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81.
Germanium dioxide (GeO2) aqueous solutions are facilely prepared and the corresponding anode buffer layers (ABLs) with solution process are demonstrated. Atomic force microscopy, X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy measurements show that solution-processed GeO2 behaves superior film morphology and enhanced work function. Using GeO2 as ABL of organic light-emitting diodes (OLEDs), the visible device with tris(8-hydroxy-quinolinato)aluminium as emitter gives maximum luminous efficiency of 6.5 cd/A and power efficiency of 3.5 lm/W, the ultraviolet device with 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole as emitter exhibits short-wavelength emission with peak of 376 nm, full-width at half-maximum of 42 nm, maximum radiance of 3.36 mW/cm2 and external quantum efficiency of 1.5%. The performances are almost comparable to the counterparts with poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) as ABL. The current, impedance, phase and capacitance as a function of voltage characteristics elucidate that the GeO2 ABL formed from appropriate concentration of GeO2 aqueous solution favors hole injection enhancement and accordingly promoting device performance.  相似文献   
82.
Bryostatins are a class of naturally occurring macrocyclic lactones with a unique fast developing portfolio of clinical applications, including treatment of AIDS, Alzheimer's disease, and cancer. This comprehensive account summarizes the recent progress (2014–present) in the development of bryostatins, including their total synthesis and biomedical applications. An emphasis is placed on the discussion of bryostatin 1 , the most-studied analogue to date. This review highlights the synthetic and biological challenges of bryostatins and provides an outlook on their future development.  相似文献   
83.
Tunneled metal oxides such as α-Mn8O16 (hollandite) have proven to be compelling candidates for charge-storage materials in high-density batteries. In particular, the tunnels can support one-dimensional chains of K+ ions (which act as structure-stabilizing dopants) and H2O molecules, as these chains are favored by strong H-bonds and electrostatic interactions. In this work, we examine the role of water molecules in enhancing the stability of K+-doped α-Mn8O16 (cryptomelane). The combined experimental and theoretical analyses show that for high enough concentrations of water and tunnel-ions, H2O displaces K+ ions from their natural binding sites. This displacement becomes energetically favorable due to the formation of K2+ dimers, thereby modifying the stoichiometric charge of the system. These findings have potentially significant technological implications for the consideration of cryptomelane as a Li+/Na+ battery electrode. Our work establishes the functional role of water in altering the energetics and structural properties of cryptomelane, an observation that has frequently been overlooked in previous studies.

Water displaces potassium ions and initiates the formation of a homonuclear dimer ion (K2+) in the tunnels of hollandite.  相似文献   
84.
85.
A first example of an Et2Zn mediated silylation of 1-aklynes is reported. A series of functional groups are tolerated in this reaction. Mechanistic studies support Zn alkynilides as intermediates in the reaction. This reaction protocol provides a practical method for the preparation of alkynylsilanes and expands the application of organometallic zinc in organic synthesis.  相似文献   
86.
短波广播能够实现远距离和大范围的覆盖,至今仍是进行地区性、全国性及国际性广播覆盖的最好手段之一。ITU在2001年4月批准的1514建议书《30MHz以下广播频段的数字声音广播系统》,正式确定了DRM系统为全球统一的数字广播系统。在短波广播由模拟向数字化过渡的进程中,如何解决短波广播频谱短缺的问题,本文根据国家相关的频谱监测和国际短波频率协调的情况,对短波广播中4~10MHz频谱的扩展可行性进行初步分析。  相似文献   
87.
A tunable dual-band quadrature hybrid coupler for mobile GSM bands (900 and 1800MHz) is proposed and characterized. The structure is composed of four quarter-wavelength sections at a frequency located between the two operating frequencies and two pairs of open-ended stubs. Frequency tuning is achieved by modifying the electrical length of the open-ended stubs with varactor-diode capacitors. A dual-band tunability of 33% and 10% is obtained for the first and the second bands, respectively  相似文献   
88.
A 10Gbit/s recirculating system is configured with Chirped Fiber Bragg Grating (CFBG) for the dispersion compensation. For the first time, the transmission distance in the loop reaches 1000km with bit error rate of 10-9. The effect of the group delay ripple of the fiber grating is also investigated in the recirculating systems, and it is shown that the transmission distance is limited to 4 cycles (4×167.1km ) in the loop with the power penalty fluctuation below 1.0dB. Thus the group delay ripple should be reduced to allow for the wavelength drift of±5GHz. At the end of this letter, the principles are given for designing long haul recirculating systems with dispersion compensation CFBG.  相似文献   
89.
通过在FPD铁路上使用LVDS技术可使具有数字RGB接口的液晶显示屏的工作距离大大增加。文章通过一个具体应用环境介绍了21位LVDS发送器/接收器DS90C363/DS90CF364传输套片的主要特性、引脚功能、工作原理,同时指出了在具体设计使用时的注意事项。  相似文献   
90.
探针馈电圆柱共形微带天线阻抗特性的FDTD法分析   总被引:1,自引:0,他引:1       下载免费PDF全文
将圆柱坐标系下非分裂式理想匹配层吸收边界条件(UPML)引入到圆柱共形微带天线的全波分析中,并给出了其中的场量迭代方程,明显地减小了计算空间,简化了编程;提出了圆柱坐标系下考虑有限尺寸探针半径的新算法,使得计算结果更加精确;应用GPOF方法预估了时域晚时响应,使计算时间减少了70%~90%。本文给出的模型能够对任意多层圆柱共形结构的微带天线进行计算,因此对此类天线的CAD设计具有实际意义。  相似文献   
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