检索结果-南通市图书馆

Kink effect in AlGaN/GaN high electron mobility transistors by electrical stress

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 Physics B 2011年第6期20卷 407-412页

作者：马晓华马骥刚杨丽媛贺强焦颖马平郝跃 School of technical Physics Xidian University Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University

The kink effect is studied in an AlGaN/GaN high electron mobility transistor by measuring DC performance during fresh, short-term stress and recovery cycle with negligible degradation. Vdg plays an assistant role in detrapping electrons and short-term stress results in no creation of new category traps but an increase in number of active traps. A possible mechanism is proposed that electrical stress supplies traps with the electric field for activation and when device is under test field-assisted hot-electrons result in electrons detrapping from traps, thus deteriorating the kink effect. In addition, experiments show that the impact ionization is at a relatively low level, which is not the dominant mechanism compared with trapping effect. We analyse the complicated link between the kink effect and stress bias through groups of electrical stress states： Pals = 0-state, off-state, on-state （on-state with low voltage, high-power state, high field state）. Finlly, a conclusion is drawn that electric field brings about more severe kink effect than hot electrons. With the assistance of electric field, hot electrons tend to be possible to modulate the charges in deep-level trap.

关键词： high electron mobility transistors AlGaN/GaN kink effect stress states

High frame rate multi-resonance imaging refractometry with distributed feedback dye laser sensor

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

Light(Science & Applications) 2015年第1期4卷 410-414页

作者： Christoph Vannahme Martin Dufva Anders Kristensen technical University of Denmark Department of Micro-and NanotechnologyDTU NanotechDK-2800 Kgs.LyngbyDenmark

High frame rate and highly sensitive imaging of refractive index changes on a surface is very promising for studying the dynamics of dissolution,mixing and biological processes without the need for ***,a highly sensitive distributed feedback(DFB)dye laser sensor for high frame rate imaging refractometry without moving parts is *** dye lasers are low-cost and highly sensitive refractive index *** unique multi-wavelength DFB laser structure presented here comprises several areas with different grating *** two dimensions of space is enabled by analyzinglaser light from all areasin parallelwith an imaging *** this multi-resonance imaging refractometry method,the spatial position in one direction is identified from the horizontal,i.e.,spectral position of the multiple laser lines which is obtained from the spectrometer charged coupled device(CCD)*** orthogonal spatial position is obtained from the vertical spatial position on the spectrometer CCD array as in established spatially resolved ***,the imaging technique is demonstrated by monitoring the motion of small sucrose molecules upon dissolution of solid sucrose in *** omission of moving parts improves the robustness of the imaging system and allows a very high frame rate of up to 12 Hz.

关键词： distributed feedback laser label-free imaging laser sensor refractive index sensor

Up-regulation of NAD(P)H quinone oxidoreductase 1 during human liver injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第12期12卷 1937-1940页

作者： Lauren M Aleksunes José EManautou Michael Goedken University of Connecticut Department of Pharmaceutical SciencesUnit 3092StorrsCTUnited States University of Connecticut Department of PathobiologyUnit 3089StorrsCTUnited States

AIM： To investigate the expression and activity of NAD（P）H quinone oxidoreductase 1 （NQO1） in human liver specimens obtained from patients with liver damage due to acetaminophen （APAP） overdose or primary biliary cirrhosis （PBC）. METHODS： NQOt activity was determined in cytosol from normal, APAP and PBC liver specimens. Western blot and immunohistochemical staining were used to determine patterns of NQO1 expression using a specific antibody against NQO1. RESULTS： NQO1 protein was very low in normal human livers. In both APAP and PBC livers, there was strong induction of NQO1 protein levels on Western blot. Correspondingly, significant up-regulation of enzyme activity （16- and 22-fold, P〈0.05） was also observed in APAP and PBC livers, respectively. Immunohistochemical analysis highlighted injury-specific patterns of NQO1 staining in both APAP and PBC livers. CONCLUSION： These data demonstrate that NQO1 protein and activity are markedly induced in human livers during both APAP overdose and PBC. Up-regulation of this cytoprotective enzyme may represent an adaptive stress response to limit further disease progression by detoxifying reactive species.

关键词： NQO1 Quinone oxidoreductase Acetaminophen, APAP, Primary biliary cirrhosis PBC Nrf2, Diaphorase

Investigation of the Current Situation of Innovation Ability Education of Vocational College Students Under the Guidance of Ideological and Political Education

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 Contemporary Educational Research 2024年第3期8卷 73-77页

作者： Xiaolin Fan Nurjulidezi Baheti Yonghong Gu Nanjing Vocational Health College Nanjing 210000Jiangsu ProvinceChina Yili Vocational and technical College Yili 835000Xinjiang Uygur Autonomous RegionChina

Innovation ability is the ability to continuously provide new ideas,theories,methods,and inventions with economic,social,and ecological values in the fields of technology and various practical *** ideological and political education of vocational school students should be student-oriented and close to reality and *** is necessary to improve the pertinence,effectiveness,attractiveness,and infectiousness of ideological and political education,and cultivate socialist builders and successors with all-round development of morality,intelligence,physique,and *** this paper,we investigate and understand the practice of innovation ability education in colleges and universities at home and abroad,especially the current situation of professional practice teaching in Xinjiang Vocational *** construction of a professional practice base in vocational colleges is systematically studied.

关键词： Ideological and political education Innovation ability education Vocational college students

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

水泥立式磨粉磨技术的改进

水泥立式磨粉磨技术的改进

Techniques for laparoscopic liver parenchymal transection

2011国内外水泥粉磨新技术交流大会暨展览会

作者： Pietro Recchi Matteo Magistri Eng.Potito D' Arcangelo Eng.Abderrahmane Talantikite 扈士凯傅子诚 Research & Development technical assistance Group Mapei SpAMilan/Italy

由于水泥工业对粉磨过程连续改进以及其成本不断降低的要求,使得立式水泥磨在全世界范围的使用快速增长。这种磨机与传统的卧式球磨机相比具有一系列的优势。然而,由于通风量不同,"传统"助磨剂在该系统中却不能达到在卧式球磨机中所能...

由于水泥工业对粉磨过程连续改进以及其成本不断降低的要求,使得立式水泥磨在全世界范围的使用快速增长。这种磨机与传统的卧式球磨机相比具有一系列的优势。然而,由于通风量不同,"传统"助磨剂在该系统中却不能达到在卧式球磨机中所能达到的相同的性能改进程度。本文介绍一种专用于立式粉磨机的新型助磨剂,此外,本文还介绍了一种可以显著提高这些产品性能的创新的配料添加工艺。这两个不同方面结合起来就组成了立式磨中水泥粉磨的有效新工艺。

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Hepatobiliary Surgery and Nutrition 2019年第6期8卷 572-581页

作者： Tomoaki Yoh Francois Cauchy Olivier Soubrane Department of Hepato-Pancreatico-Biliary Surgery and Liver Transplantation Beaujon HospitalClichyFrance assistance Publique Hopitaux de ParisParisFrance Universite Paris VII Denis Diderot ParisFrance

Laparoscopic liver surgery has gained wide acceptance resulting in a paradigm shift of liver *** innovations and accumulation of surgeon’s experience have allowed laparoscopic liver resection(LLR)to become an effective procedure with favorable peri-and post-operative *** the overall process of LLR,liver parenchymal transection remains the most critical step with the aim of minimizing blood loss and secures the appropriate cutting line,i.e.,securing major vessels and obtaining adequate surgical margin clearance for *** preoperative imaging modalities and intraoperative ultrasonography findings may contribute to the best determination of the appropriate cutting line during the LLR;however,technical expertise in minimizing and controlling bleeding during liver parenchymal transection is still a challenge for safe LLR,and therefore represents a major concern for hepatobiliary *** with the historical fact that the technique of liver parenchymal transection itself is chosen according to surgeon’s preference and"savoir-faire",the best technical modality in laparoscopic liver parenchymal transection remains to be ***,better understanding the technical issue may serve a contribution to the standardization of *** review article therefore focuses on the technical aspects of the laparoscopic liver parenchymal transection.

关键词： Technique liver parenchymal transection laparoscopy

Biosecurity risk mapping and gap analysis in South East Asia

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 Biosafety and Biosecurity 2020年第1期2卷 36-43页

作者： Emily Valentin Castriciones Viji Vijayan On-Site technical assistance to the European Union-CBRN Centres of Excellence Regional Secretariat for South-East Asia(EU-CBRN CoE Project 62) Business and Strategies in Europe S.A.Woluwe GateBoulevard de la Woluwe 21150 BrusselsBelgium Department of Safety Health Emergency ManagementResearch Integrity and ComplianceDuke-NUS Medical School8 College RoadSingapore 169857Singapore

Introduction:In today’s globalized world where travel is commonplace,a threat in one region can easily spread throughout the whole *** is,therefore,essential for multi-disciplinary risk assessment,risk mitigation,and collaborative strategies to take place among various stakeholders to mitigate *** strategic plan to deal with biosecurity,therefore,needs to be a complete loop,top to bottom and bottom to *** paper describes the results of Project 62,which involved mapping and biosecurity risk assessment in South East *** and methods:The mapping and biosecurity risk assessment activities for the participating partner countries was carried out in two *** first phase involved risk assessment by six partnercountry bio-experts for their own countries and the second phase involved conducting a joint Strengths,Weaknesses,Opportunities,and Threats(SWOT)analysis and risk assessment for the South East Asian region as whole,together with international bio-experts at a *** and discussion:The following key recommendations of the project show that biosecurity needs to be addressed through stakeholder engagement at multiple levels starting from the top echelons of the government to the worker who needs to recognize and understand the threats they might face:*** analysis of existing information from BWC ISU Article 10,IHR capacities,JEE,UN Security Council Resolution 1540 Action Plan,EU CBRN NAP,and other relevant sources to develop a common understanding of the definition of biosecurity for all stakeholders in the *** of programs for awareness building in biosecurity,not limiting them to laboratory biosecurity but using an all-inclusive approach to include border biosecurity,pandemic response,*** of a country-specific list of high-risk biological *** standardized biosecurity training,including responsible conduct in biosecurity *** for one-health and security interface

关键词： Biosecurity Biosafety Biorisk CBRN Risk mapping Risk assessment Gap analysis South East Asia

New Indoor Accelerated Weathering Condition for Approximating Molecular Weight Distribution of Outdoor-Exposed LDPE

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 Chemistry and Chemical Engineering 2015年第8期9卷 481-493页

作者： Takashl Miwa Yukitoshi Takeshita Yuichi Akage Masamitsu Watanabe Masaaki Takaya Takashi Sawada NTT Device Technology Labs NTT Corporation 3-1 Morinosato-Wakamiya Atsugi-shi Kanagawa 2430198 Japan technical assistance and Support Center NIT East Corporation 1-2-5 kamata-honcho Ota-ku Tokyo 1440053 Japan

LDPE （low-density polyethylene） photo degraded through various accelerated weathering tests has the molecular weight distribution curves unlike that through outdoor exposure. The authors therefore developed new weathering test condition based on the existing accelerated weathering test using a xenon arc lamp. Samples of LDPE were photo degraded using various accelerated weathering test conditions and outdoor exposure. The physical properties and chemical structures of the photo degraded samples were studied through a tensile test, infrared spectroscopy, and gel chromatography. The authors found that the molecular weight distribution curve of a sample photo degraded using a xenon lamp at a higher BPT （black panel temperature）（73 ~C） was more similar to that of an outdoor-exposed sample than that of a sample photo degraded at the standard BPT （63 ~C）. It is considered that higher temperature accelerates radical recombination, consequently recreating molecular enlargement similar to the outdoor-exposed sample. Multiple regression analysis using newly introduced Mp （peak-top molecular weight） and Mw （weight-average molecular weight） as explanatory variables was conducted, which successfully enabled the authors to provide a simple explanation for the decrease in polymer tensile strength.

关键词： LDPE photo degradation molecular weight distribution accelerated weathering test outdoor exposure molecular enlargement.

Engineering of Yarrowia lipolytica for production of astaxanthin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Synthetic and Systems Biotechnology 2017年第4期2卷 287-294页

作者： Kanchana Rueksomtawin Kildegaard Belen Adiego-Perez David Domenech Belda Jaspreet Kaur Khangura Carina Holkenbrink Irina Borodina The Novo Nordisk Foundation Center for Biosustainability Technical University of DenmarkKemitorvet 2202800Kgs.LyngbyDenmark

Astaxanthin is a red-colored carotenoid,used as food and feed *** is mainly produced by chemical synthesis,however,the process is expensive and synthetic astaxanthin is not approved for human *** this study,we engineered the oleaginous yeast Yarrowia lipolytica for de novo production of astaxanthin by ***,we screened 12 different *** isolates for β-carotene production by introducing two genes for β-carotene biosynthesis:bi-functional phytoene synthase/lycopene cyclase(crtYB)and phytoene desaturase(crtI)from the red yeast Xanthophyllomyces *** best strain produced 31.1±0.5 mg/L β-***,we optimized the activities of 3-hydroxy-3-methylglutaryl-coenzyme A reductase(HMG1)and geranylgeranyl diphosphate synthase(GGS1/crtE)in the best producing strain and obtained 453.9±20.2 mg/L β-*** downregulation of the competing squalene synthase SQS1 increased the β-carotene titer to 797.1±57.2 mg/*** we introduced β-carotene ketolase(crtW)from Paracoccus sp.N81106 and hydroxylase(crtZ)from Pantoea ananatis to convert β-carotene into *** constructed strain accumulated 10.4±0.5 mg/L of astaxanthin but also accumulated astaxanthin biosynthesis intermediates,5.7±0.5 mg/L canthaxanthin,and 35.3±1.8 mg/L ***,we optimized the copy numbers of crtZ and crtW to obtain 3.5 mg/g DCW(54.6 mg/L)of astaxanthin in a microtiter plate *** study for the first time reports engineering of *** for the production of *** high astaxanthin content and titer obtained even in a small-scale cultivation demonstrates a strong potential for ***-based fermentation process for astaxanthin production.

关键词： Astaxanthin β-carotene Isoprenoids Oleaginous yeast Yarrowia lipolytica Metabolic engineering