检索结果-南通市图书馆

Femtosecond laser-mediated anchoring of polymer layers on the surface of a biodegradable metal

Journal of Magnesium and Alloys 2021年第4期9卷 1380-1388页

作者： Jaeho Park Bo-In Park Young Ju Son sun hee lee Seung-Hoon Um Yu-Chan Kim Myoung-Ryul Ok Jeong-Yun sun Hyung-Seop Han Hojeong Jeon Center for Biomaterials Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Materials science and Engineering Seoul National University(SNU)Seoul 08826Republic of Korea Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Division of Bio-Medical Science and Technology KIST SchoolKorea University of Science and TechnologySeoul 02792Republic of Korea KU-KIST Graduate School of Converging Science and Technology Korea UniversitySeoul 02841Republic of Korea

Mg has received much attention as a next-generation implantable material owing to its biocompatibility,bone-like mechanical properties,and biodegradability in physiological *** application of various polymer coatings has been conducted in the past to reduce the rapid formation of hydrogen gas and the local change in pH during the initial phase of the chemical reaction with the body ***,we propose femtosecond(fs)laser-mediated Mg surface patterning for significant enhancement of the binding strength of the coating material,which eventually reduces the corrosion *** of the structural,physical,crystallographic,and chemical properties of the Mg surface have been conducted in order to understand the mechanism by which the surface adhesion increases between Mg and the polymer coating *** on the fs laser conditions,the surface structure becomes rough owing to the presence of several microscaled pits and grooves of nanoporous MgO,resulting in a tightly bonded poly(lactic-co-glycolic acid)(PLGA)*** corrosion rate of the PLGA-coated,fs laser-treated Mg is considerably slow compared with the non-treated Mg;the treated Mg is also more biocompatible compared with the non-treated *** fs laser-based surface modification technique offers a simple and quick method for introducing a rough coating on Mg;further,it does not require any chemical treatment,thereby overcoming a potential obstacle for its clinical use.

关键词： Femtosecond laser Biodegradable metal Polymer coating Surface modification Surface adhesion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on Cavitation Characteristics and Influencing Factors of Herringbone Gear Pump

引用

Computer Modeling in Engineering & Sciences 2024年第6期139卷 2917-2946页

作者： Jinlong Yang Kwang-hee lee Chul-hee lee Department of Mechanical Engineering of Inha University Incheon22212South Korea

Cavitation is a common issue in pumps,causing a decrease in pump head,a fall in volumetric efficiency,and an intensification of outlet flow *** is one of the main hazards that affect the regular operation of the *** on pump cavitation mainly focuses on mixed flow pumps,jet pumps,external spur gear pumps,***,there are few cavitation studies on external herringbone gear *** addition,pumps with different working principles significantly differ in the flow and complexity of the internal flow ***,it is urgent to study the cavitation characteristics of external herringbone gear *** with experimentalmethods,visual research and cavitation area identification are achieved through computation fluid dynamic(CFD),and changing the boundary conditions and shape of the gear rotor is *** simulation yields a head error of only 0.003%under different grid numbers,and the deviation between experimental and simulation results is less than 5%.The study revealed that cavitation causes flow pulsation at the outlet,and the cavitation serious area is mainly distributed in the meshing gap and meshing *** can be inhibited by reducing the speed,increasing the inlet pressure,and changing the helix angle can be *** example,when the inlet pressure is 5 bar,the maximumgas volume fraction in themeshing area is less than 50%.These results provide a reference for optimizing the design and finding the optimal design parameters to reduce or eliminate cavitation.

关键词： Herringbone gear pump cavitation rotating speed inlet pressure helix angle TwinMesh

来源：

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

Piglet gut microbial shifts early in life:causes and effects

引用

Journal of Animal Science and Biotechnology 2019年第3期10卷 519-528页

作者： Robin B.Guevarra Jun Hyung lee sun hee lee Min-Jae Seok Doo Wan Kim Bit Na Kang Timothy J.Johnson Richard E.Isaacson Hyeun Bum Kim Department of Animal Resources Science Dankook UniversityCheonan 31116South Korea National Institute of Animal Science Rural Development AdministrationCheonan 55365South Korea Abbvie Bioresearch Center AbbvieWorcesterMA 01605USA Department of Veterinary and Biomedical Sciences University of MinnesotaSt.PaulMN 55108USA

The gut microbiome has long been known to play fundamentally important roles in the animal health and the well-being of its host. As such, the establishment and maintenance of a beneficial gut microbiota early in life is crucial in pigs, since early gut colonizers are pivotal in the establishment of permanent microbial community structures affecting the health and growth performance of pigs later in life. Emphasizing this importance of early gut colonizers, it is critical to understand the factors impacting the establishment of the piglet gut microbiome at weaning. Factors include, among others, diet, in-feed antibiotics, probiotics and prebiotic administration. The impact of these factors on establishment of the gut microbiome of piglets at weaning includes effects on piglet gut microbial diversity, structure, and succession. In this review, we thoroughly reviewed the most recent findings on the piglet gut microbiome shifts as influenced by weaning, and how these microbiome changes brought about by various factors that have been shown to affect the development of microbiota in piglets. This review will provide a general overview of recent studies that can help to facilitate the design of new strategies to modulate the gut microbiome in order to enhance gastrointestinal health, growth performance and well-being of piglets.

关键词： Microbial diversity Next generation sequencing 16S rRNA Swine microbiota Weaning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Two-stage dynamic recrystallization and texture evolution in Al-7Mg alloy during hot torsion

引用

International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1900-1911页

作者： Kwang Tae Son Chang hee Cho Myoung Gyun Kim Ji Woon lee School of Mechanical Industrialand Manufacturing EngineeringOregon State UniversityCorvallis OR 97331USA Department of Materials Science Engineering Northwestern UniversityEvanston IL 60208USA Research Institute of Industrial Science and Technology(RIST) Pohang 37673Rep.of Korea Division of Advanced Materials Engineering Kongju National UniversityCheonan 31080Rep.of Korea Center for Advanced Materials and Parts of Powders Kongju National UniversityCheonan 31080Rep.of Korea

Hot torsion tests were performed on the Al-7Mg alloy at the temperature ranging from 300 to 500℃ and strain rates between 0.05 and 5 s^(-1) to explore the progressive dynamic recrystallization(DRX)and texture *** DRX behavior of the alloy manifested two distinct stages:Stage 1 at strain of≤2 and Stage 2 at strains of≥*** Stage 1,there was a slight increase in the DRXed grain fraction(X_(DRX))with predominance of discontinuous DRX(DDRX),followed by a modest change in X_(DRX) until the transition to Stage *** 2 was marked by an accelerated rate of DRX,culminating in a substantial final X_(DRX) of~*** backscattered diffraction(EBSD)analysis on a sample in Stage 2 revealed that continuous DRX(CDRX)predominantly occurred within the(121)[001]grains,whereas the(111)[110]grains underwent a geometric DRX(GDRX)evolution without a noticeable sub-grain ***,a modified Avrami’s DRX kinetics model was utilized to predict the microstructural refinement in the Al-7Mg alloy during the DRX *** this kinetics model did not accurately capture the DDRX behavior in Stage 1,it effectively simulated the DRX rate in Stage *** texture index was employed to assess the evolution of the texture isotropy during hot-torsion test,demonstrating significant improvement(>75%)in texture randomness before the commencement of Stage *** initial texture evolution is attributed to the rotation of parent grains and the substructure evolution,rather than to an increase in X_(DRX).

关键词： Al-7Mg alloys hot deformation hot torsion tests dynamic recrystazlliation microstructure texture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unravelling the role of the combined effect of metallic charge transfer channel and SiO_(x) overlayer in the Zr/Si-Fe_(2)O_(3):Au:SiO_(x) nanorod arrays to boost photoelectrochemical water splitting

引用

Journal of Energy Chemistry 2024年第3期90卷 370-379,I0009页

作者： Tae Sik Koh Periyasamy Anushkkaran Love Kumar Dhandole Mahadeo A.Mahadik Weon-Sik Chae Hyun Hwi lee sun hee Choi Jum Suk Jang Division of Biotechnology SafetyEnvironment and Life Science InstituteCollege of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54896Republic of Korea Department of Integrative Environmental Biotechnology College of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54596Republic of Korea Extreme Materials Research Center Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

Hematite(α-Fe_(2)O_(3)) based photoanodes have been extensively studied due to various intriguing features that make them viable candidates for a photoelectrochemical(PEC) water splitting ***,we propose a Zr-doped Fe_(2)O_(3) photoanode decorated with facilely spin-coated Au nanoparticles(NPs) and microwave-assisted attached Si co-doping in conjunction with a SiO_(x) overlayer that displayed a remarkable photocurrent density of 2.01 mA/cm^(2) at 1.23 V *** kinetic dynamics at the photoelectrode/-electrolyte interface was examined by employing systematic electrochemical *** Au NPs played a dual role in increasing PEC water ***,the Schottky interface that was formed between Au NPs and Zr-Fe_(2)O_(3) lectrode ensured the prevention of electron flow from the photoanode to the metal,increasing the number of available charges as well as suppressing surface charge ***,Au extracted photoholes from the bulk of the Zr-Fe_(2)O_(3) and transported them to the outer SiO_(x) overlayer,while the SiO_(x) overlayer efficiently collected the photoholes and promoted the hole injection into the ***,Si co-doping enhanced bulk conductivity by reducing bulk charge transfer resistance and improving charge carrier *** study outlines a technique to design a metallic charge transfer path with an overlayer for solar energy conversion.

关键词： Hematite Microwave attachment Au nanoparticles SiO_(x) overlayer Water splitting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Health risks of pest control and disinfection workers after the COVID-19 outbreak in South Korea

引用

Journal of Environmental Sciences 2024年第5期139卷 350-363页

作者： Yun-hee Choi Da-An Huh Lita Kim Sang ji lee Kyong Whan Moon Department of Health and Safety Convergence Science Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea BK21 FOUR R&E Center for Learning Health System Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Institute of Sciences Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Department of Health and Environmental Science Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea

The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019(COVID-19)outbreak,but the health risks of chemical exposure have not been *** identified these workers’chemical exposure patterns and risks before and after the COVID-19 *** used data conducted between 2018(pre-pandemic)and 2021(post-pandemic)from three-year cross-sectional surveys on pest control and disinfection *** and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental *** non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment *** found that the annual work frequency(50^(th)percentile)of foggers using disinfectants increased the most among all the work types,from 140 uses/year to 176 uses/year after the COVID-19 ***,all chemicals’non-carcinogenic and carcinogenic risks increased regardless of exposure *** the worst scenario(95^(th)percentile),the margin of exposure for citric acid,benzethonium chloride,benzyl-C12-16-alkyldimethyl chlorides,and sodium chlorite of inhalation exposure,and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable(>100)before the COVID-19outbreak but became unacceptable(10^(-6))before and after the COVID-19 outbreak but comparatively high after the COVID-19 ***,significantly more workers experienced health symptoms after the COVID-19outbreak(p<0.05),with the most common being muscle lethargy(31%),skin/face stinging(28.7%),and breath shortness/neck pain(24.1%).

关键词： Biocide Disinfection Health risk assessment Occupational exposure Pest control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tetradentate Pt(Ⅱ)complex as a singlet exciton sensitizing host for highly efficient green fluorescent organic light-emitting diodes

引用

Science China Materials 2024年第8期67卷 2618-2627页

作者： Unhyeok Jo Seung Chan Kim Chan hee Ryu Kang Mun lee Jae-Min Kim Jun Yeob lee School of Chemical Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-do 16419Republic of Korea Department of Chemistry Institute for Molecular Science and Fusion TechnologyKangwon National UniversityChuncheonGangwon 24341Republic of Korea Department of Advanced Materials Engineering Chung-Ang University4726Seodong-daeroDaedeok-myeonAnseong-siGyeonggi-do 17546Republic of Korea SKKU Advanced Institute of Nano Technology Sungkyunkwan University2066Seobu-roJangan-guSuwonGyeonggi 16419Republic of Korea SKKU Institute of Energy Science and Technology Sungkyunkwan University2066Seobu-roJangan-guSuwonGyeonggi 16419Republic of Korea

Efficient green fluorescent organic light-emitting diodes were designed with a phosphorescent metal complex as a singlet exciton sensitizing host(SESH)for achieving high efficiency and low efficiency roll-off through exciton and polaron *** Pt(Ⅱ)complex(Pt-Trz)possessing a tetradentate ligand with a bulky blocking group not only suppresses the severe formation of excimer or dimer itself but also transfers radiative excitons to fluorescent dopant *** SESH assisted fluorescence(SESHF)device with Pt-Trz as the host exhibits the maximum external quantum efficiency of 13.3%and a lower efficiency roll-off compared with exciplex host device which is a general approach for harvesting triplet *** exciton dynamics modeling unravels that the SESHF device effectively utilizes triplet excitons in the host by intersystem crossing and resonance energy transfer from the triplet state of the host to the singlet state of the terminal *** quenching rates of the SESHF device are reduced by 11 times for triplet-triplet annihilation and 1.8 times for tripletpolaron annihilation compared with the exciplex device,which demonstrates that Pt-Trz could be a platform to be used as an efficient host for fluorophores.

关键词： singlet annihilation polaron

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ionizing terahertz waves with 260 MV/cm from scalable optical rectification

引用

Light(Science & Applications) 2024年第6期13卷 1075-1087页

作者： Hyeongmun Kim Chul Kang Dogeun Jang Yulan Roh Sang Hwa lee Joong Wook lee Jae hee sung Seong Ku lee Ki-Yong Kim Advanced Photonics Research Institute GISTGwangju61005Korea Department of Physics and Optoelectronics Convergence Research Center Chonnam National UniversityGwangju61186Korea Pohang Accelerator Laboratory POSTECHPohang37673Korea Center for Relativistic Laser Science Institute for Basic ScienceGwangju61005Korea Institute for Research in Electronics and Applied Physics Department of PhysicsUniversity of MarylandCollege ParkMaryland20742USA

Terahertz(THz)waves,known as non-ionizing radiation owing to their low photon energies,can actually ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and ***,we demonstrate the generation of ionizing,multicycle,15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses.A complete characterization of the generated THz waves in energy,pulse duration,and focal spot size shows that the field strength can reach up to 260 megavolts per *** particular,a single-shot THz interferometer is employed to measure the THz pulse duration and spectrum with complementary numerical *** intense THz pulses are irradiated onto various solid targets to demonstrate THz-induced tunneling ionization and plasma *** study also discusses the potential of nonperturbative THz-driven ionization in gases,which will open up new opportunities,including nonlinear and relativistic THz physics in plasma.

关键词： optical interferometer matched

来源：

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

Correlation between hydration properties and electrochemical performances on Ln cation size effect in layered perovskite for protonic ceramic fuel cells

引用

Journal of Energy Chemistry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok Cho Jiwon Yun Boseok Seong Junseok Kim sun hee Choi Ho-Il Ji Sihyuk Choi Department of Mechanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Department of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Center for Energy Materials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Center for Hydrogen and Fuel Cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Energy and Environmental Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.

关键词： Protonic ceramic fuel cell Cathode Triple ionic and electronic conductor Hydration property Proton uptake Gibbs free energy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Random pinhole attenuator for high-power laser beams

引用

High Power Laser Science and Engineering 2024年第3期12卷 116-121页

作者： Seong Cheol Park Hyeok Yun Jin Woo Yoon Seong Ku lee Jae hee sung Il Woo Choi Chang hee Nam Kyung Taec Kim Department of Physics and Photon Science Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea Center for Relativistic Laser Science Institute for Basic ScienceGwangjuRepublic of Korea Advanced Photonics Research Institute Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea

The intensity attenuation of a high-power laser is a frequent task in the measurements of optical *** intensity can be attenuated by inserting an optical element,such as a partial reflector,polarizer or absorption *** devices are,however,not always easily applicable,especially in the case of ultra-high-power lasers,because they can alter the characteristics of a laser beam or become easily *** this study,we demonstrated that the intensity of a laser beam could be effectively attenuated using a random pinhole attenuator(RPA),a device with randomly distributed pinholes,without changing the beam *** this device,a multi-PW laser beam was successfully attenuated and the focused beam profile was measured without any alterations of its *** addition,it was confirmed that the temporal profile of a laser pulse,including the spectral phase,was ***,the RPA possesses significant potential for a wide range of applications.

关键词： high-power laser intensity attenuation laser diagnostics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：