50 GHz optical true time delay beamforming in hybrid optical/mm-wave access networks with multi-core optical fiber distribution

We propose and experimentally validate an optical true time delay beamforming scheme with straightforward integration into hybrid optical/millimeter(mm)-wave access networks. In the proposed approach, the most complex functions, including the beamforming network, are implemented in a central office, reducing the complexity and cost of remote antenna units. Different cores in a multi-core fiber are used to distribute the modulated signals to high-speed photodetectors acting as heterodyne mixers. The mm-wave carrier frequency is fixed to 50 GHz(VBand), thereby imposing a progressive delay between antenna elements of a few picoseconds. That true time delay is achieved with an accuracy lower than 1 ps and low phase noise.     

Numerical tests of theoretical models describing ionization of H(1s) atom by linearly polarized flat pulse of laser radiation

We derive the well-known Coulomb correction factor for the Gordon-Volkov wave function describing an outgoing electron in the process of ionization in an intense laser field. Although rigorous treatment would limit its use only to laser fields much lower than the so-called barrier-suppression field, it appears that in practice the correction factor may be used also close to and even above this critical value of the laser field. We compare predictions of several analytical expressions describing ionization rate of the hydrogen atom in its ground state in the strong linearly polarized laser field. We also compare ionization probabilities obtained by integrating these ionization rates over a temporal envelope of the laser pulse with predictions based on the exact numerical solution to the time-dependent Schr ¨odinger equation.     

On a certain classes of meromorphic functions with positive coefficients

In this paper certain classes of meromorphic functions in punctured unit disk are defined. Some properties including coefficient inequalities, convolution and other results are investigated.     

Depleted uranium oxide supported nickel catalyst for autothermal CO2 methanation in non-adiabatic reactor under induction heating

Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO₂ methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating. By adjusting the reaction conditions, the catalyst is able to perform CO₂ methanation reaction under autothermal process operated inside a non-adiabatic reactor, without any external energy supply. Such autothermal process is possible thanks to the...     

Towards a business model for second-life batteries: Barriers,opportunities, uncertainties,and technologies

Electric vehicles(EVs) and the recent pandemic outbreak give cities a new trend to primarily private and shared mobility with low noise and less air pollution.Crucial factors for the widespread of EVs are the electrical charging infrastructure,driving range,and the reduction of the cost of battery packets.For this reason,there is a massive effort from manufacturers,governments,and the scientific community to reduce battery costs and boost sustainable electrical production and distribution.Batter...     

F−(H2O)+CH3I配体交换反应动力学

本文介绍F^?(H₂O)+CH₃I→[FCH₃I]^?+H₂O在交叉分子束碰撞能量0.3∽2.6 eV的配体交换动力学成像结果. 产物的动能受到弱键结合配合物的稳定性的影响,大量水分子的内部激发不利于中间物有效的能量重新分配,随着碰撞增加,低动能受到抑制. 在0.3 eV时,内部亲核取代非常重要,为形成I^?和I^?(H₂O)的竞争性亲核取代途径提供了依据.     

Sn-Al合金作为锂电池负极材料的第一性原理研究

采用基于密度泛函理论的第一性原理平面波赝势方法计算了不同Al含量的固溶体Sn-Al合金的总能量与电子结构,得到Sn0.7Al0.3合金比例最适合用于锂离子电池Sn基合金材料,并对Sn0.7Al0.3合金嵌锂后的各种物理性质和电化学性质进行了理论计算,发现该固溶体合金相具有较稳定的电化学嵌锂电位和良好的充放电循环性能.同时采用磁控溅射制备了该合金薄膜材料,测试结果与理论计算具有较好的一致性.     

乾陵地理信息数据库的建设与开发

文章的目的是提供一个综合的信息管理和空间数据分析工具,为文物保护部门对乾陵历史遗址的文物保护现状进行分析评估提供决策依据。文章采用当前国内外流行的大型数据库技术和处理空间地理信息的GIS技术,开发了乾陵地理信息数据库并在ArcGIS平台上与空间地理矢量图相连接,构成一个数字化乾陵保护区空间地理信息系统。结果表明:该系统的建立和运行,不仅能对乾陵保护区各种文物资源的现状进行评估,还能对文物保护区的保护规划提供决策服务。     

Genetic background of phenotypic variation

A noteworthy feature of the living world is its bewildering variability. A key issue in several biological disciplines is the achievement of an understanding of the hereditary basis of this variability. Two opposing, but not necessarily irreconcilable conceptions attempt to explain the underlying mechanism. The gene function paradigm postulates that phenotypic variance is generated by the polymorphism in the coding sequences of genes. However, comparisons of a great number of homologous gene and protein sequences have revealed that they predominantly remained functionally conserved even across distantly related phylogenic taxa. Alternatively, the gene regulation paradigm assumes that differences in the cis-regulatory region of genes do account for phenotype variation within species. An extension of this latter concept is that phenotypic variability is generated by the polymorphism in the overall gene expression profiles of gene networks. In other words, the activity of a particular gene is a system property determined both by the cis-regulatory sequences of the given genes and by the other genes of a gene network, whose expressions vary among individuals, too. Novel proponents of gene function paradigm claim that functional genetic variance within the coding sequences of regulatory genes is critical for the generation of morphological polymorphism. Note, however, that these developmental genes play direct regulatory roles in the control of gene expression.     

┱?例杨金彪;福建省南平市第

鸨?114尼美舒利致肝功能损伤1例陈瑶;李岚;厦门市妇幼保健院药剂科,上海儿童医学中心药剂科 厦门361000,上海200000尼美舒利;;肝功能损害0海峡药学Strait Pharmaceutical Journal118-119R725.9E06938E;E069_38陈瑶;114-115门诊药房实行专科药师制度的必要性陈成辉;何丽芳;