期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
卫星重力资料分析的同解法研究及其仿真 被引量:5
1
作者 邹贤才 李建成 +2 位作者 姜卫平 张守建 徐新禹 《测绘学报》 EI CSCD 北大核心 2010年第4期344-348,共5页
对同解法的基本思想和流程进行归纳,研制相应的软件系统。利用模拟的GPS和星间测距数据进行同时确定重力场模型和卫星精密轨道的仿真模拟,验证本文设计思路的可行性和软件系统的可靠性。
关键词 同解法 卫星重力 动力法 高性能计算
下载PDF
卫星精密定轨与重力场建模的同解法 被引量:6
2
作者 邹贤才 衷路萍 李建成 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2016年第7期2413-2423,共11页
现代卫星跟踪卫星重力测量技术显著改善了地球重力场模型的中长波段信号,并拓展了重力场模型在相关科学研究中的应用.同解法作为卫星重力观测数据的主要处理手段之一,国内一直没有实质突破.本文从基本模型和关键技术的分析出发,剖析了... 现代卫星跟踪卫星重力测量技术显著改善了地球重力场模型的中长波段信号,并拓展了重力场模型在相关科学研究中的应用.同解法作为卫星重力观测数据的主要处理手段之一,国内一直没有实质突破.本文从基本模型和关键技术的分析出发,剖析了同解法的特点,特别是在建立同解法与几何法(运动学)定轨、一般动力学方法关系的基础上,给出了一种同解法的实现路线.在已有的精细数据预处理和并行计算研究基础上,结合GRACE卫星的实测飞行数据,在国内首次获得了真实卫星任务数据条件下的同解法结果,并进行了动力法轨道的外部质量检核、卫星非保守力分析、重力场模型的GPS水准检验等.利用卫星激光测距数据检验,卫星精密轨道的径向精度优于2cm,同时建立了质量可靠的卫星重力场模型,充分展示了同解法的优点.数值结果及其分析表明,本文所提的同解法实施方案合理可行,已经掌握了实现同解法的关键技术,获得了从仿真研究到实际飞行数据处理的新进展.最后,本文对同解法今后的发展思路,以及如何进一步挖掘同解法的潜力,提出了见解和今后的工作方向. 展开更多
关键词 卫星重力 同解法 加速度计校准 GRACE 动力法
下载PDF
07年一道高考题的解法探究
3
作者 刘晓东 《上海中学数学》 2007年第12期30-31,共2页
  07年数学高考浙江文科卷第22题不仅有较强的选拔功能,更是我们教与学的典型范例,下面让我们一起来探究本题.……
关键词 高考题 数形结合 同解法 单调函数
下载PDF
数理结合,三法解赛题 被引量:1
4
作者 金彪 《数理天地(高中版)》 2007年第2期37-38,共2页
题从赤道上的 C 点发射洲际导弹,使之精确地击中北极点 N,要求发射所用的能量最少.假定地球是质量均匀分布的半径为 R 的球体,R=6400km.已知质量为 m 的物体在地球引力作用下做椭圆运动时,其能量 E
关键词 初速度 地球引力 半长轴 同解法
下载PDF
八法求解一道联赛题
5
作者 李勇 《数理天地(高中版)》 2021年第10期34-35,共2页
题目数列{a_(n)}满足a_(1)=2,a_(n+1)=2(n+2)/n+1a_(n)(n∈N^(*)),则a_(2014)/a_(1)+a_(2)+…+a_(2013)=__.(2014年全国联赛)解法1累乘法由a_(n+1)=2(n+2)/n+1 a_(n),得a_(n+1)/a_(n)=2×n+2/n+1.
关键词 同解法 常数数列
下载PDF
Joint eigenvalue estimation by balanced simultaneous Schur decomposition
6
作者 付佗 高西奇 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期445-450,共6页
The problem of joint eigenvalue estimation for the non-defective commuting set of matrices A is addressed. A procedure revealing the joint eigenstructure by simultaneous diagonalization of. A with simultaneous Schur d... The problem of joint eigenvalue estimation for the non-defective commuting set of matrices A is addressed. A procedure revealing the joint eigenstructure by simultaneous diagonalization of. A with simultaneous Schur decomposition (SSD) and balance procedure alternately is proposed for performance considerations and also for overcoming the convergence difficulties of previous methods based only on simultaneous Schur form and unitary transformations, it is shown that the SSD procedure can be well incorporated with the balancing algorithm in a pingpong manner, i. e., each optimizes a cost function and at the same time serves as an acceleration procedure for the other. Under mild assumptions, the convergence of the two cost functions alternately optimized, i. e., the norm of A and the norm of the left-lower part of A is proved. Numerical experiments are conducted in a multi-dimensional harmonic retrieval application and suggest that the presented method converges considerably faster than the methods based on only unitary transformation for matrices which are not near to normality. 展开更多
关键词 direction of arrival multi-dimensional harmonic retrieval joint eigenvalue simultaneous Schur decomposition balance algorithm
下载PDF
All Single Traveling Wave Solutions to (3+1)-Dimensional Nizhnok-Novikov-Veselov Equation 被引量:12
7
作者 LIU Cheng-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第6期991-992,共2页
Using elementary integral method, a complete classification of all possible exact traveling wave solutions to (3+1)-dimensional Nizhnok-Novikov-Veselov equation is given. Some solutions are new.
关键词 (3+1)-dimensional Nizhnok-Novikov-Veselov equation traveling wave solution elementary integral method
下载PDF
Chaotic pulse position modulation ultra-wideband system based on particle filtering 被引量:1
8
作者 李辉 Zhang Li 《High Technology Letters》 EI CAS 2013年第1期48-52,共5页
Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error p... Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error propagation.Mismatch of parameters and synchronization error between the receiver and transmitter will arouse high bit error rate.To solve these problems,a demodulation algorithm of CPPM based on particle filtering is proposed.According to the mathematical model of the system,it tracks the real signal by online separation in demodulation.Simulation results show that the proposed method can track the true signal better than the traditional CPPM scheme.What's more,it has good synchronization robustness,reduced error propagation by wrong decision and low bit error rate. 展开更多
关键词 chaotic communications chaotic pulse position modulation (CPPM) particle filtering ULTRA-WIDEBAND
下载PDF
Simultaneous (M,N) Singular Value Decomposition of Matrices
9
作者 刘晓冀 《Northeastern Mathematical Journal》 CSCD 2007年第6期471-478,共8页
A necessary and sufficient condition for the existence of simultaneous (M,N)singular value decomposition of matrices is given.Some properties about the weighted partial ordering are discussed with the help of the deco... A necessary and sufficient condition for the existence of simultaneous (M,N)singular value decomposition of matrices is given.Some properties about the weighted partial ordering are discussed with the help of the decomposition. 展开更多
关键词 simultaneous (M N) singular value decomposition weighted general-ized inverse weighted star-partial ordering
下载PDF
On an Auto-Baecklund Transformation for (2+1)-Dimensional VariableCoefficient Generalized KP Equations and Exact Solutions 被引量:1
10
作者 BAICheng-Jie BAICheng-Lin +1 位作者 HANJi-Guang ZHAOHong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4期677-680,共4页
By the application of the extended homogeneous balance method, we derive anauto-Backlund transformation (BT) for (2+1)-dimensional variable coefficient generalized KPequations. Based on the BT, in which there are two ... By the application of the extended homogeneous balance method, we derive anauto-Backlund transformation (BT) for (2+1)-dimensional variable coefficient generalized KPequations. Based on the BT, in which there are two homogeneity equations to be solved, we obtainsome exact solutions containing single solitary waves. 展开更多
关键词 extended homogeneous balance method (2+1)-dimensional variable coefficientgeneralized KP equation auto-Baecklund transformation exact solutions
下载PDF
一道希望杯赛题的解法与推广
11
作者 玉炳图 《数理化学习(高中版)》 2015年第3期5-6,共2页
2014年第25届希望杯赛高二第二试第9题:在平面直角坐标系x Oy中,△ABC的两个顶点A(3,0),B(0,4),若顶点C在抛物线y2=-2x上,则△ABC面积的最小值是()(A) 87/16 (B)178/16(C)217/16(D)435/16培养数学思维能力是多方面和多层次的,在数学的... 2014年第25届希望杯赛高二第二试第9题:在平面直角坐标系x Oy中,△ABC的两个顶点A(3,0),B(0,4),若顶点C在抛物线y2=-2x上,则△ABC面积的最小值是()(A) 87/16 (B)178/16(C)217/16(D)435/16培养数学思维能力是多方面和多层次的,在数学的教与学中,我们既要重视培养善于抽象概括的"求同"思维,又要重视培养开阔发散的"求异"思维,还要重视培养大胆求变的"创新"思维,一题多解和对数学问题推广研究是培养这些思维能力的有效途径,下面对上述问题进行多方面的思考。 展开更多
关键词 同解法 最小值 抛物线 参数方程 切线方程 距离公式
原文传递
一道高考题的多种解法
12
作者 王荣峰 《中学生数学(高中版)》 2019年第6期50-50,49,共2页
问题在△ABC中,角A,B,C所对的边分别是a,b,c,∠ABC=120°,∠ABC的平分线交AC于D,且BD=1,则4a+c的最小值为______.该题为2018年高考江苏省理科试卷第13题,虽然只是一道填空题,但其内涵却特别丰富,入手点比较宽,交汇性比较强,解该题... 问题在△ABC中,角A,B,C所对的边分别是a,b,c,∠ABC=120°,∠ABC的平分线交AC于D,且BD=1,则4a+c的最小值为______.该题为2018年高考江苏省理科试卷第13题,虽然只是一道填空题,但其内涵却特别丰富,入手点比较宽,交汇性比较强,解该题的关键在于寻找出a,c的关系,下面给出几种解法,以期能对大家的学习有所启发. 展开更多
关键词 余弦定理 AD 正弦定理 同解法
原文传递
A novel current vector decomposition controller design for six-phase permanent magnet synchronous motor
13
作者 袁雷 胡冰新 +1 位作者 魏克银 林莹 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第4期841-849,共9页
The vector control algorithm based on vector space decomposition (VSD) transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a cu... The vector control algorithm based on vector space decomposition (VSD) transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a current vector decoupling control algorithm for six-phase permanent magnet synchronous motor (PMSM) is designed. Using the proposed synchronous rotating coordinate transformation matrix, the fundamental and harmonic components in d-q subspace are changed into direct current (DC) component, only using the traditional proportional integral (PI) controller can meet the non-static difference adjustment, and the controller parameter design method is given by employing intemal model principle. In addition, in order to remove the 5th and 7th harmonic components of stator current, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific harmonic component compensation. Simulation results verify the effectiveness of current decoupling vector controller. 展开更多
关键词 six-phase PMSM current vector decomposition internal control resonant control
下载PDF
高考应用题解法探索——以2018年江苏高考第17题为例
14
作者 邱红英 吴海军 《高考》 2019年第11期236-237,共2页
历年来,高考应用题让考生们既爱又恨,由于难易适中,得之,可以满载而归,不得,甚至颗粒无收。那么,解数学应用题究竟难在什么地方呢?经笔者调查发现很多不会解应用题的学生遇到的主要困难是读不懂题,他们因为缺乏试题背景的那种生活经验,... 历年来,高考应用题让考生们既爱又恨,由于难易适中,得之,可以满载而归,不得,甚至颗粒无收。那么,解数学应用题究竟难在什么地方呢?经笔者调查发现很多不会解应用题的学生遇到的主要困难是读不懂题,他们因为缺乏试题背景的那种生活经验,弄不懂那些比较复杂的实际背景,最后不得不放弃。那么如何帮助学生克服上述困难,正确的解答应用题呢?显然,让学生去一一具备试题背景中的生活经验是根本不现实的,在这种情况下应通过什么样的方式让学生克服这个困难呢?要解决这个问题得从高考数学应用题本身具有的特征来进行分析. 展开更多
关键词 江苏高考 总产值 BC 高考应用题 数学应用题 单位面积产值 CDP MN 取值范围 同解法
原文传递
“希望杯”一赛题的多解
15
作者 周天明 《中学生数学(高中版)》 2015年第11期33-33,32,共2页
关键词 函数值域 三角函数 数形结合 同解法 分式函数
原文传递
深入研究 多解一道例题 被引量:2
16
作者 蒋晓东 郭文征 《中学生数学》 2020年第8期4-6,共3页
近日阅读贵刊2018年3月下,周春荔教授的几何专题讲座《圆的基本问题(下)》,其中的例题20引发笔者的兴趣.原例题如下:如图1,△ABC中,AB=BC,∠ABC=20°,在AB上取一点M,使得BM=AC.求∠AMC的度数.解答中首先以BC为边在△ABC外作正△KBC... 近日阅读贵刊2018年3月下,周春荔教授的几何专题讲座《圆的基本问题(下)》,其中的例题20引发笔者的兴趣.原例题如下:如图1,△ABC中,AB=BC,∠ABC=20°,在AB上取一点M,使得BM=AC.求∠AMC的度数.解答中首先以BC为边在△ABC外作正△KBC,如何想出作正△KBC;其次,怎么顺势连接KM,而能利用点B、M、C在以K为圆心. 展开更多
关键词 外接圆 九边形 BCM 正三角形 DBC 等腰三角形 同解法 BDM
原文传递
高二数学测试
17
作者 佟成军 《高中数学教与学》 2011年第1期27-30,共4页
关键词 等比数列 取值范围 同解法 恒成立 通项公式
原文传递
一道解析题中的求异思维
18
作者 王海容 《中学生数理化(教与学)》 2011年第5期86-86,共1页
所谓求异思维是一种不依常规、寻求变异、从多方面探索答案的思维形式.又称为发散思维.用求异思维解题,有利于培养思维的多向性、灵活性和独特性.解题时,若能变换思维角度,多方位思考,多渠道辟径,就会超过思维障碍.现就一道高考题的多... 所谓求异思维是一种不依常规、寻求变异、从多方面探索答案的思维形式.又称为发散思维.用求异思维解题,有利于培养思维的多向性、灵活性和独特性.解题时,若能变换思维角度,多方位思考,多渠道辟径,就会超过思维障碍.现就一道高考题的多种解法加以说明. 展开更多
关键词 求异思维 三角函数 同解法
原文传递
Simulation and study on mitigation measures of frequent subsynchronous oscillation with low amplitude at multi-power plants 被引量:13
19
作者 XIAO XiangNing ZHANG Jian +4 位作者 GAO BenFeng WU YunSheng LUO Chao GUO ChunLin YANG Lin 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第6期1340-1353,共14页
Subsynchronous oscillation (SSO) with low amplitude that exceeds cumulative fatigue threshold of the generator shaft frequently could significantly reduce the shaft's service life, which is a new SSO problem that ... Subsynchronous oscillation (SSO) with low amplitude that exceeds cumulative fatigue threshold of the generator shaft frequently could significantly reduce the shaft's service life, which is a new SSO problem that emerges in recent years. According to the real recording oscillograph, the basic reason for frequently over-threshold SSO with low amplitude at multi-power plants was analyzed based on Hulunbuir League system. The sensitivities of the electrical damping to the main electrical parameters in the contributing loop of subsynchronous torsional interaction were calculated. Based on the sensitivities, a simulation method was presented, which was used to excite the same oscillation as the actual case by exerting disturbance on the firing angle. The limitation of wide-band and narrow-band supplementary subsynchronous damping controller (SSDC) for mitigating this kind of SSO was analyzed based on the electromagnetic transient simulation model of Hulunbuir League system. The difference of supplementary excitation damping controller (SEDC) and parallel-form FACTS connected to the generator terminal was compared from the aspects of response time and the ability of damping torque supplying. The analysis indicates that their response time is similar but FACTS has stronger ability of damping torque supplying than SEDC. Time-domain simulation method was used to compare the mitigation effects of SEDC, static var compensator (SVC) and static synchronous compensator (STATCOM). Considering the mitigation effect, the floor space limit of the power plant and so on, STATCOM was considered as the best mitigation measure. A control strategy of cascaded STATCOM for engineering application was presented and the capacity for SSO mitigation as well as output characteristics was analyzed. The analysis indicates that STATCOM using the proposed control strategy has better mitigation effect and output characteristics with smaller capacity. 展开更多
关键词 subsynchronous oscillation high voltage direct current (HVDC) cumulative fatigue sensitivity mitigation measure
原文传递
Analytical Solutions of a Model for Brownian Motion in the Double Well Potential
20
作者 刘爱洁 郑连存 +1 位作者 马连喜 张欣欣 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第1期51-56,共6页
In this paper, the analytical solutions of Schrodinger equation for Brownian motion in a double well potential are acquired by the homotopy analysis method and the Adomian decomposition method. Double well potential f... In this paper, the analytical solutions of Schrodinger equation for Brownian motion in a double well potential are acquired by the homotopy analysis method and the Adomian decomposition method. Double well potential for Brownian motion is always used to obtain the solutions of Fokker-P1anck equation known as the Klein-Kramers equation, which is suitable for separation and additive Hamiltonians. In essence, we could study the random motion of Brownian particles by solving Schr6dinger equation. The anaiytical results obtained from the two different methods agree with each other well The double well potentiai is affected by two parameters, which are analyzed and discussed in details with the aid of graphical illustrations. According to the final results, the shapes of the double well potential have significant influence on the probability density function. 展开更多
关键词 Brown motion homotopy analysis method Schrodinger equation double well potential
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部