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Structurally altered size, composition, shape and interface-dependent optical properties of quantized nanomaterials

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NANO RESEARCH 2024年第12期17卷 10543-10569页

作者： Qin, Neng han, Hui Guan, Guijian han, Ming-yong Tianjin Univ Inst Mol Plus Tianjin 300072 Peoples R China

The impact of the size effect on the color and photoluminescence (PL) of quantum dots (QDs) has sparked a revolutionary field of research, culminating in the prestigious Nobel Prize in 2023. Prior to their widespread popularization and large-scale commercialization, it is of paramount importance to effectively manipulate and optimize their optical properties. In this review, we place specific emphasis on the striking correlation between the optical characteristics of QDs and their size, structure, composition, and interface environment. We commence by tracing the evolution of quantum dot technology and subsequently categorizing QDs while outlining their typical synthesis methods. This is followed by a deep dive into the pivotal roles of size, composition, structure, and interfacial ligands in fine-tuning, optimizing, and enhancing the optical properties of QDs. Additionally, we illustrate the luminescence enhancement and charge transfer phenomena stemming from the heterojunction between semiconductor QDs and metal nanomaterials, which contribute to improved performance. Lastly, we introduce the burgeoning field of chiral QDs and their innovative applications. Armed with this knowledge, QDs can be readily tailored to exhibit adjustable luminous characteristics across the entire spectrum, boasting high luminous efficiency through multifaceted regulation. These advancements render QDs even more enticing and promising for a wide array of applications.

关键词： nanoclusters quantum dots size effect composition effect optical property chiral characteristics

Formation and Bioactivity of SrTiO_3 Nanotubes on Titanium by Modified Anodization and Hydrothermal Treatment

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Journal of Materials Science & Technology 2016年第9期32卷 930-936页

作者： Yanni Zhang yong han Lan Zhang State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University

SrTiO3 nanotube films with good adhesion strengths to Ti substrates were fabricated by using a hybrid approach with a modified anodization and a hydrothermal treatment （HT）. The effect of Sr^2＋ concentration in HT solutions on the morphologies and phase components of the nanotubes were investigated, the SrTiO3 nanotubes formation mechanism was explored, and the adhesion strengths, hydrophilicity and apatite-forming ability of the SrTiO3 nanotubes were also evaluated. The results demonstrated that with increasing the incorporation of Sr^2＋ into the nanotubes, no obvious changes of the lengths and outer diameters of the nanotubes were observed, but the wall thickness and the crystallinity of SrTiO3 in the nanotubes increased. The accumulation of Sr at the inner tube wall indicated that the reaction of Sr^2＋ with TiO2 mainly occurred in the vicinity of internal surfaces of the closely arranged nanotubes. The formation of the SrTiO3 nanotubes could be attributed to an in situ dissolution-recrystallization process. The SrTiO3 nanotubes exhibited good hydrophilicity and bioactivity, and the induced apatite preferred to nucleate on the nanotubes with higher crystallinity and Sr content, indicating a good hio-adaptability of the SrTiO3 nanotubes for orthopedic application.

关键词： SrTiO3 nanotubes Modified anodization Hydrothermal treatment Bio-adaptability

Virtual Reconstruction of Long Bone Fracture in Car-to-pedestrian Collisions Using Multi-body System and Finite Element Method

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Chinese Journal of Mechanical Engineering 2011年第6期24卷 1045-1055页

作者： han yong YANG Jikuang MIZUNO Koji State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China Department of Applied Mechanics Chalmers University of TechnologyGothenburg 41296Sweden Department of Mechanical Science and Engineering Nagoya UniversityNagoya 464-8601JapanState

Lower limb injures are frequently observed in passenger car traffic *** studies of the injuries focus on long bone fractures by using either cadaver component tests or simulations of the long bone kinematics,which lack in-depth study on the fractures in stress *** paper aims to investigate lower limb impact biomechanics in real-world car to pedestrian accidents and to predict fractures of long bones in term of stress parameter for femur,tibia,and *** the above purposes,a 3D finite element(FE) model of human body lower limb(HBM-LL) is developed based on human *** model consists of the pelvis,femur,tibia,fibula,patella,foot bones,primary tendons,knee joint capsule,meniscus,and *** FE model is validated by comparing the results from a lateral impact between simulations and tests with cadaver lower limb *** real-world accidents are selected from an in-depth accident database with detailed information about the accident scene,car impact speed,damage to the car,and pedestrian ***-body system(MBS) models are used to reconstruct the kinematics of the pedestrians in the two accidents and the impact conditions are calculated for initial impact velocity and orientations of the car and pedestrian during the *** FE model is used to perform injury reconstructions and predict the fractures by using physical parameters,such as von Mises stress of long *** calculated failure level of the long bones is correlated with the injury outcomes observed from the two accident *** reconstruction result shows that the HBM-LL FE model has acceptable biofidelity and can be applied to predict the risk of long bone *** study provides an efficient methodology to investigate the long bone fracture suffered from vehicle traffic collisions.

关键词： passenger car pedestrian accident lower limb FE model long bone fracture impact biomechanics

Experimental study of lightweight aggregate concrete under multiaxial stresses

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第8期11卷 545-554页

作者： han-yong LIU Yu-pu SONG Structural Engineering Institute School of Civil Engineering Faculty of lnfrastructure Engineering Dalian University of Technology Dalian 116024 China

Lightweight aggregate concrete cube specimens (100 mm×100 mm×100 mm) and plate specimens (100 mm×100 mm×50 mm) were tested under biaxial compression-compression (CC) and compression-tension (CT) load combinations. For comparison, normal concrete plate specimens (100 mm×100 mm×50 mm) were tested under the same load combinations. Based on the test results, a two-level strength criterion of lightweight aggregate concrete in both octahedral stress coordinate and principal stress coordinate was suggested. The lightweight aggregate concrete cube specimens (100 mm×100 mm×100 mm) were then tested under triaxial compression-compression-compression (CCC) load combination with corresponding tests on normal concrete cube specimens (100 mm×100 mm×100 mm). The effect of intermediate principal stress on triaxial compressive strength is further examined. A "plastic flow plateau" area was apparent in principal compressive stress-strain relationships of lightweight aggregate concrete but not in normal concrete. A quadratic formula was suggested for the expression of strength criterion under triaxial compression.

关键词： Lightweight aggregate concrete Normal concrete Biaxial loads Triaxial loads Compressive strength Tensile strength Stress-strain relationships Plastic flow plateau Lode angle

Zn and Ag Co-doped Anti-microbial TiO_2 Coatings on Ti by Micro-arc Oxidation

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Journal of Materials Science & Technology 2016年第9期32卷 919-924页

作者： Lan Zhang Qin Gao yong han State-key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University

Micro-porous TiO2 coatings co-doped with Zn^2＋ and Ag nanoparticles were fabricated on Ti by microarc oxidation （MAO） for 0.5, 1.5, 2 and 4 min, respectively. The evolutions of morphology and phase component of the coating as a function of processing time were investigated. The microstructure of the 2 min treated coating was further observed by transmission electron microscopy to explore the coating formation mechanism. The amounts of Ag and Zn released from the 2 min treated coating were measured and the antibacterial properties of the coatings against Staphylococcus aureus （S. aureus） were also investigated. The obtained results showed that with prolonged MAO time, the contents of Ag and Zn on the coating surfaces increased. All the coatings were micro-porous with pore diameters of 1 -4μm; however, some pores were blocked by deposits on the 4 min treated coating. The 2 rain treated coating was composed of amorphous TiO2, anatase, futile, ZnO, Zn2TiO4 and homogenously distributed Ag nanoparticles. After immersion, Zn^2＋, Ag^＋, Ti^2＋ and Ca^2＋ were released from the coating and with the immersion time prolonged, the accumulated concentrations of these ions increased. After immersion for 36 weeks, the accumulated Zn2. and Ag^＋ concentrations were 6.88 and 0.684 ppm, respectively, which are higher than the minimal inhibitory concentration but much lower than the cytotoxic concentration. Compared with polished Ti control, the coatings co-doped with Zn^2＋ and Ag nanoparticles significantly inhibited the ad- hesions of S. uureus and reduced the amounts of planktonic bacteria in culture medium, indicating that the Zn and Ag co-doped TiO2 could be a bio-adaptable coating for long-lasting anti-microbial performance.

关键词： Zn Ag nanoparticle Co-doped TiO2 Micro-arc oxidation Bio-adaptable

BSA-lysozyme coated NaCa_(2)HSi_(3)O_(9)nanorods on titanium for cytocompatibility and antibacterial activity

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Journal of Materials Science & Technology 2021年第29期88卷 240-249页

作者： Yang Xue Jun Chen Lan Zhang yong han State-key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong UniversityXi'an 710049China Department of Osteology Xi'an People’s Hospital(Xi'an No.4 Hospital)Xi'an 710100China Department of Osteology Tangdu HospitalFourth Military Medical UniversityXi'an 710038China

Extracellular supplement of Ca and Si accelerates osteogenisis and angiogenisis during bone ***-based ceramics are biodegradable and can release Ca and Si ions ***,locally high alkalinity induced by excessively rapid degradation limits their *** this paper,NaCa_(2)HSi_(3)O_(9)(NCS)nanorods were fabricated on Ti by micro-arc oxidation and hydrothermal treatment;protein layers consisted of different rations of bovine serum albumin(BSA)and lysozyme(LYS)were prepared on NCS nanorods by spinning coating and thermal *** microstructure,ion releasing and wettability of coatings were observed;osteoblast and endotheliocyte behaviors,as well as bacteria response in vitro,were *** protein layer did not change microstructure and phase composition of nanorods but acted as a barrier isolating nanorods from contacting medium,and it results in slowing down the degradation of *** reduced increase of pH value,released Ca and Si ions and incorporation of LYS in BSA protein layer gave NCS nanorods improved MC3 T3-E1 and HUVECs response,compared with ***,the protein layers except pure LYS endowed nanorods with a highly antibacterial effect against staphylococcus aureus and escherichia coli simultaneously,indicating the key role of BSA in resisting antibacterial *** nanorods with BSA and LYS composited protein layers should be a potential coating applied on Ti implants for increasing osseointegration.

关键词： NaCa_(2)HSi_(3)O_(9)nanorods Bovine serum albumin Lysozyme Antibacterial activity Cytocompatibility

Primordial germ cell-mediated transgenesis and genome editing in birds

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Journal of Animal Science and Biotechnology 2018年第2期9卷 257-267页

作者： Jae yong han Young Hyun Park Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Institute for Biomedical Sciences Shinshu University

Transgenesis and genome editing in birds are based on a unique germline transmission system using primordial germ cells(PGCs), which is quite different from the mammalian transgenic and genome editing system. PGCs are progenitor cells of gametes that can deliver genetic information to the next generation. Since avian PGCs were first discovered in nineteenth century, there have been numerous efforts to reveal their origin, specification, and unique migration pattern, and to improve germline transmission efficiency. Recent advances in the isolation and in vitro culture of avian PGCs with genetic manipulation and genome editing tools enable the development of valuable avian models that were unavailable before. However, many challenges remain in the production of transgenic and genome-edited birds,including the precise control of germline transmission, introduction of exogenous genes, and genome editing in ***, establishing reliable germline-competent PGCs and applying precise genome editing systems are critical current issues in the production of avian models. Here, we introduce a historical overview of avian PGCs and their application, including improved techniques and methodologies in the production of transgenic and genome-edited birds, and we discuss the future potential applications of transgenic and genome-edited birds to provide opportunities and benefits for humans.

关键词： Avian Genome editing Primordial germ cell Transgenesis

Boundedness of Caldero'n-Zygmund operators in product Hardy spaces

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Applied Mathematics(A Journal of Chinese Universities) 2009年第3期24卷 321-335页

作者： han yong-sheng YANG Da-chun Department of Mathematics Auburn University Auburn AL 36849-5310 USA School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education Beijing 100875 China (Corresponding author)

By means of vector-valued product Calderón-Zygmund operators and some subtle estimates,the boundedness in product Hardy spaces on R^n × R^m of Calderón-Zygmund operators introduced by J.L. Journé is established.

关键词： Hardy space product domain Calderón-Zygmund operator vector-valued operator

CONFORMAL RESTRICTION MEASURES ON LOOPS SURROUNDING AN INTERIOR POINT

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Acta Mathematica Scientia 2021年第6期41卷 1873-1886页

作者： yong han Yuefei WANG College of Mathematics and Statistics Shenzhen UniversityShenzhen518060China Institute of Mathematics Academy of Mathematics and Systems SciencesChinese Academy of SciencesBeijing100190China

A conformal restriction measure is a probability measure which is used to describe the law of a random connected subset in a simply connected domain that satisfies a certain conformal restriction property. Usually there are three kinds of conformal restriction measures: one (called the chordal restriction measure) has two given boundary points of the random set, the second (called the radial restriction measure) has one boundary point and one interior point in the random set, and the third (called the tri-chordal restriction measure) has three boundary points in the random set. In this article, we will define a new probability measure such that the random set associated to it contains one given interior point and does not intersect with the boundary. Furthermore, we will show that this measure can be characterized by one parameter;we will also construct this one-parameter family of measures in two ways and obtain several properties.

关键词： self-avoiding loops conformal restriction measure SLE Brownian loop measure