检索结果-南通市图书馆

Hot electron generation on metal catalysts under surface reaction:Principles, devices, and application

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2018年第6期29卷 727-733页

作者： Ievgen I.Nedrygailov Hyosun Lee Si woo Lee jeong Young Park Center for Nanomaterials and Chemical Reactions Institute for Basic Science Graduate School of EEWS Korea Advanced Institute of Science and Technology(KAIST)

Understanding the fundamental mechanisms for charge transfer in supported catalysts is of great importance for heterogeneous catalysis. Several experimental and theoretical results suggest that charge flow through metal-support interfaces leads to the catalytic enhancement that is often observed in mixed catalysts. Therefore, it is crucial to directly probe this charge flow in metal-support catalysts during catalytic reactions. In this review, we consider the main aspects of research studying the processes that create and allow interfacial transfer of highly excited（hot） charge carriers in supported catalysts, and discuss the effect of this charge transfer on catalytic activity. We show a close connection between the phenomena of hot electron creation and chemical energy dissipation that accompanies catalytic reactions at both the gas/solid and liquid/solid interfaces. The intensity of hot electron flow is well correlated with the turnover rates of corresponding reactions, which opens up the possibility for developing new operando methodologies for studying chemical processes on catalytic surfaces.

关键词： Hot electron Energy dissipation Heterogeneous catalysis Metal-support interactions Nanodiode

Preparation of human decellularized peripheral nerve allograft using amphoteric detergent and nuclease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第9期16卷 1890-1896页

作者： joo-Yul Bae Suk Young Park Young Ho Shin Shin woo Choi Jae Kwang Kim Department of Orthopedic Surgery University of Ulsan College of MedicineGangneung Asan HospitalGangneung-siKorea Department of Orthopedic Surgery University of Ulsan College of MedicineAsan Medical CenterSeoulKorea

Animal studies have shown that amphoteric detergent and nuclease(DNase I and ribonuclease A) is the most reliable decellularization method of the peripheral nerve. However, the optimal combination of chemical reagents for decellularization of human nerve allograft needs further investigation. To find the optimal protocol to remove the immunogenic cellular components of the nerve tissue and preserve the basal lamina and extracellular matrix and whether the optimal protocol can be applied to larger-diameter human peripheral nerves, in this study, we decellularized the median and sural nerves from the cadavers with two different methods: nonionic and anionic detergents(Triton X-100 and sodium deoxycholate) and amphoteric detergent and nuclease(3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate(CHAPS), deoxyribonuclease I, and ribonuclease A). All cellular components were successfully removed from the median and sural nerves by amphoteric detergent and nuclease. Not all cellular components were removed from the median nerve by nonionic and anionic detergent. Both median and sural nerves treated with amphoteric detergent and nuclease maintained a completely intact extracellular matrix. Treatment with nonionic and anionic detergent decreased collagen content in both median and sural nerves, while the amphoteric detergent and nuclease treatment did not reduce collagen content. In addition, a contact cytotoxicity assay revealed that the nerves decellularized by amphoteric detergent and nuclease was biocompatible. Strength failure testing demonstrated that the biomechanical properties of nerves decellularized with amphoteric detergent and nuclease were comparable to those of fresh controls. Decellularization with amphoteric detergent and nuclease better remove cellular components and better preserve extracellular matrix than decellularization with nonionic and anionic detergents, even in large-diameter human peripheral nerves. In Korea, cadaveric studies are not yet l

关键词： median nerve sural nerve nuclease detergent human decellularized nerve graft

(FeO)_(2)FeBO_(3) nanoparticles attached on interconnected nitrogen-doped carbon nanosheets serving as sulfur hosts for lithium-sulfur batteries

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2024年第2期18卷 75-88页

作者： Junhai Wang Huaqiu Huang Chen Chen Jiandong Zheng Yaxian Cao Sang woo joo Jiarui Huang School of Material and Chemical Engineering Chuzhou UniversityChuzhou 239000China College of Mechanical Engineering Tongling UniversityTongling 244000China Key Laboratory of Functional Molecular Solids of the Ministry of Education College of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China School of Mechanical Engineering Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea

There are still many challenges including low conductivity of cathodes,shuttle effect of polysulfides,and significant volume change of sulfur during cycling to be solved before practical applications of lithium-sulfur(Li-S)*** this work,(FeO)_(2)FeBO_(3) nanoparticles(NPs)anchored on interconnected nitrogen-doped carbon nanosheets(NcNs)were synthesized,serving as sulfur carriers for Li-S batteries to solve such *** have the cross-linked network structure,which possess good electrical conductivity,large specific surface area,and abundant micropores and mesopores,enabling the cathode to be well infiltrated and permeated by the electrolyte,ensuring the rapid electron/ion transfer,and alleviating the volume expansion during the electrochemical *** addition,polar(FeO)_(2)FeBO_(3) can enhance the adsorption of polysulfides,effectively alleviating the polysulfide shuttle *** a current density of 1.0 A·g^(-1),the initial discharging and charging specific capacities of the(FeO)_(2)FeBO_(3)@NCNs-2/S electrode were obtained to be 1113.2 and 1098.3mA·h·g^(-1),*** 1000 cycles,its capacity maintained at 436.8 mA·h·g^(-1),displaying a decay rate of 0.08%per ***,combining NCNs with(FeO)_(2)FeBO_(3) NPs is conducive to the performance improvement of Li-S batteries.

关键词： (FeO)_(2)FeBO_(3) nitrogen-doped carbon nanosheet cathode lithium-sulfurbattery

Application of direct laser metal tooling for AISI H13 tool stee

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

中国有色金属学会会刊：英文版 2009年第B9期19卷 284-287页

作者： Jae-Ho LEE jeong-Hwan JANG Byeong-Don joo Hong-Sup YIM Young-Hoon MOON School of Mechanical Engineering Pusan National University

In the die industry, it is commonly agreed that residual tool life can be successfully extended by timely repair of damaged surfaces. Traditionally, the main repair process is tungsten inert gas (TIG) welding, but a new process called direct laser metal tooling (DLMT) emerges. DLMT is a manual process, of which results depend on the materials of the powders and tools, the laser process and parameters. This technology is a direct-metal freeform fabrication technique in which a 200 W fiber laser is used. AISI H13 tool steel is a suitable material for die casting tools because of the high resistance to thermal fatigue and dimensional stability. In this research, AISI H13 tool steel was melted with metal powder by fiber laser. Before melting AISI H13, the powders were analyzed with XRF equipment. Then, hardness distribution of laser melted zone was investigated. The microstructure in laser melted zone was discussed. In order to identify the effect of particle size of powder on the melted zone, two types of particle sizes of powders were used. Experimental results show that the mold repair process using DLMT can be applied in the mold repair industry.

关键词：金属模具应用激光工具钢 H13 社会光纤激光器粉末材料修复过程

Effect of Laser Parameters on Sintered Powder Morphology

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2010年第4期26卷 375-378页

作者： Byeong-Don joo jeong-Hwan Jang Jae-Ho Lee Young-Myung Son Young-Hoon Moon Engineering Research Center for Net Shape and Die Manufacturing School of Mechanical EngineeringPusan National University

Selective laser sintering is a kind of rapid prototyping process whereby a three-dimensional part is built layerwise by laser scanning a powder. This process is highly inffuenced by powder and laser parameters such as laser power, scan rate, spot size and layer thickness. Therefore a study on fabricating a line with Fe-Ni-Cr powder on AISI H13 tool steel has been performed by selective laser sintering. In this study, fabrication was performed by experimental facilities consisting of a 200W fiber laser which can be focused to 0.08 mm and atmospheric chamber which can control atmospheric pressure with argon. The line was fabricated with various laser power, scan rate and layer thickness. Line width and surface quality were investigated. With power increase or layer thickness decrease, line width was decreased and line surface quality was improved with scan rate optimization.

关键词： Selective laser sintering Direct fabrication Fiber laser

Synchronous triple occurrence of MALT lymphoma, schwannoma, and adenocarcinoma of the stomach

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第22期23卷 4127-4131页

作者： Kyeong W Choi Mee joo Han S Kim woo Y Lee Department of Surgery Seoul Paik Hospital Inje University College of Medicine Department of Pathology Ilsan Paik Hospital Inje University College of Medicine

We present a case of a 56-year-old man with 3 synchronous gastric tumors. The patient presented with melena, and 3 gastric abnormalities were detected on gastroduodenoscopic examination, including a small ulcerative lesion in the gastric antrum, a submucosal mass in the gastric body, and severe erosion in the fundus. Histological examination of biopsy samples yielded respective diagnoses of gastric adenocarcinoma, gastritis, and mucosa-associated lymphoid tissue(MALT) lymphoma. The patient first received medication to eradicate any underlying Helicobacter pylori infection, which might have been a cause of the MALT lymphoma. Four weeks later, after examination of repeat biopsy samples revealed that the MALT lymphoma had resolved, the patient underwent subtotal gastrectomy. Further histological examination of resected tissue confirmed the antrum lesion as adenocarcinoma and the body lesion as schwannoma. To our knowledge, this is the first reported case of synchronous triple primary gastric adenocarcinoma, MALT lymphoma, and schwannoma.

关键词： Gastric cancer Synchronous Mucosa-associated lymphoid tissue lymphoma Schwannoma Triple

Characterization and sensor application of cellulose electro-active paper (EAPap)

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

Chinese Science Bulletin 2009年第15期54卷 2703-2707页

作者： LEE Sang-woo KIM joo-Hyung KIM Jaehwan KIM Heung Soo Creative Research Center for EAPap Actuator Mechanical Engineering Department Inha University School of Mechanical and Automotive Engineering Catholic University of Daegu

As a novel piezoelectric material, the mechanical and piezoelectric properties of cellulose electro-active paper (EAPap) were studied. Young's modulus of piezoelectric EAPap was dependant on the material orientation as compared with other EAP materials. The highest Young's modulus was obtained at 0° direction, while the highest direct piezoelectric charge constant was achieved at 45°. By measuring the induced output voltage from the thin piezoelectric cellulose film under the applied impact force, we demonstrate that piezoelectric EAPap film has a potential for sensor applications.

关键词：传感器应用纤维素膜压电材料表征杨氏模量压电性能电子机械输出电压

Clinical outcomes of self-expandable metal stents in palliation of malignant anastomotic strictures caused by recurrent gastric cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第28期15卷 3523-3527页

作者： Yu Kyung Cho Sang woo Kim Kwan woo Nam Jae Hyuck Chang Jae Myung Park jeong-Jo jeong In Seok Lee Myung-Gyu Choi In-Sik Chung Department of Internal Medicine The Catholic University of Korea

AIM： To examine the technical feasibility and clinical outcomes of the endoscopic insertion of a selfexpandable metal stent （SEMS） for the palliation of a malignant anastomotic stricture caused by recurrent gastric cancer. METHODS： The medical records of patients, who had obstructive symptoms caused by a malignant anastomotic stricture after gastric surgery and underwent endoscopic insertion of a SEMS from January 2001 to December 2007 at Kangnam St Mary＇s Hospital, were reviewed retrospectively. RESULTS： Twenty patients （15 male, mean age 63 years） were included. The operations were a total gastrectomy with esophagojejunostomy （n = 12）, subtotal gastrectomy with Billroth-Ⅰ reconstruction （n = 2） and subtotal gastrectomy with Billroth- Ⅱ reconstruction （n = 8）. The technical and clinical success rates were 100% and 70%, respectively. A small bowel or colon stricture was the reason for a lack of improvement in symptoms in 4 patients. Two of these patients showed improvement in symptoms after another stent was placed. Stent reobstruction caused by tumor ingrowth or overgrowth occurred in 3 patients （15%） within 1 mo after stenting. Stent migration occurred with a covered stent in 3 patients who underwent a subtotal gastrectomy with Billroth-Ⅱ reconstruction. Two cases of partial stent migration were easily treated with a second stent or stent repositioning. The median stent patency was 56 d （range, 5-439 d）. The median survival was 83 d （range, 12-439 d）. CONCLUSION： Endoscopic insertion of a SEMS provides safe and effective palliation of a recurrent anastomotic stricture caused by gastric cancer, A meticulous evaluation of the presence of other strictures before inserting the stent is essential for symptom improvement.

关键词： Stents Surgical anastomosis Stricture Endoscopic gastrointestinal surgery Stomach neoplasms

Selective laser melting of Fe-Ni-Cr layer on AISI H13 tool steel

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

中国有色金属学会会刊：英文版 2009年第4期19卷 921-924页

作者： Byeong-Don joo jeong-Hwan JANG Jae-Ho LEE Young-Myung SON Young-Hoon MOON School of Mechanical Engineering Pusan National University

An attempt to fabricate Fe-Ni-Cr coating on AISI H13 tool steel was performed with selective laser ***-Ni-Cr coating was produced by experimental facilities consisting of a 200 W fiber laser which can be focused to 80 μm and atmospheric chamber which can control atmospheric pressure with N2 or *** layer was fabricated with various process parameters such as laser power,scan rate and fill *** quality and coating thickness were measured and *** different surface patterns,such as typeⅠ,typeⅡand type Ⅲ,are shown with various test conditions and smooth regular pattern is obtained under the conditions as 10 μm of fill spacing,50-350 mm/s of scan rate and 40 μm of fill spacing,10-150 mm/s of scan *** maximum coating thickness is increased with power elevation or scan rate drop,and average thickness of 10 μm fill spacing is lower than that of 40 μm fill spacing.

关键词：镍铬涂层工具钢激光熔融社会扫描速度铁涂层厚度光纤激光器