Diode-pumped wavelength-switchable visible Pr^(3+):YLF laser and vortex laser around 670 nm

Here we developed a novel wavelength-switchable visible continuous-wave(CW)Pr^(3+):YLF laser around 670 nm.In single-wavelength laser operations,the maximum output powers of 2.60 W,1.26 W,and 0.21 W,the maximum slope efficiencies of 34.7%,27.3%,and 12.3%were achieved with good beam qualities(M^(2)<1.6)at 670.4 nm,674.2 nm,and 678.9 nm,respectively.Record-high output power(2.6 W)and record-high slope efficiency(34.7%)were achieved for the Pr^(3+):YLF laser operation at 670.4 nm.This is also the first demonstration of longer-wavelength peaks beyond 670 nm in the^(3)P_(1)→^(3)F_(3)transition of Pr^(3+):YLF.In multi-wavelength laser operations,the dual-wavelength lasings,including 670.1/674.8 nm,670.1/679.1 nm,and 675.0/679.4 nm,were obtained by fine adjustment of one/two etalons within the cavity.Furthermore,the triple-wavelength lasings,e.g.672.2/674.2/678.6 nm and 670.4/674.8/679.4 nm,were successfully demonstrated.Moreover,both the first-order vortex lasers(LG_(0)^(+1)and LG_(0)^(-1)modes)at 670.4 nm were obtained by off-axis pumping.

Dehydrogenation of methylcyclohexane over Pt supported on Mg–Al mixed oxides catalyst:The effect of promoter Ir

To enhance the hydrogen release during hydrogen storage,several Pt-Ir supported on Mg-Al mixed oxide catalysts were prepared and then applied into the dehydrogenation of methylcyclohexane(MCH)in this study.The effects of iridium content,reduction temperature on the activity and stability of the catalysts were studied in detail.In the presence of Ir,metal particle size was decrea sed and electron transfer between Ir and Pt was observed.High reduction temperature increased the metallic Ir content but enlarged the particle size of active site s.During the dehydrogenation reaction on Pt-Ir bimetallic catalyst,MCH was efficiently converted into toluene and PtIr-5/Mg-Al-275 exhibited the highe st activity.After prolonging the residence time and raising the reaction temperature to 350℃the conversion and hydrogen evolution rate were increased to 99.9%and 578.7 mmol·(g Pt)^-1·min^-1,respectively.Moreover,no carbon deposition was observed in the spent catalyst,presenting a high anti-coking ability and good potential for industrial application.

Preparation of bimetal Co-Ni supported on Mg-Al oxide for chemocatalytic upgrading of tailored fermentation products to energy intensive fuels

The great challenge in the aldol condensation of tailored fermentation products(acetone-butanol-ethanol,ABE)into energy intensive fuels is to develop a suitable catalyst with high activity and low-cost.In this study,Co,Ni,and Co-Ni supported on Mg-Al oxide catalysts were prepared and their pore diameters were enlarged via adding active carbon as a hard template into Mg-Al hydrotalcite.During the aldol condensation reaction,the catalyst activity was enhanced after enlarging the pore diameter and Co-Ni bimetal supported catalyst presented the highest activity,which was resulted from that the electron transfer between Co and Ni in Co-Ni alloy enhanced the dehydrogenation activity and large pore lowered the mass transfer resistance.After optimizing the reaction conditions,acetone conversion and the total selectivity of C_(5)-C_(11)desired products in the aldol condensation of ABE reached up to 76%and 90%,respectively.The stability study showed that the activity was decreased with the increase of reaction number because of the oxidation of metallic Co and Ni,but this could be solved via a simple hydrogen reduction method.

Optimization of Conditions of Concentrating Protein in Rapeseed Meal by Ultrasonic-assisted Alcohol Washing

This study was performed to optimize the conditions for concentrating protein in commercial rapeseed meal by ultrasonic-assisted alcohol washing method. The effects of sonication time,particle size,ultrasonic power and liquid to solid ratio on protein content were investigated. The result showed that the optimal conditions for concentrating protein in rapeseed meal were: sonication time of 40 min,particle size of 40 mesh,ultrasonic power of 800 W and liquid to solid ratio of 9∶ 1. Under these conditions,the protein content in rapeseed meal was increased to 55. 47%,which was 10. 43% higher than that in rapeseed meal not treated by sonication.

Polystyrene microsphere-immobilized palladium(Ⅱ)porphyrin as mild,reusable,and highly efficient catalyst for Heck reaction

A novel Heck reaction catalyst consisting of a palladium（ll） complex of meso-tetra（p- hydroxyphenyl）porphyrin （MTP） and cross-linked chloromethylated polystyrene microspheres （PMs） was successfully prepared via covalent ether bonds between the chloride groups in the PMs and the hydroxyl groups in MTP. The catalyst was characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and inductively coupled plasma atomic emission spectroscopy （ICP-AES）. This polystyrene-supported palladium-complex was an efficient heterogeneous catalyst for cross-coupling of aryl iodides with ethyl acrylate. The reaction of iodobenzene and ethyl acrylate under N2 at 100 °C and a catalyst concentration of 0.1% gave a gas chromatography product yield of 99.8%, which is much higher than that achieved using a free palladium（II） complex of MTP as the catalyst （41.3%）. The catalyst was recycled up to six times without significant loss of catalytic activity. These results suggest that the immobilized palladium（II） MTP catalyst has potential applications in synthetic and industrial chemistry.

移动床活性焦烟气净化工艺中废活性焦的形成与特征分析

移动床活性焦低温干法烟气多污染物脱除技术在钢铁烧结烟气脱硫脱硝工艺中具有良好的适用性,但烟气净化过程中活性焦的损耗成为制约该技术推广应用的关键因素之一。以宝钢烧结烟气脱硫脱硝工艺中所产生的废活性焦为研究对象,通过考察其比表面积、孔容结构、灰分中重金属及碱金属含量、表面官能团特征及脱硫脱硝性能,探究烟气净化过程中活性焦组成、结构及表面性质的变化。结果表明,与新鲜活性焦相比,废活性焦粒度集中分布在0.2~5 mm,其表面的氮、氧、硫元素及过渡金属氧化物含量显著增加,比表面积由191.0 m^2/g增加至499.0 m^2/g,使废活性焦颗粒在150℃下脱硝率由20%提升到70%,120℃下穿透硫容由0.27 mg SO2/g提升至11.08 mg SO2/g,显示了良好的再利用潜力。

Gas-assisted magnetic separation for the purification of proteins in batch systems

In this paper, gas-assisted magnetic separation （GAMS）, a technique that combines magnetic separation with flotation, was investigated for the potential large-scale separation of proteins, The GAMS process includes adsorption of target proteins and magnetic separation to recover protein-loaded magnetic particles from the dilute biosuspension with the assistance of bubbles, Microsized ethylenediamine- functionalized poly（glycidyl methacrylate） superparamagnetic microspheres （MPMs） and bovine serum albumin （BSA） were used as a model system. The feasibility of GAMS for capturing BSA-loaded MPMs from an appropriate medium was shown, High recovery of BSA-loaded MPMs was obtained by simple adjustment of the initial solution pH without extra detergents and antifoaming agents. The GAMS con- ditions were consistent with the adsorption conditions, and no proteins were desorbed from the MPMs during this process. Under the optimal conditions, the separation rate and recovery percentage reached 410 mL/min and 98% in 0.61 min, respectively. Conformational changes of BSA during the GAMS process were investigated by fluorescence spectroscopy and circular dichroism spectrometry,