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Stability of active trapdoors in axisymmetry

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Underground Space 2022年第1期7卷 50-57页

作者： Suraparb Keawsawasvong jim Shiau Department of Civil Engineering Thammasat School of EngineeringThammasat UniversityPathumthani 12120Thailand School of Civil Engineering and Surveying University of Southern QueenslandQLD 4350Australia

Trapdoor stability has been widely studied by many researchers in the field of tunneling engineering.A general question being fre-quently asked is that why most sinkholes have a near-perfect circular shape on the ground *** could be possibly explained by the current numerical study using finite element limit analysis under axisymmetric condition,where upper and lower bound solutions of active circular trapdoors are *** failure study of sinkholes and the associated failure mechanisms in this paper are for non-homogeneous clay with a linear increase of strength with depth under various cover depth ratios and dimensionless strength gra-dients.A design equation for predicting the stability solutions is also developed based on the novel three dimensional solutions using axisymmetry.

关键词： Numerical analysis Axisymmetry Stability Trapdoor Active failure

The key piece of the airway remodeling puzzle revealed-LIGHT signaling in the lung

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Genes & Diseases 2023年第4期10卷 1131-1132页

作者： Ziyan Rachel Chen jim Hu Programmes in Translational Medicine Research InstituteHospital for Sick ChildrenTorontoOntario M5G 0A4Canada Department of Laboratory Medicine and Pathobiology University of TorontoTorontoOntario M5S 1A8Canada Department of Paediatrics University of TorontoTorontoOntario M5S 1A8Canada

Asthma is a chronic lung disease that primarily affects the lower respiratory tract in more than 300 million people *** is often triggered by exposure to certain substances or conditions,such as allergens or cold *** overreaction to the allergens causes inflammation and narrowing of the airway,which leads to episodic or persistent symptoms including shortness of breath,nocturnal cough,chest tightness,and wheezing.

关键词： airway lung inflammation

A Transfer Function Design for Medical Volume Data Using a Knowledge Database Based on Deep Image and Primitive Intensity Profile Features Retrieval

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Journal of Computer Science & Technology 2024年第2期39卷 320-335页

作者： Younhyun Jung jim Kong 盛斌 Jinman Kim School of Computing Gachon UniversitySeongnam 13120Korea School of Computer Science The University of SydneySydney 2006Australia Department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Direct volume rendering(DVR)is a technique that emphasizes structures of interest(SOIs)within a volume visually,while simultaneously depicting adjacent regional information,e.g.,the spatial location of a structure concerning its *** DVR,transfer function(TF)plays a key role by enabling accurate identification of SOIs interactively as well as ensuring appropriate visibility of *** generation typically involves non-intuitive trial-and-error optimization of rendering parameters,which is time-consuming and *** at mitigating this manual process have led to approaches that make use of a knowledge database consisting of pre-designed TFs by domain *** these approaches,a user navigates the knowledge database to find the most suitable pre-designed TF for their input volume to visualize the *** these approaches potentially reduce the workload to generate the TFs,they,however,require manual TF navigation of the knowledge database,as well as the likely fine tuning of the selected TF to suit the *** this work,we propose a TF design approach,CBR-TF,where we introduce a new content-based retrieval(CBR)method to automatically navigate the knowledge *** of pre-designed TFs,our knowledge database contains volumes with SOI *** an input volume,our CBR-TF approach retrieves relevant volumes(with SOI labels)from the knowledge database;the retrieved labels are then used to generate and optimize TFs of the *** approach largely reduces manual TF navigation and fine *** our CBR-TF approach,we introduce a novel volumetric image feature which includes both a local primitive intensity profile along the SOIs and regional spatial semantics available from the co-planar images to the *** the regional spatial semantics,we adopt a convolutional neural network to obtain high-level image feature *** the intensity profile,we extend the dynamic time warping technique to address subtle alignment

关键词： data retrieval direct volume rendering ray analysis transfer function

Origin of light emission and enhanced Eu^(3+) photoluminescence in tin-containing glass

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Journal of Rare Earths 2015年第1期33卷 27-32页

作者： José A.jiménez Esteban Rosim Fachini Department of Chemistry University of North FloridaJacksonville FL 32224 USA Department of Physical Sciences General Studies Faculty University of Puerto RicoRío Piedras PR 00931 USA

A barium-phosphate glass matrix was co-doped with Sn O and Eu2O3 for investigating on material luminescent properties. Optical absorption and X-ray photoelectron spectroscopy（XPS） were employed in the characterization of tin species. The prevalence of divalent tin was indicated by the XPS data in accord with a conspicuous absorption band detected around 285 nm ascribed to twofold-coordinated Sn centers（isoelectronic with Sn^2＋）. Photoluminescence（PL） excitation spectra obtained by monitoring Eu^3＋ emission from the 5D0 state revealed a broad excitation band from about 250 to 340 nm, characteristic of donor/acceptor energy transfer. Under excitation of such at 290 nm, the co-doped material exhibited a bright whitish luminescence, and a four-fold enhanced Eu3＋ emission relative to a purely Eu-doped reference. Time-resolved PL spectra recorded under the excitation at 290 nm exposed a broad band characteristic of the twofold-coordinated Sn centers and emission bands of Eu^3＋ ions, which appeared well separated in time in accord with their emission decay dynamics. The data suggested that light absorption took place at the Sn centers（donors） followed by energy transfer to Eu^3＋ ions（acceptors） which resulted in populating the 5D0 emitting state. Energy transfer pathways likely resulting in the enhanced Eu3＋ photoluminescence and the consequential light emission were discussed.

关键词： energy transfer glasses luminescence optical materials rare earths

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Climate change, social unrest and dynastic transition in ancient China

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Science Bulletin 2005年第2期50卷 137-144页

作者： jim Chiyung,LEE Fung Department of Geography University of Hong Kong Hong Kong China Department of Geography University of Hong Kong Hong Kong China

The evident connection between human evolu- tion and climatic changes has been concurred by scientists. Although many people are trying to forecast the impacts of climatic changes on our future society, there are not any studies to quantitatively scrutinize the interrelation between climatic changes and social developments by using historical data. In line with this knowledge gap, this study adopted a scientific approach to compare the paleoclimatic records with the historical data of wars, social unrests, and dynastic transitions in China spanned from the late Tang to Qing Dy- nasties. Results showed that war frequency in cold phases was much higher than that in mild phases. Besides, 70%— 80% of war peaks and most of the dynastic transitions and nationwide social unrests in China took place in cold phases. This phenomenon could be attributed to the diminishing thermal energy input in cold phases resulting in the fall of land-productivity and hence, the deficiency of livelihood re- sources across society. Accompanied with certain social cir- cumstances, this kind of ecological stress was transformed into wars and social unrests, followed by dynastic transitions in most of the cases. By closer examination, it was even found that war frequency was negatively correlated with tempera- ture anomaly series. As land carrying capacities vary from one climatic zone to another, the magnitude of war-tempera- ture association also differed among different geographic regions. It is suggested that climatic change was one of the most important factors in determining the dynastic cycle and alternation of war and peace in ancient China.

关键词： climatic change war social unrest dynastic cycle temperature anomaly.

A Novel Edge Computing Based Area Navigation Scheme

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Computers, Materials & Continua 2020年第12期65卷 2385-2396页

作者： Jianzhong Qi Qingping Song jim Feng School of Information Science and Technology North China University of TechnologyBeijing100144China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing100083China Science and Technology on Information Systems Engineering Laboratory Beijing Institute of Control and Electronic TechnologyBeijing100038China Amphenol Global Interconnect Systems San JoseCA 95131USA

The area navigation system,discussed in this paper,is composed of ground responders and a navigation terminal and can position a high-velocity aircraft and measure its *** navigation system is silent at ordinary *** sends out a request signal when positioning is required for an aircraft,and then the ground responders send a signal for resolving the *** the direct sequence spread spectrum and frequency hopping,the concealed communication mode is used in the whole communication process,with short communication pulses as much as possible,so the system has strong concealment and anti-interference *** the transmission delay is apparent in the response communication mode,there is a big error where the common navigation algorithm is used for the positioning and velocity measurement of a high-velocity *** this paper,a new algorithm is proposed,which can eliminate the influence of response communication delay on the positioning of a high-velocity moving target to realize the precise positioning and velocity measurement of a high-velocity aircraft.

关键词： Navigation pseudo-noise code ranging positioning velocity measurement edge computing

Multivariate adaptive regression splines analysis for 3D slope stability in anisotropic and heterogenous clay

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 1052-1064页

作者： jim Shiau Van Qui Lai Suraparb Keawsawasvong School of Civil Engineering and Surveying University of Southern QueenslandToowoombaQueensland4350Australia Faculty of Civil Engineering Ho Chi Minh City University of Technology(HCMUT)268 Ly Thuong Kiet StreetDistrict 10Ho Chi Minh CityViet Nam Vietnam National University Ho Chi Minh City(VNU-HCM) Linh Trung WardThu Duc DistrictHo Chi Minh CityViet Nam Department of Civil Engineering Thammasat School of EngineeringThammasat UniversityPathumthaniBangkok12120Thailand

Little research can be found in relation to the stability of anisotropic and heterogenous soils in three *** this paper,we propose a study on the three-dimensional(3D)undrained slopes in anisotropic and heterogenous clay using advanced upper and lower bounds finite element limit analysis(FELA).The obtained stability solutions are normalized,and presented by a stability number that is a function of three geometrical ratios and two material ratios,*** ratio,length ratio,slope angle,shear strength gradient ratio and anisotropic strength *** results are compared with experimental data in the literature,and charts are presented to cover a wide range of design *** the multivariate adaptive regression splines(MARS)analysis,the respective influence and sensitivity of each design parameter on the stability number and the failure mechanism are *** empirical equation is also developed to effectively estimate the stability number.

关键词： 3D undrained slope Limit analysis Anisotropy Heterogeneity

A DYNAMICS APPROACH TO THE COMPUTATION OF EIGENVECTORS OF MATRICES

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Journal of Computational Mathematics 2005年第6期23卷 657-672页

作者： S. jiménez L. Vézquez Colaborador honorifico Dept. Matemátiea AplicadaUniversidad Complutense de Madrid 28040 Madrid Spain Dept. Matemdtica Aplicada Facultad de Informática Universidad Complutense de Madrid 28040 Madrid Spain Centro de Astrobiologla CSIC/INTA 28850 Torrejón de Ardoz Madrid Spain

We construct a family of dynamical systems whose evolution converges to the eigenvectors of a general square matrix, not necessarily symmetric. We analyze the convergence of those systems and perform numerical tests. ... 详细信息

关键词： Smallest real eigenvalue Iterative method

Incineration of kitchen waste with high nitrogen in vortexing fluidized-bed incinerator and its NO emission characteristics

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Journal of Environmental Sciences 2013年第9期25卷 1841-1846页

作者： Feng Duan Chiensong Chyang Jiaruei Wen jim Tso School of Metallurgy and Resource Anhui University of Technology Department of Chemical Engineering Chung Yuan Christian University Research and Development Center for Environmental Technology Chung Yuan Christian University

Some municipal solid waste （MSW） can be used as the fuel. Combustion of MSW with high nitrogen content is successfully conducted in a lab-scale vortexing fluidized-bed incinerator （VFBI）. Pigskin with 16.5 wt.% nitrogen content was used to simulate the high nitrogen content kitchen waste, and silica sand was used as the bed material. The effects of operating conditions, such as the bed temperature, freeboard temperature, excess oxygen ratio, and static bed height on the CO and NO concentrations at the exit of combustor and cyclone were investigated. The experimental results show that the freeboard temperature is the most important factor for CO emission. The order of operating conditions impact on the NO emission is：（1） excess oxygen ratio; （2） bed temperature; （3） freeboard temperature; and （4） static bed height. Utilizing cyclone can significantly reduce the CO emission concentration when the CO concentration released from the freeboard is higher than 50 ppm. On the other hand, the cyclone has no significant effect on the NO emission. Despite having high nitrogen content, a low conversion from fuel-N to NO was attained. Compared with other types of combustors, VFBI reduces the CO and NO emission concentrations much better when burning MSW with high nitrogen content.

关键词： incineration high nitrogen content vortexing fluidized bed pollutant emission

维普期刊数据库