检索结果-南通市图书馆

Rock mechanics for design of Brisbane tunnels and implications of recent thinking in relation to rock mass strength

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 676-683页

作者： l.B.McQueen A.Purwodihardjo S.V.l.Barrett Golder Associates Pty ltd. 124 Pacific HighwaySt.LeonardsNSW2065Australia Golder Associates Pty ltd. 147 Coronation DriveMiltonQueensland4064Australia Golder Associates Pty ltd. Building 7Botanicca Corporate Park570 e 588 Swan StreetRichmondVictoria3121Australia

This paper explores the potential implications of recent thinking in relation to rock mass strength for future tunnelling projects in Brisbane,Australia,particularly as they are constructed within deep horizons where the in situ stress magnitudes is *** mass failure mechanisms for the current tunnels in Brisbane are generally discontinuity controlled and the potential for stress-induced failure is relatively *** the road tunnels which have been constructed in Brisbane over the last 12 years,the strength of the more massive rock masses for continuum analysis has been estimated by the application of the hoek-Brown(h-B)failure criterion using the geological strength index(GSI)to determine the h-B parameters mb,s and *** the last few years,alternative approaches to estimating rock mass strength for‘massive to moderately jointed hard rock masses’have been proposed by others,which are built on the work completed by *** and *** in this area over their joint *** paper explores one of these alternative approaches to estimating rock mass strength for one of the geological units(the Brisbane Tuff),which is often encountered in tunnelling projects in *** potential implications of these strength forecasts for future tunnelling projects are discussed along with the additional work which will need to be undertaken to confirm the applicability of such alternative strength criteria for this rock mass.

关键词： Rock mass strength hoek-Brown(h-B)failure criterion Triaxial testing Brittle failure Brisbane Tuff

Watershed-based Image Segmentation with Region Merging and Edge Detection

在线全文

学校读者我要写书评

暂无评论

high Technology letters 2003年第1期9卷 58-63页

作者： Salman N h Institute of Image Processing Pattern Recognition Shanghai Jiaotong University Shanghai P. R. China 200030

The clustering technique is used to examine each pixel in the image which assigned to one of the clusters depending on the minimum distance to obtain primary classified image into different intensity regions. A watershed transformation technique is then employes. This includes: gradient of the classified image, dividing the image into markers, checking the Marker Image to see if it has zero points (watershed lines). The watershed lines are then deleted in the Marker Image created by watershed algorithm. A Region Adjacency Graph (RAG) and Region Adjacency Boundary (RAB) are created between two regions from Marker Image. Finally region merging is done according to region average intensity and two edge strengths (T1, T2). The approach of the authors is tested on remote sensing and brain MR medical images. The final segmentation result is one closed boundary per actual region in the image.

关键词：医学图像脑图像分水岭图象分割边缘检测区域合并

Thermal vibration of functionally graded porous nanocomposite beams reinforced by graphene platelets

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第8期41卷 1209-1226页

作者： M.h.yAS S.RAhIMI Department of Mechanical Engineering Razi UniversityKermanshah 67346-67149Iran

The thermal vibration of functionally graded(FG)porous nanocomposite beams reinforced by graphene platelets(GPls)is *** beams are exposed to the thermal gradient with a multilayer *** temperature varies linearly across the thickness *** different types of dispersion patterns of GPls as well as porosity distributions are *** material properties vary along the thickness *** using the mechanical parameters of closed-cell cellular solid,the variation of Poisson’s ratio and the relation between the porosity coefficient and the mass density under the Gaussian random field(GRF)model are *** using the halpin-Tsai micromechanics model,the elastic modulus of the nanocomposite is *** equations of motion based on the Timoshenko beam theory are obtained by using hamilton’s *** equations are discretized and solved by using the generalized differential quadrature method(GDQM)to obtain the fundamental *** effects of the weight fraction,the dispersion model,the geometry,and the size of GPls,as well as the porosity distribution,the porosity coefficient,the boundary condition,the metal matrix,the slenderness ratio,and the thermal gradient are presented.

关键词： thermal vibration functionally graded(FG) porous material graphene platelet(GPl) Timoshenko beam

Bistability in a hybrid optomechanical System under the Effect of a Nonlinear Medium

在线全文

学校读者我要写书评

暂无评论

Chinese Physics letters 2017年第8期34卷 71-75页

作者： A. Asghari Nejad h. R. Askari h. R. Baghshahi Department of Physics Faculty of Science Vali-e-Asr University of Rafsanjan Rafsanjan 77176 Iran

We investigate a hybrid optomechanical system consisting of two coupled cavities, one of them is composed of two-end fixed mirrors （called the traditional cavity）, and the other has a one-end oscillating mirror （named as the optomechanical cavity）. A Kerr medium is inside the traditional cavity to enhance the nonlinearity due to the fact that it can cause observing of bistable behavior in intracavity intensity for the optomechanical cavity. The hamiltonian of the system is written in a rotating frame and its dynamics is described by quantum langevin equations of motion. our proposed system exhibits unconventional plots for the mean photon number of the optomechanical cavity which are not observed in previous works. The present results show a deep effect of the Kerr medium on optical bistability of intracavity intensity for the optomechanical cavity. Also, coupling strength of the cavities can effectively change the stability of the system.

关键词： Bistability in a hybrid optomechanical System under the Effect of a Nonlinear Medium

Pc5 oscillation Analysis by the Satellite and Ground-Based Data

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2005年第5期25卷 393-396页

作者： A. Potapov T. Polyushkina T. l. Zhang h. Zhao A. Guglielmi J. Kultima Institute of Solar-Terrestrial Physics Siberia Branch Russian Academy of Sciences Irkutsk 664033 Russia Space Research Institute Austrian Academy of Sciences Graz Austria National Microwave Remote Sensing laboratory Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China Institute of Physics of the Earth Russian Academy of Sciences Moscow 123995 Russia Sodankylii Geophysical observatory Sodankylii Finland

large amplitude Pc5 event was observed in the space and on ground on August 3, 2001, about three hours after contact of the strong discontinuity in the solar wind with the magnetosphere according to data from ACE and Wind satellites. The Pc5 amplitude was as high as 15 nT in the tail of magnetosphere and about 5 nT at the ground based stations. In the magnetosphere Pc5 waves were observed by Cluster and Polar satellites, which occupied positions in the morning part of the near tail at the close field lines but were parted by distance of 11.5 Re, mainly along the x-axis of the GSM coordinate system. Both compressional and transverse components of the Pc5 wave activity were observed in the space, with the transverse component having the larger amplitude. Time delay between the Cluster and Polar satellites was about 8 minutes, which could be interpreted as a wave propagation from the geomagnetic tail to the Earth with the 150km/s group *** ground-based Pc5 activity was analysed by using data from the Image magnetometer network. Doubtless demonstrations of a field line resonant structure were found in variations of amplitude and polarization with latitude. Finnish chain of search coil magnetometers observed modulated Pc1 emission simultaneously with the Pc5 wave train. A possibility of non-linear impact of Pc5 wave energy on the plasma and waves in the magnetosphere is discussed.

关键词：人造卫星磁气圈太阳风太阳活动

Machine learning enabled identification and real-time prediction of living plants’ stress using terahertz waves

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第8期18卷 1330-1339页

作者： Adnan Zahid Kia Dashtipour hasan T.Abbas Ismail Ben Mabrouk Muath Al-hasan Aifeng Ren Muhammad A.Imran Akram Alomainy Qammer h.Abbasi School of Engineering and Physical Science Heriot-Watt UniversityEdinburghEH144ASUK James Watt School of Engineering University of GlasgowGlasgowG128QQUK College of Engineering Al-Ain UniversityAbu DhabiUnited Arab Emirates School of Electronic Engineering Xidian UniversityXi'anShaanxiChina School of Electronic Engineering and Computer Science Queen Mary University of LondonLondonUK

Considering the ongoing climate transformations, the appropriate and reliable phenotyping information of plant leaves is quite significant for early detection of disease, yield improvement. In real-life digital agricultural environment, the real-time prediction and identification of living plants leaves has immensely grown in recent years. hence, cost-effective and automated and timely detection of plans species is vital for sustainable agriculture. This paper presents a novel, non-invasive method aiming to establish a feasible, and viable technique for the precise identification and observation of altering behaviour of plants species at cellular level for four consecutive days by integrating machine learning (Ml) and Thz with a swissto12 materials characterization kit (MCK) in the frequency range of 0.75 to 1.1 Thz. For this purpose, measurements observations data of seven various living plants leaves were determined and incorporate three different Ml algorithms such as random forest (RF), support vector machine, (SVM), and K-nearest neighbour (KNN). The results demonstrated that RF exhibited higher accuracy of 98.87% followed by KNN and SVM with an accuracy of 94.64% and 89.67%, respectively, for precise detection of different leaves by observing their morphological features. In addition, RF outperformed other classifiers for determination of water-stressed leaves and having an accuracy of 99.42%. It is envisioned that proposed study can be proven beneficial and vital in digital agriculture technology for the timely detection of plants species to significantly help in mitigate yield and economic losses and improve crops quality.

关键词： Terahertz sensing Plants health Machine learning

Dynamic and buckling analysis of polymer hybrid composite beam with variable thickness

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 785-804页

作者： S.AFShIN M.h.yAS Department of Mechanical Engineering Razi UniversityKermanshah 67149Iran

This work deals with a study of the dynamic and buckling analysis of polymer hybrid composite(PhC) beam. The beam has variable thickness and is reinforced by carbon nanotubes(CNTs) and nanoclay(NC) simultaneously. The governing equations are derived based on the first shear deformation theory(FSDT). A three-phase halpinTsai approach is used to predict the mechanical properties of the PhC. We focus our attention on the effect of the simultaneous addition of NC and CNT on the vibration and buckling analysis of the PhC beam with variable thickness. Also a comparison study is done on the sensation of three impressive parameters including CNT, NC weight fractions, and the shape factor of fillers on the mechanical properties of PhC beams,as well as fundamental frequencies of free vibrations and critical buckling load. The results show that the increase of shape factor value, NC, and CNT weight fractions leads to considerable reinforcement in mechanical properties as well as increase of the dimensionless fundamental frequency and buckling load. The variation of CNT weight fraction on elastic modulus is more sensitive rather than shear modulus but the effect of NC weight fraction on elastic and shear moduli is fairly the same. The shape factor values more than the medium level do not affect the mechanical properties.

关键词： polymer hybrid composite(PhC) halpin-Tsai carbon nanotube(CNT) nanoclay(NC) free vibration buckling load

Twinning in Co39Ni33Al28 Alloy identified by TEM

在线全文

学校读者我要写书评

暂无评论

Twinning in Co39Ni33Al28 Alloy identified by TEM

肿瘤-膀胱壁接触长度为VIRADS评分为2～3病变提供有效风险分层

2011中国材料研讨会

作者： y.G.Wang,h.y.Wang,K.Wang Institute of Physics,Chinese Academy of Sciences

＜正＞Co-Ni-Al alloys with good ductility and a wide range of transition temperatures have been developed as a new group of the ferromagnetic shape memory alloys.[1] In addition,the Co-Ni-Al alloys have the

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

国际医学放射学杂志 2024年第1期 128-128页

作者： h.Ahn T.M.Kim S.I.hwang h.J.lee G.Choe S.K.hong 曹琳

摘要目的评价肿瘤接触长度（TCl）对预测膀胱影像报告和数据系统（VIRADS）评分为2～3的病变中肌层浸润性膀胱癌（MIBC）的诊断效能。方法回顾性纳入一个机构2019

关键词：