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六种数值Laplas逆变换方法的评价 被引量:5
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作者 张伟 《佳木斯大学学报(自然科学版)》 CAS 2002年第1期113-117,共5页
就模拟动态响应三种类型的函数 ,对六种不同的数值 Laplas逆变换方法进行了比较 .并针对瞬态响应函数的特点 。
关键词 Laplas变换 瞬态响应函数 变换有效 数值Laplas逆变换 评价 工程计算 拉普拉斯变换
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磁性参数测试中有关失真波形电压测量方法的研究
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作者 黄素娟 冯玉田 +1 位作者 章玉鉴 陈泉林 《上海大学学报(自然科学版)》 CAS CSCD 2002年第4期283-287,共5页
介绍了符合有关国际标准、数字与模拟技术相结合的、性能 /价格比较高的多功能磁性参数自动测试系统 .由于磁化曲线的非线性 ,系统中运用真有效值方法测量失真高频信号的有效值 ,在中速 A/ D转换的基础上利用内插采样技术等效提高数字... 介绍了符合有关国际标准、数字与模拟技术相结合的、性能 /价格比较高的多功能磁性参数自动测试系统 .由于磁化曲线的非线性 ,系统中运用真有效值方法测量失真高频信号的有效值 ,在中速 A/ D转换的基础上利用内插采样技术等效提高数字化速率的方法测量失真波形的峰值和平均值 .文中阐述了磁性参数的测试方法、系统结构。 展开更多
关键词 磁性参数测试 失真波形 电压测量 有效变换 内插采样 磁性材料 A/D转换 数字化速率
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禽流感病毒H5N1血凝素基因适应性进化过程中的关键位点突变规律研究
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作者 彭小川 靳远 +5 位作者 胡明达 周江林 周静 岳俊杰 任洪广 梁龙 《生物技术通讯》 CAS 2019年第1期1-9,共9页
目的:寻找导致禽流感病毒H5N1血凝素(HA)适应性进化的关键突变,建立氨基酸突变评价体系,对突变作用进行评估,印证它们与病毒适应性进化的关联性。方法:计算株频率和枝频率,寻找标记分枝,向根结点回溯寻找HA进化路径上的氨基酸突变。计... 目的:寻找导致禽流感病毒H5N1血凝素(HA)适应性进化的关键突变,建立氨基酸突变评价体系,对突变作用进行评估,印证它们与病毒适应性进化的关联性。方法:计算株频率和枝频率,寻找标记分枝,向根结点回溯寻找HA进化路径上的氨基酸突变。计算各突变位点氨基酸的频率变化、有效变换及高频次突变,基于以上几个因素建立突变评价体系。结果:建立了大规模自动化寻找突变的方法,计算得到HA进化过程中的氨基酸突变435个,通过氨基酸频率图表分析这些突变可以很好地反映病毒适应性进化过程,其中79个突变是有效变换,发生的位点为正选择位点,且多数位点落在HA抗原表位上;29个突变是高频次突变,其中多数也为有效变换,因而与病毒适应性进化密切相关。结论:大规模自动化寻找突变的方法可靠,建立的突变评价体系准确性高,找到的关键突变及位点对实验有很好的指导意义。 展开更多
关键词 禽流感病毒H5N1 血凝素 适应性进化 关键突变 氨基酸频率 有效变换 高频次突变
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多功能噪声报警器设计
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作者 茆文艺 陈可勇 +2 位作者 朱贾峰 陈毅 汤勇明 《电子器件》 CAS 2007年第4期1307-1309,共3页
满足公共环境、普通工厂或家庭噪声检测的基本需要,基于AT89C52单片机核心,并配合有效值变换芯片AD536A、高精度A/D转换芯片AD574A和串口通讯芯片MAX232的使用,给出了整套噪声报警器的软硬件实现.通过对噪声显示、报警、存储和串口通信... 满足公共环境、普通工厂或家庭噪声检测的基本需要,基于AT89C52单片机核心,并配合有效值变换芯片AD536A、高精度A/D转换芯片AD574A和串口通讯芯片MAX232的使用,给出了整套噪声报警器的软硬件实现.通过对噪声显示、报警、存储和串口通信的认真调试与校准,本报警器测量40.5—90.5分贝的噪声时,误差最大不超过0.1分贝,同时报警、数据存储和与PC通信均工作良好,基本符合一般场合需求.系统达到预期的目标,以较低的成本实现了噪声显示、报警、数据存储和串行接口数据通信等多种基本功能. 展开更多
关键词 电子设计 噪声检测 有效变换 串行数据通信
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Exact Solutions to Three-Dimensional Schrodinger Equation with anExponentially Position-Dependent Mass
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作者 CAIChang-Ying RENZhong-Zhou JUGuo-Xing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第6期1019-1022,共4页
For an exponentially position-dependent mass, we obtain the exact solutionsof the three-dimensional Schrodinger equation by using coordinate transformation method for thereference problems with Coulomb potential, Krat... For an exponentially position-dependent mass, we obtain the exact solutionsof the three-dimensional Schrodinger equation by using coordinate transformation method for thereference problems with Coulomb potential, Kratzer potential, and spherically square potential wellof infinite depth, respectively. The explicit expressions for the energy eigenvalues and thecorresponding eigenfunctions of the three systems are presented. 展开更多
关键词 schrodinger equation exact solutions coordinate transformation effectivemass
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An Efficient Algorithm for Query Transformation in Semantic Query Optimization
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作者 何增有 Deng +4 位作者 Shengchun Xu Xiaofei Song Yufu 《High Technology Letters》 EI CAS 2002年第1期32-36,共5页
Semantic query optimization (SQO) is comparatively a recent approach for the transformation of given query into equivalent alternative query using matching rules in order to select an optimal query based on the costs ... Semantic query optimization (SQO) is comparatively a recent approach for the transformation of given query into equivalent alternative query using matching rules in order to select an optimal query based on the costs of executing alternative queries. The key aspect of the algorithm proposed here is that previous proposed SQO techniques can be considered equally in the uniform cost model, with which optimization opportunities will not be missed. At the same time, the authors used the implication closure to guarantee that any matched rule will not be lost. The authors implemented their algorithm for the optimization of decomposed sub-query in local database in Multi-Database Integrator (MDBI), which is a multidatabase project. The experimental results verify that this algorithm is effective in the process of SQO. 展开更多
关键词 Semantic query optimization Implication closure Multidatabase system Predict introduction Predict elimination
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New Exact Solutions for a Class of Nonlinear Coupled Differential Equations
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作者 ZHAOHong GUOJun +1 位作者 BAICheng-Lin HANJi-Guang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期781-786,共6页
More new exact solutions for a class of nonlinear coupled differential equations are obtained by using a direct and efficient hyperbola function transform method based on the idea of the extended homogeneous balance m... More new exact solutions for a class of nonlinear coupled differential equations are obtained by using a direct and efficient hyperbola function transform method based on the idea of the extended homogeneous balance method. 展开更多
关键词 nonlinear couple differential equations new exact solutions hyperbola function transform method
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Study of the Effects of Liquid Lithium Curtain as First Wall on Plasma
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作者 DENGBaiquan HUANGJinhua YANJiancheng PENGLilin 《Southwestern Institute of Physics Annual Report》 2001年第1期41-45,共5页
The final goal of fusion energy research is to make it economically competitive and the cost of electricity (COE) as low as acceptable by the energy market. Therefore the fusion plasma has to be operating with high po... The final goal of fusion energy research is to make it economically competitive and the cost of electricity (COE) as low as acceptable by the energy market. Therefore the fusion plasma has to be operating with high power density and the plasma facing components (PFC), such as first wall and divertor, have to sustain high surface heat load and bombardment with high particle flux. Such rigorous environments consequentially lead to severe damage and erosion of PFC materials. As a result, the lifetime of PFC would be shortened. 展开更多
关键词 液态锂 燃料稀释 有效离子变换 等离子体
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ON EFFECTIVE NON-VANISHING OF WEIL DIVISORS ON ALGEBRAIC SURFACES
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作者 XIEQIHONG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2005年第1期105-110,共6页
The author gives a counterexample and some conclusions for effective non-vanishing of Weil divisors on algebraic surfaces.
关键词 Weil divisors Algebraic surfaces Effective non-vanishing
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Control Strategy Research of a Selective Catalytic Reduction System for Heavy-Duty Application
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作者 王天田 林峰 +2 位作者 胡杰 柯于强 张岳秋 《Journal of Shanghai Jiaotong university(Science)》 EI 2017年第5期577-588,共12页
An AdBlue dosing control strategy of the selective catalytic reduction (SCR) system is developed for a heavy-duty diesel (HDD) engine. The strategy includes a raw emission prediction model, an ammonia (NH3) coverage p... An AdBlue dosing control strategy of the selective catalytic reduction (SCR) system is developed for a heavy-duty diesel (HDD) engine. The strategy includes a raw emission prediction model, an ammonia (NH3) coverage prediction model, a transient heat hysteresis correction algorithm, an NH3 leakage control model for transient operation conditions, and a feedback controller (FBC). FBC has been developed by using mathematical manipulation to change output signal of sensor based on cross-sensitivity of nitrogen oxide (NOx) sensor to NH3. The quantification of control parameters is based on experiments and Nyquist stability criterion. FBC is enabled in most test conditions to satisfy the stability requirements. NOxconversion (DeNOx) efficiency of SCR system is 82.4% in European steady-state cycle (ESC) test and 80.3% in European transient cycle (ETC) test, while the leakage of NH3 is under 10−5volume fraction in average. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany. 展开更多
关键词 Nitrogen oxides Stability criteria
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