检索结果-南通市图书馆

Post-fabrication phase trimming of Mach–zehnder interferometers by laser annealing of germanium implanted waveguides

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2017年第6期5卷 97-101页

作者： XIA CHEN MILAN M.MILOSEVIC DAVID J.THOMSON ali z.khokhar YOHANN FRANz ANTOINE F.J.RUNGE SAKELLARIS MAILIS ANNA C.PEACOCK GRAHAM T.REED Optoelectronics Research Centre University of Southampton

We demonstrate a novel high-accuracy post-fabrication trimming technique to fine-tune the phase of integrated Mach–zehnder interferometers, enabling permanent correction of typical fabrication-based phase errors. The effective index change of the optical mode is 0.19 in our measurement, which is approximately an order of magnitude improvement compared to previous work with similar excess optical loss. Our measurement results suggest that a phase accuracy of 0.078 rad was achievable with active feedback control.

关键词： Post-fabrication phase trimming of Mach zehnder interferometers by laser annealing of germanium implanted waveguides MzI

All-silicon carrier accumulation modulator based on a lateral metal-oxide-semiconductor capacitor

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2018年第5期6卷 373-379页

作者： KAPIL DEBNATH DAVID J.THOMSON WEIWEI zHANG ali z.khokhar CALLUM LITTLEJOHNS JAMES BYERS LORENzO MASTRONARDI MUHAMMAD K.HUSAIN KOUTA IBUKURO FREOERIC Y.GARDES GRAHAM T,REED SHINICHI SAITO Optoelectronics Research Centre University of SouthamptonSouthampton S017 1B JUK Faculty of Physical Sciences and Engineering University of SouthamptonSouthampton SO17 1BJUK

In silicon photonics, the carrier depletion scheme has been the most commonly used mechanism for demonstrat- ing high-speed electro-optic modulation. However, in terms of phase modulation efficiency, carrier- accumnlation-based devices potentially offer almost an order of carrier depletion. Previously reported accumulation modulator magnitude improvement over those based on designs only considered vertical metal-oxide- semiconductor （MOS） capacitors, which imposes serious restrictions on the design flexibility and integratability with other photonic components. In this work, for the first time to our knowledge, we report experimental demonstration of an all-silicon accumulation phase modulator based on a lateral MOS capacitor. Using a Mach-zehnder interferometer modulator with a 500-μm-long phase shifter, we demonstrate high-speed modulation up to 25 Gbit/s with a modulation efficiency （V πLπ） of 1.53 V·cm.

关键词： All-silicon carrier accumulation modulator a lateral metal-oxide-semiconductor capacitor

Energy exchange between charged relativistic fluids in f(T)gravity

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第10期76卷 106-118页

作者： z Yousaf U A khokhar Nasser Bin Turki T Suzuki Department of Mathematics University of the PunjabQuaid-i-Azam CampusLahore-54590Pakistan Department of Mathematics College of ScienceKing Saud UniversityPO Box 2455Riyadh11451Saudi Arabia Department of Regional Management Faculty of ManagementFukushima CollegeFukushima 960-0181Japan

This study focuses on the effects of a polytropic fluid on a charged gravitational source within f(T)gravity,where T is the torsion *** investigate how the electromagnetic field affects the flow of energy in spherically symmetric and static celestial objects that contain relativistic *** using the gravitational decoupling technique,we analyze the effects of polytropic fluid on the dynamics of the gravitational source,accompanied by the matching of the interior geometry with an exterior at the hypersurfaceΣ.Finally,with the help of the TolmanⅡV solution,we observe the conduct of energy conditions with the existence of charge using f(T)field equations and got the intended outcomes.

关键词： complexity hydrodynamics anisotropy self-gravitating systems energy exchange

Physical and Kinematical Characteristics of Wolf–Rayet Central Stars and their Host Planetary Nebulae

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2023年第9期23卷 219-240页

作者： z.Awad A.ali Department of Astronomy Space Science and MeteorologyFaculty of ScienceCairo University12613 Giza

We address the physical and kinematical properties of Wolf–Rayet[WR]central stars(CSs)and their host planetary nebulae(PNe).The studied sample comprises all[WR]CSs that are currently *** analysis is based on recent observations of the parallax,proper motion,and color index of[WR]CSs from the Gaia space mission’s early third release(eDR3)catalog,as well as common nebular *** results revealed an evolutionary sequence,in terms of decreasing Teff,from the early hot[WO 1]to the late cold[WC 12]*** evolutionary sequence extends beyond[WR]CS temperature and luminosity to additional CS and nebular *** statistical analysis shows that the mean final stellar mass and evolutionary age of the[WR]CS sample are 0.595±0.13M⊙and 9449±2437 yr,respectively,with a mean nebular dynamical age of 7270±1380 *** addition,we recognize that the color of the majority(∼85%)of[WR]CSs tends to be red rather than their genuine blue *** analysis indicates that two-thirds of the apparent red color of most[WR]s is attributed to the interstellar extinction whereas the other one-third is due to the PN self-extinction effect.

关键词： Wolf-Rayet-(ISM )planetary nebulae general-ISM kinematics and dynamics

Slip effects on streamline topologies and their bifurcations for peristaltic flows of a viscous fluid

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第6期23卷 341-352页

作者： z.Asghar N.ali Department of Mathematics and Statistics International Islamic University

We discuss the effects of the surface slip on streamline patterns and their bifurcations for the peristaltic transport of a Newtonian fluid. The flow is in a two-dimensional symmetric channel or an axisymmetric tube. An exact expression for the stream function is obtained in the wave frame under the assumptions of long wavelength and low Reynolds number for both cases. For the discussion of the particle path in the wave frame, a system of nonlinear autonomous differential equations is established and the methods of dynamical systems are used to discuss the local bifurcations and their topological changes. Moreover, all types of bifurcations and their topological changes are discussed graphically. Finally, the global bifurcation diagram is used to summarize the bifurcations.

关键词： viscous fluid slip condition streamline topologies bifurcation

Notes on Curves at a Constant Distance from the Edge of Regression on a Curve in Galilean 3-Space G_(3)

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第6期135卷 2731-2742页

作者： ali Cakmak Sezai Kızıltug Gokhan Mumcu Department of Mathematics Faculty of Arts and SciencesBitlis Eren UniversityBitlis13000Turkey Graduate School of Natural and Applied Sciences Erzincan Binali Yıldırım UniversityErzincan24002Turkey Department of Mathematics Faculty of Arts and ScienceErzincan Binali Yıldırım UniversityErzincan24002Turkey

In this paper,we define the curve rλ=r+λd at a constant distance from the edge of regression on a curve r(s)with arc length parameter s in Galilean ***,d is a non-isotropic or isotropic vector defined as a vector tightly fastened to Frenet trihedron of the curve r(s)in 3-dimensional Galilean *** build the Frenet frame{Tλ,Nλ,Bλ}of the constructed curve rλwith respect to two types of the vector d and we indicate the properties related to the curvatures of the curve rλ.Also,for the curve rλ,we give the conditions to be a circular ***,we discuss ruled surfaces of type A generated via the curve rλand the vector D which is defined as tangent of the curve rλin 3-dimensional Galilean *** constructed ruled surfaces also appear in two *** first is constructed with the curve rλ(s)=r(s)+λT(s)and the non-isotropic vector *** second is formed by the curve rλ=r(s)+λ2N+λ3B and the non-isotropic vector *** calculate the distribution parameters of the constructed ruled surfaces and we show that the ruled surfaces are ***,we provide examples and visuals to back up our research.

关键词： Edge of regression Galilean space curvature helix ruled surface

A Secure Communication Protocol for Unmanned Aerial Vehicles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第1期70卷 601-618页

作者： Navid ali Khan N.z.Jhanjhi Sarfraz Nawaz Brohi Abdulwahab ali Almazroi Abdulaleem ali Almazroi School of Computer Science and Engineering(SCE) Taylor’s University Lake-side CampusSubang Jaya47500Malaysia School of Information and Technology Monash UniversityMalaysia University of Jeddah College of Computing and Information Technology at KhulaisDepartment of Information TechnologyJeddahSaudi Arabia Department of Computer Science Rafha Community CollegeNorthern Border UniversityArar91431Saudi Arabia

Mavlink is a lightweight and most widely used open-source communication protocol used for Unmanned Aerial *** UAVs and autopilot systems support it,and it provides bi-directional communication between the UAV and Ground Control *** communications contain critical information about the UAV status and basic control commands sent from GCS to UAV and UAV to *** order to increase the transfer speed and efficiency,the Mavlink does not encrypt the *** a result,the protocol is vulnerable to various security attacks such as Eavesdropping,GPS Spoofing,and *** this study,we tackle the problem and secure the Mavlink communication *** leveraging the Mavlink packet’s vulnerabilities,this research work introduces an experiment in which,first,the Mavlink packets are compromised in terms of security requirements based on our threat *** results show that the protocol is insecure and the attacks carried out are *** overcomeMavlink security,an additional security layer is added to encrypt and secure the *** encryption technique is proposed that makes the communication between the UAV and GCS *** results show that the Mavlink packets are encrypted using our technique without affecting the performance and *** results are validated in terms of transfer speed,performance,and efficiency compared to the literature solutions such as MAVSec and benchmarked with the original Mavlink *** achieved results have significant improvement over the literature and Mavlink in terms of security.

关键词： Unmanned aerial vehicles mavlink protocol drones security UAVs communication

Quick screening and easy detection method of NDM-gene in clinical isolates:A need of the time

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2012年第10期5卷 839-840页

作者： Asad U Khan Saeedut z ali Interdisciplinary Biotechnology Unit Aligarh Muslim University

The emerging trend of multidrug resistance is becoming a major threat to community acquired and nosocomial infections,worldwide[1].The carbapenems are used as last-source drugs because of increasing resistance against... 详细信息

关键词： screening lactam nosocomial antibiotics isolates threat becoming emerging resist DNA

Pressure and Discharge-Voltage Dependence of Self-Sustaining Pulses in Air-Glow Discharge

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 Letters 2012年第5期29卷 181-184页

作者： A.A.Azooz Y.A.Al-Jawaady z.T.ali Department of Physics College of ScienceMosul UniversityMosulIraq

The details of formation of micro discharges in air-glow discharge plasma are experimentally *** number of micro discharges formed per second is strongly related to both pressure and discharge *** number tends to show reflections of the Patchen curve as far as its pressure dependence is *** dischargevoltage dependence indicates that the transition from normal to abnormal glow discharge is not a sudden one,but has its roots during the normal glow stage and is initiated by the micro discharges which can be regarded as the early stage of abnormal glow.

关键词： details initiated roots