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Tidal effects based on a GUP-induced effective metric

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Communications in Theoretical Physics 2024年第9期76卷 65-74页

作者： soon-tae Hong Yong-Wan Kim Young-Jai Park Center for Quantum Spacetime and Department of Physics Sogang University Department of Physics and Research Institute of Physics and Chemistry Jeonbuk National University Department of Physics Sogang University

In this paper, we study tidal forces in the Schwarzschild black hole, whose metric explicitly includes a generalized uncertainty principle(GUP) effect. We also investigate interesting features of the geodesic equations and tidal effects that are dependent on the GUP parameter αrelated to a minimum length. Then, by solving the geodesic deviation equations explicitly with appropriate boundary conditions, we show that α in the effective metric affects both the radial and angular components of the geodesic equation, particularly near the singularities.

关键词： effective metric generalized uncertainty principle geodesic deviation equation

Surface engineering of ZnO electrocatalyst by N doping towards electrochemical CO_(2) reduction

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Journal of Energy Chemistry 2024年第1期88卷 71-81,I0002页

作者： Rohini Subhash Kanase Getasew Mulualem Zewdie Maheswari Arunachalam Jyoti Badiger Suzan Abdelfattah Sayed Kwang-soon ahn Jun-Seok Ha Uk Sim Hyeyoung Shin soon Hyung Kang Department of Interdisciplinary Program for Photonic Engineering Chonnam National UniversityGwangju 61186Republic of Korea Graduate School of Energy Science and Technology(GEST) Chungnam National University99 Daehak-roYuseong-guDaejeon 34134Republic of Korea Department of Chemistry Education and Optoelectronic Convergence Research Center Chonnam National UniversityGwangju 61186Republic of Korea Department of Advanced Chemicals and Engineering Chonnam National UniversityGwangju 61186Republic of Korea School of Chemical Engineering Yeungnam UniversityGyeongsan 38541Republic of Korea Department of Energy Engineering Korea Institute of Energy Technology(KENTECH)Naju 58217Republic of Korea

The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-based electrocatalyst was developed for use in gas-diffusion electrodes(GDE),and the effect of nitrogen(N)doping on the ECR activity of ZnO electrocatalysts was ***,a ZnO nanosheet was prepared via the hydrothermal method,and nitridation was performed at different times to control the N-doping *** an increase in the N-doping content,the morphological properties of the nanosheet changed significantly,namely,the 2D nanosheets transformed into irregularly shaped ***,the ECR performance of Zn O electrocatalysts with different N-doping content was assessed in 1.0 M KHCO_(3) electrolyte using a gas-diffusion electrode-based ECR *** the ECR activity increased after a small amount of N doping,it decreased for higher N doping *** them,the N:ZnO-1 h electrocatalysts showed the best CO selectivity,with a faradaic efficiency(FE_(CO))of 92.7%at-0.73 V *** hydrogen electrode(RHE),which was greater than that of an undoped Zn O electrocatalyst(FE_(CO)of 63.4%at-0.78 V_(RHE)).Also,the N:ZnO-1 h electrocatalyst exhibited outstanding durability for 16 h,with a partial current density of-92.1 mA cm^(-2).This improvement of N:ZnO-1 h electrocatalyst can be explained by density functional theory calculations,demonstrating that this improvement of N:ZnO-1 h electrocatalyst comes from(ⅰ)the optimized active sites lowering the free energy barrier for the rate-determining step(RDS),and(ⅱ)the modification of electronic structure enhancing the electron transfer rate by N doping.

关键词： ZnO N-doped ZnO Gas-diffusion electrode CO Selectivity Electrochemical CO_(2)reduction

Transparent high-performance piezoceramics through pressureless sintering

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Journal of Advanced Ceramics 2024年第5期13卷 561-567页

作者： Hye-Lim Yu Woo-Seok Kang Ju-Hyeon Lee Temesgen Tadeyos Zate Young-Jin Lee Bo-Kun Koo Dong-Jin Shin Min-Soo Kim soon-Jong Jeong Young Ghyu ahn Wook Jo Department of Material Science and Engineering Ulsan National Institute of Science and TechnologyUlsan 44919Republic of Korea Energy Conversion Research Center Korea Electrotechnology Research InstituteChangwon 51543Republic of Korea MLCC Development Team Component Biz.UnitSamsung Electro-Mechanics Co.Ltd.Suwon 16674Republic of Korea

Piezoelectricity offers an electromechanical coupling that is widely utilized in transducer *** has been a consistent demand for transparent piezoelectric materials for optoelectrical ***,despite the inherent tradeoff between the transparency and the piezoelectricity,numerous strategies have been explored to develop the transparent piezoelectric ***,the most transparent piezoelectric materials developed to date is either a single crystal or materials that achieve transparency via hot-press sintering,limiting its industrial ***,we introduce a novel piezoelectric material that ensures transparency through co-doping and pressureless sintering of polycrystalline *** this study,we employed a compositional optimization approach to enhance the synergistic effect between the transparency and the piezoelectric properties of 0.71Pb(Mg_(1/3)Nb_(2/3))O_(3)–0.29PbTiO_(3)(PMN–0.29PT)*** utilizing the tape casting process for mass production and large-area manufacturing,our Pb_(0.913)La_(0.0145)Sm_(0.0145)(Mg_(1/3)Nb_(2/3))_(0.71)Ti_(0.29)O_(3)(TP2.9)ceramics exhibited over 60%transparency and large piezoelectric coefficient(d33)of 1104 pC/*** material holds considerable promise for a wide range of industrial applications in both the optical and electronic domains.

关键词： piezoelectric ceramics transparency pressureless sintering co-doping tape casting

A case of unsuspected trans-orbital-cranial penetrating injury by a wooden chopstick in a one-year-old infant

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International Journal of Ophthalmology(English edition) 2022年第3期15卷 523-526页

作者： Yeon Woong Chung soon Young Lee tae Yoon La Department of Ophthalmology St.Vincent’s HospitalCollege of MedicineThe Catholic University of KoreaSeoul 16247Korea

Dear Editor,Transorbital penetrating injury is one emergency faced by ophthalmologists during primary care that requires special attention because it can lead to serious ophthalmic and neurological *** all head injuries, intracranial penetrating injuries occur at a low rate of 0.4%[1], and transorbital-cranial penetrating injuries are even more rare, but do occur more frequently in young children than in adults[2-3].

关键词： injuries infant orbital

Do different kinds of photon-pair sources have the same indistinguishability in quantum silicon photonics?

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Photonics Research 2023年第11期11卷 1820-1837页

作者： JONG-MOO LEE ALESSIO BALDAZZI MATTEO SANNA STEFANO AZZINI JOON tae ahn MYUNG-LAE LEE YOUNGIK SOHN LORENZO PAVESI Electronics and Telecommunications Research Institute(ETRI) Daejeon 34129Republic of Korea Department of Physics University of Trento38123 TrentoItaly Korea Advanced Institute of Science and Technology(KAIST) Daejeon 34141Republic of Korea

In the same silicon photonic integrated circuit,we compare two types of integrated degenerate photon-pair sources(microring resonators and waveguides)using Hong–Ou–Mandel(HOM)interference *** nominally identical microring resonators are coupled to two nominally identical waveguides,which form the arms of a Mach–Zehnder *** is pumped by two lasers at two different wavelengths to generate,by spontaneous four-wave mixing,degenerate photon *** particular,the microring resonators can be thermally tuned in or out of resonance with the pump wavelengths,thus choosing either the microring resonators or the waveguides as photon-pair sources,*** this way,an on-chip HOM visibility of 94%with microring resonators and 99%with straight waveguides is measured upon *** compare our experimental results with theoretical simulations of the joint spectral intensity and the purity of the degenerate photon *** verify that the visibility is connected to the sources’indistinguishability,which can be quantified by the overlap between the joint spectral amplitudes(JSA)of the photon pairs generated by the two *** estimate a JSA overlap of 98%with waveguides and 89%with microring resonators.

关键词： interferometer pumped pump

Development of a 3D subcutaneous construct containing insulin-producing beta cells using bioprinting

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Bio-Design and Manufacturing 2022年第2期5卷 265-276页

作者： Chi B.ahn Ji-Hyun Lee Joo H.Kim tae H.Kim Hee-Sook Jun Kuk H.Son Jin W.Lee Department of Molecular Medicine College of MedicineGachon University155Gaetbeol-roYeonsu-kuIncheonRepublic of Korea Department of Health Sciences and Technology GAIHSTGachon University155Gaetbeol-roYeonsu-kuIncheonRepublic of Korea College of Pharmacy Gachon University191Hambangmoe-roYeonsu-kuIncheonRepublic of Korea Department Thoracic and Cardiovascular Surgery Gachon University Gil Medical CenterCollege of MedicineGachon University21Namdong-daero 774 beon-gilNamdong-guIncheonRepublic of Korea

Type 1 diabetes is caused by insulin deficiency due to the loss of beta cells in the islets of *** severe cases,islet transplantation into the portal vein is ***,due to the loss of transplanted islets and the failure of islet function,the 5-year insulin independence rate of these patients is<50%.In this study,we developed a long-term,insulin-secreting,3 Dbioprinted construct implanted subcutaneously with the aim of preventing islet *** bioprinted construct was fabricated by the multi-layer bioprinting of beta-cell(mouse insulinoma-6:MIN-6)-encapsulated alginate bioink and poly(caprolactone)biodegradable polymer.A glucose response assay revealed that the bioprinted constructs proliferated and released insulin normally during the 4-week in vitro *** MIN-6 generated clusters with a diameter of 100-200μm,similar to the original pancreatic islets in the *** an in vivo study using type 1 diabetes mice,animals implanted with bioprinted constructs showed three times higher insulin secretion and controlled glucose levels at 8 weeks after *** the implanted,bioprinted constructs had a positive effect on insulin secretion in the experimental animals,the survival rate of the implanted group(75%)was three times higher than that of the non-implanted group(25%).The results suggest that the proposed,3 D-bioprinted,subcutaneous construct can be a better alternative to portal vein islet transplantation.

关键词： 3D bioprinting Subcutaneous construct Type 1 diabetes Insulin Beta cells

Curative resection of leiomyosarcoma of the descending colon with metachronous liver metastasis: A case report

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World Journal of Gastrointestinal Surgery 2023年第5期15卷 992-999页

作者： Soo-Hyeon Lee Sang-Ho Bae Sang-Cheol Lee tae-Sung ahn Zisun Kim Hae-Il Jung Department of Surgery Soonchunhyang University Cheonan HospitalCheonan 31151ChungnamSouth Korea Department of Internal Medicine Soonchunhyang University Cheonan HospitalCheonan 31151ChungnamSouth Korea Department of Surgery Soonchunhyang University Bucheon HospitalBucheon 14584GyeonggiSouth Korea

BACKGROUND Leiomyosarcoma(LMS)has a poor prognosis and rarely originates from the *** resection is possible,surgery is the first treatment most commonly ***,no standard treatment exists for hepatic metastasis of LMS;although,several treatments,such as chemotherapy,radiotherapy,and surgery,have been ***,the management of liver metastases remains *** SUMMARY We present a rare case of metachronous liver metastasis in a patient with LMS originating from the descending colon.A 38-year-old man initially reported abdominal pain and diarrhea over the previous two *** revealed a 4-cm diameter mass in the descending colon,40 cm from the anal *** tomography revealed intussusception of the descending colon due to the 4-cm *** patient underwent a left *** analysis of the tumor revealed that it was positive for smooth muscle actin and desmin,and negative for cluster of differentiation 34(CD34),CD117,and discovered on gastrointestinal stromal tumor(GIST)-1,which are characteristic of gastrointestinal LMS.A single liver metastasis developed 11 mo postoperatively;the patient subsequently underwent curative resection *** patient remained disease-free after six cycles of adjuvant chemotherapy(doxorubicin and ifosfamide),and 40 and 52 mo after liver resection and primary surgery,*** cases were obtained from a search of Embase,PubMed,MEDLINE,and Google *** Early diagnosis and surgical resection may be the only potential curative options for liver metastasis of gastrointestinal LMS.

关键词： Leiomyosarcoma Colon Liver metastasis Surgical resection Treatment Case report

Nuclear and chloroplast genome diversity revealed by low-coverage whole-genome shotgun sequence in 44 Brassica oleracea breeding lines

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Horticultural Plant Journal 2021年第6期7卷 539-551页

作者： Sampath Perumal Nomar Espinosa Waminal Jonghoon Lee Hyun-Jin Koo Boem-soon Choi Jee Young Park Kyounggu ahn tae-Jin Yang Department of Agriculture Forestry and BioresourcesPlant Genomics and Breeding Instituteand Research Institute of Agriculture and Life SciencesCollege of Agriculture and Life SciencesSeoul National UniversitySeoul 08826Republic of Korea Global Institute for Food Security University of Saskatchewan421 Downey RoadSaskatoonSK S7N 4L8Canada Agriculture and Agri-Food Canada 107 Science PlaceSaskatoon S7N 0X2Canada Chromosome Research Institute Department of Life ScienceSahmyook UniversitySeoul 01795Republic of Korea Joeun Seeds.Co. LtdGoesan-GunChungcheongbuk-Do 367-833Republic of Korea Phyzen Genomics Institute 13Seongnam-daero 331beon-gilBundang-guSeongnam-siGyeonggi-do 13558Republic of Korea

Whole-genome shogun sequence(WGS)data generated by next-generation sequencing(NGS)platforms are a valuable resource for crop *** produced 5–6×WGS coverage of 44 Brassica oleracea breeding lines representing seven subspecies/morphotypes:cabbage,broccoli,cauliflower,kailan,kale,Brussels sprout,and kohlrabi to systematically evaluate the nuclear and chloroplast(Cp)diversity in the 44 *** breeding *** then exploited the impact of low-coverage NGS by evaluating nuclear genome diversity and assembly,annotation of complete chloroplast(Cp)genomes and 45 S nuclear ribosomal DNA(45S nrDNA)sequences,and copy number variation for major *** genome diversity analysis has revealed a total of 496463 SNPs and 37493 indels in the nuclear genome across the 44 ***,some SNPs showed subspecies enrichment at certain chromosomal *** assembly of complete Cp genomes contained 153361–153372 bp with 37 variants including SNPs and *** 45S nrDNA transcription unit was 5802 bp long with a total of 31 SNPs from the 44 *** phylogenetic tree inferred from the nuclear and Cp genomes coincided and clustered broccoli,cauliflower,and kailan in one group and cabbage,Brussels sprout,kale,and kohlrabi in another *** morphotypes diverged during the last 0.17 million *** Cp genome diversity reflected the unique cytoplasm of each subspecies,and revealed that the cytoplasm of many breeding lines was replaced and intermingled via inter-subspecies crosses during the breeding process *** polymorphic Cp markers provide a classification system for the cytoplasm types in ***,copy numbers of major transposable elements(TEs)showed high diversity among the 44 accessions,indicating that many TEs have become active ***,we demonstrated a comprehensive utilization of low-coverage NGS data and might shed light on the genetic diversity and evolution of diverse *** morphotypes.

关键词： Brassica oleracea subspecies Chloroplast genome Nuclear ribosomal DNA Genetic diversity Phylogeny

Surface treatment to improve corrosion resistance of Al plate heat exchangers

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中国有色金属学会会刊：英文版 2009年第B9期19卷 28-31页

作者： Jong-soon KIM tae-Ho KANG In-Kwan KIM Department of Mechanical Engineering Pu kyong National University

The correlations between thermal and physical properties were studied through thermal conductivity measurements, hardness tests, salt spray tests (AASS) among the surface treatment samples named K20, K40 with thickness of 20, 40 μm respectively and raw sample named K00. In thermal conductivity measurements, there are little differences among the samples as K00, K20 and K40, they exhibit 153.39, 150.69 and 149.76 W/(m·K), respectively. According to hardness tests, K00, K20 and K40 exhibit 87.9, 259.7 and 344.8 in Vickers values. In the result of salt spray tests to examine the effects on corrosion resistance, K00, K20 and K40 exhibit the grade of 3?5, 2.0?9.8 and 10, respectively. The mutual relation of the above results was analyzed. It is found that the surface treatments do not affect the thermal conductivity of aluminum and result in the improvement of physical properties. As a result of the technology, the surface improvement of aluminum alloy specimen is achieved without thermal degradation. It validates the ability of the aluminum plate heat exchangers with surface treatment to enhance the corrosion resistance. Present work is performed as the first fundamental threshold in the process of aluminum plate heat exchangers development to check out its possibility, therefore the next step-experimental and numerical study of practical aluminum plate heat exchangers will be made.

关键词：板式换热器表面处理耐铝性物理性能导热系数硬度测试盐雾试验耐腐蚀性