InGaN-based green light-emitting diodes （LEDs） with different growth temperatures of superlattice grown on Si （111） substrates are investigated by temperature-dependent electroluminescence between 100 K and 350K. ...InGaN-based green light-emitting diodes （LEDs） with different growth temperatures of superlattice grown on Si （111） substrates are investigated by temperature-dependent electroluminescence between 100 K and 350K. It is observed that with the decrease of the growth temperature of the superlattice from 895℃ to 855℃, the forward voltage decreases, especially at low temperature. We presume that this is due to the existence of the larger average size of V-shaped pits, which is determined by secondary ion mass spectrometer measurements. Meanwhile, the sample with higher growth temperature of superlattice shows a severer efficiency droop at cryogenic temperatures （about 100 K-150 K）. Electron overflow into p-GaN is considered to be the cause of such phenomena, which is relevant to the poorer hole injection into multiple quantum wells and the more reduced effective active volume in the active region.展开更多
The article describes the possibilities of application of simulation modeling for the analysis of infrastructure and technology of transport services of enterprises. The main technological and possible economic effect...The article describes the possibilities of application of simulation modeling for the analysis of infrastructure and technology of transport services of enterprises. The main technological and possible economic effects for the enterprises arising at performance of modeling of a transport component of their work are resulted.展开更多
In this study,the employment of mud-pulse generators to improve the efficiency of wellbores under complex mining and geological conditions is examined.A systemic analysis is made of the primary theoretical basis of th...In this study,the employment of mud-pulse generators to improve the efficiency of wellbores under complex mining and geological conditions is examined.A systemic analysis is made of the primary theoretical basis of the study.The benefits of a mud-pulse generator(a high-impulse hydraulic hammer)for wellbore production are stated based on the presented theoretical basis.The results not only show the benefits of mud-pulse generator employment but also provide an analysis of methods that can be used to improve the high-impulse hydraulic hammer efficiency.The acquired results have a substantial practical value not only for specialists,who research,develop,and manage wellbore operations,but also for engineers,who improve the process and modernize existing wellbores,and other experts in the field of wellbore production.展开更多
Microcystins （ MCs ） are well known as hepatotoxins produced by blooms of toxic cyanobacteria （blue-green algae） abundant in surface water used as drinking water resource and have drawn attention of environmentali...Microcystins （ MCs ） are well known as hepatotoxins produced by blooms of toxic cyanobacteria （blue-green algae） abundant in surface water used as drinking water resource and have drawn attention of environmentalists world over by leading to adverse health effects. A study on efficiency and reaction kinetics of microcystin-LR （ MC-LR ） degradation by CIO2 was performed. Experimental results indicated that MC-LR was removed by CIO2 effectively and the residual concentration of MC-LR could meet the national guideline（GB5749 - 2006） （1.0 μg · L^-1）, the efficiency of removal was in positive correlation to CIO2 dosage and reaction time and in negative correlation to initial concentration of MC-LR and pH value, whereas it was affected by temperature slightly. CIO2 dosage was the most important reaction factor on base of the orthogonal test results. The reaction was second order overall and first order with respect to both CIO2 and MC- LR, and had an activation energy of 78.81 kJ · mo1^-1 . The reaction rate constant was 4.74× 10-^2 L/（mol · min） at 10 ℃. Therefore, oxidation of CIO~ could be taken as an effective technology for removing MC-LR from drinking water resources in traditional drinking water supplies.展开更多
By studying the cultural background and corporate culture in China, Japan and USA, this paper analyzes the effects of cultural background and corporation culture on the transaction cost and the efficiency of control r...By studying the cultural background and corporate culture in China, Japan and USA, this paper analyzes the effects of cultural background and corporation culture on the transaction cost and the efficiency of control right, thus shows that cultural backgrounds have great impact on merger. This paper further studies the choice and application of the mode of culture combination of the transnational merger.展开更多
In mammalians, the state of a somatic cell can be reversed from the terminal state to the totipotent state by means of somatic cell nuclear transfer （SCNT） （Gurdon, 1962） or induced pluripotent stem cells （iPSCs...In mammalians, the state of a somatic cell can be reversed from the terminal state to the totipotent state by means of somatic cell nuclear transfer （SCNT） （Gurdon, 1962） or induced pluripotent stem cells （iPSCs） （Takahashi and Yamanaka, 2006）. The DNA methylation and transcriptome profiles of embryonic stern cells （ESCs） derived from SCNT embryos （NT-ESCs） correspond closely to those of ESCs derived from in vitro fertilization embryos （IVF- ESCs）. In contrast, iPSCs differ from both NT-ESCs and IVF-ESCs in that they retain the residual DNA methylation patterns of their parental somatic cells. As SCNT can be used to faithfully reprogram human somatic cells to pluripotency, it is ideal for cell replacement therapies （Ma et al., 2014）. Following the successful production of the first human NT-ESCs （Tachibana et al., 2013） and the later gen- eration of human NT-ESCs based on cells from elderly adults or pa- tient cells （Chung et al., 2014; Yamada et al., 2014）, a version of the SCNT technique for human therapeutics comes closer to reality. However, no matter what animal species or donor cell types are used in the cloned process, the cloning efficiency remains undesir- able. Besides, there are many phenotypic abnormalities in cloned animals, containing frequent embryonic and perinatal death and placentomegaly, and the underlying mechanisms remain unclear （Yang et al, 2007）.展开更多
Lead halide perovskites attracted a lot of attention in the last several years,with a focus gradually shifting from the record power conversion efficiencies reported for photovoltaic devices based on thin perovskite f...Lead halide perovskites attracted a lot of attention in the last several years,with a focus gradually shifting from the record power conversion efficiencies reported for photovoltaic devices based on thin perovskite films[1]towards superior展开更多
In this paper, we consider solving dense linear equations on Dawning1000 byusing matrix partitioning technique. Based on this partitioning of matrix, we give aparallel block LU decomposition method. The efficiency of ...In this paper, we consider solving dense linear equations on Dawning1000 byusing matrix partitioning technique. Based on this partitioning of matrix, we give aparallel block LU decomposition method. The efficiency of solving linear equationsby different ways is analysed. The numerical results are given on Dawning1000.By running our parallel program, the best speed up on 32 processors is over 25.展开更多
This paper analyzes a mathematical model of the photosynthetic carbon metabolism, which incorporates not only the Calvin-Benson cycle, but also another two important metabolic pathways： starch synthesis and photoresp...This paper analyzes a mathematical model of the photosynthetic carbon metabolism, which incorporates not only the Calvin-Benson cycle, but also another two important metabolic pathways： starch synthesis and photorespiratory pathway. Theoretically, the paper shows the existence of steady states, stability and instability of the steady states, the effects of CO2 concentration on steady states. Especially, a critical point is found, the system has only one steady state with C02 concentration in the left neighborhood of the critical point, but has two with C02 concentration in the right neighborhood. In addition, the paper also explores the influence of C02 concentration on the efficiency of photosynthesis. These theoretical results not only provide insight to the kinetic behaviors of the photosynthetic carbon metabolism, but also can be used to help improving the efficiency of photosynthesis in plants.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61334001the National Key Research and Development Program of China under Grant Nos 2016YFB0400600,2016YFB0400601 and 2016YFB0400100+1 种基金the National Science Foundation for Young Scientists of China under Grant No 21405076the Fund for Less Developed Regions of the National Natural Science Foundation of China under Grant No 11364034
文摘InGaN-based green light-emitting diodes （LEDs） with different growth temperatures of superlattice grown on Si （111） substrates are investigated by temperature-dependent electroluminescence between 100 K and 350K. It is observed that with the decrease of the growth temperature of the superlattice from 895℃ to 855℃, the forward voltage decreases, especially at low temperature. We presume that this is due to the existence of the larger average size of V-shaped pits, which is determined by secondary ion mass spectrometer measurements. Meanwhile, the sample with higher growth temperature of superlattice shows a severer efficiency droop at cryogenic temperatures （about 100 K-150 K）. Electron overflow into p-GaN is considered to be the cause of such phenomena, which is relevant to the poorer hole injection into multiple quantum wells and the more reduced effective active volume in the active region.
文摘The article describes the possibilities of application of simulation modeling for the analysis of infrastructure and technology of transport services of enterprises. The main technological and possible economic effects for the enterprises arising at performance of modeling of a transport component of their work are resulted.
文摘In this study,the employment of mud-pulse generators to improve the efficiency of wellbores under complex mining and geological conditions is examined.A systemic analysis is made of the primary theoretical basis of the study.The benefits of a mud-pulse generator(a high-impulse hydraulic hammer)for wellbore production are stated based on the presented theoretical basis.The results not only show the benefits of mud-pulse generator employment but also provide an analysis of methods that can be used to improve the high-impulse hydraulic hammer efficiency.The acquired results have a substantial practical value not only for specialists,who research,develop,and manage wellbore operations,but also for engineers,who improve the process and modernize existing wellbores,and other experts in the field of wellbore production.
基金the National Nature Science Foundation of China(No.50178022)the National863Projects(No.2006AA06Z309)
文摘Microcystins （ MCs ） are well known as hepatotoxins produced by blooms of toxic cyanobacteria （blue-green algae） abundant in surface water used as drinking water resource and have drawn attention of environmentalists world over by leading to adverse health effects. A study on efficiency and reaction kinetics of microcystin-LR （ MC-LR ） degradation by CIO2 was performed. Experimental results indicated that MC-LR was removed by CIO2 effectively and the residual concentration of MC-LR could meet the national guideline（GB5749 - 2006） （1.0 μg · L^-1）, the efficiency of removal was in positive correlation to CIO2 dosage and reaction time and in negative correlation to initial concentration of MC-LR and pH value, whereas it was affected by temperature slightly. CIO2 dosage was the most important reaction factor on base of the orthogonal test results. The reaction was second order overall and first order with respect to both CIO2 and MC- LR, and had an activation energy of 78.81 kJ · mo1^-1 . The reaction rate constant was 4.74× 10-^2 L/（mol · min） at 10 ℃. Therefore, oxidation of CIO~ could be taken as an effective technology for removing MC-LR from drinking water resources in traditional drinking water supplies.
文摘By studying the cultural background and corporate culture in China, Japan and USA, this paper analyzes the effects of cultural background and corporation culture on the transaction cost and the efficiency of control right, thus shows that cultural backgrounds have great impact on merger. This paper further studies the choice and application of the mode of culture combination of the transnational merger.
基金supported by grants from the National Natural Science Foundation of China(No.31471395)to Q.Z.the Key Research Projects of the Frontier Science of the Chinese Academy of Sciences(QYZDY-SSW-SMC002)to Q.Z
文摘In mammalians, the state of a somatic cell can be reversed from the terminal state to the totipotent state by means of somatic cell nuclear transfer （SCNT） （Gurdon, 1962） or induced pluripotent stem cells （iPSCs） （Takahashi and Yamanaka, 2006）. The DNA methylation and transcriptome profiles of embryonic stern cells （ESCs） derived from SCNT embryos （NT-ESCs） correspond closely to those of ESCs derived from in vitro fertilization embryos （IVF- ESCs）. In contrast, iPSCs differ from both NT-ESCs and IVF-ESCs in that they retain the residual DNA methylation patterns of their parental somatic cells. As SCNT can be used to faithfully reprogram human somatic cells to pluripotency, it is ideal for cell replacement therapies （Ma et al., 2014）. Following the successful production of the first human NT-ESCs （Tachibana et al., 2013） and the later gen- eration of human NT-ESCs based on cells from elderly adults or pa- tient cells （Chung et al., 2014; Yamada et al., 2014）, a version of the SCNT technique for human therapeutics comes closer to reality. However, no matter what animal species or donor cell types are used in the cloned process, the cloning efficiency remains undesir- able. Besides, there are many phenotypic abnormalities in cloned animals, containing frequent embryonic and perinatal death and placentomegaly, and the underlying mechanisms remain unclear （Yang et al, 2007）.
文摘Lead halide perovskites attracted a lot of attention in the last several years,with a focus gradually shifting from the record power conversion efficiencies reported for photovoltaic devices based on thin perovskite films[1]towards superior
文摘In this paper, we consider solving dense linear equations on Dawning1000 byusing matrix partitioning technique. Based on this partitioning of matrix, we give aparallel block LU decomposition method. The efficiency of solving linear equationsby different ways is analysed. The numerical results are given on Dawning1000.By running our parallel program, the best speed up on 32 processors is over 25.
基金Supported by the National Natural Science Foundation of China(No.11071238)the Key Lab of Random Complex Structures and Data Science,CAS(No.2008DP173182)the National Center for Mathematics and interdisciplinary Sciences,CAS(N0.Y029184K51)
文摘This paper analyzes a mathematical model of the photosynthetic carbon metabolism, which incorporates not only the Calvin-Benson cycle, but also another two important metabolic pathways： starch synthesis and photorespiratory pathway. Theoretically, the paper shows the existence of steady states, stability and instability of the steady states, the effects of CO2 concentration on steady states. Especially, a critical point is found, the system has only one steady state with C02 concentration in the left neighborhood of the critical point, but has two with C02 concentration in the right neighborhood. In addition, the paper also explores the influence of C02 concentration on the efficiency of photosynthesis. These theoretical results not only provide insight to the kinetic behaviors of the photosynthetic carbon metabolism, but also can be used to help improving the efficiency of photosynthesis in plants.
