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Effects of Interannual Salinity Variability on the Barrier Layer in the Western-Central Equatorial Pacific:A Diagnostic Analysis from Argo

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Advances in Atmospheric Sciences 2014年第3期31卷 532-542页

作者： zheng Fei ZHANG rong-Hua ZHU Jiang International Center for Climate and Environment Science Institute of Atmospheric Physics Chinese Academy of Sciences Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Earth System Science Interdisciplinary Center University of MarylandCollege ParkMaryland 20740USA

ABSTRACT In this paper, interannual variations in the barrier layer thickness （BLT） are analyzed using Argo three-dimensional temperature and salinity data, with a locus on the effects of interannually varying salinity on the evolution of the El Nifio Southern Oscillation （ENSO）. The interannually varying BLT exhibits a zonal seesaw pattern across the equatorial Pacific during ENSO cycles. This phenomenon has been attributed to two different physical processes. During E1 Nifio （La Nifia）, the barrier layer （BL） is anomalously thin （thick） west of about 160°E, and thick （thin） to the east. In the western equatorial Pacific （the western part： 130°-160°E）, interannual variations of the BLT indicate a lead of one year relative to those of the ENSO onset. The interannual variations of the BLT can be largely attributed to the interannual temperature variability, through its dominant effect on the isothermal layer depth （ILD）. However, in the central equatorial Pacific （the eastern part： 160~E- 170~W）, interannual variations of the BL almost synchronously vary with ENSO, with a lead of about two months relative to those of the local SST. In this region, the interannual variations of the BL are significantly affected by the interannually varying salinity, mainly through its modulation effect on the mixed layer depth （MLD）. As evaluated by a onedimensional boundary layer ocean model, the BL around the dateline induced by interannual salinity anomalies can significantly affect the temperature fields in the upper ocean, indicating a positive feedback that acts to enhance ENSO.

关键词： barrier layer salinity effect ENSO Argo

Formalism of Helicity Coupling Amplitudes for J/ψ→π^＋π^-π^0

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Communications in Theoretical Physics 2007年第1期47卷 89-94页

作者： PING rong-Gang LI Gang WANG zheng Institute of High Energy Physics the Chinese Academy of Sciences Beijing 100049 China China Center for Advance Science and Technology （CCAST） Beijing 100080 China

The formalisms of helicity coupling amplitudes for J/ψ→π^＋π^-π^0 are presented. A detailed discussion is also given on the barrier factor, Breit Wigner, and density matrix. A Monte Carlo simulation of J/ψ→ρ（770）π→π^＋π^-π^0 is carried out. The results show that the p（770） resonance is well reproduced compared with experimental data.

关键词： helicity coupling amplitude J/ψ decays ρπ puzzle

Influence of the ambient air temperature on the electrical contact reliability of electromagnetic relay

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第3期8卷 485-489页

作者： YAO Fang zheng Jian-rong HUANG Zhang-wu People Electric Appliances Group Yueqing 32560 China

The dynamic contact resistances of HH52P electromagnetic relays are measured under different ambient air tem- perature. Their diagnostic parameters are extracted and determined. It is found that the ambient air temperature obviously influ- ences some parameters. In order to research its influence on the electrical contact reliability of electromagnetic relay, the statistic analysis is applied to study the static contact resistance, the max of the dynamic contact resistance and the bounce time. It is found that the ambient air temperature regularly influences the three parameters. Thoroughly, the phenomenon is studied and analyzed in the point of material science so as to probe into the essential matter of it.

关键词： Ambient air temperature Electromagnetic relay Electrical contact reliability Contact resistance Bounce time

Breakdown of Superconductivity in Small Metallic Grains

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Chinese Physics Letters 2000年第10期17卷 762-764页

作者： Chen Zhi-Qian zheng Ren-rong Department of Physicsj Southwest China Normal University Chongqing 400715 Department of Physics Shanghai Teacher's UniversityShanghai 200234 Department of Physics Suzhou UniversitySuzhou 215006

Superconductivity in small metallic grains is carefully checked as their size is decreased to a few nm when the average level spacing d could be compared with the bulk gapΔ.Using random matrix theory to the mean field,we find that the average theoretical values of the critical level spacing for both odd and even numbers of electrons and the transition temperature Tc in three Gauss ensembles are quite different for those from the model of uniformly spaced *** Sz=1/2,as grain size is reduced,the transition temperature or the granular gap decreases monotonously,and the relation 2△(0)/kB T_(c)≤3.53 always exists.

关键词： grain spacing checked

Effects of Zinc and Calcium Concentration on the Microstructure and Mechanical Properties of Hot-Rolled Mg–Zn–Ca Sheets

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Acta Metallurgica Sinica(English Letters) 2016年第2期29卷 205-216页

作者： Jun Luo Hong Yan Nan zheng rong-Shi Chen The Group of Magnesium Alloys and Their Applications Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China

Four kinds of Mg alloys with different Zn and Ca concentration were selected to analyze the effect of Zn and Ca concentration on the microstructure and the mechanical properties of Mg-Zn-Ca alloys. It was found that Zn and Ca concentration has a great influence on the volume fraction, the morphology and the size of second phase. The Mg-1.95Zn- 0.75Ca （wt%） alloy with the highest volume fraction, continuous network and largest size of Ca2Mg6Zn3 phase showed the lowest elongation to failure of about 7%, while the Mg-0.73Zn-0.12Ca （wt%） alloy with the lowest volume fraction and smallest size of Ca2Mg6Zn3 phase showed the highest elongation to failure of about 37%. It was suggested that uniform elongations of the Mg-Zn-Ca alloys were sensitive to the volume fraction of the Ca2Mg6Zn3 phases, especially the network Ca2Mg6Zn3 phases; post-uniform elongations were dependent on the size of the Ca2Mg6Zn3 phase, especially the size of network Ca2Mg6Zn3 phase. Reduction in Zn and Ca concentration was an effective way to improve the room- temperature ductility of weak textured Mg-Zn-Ca alloys.

关键词： Mg-Zn-Ca alloys Ductility Hot rolling Texture Second phase

Investigation of Ag(Ga,In)Se_(2)as thin-film solar cell absorbers:A first-principles study

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Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 101-108页

作者： rong Wang Baoying Dou Yifeng zheng Su-Huai Wei Institute of Advanced Semiconductors&Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices ZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou 311200China Beijing Computational Science Research Center Beijing 100193China

Using first-principles calculations,the structural,electronic,and defect properties of AgInSe_(2)(AIS),AgGaSe_(2)(AGS),and their alloys(AIGS)are systematically studied and compared with their Cu counterparts as potential candidates for thin-film solar cell *** bandgap energies of AIS(1.24 eV)and AGS(1.84 eV)are larger than their Cu counterparts,despite their larger lattice *** to the Shockley-Queisser theory,AIS or AIGS could be more suitable for solar-cell-absorber materials than their Cu ***,after investigating the band structures and intrinsic defect properties of AIS and AGS,we find that,(i)AIS and AGS have large negative crystal field splitting,thus low density of states near the valence band maximum(VBM);(ii)similar to the Cu counterparts,Ag vacancy(V_(Ag))is the main hole-carrier provider,while In_(Ag)(or Ga_(Ag))serves as the hole-carrier killer in p-type AIS(or AGS).However,because the positions of theVBM and conduction band minimum of AIS(or AGS)are lower than those of Cu In Se_(2)(CIS)[or Cu Ga Se_(2)(CGS)],the compensation of the p-type doping in AIS(or AGS)is more ***,the p-type doping of AIS(or AIGS)is more difficult than that of CIS(or CIGS),which is consistent with the doping limit *** improve the p-type doping of the AIS(or AIGS)as the solar-cell absorber,thus,improve the power conversion efficiency(PCE),the Ag-rich/(In,Ga)-poor/Se-rich growth condition is *** engineering of AIS with AGS can enhance the PCE because it can tune the bandgap energy of the absorber and band alignment at the absorber/buffer *** importantly,we suggest that for AIS(or AIGS)solar cell,the traditional buffer material of Cd S is not suitable anymore due to the large conduction band offset between AIS and Cd S.A new buffer layer material with a lower conduction band edge is necessary for better electron transport in AIS(or AIGS)solar cell.

关键词： thin-film solar cells chalcopyrites point defects alloys first-principles calculations

Speech emotion recognition with unsupervised feature learning

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Frontiers of Information Technology & Electronic Engineering 2015年第5期16卷 358-366页

作者： zheng-wei HUANG Wen-tao XUE Qi-rong MAO Department of Computer Science and Communication Engineering Jiangsu University

Emotion-based features are critical for achieving high performance in a speech emotion recognition(SER) system. In general, it is difficult to develop these features due to the ambiguity of the ground-truth. In this paper, we apply several unsupervised feature learning algorithms(including K-means clustering, the sparse auto-encoder, and sparse restricted Boltzmann machines), which have promise for learning task-related features by using unlabeled data, to speech emotion recognition. We then evaluate the performance of the proposed approach and present a detailed analysis of the effect of two important factors in the model setup, the content window size and the number of hidden layer nodes. Experimental results show that larger content windows and more hidden nodes contribute to higher performance. We also show that the two-layer network cannot explicitly improve performance compared to a single-layer network.

关键词： Speech emotion recognition Unsupervised feature learning Neural network Affect computing

Phylogenetically clustering of rhizobia by genome structure:application to unclassified Rhizobium

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Journal of Environmental Sciences 2006年第3期18卷 530-536页

作者： zheng Jun-fang LIU Gui-rong LIU Shu-lin Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Department of Microbiology Peking University Health Science Center Beijing 100083 China

Previous research reveals that the genome structures of rhizobial type strains and reference strains can reflect their phylogenetic relationships. In order to further explore the potential application of genome structure as a phylogenetic marker in rhizobial natural taxonomy, this study analyzed the genome structures of 29 unclassified nodule bacteria isolated from the root nodules of leguminous trees, Robinia sp., Dalbergia spp., and A lbizia spp. and 7 rhizobial reference strains by I-CeuI cleavage, then clustered these bacteria phylogenetically based on their genome structures and compared these clusters with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Eleven phylogenetic clusters were obtained, The clusters were in large part consistent with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Also there are inconsistent clusters based on the above three methods. But results are completely consistent with 16S rRNA clusters. This suggested that the genome structure clustering method can be used to lastly identify root nodule isolates and detect their phylogenetic relationships. The credibility and repeatability of the results, together with the simplicity and possibility to analyze a large number of strains in a short time of the method, indicates the broad potential application of genome structure as phylogenetic marker to categorize rhizobial isolates and should in the future facilitate biodiversity studies.

关键词： rhizobia genome structure phylogenetic analysis pulsed field gel electrophoresis I-CeuI

About 300 days Optical Quasi-periodic Oscillations in the Long-term Light Curves of the Blazar PKS 2155-304

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Research in Astronomy and Astrophysics 2022年第8期22卷 284-293页

作者： Qi zheng Xue-Guang Zhang Qi-rong Yuan School of Physics and Technology Nanjing Normal UniversityNanjing 210023China

Based on the long-term light curves collected from the Catalina Sky Survey(CSS)(from 2005 to 2013)and the All-Sky Automated Survey for Supernovae(ASAS-SN)(from 2014 to 2018),optical quasi-periodic oscillations(QPOs)about 300 days can be well determined in the well-known blazar PKS 2155-304 through four different methods:the generalized Lomb-Scargle periodogram(GLSP)method,the weighted wavelet Z-transform technique,the epoch-folded method and the redfit *** GLSP determined significance level for the periodicity is higher than 99.9999%based on a false alarm *** redfit provided confidence level for the periodicity is higher than 99%in the ASAS-SN light curve,after considering the effects of red *** on continuous autoregressive process created artificial light curves,the probability of detecting fake QPOs is lower than 0.8%.The determined optical periodicity of 300 days from the CSS and ASAS-SN light curves is well consistent with the reported optical periodicity in the ***,three possible models are discussed to explain the optical QPOs in PKS 2155-304:the relativistic frame-dragging effect,the binary black hole model and the jet precession model.

关键词： (galaxies:)BL Lacertae objects:individual(PKS 2155-304) galaxies:active (galaxies:)quasars:supermassive black holes