Understanding Bridging Sites and Accelerating Quantum Efficiency for Photocatalytic CO_(2) Reduction

We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.

DESIGN OF BEAM-WAVE INTERACTION BASED ON HIGH EFFICIENCY OF A HIGH-POWER BROADBAND KLYSTRON

The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandwidth synthetically.As a part of beam-wave interaction section,buncher section is simulated by Particle-In-Cell(PIC) code to observe the bunching process of electron beam to achieve high conversion efficiency of electron beam and RF field.When it comes to the other part,output circuit is designed as a three-section filter by an output cavity loaded with Chebyshev filter,and the cold test results are given.The beam-wave interaction is simulated by EGUN code and Arsenal-MSU code respectively.The simulated results indicated that,the existence of power dips in the operating bandwidth is verified by Arsenal-MSU code,comparing proper results by EGUN code.Then,the method that design parameters are not adjusted except parameters of buncher cavities to remove potential power dips is described.What is more,the simulated results of electron optics system are given by EGUN code and Arsenal-MSU code respectively.The further hot test results of klystron prove that the whole design of beam-wave interaction is effective.

Interaction of Carbon Dioxide Enrichment and Soil Moisture on Photosynthesis, Transpiration, and Water Use Efficiency of Soybean

Soybean (Glycine max (L.) Merrill) is one of the most important oil and protein sources in the world. Interactive effect of elevated carbon dioxide (CO2) and soil water availability potentially impact future food security of the world under climate change. A rhizotron growth chamber experiment was conducted to study soil moisture interactions with elevated CO2 on gaseous exchange parameters of soybean under two CO2 concentrations (380 and 800 μmol·mol-1) with three soil moisture levels. Elevated CO2 decreased photosynthetic rate (11.1% and 10.8%), stomatal conductance (40.5% and 36.0%), intercellular CO2 concentration (16.68% and 12.28%), relative intercellular CO2 concentration (17.4% and 11.2%), and transpiration rate (43.6% and 39%) at 42 and 47 DAP. This down-regulation of photosynthesis was probably caused by low leaf nitrogen content and decrease in uptake of nutrients due to decrease in stomatal conductance and transpiration rate. Water use efficiency (WUE) increased under elevated CO2 because increase in total dry weight of plant was greater than that of water use under high CO2 conditions. Plants under normal and high soil moisture levels had significantly higher photosynthetic rate (7% to 16%) favored by optimum soil moisture content and high specific water content of soybean plants. Total dry matter production was significantly high when plants grown under elevated CO2 with normal (74.3% to 137.3%) soil moisture level. Photosynthetic rate was significantly and positively correlated with leaf conductance and intercellular CO2 concentration but WUE was significantly negatively correlated with leaf conductance, intercellular CO2 concentration and transpiration rate. However, the effect of high CO2 on plants depends on availability of nutrients and soil moisture for positive feedback from CO2 enrichment.

Noncovalent interactions on the electrocatalytic oxidation of ethanol on a Pt/C electrocatalyst

Due to their environmentally friendly nature and high energy density,direct ethanol fuel cells have attracted extensive research attention in recent decades.However,the actual Faraday efficiency of the ethanol oxidation reaction(EOR)is much lower than its theoretical value and the reaction kinetics of the EOR is sluggish due to insufficient active sites on the electrocatalyst surface.Pt/C is recognized as one of the most promising electrocatalysts for the EOR.Thus,the microscopic interfacial reaction mechanisms of the EOR on Pt/C were systematically studied in this work.In metal hydroxide solutions,hydrated alkali cations were found to bind with OH_(ad)through noncovalent interactions to form clusters and occupy the active sites on the Pt/C electrocatalyst surface,thus resulting in low Faraday efficiency and sluggish kinetics of the EOR.To reduce the negative effect of the noncovalent interactions on the EOR,a shield was made on the electrocatalyst surface using 4-trifluoromethylphenyl,resulting in twice the EOR catalytic reactivity of Pt/C.

The Relationship between Water Resources Use Efficiency and Scientific and Technological Innovation Level: Case Study of Yangtze River Basin in China

The Yangtze River Basin’s water resource utilization efficiency(WUE)and scientific and technological innovation level(STI)are closely connected,and the comprehension of these relationships will help to improve WUE and promote local economic growth and conservation of water.This study uses 19 provinces and regions along the Yangtze River’s mainstream from 2009 to 2019 as its research objects and uses a Vector Auto Regression(VAR)model to quantitatively evaluate the spatiotemporal evolution of the coupling coordination degree(CCD)between the two subsystems of WUE and STI.The findings show that:(1)Both the WUE and STI in the Yangtze River Basin showed an upward trend during the study period,but the STI effectively lagged behind the WUE;(2)The CCD of the two subsystems generally showed an upward trend,and the CCD of each province was improved to varying degrees,but the majority of regions did not develop a high-quality coordination stage;(3)The CCD of the two systems displayed apparent positive spatial autocorrelation in the spatial correlation pattern,and there were only two types:high-high(H-H)urbanization areas and low-low(L-L)urbanization areas;(4)The STI showed no obvious response to the impact of the WUE,while the WUE responded greatly to the STI,and both of them were highly dependent on themselves.Optimizing their interaction mechanisms should be the primary focus of high-quality development in the basin of the Yangtze River in the future.These results give the government an empirical basis to enhance the WUE and promote regional sustainable development.

Efficient seismic analysis for nonlinear soil-structure interaction with a thick soil layer

The direct finite element method is a type commonly used for nonlinear seismic soil-structure interaction(SSI)analysis.This method introduces a truncated boundary referred to as an artificial boundary meant to divide the soil-structure system into finite and infinite domains.An artificial boundary condition is used on a truncated boundary to achieve seismic input and simulate the wave radiation effect of infinite domain.When the soil layer is particularly thick,especially for a three-dimensional problem,the computational efficiency of seismic SSI analysis is very low due to the large size of the finite element model,which contains an whole thick soil layer.In this paper,an accurate and efficient scheme is developed to solve the nonlinear seismic SSI problem regarding thick soil layers.The process consists of nonlinear site response and SSI analysis.The nonlinear site response analysis is still performed for the whole thick soil layer.The artificial boundary at the bottom of the SSI analysis model is subsequently relocated upward from the bottom of the soil layer(bedrock surface)to the location nearest to the structure as possible.Finally,three types of typical sites and underground structures are adopted with seismic SSI analysis to evaluate the accuracy and efficiency of the proposed efficient analysis scheme.

Numerical evaluation of passive control of shock wave/boundary layer interaction on NACA0012 airfoil using jagged wall

Shock formation due to flow compressibility and its interaction with boundary layers has adverse effects on aerodynamic characteristics, such as drag increase and flow separation. The objective of this paper is to appraise the practicability of weakening shock waves and, hence, reducing the wave drag in transonic flight regime using a two-dimensional jagged wall and thereby to gain an appropriate jagged wall shape for future empirical study. Different shapes of the jagged wall, including rectangular, circular, and triangular shapes, were employed. The numerical method was validated by experimental and numerical studies involving transonic flow over the NACA0012 airfoil, and the results presented here closely match previous experimental and numerical results. The impact of parameters, including shape and the length-to-spacing ratio of a jagged wall, was studied on aerodynamic forces and flow field. The results revealed that applying a jagged wall method on the upper surface of an airfoil changes the shock structure significantly and disintegrates it, which in turn leads to a decrease in wave drag. It was also found that the maximum drag coefficient decrease of around 17 % occurs with a triangular shape, while the maximum increase in aerodynamic efficiency（lift-to-drag ratio）of around 10 % happens with a rectangular shape at an angle of attack of 2.26？.

Shaking Table Model Test of Isolated Structure on Soft Site and Analysis on Its Isolation Efficiency

Adopting a soft site model built on soft interlayer soil foundation,a shaking table test for soft interlayer soil-isolated structure interaction is conducted to investigate the seismic response of isolated structure on soft site,and analyze its isolation effect.Test results show that the test can reflect the earthquake response characteristics of isolated structure on soft site.It is on soft site that the dynamic characteristics of isolated structure,acceleration magnification factor(AMF)of isolated structure and isolation efficiency of the isolation layer differ from those on rigid foundation with an soil-structure interaction(SSI)effect,represented by the reduction in fundamental vibration frequency of isolated structure and the increase of damping ratio with changes of the SSI effect.SSI can either increase or decrease AMF of isolated structure on soft site,depending on the characteristics of earthquake motion input.Furthermore,the isolation efficiency of isolation layer on soft site is decreased with the SSI effect,which is related to the peak ground acceleration(PGA)and the characteristics of earthquake motion input.

Effect of climate change on seasonal water use efficiency in subalpine Abies fabri

Abies fabri is a typical subalpine dark coniferous forest in southwestern China. Air temperature increases more at high elevation areas than that at low elevation areas in mountainous regions,and climate change ratio is also uneven in different seasons. Carbon gain and the response of water use efficiency(WUE) to annual and seasonal increases in temperature with or without CO_2 fertilization were simulated in Abies fabri using the atmospheric-vegetation interaction model(AVIM2). Four future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5(CMIP5) were selectively investigated. The results showed that warmer temperatures have negative effects on gross primary production(GPP) and net primary production(NPP) in growing seasons and positive effects in dormant seasons due to the variation in the leaf area index. Warmer temperatures tend to generate lower canopy WUE and higher ecosystem WUE in Abies fabri. However,warmer temperature together with rising CO_2 concentrations significantlyincrease the GPP and NPP in both growing and dormant seasons and enhance WUE in annual and dormant seasons because of the higher leaf area index(LAI) and soil temperature. The comparison of the simulated results with and without CO_2 fertilization shows that CO_2 has the potential to partially alleviate the adverse effects of climate warming on carbon gain and WUE in subalpine coniferous forests.

Effects of tin and sulphur on magnetism and its interaction in effecient non-oritened silicon steel

Based on the manufacture of efficient non-oriented silicon steel grade,the effects of tin and sulphur on magnetism and its interaction was discussed.The results showed that for present work,minor tin could improve magnetic induction sharply and had little effect on core loss when the sulphur content below 10×10^(-4)%.The precipitation of AlN could be prohibitted by tin,remarkably.As the nucleus,tin could removal any inclusions which size was 0.5μm or above,and had little effect on inclusions which size was below 0.5μm as a key factor for core loss.For final sample,the magnetic induction was improved through the change of steel texture by tin.The relationship between magnetic induction and tin,sulphur content could be regressed:B = 1.69 - 4.37S + 0.30Sn.From the regression formulation,magnetic induction could be improved for 0.03 T when 0.01%tin was added under the condition of relatively low sulphur content.

Effect of Nitrogen and Density Interaction on Yield Formation of Late Japonica Rice Under Different Transplanting Dates

[Objectives]This study was conducted to clarify the appropriate nitrogen fertilizer amount and transplanting density that should be selected for different transplanting dates.[Methods]The effects of nitrogen fertilizer rate and transplanting density on the traits and yield of late japonica rice in the Jianghuai rice-wheat cropping area under different transplanting dates(transplanting at an appropriate time and delayed transplanting)were studied.[Results]The transplanting date significantly affected the heading,maturity and whole growth period of rice,and when the transplanting date of early-maturing late japonica rice was delayed by 15 d,the growth period was shortened by about 10 d.Nitrogen and density interaction obviously affected the dry matter accumulation and effective tillers of rice,and the dry matter production and effective tiller number of rice treated with B_(1)N_(2) were greater than other treatments.Under the timely transplanting date,the best nitrogen and density combination was 225-300 kg/hm^(2) and 250500 holes/hm^(2),and the nitrogen use efficiency was ideal.It suggests that under the condition of transplanting rice in a timely manner,applying nitrogen fertilizer at an appropriate rate while ensuring a reasonable population density is conducive to the coordination of the number of stems and tillers,the number of grains per panicle,etc.,thereby ensuring the best formation of yield factors in the middle and late stages of rice growth.[Conclusions]This study provides technical support and theoretical reference for reasonable nitrogen and density interaction of rice.

基于交互式设计超材料建模与分析的MCR-WPT效率提升研究

超材料具有特殊的磁场调控能力,被广泛关注并应用于磁耦合谐振无线电能传输(MCR-WPT)领域,但寻求针对特定领域目标需求的超材料设计具有挑战性.目前,超材料的一般设计方法为S参数反演法和等效电路法,设计流程通常需要多次建模仿真得到目标参数,该过程较为繁琐耗时.对此,深入分析上述两种设计方法的特性并将二者结合,采用HFSS与MATLAB软件交互设计和优化用于MCR-WPT特性提升的超材料,有效简化了超材料的设计过程.以无线电能传输效率优化为目标设计方形和Koch两种超材料单元,分析对比两种单元的电磁特性.搭建工作频率为6.78 MHz的MCR-WPT系统实验平台,探究两种超材料对传输效率的影响.实验结果表明,方形超材料和Koch超材料分别实现了28.4%和24.6%的最大传输效率提升,证明了交互设计可以更简便地设计超材料并且用于无线电能传输系统传输效率的提升.

螺旋缝隙泄漏双向流固耦合方法

针对螺杆泵泄漏机理,利用数值模拟加数据拟合方法,提出了一种针对螺杆泵螺旋微小缝隙泄漏的双向流固耦合模拟方法.利用此方法,对比了单向流固耦合和双向流固耦合方法在螺杆泵泄漏计算结果的偏差,计算结果表明,间隙越小偏差越大,间隙为0.500 mm时两结果相差20.3%,说明螺杆泵这种刚柔配合螺旋缝隙泄漏必须利用双向流固耦合求解才能获得准确结果.随后利用双向流固耦合方法对三维螺杆泵模型进行有限元分析求解,研究了初始间隙、流体介质黏度、螺杆泵单级腔室压差、进出口压力对螺杆泵泄漏的影响.结果显示:泄漏量随初始间隙的增大而增大,随流体介质黏度的增大而减少;进出口压力变化对螺杆泵泄漏影响很小,可以忽略;腔室间的压差造成橡胶定子变形形成间隙,间隙随着压差增大呈线性增大.最后利用双向流固耦合方法计算了不同举升压力螺杆泵的容积效率,与试验结果对比误差在±5%以内.

互动仪式链视域下数字阅读的情感认同与效能提升研究

互动、分享是数字阅读的必要元素,其仪式化过程呈现出时空分散、媒介多元、符号丰富的显著特点。论文通过对“剧本体验”等社交阅读新实践的分析,提出数字阅读互动仪式链的情境营造、仪式形成、情感认同三步骤构建模型,并从营造阅读情境,建构互动仪式;强化情感共享,推进集体兴奋;激发情感能量,创造价值符号三方面实现数字阅读增值。

雾气下心电监护仪界面视觉搜索效率研究

目的研究护目镜产生雾气情况下心电监护仪界面的字符大小及颜色一致性对信息视觉搜索效率的影响。方法通过模拟护目镜在不同雾气程度下的场景,控制不同字符大小、颜色一致性,考察三者对医护人员视觉搜索效率的影响。实验中37位被试依次完成眼动实验,记录其行为数据和眼动数据,深入探讨三种变量因素的交互效应。结果使用心电监护仪时不同雾气程度、字符大小、颜色一致性三种因素的交互效应显著,其中行为数据的三种因素交互效应显著P<0.001,眼动数据的三种因素交互效应显著P<0.05。未产生雾气与低雾气场景下,大字符、颜色不一致视觉搜索效率最高;中雾气与高雾气场景下,中字符、颜色不一致的视觉搜索效率最高。结论三种因素在不同条件下,交互效应的视觉搜索效率不同,设计人员可根据护目镜产生的雾气程度,调整心电监护仪界面字符大小与颜色一致性,以提升医护人员的视觉搜索效率。

宽带无线通信系统环境的电磁处理体系与方法

围绕系统性电磁处理,分析了近年来相关研究工作和进展,提出了基于辐射端点连接面为基准的电磁处理网络架构和基站终端多维辐射体等效辐射模型,以及面向正向电磁利用、反向电磁抑制的电磁互作用分析技术和面向空中电磁特性控制的测试技术等。仿真和测试表明,所提出的多频组网电磁频谱规划突破了多频带及大带宽难题,提高了频谱利用率和复杂环境的主动电磁调控能力;所提出的基本模型及计算方法,突破了受限空间中高效电磁计算预测以及电路天线一体化难点;室外场景重构测试建模提升了精准重现及多场景辐射一致性评估水平。16双极化探头均匀分布、支持4×4的多探头方法被3GPP 5G标准TR 38.827正式采纳。

面向高效互动教学的智慧课堂教学设计研究——以《配送中心运营管理》为例

智慧课堂作为一种智能技术与智慧教学深度融合的人工生态系统,其核心特征是强交互性。文章分析了智慧课堂教学新诉求,在对《配送中心运营管理》传统课堂教学模式困扰剖析的基础上,提出了面向高效互动教学的智慧课堂教学设计,以便更好的应对复杂又多样的教学环境,实现师、生、技术三者之间的全方位、高效互动。

中国职业足球联赛制度变迁与优化:基于效率与公平的视角

采用文献资料法和数据分析法,借鉴新制度经济学和产业组织相关理论,基于效率与公平的视角,梳理中国职业足球联赛制度变迁历程。结合现行制度下足球联赛绩效现状,对联赛制度变迁的应然环境进行剖析,继而从青木昌彦提出的制度的三种历时联动机制出发探讨联赛制度的优化路径。发现:库兹涅茨曲线可用以解释我国职业体育领域收入分配与绩效之间的关系,为未来职业足球联赛制度改革指明了可能的方向;职业足球俱乐部竞技实力有限,职业足球联赛可竞争性不足,而制度失衡是联赛绩效低下的根本原因。未来应从完善市场体系和促进联赛参与主体协同方面培育中国职业足球联赛良好的制度环境。具体优化路径包括:继续深化体制改革,利用制度联动效应引导联赛市场竞争机制不断完善;创新制度互动模式,以制度联动机制再造和制度派生效应弥补非正式制度自发运行中的缺陷;形成更高层次制度互鉴,借助技术溢出效应孵化出我国特色职业联赛制度。

马铃薯钾镁互作效应研究进展

针对马铃薯生产中钾、镁肥配施不合理,钾、镁养分互作调控关系缺乏系统清晰认识的问题,本文结合国内外研究报道,系统综述了钾、镁元素交互效应对马铃薯生长发育与形态建成、养分吸收与运移、块茎产量与品质形成的影响,深入分析了适合马铃薯生长的土壤K+/Mg2+比值范围,提出了马铃薯优质高产与养分高效协同提升的钾、镁互作研究发展方向,以期为马铃薯钾、镁肥的合理施用提供参考。

某无人作战平台触控交互效率评价研究

为解决现有界面评价中存在的指标体系构建过程依据欠缺、评价数据主观程度过高、操控维度量化手段不足及评价方法客观属性考量较少等问题,本研究提出了一种基于拇指热区与眼动实验的触控交互效率评价方法.首先,从任务与人机交互过程视角切入,将拇指热区引入到评价指标体系中,并结合已有眼动指标提供了一种触控交互效率评价指标体系构建新思路;其次,分别通过改进专家评分、熵权法与CRITIC法得到各指标权值,并将其融合得到综合权重;然后,使用逼近理想解法(TOPSIS)评估地面无人机动作战平台多种原型方案的触控交互效率,得到最佳方案;最后,通过某型地面无人机动作战平台对本研究方法进行了应用与分析,验证了所提方法的有效性.