Most hulls of the ships are protected with paintings, sacrificial anode, and impressed current cathodic protection methods against corrosion problems. However, these conventional methods are not very effective because...Most hulls of the ships are protected with paintings, sacrificial anode, and impressed current cathodic protection methods against corrosion problems. However, these conventional methods are not very effective because the rudder of ships stern are exposed to very severe corrosive environment such as tides, speeds of ships, cavitations and erosion corrosion. The environmental factors such as cavitation and corrosion will cause damage for materials with the shock wave by the creation and destruction of bubble. To solve these problems, the cavitation and electrochemical experiments are executed for thermal spray coating with Al-Zn alloy wire material. Thereafter, and sealed specimens with F-Si sealer on Al-Zn alloy coated specimen are executed to improve electrochemical and anti-cavitation characteristics in sea water. The application of fluorine silicon sealing after spray coating of 15%Al-85%Zn seems to be appropriate not only in static environment but also in dynamic environment.展开更多
The Japanese aircraft industry changed its course in approximately 2007. Mitsubishi Heavy Industry （MHI） Co. launched a project in which regional jets （Mitsubishi Regional Jet （MILl）） reentered the airliner manu...The Japanese aircraft industry changed its course in approximately 2007. Mitsubishi Heavy Industry （MHI） Co. launched a project in which regional jets （Mitsubishi Regional Jet （MILl）） reentered the airliner manufacturing market. Honda announced plans to develop, manufacture, and sell small passenger jets, or Honda Jets, in the United States （US） market. This paper summarizes the historical development of the industry using aircraft production statistics and analyzes the patent portfolio strategy from 1995 to 2006, a period in which MHI and Honda accumulated patents for the upcoming market entry. The author uses the following two measurements to evaluate niche widths among aircraft manufacturing companies： the Morishita＇s index and the principal component analysis. The former index is used in population ecology to measure overlapping species. The latter measurement is presented to clarify the validity of the Morishita＇s index. The author identifies MHI as a market leader, Kawasaki Heavy Industry （KHI） Co. as a challenger, Fuji Heavy Industry （FHI） Co. as a follower, and Honda as a nicher in the aircraft patent portfolio strategy in Japan.展开更多
The nanocrystalline SiC films were prepared on Si then annealed at 800℃ and 1 000℃ for 30 minutes （111） substrates by rf magnetron sputtering and in a vacuum annealing system. The crystal structure and crystalliza...The nanocrystalline SiC films were prepared on Si then annealed at 800℃ and 1 000℃ for 30 minutes （111） substrates by rf magnetron sputtering and in a vacuum annealing system. The crystal structure and crystallization of as-annealed SiC films were determined by the Fourier transform infrared （FIR） absorption spectra and the X-ray diffraction （XRD） analysis. Measurement of photoluminescence （PL） of the nanocrystalline SiC （nc-SiC） films shows that the blue light with 473 nm and 477 nm wavelengths emitted at room temperature and that the PL peak shifts to shorter wavelength side and the PL intensity becomes stronger as the annealing temperature decreases. The time-resolved spectrum of the PL at 477 nm exhibits a bi-exponential decay process with lifetimes of 600 ps and 5 ns and a characteristic of the direct band gap. The strong blue light emission with short PL lifetimes suggests that the quantum confinement effect of the SiC nanocrystals resulted in the radiative recombination of the direct optical transitions.展开更多
The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico （GOM）. Here the paper analyzes available sediment datasets to determine whether changes in petrogenic cont...The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico （GOM）. Here the paper analyzes available sediment datasets to determine whether changes in petrogenic contaminants are evident in GOM sediment following the blowout. Locations sampled by EPA （Environmental Protection Agency）, British Petroleum （BP） and NOAA （National Oceanic and Atmospheric Administration） were reduced and grouped into 46 similar locations and analyzed. Eleven groups suggested an increase in PAIl （polycyclic aromatic hydrocarbon） and nickel, one group showed a statistically significant increase in Phenanthrene. Four locations were analyzed for time trends and differences between initial and peak concentrations of oil range organics （ORO）, diesel range organics （DRO）, vanadium and nickel. One location had significant increases in ORO, DRO and vanadium and a suggestive increase in nickel. Correlations between ORO/DRO, ORO/V, ORO/Ni, V/Ni were computed （RE= 0.85, 0.67, 0.64, 0.92, respectively）. Overall, the analyses suggest that future monitoring should employ a sampling strategy that coordinates response sampling to previously sampled locations, such that baseline datasets can be used in detection of event associated contamination.展开更多
A visible magnified and simulated nozzle was designed and installed on a winding machine according to the similarity principle of Reynolds number, to study the yarn motion track in hairiness-reducing nozzle. High-spee...A visible magnified and simulated nozzle was designed and installed on a winding machine according to the similarity principle of Reynolds number, to study the yarn motion track in hairiness-reducing nozzle. High-speed photography was used to observe the yam instantaneous motion state in the nozzle. The results show that the yarn motion track seems to be a cylindrical helix which is close to inner wall in the twisting chamber and kept the same with different technical parameters, such as diameter of the twisting chamber and jet pressure in orifices. According to simulation results and reasonable simplification, the motion track equation and the rotational equation of the yarn could be derived. The velocity of the swirl and hairiness is faster than that of the yarn balloon, so there is enough time for hairiness to be wrapped into the main body of yarn and hence the hairiness is reduced.展开更多
Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carrie...Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carried out. And the improved attenuation curves were obtained, by which the engine noise was predicted. The effect of fuel injection parameters in combustion noise was investigated during the combustion process. At last, the method combining single variable optimization and multivariate combination was introduced to online optimize the combustion noise. The results show that injection parameters can affect the cylinder pressure rise rate and heat release rate, and consequently affect the cylinder pressure load and pressure oscillation to influence the combustion noise. Among these parameters, main injection advance angle has the greatest influence on the combustion noise, while the pilot injection interval time takes the second place, and the pilot injection quantity is of minimal impact. After the optimal design of the combustion noise, the average sound pressure level of the engine is distinctly reduced by 1.0 d B(A) generally. Meanwhile, the power, emission and economy performances are ensured.展开更多
Irrigation advances in precision irrigation （PI） or site specific irrigation （SSI） have been considerable in research; however, commercialization lags. SSI/PI has applications when soil texture variability affects...Irrigation advances in precision irrigation （PI） or site specific irrigation （SSI） have been considerable in research; however, commercialization lags. SSI/PI has applications when soil texture variability affects soil water holding capacity or when crop yield or biotic stresses （insects or diseases） are spatially variable. SSI/PI uses variable rate application technologies, mainly with center-pivots or lateral-move or linear irrigation machines, to match crop needs or soil water holding constraints. Variable rate applications are achieved by variable nozzle flow rates, pulsing nozzle flows, or multiple nozzles on separate submains. Newer center pivot and linear machines are controlled by on-board microprocessor systems that can be integrated with supervisory control and data acquisition controllers for both communication and control of the variable rate application for specific sets of nozzles or individual nozzles for management zones. Communication for center pivot or linear controllers typically uses radio telemetry, wireless interact links, or cellular telephones. Precision irrigation has limited utility without precise irrigation scheduling （temporally and spatially）. Plant or soil sensors are used to initiate or complete an irrigation event. Automated weather stations provide site information for determining the irrigation requirement using crop models or simpler reference evapotranspiration （ET）, data to be used with crop coefficients. Remote sensing is being used to measure crop water status or crop development from spectral reflectance. Near-surface remote sensing with sensors mounted on moving irrigation systems provide critical spatial integration from point weather networks and feedback on crop ET and irrigation controls in advanced automated systems for SSI/PI.展开更多
We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between ...We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.展开更多
Vortex spinning is an innovative air-jet spinning technology with promising features.A comparison of the vortex and ring spun cotton yarns and their knitted fabric properties was provided to evaluate the latent capabi...Vortex spinning is an innovative air-jet spinning technology with promising features.A comparison of the vortex and ring spun cotton yarns and their knitted fabric properties was provided to evaluate the latent capability of the vortex spinning technology.The results show that the vortex yarn has better elongation,evenness and much less hairiness than the ring yarn.The vortex fabric is found to have better air permeability,bursting properties,and pilling resistance than the ring fabric,while the drapeability and abrasion resistance of the ring fabric are better than the vortex fabric.展开更多
An A1 coating on Mg substrate was achieved by droplet spraying treatment. The microstructure was studied by electron probe microanalysis （EPMA） and X-ray diffraction （XRD）. The coating layer is composed of AI phas...An A1 coating on Mg substrate was achieved by droplet spraying treatment. The microstructure was studied by electron probe microanalysis （EPMA） and X-ray diffraction （XRD）. The coating layer is composed of AI phase and exhibits superior corrosion resistance. The formation of the coating is mainly attributed to the obstruction of expansion of the transition zone by primarily solidified Mg]7All2 during rapid cooling, and the diffusion is restricted in a thin layer. These results show that droplet spraying is a promising way to protect magnesium by using corrosion-resistant materials available now.展开更多
A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with ...A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with the basic phenomenon of the interaction between a bubble and a wall, the dynamics of bubbles near rigid walls were studied systematically with the program. Calculated results agreed well with experimental results. The relationship between the Bjerknes effect of a wall and characteristic parameters was then studied and the calculated results of various cases were compared and discussed with the Blake criterion based on the Kelvin-impulse theory. Our analyses show that the angle of the jet’s direction and the pressure on the rigid wall have a close relationship with collapse force and the bubble’s characteristic parameters. From this, the application range of Blake criterion can be determined. This paper aims to provide a basis for future research on the dynamics of bubbles near a wall.展开更多
Without any preprocessing,polyester fabric has lower ability to hold on water and inks due to the smooth morphology of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields an...Without any preprocessing,polyester fabric has lower ability to hold on water and inks due to the smooth morphology of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields and bleed easily. Pretreatments of polyester fabric were carried out with atmospheric air plasma under different experimental conditions. After plasma treatment the samples were printed with magenta pigment ink. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses indicated that the enhanced color performance was mainly contributed by not only the etching effect but also oxygen-containing polar groups induced onto fiber surfaces through plasma treatment. Thereby the surface modification of polyester fabrics using atmospheric-pressure air plasma offers a potential way to fabric pretreatment for pigment inkjet printing with the advantages of environmental friendly and energy saving over traditional pretreatment methods.展开更多
文摘Most hulls of the ships are protected with paintings, sacrificial anode, and impressed current cathodic protection methods against corrosion problems. However, these conventional methods are not very effective because the rudder of ships stern are exposed to very severe corrosive environment such as tides, speeds of ships, cavitations and erosion corrosion. The environmental factors such as cavitation and corrosion will cause damage for materials with the shock wave by the creation and destruction of bubble. To solve these problems, the cavitation and electrochemical experiments are executed for thermal spray coating with Al-Zn alloy wire material. Thereafter, and sealed specimens with F-Si sealer on Al-Zn alloy coated specimen are executed to improve electrochemical and anti-cavitation characteristics in sea water. The application of fluorine silicon sealing after spray coating of 15%Al-85%Zn seems to be appropriate not only in static environment but also in dynamic environment.
文摘The Japanese aircraft industry changed its course in approximately 2007. Mitsubishi Heavy Industry （MHI） Co. launched a project in which regional jets （Mitsubishi Regional Jet （MILl）） reentered the airliner manufacturing market. Honda announced plans to develop, manufacture, and sell small passenger jets, or Honda Jets, in the United States （US） market. This paper summarizes the historical development of the industry using aircraft production statistics and analyzes the patent portfolio strategy from 1995 to 2006, a period in which MHI and Honda accumulated patents for the upcoming market entry. The author uses the following two measurements to evaluate niche widths among aircraft manufacturing companies： the Morishita＇s index and the principal component analysis. The former index is used in population ecology to measure overlapping species. The latter measurement is presented to clarify the validity of the Morishita＇s index. The author identifies MHI as a market leader, Kawasaki Heavy Industry （KHI） Co. as a challenger, Fuji Heavy Industry （FHI） Co. as a follower, and Honda as a nicher in the aircraft patent portfolio strategy in Japan.
基金The project supported by the National Natural Science Founda-tion of China(Grant No.60476003)
文摘The nanocrystalline SiC films were prepared on Si then annealed at 800℃ and 1 000℃ for 30 minutes （111） substrates by rf magnetron sputtering and in a vacuum annealing system. The crystal structure and crystallization of as-annealed SiC films were determined by the Fourier transform infrared （FIR） absorption spectra and the X-ray diffraction （XRD） analysis. Measurement of photoluminescence （PL） of the nanocrystalline SiC （nc-SiC） films shows that the blue light with 473 nm and 477 nm wavelengths emitted at room temperature and that the PL peak shifts to shorter wavelength side and the PL intensity becomes stronger as the annealing temperature decreases. The time-resolved spectrum of the PL at 477 nm exhibits a bi-exponential decay process with lifetimes of 600 ps and 5 ns and a characteristic of the direct band gap. The strong blue light emission with short PL lifetimes suggests that the quantum confinement effect of the SiC nanocrystals resulted in the radiative recombination of the direct optical transitions.
文摘The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico （GOM）. Here the paper analyzes available sediment datasets to determine whether changes in petrogenic contaminants are evident in GOM sediment following the blowout. Locations sampled by EPA （Environmental Protection Agency）, British Petroleum （BP） and NOAA （National Oceanic and Atmospheric Administration） were reduced and grouped into 46 similar locations and analyzed. Eleven groups suggested an increase in PAIl （polycyclic aromatic hydrocarbon） and nickel, one group showed a statistically significant increase in Phenanthrene. Four locations were analyzed for time trends and differences between initial and peak concentrations of oil range organics （ORO）, diesel range organics （DRO）, vanadium and nickel. One location had significant increases in ORO, DRO and vanadium and a suggestive increase in nickel. Correlations between ORO/DRO, ORO/V, ORO/Ni, V/Ni were computed （RE= 0.85, 0.67, 0.64, 0.92, respectively）. Overall, the analyses suggest that future monitoring should employ a sampling strategy that coordinates response sampling to previously sampled locations, such that baseline datasets can be used in detection of event associated contamination.
基金Tianjin Science and Technology Planning Projects,China(No.04310471)
文摘A visible magnified and simulated nozzle was designed and installed on a winding machine according to the similarity principle of Reynolds number, to study the yarn motion track in hairiness-reducing nozzle. High-speed photography was used to observe the yam instantaneous motion state in the nozzle. The results show that the yarn motion track seems to be a cylindrical helix which is close to inner wall in the twisting chamber and kept the same with different technical parameters, such as diameter of the twisting chamber and jet pressure in orifices. According to simulation results and reasonable simplification, the motion track equation and the rotational equation of the yarn could be derived. The velocity of the swirl and hairiness is faster than that of the yarn balloon, so there is enough time for hairiness to be wrapped into the main body of yarn and hence the hairiness is reduced.
基金Project(2011BAE22B05)supported by the National Science and Technology Pillar Program during the 12th Five-year Plan of China
文摘Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carried out. And the improved attenuation curves were obtained, by which the engine noise was predicted. The effect of fuel injection parameters in combustion noise was investigated during the combustion process. At last, the method combining single variable optimization and multivariate combination was introduced to online optimize the combustion noise. The results show that injection parameters can affect the cylinder pressure rise rate and heat release rate, and consequently affect the cylinder pressure load and pressure oscillation to influence the combustion noise. Among these parameters, main injection advance angle has the greatest influence on the combustion noise, while the pilot injection interval time takes the second place, and the pilot injection quantity is of minimal impact. After the optimal design of the combustion noise, the average sound pressure level of the engine is distinctly reduced by 1.0 d B(A) generally. Meanwhile, the power, emission and economy performances are ensured.
文摘Irrigation advances in precision irrigation （PI） or site specific irrigation （SSI） have been considerable in research; however, commercialization lags. SSI/PI has applications when soil texture variability affects soil water holding capacity or when crop yield or biotic stresses （insects or diseases） are spatially variable. SSI/PI uses variable rate application technologies, mainly with center-pivots or lateral-move or linear irrigation machines, to match crop needs or soil water holding constraints. Variable rate applications are achieved by variable nozzle flow rates, pulsing nozzle flows, or multiple nozzles on separate submains. Newer center pivot and linear machines are controlled by on-board microprocessor systems that can be integrated with supervisory control and data acquisition controllers for both communication and control of the variable rate application for specific sets of nozzles or individual nozzles for management zones. Communication for center pivot or linear controllers typically uses radio telemetry, wireless interact links, or cellular telephones. Precision irrigation has limited utility without precise irrigation scheduling （temporally and spatially）. Plant or soil sensors are used to initiate or complete an irrigation event. Automated weather stations provide site information for determining the irrigation requirement using crop models or simpler reference evapotranspiration （ET）, data to be used with crop coefficients. Remote sensing is being used to measure crop water status or crop development from spectral reflectance. Near-surface remote sensing with sensors mounted on moving irrigation systems provide critical spatial integration from point weather networks and feedback on crop ET and irrigation controls in advanced automated systems for SSI/PI.
基金The project supported in part by National Natural Science Foundation of China under Grant No. 10421503 and the Key Project of the Ministry of Education under Grant No. 305001, and the Research Found of Doctorial Programs of Higher Education of China. We thank E. Berger for bringing their earlier work on inelastic photoproduction of T （Ref. [12]） to our attention. We would also like to thank Ce Meng for valuable discussions.
文摘We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.
基金National Natural Science Foundation of China(No.51076026)Natural Science Foundation of Shanghai,China(No.12ZR1440300)the Fundamental Research Funds for the Central Universities of China
文摘Vortex spinning is an innovative air-jet spinning technology with promising features.A comparison of the vortex and ring spun cotton yarns and their knitted fabric properties was provided to evaluate the latent capability of the vortex spinning technology.The results show that the vortex yarn has better elongation,evenness and much less hairiness than the ring yarn.The vortex fabric is found to have better air permeability,bursting properties,and pilling resistance than the ring fabric,while the drapeability and abrasion resistance of the ring fabric are better than the vortex fabric.
基金Project(J12LA53)supported by Shangdong Provincial Higher Education Science and Technology Program,ChinaProject(KZJ-48)supported by the Science and Technology Development Program of Qingdao,China
文摘An A1 coating on Mg substrate was achieved by droplet spraying treatment. The microstructure was studied by electron probe microanalysis （EPMA） and X-ray diffraction （XRD）. The coating layer is composed of AI phase and exhibits superior corrosion resistance. The formation of the coating is mainly attributed to the obstruction of expansion of the transition zone by primarily solidified Mg]7All2 during rapid cooling, and the diffusion is restricted in a thin layer. These results show that droplet spraying is a promising way to protect magnesium by using corrosion-resistant materials available now.
基金the National Natural Science Foundation of China under Grant No. 50779007the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20070217074)+1 种基金the Defence Advance Research Program of Science and Technology of Ship Industry under Grant No. 07J1.1.6Harbin Engineering University Foundation under Grant No. HEUFT07069
文摘A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with the basic phenomenon of the interaction between a bubble and a wall, the dynamics of bubbles near rigid walls were studied systematically with the program. Calculated results agreed well with experimental results. The relationship between the Bjerknes effect of a wall and characteristic parameters was then studied and the calculated results of various cases were compared and discussed with the Blake criterion based on the Kelvin-impulse theory. Our analyses show that the angle of the jet’s direction and the pressure on the rigid wall have a close relationship with collapse force and the bubble’s characteristic parameters. From this, the application range of Blake criterion can be determined. This paper aims to provide a basis for future research on the dynamics of bubbles near a wall.
基金New Century Excellent Talents of China ( NCET,No.040495)National Natural Science Foundation of China(NSFC, No.20474025)+1 种基金National Key Technology R&DProgram,China (No.2007BAE40B01)Innovative Research Team of Jiangnan University,China
文摘Without any preprocessing,polyester fabric has lower ability to hold on water and inks due to the smooth morphology of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields and bleed easily. Pretreatments of polyester fabric were carried out with atmospheric air plasma under different experimental conditions. After plasma treatment the samples were printed with magenta pigment ink. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses indicated that the enhanced color performance was mainly contributed by not only the etching effect but also oxygen-containing polar groups induced onto fiber surfaces through plasma treatment. Thereby the surface modification of polyester fabrics using atmospheric-pressure air plasma offers a potential way to fabric pretreatment for pigment inkjet printing with the advantages of environmental friendly and energy saving over traditional pretreatment methods.
