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Polarization and phase control of two-photon absorption in an isotropic molecular system 认领 引用 被引量：1
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作者 卢晨晖 张晖 +1 位作者 张诗按 孙真荣 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第12期187-190,共4页
We theoretically and experimentally study the polarization and phase control of two-photon absorption in an isotropic molecular system. We theoretically show that the two-photon transition probability decreases when t... We theoretically and experimentally study the polarization and phase control of two-photon absorption in an isotropic molecular system. We theoretically show that the two-photon transition probability decreases when the laser polarization changes from linear through elliptical to circular, and the laser polarization does not affect the control efficiency of two-photon transition probability by shaping the spectral phase. These theoretical results are experimentally confirmed in coumarin 480. Furthermore, we propose that the combination of the laser polarization with the spectral phase modulation can further increase the control efficiency of the two-photon absorption. 展开更多
关键词 two-photon absorption laser polarization spectral phase modulation
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Chaining Distributed Geographic Information Web Services Based on Ontology 认领 引用 被引量：2
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作者 WU Shanming SHEN Jianjing 《Wuhan University Journal of Natural Sciences》 CAS 2008年第4期401-406,共6页
To solve the problem of chaining distributed geographic information Web services （GI Web services）, this paper provides an ontology-based method. With this method, semantic service description can be achieved by sem... To solve the problem of chaining distributed geographic information Web services （GI Web services）, this paper provides an ontology-based method. With this method, semantic service description can be achieved by semantic annotation of the elements in a Web service description language（WSDL） document with concepts of geographic ontology, and then a common under-standing about service semantics between customers and providers of Web services is built. Based on the decomposition and formalization of customer requirements, the discovery, composition and execution of GI Web services are explained in detail, and then a chaining of GI Web services is built and used to achieve the customer＇s requirement. Finally, an example based on Web ontology language for service （OWL-S） is provided for testing the feasibility of this method. 展开更多
关键词 Web service geographic information Web services ontology description logic Web ontology langugae （OWL）
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Iterative Solution of Regularization to Ill-conditioned Problems in Geodesy and Geophysics 认领 引用 被引量：6
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作者 Yongwei GU Qingming GUI +1 位作者 Xuan ZHANG Songhui HAN 《Journal of Geodesy and Geoinformation Science》 2019年第1期59-65,共7页
In geodesy and geophysics,many large-scale over-determined linear equations need to be solved which are often ill-conditioned.When the conjugate gradient method is used,their ill-conditioning effects to the solutions ... In geodesy and geophysics,many large-scale over-determined linear equations need to be solved which are often ill-conditioned.When the conjugate gradient method is used,their ill-conditioning effects to the solutions must be overcome,which is studied in this paper.Through the regularization ideas,the conjugate gradient method is improved,and the regularization iterative solution based on controlling condition number is put forward.Firstly by constructing the interference source vector,a new equation is derived with ill-condition diminished greatly,which has the same solution to the original normal equation.Then the new equation is solved by conjugate gradient method.Finally the effectiveness of the new method is verified by some numerical experiments of airborne gravity downward to the earth surface.In the numerical experiments the new method is compared with LS,CG and Tikhonov methods,and its accuracy is the highest. 展开更多
关键词 ill-condition regularization condition number interference source vector iteration
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Researches on Countermeasures and the Status Quo of Agricultural Industrialized Cluster in Henan Province 认领 引用 被引量：3
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作者 ZHAO Yu-lian 《Asian Agricultural Research》 2010年第11期26-29,33,共4页
On the basis of the introduction of the connotation of agricultural industrialized cluster,the thesis introduces the competitive advantages of agricultural industrialized cluster as follows:firstly,it makes the agricu... On the basis of the introduction of the connotation of agricultural industrialized cluster,the thesis introduces the competitive advantages of agricultural industrialized cluster as follows:firstly,it makes the agricultural production factors cluster and curtails the agricultural production costs;secondly it enhances the innovation abilities of industries;thirdly it improves the urbanization level of rural areas and increases farmers'income.The thesis also analyzes the status quo of agricultural industrialized cluster in Henan Province,points out the advantages of resources,cost,location and so on,and discuses the existing problems of the agricultural industrialized cluster in Henan Province as follows:firstly,the scale of agricultural industrialized cluster is small and the industrialized chain is short;secondly,there is a shortage of leading enterprises,and the radiating effect within industrialized cluster is not prominent;thirdly,the organization degree of agricultural industrialized cluster is weak,lacking scientific innovation ability.In order to solve the existing problems,the corresponding countermeasures are put forward as follows:firstly,take the market as the orientation,strengthen the policies formulation and accelerate the development of agricultural industrialized cluster in Henan by leaps and bounds;secondly,choose suitable developing models of agricultural industrialized cluster. 展开更多
关键词 Agricultural industrialized cluster Industrialized chains Leading enterprises Henan Province China
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A Mathematical Interpretation of Hawking’s Black Hole Theory by Ricci Flow 认领 引用
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作者 Qiaofang Xing Xiang Gao 《Journal of Applied Mathematics and Physics》 2017年第2期321-328,共8页
In this paper, using Perelman’s no local collapsing theorem and the geometric interpretation of Hamilton’s Harnack expressions along the Ricci flow introduced by R. Hamilton, we present a mathematical interpretation... In this paper, using Perelman’s no local collapsing theorem and the geometric interpretation of Hamilton’s Harnack expressions along the Ricci flow introduced by R. Hamilton, we present a mathematical interpretation of Hawking’s black hole theory in [1]. 展开更多
关键词 Black Hole Ricci Flow No Local Collapsing Theorem Uncertainty Principle Harnack Expression
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Universally Composable Three Party Password-based Key Exchange Protocol 认领 引用 被引量：5
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作者 Deng Miaolei Ma Jianfeng Le Fulong 《China Communications》 SCIE 2009年第3期150-155,共6页
Within the framework of universal composability,an appropriate ideal functionality that captures the basic security requirements of three party password-based key exchange was defined. An efficient real-word three par... Within the framework of universal composability,an appropriate ideal functionality that captures the basic security requirements of three party password-based key exchange was defined. An efficient real-word three party password-based key exchange protocol was also proposed.This protocol securely realizes the ideal functionality with respect to static party corruption.Thus it provides security guarantees under arbitrary composition with other protocols. 展开更多
关键词 Diffie-Hellman attack key exchange universally composable protocol security
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Up-conversion luminescence polarization control in Er3+-doped NaYF_4 nanocrystals 认领 引用 被引量：1
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作者 张晖 姚云华 +2 位作者 张诗按 卢晨晖 孙真荣 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期123-128,共6页
We propose a femtosecond laser polarization modulation scheme to control the up-conversion（UC） luminescence in Er^（3＋）-doped NaYF_4 nanocrystals dispersed in the silicate glass. We show that the UC luminescence c... We propose a femtosecond laser polarization modulation scheme to control the up-conversion（UC） luminescence in Er^（3＋）-doped NaYF_4 nanocrystals dispersed in the silicate glass. We show that the UC luminescence can be suppressed when the laser polarization is changed from linear through elliptical to circular, and the higher repetition rate will yield the lower control efficiency. We theoretically analyze the physical control mechanism of the UC luminescence polarization modulation by considering on- and near-resonant two-photon absorption, energy transfer up-conversion, and excited state absorption, and show that the polarization control mainly comes from the contribution of near-resonant two-photon absorption. Furthermore, we propose a method to improve the polarization control efficiency of UC luminescence in rare-earth ions by applying a two-color femtosecond laser field. 展开更多
关键词 up-conversion luminescence laser polarization nanocrystal
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A New Protocol for Multi-Item Electronic Auctions 认领 引用
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作者 HUANG Genxun ZHOU Ran WEI Fushan YU Gang 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第6期1891-1894,共4页
The authors propose a new protocol for muhizzitem electronic auctions. It has the following advantages： first, the protocol is more applicable and flexible than the previous protocols, in this protocol, each bidder c... The authors propose a new protocol for muhizzitem electronic auctions. It has the following advantages： first, the protocol is more applicable and flexible than the previous protocols, in this protocol, each bidder can decide how many items to buy according to diiferent bidding prices, which are set by the seller at the beginning of the auction; second, privacy is well preserved, no third parties are needed in the protocol and the auction outcome is jointly computed by the bidders on their own without uncovering any additional information. 展开更多
关键词 electronic auction homomorphism zero-knowledge proof
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Solving ill-conditioning observation equations via truncated SVD 认领 引用 被引量：2
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作者 GUI Qing-ming GUO Jian-feng 《中国有色金属学会会刊：英文版》 2005年第S1期142-144,共3页
To mitigate the ill effects and obtain more accurate and stable solution of the observation equations,the so-called truncated singular-value decomposition(TSVD)method is introduced by modifying the small(nonzero)singu... To mitigate the ill effects and obtain more accurate and stable solution of the observation equations,the so-called truncated singular-value decomposition(TSVD)method is introduced by modifying the small(nonzero)singular values of the coefficients matrix.The proposed method directly disposed the ill-conditioning observation equations,which differs considerably from the traditional normal equation method.An application explains that TSVD can mitigate the ill conditioning. 展开更多
关键词 ill conditioning condition number truncated SVD
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Prediction of Chinese color system appearance scales using various color appearance models 认领 引用 被引量：3
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作者 廉玉生 王秀泽 孟伟 《Chinese Optics Letters》 SCIE EI CAS 2007年第10期617-620,共4页
The chromaticities of the Chinese color system dataset are applied to eight color appearance models （CAMs）. Models used are： CIELAB, Hunt, Nayatani, RLAB, LLAB, ZLAB, CIECAM97s, CIECAM02. Three color appearance att... The chromaticities of the Chinese color system dataset are applied to eight color appearance models （CAMs）. Models used are： CIELAB, Hunt, Nayatani, RLAB, LLAB, ZLAB, CIECAM97s, CIECAM02. Three color appearance attributes （lightness, chroma, and hue） are discussed for their uniformity, in terms of the constant perceptual nature of the Chinese color system dataset. The results show that no particular model can excel at all metrics. Comparison can lead to the conclusion that Chinese color system appearance scales can be predicted only slightly poorer than Munsell appearance scales using the eight CAMs. 展开更多
关键词 China Data processing Mathematical models
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Synchronization of chaotic VCSELs by external chaotic signal parameter modulation 认领 引用 被引量：1
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作者 王伟 张胜海 +1 位作者 钱兴中 王彦斌 《Chinese Optics Letters》 SCIE EI CAS 2009年第10期945-948,共4页
Synchronization of chaotic vertical-cavity surface-emitting lasers （VCSELs） is achieved by external chaotic signal modulation successfully. Simulation indicates that we can get chaos synchronization if the intensity... Synchronization of chaotic vertical-cavity surface-emitting lasers （VCSELs） is achieved by external chaotic signal modulation successfully. Simulation indicates that we can get chaos synchronization if the intensity of external chaotic signal is large enough. First of all, we use direct current modulation to achieve the chaos of VCSELs, and determine the laser＇s chaotic state by analyzing time series of the output and the corresponding power spectrum. And then we achieve synchronization of the two chaotic systems by external chaotic signal parameter modulation. We also find that the larger the modulation intensity is, the easier it is to achieve synchronization for chaotic VCSELs. This approach can also be applied to systems with a number of modulated lasers. 展开更多
关键词 Lasers Power spectrum Pulse modulation Surface emitting lasers Synchronization Time series
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Analysis of the connectivity and robustness of inter-satellite links in a constellation 认领 引用 被引量：2
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作者 HAN SongHui GUI QingMing LI JianWen 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第6期991-995,共5页
In the design of new constellation configurations or research of existing constellation performance,the connectivity and robustness of inter-satellite links (ISL) are needed for analysis.In this paper,graph theory is ... In the design of new constellation configurations or research of existing constellation performance,the connectivity and robustness of inter-satellite links (ISL) are needed for analysis.In this paper,graph theory is used to analyze the connectivity and robustness of the ISL in constellations,which are measured under the requirements of a short average distance and a small range of ISL azimuth angles,elevation angles and distances.The method to determine ISL connectivity by using the adjacency matrix of graph theory is put forward for the first time,and the standards of the ISL performance are given using:the number of ways between any two satellites,cutting point,cutting edge,k-connectivity degree and k-edge connectivity degree of graph theory.Finally,in the simulation,the ISLs in the Walker 24/6/1 constellation and the ISLs in the Walker 24/3/1 constellation are established from the optimal perspective of the azimuth angle,elevation angle and distance,and the characteristics of ISL in the Walker 24/6/1 and Walker 24/3/1 constellations are compared.The conclusions of this paper can be used as a reference for the design of new constellation configurations and analysis of existing ISLs. 展开更多
关键词 constellation inter-satellite link ISL connectivity
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