Gracilariopsis lemaneiformis is an economically important agarophyte, which contains high quality gel and shows a high growth rate. Wild population of G. lemaneiformis displayed resident divergence, though with a low ...Gracilariopsis lemaneiformis is an economically important agarophyte, which contains high quality gel and shows a high growth rate. Wild population of G. lemaneiformis displayed resident divergence, though with a low genetic diversity as was revealed by amplified fragment length polymorphism(AFLP) and simple sequence repeat(SSR) analyses. In addition, different strains of G. lemaneiformis are diverse in morphology. The highly inconsistence between genetic background and physiological characteristics recommends strongly to the regulation at epigenetic level. In this study, the DNA methylation change in G. lemaneiformis among different generation branches and under different temperature stresses was assessed using methylation sensitive amplified polymorphism(MSAP) technique. It was shown that DNA methylation level among different generation branches was diverse. The full and total methylated DNA level was the lowest in the second generation branch and the highest in the third generation. The total methylation level was 61.11%, 60.88% and 64.12% at 15℃, 22℃ and 26℃, respectively. Compared with the control group(22℃), the fully methylated and totally methylated ratios were increased in both experiment groups(15℃ and 26℃). All of the cytosine methylation/demethylation transform(CMDT) was further analyzed. High temperature treatment could induce more CMDT than low temperature treatment did.展开更多
An experiment on critical flow of water was conducted in two nozzles of 1.41 mm in diameter and 4.35 mm in length with rounded-edge and sharp-edge respectively, covering the ranges of inlet pressure of 22.1-29.1 MPa a...An experiment on critical flow of water was conducted in two nozzles of 1.41 mm in diameter and 4.35 mm in length with rounded-edge and sharp-edge respectively, covering the ranges of inlet pressure of 22.1-29.1 MPa and inlet temperature of 38-474 ℃. More than 200 data points were obtained and the characteristics and parametric trends were investigated. In the region of near and beyond pseudo-critical temperature the thermal-equilibrium is dominant, and the flow rate can be estimated by the modified homogeneous equilibrium model. In the below pseudo-critical region the results exhibit scattered feature as a result of hysteresis effect in the onset of vaporization, characterizing a bifurcation behavior. This effect is more significant in the nozzle with sharp-edge, especially at higher pressure. For temperature well below the pseudo-critical point, the flow is not at critical condition and the flow rate can be represented by the Bernoulli equation reasonably.展开更多
Critical temperature of Mg1-xAlxB2, MgB2-xCx are calculated using two-band Eliashberg theory in intermediate e-ph coupling. Analytical calculations are conducted for different values of doping parameters x in this com...Critical temperature of Mg1-xAlxB2, MgB2-xCx are calculated using two-band Eliashberg theory in intermediate e-ph coupling. Analytical calculations are conducted for different values of doping parameters x in this compounds. Pressure effects on critical temperature in MgB2 and nonmagnetic borocarbide YNi2B2C are also investigated. Results is compared with available experimental data and good agreement is achieved.展开更多
We consider a Ginzburg-Landau modified model of layered high-temperature superconductor under pressure. We have theoretically studied the relation between the pressure and the temperature of layered high-temperature s...We consider a Ginzburg-Landau modified model of layered high-temperature superconductor under pressure. We have theoretically studied the relation between the pressure and the temperature of layered high-temperature superconductor. If the pressure is not a constant, we have a relation of quadratic equation between the pressure and the temperature of layered high-temperature superconductor. In a special case, we find the critical temperature decreases with further increasing pressure. In another special ease, the critical temperature increases with further increasing pressure.展开更多
The high temperature heat pump and desiccant wheel(HTHP&DW) system can make full use of heat released from the condenser of heat pump for DW regeneration without additional heat. In this study, DW operation in the...The high temperature heat pump and desiccant wheel(HTHP&DW) system can make full use of heat released from the condenser of heat pump for DW regeneration without additional heat. In this study, DW operation in the HTHP&DW system was investigated experimentally, and the optimization analysis of HTHP&DW system was carried out. The performance of DW had influence on the dehumidification(evaluated by dehumidification and regeneration effectiveness) and cooling load(evaluated by thermal and adiabatic effectiveness). The results show that the enthalpy increase occurred in all the experiments. Compared to the isosteric heat, heat accumulation in the desiccant and matrix material and heat leakage from regeneration side to process side have greater influence on the adiabatic effectiveness. Higher regeneration temperature leads to lower adiabatic effectiveness that increases more cooling load of the system. When the regeneration temperature is 63℃, the maximal dehumidification effectiveness is 35.4% and the satisfied adiabatic effectiveness is 88%, which contributes to the optimal balance between dehumidification and cooling.展开更多
Thirty bread wheat genotypes were used as material during the 2014-2015 cropping season. The experimental layout was a randomized complete block design with 3 replications. The sowing rate was 500 seeds square meter. ...Thirty bread wheat genotypes were used as material during the 2014-2015 cropping season. The experimental layout was a randomized complete block design with 3 replications. The sowing rate was 500 seeds square meter. Sowing was done in plots of 6 rows (1.2 m × 5 m, spaced 20 cm apart) in Namlk Kemal University, Faculty of Agriculture, Field Crops Department experimental area. Two sowing times were performed. First sowing was made in November suggested usual (standard) and second one was made in January as delayed sown in order to push growing stages of plants into periods in which heat stress is expected will be effected. Sowing times were allotted to main-plots while genotypes were allotted to sub-plots. When the bread wheat varieties and lines used in the experiment are evaluated in terms of tolerance to high temperature, it was shown that Dropia and Nota varieties and CIMMYT-HTN 2014/15-2, CIMMYT-HTN 2014/15 -6, CIMMYT-HTN 2014/15 - 10 lines were better tolerance to high temperature. However, it was noticed that these genotypes were not included in the first groups in terms of grain yield. It is possible to utilize these genotypes as a genitor in cross-breeding programs for breeding studies for tolerance to high temperatures.展开更多
Twenty-one square concrete columns were constructed and tested. The testing results indicate that bonded carbon fiber reinforced plastics(CFRP) sheets can be used to increase the strength and improve the serviceabilit...Twenty-one square concrete columns were constructed and tested. The testing results indicate that bonded carbon fiber reinforced plastics(CFRP) sheets can be used to increase the strength and improve the serviceability of damaged concrete columns at low temperatures. The failure of the specimens,in most cases,takes place within the middle half of the columns. And the failure of strengthened columns is sudden and explosive. The CFRP sheets increase both the axial load capacity and the ultimate concrete compressive strain of the columns. The ultimate loads of strengthened columns at-10,0 and 10 ℃ increase averagely by 9.09%,6.63% and 17.83%,respectively,as compared with those of the control specimens. The axial compressive strength of strengthened columns is related to the curing temperatures. The improvement of axial compressive strength decreases with reducing temperature,and when the temperature drops to a certain value,the improvement increases with falling temperature.展开更多
Based on the NCEP (National Centers for Environmental Prediction) data,the relationship between the Sea Surface Temperature Anomalies (SSTAs) in the North Pacific and the atmospheric circulation anomalies in January 2...Based on the NCEP (National Centers for Environmental Prediction) data,the relationship between the Sea Surface Temperature Anomalies (SSTAs) in the North Pacific and the atmospheric circulation anomalies in January 2008 is analyzed in this study.The SSTA mode most correlated with the Geopotential Height anomalies (GHAs) in January 2008 in the North Pacific exhibited a basin-wide horseshoe pattern with a warm center in November 2007.This persistent SSTA pattern would induce positive GHAs in the Aleutian Low area and East Asia and the northward extension of the West Pacific Subtropical High in January 2008 by maximum diabatic heating in the atmosphere over the Kuroshio Oyashio Extension (KOE) area,leading to the occurence of the circumpolar trough-ridge wave train anomaly in January 2008.展开更多
In this paper, a detailed thermodynamic analysis of the pure low-temperature waste heat recovery generation system is presented. The parameters affecting the system performance are compared to obtain the most signific...In this paper, a detailed thermodynamic analysis of the pure low-temperature waste heat recovery generation system is presented. The parameters affecting the system performance are compared to obtain the most significant ones; furthermore, parameter values are optimized for the largest power generating capability of the system. It is found that the most important parameters are inlet flue gas temperature, steam pressure and the pinch point temperature difference. There is an optimal superheated steam pressure value for giving the maximum generation power per unit flue gas. With the increase of inlet flue gas temperature, the generating power increases and the optimized steam pressure rises as well. However, with increase in pinch point temperature difference, the generating power decreases and the optimized steam pressure decreases as well. The theoretical calculation provides a theoretical basis for the parameters optimization in the design of the pure low-temperature waste heat recovery eeneration swtem展开更多
The elasticity of minerals at high temperature and pressure (PT) is critical for constraining the composition and temperature of the Earth's interior and understand better the deep water cycle and the dynamic Earth...The elasticity of minerals at high temperature and pressure (PT) is critical for constraining the composition and temperature of the Earth's interior and understand better the deep water cycle and the dynamic Earth. First-principles calcula- tions without introducing any adjustable parameters, whose results can be comparable to experimental data, play a more and more important role in investigating the elasticity of minerals at high PT mainly because of (1) the quick increasing of computational powers and (2) advances in method. For example, the new method reduces the computation loads to one-tenth of the traditional method with the comparable precise as the traditional method. This is extraordinarily helpful because first-principles calculations of the elasticity of minerals at high PT are extremely time-consuming. So far the elasticity of most of lower mantle minerals has been investigated in detail. We have good idea on the effect of temperature, pressure, and iron concentration on elasticity of main minerals of the lower mantle and the unusual softening in bulk modulus by the spin crosso- ver of iron in ferropericlase. With these elastic data the lower mantle has been constrained to have 10-15 wt% ferropericlase, which is sufficient to generate some visible effects of spin crossover in seismic tomography. For example, the spin crossover causes that the temperature sensitivity of P wave at the depth of -1700 km is only a fraction of that at the depth of -2300 kin. The disruptions of global P wave structure and of P wave image below hotspots such as Hawaii and Iceland at similar depth are in consistence with the spin crossover effect of iron in ferropericlase. The spin crossover, which causes anomalous ther- modynamic properties of ferropericlase, has also been found to play a control role for the two features of the large low shear velocity provinces (LLSVPs): the sharp edge and high elevation up to 1000 km above core-mantle boundary. All these results clearly suggest the spin crossover of iron in the lower mantle. The theoretical investigations for the elasticity of minerals at the upper mantle and water effect on elasticity of minerals at the mantle transition zone and subducting slab have also been con- ducted extensively. These researches are critical for understanding better the composition of the upper mantle and water dis- tribution and transport in the Earth's mantle. Most of these were static calculations, which did not include the vibrational (temperature) effect on elasticity, although temperature effect on elasticity is basic because of high temperature at the Earth's interior and huge temperature difference between the ambient mantle and the subducting slab. Including temperature effect on elasticity of minerals should be important future work. New method developed is helpful for these directions. The elasticity of iron and iron-alloy with various light elements has also been calculated extensively. However, more work is necessary in order to meet the demand for constraining the types and amount of light elements at the Earth's core. Keywords Mantle temperature, Mantle composition, Composition of Earth's core, Ab initio method展开更多
The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power ha...The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power has been carefully studied for the Si solar cells.The results show that one of the environment temperatures plays the major role,and the temperature dependence of device performance parameters is different for single crystalline and polycrystalline Si solar cells.Furthermore,the ambient air temperature builds a bridge for the comparison of the effect between the cell temperature and the illumination intensity on solar cell performance.Based on the experimental results,the reasons which cause the difference of the environment temperatures dependence are analyzed.展开更多
One of the most strikingly universal features of the high-temperature superconductors is that the super- conducting phase emerges in the close proximity of the antiferromagnetic phase, and the interplay between these ...One of the most strikingly universal features of the high-temperature superconductors is that the super- conducting phase emerges in the close proximity of the antiferromagnetic phase, and the interplay between these two phases poses a long-standing challenge. It is commonly believed that, as the antifer- romagnetic transition temperature is continuously suppressed to zero, there appears a quantum critical point, around which the existence of antiferromagnetic fluctuation is responsible for the development of the superconductivity. In contrast to this scenario, we report the observation of a bi-critical point identified at 2,88 GPa and 26.02 K in the pressurized high-quality single crystal Cao.73Lao.27FeAs2 by com- plementary in-situ high pressure measurements. At the critical pressure, we find that the antiferromag- netism suddenly disappears and superconductivity simultaneously emerges at almost the same temperature, and that the external magnetic field suppresses the superconducting transition temperature but hardly affects the antiferromagnetic transition temperature.展开更多
The voltage-biased current-voltage (I-V) characteristics of intrinsic Josephson junctions (IJJs), which are fabricated with misa- ligned high temperature superconducting Tl2Ba2CaCu2O8 (T1-2212) thin film, are in...The voltage-biased current-voltage (I-V) characteristics of intrinsic Josephson junctions (IJJs), which are fabricated with misa- ligned high temperature superconducting Tl2Ba2CaCu2O8 (T1-2212) thin film, are investigated experimentally. Three charac- teristic regions in the I-V curve are observed at 47 K. In the low voltage part, the current firstly increases and then decreases slowly with increasing the biased voltage, which is shown as a bump. In the next region, the current slightly increases with in- creasing the biased voltage until a sudden decrease of the current appears. Thereafter, branch structure forms with increasing the voltage on the I-V characteristic. The influence of the self-heating on the I-V characteristics is investigated and the temper- ature dependence of the I-V characteristics is measured to explore these characteristics in detail.展开更多
In this paper, we present a stable single-photon detection method based on Si-avalanche photodiode(Si-APD) operating in Geiger mode with a large temperature variation range. By accurate temperature sensing and direct ...In this paper, we present a stable single-photon detection method based on Si-avalanche photodiode(Si-APD) operating in Geiger mode with a large temperature variation range. By accurate temperature sensing and direct current(DC) bias voltage compensation, the single-photon detector can work stably in Geiger mode from-40 °C to 35 °C with an almost constant avalanche gain. It provides a solution for single-photon detection at outdoor operation in all-weather conditions.展开更多
基金supported by the National Natural Science Foundation of China (No. 31372529)the Fundamental Research Funds for the Central Universities (No. 201762016)China Agriculture Research System (No. CARS-50)
文摘Gracilariopsis lemaneiformis is an economically important agarophyte, which contains high quality gel and shows a high growth rate. Wild population of G. lemaneiformis displayed resident divergence, though with a low genetic diversity as was revealed by amplified fragment length polymorphism(AFLP) and simple sequence repeat(SSR) analyses. In addition, different strains of G. lemaneiformis are diverse in morphology. The highly inconsistence between genetic background and physiological characteristics recommends strongly to the regulation at epigenetic level. In this study, the DNA methylation change in G. lemaneiformis among different generation branches and under different temperature stresses was assessed using methylation sensitive amplified polymorphism(MSAP) technique. It was shown that DNA methylation level among different generation branches was diverse. The full and total methylated DNA level was the lowest in the second generation branch and the highest in the third generation. The total methylation level was 61.11%, 60.88% and 64.12% at 15℃, 22℃ and 26℃, respectively. Compared with the control group(22℃), the fully methylated and totally methylated ratios were increased in both experiment groups(15℃ and 26℃). All of the cytosine methylation/demethylation transform(CMDT) was further analyzed. High temperature treatment could induce more CMDT than low temperature treatment did.
文摘An experiment on critical flow of water was conducted in two nozzles of 1.41 mm in diameter and 4.35 mm in length with rounded-edge and sharp-edge respectively, covering the ranges of inlet pressure of 22.1-29.1 MPa and inlet temperature of 38-474 ℃. More than 200 data points were obtained and the characteristics and parametric trends were investigated. In the region of near and beyond pseudo-critical temperature the thermal-equilibrium is dominant, and the flow rate can be estimated by the modified homogeneous equilibrium model. In the below pseudo-critical region the results exhibit scattered feature as a result of hysteresis effect in the onset of vaporization, characterizing a bifurcation behavior. This effect is more significant in the nozzle with sharp-edge, especially at higher pressure. For temperature well below the pseudo-critical point, the flow is not at critical condition and the flow rate can be represented by the Bernoulli equation reasonably.
文摘Critical temperature of Mg1-xAlxB2, MgB2-xCx are calculated using two-band Eliashberg theory in intermediate e-ph coupling. Analytical calculations are conducted for different values of doping parameters x in this compounds. Pressure effects on critical temperature in MgB2 and nonmagnetic borocarbide YNi2B2C are also investigated. Results is compared with available experimental data and good agreement is achieved.
文摘We consider a Ginzburg-Landau modified model of layered high-temperature superconductor under pressure. We have theoretically studied the relation between the pressure and the temperature of layered high-temperature superconductor. If the pressure is not a constant, we have a relation of quadratic equation between the pressure and the temperature of layered high-temperature superconductor. In a special case, we find the critical temperature decreases with further increasing pressure. In another special ease, the critical temperature increases with further increasing pressure.
基金Supported by the Danish International DSF Project(No.09-71598)Chinese International Collaboration Project(No.2010DFA62410)
文摘The high temperature heat pump and desiccant wheel(HTHP&DW) system can make full use of heat released from the condenser of heat pump for DW regeneration without additional heat. In this study, DW operation in the HTHP&DW system was investigated experimentally, and the optimization analysis of HTHP&DW system was carried out. The performance of DW had influence on the dehumidification(evaluated by dehumidification and regeneration effectiveness) and cooling load(evaluated by thermal and adiabatic effectiveness). The results show that the enthalpy increase occurred in all the experiments. Compared to the isosteric heat, heat accumulation in the desiccant and matrix material and heat leakage from regeneration side to process side have greater influence on the adiabatic effectiveness. Higher regeneration temperature leads to lower adiabatic effectiveness that increases more cooling load of the system. When the regeneration temperature is 63℃, the maximal dehumidification effectiveness is 35.4% and the satisfied adiabatic effectiveness is 88%, which contributes to the optimal balance between dehumidification and cooling.
文摘Thirty bread wheat genotypes were used as material during the 2014-2015 cropping season. The experimental layout was a randomized complete block design with 3 replications. The sowing rate was 500 seeds square meter. Sowing was done in plots of 6 rows (1.2 m × 5 m, spaced 20 cm apart) in Namlk Kemal University, Faculty of Agriculture, Field Crops Department experimental area. Two sowing times were performed. First sowing was made in November suggested usual (standard) and second one was made in January as delayed sown in order to push growing stages of plants into periods in which heat stress is expected will be effected. Sowing times were allotted to main-plots while genotypes were allotted to sub-plots. When the bread wheat varieties and lines used in the experiment are evaluated in terms of tolerance to high temperature, it was shown that Dropia and Nota varieties and CIMMYT-HTN 2014/15-2, CIMMYT-HTN 2014/15 -6, CIMMYT-HTN 2014/15 - 10 lines were better tolerance to high temperature. However, it was noticed that these genotypes were not included in the first groups in terms of grain yield. It is possible to utilize these genotypes as a genitor in cross-breeding programs for breeding studies for tolerance to high temperatures.
基金Project(04043076) supported by the Outstanding Youth Foundation for Scientific and Technological Research of Anhui Province, ChinaProject(2007jq1035) supported by the Scientific Research Projects for Young College Teachers of Anhui Province, China
文摘Twenty-one square concrete columns were constructed and tested. The testing results indicate that bonded carbon fiber reinforced plastics(CFRP) sheets can be used to increase the strength and improve the serviceability of damaged concrete columns at low temperatures. The failure of the specimens,in most cases,takes place within the middle half of the columns. And the failure of strengthened columns is sudden and explosive. The CFRP sheets increase both the axial load capacity and the ultimate concrete compressive strain of the columns. The ultimate loads of strengthened columns at-10,0 and 10 ℃ increase averagely by 9.09%,6.63% and 17.83%,respectively,as compared with those of the control specimens. The axial compressive strength of strengthened columns is related to the curing temperatures. The improvement of axial compressive strength decreases with reducing temperature,and when the temperature drops to a certain value,the improvement increases with falling temperature.
基金supported by Chinese NSFC (Grant Nos.40830106 and 40676010)the Ministry of Science and Technology of China (National Key Program for Developing Basic Science,Grant No. 2007CB411803)
文摘Based on the NCEP (National Centers for Environmental Prediction) data,the relationship between the Sea Surface Temperature Anomalies (SSTAs) in the North Pacific and the atmospheric circulation anomalies in January 2008 is analyzed in this study.The SSTA mode most correlated with the Geopotential Height anomalies (GHAs) in January 2008 in the North Pacific exhibited a basin-wide horseshoe pattern with a warm center in November 2007.This persistent SSTA pattern would induce positive GHAs in the Aleutian Low area and East Asia and the northward extension of the West Pacific Subtropical High in January 2008 by maximum diabatic heating in the atmosphere over the Kuroshio Oyashio Extension (KOE) area,leading to the occurence of the circumpolar trough-ridge wave train anomaly in January 2008.
文摘In this paper, a detailed thermodynamic analysis of the pure low-temperature waste heat recovery generation system is presented. The parameters affecting the system performance are compared to obtain the most significant ones; furthermore, parameter values are optimized for the largest power generating capability of the system. It is found that the most important parameters are inlet flue gas temperature, steam pressure and the pinch point temperature difference. There is an optimal superheated steam pressure value for giving the maximum generation power per unit flue gas. With the increase of inlet flue gas temperature, the generating power increases and the optimized steam pressure rises as well. However, with increase in pinch point temperature difference, the generating power decreases and the optimized steam pressure decreases as well. The theoretical calculation provides a theoretical basis for the parameters optimization in the design of the pure low-temperature waste heat recovery eeneration swtem
基金supported by the State Key Development Program of Basic Research of China(Grant No.2014CB845905)the National Natural Science Foundation of China(Grant Nos.41590621,41274087,41473011)the Chinese Academy of Sciences/State Administration of Foreign Experts Affairs International Partnership Program for Creative Research Teams
文摘The elasticity of minerals at high temperature and pressure (PT) is critical for constraining the composition and temperature of the Earth's interior and understand better the deep water cycle and the dynamic Earth. First-principles calcula- tions without introducing any adjustable parameters, whose results can be comparable to experimental data, play a more and more important role in investigating the elasticity of minerals at high PT mainly because of (1) the quick increasing of computational powers and (2) advances in method. For example, the new method reduces the computation loads to one-tenth of the traditional method with the comparable precise as the traditional method. This is extraordinarily helpful because first-principles calculations of the elasticity of minerals at high PT are extremely time-consuming. So far the elasticity of most of lower mantle minerals has been investigated in detail. We have good idea on the effect of temperature, pressure, and iron concentration on elasticity of main minerals of the lower mantle and the unusual softening in bulk modulus by the spin crosso- ver of iron in ferropericlase. With these elastic data the lower mantle has been constrained to have 10-15 wt% ferropericlase, which is sufficient to generate some visible effects of spin crossover in seismic tomography. For example, the spin crossover causes that the temperature sensitivity of P wave at the depth of -1700 km is only a fraction of that at the depth of -2300 kin. The disruptions of global P wave structure and of P wave image below hotspots such as Hawaii and Iceland at similar depth are in consistence with the spin crossover effect of iron in ferropericlase. The spin crossover, which causes anomalous ther- modynamic properties of ferropericlase, has also been found to play a control role for the two features of the large low shear velocity provinces (LLSVPs): the sharp edge and high elevation up to 1000 km above core-mantle boundary. All these results clearly suggest the spin crossover of iron in the lower mantle. The theoretical investigations for the elasticity of minerals at the upper mantle and water effect on elasticity of minerals at the mantle transition zone and subducting slab have also been con- ducted extensively. These researches are critical for understanding better the composition of the upper mantle and water dis- tribution and transport in the Earth's mantle. Most of these were static calculations, which did not include the vibrational (temperature) effect on elasticity, although temperature effect on elasticity is basic because of high temperature at the Earth's interior and huge temperature difference between the ambient mantle and the subducting slab. Including temperature effect on elasticity of minerals should be important future work. New method developed is helpful for these directions. The elasticity of iron and iron-alloy with various light elements has also been calculated extensively. However, more work is necessary in order to meet the demand for constraining the types and amount of light elements at the Earth's core. Keywords Mantle temperature, Mantle composition, Composition of Earth's core, Ab initio method
基金supported by the Doctoral Research Foundation of Southwest University of Science and Technology (Grant No.10zx7102)the National Natural Science Foundation of China (Grant No.11104226)
文摘The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power has been carefully studied for the Si solar cells.The results show that one of the environment temperatures plays the major role,and the temperature dependence of device performance parameters is different for single crystalline and polycrystalline Si solar cells.Furthermore,the ambient air temperature builds a bridge for the comparison of the effect between the cell temperature and the illumination intensity on solar cell performance.Based on the experimental results,the reasons which cause the difference of the environment temperatures dependence are analyzed.
基金supported by the National Natural Science Foundation of China(91321207,11427805,U1532267,11404384)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB07020300)+2 种基金the National Key Research and Development Program of China(2016YFA0300300)the Russian Foundation for Basic Research(15-02-02040)the U.S.NSF DMREF(DMR-1435672)
文摘One of the most strikingly universal features of the high-temperature superconductors is that the super- conducting phase emerges in the close proximity of the antiferromagnetic phase, and the interplay between these two phases poses a long-standing challenge. It is commonly believed that, as the antifer- romagnetic transition temperature is continuously suppressed to zero, there appears a quantum critical point, around which the existence of antiferromagnetic fluctuation is responsible for the development of the superconductivity. In contrast to this scenario, we report the observation of a bi-critical point identified at 2,88 GPa and 26.02 K in the pressurized high-quality single crystal Cao.73Lao.27FeAs2 by com- plementary in-situ high pressure measurements. At the critical pressure, we find that the antiferromag- netism suddenly disappears and superconductivity simultaneously emerges at almost the same temperature, and that the external magnetic field suppresses the superconducting transition temperature but hardly affects the antiferromagnetic transition temperature.
基金supported by the National Natural Science Foundation of China(Grant Nos.61176119,61171028,51002081 and 61101018)
文摘The voltage-biased current-voltage (I-V) characteristics of intrinsic Josephson junctions (IJJs), which are fabricated with misa- ligned high temperature superconducting Tl2Ba2CaCu2O8 (T1-2212) thin film, are investigated experimentally. Three charac- teristic regions in the I-V curve are observed at 47 K. In the low voltage part, the current firstly increases and then decreases slowly with increasing the biased voltage, which is shown as a bump. In the next region, the current slightly increases with in- creasing the biased voltage until a sudden decrease of the current appears. Thereafter, branch structure forms with increasing the voltage on the I-V characteristic. The influence of the self-heating on the I-V characteristics is investigated and the temper- ature dependence of the I-V characteristics is measured to explore these characteristics in detail.
基金supported by the National Natural Science Foundation of China(No.11374105)
文摘In this paper, we present a stable single-photon detection method based on Si-avalanche photodiode(Si-APD) operating in Geiger mode with a large temperature variation range. By accurate temperature sensing and direct current(DC) bias voltage compensation, the single-photon detector can work stably in Geiger mode from-40 °C to 35 °C with an almost constant avalanche gain. It provides a solution for single-photon detection at outdoor operation in all-weather conditions.