Two micrometer fluorescence emission and energy transfer in Yb3+/Ho3+ co-doped lead silicate glass

Enhanced 2.0 μm and visible up-conversion emissions from Ho³⁺ via Yb³⁺ sensitization in lead silicate glasses have been obtained under the excitation of 980-nm laser diode. The possible energy transfer mechanism has been analyzed based on the photoemission spectroscopy and lifetime measurement. The lifetime of Ho³⁺: ⁵I₇ laser upper level has also been measured. Based on the absorption spectra, Judd–Ofelt parameters, spontaneous emission probability, the absorption, emission cross sections, and gain coefficients have been calculated and analyzed. The results indicate that the Yb³⁺/Ho³⁺ co-doped lead silicate glass has potential application in mid-infrared wavelengths.     

Palladium‐Catalyzed Oxidative Carbonylation of Aromatic C−H Bonds with Alcohols using Molybdenum Hexacarbonyl as the Carbon Monoxide Source

With molybdenum hexacarbonyl as the carbon monoxide source, a general palladium‐catalyzed carbonylative transformation of the C−H bond on aromatic rings to produce esters has been developed. Good yields of the corresponding products have been obtained with wide functional group tolerance and excellent regioselectivity. A variety of aliphatic alcohols are suitable reactants here.

     

Editorial for rare metals,special issue on photocatalysis

<正>Burning of fuels is an irreversible entropy increasing process, requiring additional energies derived from the environment to let the process cycle. In theory, photon energy delivered from the sun could fix the huge energy demand in a clean and sustainable way. Photocatalysis is such an ideal approach to reconvert inert molecules directly into fuels and other chemical feedstocks using photon energy without     

Pharmacokinetic Comparison of Berberine in Rat Plasma after Oral Administration of Berberine Hydrochloride in Normal and Post Inflammation Irritable Bowel Syndrome Rats

In the present study, post inflammation irritable bowel syndrome (PI-IBS) rats were firstly established by intracolonic instillation of acetic acid with restraint stress. Then the pharmacokinetics of berberine in the rat plasma were compared after oral administration of berberine hydrochloride (25 mg/kg) to normal rats and PI-IBS rats. Quantification of berberine in the rat plasma was achieved by using a sensitive and rapid UPLC-MS/MS method. Plasma samples were collected at 15 different points in time and the pharmacokinetic parameters were analyzed by WinNonlin software. Compared with the normal group, area under the plasma concentration vs. time curve from zero to last sampling time (AUC_0–t) and total body clearance (CL/F) in the model group significantly increased or decreased, (2039.49 ± 492.24 vs. 2763.43 ± 203.14; 4999.34 ± 1198.79 vs. 3270.57 ± 58.32) respectively. The results indicated that the pharmacokinetic process of berberine could be altered in PI-IBS pathological conditions.     

Quench Sensitivity of AA7N01 Alloy Used for High-Speed Train Body Structure

JOM - The quench sensitivity of AA7N01 aluminum alloy used for high-speed train body structure was investigated by end-quenching test, time–temperature-transformation curves simulation,...     

Thickness and scratch resistance of adsorbed film formed by triblock symmetrical copolymer solutions

The thickness and scratch resistance of adsorbed films formed on mild steel samples (MS1020), which have been immersed in water copolymer solutions, are reported. The effects of bulk temperature and the copolymer structures, normal, poly(ethylene oxide)_m‐poly(propylene oxide)_n‐poly(ethylene oxide)_m, and reverse, poly(propylene oxide)_n‐poly(ethylene oxide)_m‐poly(propylene oxide)_n, are elucidated. The films' thicknesses are independent of structure but not of temperature. The adsorbed films of above cloud point solutions are thicker than below cloud point. However, nanoscratch experiments carried out to measure the scratch resistance of the films reveal that despite of thicker film formed by above cloud point solutions, it is relatively more prone to being detached than the thinner films of below cloud point solutions. The effect of extreme pressure additive, alkyl phosphate ester (APE), is also investigated suggesting the normal copolymer has comparable scratch resistance with APE when used at below the cloud point. Copyright © 2016 John Wiley & Sons, Ltd.     

高层建筑施工中大体积混凝土的裂缝控制

高层混凝土建筑的裂缝控制应该防患于未然,尽量预防有害裂缝,科学地将其有害程度控制在规范允许的范围内。只要使设计与施工能紧密结合,将裂缝控制在无害范围内是完全可以做到的。本文探讨了高层建筑施工中大体积混凝土的裂缝控制措施。     

便携式斯特林深冷冰箱研制

研制了一种以斯特林低温制冷机为冷源,有效容积6L,工作温度范围-60℃～-160℃的深冷冰箱.小型斯特林制冷机采用直线电机驱动,电机与压缩机一体化设计,采用氦气制冷工质.斯特林制冷机的冷指置于冰箱内底端直接冷却.圆柱形箱体采用了内环为真空层、外环为硬质聚氨酯发泡层的复合绝热技术,设计了具有3层辐射屏的内盖和真空箱盖.该冰箱具有环境友好、热效率高、制冷温区宽、制冷量易控和体积小等特点,可以满足低温保存和实验等需求.输入功率170W时冰箱内温度低于-150℃,对应-100℃低温时的制冷量为7W.     

HIPS/PPO共混物拉伸和冲击断裂面的电镜观察

研究了高冲击强度聚苯乙烯(HIPS)/聚苯醚(PPO)共混物断面3个特征区的形貌特征及形成机制,分析了它们对材料力学性能的影响。     

核电厂主螺栓超声检测与信号分析

依据RSE-M标准需要定期对核电厂反应堆压力容器(RPV)主螺栓进行超声检测,为了保证主螺栓螺纹区及光杆区不同深度刻槽的超声检测灵敏度,本文对检测工艺进行声场仿真计算,分析与判断数据采集中的相关信号与非相关信号,并重点分析裂纹信号的特征,验证了超声工艺的可靠性。结合现场实施案例,通过45°横波端角反射率高的特性,综合其他检测方法如涡流和渗透检测对缺陷性质进行判定,可有效确定异常信号。