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铜银纳米合金团簇结构转变的原子模拟

原子与分子物理学报 2025年第6期42卷 101-112页

作者：李博宇刘贯惟张林东北大学材料科学与工程学院沈阳110819 东北大学材料各向异性与织构教育部重点实验室沈阳110819

采用基于嵌入原子方法势的分子动力学方法对熔融Cu_(n)Ag_(53-n)(n=0~53)和Cu_(n)Ag_(54-n)(n=0~54)合金团簇的降温凝结过程进行模拟.通过结构相图、自由能、原子化能、形状因子、对分布函数、熵和直观可视化的原子堆积结构等多种计算... 详细信息

采用基于嵌入原子方法势的分子动力学方法对熔融Cu_(n)Ag_(53-n)(n=0~53)和Cu_(n)Ag_(54-n)(n=0~54)合金团簇的降温凝结过程进行模拟.通过结构相图、自由能、原子化能、形状因子、对分布函数、熵和直观可视化的原子堆积结构等多种计算分析手段,在原子尺度上探究温度、组分和初始构型等对小尺寸Cu-Ag合金团簇在降温凝结中的结构转变以及热力学量的影响.模拟结果表明,在室温下含有少量Cu原子的二元合金团簇可以形成的核壳式二十面体几何结构,同时Cu原子取代Ag原子也有助于合金团簇的稳定.组分的改变和温度的降低使堆积结构由无序变为有序,同时伴随着原子势能、形状因子、熵的振荡下降,低温阶段熵值下降明显.

关键词：纳米合金降温凝结分子动力学结构转变

Magnesium based degradable biomaterials： A review

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Frontiers of Materials Science 2014年第3期8卷 200-218页

作者： Xue-Nan GU Shuang-Shuang li Xiao-Ming li yu-bo FAN Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science and Medical Engineering Beihang University Beijing 100191 China

Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibits the localized corrosion mechanism. Thus it is necessary to control the corrosion behaviors of magnesium for their practical use. This paper comprehensively reviews the research progress on the development of representative magnesium based alloys, including Mg-Ca, Mg-Sr, Mg-Zn and Mg-REE alloy systems as well as the bulk metallic glass. The influence of alloying element on their microstructures, mechanical properties and corrosion behaviors is summarized. The mechanical and corrosion properties of wrought magnesium alloys are also discussed in comparison with those of cast alloys. Furthermore, this review also covers research carried out in the field of the degradable coatings on magnesium alloys for biomedical applications. Calcium phosphate and biodegradable polymer coatings are discussed based on different preparation techniques used. We also compare the effect of different coatings on the corrosion behaviors of magnesium alloys substrate.

关键词： magnesium alloy degradable biomaterial coating degradation corrosion

Micropillar Cavity Design for 1.55-μm Quantum-Dot Single-Photon Sources

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Journal of Electronic Science and Technology 2019年第3期17卷 221-230页

作者： Hai-Zhi Song Wei Zhang li-bo yu Zhiming M.Wang the Institute of Fundamental and Frontier Sciences University of Electronic Science and TechnologyChengdu 610054 Southwest Institute of Technical Physics Chengdu 610041

The 1.55-μm quantum-dot (QD) micropillar cavities are strongly required as single photon sources (SPSs) for silica-fiber-based quantum information processing. Theoretical analysis shows that the adiabatic distributed Bragg reflector (DBR) structure may greatly improve the quality of a micropillar cavity. An InGaAsP/InP micropillar cavity is originally difficult, but it becomes more likely usable with inserted tapered (thickness decreased towards the center) distributed DBRs. Simulation turns out that, incorporating adiabatically tapered DBRs, a Si/SiO2- InP hybrid micropillar cavity, which enables weakly coupling InAs/InP quantum dots (QDs), can even well satisfy strong coupling at a smaller diameter. Certainly, not only the tapered structure, other adiabatic designs, e.g., both DBR layers getting thicker and one thicker one thinner, also improve the quality, reduce the diameter, and degrade the fabrication difficulty of Si/SiO2-InP hybrid micropillar cavities. Furthermore, the problem of the thin epitaxial semiconductor layer can also be greatly resolved by inserting adiabatic InGaAsP/InP DBRs. With tapered DBRs, the InGaAsP/InP-air-aperture micro-pillar cavity serves as an efficient, coherent, and monolithically producible 1.55-μm single-photon source (SPS). The adiabatic design is thus an effective way to obtain prospective candidates for 1.55-μm QD SPSs.

关键词： Cavity distributed Bragg reflectors(DBRs) micropillar quantum dot(QD) single-photon source(SPS)

Image Field Deformation of LAMOST due to Differential Atmospheric Refraction

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Chinese Journal of Astronomy and Astrophysics 2006年第4期6卷 495-502页

作者： Jin-ling li bo Zhang Yong yu Zhao-Xiang Qi Ming Zhao Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030

A vectorial expression of the image field deformation of LAMOST due to the differential atmospheric refraction is presented. The calculated results are compared with those from previous analyses based on the traditional spherical trigonometric formulas. It is demonstrated that different tangential displacements of star images during the observation tracking given by various authors are simply due to different reference points adopted. It is pointed out that the observational celestial pole is the center of the apparent diurnal motion, that, by referring to the observational celestial pole, the effect of the differential refraction on the image field of LAMOST during the 1.5-hour tracking period is approximately equivalent to a constant rotation of - 13.65″ for all declination belts. It is therefore unnecessary to design a particular tracking velocity for each observation, and this will be obviously advantageous to the observation implementation. If the maximum tracking error of the fibers is 0.2″, then the fibers are required to be able to re-position during observational tracking for sky regions south of declination ＋20° and north of declination ＋60°.

关键词： telescopes -- atmospheric effects -- methods: analytical-- methods: statistical-- astrometry

An Eight-Channel 400 GHz-Spacing Etched Diffraction Grating Multi/Demultiplexer on a Nanophotonic Silicon-on-Insulator Platform

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Chinese Physics Letters 2013年第8期30卷 74-77页

作者： SHEN Ao QIU Chen HU Ting XU Chao JIANG Xiao-Qing li yu-bo YANG Jian-Yi Department of Information Science and Electronics Engineering Zhejiang UniversityHangzhou 310027 Cyrus Tang Center for Sensor Materials and Applications Zhejiang UniversityHangzhou 310027

An eight-channel 400 GHz-spacing planar waveguide multi/demultiplexer employing etched diffraction grating is designed and fabricated on a silicon-on-insulator platform with a 220 nm thick top *** design parameters are optimized by scalar diffraction simulation to obtain optimal performance with a small footprint of only 0.75 mm^(2).A bi-level adiabatic taper is used to connect the input/output waveguide and the slab waveguide so as to reduce the insertion loss and the broadening of the diffraction angle of the propagating *** device is fabricated in a two-step process with E-beam lithography and dry etching,and the alignment accuracy is 10 nm or even *** show that the insertion loss is 7.35 dB and the crosstalk between adjacent channels is about-15 *** to improve the performance are also investigated in detail.

关键词： waveguide lithography insertion

Synthesis and characterization of non-symmetrical liquid crystals containing a cholesteryl ester moiety

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Chinese Chemical Letters 2009年第5期20卷 562-565页

作者： Duo Wei Zhang Wei Huang Guo Hui Pan Wan li He yu bo Cao Jin Bao Guo Hui Cao Huai Yang Department of Materials Physics and Chemistry School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

In this paper, a series of chiral non-symmetrical liquid crystals （nBA-chol） consisting of a cholesteryl ester moiety as chiral entity and a biphenyl aromatic core with different terminal alkyl chain has been synthesized and investigated for their liquid crystalline properties. Effects of numbers of methylene units in the terminal alkyl chain on the phase transition temperatures and on the temperature-dependent pitch lengths of the chiral liquid crystals have been studied. The long terminal alkyl chain tends to exhibit smectic A mesophases. The pitch lengths of the cholesteric mesophases of the chiral liquid crystals decrease with increasing temperature and with increasing numbers of methylene units in the terminal alkyl chain, respectively.

关键词： liquid crystals Non-symmetrical Chiral Mesophase Pitch

Changes in percentage of lymphocyte subsets after ^(131)I treatment in patients with differentiated thyroid cancer

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Nuclear Science and Techniques 2005年第4期16卷 214-216页

作者： LUO Quan-Yong CHEN li-bo yu Yong-li LU Han-Kui ZHU Rui-Sen Department of Nuclear Medicine Shanghai Sixth People＇s Hospital. Shanghai Jiaotong University Shanghai 200233

To monitor the extent and the duration of lymphocyte subset changes in patients with thyroid carcinoma undergoing therapeutic 131I administration, the percentage of lymphocyte subsets were serially analyzed before and after 131I treatment. In patients who received 1850 MBq of 131I for ablation of thyroid remnants, only for NK cells and B cells showed a significant reduction. In patients received 3700 MBq of 131I for treatment of local lymph node me-tastases, NK cells, B cells and CD4+ were found decreased. In patients received 7400 MBq of 131I for treatment of distant metastases, NK cells, B cells and CD4+ and CD8+ were all affected. However, there is no significant reduc-tion compared to the baseline in the percentage of all lymphocyte subsets three months after 131I treatment. The re-sults show that the sensitivity of lymphocytes to 131I internal radiation depends upon lymphocyte phenotype and 131I activity. The immunosuppression effects are temporary and reversible.

关键词：淋巴细胞 ^131I 甲状腺癌症放射性疗法抑制免抑反应

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二维四元零相关区周期互补阵列集构造法

系统工程与电子技术 2013年第5期35卷 924-929页

作者：刘凯俞赛李玉博燕山大学信息科学与工程学院河北秦皇岛066004

基于二维二元周期互补阵列集和移位序列,利用逆Gray映射,提出了一类二维四元零相关区周期互补阵列集的构造方法。获得的阵列集由多个四元零相关区周期互补阵列子集组成,不同子集之间具有完全正交互补特性。本文的构造方法可分别对阵列... 详细信息

基于二维二元周期互补阵列集和移位序列,利用逆Gray映射,提出了一类二维四元零相关区周期互补阵列集的构造方法。获得的阵列集由多个四元零相关区周期互补阵列子集组成,不同子集之间具有完全正交互补特性。本文的构造方法可分别对阵列的行列进行移位,能够获得具有不同参数形式的二维四元零相关区周期互补阵列集。同时行(列)方向上的零相关区长度可以灵活设置,从而能获得不同的移位序列集,构造出多个二维四元零相关区周期互补阵列集。构造结果表明,本文方法可有效地增加工程应用所需的阵列信号。

关键词：二维周期互补阵列集移位序列零相关区逆Gray映射

Effect of a nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester on invasion of human colorectal cancer cell line SL-174T

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World Journal of Gastroenterology 2005年第40期11卷 6385-6388页

作者： li-bo yu Xin-Shu Dong Wen-Zhou sun Dong-Lu Zhao yue Yang Department of GeneralSurgery the Affiliated Tumor Hospital of Harbin MedicalUniversity Harbin 150040 Heilongiiang Province China Cancer Research Institute of HarbinMedical University Harbin 150040 Heilongjiang Province China

AIML To investigate the effect and mechanism of action of the nitric oxide synthase （NOS） inhibitor NG-nitro-L-arginine methyl ester （L-NAME） on invasion and metastasis of human colorectal cancer cell line SL-174T. METHODS： Human colorectal cancer cel4 line SL-174T was cultured and treated separately with four different dosages of L-NAME for 72 h, Nitric oxide （NO） production was measured with Griess reagent, The effect of L-NAME on invasion and migration of SL-174T cells were evaluated by using Transwell chambers attached with polycarbonate filters and reconstituted basement membrane （Matrigel）, RT-PCR was performed to determine the mRNA levels of matrix metalloproteinase-2 （MMP-2） and tissue inhibitor metalloproteinase-2 （TIMP-2）,RESULTS： L-NAME could significantly inhibit NO production of SL-174T in a dose-dependent manner. After being treated for 72 h with 0.2, 0.4, 0.8, and 1.0 mmol/L L- NAME, respectively, the ability of the L-NAME treated SL- 174T cells to invade the reconstituted basement membrane decreased significantly （t = 8.056, P〈0.05; t= 14.467, P〈0.01; t= 27.785, P〈0.01; and t= 29.405, P〈0.01, respectively） and the inhibition rates were 10.29%, 19.62%, 34.08%, and 42.23%, respectively. Moreover, L-NAME could inhibit migration of SL-174T cells, and the inhibition rates were 20.76%, 24.95%, 39.43%, and 46. 85% for L-NAME at 0.2, 0.4, 0.8, and 1.0 mmol/L, respectively （t = 15.116, P〈0.01）. In addition, after treatment with L-NAME, expression of MMP-2 mRNA was significantly decreased （t = 71.238, P〈0.01） and that of TIMP-2 mRNA was markedly increased （t = -13.020, P〈0.01）. CONCLUSION： L-NAME exerts anti-invasive and anti- metastatic effects on SL-174T cell line via downregulating MNP-2 mRNA expression and upregulating TIMP-2 mRNA expression.

关键词： Colorectal Neoplasms Neoplasm Invasiveness Cell line, Tumor Cell Movement Dose-Response Relationship, Drug Female Gelatinase A Humans Male NG-Nitroarginine Methyl Ester Nitric Oxide Nitric Oxide Synthase inhibitors Tissue Inhibitor of Metalloproteinase-2