Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and ...Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and non-linear. In this paper, the effects of charging ratio, inclination angle, and heat input and their interaction effects on heat transfer performance of a looped copper-water OHP are analyzed. First, suppose that the relationship between the response and the variables approximates a second-order model. And use the central composite design to arrange the ex- periment. Then, the method of least squares is used to estimate the parameters in the second-order model. Finally, multi- variate variance analysis is used to analyze the model. The results show that the assumption is right, that is to say, the re- lationship is well modeled by a second-order function. Among the three main effect variables, the effect of inclination angle is the most significant, but their interaction effects are not significant. In the range of the considered factors, both the optimum charging ratio and the optimum inclination angle increase as the heating water flow rate increases.展开更多
The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempte...The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate (SGR) and three important environmental factors (temperature, salinity, and pH) using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant (P〈0.05), and they were equally important in impacting T. subcordiformis specific growth; the linear effect of pH was not significant (P〉0.05); the interactive effect of temperature and pH was significant (P〈0.05), whereas the temperature ~ salinity and salinity x pH interactions were not significant (P〉0.05); all of the quadratic effects of the three factors were significant (P〈0.05). A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25~C/35 of salinity/pH 7.9 was obtained, at which the maximum specific growth rate (0.65) was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.展开更多
Objective: Through the application of the physiological indicator of heart rate variability by some equipments, to assess the psychological quality objectively, quickly and accurately instead of subjectively in the cu...Objective: Through the application of the physiological indicator of heart rate variability by some equipments, to assess the psychological quality objectively, quickly and accurately instead of subjectively in the current methods of the assessment. Methods: Apply the new psychological assessment system to collect the signal of heart rate variability which will be converted to waveforms in time-domain and frequency-domain to analyze people's psychological state. Results: According to heart rate variability parameters in the time domain and frequency domain, we can analyze the autonomic nervous system functions objectively and accurately, then assess mental state. Conclusion: Heart rate variability plays an important role in the psychological assessment system, which has broad prospects for the future development.展开更多
In his quest for spiritual fulfillment, Thomas Stearns Eliot conducts a meticulous religious study which teaches him distinctive interpretations of human existence and their various functions that they are supposed to...In his quest for spiritual fulfillment, Thomas Stearns Eliot conducts a meticulous religious study which teaches him distinctive interpretations of human existence and their various functions that they are supposed to assume in the world. Eliot's personal attachment to religious knowledge and his reflections of religious studies inevitably manifest themselves in his literary works; be it his dramas or poems, mostly in the forms of philosophical and psychoanalytical analysis of his characters and the detected problems observed in their relationships. The Cocktail Party, a play starting off as a drawing-room comedy soon converts to a serious analysis of human psychology and the nature of human interactions. While engaging with these particular points, the play offers possibilities to discuss several religious allusions, though dealt with subtly. Integrated with religion, characters' attitudes towards a given situation and their final decision position them in their quest either in "hypothetical" enlightenment or in a "supposed" repetition of a vicious circle. The enforcing power behind the play is interestingly a psychiatrist, who adds dynamism and mystery to the plot and has a special task in making the play a drama of conversion. The inner conflicts of the characters which ultimately lead to a series of problems in their relationships are the main concern which causes the characters search for different solutions. Accordingly, they make their own choices to cease their inner struggles. This paper aims to explore the concept of conversion in Eliot's The Cocktail Party with references to the playwright's religious journey in his literary career.展开更多
Efficient charge separation and rapid interfacial reaction kinetics are crucial factors that determine the efficiency of photocatalytic hydrogen evolution.Herein,a fascinating 2D heterojunction photocatalyst with supe...Efficient charge separation and rapid interfacial reaction kinetics are crucial factors that determine the efficiency of photocatalytic hydrogen evolution.Herein,a fascinating 2D heterojunction photocatalyst with superior photocatalytic hydrogen evolution performance–holey C_(3)N_(4)nanosheets nested with TiO_(2)nanocrystals(denoted as HCN/TiO_(2))–is designed and fabricated via an in situ exfoliation and conversion strategy.The HCN/TiO_(2)is found to exhibit an ultrathin 2D heteroarchitecture with intimate interfacial contact,highly porous structures and ultrasmall TiO_(2)nanocrystals,leading to drastically improved charge carrier separation,maximized active sites and the promotion of mass transport for photocatalysis.Consequently,the HCN/TiO_(2)delivers an impressive hydrogen production rate of 282.3 lmol h^(-1)per10 mg under AM 1.5 illumination and an apparent quantum efficiency of 13.4%at a wavelength of 420 nm due to the synergetic enhancement of surface reactions and charge separation.The present work provides a promising strategy for developing high-performance 2D heterojunctions for clean energy applications.展开更多
Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view ...Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view that AS of DE is induced by the Maxwell stress.According to this theory,materials have similar ratios of permittivity and Young’s modulus should have similar AS,while the experimental results are on contrary to this theory,and the experimental AS has no relationship with ideal AS.Here,a new dipole-conformation-actuated strain cross-scale model is proposed,which can be generally applied to explain the AS of DE without pre-strain.According to this model,several characteristics of an ideal DE are listed in this work and a new DE based on polyphosphazene(PPZ)is synthesized.The AS of PPZ can reach 84%without any pre-strain.At last,a PPZ-based all soft artificial heart(ASAH)is built,which works in the similar way with natural myocardium,indicating that this material has great application potential and possibility in the construction of an ASAH for heart failure(HF)patients.展开更多
The aerodynamic performance, structural strength, and wheel weight are three important factors in the design process of the radial turbine for micro gas turbines. This study presents the experimental validation proces...The aerodynamic performance, structural strength, and wheel weight are three important factors in the design process of the radial turbine for micro gas turbines. This study presents the experimental validation process of this integrated optimization design method by using the similarity theory. Cold modeling tests and investigations into the aerodynamic characteristics were performed. Experimental results showed that the aerodynamic efficiency of the micro radial turbine is 84.3% at the design point while also satisfying the aerodynamic and strength requirements. Meanwhile, the total weight of the turbine wheel is 3.8 kg which has only a 52.8% mass of the original design. This indicates that the radial turbine designed through this technique has a high aerodynamic performance, and thus can be applied to micro gas turbines. The results validated that this integrated optimization design method is reliable.展开更多
Very high flow coefficient centrifugal compressor stages are mostly performance of this type of stages is critical to the entire centrifugal applied as the first stages of multistage compressors. The compressors, but ...Very high flow coefficient centrifugal compressor stages are mostly performance of this type of stages is critical to the entire centrifugal applied as the first stages of multistage compressors. The compressors, but surprisingly little related information is available in the open literature. A centrifugal compressor with high inlet flow coefficient of 0.2, presenting a narrow operating range and unstable running situation even at design speed during the test, is investigated here. To reveal flow details in this centrifugal compressor, numerical simulations have been carried out and indicate that excessive impeller flow diffusion results in the poor performance of this centrifugal compressor. With the same inlet flow coefficient, six redesign cases coming from an in-house one-dimensional analysis program are proposed together with impeller trimming and equal flow area design method for corresponding vaneless diffuser. Performance comparison among these redesign centrifugal compressors is presented and the most suitable one is recommended for test in the future. In addition, three redesign cases with lower inlet flow coefficient developed by means of flow trimming are shown in the end to satisfy potential application areas. Finally, the results in this study can provide valuable reference information for multistage centrifugal compressor design.展开更多
基金Supported by the Natural Science Foundation of Ministry of Education of Jiangsu Province (02KJB470001).
文摘Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and non-linear. In this paper, the effects of charging ratio, inclination angle, and heat input and their interaction effects on heat transfer performance of a looped copper-water OHP are analyzed. First, suppose that the relationship between the response and the variables approximates a second-order model. And use the central composite design to arrange the ex- periment. Then, the method of least squares is used to estimate the parameters in the second-order model. Finally, multi- variate variance analysis is used to analyze the model. The results show that the assumption is right, that is to say, the re- lationship is well modeled by a second-order function. Among the three main effect variables, the effect of inclination angle is the most significant, but their interaction effects are not significant. In the range of the considered factors, both the optimum charging ratio and the optimum inclination angle increase as the heating water flow rate increases.
基金Supported by the Guangdong Province Science and Technology Project(No.2010B020201014)the Guangdong Province South China Sea Invertebrates Healthy Culture Engineering Technology Research Center(No.GCZX-A0909)+2 种基金the Guangdong Province Ocean and Fisheries Science and Technology Extension Project(No.20120980)the Guangdong Province Industry-University-Science Partnership Project(No.20110908)the Sci&Tech Plan of Huaiyin Normal University(No.WH0031)
文摘The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate (SGR) and three important environmental factors (temperature, salinity, and pH) using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant (P〈0.05), and they were equally important in impacting T. subcordiformis specific growth; the linear effect of pH was not significant (P〉0.05); the interactive effect of temperature and pH was significant (P〈0.05), whereas the temperature ~ salinity and salinity x pH interactions were not significant (P〉0.05); all of the quadratic effects of the three factors were significant (P〈0.05). A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25~C/35 of salinity/pH 7.9 was obtained, at which the maximum specific growth rate (0.65) was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.
文摘Objective: Through the application of the physiological indicator of heart rate variability by some equipments, to assess the psychological quality objectively, quickly and accurately instead of subjectively in the current methods of the assessment. Methods: Apply the new psychological assessment system to collect the signal of heart rate variability which will be converted to waveforms in time-domain and frequency-domain to analyze people's psychological state. Results: According to heart rate variability parameters in the time domain and frequency domain, we can analyze the autonomic nervous system functions objectively and accurately, then assess mental state. Conclusion: Heart rate variability plays an important role in the psychological assessment system, which has broad prospects for the future development.
文摘In his quest for spiritual fulfillment, Thomas Stearns Eliot conducts a meticulous religious study which teaches him distinctive interpretations of human existence and their various functions that they are supposed to assume in the world. Eliot's personal attachment to religious knowledge and his reflections of religious studies inevitably manifest themselves in his literary works; be it his dramas or poems, mostly in the forms of philosophical and psychoanalytical analysis of his characters and the detected problems observed in their relationships. The Cocktail Party, a play starting off as a drawing-room comedy soon converts to a serious analysis of human psychology and the nature of human interactions. While engaging with these particular points, the play offers possibilities to discuss several religious allusions, though dealt with subtly. Integrated with religion, characters' attitudes towards a given situation and their final decision position them in their quest either in "hypothetical" enlightenment or in a "supposed" repetition of a vicious circle. The enforcing power behind the play is interestingly a psychiatrist, who adds dynamism and mystery to the plot and has a special task in making the play a drama of conversion. The inner conflicts of the characters which ultimately lead to a series of problems in their relationships are the main concern which causes the characters search for different solutions. Accordingly, they make their own choices to cease their inner struggles. This paper aims to explore the concept of conversion in Eliot's The Cocktail Party with references to the playwright's religious journey in his literary career.
基金the National Key R&D Program of China(2018YFE0201704 and 2018YFE0201701)the National Natural Science Foundation of China(21673256,21533011,2163100,and 21603036)Shanghai Rising-Star Program.
文摘Efficient charge separation and rapid interfacial reaction kinetics are crucial factors that determine the efficiency of photocatalytic hydrogen evolution.Herein,a fascinating 2D heterojunction photocatalyst with superior photocatalytic hydrogen evolution performance–holey C_(3)N_(4)nanosheets nested with TiO_(2)nanocrystals(denoted as HCN/TiO_(2))–is designed and fabricated via an in situ exfoliation and conversion strategy.The HCN/TiO_(2)is found to exhibit an ultrathin 2D heteroarchitecture with intimate interfacial contact,highly porous structures and ultrasmall TiO_(2)nanocrystals,leading to drastically improved charge carrier separation,maximized active sites and the promotion of mass transport for photocatalysis.Consequently,the HCN/TiO_(2)delivers an impressive hydrogen production rate of 282.3 lmol h^(-1)per10 mg under AM 1.5 illumination and an apparent quantum efficiency of 13.4%at a wavelength of 420 nm due to the synergetic enhancement of surface reactions and charge separation.The present work provides a promising strategy for developing high-performance 2D heterojunctions for clean energy applications.
基金supported by the Basic Science Center Program of the National Natural Science Foundation of China (51988102)the National Key Research and Development Program of China (2017YFB0306903)+2 种基金the Major Program of National Natural Science Foundation of China (51790501)the Innovative Research Groups (51221002 and 51521062)the National Natural Science Foundation of China (52003024)
文摘Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view that AS of DE is induced by the Maxwell stress.According to this theory,materials have similar ratios of permittivity and Young’s modulus should have similar AS,while the experimental results are on contrary to this theory,and the experimental AS has no relationship with ideal AS.Here,a new dipole-conformation-actuated strain cross-scale model is proposed,which can be generally applied to explain the AS of DE without pre-strain.According to this model,several characteristics of an ideal DE are listed in this work and a new DE based on polyphosphazene(PPZ)is synthesized.The AS of PPZ can reach 84%without any pre-strain.At last,a PPZ-based all soft artificial heart(ASAH)is built,which works in the similar way with natural myocardium,indicating that this material has great application potential and possibility in the construction of an ASAH for heart failure(HF)patients.
基金the National Natural Science Foundation of China,the China Postdoctoral Science Founda-tion
文摘The aerodynamic performance, structural strength, and wheel weight are three important factors in the design process of the radial turbine for micro gas turbines. This study presents the experimental validation process of this integrated optimization design method by using the similarity theory. Cold modeling tests and investigations into the aerodynamic characteristics were performed. Experimental results showed that the aerodynamic efficiency of the micro radial turbine is 84.3% at the design point while also satisfying the aerodynamic and strength requirements. Meanwhile, the total weight of the turbine wheel is 3.8 kg which has only a 52.8% mass of the original design. This indicates that the radial turbine designed through this technique has a high aerodynamic performance, and thus can be applied to micro gas turbines. The results validated that this integrated optimization design method is reliable.
基金supported by the National Natural Science Foundation of China(Grant Nos.51206164 and 51010007)
文摘Very high flow coefficient centrifugal compressor stages are mostly performance of this type of stages is critical to the entire centrifugal applied as the first stages of multistage compressors. The compressors, but surprisingly little related information is available in the open literature. A centrifugal compressor with high inlet flow coefficient of 0.2, presenting a narrow operating range and unstable running situation even at design speed during the test, is investigated here. To reveal flow details in this centrifugal compressor, numerical simulations have been carried out and indicate that excessive impeller flow diffusion results in the poor performance of this centrifugal compressor. With the same inlet flow coefficient, six redesign cases coming from an in-house one-dimensional analysis program are proposed together with impeller trimming and equal flow area design method for corresponding vaneless diffuser. Performance comparison among these redesign centrifugal compressors is presented and the most suitable one is recommended for test in the future. In addition, three redesign cases with lower inlet flow coefficient developed by means of flow trimming are shown in the end to satisfy potential application areas. Finally, the results in this study can provide valuable reference information for multistage centrifugal compressor design.