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如何给砷化镓场效应晶体管偏置以获得最佳性能

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微纳电子技术 1975年第2期 19-26页

作者： g.e.brehm 行军赵克俊

经过过去二到三年的发展,砷化镓微波场效应晶体管已从实验室阶段进入到实用化阶段。目前正在用作C波段和X波段低噪声放大器,振荡器方面的应用正在研究。由于砷化镓场效应晶体管是较为新型的器件,许多使用者对其性能和功用可能还不太熟... 详细信息

经过过去二到三年的发展,砷化镓微波场效应晶体管已从实验室阶段进入到实用化阶段。目前正在用作C波段和X波段低噪声放大器,振荡器方面的应用正在研究。由于砷化镓场效应晶体管是较为新型的器件,许多使用者对其性能和功用可能还不太熟悉。为了选择放大器或振荡器的工作点,有必要了解器件的特性;要确定偏置的变化对S参数和噪声系数的影响,则这种了解更为重要。例如。随着漏电流的变化,由S参数计算出来的增益在相当宽的范围内保持一峰值,这说明最佳增益并不需要临界偏

关键词：噪声系数放大器振荡器可用电子设备千兆赫寄生参数偏置点同轴封装 FMT 场效应器件场效应晶体管单极晶体管漏电流

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X波段单片VCO制造技术

微纳电子技术 1982年第6期 48-51页

作者： g.e.brehm 梁春广

已经设计和制造了采用亚微米栅FeT、大电容比变容二极管、MIM电容器、微带线电感器、电阻器和空气桥互连在单一gaAs芯片的单片gaAsFeTVCO。给出了这些元件的设计考虑和制造技术。

关键词： VCO FeT gaAs 变容管变容二极管单片电容器电器空气桥制造技术波段

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X和Ku波段单片VCO

微纳电子技术 1983年第1期 58-62页

作者： B.N.Scott g.e.brehm 梁春广

已经设计和制造了可从11.15调到14.39gHz以及16.0调到18.74gHz的gaAsVCO(电压控制振荡器)电路。1.1mm×1.2mm芯片上包含有两个变容管、一个300μmFeT以及旁路电容器、调谐电感器和隔离电阻器。叙述了宽带电路设计技术。对引起带宽不连... 详细信息

已经设计和制造了可从11.15调到14.39gHz以及16.0调到18.74gHz的gaAsVCO(电压控制振荡器)电路。1.1mm×1.2mm芯片上包含有两个变容管、一个300μmFeT以及旁路电容器、调谐电感器和隔离电阻器。叙述了宽带电路设计技术。对引起带宽不连续的变容管和电路效应进行讨论,表明用单个gaAs芯片有可能实现从11～18gHz连续调谐。

关键词：变容管源极栅极 Ku 单片 VCO 变容二极管负阻抗半绝缘衬底电压控制振荡器波段

First-principles calculation on the electronic structures, phonon dynamics, and electrical conductivities of Pb_(10)(PO_(4))_(6O) and Pb_(9)Cu(PO_(4))_(6O) compounds

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Journal of Materials Science & Technology 2024年第6期173卷 218-224页

作者： L.Y.Hao e.g.Fu State Key Laboratory of Nuclear Physics and Technology Department of Technical PhysicsSchool of PhysicsPeking UniversityBeijing 100871China

Superconducting materials with high critical temperature have the potential to revolutionize many fields,including military,electronic communications,and power ***,scientists around the world have been tirelessly working with the ultimate goal of achieving high-temperature *** 2023,a preprint by Lee et *** South Korea claimed the discovery of ultra-high-temperature superconductivity with a critical temperature of up to 423 K in Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037),which caused a worldwide sensation and ***,the electronic structures,phonon dynamics,and electrical conductivities of LK-99 and its parent compound lead-apatite have been calculated using first-principles *** results show that the lead-apatite compound and the LK-99 compound are insulator and half-metal *** flat band characteristic is consistent with previous *** electrical conductivity of the LK-99 compound shows two extreme points,and the electrical conductivity along the C-axis increases significantly after 400 *** phonon dispersion spectra of the compounds were investigated,demonstrating their dynamic instability.

关键词： Superconductivity LK-99 Lead-apatite First-principles calculation

Investigation of the transformation of organic matter of carbonate deposits of the Semiluksky-Mendymsky horizon under hydrothermal conditions

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Petroleum 2024年第2期10卷 216-223页

作者： S.M.Petrov A.I.Lakhova e.g.Moiseeva A.g.Safiulina Institute of Petroleum Chemistry and NanotechnologiesKazan National Research Technological UniversityKazan420015Russia Institute of geology and Oil and gas Technologies Kazan Federal UniversityKazan420008Russia

The paper presents the results of studies on the transformation of the organic matter of siliceous-clayey carbonate rocks of the Semiluksko-Mendymsky horizon of the Romashkino oil field in a hydrothermal fluid for an hour(with a water-to-rock ratio of 33)at 340℃and 380℃and pressu res of 17 and 20 *** a result of hydrothermal treatment,at 340℃and 17 MPa,based on nitrogen porosimetry and electron microscopy data,transformations of rock-forming minerals in the rock are *** lead to an increase in the volume and average diameter of mesopores in it and the formation of micropores,as well,which improve its filtration *** the same time,the amount of kerogen in the composition of the organic matter decreases and the yield of the petroleum hydrocarbon extract increases,in which,according to the SARA analysis,the content of asphaltenes increases and the content of resins,aromatic and saturated hydrocarbons *** the composition of aroatic hydrocarbons,the proportion of a lkyltri methyl benzenes and dibenzothiophenes increases,phenanthrene homologues appear,and in the composition of saturated hydrocarbons,the amount of iso-structure alkanes decreases relative to the content of linear *** the temperature and pressure of the hydrothermal fluid to 380℃and 20 MPa increases the degree of kerogen conversion from 12.4%to 23.6%.At the same time,changes occurring in the component composition of petroleum hydrocarbon extracts remains similar to the experiments carried out at 340℃and 17 MPa;the content of naphthalenes decreases,the content of dibenzothiophenes increases and C_(11)-C_(17),C_(19)-C_(22)alkyltrimethylbenzenes *** to IR spectroscopy,with increasing temperature and pressure of the hydrothermal fluid the intensity of the absorption bands of the aromatic ring,aliphatic fragments,and oxygen-containing groups increases in resins;the structural-group composition of asphaltenes changes little:aromaticity and the content of conde

关键词： Carbonate deposits Organic matter Hydrothermal fluid Mobile hydrocarbons

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Pressurized environments directly influence friction and wear of dry steel contacts—Investigations in a novel high fluid pressure tribometer

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Friction 2024年第7期12卷 1599-1617页

作者： Paul ReICHLe Jakob BARZ georg UMLAUF günter e.M.TOVAR Institute of Interfacial Process engineering and Plasma Technology(IgVP) University of StuttgartStuttgart 70569Germany Fraunhofer Institute for Interfacial engineering and Biotechnology(IgB) Stuttgart 70569Germany

To reduce the usage of classical lubricants in deep drawing,a new tribological system based on volatile lubricants was ***,a volatile medium is injected under high pressure into the interstice between drawing tool and sheet *** on temperature and pressure,the temporary lubricant may exist in its gaseous or liquid *** this study,a novel high fluid pressure tribometer was designed to investigate the friction and wear of dry steel contacts under comparable conditions like in dry deep ***,a new ball-on-disc tribometer was designed and integrated into a high-pressure *** specifically investigate the effects of different environments(technical air,liquid and gaseous carbon dioxide,nitrogen,argon)at atmospheric and high pressure(0.1 MPa,6 MPa)on tribology,the specimens and all components were operating *** the experiments,the friction was measured *** show that the highest friction occurs in air and the lowest in carbon dioxide *** to the experiments,the wear of the specimens was assessed along with changes in surface chemistry related to tribochemical ***,the tribology of the dry sliding contacts is correlated to changes of the surface *** differences as well as similarities regarding the different fluid environments are *** the results show,the differences between the media used are most pronounced at elevated ***,this work gives clear indications on the suitability of volatile lubricants in dry friction or rather gas lubrication,especially for dry deep drawing.

关键词： dry friction and dry wear gas lubrication carbon dioxide tribo-layer dry metal forming

Management of early oesophageal cancer:An overview

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World Journal of gastrointestinal Surgery 2024年第5期16卷 1255-1258页

作者： gavin g Calpin Matthew g Davey Noel e Donlon Department of Surgery Royal College of Surgeons in IrelandDublin D2Ireland Department of Upper gastrointestinal Surgery Beaumont HospitalDublin D09V2N0Ireland

The incidence of esophageal cancer,namely the adenocarcinoma subtype,continues to increase exponentially on an annual *** indolent nature of the disease renders a significant proportion inoperable at first presentation,however,with the increased utilisation of endoscopy,many early lesions are now being identified which are suitable for endotherapeutic *** article details the options available for dealing with early esophageal cancer by endoscopic mean obviating the need for surgery thereby avoiding the potential morbidity and mortality of such intervention.

关键词： esophageal cancer endotherapy endoscopic submucosal resection endoscopic mucosal resection endoscopy

enhancing fault-clearing algorithm for renewable-energy-based distribution systems using artificial neural networks

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Clean energy 2024年第5期8卷 97-116页

作者： Rania g.Mohamed M.A.ebrahim Shady H.e.Abdel Aleem electrical engineering Department Institute of Aviation Engineering and TechnologyGiza12658Egypt electrical engineering Department Faculty of Engineering at ShoubraBenha UniversityCairo11629Egypt

Integrating small and large-scale photovoltaic(PV)solar systems into electrical distribution systems has become mandatory due to increased electricity bills and the concern for limiting greenhouse ***,the reliable and efficient operation of PV-based distribution systems can be confronted by the intermittence and high variability of solar sources and their consequential *** this regard,this article suggests a moderated fault-clearing strategy based on the incremental conductance–maximum power point tracking(IC–MPPT)technique and artificial neural networks(ANNs)to enhance fault detection,localization,and restoration pro-cesses in PV-based distribution *** proposed strategy leverages IC–MPPT to ensure optimal power generation from the PV solar system,even in the presence of *** tracking the maximum power point,the algorithm maintains the performance of the system and mitigates against the impact of faults on the output ***,an ANN is employed to improve fault detec-tion and localization *** developed ANN-based moderated fault-clearing strategy is trained using historical data and fault scenarios,enabling it to recognize fault patterns and make informed decisions through extensive simulations and comparisons with traditional fault-clearing *** accomplish this study,benchmarks in PV-based distribution systems are constructed and em-ployed using the MATLAB®/Simulink®software ***,to validate the efficacy of the developed ANN-based moderated fault-clearing strategy,a real case study of a 1-MW PV-based distribution system in an industrial field located in giza governorate,egypt,is tested and *** obtained results demonstrate the effectiveness of the IC–MPPT and ANN-based moderated fault-clearing strategy in achieving faster fault detection,precise fault localization,and efficient restoration in PV solar-based dis-tribution systems while preserving maximum power extraction under small and larg

关键词： photovoltaic solar systems fault-clearing algorithm incremental conductance renewable energy artificial neural network maximum power point tracking

Combination treatment of inflammatory bowel disease:Present status and future perspectives

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World Journal of gastroenterology 2024年第15期30卷 2068-2080页

作者： John K Triantafillidis Constantinos g Zografos Manousos M Konstadoulakis Apostolos e Papalois Inflammatory Bowel Disease Unit "Metropolitan General"HospitalHolargos 15562AtticaGreece Hellenic Society for gastrointestinal Oncology 354 Iera OdosChaidari 12461AtticaGreece The 2^(nd)Department of Surgery University of AthensSchool of MedicineAretaieion HospitalAthens 11528Greece Unit of Surgical Research and Training The 2^(nd)Department of SurgeryUniversity of AthensSchool of MedicineAretaieion HospitalAthens 11528Greece

The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical *** seems to be no exaggeration to say that in these patients,not only the scientific background of the gastroenterologist is tested,but also the abundance of“gifts”that he should possess(insight,intuition,determ-ination,ability to take initiative,etc.)for the successful outcome of the *** daily clinical practice,depending on the severity of the attack,IBD is treated with one or a combination of two or more pharmaceutical *** combin-ations include not only the first-line drugs(e.g.,mesalazine,corticosteroids,antibiotics,etc)but also second-and third-line drugs(immunosuppressants and biologic agents).It is a fact that despite the significant therapeutic advances there is still a significant percentage of patients who do not satisfactorily respond to the treatment ***,a part of these patients are going to *** recent years,several small-size clinical studies,reviews,and case reports have been published combining not only biological agents with other drugs(e.g.,immunosuppressants or corticosteroids)but also the combination of two biologi-cal agents simultaneously,especially in severe *** our opinion,it is at least a strange(and largely unexplained)fact that we often use combinations of drugs in a given patient although studies comparing the simultaneous administration of two or more drugs with monotherapy are very *** mentioned above,there is a timid tendency in the literature to combine two biological agents in severe cases unresponsive to the applied treatment or patients with severe extraintestinal *** appropriate dosage,the duration of the administration,the suitable timing for checking the clinical and laboratory outcome,as well as the treatment side-effects,should be the subject of intense clinical research *** this

关键词： Biologics for immune-mediated conditions Dual-targeted treatment Combination treatment Inflammatory bowel disease Crohn’s