检索结果-南通市图书馆

Tight-binding study of quantum transport in nanoscale GaAs Schottky MOSFET

Chinese Physics B 2013年第9期22卷 634-639页

作者： zahra ahangari Morteza Fathipour Department of Electrical Engineering Science and Research BranchIslamic Azad University School of Electrical and Computer Engineering University of Tehran

This paper explores the band structure effect to elucidate the feasibility of an ultra-scaled GaAs Schottky MOSFET （SBFET） in a nanoscale regime. We have employed a 20-band sp3dSs＊ tight-binding （TB） approach to compute E - K dis- persion. The considerable difference between the extracted effective masses from the TB approach and bulk values implies that quantum confinement affects the device performance. Beside high injection velocity, the ultra-scaled GaAs SBFET suffers from a low conduction band DOS in the F valley that results in serious degradation of the gate capacitance. Quan- tum confinement also results in an increment of the effective Schottky barrier height （SBH）. Enhanced Schottky barriers form a double barrier potential well along the channel that leads to resonant tunneling and alters the normal operation of the SBFET. Major factors that may lead to resonant tunneling are investigated. Resonant tunneling occurs at low temperatures and low drain voltages, and gradually diminishes as the channel thickness and the gate length scale down. Accordingly, the GaAs （100） SBFET has poor ballistic performance in nanoscale regime.

关键词： band structure quantum confinement effects resonant tunneling Schottky MOSFET

来源：

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

Improved double-gate armchair silicene nanoribbon field-effect-transistor at large transport bandgap

引用

Chinese Physics B 2016年第1期25卷 809-816页

作者： Mohsen Mahmoudi zahra ahangari Morteza Fathipour Department of Electrical and Computer Engineering University of Tehran Young Researchers and Elite Club Yadegar-e-Imam Khomeini (RAH) Shahre-Rey Branch Islamic Azad University

The electrical characteristics of a double-gate armchair silicene nanoribbon field-effect-transistor （DG ASiNR FET） are thoroughly investigated by using a ballistic quantum transport model based on non-equilibrium Green＇s function （NEGF） approach self-consistently coupled with a three-dimensional （3D） Poisson equation. We evaluate the influence of variation in uniaxial tensile strain, ribbon temperature and oxide thickness on the on-off current ratio, subthreshold swing, transconductance and the delay time of a 12-nm-length ultranarrow ASiNR FET. A novel two-parameter strain mag- nitude and temperature-dependent model is presented for designing an optimized device possessing balanced amelioration of all the electrical parameters. We demonstrate that employing HfO2 as the gate insulator can be a favorable choice and simultaneous use of it with proper combination of temperature and strain magnitude can achieve better device performance. Furthermore, a general model power （GMP） is derived which explicitly provides the electron effective mass as a function of the bandgap of a hydrogen passivated ASiNR under strain.

关键词： silicene double-gate field-effect-transistor non-equilibrium Green's function tight binding

来源：

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

Placental pathologies and fetal outcome in pregnant women with COVID-19: A retrospective study

引用

Asian pacific Journal of Reproduction 2022年第3期11卷 132-137,I0001-I0003页

作者： Soheila Sarmadi Ara Omranipour Elham Mirzaian Roghayyeh ahangari zahra Yazdi Azadeh Asgarian Monireh Mirzaie Department of Pathology Yas HospitalTehran University of Medical SciencesTehranIran Department of Obstetrics and Gynecology School of MedicineShahid Beheshti HospitalQom University of Medical SciencesQomIran Department of Pathology Shariati HospitalSchool of MedicineTehran University of Medical SciencesTehranIran Department of Obstetrics and Gynecology Clinical Research Development UnitSchool of MedicineNekouei-Hedayati-Forghani HospitalQom University of Medical SciencesQomIran Department of Nursing Clinical Research Development UnitNekouei-Hedayati-Forghani HospitalQom University of Medical SciencesQomIran

Objective:To describe histopathologic findings in the placentas in women with coronavirus disease 2019(COVID-19)during ***:In a cross-sectional study,38 pregnant women with COVID-19 and undergoing delivery between March 2020 and January 2022,were *** patients had positive polymerase chain reaction(PCR)test for SARS-CoV-2 infection and the placentas after delivery were sent for histopathologic evaluation based on the Amsterdam Placental Workshop Group Consensus Statement and assessed by two ***:Our results showed that maternal vascular malperfusion was the most common and was present in 17 cases(44.7%).These features included accelerated villous maturation(36.8%)distal villous hypoplasia(5.3%),placental infarction(5.3%)and intervillous fibrin deposition(10.5%).Other pathologic findings included focal calcification(10.5%),intravillous congestion and hemorrhage(10.5%),sub-chorionic hemorrhage(5.3%),acute villitis,chronic histiocytic intervillositis and delayed villous maturation each in one case(2.6%).Twelve out of 38 cases showed no significant pathologic *** outcomes included neonatal intensive care unit admission rate of 13.2%,dyspnea 31.6%,newborn’s anosmia 7.9%,intrauterine fetal demise 2.6%,asphyxia 2.6%and neonate COVID infection 5.3%.Conclusions:Microvasculopathy,as a sign of maternal vascular malperfusion,is a common finding in placentas from SARS-CoV-2 positive pregnant women in the present *** studies with larger sample sizes and comparative studies between COVID-19 positive and negative,as well as information from patient follow-up are suggested.

关键词： Pregnant women Placental Pregnancy Pathology Mother Maternal arteries sitefusion COVID-19

来源：

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

Maternal death due to severe and critical COVID-19 in Qom,Iran:A case series

引用

Journal of Acute Disease 2022年第6期11卷 243-246,I0001-I0004页

作者： Mojtaba Yousefzadeh Azadeh Asgarian Roghayyeh ahangari zahra Yazdi Marzieh Savari Monireh Mirzaie Fatemeh Bagheri Abolfazl Mohammadbeigi Center of Clinical Research Development Shahid Beheshti HospitalQom University of Medical SciencesQomIran Center of Clinical Research Development NHFI HospitalQom University of Medical SciencesQomIran Department of Obstetrics and Gynecology School of MedicineNHFI HospitalQom University of Medical SciencesQomIran Department of Epidemiology Faculty of HealthQom University of Medical SciencesQomIran

Objective:To report the maternal death due to ***:A total of 14 maternal deaths due to severe and critical COVID-19 who were referred to the obstetric department of Nekouie-Forghani-Hedayati Hospital,Qom,Iran from December 2019 to May 2022 were *** clinical manifestations and maternal and perinatal outcomes were ***:Dexamethasone was used in 7 cases,while remdesivir was used in 5 *** respiratory distress syndrome,multiple organ failure,and sepsis were the main cause of mother *** pregnancy in 8 cases were terminated by caesarean and only one neonatal death was reported from a mother at 13th week of gestational age,while all other fetus delivered were healthy and ***:COVID-19 in pregnancy is an *** appraisal is needed to detect the other comorbidities and positive PCR test by throat swap should be performed as soon as possible.

关键词： Maternal death COVID-19 Newborn Mother Mortality Case series

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：