Search

Surface mechanical attrition treatment (SMAT) is a unique method for the nanoscale refinement of a surface grain structure without changing the alloy chemical composition. Herein, the effect of SMA...

Additional file 1. Original findings of the included studies (N = 39).

Quantum-dot light-emitting diodes (QLEDs) promise high-performance and cost-effective electroluminescent devices. However, shelf stability of QLEDs, a must for practical applications, is currently overlooked. Here we reveal that the state-of-the-art QLEDs exhibit abnormal shelf-ageing behaviours, i.e., improvements in performance (positive ageing), followed by deterioration of performance (negative ageing). Mechanism studies show that the organic acids in the encapsulation acrylic resin induce in-situ reactions, which simultaneously improve electrical conductance and minimize interfacial exciton quenching at the positive-ageing stage. Progression of the in-situ reactions results in negative ageing. Inspired by these findings, we design an electron-transporting bi-layer structure, which delivers both improved electrical conductivity and suppressed interfacial exciton quenching. This design enables shelf-stable QLEDs with high operational performance, i.e., neglectable changes of external quantum efficiency (>20.0%) and ultra-long operational lifetime (T95: 5,500 hours at 1,000 cd m-2) after storage for 180 days. Our work paves the way towards the commercialization of QLEDs.

A fast SVM learning algorithm is proposed according to incremental learning and center convex hull operator. It is established on analyzing the relevance of support vector and convex hull from the angle of calculation geometry. The convex hull of current training samples is solved in the first place. Further, Euclidean distance elimination is applied to convex hull. Meanwhile, every time when the incremental learning is going on, the training samples should contain samples violated KKT condition in previous sample set, experiment results indicate that the algorithm effectively shortens training time while classification accuracy keep a satisfied level.

Industry cluster is a quite typical economic form. It can drive industrial upgrading, improve the regional competitiveness. So it becomes an urgent problem to solve how to play and keep competitive advantage and realize orderly development. The article sees the industrial cluster as a self-organizing system and analyses industrial cluster's evolution by using the theory of self organization, then put forward the measure for the sustainable development of industrial clusters.

In the growth of world economy, the innovation of science and technology is more and more important. Production-study-research cooperation can promote the ability of technical innovation, conform with integration trend of technical economy. In order to encourage production-study-research alliances, this paper try to built the game model of production-study-research alliances under the condition of incomplete information and the formation mechanism of production-study-research alliances is deeply analyzed. After that, relevant advice of developing production-study-research alliances is given.