Metal‐Free Reaction of ortho‐Carbonylated Alkynyl‐Substituted Arylaldehydes with Common Amines: Selective Access to Functionalized Isoindolinone and Indenamine Derivatives

Herein we describe a reaction of ortho‐carbonylated alkynyl‐substituted arylaldehydes with common primary amines that can provide functionalized isoindolinone and 3‐hydroxylindenamine products in high yields. Depending on the substituent size of primary amines, two distinct reaction pathways were exploited selectively, that are, an initial aza‐conjugate addition followed by hydrogen transfer to access isoindolinone framework and a unique oxa‐conjugate addition followed by Petasis–Ferrier rearrangement to afford indenamine derivatives. In the presence of Et₃N, the reaction property of small primary amines was changed, proceeding to afford 3‐hydroxylindenamine derivatives efficiently. These products contain interesting substructures that exist in many natural products and bioactive molecules. The reaction features contain the use of transition‐metal‐free catalysts, simple operation, broad substrate scope, and product diversity.     

CdS/Si nanofilm heterojunctions based on amorphous silicon films:Fabrication,structures,and electrical properties

Shortening the distance between the depletion region and the electrodes to reduce the trapped probability of carriers is a useful approach for improving the performance of heterojunction.The CdS/Si nanofilm heterojunctions are fabricated by using the radio frequency magnetron sputtering method to deposit the amorphous silicon nanofilms and Cd S nanofilms on the ITO glass in turn.The relation of current density to applied voltage(I-V)shows the obvious rectification effect.From the analysis of the double logarithm I-V curve it follows that below~2.73 V the electron behaviors obey the Ohmic mechanism and above~2.73 V the electron behaviors conform to the space charge limited current(SCLC)mechanism.In the SCLC region part of the traps between the Fermi level and conduction band are occupied,and with the increase of voltage most of the traps are occupied.It is believed that Cd S/Si nanofilm heterojunction is a potential candidate in the field of nano electronic and optoelectronic devices by optimizing its fabricating procedure.     

Multichromophoric π‐Conjugation: Modular Design for Gated and Cascade Energy Transfer

Multichromophore arrays allow for cascade energy transfer. As an isoelectronic analogue of indacenyl, bis(triazolo)benzene features a fused tricyclic skeleton that rigidly places two π‐extended triazoles in close proximity. Such triazole‐based fluorophores behave as electronically independent modules in the ground states, but become tightly coupled upon photoexcitation for highly efficient excitation energy transfer (EET) that can be gated by external stimuli. Taking this donor–acceptor fluorophore system a step further, we have designed and implemented a cascade EET. Here, the initial excitation takes part in a circular relay to arrive at the longest‐wavelength emitting site as the final destination. Modularly constructed triazoloarenes should serve as versatile platforms for chemically controlled optical signaling.     

Annealing-free Poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester-based organic solar cells

We report on the fabrication of efficient annealing-free organic solar cells using co-solvent solution considered as a promising method for low-cost and time-saving manufacturing. Higher device efficiency could be obtained compared to the pure solvent casted device, resulting from the improved crystallinity, optical absorption and transport properties. The power conversion efficiency of 2.8% was obtained, demonstrating the feasibility of achieving low-cost and high-efficiency organic solar cells without any additional treatment and processing additives.     

Sorption equilibria of CO2 on silica-gels in the presence of water

The sorption equilibria of carbon dioxide on three types of silica gel (SG) with different pore size distributions in the presence of water were studied experimentally using a volumetric method at 275?K with pressures from 0 to 3.7?MPa. Both the pore size distribution of the silica gel and the quantity of pre-sorbed water impact the formation of the CO₂ hydrates. For wet silicon gel A(SG-A) with water loading ratio of 0.75, the highest CO₂ sorption was about 2.5?mmol of CO₂ per gram of dry sorbent at 275?K. Similarly, the highest sorption was about 2.7?mmol for wet SG-B with R _w =0.81. However, CO₂ hydrate did not form on the wet surface of SG-C due to its large pore sizes.     

Rapid matching algorithm for hyperspectral image based on norm sifting

We propose a rapid spectral matching method by lowering number of comparisons, processing time can be saved. Firstly, 1-norm is chosen as length measure of spectrum, and with this criterion, a 1-norm database is built. Secondly, a subspace is constructed from the whole reference library by retaining the references with the most similar 1-norm values. Finally, matching operations are performed in the subspace to obtain the match result. Simulations of geological mapping with ASTER spectral library show that the proposed method can significantly reduce processing time and enhance accuracy compared with traditional and dimension reduction methods.