Yanshan University

About: Yanshan University is a education organization based out in Qinhuangdao, China. It is known for research contribution in the topics: Microstructure & Control theory. The organization has 19544 authors who have published 16904 publications receiving 184378 citations. The organization is also known as: Yānshān dàxué.

All‐Elastomeric, Strain‐Responsive Thermochromic Color Indicators

Abstract: Recent advances in materials for stretchable electronics create new areas of application, particularly in systems that involve intimate integration with the human body. Examples include wearable electronics, [ 1–6 ] soft surgical instruments, [ 5,7–13 ] and skin-integrated health/wellness monitors. [ 1,14–18 ] Many envisioned systems require schemes for visual information display. Such functionality can be provided by organic or inorganic light emitting diodes (LEDs), either as arrays of non-stretchable devices joined by deformable interconnects, [ 7,19,20 ] or as elements in buckled geometries. [ 19,21 ] Intrinsically stretchable LEDs have also recently been achieved, using all polymer designs. [ 22 ] Here we present a simple, non-emissive option in display materials that likewise offer intrinsic stretchability. The approach uses elastomeric composites of thermochromic materials and metallic particles as the photonic and electronic components, respectively, in concepts that build on related materials [ 23 ]

Ultrafast and Stable Li‐(De)intercalation in a Large Single Crystal H‐Nb2O5 Anode via Optimizing the Homogeneity of Electron and Ion Transport

Abstract: Exploring anode materials with fast, safe, and stable Li-(de)intercalation is of great significance for developing next-generation lithium-ion batteries. Monoclinic H-type niobium pentoxide possesses outstanding intrinsic fast Li-(de)intercalation kinetics, high specific capacity, and safety; however, its practical rate capability and cycling stability are still limited, ascribed to the asynchronism of phase change throughout the crystals. Herein this problem is addressed by homogenizing the electron and Li-ion conductivity surrounding the crystals. An amorphous N-doped carbon layer is introduced on the micrometer single-crystal H-Nb2 O5 particle to optimize the homogeneity of electron and Li-ion transport. As a result, the as-prepared H-Nb2 O5 exhibits high reversible capacity (>250 mAh g-1 at 50 mA g-1 ), unprecedented high-rate performance (≈120 mAh g-1 at 16.0 A g-1 ) and excellent cycling stability (≈170 mAh g-1 at 2.0 A g-1 after 1000 cycles), which is by far the highest performance among the H-Nb2 O5 materials. The inherent principle is further confirmed via operando transmission electron microscopy and X-ray diffraction. A novel insight into the further development of electrode materials forlithium-ion batteries is thus provided.

Effects of backward extrusion on mechanical and degradation properties of Mg–Zn biomaterial

Abstract: Backward extrusion was used to improve the properties of Mg-based biomaterials. The microstructures, mechanical performance and corrosion properties of as-cast and backward extruded Mg-xZn (x = 0.5, 1, 1.5, 2, wt.%) alloys were investigated. The secondary dendrite arm spacing of as-cast Mg-xZn alloys and the grain size of backward extruded Mg-xZn alloys were decreased with the increment of Zn content. Meanwhile, both strength and elongation were improved by backward extruded treatment. With increasing Zn addition, the corrosion properties of both as-cast and backward extruded Mg-xZn alloys were decreased. However, the corrosion performance of backward extruded sample was improved obviously compared to the corresponding as-cast one. More importantly, the degradation rate of the backward extruded alloy was stable, which was mainly associated with the fine second precipitates and the homogeneous microstructure. It was demonstrated that backward extrusion was an effective approach to manufacture high performance Mg-based biomaterials. (C) 2012 Elsevier Ltd. All rights reserved.

Ag@Au core-shell dendrites: a stable, reusable and sensitive surface enhanced Raman scattering substrate.

Abstract: Surface enhanced Raman scattering (SERS) substrate based on fabricated Ag@Au core-shell dendrite was achieved. Ag dendrites were grown on Si wafer by the hydrothermal corrosion method and Au nanofilm on the surface of Ag dendritic nanostructure was then fabricated by chemical reduction. With the help of sodium borohydride in water, Au surface absorbates such as thiophene, adenine, rhodamine, small anions (Br(-) and I(-)), and a polymer (PVP, poly(N-vinylpyrrolidone)) can be completely and rapidly removed. After four repeatable experiments, the substrate SERS function did not decrease at all, indicating that the Ag@Au dendrite should be of great significance to SERS application because it can save much resource. Six-month-duration stability tests showed that the Ag@Au core-shell dendrite substrate is much more stable than the Ag dendrite substrates. We have also experimented on fast detection of Cd(2+) at 10(-8) M concentration by decorating single-stranded DNA containing adenine and guanine bases on the surface of this Ag@Au dendrite. Finite-difference time-domain simulations were carried out to investigate the influence of Au nanolayer on Ag dendrites, which showed that the local electric fields and enhancement factor are hardly affected when a 4 nm Au nanolayer is coated on Ag dendrite surface.