Electrochromic characteristics of fibrous reticulated WO3 thin films prepared by pulsed spray pyrolysis technique

The electrochromic (EC) behavior of fibrous reticulated WO₃ films prepared from ammonium tungstate precursor by pulsed spray pyrolysis method was investigated. All the films were prepared using identical technological parameters and a thorough investigation of the electrochromic properties of the films deposited at 300 °C is reported. The structural properties were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochromic and optical properties were measured using cyclic voltammetry and ultraviolet (UV)-visible spectrophotometry. The films are amorphous and have a fibrous reticulate-like morphology having micron-size circular rings. The films show high transparency in the visible range and the optical band gap energy is about 3.1 eV. Electrical measurements show that the resistivity monotonically decreases as temperature increases, which indicates thermal hopping transport. The activation energy for hopping transport is of the order 4×10⁻⁴ eV. The electrochromic coloration efficiency (CE) is found to be 34 cm²/C at 630 nm.     

威坪大桥的空间有限元分析与静荷载试验研究

采用通用的有限元程序ANSYS对中承式劲性骨架钢筋混凝土拱桥-威坪大桥进行了空间分析,介绍了该桥的静荷载试验,并将荷载试验的实测结果与理论计算结果进行了分析比较.结果表明,采用控制截面内力等效的原则进行成桥试验比较方便、准确;劲性骨架钢筋混凝土拱肋截面受力后变形仍符合平截面假定;威坪大桥的横撑在横桥向偏载时的二次分配内力的作用较弱.     

Comparison of chemical, physical, micro-structural, and microbial properties of breads supplemented with sweetpotato flour and high-gluten dough enhancers

The objective of this study was to compare the chemical, physical, micro-structural, and microbial properties of breads supplemented with sweetpotato flour and high-gluten dough enhancers. Six breads, with and without dough enhancers (DE) and varying percentages of sweetpotato flour (SPF) were processed. Breads were stored at 22±2 °C, and samples were measured on Days 0, 2, 4, 6, and 8. Moisture, ash, fat, a_w, color, loaf volume, specific volume, density, texture, and weight loss were analyzed on Day 0, and β-carotene on the Days 0 and 8. The micro-structural and microbial properties of the sweetpotato breads were also compared. The fresh breads (Day 0) had moisture contents ranging from 36.66 to 41.56. β-Carotene was highest in breads containing 65% SPF. All breads were significantly (P<0.05) lighter in color by the last day of storage, while those containing 50% SPF with DE had the highest loaf volumes. Intact and damaged granules, cavities, and protein network were observed on the micrographs of the fresh breads. Further studies to include varying storage conditions, sensory, and consumer properties of the breads are needed.     

渗铝碳钢换热管管头的焊接

通过不同的焊接试验方案,经宏观检查、金相分析、拉脱力试验等方法,对渗铝碳钢换热管与16Mn管板管头角焊缝的焊接工艺进行了探讨,获得了适合此类材质管头的焊接方法及相应的工艺参数。     

环焊缝超声检测缺陷检出率问题的研究

针对油气集输管道多为薄壁管、探伤面为曲面且多在野外易受环境影响等特点,对超声波检测时存在的管道缺陷漏检情况,通过在现场超声检测工艺的实践和观察,从探头、扫查方式、用于校准的标准试块和对比试块等方面来改进超声检测工艺,从而达到提高超声检测缺陷检出率的目的。研究结果对于提高油气集输管道现场焊接的超声检测质量具有一定的指导意义。     

基于高斯束的初至波菲涅尔体地震层析成像

在中心射线路径作为唯一已知条件的前提下,利用动力学射线追踪可以方便地实现射线路径上格林函数的计算,但傍轴格林函数则难以计算。高斯束是动力学射线追踪的一个重要应用。在高频假设前提下,本文将高斯束作为源点产生的格林函数,进而实现菲涅尔体地震层析成像中核函数的快速计算,最后应用此方法进行菲涅尔体走时地震层析成像的理论模型试验。与波动方程菲涅尔体走时地震层析成像反演结果的对比表明,在高频假设前提下,基于动力学射线追踪进行菲涅尔体地震层析成像反演是可行的。     

国产电子式井下压力计的发展

阐述了国产压力计的发展过程,说明了由单片机８０Ｃ３１为核心芯片,选用应变式压力传感器转向第二代压力计,采用地单片机、Ａ／Ｄ片,数据存储器。经过发展,国产压力计在温度误差修正技术方面有所提高。功能上有一些进步,在元件成本降低及简单生产工艺等方面有了较大的进步。但整体技术水平没有突破,目前国内使温方向发展。而目前影响国内压力计发展的主要因素是,压力计的行业标准存在问题,应忙修改现行的压力计两个行业标准     

In situ scanning electron microscopy on lithium-ion battery electrodes using an ionic liquid

We present an experimental platform that can be used for investigating lithium-ion batteries with very high spatial resolution. This in situ experiment runs inside a scanning electron microscope (SEM) and is able to track the morphology of an electrode including active and passive materials in real time. In this work it has been used to observe SnO₂ during lithium uptake and release inside a working battery electrode. The experiment strongly relies on an ionic liquid which has very low vapor pressure and can therefore be used as an electrolyte inside the vacuum chamber of the SEM. In contrast to common electrochemical characterization tools, this method allows for the observation of microscopic mechanisms in electrodes. Depending on the SEM, resolutions down to 1 nm can be achieved. As a result, the experimental platform can be used to investigate chemical reaction pathways, to monitor phase changes in electrodes or to investigate degradation effects in batteries. SnO₂ is a potential anode material for future high capacity lithium-ion batteries. Our observations reveal the formation of interface layers, large volume expansions, growth of extrusions, as well as mechanically induced cracks in the electrode particles during cycling.     

Photoluminescence enhancement and atmosphere-dependent photovoltaic performance in CdS nanorod arrays/MEH-PPV hybrid

Performance improvement of CdS nanorod arrays (NRA)/poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) hybrid solar cells (HSCs) during the storage in ambient atmosphere has been demonstrated. An unusual photoluminescence (PL) enhancement was observed after MEH-PPV hybridizing with CdS NRA due to the abundance of S-vacancy-induced interface electron traps in CdS NRA, which was confirmed by temperature-dependent PL and charge transport analysis. By investigating on the time-resolved photoluminescence (TRPL) and current-voltage characteristics, we demonstrated that the performance improvement of CdS NRA/MEH-PPV HSCs was contributed to the co-effects of interface electron trap-oxygen interaction and MEH-PPV-oxygen interaction, and the contribution ratio between these two interactions was varied over time in air.     

CFB锅炉磨损的发生与综合治理

磨损是影响CFB锅炉安全经济运行最主要的障碍,阐述了对磨损的发生过程进行研究和分析。结果显示,应当针对磨损问题采取恰当的防磨措施,主动多阶防磨梁是目前大容量CFB锅炉普遍采用的防磨技术,该技术从降低贴壁流速度着手,有效降低了受热面磨损,提高了机组的连续运行时间,取得了很好的应用效果。