三氯化铁分光光度法测定药物中亚甲基二膦酸

通过三氯化铁与亚甲基二膦酸形成络合物，采用分光光度法，建立了注射用亚锡亚甲基二膦酸盐冻干药盒中亚甲基二膦酸含量的测定方法。结果表明，亚甲基二膦酸质量浓度在0.02~0.08 g/L范围内与吸光度A呈良好线性关系，线性回归方程y=14.61x+0.029 7，线性相关系数r=0.999 1。加标回收率为98.8%~102.0%，相对标准偏差为0.97%(n=6)。该方法可用于快速准确地测定注射用亚锡亚甲基二膦酸盐冻干药盒中亚甲基二膦酸的含量。     

A Blue Photosensitizer Realizing Efficient and Stable Green Solar Cells via Color Tuning by the Electrolyte

Semitransparent dye-sensitized solar cells (DSCs) are appealing as aesthetically pleasing and colorful see-through photovoltaics. Green semitransparent DSCs have been presented, but the best ones rely on green zinc porphyrin photosensitizers and high volatile electrolytes. For potential outdoor applications, the zinc porphyrin DSCs employing ionic liquid electrolytes merely reached a power conversion efficiency (PCE) of 6.3% even with opaque mesoporous TiO₂ films. Herein, the new green DSC is realized by using a blue organic photosensitizer in conjunction with an orange ionic-liquid-based electrolyte, presenting a simple and an effective path for color tuning of photovoltaics. The new approach allows for broadly modulating the color from spring green to cyan by tuning the contributions of the light absorption by the dye-sensitized TiO₂ film and the electrolyte layer. The new semitransparent DSCs with spring green to cyan colors have PCEs ranging from 6.7% to 8.1% and show stability for 1000 h under accelerated ageing test at 80 °C, superior to the zinc porphyrin DSCs. The findings pave a new way to achieve efficient and stable colorful solar cells.     

A correlation story of syntheses of ZnO and their influence on photocatalysis

The crystallinity, surface morphology, porosity and band structure of semiconducting catalytic materials greatly influence their photocatalytic efficiency. Here, the semiconducting ZnOs were synthesized with three different synthetic routes of precipitation, solution combustion and direct calcination of precursor. All the synthesized catalysts were characterized thoroughly by X-ray diffraction, Field emission scanning electron microscopy, diffuse reflectance spectroscopy, Brunauer–Emmett–Teller surface area and photoluminescence. The synthesized catalysts show different nano-crystallinity, morphology, surface properties and band structure depending on the synthetic methods. All the synthesized catalysts were explored for photocatalytic degradation of methylene blue under visible and UV light illumination. The correlation between the physical properties and catalytic efficacy were established. The complete mechanism for the photocatalytic degradation of methylene blue was also proposed. The typical band structure and the longer life of excitons due to the presence of defects in solution combustion synthesized ZnO overpowered the other physical properties in influencing the visible and UV light assisted methylene blue degradation. This work shades light on the key controlling factors of a photocatalytic reactions and provides simple strategy for the development of efficient photocatalysts for solar energy conversion applications in solving energy crisis and environmental pollution problems.     

中国古瓷中的明青花牡丹纹的艺术特征

牡丹纹作为为元明清青花瓷中重要的装饰之一最晚出现瓷器不过宋代,布局和绘画方式变化多样。主要特点为枝叶舒展或是多枝相交,花朵怒放被枝头环抱。明朝时期也是青花瓷发展的一个重要阶段,本文通过对现存明朝时期的青花牡丹纹饰例,分别分析不同风格和技法的青花牡丹纹饰,从而论证其艺术特色,以及对后期造成的影响。     

Electrochemical growth of tin(II) oxide films: Application in photocatalytic degradation of methylene blue

We have investigated the semiconducting and photoelectrochemical properties of SnO films grown potentiostatically on tin substrate. The oxide is characterized by X-ray diffraction, scanning electron microscopy and Raman spectroscopy. The anodic process corresponds to the formation of SnO·nH₂O pre-passive layer that is removed upon increasing potential due to surface etching at the metal/oxide interface. SnO films deposited for long durations (>50 mn) are uniform and well adhered; they thicken up to ~50 nm by diffusion-controlled process and the growth follows a direct logarithmic law. The thickness is determined by coulometry and the X-ray diffraction indicates the tetragonal SnO phase (SG: P4/mmm) with a crystallite size of 32 nm. The Mott–Schottky plot is characteristic of n type conductivity with an electrons density of 5.72×10¹⁸ cm⁻³, a flat band potential of −0.09 V_SCE and a depletion width of ~10 nm. The valence band, located at 5.91 eV below, vacuum is made up of hybridized O²⁻:2p Sn²⁺:5s while the conduction band (4.45 eV) derives from Sn²⁺:5p orbital. The electrochemical impedance spectroscopy (EIS) measured in the range (10⁻²–10⁵ Hz) shows the contribution of the bulk and grain boundaries. The energy band diagram predicts the photodegradation of methylene blue on SnO films. 67% of the initial concentration (10 mg L⁻¹) disappears after 3 h of exposure to visible light (9 mW cm⁻²) with a quantum yield of 0.072.     

Cr2WO6 nanoparticles prepared by hydrothermal assisted method with selective adsorption properties for methylene blue in water

Cr₂WO₆ nanocrystallites were prepared using a facile hydrothermal assisted process. The microstructures and preferential adsorption performance for methylene blue (MB) of the prepared nanoparticles were investigated using a solid state reaction resulted in Cr₂WO₆ crystallites as a baseline. Their structural information were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer, transmission electron microscopy, N₂–sorption BET surface area, thermogravimetric and differential scanning calorimeters. Results show that the Cr₂WO₆ nanocrystallines with ~50 nm in size are achieved by calcination at 650 °C for only 2 h using a hydrothermal product as precursor, while the micrometer sized Cr₂WO₆ crystallites synthesized by the solid state reaction at higher temperature (950 °C) for at least 20 h. For the as-prepared Cr₂WO₆ nanocrystallines, the adsorption performance were tested using methyl orange (MO), Rhodamine B (RhB) and methylene blue (MB). The adsorption ability was found to be in the order of MB>>RhB>MO owing to electrostatic interactions between the adsorbent and the dye. Results of this study provide a kind of promising alternative adsorbent for color removal from industrial wastewaters.     

硅钼蓝分光光度法测定高铍铍铝合金中硅

高铍铍铝合金中的杂质元素硅对高铍铍铝合金热等静压、精密铸造及耐腐蚀性能影响较大,需要对其含量进行严格控制,所以测定高铍铍铝合金中的硅具有重要意义。采用硫酸(1+1)、硝酸和氢氟酸于水浴条件下溶解试样,用硼酸掩蔽剩余氟离子,在0.10~0.15mol/L硫硝混酸介质下,钼酸铵与硅反应生成硅钼黄杂多酸,稳定20min后,用草酸掩蔽铁离子,同时加入抗坏血酸将硅钼黄还原成硅钼蓝,放置10min,于波长820nm处采用分光光度法进行测定,实现了硅钼蓝分光光度法对高铍铍铝合金(铍的质量分数为60%~70%)中硅的测定。在优化的实验条件下,试液中硅质量在10~60μg范围内与其对应的吸光度呈良好的线性关系,相关系数为1.000,方法中硅的检出限和测定下限分别为0.0021%(质量分数,下同)和0.0071%。按照实验方法测定60BeAl和70BeAl两个高铍铍铝合金试样中硅含量,测得结果的相对标准偏差(RSD,n=8)为2.9%~3.4%。将实验方法用于测定高铍铍铝合金实际试样中硅含量,结果与电感耦合等离子体原子发射光谱法(ICP-AES)相吻合。     

钼蓝分光光度法联合测定铁矿石中磷和二氧化硅

以往铁矿石中磷和二氧化硅含量的测定需要分别采用钼蓝分光光度法。在使用磷钼蓝分光光度法时,常会因钒、砷等的干扰使得磷测定结果不准确,需要将样品再处理后才能测定。实验采用石墨垫底铁坩埚,碳酸钠和硼酸混合熔剂高温熔融铁矿石,使铁矿石样品分解彻底,再分别采用铋磷钼蓝和硅钼蓝分光光度法测定磷和二氧化硅含量,从而实现了采用钼蓝分光光度法联合测定铁矿石中磷和二氧化硅。干扰试验表明,在高温熔融时,石墨可将钒(V)还原为钒(III),使样品中钒不干扰磷的测定;显色液中加入15mg硫代硫酸钠溶液可将砷(V)还原为砷(III),继而消除砷对磷测定的干扰。磷的质量浓度在0~3μg/mL范围内遵守比尔定律,校准曲线的线性相关系数为0.9999,表观摩尔吸光系数为2.242×10⁴ L·mol^-1·cm^-1;二氧化硅的质量浓度在0~5μg/mL范围内遵守比尔定律,校准曲线的线性相关系数为0.9995,表观摩尔吸光系数为9.342×10³ L·mol^-1·cm^-1。方法中磷和二氧化硅的检出限分别为0.0026μg/mL和0.0081μg/mL。按照实验方法测定6个铁矿石标准样品中磷和二氧化硅,磷测定结果的相对标准偏差(n=8)小于5%,相对误差小于2%;二氧化硅测定结果的相对标准偏差(n=8)小于2%,相对误差小于1.5%。按照实验方法测定5个铁矿石样品中磷和二氧化硅,磷测定结果的相对标准偏差(RSD,n=8)小于7%,二氧化硅测定结果的相对标准偏差(n=8)小于1%;磷和二氧化硅的测定值均与电感耦合等离子体原子发射光谱法的测定值相一致。     

Adsorption efficiency and photocatalytic activity of fly ash-based geopolymer foam mortar

Fly ash-based geopolymer foam mortar (GFM) was used as an adsorbent material to methylene blue (MB) and also the dye removal material using the photocatalytic mechanism. The GFM, containing 50 wt% river sand aggregate, was prepared to have approximately 46% open porosity, pore size distribution between 0.01 and 3.5 mm, and water permeability of 0.2 cm/s. The variation of adsorption efficiency and adsorption capacity with the contact time of the GFM was first evaluated using various GFM dosages (10, 20, 50, 80, and 100 g/L). The adsorption efficiency at equilibrium (AE_e) was found to linearly increase, while adsorption capacity (q_ae) exponentially decayed, with an increase of loading dosages. The photocatalytic removal efficiency of ~100% was obtained with 50, 80, and 100 g/L GFM loading dosages, with a shorter time at higher dosages. The GFM could be reused, without regeneration, for 5 cycles. The AE_e and q_ae for each reused cycle did not noticeably change suggesting the reusability. The photocatalytic removal efficiency, however, was found to decrease with an increase of the reused cycle. After the 5^th cycle, the highest removal efficiency was reduced to ~70%. The attempts to treat the GFMs with hydrochloric (HCl) and phosphoric (H₃PO₄) acid to reduce the excess alkaline did not give satisfactory results as expected. The photocatalytic removal efficiency had subsided after the treatment with both acids.