In this paper, the magnetic-elastic-plastic deformation behavior is studied for a ferromagnetic plate with simple supports. The perturbation formula of magnetic force is first derived based on the perturbation techniq...In this paper, the magnetic-elastic-plastic deformation behavior is studied for a ferromagnetic plate with simple supports. The perturbation formula of magnetic force is first derived based on the perturbation technique, and is then applied to the analysis of deformation characteristics with emphasis laid on the analyses of modes, symmetry of deformation and influences of incident angle of applied magnetic field on the plate deformation. The theoretical analyses offer explanations why the configuration offer- romagnetic rectangular plate with simple supports under an oblique magnetic field is in-wavy type along the x-direction, and why the largest deformation of the ferromagnetic plate occurs at the incident angle of 45°for the magnetic field. A numerical code based on the finite element method is developed to simulate quantitatively behaviors of the nonlinearly coupled multi-field problem. Some characteristic curves are plotted to illustrate the magneto--elastic-plastic deflections, and to reveal how the deflections can be influenced by the incident angle of applied magnetic field. The deformation characteristics obtained from the numerical simulations are found in good agreement with the theoretical analyses.展开更多
Many researchers have studied on perovskite oxide for its unique structure.Perovskite oxides,ABO3-δ,with different A and B metals have shown wide applications in many fields,in particular solid oxide electrolysers.Sr...Many researchers have studied on perovskite oxide for its unique structure.Perovskite oxides,ABO3-δ,with different A and B metals have shown wide applications in many fields,in particular solid oxide electrolysers.SrFeO3-δ,typical perovskite oxides,in which iron is the mixed-valence cation with the capacity to change the chemical valence,have a wide range of oxygen nonstoichiometry.In this study,Sr(0.9)Fe(0.9)Zr(0.1)O3-δ(SFZO) is synthesized and then treated in 5%H2/Ar and air at high temperature,exhibiting excellent redox stability.Redox-stable structure,oxygen vacancy and electrical properties of SFZO are investigated.Steam electrolysis is then performed with SFZO cathode under 5%H2O/5%H2/Ar and 5%H2O/Ar atmospheres,respectively.The present results indicate that the SFZO is a novel promising cathode material for solid oxide steam electrolyser.展开更多
The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, a...The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al + 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al + 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides: AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.展开更多
The pressing bonding of steel plate to QTi3.5-3.5 graphite slurry was conducted. Under the conditions of 530 ℃ for the preheat temperature of dies, 45% for the solid fraction of QTi3.5- 3.5 graphite slurry, 50 MPa fo...The pressing bonding of steel plate to QTi3.5-3.5 graphite slurry was conducted. Under the conditions of 530 ℃ for the preheat temperature of dies, 45% for the solid fraction of QTi3.5- 3.5 graphite slurry, 50 MPa for the pressure and 2 min for the pressing time, the relationship between the preheat temperature of steel plate and interfacial mechanical property of bonding plate was studied. The results show that when the preheat temperature of steel plate is lower titan 618 ℃ , the interfacial shear strength of bonding plate increases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is higher than 618 ℃ , the interfacial shear strength decreases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is 618 ℃ , the highest interfacial shear strength of bonding plate of 127.8 MPa can be got.展开更多
Hydrogen energy,whether in generation plants or utilization facilities,plays a decisive role in the mission to achieve net-zero greenhouse gas emissions,all to minimize pollution.The growing demand for clean energy ca...Hydrogen energy,whether in generation plants or utilization facilities,plays a decisive role in the mission to achieve net-zero greenhouse gas emissions,all to minimize pollution.The growing demand for clean energy carrier steadily accelerates the development of hydrogen production processes,and therein proton exchange membrane(PEM)water electrolysis is deemed a promising long-term strategy for hydrogen preparation and collection.This review retrospects recent developments and applications of bipolar plates(BPs)as key components in PEM fuel cells and water electrolysers.The main content includes multifaceted challenges in the R&D or fabrication of BPs and potential future trends have also been proposed.Specific details cover the BPs matrix(metallic materials and carbon composites)and the surface coating types(metal and compound coatings,carbon-based coatings,and polymer coatings),as well as the influence of flow field design for mass transport.Long-term development and feasible researches of BPs are prospected.Especially in the following aspects:(1)Structural and functional integration of components,such as material fabrication and flow field geometry optimization using 3D printing technology;(2)Introduction of environment-friendly renewable energy for hydrogen production;(3)Research on hydrogen energy reversible systems;(4)Composition optimization of surface coatings based on computational materials science and(5)systematic design expected to evolve into the next generation of BPs.展开更多
A new theory and method that differs from the tradition-al single plated weft - knitting theory and method hasbeen expounded after theoretical analyzing and experi-mental proving. If the new method is used when platin...A new theory and method that differs from the tradition-al single plated weft - knitting theory and method hasbeen expounded after theoretical analyzing and experi-mental proving. If the new method is used when platingstitch is knitted on large diameter weft knitting machine,the thorny problem of long standing that ground yarn iseasy to appear on the face side of fabric is solved. Thenew method, i.e, the production of physical ability oftraining uniform for serviceman has been used.展开更多
Applying Lagrange-Germain's theory of elas- tic thin plates and Hamiltonian formulation, the dynamics of cantilever plates and the problem of its vibration control are studied, and a general solution is finally given...Applying Lagrange-Germain's theory of elas- tic thin plates and Hamiltonian formulation, the dynamics of cantilever plates and the problem of its vibration control are studied, and a general solution is finally given. Based on Hamiltonian and Lagrangian density function, we can obtain the flexural wave equation of the plate and the relationship between the transverse and the longitudinal eigenvalues. Based on eigenfunction expansion, dispersion equations of propagation mode of cantilever plates are deduced. By satisfying the boundary conditions of cantilever plates, the natural frequencies of the cantilever plate structure can be given. Then, analytic solution of the problem in plate structure is obtained. An hybrid wave/mode control approach, which is based on both independent modal space control and wave control methods, is described and adopted to analyze the active vibration control of cantilever plates. The low-order (controlled by modal control) and the high-order (controlled by wave control) frequency response of plates are both improved. The control spillover is avoided and the robustness of the system is also improved. Finally, simulation results are analyzed and discussed.展开更多
Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for ...Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for 3 h in carbon embedded condition. Thermo-mechanical properties of Al2 O3 - SiC - SiAlON composites have been studied. The results show : ( 1 ) Al2 O3 - SiC - SiAION composites can be prepared and sintered at 1 500 ℃ under carbon embedded condition. When Si/Al ratio is 8/0 and 7/1, the prepared composite is Al2O3 - SiC - O' -SiAlON; when Si/Al ratio is 5/3 and 3/5, the pre- pared composite is Al2 O3 - SiC - β-SiAION. ( 2 ) The composites possess high temperature strength properties. Hot modulus of rupture at 1 400 ℃ is 10 - 30 MPa. They are in elastic range up to 1 000 ℃, after which plastic deformation is observed; even at 1 400 ℃, amount of deformation is relatively low. (3) The com- posites possess good thermal shock resistance, their resid- ual strength ratio (AT = 1 100 ℃ ) is 65% - 80%. (4) The marked improvement in thermo-mechanical properties of Al2O3 - SiC - SiAlON composites may be at- tributed to the in-situ formation of SiC, SiAlON and AIN, the fibrous SiC, columnar SiAlON and tabular-like AlN fill in the corundum skeleton structure creating strengthening and toughening effects.展开更多
Measurement of out-of-plane deformation is significant to understanding of the deflection mechanisms of the plate and tube structures.In this study,a new surface contouring technique with color structured light is app...Measurement of out-of-plane deformation is significant to understanding of the deflection mechanisms of the plate and tube structures.In this study,a new surface contouring technique with color structured light is applied to measure the out-of-plane deformation of structures with one-shot projection.Through color fringe recognizing,decoding and triangulation processing for the captured images corresponding to each deformation state,the feasibility of the method is testified by the measurement of elastic deflections of a flexible square plate,showing good agreement with those from the calibrated displacement driver.The plastic deformation of two alloy aluminum rectangular tubes is measured to show the technique application to surface topographic evaluation of the buckling structures with large displacements.展开更多
Poly(1,1,2,2- tetrahydroperfluorodecyl acrylate) (poly (TA-N)) was synthesized in laboratory. The resulting morphology of rapid expansion of supercritical solution (RESS) sprays of poly(TA - N) was investigated. At ap...Poly(1,1,2,2- tetrahydroperfluorodecyl acrylate) (poly (TA-N)) was synthesized in laboratory. The resulting morphology of rapid expansion of supercritical solution (RESS) sprays of poly(TA - N) was investigated. At apre - expansion temperature of 45℃), amorphous polymer was formed. At temperature around 60 ℃ to 80 ℃ , fibers were formed. Increase of temperature increasesparticle size slightly. At temperature of 105℃ , most of particles are spheres. The RESS is an attractive process. To apply the polymers desired for coating applications in an organic solvent - free process that is economically viable , and it will have implications for pollution prevention during polymer film展开更多
Multichip on Ahnnintnn Metal Plate(MOAMP) technology with simple structure and low thermal resistance is developed for effective heat reratrval of Light Emitting Diode(LED) p-n junction and LED lighting module to ...Multichip on Ahnnintnn Metal Plate(MOAMP) technology with simple structure and low thermal resistance is developed for effective heat reratrval of Light Emitting Diode(LED) p-n junction and LED lighting module to have high reliability. The thermal resistance of LED modules was numerical and experimental. Thermal resistance from the jtnction to aluminten metal plate, considering input power of IFD module using MOAMP technology, is 3.02 K/W, 3.23 K/W for the measured and calculated, respectively. We expect that the reported MOAMP technology with low thermal resistance will be a promising solution for high power LED fighting modules.展开更多
Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-...Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].展开更多
The current “mega” interest in Lithium resources was spurred by the development of Lithium-Ion batteries to aid in restructuring the world’s reliance on carbon spewing power petroleum reserves. Current resources of...The current “mega” interest in Lithium resources was spurred by the development of Lithium-Ion batteries to aid in restructuring the world’s reliance on carbon spewing power petroleum reserves. Current resources of lithium recovery have fallen into two main categories—Pegmatite, found worldwide associated with felsic intrusions and Brine Related, and now with development in the Southwest United States of America (SWUS), a third category— Tertiary Volcanic clays, are specifically associated with Tertiary volcanics and major Tectonic Plate interactions. “Active” Plate tectonics is important as both the SWUS, the Lithium Triangle of South America (LTSA) and the Tibetan Plateau of China (TPC) producing tertiary (Miocene) volcanism that is important to the development of Lithium resources. The Tanzanian part of the East Africa Rift System (EARS) has features of both the SWUS, tertiary volcanic related “playas” and Continental rifting, the LTSA, tertiary volcanic related “Brines” and a major Tectonic plate event (subduction of an Oceanic Plate beneath the Continental South American Plate) and the TPC, tertiary volcanics (?) and major tectonic plate event (subduction of the Indian Continental Plate under the Eurasian Continental Plate). As well as the association of peralkaline and metaluminous felsic volcanics with Lithium playas of the SWUS and the EARS (Tanzania) “playas”. These similarities led to an analysis of a volcanic rock in Northeast Tanzania. When it returned 1.76% Lithium, a one-kilometer spaced soil sampling program returned, in consecutive samples over 0.20% Lithium (several samples over 1.0% lithium and a high of 2.24% lithium). It is proposed that these four regions with very similar past and present geologic characteristics, occur nowhere else in the world. That three of them have produced Lithium operations and two of them have identified resources of Lithium clay and “highly” anomalous Lithium clays should be regarded as more than “coincidental”.展开更多
After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments (Fahliyan, Gadvan, and Dariyan Formations) deposited over Jurassic sediments. The Lower Cretaceous (Aptian) Dariyan Forma...After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments (Fahliyan, Gadvan, and Dariyan Formations) deposited over Jurassic sediments. The Lower Cretaceous (Aptian) Dariyan Formation (equivalent to the Shu'aiba Formation and Hawar Member of the Arabian Plate) carbonates, which have hydrocarbon reservoir potential, form the uppermost portion of the Khami Group that unconformably overlays the Gadvan Formation and was unconformably covered by the Kazhdumi Formation and Burgan sandstones. Detailed paleontological, sedimentological, and well log analysis were performed on seven wells from Qeshm Island and offshore in order to analyze the sequence stratigraphy of this interval and correlate with other studies of the Dariyan Formation in this region. According to this study, the Dariyan Formation contains 14 carbonate lithofacies, which deposited on a ramp system that deepened in both directions (NE-wells 5, 6 and SWIwells 1, 2). Sequence stratigraphy led to recognition of 5 Aptian third-order sequences toward the Bab Basin (SW-well 1) and 4 Aptian third-order sequences toward Qeshm Island (NE-wells 5 and 6) so these areas show higher gamma on the gamma ray logs and probably have higher source rock potential. Other wells (wells 2-4 and 7) mainly deposited in shallower ramp systems and contain 3 Aptian third-order sequences. On the other hand, rudstone and boundstone lithofacies of studied wells have higher reservoir potential and were deposited during Apt 3 and Apt 4 sequences of the Arabian Plate. The Dariyan Formation in Qeshm Island (well 6) and adjacent well (well 5) was deposited in an intrashelf basin that should be classified as a new intrashelf basin in future Aptian paleogeographic maps. We interpret that salt-related differential subsidence, crustal warping, and reactivation of basement faults of the Arabian Plate boundary were responsible for the creation of the intrashelf basin in the Qeshm area.展开更多
An analysis is performed to study the heat transfer characteristics of steady two-dimensional boundary layer flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the ...An analysis is performed to study the heat transfer characteristics of steady two-dimensional boundary layer flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the flow field and heat transfer characteristics are numerically studied by using an implicit finite difference method. It is found that dual solutions exist when the plate and the free stream move in the opposite directions. The results indicate that suction delays the boundary layer separation, while injection accelerates it.展开更多
Cytokinesis, the partitioning of the cytoplasm following nuclear division, requires extensive coordination between membrane trafficking and cytoskeletal dynamics. In plants, the onset of cytokinesis is characterized b...Cytokinesis, the partitioning of the cytoplasm following nuclear division, requires extensive coordination between membrane trafficking and cytoskeletal dynamics. In plants, the onset of cytokinesis is characterized by the assembly of a bipolar microtubule array, the phragmoplast, and of a transient membrane compartment, the cell plate. Little is known about the coordination between membrane deposition at the cell plate and the dynamics of phragmoplast microtubules. In this study, we monitor the localization dynamics of microtubule and membrane markers throughout cytokinesis. Our spatiotemporal resolution is consistent with the general view that microtubule dynamics drive membrane movements. Nonetheless, we provide evidence for active sorting at the cell plate and show that this is, at least in part, mediated by the TRAPPII tethering complex. We also characterize phragmoplast microtubule organization and cell plate formation in a suite of cytokinesis-defective mutants. Of four mutant lines with defects in phragmoplast microtubule organization, only morl microtubule-associated mutants exhibited aberrant cell plates. Conversely, the mutants with the strongest impairment in phragmoplast microtubule reorganization are keule alleles, which have a primary defect in membrane fusion. Our findings identify the SEC1/Munc18 protein KEULE as a central regulatory node in the coordination of membrane and microtubule dynamics during plant cytokinesis.展开更多
基金the National Natural Science Foundation of China (10672070, 10302009)the National Basic Research Program of China (2007CB607560)+1 种基金the Program for New Century Talented (NCET-06-0896) the Natural Science Fund of Gansu Province
文摘In this paper, the magnetic-elastic-plastic deformation behavior is studied for a ferromagnetic plate with simple supports. The perturbation formula of magnetic force is first derived based on the perturbation technique, and is then applied to the analysis of deformation characteristics with emphasis laid on the analyses of modes, symmetry of deformation and influences of incident angle of applied magnetic field on the plate deformation. The theoretical analyses offer explanations why the configuration offer- romagnetic rectangular plate with simple supports under an oblique magnetic field is in-wavy type along the x-direction, and why the largest deformation of the ferromagnetic plate occurs at the incident angle of 45°for the magnetic field. A numerical code based on the finite element method is developed to simulate quantitatively behaviors of the nonlinearly coupled multi-field problem. Some characteristic curves are plotted to illustrate the magneto--elastic-plastic deflections, and to reveal how the deflections can be influenced by the incident angle of applied magnetic field. The deformation characteristics obtained from the numerical simulations are found in good agreement with the theoretical analyses.
基金Supported by the National Natural Science Foundation of China(91545123)and the Natural Science Foundation of Fujian Province(2016J01275)
文摘Many researchers have studied on perovskite oxide for its unique structure.Perovskite oxides,ABO3-δ,with different A and B metals have shown wide applications in many fields,in particular solid oxide electrolysers.SrFeO3-δ,typical perovskite oxides,in which iron is the mixed-valence cation with the capacity to change the chemical valence,have a wide range of oxygen nonstoichiometry.In this study,Sr(0.9)Fe(0.9)Zr(0.1)O3-δ(SFZO) is synthesized and then treated in 5%H2/Ar and air at high temperature,exhibiting excellent redox stability.Redox-stable structure,oxygen vacancy and electrical properties of SFZO are investigated.Steam electrolysis is then performed with SFZO cathode under 5%H2O/5%H2/Ar and 5%H2O/Ar atmospheres,respectively.The present results indicate that the SFZO is a novel promising cathode material for solid oxide steam electrolyser.
文摘The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al + 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al + 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides: AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.
基金Funded by the National Natural Science Foundation of China(No.50274047 and 50304001) Beijing Jiaotong University ScienceFoundation,andthe Ministry of Education Foundation
文摘The pressing bonding of steel plate to QTi3.5-3.5 graphite slurry was conducted. Under the conditions of 530 ℃ for the preheat temperature of dies, 45% for the solid fraction of QTi3.5- 3.5 graphite slurry, 50 MPa for the pressure and 2 min for the pressing time, the relationship between the preheat temperature of steel plate and interfacial mechanical property of bonding plate was studied. The results show that when the preheat temperature of steel plate is lower titan 618 ℃ , the interfacial shear strength of bonding plate increases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is higher than 618 ℃ , the interfacial shear strength decreases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is 618 ℃ , the highest interfacial shear strength of bonding plate of 127.8 MPa can be got.
基金supported by the National Key Research and Development Program of China(No.2021YFB4000101)the National Natural Science Foundation of China(No.52125102)the Fundamental Research Funds for the Central Universities(No.FRF-TP-2021–02C2).
文摘Hydrogen energy,whether in generation plants or utilization facilities,plays a decisive role in the mission to achieve net-zero greenhouse gas emissions,all to minimize pollution.The growing demand for clean energy carrier steadily accelerates the development of hydrogen production processes,and therein proton exchange membrane(PEM)water electrolysis is deemed a promising long-term strategy for hydrogen preparation and collection.This review retrospects recent developments and applications of bipolar plates(BPs)as key components in PEM fuel cells and water electrolysers.The main content includes multifaceted challenges in the R&D or fabrication of BPs and potential future trends have also been proposed.Specific details cover the BPs matrix(metallic materials and carbon composites)and the surface coating types(metal and compound coatings,carbon-based coatings,and polymer coatings),as well as the influence of flow field design for mass transport.Long-term development and feasible researches of BPs are prospected.Especially in the following aspects:(1)Structural and functional integration of components,such as material fabrication and flow field geometry optimization using 3D printing technology;(2)Introduction of environment-friendly renewable energy for hydrogen production;(3)Research on hydrogen energy reversible systems;(4)Composition optimization of surface coatings based on computational materials science and(5)systematic design expected to evolve into the next generation of BPs.
文摘A new theory and method that differs from the tradition-al single plated weft - knitting theory and method hasbeen expounded after theoretical analyzing and experi-mental proving. If the new method is used when platingstitch is knitted on large diameter weft knitting machine,the thorny problem of long standing that ground yarn iseasy to appear on the face side of fabric is solved. Thenew method, i.e, the production of physical ability oftraining uniform for serviceman has been used.
基金supported by the National Natural Science Foundation of China(10572045)
文摘Applying Lagrange-Germain's theory of elas- tic thin plates and Hamiltonian formulation, the dynamics of cantilever plates and the problem of its vibration control are studied, and a general solution is finally given. Based on Hamiltonian and Lagrangian density function, we can obtain the flexural wave equation of the plate and the relationship between the transverse and the longitudinal eigenvalues. Based on eigenfunction expansion, dispersion equations of propagation mode of cantilever plates are deduced. By satisfying the boundary conditions of cantilever plates, the natural frequencies of the cantilever plate structure can be given. Then, analytic solution of the problem in plate structure is obtained. An hybrid wave/mode control approach, which is based on both independent modal space control and wave control methods, is described and adopted to analyze the active vibration control of cantilever plates. The low-order (controlled by modal control) and the high-order (controlled by wave control) frequency response of plates are both improved. The control spillover is avoided and the robustness of the system is also improved. Finally, simulation results are analyzed and discussed.
基金the financial support of Science Fund for International Cooperation Project(No.152102410014)the Education Department of Henan Province Foundation(14A430030)Research Foundation of Zhengzhou City(131PPTGG-409-3)
文摘Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for 3 h in carbon embedded condition. Thermo-mechanical properties of Al2 O3 - SiC - SiAlON composites have been studied. The results show : ( 1 ) Al2 O3 - SiC - SiAION composites can be prepared and sintered at 1 500 ℃ under carbon embedded condition. When Si/Al ratio is 8/0 and 7/1, the prepared composite is Al2O3 - SiC - O' -SiAlON; when Si/Al ratio is 5/3 and 3/5, the pre- pared composite is Al2 O3 - SiC - β-SiAION. ( 2 ) The composites possess high temperature strength properties. Hot modulus of rupture at 1 400 ℃ is 10 - 30 MPa. They are in elastic range up to 1 000 ℃, after which plastic deformation is observed; even at 1 400 ℃, amount of deformation is relatively low. (3) The com- posites possess good thermal shock resistance, their resid- ual strength ratio (AT = 1 100 ℃ ) is 65% - 80%. (4) The marked improvement in thermo-mechanical properties of Al2O3 - SiC - SiAlON composites may be at- tributed to the in-situ formation of SiC, SiAlON and AIN, the fibrous SiC, columnar SiAlON and tabular-like AlN fill in the corundum skeleton structure creating strengthening and toughening effects.
文摘Measurement of out-of-plane deformation is significant to understanding of the deflection mechanisms of the plate and tube structures.In this study,a new surface contouring technique with color structured light is applied to measure the out-of-plane deformation of structures with one-shot projection.Through color fringe recognizing,decoding and triangulation processing for the captured images corresponding to each deformation state,the feasibility of the method is testified by the measurement of elastic deflections of a flexible square plate,showing good agreement with those from the calibrated displacement driver.The plastic deformation of two alloy aluminum rectangular tubes is measured to show the technique application to surface topographic evaluation of the buckling structures with large displacements.
文摘Poly(1,1,2,2- tetrahydroperfluorodecyl acrylate) (poly (TA-N)) was synthesized in laboratory. The resulting morphology of rapid expansion of supercritical solution (RESS) sprays of poly(TA - N) was investigated. At apre - expansion temperature of 45℃), amorphous polymer was formed. At temperature around 60 ℃ to 80 ℃ , fibers were formed. Increase of temperature increasesparticle size slightly. At temperature of 105℃ , most of particles are spheres. The RESS is an attractive process. To apply the polymers desired for coating applications in an organic solvent - free process that is economically viable , and it will have implications for pollution prevention during polymer film
文摘Multichip on Ahnnintnn Metal Plate(MOAMP) technology with simple structure and low thermal resistance is developed for effective heat reratrval of Light Emitting Diode(LED) p-n junction and LED lighting module to have high reliability. The thermal resistance of LED modules was numerical and experimental. Thermal resistance from the jtnction to aluminten metal plate, considering input power of IFD module using MOAMP technology, is 3.02 K/W, 3.23 K/W for the measured and calculated, respectively. We expect that the reported MOAMP technology with low thermal resistance will be a promising solution for high power LED fighting modules.
基金supported by CAPES/PROEX,FAPESP(2010/10936-5)A.F.Donatti has a doctorate scholarship from CAPESC.R.A.Leite-Panissi also received grants from the CNPq(Grant No.307383/2012-1).
文摘Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].
文摘The current “mega” interest in Lithium resources was spurred by the development of Lithium-Ion batteries to aid in restructuring the world’s reliance on carbon spewing power petroleum reserves. Current resources of lithium recovery have fallen into two main categories—Pegmatite, found worldwide associated with felsic intrusions and Brine Related, and now with development in the Southwest United States of America (SWUS), a third category— Tertiary Volcanic clays, are specifically associated with Tertiary volcanics and major Tectonic Plate interactions. “Active” Plate tectonics is important as both the SWUS, the Lithium Triangle of South America (LTSA) and the Tibetan Plateau of China (TPC) producing tertiary (Miocene) volcanism that is important to the development of Lithium resources. The Tanzanian part of the East Africa Rift System (EARS) has features of both the SWUS, tertiary volcanic related “playas” and Continental rifting, the LTSA, tertiary volcanic related “Brines” and a major Tectonic plate event (subduction of an Oceanic Plate beneath the Continental South American Plate) and the TPC, tertiary volcanics (?) and major tectonic plate event (subduction of the Indian Continental Plate under the Eurasian Continental Plate). As well as the association of peralkaline and metaluminous felsic volcanics with Lithium playas of the SWUS and the EARS (Tanzania) “playas”. These similarities led to an analysis of a volcanic rock in Northeast Tanzania. When it returned 1.76% Lithium, a one-kilometer spaced soil sampling program returned, in consecutive samples over 0.20% Lithium (several samples over 1.0% lithium and a high of 2.24% lithium). It is proposed that these four regions with very similar past and present geologic characteristics, occur nowhere else in the world. That three of them have produced Lithium operations and two of them have identified resources of Lithium clay and “highly” anomalous Lithium clays should be regarded as more than “coincidental”.
基金the National Iranian Oil Company,Exploration Directorate,for the support of this researchthe Department of Geology at Ferdowsi University of Mashhad for their support
文摘After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments (Fahliyan, Gadvan, and Dariyan Formations) deposited over Jurassic sediments. The Lower Cretaceous (Aptian) Dariyan Formation (equivalent to the Shu'aiba Formation and Hawar Member of the Arabian Plate) carbonates, which have hydrocarbon reservoir potential, form the uppermost portion of the Khami Group that unconformably overlays the Gadvan Formation and was unconformably covered by the Kazhdumi Formation and Burgan sandstones. Detailed paleontological, sedimentological, and well log analysis were performed on seven wells from Qeshm Island and offshore in order to analyze the sequence stratigraphy of this interval and correlate with other studies of the Dariyan Formation in this region. According to this study, the Dariyan Formation contains 14 carbonate lithofacies, which deposited on a ramp system that deepened in both directions (NE-wells 5, 6 and SWIwells 1, 2). Sequence stratigraphy led to recognition of 5 Aptian third-order sequences toward the Bab Basin (SW-well 1) and 4 Aptian third-order sequences toward Qeshm Island (NE-wells 5 and 6) so these areas show higher gamma on the gamma ray logs and probably have higher source rock potential. Other wells (wells 2-4 and 7) mainly deposited in shallower ramp systems and contain 3 Aptian third-order sequences. On the other hand, rudstone and boundstone lithofacies of studied wells have higher reservoir potential and were deposited during Apt 3 and Apt 4 sequences of the Arabian Plate. The Dariyan Formation in Qeshm Island (well 6) and adjacent well (well 5) was deposited in an intrashelf basin that should be classified as a new intrashelf basin in future Aptian paleogeographic maps. We interpret that salt-related differential subsidence, crustal warping, and reactivation of basement faults of the Arabian Plate boundary were responsible for the creation of the intrashelf basin in the Qeshm area.
基金supported by a research grant from the Universiti Kebangsaan Malaysia (Project Code: UKM-GGPM-NBT-080-2010)
文摘An analysis is performed to study the heat transfer characteristics of steady two-dimensional boundary layer flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the flow field and heat transfer characteristics are numerically studied by using an implicit finite difference method. It is found that dual solutions exist when the plate and the free stream move in the opposite directions. The results indicate that suction delays the boundary layer separation, while injection accelerates it.
文摘Cytokinesis, the partitioning of the cytoplasm following nuclear division, requires extensive coordination between membrane trafficking and cytoskeletal dynamics. In plants, the onset of cytokinesis is characterized by the assembly of a bipolar microtubule array, the phragmoplast, and of a transient membrane compartment, the cell plate. Little is known about the coordination between membrane deposition at the cell plate and the dynamics of phragmoplast microtubules. In this study, we monitor the localization dynamics of microtubule and membrane markers throughout cytokinesis. Our spatiotemporal resolution is consistent with the general view that microtubule dynamics drive membrane movements. Nonetheless, we provide evidence for active sorting at the cell plate and show that this is, at least in part, mediated by the TRAPPII tethering complex. We also characterize phragmoplast microtubule organization and cell plate formation in a suite of cytokinesis-defective mutants. Of four mutant lines with defects in phragmoplast microtubule organization, only morl microtubule-associated mutants exhibited aberrant cell plates. Conversely, the mutants with the strongest impairment in phragmoplast microtubule reorganization are keule alleles, which have a primary defect in membrane fusion. Our findings identify the SEC1/Munc18 protein KEULE as a central regulatory node in the coordination of membrane and microtubule dynamics during plant cytokinesis.