微波辐射下LaNaY沸石的水热交换反应

报道微波辐射应用于ＮａＹ沸石与Ｌａ（ＮＯ＿３）＿３溶液的离子交换反应，结果表明微波辐射可提高Ｌａ￣＋的交换度，缩短交换时间。     

The effect of the third component on butadiene–propylene alternating copolymerization catalyzed by vanadium–aluminum system

The effects of five ethers and four AliBu₂OR's with varied R' on butadiene–propylene alternating copolymerization were investigated. It was found that by adding the proper third component, both the conversion and the catalytic efficiency could be increased. The effect of the third component on the valence state of vanadium ion was also studied. A model of the active center of the ternary-component catalyst system was proposed.     

Hybridized local and charge-transfer excited state fluorophores enabling organic light-emitting diodes with record high efficiencies close to 20%

Pure organic emitters with full utilization of triplet excitons are in high demand for organic light-emitting diodes (OLEDs). Herein, through modulation of electron donors and introduction of phenyl rings as π spacers, we present three pure organic fluorophores (BCz, BTCz and BPTCz) with the hybridized local and charge-transfer (HLCT) excited state feature for OLED fabrication. Importantly, the introduction of π spacers in BPTCz not only enhances locally excited character with a fast radiative decay but also promotes intermolecular interactions to suppress non-radiative decays, contributing to a high solid-state fluorescence efficiency over 90%. Significantly, BPTCz not only endows its doped OLEDs with an external quantum efficiency (EQE) up to 19.5%, but also its non-doped OLED with a high EQE of 17.8%, and these outstanding efficiencies are the state-of-the-art performances of HLCT-based OLEDs.

Three purely organic fluorophores with a hybridized local and charge-transfer excited state feature are presented and enabled organic light-emitting diodes with record high external quantum efficiencies close to 20%.     

Preparation and thermal properties of a novel flame-retardant coating

A novel silicone and phosphate modified acrylate (DGTH) was synthesized and characterized by ¹H NMR and FTIR. It was found that DGTH could be cured both by UV radiation and moisture mode with FTIR. The flammability and thermal behavior of the cured film were studied by the limited oxygen index (LOI), thermogravimetric analysis (TG) and real time Fourier transform infrared (RT-FTIR). The LOI value of the cured film is 48 and the TG data shows that the cured film has three characteristic degradation temperature regions, attributing to the decomposition of phosphate and polyurethane to alcohols and isocyanates, thermal pyrolysis of alkyl chains, and decomposition of unstable structures in char, respectively. The RT-FTIR data implies that the degraded products of phosphate form poly(phosphoric acid) further catalyse the breakage of carbonyl groups to form an intumescent char, preventing the samples from further burning.     

Z‐bpy,a New C2‐Symmetric Bipyridine Ligand and Its Application in Enantioselective Copper(I)‐Catalyzed Cyclopropanation of Olefins

A rigid C₂‐symmetric chiral bipyridine ligand Z‐bpy with a triptycene‐like backbone was designed and synthesized from simple chemicals in a scalable route. Using this new ligand, copper(I) catalyzed cyclopropanation of styrenes with commercial ethyl diazoacetate produced various corresponding cyclopropanes in high yields, diastereoselectivity and enantioselectivity up to 97% ee.     

Temperature effects for isothermal polymer crystallization kinetics

We adopt the cluster size distribution model to investigate the effect of temperature on homogeneous nucleation and crystal growth for isothermal polymer crystallization. The model includes the temperature effects of interfacial energy, nucleation rate, growth and dissociation rate coefficients, and equilibrium solubility. The time dependencies of polymer concentration, number and size of crystals, and crystallinity (in Avrami plots) are presented for different temperatures. The denucleation (Ostwald ripening effect) is also investigated by comparing moment and numerical solutions of the population balance equations. Agreement between the model results and temperature-sensitive experimental measurements for different polymer systems required strong temperature dependence for the crystal-melt interfacial energy.     

Machine learning-based direct solver for one-to-many problems on temporal shaping of relativistic electron beams

To control the temporal profile of a relativistic electron beam to meet requirements of various advanced scientific applications like free-electron-laser and plasma wakefield acceleration, a widely-used technique is to manipulate the dispersion terms which turns out to be one-to-many problems. Due to their intrinsic one-to-many property, current popular stochastic optimization approaches on temporal shaping may face the problems of long computing time or sometimes suggesting only one solution. Here we propose a real-time solver for one-to-many problems of temporal shaping, with the aid of a semi-supervised machine learning method, the conditional generative adversarial network (CGAN). We demonstrate that the CGAN solver can learn the one-to-many dynamics and is able to accurately and quickly predict the required dispersion terms for different custom temporal profiles. This machine learning-based solver is expected to have the potential for wide applications to one-to-many problems in other scientific fields.     

Cluster synchronization in a network of non-identical dynamic systems

Cluster synchronization in a network of non-identical dynamic systems is studied in this paper, using two-cluster synchronization for detailed analysis and discussion. The results show that the common intercluster coupling condition is not always needed for the diffusively coupled network. Several sufficient conditions are obtained by using the Schur unitary triangularization theorem, which extends previous results. Some numerical examples are presented for illustration.     

Interaction between β‐Cyclodextrin and Mixed Cationic‐Anionic Surfactants (2): Aggregation Behavior

The interactions between β‐cyclodextrin (β‐CD) and the mixtures of cationic‐anionic surfactants in the aqueous solution were investigated by surface tension, rheology, and dynamic light scattering measurements. It was shown that the key‐lock interactions between β‐CD and mixed cationic‐anionic surfactants were stronger than the electrostatic/hydrophobic interactions between cationic and anionic surfactants. The inclusion of β‐CD to surfactants could destroy the ion‐pair and aggregates of cationic‐anionic surfactants, and even inhibited the precipitation of the mixed cationic‐anionic surfactants. Furthermore, the inclusion of β‐CD to surfactants could also destroy the hydrogen bond between β‐CD molecules, inducing the disassociation of the aggregation formed by β‐CD themselves.