检索结果-南通市图书馆

Enhancing ammonia production rates from electrochemical nitrogen reduction by engineering three-phase boundary with phosphorus-activated Cu catalysts

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 Energy Chemistry 2023年第9期84卷 394-401页

作者： Jeehye kim Cho hee Lee Yong Hyun Moon Min hee Lee Eun Hyup kim Sun hee Choi Youn Jeong Jang Jae Sung Lee School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Department of Chemical Engineering Hanyang UniversitySeoul 04763Republic of Korea Pohang Accelerator Laboratory(PAL) Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous ***,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) *** eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic *** a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic *** work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.

关键词： Electrochemical nitrogen reduction reaction Ammonia production Phosphorous modified copper electrodes Gas diffusion electrodes Three-phase boundary PTFE coating

Development and application of a multi-step porcine in vitro system to evaluate feedstuffs and feed additives for their efficacy in nutrient digestion, digesta characteristics, and intestinal immune responses

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第2期17卷 265-282页

作者： hee Yeon kim Jun-Ok Moon Sung Woo kim Application Center CJ Blossom Park Department of Animal Science North Carolina State University

In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs(corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and Corynebacterium glutamicum cell mass [CGCM]), feed enzymes(xylanase and phytase), and supplemental amino acids(arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included(1) nutrient digestibility of feedstuffs,(2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and(3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects(P < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected(P < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated(P < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P < 0.05. This indicates in vitro models can have increased prec

关键词： Digestion Feed additive Feedstuff In vitro Intestine Pig

On the Classification of Positive Quaternionic Khler Manifolds with b_4=1

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2010年第5期26卷 875-884页

作者： Jin Hong kim hee Kwon LEE Department of Mathematical Sciences Korea Advanced Institute of Science and Technology Guseong-dong

Let M be a positive quaternionic Kahler manifold of dimension 4m. We already showed that if the symmetry rank is greater than or equal to [m/2] ＋ 2 and the fourth Betti number b4 is equal to one, then M is isometric to HPm. The goal of this paper is to report that we can improve the lower bound of the symmetry rank by one for higher even-dimensional positive quaternionic Kahler manifolds. Namely, it is shown in this paper that if the symmetry rank of M with b4（M） = 1 is greater than or equal to m/2 ＋ 1 for m ≥ 10, then M is isometric to HPm. One of the main strategies of this paper is to apply a more delicate argument of Frankel type to positive quaternionic Kahler manifolds with certain symmetry rank.

关键词： positive quaternionic Kahler symmetry

Segregation of voiced and unvoiced components from residual of speech signal

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2012年第2期19卷 496-503页

作者： JO Cheol-woo kim Jae-hee School of Mechatronics Changwon National University

In conventional source-filter models, voiced and unvoiced components were considered independently. However, in practice it was difficult to separate the source into two parts. An actual source consists of a mixture of two sources and the ratio varies according to the content or the intention of speaker. It had been investigated to separate the voiced and unvoiced components for different source models. Source signals were modeled based on the residual signal measured from inverse filtering. Three different source models were assumed. The parameters of each model were optimized for the original speech signal using a genetic algorithm. The resulting parameters were compared in terms of the mel-cepstral distance to the original signal, the spectrogram and the spectral envelope from the synthesized signal. The optimization method achieves an improvement of 15% for the Klatt model, but there is little improvement in the modified residual case.

关键词： voice source model synthesis optimization genetic algorithm

Module-level design and characterization of thermoelectric power generator

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第4期31卷 39-47页

作者： Kang Zhu Shengqiang Bai hee Seok kim Weishu Liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices Southern University of Science and TechnologyShenzhen 518055China The State Key Laboratory of High-Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Mechanical Engineering School of Engineering&TechnologyUniversity of Washington TacomaTacomaWA 98402USA

Thermoelectric power generation provides us the unique capability to explore the deep space and holds promise for harvesting the waste heat and providing a battery-free power supply for *** past years have witnessed massive progress in thermoelectric materials,while the module-level development is still lagged *** would like to shine some light on the module-level design and characterization of thermoelectric power generators(TEGs).In the module-level design,we review material selection,thermal management,and the determination of structural *** also look into the module-level characterization,with particular attention on the heat flux ***,the challenge in the optimal design and reliable characterization of thermoelectric power generators is discussed,together with a calling to establish a standard test procedure.

关键词： thermoelectric module-level design characterization

Antioxidant and anticancer activity of Artemisia princeps *** extract in HepG2 and Hep3B hepatocellular carcinoma cells

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2013年第5期25卷 536-543页

作者： Eun-Jeong Choi Gun-hee kim Plant Resources Research Institute Duksung Women's University

Objective：The aim of the present study was to investigate antioxidant and the anticancerigen activity of a methanol extract from Artemisia princeps *** （APME）,a well-known traditional herbal medicine in Asia,in hepatocellular cancer ***：To evaluate the antioxidant activity of APME,reactive oxygen species （ROS） and the antioxidant enzymes,superoxide dismutase （SOD） and catalase were investigated in HepG2 cells exposed to APME （5,100,and 200 μg/mL） for 72 ***,to evaluate the anticancer activity of APME,we investigated the proliferation and apoptosis induction of HepG2 and Hep3B cells exposed to APME （1-200 μg/mL） for 24,48,and 72 ***：APME dose-dependently reduced the generation of ROS in the presence of H2O2 compared with control ***,it increased catalase and SOD ***,APME inhibited cell proliferation in a dose-and time-dependcnt manner,but at concentrations lower than 100 μg/mL,the inhibition was less dose-dependent than ***2 and Hep3B cells exposed to 5,100,and 200 μg/mL APME for 72 h underwent cell cycle arrest and *** to APME resulted in a significant increase in the number of cells in G1 phase and a decrease in the G2/M phase cell *** addition,APME induced P53 expression of HepG2 cells in a dose-dependent manner,and played a role in the downregulation of Bcl-2 and upregulation of Bax in both HepG2 and Hep3B ***：These results indicate the potential role of APME as an antioxidant and anticancerigen agent in hepatocarcinoma cell lines.

关键词： Artemisia princeps var.orientalis antioxidant anticancer hepatocellular carcinoma

Risk factors for complications associated with upper gastrointestinal foreign bodies

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2015年第26期21卷 8125-8131页

作者： Kyong hee Hong Yoon Jae kim Jae Hak kim Song Wook Chun hee Man kim Jae hee Cho Division of Gastroenterology Department of Internal MedicineDongguk University Ilsan HospitalGraduate School Division of Gastroenterology Department of Internal MedicineGachon University Gil Medical Center Division of Gastroenterology Department of Internal MedicineMyongji Hospital Division of Gastroenterology and Hepatology Department of Internal MedicineYonsei University Wonju College of Medicine

AIM: To investigate predictive risk factors associated with complications in the endoscopic removal of foreign bodies from the upper gastrointestinal ***: We retrospectively reviewed the medical records of 194 patients with a diagnosis of foreign body impaction in the upper gastrointestinal tract,confirmed by endoscopy,at two university hospital in South *** demographic data,including age,gender,intention to ingestion,symptoms at admission,and comorbidities,were *** features of the foreign bodies,such as type,size,sharpness of edges,number,and location,were *** data those were analyzed included duration of foreign body impaction,duration of endoscopic performance,endoscopic device,days of hospitalization,complication rate,30-d mortality rate,and the number of operationsrelated to foreign body ***: The types of upper gastrointestinal foreign bodies included fish bones,drugs,shells,meat,metal,and animal *** locations of impacted foreign bodies were the upper esophagus(57.2%),mid esophagus(28.4%),stomach(10.8%),and lower esophagus(3.6%).The median size of the foreign bodies was 26.2 ± 16.7 *** 194 patients,endoscopic removal was achieved in 189,and complications developed in 51 patients(26.9%).Significant complications associated with foreign body impaction and removal included deep lacerations with minor bleeding(n = 31,16%),ulcer(n = 11,5.7%),perforation(n = 3,1.5%),and abscess(n = 1,0.5%).Four patients underwent operations because of incomplete endoscopic foreign body *** multivariate analyses,risk factors for endoscopic complications and failure were sharpness(HR = 2.48,95%CI: 1.07-5.72; P = 0.034) and a greater than 12-h duration of impaction(HR = 2.42,95%CI: 1.12-5.25,P = 0.025).CONCLUSION: In cases of longer than 12 h since foreign body ingestion or sharp-pointed objects,rapid endoscopic intervention should be provided in patients with ingested foreign bodies.

关键词： Emergency department Foreign body Upper gastrointestinal tract Endoscopy Complication

Impact of nonalcoholic fatty liver disease on the risk of gallbladder polyps in lean and non-obese individuals:A cohort study

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

Hepatobiliary & Pancreatic Diseases International 2024年第6期23卷 573-578页

作者： Nam hee kim Ji Hun Kang Hong Joo kim Division of Gastroenterology Department of Internal MedicineKangbuk Samsung HospitalSungkyunkwan University School of MedicineSeoulKorea Department of Radiology Hanyang University Guri HospitalHanyang University College of MedicineGuriKorea

Background:The association between non-obese or lean nonalcoholic fatty liver disease(NAFLD)and gallbladder polyps(GBPs)has not yet been *** aimed to determine whether NAFLD is an independent risk factor for the development of GBPs,even in non-obese and lean ***:We analyzed a cohort of 331208 asymptomatic adults who underwent abdominal ultrasonography(US).The risk of GBP development was evaluated according to the obesity and NAFLD ***:The overall prevalence of NAFLD and GBPs≥5 mm was 28.5%and 2.9%,*** prevalence of NAFLD among 160276 lean,77676 overweight and 93256 obese participants was 8.2%,31.2%,and 61.1%,*** with NAFLD had a significantly higher incidence of GBPs with a size of≥5 mm[adjusted odds ratio(OR)=1.18;95%confidence interval(CI):1.11–1.25].A higher body mass index and its categories were also significantly associated with an increased risk of GBPs≥5 ***,risk of GBPs≥5 mm was significantly increased even in NAFLD individuals who are not obese(lean:adjusted OR=1.36,95%CI:1.19-1.54;overweight:adjusted OR=1.14,95%CI:1.03–1.26,respectively).Conclusions:Non-obese/lean NAFLD is an independent risk factor for GBP development,suggesting that NAFLD may play an important role in the pathogenesis of GBPs regardless of the obesity ***,a more thorough evaluation for GBPs may be necessary when hepatic steatosis is detected on abdominal US,even in non-obese or lean individuals.

关键词： Nonalcoholic fatty liver disease Non-obese Lean Gallbladder polyps

Surface properties of Al-doped ZnO thin film before and after CF_4/Ar plasma etching

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2022年第7期24卷 194-200页

作者： Young-hee JOO Gwan-Ha kim Doo-Seung UM Chang-Il kim School of Electrical and Electronics Engineering Chung-Ang UniversitySeoul 06974Republic of Korea Department of Semiconductor Materials and Applications Korea PolytechnicSeongnam 13122Republic of Korea Department of Electrical Engineering Sejong UniversitySeoul 05006Republic of Korea

Al-doped ZnO(AZO) is considered as an alternative to transparent conductive oxide *** and achieving a stable surface are important challenges in the development and optimization of dry etching processes, which must be overcome for the application of AZO in various devices. Therefore, in this study, the etch rate and surface properties of an AZO thin film after plasma etching using the adaptive coupled plasma system were investigated. The fastest etch rate was achieved with a CF_(4)/Ar ratio of 50:50 sccm. Regardless of the ratio of CF_(4) to Ar,the transmittance of the film in the visible region exceeded 80%. X-ray photoelectron spectroscopy analysis of the AZO thin film confirmed that metal-F bonding persists on the surface after plasma etching. It was also shown that F eliminates O vacancies. Consequently, the work function and bandgap energy increased as the ratio of CF-4 increased. This study not only provides information on the effect of plasma on AZO thin film, but identifies the cause of changes in the device characteristics during device fabrication.

关键词： Al-doped ZnO plasma etching F-based plasma surface characteristics X-ray photoelectron spectroscopy ultraviolet photoelectron spectroscopy