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volumetric changes in the focal areas of seismic events corresponding to destress blasting

International Journal of Mining Science and Technology 2019年第4期29卷 541-547页

作者： P.Konicek J.Schreiber L.Nazarova Department of Geomechanics and Mining Research Institute of Geonics of the Czech Academy of SciencesOstrava 70800Czech Republic Laboratory of Mining Informatics Chinakal Institute of Mining of the Siberian Branch of the Russian Academy of ScienceNovosibirsk 630091Russia

The typical development of total volumetric change in the focal areas of seismic events,corresponding to destress blasting,is characterized as an explosive phase followed by an implosive phase and with alternating additional phases following on from that.In a few cases,a non-typical development of volumetric change was identified,where the first phase was implosive and the second phase,explosive.This development is mainly typical for induced seismic events recorded during mining,not for destress blasting.Seismic events were recorded during longwall mining in the Czech part of the Upper Silesian Coal Basin,where the destress blasting technique is used as a rockburst prevention active measure.Kinematic source processes in the focal areas of selected seismic events were analyzed by the seismic moment tensor inversion method,as well as by studying geomechanical rock mass conditions at the localities of the seismic events.The main goal of the analysis was to attempt to identify the reasons for non-typical development of volumetric changes in these cases.volumetric changes were analyzed for seismic events with energy greater than 104 J,recorded in the period of time from 1993 to 2009(1109 events).80%(891)of the recorded seismic events were induced seismic events that were registered during longwall mining and 20%(218)corresponded to destress blasting events.Research shows that the main reason for the non-typical development of volumetric changes in the focal areas of seismic events is an association with destress blasting in the rock mass,which is very close to rock mass overstressing.The detonation of explosives in boreholes,which would dominate the first phase of volumetric changes,probably obscured stress release in the rock mass,as manifested in the first implosion phase of the volumetric changes in this case.

关键词： Destress blasting Seismic event volumetric changes Stress release

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2D polyaniline with exchangeable interlayer fluid for fast and stable volumetric dual ion storage

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Journal of Energy Chemistry 2021年第3期30卷 587-594页

作者： Xiaochen Yang Jiaxing Liang Aditya Rawal Kefeng Xiao Yuan Pu Xiao Li Zhang Ruopian Fang Da-Wei Wang Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic Inorganic CompositesBeijing University of Chemical TechnologyBeijing 100029China School of Chemical Engineering The University of New South WalesSydneyNSW 2052Australia NMR Facility Mark Wainwright Analytical CentreThe University of New South WalesSydney 2052NSWAustralia Research Centre of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China School of Materials Science and Engineering Zhengzhou University450001China UNSW Digital Grid Futures Institute The University of New South WalesSydney 2052NSWAustralia

Two-dimensional(2D) layered materials are widely applied in energy devices including lithium-ion battery and supercapacitor due to their unique properties,such as tunable interlayer structure,numerous active sites,large aspect ratio versatile interlayer chemistry.In this work,2D layered tungstate acidlinked polyaniline(TALP) presented a fluid-in-solid structure,which allowed facile exchange of the interlayer fluid from moisture to conventional Li^(+) containing electrolyte.With fast and stable dual ion storage(Li^(+) and PF_(6)^(-)),TALP demonstrates high-rate volumetric capacity(39 mAh cm_(-3) at 2000 mA g^(-1)) and good stability(2000 cycles at 200 mA g^(-1)) within the working potential window of 1.5-4.5 V versus Li^(+)/Li.

关键词： Tungsten acid-linked polyaniline 2D material Fluid-in-solid Lithium-ion capacitor volumetric

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Thermal Analysis of a volumetric Solar Receiver

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Journal of Thermal Science 2019年第6期28卷 1176-1185页

作者： CHEN Longfei YANG Ming LI Jinping BAI Yakai LI Xiaoxia TANG Wenxue YANG Nancong WANG Zhifeng Lanzhou University of Technology Lanzhou 730050China Key Laboratory of Solar Thermal Energy and Photovoltaic Systems Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Engineering Research Center of Solar Thermal Power Beijing 100190China Beijing CSP International Cooperation Centre Beijing 100190China Joint Laboratory Institute of Electrical EngineeringChinese Academy of Sciences and Guangdong Five Star Solar Energy Co.Ltd.Beijing 100190China Guangdong 5 Star Solar Energy CO.LTD Dongguan 523051China

The volumetric receiver has received wide attention due to its high thermal efficiency. This paper studied a new type of a solid-liquid composite volumetric receiver. The heat transfer in a solid-liquid composite volumetric solar receiver was analyzed using a one-dimensional unsteady simulation model of the solid-liquid receiver. The model included absorption of the incident solar radiation by the glass window, the silicon carbide porous ceramic heat absorber panel and the water. The results were verified against experimental data for a volumetric receiver and the error did not exceed 10%. It can be used to predict the heat transfer in solid-liquid composite volumetric receivers.

关键词： solar receiver solid-liquid composite absorber silicon carbide porous ceramic volumetric solar collector

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A volumetric Model for Evaluating Tight Sandstone Gas Reserves in the Permian Sulige Gas Field,Ordos Basin,Central China

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Acta Geologica Sinica(English Edition) 2019年第2期93卷 386-399页

作者： CUI Mingming FAN Aiping WANG Zongxiu GAO Wanli LI Jinbu LI Yijun Key Laboratory of Shale oil and Gas Geological Survey Institute of Geomechanics Chinese Academy of Geological Sciences College of Geological Science & Engineering Shandong University of Science and Technology Institute of Exploration and Development Changqing Oilfield Company Petrochina

To accurately measure and evaluate reserves is critical for ensuring successful production of unconventional oil and gas. This work proposes a volumetric model to evaluate the tight sandstone gas reserves of the Permian Sulige gas field in the Ordos Basin. The reserves can be determined by four major parameters of reservoir cutoffs, net pay, gas-bearing area and compression factor Z, which are controlled by reservoir characteristics and sedimentation. Well logging, seismic analysis, core analysis and gas testing, as well as thin section identification and SEM analysis were used to analyze the pore evolution and pore-throat structure. The porosity and permeability cutoffs are determined by distribution function curve,empirical statistics and intersection plot. Net pay and gas-bearing area are determined based on the cutoffs, gas testing and sand body distribution, and the compression factor Z is obtained by gas component. The results demonstrate that the reservoir in the Sulige gas field is characterized by ultralow porosity and permeability, and the cutoffs of porosity and permeability are 5% and 0.15×10^(–3) μm^2, respectively. The net pay and gas-bearing area are mainly affected by the sedimentary facies, sand body types and distribution. The gas component is dominated by methane which accounts for more than 90%, and the compression factor Z of H_8(P_2h_8) and S_1(P_1s_1) are 0.98 and 0.985, respectively. The distributary channels stacked and overlapped, forming a wide and thick sand body with good developed intergranular pores and intercrystalline pores. The upper part of channel sand with good porosity and permeability can be sweet spot for gas exploration. The complete set of calculation systems proposed for tight gas reserve calculation has proved to be effective based on application and feedback. This model provides a new concept and consideration for reserve prediction and calculation in other areas.

关键词： tight sandstone reservoir volumetric gas reserve Permian Sulige gas field Ordos Basin

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Numerical study of MHD mixed convection under volumetric heat source in vertical square duct with wall effects

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Theoretical & Applied Mechanics Letters 2019年第3期9卷 152-160页

作者： Zhi-Hong Liu Ming-Jiu Ni Nian-Mei Zhang School of Engineering Sciences University of Chinese Academy of Sciences

Magnetohydrodynamic (MHD) mixed convection under strong magnetic field and volumetric heat source for buoyancy-assisted flows are studied numerically in this paper. Blanket is one of key components for energy conversion in Tokamak fusion reactor. The physical model employed for simulations is refined from dual-coolant lead-lithium (DCLL) blanket. A magnetic-convection code based on a consistent and conservative scheme is developed with the help of finite volume method, and validated by some Benchmark analytical solutions. The flows inside duct with thermal insulating and electric conducting walls under exponential neutron volumetric heat source are simulated. Based on Boussinesq assumption, the influences of wall electrical conductivity and buoyancy on velocity fields, temperature distributions and Nusselt numbers are investigated. Results illustrates that the wall conductance ratio dominates the flow at low Grashof numbers and high wall conductance ratio, while buoyancy effect dominates the jet flow near side wall at a high Grashof number. In addition, the velocity along flow direction substantially impacts features of the Nusselt number and temperature distribution. Besides, the jet flow results in a higher Nusselt number and lower temperature.

关键词： Mixed convection Magnetohydrodynamic (MHD) volumetric heat source

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A prospective trial of volumetric intensity-modulated arc therapy vs conventional intensity modulated radiation therapy in advanced head and neck cancer

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World Journal of Clinical Oncology 2012年第4期3卷 57-62页

作者： Simon D Fung-Kee-Fung Rachel Hackett Lee Hales Graham Warren Anurag K Singh Department of Radiation Medicine Roswell Park Cancer Institute University at Buffalo School of Medicine Elm and Carlton Streets Buffalo NY 14214 United States

AIM: To prospectively compare volumetric intensitymodulated arc therapy(VMAT) and conventional intensity-modulated radiation therapy(IMRT) in coverage of planning target volumes and avoidance of multiple organs at risk(OARs) in patients undergoing definitive chemoradiotherapy for advanced(stage Ⅲ or Ⅳ)squamous cell cancer of the head and neck. METHODS: Computed tomography scans of 20 patients with advanced tumors of the larynx, naso-, oroand hypopharynx were prospectively planned using IMRT(7 field) and VMAT using two arcs. Calculated doses to planning target volume(PTV) and OAR were compared between IMRT and VMAT plans. Dose-volume histograms(DVH) were utilized to obtain calculated doses to PTV and OAR, including parotids, cochlea,spinal cord, brainstem, anterior tongue, pituitary and brachial plexus. DVH's for all structures were compared between IMRT and VMAT plans. In addition the planswere compared for dose conformity and homogeneity. The final treatment plan was chosen by the treating radiation oncologist. RESULTS: VMAT was chosen as the ultimate plan in 18 of 20 patients(90%) because the plans were thought to be otherwise clinically equivalent. The IMRT plan was chosen in 2 of 20 patients because the VMAT plan produced concentric irradiation of the cord which was not overcome even with an avoidance structure. For all patients, VMAT plans had a lower number of average monitor units on average(MU = 542.85) than IMRT plans(MU = 1612.58)(P < 0.001). Using the conformity index(CI), defined as the 95% isodose volume divided by the PTV, the IMRT plan was more conformal with a lower conformity index(CI = 1.61) than the VMAT plan(CI = 2.00)(P = 0.003). Dose homogeneity, as measured by average standard deviation of dose distribution over the PTV, was not different with VMAT(1.45 Gy) or IMRT(1.73 Gy)(P = 0.069). There were no differences in sparing organs at risk.CONCLUSION: In this prospective study, VMAT plans were chosen over IMRT 90% of the time. Compared to IMRT, VMAT plans used only one third of the MUs, had sh

关键词： volumetric intensity-modulated arc therapy Intensity-modulated radiation therapy Target coverage Organs at risk

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Co-continuous Composite Material Design Using the volumetric Distance Field Based on Analytic Shape Functions

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Journal of Harbin Institute of Technology(New Series) 2019年第1期26卷 88-96页

作者： Huimin Han Dong-Jin Yoo Yan Liang Department of Computer Aided Mechanical Design Engineering Daejin University Department of Mechanical and Electrical Engineering Hainan Institute of Science and Technology

An effective and simple design method for co-continuous composite material construction is proposed by using a hybrid methodology with triply periodic minimal surface( TPMS) cellular topology and the volumetric distance field( VDF). After generating a set of VDF-based features for the given exterior shape and desired internal core structure,a series of simple modifications in distance fields enabled us to obtain an arbitrarily-shaped complex co-continuous composite material computational model. Design results and manufactured prototypes through 3 D printing technology show that the proposed methodology has the potential to open a new paradigm for producing multifunctional next generation co-continuous composite materials which are impossible to design and manufacture using traditional CAD and CAM.

关键词： triply periodic minimal surface (TPMS) cellular topology volumetric distance field (VDF) co-continuous composite material model basic feature 3D printing technology

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Experimental Determination and Modeling of Bubble Size Distributions in Bubble Columns

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Chinese Journal of Chemical Engineering 1998年第1期6卷 33-45页

作者： H.F.Svendsen 罗和安 K.W.Hjarbo H.A.Jakobsen Department of Chemical Engineering Norwegian University of Science and Technology Department of Chemical Engineering Xiangtan University SINTEF Applied Chemistry DNMI P.O.Box 43Blindern

Using a five point conductivity technique local values of bubble size,bubble velocity and gas fractionhave been experimentally determined in a 288 mmID and 4.3 m high bubble column as a function of axial andradial position for the air/water and CO2/N2/aqueous MDEA systems.The experimental results are comparedwith predictions from a fundamental two-fluid model.The implementation of a non-steady lateral drag term inthe two-fluid model has been shown.In addition to improving the physical realism of the model,it is found togive slight improvements in the predictions of the distributions of local bubble size.Predictions of bubble size arefound in reasonable agreement with experimental values in the heterogeous flow regime,whereas they are stil1found to be unreliable at low gas velocities.Local void predictions are found in reasonable agreement with experi-mental values,but deviations occur in the homogeneous flow regime towards the wall.This is attributed to defi-ciencies in the simplified bubble size

关键词： Bubble column bubble size distribution volumetric velocity gas fraction two-fluid model

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Performance comparison between waverider and wide-speed-range gliding vehicle based on CFD approaches

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Science China(Technological Sciences) 2019年第10期62卷 1861-1870页

作者： ZHANG TianTian WANG ZhenGuo HUANG Wei YAN XiaoTing Science and Technology on Scramjet Laboratory National University of Defense Technology

Wide-speed-range gliding vehicle(WSRGV) is designed to adapt to the variable cruising environment that hypersonic vehicles will encounter during the mission implementation. Based on the cone-derived theory, a novel design technique of WSRGV has been developed. Theoretically, the functional relationship between cone-derived waverider’s volumetric efficiency and its design Mach number can be built through sampling approach as long as the geometries of design conical shock wave and the upper base curve are fixed. Based on the functional relationship, a cone-derived waverider that owns the same volumetric efficiency with a giving WSRGV can be acquired. This paper compared the aerodynamic performance between WSRGV and the cone-derived waverider sharing the same volumetric efficiency in a wide Mach number range. Their aerodynamic properties versus angle of attack have also been compared under the waverider’s design Mach number. The obtained result shows that WSRGV shares similar aerodynamic performance with the cone-derived waverider with the same volumetric efficiency. The aero-surfaces in the margin area of this kind of configuration have a larger contribution to the lift-to-drag ratio in comparison with the aero-surfaces in the central area. The configuration with a thick central body and thin margin place owns not only better aerodynamic performance but also better loading property.

关键词： wide-speed range cone-derived waverider volumetric efficiency lift-to-drag ratio loading property

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The study of two-color excitation upconversion of Pr(0.5)Yb(3):ZBLAN

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Science China(Physics,Mechanics & Astronomy) 2006年第2期49卷 169-177页

作者： CHEN Xiaobo1 & SONG Zengfu2 1. Applied Optics Beijing Area Major Laboratory, Analysis and testing center, Beijing Normal University, Beijing 100875, China 2. Peking University, Physics School, Beijing 100871, China Applied Optics Beijing Area Major Laboratory Analysis and testing center Beijing Normal University Beijing China Physics School Peking University Beijing China

The excited state absorption upconversion of Pr(0.5)Yb(3):ZBLAN glass material, under two-color excitation of the 960 nm semiconductor laser and the Xe lamp light simultaneously, is reported in this article. It was found that the upconversion emission spectra of 480.1, 519.0, 601.9 and 631.8 nm coincide with the common emission spectra. Meanwhile, the upconversion-excitation spectrum has three obvious peaks under two-color excitation, and they respectively correspond to the 856.0 nm upconversion ex-citation transition [1G4(Pr3+)→1I6(Pr3+) and 1G4(Pr3+)→3P1(Pr3+)], the 789.0 nm upconver-sion excitation transition 1G4(Pr3+)→3P2(Pr3+), and the 803.7 nm upconversion excitation transition 3H6(Pr3+)→1D2(Pr3+). The upconversion excitation transition 1G4(Pr3+)→1I6(Pr3+) is strong because its oscillator strength f = 23.040×10?6 is large, which results in a large peak appearing in the upconversion excitation spectrum. That is just the new interesting two-color excitation upconversion luminescence phenomenon of Pr(0.5)Yb(3):ZBLAN induced by one laser and one continuous normal light simultaneously.

关键词： upconversion volumetric three-dimensional display two-color excitation.

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