This article described the characteristics of the liquid nitrogen engine's ideal open cycle.Using two interconnecting strokes to achieve the power output can mitigate the trade-off between high efficiency and the ...This article described the characteristics of the liquid nitrogen engine's ideal open cycle.Using two interconnecting strokes to achieve the power output can mitigate the trade-off between high efficiency and the potential mechanical complexity of multiple-cylinder engines. The total specific energy of the binary media (methane-nitrogen) cycle system could be much higher than the unitary medium (liquid nitrogen) cycle system. By theoretical analysis, the reasonably acceptable driving range proved the feasibility of the liquid nitrogen engine used for supplying power for a lightweight car.展开更多
AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver cirrhosis.METHODSWe reviewed the data of na&#...AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver cirrhosis.METHODSWe reviewed the data of naïve patients with HBV-related liver cirrhosis, who had taken oral NUCs therapy, between 2003 and 2007 at Chonbuk University Hospital. We analyzed two consecutive sets of abdominal computerized tomography scans-one at the time of treatment initiation and another at the second-year follow-up. Liver volume was calculated by 3-dimensional liver extraction volumetry program.RESULTSA total of 55 patients (34 males) were included. There was 114.3 mL ± 167.8 mL (12.9% ± 17.9%) of increase in liver volume during the two years of NUCs therapy (993.8 mL ± 242.8 mL at baseline vs 1108.1 mL ± 263.3 mL at two-year follow-up, P < 0.001). The ratio of the measured baseline liver volume to the estimated standard liver volume was improved from 70.8% to 78.0%. An increase in liver volume was shown not only in patients with compensated cirrhosis (P = 0.046) but also in those with decompensated cirrhosis (P < 0.001). Significant factors for volume increases were Child-Turcotte-Pugh grade and model for end-stage liver disease score improvement without virological breakthrough. In multiple linear regression analysis, delta albumin and delta alanine aminotransferase levels showed a significant association with the increase in liver volume (P = 0.002 and 0.005, respectively).CONCLUSIONLong-term oral NUCs therapy in patients with HBV-related liver cirrhosis lead to significant increase in liver volume assessed with 3-dimensional liver extraction volumetry program.展开更多
The idea of Cyborg initiates the blurring of frontiers between traditional gender roles in the post-modem era, transforming itself into a politicized entity. William Gibson＇s Neuromancer as an early introducer of the...The idea of Cyborg initiates the blurring of frontiers between traditional gender roles in the post-modem era, transforming itself into a politicized entity. William Gibson＇s Neuromancer as an early introducer of the Cyborg characters tries to dissolve the boundaries through his female characters by balancing the power quota with the help of the non-gendered entity of the Cyborg. According to Donna Haraway, there will be a dawn of new cyborg era causing a gender role reversal. The objective of this paper is to find whether such role reversal is at all possible.展开更多
A multicellular DCX （dc-dc transformer） using unregulated cell converters has been proposed for the environmentally friendly data centers. The high speed cell converter with the switching frequency over MHz behaves ...A multicellular DCX （dc-dc transformer） using unregulated cell converters has been proposed for the environmentally friendly data centers. The high speed cell converter with the switching frequency over MHz behaves as an ideal transformer, and this behavior solves the voltage imbalance issue in the multicellular converter topology. The analysis of the unregulated cell converter is conducted by using the state space averaging method, and the operation condition for the ideal transformer is specified. The behavior of the multicellular DCX using the high speed cell converters has been also analyzed, and the voltage imbalance issue among cell converters is discussed quantitatively. A prototype of a 19.2 kW 384 V-384 V multicellular DCX using sixty-four unregulated cell converters is fabricated and the validity of the analyses is verified.展开更多
In this work, the stability of an endoreversible Curzon-Ahlbom engine is analyzed, using Van der Waals gas as a working substance and the corresponding efficiency for this engine working at temperatures withinthe maxi...In this work, the stability of an endoreversible Curzon-Ahlbom engine is analyzed, using Van der Waals gas as a working substance and the corresponding efficiency for this engine working at temperatures withinthe maximum ecological regime. By mean s of a local stability analysis we find that a critical point of an almost linear system is stable andanalytically expressed in eigenvalues. After an arbitrarily small perturbation, the system state exponentially decays to a critical point, with either of two characteristic relaxation times, which are a function of the thermal conductance （a）, heat capacity （C） and T=T2/T1. The behavior of relaxation times and solution of the systems are qualitatively shown by sketching its phase portrait, which results susceptible to operating regimes, i.e., the eigenvectors in the maximum ecological regime have a clockwise rotation with respect to the eigenvectors in the regime of maximumpower. Finally, it has to observe that afterto λvw = 1, approximation,ηVWE=4^-3ηC is obtained, where ηVWE is the Van der Waals efficiency atrnaximum ecological regime and r/c is Carnot＇s efficiency. Finally, it discussed the local stability and steady state of the energetic properties of the endoreversible engine.展开更多
This study investigates Chinese elementary, middle, and high school students＇ L2 perceptual learning styles, imagination, ideal L2 self, and motivated L2 behavior. A perceptual learning style and L2 learning motivati...This study investigates Chinese elementary, middle, and high school students＇ L2 perceptual learning styles, imagination, ideal L2 self, and motivated L2 behavior. A perceptual learning style and L2 learning motivation questionnaire was administered to 1,667 students from elementary to high school. Statistical results revealed that Chinese elementary, middle, and high school students were more in favor of a visual learning style in comparison to their auditory and kinesthetic learning styles. This visually oriented style was significantly correlated with their ideal L2 self and motivated L2 behavior. The sequential regression analysis results indicated that the ideal L2 self and visual learning style were the most meaningful predictors for Chinese students＇ motivated L2 behavior. This study suggests that teachers need to help students create and maintain their ideal L2 self and facilitate their L2 learning motivation by providing more adequate visual teaching materials.展开更多
Electrical resistance strain gauges(SGs) are useful tools for experimental stress analysis and the strain sensing elements in many electromechanical transducers including load cells,pressure transducers,torque meters,...Electrical resistance strain gauges(SGs) are useful tools for experimental stress analysis and the strain sensing elements in many electromechanical transducers including load cells,pressure transducers,torque meters,accelerometers,force cells,displacement transducers and so forth.The commonly used commercial crystalline strain sensing materials of SGs are in the form of wire or foil of which performance and reliability is not good enough due to their low electrical resistivity and incapacity to get thin thickness.Smaller SGs with single straight strand strain sensing materials,which are called ideal SG,are highly desirable for more than seven decades since the first SG was invented.Here,we show the development of a type of minuscule length scale strain gauge by using a bare and single straight strand metallic glassy fiber(MGF) with high resistivity,much smaller lengthscale,high elastic limits(2.16%) and especially the super piezoresistance effect.We anticipate that our metallic glassy fiber strain gauge(MGFSG),which moves toward the ideal SGs,would have wide applications for electromechanical transducers and stress analysis and catalyze development of more micro-and nanoscale metallic glass applications.展开更多
An efficient algorithm is proposed for factoring polynomials over an algebraic extension field defined by a polynomial ring modulo a maximal ideal. If the maximal ideal is given by its CrSbner basis, no extra Grbbner ...An efficient algorithm is proposed for factoring polynomials over an algebraic extension field defined by a polynomial ring modulo a maximal ideal. If the maximal ideal is given by its CrSbner basis, no extra Grbbner basis computation is needed for factoring a polynomial over this extension field. Nothing more than linear algebraic technique is used to get a characteristic polynomial of a generic linear map. Then this polynomial is factorized over the ground field. From its factors, the factorization of the polynomial over the extension field is obtained. The algorithm has been implemented in Magma and computer experiments indicate that it is very efficient, particularly for complicated examples.展开更多
This letter investigates the time-machine problem in perfect fluid cosmologies. It solves the Einstein’s field equations with the energy-momentum tensors for perfect fluid and constructs a class of time-machine solut...This letter investigates the time-machine problem in perfect fluid cosmologies. It solves the Einstein’s field equations with the energy-momentum tensors for perfect fluid and constructs a class of time-machine solutions, by which the time-machine problem in the perfect fluid cosmologies is solved.展开更多
文摘This article described the characteristics of the liquid nitrogen engine's ideal open cycle.Using two interconnecting strokes to achieve the power output can mitigate the trade-off between high efficiency and the potential mechanical complexity of multiple-cylinder engines. The total specific energy of the binary media (methane-nitrogen) cycle system could be much higher than the unitary medium (liquid nitrogen) cycle system. By theoretical analysis, the reasonably acceptable driving range proved the feasibility of the liquid nitrogen engine used for supplying power for a lightweight car.
文摘AIMTo assess the effect of long-term oral nucleos(t)ide analogues (NUCs) therapy on liver volume change in patients with suppress hepatitis B virus (HBV)-related liver cirrhosis.METHODSWe reviewed the data of naïve patients with HBV-related liver cirrhosis, who had taken oral NUCs therapy, between 2003 and 2007 at Chonbuk University Hospital. We analyzed two consecutive sets of abdominal computerized tomography scans-one at the time of treatment initiation and another at the second-year follow-up. Liver volume was calculated by 3-dimensional liver extraction volumetry program.RESULTSA total of 55 patients (34 males) were included. There was 114.3 mL ± 167.8 mL (12.9% ± 17.9%) of increase in liver volume during the two years of NUCs therapy (993.8 mL ± 242.8 mL at baseline vs 1108.1 mL ± 263.3 mL at two-year follow-up, P < 0.001). The ratio of the measured baseline liver volume to the estimated standard liver volume was improved from 70.8% to 78.0%. An increase in liver volume was shown not only in patients with compensated cirrhosis (P = 0.046) but also in those with decompensated cirrhosis (P < 0.001). Significant factors for volume increases were Child-Turcotte-Pugh grade and model for end-stage liver disease score improvement without virological breakthrough. In multiple linear regression analysis, delta albumin and delta alanine aminotransferase levels showed a significant association with the increase in liver volume (P = 0.002 and 0.005, respectively).CONCLUSIONLong-term oral NUCs therapy in patients with HBV-related liver cirrhosis lead to significant increase in liver volume assessed with 3-dimensional liver extraction volumetry program.
文摘The idea of Cyborg initiates the blurring of frontiers between traditional gender roles in the post-modem era, transforming itself into a politicized entity. William Gibson＇s Neuromancer as an early introducer of the Cyborg characters tries to dissolve the boundaries through his female characters by balancing the power quota with the help of the non-gendered entity of the Cyborg. According to Donna Haraway, there will be a dawn of new cyborg era causing a gender role reversal. The objective of this paper is to find whether such role reversal is at all possible.
文摘A multicellular DCX （dc-dc transformer） using unregulated cell converters has been proposed for the environmentally friendly data centers. The high speed cell converter with the switching frequency over MHz behaves as an ideal transformer, and this behavior solves the voltage imbalance issue in the multicellular converter topology. The analysis of the unregulated cell converter is conducted by using the state space averaging method, and the operation condition for the ideal transformer is specified. The behavior of the multicellular DCX using the high speed cell converters has been also analyzed, and the voltage imbalance issue among cell converters is discussed quantitatively. A prototype of a 19.2 kW 384 V-384 V multicellular DCX using sixty-four unregulated cell converters is fabricated and the validity of the analyses is verified.
文摘In this work, the stability of an endoreversible Curzon-Ahlbom engine is analyzed, using Van der Waals gas as a working substance and the corresponding efficiency for this engine working at temperatures withinthe maximum ecological regime. By mean s of a local stability analysis we find that a critical point of an almost linear system is stable andanalytically expressed in eigenvalues. After an arbitrarily small perturbation, the system state exponentially decays to a critical point, with either of two characteristic relaxation times, which are a function of the thermal conductance （a）, heat capacity （C） and T=T2/T1. The behavior of relaxation times and solution of the systems are qualitatively shown by sketching its phase portrait, which results susceptible to operating regimes, i.e., the eigenvectors in the maximum ecological regime have a clockwise rotation with respect to the eigenvectors in the regime of maximumpower. Finally, it has to observe that afterto λvw = 1, approximation,ηVWE=4^-3ηC is obtained, where ηVWE is the Van der Waals efficiency atrnaximum ecological regime and r/c is Carnot＇s efficiency. Finally, it discussed the local stability and steady state of the energetic properties of the endoreversible engine.
文摘This study investigates Chinese elementary, middle, and high school students＇ L2 perceptual learning styles, imagination, ideal L2 self, and motivated L2 behavior. A perceptual learning style and L2 learning motivation questionnaire was administered to 1,667 students from elementary to high school. Statistical results revealed that Chinese elementary, middle, and high school students were more in favor of a visual learning style in comparison to their auditory and kinesthetic learning styles. This visually oriented style was significantly correlated with their ideal L2 self and motivated L2 behavior. The sequential regression analysis results indicated that the ideal L2 self and visual learning style were the most meaningful predictors for Chinese students＇ motivated L2 behavior. This study suggests that teachers need to help students create and maintain their ideal L2 self and facilitate their L2 learning motivation by providing more adequate visual teaching materials.
基金support from the National Natural Science Foundation of China (Grant Nos. 50921091 and 50731008)the National Basic Research Program of China (973) (Grant Nos. 2007CB613904 and2010CB731603)
文摘Electrical resistance strain gauges(SGs) are useful tools for experimental stress analysis and the strain sensing elements in many electromechanical transducers including load cells,pressure transducers,torque meters,accelerometers,force cells,displacement transducers and so forth.The commonly used commercial crystalline strain sensing materials of SGs are in the form of wire or foil of which performance and reliability is not good enough due to their low electrical resistivity and incapacity to get thin thickness.Smaller SGs with single straight strand strain sensing materials,which are called ideal SG,are highly desirable for more than seven decades since the first SG was invented.Here,we show the development of a type of minuscule length scale strain gauge by using a bare and single straight strand metallic glassy fiber(MGF) with high resistivity,much smaller lengthscale,high elastic limits(2.16%) and especially the super piezoresistance effect.We anticipate that our metallic glassy fiber strain gauge(MGFSG),which moves toward the ideal SGs,would have wide applications for electromechanical transducers and stress analysis and catalyze development of more micro-and nanoscale metallic glass applications.
基金supported by National Key Basic Research Project of China (Grant No.2011CB302400)National Natural Science Foundation of China (Grant Nos. 10971217, 60970152 and 61121062)IIE'S Research Project on Cryptography (Grant No. Y3Z0013102)
文摘An efficient algorithm is proposed for factoring polynomials over an algebraic extension field defined by a polynomial ring modulo a maximal ideal. If the maximal ideal is given by its CrSbner basis, no extra Grbbner basis computation is needed for factoring a polynomial over this extension field. Nothing more than linear algebraic technique is used to get a characteristic polynomial of a generic linear map. Then this polynomial is factorized over the ground field. From its factors, the factorization of the polynomial over the extension field is obtained. The algorithm has been implemented in Magma and computer experiments indicate that it is very efficient, particularly for complicated examples.
文摘This letter investigates the time-machine problem in perfect fluid cosmologies. It solves the Einstein’s field equations with the energy-momentum tensors for perfect fluid and constructs a class of time-machine solutions, by which the time-machine problem in the perfect fluid cosmologies is solved.
