检索结果-南通市图书馆

Development of a Front End Array for Broadband Phased Array Receiver

Research in Astronomy and Astrophysics 2024年第4期24卷 60-70页

作者： Kai Wang liang Cao Jun Ma Xue-Feng Duan Hao Yan Mao-Zheng Chen Yun-Wei Ning Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 8300lChina University of the Chinese Academy of Sciences Beijing 100049China Xinjiang Key laboratory of Microwave Technology Urumqi 830011China

The receiver is a signal receiving device placed at the focus of the *** order to improve the observation efficiency,the concept of phased array receiver has been proposed in recent years,which places a small phased array at the focal plane of the reflector,and flexible pattern and beam scanning functions can be achieved through a beamforming *** combined with the element multiplexing,all beams within the entire field of view can be observed simultaneously to achieve continuous sky *** article focuses on the front-end array of phased array receiver at 0.7-1.8 GHz for QiTai Telescope,and designs a Vivaldi antenna array of PCB structure with dual line *** polarization antenna is designed to arrange in a rectangle manner by 11×*** on the simulation results of the focal field,32,18,and eight elements were selected to form one beam at 0.7,1.25,and1.8 *** analog beamforming network was constructed,and the measured gains of axial beam under uniform weighting were 19.32,13.72,and 15.22 *** the beam scanning method of reflector antenna,the pattern test of different position element sets required for PAF beam scanning was carried out under independent *** pattern optimization at 1.25 GHz was carried out by weighting method of conjugate field *** with uniform weighting,the gain,sidelobe level,and main beam direction under conjugate field matching have been *** the above test and simulation results are slightly different,which is related to the passive array and laboratory testing condition,the relevant work has accumulated experience in the development of the front-end array for the phased array receiver,and has good guiding significance for future performance verification after the array is installed on the telescope.

关键词： telescopes instrumentation:detectors techniques:radar astronomy

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

Mathematical model of absorption and hybrid heat pump

引用

Chinese Journal of Chemical Engineering 2017年第10期25卷 1492-1504页

作者： Grazia leonzio Department of Industrial and Information Engineering and Economics University of L'Aquila Via Giovanni Gronchi 18 67100 UAquila Italy

Recovering waste heat from industrial processes is bene ficial in order to reduce the primary energy demands and heat pumps can be used to this *** heat pumps are energy-saving and environment-friendly because use working fluids that do not cause ozone depletion and can reduce the global warming *** hybrid heat pump processes combine the conventional vapor-compression and the absorption heat pump *** about the simulations and modeling of hybrid heat pumps are few in *** this research a mathematical model for single effect absorption and hybrid heat pump is carried out with Chem Cad? ***–H_2O is used as working fluid while electrolytic NRTl and electrolytes latent heat are used as thermodynamic model due to the better *** parameters of activity coef ficients are regressed from experimental vapor pressure data while default constants are used for the solubility expressions.A design of heat pumps is developed and a new modeling of generator is *** coef ficient of performance of absorption heat pump and hybrid heat pump is equal to 0.7 and 0.83 *** absorption heat pump a sensitivity analysis is carried out to evaluate the effect of temperature and pressure generator,the concentration of li–Br solution on coef ficient of performance,cooling capacity and working fluid *** hybrid heat pump,the different coef ficients of performance,the primary energy ratio,the generator heat,and the compressor power are analyzed for different values of compressor *** show that comparing the two systems the hybrid pump allows to save more primary energy,costs and carbon dioxide emissions with respect to absorption heat pump with the increasing of compressor proportion *** researches should focus on the construction of this heat pumps integrated in chemical processes as a biogas plant or trigeneration systems.

关键词： Absorption heat pumps Hybrid heat pumps liBr–H2O modeling Energy efficiency Process simulation Mathematical model

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

Electromagnetic chirality induced by graphene inclusions in multilayered metamaterials

引用

Photonics Research 2014年第5期2卷 121-125页

作者： Carlo Rizza Elia Palange Alessandro Ciattoni Dipartimento di Scienza e Alta Tecnologia Universitàdell’Insubriavia Valleggio 1122100 ComoItaly Consiglio Nazionale delle Ricerche CNR-SPIN67100 Coppito L’AquilaItaly Dipartimento di Scienze fisiche e chimiche Universitàdi L’Aquilavia Vetoio67100 Coppito L’AquilaItaly

We theoretically investigate the electromagnetic response of a novel class of multilayered metamaterials obtained by alternating graphene sheets and dielectric layers,the whole structure not exhibiting a plane of reflection symmetry along the stacking *** show that the electromagnetic response of the structure is characterized by a magneto-electric coupling described by an effective chiral *** the intrinsic tunability of graphene–light coupling,we prove that one can tune both the dielectric and the chiral electromagnetic response by varying the graphene chemical potential through external voltage gating.

关键词： parameter. dielectric chiral

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

Palladium-catalyzed S_(N)2 glycosylation of phenols

引用

Science China Chemistry 2024年第4期67卷 1037-1038页

作者： Yu Zhu P.Andrew Evans Department of Chemistry Queen’s University90 Bader LaneKingstonK7L 3N6Canada Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha 410013China

Glycosides are essential structural motifs present in an array of important medicines,materials,and natural products[1].Nevertheless,the chemo-and stereoselective construction of the glycosidic linkage is a long-standing challenge because relatively minor variations in the glycosyl donor or acceptor’s structure can impact stereoselectivity,thus influencing the product's functional properties.

关键词： properties Palladium catalyzed

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

含二硫化硒洗发水对中-重度头皮脂溢性皮炎外用糖皮质激素/水杨酸治疗后的疗效维持作用

引用

中华皮肤科杂志 2024年第5期57卷 483-484页

作者： Philippe Massiot Pascal Reygagne Corinne Chagnoleau leila Kanoun-Copy Florence Pouradier Geneviève loussouarn Catherine Queille-Roussel Hussein Jouni Delphine Kerob l'Oréal Research and Innovation Saint-Ouen France. Centre Sabouraud Hôpital Saint-Louis 1 avenue Claude-Vellefaux 75010 Paris France. CPCAD Hôpital l'Archet Nice France. l'Oréal Research and Innovation Aulnay-sous-Bois France. Cosmetic Active International Levallois-Perret France.

脂溢性皮炎是一种慢性炎症性皮肤病,好发于头皮、面部和躯干等皮脂腺分布丰富的部位。头皮脂溢性皮炎主要表现为红斑和片状鳞屑,程度从轻度鳞屑到弥漫性大片黏着性鳞屑不等,伴有明显的瘙痒,并容易反复发作。目前认为脂溢性皮炎的发生与... 详细信息

脂溢性皮炎是一种慢性炎症性皮肤病,好发于头皮、面部和躯干等皮脂腺分布丰富的部位。头皮脂溢性皮炎主要表现为红斑和片状鳞屑,程度从轻度鳞屑到弥漫性大片黏着性鳞屑不等,伴有明显的瘙痒,并容易反复发作。目前认为脂溢性皮炎的发生与亲脂性马拉色菌定植增加以及遗传、环境和全身健康状况等因素相关,上述因素共同导致皮脂腺代谢活动异常、皮脂成分改变、表皮屏障功能障碍,最终加重炎症反应。

关键词：头皮脂溢性皮炎二硫化硒洗发水亲脂性炎症反应马拉色菌皮脂腺黏着性

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

CFD-DEM analysis of particle polydispersity on the performance of fluidised bed reactor during silane pyrolysis Author links open overlay panel

引用

Particuology 2024年第8期91卷 72-87页

作者： Akshayveer Vijay M.Shinde MS2Discovery Interdisciplinary Research Institute Wilfrid Laurier UniversityWaterlooOntarioN2L3C5Canada Department of Chemical Engineering Indian Institute of Technology(BHU)Varanasi221005India

A CFD-DEM model is developed for chemical vapour deposition of silane in a fluidized bed reactor to investigate the effect of polydispersity on local phase dynamics,mass and heat transport,as well as the rate of Si *** gas-phase fines formation and heterogeneous deposition on the seed particle,as well as the scavenging effect for Si particle growth,are *** method is first validated against the experimentally measured Si deposition rate,percentage of fine production and minimum fluidisation ***,the properties,primarily particle intermixing,fluidisation behaviour and bubble dynamics along with the deposition process,are analyzed for several polydisperse beds under various operating *** effect of polydispersity of the bed on a fraction of the bubble size,dense phase expansion and interchange coefficient between various phases is thoroughly investigated to establish a correlation with reactor *** results show that broad-Gaussian particle size distribution(PSD)exhibits excellent improvement in fluidisation behaviour,resulting in a high deposition rate,and minimum formation of Si fines.

关键词： CFD-DEM method Chemical vapour deposition(CVD) Particle size distribution Silicon Gas-solid fluidized bed

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

Semimartingale dynamics for a backward exchange rate process

引用

Probability, Uncertainty and Quantitative Risk 2024年第3期9卷 371-388页

作者： Gregory Gagnon Department of Economics University of Toronto Mississauga3359 Mississauga RoadMississaugaOntarioL5L 1C6Canada

Via a forward SDE solution(k_(t),t≥O)that captures money supply dynamics,a macroeconomic model known as the monetary model generates a backward exchange rate process(y_(t),t≥0).For any t≥0,y_(t)=k_(t)+α^(-1)μ_(t) where(μ_(t),t≥0)is a backward process andα>0 is a ***,(y_(t),t≥O)does not satisfy a conventional *** paper proves(y_(t),t≥O)is a continuous semimartingale when restrictions on the SDE for(k_(t),t≥O)capture anti-inflationary *** new result in economic dynamics does not require the filtration to be the Brownian filtration.

关键词： Backward process Semimartingale Anti-inflationary SDE policy

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

Ethical decision-making in older drivers during critical driving situations: An online experiment

Journal of Intelligent and Connected Vehicles

引用

Journal of Intelligent and Connected Vehicles 2024年第1期7卷 30-37页

作者： Amandeep Singh Sarah Yahoodik Yovela Murzello Samuel Petkac Yusuke Yamani Siby Samuel Department of Systems Design Engineering University of WaterlooWaterloo N2L 3G1Canada Department of Psychology Old Dominion UniversityNorfolk 23529USA

The present study examined the impact of aging on ethical decision-making in simulated critical driving scenarios.204 participants from North America,grouped into two age groups(18–30 years and 65 years and above),were asked to decide whether their simulated automated vehicle should stay in or change from the current lane in scenarios mimicking the Trolley *** participant viewed a video clip rendered by the driving simulator at Old Dominion University and pressed the space-bar if they decided to intervene in the control of the simulated automated vehicle in an online *** hierarchical models were used to analyze participants’responses,response time,and acceptability of utilitarian ethical *** results showed significant pedestrian placement,age,and time-to-collision(TTC)effects on participants’ethical *** pedestrians were in the right lane,participants were more likely to switch lanes,indicating a utilitarian approach prioritizing pedestrian *** participants were more likely to switch lanes in general compared to older *** results imply that older drivers can maintain their ability to respond to ethically fraught scenarios with their tendency to switch lanes more frequently than younger counterparts,even when the tasks interacting with an automated driving *** current findings may inform the development of decision algorithms for intelligent and connected vehicles by considering potential ethical dilemmas faced by human drivers across different age groups.

关键词： ethical decision making age-differences utilitarianism moral dilemmas driver behavior simulated driving bayesian hierarchical model

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

Childhood absence epilepsy and benign epilepsy with centro-temporal spikes: a narrative review analysis

引用

World Journal of Pediatrics 2017年第2期13卷 106-111页

作者： Alberto Verrotti Renato D'Alonzo Victoria Elisa Rinaldi Sara Casciato Alfredo D'Aniello Giancarlo Di Gennaro Department of Pediatrics University of L'AquilaL'AquilaItaly Department of Paediatrics University of PerugiaPerugiaItaly Department of Neurology and Psychiatry University of Rome'La Sapienza'RomeItaly IRCCS NEUROMED Pozzilli(IS)Italy

Background:Recent studies have shown a possible coexistence of absence seizures with other forms of *** purpose of this study was to ascertain the possible contemporary or subsequent presence of childhood absence epilepsy (CAE) and benign epilepsy with centro-temporal spikes (BECTS) in pediatric epileptic *** sources:A PubMed systematic search indexed for MEDlINE,PubMed and EMBASE was undertaken to identify studies in children including articles written between 1996 and *** studies,meta-analysis and case reports were *** list of references of all the relevant articles was also *** date of our last search was December ***:Review of the literature revealed 19 cases,8 females and 11 males,reporting a consecutive or contemporary coexistence of CAE and BECTS within the same ***'s age ranged between 4 and 12 *** out of 19 patients presented concomitant features of both syndromes,whereas 16 patients experienced the two syndromes at different ***:BECTS and CAE may be pathophysiologically related,and the two epileptic phenotypes may indicate a neurobiological *** studies are needed to elucidate a probable genetic or functional link between partial and primarily generalized electro-clinical patterns in idiopathic childhood epilepsies.

关键词： absence seizures benign epilepsy with centro-temporal spikes childhood abscence epilepsy

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

Parallelization of frequency domain quantum gates:manipulation and distribution of frequency-entangled photon pairs generated by a 21 GHz silicon microresonator

引用

Advanced Photonics 2024年第3期6卷 60-69页

作者： Antoine Henry Dario A.Fioretto lorenzo M.Procopio Stéphane Monfray Frédéric Boeuf laurent Vivien Eric Cassan Carlos Alonzo-Ramos Kamel Bencheikh Isabelle Zaquine Nadia Belabas Institut Polytechnique de Paris LTCITélécom ParisPalaiseauFrance Université Paris-Saclay CNRSCentre for Nanosciences and NanotechnologyUMR 9001PalaiseauFrance Weizmann Institute of Science RehovotIsrael STMicroelectronics SAS CrollesFrance

Harnessing the frequency dimension in integrated photonics offers key advantages in terms of scalability,noise resilience,parallelization,and compatibility with telecom multiplexing *** ring resonators have been used to generate frequency-entangled states through spontaneous four-wave ***,state-of-the-art integrated resonators are limited by trade-offs among size,spectral separation,and efficient photon pair *** have developed silicon ring resonators with a footprint below 0.05 mm^(2)providing more than 70 frequency channels separated by 21 *** exploit the narrow frequency separation to parallelize and independently control 34 single qubit-gates with a single set of three off-the-shelf electro-optic *** fully characterize 17 frequency-bin maximally entangled qubit pairs by performing quantum state *** demonstrate for the first time,we believe,a fully connected five-user quantum network in the frequency *** results are a step towards a generation of quantum circuits implemented with scalable silicon photonics technology,for applications in quantum computing and secure communications.

关键词： integrated photonics frequency domain quantum gates quantum networks

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

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：