检索结果-南通市图书馆

Advances in Atmospheric Sciences 1999年第1期16卷 135-148页

作者： Swati Basu K. j. Ramesh Z. N. Begum National Centre for Medium Range Weather Forecasting (NCMRWF) Department of Science and Technology New Delhi India

A detailed examination on various aspects of the southwest monsoon over the Indian subcontinent using analyses and forecasts of the NCMRWF global data assimilation and forecast system for the years 1994 and 1996 is carried out in this study. Objective procedures developed by Ramesh et al. (1996) based on the monsoon 1995 data are employed in the present work. It is found that all the deterministic features of the summer monsoon viz., the onset, its advancement, stagnation/revival and the withdrawal, can reasonably by prognosticated after employing the objective methodologies and monitoring daily variations of certain derived quantities from the large scale analyses and forecasts. Further, a good correspondence of the observed large scale/synoptic scale circulation features and the observed rainfall etc. with the deterministic characteristics of the summer monsoon show a good prospect for real time prognosis of the important summer monsoon activities over the Indian subcontinent.

关键词： Summer monsoon Objective procedure Onset Advancement Withdrawal

Pelviureteric junction obstruction in adults:A systematic review of the literature

在线全文

学校读者我要写书评

暂无评论

Current Urology 2023年第2期17卷 86-91页

作者： Niall j.O'Sullivan Steven Anderson Department of Urology Tallaght University HospitalDublin24D24 NROAIreland Department of Urology Beaumont HospitalDublinIreland

Background:Pelviureteric junction obstruction(PUjO)is a common urological disorder that can present at any stage of *** underlying etiology in children has been well studied;however,a gap exists in the literature for the adult ***,we performed a systematic review of the literature to evaluate the current evidence on the underlying etiologies of adult patients presenting with *** and methods:Four electronic databases were searched for relevant studies assessing the underlying etiologies of pelviureteric junction obstruction in *** were assessed for eligibility based on predefined inclusion and exclusion criteria,and a critical appraisal of methodological quality and risk of bias was ***,qualitative and quantitative data analyses were ***:Twelve studies comprising a total of 513 patients with radiologically confirmed PUjO met the inclusion criteria and were included in our *** most common finding was crossing vessels,which were observed in 50.5%of patients,followed by intrinsic ureteral stenosis(27.1%),adhesions(15.3%),and high insertion of the ureter(10.1%).Conclusions:The underlying etiologies of PUjO in adults remain *** studyindicated that obstruction secondary to crossing vessels is the most common cause of obstruction in adults and occurs more frequently than in the pediatric population.

关键词： Adults Etiology Pelviureteric junction obstruction Ureteropelvic junction obstruction

Inverse estimation for unknown fouling geometry on inner wall of forced-convection pipe

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

Applied Mathematics and Mechanics(English Edition) 2011年第1期32卷 55-68页

作者：陳文立楊俞青李浩榕 j.L.SALAZAR Clean Energy Center Department of Mechanical EngineeringKun Shan University

A conjugate gradient method （CGM） based on the inverse algorithm is used to estimate the unknown fouling-layer profile on the inner wall of a pipe system using simulated temperature measurements taken within the pipe wall. It is assumed that no prior information is available about the functional form of the unknown profile. Therefore, the procedure is classified as the function estimation in inverse calculation. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The accuracy of the inverse analysis is examined using the simulated exact and inexact temperature measurements. The results show that the excellent estimation of the fouling-layer profile can be obtained for the test case considered in this study. The technique presented in this study can be used in a warning system to call for pipe maintenance when the thickness of fouling exceeds a predefined criterion.

关键词： inverse problem fouling layer pipe system conjugate gradient method

Consensus on Intervals of Communication Delay

在线全文

学校读者我要写书评

暂无评论

International journal of Automation and computing 2018年第1期15卷 13-24页

作者： Heitor j.Savino Fernando O.Souza Luciano C.A.Pimenta Graduate Program in Electrical Engineering Federal University of Minas Gerais Institute of Computing Federal University of Alagoas Department of Electronic Engineering Federal University of Minas Gerais

This paper brings out a structured methodology for identifying intervals of communication time-delay where consensus in directed networks of multiple agents with high-order integrator dynamics is achieved. It is built upon the stability analysis of a transformed consensus problem which preserves all the nonzero eigenvalues of the Laplacian matrix of the associated communication topology graph. It is shown that networks of agents with first-order integrator dynamics can be brought to consensus independently of communication delay, on the other hand, for agents with second-order integrator dynamics, the consensus is achieved independently of communication delay only if certain conditions axe satisfied. Conversely, if such conditions axe not satisfied, it is shown how to compute the intervals of communication delay where multiple agents with second-order or higher-order can be brought to consensus. The paper is ended by showing an interesting example of a network of agents with second-order integrator dynamics which is consensable on the first time-delay interval, but as the time-delay increases, it loses consensability on the second time-delay interval, then it becomes consensable again on the third time-delay interval, and finally it does not achieve consensus any more on the fourth time-delay interval. This example shows the importance of analyzing consensus with time-delay in different intervals.

关键词： Time delay systems multi-agent systems consensus communication delay roots location.

DRYING OF GRANULAR MATERIALS IN AGITATED FLUIDIZED BED

在线全文

学校读者我要写书评

暂无评论

journal of Hydrodynamics 2001年第2期13卷 29-31页

作者： Ma, j.H. Liu, H. Feng, D.Z. Dept. of Air-Condition Eng. Shandong Inst. of Civil Eng. Jinan 250014 China

An experimental study of the drying characteristics of an agitated fluidized bed dryer is presented and discussed. In the study, the citric acid particles were used as bed material with the diameters ranging from 0.2 mm to 1.3 mm. The variables affecting apparently the drying rate were found to be the mass flow rate, the inlet air temperature, the rotary speed of agitating mechanism and the particles feed rate. Comparing with other variables considered, mass flow rate was found to have the least important influence on the drying rate. The agitated fluidized bed dryer is suitable to drying agglomerating or sticky materials.

关键词： Dryers (equipment) Drying Experiments Mass transfer

Semiconducting Carbon Nanotube/Fullerene Blended Heterojunctions for Photovoltaic Near-Infrared Photon Harvesting

在线全文

学校读者我要写书评

暂无评论

Nano Research 2011年第11期4卷 1174-1179页

作者： Dominick j. Bindl Adam S. Brewer Michael S. Arnold 1509 University Ave. Materials Science and Engineering Dept. University of Wisconsin-Madison Madison WI 53706 USA

We demonstrate that the near-infrared （NIR） absorptivity of semiconducfing single-walled carbon nanotubes （s-SWCNTs） can be harnessed in blended heterojunctions with the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester （PCBM）. Photogenerated charge separation is efficiently driven by the ultrahigh interracial area of the blends and the favorable energy offsets between the two materials. NIR-sensitive photovoltaic and photodetector devices utilizing the stack （indium tin oxide/ca. 10 nm s-SWCNT：PCBM/100 nm Cj10 nm 2,9- dimethyl-4,7-diphenyl-],10-phenanthroline （BCP）/Ag） were fabricated with NIR power conversion efficiencies 〉1.3% and peak, zero bias external quantum efficiency of 18% at λ = 1205 nm.

关键词： Carbon nanotube bulk heterojunction photovoltaic photodetector near-infrared (NIR)

Behavior of transporting pipeline sections without and with hydrogen exposure based on full-scale tests

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

China Welding 2024年第3期33卷 14-24页

作者： Nóra Nagy jános Lukács Institute of Materials Science and Technology Faculty of Mechanical Engineering and InformaticsUniversity of MiskolcMiskolc 3515Hungary

Pipeline transport of hydrogen is one of today’s economic and environmental *** order to find safe and reliable application of both existing gas and build new pipelines,it is essential to carry out tests on full-scale pipeline section,including the potentially more dangerous places than the main pipe,the girth *** the investigations,pipeline sections of P355NH steel with girth welds were prepared and exposed to pure hydrogen at twice the maximum allowable operating pressure for 41 ***,full-scale burst tests were carried out and specimens were cut and prepared from the typical locations of the failed pipeline sections for mechanical,and macro-and microstructural *** results obtained were evaluated and compared with data from previous full-scale tests on pipeline sections without hydrogen *** results showed differences in the behavior of pipeline sections loaded in different ways,with different characteristics of the materials and the welded joints,both in the cases without hydrogen exposure and in the cases exposed to hydrogen.

关键词： gas transporting pipeline full-scale pipeline test complex loading condition hydrogen exposure safety factor

Modulation of the Aleutian–Icelandic Low Seesaw and Its Surface Impacts by the Atlantic Multidecadal Oscillation

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2018年第1期35卷 95-105页

作者： Fei LI Yvan j.ORSOLINI Huijun WANG Yongqi GAO Shengping HE NILU--Norwegian Institute for Air Research Kjeller 2007Norway Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters~Key Laboratory of Meteorological Disaster Ministry of EducationNanjing University of Information Science and TechnologyNanjing 210044China Climate Change Research Center Chinese Academy of SciencesBeijing 100029China Nansen Environmental and Remote Sensing Center and Bjerknes Center for Climate Research Bergen 5006Norway Geophysical Institute University of Bergen and Bjerknes Center for Climate ResearchBergen 5007Norway

Early studies suggested that the Aleutian–Icelandic low seesaw(AIS) features multidecadal variation. In this study, the multidecadal modulation of the AIS and associated surface climate by the Atlantic Multidecadal Oscillation(AMO) during late winter(February–March) is explored with observational data. It is shown that, in the cold phase of the AMO(AMO|-),a clear AIS is established, while this is not the case in the warm phase of the AMO(AMO|+). The surface climate over Eurasia is significantly influenced by the AMO’s modulation of the Aleutian low(AL). For example, the weak AL in AMO|-displays warmer surface temperatures over the entire Far East and along the Russian Arctic coast and into Northern Europe,but only over the Russian Far East in AMO|+. Similarly, precipitation decreases over central Europe with the weak AL in AMO|-, but decreases over northern Europe and increases over southern Europe in AMO|+.The mechanism underlying the influence of AMO|-on the AIS can be described as follows: AMO|-weakens the upward component of the Eliassen–Palm flux along the polar waveguide by reducing atmospheric blocking occurrence over the Euro–Atlantic sector, and hence drives an enhanced stratospheric polar vortex. With the intensified polar night jet, the wave trains originating over the central North Pacific can propagate horizontally through North America and extend into the North Atlantic, favoring an eastward-extended Pacific–North America–Atlantic pattern, and resulting in a significant AIS at the surface during late winter.

关键词： Aleutian–Icelandic low seesaw Atlantic Multidecadal Oscillation Pacific–North America–Atlantic pattern stratospheric polar vortex

Application of None Cement Aluminamagnesia Gunning Mix with Special High Reactive Alumina in Steel Ladles

在线全文

学校读者我要写书评

暂无评论

China's Refractories 2020年第1期29卷 20-26页

作者： jérome KIENNEMANN Paul SOLER johnson LEE Alteo Gardanne 20062France

During calcining the aluminum hydroxide according to the Bayer process in a rotary kiln,the process of incomplete conversion to alpha alumina by soft calcination leads to a special intermediate alumina product containing microcrystalline of primary crystal alpha alumina particles less than 0.4μm,and other alumina phases with finer microcrystalline of less than 0.2μm *** special alumina powder has similar properties to silica fume or clay,such as high surface area and reactivity,fast wetting,low water demand and high *** can partially or completely replace silica fume and clay in dry gunning *** works towards improving the high temperature resistance of the gunning material matrix as well as the corrosion resistance and service life of the gunning *** application results show that:the ladle cementfree alumina-magnesia dry gunning mix with this special alumina sub-micro powder,compared with traditional dry gunning materials,has lower rebound loss(<10%),better adhesion rate,higher corrosion resistance and peeling resistance;and it can replace the veneering casting repair to achieve the similar performance.A further improvement goal is to replace the initial casting linings,thus this concept will give a new revolution to the monolithic steel ladles.

关键词： none cement gunning mix special reactive alumina monolithic steel ladles

在线全文

学校读者我要写书评

暂无评论

独自和解

独自和解