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Spin squeezing in Bose-Einstein condensates： Limits imposed by decoherence and non-zero temperature

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Frontiers of physics 2012年第1期7卷 86-97页

作者： Alice Sinatra (1) Jean-Christophe Dornstetter (1) Yvan Castin (1) 1. Laboratoire Kastler Brossel Ecole Normale Supérieure UPMC and CNRS Paris France

We consider dynamically generated spin squeezing in interacting bimodal condensates. We show that particle losses and non-zero temperature effects in a multimode theory completely change the scaling of the best squeezing for large atom numbers. We present the new scalings and we give approximate analytical expressions for the squeezing in the thermodynamic limit. Besides reviewing our recent theoretical results, we give here a simple physical picture of how decoherence acts to limit the squeezing. We show in particular that under certain conditions the decoherence due to losses and non-zero temperature acts as a simple dephasing.

关键词： Bose-Einstein condensate decoherence

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中国免签的“朋友圈”持续扩容

重庆与世界 2024年第6期 38-43页

作者： 1.中国领事服务网 2.新华网中国领事服务网新华网

今年以来，中国与巴勒斯坦、新加坡、泰国、安提瓜和巴布达等国签署的互免签证协定相继生效，中国对外单方面免签和互免签证的力度越来越大。外交部发言人表示，中国免签的“朋友圈”持续扩容，与越来越多国家正式迈入“免签时代”，其...

今年以来，中国与巴勒斯坦、新加坡、泰国、安提瓜和巴布达等国签署的互免签证协定相继生效，中国对外单方面免签和互免签证的力度越来越大。外交部发言人表示，中国免签的“朋友圈”持续扩容，与越来越多国家正式迈入“免签时代”，其积极效应正在不断显现。截至5月10日，中国已与157个国家缔结涵盖不同护照的互免签证协定；与44个国家达成简化签证手续协定或安排；与23个国家实现全面互免签证；还有60多个国家和地区给予中国公民免签或落地签证便利。

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Cloning and Expression Analysis of p26 Gene in Artemia sinica

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Acta Biochimica et Biophysica Sinica 2007年第5期39卷 351-358页

作者： Lijuan JIANG~1, Lin HOU~(1*), Xiangyang ZOU2, Ruifeng ZHANG~1, Jiaqing WANG~1, We njing SUN~1, Xintao ZHAO~1, and Jialu AN~1 1 College of Life Sciences, Liaoning Normal University, Dalian 116029, China 2 Department of Biology, Dalian Medical University, Dalian 116027, China College of Life Sciences Liaoning Normal UniversityDalian 116029 China Department of Biology Dalian Medical UniversityDalian 116027 China

The protein p26 is a small heat shock protein that functions as a molecular chaperone to protect embryos by preventing irreversible protein damage during embryonic development. A 542 bp fragment of the p26 gene was cloned and sequenced. The fragment encoded 174 amino acid residues and the amino acid sequence contained the α-crystallin domain. Phylogenetic analysis showed that eight Artemia populations were divided into four major groups. Artemia sinica (YC) belonged to the East Asia bisexual group. Expression of the p26 gene at different developmental stages ofA. sinica was quantified using real-time quantitative polymerase chain reaction followed by cloning and sequencing. The relationship between the quantity of p26 gene expression and embryonic development was analyzed. The results indicated that massive amounts of p26 were expressed during the development of A. sinica. At the developmental stage of 0 h, A. sinica expressed the highest level of p26. As development proceeded, expression levels of the p26 gene reduced significantly. There was a small quantity of p26 gene expression at the developmental stages of 16 h and 24 h. We concluded that p26 might be involved in protecting the embryo from physiological stress during embryonic development.

关键词： Artemia sinica cloning expression p26 gene real-time quantitative PCR

Quantum phase transition of cold atoms trapped in optical lattices

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Frontiers of physics 2012年第2期7卷 223-234页

作者： Yao-hua Chen (1) Wei Wu (1) Guo-cai Liu (1) Hong-shuai Tao (1) Wu-ming Liu (1) 1. Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

We review our recent theoretical advances in phase transition of cold atoms in optical lattices, such as triangular lattice, honeycomb lattice, and Kagome lattice. By employing the new developed numerical methods called dynamical cluster approximation and cellular dynamical mean-field theory, the properties in different phases of cold atoms in optical lattices are studied, such as density of states, Fermi surface and double occupancy. On triangular lattice, a reentrant behavior of phase translation line between Fermi liquid state and pseudogap state is found due to the Kondo effect. We find the system undergoes a second order Mott transition from a metallic state into a Mott insulator state on honeycomb lattice and triangular Kagom~ lattice. The stability of quantum spin Hall phase towards interaction on honeycomb lattice with spin-orbital coupling is systematically discussed. And we investigate the transition from quantum spin Hall insulator to normal insulator in Kagom~ lattice which includes a nearest-neighbor intrinsic spin-orbit coupling and a trimerized Hamiltonian. In addition, we propose the experimental protocols to observe these phase transition of cold atoms in optical lattices.

关键词： quantum phase transition optical lattice DMFT spin-orbit coupling

Generation of cell-type-specific gene mutations by expressing the sgRNA of the CRISPR system from the RNA polymerase II promoters

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Protein & Cell 2015年第9期6卷 689-692页

作者： Jiaqiang Wang (1) Xin Li (1) (2) Yanhua Zhao (1) Jingyu Li (1) Qi Zhou (1) (2) Zhonghua Liu (1) 1.College of Life Sciences Northeast Agricultural University Harbin 150030 China 2.State Key Laboratory of Reproductive Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China

Recently, the CRISPR/Cas9 system is emerging as a powerful tool for genome editing （Chang et al., 2013; Li et al., 2013; Niu et al., 2014; Shen et al., 2013; Wan et al., 2015; Wang et al., 2013） and genetic screening （Konermann et al., 2015）, and holds great promise for biomedical applications in disease modeling and gene therapy by in vivo genome editing （Mad- dalo et al., 2014; Xue et al., 2014）.

关键词： Sanger Sequencing Genome Editing Gene Editing CRISPR System Produce Gene Mutation

维普期刊数据库

Human atlastin GTPases mediate differentiated fusion of endoplasmic reticulum membranes

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Protein & Cell 2015年第4期6卷 307-311页

作者： Xiaoyu Hu (1) Fuyun Wu (1) Sha Sun (1) Wenying Yu (1) Junjie Hu (1) (2) 1.Tianjin Key Laboratory of Protein Sciences Department of Genetics and Cell Biology College of Life Sciences Nankai University Tianjin 300071 China 2.National Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

Dear Editor,In eukaryotic cells, the endoplasmic reticulum （ER） is a continuous membrane system with interconnected tubules and sheets. The formation of a typical network requires constant fusion between ER membranes.

关键词： Endoplasmic Reticulum GTPase Activity Hereditary Spastic Paraplegia GTPase Domain Endoplasmic Reticulum Network

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Fuzzy c-means clustering with non local spatial information for noisy image segmentation

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Frontiers of Computer Science 2011年第1期5卷 45-56页

作者： Feng Zhao (1) add_zf1119@*** Licheng Jiao (1) Hanqiang Liu (1) Xidian Univ Key Lab Intelligent Percept & Image Understanding Minist Educ China Inst Intelligent Informat Proc Xian 710071 Peoples R China

As an effective image segmentation method, the standard fuzzy c-means （FCM） clustering algorithm is very sensitive to noise in images. Several modified FCM algorithms, using local spatial information, can overcome this problem to some degree. However, when the noise level in the image is high, these algorithms still cannot obtain satisfactory segmentation performance. In this paper, we introduce a non local spatial constraint term into the objective function of FCM and propose a fuzzy c- means clustering algorithm with non local spatial information （FCM_NLS）. FCM_NLS can deal more effectively with the image noise and preserve geometrical edges in the image. Performance evaluation experiments on synthetic and real images, especially magnetic resonance （MR） images, show that FCM NLS is more robust than both the standard FCM and the modified FCM algorithms using local spatial information for noisy image segmentation.

关键词： image segmentation fuzzy clustering algo-rithm non local spatial information magnetic resonance(MR) image

Superconductivity of topological matters induced via pressure

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Frontiers of physics 2012年第2期7卷 193-199页

作者： Jun-liang Zhang (1) (2) Si-jia Zhang (1) Hong-ming Weng (1) Wei Zhang (1) Liu-xiang Yang (1) Qing-qing Liu (1) Pan-pan Kong (1) Jie Zhu (1) Shao-min Feng (1) Xian-cheng Wang (1) Ri-cheng Yu (1) Lie-zhao Cao (2) Shoucheng Zhang (3) (4) Xi Dai (1) Zhong Fang (1) Chang-qing Jin (1) 1. Beijing National Laboratory for Condensed Matter Physics & Institute of Physics Chinese Academy of Sciences Beijing 100190 China2. Department of Physics University of Science & Technology of China Hefei 230026 China3. Department of Physics McCullough Building Stanford University Stanford CA 94305-4045 USA4. Center for Advanced Study Tsinghua University Beijing 100084 China

By applying pressure on the topological insulator Bi2Te3 single crystal, superconducting phase was found without a crystal structure phase transition. The new superconducting phase is under the pressure range of 3 GPa to 6 GPa. The high pressure Hall effect measurements indicated that the superconductivity caused by bulk hole pockets. The high pressure structure investigations with synchrotron X-ray diffraction indicated that the superconducting phase is of similar structure to that of ambient phase structure with only slight change with lattice parameter and internal atomic position. The topological band structures indicate the superconducting phase under high pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi2Te3 due to the proximity effect between superconducting bulk states and Dirac- type surface states. We also discussed the possibility that the bulk state could be a topological superconductor.

关键词： topological insulator high pressure

An analytical model for Network-on-Chip with finite input buffer

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Frontiers of Computer Science 2011年第1期5卷 126-134页

作者： Jian Wang (1) wangjian3630@*** Yu-bai Li (1) Chang Wu (1) Univ Elect Sci & Technol China Didital Signal Proc Lab Sch Commun & Informat Engn Chengdu 610054 Peoples R China

An analytical model is proposed for input buffer router architecture Network-on-Chip （NoC） with finite size buffers. The model is developed based on M/G/ 1/K queuing theory and takes into consideration the restriction of buffer sizes in NoC. It analyzes the packet＇s sojourn time in each buffer and calculates the packets average latency in NoC The validity of the model is verified through simulation. By comparing our analytical outcomes to the simulation results, we show that the proposed model successfully captures the performance characteristics of NoC, which provides an efficient performance analysis tool for NoC design.

关键词： analytical model finite buffer Network-on-Chip (NoC) queue system