检索结果-南通市图书馆

Kinetic characteristics of liquid phase sintering of mechanically activated W-15wt%Cu powder

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2006年第4期13卷 338-345页

作者： Zhigang Li chengchang jia Yuntao he Liliang chen Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The kinetic characteristics of W grain growth operated by diffusion controlled Oswald ripening （DOR） during liquid phase sintering were studied. A liquid phase sintering of W-15wt%Cu was carried out by pushing compacts into a furnace at the moment when the temperature increased to 1340℃ for different sintering times. The results show that liquid phase sintering produces the compacts with considerably low relative density and inversely, rather high homogeneity. On the basis of the data extracted from the SEM images, the kinetic equation of W grain growth, G^n = G0^n ＋ kt, is determined in which the grain growth exponent n is 3 and the grain growth rate constant k is 0.15 μm^3/s. The cumulative normalized grain size distributions produced by different sintering times show self-similar. The cumulative distribution function is extracted from the curves by non-linear fitting. In addition, the sintering kinetic characteristics of W-15wt%Cu compacts were also investigated.

关键词： liquid phase sintering mechanical alloying grain growth kinetics W-Cu alloy

Investigation of vortex arms in electron vortices by counter-rotating elliptically polarized attosecond laser pulses

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2022年第1期74卷 84-91页

作者： Zhuo Wang Qi Zhen Yue Sun jia-he chen Xue-Shen Liu Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China School of Civil Engineering Changchun Institute of TechnologyChangchun 130012China

We theoretically investigate the vortex patterns in photoelectron momentum distributions of he^(+)driven by counter-rotating elliptically polarized,time delayed attosecond laser pulses by numerically solving the two-dimensional time-dependent Schrodinger *** is found that the number of vortex arms is extremely sensitive to the ellipticity and wavelength of counterrotating elliptically polarized laser pulses,which is illustrated by the attosecond perturbation ionization *** addition,the effect of different time delays between two pulses on the interference patterns is also investigated and the corresponding physical mechanism is *** the wavelength,ellipticity and time delay have a significant effect on the vortex interference patterns,this may be a new method for laser field detection.

关键词： vortex arms photoelectron momentum distributions elliptically polarized laser pulses

Combined effects of massive reclamation and dredging on the variations in hydrodynamic and sediment transport in Lingdingyang Estuary,China

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2024年第1期18卷 127-147页

作者： Kanglin chen Yitong LIN Jing LIU Zixiao he Liangwen jia School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006China School of Marine Science Sun Yat-Sen UniversityGuangzhou 510275China School of Marine Engineering and Technology Sun Yat-Sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519080China Guangdong Province Engineering Research Center of Coasts Islands and ReefsGuangzhou 510275China

Anthropogenic disturbances associated with the rapid development of coastal cities have drastically influenced the hydrodynamics and sediment transport processes in many large estuaries *** Estuary(LE),located in the central and southern part of the Pearl River Delta,southern China with a long history of high-intensity anthropogenic disturbances,was studied to explore the contribution rate and mechanism underlying the alteration in hydrodynamics and sediment transport under each phase of human activity.A state-of-the-art modeling tool(TELEMAC-2D),was used to study the variations in the hydrodynamics and sediment transport,accounting for reclamation-induced shoreline and dredging-induced topography *** results indicated that:i)under the influence of successive land reclamation,the general distribution of the Confluence Hydrodynamic Zone(CHZ)in LE varied from scattered to concentrated,and these zones moved 3–5 km ***)Large-scale channel dredging weakened the residual flow in LE,decreasing the residual flow in the Inner-Lingding Estuary(ILE)by 62.45%.This was initiated by the enhancement of tidal dynamics through changes in the bottom friction caused by dredging in the *** contrast,massive reclamation decreased the residual flow in the ILE by 17.55%and increased that in the Outer-Lingding Estuary(OLE).iii)Despite disturbances related to land reclamation and dredging,the estuarine jet flow in LE remained a turbulent jet system,and the estuarine jet flow became more *** addition,the position of the estuarine jet source moved 6–13 km ***)Both reclamation and dredging decreased the SSC in the ILE and increased the SSC in the *** weakened the SSC in the ILE by 62.19%,whereas dredging enhanced the SSC in the OLE by 49%.Spatially,reclamation resulted in an increase in the SSC near the outlets and a decrease in the SSC in the northern portion of the Western *** mainly increased the SSC in the north

关键词： reclamation and dredging estuarine jet flow dynamics and sediment transport mechanism Lingdingyang Estuary

Damage on intestinal barrier function and microbial detoxification of deoxynivalenol:A review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第8期23卷 2507-2524页

作者： jia chen Xinran Zhang Ziqi he Dongwei Xiong Miao Long Key Laboratory of Livestock Infectious Diseases Ministry of Education/College of Animal Science and Veterinary Medicine ShenyangAgricultural UniversityShenyang 110866China

Deoxynivalenol(DON)is a mycotoxin that is produced by various species of Fusarium and is ubiquitous in food and *** low concentrations,it can cause metabolic disorders in animals and humans and,at high concentrations,it can lead to pathological changes in the *** impact of DON on human/animal health and animal productivity has thus attracted a great deal of attention around the *** causes severe damage to the intestine,including compromised intestinal barrier,mucosal damage,weakened immune function,and alterations in gut microbiota *** effects exacerbate intestinal infections and inflammation in livestock and poultry,posing adverse effects on overall ***,research into biological methods for DON detoxification is a crucial avenue for future *** includes the utilization of adsorption,enzymatic degradation,and other biological approaches to mitigate DON's impact,offering new strategies for prevention and treatment of DON-induced *** research will focus on identifying highly efficient detoxifying microorganisms or enzymes to reduce DON levels in food and feed,thereby mitigating its risks to both animals and human health.

关键词： deoxynivalenol(DON) intestinal barrier function mucus barrier immune function flora composition biological detoxification

Effects of initial electronic state on vortex patterns in counter-rotating circularly polarized attosecond pulses

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第2期30卷 293-297页

作者： Qi Zhen jia-he chen Si-Qi Zhang Zhi-Jie Yang Xue-Shen Liu Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China

We theoretically investigate the effects of different electronic states as the initial state on the vortex patterns in photoelectron momentum distributions(PMDs)from numerical solutions of the two-dimensional(2D)time-dependent Schrodinger equation(TDSE)of he^(+)with a pair of counter-rotating circularly polarized attosecond *** is found that the number of spiral arms in vortex patterns is equal to the number of the absorbed photons when the initial state is the ground ***,the number of spiral arms in vortex patterns is always two more than the number of the absorbed photons when the initial state is the excited *** sensitivity is attributed to the initial electron density *** addition,we have demonstrated the PMDs for different initial electronic states with the same wavelengths and analyzed their corresponding physical *** is illustrated that the method presented can be employed to effectively control the distribution of the electron vortices.

关键词： initial electronic state counter-rotating circularly polarized attosecond pulses vortex patterns photoelectron momentum distributions

Relative phase effect of nonsequential double ionization in Ar by two-color elliptically polarized laser field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第1期29卷 229-234页

作者： jia-he chen Tong-Tong Xu Tao Han Yue Sun Qing-Yun Xu Xue-Shen Liu Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China College of Sciences Northeastern UniversityShenyang 110819China

We investigated the nonsequential double ionization(NSDI)in Ar by two-color elliptically polarized laser field with a three-dimensional(3D)classical ensemble *** study the relative phase effect of NSDI and distinguish two particular recollision channels in NSDI,which are recollision–impact ionization(RII)and recollision-induced excitation with subsequent ionization(RESI),according to the delay-time between the recollision and the final double *** numerical results indicate that the ion momentum distribution is changed and the triangle structure is more obvious with the decrease of the relative *** also demonstrate that the RESI process always dominates in the whole double ionization process and the ratio of RESI and RII channels can be influenced by the relative phase.

关键词： nonsequential double ionization two-color elliptically polarized laser field recollision-impact ionization recollision-induced excitation with subsequent ionization

Ultra-high NA graphene oxide flat lens on a fiber facet with near diffraction-limited focusing

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第7期12卷 1457-1463页

作者： XIAOKE chen LIN MA ZUYUAN he GUIYUAN CAO HAN LIN BAOHUA jia State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong UniversityShanghai 200240China Nanophotonics Research Center Shenzhen Key Laboratory of Micro-Scale Optical Information TechnologyShenzhen UniversityShenzhen 518060China School of Science RMIT UniversityMelbourne VIC 3000Australia The Australian Research Council(ARC)Industrial Transformation Training Centre in Surface Engineering for Advanced Materials(SEAM) RMIT UniversityMelbourne VIC 3000Australia

The realization of a high numerical aperture(NA) fiber lens is critical for achieving high imaging resolution in endoscopes, enabling subwavelength operation in optical tweezers and high efficiency coupling between optical fibers and photonic chips. However, it remains challenging with conventional design and fabrication. here we propose an ultrathin(400 nm) graphene oxide(GO) film lens fabricated in situ on a standard single-mode fiber facet using the femtosecond laser direct writing technique. An extremely high NA of 0.89 is achieved with a near diffraction-limited focal spot(FWHM = 0.68λ), which is verified theoretically and experimentally. The diameter of the fabricated fiber GO lens is as small as 12 μm with no beam expansion structure. The proposed fiber GO lens is promising for applications such as super-resolution imaging, compact optical tweezers, medical endoscopes,and on-chip integration.

关键词： fiber high oxide

Research progress on electronic and active site engineering of cobalt‐based electrocatalysts for oxygen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第8期6卷 134-165页

作者： Chuansheng he Linlin Yang jia Wang Tingting Wang jian Ju Yizhong Lu Wei chen School of Materials Science and Engineering University of JinanJinanChina Catalonia Energy Research Institute—IREC Sant Adriàde BesòsBarcelonaSpain Department of Electronic and Biomedical Engineering University of BarcelonaBarcelonaSpain Graduate School of Integrated Sciences for Life Hiroshima UniversityHigashi‐HiroshimaHiroshimaJapan Wenzhou Institute University of Chinese Academy of SciencesWenzhouChina Oujiang Lab WenzhouChina School of Chemistry and Pharmaceutical Science Guangxi Normal UniversityGuilinChina

Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon ***,the sluggish kinetics of oxygen evolution reaction on the anode side of the watersplitting device significantly hinders its practical ***,the efficiency of oxygen evolution processes depends greatly on the availability of cost‐effective catalysts with high activity and *** recent years,extensive theoretical and experimental studies have demonstrated that cobalt(Co)‐based nanomaterials,especially low‐dimensional Co‐based nanomaterials with a huge specific surface area and abundant unsaturated active sites,have emerged as versatile electrocatalysts for oxygen evolution reactions,and thus,great progress has been made in the rational design and synthesis of Co‐based nanomaterials for electrocatalytic oxygen evolution *** the remarkable progress in this area,in this timely review,we highlight the most recent developments in Co‐based nanomaterials relating to their dimensional control,defect regulation(conductivity),electronic structure regulation,and so ***,a brief conclusion about recent progress achieved in oxygen evolution on Co‐based nanomaterials,as well as an outlook on future research challenges,is given.

关键词： Co‐based nanomaterial dimension regulation electronic structure and active site oxygen evolution reaction

A nitric oxide-triggered hydrolysis reaction to construct controlled self-assemblies with complex topologies

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1289-1299页

作者： Wenzhuo chen Yuping Tang Shuai chen Zipei chen jia he Hongbin Huo Juan Zhang jiajia Li Fei Yan Wei Tian Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs ResearchCollege of PharmacyShaanxi University of Chinese MedicineXianyang 712046China Shaanxi Key Laboratory of Macromolecular Science and Technology Xi’an Key Laboratory of Hybrid Luminescent Materials and Photonic DeviceMOE Key Laboratory of Material Physics and Chemistry under Extraordinary ConditionsSchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Department of Polymeric Materials School of Materials Science and EngineeringTongji UniversityShanghai 201804China

Hydrolysis reactions are capable of directing the non-equilibrium assembly of biomolecular scaffolds to realize sophisticated structures and functions in natural ***,utilizing the proper hydrolysis reactions to construct controlled assemblies with complex topologies is still an arduous challenge in artificial systems and needs to be ***,we report a nitric oxide(NO)-triggered slow hydrolysis strategy for the controlled construction of biomimetic supramolecular toroids(STs),thus realizing their visualization of intermediate structures and regulation of geometry *** presented protocol harnesses hydrolysis reactions to control of non-equilibrium self-assembly processes for the construction of self-assemblies with complex topologies successfully,which sheds light on how the hydrolysis reaction rate can modulate the kinetic pathway of assembly,thus realizing the artificial establishment of bio-inspired hierarchical structures.

关键词： supramolecular toroids controlled self-assembly nitic oxide-triggered hydrolysis pathway regulation