Single‐Mode Lasing from Colloidal Water‐Soluble CdSe/CdS Quantum Dot‐in‐Rods

Core–shell CdSe/CdS nanocrystals are a very promising material for light emitting applications. Their solution‐phase synthesis is based on surface‐stabilizing ligands that make them soluble in organic solvents, like toluene or chloroform. However, solubility of these materials in water provides many advantages, such as additional process routes and easier handling. So far, solubilization of CdSe/CdS nanocrystals in water that avoids detrimental effects on the luminescent properties poses a major challenge. This work demonstrates how core–shell CdSe/CdS quantum dot‐in‐rods can be transferred into water using a ligand exchange method employing mercaptopropionic acid (MPA). Key to maintaining the light‐emitting properties is an enlarged CdS rod diameter, which prevents potential surface defects formed during the ligand exchange from affecting the photophysics of the dot‐in‐rods. Films made from water‐soluble dot‐in‐rods show amplified spontaneous emission (ASE) with a similar threshold (130 μJ/cm²) as the pristine material (115 μJ/cm²). To demonstrate feasibility for lasing applications, self‐assembled microlasers are fabricated via the “coffee‐ring effect” that display single‐mode operation and a very low threshold of ～10 μJ/cm². The performance of these microlasers is enhanced by the small size of MPA ligands, enabling a high packing density of the dot‐in‐rods.     

Polymer solar cells with a TiO2:Ag layer

Photovoltaic (PV) polymer solar cells with Ag and titanium dioxide were fabricated to improve the PV performance by increasing the amount of Ag in TiO₂ (by 3, 5, 7, and 10%). Sol–gel method was used to obtain amorphous or crystalline form of titanium dioxide layers. The solar cells with poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester active layer in two various positions of titanium dioxide in device were tested. Higher PV performance was received by introducing TiO₂ with 5% of Ag between ITO and PEDOT:PSS in device and by heating the layer at 130 °C. The viscosity of applied PEDOT:PSS strongly influences the values of power conversion efficiency of the constructed polymer devices with titanium dioxide.     

Measurement and Analysis of Object Reflectance Spectra

Recent algorithms developed in the field of color vision make assumptions based on the spectral reflectance curves of Munsell chips and natural materials. Some of them rely on data collected many years ago. which is partially incomplete in the visible spectrum. or contains many occurrences of the same material in it. In this article. we present a set of new measurements of different materials. In particular. we measured the spectral reflectance of Munsell chips, paints. and various natural materials in the 390–730-nm range. In addition, we have analyzed. through principal-component analysis, the possibility of representing the data collected with a set of basis functions. We show the implications of varying the number of principal components used (from 7 down to 3) on the errors introduced using this method.     

Nanofractionation spotter technology for rapid contactless and high-resolution deposition of LC eluent for further off-line analysis

The development of a contactless postcolumn spotter technology capable of rapidly and accurately depositing LC eluent onto another platform (e.g., 1536-well microtiter plates) is described. Many detection methodologies are suitable for online analysis, such as mass spectrometry, UV-vis, and fluorescence. In some cases, when online analysis is less suitable, off-line postcolumn analysis is the methodology of choice and usually relies on LC-based fractionation prior to detection (e.g., MALDI-MS, Raman spectrsocopy, biochemical assays). As fractionation generally involves loss in resolution, the technology described here allows high-resolution contactless fractionation by tailoring the fractionation frequency to the chromatographic peaks and mixing in of postcolumn reagents. Droplet ejection at frequencies of at least 6 Hz could be performed in the nanoliter to low microliter range with repeatabilities of ～6%. Furthermore, multiple droplets can be ejected at the same position thereby allowing adjustment of fractionation volume and speed. The technology was evaluated, optimized, and validated prior to two proof-of-principle demonstrations comprising off-line chemical detection of injected fluorescein and off-line postcolumn biochemical detection of acetylcholine-binding protein ligands, both based on 1536-well plate reader analysis.     

Structure-Activity Relationship of Phenylpyrazolones against Trypanosoma cruzi

Chagas disease is a neglected parasitic disease caused by the parasitic protozoan Trypanosoma cruzi and currently affects around 8 million people. Previously, 2-isopropyl-5-(4-methoxy-3-(pyridin-3-yl)phenyl)-4,4-dimethyl-2,4-dihydro-3H-pyrazol-3-one (NPD-0227) was discovered to be a sub-micromolar inhibitor (pIC₅₀=6.4) of T. cruzi. So far, SAR investigations of this scaffold have focused on the alkoxy substituent, the pyrazolone nitrogen substituent and the aromatic substituent of the core phenylpyrazolone. In this study, modifications of the phenyldihydropyrazolone scaffold are described. Variations were introduced by installing different substituents on the phenyl core, modifying the geminal dimethyl and installing various bio-isosteres of the dihydropyrazolone group. The anti T. cruzi activity of NPD-0227 could not be surpassed as the most potent compounds show pIC₅₀ values of around 6.3. However, valuable additional SAR data for this interesting scaffold was obtained, and the data suggest that a scaffold hop is feasible as the pyrazolone moiety can be replaced by a oxazole or oxadiazole with minimal loss of activity.     

未完成建筑的完成式

"烂尾楼"一直都是遭人唾弃的城市景观的"大恶瘤",也是一个让投资商望而却步的黑洞,犹如一个个濒临死亡的生命,饱含着叹息和无奈。身为设计师或与设计师有过合作的人,也许都曾遭遇或耳闻过这     

JEONGOK史前博物馆

开端之峭壁悬桥:设计者希望向场地周边的景观和临水区域致以敬意,只因这里曾经孕育了朝鲜的第一代居民,突出了山势的曲线美,呼应着蜿蜒的河流。项目将如何展现现存形态和地下地质断层的价值?发掘断层,让它讲述地球的历史;减少可见工程的影响,给予断层话语权;山丘被挖掘并建造成储藏空间,     

Über die polymerisation der kokschemischen inden-cumaron-fraktion

The influence of the catalysts BF₃O(C₂H₅)₂, FeCl₃ and J₂ on the polymerization of inden-cumaron-fractions was investigated. The dependence of the polymerization time on the resin yield was shown. Kinetic constants and reaction orders were determined.