With the opening of the Kela No. 2 gas field in the Tarim basin in China’s northwest Xinjiang Uygur Autonomous Region on Dec. 1, Xinjiang will produce 10 billion cubic meters of natural gas next year, becoming the co...With the opening of the Kela No. 2 gas field in the Tarim basin in China’s northwest Xinjiang Uygur Autonomous Region on Dec. 1, Xinjiang will produce 10 billion cubic meters of natural gas next year, becoming the country’s largest gas producer, according to an official with the China National Petroleum Corporation.展开更多
Music from a piano embodies widetechniques of expression, so thepiano is reputed as the king of musicalinstruments. China’s piano production datesback four decades. At present, there are 20piano production enterprise...Music from a piano embodies widetechniques of expression, so thepiano is reputed as the king of musicalinstruments. China’s piano production datesback four decades. At present, there are 20piano production enterprises in the county,including such backbone enterprises as theGuangzhou Pearl River Piano IndustrialCorporation, the Beijing Xinghai MusicalInstruments Corporation Ltd., the ShanghaiPiano Corporation, the Yingkou NortheastPiano(Group) Corporation and the展开更多
As sales and demand increased in the electric car industry,Lynas,a rare earth producer in Australia,announced a surge in revenue in the second half of 2017.It was reported that the company’s six month sales up to Dec...As sales and demand increased in the electric car industry,Lynas,a rare earth producer in Australia,announced a surge in revenue in the second half of 2017.It was reported that the company’s six month sales up to December 31,2017 was209 million Australian dollars($155.7 million),compared with a$114.6 million in展开更多
High-pressure vapor-liquid equilibrium data for the binary systems of methyl propionate+carbon dioxide and propyl propionate+carbon dioxide were measured at pressure from 1.00 MPa to 12.00 MPa and temperature in the...High-pressure vapor-liquid equilibrium data for the binary systems of methyl propionate+carbon dioxide and propyl propionate+carbon dioxide were measured at pressure from 1.00 MPa to 12.00 MPa and temperature in the range from 313 K to 373 K. Experimental results were correlated with the Peng-Robinson equation of state with the two-parameter van der Waals mixing rule. At the same time, the Henry's coefficient, partial molar enthalpy change and partial molar entropy change of CO2 during dissolution at different temperature were also calculated.展开更多
A PCR-DGGE (denaturing gradient gel electrophoresis of polymerase chain reaction) protocol was used for monitoring the dynamic changes in the microbial population during photohydrogen production. Total DNA was extract...A PCR-DGGE (denaturing gradient gel electrophoresis of polymerase chain reaction) protocol was used for monitoring the dynamic changes in the microbial population during photohydrogen production. Total DNA was extracted directly from the mixed bacterial community in the reactor and subjected to PCR with V3-16S rDNA and pufM gene primers, and the amplifications were then analyzed by DGGE. The DGGE patterns demonstrated the dynamics of community structure and the shift of microbial diversity, which correspond...展开更多
The electromotive force (e.m.f.) of solid oxide fuel cells using biomass produced gas (BPG) as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis...The electromotive force (e.m.f.) of solid oxide fuel cells using biomass produced gas (BPG) as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.展开更多
The microbial community structure and functionally distinct groups in three kinds of produced water samples from the shallow,mesothermic and low-salinity Daqing oil reservoir were systematically evaluated using both c...The microbial community structure and functionally distinct groups in three kinds of produced water samples from the shallow,mesothermic and low-salinity Daqing oil reservoir were systematically evaluated using both culture-dependent and culture-independent methods.Sequence analysis of the 16S rRNA genes indicated that the bacterial library was dominated by Acinetobacter and Arcobacter and the archaeal community was dominated by Methanosaeta and Methanolinea.Two isolated methanogens were closely related with Methanothermobacter thermautotrophicus and Methanoculleus receptaculi.The fermentative bacteria were identified as Pseudomonas,Haloanaerobium,Alcalibacter,Arcobacter,and Pannonibacter.The predominant nitrate-reducing bacteria fell within the genus Pseudomonas.The dominant members of the cultured hydrocarbon-oxidizing bacteria were phylogenetically associated with Micrococcus,Pseudomonas,and Bacillus.Enrichments of biosurfactants and biopolymer producing groups mainly yielded Pseudomonas,Bacillus,and Acenitobacter-related members.The functional groups related to polymer degradation were also affiliated with Pseudomonas and Bacillus.Results from this study provide the fresh insight into the diversity of microbial communities in Daqing petroleum reservoirs.The vast pool of functional strains retrieved in this study was presumed to include the promising strains that could be applied in microbial-enhanced oil recovery in future.展开更多
In this paper, we introduce a concept of quasi C-lower semicontinuity for setvalued mapping and provide a vector version of Ekeland's theorem related to set-valued vector equilibrium problems. As applications, we der...In this paper, we introduce a concept of quasi C-lower semicontinuity for setvalued mapping and provide a vector version of Ekeland's theorem related to set-valued vector equilibrium problems. As applications, we derive an existence theorem of weakly efficient solution for set-valued vector equilibrium problems without the assumption of convexity of the constraint set and the assumptions of convexity and monotonicity of the set-valued mapping. We also obtain an existence theorem of ε-approximate solution for set-valued vector equilibrium problems without the assumptions of compactness and convexity of the constraint set.展开更多
This study introduces three typical models on equilibrium beach profile, and discusses the application limitations of these models. Then this study examines the selections for applying these models on different coasta...This study introduces three typical models on equilibrium beach profile, and discusses the application limitations of these models. Then this study examines the selections for applying these models on different coastal segments of a headland-bay beach in west Guangdong, South China, and explores the physical significances of those parameters in the models. The results indicate that:(1) Bodge's model is more in line with the equilibrium beach profile of the tangential or transitional segment, whereas Lee's model is more consistent with the shadow profile;(2) most of the parameters in three models have clear physical significances in accordance with the actual characteristics of this headland-bay beach; and(3) both the selections for the equilibrium beach profile from different segments and significances of most of the parameters in three models are in essence correlated with the morphodynamic states at various coastal locations.展开更多
The protein composition of the egg development in the high royal jelly producing bees (Apis mellifera L.) was investigated. This pioneer study was to separate and quantify the proteins in the egg of the high royal j...The protein composition of the egg development in the high royal jelly producing bees (Apis mellifera L.) was investigated. This pioneer study was to separate and quantify the proteins in the egg of the high royal jelly producing worker bees (Apis mellifera L.) by using two-dimensional gel electrophoresis along with their three-day development. The results showed that 160, 195, and 176 proteins, with a wide range of molecular weight (17-80 KDa) and relatively narrow scope of pI (4. 00-8.40) could be detected on day 1, day 2, and day 3, respectively, during the developmental process of the egg. Meanwhile 44 protein spots were constantly detected along with the egg development. Among them 36% were in the uptrend along with the egg development, 14% were in the downtrend, and 39% were of the largest expressed volume on day 2. In addition, the specific proteins were expressed on day 1, day 2, and day 3 (89, 77, and 80, respectively). Besides the coexistent and specific proteins, 24 proteins were expressed on day 1 and day 2, but silenced on day 3, 49 proteins were expressed on day 2 and day 3, but silenced on day 1, only 3 proteins were expressed on day 1 and day 3, but silenced on day 2. The result indicates that egg development is a sequential and complex gene controlled process, where the eggs of day 2 express the most active proteins. The coexistent proteins suggest that it is conservative and indispensable for this event. These specific proteins suggest that the different developmental stage needs specific proteins to regulate it.展开更多
In this paper,we investigate the equilibrium stability of a Filippov-type system having multiple stick regions based upon a smooth and discontinuous(SD) oscillator with dry friction.The sets of equilibrium states of...In this paper,we investigate the equilibrium stability of a Filippov-type system having multiple stick regions based upon a smooth and discontinuous(SD) oscillator with dry friction.The sets of equilibrium states of the system are analyzed together with Coulomb friction conditions in both( f_n,f_s) and(x,˙x) planes.In the stability analysis,Lyapunov functions are constructed to derive the instability for the equilibrium set of the hyperbolic type and La Salle's invariance principle is employed to obtain the stability of the nonhyperbolic type.Analysis demonstrates the existence of a thick stable manifold and the interior stability of the hyperbolic equilibrium set due to the attractive sliding mode of the Filippov property,and also shows that the unstable manifolds of the hyperbolic-type are that of the endpoints with their saddle property.Numerical calculations show a good agreement with the theoretical analysis and an excellent efficien y of the approach for equilibrium states in this particular Filippov system.Furthermore,the equilibrium bifurcations are presented to demonstrate the transition between the smooth and the discontinuous regimes.展开更多
The equilibrium of Mg-S in Ni melt was studied by the method of vapour equilibrium in a sealed chamber.At 1530℃ the equilibrium constant of the reaction MgS_(s)=Mg_(Ni)+S_(Ni)and the activity interaction coefficient ...The equilibrium of Mg-S in Ni melt was studied by the method of vapour equilibrium in a sealed chamber.At 1530℃ the equilibrium constant of the reaction MgS_(s)=Mg_(Ni)+S_(Ni)and the activity interaction coefficient were determined as K_(MgS)=6.76×10^(-5)and e_S^(Mg)=-9.1.展开更多
In this paper, equilibrium stability of generalized Birkhoff's autonomous system is discussed. First, equilibrium equations of generalized Birkhoff's autonomous system are set up, and the n the linear approx...In this paper, equilibrium stability of generalized Birkhoff's autonomous system is discussed. First, equilibrium equations of generalized Birkhoff's autonomous system are set up, and the n the linear approximate method and direct method of stability in equilibrium st ate are studied. Some results on equilibrium of generalized Birkhoff's autonomou s system are obtained on the basis of Lyapunov's thorem. Last, the applica tion of the results is illustrated with an example.展开更多
In this article, we introduce a hybrid iterative scheme for finding a common element of the set of solutions for a generalized equilibrium problems, the set of common fixed point for a family of infinite k-strict pseu...In this article, we introduce a hybrid iterative scheme for finding a common element of the set of solutions for a generalized equilibrium problems, the set of common fixed point for a family of infinite k-strict pseudo-contractive mappings, and the set of solutions of the variational inclusion problem with multi-valued maximal monotone mappings and inverse-strongly monotone mappings in Hilbert space. Under suitable conditions, some strong convergence theorems are proved. Our results extends the recent results in G.L.Acedo and H.K.Xu [2], Zhang, Lee and Chan [8], Wakahashi and Toyoda [9], Takahashi and Takahashi [I0] and S. S. Chang, H. W. Joseph Lee and C. K. Chan [II], S.Takahashi and W.Takahashi [12]. Moreover, the method of proof adopted in this article is different from those of [4] and [12].展开更多
Frank’s theory describes that a screw dislocation will produce a pit on the surface,and has been evidenced in many material systems including GaN.However,the size of the pit calculated from the theory deviates signif...Frank’s theory describes that a screw dislocation will produce a pit on the surface,and has been evidenced in many material systems including GaN.However,the size of the pit calculated from the theory deviates significantly from experimental result.Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN,we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same.If the kinetic process is too vigorous or too slow to reach a balance,the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state.When the curvature at the center of the dislocation core reaches the critical value 1/r0,at the edge of the spiral,the accelerating rate of the curvature may not fall to zero,so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit.展开更多
Chua's circuit is a well-known nonlinear electronic model, having complicated nonsmooth dynamic behaviors. The stability and boundary equilibrium bifurcations for a modified Chua's circuit system with the smooth deg...Chua's circuit is a well-known nonlinear electronic model, having complicated nonsmooth dynamic behaviors. The stability and boundary equilibrium bifurcations for a modified Chua's circuit system with the smooth degree of 3 are studied. The parametric areas of stability are specified in detail. It is found that the bifurcation graphs of the su- percritical and irregular pitchfork bifurcations are similar to those of the piecewise-smooth continuous (PWSC) systems caused by piecewise smoothness. However, the bifurcation graph of the supercritical Hopf bifurcation is similar to those of smooth systems. There- fore, the boundary equilibrium bifurcations of the non-smooth systems with the smooth degree of 3 should receive more attention due to their special features.展开更多
China, as many other parts of the world, has a serious shortage of water resources. In China, there is a total amount of 2.8×10^12 m3 of freshwater, but that is only 2000 m3 per capita, which is about one quarter...China, as many other parts of the world, has a serious shortage of water resources. In China, there is a total amount of 2.8×10^12 m3 of freshwater, but that is only 2000 m3 per capita, which is about one quarter of the world average. Thereforc, seawater desalination engineering is of great significance to the nation.展开更多
On October 17, 2017, the first stay ring of Baihetan 1 million kW hydropower units, with the largest unit capacity in the world, passed the acceptance inspection. Shenyang Research Institute of Foundry (SRIF) has be...On October 17, 2017, the first stay ring of Baihetan 1 million kW hydropower units, with the largest unit capacity in the world, passed the acceptance inspection. Shenyang Research Institute of Foundry (SRIF) has been recognized by owners and OEMs of Baihetan Hydropower Station for its long-term and stable (electroslag remelting)" and technology of "AOD + ESR good performance of guide vanes at several major hydropower projects both at home and abroad.展开更多
文摘With the opening of the Kela No. 2 gas field in the Tarim basin in China’s northwest Xinjiang Uygur Autonomous Region on Dec. 1, Xinjiang will produce 10 billion cubic meters of natural gas next year, becoming the country’s largest gas producer, according to an official with the China National Petroleum Corporation.
文摘Music from a piano embodies widetechniques of expression, so thepiano is reputed as the king of musicalinstruments. China’s piano production datesback four decades. At present, there are 20piano production enterprises in the county,including such backbone enterprises as theGuangzhou Pearl River Piano IndustrialCorporation, the Beijing Xinghai MusicalInstruments Corporation Ltd., the ShanghaiPiano Corporation, the Yingkou NortheastPiano(Group) Corporation and the
文摘As sales and demand increased in the electric car industry,Lynas,a rare earth producer in Australia,announced a surge in revenue in the second half of 2017.It was reported that the company’s six month sales up to December 31,2017 was209 million Australian dollars($155.7 million),compared with a$114.6 million in
文摘High-pressure vapor-liquid equilibrium data for the binary systems of methyl propionate+carbon dioxide and propyl propionate+carbon dioxide were measured at pressure from 1.00 MPa to 12.00 MPa and temperature in the range from 313 K to 373 K. Experimental results were correlated with the Peng-Robinson equation of state with the two-parameter van der Waals mixing rule. At the same time, the Henry's coefficient, partial molar enthalpy change and partial molar entropy change of CO2 during dissolution at different temperature were also calculated.
基金the National NaturalScience Foundation (No. 30570053)the Fund of CrossSubjects of Zhejiang University (No. 109000-812651)+2 种基金the National Natural Science Foundation of China (No.50406022)the National High Technology Research and Development Program of China (No. 2007AA10Z409)the National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science &Technology of China (No. 2006BAJ08B01)
文摘A PCR-DGGE (denaturing gradient gel electrophoresis of polymerase chain reaction) protocol was used for monitoring the dynamic changes in the microbial population during photohydrogen production. Total DNA was extracted directly from the mixed bacterial community in the reactor and subjected to PCR with V3-16S rDNA and pufM gene primers, and the amplifications were then analyzed by DGGE. The DGGE patterns demonstrated the dynamics of community structure and the shift of microbial diversity, which correspond...
基金V. ACKN0WLEDGMENT This work was supported by the National Natural Science Foundation of China (No.50372066 and No.50332040).
文摘The electromotive force (e.m.f.) of solid oxide fuel cells using biomass produced gas (BPG) as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.
基金supported by Chinese Academy of Science through the Knowledge Innovation Project of The Chinese Academy of Sciences (06LYQY3001)Funding for this project was also provided by Daqing Oilfield Co. Ltd., China
文摘The microbial community structure and functionally distinct groups in three kinds of produced water samples from the shallow,mesothermic and low-salinity Daqing oil reservoir were systematically evaluated using both culture-dependent and culture-independent methods.Sequence analysis of the 16S rRNA genes indicated that the bacterial library was dominated by Acinetobacter and Arcobacter and the archaeal community was dominated by Methanosaeta and Methanolinea.Two isolated methanogens were closely related with Methanothermobacter thermautotrophicus and Methanoculleus receptaculi.The fermentative bacteria were identified as Pseudomonas,Haloanaerobium,Alcalibacter,Arcobacter,and Pannonibacter.The predominant nitrate-reducing bacteria fell within the genus Pseudomonas.The dominant members of the cultured hydrocarbon-oxidizing bacteria were phylogenetically associated with Micrococcus,Pseudomonas,and Bacillus.Enrichments of biosurfactants and biopolymer producing groups mainly yielded Pseudomonas,Bacillus,and Acenitobacter-related members.The functional groups related to polymer degradation were also affiliated with Pseudomonas and Bacillus.Results from this study provide the fresh insight into the diversity of microbial communities in Daqing petroleum reservoirs.The vast pool of functional strains retrieved in this study was presumed to include the promising strains that could be applied in microbial-enhanced oil recovery in future.
基金supported by the National Natural Science Foundation of China (11061023)
文摘In this paper, we introduce a concept of quasi C-lower semicontinuity for setvalued mapping and provide a vector version of Ekeland's theorem related to set-valued vector equilibrium problems. As applications, we derive an existence theorem of weakly efficient solution for set-valued vector equilibrium problems without the assumption of convexity of the constraint set and the assumptions of convexity and monotonicity of the set-valued mapping. We also obtain an existence theorem of ε-approximate solution for set-valued vector equilibrium problems without the assumptions of compactness and convexity of the constraint set.
基金financially supported by the National Natural Science Foundation of China(Grant No.41301005)Postdoctoral Science Foundation of China(Grant No.2014M552118)
文摘This study introduces three typical models on equilibrium beach profile, and discusses the application limitations of these models. Then this study examines the selections for applying these models on different coastal segments of a headland-bay beach in west Guangdong, South China, and explores the physical significances of those parameters in the models. The results indicate that:(1) Bodge's model is more in line with the equilibrium beach profile of the tangential or transitional segment, whereas Lee's model is more consistent with the shadow profile;(2) most of the parameters in three models have clear physical significances in accordance with the actual characteristics of this headland-bay beach; and(3) both the selections for the equilibrium beach profile from different segments and significances of most of the parameters in three models are in essence correlated with the morphodynamic states at various coastal locations.
文摘The protein composition of the egg development in the high royal jelly producing bees (Apis mellifera L.) was investigated. This pioneer study was to separate and quantify the proteins in the egg of the high royal jelly producing worker bees (Apis mellifera L.) by using two-dimensional gel electrophoresis along with their three-day development. The results showed that 160, 195, and 176 proteins, with a wide range of molecular weight (17-80 KDa) and relatively narrow scope of pI (4. 00-8.40) could be detected on day 1, day 2, and day 3, respectively, during the developmental process of the egg. Meanwhile 44 protein spots were constantly detected along with the egg development. Among them 36% were in the uptrend along with the egg development, 14% were in the downtrend, and 39% were of the largest expressed volume on day 2. In addition, the specific proteins were expressed on day 1, day 2, and day 3 (89, 77, and 80, respectively). Besides the coexistent and specific proteins, 24 proteins were expressed on day 1 and day 2, but silenced on day 3, 49 proteins were expressed on day 2 and day 3, but silenced on day 1, only 3 proteins were expressed on day 1 and day 3, but silenced on day 2. The result indicates that egg development is a sequential and complex gene controlled process, where the eggs of day 2 express the most active proteins. The coexistent proteins suggest that it is conservative and indispensable for this event. These specific proteins suggest that the different developmental stage needs specific proteins to regulate it.
基金supported by the National Natural Science Foundation of China(Grant 11372082)the National Basic Research Program of China(Grant 2015CB057405)
文摘In this paper,we investigate the equilibrium stability of a Filippov-type system having multiple stick regions based upon a smooth and discontinuous(SD) oscillator with dry friction.The sets of equilibrium states of the system are analyzed together with Coulomb friction conditions in both( f_n,f_s) and(x,˙x) planes.In the stability analysis,Lyapunov functions are constructed to derive the instability for the equilibrium set of the hyperbolic type and La Salle's invariance principle is employed to obtain the stability of the nonhyperbolic type.Analysis demonstrates the existence of a thick stable manifold and the interior stability of the hyperbolic equilibrium set due to the attractive sliding mode of the Filippov property,and also shows that the unstable manifolds of the hyperbolic-type are that of the endpoints with their saddle property.Numerical calculations show a good agreement with the theoretical analysis and an excellent efficien y of the approach for equilibrium states in this particular Filippov system.Furthermore,the equilibrium bifurcations are presented to demonstrate the transition between the smooth and the discontinuous regimes.
文摘The equilibrium of Mg-S in Ni melt was studied by the method of vapour equilibrium in a sealed chamber.At 1530℃ the equilibrium constant of the reaction MgS_(s)=Mg_(Ni)+S_(Ni)and the activity interaction coefficient were determined as K_(MgS)=6.76×10^(-5)and e_S^(Mg)=-9.1.
文摘In this paper, equilibrium stability of generalized Birkhoff's autonomous system is discussed. First, equilibrium equations of generalized Birkhoff's autonomous system are set up, and the n the linear approximate method and direct method of stability in equilibrium st ate are studied. Some results on equilibrium of generalized Birkhoff's autonomou s system are obtained on the basis of Lyapunov's thorem. Last, the applica tion of the results is illustrated with an example.
基金supported by Scientific Research Fund of Sichuan Provincial Education Department (09ZB102)Scientific Research Fund of Science and Technology Deportment of Sichuan Provincial (2011JYZ011)
文摘In this article, we introduce a hybrid iterative scheme for finding a common element of the set of solutions for a generalized equilibrium problems, the set of common fixed point for a family of infinite k-strict pseudo-contractive mappings, and the set of solutions of the variational inclusion problem with multi-valued maximal monotone mappings and inverse-strongly monotone mappings in Hilbert space. Under suitable conditions, some strong convergence theorems are proved. Our results extends the recent results in G.L.Acedo and H.K.Xu [2], Zhang, Lee and Chan [8], Wakahashi and Toyoda [9], Takahashi and Takahashi [I0] and S. S. Chang, H. W. Joseph Lee and C. K. Chan [II], S.Takahashi and W.Takahashi [12]. Moreover, the method of proof adopted in this article is different from those of [4] and [12].
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11204009 and 61204011)the Beijing Municipal Natural Science Foundation,China(Grant No.4142005)
文摘Frank’s theory describes that a screw dislocation will produce a pit on the surface,and has been evidenced in many material systems including GaN.However,the size of the pit calculated from the theory deviates significantly from experimental result.Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN,we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same.If the kinetic process is too vigorous or too slow to reach a balance,the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state.When the curvature at the center of the dislocation core reaches the critical value 1/r0,at the edge of the spiral,the accelerating rate of the curvature may not fall to zero,so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit.
基金supported by the National Natural Science Foundation of China(Nos.U1204106,11372282,11272024,and 11371046)the National Basic Research Program of China(973 Program)(Nos.2012CB821200 and 2012CB821202)
文摘Chua's circuit is a well-known nonlinear electronic model, having complicated nonsmooth dynamic behaviors. The stability and boundary equilibrium bifurcations for a modified Chua's circuit system with the smooth degree of 3 are studied. The parametric areas of stability are specified in detail. It is found that the bifurcation graphs of the su- percritical and irregular pitchfork bifurcations are similar to those of the piecewise-smooth continuous (PWSC) systems caused by piecewise smoothness. However, the bifurcation graph of the supercritical Hopf bifurcation is similar to those of smooth systems. There- fore, the boundary equilibrium bifurcations of the non-smooth systems with the smooth degree of 3 should receive more attention due to their special features.
文摘China, as many other parts of the world, has a serious shortage of water resources. In China, there is a total amount of 2.8×10^12 m3 of freshwater, but that is only 2000 m3 per capita, which is about one quarter of the world average. Thereforc, seawater desalination engineering is of great significance to the nation.
文摘On October 17, 2017, the first stay ring of Baihetan 1 million kW hydropower units, with the largest unit capacity in the world, passed the acceptance inspection. Shenyang Research Institute of Foundry (SRIF) has been recognized by owners and OEMs of Baihetan Hydropower Station for its long-term and stable (electroslag remelting)" and technology of "AOD + ESR good performance of guide vanes at several major hydropower projects both at home and abroad.