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11.
The wave equation of light beam propagation was written in the form of an axial-coordinate-dependent Schrdinger equation, and the expectation value of a dynamical variable, the trial function of variational approach and the ABCD law were discussed by use of quantum mechanics approach. In view of the evolution equations of expectation values of dynamical variables in the framework of quantum mechanics, the definition of a potential function representing the beam propagation stability and its universal formula with the quality factor, the universal formula of beam width and curvature radius for a paraxial beam and cylindrically symmetric non-paraxial beam, the general formula of second derivative of beam width with respect to the axial coordinate of beam for a paraxial beam, and the general criteria of the conservation of beam quality factor and the existence of a potential well of a potential function for a paraxial beam, were given or derived, respectively. Starting with the same trial function, the comparative research of our formulation with variational approach was done, which gave some further insight into the physical nature of a beam propagation parameters. The ABCD law of non-paraxial beam was discussed in terms of the definition of the non-paraxial expectation value of a dynamical variable for the first time. The applications to the media of constant second derivative of beam width with respect to the axial coordinate of a beam, square law media and the media of constant refractive index in the momentum representation were discussed, respectively. 相似文献
12.
芳香烃受体(Aryl hydrocarbon receptor,AhR)属于配体依赖性的转录因子蛋白。本文通过对AhR配体结合区域(Ligand binding domain,LBD)的结构功能及物种特异性分析,发现在其结合腔口有一些关键残基可能起到"门控"作用,进一步将野生型(WT)和3个突变模型(Phe289Ala、Tyr316Ala、Ile319Ala)进行分子动力学模拟,从蛋白稳定性、蛋白结构变化、蛋白结合腔变化及蛋白和配体结合能力4个方面分析3个残基的门控作用。研究发现,Phe289、Tyr316、Ile319氨基酸残基通过形成疏水作用为AhR LBD起到"门控"作用;而将这些氨基酸分别突变后,其蛋白稳定性降低,整体运动性增加,配体亲和力减弱,其中Tyr316、Ile319对腔内体积影响较大,Phe289使腔内环境稳定性降低。本研究可为基于芳香烃受体的药物设计提供相关理论指导。 相似文献
13.
Transportation discrete network design problem (DNDP) is about how to modify an existing network of roads and highways in order to improve its total system travel time, and the candidate road building or expansion plan can only be added as a whole. DNDP can be formulated into a bi-level problem with binary variables. An active set algorithm has been proposed to solve the bi-level discrete network design problem, while it made an assumption that the capacity increase and construction cost of each road are based on the number of lanes. This paper considers a more general case when the capacity increase and construction cost are specified for each candidate plan. This paper also uses numerical methods instead of solvers to solve each step, so it provides a more direct understanding and control of the algorithm and running procedure. By analyzing the differences and getting corresponding solving methods, a modified active set algorithm is proposed in the paper. In the implementation of the algorithm and the validation, we use binary numeral system and ternary numeral system to avoid too many layers of loop and save storage space. Numerical experiments show the correctness and efficiency of the proposed modified active set algorithm. 相似文献
14.
Shanshan Tong Min Fu Xia Cao Caleb Kesse Firempong Chengxue Yi Qianfeng Zhen Hui Zhong Jiangnan Yu Ximing Xu 《Chromatographia》2014,77(5-6):419-429
For the first time, a novel biological affinity separating system called lipid raft stationary phase chromatography (LRSC) was developed. It was employed to screen bioactive components from Chinese gallnut, a traditional Chinese medicine (TCM). The LRSC was prepared by the addition of activated silica to Tris–HCl solution, which contains the isolated lipid rafts of U251 cells. This was followed by agitation, washing, centrifugation and then re-suspension of the residue in another Tris–HCl solution. The lipid rafts possess abundant receptor tyrosine kinase, specifically tropomyosin-related kinase A (TrkA), which is a widely researched anti-tumor drug target. Thus, TrkA provided the LRSC model with the ability to select fractions that specifically interact with it. Using a non-TrkA targeted anti-tumor drug (gemcitabine) and TrkA targeted anti-tumor drugs (lestaurtinib and gefitinib) as controls to evaluate the specific affinity of the LRSC column, the different fractions of Chinese gallnut were subjected to LRSC screening for the identification of anti-tumor components. As a result, the ether fraction of Chinese gallnut manifested desirable affinity properties. The methyl thiazolyl tetrazolium assay confirmed the anti-tumor effect of the screened ether fraction, and more importantly, the ether fraction failed woefully to exhibit its anti-proliferative activity in the presence of TrkA inhibitors (K252a and primary antibody). This further proves the selectivity of LRSC on TrkA-targeted drugs. The LRSC model has, therefore, shown to be of high efficiency and selectivity in screening bioactive components from the complex TCM extracts, thus offering an effective approach for the development of anticancer natural products. 相似文献
15.
Ying Liu Dr. Ximing Rong Mingze Li Prof. Maxim S. Molokeev Prof. Jing Zhao Prof. Zhiguo Xia 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(28):11731-11737
The incorporation of impurity ions or doping is a promising method for controlling the electronic and optical properties and the structural stability of halide perovskite nanocrystals (NCs). Herein, we establish relationships between rare-earth ions doping and intrinsic emission of lead-free double perovskite Cs2AgInCl6 NCs to impart and tune the optical performances in the visible light region. Tb3+ ions were incorporated into Cs2AgInCl6 NCs and occupied In3+ sites as verified by both crystallographic analyses and first-principles calculations. Trace amounts of Bi doping endowed the characteristic emission (5D4→7F6-3) of Tb3+ ions with a new excitation peak at 368 nm rather than the single characteristic excitation at 290 nm of Tb3+. By controlling Tb3+ ions concentration, the emission colors of Bi-doped Cs2Ag(In1−xTbx)Cl6 NCs could be continuously tuned from green to orange, through the efficient energy-transfer channel from self-trapped excitons to Tb3+ ions. Our study provides the salient features of the material design of lead-free perovskite NCs and to expand their luminescence applications. 相似文献
16.
佳木斯地区中草药微量元素的测定 总被引:1,自引:0,他引:1
采用原子吸收分光光度法测定了佳木斯地区产12种中草药的元素含量,为本地区中草药资源的开发和利用提供了有意义的数据。 相似文献
17.
LiNbO3电光偏转器的研究 总被引:8,自引:1,他引:7
从电光效应出发,对LiNbO3电光偏转器的基本品质因子进行研究,导出了偏转器的设计公式,用有限差分法计算了四柱面电极电光偏转器的电场分布,对不同结构参数,给出了梯度线性度和结构因子。 相似文献
18.
理论分析用二种不同材料组成复合色散棱镜的色散量,提出变相色散棱镜,以增大色散量。结论在实验中得到验证。 相似文献
19.
Gypsophila L.中国有25种。1980年出版的“新疆植物检索表”第二册中收载了5种。“新疆植物名录”中收载了4种。中国高等植物图鉴补编(1:336,1982)收载了11种。本文按现行新疆维吾尔自治区的行政范围进行整理研究,共收载了12种,其中发现全国分布新纪录2种—G.capitata M.B.,G.sericea(Ser.)Kryl.新疆分布新纪录1种—G.licentiana Hand—Mazz。本文阐明了新疆境内石头花属植物的生态、地理分布特点。在新疆境内本属植物的区系地理成分主要是亚洲中部的草原和荒漠成分。 相似文献
20.
度规光学中的聚焦定理被导出。给出了光束的聚焦,散焦和陷的条件。讨论了分析在静态曲对称介质中的应用。 相似文献