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41.
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.  相似文献   
42.
Advances in microbiology rely on innovations in technology. Droplet microfluidics, as a versatile and powerful technique that allows high-throughput generation and manipulation of subnanoliter volume droplets, has become an indispensable tool shifting experimental paradigms in microbiology. Droplet microfluidics has opened new avenues to various microbiological research, from resolving single-cell heterogeneity to investigating spatiotemporal dynamics of microbial communities, from precise quant...  相似文献   
43.
Owing to the diversity of structure and potential applications in the field of electrics,sensors,and light-emitting diodes,lead halide perovskites have attracted great attention in recent years.Especially those lead halide perovskites with non-centrosymmetric crystal structures usually exhibit nonlinear optical(NLO) characteristics,which may endow them photoelectricity switching functionality.In this work,a lead-based hybrid organic-inorganic perovskite(HOIP) material,trimethyliodomethylammonium...  相似文献   
44.
Improving the transfer hydrogenation of N-heteroarenes is of key importance for various industrial processes and remains a challenge so far. We reported here a microcapsule-pyrolysis strategy to quasicontinuous synthesis S, N co-doped carbon supported Co single atom catalysts(Co/SNC), which was used for transfer hydrogenation of quinoline with formic acid as the hydrogen donor. Given the unique geometric and electronic properties of the Co single atoms, the excellent catalytic activity, selectiv...  相似文献   
45.
Nowadays, conjugated polymers have garnered numerous attention as a new class of organic photocatalysts due to their tunable electronic properties, low cost, excellent stability and sufficient light-absorption performance. In particular, pyrene-benzothiadiazolebased conjugated polymer(PBBP) has been considered to be a new type of conjugated polymers for photocatalytic H2 evolution. However, the poor charge separation seriously limits its practical application in H2 evolutio...  相似文献   
46.
Thermoset plastics have become one of the most important chemical products in the world. The consequent problem is that although the thermosets possess excellent performance in mechanical strength, they cannot be reprocessed because of the internal permanent network structures. Optimizing the molecular design of thermosets is one of the most feasible ways to improve their recyclability. Here we present a facile and robust strategy to engineer the reprocessability of thermoset polyurethanes without compromising their mechanical toughness and chemical resistance via adding supramolecular additives during the polymer synthesis process. By using a multiple hydrogen bonding moiety as the model supramolecular additive, we demonstrate that the mechanical properties, recyclability, and chemical resistance of the crosslinked polyurethanes can be precisely controlled by adjusting the contents of the supramolecular additive. Systematic studies on the relations between molecular design and material properties are performed, and the optimized polyurethane network with a moderate amount of the supramolecular additive achieves the right balance between the robustness and recyclability. This work provides a cost-effective and practical way to chemically engineer thermoset plastics, aiming to enable the recycling of mechanically tough and chemically stable polymer materials.  相似文献   
47.
Based on first-principles calculations within density functional theory, we propose a kinetic pathway for Mn incorporation on reconstructed 2 x 2-T4 GaN(0001), characterized by concerted substitution of a Ga atom by a Mn adatom via a precursor surface site T4. The Mn dopants at low densities are randomly distributed, resulting in intrinsic diluted magnetic semiconductors (DMS). At high Mn densities, planar ferromagnetic clusters oriented in the (0001) plane can be readily formed at relatively low growth temperatures, but ferrimagnetic zigzag columns along the growth orientation will be formed at high temperatures. Furthermore, intrinsic DMS are more likely to be formed via codeposition of Mn+Ga+N at high growth rates. These findings help to explain the observed variations in both the magnetic ordering temperature TC and the magnetic nature of Ga1-xMnxN.  相似文献   
48.
It remains a challenge to use a simple approach to fabricate a multi-shape memory material with high mechanical performances. Here,we report a triple crosslinking design to construct a multi-shape memory epoxy vitrimer(MSMEV), which exhibits high mechanical properties,multi-shape memory property and malleability. The triple crosslinking network is formed by reacting diglycidyl ether of bisphenol F(DGEBF) with4-aminophenyl disulfide, γ-aminopropyltriethoxysilane(APTS) and poly(propylene glycol) bis(2-aminopropyl ether)(D2000). The triple crosslinking manifests triple functions: the disulfide bonds and the silyl ether linkages enable malleability of the epoxy network; the silyl ether linkages impart the network with high heterogeneity and broaden the glass transition region, leading to multi-shape memory property; a small amount of D2000 increases the modulus difference between the glassy and rubbery states, thereby improving the shape fixity ratio. Meanwhile,the high crosslinking density and rigid structure provide the MSMEV with high tensile strength and Young's modulus. Moreover, integrating carbon fibers and MSMEV results in shape memory composites. The superior mechanical properties of the composites and the recyclability of carbon fiber derived from the dissolvability of MSMEV make the composites hold great promise as structural materials in varied applications.  相似文献   
49.
The E3 ligase adaptor SPOP,overexpressed in the nucleus but frequently dislocated into the cytoplasm in all clear cell Renal Cell Carcinomas(ccRCC),serves as a regulatory hub to promote kidney cancer through the ubiquitination and degradation of multiple downstream cancer proteins.Recently,our identification of a selective small-molecule inhibitor of the SPOP-phosphatase and tensin homolog(PTEN)interaction has demonstrated that the oncogenic SPOP-protein interaction would be a druggable target specific to ccRCC therapy.To our knowledge,this is the first time such a small-molecule inhibitor has been developed.Herein,we have identified a peptide binder for the SPOP-MATH domain that disrupts the oncogenic SPOP-protein interactions in kidney cancer cells.Computational design and biophysical characterization yielded peptide Pep38 that binds to the MATH domain of SPOP and competes on PTEN-binding to SPOP in vitro.The X-ray complex structure reveals that the peptide binder features the following combination:one,a mimic of the native peptide binder and two,an additionalβ-strand motif in sequence,which could contribute to increased binding affinity.In order to improve cellular permeability,we fused Pep38 with the delivery peptide TAT to prepare peptide TAT38,which inhibits the endogenous substrate binding to SPOP and suppresses the proliferation of the ccRCC cells.Our identification of the peptide inhibitors for SPOP-protein interactions provides further validation that the oncogenic SPOP-signaling pathway in ccRCC could be a druggable target specifically applicable to the therapy of kidney cancers.  相似文献   
50.
g-C3N4 have been widely used in the fields of photocatalytic hydrogen production,photocatalytic degradation of dyes and oxidative degradation of toxic gases due to their excellent performance.It has attracted extensive attention in recent years due to its highly efficient photocatalytic capacity of hydrogen generation,water oxidation,carbon dioxide reduction and degradation of organic pollutants.Because of the abundant carbon and nitrogen composition of the earth,large-scale production and industrial applications of this material are possible.The modification of this material makes its performance more excellent so that this new material can obtain a steady stream of vitality.These outstanding works have become important materials and milestones on the road to mankind's photocatalytic hydrogen production.This review will begin with the basic idea of designing,synthesizing and improving g-C3N4 based photocatalytic materials,and introduce the latest development of g-C3N4 photocatalysts in hydrogen production from four aspects of controlling the carbon/nitrogen ratio,morphology,element doping and heterojunction structure of g-C3N4 materials.  相似文献   
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