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Controllable nucleation and deformation of skyrmions on surface of magnetic nanotubular monolayer

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Rare Metals 2024年第7期43卷 3250-3259页

作者： Xin-Xin zhang chen-yu zhang Yi-Xin Xing Chao Man Jiao Liu Yong Hu Department of Physics College of SciencesNortheastern University School of Materials and Mineral Resources Engineering Universiti Sains MalaysiaEngineering Campus State Key Laboratory of Rolling and Automation Northeastern University

Magnetic skyrmions emerge when the energy of ferromagnetic exchange interaction promoting parallel alignment of spins enters in competition with energies favoring non-collinear alignment of spins such as Dzy aloshinskii-Moriya interaction(DMI),long-rang dipole-dipole interaction(DDI),or higher-order exchange *** perform an unbiased Monte Carlo simulation to study the DMI-based skyrmion nucleation and stabilization on the surface of magnetic nanotubular monolayer controlled by tuning constants of DDI(g) and next-nearest-neighbor antiferromagnetic exchange interaction(j') with appropriate *** g and j',the loosely distributed skyrmions initially nucleate on the surface of nanotube approaching to the magnetic field(h) direction with increasing h in the intermediate ***,the skyrmion size,shape,density,distribution and crystal structure,as well as its driven field range,are tailored by g and j'.This work demonstrates the skyrmion nucleation mechanisms in three-dimensional magnetic nanostructures with curvature effect and multiple interactions,serving as a benchmark for a guide to experimentalists for preparation of samples in magnetic skyrmion states.

关键词： Magnetic nanotube Magnetic skyrmion Dzyaloshinskii–Moriya interaction Dipole–dipole interaction Monte Carlo simulation

Catalytic Asymmetric Diastereodivergent Synthesis of 2-Alkenylindoles Bearing both Axial and Central Chirality

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Precision Chemistry 2024年第5期2卷 208-220页

作者： Shuang Yang Jia-Bo Huang Da-Hua Wang Ning-Yi Wang yu-yu chen Xin-Yan Ke Hao chen Shao-Fei Ni yu-chen zhang Feng Shi Research Center of Chiral Functional Heterocycles School of Chemistry and Materials ScienceJiangsu Normal UniversityXuzhou 221116China Department of Chemistry Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong ProvinceShantou UniversityShantou 515063China Department of Otolaryngology Xuzhou First People’s HospitalAffiliated Xuzhou Municipal Hospital of Xuzhou Medical UniversityXuzhou 221002China School of Petrochemical Engineering Changzhou UniversityChangzhou 213164China

The catalytic asymmetric diastereodivergent synthesis of axially chiral 2-alkenylindoles was established via chiral phosphoric acid-catalyzed addition reactions of C3-unsubstituted 2-alkenylindoles with o-hydroxybenzyl alcohols under different reaction *** this strategy,two series of 2-alkenylindoles bearing both axial and central chirality were synthesized in a diastereodivergent fashion with moderate to high yields and good stereoselectivities(up to 99%yield,95:5 er,>95:5 dr).Moreover,theoretical calculations were performed on the key transition states leading to different stereoisomers,which provided an in-depth understanding of the origin of the observed stereoselectivity and diastereodivergence of the products under different reaction *** importantly,these 2-alkenylindoles were utilized in asymmetric catalysis as chiral organocatalysts and in medicinal chemistry for evaluation of their cytotoxicity,which demonstrated their potential *** study has not only established the catalytic atroposelective synthesis of axially chiral 2-alkenylindoles,but also provided an efficient strategy for catalytic asymmetric diastereodivergent construction of indole-based scaffolds bearing both axial and central chirality.

关键词： 2-Alkenylindole Axial chirality Central chirality Diastereodivergent synthesis Chiral phosphoric acid

条带垄覆对西南黄壤坡耕地径流和高粱水分利用的影响

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作物学报 2024年第5期50卷 1325-1340页

作者：陈玉章吴松果卢成霖李瑞龚利娟文悦宁佳欣吴宇涵四川轻化工大学生物工程学院四川宜宾644005 四川省酿酒专用粮工程技术研究中心四川宜宾644005 广西大学农学院广西南宁530004

针对西南区坡耕地季节性干旱突出、降水径流损失大、高粱低产低效益等问题。2020—2021年,在黔西南山区以前茬种植春玉米的7°黄壤缓坡耕地为研究对象,研究了横坡种植模式(作物行向与坡向垂直)下传统露地平作(CK)、条带垄覆地膜(RFM)和... 详细信息

针对西南区坡耕地季节性干旱突出、降水径流损失大、高粱低产低效益等问题。2020—2021年,在黔西南山区以前茬种植春玉米的7°黄壤缓坡耕地为研究对象,研究了横坡种植模式(作物行向与坡向垂直)下传统露地平作(CK)、条带垄覆地膜(RFM)和条带垄覆玉米整秆(RSM)3种不同处理对径流、以及高粱耗水特性、水分利用效率、产量和纯收效益的影响。结果表明,与CK相比,在横坡垄作模式下,RFM和RSM处理高粱生育期内的降雨径流深度分别平均显著下降27.3%和42.1%,纳水系数分别平均增加9.5和14.6个百分点。2个条带垄覆横坡种植较CK显著增加高粱生育期的耗水量,其中拔节至抽穗阶段、灌浆至成熟阶段耗水量与产量分别呈显著(r=0.51^(*))和极显著(r=0.81^(**))正相关。与CK相比,RFM、RSM显著增加高粱成熟期生物量、穗粒数和千粒重,籽粒产量分别平均显著增加8.5%和6.2%,但水分利用效率分别平均显著下降12.6%和21.4%。主要原因是,条带垄覆可显著增加高粱全生育期0~100 cm土壤贮水量,提高拔节至抽穗、灌浆至成熟阶段的耗水量,促进了高粱植株的生长发育和产量形成,且高粱秸秆产量的增幅(21.4%)显著高于籽粒产量增幅(7.3%),秸秆产量的大幅增加虽然降低了水分利用效率,但秸秆产量的增加是籽粒增产的重要保障。RSM处理的纯收益和产投比分别平均较CK增加2962.9元hm^(-2)和2.3%,而RFM处理由于增加了劳动强度、机械和地膜投入,导致纯收益和产投比分别平均较CK下降1502.6元hm^(-2)和32.6%。因此,条带垄覆玉米整秆横坡种植在显著提高降水有效性的同时,可实现产量和纯收益双增的目的,是西南黄壤旱坡耕地高粱增产增收的可行模式。

关键词：条带垄覆径流水分利用高粱产量纯效益

Synergistic reaction behavior of pyrolysis and reduction of briquette prepared by weakly caking coal and metallurgical dust

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Journal of Iron and Steel Research(International) 2023年第7期30卷 1367-1380页

作者： Zheng-jian Liu Ming-hui Cao Jian-liang zhang Run-sheng Xu Yao-zu Wang Ji-yong yu yu-chen zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Co-carbonization of weakly caking coal and zinc-containing dust to prepare highly reactive ferro-coke and collaboratively recover zinc powder is one of the feasible ways for steel enterprises to recycle zinc-containing *** pyrolysis mass loss behavior of adding blast furnace dust with different zinc contents to different ferro-coke materials was systematically studied by thermogravimetry and differential thermogravimetry analysis,and the kinetic mechanism of pyrolysis-reduction reaction of hybrid briquette was *** results of thermogravimetric curve analysis show that the addition of zinc oxide to the sample has no significant effect on the mass loss rate of the sample below 580℃,and the pyrolysis mass loss of zinc oxide mainly occurs between 800 and 1000℃.Kinetic analysis results show that the pyrolysis of zinc-containing samples is controlled by chemical reactions below 580℃.The reaction at 580–700℃ is controlled by the nucleation and growth model,and that above 700℃ is mainly controlled by *** results of X-ray diffraction analysis show that the pyrolysis process can effectively remove zinc oxide from ferro-coke.

关键词： Zinc-containing dust Weakly caking coal Ferro-coke Pyrolysis Reduction Thermal reaction analysis Kinetic analysis

Heat Transfer Characteristics of a Microchannel Heat Sink with Highly-Dense Micro-Jet Arrays

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Journal of Thermal Science 2024年第3期33卷 1148-1160页

作者： zhang yu chen Xiaoyan MIAO Lin chen Liang HOU yu State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China Beijing Aerospace Technology Institute Beijing100083China

This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the influence of structure and flow parameters on the convective heat transfer of water jet cooling in confined *** simulation results show that the optimal jet width,jet spacing and impingement distance are around 0.2 mm,0.2 mm and 0.3 mm,respectively,which can achieve a low thermal resistance as well as a relatively low pressure *** analysis of the heat transfer pathways shows that the micro-fin jet structures can extend the impinging heat transfer area and conduct a considerable proportion of heat,which can reach up to 38.9%with the Reynolds number ranging from 797.1 to *** heat transfer characteristics in the heat sink will shift from impingement dominated heat transfer to the channel-convection dominated heat transfer as the jet impingement distance increases.A correlation is proposed to predict the average Nusselt number on the stagnation area for the heat sink with different structure parameters,and the deviations of predictions from the numerical results are less than 10%.

关键词： hybrid heat sink impingement microchannel thermal management high heat flux

Deeply functional identification of TCS1 alleles provides efficient technical paths for low-caffeine breeding of tea plants

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Horticulture Research 2023年第2期10卷 266-274页

作者： Yi Wang yu-Fei Liu Meng-yuan Wei chen-yu zhang Jie-Dan chen Ming-Zhe Yao Liang chen Ji-Qiang Jin Key Laboratory of Biology Genetics and Breeding of Special Economic Animals and PlantsMinistry of Agriculture and Rural AffairsTea Research Institute of the Chinese Academy of Agricultural SciencesHangzhou 310008China yunnan Provincial Key Laboratory of Tea Science Tea Research InstituteYunnan Academy of Agricultural Sciences2 Jingnan RoadMenghaiYunnan 666201China

Caffeine is an important functional component in tea,which has the effect of excitement and nerve stimulation,but excessive intake can cause insomnia and ***,the production of tea with low-caffeine content can meet the consumption needs of certain ***,in addition to the previous alleles of the tea caffeine synthase(TCS1)gene,a new allele(TCS1h)from tea germplasms was *** of in vitro activity analysis showed that TCS1h had both theobromine synthase(TS)and caffeine synthase(CS)***-directed mutagenesis experiments of TCS1a,TCS1c,and TCS1h demonstrated that apart from the 225th amino acid residue,the 269th amino acid also determined the CS *** histochemical analysis and dual-luciferase assay indicated the low promoter activity of TCS1e and *** parallel,insertion and deletion mutations in large fragments of alleles and experiments of site-directed mutagenesis identified a key cis-acting element(G-box).Furthermore,it was found that the contents of purine alkaloids were related to the expression of corresponding functional genes and alleles,and the absence or presence and level of gene expression determined the content of purine alkaloids in tea plants to a certain *** summary,we concluded TCS1 alleles into three types with different functions and proposed a strategy to effectively enhance low-caffeine tea germplasms in breeding *** research provided an applicable technical avenue for accelerating the cultivation of specific low-caffeine tea plants.

关键词： functional alkaloids directed

Chloride-Promoted Photoelectrochemical C-H Silylation of Heteroarenes

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Chinese Journal of Chemistry 2023年第22期41卷 2963-2968页

作者： Xin-Ru Zhao yu-chen zhang Zhong-Wei Hou Lei Wang Advanced Research Institute and School of Pharmaceutical Sciences Taizhou UniversityJiaojiangZhejiang 318000China Department of Chemistry Huaibei Normal UniversityHuaibeiAnhui 235000China State Key Laboratory of Organometalic Chemistry Shanghai lnstitute of Organic ChemistryChinese Academy of SciencsShanghai200032China

A photoelectrochemical approach for the C-H silylation of heteroarenes through dehydrogenation cross-coupling with H2 evolution has been *** photoelectrochemical C-H silylation depends on hydrogen atom transfer(HAT)from silanes to Cl-radical generated through the light-induced homolytic cleavage of Cl2,in which Cl2 was produced by electrochemical oxidation of chloride.A large number of silylated heterocyclic molecules are rapidly constructed in satisfactory yields without relying on oxidants and metal reagents.

关键词： Photoelectrochemistry Silyl radicals C-H silylation Dehydrogenation N-Heterocycles Cross-coupling Oxidation

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries

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Nano-Micro Letters 2024年第2期16卷 154-164页

作者： Xin chen yu zhang Chang chen Huinan Li yuran Lin Ke yu Caiyun Nan chen chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at ***,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen *** one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox *** the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic ***,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product Lithium Oxygen battery

Catalytic Asymmetric Synthesis of Axially Chiral 3,3'-Bisindoles by Direct Coupling of Indole Rings

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Chinese Journal of Chemistry 2022年第18期40卷 2151-2160页

作者： Feng-Tao Sheng Shuang Yang Shu-Fang Wu yu-chen zhang Feng Shi School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhouJiangsu221116 China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan453007 China

Comprehensive Summary A new strategy for the enantioselective synthesis of axially chiral 3,3'-bisindoles was devised by the direct coupling of two indole *** strategy makes use of the C3-umpolung reactivity of 2-indolylmethanols,which enables the catalytic asymmetric addition reaction of 2-indolylmethanols with rationally designed 2-substituted indoles,thus constructing axially chiral 3,3'-bisindole scaffolds in overall excellent yields(up to 98%)with high enantioselectivities(up to 96:4 er).This approach not only has overcome the challenges in constructing axially chiral five-five-membered heterobiaryls,but also represents a new application of the C3-umpolung reactivity of 2-indolylmethanols in asymmetric *** importantly,this class of axially chiral 3,3'-bisindoles can undergo a variety of post-functionalizations to give axially chiral 3,3'-bisindole-based organocatalysts,which have found their preliminary applications in asymmetric catalysis.

关键词： Asymmetric catalysis Atroposelectivity Axial chirality Organocatalysis Enantioselectivity