晶体物理学中的美学渊原

本文对晶体物理学中的对称美学历史和准晶态引起晶态对称美破缺和产生新的对称美的过程作了概述,并指出这种对称破缺美是自然界客观存在的。

研究生专业课程中实施“课程思政”的探索——以“晶体物理学”为例

研究生是我国未来事业的引领者,其政治素养、专业素养、人文素养应相辅相成,这也是新时期人才培养的基本导向。"课程思政"理应在研究生培养中发挥重要作用,然而这方面的探索还在起步阶段。本文基于"晶体物理学"的教学经验,首先针对研究生专业课教学中以学生为主的特点,探讨了将思政元素融入课堂教学的基本理念;然后以大量素材为基础,讨论了课程思政的实施策略。实践证明,在教学过程中恰当地引入思政元素可以得到研究生的普遍欢迎,是提高研究生培养质量的有效手段。

正弦平方势与沟道辐射的谱线展宽

利用曾经提出的正弦平方势解析地处理了非线性效应和偶极效应对沟道谱线宽度的影响,解释了正电子能量在5GeV附近的Si(110)面沟道辐射谱特征.

谋事在人——冯端教授谈治学

最近,我走访了冯端教授。冯教授身兼多职,他是中国科学院学部委员、江苏省科协主席、南京大学研究生院院长、固体物理研究所所长。在国内晶体物理学界他是著名的权威,在国际上也是有影响的专家。然而,他既没有出国留学,也没有大名鼎鼎的学者指点。

Supercontinuum Generationin Normal-dispersion Photonic Crystal Fiber Using Picosecond Pulse

Studied is the Super-continuum(SC) generation of a normal-dispersion photonic crystal fiber(PCF) using picosecond pulse excitation. In experimental analyses, a 237 nm broadband infrared continuum was generated pumped at 1 550 nm(normal dispersion regime) by 1.6 ps pulses from an erbium-doped fiber laser. In addition, we conduct the numerical analyses of SC based on generalized nonlinear Schr dionger equation. The results have been applied to investigate the dominant physical processes underlie the generation of SC. We conclude that dispersion, self-phase modulation(SPM),four-wave-mixing(FWM) and Raman scattering are determinants of SC generation rather than fission of soliton in normal-dispersion PCF.

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm

Bloom Forming Species of Phytoplankton in Two Coastal Waters in the Southeast Coast of India

The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters （Southeast coast of India） are reported. Air and surface water temperatures （℃） varied from 25.1 to 30.1 and 24.5 to 28.5, respectively, in the former waters and from 25.5 to 31.2 and 25.0 to 29.3 in the latter waters. The respective salinities varied from 6.0 to 28.5 and 5.0 to 33.1 and the respective pH ranged between 7.0 and 8.3 and 7.2 and 8.3. Correspondingly, the dissolved oxygen content varied from 3.1 to 7.5 and 3.1 to 7.9 mgL1 while the light extinction coefficient （LEC） values ranged between 3.1 and 10.1 and 1.8 and 11.0. The content ranges of inorganic nutrients, i.e., nitrate, nitrite, phosphate and silicate （μmolL^-1）, in the Parangipettai and Coleroon coastal waters were： 6.5- 27.0; 1.0- 8.9; 0.1-3.0 and 15.0 -140 and 10.1-23.4; 1.2-8.9; 0.2-3.1 and 55-125 respectively. The chlorophyll α contents in both waters ranged from 2.0-7.5 μgL^-1. Presently, 124 phytoplankton species representing different classes were recorded in the Coleroon coast, viz, Bacillariophyceae （77）; Dinophyceae （19）; Cyanophyceae （15）; Chlorophyceae （10） and Chrysophyceae （3）, whereas 117 phytoplankton species were recorded in the Parangipettai coast, viz, Bacillariophyceae （66）; Dinophyceae （22）; Cyanophyceae （19）; Chlorophyceae （7） and Chrysophyceae （3）. The phytoplankton cell abundance in the Parangipettai and Coleroon coastal waters varied from 290 to 111662 and 140 to 132 757 cells L^-1, respectively, with peak diversity （3.38 and 3.52 bits indl.） recorded in summer. The maximum abundance occurred in summer coinciding with the stable hydrographical conditions. The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters. Totally 31 and 24 species of phytoplankton were found to be bloom-forming in the Parangipettai and Coleroon coastal waters, respectively. Presently Trichodesmium bloom was also observed, which appeared at the 10 fathom level of the coastal water and quickly spread to the marine zone of the Vellar estuary and near the mouth region of the mangrove waters. The Parangipettai and Coleroon coastal waters are subject to long term fluctuations in physico-chemical conditions depending upon the seasonal tidal range and freshwater influx, resulting in a continuous exchange of organic, inorganic, plant and animal matters.

纪念余瑞璜教授诞辰一百周年

我国著名物理学家余瑞璜教授是国际知名的晶体物理学家，是吉林大学物理系的创始人。他几十年如一日，满腔热情地投身到我国的科学、教育事业。早年在固体物理的X光晶体结构以及后来在经验电子论研究等方面做出了卓越的贡献。解放后，他以高涨的热情参与制订和组织实施我国科技政策和科技发展计划，并创办了吉林大学物理系，为祖国培养了大批的高级专门人才作出了重要贡献。

Ionic liquid crystal-based electrolyte with enhanced charge transport for dye-sensitized solar cells

A room temperature ionic liquid crystal, 1-dodecyl-3-ethylimidazolium iodide （C12EImI）, and an ionic liquid, 1-decyl-3- ethylimidazolium iodide （Cl0EImI）, have been synthesized, characterized and employed as the electrolyte for dye-sensitized solar cells （DSSC）. The physicochemical properties show that a smectic A （SmA） phase with a lamellar structure is formed in CIzEImI. Both C^2EImI and Cl0EImI have good electrochemical and thermal stability facilitating their use in DSSC. The steady-state voltammograms reveal that the diffusion coefficient of I3- in C^2EImI is larger than that in CmEImI, which is at- tributed to the existence of the SmA phase in Ca2EImI. Because the iodide species are located between the layers of imidazo- lium cations in CjzEImI, exchange reaction-based diffusion is increased with a consequent increase in, the overall diffusion. The electrochemical impedance spectrum reveals that charge recombination at the dyed TiOJelectrolyte interface of a C12EImI-based DSSC is reduced due to the increase in I3- diffusion, resulting in higher open-circuit voltage. Moreover, both short-circuit current density and fill factor of the Cl2EImI based DSSC increase, as a result of the increasing transport of I3 in C^2EImI. Consequently, the photoelectric conversion efficiency of C^2EImI-based DSSC is higher than that of the Cl0EImI-based DSSC.

RNA-protein distance patterns in ribosomes reveal the mechanism of translational attenuation

Elucidating protein translational regulation is crucial for understanding cellular function and drug development.A key molecule in protein translation is ribosome,which is a super-molecular complex extensively studied for more than a half century.The structure and dynamics of ribosome complexes were resolved recently thanks to the development of X-ray crystallography,Cryo-EM,and single molecule biophysics.Current studies of the ribosome have shown multiple functional states,each with a unique conformation.In this study,we analyzed the RNA-protein distances of ribosome(2.5 MDa)complexes and compared these changes among different ribosome complexes.We found that the RNA-protein distance is significantly correlated with the ribosomal functional state.Thus,the analysis of RNA-protein binding distances at important functional sites can distinguish ribosomal functional states and help understand ribosome functions.In particular,the mechanism of translational attenuation by nascent peptides and antibiotics was revealed by the conformational changes of local functional sites.