浅谈如何上好一堂中学生物课

人们往往会认为生物学教师的任务只是传授给学生一些生物方面的知识,只要具有生物学专业知识的人就能够胜任这一工作。这种认识与当今学校生物学教师的实际任务和对教师的对教师的要求有很大的偏差。要胜任当代生物学教师的工作,不仅要有坚实的生物学专业知识和实验技能为基础,同时还要理解中学生物学课程的性质和价值,掌握学生学习规律和学习特点,还要能够利用评价方式来反映学生的进步。     

国际科学教育中的生物学教育研究进展与启示 ——基于CiteSpace的可视化分析

以Web of Science数据库核心合集收录的8种国际知名SSCI期刊论文为基础,借助CiteSpace软件对国际生物学教育研究领域2000—2019年的文献进行知识图谱可视化分析,系统梳理近二十年来国际生物学教育研究领域的进展和趋势后发现:国际科学教育界对生物学教育的关注呈上升趋势;欧美国家在生物学教育研究领域占主导地位;国际生物学教育研究可归类为六大热点领域,体现出国际生物学教育研究重视科学素养培养,注重情景化、时代性、现代化,并具有一定文化独特性的特点;最新的研究前沿主要围绕学习进阶和生物进化主题展开,课程标准类文件的引用率最高.我国生物学和科学教育研究领域尚有很大的发展潜力,需关注课程标准落实,发展学生核心素养;加强国内外互通合作,鼓励研究成果交流与转化;把握国际研究热点与趋势,关注现有研究中较为薄弱的领域,促进本土科学教育发展.     

激光在生物学医学上应用

一、生物医学工程兴起及其特点 激光在生物学医学上的应用实质上是生物医学工程的一个分支，它就是应用激光这种物理技术手段去了解生物的生命活动过程，对医学临床进行诊断、防治的研究。先进的工程技术，从四十年代开始大量引进生物学医学领域，产生了生物学工程、医学工程．生物医学工程。     

激光在生物学领域中应用研究进展

本文综述了近些年来激光在生物学领域中研究的进展,对激光的生物学刺激效应、激光诱变育种、激光处理对生物细胞学的影响进行了介绍.     

激光技术在生物学中的研究领域及应用前景

激光作为工具、测量装置和分析仪器已在生物学和相近学科中得到广泛应用。与其他研究领域一样，激光技术也明显存在与其他学科的交叉联系。首先是医学，从生物学到医学的应用一直是激光界与生物界、医学界科研人员研究的课题。本文介绍激光技术在生物学中的一些研究领域以及这些领域的技术成熟程度及应用前景。1．激光技术在生物学中的研究领域图1示出激光技术在生物学中的各个研究领域。1．1激光微加工和激光控制生物体，如细菌、病毒、整个细胞或亚细胞粒子的精密处理和控制是先进的生物、医学和生物工程研究的必要先决条件。激光系统和显…     

微流控芯片技术在细胞生物学研究中的应用进展

微流控芯片作为生物学研究平台的一种,优势显著,如：集成化、低消耗、高通量等,其所提供的细胞研究条件不仅具有较强的可控性,同时也十分精细,因此,该平台得到了细胞生物学学者的广泛关注。本文介绍了微流控芯片技术的概况,重点阐述了其在细胞生物学研究中的应用。     

基于生物信息学特征的DNA序列数据压缩算法

本文通过将生物学特征和生物学含义引入DNA序列数据的压缩处理中,提出了基于生物信息学特征的BioLZMA压缩算法.在BioLZMA算法中,DNA序列根据组成部分生物学含义的不同切分重组为四个集合:编码序列CDS集合、内含子序列集合、RNA序列集合以及剩余序列的集合.根据各集合中序列的具体生物学特征分别使用针对性的压缩策略进行预处理,并通过LZMA算法进行压缩编码.实验结果表明,BioLZMA算法在基准测试序列上的压缩性能优于原有的DNA序列压缩方法.特别是对于生物信息学特征清晰的长序列,算法能够在较短的时间内获得较高的压缩率.     

对激光生物学和医学发展的我见与建议

生命科学的发展依赖基础学科提供的理论和技术学科提供的工具。光学和光电子学技术曾对生物学和医学起过质的促进作用,光学显微镜的出现将生命科学的研究深入到细胞水平;电子显微镜则使人们能探索细胞内的超微结构和细胞器的功能;当今生物学的前沿学科一分子生物学则需量子力学和化学的理论指导及Ｘ光衍射技术提供的实验手段。激光出现之后,立即为生物学和医学所用：开创了激光照射治疗眼病代替了复杂的眼科手术;利用激光的局部加热和光敏作用治疗浅表和内腔肿瘤获得很好的疗效;激光使细胞荧光提高了几个数量级,使流式细胞分析技术得…     

量子点标记及其在植物细胞生物学中的应用

量子点是一种直径在1-100 nm,能接受激发光产生荧光的半导体纳米晶粒,由于其独特的物理、化学特性,在生物学中的应用不断扩大。本文介绍了量子点的合成及功能方面的进展,同时也对其在细胞生物学中的应用进展,特别是对其在植物细胞生物学中的应用进行了评述。此外,对量子点在单分子检测、高分辨率细胞成像及活体动态长时追踪方面的应用前景进行了展望。     

随机游走技术在网络生物学中的研究进展

网络生物学是近年来受到国际学术界广泛关注的学术前沿领域,在疾病研究和药物预测等领域有重要应用.随机游走（Random Walk）又称随机游动或随机漫步,是一种数学统计模型,在金融、物理和社会网络分析中都有广泛应用.近年来逐渐被应用到网络生物学,并在技术上得到了新的发展.本文以生物网络为基础,介绍了随机游走技术及其基本理论,并详细阐述了随机游走技术在网络生物学中的应用,具体包括蛋白质功能预测、关键蛋白质识别、疾病基因预测、疾病相关非编码RNA预测、药物相关预测等.最后讨论了随机游走技术在网络生物学研究中存在的问题以及未来的研究方向.     

一种新的变步长LMS算法在通信对消技术的应用

本文通过分析几种变步长LMS算法,结合VSS-NLMS算发和NLMS算法的优点,采用符号函数降低原有算法的计算复杂度,对变步长参数进行调整,提出了一种改进的变步长LMS算法,通过仿真验证,新提出的算法在收敛速度和稳态误差上也有一定优点,具有工程实际意义。     

Effect of sodium selenite on the activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase) during hepatocarcinogenesis

Influence of sodium selenite on functioning of the systems of intracellular generation and detoxication of active oxygen compounds in hepatocarcinogenesis induced by diethylnitrosamine has been studied in experiments on rats. It has been shown that the duration of latent period initiated by ions of Fe2+ chemiluminescence of homogenate of the liver rather objectively reflects the state of the functioning of the systems in charge of the formation and utilization of free radicals of oxygen in a cell. It is supposed that one of the mechanisms of anticarcinogenic action of selenium is connected with its antioxidant functions in the organism and consists in the increase of the activity of superoxide dismutation and selenium-dependent glutathione peroxidases, providing a reliable level of enzymatic protection of normal cells from disturbing action of "active oxygen".     

Statistical characteristics of chaoticity and incomplete chaoticity of irregular oscillations generated by a strongly nonlinear autonomous system with two degrees of freedom

The notion of the interval of nonergodicity as one of the statistical characteristics for time realizations of an irregular process is introduced. A method for determination of this factor based from the analysis of autocorrelation functions of truncated realizations is developed. The chaoticity of irregular oscillations in a strongly nonlinear autonomous system with two degrees of freedom is proved using the criterion of decomposition of time correlations. The statistical indication of the existence of incomplete chaoticity of oscillations in the case of incomplete decomposition of correlations is formulated. Conditions of weak distortions of the energy spectrum for truncated realizations are determined. Probability distribution functions for the characteristics of an irregular time process in the studied system are considered.     

Modeling of wideband slow-wave structures of coupled-cavities-chain type by the impedance design of experiments

The results of investigation on the possibility of a substantial extension of the operating-frequency band of a slow-wave structure of coupled-cavities-chain type are presented for the case of a small variation in the slowing factor of the phase velocity of a wave, including, in the case of convergence of the cavity and slot passbands. The investigation is performed with the use of regression models for electrodynamic characteristics of the slowing structure that are constructed on the basis of the results obtained by the impedance design of experiments. Variants of wideband chains of coupled cavities with differences in the phase-velocity slowing factor of ±3% and the operating width of the cavity passband of up to 35%, as well as structures with merging of the cavity and slot passbands and a resulting passband of up to 70% and a coupling impedance of 18–0.4 Ω, are obtained.     

基于物联网的图书馆管理系统

针对物联网的基本概念、起源、发展以及物联网关键技术,针对图书馆借书流程、图书快速定位、图书安全等问题与RFID技术的应用进行设计。通过介绍智能图书馆对于物联网技术的应用,提出智能图书馆的智能化和便捷化,同时也提出了发展物联网的重要意义,通过对只能图书馆的设计,让人们真切感受到物联网对人们生活的提升。     

Radiation from a Plasma Layer with a Strong Longitudinal Irregularity

The efficiency of conversion of the energy of a surface wave into radiation at longitudinal irregularities of a planar plasma layer is studied. The analysis is performed by the spectral expansion of the field in a complete set of surface and pseudosurface waves. The system of integro-differential equations for the coefficients of expansion that determine the amplitudes of the transmitted, reflected, and scattered waves as well as the radiation pattern is solved in the case of a rapid change in the plasma density. The coefficients of transformation of energy into the energy of radiation as functions of the gradient of the plasma density for different values of the electrical length of the region of plasma irregularity and the electric thickness of the plasma layer are found. Examples are demonstrated when the fraction of the energy of the surface wave transformed into radiation reaches 60–70%. Radiation patterns that proved to be highly directional and having one lobe with the maximum at an angle of a few degrees to the direction of propagation of the surface wave are calculated.     

左手材料的色散和等倾干涉

研究了左手材料棱镜的色散特性和左手材料平行平板的等倾干涉特性。对于左手材料棱镜而言,其色散时出射光偏离原来的传播方向与右手材料棱镜的色散规律恰好相反,且对于同一种单色光而言,当入射角相同时,左手材料棱镜的色散偏向角大于右手材料棱镜的色散偏向角。在研究左手材料平行平板的等倾干涉特性时,推导了反射光和透射光焦平面上的光强分布公式,分析了等倾干涉条纹的级数与亮、暗条纹的关系,讨论了光程差的影响因素及影响规律,推导了存在半波损失情况下的等倾圆环的亮环半径公式和暗环宽度公式。研究发现:对于左手材料平行平板的等倾干涉条纹而言,等倾干涉圆环中心处的干涉级数较小;偏离圆环中心越远,干涉条纹的级数越大。这一规律和右手材料平行平板的等倾干涉条纹规律不同。     

Simulation of the absorption of a femtosecond laser pulse in crystalline silicon

The effect of the nonlinearity of the absorptivity and absorption coefficient on the process of the intense photoexcitation of silicon is studied on the basis of a model of the two-photon excitation of a semiconductor with consideration for external emission. Correlation between the results of simulation of the absorption of a femtosecond laser pulse in single-crystal silicon and experimental data under conditions of the femtosecond excitation of surface plasmon polaritons makes it possible to refine the mechanism of changes in the absorptivity and to make an inference regarding the necessity of considering these changes when assessing the conditions of the laser treatment of semiconductors. Avenues for further improvement of the theoretical model are discussed.     

Elimination of cyclic phase slips of single-frequency kinematic GNSS observations

The results of development of a new method for the estimation and elimination of cyclic phase slips of single-frequency kinematic GNSS observations have been presented. The investigations and verification of the proposed method were performed using simulations and real GPS observations. Conditions of the continuity restoration of phase observations were determined; the specified conditions ensure a reliable elimination of cyclic phase slips under conditions of the partial and total loss of observations on intervals of up to 30 s. The possibilities of enhancing the reliability of elimination of phase slips were investigated using a group of increments of observations obtained under the free running and differential modes of coordinate determinations. It was shown that the reliability of solving the problem in question was critically dependent on the use of smoothed code observations. The smoothing of code observations makes it possible to achieve a much larger effect as compared with an attempt of increasing the number of satellites in the current constellation.     

Prospects of a slotline utilization as the excitation element of a quasi-optical hemispherical resonator for the problems of liquids dielectrometry

Inthis article we propose the utilization of a quasi-optical resonator in the form of the resonant cavity of hemispherical shape in the metal as a measurement cell of a dielectrometer for the investigation of electrophysical properties of liquids. We have carried out the investigations of electromagnetic characteristics of the utilized resonator in the case of the air filling and of the partial filling by the analyzed liquids (benzene, butanol, ethanol, methanol). The possibility of effective excitation of whispering gallery modes using the slot line has been demonstrated. We have determined the possibilities of the utilized investigation technique of the electrophysical properties of different liquids and of their identification based on the variations of electromagnetic characteristics of the proposed measurement cell. It has been shown that in the case of a small perturbation of the resonance fields by samples of liquids (with volume up to 3 ml) this technique for the proposed resonator possesses a high sensitivity and resolution capability for the identification of liquids with a relatively small difference of the electrophysical parameters.