检索结果-南通市图书馆

Quantum spin Hall and quantum valley Hall effects in trilayer graphene and their topological structures

Chinese Physics B 2017年第12期26卷 481-490页

作者： majeed Ur Rehman A A abid ICQD Hefei National Laboratory for Physical Sciences at Microscale Department of Physics University of Science and Technology of China Hefei 230026 China Key Laboratory of Geospace Environment(Chinese Academy of Sciences) Department of Geophysics and Planetary Science University of Science and Technology of China Hefei 230026 China

The present study pertains to the trilayer graphene in the presence of spin orbit coupling to probe the quantum spin/valley Hall effect. The spin Chern-number Cs for energy-bands of trilayer graphene having the essence of intrinsic spin-orbit coupling is analytically calculated. We find that for each valley and spin, Cs is three times larger in trilayer graphene as compared to single layer graphene. Since the spin Chern-number corresponds to the number of edge states, consequently the trilayer graphene has edge states, three times more in comparison to single layer graphene. We also study the trilayer graphene in the presence of both electric-field and intrinsic spin-orbit coupling and investigate that the trilayer graphene goes through a phase transition from a quantum spin Hall state to a quantum valley Hall state when the strength of the electric field exceeds the intrinsic spin coupling strength. The robustness of the associated topological bulk-state of the trilayer graphene is evaluated by adding various perturbations such as Rashba spin-orbit （RSO） interaction αR, and exchange-magnetization m. In addition, we consider a theoretical model, where only one of the outer layers in trilayer graphene has the essence of intrinsic spin-orbit coupling, while the other two layers have zero intrinsic spin-orbit coupling. Although the first Chern number is non-zero for individual valleys of trilayer graphene in this model, however, we find that the system cannot be regarded as a topological insulator because the system as a whole is not gaped.

关键词： trilayer graphene quantum spin Hall effect topological insulator quantum phase transition

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

Helicobacter pylori and other Helicobacter species DNA in human bile samples from patients with various hepato-biliary diseases

引用

World Journal of Gastroenterology 2006年第14期12卷 2181-2186页

作者： Santosh K Tiwari aleem A Khan mohd Ibrahim mohd Aejaz Habeeb C m Habibullah Center for Liver Research and Diagnostics Deccan College of medical Sciences KanchanbaghHyderabad 500 058Andhra PradeshIndia Center for Liver Research and Diagnostics Deccan College of medical Sciences KanchanbaghHyderabad 500 058Andhra PradeshIndia Department of GastroenterologyDeccan College of Medical Sciences Hyderabad 500 058Andhra PradeshIndia

AIm： To investigate the presence of Helicobacter species by nested PCR of 16S rRNA genes followed by the presence of flelicobacter pylori （H pylori） 16S rRNA, ureA, cagA genes in bile obtained at endoscopic retrograde cholangio-pancreatography （ERCP） from 60 Indian subjects. mETHODS： Sixty bile samples were obtained from patients diagnosed with various hepato-biliary diseases and control subjects at ERCP. PCR analysis was carried out using primers for Helicobacter genus 16S rRNA gene and H pylori （16S rRNA, urea and cagA） genes. Gastric H pylori status was also assessed from biopsies obtained at endoscopy from patients with various hepatobiliary diseases and controls. The control group mainly consisted of subjects with gastric disorders. Sequencing analysis was performed to confirm that PCR products with 16S rRNA and cagA primers were derived from H pylori. RESULTS No Helicobacters were grown in culture from the bile samples. Helicobacter DNA was detected in bile of 96.7% and 6.6% of groups Ⅰ and Ⅱ respectively. Ten from group Ⅰ were positive for 16S rRNA and ureA and 9 were positive for cagA gene. In contrast of the 2 from the control, 1 amplified with 16S rRNA, ureA and cagA primers used. The sequences of the 16S rRNA genes and cagA were 99% similar to Helicobacter pylori. CONCLUSION： Helicobacters are associated with the pathogenesis of various hepato-biliary disorders.

关键词： Helicobacter pylori Bile Hepato-biliary diseases PCR, Sequence analysis

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

Selective catalytic reduction of NO by NH3 on cerium modified faujasite zeolite prepared from aluminum scraps and industrial metasilicate

引用

Journal of Rare Earths 2020年第3期38卷 250-256页

作者： Rahma abid Gerard Delahay Hassib Tounsi Laboratory of advanced materials National School of Engineers of SfaxUniversity of SfaxTunisia Institut Charles Gerhardt ENSCM"Advanced Materials for Health and Catalysis"240 Av Professor Emile Jeanbrau34296 MontpellierFrance

This work was devoted to the study of the selective catalytic reduction of NO by NH3 on calcined and hydrothermal treated cerium loaded zeolite *** parent faujasite zeolite Na-f(Si/Al=1.32 and SBET=749 m^2/g) used as support for the preparation of the catalysts was obtained from industrial sodium metasilicate and aluminum *** expected,the NO conversion increases with increasing the percentage of cerium in the structure of the faujasite *** NO conversion into N2 is reached at 400℃at a space velocity of 250 000 h^-*** high conversion is due to the redox shift between Ce^3+/Ce^4+and the strong acid sites related to the rare earth present in the framework that is the key in SCR of NO ***,the highest loaded cerium catalyst retains almost its activity after hydrothermal treatment at 850℃.This higher loading is desirable for both activity and stability provided that two stages of preparation are used to put the Ce ions in the sodalite cages.

关键词： Aluminum scraps Ce-Y NH3-SCR Hydrothermal stability

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

P-type double gate junctionless tunnel field effect transistor

引用

Journal of Semiconductors 2014年第1期35卷 27-33页

作者： m.W.akram Bahniman Ghosh Punyasloka Bal Partha mondal Department of Electrical Engineering Indian Institute of Technology Kanpur microelectronics Research Center

We have investigated the 20 nm p-type double gate junctionless tunnel field effect transistor （P-DGJLTfET） and the impact of variation of different device parameters on the performance parameters of the P-DGJLTfET is discussed. We achieved excellent results of different performance parameters by taking the optimized device parameters of the P-DGJLTfET. Together with a high-k dielectric material （TiO2） of 20 nm gate length, the simulation results of the P-DGJLTfET show excellent characteristics with a high IoN of ～ 0.3 mA/μm, a low/Off of ～ 30 fA/μm, a high ION/IOff ratio of ～ 1×10^10, a subthreshold slope （SS） point of ～ 23 mV/decade, and an average SS of ～ 49 mV/decade at a supply voltage of -1 V and at room temperature, which indicates that PDGJLTfET is a promising candidate for sub-22 nm technology nodes in the implementation of integrated circuits.

关键词： junctionless field effect transistor tunnel field effect transistor subthreshold slope

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

Endoscopic ultrasound-guided gastroenterostomy for gastric outlet obstruction in mexico

引用

World Journal of Surgical Procedures 2024年第3期14卷 15-20页

作者： massiel madelin Rosario-morel Rodrigo Soto-Solis Katia Picazo-ferrera miriam Idalia Torres-Ruiz JoséAlberto Estradas-Trujillo mario Alberto Gallardo-Ramírez Gerardo akram Darwich-del moral Luis Ariel Waller-González Department of Endoscopy Centro Médico Nacional“20 de Noviembre”ISSSTEMexico City 03229Mexico Department of Gastroenterology HospitalÁngeles PedregalMexico City 10700Mexico Department of Endoscopy Centro Médico ABCMexico City 01120Mexico Department of Endoscopy Hospital General de México“Dr.Eduardo Liceaga”Mexico City 06720Mexico

BACKGROUND Endoscopic ultrasound-guided gastroenterostomy(EUS-GE)has recently emerged as an alternative treatment for gastric outlet obstruction(GOO)in selected *** To report the initial experience of EUS-GE in patients with *** This study was a retrospective,observational,multicenter study in which the data from 10 patients who underwent EUS-GE due to GOO between September 2021 and may 2023 were *** analyzed technical success,clinical success,adverse events,and *** success was defined as adequate positioning and deployment of the *** success was defined as the patient’s ability to tolerate oral intake without vomiting 7 d after the *** adverse events were *** Eleven procedures in 10 patients with GOO were *** mean age of the patients was 67.5 years(range:56-77 years).malignant GOO was present in 9 *** success was achieved in 9/11 procedures(82%).Among them,clinical success was achieved in 9 patients(100%).adverse events occurred in 1 patient(9%).The median survival was 3 months(n=7;range:1-8 months).CONCLUSION EUS-GE is a feasible therapeutic option in the treatment of GOO.

关键词： Endoscopic ultrasound-guided gastroenterostomy Gastric outlet obstruction Lumen apposing metal stent Interventional endoscopic ultrasound Gastrojejunostomy Duodenal stenting

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

A New Algorithm for a Condenser Design for Large-Scale Nuclear Power Plants in Tropical Region

引用

Journal of Thermal Science 2020年第5期29卷 1370-1389页

作者： KHAN abid Hossain ISLAm md.Shafiqul Department of Industrial and Production Engineering Jashore University of Science and TechnologyJashore 7408Bangladesh Department of Nuclear Engineering University of DhakaDhaka 1000Bangladesh

This work presents a new velocity search algorithm for designing a condenser of a 1200 mWe large-scale nuclear power plant situated in tropical *** this,the condenser pressure was considered in the range of 7.5-15 kPa while its tube inner diameter was taken as 28 mm with 1 mm tube wall *** longitudinal and transverse condensers with multiple shell tanks and varied shell tank lengths from 8-14 m have been considered in this *** different tertiary coolant temperature rises were chosen as 4°C,8°C and 12°C by considering tropical region average reservoir water temperature range of 28°C to 32°C during *** of tertiary coolant was kept within 0.75-1.5 m/s to ensure sufficient turbulence to avoid erosion-corrosion of the *** simulation has been employed to obtain tube-side pressure drop and convection heat transfer coefficient directly from tertiary coolant inlet velocity using κ-ω turbulent flow model.A new iterative“Velocity-search algorithm”has been developed that focuses on finding the correct tertiary coolant velocity instead of overall heat transfer *** revealed that velocity-search algorithm yielded very close to the important physical and thermal parameters of condenser compared to the existing design data in large scale nuclear power ***-search algorithm has given less number of condenser design physical parameters that meets the velocity acceptance criteria for longitudinal condenser compared to the transverse ***,velocity-search algorithm is found to be more reliable,robust,and consistent for condenser design compared to the conventional design algorithm used in Log-mean Temperature Difference method.

关键词： nuclear power plant vacuum condenser velocity-search algorithm tropical region

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

Cardiac papillary fibroelastoma

引用

Journal of Geriatric Cardiology 2021年第5期18卷 346-351页

作者： Dominika m Zoltowska Edin Sadic Kyeesha Becoats Shreya Ghetiya aleem Azal Ali Srinivasan Sattiraju Emil missov Department of Cardiovascular Disease University of Florida College of MedicineJacksonvilleFLUSA

Papillary fibroelastoma(PfE)is a primary,histologically benign endocardial *** PfE has long been reported as the second most common primary cardiac neoplasm,it has since pulled ahead of cardiac myxomas,largely due to evolving cardiac imaging *** PfEs are benign histologically,they have the potential for devastating clinical consequences,transient ischemic attack,stroke,myocardial infarction,syncope,pulmonary,and peripheral *** increased detection rate,there remains uncertainty regarding etiology,exact prevalence,and clinical management of *** paucity of information is reflected by the lack of official guidelines on this *** this article,we aim to summarize the current state of understanding regarding PfE and discuss areas of ongoing controversy.

关键词： cardiac neoplasm clinical

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

The effect of positive/negative ion on the dust grain charging process in a Vasyliunas-Cairns (VC)-distributed dusty plasma system

引用

Plasma Science and Technology 2019年第6期21卷 58-62页

作者： N AHmad A A abid Y AL-HadEETHI m N S QURESHI Saqib REHmAN Department of Engineering and Applied Physics University of Science and Technology of China Hefei 230026 People's Republic of China CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of China Hefei 230026 People's Republic of China Department of Physics Faculty of Sciences King Abdulaziz Unniversity Jeddah 21589 Saudi Arabia Department of Physics GC University Lahore 54000 Pakistan Department of Chemical Physics University of Science and Technology of China Hefei 230026People's Republic of China

Charging mechanism of dust particles has been considered as a growing research area in dusty plasma physics because of its exciting *** this paper,we consider a low-temperature non-equilibrium multispecies plasma model,which consists of Vasyliunas-Caims (VC) distributed electrons,negative/positive streaming ions,and negatively-charged dust grains to explain the charging mechanism of dust *** main theme of this work is to derive expressions of currents for negatively-charged dust grains (considering an equilibrium state position) in the plasma environment comprised of electrons and positive/negative streaming ions using the VC distribution *** proposed model shows that the dust grain surface potential is significantly affected by different plasma parameters such as the negative ion streaming velocity (Sn),positive ion streaming velocity (Si),spectral indices of VC distribution,negative ion charging state (Zn),positive ion charging state (Zi),and negative ion number density (ρ).

关键词： dust grain surface potential vasyliunas-cairns power law velocity distribution function multi species plasma

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

A laterally graded junctionless transistor

引用

Journal of Semiconductors 2014年第3期35卷 29-32页

作者： Punyasloka Bal Bahniman Ghosh Partha mondal m.W.akram Department of Electrical Engineering Indian Institute of Technology Kanpur microelectronics Research Center 10100 Burnet Road University of Texas at Austin

This paper proposes a laterally graded junctionless transistor taking peak doping concentration near the source and drain region, and a gradual decrease in doping concentration towards the center of the channel to improve the I Off and I ON/I Off ratio. The decrease of doping concentration in the lateral direction of the channel region depletes a greater number of charge carriers compared to the uniformly doped channel in the Off-state,which in turn suppresses the Off state current flowing through the device without greatly affecting the ON state current.

关键词： junctionless field effect transistor laterally graded subthreshold slope

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

fuzzy Based Hybrid focus Value Estimation for multi focus Image fusion

引用

Computers, materials & Continua 2022年第4期71卷 735-752页

作者： m.ham.ad Ahmad m.Arfan Jaffar fawad Nasim Tehreem masood Sheeraz akram The Superior University Lahore 54000Pakistan University of Pittsburgh 15213USA

Due to limited depth-of-field of digital single-lens reflex cameras,the scene content within a limited distance from the imaging plane remains in focus while other objects closer to or further away from the point of focus appear as blurred(out-of-focus)in the ***-focus Image fusion can be used to reconstruct a fully focused image from two or more partially focused images of the same *** this paper,a new fuzzy Based Hybrid focus measure(fBHfm)for multi-focus image fusion has been *** block size is very critical step for multi-focus image *** Swarm Optimization(PSO)algorithm has been used to find optimal size of the block of the images for extraction of focus measure *** finding optimal blocks,three focus measures Sum of modified Laplacian,Gray Level Variance and Contrast Visibility has been extracted and combined these focus measures by using intelligent fuzzy *** based hybrid intelligent focus values were estimated using contrast visibility measure to generate focused *** sets of multi-focus images have been used in detailed experimentation and compared the results with state-of-the-art existing techniques such as Genetic Algorithm(GA),Principal Component Analysis(PCA),Laplacian Pyramid discrete wavelet transform(DWT),and adWT for image *** has been found that proposed method performs well as compare to existing methods.

关键词： fuzzy logic multi-focus image fusion defocus focus contrast visibility focus measure

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

在线全文

在线全文

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

在线全文

在线全文

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：