Miyaura Borylation and One‐Pot Two‐Step Homocoupling of Aryl Chlorides and Bromides under Solvent‐Free Conditions

Solvent‐free protocols for Miyaura borylation and the one‐pot, two‐step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)₂] is an optimal source of palladium for Miyaura borylation, while for one‐pot two‐step homocoupling palladium(II) acetate [Pd(OAc)₂] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.

     

利用高性能同时采样ADC降低高级电力线监测系统的成本

人们对电力需求的增长以及节能意识的增强使得全球在电力传输基础架构领域的投资迅速增长,这也带动了高级电力线监控系统在单相和多相应用中的市场,使其成为新一代智能电网的关键技术。随着对系统性能的要求越来越严格,设计人员开始在电力线监测或多通道SCADA(管理控制和数据采集)系统中关注同时采样、多通道、高性能ADC的使用。     

Modeling of Dynamic Effects in a Laser-Driven Semiconductor Switch of High-Power Microwaves

Problems of high-power microwaves penetrating into and reflecting from a semiconductor (silicon) plate with non-stationary processes are investigated. The plate is the basis of switches activated by laser-driven photoconductivity which changes its properties when heated by the switched microwave power. Analytical criteria for the stationary solutions of the activated (quasi-metallic) and deactivated (dielectric) states of the switch under the conditions of high-power microwave heating and external cooling are found. Results of numerical simulations are also given for the problems of the switch activation by microwave heating initiated by pulsed laser radiation, which increases the carrier density rapidly. Numerical simulations are carried out using the finite-difference time-domain method with the unsplit perfectly matched layer absorbing boundary conditions. We demonstrate various types of solutions depending on the basic parameters of the problems - microwave field intensity, laser pulse energy and semiconductor doping.     

遥控钥匙门禁系统的路径损耗

在遥控钥匙门禁(RKE)系统中,可以用钥匙扣上的发射器从远端开锁,发射器将无线编码发送到汽车内的接收机。遥控钥匙门禁(RKE)系统通常工作在ISM频段,包括315MHz和433．92MHz。随着远程启动和带校验的RKE的出现,设计     

The incorporation of mono- and bi-functionalized multiwall carbon nanotubes in organic photovoltaic cells

We have successfully prepared mono- and bi-functionalized multiwall carbon nanotubes (MWCNT) with thiophene, amine and thiophene-amine groups. The dispersion of nanotubes has been enhanced and stable optimized dispersions in organic solvents were obtained. These functionalized nanotubes have been successfully incorporated into bulk heterojunction (BHJ) organic photovoltaic (OPV) cells with a poly (3-hexyl thiophene) (P3HT) and [6, 6]-phenyl-C(61)-butyric acid methyl ester (PCBM) photoactive blended layer. The incorporation of MWCNT with different functional groups, in the active layer, results in different cell performance with respect to a reference cell. A maximum power conversion efficiency of 2.5% is achieved with the inclusion of thiophene functionalized nanotubes. This improvement in the device performance is attributed to an extension of the exciton dissociation volume and charge transport properties through the nanotube percolation network in P3HT/CNT, PCBM/CNT or both phases. This is believed to be due to more efficient dispersion of the functionalized nanotubes within the photoactive composite layer.     

Viral quantitative capillary electrophoresis for counting intact viruses

The quantification of a virus plays an important role in vaccine development, clinical diagnostics, and environmental contamination assays. In all these cases, it is essential to calculate the concentration or number of intact virus particles (ivp) and estimate the degree of degradation and contamination of virus samples. In this work, we propose a cost-efficient, robust method for the quantification and characterization of intact viruses based on capillary zone electrophoresis. This separation method is demonstrated on vaccinia virus (VV) with oncolytic properties. After virus sample preparation, the solution contains intact VV as well as broken viruses and residual DNA from the host cell used for preparation. Regulatory requirements limit the amount of the host cell DNA that can be present in vaccines or human therapeutics. We apply capillary electrophoresis to separate intact virus particles and the residual DNA and to measure the level of virus contamination with DNA impurities. Intercalating YOYO-1 dye is used to detect the encapsulated and free DNA by laser-induced fluorescence. After soft lysis of VV with proteinase K, all encapsulated DNA is dissolved to the free DNA. The change in peak areas and a DNA calibration curve help determine the initial concentration of intact viruses. This viral quantitative capillary electrophoresis (Viral qCE) is able to quantify the oncolytic vaccinia virus in the range of 10(6) to 10(12) ivp/mL.     

NiZnCu Ferrite Thick Film with Nano Scale Crystallites Formed by the Aerosol Deposition Method

This paper describes the magnetic properties of NiZnCu ferrite film deposited at room temperature by an aerosol deposition method (ADM). The thickness of the film was 6 μm and the deposition rate was estimated as 2 μm/min. The microstructure of as-deposited at room temperature films consists of randomly oriented nanocrystallites with a size of 20 nm. As-deposited and annealed films exhibited the following magnetic properties: intensity of magnetization M _s= 0.147 T (117 emu/cm³), coercivity H _c= 40.58 kA/m (510 Oe); and M _s= 0.3 T (250 emu/cm³), H _c= 14.95 kA/m (188 Oe), respectively.     

Digitizing a Dictionary of Medieval Irish: the eDIL Project

The Centre for Irish and Celtic Studies at the University ofUlster is currently producing a digital dictionary of medievalIrish (eDIL) based on the standard Dictionary of the Irish Languagepublished by the Royal Irish Academy, Dublin. This paper addressessome of the problems encountered in the digitization process,including data capture, processing non-standard characters,modifications to the TEI guidelines, automatic generation oftags, and the establishment of a lexical view while preservingthe original format of the paper dictionary.