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第6届巴尔干数学竞赛试题及解答
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作者 单墫 刘亚强 《中等数学》 北大核心 1990年第5期32-33,共2页
关键词 竞赛试题 整系数多项式 子集族 正整数 元灵 刘亚强 十进 题设 中京 南京师大
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Shape Optimization With Sensitivity Analysis in Local Domain 被引量:3
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作者 左正兴 蔡坪 《Journal of Beijing Institute of Technology》 EI CAS 1993年第2期127-133,共7页
For complicated geometries, it is ineflicient to integrate over the entire domain. A new approach for optimization is presented here, based on sensitivity analysis of local do- main and deformation of full domain. Acc... For complicated geometries, it is ineflicient to integrate over the entire domain. A new approach for optimization is presented here, based on sensitivity analysis of local do- main and deformation of full domain. Accurate results of design sensitivity analysis are ob- tained with this approach in shape optimization. This method is shown to be efficient when used in optimization programs and results in less distortion of the mesh. 展开更多
关键词 finite element methods structural optimization sensitivity/ velocity field material derivatives
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细嚼品味 开拓前进——“首届国际暨第二届海峡两岸蜂疗高峰论坛”有感
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作者 王金庸 《中国蜂业》 2013年第7X期32-34,共3页
2013年5月25日,"首届国际暨第二届海峡两岸蜂疗高峰论坛"于福州隆重开幕。与会,嘉宾如云,盛友集聚,欧亚专家,台湾学者,国内蜂业领导,福建农林大学相关领导,两岸蜂疗科技人才,欢聚一堂,促膝交流,成果丰硕,喜气洋洋。参与蜂疗... 2013年5月25日,"首届国际暨第二届海峡两岸蜂疗高峰论坛"于福州隆重开幕。与会,嘉宾如云,盛友集聚,欧亚专家,台湾学者,国内蜂业领导,福建农林大学相关领导,两岸蜂疗科技人才,欢聚一堂,促膝交流,成果丰硕,喜气洋洋。参与蜂疗高端论坛,收益颇丰,且不说会议盛况,亦不论花絮朵朵,仅就蜂疗学术水平,做以分析。会议交流,匆匆而过,细阅会议《论文集》,领略当今蜂疗实况,可谓发展迅速,成果累累。就诸篇蜂疗文章而论,能看出当今蜂疗的特点与趋向,故作如下分析。 展开更多
关键词 蜂疗 海峡两岸 蜂毒肽 会议交流 开拓前进 蜂业 元灵 衰老小鼠 巴西蜂胶 治疗作用
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Finite Element Simulation of the Vibratory Characteristics for Quartz Tuning Fork Gyroscope 被引量:2
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作者 王莹 孙雨南 秦秉坤 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期155-158,共4页
The micro quartz crystal tuning fork gyroscope is a new type of vibratory gyroscope. The gyroscope should be analyzed and simulated early in the design stage in order to offer reliable basis for design and to shorten ... The micro quartz crystal tuning fork gyroscope is a new type of vibratory gyroscope. The gyroscope should be analyzed and simulated early in the design stage in order to offer reliable basis for design and to shorten the period of development. Thus the vibratory characteristics of the gyroscope is simulated with the finite element method of coupled field. The optimum exciting frequency and the factors which influence the gyroscope sensitivity are determined. The method for adjusting the frequency deviation between driving and detecting modes is also proposed. 展开更多
关键词 quartz gyroscope tuning fork finite element method
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APPROXIMATION TECHNIQUES FOR APPLICATION OF GENETIC ALGORITHMS TO STRUCTURAL OPTIMIZATION 被引量:1
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作者 金海波 丁运亮 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期147-154,共8页
Although the genetic algorithm (GA) has very powerful robustness and fitness, it needs a large size of population and a large number of iterations to reach the optimum result. Especially when GA is used in complex str... Although the genetic algorithm (GA) has very powerful robustness and fitness, it needs a large size of population and a large number of iterations to reach the optimum result. Especially when GA is used in complex structural optimization problems, if the structural reanalysis technique is not adopted, the more the number of finite element analysis (FEA) is, the more the consuming time is. In the conventional structural optimization the number of FEA can be reduced by the structural reanalysis technique based on the approximation techniques and sensitivity analysis. With these techniques, this paper provides a new approximation model-segment approximation model, adopted for the GA application. This segment approximation model can decrease the number of FEA and increase the convergence rate of GA. So it can apparently decrease the computation time of GA. Two examples demonstrate the availability of the new segment approximation model. 展开更多
关键词 approximation techniques segment approximation model genetic algorithms structural optimization sensitivity analysis
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Dynamic probabilistic analysis of stress and deformation for bladed disk assemblies of aeroengine 被引量:3
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作者 白斌 白广忱 《Journal of Central South University》 SCIE EI CAS 2014年第10期3722-3735,共14页
In order to describe and control the stress distribution and total deformation of bladed disk assemblies used in the aeroengine, a highly efficient and precise method of probabilistic analysis which is called extremum... In order to describe and control the stress distribution and total deformation of bladed disk assemblies used in the aeroengine, a highly efficient and precise method of probabilistic analysis which is called extremum response surface method(ERSM) is produced based on the previous deterministic analysis results with the finite element model(FEM). In this work, many key nonlinear factors, such as the dynamic feature of the temperature load, the centrifugal force and the boundary conditions, are taken into consideration for the model. The changing patterns with time of bladed disk assemblies about stress distribution and total deformation are obtained during the deterministic analysis, and at the same time, the largest deformation and stress nodes of bladed disk assemblies are found and taken as input target of probabilistic analysis in a scientific and reasonable way. Not only their reliability, historical sample, extreme response surface(ERS) and the cumulative probability distribution function but also their sensitivity and effect probability are obtained. Main factors affecting stress distribution and total deformation of bladed disk assemblies are investigated through the sensitivity analysis of the model. Finally, compared with the response surface method(RSM) and the Monte Carlo simulation(MCS), the results show that this new approach is effective. 展开更多
关键词 bladed disk assemblies probabilistic analysis finite element model extremum response surface method sensitivity analysis transient dynamic analysis
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A novel fully-integrated miniature six-axis force/torque sensor 被引量:5
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作者 王嘉力 Xie Zongwu +2 位作者 Liu Hong Jiang Li Gao Xiaohui 《High Technology Letters》 EI CAS 2006年第3期235-238,共4页
This paper presents a new designed miniature six DOF (degree of freedom) force/torque sensor. This sensor is fully integrated with a micro DSP (digital signal processor), so all the signal conditioning, A/D, decou... This paper presents a new designed miniature six DOF (degree of freedom) force/torque sensor. This sensor is fully integrated with a micro DSP (digital signal processor), so all the signal conditioning, A/D, decoupling, digital-signals serial output are performed in the sensor. Some experimental results are presented to demonstrate the capability of the proposed design. Finally, a neural network was used for decoupling the interacting signals, compared with the conventional method using the inverse matrix, this new method is more accurate. 展开更多
关键词 six-axis force sensor sensing element CALIBRATION neural network
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Enumeration Order Equivalence in Rational Numbers
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作者 Saeed Asaeedi Farzad Didehvar Aliakbar Safilian 《Computer Technology and Application》 2013年第11期615-619,共5页
The enumeration of elements of c.e. sets in the theory of computability and computational complexity has already been investigated. However, the order of this enumeration has received less attention. The enumeration o... The enumeration of elements of c.e. sets in the theory of computability and computational complexity has already been investigated. However, the order of this enumeration has received less attention. The enumeration orders of elements of c.e. sets by means of Turing machines on natural numbers are investigated. In this paper, we consider the enumeration orders of elements of c.e. sets on rational numbers. We present enumeration order reducibility and enumeration order equivalence on rational numbers and propose some lemmas and theorems on these concepts. Also, we show that the theories here hold for Rc and we could repeat the same theories in this domain, in a same way. 展开更多
关键词 Turing machine LISTINGS enumeration order reducibility enumeration order equivalence
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STUDY ON DETERMINATION OF TRACE Cu(Ⅱ) BY DDCT CHELATING RESIN PRECONCENTRATION AND THIN LAYER RESIN PHASE SPECTROPHOTOMETRY
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作者 LI Chunxiang YAN Yongsheng +1 位作者 SONG Huanyu WANG Yun 《Chinese Journal of Reactive Polymers》 2006年第2期161-166,共6页
A new method for determination of Cu(Ⅱ) by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity (ε455= 3.6×10^5L/mol·cm), ... A new method for determination of Cu(Ⅱ) by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity (ε455= 3.6×10^5L/mol·cm), which is 33 times higher than that of liquid phase spectrophotometry. It has a good selectivity (most coexisting ions could not influence determination) and an ideal precision [30μg Cu(Ⅱ), n=6, RSD= l.67%]. The content of Cu(Ⅱ) in water, high purity rare earth and its oxide was determined. The detection limit of Cu(Ⅱ) is 5.3μg/L , and the linear range is 0-7.2μg/ml. The result is satisfactory. 展开更多
关键词 Chelating resin PRECONCENTRATION Thin layer resin phase spectrophotometry TRACE Cu(Ⅱ)
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microRNAs and Alu elements in the p53-Mdm2-Mdm4 regulatory network 被引量:2
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作者 Yonit Hoffman Yitzhak Pilpel Moshe Oren 《Journal of Molecular Cell Biology》 SCIE CAS CSCD 2014年第3期192-197,共6页
p53 is a transcription factor that governs numerous stress response pathways within the ceil. Maintaining the right levels of p53 is crucial for ceil survival and proper cellular homeostasis, The tight regulation of p... p53 is a transcription factor that governs numerous stress response pathways within the ceil. Maintaining the right levels of p53 is crucial for ceil survival and proper cellular homeostasis, The tight regulation of p53 involves many cellular components, most notably its major negative regulators Mdm2 and Mdm4, which maintain p53 protein amount and activity in tight check, microRNAs (miRNAs) are small non-coding RNAs that target specific mRNAs to translational arrest and degradation, miRNAs are also key compo- nents of the normal p53 pathway, joining forces with Mdm2 and Mdm4 to maintain proper p53 activity. Here we review the current knowledge of miRNAs targeting Mdm2 and Mdm4, and their importance in different tissues and in pathological states such as cancer. In addition, we address the role of Alu sequences-highly abundant retroelements spread throughout the human genome, and their impact on gene regulation via the miRNA machinery. Aius occupy a significant portion of genes' 31UTR, and as such they have the potential to impact mRNA regulation. Since Alus are primate-specific, they introduce a new regulatory layer into primate genomes. Atus can influence and alter gene regulation, creating primate-specific cancer-preventive regulatory mechanisms to sustain the transition to longer life span in primates. We review the possible influence of Alu sequences on miRNA functionality in general and specifically within the p53 network. 展开更多
关键词 MICRORNA P53 MDM2 Mdm4 ALU
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Design and Optimization of Index-Guiding Photonic Crystal Fiber Gas Sensor 被引量:3
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作者 Saeed OLYAEE Alieh NARAGHI 《Photonic Sensors》 SCIE EI CAS 2013年第2期131-136,共6页
An index guiding photonic crystal fiber used in gas sensing applications is presented. The dependency of the confinement loss and relative sensitivity on the fiber parameters and wavelength is numerically investigated... An index guiding photonic crystal fiber used in gas sensing applications is presented. The dependency of the confinement loss and relative sensitivity on the fiber parameters and wavelength is numerically investigated by using the full-vectorial finite element method (FEM). The simulations showed that the gas sensing sensitivity increased with an increase in the core diameter and a decrease in the distance between centers of two adjacent holes. Increasing the hole size of two outer cladding rings, this structure simultaneously showed up to 10% improved sensitivity, and the confinement loss reached 6x 10-4 times less than that of the prior sensor at the wavelength of 1.5 μm. This proved the ability of this fiber used in gas and chemicals sensing applications. 展开更多
关键词 Confinement loss evanescent field gas sensor relative sensitivity photonic crystal fiber
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Anthropic considerations in nuclear physics
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作者 Ulf-G.Meiner 《Science Bulletin》 SCIE EI CAS CSCD 2015年第1期43-54,共12页
In this short review, I discuss the sensitivity of the generation of the light and the life-relevant elements such as carbon and oxygen under changes of the parame- ters of the Standard Model pertinent to nuclear phys... In this short review, I discuss the sensitivity of the generation of the light and the life-relevant elements such as carbon and oxygen under changes of the parame- ters of the Standard Model pertinent to nuclear physics. Chiral effective field theory allows for a systematic and precise description of the forces between two, three and four nucleons. In this framework, variations under the light quark masses and the electromagnetic fine-structure constant can also be consistently calculated. Combining chiral nuclear effective field theory with Monte Carlo simulations allows to further calculate the properties of nuclei, in particular of the Hoyle state in carbon, that plays a crucial role in the gener- ation of the life-relevant elements in hot, old stars. The dependence of the triple-alpha process on the fundamental constants of nature is calculated, and some implications for our anthropic view of the Universe are discussed. 展开更多
关键词 Anthropic principle Nuclear physics Effective field theory
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