检索结果-南通市图书馆

On selection and scaling of ground motions for analysis of seismically isolated structures

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2016年第4期15卷 633-648页

作者： Deepak r. Pant Manika Maharjan Department of Civil Engineering University of Toronto Toronto ON M5S 1A4 Canada Atkins Limited The Wells Church Street Epsom KT17 4PE United Kingdom

A broader consensus on the number of ground motions to be used and the method of scaling to be adopted for nonlinear response history analysis （rHA） of structures is yet to be reached. Therefore, in this study, the effects of selection and scaling of ground motions on the response of seismically isolated structures, which are routinely designed using nonlinear rHA, are investigated. for this purpose, isolation systems with a range of properties subjected to bidirectional excitation are considered. Benchmark response of the isolation systems is established using large sets of unscaled ground motions systematically categorized into pulse-like, non-pulse-like, and mixed set of motions. Different subsets of seven to 14 ground motions are selected from these large sets using （a） random selection and （b） selection based on the best match of the shape of the response spectrum of ground motions to the target spectrum. Consequences of weighted scaling （also commonly referred to as amplitude scaling or linear scaling） as well as spectral matching are investigated. The ground motion selection and scaling procedures are evaluated from the viewpoint of their accuracy, efficiency, and consistency in predicting the benchmark response. It is confirmed that seven time histories are sufficient for a reliable prediction of isolation system displacement demands, for all ground motion subsets, selection and scaling procedures, and isolation systems considered. If ground motions are selected based on their best match to the shape of the target response spectrum （which should be preferred over randomly selected motions）, weighted scaling should be used if pulse-like motions are considered, either of weighted scaling or spectral matching can be used if non-pulse-like motions are considered, and an average of.r.s.onses from weighted-scaled and spectrum-matched ground motions should be used for a mixed set of motions. On the other hand, the importance of randomly selected motions in represen

关键词： bidirectional excitation seismic isolation selection and scaling spectral matching weighted scaling

Dual Opposite Carbon-fiber Micro-disk Electrodes for Detection And Purity Assessment Of CE Peaks from Polyphenols In red Wine

在线全文

学校读者我要写书评

暂无评论

Dual Opposite Carbon-fiber Micro-disk Electrodes For Detecti...

Two-dimensional analysis of a negative differential conductance gate transistor as a THz emitter

第十一届全国电分析化学会议

作者： f.Y.Du Y.s.fung Department of Chemistry Hong Kong University

＜正＞The various benefits attributed to polyphenols in red wine have recently attracted ***,the determination of polyphenols in red wine have met interfering problems due to peak overlapping from complicated sample *...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Plasma science and Technology 2017年第4期19卷 15-22页

作者： sh rAHMATALLAHPUr A rOsTAMI s KHOrrAM Photonics and Nanocrystal research Lab.(PNrL) Faculty of Electrical and Computer EngineeringUniversity of TabrizTabriz 51666-14761Iran Photonics Group Research Institute for Applied Physics and Astronomy(RIAPA)University of TabrizTabriz 51664-14761Iran

We investigate plasma modes in a transistor including a negative differential conductance in the gate. The analytical results show that the plasma wave generation is substantially influenced by the lateral direction （width of the transistor）, gate leakage current and ＇viscosity. The injection from the gate （opposed to the gate leakage current） can improve the plasma oscillations and their amplitude with respect to ordinary transistors. We also estimate, which to our best knowledge has been derived for the first time, the total power emitted by the transistor and the emitted pattern which qualitatively gives reasonable agreement with the experimental data. The results show that the radiated power depends on various parameters such as drift velocity, momentum relaxation time, gate leakage current and especially the lateral direction. A negative gate current enhances the power while the gate leakage current decreases the power.

关键词： terahertz emitter solid state plasma two-dimensional analysis negative differentialconductance

study of the structural,ferroelectric,dielectric,and pyroelectric properties of the K0.5Na0.5NbO3 system doped with Li+,La3+,and Ti4+

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2020年第3期9卷 329-338页

作者： C.MONTErO-TAVErA M.D.DUrrUTHY-rODriGUEZ f.D.COrTEs-VEGA J.M.YANEZ-LIMON Center for research and Advanced studies of IPN Campus QueretaroMexico National Evangelical University Paseo de los Periodistas#54Ensanche MirafloresSanto DomingoDistrito NacionalRepiblica Dominicana

Pure *** sNbO3(KNN)and KNN doped with Lit(6%mole),Lat(1.66%,5%,6%mole),and Ti+t(10%mole)were prepared by mixture of oxides using high-energy milling and conventional solid-state *** effects of the dopant on the physical properties of pure KNN have been evaluated based on the structural,ferroelectric,pyroelectric,and dielectric *** XrD measurements show that KNN pure sample contains a mixture of monoclinic and orthorhombic crystalline phases,with a slightly higher concentration of monoclinic *** contrast,all doped samples show a higher concentration of the orthorhombic phase,as well as the presence of a secondary phase(K6Nb10.8O3o),also detected by raman *** samples with a higher concentration of this secondary phase,also present greater dielectric losses and lower values of remnant *** dielectric measurements allowed us to detect temperatures of structural transitions(orthorhombic-tetragonal,O-T)previous to the ferroelectric paraelectric transition(tetragonal-cubic,T-C),and also in this set of samples,a direct correlation was found between the values of remnant polarization and the corresponding pyroelectric signal response.

关键词： K0.5Na0.5NbO3(KNN) lead-free solid-state reaction structural properties pyroelectric properties dielectric properties Li,La,Ti doping elements

Nanosecond Pulses Generation with samarium Oxide film saturable Absorber

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2019年第7期36卷 48-51页

作者： N.f.Zulkipli M.Batumalay f.s.M.samsamnun M.B.H.Mahyuddin E.Hanafi T.f.T.M.N.Izam M.I.M.A.Khudus s.W.Harun Photonics Engineering Laboratory Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia faculty of Information Technology & sciences Inti International University Perdana BBN Putra Nilai Nilai 71800 Negeri Sembilan Department of Physics University of Malaya Kuala Lumpur 50603 Malaysia Department of Physics Faculty of Science and Technology Airlangga University Surabaya Indonesia

Nanosecond pulse generation is demonstrated in a mode-locked erbium-doped fiber laser(EDfL) utilizing a samarium oxide(sm2O3) film. The sm2O3 film exhibits a modulation depth of 33%, which is suitable for modelocking operation. The passively pulsed EDfL operates stably at 1569.8 nm within a pumping power from 109 to 146 m W. The train of generated output pulses has a pulse width of 356 nm repeated at a fundamental frequency of 0.97 MHz. The average output power of 3.91 m W is obtained at a pump power of 146 m W, corresponding to 4.0 nJ pulse energy. The experimental result indicates that the proposed sm2O3 saturable absorber is viable for the construction of a flexible and reliably stable mode-locked pulsed fiber laser operating in the 1.5 m region.

关键词： Nanosecond pulse generation erbium-doped fiber laser in the 1.5 m region

Link between irritable bowel syndrome,depression,and colorectal cancer risk in young patients:Age-matched nationwide populationbased study

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Pathophysiology 2024年第3期15卷 1-8页

作者： sai Priyanka Mellacheruvu sai Prasanna Lekkala sukhjinder Chauhan Adil sarvar Mohammed sravya r Mundla Ankita shenoy Bilal Khan Mohammed Jerrin Bawa shantha Nallapothula Priyatham Gurram Akhil Jain rupak Desai Mohammed Mustafa Nayeem Department of Public Health University of MassachusettsLowellMA 01854United States Department of Internal Medicine Mamata Medical CollegeTelanganaKhammam 507002India Department of Internal Medicine Mountainview HospitalLas VegasNV 89128United States Department of Internal Medicine Central Michigan University College of MedicineSaginawMI 48602United States Department of Public Health Apollo Institute of Medical Sciences and ResearchTelanganaHyderabad 500090India Department of Medicine Dr D.Y.Patil University School of MedicineMaharashtraNavi Mumbai 400706India Department of Medicine Northwestern University Feinberg School of MedicineChicagoIL 60611United States Department of Internal Medicine Flushing Hospital Medical CenterQueensNY 11355United States Department of Internal Medicine PES Institute of Medical Sciences and ResearchAndhra PradeshKuppam 517425India Department of Gastroenterology Mayo ClinicScottsdaleAZ 85259United States Division of Leukemia The University of Texas MD Anderson Cancer CenterHoustonTX 77079United States Independent researcher AtlantaGA 30079United States Department of Internal Medicine Parkview Medical CenterPuebloCO 81003United States

BACKGrOUND There exists a link between irritable bowel syndrome(IBs)and ***,chronic depression is known to increase the risk of cancer in *** this population-based analysis,we investigated the prevalence and the odds of colorectal cancer(CrC)in young-depressed patients with *** To investigate the relationship between IBs and CrC in young,depressed patients using a nationally representative United states inpatient *** The 2019 National Inpatient sample was used to identify young(18-44 years)patients admitted with comorbid depression in the presence vs absence of IBs using relevant International Classification of Diseases,Tenth revision,Clinical Modification *** endpoint was the prevalence and odds of CrC in age matched(1:1)youngdepressed cohort hospitalized with IBs(IBs+)vs without IBs(IBs-).Multivariable regression analysis was performed adjusting for potential *** Age-matched(1:1)young-depressed IBs+(83.9%females,median age 36 years)and IBs-(65.8%females,median age 36 years)cohorts consisted of 14370 patients in each ***+cohort had higher rates of hypertension,uncomplicated diabetes,hyperlipidemia,obesity,peripheral vascular disease,chronic obstructive pulmonary disease,hypothyroidism,prior stroke,prior venous thromboembolism,anxiety,bipolar disorder,and borderline personality disorder(Ps the ***,prior myocardial infarction,acquired immunodeficiency syndrome,dementia,smoking,alcohol abuse,and drug abuse(Pre high in *** rate of CrC was comparable in both cohorts[IBs+n=25(0.17%)vs IBs-n=35(0.24%)].Compared to the IBs-cohort,the odds ratio(Or)of developing CrC was not significantly higher[Or 0.71,95% confidence interval(CI)0.23-2.25]in IBs+***,adjusting for baseline sociodemographic and hospital characteristics and relevant comorbidities,the Or was found to be non-significant(Or 0.89,95%CI 0.21-3.83).CONCLUsION This nationwide propensity-matched ana

关键词： Colorectal cancer Depression Irritable bowel syndrome Young patients National inpatient sample Comorbidities

Alpha-particle decays from excited states in ^(24)Mg

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

science China(Physics,Mechanics & Astronomy) 2011年第S1期54卷 130-135页

作者： LIOTTA r J royal Institute of Technology (KTH) AlbaNova University Center Stockholm S-10691 Sweden

Using a cluster model based on the Woods-saxon potential, alpha-particle decays from excited states in 24Mg have been system atically investigated. Calculations can in general reproduce experimental data, noticing the fact that the preformation factor P of alpha particle in alpha-decaying nuclei is of order from 100 to 10?2. This can be the evidence for the α+20Ne structure in 24Mg. Meanwhile, the results also show the existence of other configurations, such as 16O+2α. since the calculated decay widths are very sensitive to the angular momentum carried by the outgoing cluster (α particle), our results could serve as a guide to experimental spin assignments.

关键词： alpha decay cluster structure cluster model 24Mg

Conifer establishment after the eruption of the Paricutin volcano in central Mexico

在线全文

学校读者我要写书评

暂无评论

f.r.s. Ecosystems 2022年第1期9卷 71-82页

作者： Jesús Eduardo sáenz-Ceja Blanca Lizeth sáenz-Ceja J.Trinidad sáenz-reyes Diego rafael Pérez-salicrup Instituto de Investigaciones en Ecosistemas y sustentabilidad Universidad Nacional Autéonoma de MéxicoAntigua Carretera a Patzcuaro 8701 Col.Ex hacienda San Joséde la Huerta58190MoreliaMexico Escuela Nacional de Estudios superiores Unidad Morelia Universidad Nacional Autónoma de MéxicoAntigua Carretera a Patzcuaro 8701 Col.Ex hacienda San Joséde la Huerta58190MoreliaMexico Instituto Nacional de Investigaciones f.r.s.ales Agrícolas y PecuariasCampo Experimental UruapanAv.Latinoamericana 1101Col.Revolución60500UruapanMexico

Background:Volcanic eruptions have large effects on f.r.s. ecosystems and create new substrates,triggering primary succession *** Paricutín volcano,born in central-western Mexico,erupted between 1943 and *** the cessation of the eruptive activity,plant colonization began on the lava flows and tephra deposits,including the conif.r.s.ecies that dominate the surrounding mature *** study aims to reconstruct the history of the establishment of conifer trees on the substrates created by the Paricutín ***:16 sampling plots were established along three transects with northern,southern,and south-western aspects,located every 250 m from the preserved f.r.s. to the volcanic *** cores from 400 conifer trees were extracted and their age was determined by cross-dating annual tree *** order of the species colonization and the tree establishment,abundance,and dominance patterns were ***,the influence of the distance from the mature f.r.s.s and the inter-annual climatic conditions on the temporal tree establishment pattern was ***:Eight pine and one f.r.s.ecies have been established since 1970,only 18 years after the end of the eruptive ***,tree establishment increased by 12.9%annually after 1995,with the youngest tree in our sample getting established in *** did not find a well-defined temporal and spatial pattern of species arrival,which suggests that colonization occurred randomly,although the four pine species that were established early became the most abundant and *** establishment was not influenced by the distance from the mature f.r.s.,and wet inter-annual conditions did not enhance pulses of tree recruitment,exhibiting a continuous tree establishment ***:Conif.r.s.ecies have shown a great capacity for colonizing volcanic substrates created by the Paricutín eruption,which suggests that tropical montane conifers can regenerate rapidly under high-magni

关键词： Age structure Dendrochronology Lava flow Primary succession Tropical montane f.r.s.

Cross-sections for the 27Al(γ,x)22Na multichannel reaction with the 28.3 MeV difference of reaction thresholds

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第6期46卷 129-137页

作者： O.s.Deiev I.s.Timchenko s.N.Olejnik V.A.Kushnir V.V.Mytrochenko s.A.Perezhogin National science Center"Kharkov Institute of Physics and Technology" 1 Akademichna St.61108 KharkivUkraine

The bremsstrahlung flux-averaged cross-sections(σ(Eγmax))and the cross-sections per equivalent photon(σ(Eγmax)Q)were first measured for the photonuclear multichannel reaction ^(27)Al(γ,x)22 Na at end-point bremsstrahlung gamma energies ranging from 35 MeV to 95 *** experiments were performed with the beam from the NsC KIPT electron linear accelerator LUE-40 using theγ-activation *** bremsstrahlung quantum flux was calculated with the GEANT4.9.2 program and was also monitored via the ^(100)Mo(γ,n)^(99)Mo *** flux-averaged cross-sections were calculated using the partial cross-sectionσ(E)values computed with the TALYs1.95 code for different level density *** is given to special features of calculating the cross-sectionsandfor the case of the final nucleus ^(22)Na via several partial channels x:nα+dt+npt+2 n^(3) He+n2d+2 npd+2 p3 n.

关键词： bremsstrahlung flux-averaged cross-section bremsstrahlung end-point energy of 35-95 MeV activation and off-lineγ-ray spectrometric technique TALYs1.95 GEANT4.9.2