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The asymptotic relation between the first crossing point and the last exit time of Gaussian order statistics sequences
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作者 NING Zi-jun TAN Zhong-quan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第4期545-561,共17页
In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.I... In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.It is shown that the first crossing point and the last exit time are asymptotically independent and dependent for weakly and strongly dependent cases,respectively.The asymptotic relations between the first crossing point and the last exit time for stationary weakly and strongly dependent Gaussian sequences are also obtained. 展开更多
关键词 rst crossing point last exit time stationary Gaussian sequences Gaussian order statistic se-quences
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Regular-Singular Crossings on Nonlinear Systems with Turning Point
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作者 Zhang Hanlin (Beijing Polytechnic University) Zhang Heping (Beijing Electric Power College) 《Advances in Manufacturing》 SCIE CAS 1998年第3期21-23,共3页
We consider in this paper the boundary value problems of nonlinear systems the form εY″=F(t,Y,Y′,ε), -1<t<1, Y(-1,ε)=A(ε), Y(1,ε)=B(ε). Supoosing some or all of the components of F , that is, ... We consider in this paper the boundary value problems of nonlinear systems the form εY″=F(t,Y,Y′,ε), -1<t<1, Y(-1,ε)=A(ε), Y(1,ε)=B(ε). Supoosing some or all of the components of F , that is, f i satisfy 2 f y′ 2 i t =0 =0, we say that F possesses a generalized turning point at t =0. Our goal is to give sufficient conditions for the existence of solution of the problems and to study the asymptotic behavior of the solution when F possesses a generalized turning point at t =0. We mainly discuss regular singular crossings. 展开更多
关键词 turning point regular singular crossing differential inequality
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Cross-Correlation Detection of Point Sources in the WMAP First Year Data
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作者 Jian-Yin Nie Shuang-Nan Zhang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第2期199-208,共10页
We apply a Cross-Correlation (CC) method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We... We apply a Cross-Correlation (CC) method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We find that the CC method is a powerful tool to examine the WMAP foreground residuals which can be further cleaned accord- ingly. Evident foreground signals are found in the WMAP foreground cleaned maps and the Tegmark cleaned map. In this process 101 point sources are detected, and 26 of them are new sources additional to the originally listed WMAP 208 sources. We estimate the flux of these new sources and verify them by another method. As a result, a revised mask file based on the WMAP first year data is produced by including these new sources. 展开更多
关键词 cosmic microwave background: WMAP - cross-correlation - radio point source
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Cross Point Assignment Algorithm Under Consideration of Very Long Nets
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作者 张轶谦 谢民 +1 位作者 洪先龙 蔡懿慈 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第6期582-588,共7页
A cross point assignment algorithm is proposed under consideration of very long nets (LCPA).It is to consider not only the cost of connection between cross points and pins and the exclusive cost among cross points on ... A cross point assignment algorithm is proposed under consideration of very long nets (LCPA).It is to consider not only the cost of connection between cross points and pins and the exclusive cost among cross points on the boundary of a global routing cell,but also the cost of displacement among cross points of the same net.The experiment results show that the quality and speed in the following detailed routing are improved obviously,especially for very long nets. 展开更多
关键词 cross point assignment layout VLSI
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Cross Point Assignment Algorithm with Crosstalk Constraint
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作者 姚海龙 周强 +1 位作者 洪先龙 蔡懿慈 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第4期388-393,共6页
An algorithm to resolve the coupling effect problem is proposed during the cross point assignment (CPA) stage.In the algorithm,the priority queue concept and the rip-up and reroute strategy are combined to control cro... An algorithm to resolve the coupling effect problem is proposed during the cross point assignment (CPA) stage.In the algorithm,the priority queue concept and the rip-up and reroute strategy are combined to control crosstalk noise caused by interconnect coupling capacitance.First,the nets are arranged into different priority queues according to their weighted sum of their length and criticality.Then,the CPA problem for one queue of nets is translated into a linear assignment problem.After the assignment of one queue of nets,a post-CPA checking routine is performed to check and rip up the net pairs which violate the crosstalk noise constraint and then push them into the next queue to be reassigned.The algorithm is tested by a set of bench mark examples,and the experimental results are promising... 展开更多
关键词 routing cross point assignment crossTALK INTERCONNECT
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Crossing point temperature of coal 被引量:5
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作者 Qi xuyao Deming Wang +1 位作者 James A. Milke Xiaoxing Zhong 《Mining Science and Technology》 EI CAS 2011年第2期255-260,共6页
A further understanding of the self-heating of coal was obtained by investigating the crossing point temperature(CPT) of different ranks of coal.The tests were carried out using a self-designed experimental system f... A further understanding of the self-heating of coal was obtained by investigating the crossing point temperature(CPT) of different ranks of coal.The tests were carried out using a self-designed experimental system for coal self-heating.50 g(±0.01 g) of coal particles ranging from 0.18 mm to 0.38 mm in size were put into a pure copper reaction vessel attached to the center of a temperature programmed enclosure.The temperature program increased the temperature at a rate of 0.8℃/min.Dry air was permitted to flow into the coal reaction vessel at different rates.The surrounding temperature and the coal temperature were monitored by a temperature logger.The results indicate that CPT is affected by coal rank,moisture,sulfur, and the experimental conditions.Higher ranked coals show higher CPT values.A high moisture content causes a delay phenomenon during the self-heating of the coal.Drying at 40℃decreases the effects of moisture.The reactivity of sulfur components in the coal is low under dry and low-temperature conditions. These components form a film that covers the coal surface and slightly inhibits the self-heating of the coal. The flow rate of dry air,and the heating rate of the surroundings,also affect the self-heating of the coal.The most appropriate experimental conditions for coal samples of a given weight and particle size were determined through contrastive analysis.Based on this analysis we propose that CPTs be determined under the same,or nearly the same conditions,for evaluation of the spontaneous combustion of coal. 展开更多
关键词 COAL Spontaneous combustion crossing point temperature MOISTURE SULFUR Coal rank
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An analytical model for the prediction of cross-section profile and mean roll radius in alloy bar rolling 被引量:8
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作者 Yonggang Dong Wenzhi Zhang Jianfeng Song 《Journal of University of Science and Technology Beijing》 CSCD 2008年第3期344-351,共8页
In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept "critical point on the contact boundary" was proposed... In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept "critical point on the contact boundary" was proposed and the coordinates of the critical point were solved. The equivalent contact section area was represented and the mean roll radius was determined. The validity of this model was examined by alloy bar rolling experiment and rigid-plastic FEM simulation. Compared with the existing models, the mean roll radius obtained by this model is similar to experiment data. 展开更多
关键词 alloy steel critical point cross-section profile mean roll radius round-oval-round
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Computation of the locus crossing point location of MC circuit
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作者 刘海军 李智炜 +2 位作者 步凯 孙兆林 聂洪山 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期682-685,共4页
In this paper, the crossing point property of the i-v hysteresis curve in a memristor-capacitor (MC) circuit is analyzed. First, the ideal passive memristor on the crossing point property of i-v hysteresis curve is ... In this paper, the crossing point property of the i-v hysteresis curve in a memristor-capacitor (MC) circuit is analyzed. First, the ideal passive memristor on the crossing point property of i-v hysteresis curve is studied. Based on the analysis, the analytical derivation with respect to the crossing point location of MC circuit is given. Then the example of MC with linear memristance-versus-charge state map is demonstrated to discuss the drift property of cross-point location, caused by the frequency and capacitance value. 展开更多
关键词 MEMRISTOR memristive system crossing point pinched hysteresis loop
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一种基于Cross-Validation的盲图像恢复方法 被引量:1
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作者 康云 《测绘学院学报》 北大核心 2004年第4期259-261,265,共4页
图像盲复原所面临的主要问题是可利用的信息不足,目前已有的图像盲复原算法一般都是有先验知识,如非负和有限支持域的限制。但在实际中目标的支持域是未知的。文中介绍了CV(cross validation)的基本原理,给出了一种基于CV原理的支持域... 图像盲复原所面临的主要问题是可利用的信息不足,目前已有的图像盲复原算法一般都是有先验知识,如非负和有限支持域的限制。但在实际中目标的支持域是未知的。文中介绍了CV(cross validation)的基本原理,给出了一种基于CV原理的支持域确定方法的详细步骤;并针对计算大的问题提出了一定的改进。最后给出了实验结果,证明CV确定支持域的方法对于图像盲复原是有一定价值的。 展开更多
关键词 图像盲复原 点扩散函数 CV(交叉确定)
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Simulation Model of Mechanical Properties of Point - Bonded Nonwovens
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作者 李作攀 储才元 《Journal of China Textile University(English Edition)》 EI CAS 1999年第2期43-45,共3页
A computer model for studying the mechanical properties of point - bonded nonwovens is established. The simulation tensile curve of a nonwoven fabric may be obtained based on relaxation procedure when the mechanical p... A computer model for studying the mechanical properties of point - bonded nonwovens is established. The simulation tensile curve of a nonwoven fabric may be obtained based on relaxation procedure when the mechanical properties of fibers, the arrangement of bond points in the fibrous web and specimen size are inputted into the computer. Relaxation method and relevant algorithms of computer simulation are described in detail. The validity of the model is also demonstrated. 展开更多
关键词 Computer SIMULATION point - BOND Non-wovem MECHANICAL Properties
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GRAPHICAL COMPUTING METHOD ON FOUR-BAR LINKAGE(1)——Inflexion Circle,Focal Axis,Ball's Point,Centering-point Curve and Circling-point Curve For Four ISPs,Coupler Curves Based on Ball's Points——
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作者 周晋康 《苏州大学学报(工科版)》 CAS 1992年第S2期27-34,共8页
By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we... By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points. 展开更多
关键词 Ball’s point centering - point CURVE and CIRCLING CURVE four ISPS Coupler curves based on BALLS points
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Lupaş q-Bézier曲线的离散卷积生成与求值算法
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作者 耿梦圆 解滨 韩力文 《计算机工程与科学》 CSCD 北大核心 2023年第1期104-112,共9页
Lupaşq-Bernstein算子是最早提出的有理形式下基于q-整数的q-模拟Bernstein算子。通过Lupaşq-Bernstein基函数的递推关系反向使用金字塔算法,离散卷积生成n次Lupaşq-Bernstein基函数序列。结合离散卷积满足的交换性,针对n次Lupaşq-B... Lupaşq-Bernstein算子是最早提出的有理形式下基于q-整数的q-模拟Bernstein算子。通过Lupaşq-Bernstein基函数的递推关系反向使用金字塔算法,离散卷积生成n次Lupaşq-Bernstein基函数序列。结合离散卷积满足的交换性,针对n次Lupaşq-Bézier曲线推导出其速端曲线及n!种de Casteljau算法。与Bézier曲线de Casteljau算法得到的切点不同,Lupaşq-Bézier曲线的de Casteljau算法得到的曲线上的一点是直线与曲线相交的2个割点之一。针对二次Lupaşq-Bézier曲线,给出了计算左/右割点的充分必要条件,然后通过提出双割点算法,可以同时得到左/右割点。 展开更多
关键词 离散卷积 速端曲线 de Casteljau算法 割点 交比不变性
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Coupled Fixed Point for (<i>&alpha;</i>, <i>&Psi;</i>)-Contractive in Partially Ordered Metric Spaces Using Compatible Mappings
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作者   Preeti Sanjay Kumar 《Applied Mathematics》 2015年第8期1380-1388,共9页
In this paper, first we introduce notions of (α, Ψ)-contractive and (α)-admissible for a pair of map and prove a coupled coincidence point theorem for compatible mappings using these notions. Our work extends and g... In this paper, first we introduce notions of (α, Ψ)-contractive and (α)-admissible for a pair of map and prove a coupled coincidence point theorem for compatible mappings using these notions. Our work extends and generalizes the results of Mursaleen et al. [1]. At the end, we will provide an example in support of our result. 展开更多
关键词 Coupled COINCIDENCE point α-ψ-Contractive Mapping Compatible MAPPINGS
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具有交叉扩散项与修正Leslie-Gower反应项的捕食-食饵模型的共存解
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作者 刘梦妍 冯孝周 +1 位作者 程丹丹 王预震 《西安工业大学学报》 CAS 2023年第5期420-429,共10页
为了研究一类具有交叉扩散项与修正Leslie-Gower反应项的捕食-食饵模型在Dirichlet边界条件下平衡态解的共存性,文中利用非线性理论给出了系统的平凡解与半平凡解的稳定性结论,利用最大值原理阐明了捕食-食饵模型共存态解的先验估计,利... 为了研究一类具有交叉扩散项与修正Leslie-Gower反应项的捕食-食饵模型在Dirichlet边界条件下平衡态解的共存性,文中利用非线性理论给出了系统的平凡解与半平凡解的稳定性结论,利用最大值原理阐明了捕食-食饵模型共存态解的先验估计,利用Leray-Schauder度理论及不动点指标理论证明了共存态解存在的充分条件,利用数值模拟实现了一维方程的平衡态解的可视化。研究结果表明:具有交叉扩散项与修正Leslie-Gower反应项的捕食-食饵模型中的参数满足相应的数值时,系统中的两种生物可以共存。 展开更多
关键词 捕食-食饵模型 交叉扩散 不动点指标 数值模拟
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Epidemio-Clinical, Therapeutic and Evolutive Aspects of Pulmonary Embolism in Young Subject in the Cardiology Department in Point “G” Hospital University Center Bamako
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作者 M. Sako S. Sidibé +12 位作者 M. Konaté B. Sonfo N. Diallo M. Diakité C. Thiam A. Keita I. Sangaré H. O. Ba Y. Camara L. Bouaré Y. R. Koumaré S. Coulibaly I. Minta 《Open Journal of Epidemiology》 2020年第4期393-398,共6页
<strong>Objective:</strong> The purpose of this work was to determine the epidemiological, clinical and evolutionary aspects of the pulmonary embolism of the young person in the cardiology department of th... <strong>Objective:</strong> The purpose of this work was to determine the epidemiological, clinical and evolutionary aspects of the pulmonary embolism of the young person in the cardiology department of the University Hospital Center (CHU) Point G in Bamako-Mali. <strong>Methodology:</strong> This was an analytical study from January 01, 2018 to December 31, 2018 in the CHU Point G cardiology department, including all patients hospitalized during this period. <strong>Results:</strong> Of 1379 hospitalized patients, 19 patients were concerned by pulmonary embolism of the young person. The prevalence of pulmonary embolism of the young person was 1.37%. The most affected age group was 21 - 30 (47.4%) of patients. The predominance was female (89.47%) with a gender ratio of 0.11 in favour of women. The average age in the series was 29.79 years with extremes of 16 years and 40 years. Factors predisposing to pulmonary embolism were dominated by peri partum, cardiomyopathy and obesity with 47.3%, 31.57% and 21.1%, respectively. The dominant signs were chest pain and dyspnea in 94.7% and 89.5% of cases respectively. Pulmonary embolism was unlikely in 60.52% according to the Geneva and Wells score simplified. At the thoracic angioscanner, the embolism was bilateral in 52.6% of cases and distal in 36.8% of patients;in 10 patients who performed cardiac ultrasound, pulmonary arterial hypertension (70%), dilation of the right ventricle (20%) and left ventricular dilation (40%). Hyper leucocytosis (47.4%), anemia and low prothrombin rate (TP) (22.2%) were the most found biological abnormalities. More than 2/3 (68.5%) our patients had an intermediate mortality risk according to the PESI (Pulmonary Embolism Severity Index) score. The average hospital stay was 10 days. Hospital mortality was 10.5%. <strong>Conclusion:</strong> The pulmonary embolism of the young person is a frequent, serious and multifactorial pathology and the female sex is most affected especially during peri partum periods, hence the need for preventive measures. Clinical signs are not specific and based on the assessment of clinical probability. Pulmonary angioscanner remains the confirmation review in our context. 展开更多
关键词 Pulmonary Embolism Young Subject 15 - 40 Years CARDIOLOGY point G Hospital
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Variance Reduction Technique for Estimating Value-at-Risk based on the Cross - Entropy
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作者 Mykhailo Pupashenko 《Journal of Mathematics and System Science》 2014年第1期37-48,共12页
Value-at-Risk (VaR) estimation via Monte Carlo (MC) simulation is studied here. The variance reduction technique is proposed in order to speed up MC algorithm. The algorithm for estimating the probability of high ... Value-at-Risk (VaR) estimation via Monte Carlo (MC) simulation is studied here. The variance reduction technique is proposed in order to speed up MC algorithm. The algorithm for estimating the probability of high portfolio losses (more general risk measure) based on the Cross - Entropy importance sampling is developed. This algorithm can easily be applied in any light- or heavy-tailed case without an extra adaptation. Besides, it does not loose in the performance in comparison to other known methods. A numerical study in both cases is performed and the variance reduction rate is compared with other known methods. The problem of VaR estimation using procedures for estimating the probability of high portfolio losses is also discussed. 展开更多
关键词 VALUE-AT-RISK Monte Carlo simulation cross - Entropy method variance reduction importance sampling stratifiedsampling.
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CAS 132-2006 Standard for Flat Panel Display TV Set Installation Service Formulating and Enforcing Main Point Explanation and Analysis
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作者 TCL group, TTE China Business Center Technical Service Depart-ment. 《China Standardization》 2007年第4期26-31,共6页
  CAS 132-2006 formulation background and work courses   Flat panel display technology is maturing alongside the development of science and technology. The prices of flat panel display TV sets are becoming lower ...   CAS 132-2006 formulation background and work courses   Flat panel display technology is maturing alongside the development of science and technology. The prices of flat panel display TV sets are becoming lower and lower. Flat panel display TV sets have begun entering the mainstream and are now the first choice of some consumers when making new TV purchases.Display TV Set Installation Service Point Explanation and AnalysisRepair, Retreat and Change Duty Stipulations. Peculiar use conditions, usage environments, and the practical circumstances of user consumption service requirements, etc., were also taken into account on the basis of extensive investigation, testing, and verification.…… 展开更多
关键词 TV In CAS 132-2006 Standard for Flat Panel Display TV Set Installation Service Formulating and Enforcing Main point Explanation and An
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First assessment of Noise-Equivalent Sigma-Zero in GF3-02 TOPSAR mode with sea surface wind speed retrieval
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作者 Junxin Yang Lihua Zhong +3 位作者 Xinzhe Yuan Xiaochen Wang Bing Han Yuxin Hu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第10期84-96,共13页
Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment mon... Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment monitoring.Given the weak scattering characteristics of the ocean,the system thermal noise superimposed on SAR images has significant interference,especially in cross-polarization channels.Noise-Equivalent Sigma-Zero(NESZ)is a measure of the sensitivity of the radar to areas of low backscatter.The NESZ is defined to be the scattering cross-section coefficient of an area which contributes a mean level in the image equal to the signal-independent additive noise level.For TOPSAR,NESZ exhibits the shape of the SAR scanning gain curve in the azimuth and the shape of the antenna pattern in the range.Therefore,the accurate measurement of NESZ plays a vital role in the application of spaceborne SAR sea surface cross-polarization data.This paper proposes a theoretical calculation method for the NESZ curve in GF3-02 TOPSAR mode based on SAR noise inner calibration data and the imaging algorithm.A method for correcting the error existing in the theoretical curve of NESZ is also proposed according to the relationship between sea surface backscattering and wind speed and the same characteristics of target scattering in the overlapping area of adjacent sub-swaths.According to assessment with wide-swath TOPSAR cross-polarization data,the GF3-02 TOPSAR mode has a very low thermal noise level,which is better than−33 dB at the edge of each beam,and controlled below−38 dB at the center of the beam.The two-dimensional reference curves of the NESZ of each beam are provided to the GF3-02 TOPSAR users.After discussing the relationship between normalized radar cross section(NRCS)and wind speed,we provide a formula for NRCS related to wind speed and radar incidence angle.Compared with the NRCS derived from this formula and the NESZ-subtracted NRCS of SAR images,the bias is−0.0048 dB,the Root Mean Square Error is 1.671 dB and the correlation coefficient is 0.939. 展开更多
关键词 GF3-02 TOPSAR Noise-Equivalent Sigma-Zero(NESZ) cross-POLARIZATION normalized radar cross section(NRCS) sea surface wind
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具有非线性交叉扩散的Lotka-Volterra竞争系统的共存解
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作者 贺子鹏 董亚莹 《吉林大学学报(理学版)》 CAS 北大核心 2023年第3期459-468,共10页
考虑一类齐次Dirichlet边界条件下具有非线性交叉扩散的Lotka-Volterra竞争系统的共存解问题.首先,借助线性算子的谱理论分析该问题平凡解和半平凡解的稳定性;其次,利用正锥上的不动点指数理论给出该问题共存解存在的充分条件.
关键词 竞争模型 交叉扩散 稳定性 不动点指数 共存解
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煤自燃程序升温实验及其在实验教学中的应用
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作者 王刚 杨宝东 +2 位作者 徐浩 孙路路 黄启铭 《实验技术与管理》 CAS 北大核心 2024年第3期225-231,共7页
该文利用程序升温实验系统,对三种氧气浓度(20.9%、10%和7%)所代表的采空区散热带、氧化带、窒息带进行了煤样自燃发火实验,采集了不同温度阶段的气体产物,分析了温度及氧气浓度对气体产物浓度的影响,并对指标气体进行了详细分类和评估... 该文利用程序升温实验系统,对三种氧气浓度(20.9%、10%和7%)所代表的采空区散热带、氧化带、窒息带进行了煤样自燃发火实验,采集了不同温度阶段的气体产物,分析了温度及氧气浓度对气体产物浓度的影响,并对指标气体进行了详细分类和评估。实验结果表明:交叉点温度CPT随着氧气浓度的升高而降低,干空气的交叉点温度为144.6℃,由经验关系计算得到的CPT值与实验数据相差仅6.08%;氧气浓度越高,临界温度越低,所产生的气体浓度越高;CO气体在不同的含氧环境下都是主要的氧化产物,可作为判断煤自燃发火的主要指标,C_(2)H_(4)和C_(3)H_(6)的产生表示煤体进入加速氧化状态,可作为判断煤自燃发火的辅助指标。 展开更多
关键词 煤自燃 程序升温 氧气浓度 交叉点温度 指标体系
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