Enhanced Potassium‑Ion Storage of the 3D Carbon Superstructure by Manipulating the Nitrogen‑Doped Species and Morphology

Potassium-ion batteries(PIBs)are attractive for gridscale energy storage due to the abundant potassium resource and high energy density.The key to achieving high-performance and large-scale energy storage technology lies in seeking eco-efficient synthetic processes to the design of suitable anode materials.Herein,a spherical sponge-like carbon superstructure(NCS)assembled by 2D nanosheets is rationally and efficiently designed for K+storage.The optimized NCS electrode exhibits an outstanding rate capability,high reversible specific capacity(250 mAh g^(−1) at 200 mA g^(−1) after 300 cycles),and promising cycling performance(205 mAh g^(−1) at 1000 mA g^(−1) after 2000 cycles).The superior performance can be attributed to the unique robust spherical structure and 3D electrical transfer network together with nitrogen-rich nanosheets.Moreover,the regulation of the nitrogen doping types and morphology of NCS-5 is also discussed in detail based on the experiments results and density functional theory calculations.This strategy for manipulating the structure and properties of 3D materials is expected to meet the grand challenges for advanced carbon materials as high-performance PIB anodes in practical applications.

Hydrogen absorption of slurry system composed of different MgNi alloy and benzene

The hydrogen absorption amount and kinetics of the slurry formed by suspending the MgNi alloy powder in liquid benzene were studied. It is discovered that hydrogen is absorbed by both the solid phase(alloy) and liquid phase(C 6H 6) and the hydrogen absorption rate varies with the temperature and the content of the Mg-Ni in the slurry. Most hydrogen absorption curves of the slurry fall into two regions, in which the mechanism of hydriding reaction in the slurry system is different. In the former region, the hydriding of the alloy proceeds with hydrogen diffusing through C 6H 6. The part in the second region is the outcome of the hydrogenation of C 6H 6. At 548 K and under the hydrogen pressure of 4.5 MPa the saturation capacity for the slurry of 80% C 6H 6(mass fraction)+20% MgNi(mass fraction) is 5.9% (mass fraction) hydrogen, which is 97% of the theoretic capacity of the slurry system. The hydride of the alloy MgNi, which is only the hydride of Mg 2Ni phase, Mg 2NiH 4, is an efficient catalyst for the hydrogenation of C 6H 6 into C 6H 12(C 6H 6+3H 2→C 6H 12) in the slurry system.

An AIEgens and exonuclease Ⅲ aided quadratic amplification assay for detecting and cellular imaging of telomerase activity

Monitoring telomerase activity with high sensitive and reliable is of great importance to cancer analysis.In this paper, we report a sensitive and facile method to detect telomerase activity using AIEgens modified probe(TPE-Py-DNA) as a fluorescence reporter and exonuclease Ⅲ(Exo Ⅲ) as a signal amplifier.With the aid of telomerase, repeat units(TTAGGG)n are extended from the end of template substrate oligonucleotides(TS primer) that form duplex DNAs with TPE-Py-DNA. Then, Exo Ⅲ catalyzes the digestion of duplex DNAs, liberating elongation product and releasing hydrophobic TPE-Py. The released hydrophobic TPE-Py aggregate together and produce a telomerase-activity-related fluorescence signal.The liberated product hybridizes with another TPE-Py-DNA probe, starting the second cycle. Finally,we obtain the target-to-signal amplification ratio of 1:N^2. This strategy exhibits good performance for detecting clinical urine samples(distinguishing 15 cancer patients' samples from 8 healthy ones) and checking intracellular telomerase activity(differentiating cell lines including He La, MDA-MB-231,MCF-7, A375, HLF and MRC-5 from the cells pretreated with telomerase-related drug), which shows its potential in clinical diagnosis as well as therapeutic monitoring of cancer.

具有改进的导热性能和力学性能的3D石墨烯/聚酰亚胺纤维框架

电子元器件的集成化和柔性器件的普及,对热管理材料的散热能力和综合力学性能提出了更高要求。本文通过预氧化和氨基化对聚酰亚胺(PI)纤维进行改性,获得表面活性较强的PDA@OPI纤维,将其与氧化石墨烯(GO)充分混合,形成GO-PDA@OPI混合浆料。随后采用蒸发、碳化、石墨化和机械压实等工艺,制备得到具有3D长程互连结构的G-g PDA@OPI复合薄膜。PDA@OPI纤维通过构成稳定的共价键将相邻的GO片“焊接”在一起,有利于石墨化样品中负载的传递和应力的耗散。同时,这种增强的界面相互作用还显著促进了GO和PI纤维在石墨化过程中的协同效应,以此提高石墨产品的结晶度。另外,PDA@OPI纤维还为热处理进程中因含氧基团分解而产生的气体提供逸出通道,从而使GO片的膨胀效应得到抑制。结果显示,当PDA@OPI纤维的添加量为30%时,G-g PDA@OPI复合薄膜的拉伸强度、极限应变率以及热导率分别达到78.5 MPa,19.4%,1028 W/(m·K),表现出优异的柔韧性和高回弹率。

Photorefractive Effect in an Azobenzene Chromophore Side Groups Polymer

We have analyzed the photorefractive（PR） effect of a polymer composite was reported which combines a novel bi-functional poly（N-vinyl）-3-[p-nitrophenylazo]carbazolyl（PVNPAK） and 2,4,7-trinitro-9-fluorenone（TNF）. PVNPAK was synthesized by a post-azo-coupling reaction, with an azo derivative as the electrooptic chromophore and carbazolyl as photoconductive moiety. The asymmetric two-beam coupling gain of 13.9 cm-1 and diffraction efficiency of 1.2% for poled polymer film fabricated using a corona poling are obtained at the wavelength of 647.1 nm, confirming photorefractivity. We interpreted this result as the orientational enhancement, in which the spatial charge field may enhance the modulated orientation of the azobenzen chromophore. It is unexpected that the photorefractive gain of 9.5 cm-1 for the unpoled polymer film also was observed without external field in two-beam coupling（TBC） experiment. This phenomenon is attributed to a light-induced orientational grating when the azobenzene groups are illuminated by polarized light.