关于无线电技术在智能家庭系统中应用的探讨

如今,人工智能的发展成果已经走进千家万户,智能家庭的出现也使人工智能技术融入传统家电设施,并逐步实现对家电和相关设备的智能控制以及设备之间的自由联通。智能家庭成为未来家电家居的发展方向之一,而利用无线电技术实现设备间的互联和通信则是智能家庭系统的技术核心。从智能家庭产业发展现状入手,对智能家庭系统中无线电通信技术的应用进行阐述和分析,并对智能家庭的未来发展进行展望。     

基于5G、物联网的新一代智能交通路口研究与设计

与4G通信传输技术相比,5G传输技术在终端密度、峰值速率、传输延时以及传输容量等多个方面取得突破性进展。这种优势有利于实现信息的高速传递,有助于构建出“人-车-路”智能化的通信系统,进而降低交通事故的风险率,构建出靓丽的城市交通风景线。对此,文章从新一代智能交通道路的发展以及5G的新一代智能交通道路的构成、功用、开发以及瓶颈五方面对此做了介绍。     

短波通信频率的选择技术研究与实现

短波通信技术具有传输距离远、灵活性强、机动性高、应用成本低等优势,在诸多领域都有着广泛的应用。短波通信主要时利用电离层与地面之间的反射实现通信功能,受到太阳辐射等多方面因素的影响,电离层具有不稳定性和变化的不规则性,短波通信的稳定性、可靠性和持久性也会受到较大的影,保证短波通信的质量,要结合通信需求和电离层变化的规律,选择合适的通信信道和通信频率。     

n型单晶硅片的电阻率和扩散方阻对IBC太阳电池电性能的影响

叉指背接触式(IBC)太阳电池因正面没有金属栅线遮挡,具有较高的短路电流,且组件外观更加美观。但由于IBC太阳电池正负电极在背面交叉式分布,在制备过程中需要采用光刻掩模技术进行隔离,难以实现大规模生产。采用Quokka软件仿真模拟了电阻率和扩散方阻对n型IBC太阳电池效率的影响,并对不同电阻率和扩散方阻的电池片进行了实验验证,从n型单晶硅片电阻率的选择和扩散工艺优化方面为IBC太阳电池的规模化生产提供了理论基础。实验结果表明,电阻率为3~5Ω·cm、扩散方阻为70Ω/时,小批量生产的IBC太阳电池平均光电转换效率可达23.73%,开路电压为693 mV,短路电流密度为42.44 mA/cm²,填充因子为80.69%。     

An analysis of avidin, biotin and their interaction at attomole levels by voltammetric and chromatographic techniques

The electroanalytical determination of avidin in solution, in a carbon paste, and in a transgenic maize extract was performed in acidic medium at a carbon paste electrode (CPE). The oxidative voltammetric signal resulting from the presence of tyrosine and tryptophan in avidin was observed using square-wave voltammetry. The process could be used to determine avidin concentrations up to 3 fM (100 amol in 3 l drop) in solution, 700 fM (174 fmol in 250 l solution) in an avidin-modified electrode, and 174 nM in a maize seed extract. In the case of the avidin-modified CPE, several parameters were studied in order to optimize the measurements, such as electrode accumulation time, composition of the avidin-modified CPE, and the elution time of avidin. In addition, the avidin-modified electrode was used to detect biotin in solution (the detection limit was 7.6 pmol in a 6 l drop) and to detect biotin in a pharmaceutical drug after various solvent extraction procedures. Comparable studies for the detection of biotin were developed using HPLC with diode array detection (HPLC-DAD) and flow injection analysis with electrochemical detection, which allowed biotin to be detected at levels as low as 614 pM and 6.6 nM, respectively. The effects of applied potential, acetonitrile content, and flow rate of the mobile phase on the FIA-ED signal were also studied.     

低钴AB5型稀土系贮氢电极合金的研究

为了进一步降低AB5型混合稀土系贮氢合金的成本,采用Cr,Si,Cu替代Co和调节化学计量比的方法制备低钴AB5型贮氢合金。结果表明:3种取代元素在寿命方面的效果依次为Si>Cr>Cu,在放电容量和活化性能方面依次是Cu>Cr>Si。Cr,Cu,Si只有少量的替代才可能发挥其有利影响;通过非化学计量比的调节,低钴混合稀土系贮氢电极合金的放电容量、活化性能及倍率放电能力都能较好地达到实用要求,但是循环寿命有待提高。     

液相组合合成的纯化方法

综述了近8年来液相平行合成和组合合成中应用的不同技术, 包括可溶性载体、氟合成技术、离子液体、固相试剂树脂以及低聚乙烯二醇(OEG)衍生物的应用等几方面内容. 论述了它们的基本原理以及相关的应用实例, 并着重强调了目标化合物的分离纯化方法.     

Photoelectrochemical behavior of coupled SnO2|CdSe nanocrystalline semiconductor films

A photoelectrochemical cell with a coupled SnO₂|CdSe nanocrystalline semiconductor electrode has been prepared by sequential deposition of SnO₂ and CdSe films onto an optically transparent electrode (OTE), and its photoelectrochemical behavior has been studied. The results show that the coupling of CdSe with SnO₂ leads to an improvement in the performance of OTE|SnO₂|CdSe over OTE|CdSe cells in terms of increased incident photon-to-current conversion efficiency, increased stability and smaller reversal of current. The favorable positioning of the energy bands of SnO₂ and CdSe is responsible for the above observations. Various photoelectrochemical parameters of the OTE|SnO₂|CdSe cell obtained for an incident light power of 0.31 mW cm⁻² at 470nm, are as follows: I_sc ≈ 25–30 μA cm⁻², V_oc ≈ 0.5–0.6 V, ƒƒ = 0.47 and a power conversion efficiency of about 2.25%.     

Sonochemical synthesis of mass single-crystal PbS nanobelts

Based on sonochemical technique, large-scale PbS nanobelts are successfully synthesized in the mixed solution of PbCl₂ and Na₂S₂O₃. These nanobelts are characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), selected area electronic diffraction, energy dispersive X-ray spectroscopy, and high-resolution TEM. The as-synthesized PbS nanobelts have width of about 80 nm, length up to several millimeters, and width-to-thickness ratio of about 5. In addition, the growth mechanism of PbS nanobelts is suggested.     

Determining PPARγ-ligand binding affinity using fluorescent assay with cis-parinaric acid as a probe

Upon the study of small-molecules binding to proteins, the traditional methods for calculating dissociation constants (Kd and Ki) have shortcomings in dealing with the single binding site models. In this paper, two equations have been derived to solve this problem. These two equations are independent of the total concentration or initial degree of saturation of receptor and the activity of the competitive molecule. Through nonlinear fitting against these two equations, Kd value of a probe can be obtained by binding assay, and Ki value of a ligand can be obtained by competitive assay. Moreover, only the total concentrations of receptor([R]t), ligand([L]t) and probe([P]t) are required for the data fitting. In this work, Ki values of some typical ligands of PPARγ were successfully determined by use of our equations, among which the Ki value of PPARγ-LY171883 was reported for the first time.