Metallic Zinc Anode Working at 50 and 50 mAh cm−2 with High Depth of Discharge via Electrical Double Layer Reconstruction

Achieving high-rate and high-areal-capacity Zn anode with high depth of discharge (DOD) offers a bright future for large-scale aqueous batteries. However, Zn deposition suffers from severe dendrite growth and side reactions, which compromises achievable lifetime. Herein, an electrical double layer (EDL) reconstruction strategy is proposed by employing acetone as electrolyte additive to fully address these issues. Experimental and theoretical simulation results reveal that the adsorption priority of acetone to water on Zn creates a water-poor inner Helmholtz layer. Meanwhile, the intense hydrogen bonding effect between acetone and water confines the activity of free water and weakens the Zn²⁺ solvation in the outer Helmholtz layer and diffusion layer. Such ion/molecule rearrangement in EDL suppresses hydrogen evolution, facilitates the desolvation process, and promotes the Zn²⁺ diffusion kinetics, which guides homogeneous Zn nucleation and uniform growth, even in extreme situations. At both ultrahigh current density of 50 mA cm⁻² and areal capacity of 50 mAh cm⁻², the addition of 20 v/v% acetone in 2 m ZnSO₄ extends the lifespan of Zn//Zn symmetric cells from 12 to 800 h, with a high DOD of 73.5%. The effectiveness of this strategy is further demonstrated in the Zn-MnO₂ full batteries at wide temperature range from −30 to 40 °C.     

工艺参数对磁力搅拌-化学沉积Ni-P-SiC镀层的影响

用磁力搅拌-化学沉积的方法,在45钢表面沉积Ni-P-SiC镀层。研究了SiC微粒添加量、搅拌速率以及镀液温度等对镀层硬度和表面形貌的影响,借助扫描电子显微镜(SEM)对镀层进行观察。结果表明:当SiC的质量浓度为10 g/L时,镀层显微硬度最大(615.2HV);当磁力搅拌速率为300 r/min时,镀层的显微硬度最大(632.8HV)。磁力搅拌-化学沉积Ni-P-SiC镀层的最佳工艺参数为:SiC添加的质量浓度10 g/L,搅拌速率300 r/min,温度85℃。     

发射药喷涂涂覆中涂覆液溶剂比的选择

为了优化端面局部阻燃发射药(端面涂覆,且小孔保持通气状态)涂覆层制备的喷涂工艺中涂覆液溶剂比,采用醋酸丁酸纤维素(CAB)作钝感剂,CAB与吸收药片TG-1(皮罗棉和硝化甘油为主要组分)作溶质,乙醇-丙酮(V/V=1/1)为溶剂,按照不同溶剂比制备得到涂覆液,用此涂覆液采用喷涂的工艺制成了涂覆层薄膜和涂覆发射药,利用万能材料测试仪获得涂覆层薄膜的力学强度,并利用三维视频对涂覆层在拉伸前、后的表面结构进行了局部放大观察分析,对不同溶剂比的涂覆发射药进行了密闭爆发器试验。结果表明,涂覆层的力学强度、表面及断裂处形貌与溶剂比有明显联系,溶剂比主要影响了涂覆层材质的均匀性和致密性,是影响涂覆层力学强度的重要因素,从而对涂覆发射药的燃烧渐增性产生影响。当溶剂比为8∶1时,露孔率达到95%以上,同时获得的涂覆层表面最为光滑,其薄膜的拉伸强度最大,为49.75 MPa,断裂处最为整齐,涂覆发射药的燃气动态活度变化值达到0.0920 MPa~(-1)·s~(-1),为所有样品中的最大值。     

Growth of thick CdTe epilayers on GaAs substrates and evaluation of CdTe/n<Superscript>+</Superscript>-GaAs heterojunction diodes for an X-ray imaging detector

The growth characteristics of thick (100) CdTe epitaxial layers of a thickness up to 200 μm on a (100) GaAs substrate in a metal-organic vapor-phase epitaxy (MOVPE) system and fabrication of CdTe/n⁺-GaAs heterojunction diodes for their possible applications in low-energy x-ray imaging detectors are reported. The grown epilayers were of high structural quality as revealed from the x-ray double-crystal rocking curve (DCRC) analysis, where the full-width at half-maximum (FWHM) values of the (400) diffraction peaks was between 50 arcsec and 70 arcsec. The 4.2-K photoluminescence (PL) showed high-intensity bound-excitonic emission and very small defect-related peaks. The heterojunction diode fabricated had a good rectification property with a low value of reverse-bias current. The x-ray detection capability of the diode was examined by the time-of-flight (TOF) measurement, where good bias-dependent photoresponse was observed, but no carrier transport property could be deduced. It was found that the CdTe layer has a large number of trapping states as attributed to the cadmium-related vacancy and Ga-impurity, diffused from the substrate, related defect complexes.     

Growth condition of iodine-doped n+-CdTe layers in metal-organic vapor phase epitaxy

Iodine doping of CdTe layers grown on (100) GaAs by metal-organic vapor phase epitaxy (MOVPE) was studied using diethyltelluride (DETe) and diisopropyltelluride (DiPTe) as tellurium precursors and ethyliodine (EI) as a dopant. Electron densities of doped layers increased gradually with decreasing the growth temperature from 425°C to 325°C. Doped layers grown with DETe had higher electron densities than those grown with DiPTe. When the hot-wall temperature was increased from 200°C to 250°C at the growth temperature of 325°C, doped layers grown with DETe showed an increase of the electron density from 3.7×10¹⁶ cm⁻³ to 2.6×10¹⁸ cm⁻³. On the other hand, such an increase of the electron density was not observed for layers grown with DiPTe. The mechanisms for different doping properties for DETe and DiPTe were studied on the basis of the growth characteristics for these precursors. Higher thermal stability of DETe than that of DiPTe was considered to cause the difference of doping properties. With increasing the hot-wall temperature from 200°C to 250°C, the effective ratio of Cd to Te species on the growth surface became larger for layers grown with DETe than those grown with DiPTe. This was considered to decrease the compensation of doped iodine and to increase the electron density of layers grown with DETe. The effective ratio of Cd to Te species on the growth surface also increased with decreasing growth temperature. This was considered to increase the electron density with decreasing growth temperature.     

Lithium Phenolate Complexes with a Pyridine‐Containing Polymer for Solution‐Processable Electron Injection Layers in PLEDs

A series of (vinylphenyl)pyridine‐based polymer binders, PVPh2Py, PVPh3Py, and PVPh4Py, are designed and synthesized and it is found that mixtures of Liq and the polymers exhibit superior electron injection characteristics as ultrathin (1.6 nm) electron injection layer (EIL) films. They are comparable to those of EILs composed only of Liq. The addition of the polymers does not deteriorate the performance of Liq EILs. Additionally, when the EIL thickness is increased from 1.6 nm to 16 nm, the driving voltages increase and the external quantum efficiencies decrease. The increase in the voltage and decrease in the EQE are suppressed in the device with mixed EILs compared to those observed for the device composed of 100 wt% Liq. Furthermore, the position of the nitrogen in the pyridine ring is considered to influence the electron transport properties of the EILs. The mixing PVPh4Py with Liq improves the driving voltage of the fabricated devices, even with a thick mixed EIL. This reduced dependence of the performance of EILs on their thickness will be advantageous for the coating of large areas using solution processes.     

基于.Net Framework的N层分布式开发

.Net Framework推出的许多新技术(比如Web Service)为建立可维护、可扩展的站点，开发高效率、高伸缩性的应用程序提供了相对简单的解决方案。本文介绍如何利用这些技术结合SQL Server数据存储技术或Xml文档创建N层分布式应用程序、实现跨平台、跨Internet的应用集成。     

理想匹配层的综合优化

本文讨论了理想匹配层的吸收性能 ,给出了一种有效截断理想匹配层的边界条件 ,分析了不同导率剖面和边界条件对理想匹配层吸收性能的影响 ,给出了最小反射意义下的优化理想匹配层。     

Tuning a Solvation Structure of Lithium Ions Coordinated with Nitrate Anions through Ionic Liquid-Based Solvent for Highly Stable Lithium Metal Batteries

Rational design of promising electrolyte is considered as an effective strategy to improve the cycling stability of lithium metal batteries (LMBs). Here, an elaborately designed ionic liquid-based electrolyte is proposed that is composed of lithium bis(trifluoromethanesulfonyl)imide as the lithium salt, 1-ethyl-3-methylimidazolium nitrate ionic liquid ([EMIm][NO₃] IL) and fluoroethylene carbonate (FEC) as the functional solvents, and 1,2-dimethoxyethane (DME) as the diluent solvent. Using [EMIm][NO₃] IL as the solvent component facilitates a special Li⁺-coordinated NO₃⁻ solvation structure, which enables the continues electrochemical reduction of solvated NO₃⁻ and the formation of remarkably stable and conductive solid electrolyte interface. With FEC as another functional solvent and DME as the diluent solvent, the formulated electrolyte delivers high oxidative stability and ionic conductivity, and endows improved electrochemical reaction kinetics. Therefore, the formulated electrolyte demonstrates exceedingly reversible and stable Li stripping/plating behavior with high average Coulombic efficiency (98.8%) and ultralong cycling stability (3500 h). Notably, the high-voltage Li|LiNi_0.8Co_0.1Mn_0.1O₂ full cell with IL-based electrolyte exhibits enhanced cyclability with a capacity retention of 65% after 200 cycles under harsh conditions of low negative/positive ratio (3.1) and lean electrolyte (2.5 µL mg⁻¹). This study creates the first NO₃⁻-based ionic liquid electrolyte and evokes the avenue for practical high-voltage LMBs.     

作为携带、沉积纳米荧光粉颗粒和纳米铁电体颗粒到FEDs 和 EL 器件上的载体的可印刷的油墨、粘结剂

文章介绍了两种移植和可控纳米沉积荧光粉颗粒和纳米铁电体颗粒的载体.第一种载体是一种可以悬浮和沉积合成的具有亚微米级尺寸大小的荧光粉颗粒的油墨.解决了该油墨的聚集和沉降问题,并发现该油墨具有良好的液流学性能,从而可用于印刷高分辨率的荧光粉.测量了相关的单个象素的阴极发光密度以评定这种丝网印刷油墨的可重复性.第二种载体是一种粘结剂,这种粘结剂不仅可以携带 30 μm 以及更大的尺寸的电致发光的荧光粉,还可以携带纳米铁电体颗粒.这种新型的粘结剂可应用于不需要额外的绝缘反射层的低造价的 EL 显示器.从衬底按要求将发射层剥下来就形成了柔性薄膜,将该薄膜置于两电极之间,仍可保持其电致发光的活性.该粘结剂薄膜可以很容易地印刷和定型制成显示屏.