Based on analyzing the thermal process of a CDQ (coke dry quenching)-Boiler system, the mathematical model for opti-mized operation and control in the CDQ-Boiler system was developed. It includes a mathematical mode...Based on analyzing the thermal process of a CDQ (coke dry quenching)-Boiler system, the mathematical model for opti-mized operation and control in the CDQ-Boiler system was developed. It includes a mathematical model for heat transferring process in the CDQ unit, a mathematical model for heat transferring process in the boiler and a combustion model for circulating gas in the CDQ-Boiler system. The model was verified by field data, then a series of simulations under several typical operating conditions of CDQ-Boiler were carried on, and in turn, the online relation formulas between the productivity and the optimal circulating gas, and the one between the productivity and the optimal second air, were achieved respectively. These relation equations have been success- fully used in a CDQ-Boiler computer control system in the Baosteel, to realize online optimized guide and control, and meanwhile high efficiency in the CDQ-Boiler system has been achieved.展开更多
Rice grain yield and quality are negatively impacted by high temperature stress.Irrigation water temperature significantly affects rice growth and development,thus influencing yield and quality.The role of cooler irri...Rice grain yield and quality are negatively impacted by high temperature stress.Irrigation water temperature significantly affects rice growth and development,thus influencing yield and quality.The role of cooler irrigation water in counteracting high temperature induced damages in rice grain yield and quality are not explored.Hence,in the present study two rice hybrids,Liangyoupeijiu(LYPJ)and IIyou 602(IIY602)were exposed to heat stress and irrigated with water having different temperatures in a splitsplit plot experimental design.The stress was imposed starting from heading until maturity under field-based heat tents,over two consecutive years.The maximum day temperature inside the heat tents was set at 38℃.For the irrigation treatments,two different water sources were used including belowground water with cooler water temperature and pond water with relatively higher water temperature.Daytime mean temperatures in the heat tents were increased by 1.2–2.0℃ across two years,while nighttime temperature remained similar at both within and outside the heat tents.Cooler belowground water irrigation did have little effect on air temperature at the canopy level but decreased soil temperature(0.2–1.4℃)especially under control.Heat stress significantly reduced grain yield(33%to 43%),panicles m^(-2)(9%to 10%),spikelets m^(-2)(15%to 22%),grain-filling percentage(13%to 26%)and 1000-grain weight(3%to 5%).Heat stress significantly increased chalkiness and protein content and decreased grain length and amylose content.Grain yield was negatively related to air temperature at the canopy level and soil temperature.Whereas grain quality parameters like chalkiness recorded a significantly positive association with both air and soil temperatures.Irrigating with cooler belowground water reduced the negative effect of heat stress on grain yield by 8.8%in LYPJ,while the same effect was not seen in IIY602,indicating cultivar differences in their response to irrigation water temperature.Our findings reveal that irrigating with cooler belowground water would not significantly mitigate yield loss or improve grain quality under realistic field condition.The outcome of this study adds to the scientific knowledge in understanding the interaction between heat stress and irrigation as a mitigation tool.Irrigation water temperature regulation at the rhizosphere was unable to counteract heat stress damages in rice and hence a more integrated management and genetic options at canopy levels should be explored in the future.展开更多
Responses to biotic and abiotic stress have been extensively studied in plants. In the current proteomic study, the cotton (Gossypium hirsutum L.) seedlings were infected with Verticillium dahliae by root-dip inoculat...Responses to biotic and abiotic stress have been extensively studied in plants. In the current proteomic study, the cotton (Gossypium hirsutum L.) seedlings were infected with Verticillium dahliae by root-dip inoculation using suspension of fungal conidia. The different proteins were analyzed by two-dimensional gel elactrophoresis (2-DE), and flavanone 3-hydroxylase (F3H) showed a significantly up-regulation in cotton leaf after V. dahliae infection. Further research revealed F3H and the downstream genes of F3H in proanthocyanidins (PAs) biosynthesis were also significantly induced and showed coordinate expression patterns during wounding. The results indicate that PAs in cotton act an important role in response to infection V. dahliae and wounding.展开更多
High-precision angle measurement of pulsars is critical for realizing pulsar navigation.Compared to visible light and radio waves,the wavelength of X-rays is incredibly short,which provides the possibility of achievin...High-precision angle measurement of pulsars is critical for realizing pulsar navigation.Compared to visible light and radio waves,the wavelength of X-rays is incredibly short,which provides the possibility of achieving better spatial resolution.However,due to the lack of applicable X-ray apparatus,extracting the angle information of pulsars through conventional X-ray methods is challenging.Here,we propose an approach of pulsar angle measurement based on spatially modulated X-ray intensity correlation(SMXIC),in which the angle information is obtained by measuring the spatial intensity correlation between two radiation fields.The theoretical model for this method has been established,and a proof-of-concept experiment was carried out.The SMXIC measurement of observing angles has been demonstrated,and the experimental results are consistent with the theoretical values.The potential of this method in future applications is discussed,and theoretically,the angular measurement at the level of micro-arcsecond can be expected.The sphere of pulsar navigation may benefit from our fresh insights.展开更多
As modern electronics are developed towards miniaturisation,high-degree integration and intelligentisation,a large amount of heat will be generated during the operation of devices.How to efficiently remove needless he...As modern electronics are developed towards miniaturisation,high-degree integration and intelligentisation,a large amount of heat will be generated during the operation of devices.How to efficiently remove needless heat is becoming more and more crucial for the lifetime and performance of electronic devices.Many efforts have been made to improve the thermal conductivity of polymer composites,which is an important component of electronics.Herein,the authors report on preparation of boron nitride micosphere/epoxy composites.The cross-plane thermal conductivity of the resultant composites is up to 1.03 Wm‒1K‒1.This is attributed to the thermally conductive network formed by the peeled hexagonal boron nitride flakes.Thanks to the superior thermal stability of boron nitride micosphere,the boron nitride micosphere/epoxy composite shows a decreased coefficient of thermal expansion(53.47 ppm/K)and an increased glass transition temperature(147.2℃)compared with the pure epoxy resin.In addition,the boron nitride micosphere/epoxy composite exhibits a lower dielectric constant compared with that of the hexagonal boron nitride/epoxy composite.This strategy can potentially pave the way for the design and fabrication of materials with high cross-plane thermal conductivity and lower dielectric properties.展开更多
To the Editor:Total aortic arch replacement(TAR)is a surgical procedure associated with significant perioperative risks,leading to a higher rate of mortality and neurologic complications.Ascending aortic or hemiarch r...To the Editor:Total aortic arch replacement(TAR)is a surgical procedure associated with significant perioperative risks,leading to a higher rate of mortality and neurologic complications.Ascending aortic or hemiarch replacement is associated with less complicated procedures,which can be used to effectively resect the proximal intimal tear and potentially improve the survival rates in these patients.[1]Hybrid aortic repair,combining openchest surgery and stent placement has been effectively used in patients with an aortic arch aneurysm.[2]Although a hybrid technique is often followed,only a limited number of studies with a small number of cases have investigated the application of this procedure for the treatment of type I aortic dissection.[1,2]This study aimed to evaluate the early and mid-term safety and efficacy of the hybrid technique in this cohort by analyzing a large sample size.展开更多
Aims The mechanisms of plant community assembly are hypothesized to vary at different stages of succession.Here,we explore the local assemblage structure of a herbaceous plant community at its early stage of successio...Aims The mechanisms of plant community assembly are hypothesized to vary at different stages of succession.Here,we explore the local assemblage structure of a herbaceous plant community at its early stage of succession in a supratidal wetland.specifically,we assess the role of Chinese saltcedar(Tamarix chinensis),the lone dominant shrub species,in shaping the spatial structure and species composi-tion in the local plant community,after landscape alteration.Methods We used the multivariate trend-surface analysis for analyzing the spatial structure of the community composition.a null model was also used to detect potential biotic interactions between species.statistical significance was derived from a permutation test by randomizing the presence-absence matrix and functional traits independently.sensitivity analysis by randomly selecting 50 subplots and repeating the null model tests was also done.Finally,rank correlation analysis was used to study the relationship between effect sizes and distance to nearest T.chinensis individuals.Important Findings The herbaceous plant community was highly structured and shaped by the presence of T.chinensis.at local scale,two functional traits,plant height and leaf area,were found to be significantly convergent.Dispersal,environmental stress and interspecific competition played a trivial effect on the local community assembly.The facilitating effect of T.chinensis on the pioneering herbaceous plants,through acting as a wind shelter,was put forward as the dominant community assembly process.展开更多
Taking the Enning Road Neighborhood Renovation Project in Guangzhou as a case, the paper aims to illustrate, based on the materials collected from interviews and news media, the dilemma of public participation in Chin...Taking the Enning Road Neighborhood Renovation Project in Guangzhou as a case, the paper aims to illustrate, based on the materials collected from interviews and news media, the dilemma of public participation in China's urban planning, as well as the role of a third party in urban planning. It argues that, within the current public participation framework, neither the "bottom-up" active participation nor the "top-down" passive participation can generate satisfactory effects or mediate multiple interests, whereas a professional third party could effectively promote public participation by bridging the public with the government. Besides, the third party plays an increasingly significant role in maintaining public interest, particularly in a context where the government often overemphasizes economic interests and there is a ubiquitous lack of awareness among the general public.展开更多
文摘Based on analyzing the thermal process of a CDQ (coke dry quenching)-Boiler system, the mathematical model for opti-mized operation and control in the CDQ-Boiler system was developed. It includes a mathematical model for heat transferring process in the CDQ unit, a mathematical model for heat transferring process in the boiler and a combustion model for circulating gas in the CDQ-Boiler system. The model was verified by field data, then a series of simulations under several typical operating conditions of CDQ-Boiler were carried on, and in turn, the online relation formulas between the productivity and the optimal circulating gas, and the one between the productivity and the optimal second air, were achieved respectively. These relation equations have been success- fully used in a CDQ-Boiler computer control system in the Baosteel, to realize online optimized guide and control, and meanwhile high efficiency in the CDQ-Boiler system has been achieved.
基金provided by Science and Technology Plan Project of Hunan Province(2019RS1054)Open Research Fund of State Key Laboratory of Hybrid Rice provided by Hunan Hybrid Rice Research Center(2018KF05)+4 种基金Scientific Research Fund of Hunan Provincial Education Department(18B109)Scientific Research Funding for Crop Science(YXQN2018-6)Hundred Talents Program of the Hunan Provincethe grant support from Hong Kong Research Grants Council(GRF 12103219 and 12103220 and Ao E/M-403/16)a Scholarship from Hong Kong Scholars Program。
文摘Rice grain yield and quality are negatively impacted by high temperature stress.Irrigation water temperature significantly affects rice growth and development,thus influencing yield and quality.The role of cooler irrigation water in counteracting high temperature induced damages in rice grain yield and quality are not explored.Hence,in the present study two rice hybrids,Liangyoupeijiu(LYPJ)and IIyou 602(IIY602)were exposed to heat stress and irrigated with water having different temperatures in a splitsplit plot experimental design.The stress was imposed starting from heading until maturity under field-based heat tents,over two consecutive years.The maximum day temperature inside the heat tents was set at 38℃.For the irrigation treatments,two different water sources were used including belowground water with cooler water temperature and pond water with relatively higher water temperature.Daytime mean temperatures in the heat tents were increased by 1.2–2.0℃ across two years,while nighttime temperature remained similar at both within and outside the heat tents.Cooler belowground water irrigation did have little effect on air temperature at the canopy level but decreased soil temperature(0.2–1.4℃)especially under control.Heat stress significantly reduced grain yield(33%to 43%),panicles m^(-2)(9%to 10%),spikelets m^(-2)(15%to 22%),grain-filling percentage(13%to 26%)and 1000-grain weight(3%to 5%).Heat stress significantly increased chalkiness and protein content and decreased grain length and amylose content.Grain yield was negatively related to air temperature at the canopy level and soil temperature.Whereas grain quality parameters like chalkiness recorded a significantly positive association with both air and soil temperatures.Irrigating with cooler belowground water reduced the negative effect of heat stress on grain yield by 8.8%in LYPJ,while the same effect was not seen in IIY602,indicating cultivar differences in their response to irrigation water temperature.Our findings reveal that irrigating with cooler belowground water would not significantly mitigate yield loss or improve grain quality under realistic field condition.The outcome of this study adds to the scientific knowledge in understanding the interaction between heat stress and irrigation as a mitigation tool.Irrigation water temperature regulation at the rhizosphere was unable to counteract heat stress damages in rice and hence a more integrated management and genetic options at canopy levels should be explored in the future.
文摘Responses to biotic and abiotic stress have been extensively studied in plants. In the current proteomic study, the cotton (Gossypium hirsutum L.) seedlings were infected with Verticillium dahliae by root-dip inoculation using suspension of fungal conidia. The different proteins were analyzed by two-dimensional gel elactrophoresis (2-DE), and flavanone 3-hydroxylase (F3H) showed a significantly up-regulation in cotton leaf after V. dahliae infection. Further research revealed F3H and the downstream genes of F3H in proanthocyanidins (PAs) biosynthesis were also significantly induced and showed coordinate expression patterns during wounding. The results indicate that PAs in cotton act an important role in response to infection V. dahliae and wounding.
基金financially supported by the National Natural Science Foundation of China(No.11627811)the National Key Research and Development Program of China(No.2017YFB0503303)Zhangjiang Laboratory。
文摘High-precision angle measurement of pulsars is critical for realizing pulsar navigation.Compared to visible light and radio waves,the wavelength of X-rays is incredibly short,which provides the possibility of achieving better spatial resolution.However,due to the lack of applicable X-ray apparatus,extracting the angle information of pulsars through conventional X-ray methods is challenging.Here,we propose an approach of pulsar angle measurement based on spatially modulated X-ray intensity correlation(SMXIC),in which the angle information is obtained by measuring the spatial intensity correlation between two radiation fields.The theoretical model for this method has been established,and a proof-of-concept experiment was carried out.The SMXIC measurement of observing angles has been demonstrated,and the experimental results are consistent with the theoretical values.The potential of this method in future applications is discussed,and theoretically,the angular measurement at the level of micro-arcsecond can be expected.The sphere of pulsar navigation may benefit from our fresh insights.
基金The authors acknowledge the financial support from National Natural Science Foundation of China(no.51603226)the National Key R&D Project from Minister of Science and Technology of China(2016YFA0202702)Shenzhen Fundamental Research Program(JCYJ20150831154213681).
文摘As modern electronics are developed towards miniaturisation,high-degree integration and intelligentisation,a large amount of heat will be generated during the operation of devices.How to efficiently remove needless heat is becoming more and more crucial for the lifetime and performance of electronic devices.Many efforts have been made to improve the thermal conductivity of polymer composites,which is an important component of electronics.Herein,the authors report on preparation of boron nitride micosphere/epoxy composites.The cross-plane thermal conductivity of the resultant composites is up to 1.03 Wm‒1K‒1.This is attributed to the thermally conductive network formed by the peeled hexagonal boron nitride flakes.Thanks to the superior thermal stability of boron nitride micosphere,the boron nitride micosphere/epoxy composite shows a decreased coefficient of thermal expansion(53.47 ppm/K)and an increased glass transition temperature(147.2℃)compared with the pure epoxy resin.In addition,the boron nitride micosphere/epoxy composite exhibits a lower dielectric constant compared with that of the hexagonal boron nitride/epoxy composite.This strategy can potentially pave the way for the design and fabrication of materials with high cross-plane thermal conductivity and lower dielectric properties.
文摘To the Editor:Total aortic arch replacement(TAR)is a surgical procedure associated with significant perioperative risks,leading to a higher rate of mortality and neurologic complications.Ascending aortic or hemiarch replacement is associated with less complicated procedures,which can be used to effectively resect the proximal intimal tear and potentially improve the survival rates in these patients.[1]Hybrid aortic repair,combining openchest surgery and stent placement has been effectively used in patients with an aortic arch aneurysm.[2]Although a hybrid technique is often followed,only a limited number of studies with a small number of cases have investigated the application of this procedure for the treatment of type I aortic dissection.[1,2]This study aimed to evaluate the early and mid-term safety and efficacy of the hybrid technique in this cohort by analyzing a large sample size.
基金National Natural Science Foundation of China(31000197 and 41101169)Knowledge Innovation Project of CAS(KZCX2-EW-QN209)+1 种基金National High Technology Research and Development Program of China(2013AA06A211-4)National Research Foundation of South Africa(89967 and 81825).
文摘Aims The mechanisms of plant community assembly are hypothesized to vary at different stages of succession.Here,we explore the local assemblage structure of a herbaceous plant community at its early stage of succession in a supratidal wetland.specifically,we assess the role of Chinese saltcedar(Tamarix chinensis),the lone dominant shrub species,in shaping the spatial structure and species composi-tion in the local plant community,after landscape alteration.Methods We used the multivariate trend-surface analysis for analyzing the spatial structure of the community composition.a null model was also used to detect potential biotic interactions between species.statistical significance was derived from a permutation test by randomizing the presence-absence matrix and functional traits independently.sensitivity analysis by randomly selecting 50 subplots and repeating the null model tests was also done.Finally,rank correlation analysis was used to study the relationship between effect sizes and distance to nearest T.chinensis individuals.Important Findings The herbaceous plant community was highly structured and shaped by the presence of T.chinensis.at local scale,two functional traits,plant height and leaf area,were found to be significantly convergent.Dispersal,environmental stress and interspecific competition played a trivial effect on the local community assembly.The facilitating effect of T.chinensis on the pioneering herbaceous plants,through acting as a wind shelter,was put forward as the dominant community assembly process.
基金the Third Prize at the 7th Youth Paper Awards of Urban Planning Society of China, which was also named as the 13th National Youth Thesis Competition on Urban Planning, sponsored by the Urban Planning Society of China
文摘Taking the Enning Road Neighborhood Renovation Project in Guangzhou as a case, the paper aims to illustrate, based on the materials collected from interviews and news media, the dilemma of public participation in China's urban planning, as well as the role of a third party in urban planning. It argues that, within the current public participation framework, neither the "bottom-up" active participation nor the "top-down" passive participation can generate satisfactory effects or mediate multiple interests, whereas a professional third party could effectively promote public participation by bridging the public with the government. Besides, the third party plays an increasingly significant role in maintaining public interest, particularly in a context where the government often overemphasizes economic interests and there is a ubiquitous lack of awareness among the general public.