All-inorganic lead-free Cs_(2)AgBiBr_(6) double perovskite is a promising semiconductor for photodetection in daily life due to its outstanding photoelectrical properties,non-toxicity,and high stability.Compared with ...All-inorganic lead-free Cs_(2)AgBiBr_(6) double perovskite is a promising semiconductor for photodetection in daily life due to its outstanding photoelectrical properties,non-toxicity,and high stability.Compared with its organic-inorganic hybrid analogs,the fabrication method for Cs_(2)AgBiBr_(6) is not well developed.Solution-processed Cs_(2)AgBiBr_(6) films usually exhibit loosened morphology with small grains,many pin-holes,and abundant nonradiative defects.In particular,the disordered arrangements of Ag/Bi cations are thermodynamically favorable in Cs_(2)AgBiBr_(6),which contribute to the formation of self-trapped excitons and heavily restrict charge transport.Here in this work,a modified green antisolvent engineering strat-egy with phenethyl-ammonium bromide(PEABr)dissolved isopropyl alcohol(IPA)solution is developed to prepare high-quality Cs_(2)AgBiBr_(6) films.The PEABr/IPA treatment results in compact morphology with enlarged grains and promotes the ordered arrangements of Ag/Bi cations with improved charge transport.Through optimization,the target self-powered photodetector exhibits a responsivity of 0.38 AW−1,a spe-cific detectivity of 1.9×10^(12) Jones,a response time of 54/63μs,and a linear dynamic range of 107 dB,which is among the best-performing self-powered photodetectors based on lead-free perovskites.Our work thus provides a facile and green fabrication method for high-performance optoelectronic devices based on eco-friendly Cs_(2)AgBiBr_(6).展开更多
近三年,以大语言模型(large language models,LLMs)为代表的人工智能技术和产业得到快速发展,实际应用也取得显著效果。为应对国家和行业发展的需求,国内许多高校纷纷设置人工智能学院、学科和专业,但与计算机学院、学科及专业的边界仍...近三年,以大语言模型(large language models,LLMs)为代表的人工智能技术和产业得到快速发展,实际应用也取得显著效果。为应对国家和行业发展的需求,国内许多高校纷纷设置人工智能学院、学科和专业,但与计算机学院、学科及专业的边界仍不够明晰。为此,本文描述了人工智能的含义、组成,并试图厘清与计算机学科及专业的关系,提出人工智能学院与计算机学院学科、专业发展的一些建议,期望为后续相关研究提供参考。展开更多
[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other f...[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows： under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows： jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality.展开更多
利用CFPS(China family panel studies,中国家庭追踪调查)的混合截面数据,采用熵值法测度跨境电商发展水平,分析跨境电商发展对性别收入差距的影响及其内在作用机制。研究发现,跨境电商主要通过两个渠道显著缩小性别收入差距:一是就业效...利用CFPS(China family panel studies,中国家庭追踪调查)的混合截面数据,采用熵值法测度跨境电商发展水平,分析跨境电商发展对性别收入差距的影响及其内在作用机制。研究发现,跨境电商主要通过两个渠道显著缩小性别收入差距:一是就业效应,即提供女性就业机会;二是晋升效应,即拓展女性职业发展空间。异质性分析进一步表明,跨境电商的收入平等化效应在低技能劳动力群体中表现尤为突出,但在不同婚姻状况群体中未呈现显著差异。基于此,提出推动跨境电商包容性发展、完善有利于女性发展的跨境电商制度与政策环境等建议。展开更多
With the gradual implementation of a series of institutional arrangements, H ainan is becoming a new hot spot for global investment and an ideal destination for starting businesses and developing industry. While attra...With the gradual implementation of a series of institutional arrangements, H ainan is becoming a new hot spot for global investment and an ideal destination for starting businesses and developing industry. While attracting foreign investment projects, it is also creating more favorable conditions for local enterprises to expand into international markets.展开更多
Enamel,the inorganic tissue covering the crowns of teeth,is known for its remarkable resilience and hardness.These properties originate from its high proportion of mineralized matrix and complex internal microarchitec...Enamel,the inorganic tissue covering the crowns of teeth,is known for its remarkable resilience and hardness.These properties originate from its high proportion of mineralized matrix and complex internal microarchitecture.On an ultrastructural level,it consists of directionally arranged enamel prisms.Continuously growing rodent incisors are an exemplary case of this phenomenon.Their enamel has a consistent decussation pattern,providing teeth with extremely high resistance and ensuring they remain constantly sharp.While the decussation pattern has been described in detail,mechanisms behind its formation have not been experimentally proven.Here,we show that the highly organized enamel micropattern is generated by directional epithelial sliding of enamel-forming ameloblasts in vivo.Our results detail how enamel micropatterning stems from individual cell cluster segregation and subsequent reciprocal interweaving.Based on this determination,we introduce and experimentally demonstrate a new model of enamel decussation pattern formation.展开更多
To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains i...To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains in a subcritical state during routine,normal,and accidental transport conditions.In the event of an accident,the rods within the storage tank may become rearranged,introducing uncertainty that must be accounted for to ensure that criticality analysis results are conservative.Historically,this uncertainty was addressed overly conservatively due to limited research on non-uniform arrangement scenarios,which proved unsuitable for criticality safety analysis of spent fuel packages.This paper introduced three distinct methods to non-uniformly rearrange fuel rods—Uniform Arrangement by Blocks,Layer-by-Layer Determination,and Birdcage Deformation—and meticulously evaluates the influences of rod rearrangement on the effective multiplication factor of neutrons,k eff,utilizing the Monte Carlo method.Ultimately,this study presents a holistic method capable of encompassing the entire spectrum of potential effects stemming from the rearrangement of fuel rods during rods mispositioning accident.By augmenting the safety margin,this approach proves to be adeptly suited for the criticality safety analysis of nuclear fuel transport containers.展开更多
The possible states in the flow past two identical cylinders in tandem arrangements are investigated. The effect of the gap （L/D = 1.5, 1.75 and 2） between the two cylinders at Reynolds number （Re = 52,639） is tak...The possible states in the flow past two identical cylinders in tandem arrangements are investigated. The effect of the gap （L/D = 1.5, 1.75 and 2） between the two cylinders at Reynolds number （Re = 52,639） is taken into consideration. The presence of three-dimensional flow structures was observed to include notable changes to the response of the flow as result of variation of cylinder separation. A number of planes （z/h = 0.02, 0.25, 0.5 and 0.98） were taken at 20 step times of interval 0.005 s. to cover the details of flow along the cylinders. CFD FLUENT program was used to detect the flow structure. It is observed that the gap between the two cylinders affects the flow regime, i.e., there is no distinct vortex shedding downstream of the first cylinder.展开更多
基金supported by the National Natural Science Foundation of China(No.61704154)the Natural Science Foundation of Zhejiang Province(No.LY20F040006)the Open Foundation of the State Key Laboratory of Fluid Power and Mecha-tronic Systems(No.GZKF-202313).
文摘All-inorganic lead-free Cs_(2)AgBiBr_(6) double perovskite is a promising semiconductor for photodetection in daily life due to its outstanding photoelectrical properties,non-toxicity,and high stability.Compared with its organic-inorganic hybrid analogs,the fabrication method for Cs_(2)AgBiBr_(6) is not well developed.Solution-processed Cs_(2)AgBiBr_(6) films usually exhibit loosened morphology with small grains,many pin-holes,and abundant nonradiative defects.In particular,the disordered arrangements of Ag/Bi cations are thermodynamically favorable in Cs_(2)AgBiBr_(6),which contribute to the formation of self-trapped excitons and heavily restrict charge transport.Here in this work,a modified green antisolvent engineering strat-egy with phenethyl-ammonium bromide(PEABr)dissolved isopropyl alcohol(IPA)solution is developed to prepare high-quality Cs_(2)AgBiBr_(6) films.The PEABr/IPA treatment results in compact morphology with enlarged grains and promotes the ordered arrangements of Ag/Bi cations with improved charge transport.Through optimization,the target self-powered photodetector exhibits a responsivity of 0.38 AW−1,a spe-cific detectivity of 1.9×10^(12) Jones,a response time of 54/63μs,and a linear dynamic range of 107 dB,which is among the best-performing self-powered photodetectors based on lead-free perovskites.Our work thus provides a facile and green fabrication method for high-performance optoelectronic devices based on eco-friendly Cs_(2)AgBiBr_(6).
文摘近三年,以大语言模型(large language models,LLMs)为代表的人工智能技术和产业得到快速发展,实际应用也取得显著效果。为应对国家和行业发展的需求,国内许多高校纷纷设置人工智能学院、学科和专业,但与计算机学院、学科及专业的边界仍不够明晰。为此,本文描述了人工智能的含义、组成,并试图厘清与计算机学科及专业的关系,提出人工智能学院与计算机学院学科、专业发展的一些建议,期望为后续相关研究提供参考。
基金Supported by Special Foundation for Young Scientific and Technological Talents,Xinjiang Academy of Agricultural Sciences(xjnky-2012-009)Special Fund for Agroscientific Research in the Public Interest(201003043-07)+1 种基金Scientific Research Programof the Higher Education Institution of XinJiang(XJEDU2012S14)National-level College Students’Innovative Entrepreneurial Training Plan Program(201210758002)~~
文摘[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows： under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows： jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality.
文摘利用CFPS(China family panel studies,中国家庭追踪调查)的混合截面数据,采用熵值法测度跨境电商发展水平,分析跨境电商发展对性别收入差距的影响及其内在作用机制。研究发现,跨境电商主要通过两个渠道显著缩小性别收入差距:一是就业效应,即提供女性就业机会;二是晋升效应,即拓展女性职业发展空间。异质性分析进一步表明,跨境电商的收入平等化效应在低技能劳动力群体中表现尤为突出,但在不同婚姻状况群体中未呈现显著差异。基于此,提出推动跨境电商包容性发展、完善有利于女性发展的跨境电商制度与政策环境等建议。
文摘With the gradual implementation of a series of institutional arrangements, H ainan is becoming a new hot spot for global investment and an ideal destination for starting businesses and developing industry. While attracting foreign investment projects, it is also creating more favorable conditions for local enterprises to expand into international markets.
基金supported by the Czech Science Foundation (23-06160S)by the Faculty of Medicine of Masaryk University (MUNI/A/1738/2024)。
文摘Enamel,the inorganic tissue covering the crowns of teeth,is known for its remarkable resilience and hardness.These properties originate from its high proportion of mineralized matrix and complex internal microarchitecture.On an ultrastructural level,it consists of directionally arranged enamel prisms.Continuously growing rodent incisors are an exemplary case of this phenomenon.Their enamel has a consistent decussation pattern,providing teeth with extremely high resistance and ensuring they remain constantly sharp.While the decussation pattern has been described in detail,mechanisms behind its formation have not been experimentally proven.Here,we show that the highly organized enamel micropattern is generated by directional epithelial sliding of enamel-forming ameloblasts in vivo.Our results detail how enamel micropatterning stems from individual cell cluster segregation and subsequent reciprocal interweaving.Based on this determination,we introduce and experimentally demonstrate a new model of enamel decussation pattern formation.
文摘To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains in a subcritical state during routine,normal,and accidental transport conditions.In the event of an accident,the rods within the storage tank may become rearranged,introducing uncertainty that must be accounted for to ensure that criticality analysis results are conservative.Historically,this uncertainty was addressed overly conservatively due to limited research on non-uniform arrangement scenarios,which proved unsuitable for criticality safety analysis of spent fuel packages.This paper introduced three distinct methods to non-uniformly rearrange fuel rods—Uniform Arrangement by Blocks,Layer-by-Layer Determination,and Birdcage Deformation—and meticulously evaluates the influences of rod rearrangement on the effective multiplication factor of neutrons,k eff,utilizing the Monte Carlo method.Ultimately,this study presents a holistic method capable of encompassing the entire spectrum of potential effects stemming from the rearrangement of fuel rods during rods mispositioning accident.By augmenting the safety margin,this approach proves to be adeptly suited for the criticality safety analysis of nuclear fuel transport containers.
文摘The possible states in the flow past two identical cylinders in tandem arrangements are investigated. The effect of the gap （L/D = 1.5, 1.75 and 2） between the two cylinders at Reynolds number （Re = 52,639） is taken into consideration. The presence of three-dimensional flow structures was observed to include notable changes to the response of the flow as result of variation of cylinder separation. A number of planes （z/h = 0.02, 0.25, 0.5 and 0.98） were taken at 20 step times of interval 0.005 s. to cover the details of flow along the cylinders. CFD FLUENT program was used to detect the flow structure. It is observed that the gap between the two cylinders affects the flow regime, i.e., there is no distinct vortex shedding downstream of the first cylinder.
