期刊文献+
共找到16篇文章
< 1 >
每页显示 20 50 100
X射线应力测定中的交相关定峰法的改进 被引量:2
1
作者 徐寒冰 宋小平 +2 位作者 盖秀颖 覃明 李家宝 《材料研究学报》 EI CAS CSCD 北大核心 2000年第B01期13-18,共6页
对于X射线应力测定的交相关定峰方法,提出了对交相关函数曲线的峰顶作抛物线拟合和使定 峰结果自协调的两种改进措施对 40SiMnCrNiMoV超高强度钢、含碳量为 0.8%的高碳钢和 GH39 镍基合金三种试样所作的实验结... 对于X射线应力测定的交相关定峰方法,提出了对交相关函数曲线的峰顶作抛物线拟合和使定 峰结果自协调的两种改进措施对 40SiMnCrNiMoV超高强度钢、含碳量为 0.8%的高碳钢和 GH39 镍基合金三种试样所作的实验结果表明,该定峰法的定峰误差明显低于目前使用的半高宽定峰法的误差, 展开更多
关键词 交相关定峰 抛物线拟合 X射线应力测定 定峰精度 金属
全文增补中
X射线衍射法测残余应力的“突变”现象与定峰技巧探讨 被引量:5
2
作者 郑卜祥 宋永伦 席峰 《理化检验(物理分册)》 CAS 2008年第3期119-122,164,共5页
X射线衍射法(XRD)是一种常用的测试金属表面残余应力的无损检测法。依据X射线应力测试的原理,对试验中遇到的衍射强度"突变"现象进行了初步探讨,并对其产生的原因和定峰中的处理方法进行了具体分析,为进一步发展和完善铝合金... X射线衍射法(XRD)是一种常用的测试金属表面残余应力的无损检测法。依据X射线应力测试的原理,对试验中遇到的衍射强度"突变"现象进行了初步探讨,并对其产生的原因和定峰中的处理方法进行了具体分析,为进一步发展和完善铝合金焊接残余应力的X射线分析技术提供了参考。 展开更多
关键词 X射线衍射法 残余应力 测试 突变 定峰
下载PDF
X射线应力测定中的交相关定峰法 被引量:5
3
作者 徐寒冰 盖秀颍 +1 位作者 宋小平 李家宝 《理化检验(物理分册)》 CAS 1998年第7期16-18,共3页
在X射线应力测定过程中,定峰方法会显著影响应力测量结果的精确度.介绍了一种新的定峰法——交相关定峰法的原理,并将其试验结果与用传统的半高宽定峰法定峰的试验结果作了比较.
关键词 X射线应力测定 衍射线 交相关定峰
下载PDF
示差定峰法的研究及其应用 被引量:1
4
作者 杨于兴 谢蔚 王强 《仪器仪表学报》 EI CAS 1987年第3期280-286,共7页
本文提出了一种精确的定峰方法—示差定峰法,其基本步骤为,在相同实验条件下测定一对试祥同组晶面(hkl)的衍射峰,利用相关函数求出它们之间的布拉格角度差(Δ2θ)。试验证明,该法测得的Δ2θ的精度明显高于常规定峰法(Δ2θ的相对偏差小... 本文提出了一种精确的定峰方法—示差定峰法,其基本步骤为,在相同实验条件下测定一对试祥同组晶面(hkl)的衍射峰,利用相关函数求出它们之间的布拉格角度差(Δ2θ)。试验证明,该法测得的Δ2θ的精度明显高于常规定峰法(Δ2θ的相对偏差小于±0.01°),由于它具有较高的测量精度,因此可应用于测定点阵常数的微小变化(Δα)和宏观残余应力分析方面。 展开更多
关键词 定峰 残余应力分析 点阵常数 角度差 相同实验条件 衍射峰 相关函数 相对偏差 最小二乘方 示差
下载PDF
SiCw/6061Al复合材料X射线应力测量中定峰方法研究
5
作者 姜传海 李寰 +1 位作者 王德尊 王中光 《物理测试》 CAS 1998年第3期37-39,共3页
本文借助X-射线应力仪,采用半高宽中点及高斯曲线定峰方法,测量SiCw/6061A1复合材料基体中的热错配应力,结果表明,高斯曲线具有较高的定峰精度,是复合材料X-射线应力测量中的理想定峰方法。
关键词 复合材料 定峰方法 应力测量 铝基 碳化硅
下载PDF
铝合金X射线应力测量定峰方法评估 被引量:2
6
作者 任建亮 王俊元 +3 位作者 杜文华 段能全 庞瑞强 杜聪 《热加工工艺》 CSCD 北大核心 2014年第20期23-27,共5页
将X射线法(XRD)的绝对应力测量评定转化为相对应力测量评定,以测量精确度和重复性为评价指标,对各种定峰方法的优劣性进行研究。实验证明,交相关法通过逐差法利用全部衍射峰信息,直接获取XRD法所需的布拉格角差值,有最好的测量精度和重... 将X射线法(XRD)的绝对应力测量评定转化为相对应力测量评定,以测量精确度和重复性为评价指标,对各种定峰方法的优劣性进行研究。实验证明,交相关法通过逐差法利用全部衍射峰信息,直接获取XRD法所需的布拉格角差值,有最好的测量精度和重复性。最大值法和抛物线法利用峰顶信息,具有较高的应力测量精度,但由于信息利用区间较窄,测量重复性较差,半高宽法(FWHM)测量精度和重复性很差,不适于对铝合金定峰。远离布拉格角处信息对重心法影响很大,对衍射峰的预处理要求也高,力臂的存在使得测量精度变差;力臂和波谱边缘随机性使测量重复性很差。交相关法对铝合金X射线应力测量有最好的定峰效果。 展开更多
关键词 X射线法(XRD) 定峰方法 应力测量 交相关法
下载PDF
离子束增强沉积表面层的应力分析
7
作者 常明 邢金华 《天津城市建设学院学报》 CAS 1996年第1期23-27,共5页
分析了采用X射线衍射方法测量金属材料表面经离子束增强沉积后表面应力的实验方法,并对实测结果进行了分析.
关键词 X射线衍射方法 金属材料 离子束 表面层 应力分析 三点抛物线法 定峰计算 误差分析
下载PDF
Quantitative prediction of channel sand bodies based on seismic peak attributes in the frequency domain and its application 被引量:2
8
作者 孙鲁平 郑晓东 +2 位作者 首皓 李劲松 李艳东 《Applied Geophysics》 SCIE CSCD 2010年第1期10-17,98,共9页
The boundary identification and quantitative thickness prediction of channel sand bodies are always difficult in seismic exploration.We present a new method for boundary identification and quantitative thickness predi... The boundary identification and quantitative thickness prediction of channel sand bodies are always difficult in seismic exploration.We present a new method for boundary identification and quantitative thickness prediction of channel sand bodies based on seismic peak attributes in the frequency domain.Using seismic forward modeling of a typical thin channel sand body,a new seismic attribute-the ratio of peak frequency to amplitude was constructed.Theoretical study demonstrated that seismic peak frequency is sensitive to the thickness of the channel sand bodies,while the amplitude attribute is sensitive to the strata lithology.The ratio of the two attributes can highlight the boundaries of the channel sand body.Moreover,the thickness of the thin channel sand bodies can be determined using the relationship between seismic peak frequency and thin layer thickness.Practical applications have demonstrated that the seismic peak frequency attribute can depict the horizontal distribution characteristics of channels very well.The ratio of peak frequency to amplitude attribute can improve the identification ability of channel sand body boundaries.Quantitative prediction and boundary identification of channel sand bodies with seismic peak attributes in the frequency domain are feasible. 展开更多
关键词 channel sand bodies seismic peak frequency attribute seismic peak amplitude attribute boundary identification quantitative prediction
下载PDF
北京市门头沟区大峪第一小学——深耕特色课程 构建中华优秀传统文化教育新格局
9
作者 高瑞红 王消冰 《中小学信息技术教育》 2022年第7期F0002-F0002,共1页
门头沟区大峪第一小学始建于1914年,是一所百年老校。学校坐落于定都峰下,独特的地理位置和百年文化的深厚底蕴,孕育了学校“定峰为始日高日新”的课程理念。学校构建了“定峰”课程体系,创新了中华优秀传统文化传承途径,形成了中华优... 门头沟区大峪第一小学始建于1914年,是一所百年老校。学校坐落于定都峰下,独特的地理位置和百年文化的深厚底蕴,孕育了学校“定峰为始日高日新”的课程理念。学校构建了“定峰”课程体系,创新了中华优秀传统文化传承途径,形成了中华优秀传统文化特色课程。 展开更多
关键词 特色课程 中华优秀传统文化 课程理念 定峰 一所 百年老校 大峪 北京市门头沟区
下载PDF
Existence of multi-bump solutions for coupled Schr dinger systems
10
作者 李玉祥 温学飞 《Journal of Southeast University(English Edition)》 EI CAS 2012年第4期496-501,共6页
The Schrodinger equation -△u+λ2u=|u|2q-2u has a unique positive radial solution Uλ, which decays exponentially at infinity. Hence it is reasonable that the Schrolinger system -△u1+u1=|u1|2q-1u1-εb(x)|u2... The Schrodinger equation -△u+λ2u=|u|2q-2u has a unique positive radial solution Uλ, which decays exponentially at infinity. Hence it is reasonable that the Schrolinger system -△u1+u1=|u1|2q-1u1-εb(x)|u2|1|u1|q-1u1,-△u2+u2=|u2|2q-2u2-εb(x)|u1|1|u2|q-1u2 has multiple-bump solutions which behave like Uλ in the neighborhood of some points. For u=(u1,u2)∈H1(R3)×H1(R3), a nonlinear functional Iε(u)=I1(u1)+I2(u2)-ε/q∫R3b(x)|u1|q|u2|qdx,is defined,where I1(u1)=1/2||u1||2-1/2q∫R3|u1|2qdx and I2(u2)=1/2||u2||2ω-1/2q∫R3|u2|2qdx. It is proved that the solutions of the system are the critical points of I,. Let Z be the smooth solution manifold of the unperturbed problem and TzZ is the tangent space. The critical point of I is rewritten as the form of z + w, where w ∈ (TzZ)⊥. Using some properties of Iε, it is proved that there exists a critical point of I, close to the form which is a multi-bump solution. 展开更多
关键词 coupled Schrodinger system multi-bump solution variational reduction method
下载PDF
Effect of ageing temperature on precipitation of A1-Cu-Li-Mn-Zr alloy 被引量:4
11
作者 DENG Yan-jun HUANG Guang-jie +2 位作者 CAO Ling-fei WU Xiao-dong HUANG Li 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第6期1340-1349,共10页
The precipitation behaviors of an A1-Cu-Li-Mn-Zr alloy at different ageing temperatures (120, 160 and 200 ~C) were investigated using Vickers hardness measurements and transmission electron microscopy (TEM) charac... The precipitation behaviors of an A1-Cu-Li-Mn-Zr alloy at different ageing temperatures (120, 160 and 200 ~C) were investigated using Vickers hardness measurements and transmission electron microscopy (TEM) characterization. Age hardening curves show an increase in precipitation kinetics with increasing ageing temperature. The results of TEM show that for the samples peak aged at 120 ~C, the amount of g' (A13Li), GP zones/0' (A12Cu) and Z (A15Cu6Li2) phases is obviously higher than that of T1 (A12CuLi) precipitates; while the samples peak aged at 160 and 200 ~C are usually dominated by T1 phase with a minor fraction of GP zones/0' and g', and the Z phase almost does not form. In addition, quantitative analysis on the T1 platelets demonstrates that the samples peak aged at 200 ~C have larger plate diameter and smaller area fraction of T1, as compared to the samples peak aged at 160 ~C. Correspondingly, the possible reasons for such phenomena are discussed. 展开更多
关键词 ageing temperature PRECIPITATION A1-Cu-Li-Mn-Zr alloy T1 phase Z (A15Cu6Li2) phase
下载PDF
Emotion recognition of Uyghur speech using uncertain linear discriminant analysis
12
作者 Tashpolat Nizamidin Zhao Li +2 位作者 Zhang Mingyang Xu Xinzhou Askar Hamdulla 《Journal of Southeast University(English Edition)》 EI CAS 2017年第4期437-443,共7页
To achieve efficient a d compact low-dimensional features for speech emotion recognition,a novel featurereduction method using uncertain linear discriminant analysis is proposed.Using the same principles as for conven... To achieve efficient a d compact low-dimensional features for speech emotion recognition,a novel featurereduction method using uncertain linear discriminant analysis is proposed.Using the same principles as for conventional linear discriminant analysis(LDA),uncertainties of the noisy or distorted input data ae employed in order to estimate maximaiy discriminant directions.The effectiveness of the proposed uncertain LDA(ULDA)is demonstrated in the Uyghur speech emotion recognition task.The emotional features of Uyghur speech,especially,the fundamental fequency and formant,a e analyzed in the collected emotional data.Then,ULDA is employed in dimensionality reduction of emotional features and better performance is achieved compared with other dimensionality reduction techniques.The speech emotion recognition of Uyghur is implemented by feeding the low-dimensional data to support vector machine(SVM)based on the proposed ULDA.The experimental results show that when employing a appropriate uncertainty estimation algorithm,uncertain LDA outperforms the conveetional LDA counterpart on Uyghur speech emotion recognition. 展开更多
关键词 Uyghur language speech emotion corpus PITCH FORMANT uncertain linear discriminant analysis (ULDA)
下载PDF
Power "Smart Pricing" with and without Smart Meters
13
作者 King Min Wang Yu Ju Cheng 《Journal of Energy and Power Engineering》 2013年第7期1316-1330,共15页
Over the past several years, the Taiwan Power Company has launched two smart pricing programs to assess the demand response of residential customers: the TOU (time-of-use) rate scheme and the DRI (demand reduction... Over the past several years, the Taiwan Power Company has launched two smart pricing programs to assess the demand response of residential customers: the TOU (time-of-use) rate scheme and the DRI (demand reduction incentive) scheme. This paper discusses these two programs and evaluates their respective performances. We develop an efficient approach based on marginal cost pricing to redesign the TOU rate scheme. In our finding, the TOU price levels could be revised to encourage more customers to participate by enlarging the price gap. Moreover, the DRI scheme can be further improved in order to reach an efficient win-win solution among customers, the utility and society. This can be achieved via a careful design of incentive tariff discounts to take account of the time-of-use or location-specific features of the power supply/demand condition. 展开更多
关键词 Time-of-use rate energy saving and carbon reduction electricity pricing strategy smart meter.
下载PDF
叙永:“问”出来的茶叶营销新路子
14
作者 淡丽 《廉政瞭望》 2021年第13期81-81,共1页
"这是我们定峰茶业的种植基地,这里的海拔和气温都适合茶叶的生长……朋友们,双击给个小红心哦!"近日,泸州叙永县定峰茶业邀请了当地"网红"来到种植基地,来了一场原生态的现场直播带货。这场鲜活的直播,一口气给公... "这是我们定峰茶业的种植基地,这里的海拔和气温都适合茶叶的生长……朋友们,双击给个小红心哦!"近日,泸州叙永县定峰茶业邀请了当地"网红"来到种植基地,来了一场原生态的现场直播带货。这场鲜活的直播,一口气给公司带来了7万元的销售额。然而,在此之前,这家村集体公司还在为如何让更多群众拿到分红而发愁。问廉:集体公司为何没体现红利?从传统经营到直播销售模式的转变,源于一场阳光问廉上群众的发问。"红岩村集体公司都成立几年了,但我们咋没得到什么实惠呢? 展开更多
关键词 红岩村 茶叶营销 种植基地 定峰 茶业 叙永县 现场直播 原生态
下载PDF
The variation of the estimated GPS instrumental bias and its possible connection with ionospheric variability 被引量:14
15
作者 ZHANG DongHe SHI Hao +3 位作者 JIN YaQi ZHANG Wei HAO YongQiang XIAO Zuo 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第1期67-79,共13页
Based on the analysis of the satellite DCB data estimated by our method and the Center for Orbit Determination in Europe(CODE)from 1999 to 2011,the features of the temporal variation of differential code biases(DCB)ar... Based on the analysis of the satellite DCB data estimated by our method and the Center for Orbit Determination in Europe(CODE)from 1999 to 2011,the features of the temporal variation of differential code biases(DCB)are studied.Summarily,there are three types of variations in DCB on different time scales.The first one is the day-to-day variation that exhibits more obviously in solar maximum years.The second one is the variation with about one year periodic variation that behaves more obviously from 1999 to 2004.The last one is the monotonously descending tendency from 1999 to 2010.Considering the basic ionospheric approximation in DCB estimation method,the features of the variability of the ionospheric morphology from 1999to 2010 are also displayed based on the ionospheric characteristic parameters.It can be concluded that the day-to-day and annual variation of the estimated global positioning system(GPS).DCB is related to the ionospheric variability.The variation of DCBs on solar cycle time scale includes the real hardware DCBs and pseudo-DCBs induced by ionospheric variation.No doubt,these kinds of"pseudo"variations of DCB will affect the precision of ionospheric total electron content(TEC)derived from the GPS data.In addition,this study is helpful for evaluating the influence of ionospheric weather on TEC derivation and is also useful for developing one estimation method of DCB with more stability and precision through introducing a more practical ionospheric model. 展开更多
关键词 DCB ionospheric variability GPS instrumental bias solar cycle
原文传递
Stability and a fast calculation method of travel speed of pulse peak in convergence zone 被引量:4
16
作者 REN Yun ZHANG RenHe +2 位作者 WANG Jun GUO YongGang Luo WenYu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第7期1274-1282,共9页
A long-range sound propagation experiment was conducted in the West Pacific Ocean in summer 2013.The signals received by a towed array indicate that the travel speed of pulse peak(TSPP)in the convergence zones is stab... A long-range sound propagation experiment was conducted in the West Pacific Ocean in summer 2013.The signals received by a towed array indicate that the travel speed of pulse peak(TSPP)in the convergence zones is stable.Therefore,an equivalent sound speed can be used at all ranges in the convergence zones.A fast calculation method based on the beam-displace-ment ray-mode(BDRM)theory and convergence zone theory is proposed to calculate this equivalent sound speed.The computation speed of this proposed method is over 1000 times faster than that of the conventional calculation method based on the normal mode theory,with the computation error less than 0.4%compared with the experimental result.Also,the effect of frequency and sound speed profile on the TSPP is studied with the conventional and fast calculation methods,showing that the TSPP is almost independent of the frequency and sound speed profile in the ocean surface layer. 展开更多
关键词 travel speed pulse peak pulse propagation BDRM theory turning point convergence zone
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部