Fig. 3 Curve between ring strain and Fig. 4 Stress distribution of the inner time of the outer wall of a steel pipe surface
Load reach more than 300 kN, strain rate of increase is less than the rate of increase stress, at this time, the top of the steel tube individual local appear the bulking phenomenon, produce the situation are the main reasons why here is the lack of concrete watered close-grained.
Table. 4 Measured value of failure limit load of specimens in each group Number A B C D E Failure load 1740 1890 1850 1860 1700 Fig. 7 Curve of load-displacement of A, D, E Fig. 8 Curve of load-pipe wall ring strain of A, specimens B, C specimens Fig. 9 Curve of load-pipe wall ring strain of A, D, E specimens It can be seen from table 4: B, C, D load of the specimens are damaged is close, and they are larger than A, E group destructive load, group E destructive load less than group A destructive load, which indicates that the mixed with moderate expansion agent specimens of damage to the limit load increases; But the mixed quantity of expansive agent will affect their own strength of the concrete too much, and make its limit fracture load oppositely lower.
Online since: May 2012
Authors: Peng Guang Zhou, Cong Xia Zhao
In the process of industrialization, a number of cities raised rapidly, which had concentrated lots of industrial and mining enterprises, or located along the traffic trunk lines or were near harbor.
These led to the large number of rural population transfer.
Later, with the rapid development of traffic, a large number of the middle class also migrated to suburbs for good living environment, and take it as a symbol of status.
Through the census registration system, grain and oil supplying system, labor and employment system, medical security system and other policies, the government control over the transfer of the rural population to cities strictly.
Then a large number of rural populations have gone into the city, which increased the supply pressure of housing, infrastructure and public service facilities, and forced urban expansion.
These led to the large number of rural population transfer.
Later, with the rapid development of traffic, a large number of the middle class also migrated to suburbs for good living environment, and take it as a symbol of status.
Through the census registration system, grain and oil supplying system, labor and employment system, medical security system and other policies, the government control over the transfer of the rural population to cities strictly.
Then a large number of rural populations have gone into the city, which increased the supply pressure of housing, infrastructure and public service facilities, and forced urban expansion.
Online since: August 2010
Authors: Ya Dong Gong, Ting Chao Han, Yue Ming Liu, Jun Cheng
As a material removal process, there are two key factors in the grinding process to
affect the surface performance: the geomorphology of the wheel and the chip formation process
involved[3], which considers the interaction of the workpiece surface and the abrasive grains.
But in super-high speed(SHS) grinding process, the number of particles involved in interaction is much more than that in common grinding, which makes the surface performance become better after grinding in theory because of more particles joining in machining.
Fig.1 The layout of point grinding Fig.2 Contact area with α Table1 The explanation for the parameters in the paper α swivel angle between wheel axis and workpiece axis ds diameter of wheel dw diameter of workpiece de equivalent diameter of wheel lc length of contact arc ap depth of cutting b contact width in theory br contact width in actual A contact area between wheel and workpiece h thickness of chip f(h) statistical distribution of thickness of chip K revised coefficient Ra surface roughness E(Ra) expectation of roughness ha average thickness of chip vw speed of workpiece vs speed of wheel C number of particles in the unit of area r ratio between width and thickness of chip In the process of grinding, the contact zone between the wheel and the workpiece has been assumed to a rectangle include the width and the length, which are indicated by the contact width and the length of contact arc between the wheel
The effective particles of joining in cutting becomes more than common cylindrical grinding, which makes the more number of particles interfere to the removal material of the workpiece to decrease the distance between the peak and the valley in the unit time.
The surface quality has been improved in theory based on the number of cutting from effective particles in SHSP grinding while grinding in the same wheel speed and other factors compared to SHS grinding.
But in super-high speed(SHS) grinding process, the number of particles involved in interaction is much more than that in common grinding, which makes the surface performance become better after grinding in theory because of more particles joining in machining.
Fig.1 The layout of point grinding Fig.2 Contact area with α Table1 The explanation for the parameters in the paper α swivel angle between wheel axis and workpiece axis ds diameter of wheel dw diameter of workpiece de equivalent diameter of wheel lc length of contact arc ap depth of cutting b contact width in theory br contact width in actual A contact area between wheel and workpiece h thickness of chip f(h) statistical distribution of thickness of chip K revised coefficient Ra surface roughness E(Ra) expectation of roughness ha average thickness of chip vw speed of workpiece vs speed of wheel C number of particles in the unit of area r ratio between width and thickness of chip In the process of grinding, the contact zone between the wheel and the workpiece has been assumed to a rectangle include the width and the length, which are indicated by the contact width and the length of contact arc between the wheel
The effective particles of joining in cutting becomes more than common cylindrical grinding, which makes the more number of particles interfere to the removal material of the workpiece to decrease the distance between the peak and the valley in the unit time.
The surface quality has been improved in theory based on the number of cutting from effective particles in SHSP grinding while grinding in the same wheel speed and other factors compared to SHS grinding.