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Passive Control of Turbulent Jet Flow with Wedged Nozzle 被引量:2
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作者 LIU Xin(刘欣) +1 位作者 JIANG Nan(姜楠) 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第4期451-456,共6页
Turbulent flow field of the free jet with circular nozzle and wedged nozzles is measured using hot wire anemometry with resolution higher than the smallest turbulence time scale. Wavelet analysis is employed to perfor... Turbulent flow field of the free jet with circular nozzle and wedged nozzles is measured using hot wire anemometry with resolution higher than the smallest turbulence time scale. Wavelet analysis is employed to perform multi-scale decomposition of instantaneous turbulence fluctuating velocity signals, and the energy distribution of the turbulent multi-scale eddy structures over scales is studied using wavelet coefficients. Investigation of the multi-scale eddy structures of circular jet and various wedged jets reveals the transport of the energy of these wedged jets in the space from the axis to the side of the jet, as compared with the circular jet. Furthermore, not only the eddy structures at the wedge tines in the near field are crashed, but also the interactions such as eddy structure union and entrainment take place at different longitudinal and normal locations along with the development of the jets because of the existence of wedges. 展开更多
关键词 jet with wedged nozzle passive control MULTI-SCALE wavelet analysis
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Dose Validation of Physical Wedged Asymmetric Fields in Artiste Linear Accelerator
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作者 Tamer Dawod E. M. Abdelrazek +1 位作者 Mostafa Elnaggar Rehab Omar 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2014年第4期201-209,共9页
Aim: The purpose of this study was to make a comparison between measured and calculated physical wedge dose distributions using the superposition algorithm. Settings and Design: The accurate determination of absorbed ... Aim: The purpose of this study was to make a comparison between measured and calculated physical wedge dose distributions using the superposition algorithm. Settings and Design: The accurate determination of absorbed dose is important radiotherapy because of the relatively steep sigmoidal dose response curves for both tumor control and normal-tissue damage. Materials and Methods: High-energy photons (6 and 10 MV) from Artiste Treatment System Linear Accelerator Machine, available at Alexandria Ayadi Al-Mostakbal Oncology Center, were used. Results and Discussion: The results showed that the difference between measured and calculated wedged isodose curves depends on field size, beam energy, and the angle of the used wedge. Conclusion: The results showed that the presence of a wedge alters the primary and scattered components generated by a linear accelerator and causes beam hardening in 6 and 10 MV. The beam hardening increased as the wedge angle increased. 展开更多
关键词 RADIOTHERAPY WEDGE Linear ACCELERATOR COMPUTERIZED Treatment Planning System
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Genetic Analysis of Structural Styles in the Makran Accretionary Wedge–Insight from Physical Simulations
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作者 SHAO Longfei YU Fusheng +6 位作者 GONG Jianming LIAO Jing YU Zhifeng TANG Liang CHEN Jiangong WANG Yuefeng NENG Yuan 《Journal of Ocean University of China》 CAS CSCD 2024年第1期157-172,共16页
The Makran accretionary wedge has the smallest subduction angle among any accretionary prism in the world. The factors controlling the spacing and morphological development of its deep thrust faults, as well as the fo... The Makran accretionary wedge has the smallest subduction angle among any accretionary prism in the world. The factors controlling the spacing and morphological development of its deep thrust faults, as well as the formation mechanism of shallow normal faults, remain unclear. Meanwhile, the factors affecting the continuity of plane faults must be comprehensively discussed. Clarifying the development characteristics and deformation mechanisms of the Makran accretionary wedge is crucial to effectively guide the exploration of gas hydrate deposits in the area. This study aims to interpret seismic data to identify typical structures in the Makran accretionary wedge, including deep imbricate thrust faults, shallow and small normal faults, wedge-shaped piggyback basins, mud diapirs with fuzzy and disorderly characteristics of reflection, décollements with a northward tilt of 1° – 2°, and large seamounts. Physical simulation-based experiments are performed to comprehensively analyze the results of the plane, section, and slices of the wedge. Results reveal that the distances between and shapes of thrust faults in the deep parts of the Makran accretionary wedge are controlled by the bottom décollement. The uplift of the thrust fault-related folds and the upwelling of the mud diapirs primarily contribute to the formation of small normal faults in the shallow part of the area. The mud diapirs originate from plastic material at the bottom, while those that have developed in the area near the trench are larger. Seamounts and mud diapirs break the continuity of fault plane distribution. 展开更多
关键词 Makran accretionary wedge structural styles faults distribution physical simulation
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Failure mechanism and simulation for long run-out of the catastrophic rock landslide in the Shanyang Vanadium Mine,China
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作者 LIU Yinpeng Mumtaz HAIDER +3 位作者 David-darnor LAWRENCE LI Tonglu SHEN Wei LI Ping 《Journal of Mountain Science》 SCIE CSCD 2024年第9期2905-2917,共13页
On 12th August 2015,a massive rapid long run-out rock landslide occurred in the Shanyang Vanadium Mine in Shaanxi Province,China,which claimed the lives of 65 miners.No heavy rainfalls,earthquakes,and mining blasts we... On 12th August 2015,a massive rapid long run-out rock landslide occurred in the Shanyang Vanadium Mine in Shaanxi Province,China,which claimed the lives of 65 miners.No heavy rainfalls,earthquakes,and mining blasts were recorded before the incident.Therefore,the failure mechanism and the cause of the long run-out movement are always in arguments.In this paper,we conducted a detailed field investigation,laboratory tests,block theory analysis,and numerical simulation to investigate the failure and long run-out mechanisms of the landslide.The field investigation results show that the source material of the rock landslide is a huge dolomite wedge block bedding on siliceous shale layers.Uniaxial compression tests indicate that the uniaxial compression strength of the intact dolomite is 130-140MPa and the dolomite shows a brittle failure mode.Due to the progressive downward erosion of the gully,the dolomite rock bridge at the slope toe became thinner.As the compression stress in the dolomite bridge increased to surpass its strength,the brittle failure of the bridge occurred.Then huge potential energy was released following the disintegration of the landslide,which led to the high acceleration of this rock landslide.The 3D discrete element simulation results suggest that the low intergranular friction contributes to the long run-out movement of this rock landslide. 展开更多
关键词 Rock landslide Gully erosion Long run-out Wedge block Discrete element method
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Integrated simulation and monitoring to analyze failure mechanism of the anti-dip layered slope with soft and hard rock interbedding 被引量:1
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作者 Jinduo Li Yuan Gao +5 位作者 Tianhong Yang Penghai Zhang Yong Zhao Wenxue Deng Honglei Liu Feiyue Liu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第9期1147-1164,共18页
The significant difference between the mechanical properties of soft rock and hard rock results in the complexity of the failure mode of the anti-dip layered slope with soft and hard rock interbedding.In order to reve... The significant difference between the mechanical properties of soft rock and hard rock results in the complexity of the failure mode of the anti-dip layered slope with soft and hard rock interbedding.In order to reveal the landslide mechanism,taking the north slope of Fushun West Open-pit Mine as an example,this paper analyzed the failure mechanism of different landslides with monitoring and field surveys,and simulated the evolution of landslides.The study indicated that when the green mudstone(hard rock)of the anti-dip slope contains siltized intercalations(soft rock),the existence of weak layers not only aggravates the toppling deformation of anti-dip layered slope with high dip,but also causes the shear failure of anti-dip layered slope with stable low dip.The shear failure including subsidence induced sliding and wedge failure mainly exists in the unloading zone of the slope.Its failure depth and failure time were far less than that of toppling failure.In terms of the development characteristics of deformation,toppling deformation has the long-term and progressive characteristics,but shear failure deformation has the abrupt and transient characteristics.This study has deepened the understanding of such slope landslide mechanism,and can provide reference for similar engineering. 展开更多
关键词 Anti-dip layered slope Soft and hard rock interbedding Toppling failure Wedge failure Fushun West Open-pit Mine
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Comparative Study of the Rock-breaking Mechanism of a Disc Cutter and Wedge Tooth Cutter by Discrete Element Modelling 被引量:1
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作者 Hua Jiang Huiyan Zhao +2 位作者 Xiaoyan Zhang Yusheng Jiang Yaofu Zheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期269-285,共17页
The operation of a shield tunnel boring machine(TBM)in a high-strength hard rock stratum results in significant cutter damage,adversely affecting the thrust and torque of the cutter head.Therefore,it is very important... The operation of a shield tunnel boring machine(TBM)in a high-strength hard rock stratum results in significant cutter damage,adversely affecting the thrust and torque of the cutter head.Therefore,it is very important to carry out the research on the stress characteristics and optimize the cutter parameters of cutters break high-strength hard rock.In this paper,the rock-breaking performance of cutters in an andesite stratum in the tunnel of Qingdao Metro Line No.8 was investigated using the discrete element method and theoretical analysis.The rock-breaking processes of a disc cutter and wedge tooth cutter were simulated by software particle flow code PFC^(3D),and the rock-breaking degree,stress of the cutter,and rock-breaking specific energy were analyzed.The rock damage caused by the cutter in a specific section was divided into three stages:the advanced influence,crushing,and stabilizing stages.The rock-breaking degree and the tangential and normal forces of the wedge tooth cutter are larger than that of the disc cutter under the same conditions.The disc cutter(wedge tooth cutter)has the highest rock-breaking efficiency at a cutter spacing of 100 mm(110 mm)and a penetration depth of 8 mm(10 mm),and the rock-breaking specific energy is 11.48 MJ/m^(3)(12.05 MJ/m^(3)).Therefore,two types of cutters with different penetration depths or cutter spacing should be considered.The number of teeth of wedge tooth cutters can be increased in hard strata to improve the rock-breaking efficiency of the shield.The research results provide a reference for shield cutterhead selection and cutter layout in similar projects. 展开更多
关键词 Qingdao andesite Rock breaking with cutter Wedge tooth cutter Specific energy PFC^(3D)
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Computational Analysis of Surface Pressure Distribution over a 2D Wedge in the Supersonic and Hypersonic Flow Regimes
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作者 Javed S.Shaikh Krishna Kumar +1 位作者 Khizar A.Pathan Sher A.Khan 《Fluid Dynamics & Materials Processing》 EI 2023年第6期1637-1653,共17页
The complex fluid-dynamic instabilities and shock waves occurring along the surface of a two-dimensional wedge at high values of the Mach number are studied here through numerical solution of the governing equations.M... The complex fluid-dynamic instabilities and shock waves occurring along the surface of a two-dimensional wedge at high values of the Mach number are studied here through numerical solution of the governing equations.Moreover,a regression model is implemented to determine the pressure distribution for various Mach numbers and angles of incidence.The Mach number spans the interval from 1.5 to 12.The wedge angles(θ)are from 5°to 25°.The pressure ratio(P2/P1)is reported at various locations(x/L)along the 2D wedge.The results of the numerical simulations are compared with the regression model showing good agreement. 展开更多
关键词 CFD analysis SUPERSONIC wedge angle Mach number
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Gastric inflammatory myofibroblastic tumor, a rare mesenchymalneoplasm: A case report
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作者 Manuel Fernandez Rodriguez Pedro Joaquin Artuñedo Pe +4 位作者 Alejandro Callejas Diaz Gala Silvestre Egea Cristián Grillo Marín Eva Iglesias Garcia Jose Luis Lucena de La Poza 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第11期2657-2662,共6页
BACKGROUND The inflammatory myofibroblastic tumor(IMT)is a rare mesenquimal tumor of doubtful biological behaviour.It’s characterised for affecting mainly children and young adults,although it can appear at any age,b... BACKGROUND The inflammatory myofibroblastic tumor(IMT)is a rare mesenquimal tumor of doubtful biological behaviour.It’s characterised for affecting mainly children and young adults,although it can appear at any age,being the lungs the primary affected organ(in children it represents 20%of all primary pulmonary tumors).CASE SUMMARY We present the case of a 45 year old woman,with a computed tomography(CT)finding of injury on the anterior surface of the fundus/gastric body and a solid perigastric injury of 12 mm in the ecoendoscopy.The case is presented in the tumor committee deciding to perform a laparoscopic wedge resection.The histological diagnosis was a IMT.The diagnosis is based on imaging tests like the abdominal CT,abdominal ecography and the ecoendoscopy but to confirm the diagnosis a pathological study is necessary.CONCLUSION Due to the unpredictable nature of this tumor,surgical resection is the best therapeutic option. 展开更多
关键词 Inflammatory myofibroblastic tumor GASTRIC Wedge resection ALK-mutation Case report
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线电极磨削系统电极丝恒张力模糊控制研究 被引量:4
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作者 吉方 张连新 +2 位作者 吴祉群 刘广民 张勇斌 《制造技术与机床》 CSCD 北大核心 2011年第3期26-29,共4页
针对自主设计的一种新型WEDG系统走丝机构,提出了采用模糊控制的方法实现电极丝的恒张力控制。首先分析了该新型WEDG系统走丝机构的工作原理,建立了系统的走丝机构控制模型。在此基础上,基于模糊控制理论,根据张力反馈对送丝轮的转速进... 针对自主设计的一种新型WEDG系统走丝机构,提出了采用模糊控制的方法实现电极丝的恒张力控制。首先分析了该新型WEDG系统走丝机构的工作原理,建立了系统的走丝机构控制模型。在此基础上,基于模糊控制理论,根据张力反馈对送丝轮的转速进行闭环控制,最终实现了电极丝的恒张力控制。基于该WEDG系统进行了微小工具电极的加工实验。结果表明,该WEDG系统走丝稳定、张力恒定,能够以很高的效率制作出直径小(直径小于10μm)、几乎没有锥度的工具电极,很好地满足了的微细电火花加工机床微小工具电极的制作需要。 展开更多
关键词 微细电火花加工 WEDG 走丝机构 恒张力控制 模糊控制
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An Improved Angle Polishing Method for Measuring Subsurface Damage in Silicon Wafers 被引量:2
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作者 霍凤伟 康仁科 +2 位作者 郭东明 赵福令 金洙吉 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第3期506-510,共5页
We present an improved angle polishing method in which the end of the cover slice near the glue layer is beveled into a thin,defect-free wedge,the straight edge of which is used as the datum for measuring the depth of... We present an improved angle polishing method in which the end of the cover slice near the glue layer is beveled into a thin,defect-free wedge,the straight edge of which is used as the datum for measuring the depth of subsurface damage. The bevel angle can be calculated from the interference fringes formed in the wedge. The minimum depth of the subsurface damage that can be measured by this method is a few hundred nanometers. Our results show that the method is straightforward, accurate, and convenient. 展开更多
关键词 silicon wafer subsurface damage angle polishing defect etching wedge fringes
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Stability of undercut space in fragment orebody based on key block theory 被引量:1
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作者 胡建华 杨春 +2 位作者 周科平 李杰林 高峰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第7期1946-1954,共9页
Undercut is one kind of important spaces to place the mining blocks in the mass underground mining. This structure is also used as a compensation space during blasting. In the process of underground mining in the frag... Undercut is one kind of important spaces to place the mining blocks in the mass underground mining. This structure is also used as a compensation space during blasting. In the process of underground mining in the fragment orebody, it is important and critical to analyze the stability and blockage of the three-dimensional wedges created around the undercut space. The wedge stability is mainly controlled by factors including geometry (i.e., the size, shape and spatial location of the wedge and undercut), the strength (shear and tensile) of the discontinuities that created the wedge, and the stress distribution within the rock mass. The Unwedge software was used to conduct the orthogonal simulation tests (three factors and five levels) that considered different cross sections, trends, and plunges of the undercut space. The results demonstrate that the control value of the safety factor of wedge is set to be 1.2. The optimal parameters are determined in the undercut space, such as the blasting fragmentation, orientation of the fluid flow, and the equipment gradeability;the wedge stability can be evaluated in the light of the block images and continuous falling;the stability of the key block meets the needs of the undercut space, the parameters gained are reasonable and optimal. Cross section is 27°, trend is from 315°to 325°(it is 320°at in-suit test) and plunge is 5°. 展开更多
关键词 wedge stability fragment orebody UNDERCUT Unwedge software optimization
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Contrast of Seismic Reflection Characteristics of Gas Hydrate Distribution between Northeast SCS Slope and Hengchun Ridge 被引量:1
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作者 尚继宏 李家彪 章家保 《Marine Science Bulletin》 CAS 2008年第1期64-74,共11页
By analyzing and interpreting the newly acquired seismic profile supported by the national 973 Program and synthesizing the data with other geologic & geographic information, we draw conclusions as follows, a) Two s... By analyzing and interpreting the newly acquired seismic profile supported by the national 973 Program and synthesizing the data with other geologic & geographic information, we draw conclusions as follows, a) Two seismic reflections located at the northeast South China Sea (SCS) slope and the Hengchun ridge are the Bottom Simulated Reflections (BSRs). Yet, the genesis and process of the gas hydrate in these two areas are different because of different regional tectonics and geological environments; b) The genesis of gas hydrate located at the northeast SCS slope area is related to the broadly existing fracture zones, slumping tectosomes, and the distinctive shielding environment of pressure masking field formed by them. But the genesis of the gas hydrate at the Hengchun ridge is associated with the thrust nappe structures and accretionary wedges formed along the Manila subduction zone and the related sub-floor fluid channel system built by them; c) Since the analogous geologic bodies are broadly distributed at slope areas around SCS and the temperature-press environment is very suitable to the formation and conservation of the gas hydrate, we suggest that much more of this resource should be stored in these areas. 展开更多
关键词 BSR gas hydrate slumping block accretionary wedge thrust nappe tectosome DIAPIR
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微铣刀在位制备方法研究 被引量:1
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作者 杨正杰 张勇斌 徐凌羿 《机械科学与技术》 CSCD 北大核心 2017年第9期1396-1401,共6页
提出基于WEDG技术的微铣刀在位制备方法,将微铣刀的制备与使用结合起来,在同一台微细电火花加工机床上完成微铣刀的在位制备与在位铣削过程,可实现微铣刀的低成本高精度制备,同时避免微铣刀的二次装夹所造成的倾斜和偏心误差,提高微铣... 提出基于WEDG技术的微铣刀在位制备方法,将微铣刀的制备与使用结合起来,在同一台微细电火花加工机床上完成微铣刀的在位制备与在位铣削过程,可实现微铣刀的低成本高精度制备,同时避免微铣刀的二次装夹所造成的倾斜和偏心误差,提高微铣削整体质量。为验证基于WEDG技术的微铣刀在位制备工艺方法的可行性,基于自研μEM-200CDS2型双主轴三工位微细组合电加工机床平台,进行了微铣刀在位制备与在位铣削的实验研究。结合WEDG工艺特点对微铣刀进行材料选用与构型设计,实现了直径小于100μm、刃口锋利的D型微铣刀的制备,并利用所制备微铣刀在位铣削出最小壁厚小于20μm的一组薄壁结构。实验结果表明:基于WEDG技术的微铣刀在位制备方法在原理和技术上是可行的。 展开更多
关键词 微铣刀 WEDG 在位制备
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Joint inversion of P-wave velocity and Vp–Vs ratio: imaging the deep structure in NE Japan 被引量:3
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作者 王志 《Applied Geophysics》 SCIE CSCD 2014年第2期119-127,252,共10页
A new inversion scheme is presented to obtain three-dimensional images of P-wave velocity(Vp) and P–S-wave velocity ratio(Vp/Vs) using P- and S-phase pairs, i.e., the same source–receiver pairs for the P- and S-... A new inversion scheme is presented to obtain three-dimensional images of P-wave velocity(Vp) and P–S-wave velocity ratio(Vp/Vs) using P- and S-phase pairs, i.e., the same source–receiver pairs for the P- and S-wave arrival-time data. The S-wave velocity(Vs) was separately inverted using the S-phase arrival times. The earthquake hypocenters were simultaneously relocated in the joint inversion. The method considers the Vp/Vs anomaly as a model parameter in the inversion. The proposed method thus provides a more robust calculation of the Vp/Vs anomaly than the conventional method of dividing Vp by Vs. The method also takes into account the ray path difference between P- and S-waves, and hence yields a less biased Vp–Vs ratio than the method of inverting S–P-wave data for Vp and Vp/Vs anomalies under the assumption of identical P and S ray paths. The proposed method was used to image the crust and upper mantle in northeastern(NE) Japan taking advantage of a large number of high-quality arrival times of P- and S-wave source–receiver pairs. The inverted structures suggest that the subducting slab of the Pacific plate is an inclined zone of high-Vp and Vs anomalies with low Vp/Vs perturbation. The mantle wedge is characterized by low-Vp, low-Vs, and high-Vp/Vs anomalies at shallow depths beneath active volcanoes. These features are also observed at greater depths in the back-arc region. Although these features have been previously reported, the Vp/Vs anomaly pattern obtained in this study shows much less scatter and is much better correlated with the seismic velocity perturbation patterns than previous studies. The proposed method can be used, in conjunction with velocity anomaly patterns, to quantify thermal processes associated with plate subduction. 展开更多
关键词 Seismic tomography P and S source–receiver pairs Pacific subduction zone Mantle wedge
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微细电火花加工用伺服进给控制系统的设计
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作者 夏继强 刘晋春 +1 位作者 韦红雨 赵万生 《电加工》 1996年第5期12-14,共3页
本文简要介绍了电火花线电极磨削法(WEDG法)的加工原理。分析了应用该方法进行实验研究中伺服进给的特点,并根据这些特点设计了微细电火花加工用伺服进给控制系统。系统中采用了8031单片机作为CPU,使用方便灵活;系统应... 本文简要介绍了电火花线电极磨削法(WEDG法)的加工原理。分析了应用该方法进行实验研究中伺服进给的特点,并根据这些特点设计了微细电火花加工用伺服进给控制系统。系统中采用了8031单片机作为CPU,使用方便灵活;系统应用脉宽调制式细分驱动技术,不但提高了加工中的进给分辨率,也使进给系统的频率响应大大提高,满足了微细电火花加工的要求。 展开更多
关键词 电火花加工 伺服系统 进给控制系统 WEDG法
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微细电极在线制备技术的研究进展 被引量:7
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作者 郭帅 罗红平 郭钟宁 《制造技术与机床》 CSCD 北大核心 2011年第8期73-78,共6页
介绍了反拷块法、WEDG法、电化学腐蚀法、EEDG法等几种微细电极的在线制备方法、基本原理、研究现状及最新进展,为实际加工轴类工件及制备工具电极等提供了有益参考。
关键词 反拷块法 WEDG法 电化学腐蚀法 EEDG法
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基于XML的BSP敏捷开发方法 被引量:1
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作者 楼骥洲 陈天洲 戴鸿君 《计算机应用研究》 CSCD 北大核心 2007年第4期108-110,共3页
简要分析了目前Linux BSP开发存在的缺陷,通过分析两个不同版本嵌入式Linux的Ac97声卡驱动程序的异同,针对不同处理器提出了一种基于Linux的BSP标准。在此基础上,实现了一套基于XML的Linux BSP标准化配置工具,实现了基于图形界面的Linux... 简要分析了目前Linux BSP开发存在的缺陷,通过分析两个不同版本嵌入式Linux的Ac97声卡驱动程序的异同,针对不同处理器提出了一种基于Linux的BSP标准。在此基础上,实现了一套基于XML的Linux BSP标准化配置工具,实现了基于图形界面的Linux BSP生成方式,提高了嵌入式Linux BSP的开发效率。 展开更多
关键词 Linux板级支持包标准 Linux板级支持包配置工具 SLOT驱动开发 WEDGE驱动开发
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TTI介质纯准P波一阶压力-速度方程及求解方法 被引量:3
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作者 李佳珂 张会星 +1 位作者 白冰 张建敏 《中国煤炭地质》 2018年第7期72-78,共7页
以具有倾斜对称轴的横向各向同性(Titled Transverse Isotropic,TTI)介质中纯准P波二阶方程为基础,通过引入辅助波场实现了方程的降阶,推导出了TTI介质纯准P波一阶压力-速度方程,并利用旋转交错网格高阶有限差分方法对方程进行数值求解... 以具有倾斜对称轴的横向各向同性(Titled Transverse Isotropic,TTI)介质中纯准P波二阶方程为基础,通过引入辅助波场实现了方程的降阶,推导出了TTI介质纯准P波一阶压力-速度方程,并利用旋转交错网格高阶有限差分方法对方程进行数值求解,给出了完全匹配层(Perfectly Matched Layers,PML)吸收边界条件在该方程中应用的方法。理论分析及数值模拟结果表明:相对于二阶形式的准P波方程,该TTI介质纯准P波一阶压力-速度方程在计算精度相同的情况下,具有更高的计算效率;同时能更准确地描述对称轴参数变化剧烈的TTI介质中准P波的传播规律。 展开更多
关键词 TTI介质 纯准P波 旋转交错网格 PML边界 Wedge模型
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利用Elekta Omni-Wedge技术提高靶区剂量均匀性的初步探讨 被引量:1
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作者 董志祥 崔建国 +2 位作者 柏晗 赵彪 潘香 《肿瘤基础与临床》 2012年第6期542-544,共3页
放疗临床剂量学四原则要求接受照射的靶区剂量均匀性要达到一定的标准,通常为±5%。因受人体体表不平整和体内密度不均匀性的影响,有时需要采用一些物理学方法改变野内束流强度分布,插入楔形板就是其中之一。
关键词 Omni—Wedge 靶区 剂量均匀性
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Anti-plane deformations around arbitrary-shaped canyons on a wedge-shape half-space:moment method solutions 被引量:19
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作者 Nazaret Dermendjian Vincent W.Lee 梁建文 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第2期281-287,共7页
The wave propagation behavior in an elastic wedge-shaped medium with an arbitrary shaped cylindrical canyon at its vertex has been studied.Numerical computation of the wave displacement field is carried out on and nea... The wave propagation behavior in an elastic wedge-shaped medium with an arbitrary shaped cylindrical canyon at its vertex has been studied.Numerical computation of the wave displacement field is carried out on and near the canyon surfaces using weighted-residuals(moment method).The wave displacement fields are computed by the residual method for the cases of elliptic,circular,rounded-rectangular and flat-elliptic canyons,The analysis demonstrates that the resulting surface displacement depends,as in similar previous analyses,on several factors including,but not limited,to the angle of the wedge,the geometry of the vertex,the frequencies of the incident waves,the angles of incidence,and the material properties of the media.The analysis provides intriguing results that help to explain geophysical observations regarding the amplification of seismic energy as a function of site conditions. 展开更多
关键词 weighted-residual moment method wedge half-space arbitrary-shaped cicular elliptic rectangular canyons
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