水杨醛亚胺共价修饰碳纳米管负载镍催化剂的合成及催化乙烯齐聚性能

以1,4-丁二胺为起始剂,4-羟基水杨醛和四水合乙酸镍为原料,经亲核加成和配位反应合成具有配位能力的水杨醛亚胺配体和含有活性羟基的水杨醛亚胺镍催化剂。通过缩合反应将水杨醛亚胺镍催化剂共价接枝到碳纳米管上,合成有机配体共价修饰碳纳米管催化剂。傅里叶变换红外光谱、核磁共振氢谱、X射线衍射等表征结果证实了合成的水杨醛亚胺配体及催化剂结构与理论结构相符。经助催化剂MAO活化后,2种催化剂均表现出良好的催化乙烯齐聚性能。条件优化实验确定了2种催化剂的较佳聚合条件,Ni用量5μmol、Al/Ni为500、反应压力0.7 MPa、反应时间30 min,均相催化剂和负载催化剂最佳反应温度分别为25℃和35℃。此条件下,均相催化剂催化乙烯齐聚活性为1.99×10^(5) g/(mol·Ni·h),齐聚产物C8和C10+选择性分别为30.38%和29.65%。负载催化剂催化乙烯齐聚活性为5.25×10^(5) g/(mol·Ni·h),齐聚产物C8和C10+选择性分别为38.14%和15.28%。与均相催化剂相比,负载催化剂具有更好的催化活性和重复利用性。

Crystal plane induced in-situ electrochemical activation of manganese-based cathode enable long-term aqueous zinc-ion batteries

Rapid capacity decay and sluggish reaction kinetics are major barriers hindering the applications of manganese-based cathode materials for aqueous zinc-ion batteries.Herein,the effects of crystal plane on the in-situ transformation behavior and electrochemical performance of manganese-based cathode is discussed.A comprehensive discussion manifests that the exposed(100)crystal plane is beneficial to the phase transformation from tunnel-structured MnO_(2) to layer-structured ZnMn_(3)O_(7)·3H_(2)O,which plays a critical role for the high reactivity,high capacity,fast diffusion kinetics and long cycling stability.Additionally,a two-stage zinc storage mechanism can be demonstrated,involving continuous activation reaction and phase transition reaction.As expected,it exhibits a high capacity of 275 mAh g^(-1)at 100 mA g^(-1),a superior durability over 1000 cycles and good rate capability.This study may open new windows toward developing advanced cathodes for ZIBs,and facilitate the applications of ZIBs in large-scale energy storage system.

Fundamental Understanding and Effect of Anionic Chemistry in Zinc Batteries

With the merit of high capacity,high safety,and low cost,zinc-ion batteries(ZIBs)possess huge application potential in the domain of large-scale energy storage.However,due to the relatively narrow voltage window and large lattice distortion of cationic redox reaction,ZIBs tend to present low energy density,poor kinetics,and unstable cyclic performance.Anion chemistry seems to provide a novel strategy to solve these issues from different aspects,such as enhanced operating voltage,extra capacity contribution,and boosted reaction kinetics.Considering the significance of this theory and the lack of relevant literatures,herein,in-depth comprehension of anionic chemistry and its positive effects on zinc storage performance have been emphasized and summarized.This review aims to present a full scope of anionic chemistry and furnish systematic cognition for rational design of advanced ZIBs with high energy density.Furthermore,insightful analysis and perspectives based on the current research status also have been proposed,which may point out some scientific suggestions and directions for the future research.

Feasibility study on sinkhole monitoring with fiber optic strain sensing nerves

Anthropogenic activity-induced sinkholes pose a serious threat to building safety and human life nowadays.Real-time detection and early warning of sinkhole formation are a key and urgent problem in urban areas.This paper presents an experimental study to evaluate the feasibility of fiber optic strain sensing nerves in sinkhole monitoring.Combining the artificial neural network(ANN)and particle image velocimetry(PIV)techniques,a series of model tests have been performed to explore the relationship between strain measurements and sinkhole development and to establish a conversion model from strain data to ground settlements.It is demonstrated that the failure mechanism of the soil above the sinkhole developed from a triangle failure plane to a vertical failure plane with increasing collapse volume.Meanwhile,the soil-embedded fiber optic strain sensing nerves allowed deformation monitoring of the ground soil in real time.Furthermore,the characteristics of the measured strain profiles indicate the locations of sinkholes and the associated shear bands.Based on the strain data,the ANN model predicts the ground settlement well.Additionally,micro-anchored fiber optic cables have been proven to increase the soil-to-fiber strain transfer efficiency for large deformation monitoring of ground collapse.

Nanofiber Composite Reinforced Organohydrogels for Multifunctional and Wearable Electronics

Composite organohydrogels have been widely used in wearable electronics.However,it remains a great challenge to develop mechanically robust and multifunctional composite organohydrogels with good dispersion of nanofillers and strong interfacial interactions.Here,multifunctional nanofiber composite reinforced organohydrogels(NCROs)are prepared.The NCRO with a sandwich-like structure possesses excellent multi-level interfacial bonding.Simultaneously,the synergistic strengthening and toughening mechanism at three different length scales endow the NCRO with outstanding mechanical properties with a tensile strength(up to 7.38±0.24 MPa),fracture strain(up to 941±17%),toughness(up to 31.59±1.53 MJ m~(-3))and fracture energy(up to 5.41±0.63 kJ m~(-2)).Moreover,the NCRO can be used for high performance electromagnetic interference shielding and strain sensing due to its high conductivity and excellent environmental tolerance such as anti-freezing performance.Remarkably,owing to the organohydrogel stabilized conductive network,the NCRO exhibits superior long-term sensing stability and durability compared to the nanofiber composite itself.This work provides new ideas for the design of high-strength,tough,stretchable,anti-freezing and conductive organohydrogels with potential applications in multifunctional and wearable electronics.

基于Cite-Space的国有企业混合所有制改革研究可视化分析

国有企业实现经济高质量发展的关键一步就是实行混合所有制改革,发展公有制经济,学术界对其改革历程一直极为关注。文章以中国知网2014—2022年2488份文献资料为基础,利用Cite-Space数据统计软件,对其进行了可视化分析。研究发现:改革路径方法、过程机制、影响结果和问题对策是国企改革中的重要问题。在新时代背景下,股权结构、公司治理等改革路径、改革影响效应中的投资效益问题是混合所有制改革中研究的最新动向。

多肉状微马达用于动态检测和降解四环素

四环素是一种广泛使用的抗生素,但它在环境中难以降解,而且会促使耐药细菌的出现.因此,迫切需要采取有效的措施对其进行检测和分解.在此背景下,我们设计了一种多肉状的ZnO/MOF/Fe_(3)O_(4)混合微型马达,用于动态检测和光催化降解四环素.我们使用微纳米加工和种子生长方法成功制备了具有多肉植物状结构的ZnO微型马达.在氧化锌马达阵列上,通过表面修饰,比如改变其表面电位、负载响应性检测功能MOF、磁性纳米颗粒和催化剂,最终得到了可用于动态荧光检测和高效降解的自驱动可控微马达.这种功能性微马达在环境检测和治理等方面具有很好发展前景.

Characterizing the complete mitochondrial genome of Psephenothrips eriobotryae Dang&Qiao(Thysanoptera:Phlaeothripidae)with massive gene arrangement in Phlaeothripidae

Each species within the order Thysanoptera has a distinct mitochondrial gene order displaying a high level of gene rearrangement,particularly massive in Phlaeothripidae.To understand the evolutionary patterns of rearrangement in this family,we sequenced the complete mitochondrial genome of Psephenothrips eriobotryae,a notable potential pest of loquat trees.Its mitogenome is a circular DNA molecule(15,413 bp in size)composed of 37 genes:13 PCGs,22 tRNAs,two rRNAs,and two putative control regions(CRs).By comparing with the ancestral mitogenome of arthropods,P.eriobotryae exhibits notable gene rearrangement variations.However,it shares four conserved gene blocks with three closely related species in Phlaeothripinae.In the phylogenetic tree,P.eriobotryae was clustered with these three leaffeeding Phlaeothripinae species.The presence of more similar conserved gene blocks probably indicates a strong correlation between gene rearrangements and the phylogeny within Phlaeothripidae.Furthermore,the mitogenome of P.eriobotryae shows some characteristics:(a)two putative CRs in which CR2 is the copy of partial CR1 with 99.62%sequence similarity,and CR1 consists of two 237 bp repeat unites;(b)high A+T content of 82.6%in overall base composition;(c)trn S1 lacking a complete dihydrouridine(DHU)arm;(d)the protein coding gene,atp8 started with TTG instead of the more common ATN,while nad3 terminated by TAG rather than TAA;(e)translocations and inversions observed in fifteen of the 37 genes.

Pore structure and oxygen content design of amorphous carbon toward a durable anode for potassium/sodium-ion batteries

Both sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)are considered as promising candidates in grid-level energy storage devices.Unfortunately,the larger ionic radii of K+and Na+induce poor diffusion kinetics and cycling stability of carbon anode materials.Pore structure regulation is an ideal strategy to promote the diffusion kinetics and cyclic stability of carbon materials by facilitating electrolyte infiltration,increasing the transport channels,and alleviating the volume change.However,traditional pore-forming agent-assisted methods considerably increase the difficulty of synthesis and limit practical applications of porous carbon materials.Herein,porous carbon materials(Ca-PC/Na-PC/K-PC)with different pore structures have been prepared with gluconates as the precursors,and the amorphous structure,abundant micropores,and oxygen-doping active sites endow the Ca-PC anode with excellent potassium and sodium storage performance.For PIBs,the capacitive contribution ratio of Ca-PC is 82%at 5.0 mV s^(-1) due to the introduction of micropores and high oxygen-doping content,while a high reversible capacity of 121.4 mAh g^(-1) can be reached at 5 A g^(-1) after 2000 cycles.For SIBs,stable sodium storage capacity of 101.4 mAh g^(-1) can be achieved at 2 A g^(-1) after 8000 cycles with a very low decay rate of 0.65%for per cycle.This work may provide an avenue for the application of porous carbon materials in the energy storage field.

All-inorganic lead-free NiO_(x)/Cs_(3)Bi_(2)Br_(9) perovskite heterojunction photodetectors for ultraviolet multispectral imaging

Bismuth-based perovskites are considered to be promising candidates to substitute the toxic lead-based perovskite in optoelectronics due to their excellent optoelectronic properties,high environmental friendliness,and(moisture,light,and heat)stability.However,there are still few reports about high performance bismuth-based perovskite ultraviolet photodetectors,and is more lacking in ultraviolet imaging demonstration.Herein,we reported a self-powered NiO_(x)/Cs_(3)Bi_(2)Br_(9) heterojunction photodetector with excellent photodetection performance by electrochemical depositing NiOx as the hole transport layer.The optimized NiO_(x)/CsaBi_(2)Brg heterojunction photodetector exhibits excellent ultraviolet detection performance with a fast response speed of 3.04/4.65 ms,wide linear dynamic range of 116.6 dB,decent responsivity of 4.33 mA·W^(-1) at 0 V bias,and high detectivity of 1.3×10^(11) jones.The outstanding performance of the optimized NiO_(x)/Cs_(3)Bi_(2)Br_(9) heterojunction photodetector is enough to meet the high-quality ultraviolet imaging.Therefore,we further integrated the optimized NiO_(x)/Cs_(3)Bi_(2)Br_(9) heterojunction photodetector to the transmission mode ultraviolet multispectral imaging system,achieving admirable imaging results at weak light condition.This work will play a positive role in promoting the development of bismuth-based ultraviolet photodetection and ultraviolet multispectral imaging.

Light hybrid micro/nano-robots:From propulsion to functional signals

Untethered motile micro/nanorobots(MNRs)that can operate in hard-to-reach small space and perform noninvasive tasks in cellular level hold bright future in healthcare,nanomanufacturing,biosensing,and environmental remediation.Light,as a flexible encoding method with tunable freedom of intensity,wavelength,polarization,and propagation direction,endows unique spatialtemporal precision and dexterity to the manipulation of MNRs.Meanwhile,light has been extensively investigated as functional signals in bioimaging,phototherapy,as well as photoelectrochemical reactions.The hybridization of light and other actuation method ushers in novel MNRs with broadened design space,improved controllability,and advanced functionality.In this review,the fundamental mechanisms of light-driven MNRs will be revisited.On top of it,light hybrid systems,coupling with magnetic,electric,chemical,or ultrasound field,will be reviewed,with light for propulsion or as functional signal.The rational hybridization of multiple stimulus in MNRs not only promises simple combination of two driving forces,but more importantly,motivates rethinking of light-driven MNRs for unprecedented applications.

High-repetition-rate pulsed fiber laser based on virtually imaged phased array

High-repetition-rate(HRR) pulsed fiber lasers have attracted much attention in various fields. To effectively achieve HRR pulses in fiber lasers, dissipative four-wave-mixing mode-locking is a promising method. In this work, we demonstrated an HRR pulsed fiber laser based on a virtually imaged phased array(VIPA), serving as a comb filter. Due to the high spectral resolution and low polarization sensitivity features of VIPA, the 30 GHz pulse with high quality and high stability could be obtained. In the experiments, both the single-waveband and dual-waveband HRR pulses were achieved. Such an HRR pulsed fiber laser could have potential applications in related fields, such as optical communications.

Selectivity of biopolymer membranes using HepG2 cells

Bioartificial liver(BAL)system has emerged as an alternative treatment to bridge acute liver failure to either liver transplantation or liver regeneration.One of the main reasons that the efficacy of the current BAL systems was not convincing in clinical trials is attributed to the lack of friendly interface between the membrane and the hepatocytes in liver bioreactor,the core unit of BAL system.Here,we systematically compared the biological responses of hepatosarcoma HepG2 cells seeded on eight,commercially available biocompatible membranes made of acetyl cellulose–nitrocellulose mixed cellulose(CA–NC),acetyl cellulose(CA),nylon(JN),polypropylene(PP),nitrocellulose(NC),polyvinylidene fluoride(PVDF),polycarbonate(PC)and polytetrafluoroethylene(PTFE).Physicochemical analysis and mechanical tests indicated that CA,JN and PP membranes yield high adhesivity and reasonable compressive and/or tensile features with friendly surface topography for cell seeding.Cells prefer to adhere on CA,JN,PP or PTFE membranes with high proliferation rate in spheriod-like shape.Actin,albumin and cytokeratin 18 expressions are favorable for cells on CA or PP membrane,whereas protein filtration is consistent among all the eight membranes.These results further the understandings of cell growth,morphology and spreading,as well as protein filtration on distinct membranes in designing a liver bioreactor.