The thermal-electrical characteristic of a GaN light-emitting diode (LED) with the hybrid transparent conductive layers (TCLs) of graphene (Gr) and NiOx is investigated by a finite element method. It is indicate...The thermal-electrical characteristic of a GaN light-emitting diode (LED) with the hybrid transparent conductive layers (TCLs) of graphene (Gr) and NiOx is investigated by a finite element method. It is indicated that the LED with the compound TCL of 3-layer Gr and 1 nm NiOx has the best thermal-electrical performance from the view point of the maximum temperature and the current density deviation of multiple quantum wells, and the maximum temperature occurs near the n-electrode rather than p-electrode. Furthermore, to depress the current crowding on the LED, the electrode pattern parameters including p- and n-electrode length, p-electrode buried depth and the distance of n-electrode to active area are optimized. It is found that either increasing p- or n-electrode length and buried depth or decreasing the distance of n-electrode from the active area will decrease the temperature of the LED, while the increase of the n-electrode length has more prominent effect. Typically, when the n-electrode length increases to 0.8 times of the chip size, the temperature of the GaN LED with the inm NiOx/3-1ayer-Gr hybrid TCLs could drop about 7K and the current density uniformity could increase by 23.8%, compared to 0.4 times of the chip size. This new finding will be beneficial for improvement of the thermal- electrical performance of LEDs with various conductive TCLs such as NiOx/Gr or ITO/Gr as current spreading layers.展开更多
Background: The Great Plains of the United States includes a large number of hybrid and contact zones between bird species. The amount of gene flow between sister species in these zones ranges from very rare hybridiza...Background: The Great Plains of the United States includes a large number of hybrid and contact zones between bird species. The amount of gene flow between sister species in these zones ranges from very rare hybridization events to widespread and prevalent introgression. Some of these avian systems have been studied extensively, while others have been indeterminate of whether hybridization exists in areas of sympatry. Using genomic-level approaches allows investigation of genomic patterns of hybridization and gene flow between species—or lack thereof.Methods: We investigated a narrow zone of sympatry in Nebraska, USA between pewee species(Contopus sordidulus and C. virens), for which no hybridization has been confirmed. We used thousands of single nucleotide polymorphisms to identify potential hybridization and investigate genomic patterns of differentiation between these two species.Results: We found evidence of multiple hybrid individuals in the contact zone. Little genomic variation was fixed between species, but a large proportion had differentiated allele frequencies between species. There was a positive relationship between genetic differentiation and chromosome size.Conclusions: We provided the first conclusive evidence of hybridization between C. sordidulus and C. virens, in a region where secondary contact likely occurred due to human disturbance and habitat modification. The genomic patterns of differentiation affirm that these species split in the relatively recent past. Finally, the relationship of chromosome size and genetic differentiation may have resulted from differential rates of chromosomal recombination in songbirds and genetic differentiation between species largely due to genetic drift(possibly in concert with selection).展开更多
Seasonal variations in environmental conditions can have significant influence on flowering pattern and yield of roses. Evaluation studies were conducted to determine the flowering pattern and yield determinants of tw...Seasonal variations in environmental conditions can have significant influence on flowering pattern and yield of roses. Evaluation studies were conducted to determine the flowering pattern and yield determinants of two Hybrid Tea rose cultivars in response to seasonal variations under rain-fed conditions. The 2 × 2 × 4 factorial experiment arranged in split plot design at three replications was conducted at two seasons (dry and wet) using two cultivars (cv. “Immaculate” and “P.H. Baby”, white and red flowers respectively) supplied with poultry manure (PM) application rates at 5, 10 and 20 t/ha where the unfertilized (0 t/ha) served as control. The result showed that the year two environmental conditions of both experiment I and II significantly improved plant height, number of leaves, number of buds (CNB) and opened flowers (CNF) and flower yield (FYD). “Immaculate” was significantly (p ≤ 0.05) taller with more leaves but thinner girth. Although generally lower in NF/NB, and not different in FYD, the “P.H. Baby” had more flowers (CNB and CNF) in experiment I. Except for no significant difference in FYD and lower NF/NB recorded by all manure rates compared to control in experiment II, plants treated with 5 t/ha PM recorded more flowers (CNB and CNF). Significant first and second order interaction effects (p ≤ 0.05) showed that “Immaculate” had taller height and more leaves but “P.H. Baby” had more CNB and CNF, although both were not different in FYD. In addition, plants supplied with 5 t/ha PM rates were better in plant height, number of leaves, CNB and CNF compared to other manure rates. In conclusion, year two environmental conditions supported better crop growth and yield, “Immaculate” grew better vegetatively but both were not different in floral yield, while the 5 t/ha PM was considered the optimum manure application rate under the rain-fed condition.展开更多
Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigment by using photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin f...Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigment by using photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin film modified with methoxysilane containing PAG was formed on a glass substrate and irradiated with ultraviolet rays to promote sol-gel reaction by catalytic action of acid which was generated from PAG. And then the film was hardened with microwave irradiation, yielding organic-inorganic hybrid polymer film having hardness, highly transparency and strong adhesion with a glass substrate. Since this reaction only occurred in the optically (UV) irradiated regions, by exploiting the difference between the adhesivenesses of these regions photo-irradiated through photomask with a glass substrate, it was possible to form a patterned film with pitch of 100 to 50 μm by a simple lift-off method. A pigment-containing film using latent pigments (with subtractive three primary colors of coloring materials) and a patterned film were prepared, and it was possible to make these films multi-colored by varying the mixing ratio of the pigments. This multi-colored film-preparation method is effective for simply and efficiently forming a color-filter film by applying optical and microwave irradiation.展开更多
The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE univer...The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE universal material testing machine and Aramis V6 digital image correlation( DIC) technique.More specifically,the composite samples own four hybrid ratios(Na∶ Nc= 12∶ 0,8 ∶ 4,6 ∶ 6 and 4 ∶ 8). The results showed that the aramid/carbon hybrid MBWK fabric reinforced composites showed nearly linear response until reaching the maximum load and the inserting yarns distribution on the surface of MBWK fabrics reinforced composites had a great influence on the strain pattern distribution. Besides,the tensile strength,the tensile modulus and the elongation at breakage of 0° samples and 90° samples increased with the decreasing of aramid/carbon hybrid ratio. In a word,the changes of tensile strength, tensile modulus and elongation at breakage have a lot to do with the difference of aramid/carbon hybrid ratio.展开更多
Recently, the National Typhoon Center (NTC) at the Korea Meteorological Administration launched a track-pattern-based model that predicts the horizontal distribution of tropical cyclone (TC) track density from Jun...Recently, the National Typhoon Center (NTC) at the Korea Meteorological Administration launched a track-pattern-based model that predicts the horizontal distribution of tropical cyclone (TC) track density from June to October. This model is the first approach to target seasonal TC track clusters covering the entire western North Pacific (WNP) basin, and may represent a milestone for seasonal TC forecasting, using a simple statistical method that can be applied at weather operation centers. In this note, we describe the procedure of the track-pattern-based model with brief technical background to provide practical information on the use and operation of the model. The model comprises three major steps. First, long-term data of WNP TC tracks reveal seven climatological track clusters. Second, the TC counts for each cluster are predicted using a hybrid statistical-dynamical method, using the seasonal prediction of large-scale environments. Third, the final forecast map of track density is constructed by merging the spatial probabilities of the seven clusters and applying necessary bias corrections. Although the model is developed to issue the seasonal forecast in mid-May, it can be applied to alternative dates and target seasons following the procedure described in this note. Work continues on establishing an automatic system for this model at the NTC.展开更多
针对特征权重难以准确量化的问题,提出一种基于灰狼优化(grey wolf optimizer, GWO)算法和鸟群算法(bird swarm algorithm, BSA)的混合算法,用于特征权重的寻优。首先,将Chebyshev映射、反向学习与精英策略用于混合算法的初始种群生成;...针对特征权重难以准确量化的问题,提出一种基于灰狼优化(grey wolf optimizer, GWO)算法和鸟群算法(bird swarm algorithm, BSA)的混合算法,用于特征权重的寻优。首先,将Chebyshev映射、反向学习与精英策略用于混合算法的初始种群生成;其次,将改进后的GWO算法位置更新策略融入BSA的觅食行为中,得到一种新的局部搜索策略;然后,将BSA的警觉行为与飞行行为用作混合算法的全局搜索平衡策略,从而得到一种收敛的灰狼-鸟群算法(grey wolf and bird swarm algorithm, GWBSA),通过GWBSA的迭代寻优可获得各特征的权重值。利用标准测试函数和标准分类数据集进行了对比实验,与遗传算法、蚁狮算法等方法相比,GWBSA具有较快的收敛速度且不易陷入局部最优,可以提高模式分类问题的求解质量。展开更多
基金Supported by the Foundation of the State Key Laboratory of Mechanical Transmission of Chongqing University under Grant Nos SKLMT-KFKT-201419 and SKLM-ZZKT-2015Z16the National High-Technology Research and Development Program of China under Grant No 2015AA034801+4 种基金the National Natural Science Foundation of China under Grant Nos 11374359,11304405,11544010 and 11547305the Chongqing Education Commission Scientific Project under Grant No KJ132209the Natural Science Foundation of Chongqing under Grant Nos cstc2013jcyjA50031,cstc2015jcyjA50035 and cstc2015jcyjA1660the Fundamental Research Funds for the Central Universities under Grant Nos CDJZR14135502,CDJZR14300050,106112016CDJZR288805 and 106112015CDJXY300002the Sharing Fund of Large-scale Equipment of Chongqing University under Grant Nos 201512150017,201512150029 and 201512150030
文摘The thermal-electrical characteristic of a GaN light-emitting diode (LED) with the hybrid transparent conductive layers (TCLs) of graphene (Gr) and NiOx is investigated by a finite element method. It is indicated that the LED with the compound TCL of 3-layer Gr and 1 nm NiOx has the best thermal-electrical performance from the view point of the maximum temperature and the current density deviation of multiple quantum wells, and the maximum temperature occurs near the n-electrode rather than p-electrode. Furthermore, to depress the current crowding on the LED, the electrode pattern parameters including p- and n-electrode length, p-electrode buried depth and the distance of n-electrode to active area are optimized. It is found that either increasing p- or n-electrode length and buried depth or decreasing the distance of n-electrode from the active area will decrease the temperature of the LED, while the increase of the n-electrode length has more prominent effect. Typically, when the n-electrode length increases to 0.8 times of the chip size, the temperature of the GaN LED with the inm NiOx/3-1ayer-Gr hybrid TCLs could drop about 7K and the current density uniformity could increase by 23.8%, compared to 0.4 times of the chip size. This new finding will be beneficial for improvement of the thermal- electrical performance of LEDs with various conductive TCLs such as NiOx/Gr or ITO/Gr as current spreading layers.
基金funded through an NSF Doctoral Dissertation Improvement Grant(DEB-1406989)funded through NIH award number P20GM103638
文摘Background: The Great Plains of the United States includes a large number of hybrid and contact zones between bird species. The amount of gene flow between sister species in these zones ranges from very rare hybridization events to widespread and prevalent introgression. Some of these avian systems have been studied extensively, while others have been indeterminate of whether hybridization exists in areas of sympatry. Using genomic-level approaches allows investigation of genomic patterns of hybridization and gene flow between species—or lack thereof.Methods: We investigated a narrow zone of sympatry in Nebraska, USA between pewee species(Contopus sordidulus and C. virens), for which no hybridization has been confirmed. We used thousands of single nucleotide polymorphisms to identify potential hybridization and investigate genomic patterns of differentiation between these two species.Results: We found evidence of multiple hybrid individuals in the contact zone. Little genomic variation was fixed between species, but a large proportion had differentiated allele frequencies between species. There was a positive relationship between genetic differentiation and chromosome size.Conclusions: We provided the first conclusive evidence of hybridization between C. sordidulus and C. virens, in a region where secondary contact likely occurred due to human disturbance and habitat modification. The genomic patterns of differentiation affirm that these species split in the relatively recent past. Finally, the relationship of chromosome size and genetic differentiation may have resulted from differential rates of chromosomal recombination in songbirds and genetic differentiation between species largely due to genetic drift(possibly in concert with selection).
文摘Seasonal variations in environmental conditions can have significant influence on flowering pattern and yield of roses. Evaluation studies were conducted to determine the flowering pattern and yield determinants of two Hybrid Tea rose cultivars in response to seasonal variations under rain-fed conditions. The 2 × 2 × 4 factorial experiment arranged in split plot design at three replications was conducted at two seasons (dry and wet) using two cultivars (cv. “Immaculate” and “P.H. Baby”, white and red flowers respectively) supplied with poultry manure (PM) application rates at 5, 10 and 20 t/ha where the unfertilized (0 t/ha) served as control. The result showed that the year two environmental conditions of both experiment I and II significantly improved plant height, number of leaves, number of buds (CNB) and opened flowers (CNF) and flower yield (FYD). “Immaculate” was significantly (p ≤ 0.05) taller with more leaves but thinner girth. Although generally lower in NF/NB, and not different in FYD, the “P.H. Baby” had more flowers (CNB and CNF) in experiment I. Except for no significant difference in FYD and lower NF/NB recorded by all manure rates compared to control in experiment II, plants treated with 5 t/ha PM recorded more flowers (CNB and CNF). Significant first and second order interaction effects (p ≤ 0.05) showed that “Immaculate” had taller height and more leaves but “P.H. Baby” had more CNB and CNF, although both were not different in FYD. In addition, plants supplied with 5 t/ha PM rates were better in plant height, number of leaves, CNB and CNF compared to other manure rates. In conclusion, year two environmental conditions supported better crop growth and yield, “Immaculate” grew better vegetatively but both were not different in floral yield, while the 5 t/ha PM was considered the optimum manure application rate under the rain-fed condition.
文摘Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigment by using photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin film modified with methoxysilane containing PAG was formed on a glass substrate and irradiated with ultraviolet rays to promote sol-gel reaction by catalytic action of acid which was generated from PAG. And then the film was hardened with microwave irradiation, yielding organic-inorganic hybrid polymer film having hardness, highly transparency and strong adhesion with a glass substrate. Since this reaction only occurred in the optically (UV) irradiated regions, by exploiting the difference between the adhesivenesses of these regions photo-irradiated through photomask with a glass substrate, it was possible to form a patterned film with pitch of 100 to 50 μm by a simple lift-off method. A pigment-containing film using latent pigments (with subtractive three primary colors of coloring materials) and a patterned film were prepared, and it was possible to make these films multi-colored by varying the mixing ratio of the pigments. This multi-colored film-preparation method is effective for simply and efficiently forming a color-filter film by applying optical and microwave irradiation.
基金Tianjin Municipal Science and Technology Commission for the Financial Supports,China(No.11ZCKFSF00500)China's General Administration of Quality Supervision,Inspection and Quarantine for the Financial Supports,China(No.201210260)
文摘The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE universal material testing machine and Aramis V6 digital image correlation( DIC) technique.More specifically,the composite samples own four hybrid ratios(Na∶ Nc= 12∶ 0,8 ∶ 4,6 ∶ 6 and 4 ∶ 8). The results showed that the aramid/carbon hybrid MBWK fabric reinforced composites showed nearly linear response until reaching the maximum load and the inserting yarns distribution on the surface of MBWK fabrics reinforced composites had a great influence on the strain pattern distribution. Besides,the tensile strength,the tensile modulus and the elongation at breakage of 0° samples and 90° samples increased with the decreasing of aramid/carbon hybrid ratio. In a word,the changes of tensile strength, tensile modulus and elongation at breakage have a lot to do with the difference of aramid/carbon hybrid ratio.
基金funded by the Korea Meteorological Administration Research and Development Program under Grant CATER 2012-2040supported by the BK21 project of the Korean government
文摘Recently, the National Typhoon Center (NTC) at the Korea Meteorological Administration launched a track-pattern-based model that predicts the horizontal distribution of tropical cyclone (TC) track density from June to October. This model is the first approach to target seasonal TC track clusters covering the entire western North Pacific (WNP) basin, and may represent a milestone for seasonal TC forecasting, using a simple statistical method that can be applied at weather operation centers. In this note, we describe the procedure of the track-pattern-based model with brief technical background to provide practical information on the use and operation of the model. The model comprises three major steps. First, long-term data of WNP TC tracks reveal seven climatological track clusters. Second, the TC counts for each cluster are predicted using a hybrid statistical-dynamical method, using the seasonal prediction of large-scale environments. Third, the final forecast map of track density is constructed by merging the spatial probabilities of the seven clusters and applying necessary bias corrections. Although the model is developed to issue the seasonal forecast in mid-May, it can be applied to alternative dates and target seasons following the procedure described in this note. Work continues on establishing an automatic system for this model at the NTC.
文摘针对特征权重难以准确量化的问题,提出一种基于灰狼优化(grey wolf optimizer, GWO)算法和鸟群算法(bird swarm algorithm, BSA)的混合算法,用于特征权重的寻优。首先,将Chebyshev映射、反向学习与精英策略用于混合算法的初始种群生成;其次,将改进后的GWO算法位置更新策略融入BSA的觅食行为中,得到一种新的局部搜索策略;然后,将BSA的警觉行为与飞行行为用作混合算法的全局搜索平衡策略,从而得到一种收敛的灰狼-鸟群算法(grey wolf and bird swarm algorithm, GWBSA),通过GWBSA的迭代寻优可获得各特征的权重值。利用标准测试函数和标准分类数据集进行了对比实验,与遗传算法、蚁狮算法等方法相比,GWBSA具有较快的收敛速度且不易陷入局部最优,可以提高模式分类问题的求解质量。