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.     

优化作业方式提高始极片质量

针对某厂铜电解种板工序存在的始极片质量波动较大的问题,从种板系统体积控制和添加剂匹配的角度出发,分析各种因素对始极片质量的影响,做出了相应的改进措施,使种板系统运行更加稳定,始极片质量得到进一步提升。     

Biphenyl liquid crystal epoxy containing flexible chain: Synthesis and thermal properties

A biphenyl type liquid crystal epoxy (LCE) monomer 4,4′-di(2,3-epoxyhexyloxy)biphenyl (LCBP4) containing flexible chain was synthesized and the curing behavior was investigated using 4,4′-diaminodiphenylmethane (DDM) as the curing agent. The effect of curing condition on the formation of the liquid crystalline phase was examined. The cured samples show good mechanical properties and thermal stabilities. Moreover, the relationship between thermal conductivity and structure of liquid crystalline domain was also discussed. The samples show high thermal conductivity up to 0.28–0.31 W/(m*K), which is 1.5 times as high as that of conventional epoxy systems. In addition, thermal conductive filler, Al₂O₃, was introduced into LCBP4/DDM to obtain higher thermal conductive composites. When the content of Al₂O₃ was 80 wt%, the thermal conductivity of the composite reached to 1.86 W/(m*K), while that of diglycidyl ether of bisphenol A (Bis-A) epoxy resin/DDM/Al₂O₃ was 1.15 W/(m*K). Compared with Bis-A epoxy resin, the formation of liquid crystal domains in the cured LCE resin enhanced the thermal conductivity synergistically with the presence of Al₂O₃. Furthermore, the introduction of Al₂O₃ also slightly increased the thermal stabilities of the cured LCE.     

Fast Measurements of the Gas‐Liquid Diffusion Coefficient in the Gaussian Wake of a Spherical Bubble

A fast method is proposed for determining the oxygen gas‐liquid diffusion coefficient from measurements of the fluorescence quenching behind a bubble. The approach consists of capturing pictures of the concentration field at micro‐scale in the laminar bubble wake. The Gaussian concentration profiles measured in the wake are demonstrated to be systematically equivalent to an instantaneous plane diffusion case. The approach permits to accurately evaluate the gas‐liquid diffusivity in a very short time of around one second.     

Biogas upgrading using ionic liquid [Bmim][PF6] followed by thermal-plasma-assisted renewable hydrogen and solid carbon production

The use of hydrogen as clean energy has attracted significant attention because conventional industrial hydrogen production processes show negative environmental impact, require intensive energy, and/or are dependent on natural gas. The main objective of this study is to develop an innovative and environment-friendly hydrogen production process utilizing biogas as an alternative to natural gas. Ionic liquid [Bmim][PF₆] shows high potential for the replacement of aqueous amine solutions for CO₂ absorption and are employed for biogas upgrading, while thermal plasma (TP), which is beneficial for converting electrical energy to chemical energy, is employed for the simultaneous production of clean “turquoise” hydrogen and solid carbon. In addition, an intercooler is used to improve CO₂ removal in the absorber. Heat and power integration are employed to enhance the performance of the upgrading process and thermal-plasma-assisted hydrogen production. All simulations were conducted using Aspen Plus V10.0 software. The simulated results show that the solid carbon production from biomethane increases compared to that in the proposed base case. The savings in both the heater used to preheat the TP reactor and the third flash drum are 100%, while the saving in power consumption in the compression section is 62.0%. Furthermore, sensitivity is investigated to determine the effect of biomethane composition on the performance of the proposed configuration.     

Transient liquid phase diffusion process for porous mullite ceramics with excellent mechanical properties

Porous mullite ceramics were fabricated by the transient liquid phase diffusion process, using quartz and fly-ash floating bead (FABA) particles and corundum fines as starting materials. The effects of sintering temperatures on the evolution of phase composition and microstructure, linear shrinkage, porosity and compressive strength of ceramics were investigated. It is found that a large amount of quartz and FABA particles can be transformed into SiO₂-rich liquid phase during the sintering process, and the liquid phase is transient in the Al₂O₃-SiO₂ system, which can accelerate the mullitization rate and promote the growth of mullite grains. A large number of closed pores in the mullite ceramics are formed due to the transient liquid phase diffusion at elevated temperatures. The porous mullite ceramics with high closed porosity (about 30%) and excellent compressive strength (maximum 105?MPa) have been obtained after fried at 1700?°C.     

Geopolymer assembly by emulsion templating: Emulsion stability and hardening mechanisms

This work investigates emulsion templating to synthesize hexadecane oil/geopolymer composites. In a system with hexadecane as the internal (dispersed) phase and an alkali activated continuous phase without added surfactant, adding aluminosilicate clay particles does not increase resistance against creaming or coalescence, while adding a surfactant (L35 or CTAB) stabilizes the solid-liquid interface. Infrared studies and rheological studies of the associated geopolymerization determined that the presence of the organic phase or surfactant has no significant effect on the geopolymerization kinetics, as determined by the change in time of the Si-O-T IR stretching frequency and the rheological moduli involved during the process. The stabilization of the organic template is reminiscent of Pickering emulsion even though we employ a much greater amount of inorganic material for geopolymer formation. Although the addition of surfactant has a significant effect on the behavior of the paste, the percolation of the network remains unmodified, highlighting the fact that the phenomenon is not dependent on viscosity. Finally, rheological measurements were used to obtain the mass fractal dimension of the as-made gel network, which is able to differentiate the interfacial effect between surfactant molecules with a slightly denser interphase when a cationic surfactant is used.     

Fermentation dynamics of Lactobacillus helveticus H9 revealed by ultra‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry

Lactobacillus (L.) helveticus H9 is a probiotic strain that can produce antihypertensive peptides during milk fermentation. This study analysed the dynamics of skim milk fermentation by L. helveticus H9 by ultra‐performance liquid chromatography coupled to quadrupole time‐of‐flight mass spectrometry (UPLC/Q‐TOF MS). A total of 1992 metabolites were detected from all of the fermented samples in the LC‐MS analysis by multivariate statistical analysis. Metabolites with variable importance in projection (VIP) values ≥2 were considered differentially abundant among samples and were responsible for the unique taste and nutritional and functional qualities of fermented milk. Valine, threonine, l ‐methionine, tyrosine, asparagine and leucine were the predominant amino acids produced during fermentation, and their quantities changed remarkably during the fermentation process. Citric acid and uric acid were the major, and only detectable, organic acids. Some intermediate metabolites, such as N‐acryloylglycine and nicotinamide‐N‐oxide, were also detected. Moreover, certain oligopeptides such as Val‐Leu, Lys‐Gly, Ala‐Glu, Asp‐Ser, Leu‐Pro and Val‐Phe‐Ala were not detected until the middle and late fermentation periods. This study demonstrated dynamic metabolic changes, providing a strong foundation for deciphering the physiological and biochemical mechanisms of the fermentation process.     

Development of a green two‐dimensional HPLC‐DAD/ESI‐MS method for the determination of anthocyanins from Prunus cerasifera var. atropurpurea leaf and improvement of their stability in energy drinks

This study aimed to develop a green two‐dimensional HPLC‐DAD/ESI‐MS method for analysing anthocyanins from Prunus cerasifera var. atropurpurea leaf and improve their stability in energy drinks by the addition of phenolic acids. Ethanol and tartaric acid solutions were used as mobile phases for one‐dimensional HPLC‐DAD for quantitative analysis of anthocyanins, and the primary anthocyanins were identified as cyanidin‐3‐O‐galactoside, cyanidin‐3‐O‐glucoside and cyanidin‐3‐O‐rutinoside using two‐dimensional HPLC‐MS. Method validation showed that the developed method was accurate, stable and reliable for the analysis of P. cerasifera anthocyanins. The effects of gallic, ferulic and caffeic acid on the stability of cyanidin‐3‐O‐galactoside, cyanidin‐3‐O‐glucoside, cyanidin‐3‐O‐rutinoside and total anthocyanins from P. cerasifera leaf in energy drinks were evaluated, and the degradation of P. cerasifera anthocyanins ideally followed a first‐order model (R² > 0.98). Gallic acid showed stronger protective effects on P. cerasifera anthocyanins in energy drinks, and adding/increasing ferulic and caffeic acids accelerated the degradation reactions.