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Chinese Journal of Aeronautics 2024年第5期37卷 180-198页

作者： Runfu LIU Zhenyao LI Huiliu zhang Qixing WANG yue HUANG Yancheng YOU School of Aerospace Engineering Xiamen UniversityXiamen 361000China

The mixing effectiveness of the airflow between the inner and outer bypass inlets of a Rear Variable-Area Bypass Injector(RVABI)is the key to the afterburner performance of variable cycle *** paper describes an optimized RVABI design based on an alternating area regulator to improve the velocity/temperature uniformity of the incoming flow at the *** with a classical RVABI,numerical simulations show that the proposed alternating RVABI performs better in terms of thermal mixing efficiency and total pressure loss in different variable cycle engine *** the increasing air contact area between the inner and outer bypass of alternating structure RVABI,and a larger streamwise vortex in the inner bypass inlet due to the proposed alternating lobe structure in the RVABI contribute to the significantly increase of mixing ***,the alternating regulator induces strong streamwise vortex,which helps to improve the airflow mixing with its vortex-induced *** interaction between the streamwise vortex and azimuthal vortex further promises the velocity/temperature uniformity after the *** the increase of alternating lobe’s height ratio,the covering area of the streamwise vortex and the azimuthal vortex is enlarged,which further enhances the thermal mixing efficiency of the *** design gives an insight into the future design and optimization of RVABI.

关键词： Alternating area regulator Lobed mixer Variable cycle engine Rear Variable-Area Bypass Injector(RVABI) Streamwise vortex

Dietary fat and carbohydrate-balancing the lactation performance and methane emissions in the dairy cow industry: A meta-analysis

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Animal Nutrition 2024年第2期17卷 347-357页

作者： Chenguang zhang Xingwei Jiang Shengru Wu Jun zhang yue Wang Zongjun Li Junhu Yao College of Animal Science and Technology Northwest A&F University

For the agroecosystems of the dairy cow industry, dietary carbohydrate（starch, neutral detergent fiber[NDF]） and fat could directly affect rumen methane emissions and host energy utilization. However, the relationships among diet, lactation performance, and methane emissions need to be further determined to assist dairy farms to adjust diet formulations and feeding strategies for environmental and production management. A meta-analysis was conducted in the current study to explore quantitative patterns of dietary fat and carbohydrate at different levels in balancing lactation performance and environment sustainability of dairy cows, and to establish a methane emission prediction model using the artificial neural network（ANN）model. The results showed that the regression relationship between dietary fat, carbohydrate and methane emissions could be shown by the following models: methane = 106.78 +（14.86 × DMI）, R2= 0.80;methane = 443.17-（46.41 × starch/NDF）, R2= 0.76; and methane = 3.8.91 +（3..40 × fat）-（5.42 × fat2）,R2= 0.80. The regression relationships between dietary fat, carbohydrate and lactation performance could be shown by the following models: milk fat yield = 1.08 +（0.43.× starch/NDF）-[0.3. ×（starch/NDF）2],R2= 0.79; milk protein yield = 0.68 +（0.15 × fat）-（0.016 × fat2）, R2= 0.82. In the structural equation model, we found that when formulating dietary carbohydrates and fats, it was necessary to balance the relationship between methane emissions and lactation performance. Specifically, dietary starch/NDF was lower than 0.63.extremum point） and dietary fat was between 2.89% and 4.69%（extremum point）, it could ensure that the aim of methane emission reduction（methane emissions decrease with increasing dietary starch/NDF and fat） was achieved without losing lactation performance of dairy cows（lactation performance increase with increasing dietary starch/NDF and fat）. Finally, we established the ANN model to predict methane emissions（training set: R2= 0.62; vali

关键词： Dietary fat and carbohydrate Environment sustainability Lactation performance Dairy cow Meta-analysis

A Mass-Preserving Characteristic Finite Difference Method For Miscible Displacement Problem

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Advances in Applied Mathematics and Mechanics 2024年第1期16卷 164-180页

作者： Jiansong zhang yue Yu Rong Qin Zhaohui Liu Department of Applied Mathematics China University of PetroleumQingdaoShandong 266580China

In this article,a new characteristic finite difference method is developed for solving miscible displacement problem in porous *** new method combines the characteristic technique with mass-preserving interpolation,not only keeps mass balance but also is of second-order accuracy both in time and *** results are presented to confirm the convergence and the accuracy in time and space.

关键词： The method of characteristics mass-preserving finite difference miscible displacement problem

Learning background restoration and local sparse dictionary for infrared small target detection

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Optoelectronics Letters 2024年第7期20卷 437-448页

作者： HE yue zhang Rui XI Chunmei ZHU Hu School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China12

This paper proposes a method for learning background restoration for infrared small target detection,employing a local sparse dictionary alongside an equalized structural texture *** method is specifically designed for the detection of small infrared targets,accommodating various levels of brightness,spatial size,and *** proposed model intelligently combines global low-rankness and local sparsity to estimate the rank of the background tensor,leveraging spatial and structural information to overcome the limitations posed by insufficient detailed texture ***,a structural texture representation,combining local gradient maps and local intensity maps,is applied to emphasize small *** comparing our method with nine advanced and representative approaches and quantifying the comparison using various metrics,the experimental results indicate that our proposed method has achieved favorable outcomes in both quantitative assessments and visual results.

关键词： local structural overcome

Identification of carbonates with high positive carbon isotope excursion from the Liaohe Group in the northeastern North China Craton and implications for the Lomagundi-Jatuli Event

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Science China Earth Sciences 2024年第9期67卷 2824-2844页

作者： Hongyu WANG Shuanhong zhang Sen WANG Linghao KONG yue ZHAO Qiqi zhang Sen GAO Guohui HU Institute of Geomechanics Chinese Academy of Geological SciencesBeijing 100081China Key Laboratory of Paleomagnetism and Tectonic Reconstruction Ministry of Natural ResourcesBeijing 100081China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100037China School of Earth Science and Mineral Resources China University of GeosciencesBeijing 100083China

The Great Oxidation Event(GOE)during the early Paleoproterozoic represents the first significant buildup in Earth’s atmospheric oxygen and resulted in a series of significant changes in the Earth’s surface *** them is the 2.22(or 2.3.)–2.06 Ga Lomagundi-Jatuli Event(LJE),which is globally,the largest magnitude and longest duration,marine carbonate positive carbon isotope excursion(δ^(13.C_(V-PDB)>10‰)*** event has attracted the attention of scholars all over the ***,except for a high positive carbon isotope excursion(δ^(13.C_(V-PDB)>10‰)recently identified from marine carbonate rocks within the Daposhan Formation in the lower Fanhe Group(or the Sanchazi Group)in the Longgang Block in the northeast North China Craton(NCC),Paleoproterozoic carbonates in the NCC are characterized by a low-amplitude positive carbon isotope excursion(δ^(13.C_(V-PDB)3.C excursion of the Paleoproterozoic carbonates obtained by the previous studies,we conducted field investigations,carbon-oxygen isotopes,and whole-rock major and trace element geochemical analyses of Liaohe Group carbonate rocks from the Anshan area in the northwestern margin of the Jiao-Liao-Ji Belt in the northeast *** results show that the Gaojiayu Formation of the Liaohe Group in the Anshan area has high positive δ^(13.C_(V-PDB) values from 8.6‰ to 12.4‰ and δ^(18)O_(V-SMOW) values of 17.9‰-27.4‰(δ^(18)O_(V-PDB) values ranging from−12.6‰to -3.4‰).This provides solid evidence for the preservation of reliable sedimentary records of the LJE in the northeastern *** of the high positive δ^(13.C excursion(>10‰)of marine carbonate rocks occurred at about 2.15 *** co

关键词： Lomagundi-Jatuli Event(LJE) Great Oxidation Event(GOE) Carbon-oxygen isotopes Liaohe Group Marine carbonate Jiao-Liao-Ji Belt North China Craton

Development of Zn^(2+)-controlled expression system for lactic acid bacteria and its application in engineered probiotics

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Synthetic and Systems Biotechnology 2024年第1期9卷 152-158页

作者： Xiaoning Xu Lingwen zhang yue Cui Jian Kong Tingting Guo State Key Laboratory of Microbial Technology Shandong UniversityNo.72 Binhai RoadQingdao266237PR China

Lactococcus lactis and Streptococcus thermophilus are considered as ideal chassis of engineered probiotics,while food-grade genetic tools are limited in those ***,a Zn^(2+)-controlled gene expression(ZICE)system was identified in the genome of *** CGMCC7.179,including a transcriptional regulator sczAst and a promoter region of cation transporter czcD(PczcDst).Specific binding of the SczAst to the palindromic sequences in PczcDst was demonstrated by EMSA analysis,suggesting the regulation role of SczAst on *** evaluate their possibility to control gene expression in vivo,the sczAst-PczcDst was employed to drive the expression of green fluorescence protein(GFP)gene in *** NZ9000 and *** CGMCC7.179,*** of the transformants could express GFP under Zn^(2+)induction,while no fluorescence without Zn^(2+)*** optimal conditions,Zn^(2+)was used at a final concentration of 0.8 mM in *** and 0.16 mM in *** at OD600 close to 0.4,and omitting yeast extract powder in the medium unexpectedly improved GFP expression level by *** the help of the ZICE system,engineered *** and *** strains were constructed to secret cytokine interleukin-10(IL-10)with immunogenicity,and the IL-10 content in the supernatant of the engineered *** was 59.3.%of that under the nisin controlled expression *** study provided a tightly controlled expression system by the food-grade inducer Zn^(2+),having potential in development of engineered probiotics.

关键词： Lactococcus lactis Streptococcus thermophilus Food-grade expression system Engineered probiotic

Free Vibration of Stiffened Plate with Cracked Stiffeners

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Advances in Applied Mathematics and Mechanics 2024年第1期16卷 253-278页

作者： Jian Xue Lihua Chen yue Sun Wei zhang Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Department of Mechanics School of ScienceHarbin Institute of TechnologyShenzhenGuangdong 518055China Institute of Textiles and Clothing The Hong Kong Polytechnic UniversityHong KongChina

In this paper,a new cracked stiffener model for the stiffener with a partthrough and open crack is proposed,considering the compatibility condition of displacements between the plate and the *** on the first-order shear deformation theory,the free vibration of stiffened isotropic plates with cracked stiffeners are investigated for the first *** description of the crack parameters is based on the continuous equivalent bending stiffness and equivalent depth of the cracked beam,and it takes into consideration of shear deformation,bending-extensional coupling vibration,and eccentricity between the stiffeners and the *** stiffened plates with single or multiple cracked stiffeners are formulated and *** Ritz method with the modified characteristic functions is applied to demonstrate the effects of crack parameters(crack depth and location)coupling with the position and number of the cracked stiffeners on the vibration frequencies and modes of the stiffened *** validity and accuracy of the present solutions are verified through convergence studies and compared with the finite element results.

关键词： Free vibration stiffened plate cracked stiffener model crack Ritz method

Tailoring the surface and interface structures of photocatalysts to enhance hydrogen production

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Science China Chemistry 2024年第4期67卷 1161-1174页

作者： Tao zhang Pengfei Wang Shuai yue Fei Li Zhiyong Zhao Sihui Zhan MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Photocatalytic water splitting using semiconductor photocatalysts is a promising approach for the production of carbon-neutral,sustainable and clean hydrogen ***,the separation and transport of photoinduced carriers are generally considered to be rate-limiting steps,and their low efficiency remains a major ***,much effort has been devoted to developing new strategies in surface/interface engineering of photocatalysts to improve the dynamics of charge separation/*** feature article briefly summarizes recent advances in photocatalyst surface/interface engineering by our research group,which have been achieved through the design of various novel photocatalysts,including interfacial modulation,heterostructure construction,heteroatom doping,single atom and diatom *** article is divided into three parts:first,we briefly introduce the three key processes involved in solar water splitting and reveal relationships between the properties of nanostructural photocatalysts and the fundamentals of water splitting;second,we detail methods and strategies for surface and interfacial structures to improve the efficiency of the fundamental processes,especially charge separation;finally,we explore prospects for photocatalytic water splitting *** article provides a valuable resource and strategies for researchers currently working in the field of photocatalytic water splitting.

关键词： photocatalytic water splitting surface/interface structures dual-functional photocatalysis

Initiation,organizational modes and environmental conditions of severe convective wind events during the warm season over North China

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Science China Earth Sciences 2024年第9期67卷 2876-2894页

作者： yue HUANG Jianhua SUN Yuanchun zhang Ruoyun MA Xinlin YANG Fuyou TIAN Key Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of the Chinese Academy of Sciences Beijing 100049China Earth System Modeling and Prediction Center China Meteorological AdministrationBeijing 100081China College of Aviation Meteorology Civil Aviation Flight University of ChinaGuanghan 618307China National Meteorological Center China Meteorological AdministrationBeijing 100081China

Based on the significant weather report,CG lightning,composite radar reflectivity,and ERA5 reanalysis data,we first studied the spatiotemporal distribution characteristics of four types(only severe convective wind(SCW);SCW and hail;SCW and short-duration heavy rainfall(SDHR);and SCW,hail,and SDHR)of convective weather events related to SCW during the warm season(May to September)from 2011 to 2018 in North ***,severe convective cases producing SCW were selected to statistically analyze the initiation,decay,lifetime,and organizational characteristics of convective ***,using ERA5 reanalysis data and conventional surface observation data,preconvective soundings were constructed to explore the differences in environmental conditions for initiating convective systems between SCW and *** results indicate that mixed-type of SCW and SDHR events occur more frequently over plains,while other types of convective weather occur more frequently over *** frequency peak of SCW occurs in June,while mixed convective weather peaks in *** initiation time of convective systems is concentrated between 1000 and 13.0 BST,with a peak at 1200 *** mountains,the daily peaks of ordinary and significant SCW generally occur at 1700-1800 BST and 1600-1700 BST,respectively,while over plains,the peak of ordinary SCW typically lags behind that of mountains by 1-2 ***,SCW systems are mainly initiated over mountains,with most lifetimes lasting 7–13.*** convective systems produce the most SCW events,followed by trailing-stratiform convective *** convective available potential energy(CAPE),downdraft convective available potential energy,and the temperature difference between 850 and 500 hPa can all distinguish between SCW systems and non-SCW systems occurring over *** to non-SCW convective systems,SCW convective systems over mountains are more likely to occur in environments with less precipitable water,while S

关键词： Severe convective wind Convective systems Initiation Organizational modes Environmental conditions

Rational design of new in situ reduction of Ni(II)catalytic system for low-cost and large-scale preparation of porous aromatic frameworks

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Carbon Energy 2024年第5期6卷 105-113页

作者： Shanshan Wang yue Wu Wenxiang zhang Hao Ren Guangshan Zhu Heping Ma School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'anChina State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchunChina College of Chemistry Northeast Normal UniversityChangchunChina

Porous aromatic framework 1(PAF-1)is an extremely representative nanoporous organic framework owing to its high stability and exceptionally high surface ***,the synthesis of PAF-1 is catalyzed by the Ni(COD)2/COD/bpy system,suffering from great instability and high ***,we developed an in situ reduction of the Ni(II)catalytic system to synthesize PAF-1 in low cost and high *** active Ni(0)species produced from the NiCl_(2)/bpy/NaI/Mg catalyst system can effectively catalyze homocoupling of tetrakis(4-bromophenyl)methane at the room temperature to form PAF-1 with high Brunauer-Emmett-Teller(BET)-specific surface area up to 4948 m^(2) g^(−1)(Langmuir surface area,6785 m2 g−1).The possible halogen exchange and dehalogenation coupling mechanisms for this new catalytic process in PAF's synthesis are discussed in *** efficiency and universality of this innovative catalyst system have also been demonstrated in other PAFs'*** work provides a cheap,facile,and efficient method for scalable synthesis of PAFs and explores their application for high-pressure storage of Xe and Kr.

关键词： adsorption carbon material nickel catalysis porous aromatic framework porous organic polymer