Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/008
Jingqing Fang, Guanrong Chen
A higher-order approximation analytical solution for a current-carrying ion sheath is automatically derived in computer by decomposition method. Chaos behaviors in the system driven by an external periodic oscillation are controlled using feedback control strategy. Its effectiveness is verified by numerical simulations.
{"title":"APPROXIMATION ANALYTICAL SOLUTION FOR A CURRENT-CARRYING ION SHEATH AND ITS CHAOS CONTROL","authors":"Jingqing Fang, Guanrong Chen","doi":"10.1088/1004-423X/8/7/008","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/008","url":null,"abstract":"A higher-order approximation analytical solution for a current-carrying ion sheath is automatically derived in computer by decomposition method. Chaos behaviors in the system driven by an external periodic oscillation are controlled using feedback control strategy. Its effectiveness is verified by numerical simulations.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125848091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/006
Shi-an Liu, Shi-ming Lin, Qi-Ming Wang
In this paper, we introduced the dressed exciton model of the semiconductor micro-cavity device. In the semiconductor micro cavity of vertical-cavity surface-emission device, the excitons first coupled with the cavity through an intra-electromagnetic field and formed the dressed excitons. Then these dressed excitons decayed into the vacuum cavity optical mode, as a multiparticle process. Through the quantum electrodynamics method, the dipole emission density and system energy decayed equation were obtained. And it was predicted that the excitons decay into a very narrow mode when the exciton-cavity coupling becomes strong enough.
{"title":"RADIATION OF DRESSED EXCITONS IN THE SEMICONDUCTOR MICROCAVITY","authors":"Shi-an Liu, Shi-ming Lin, Qi-Ming Wang","doi":"10.1088/1004-423X/8/7/006","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/006","url":null,"abstract":"In this paper, we introduced the dressed exciton model of the semiconductor micro-cavity device. In the semiconductor micro cavity of vertical-cavity surface-emission device, the excitons first coupled with the cavity through an intra-electromagnetic field and formed the dressed excitons. Then these dressed excitons decayed into the vacuum cavity optical mode, as a multiparticle process. Through the quantum electrodynamics method, the dipole emission density and system energy decayed equation were obtained. And it was predicted that the excitons decay into a very narrow mode when the exciton-cavity coupling becomes strong enough.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130200658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/001
Tao Bi-xiu
The existence and evolution of spherical membrane configurations in spherical-symmetric and self-similar spacetimes are studied, and a solution for the dynamics of membranes is obtained. A new interpretation for the origin and evolution of the cosmic matter-structures is acquired. It agrees well with the survey of astronomy.
{"title":"Self-similar global textures and membranes","authors":"Tao Bi-xiu","doi":"10.1088/1004-423X/8/7/001","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/001","url":null,"abstract":"The existence and evolution of spherical membrane configurations in spherical-symmetric and self-similar spacetimes are studied, and a solution for the dynamics of membranes is obtained. A new interpretation for the origin and evolution of the cosmic matter-structures is acquired. It agrees well with the survey of astronomy.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129249217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/002
Kou Su-peng, Liang Jiu-qing, Zhang Yun-bo, W. Xiaobing, Pu Fu-ke
The crossover from thermal hopping to quantum tunneling is studied. We show that the decay rate Γ with dissipation can accurately be determined near the crossover temperature. Besides considering the Wentzel-Kramers-Brillouin exponent, we also calculate contribution of the fluctuation modes around the saddle point and give an extended account of a previous study of crossover region. We deal with two dangerous fluctuation modes whose contribution cannot be calculated by the steepest descent method and show that higher order couplings between the two dangerous modes need to be taken into consideration.
{"title":"Crossover from thermal hopping to quantum tunneling in ferromagnetic particle","authors":"Kou Su-peng, Liang Jiu-qing, Zhang Yun-bo, W. Xiaobing, Pu Fu-ke","doi":"10.1088/1004-423X/8/7/002","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/002","url":null,"abstract":"The crossover from thermal hopping to quantum tunneling is studied. We show that the decay rate Γ with dissipation can accurately be determined near the crossover temperature. Besides considering the Wentzel-Kramers-Brillouin exponent, we also calculate contribution of the fluctuation modes around the saddle point and give an extended account of a previous study of crossover region. We deal with two dangerous fluctuation modes whose contribution cannot be calculated by the steepest descent method and show that higher order couplings between the two dangerous modes need to be taken into consideration.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122620129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/011
Sun Lianfeng, Mao Jian-min, Chang Bao-He, Pan Zheng-wei, Wang Gang, Zhou Wei-ya
The zeolite-supported catalysts were prepared in nickel and cobalt nitrate aqueous solutions by ion exchange method. After reducing these substrates by hydrogen, we grew carbon nanotubes on them by chemical vapor deposition under different conditions. The results reveal that nickel/zeolite, cobalt/zeolite and nickel+cobalt/zeolite have different optimal conditions. When nickel+cobalt/zeolite was used as the catalyst, we can get straight carbon nanotubes. The Raman spectrum of the straight nanotubes shows they have fewer defects. We propose a growth mechanism for the growth of these nanotubes.
{"title":"Structure and morphology of carbon nanotubes grown on zeolite-supported catalysts by chemical vapor deposition","authors":"Sun Lianfeng, Mao Jian-min, Chang Bao-He, Pan Zheng-wei, Wang Gang, Zhou Wei-ya","doi":"10.1088/1004-423X/8/7/011","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/011","url":null,"abstract":"The zeolite-supported catalysts were prepared in nickel and cobalt nitrate aqueous solutions by ion exchange method. After reducing these substrates by hydrogen, we grew carbon nanotubes on them by chemical vapor deposition under different conditions. The results reveal that nickel/zeolite, cobalt/zeolite and nickel+cobalt/zeolite have different optimal conditions. When nickel+cobalt/zeolite was used as the catalyst, we can get straight carbon nanotubes. The Raman spectrum of the straight nanotubes shows they have fewer defects. We propose a growth mechanism for the growth of these nanotubes.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121415142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/009
Yang Wan-min, Z. Lian, Feng Yong, Z. Pingxiang, Wu Min-zhi, Wu Xiaozu, W. Gawalek
Single-domain YBCO bulk superconductors have been fabricated by Top Seeded Melt Slow Cooling Growth(TSSCG) process. Two typical YBCO cylinder samples with differential grain-alignment were selected for the investigation of the relationship between the grain-alignment and the levitation force under the same testing condition at liquid nitrogen temperature. It is found that the levitation force values is much different for the two samples, the levitation force of the sample with H ∥ c-axis is more than two times higher than that of the samples with H ⊥ c-axis. So it is necessary to take account of this anisotropy in practical applications. The relationship between a magnet and a superconductor can be well described with a double exponential function. All the results are discussed in details.
{"title":"EFFECT OF GRAIN-ALIGNMENT ON THE LEVITATION FORCE OF MELT-PROCESSED YBCO BULK SUPERCONDUCTORS","authors":"Yang Wan-min, Z. Lian, Feng Yong, Z. Pingxiang, Wu Min-zhi, Wu Xiaozu, W. Gawalek","doi":"10.1088/1004-423X/8/7/009","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/009","url":null,"abstract":"Single-domain YBCO bulk superconductors have been fabricated by Top Seeded Melt Slow Cooling Growth(TSSCG) process. Two typical YBCO cylinder samples with differential grain-alignment were selected for the investigation of the relationship between the grain-alignment and the levitation force under the same testing condition at liquid nitrogen temperature. It is found that the levitation force values is much different for the two samples, the levitation force of the sample with H ∥ c-axis is more than two times higher than that of the samples with H ⊥ c-axis. So it is necessary to take account of this anisotropy in practical applications. The relationship between a magnet and a superconductor can be well described with a double exponential function. All the results are discussed in details.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127065331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-07-01DOI: 10.1088/1004-423X/8/7/007
Shen Dan-xun, Gu Wan-yi, Xu Da-xiong
A new algorithm based on transfer matrix method is given to analyse a new distributed feedback (DFB) structure–the distributed phase- shifted (DPS) DFB laser. In the small signal analysis, a new model is proposed with this algorithm. Considering different structures of DFB laser diode, we define a spatial-hole-burning (SHB) factor to measure the SHB effect. Compared with the λ/4 phase-shifted DFB and 3 phase-shifted DFB, the DPS-DFB structure shows a superior characteristics both in static and dynamic behavior.
{"title":"Study of spatial hole burning in distributed phase-shifted distributed feedback semiconductor lasers","authors":"Shen Dan-xun, Gu Wan-yi, Xu Da-xiong","doi":"10.1088/1004-423X/8/7/007","DOIUrl":"https://doi.org/10.1088/1004-423X/8/7/007","url":null,"abstract":"A new algorithm based on transfer matrix method is given to analyse a new distributed feedback (DFB) structure–the distributed phase- shifted (DPS) DFB laser. In the small signal analysis, a new model is proposed with this algorithm. Considering different structures of DFB laser diode, we define a spatial-hole-burning (SHB) factor to measure the SHB effect. Compared with the λ/4 phase-shifted DFB and 3 phase-shifted DFB, the DPS-DFB structure shows a superior characteristics both in static and dynamic behavior.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"36 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121338010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-20DOI: 10.1088/1004-423X/8/6/008
Yan Su-hui, Wang Dong, Gao Jin-yue
A new scheme of electromagnetically induced two-photon transparency in a four-level V-type Doppler-broadened medium is presented in this paper. Under a proper condition, the two-photon absorption can be greatly reduced by applying a control laser field with relatively lower intensity compared with that needed in other field-induced multi-photon absorption reduction.
{"title":"Electromagnetically induced two-photon transparency in V model","authors":"Yan Su-hui, Wang Dong, Gao Jin-yue","doi":"10.1088/1004-423X/8/6/008","DOIUrl":"https://doi.org/10.1088/1004-423X/8/6/008","url":null,"abstract":"A new scheme of electromagnetically induced two-photon transparency in a four-level V-type Doppler-broadened medium is presented in this paper. Under a proper condition, the two-photon absorption can be greatly reduced by applying a control laser field with relatively lower intensity compared with that needed in other field-induced multi-photon absorption reduction.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130741396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1088/1004-423X/8/6/004
Qu Lian-hua, Wang Zhi-wen, Li Bai-wen
The nonrelativistic energies of the 1s(2)nd and 1s(2)nf(n=6, 7, 8 and 9) states for the lithium isoelectronic sequence from Li I to Ne VIII are calculated by using a full core plus correlation method with multiconfiguration interaction wave function. Relativistic and mass-polarization effects on the energy are evaluated as the first-order perturbation theory. In most cases with nuclear charge, Z less than or equal to 7, the agreement between our predicted excitation energies and the experimental data is less than 1 cm(-1).
用多组态相互作用波函数的全核加相关方法计算了Li I ~ Ne VIII等电子序列的1s(2)nd和1s(2)nf(n=6、7、8和9)态的非相对论能量。用一阶微扰理论评价了相对论和质量极化对能量的影响。在核电荷数Z小于等于7的大多数情况下，我们的预测激发能与实验数据之间的一致性小于1 cm(-1)。
{"title":"Excitation energies of 1s2nd and 1s2nf states for the lithium isoelectronic sequence","authors":"Qu Lian-hua, Wang Zhi-wen, Li Bai-wen","doi":"10.1088/1004-423X/8/6/004","DOIUrl":"https://doi.org/10.1088/1004-423X/8/6/004","url":null,"abstract":"The nonrelativistic energies of the 1s(2)nd and 1s(2)nf(n=6, 7, 8 and 9) states for the lithium isoelectronic sequence from Li I to Ne VIII are calculated by using a full core plus correlation method with multiconfiguration interaction wave function. Relativistic and mass-polarization effects on the energy are evaluated as the first-order perturbation theory. In most cases with nuclear charge, Z less than or equal to 7, the agreement between our predicted excitation energies and the experimental data is less than 1 cm(-1).","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128377434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1088/1004-423X/8/6/007
Zhang Jun-Xiang, Zhang Tian-cai, Xie Chang-De, P. Kunchi
An interferometric detection scheme to measure optical phase shift with sensitivity beyond the shot noise limit is proposed. The theoretical calculation shows that using the quantum correlated twin beams produced from an optical parametric amplifier as the input fields of a Mach-Zehnder interferometer, the minimum detectable phase shift will exceed the shot noise limit N-1/2 and approach the Heisenberg limit N-1. The parametric dependences of the minimum detectable phase shift on the nonlinear interaction, input photon number, and detection efficiency are shown.
{"title":"Interferometric detection of optical phase shift using twin beams","authors":"Zhang Jun-Xiang, Zhang Tian-cai, Xie Chang-De, P. Kunchi","doi":"10.1088/1004-423X/8/6/007","DOIUrl":"https://doi.org/10.1088/1004-423X/8/6/007","url":null,"abstract":"An interferometric detection scheme to measure optical phase shift with sensitivity beyond the shot noise limit is proposed. The theoretical calculation shows that using the quantum correlated twin beams produced from an optical parametric amplifier as the input fields of a Mach-Zehnder interferometer, the minimum detectable phase shift will exceed the shot noise limit N-1/2 and approach the Heisenberg limit N-1. The parametric dependences of the minimum detectable phase shift on the nonlinear interaction, input photon number, and detection efficiency are shown.","PeriodicalId":188146,"journal":{"name":"Acta Physica Sinica (overseas Edition)","volume":"1980 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130396069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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