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Patterns and drivers of seasonal water sources for artificial sand-fixing plants in the northeastern Mu Us sandy land,Northwest China

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Pedosphere 2024年第1期34卷 63-77页

作者： Yanwu PEI Laiming HUANG Ming'an shao jiao WANG Yinglong ZHANG Yellow River Delta Modern Agricultural Engineering Laboratory Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Natural Resources and Environment Northwest Agriculture and Forestry UniversityYangling 712100China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences of Chinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Shenmu Ecological Association Shenmu 719399China

Understanding plant water-use patterns is important for improving water-use efficiency and for sustainable vegetation restoration in arid and semi-arid regions. However, seasonal variations in water sources and their control by different sand-fixing plants in water-limited desert ecosystems remain poorly understood. In this study, stable isotopic ratios of hydrogen(δ^(2)H) and oxygen(δ^(18)O) in precipitation, soil water, groundwater, and xylem water were determined to document seasonal changes in water uptake by three representative plant species(Pinus sylvestris var. mongolica Litv., Amygdalus pedunculata Pall., and Salix psammophila) in the northeastern Mu Us sandy land, Northwest China. Based on the depth distribution and temporal variation of measured gravimetric soil water content(SWC), the soil water profile of the three species stands was divided into active(0.01 g g^(-1)45%) layers. Annually, P. sylvestris, A. pedunculata, and S. psammophila obtained most water from deep(59.2%±9.7%, moist layer and groundwater),intermediate(57.4%±9.8%, stable and moist layers), and shallow(54.4%±10.5%, active and stable layers) sources, respectively. Seasonally, the three plant species absorbed more than 60% of their total water uptake from the moist layer and groundwater in the early(June) dry season;then, they switched to the active and stable layers in the rainy season(July–September) for water resources(50.1%–62.5%). In the late(October–November) dry season, P. sylvestris(54.5%–66.2%) and A. pedunculata(52.9%–63.6%) mainly used water from stable and moist layers, whereas S. psammophila(52.6%–70.7%) still extracted water predominantly from active and stable layers. Variations in the soil water profile induced by seasonal fluctuations in precipitation and groundwater levels and discrepancies in plant pheno

关键词： desert ecosystem MixSIAR model plant water uptake soil moisture stable isotopes vegetation restoration water-use efficiency

3-D Tunnel Seismic Advance Prediction Method with Wide Illumination and High-Precision

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Journal of Earth Science 2024年第3期35卷 970-979页

作者： Peng Guan Cuifa shao Yuyong jiao Guohua Zhang Junpeng Zou Fei Tan Faculty of Engineering China University of GeosciencesWuhan 430074China

Tunnel seismic advance prediction can effectively reduce the construction risk during tunnel *** with the 2-D method,the 3-D method is more conducive to describing the spatial characteristics of the geological body by adding the seismic data in the vertical ***,some drawbacks still need improvement in the current 3-D tunnel seismic prediction method.(1)The geometry is complex,which is destructiveness,high cost,and time-consuming,and will delay the tunnel construction schedule.(2)Illumination of the anomalous body is insufficient,and the precision of migration imaging is low.(3)Shot points are far away from the tunnel face,the energy loss at the shot points is more serious.(4)The received signals at the tunnel wall have the surface wave with strong energy when the shot points are placed on the tunnel wall.(5)The geometry is not linear,so the directional filtering method cannot be used to extract the reflection *** overcome the drawbacks of the current prediction method,a new 3-D symmetrical tunnel seismic prediction method is *** geophones are installed on the tunnel wall,two on the left side,two on the right side,and two on the top ***-four shot points are placed on the tunnel face and near both sides of the tunnel wall,twelve shot points on the left side and twelve shot points on the right *** shot points will move along with the forward excavation of the *** wavefield analysis,illumination statistics,and 3-D reverse time migration imaging are used to evaluate the proposed *** result of modeled data indicates that the proposed 3-D geometry has some advantages:(1)the geometry is simple and the geophone installation time is short;(2)it has high illumination energy,wide illumination range,and can improve the prediction distance and imaging accuracy;(3)the proposed 3-D method can better estimate the velocity of surrounding rock and is more conducive to extracting the reflection wave with high resolut

关键词： tunnels excavation geophone shot points migration imaging method engineering ge-ology.

Hollow Ni Mo-based nitride heterojunction with super-hydrophilic/aerophobic surface for efficient urea-assisted hydrogen production

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Journal of Energy Chemistry 2024年第8期95卷 428-439,I0009页

作者： Yuying Fan Ying Gu Dongxu Wang Yanqing jiao Aiping Wu Chungui tian Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080HeilongjiangChina College of Chemistry Chemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040HeilongjiangChina

Hydrogen evolution reaction(HER)and urea oxidation reaction(UOR)are key reactions of the watercycling associated catalytic process/*** design of catalysts with a super-hydrophilic/aerophobic structure and optimized electron distribution holds great ***,we have designed a threedimensional(3D)hollow Ni/NiMoN hierarchical structure with arrayed-sheet surface based on a onepot hydrothermal route for efficient urea-assisted HER based on a simple hydrothermal *** Ni/NiMoN catalyst exhibits super-hydrophilic/aerophobic properties with a small droplet contact angle of 6.07°and an underwater bubble contact angle of 155.7°,thus facilitating an escape of bubbles from the *** functional theory calculations and X-ray photoelectron spectroscopy results indicate the optimized electronic structure at the interface of Ni and NiMoN,which can promote the adsorption/desorption of reactants and *** virtues combining with a large specific surface area endow Ni/NiMoN with efficient catalytic activity of low potentials of 25 mV for HER and 1.33 V for UOR at10 mA cm^(-2).The coupled HER and UOR system demonstrates a low cell voltage of 1.42 V at 10 mA cm^(-2),which is approximately 209 mV lower than water electrolysis.

关键词： Hydrogen evolution Transition metal nitrides Hollow heterojunctions Urea electrooxidation Super hydrophilic/aerophobic

Atomically Dispersed Zinc Active Sites Efficiently Promote the Electrochemical Conversion of N_(2) to NH_(3)

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Energy & Environmental Materials 2024年第3期7卷 175-181页

作者： Yanjiao Wei Xinyu Wang Mengjie Sun Min Ma Jian tian Minhua shao School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong 999077China Energy Institute and Chinese National Engineering Research Center for Control&Treatment of Heavy Metal PollutionThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong China

At present,the research on highly active and stable nitrogen reduction reaction catalysts is still challenging work for the electrosynthesis of ammonia(NH_(3)).Herein,we synthesized atomically dispersed zinc active sites supported on N-doped carbon nanosheets(Zn/NC NSs)as an efficient nitrogen reduction reaction catalyst,which achieves a high ammonia yield of 46.62μg h^(-1)mg^(-1)_(cat).at-0.85 V(vs RHE)and Faradaic efficiency of 95.8%at-0.70 V(vs RHE).In addition,Zn/NC NSs present great stability and selectivity,and there is no significant change in NH_(3)rate and Faradaic efficiencies after multiple *** structural characterization shows that the active center in the nitrogen reduction reaction process is the Zn-N_(4)sites in the *** calculation confirms that Zn/NC with Zn-N_(4)configuration has a lower energy barrier for the formation of^(*)NNH intermediate compared with pure N-doped carbon nanosheets(N-C NSs),thus promoting the hydrogenation kinetics in the whole nitrogen reduction reaction process.

关键词： electrocatalysis nitrogen reduction single-atom catalyst Zn-N_(4)

Integrated interconnected porous and lamellar structures realized fast ion/electron conductivity in high-performance lithium-sulfur batteries

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Chinese Chemical Letters 2024年第6期35卷 161-167页

作者： Ya Song Mingxia Zhou Zhu Chen Huali Nie jiao-Jing shao Guangmin Zhou School of Materials and Metallurgy Guizhou UniversityGuiyang 550025China Medical College of Guizhou University Guiyang 550025China College of Biological Science and Medical Engineering Donghua UniversityShanghai 201620China Shenzhen Geim Graphene Center Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China

The practical application of high-energy-density lithium-sulfur(Li-S)batteries have been highly praised for energy storage devices,while are largely hindered by the“shuttling effect”.Herein,core-shell carbon spheres composed of interlinked porous core and lamellar shell were designed to restrain the polysulfide *** microporous structure with pore size of around 1 nm effectively trap lithium ***,the interconnected porous core shortens the ion transfer distance and the lamellar carbon shell endows the carbon spheres with fast electron conduction,finally facilitating polysulfide conversion ***,the Li-S batteries with the carbon spheres as the interlayer show high discharge specific capacity of 1002 m Ah/g at 2 C with 574 m Ah/g remaining after 600 cycles,and high areal capacity of 5.48 m Ah/cm^(2) with sulfur loading of 4.67 mg/cm^(2) at 0.1 *** corresponding pouch cells also exhibit stable cycling stability with an initial discharge specific capacity of 1082 m Ah/g at 0.1 C.

关键词： Interlayer Shuttle effect Strong adsorption Porous carbon spheres Lithium-sulfur batteries

Analysis on unit maximum capacity of orthogonal multiple watermarking for multimedia signals in B5G wireless communications

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Digital Communications and Networks 2024年第1期10卷 38-44页

作者： Mianjie Li Senfeng Lai jiao Wang Zhihong tian Nadra Guizani Xiaojiang Du Chun Shan School of Electronics and Information Guangdong Polytechnic Normal UniversityGuangzhou510665China Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhou510006China Schoolof Electrical Engineering and Computer Science Washington State UniversityPullmanWA99164USA Department of Computer and Information Science Temple UniversityPhiladelphiaPA19122USA

Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication *** that intelligent applications to B5G wireless communications will involve security issues regarding user data and operational data,this paper analyzes the maximum capacity of the multi-watermarking method for multimedia signal hiding as a means of alleviating the information security problem of *** multiwatermarking process employs spread transform dither *** the watermarking procedure,Gram-Schmidt orthogonalization is used to obtain the multiple spreading ***,multiple watermarks can be simultaneously embedded into the same position of a multimedia ***,the multiple watermarks can be extracted without affecting one another during the extraction *** analyze the effect of the size of the spreading vector on the unit maximum capacity,and consequently derive the theoretical relationship between the size of the spreading vector and the unit maximum capacity.A number of experiments are conducted to determine the optimal parameter values for maximum robustness on the premise of high capacity and good imperceptibility.

关键词： B5G Multimedia information security Spread transform dither modulation Spreading vector measurement Unit maximum capacity

Nonlinear change of ion-induced secondary electron emission in theκ-Al_(2)O_(3) surface charging from first-principle modelling

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Plasma Science and Technology 2024年第9期26卷 40-50页

作者： Zhicheng jiao Mingrui ZHU Dong DAI Tao shao Buang WANG South China University of Technology Guangzhou 510641People’s Republic of China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190People’s Republic of China University of Richmond Richmond 23173United States of America

Secondary electron emission(SEE)induced by the positive ion is an essential physical process to influence the dynamics of gas discharge which relies on the specific surface *** charging has a significant impact on the material properties,thereby affecting the SEE in the plasma-surface ***,it does not attract enough attention in the previous *** this paper,SEE dependent on the charged surface of specific materials is described with the computational method combining a density functional theory(DFT)model from the first-principle theory and the theory of Auger *** effect ofκ-Al2O3 surface charge,as an example,on the ion-induced secondary electron emission coefficient(SEEC)is investigated by analyzing the defect energy level and band structure on the charged *** results indicate that,with the surface charge from negative to positive,the SEEC of a part of low ionization energy ions(such as Ei=12.6 eV)increases first and then decreases,exhibiting a nonlinear changing *** is quite different from the monotonic decreasing tendency observed in the previous model which simplifies the electronic *** irregular increase of the SEEC can be attributed to the lower escaped probability of orbital *** results further illustrate that the excessive charge could cause the bottom of the conduction band close to the valence band,thus leading to the decrease of the orbital energy occupied by the excited *** nonlinear change of SEEC demonstrates a more realistic situation of how the electronic structure of material surface influences the SEE *** work provides an accurate method of calculating SEEC from specific materials,which is urgent in widespread physical scenarios sensitive to surface materials,such as increasingly growing practical applications concerning plasma-surface interactions.

关键词： secondary electron emission charged surface density functional theory defect energy level

Recent Advance in Electrocatalytic Water Splitting for Hydrogen Production by Layered Double Hydroxides

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Chemical Research in Chinese Universities 2024年第4期40卷 577-589页

作者： XIA tian REN Qinghui YANG Jiangrong LI Zhenhua shao Mingfei DUAN Xue State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing100029P.R.China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou324000P.R.China

Collecting green hydrogen(H2)from water splitting driven by renewable energy is a new competition to implement the construction of H2 energy industry and promote new economic growth for global *** common strategy to enhance the efficiency of H2 production is to reduce the potential of electrolytic cell that is the mainstream way to prepare efficient *** double hydroxides(LDHs)are one of the most active electrocatalysts with adjustable active sites in contemporary *** this review,we discuss the recent advanced progress of LDHs for hydrogen evolution reaction(HER)on cathode and oxygen evolution reaction(OER)or organic oxidation on anode and emphasize the influence of LDHs structure regulation in water electrolysis process(HER/OER)as well as the current development status of organic oxidation catalyzed by active oxygen species on ***,we propose the current challenges of LDHs in electrocatalysis and prospect their developing tendency and further application.

关键词： Layered double hydroxide Hydrogen production Hydrogen evolution reaction(HER) Oxygen evolution reaction(OER) Electrocatalytic organic oxidation

Piezoelectric Drop-on-Demand Inkjet Printing with Ultra-High Droplet Velocity

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Research 2024年第3期2023卷 123-137页

作者： Zhengjie Yang Hongmiao tian Chunhui Wang Xiangming Li Xiaoliang Chen Xiaoming Chen Jinyou shao State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’anShaanxi 710049China Frontier Institute of Science and Technology(FIST) Xi’an Jiaotong UniversityXi’anShaanxi 710049China.

Improving droplet velocity as much as possible is considered as the key to improving both printing speed and printing distance of the piezoelectric drop-on-demand inkjet printing *** are 3 tough and contradictory issues that need to be addressed simultaneously,namely,the actuation pressure of the piezoelectric printhead,satellite droplets,and the air resistance,which seems almost impossible to achieve with classical ***,a novel solution is *** modulating the positive crosstalk effect inside and outside the printhead,self-tuning can be achieved,including self-reinforcing of the actuation pressure,self-restraining of satellite droplets,and self-weakening of the air resistance,thereby greatly improving droplet *** on these mechanisms,waveform design methods for different inks and printheads are *** results demonstrate that monodisperse droplet jetting with a maximum velocity of 27.53 m/s can be achieved,reaching 3 to 5 times that of the classical method(5 to 8 m/s).Correspondingly,the printing speed and distance can be simultaneously increased by almost 10 times,demonstrating an ability of direct printing on irregular ***,the compatibility of ink materials is expanded,as the Ohnesorge number and the viscosity of printable inks for the printhead used are increased from 0.36–0.72 to 0.03–1.18 and from 10–12 cp to 1–40.3 cp,respectively,even breaking the traditional limitations of the piezoelectric printing technology(Ohnesorge number of 0.1 to 1;viscosity of 1 to 25 cp).All the above provide a new perspective for improving droplet velocity and may even offer a game-changing choice for expanding the boundaries of the piezoelectric drop-on-demand inkjet printing technology.

关键词： piezoelectric viscosity thereby