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high-stability spherical lanthanide nanoclusters for magnetic resonance imaging

National Science Review 2023年第4期10卷 123-132页

作者： Hai-Ling Wang Donglin Liu Jian-Hua Jia Jun-Liang Liu Ze-Yu Ruan Wei Deng Shiping Yang Si-Guo Wu Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-sen University College of Chemistry and Materials Science Shanghai Normal University

high-nuclear lanthanide clusters have shown great potential for the administration of high-dose mononuclear gadolinium chelates in magnetic resonance imaging(MRI). The development of high-nuclear lanthanide clusters with excellent solubility and high stability in water or solution has been challenging and is very important for expanding the performance of MRI. We used N-methylbenzimidazole-2-methanol(HL) and LnCl3·6H2O to synthesize two spherical lanthanide clusters, Ln32(Ln = Ho, Ho32; and Ln =Gd, Gd32), which are highly stable in solution. The 24 ligands L-are all distributed on the periphery of Ln32and tightly wrap the cluster core, ensuring that the cluster is stable. Notably, Ho32can remain highly stable when bombarded with different ion source energies in HRESI-MS or immersed in an aqueous solution of different pH values for 24 h. The possible formation mechanism of Ho32was proposed to be Ho(Ⅲ),(L)-and H2O → Ho3(L)3/Ho3(L)4→ Ho4(L)4/Ho4(L)5→ Ho6(L)6/Ho6(L)7→ Ho16(L)19→Ho28(L)15→ Ho32(L)24/Ho32(L)21/Ho32(L)23. To the best of our knowledge, this is the first study of the assembly mechanism of spherical high-nuclear lanthanide clusters. Spherical cluster Gd32, a form of highly aggregated Gd(Ⅲ), exhibits a high longitudinal relaxation rate(1 T, r1= 265.87 mM-1·s-1). More notably, compared with the clinically used commercial material Gd-DTPA, Gd32has a clearer and higher-contrast T1-weighted MRI effect in mice bearing 4T1 tumors. This is the first time that high-nuclear lanthanide clusters with high water stability have been utilized for MRI. high-nuclear Gd clusters containing highly aggregated Gd(Ⅲ) at the molecular level have higher imaging contrast than traditional Gd chelates; thus, using large doses of traditional gadolinium contrast agents can be avoided.

关键词： T1-weighted MRI lanthanide clusters high stability low toxicity assembly mechanism

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Pt nanodendrites with a PtIr alloy surface structure exhibit excellent stability toward acidic hydrogen evolution reaction

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Nano Research 2024年第6期17卷 4844-4849页

作者： Chang Liu Zongnan Wei Minna Cao Rong Cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

The development of effective and stable electrocatalysts for the hydrogen evolution reaction(HER)in acidic electrolytes is a significant challenge.In this work,homogeneous Pt nanodendrites(Pt NDs)with a PtIr shell were successfully synthesized by a two-step wet chemical method.This open three-dimensional(3D)dendritic structure exhibited exceptional electrocatalytic characteristics,exposing as many active sites as feasible.Furthermore,by alloying Ir with Pt on the surface,catalytic activity was greatly enhanced while ensuring extremely high stability.Iridium surface-enriched platinum nanodendritic catalysts(Pt@PtIr NDs)outperformed the control samples and the commercial catalysts.In acidic HER test,Pt@PtIr NDs had a lower overpotential(22 mV)than Pt NDs(26 mV)and commercial Pt/C(31 mV)at 10 mA/cm^(2),and the activity of Pt@PtIr NDs remained consistent even after undergoing a continuous durability test for at least 168 h,which was much superior to the performance of commercial Pt/C(10 h)under identical test conditions.This study revealed that the application of 3D Pt dendritic metal alloys may offer a chance for the development of enhanced electrocatalysts in acidic HER.

关键词： Pt nanodendrites iridium high stability hydrogen evolution reaction alloy

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In-situ growth of polypyrrole on aramid nanofibers for electromagnetic interference shielding films with high stability

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Nano Research 2022年第9期15卷 8536-8545页

作者： Jianyu Zhou Sineenat Thaiboonrod Jianhui Fang Shaomei Cao Miao Miao Xin Feng Research Center of Nano Science and Technology College of SciencesShanghai UniversityShanghai 200444China National Nanotechnology Center(NANOTEC) National Science and Technology Development Agency(NSTDA)Thailand Science ParkPathum Thani 12120Thailand

Flexible electromagnetic interference(EMI)shielding films with high stability have shown promising prospect in harsh working conditions such as military,communication,and special protection fields.Herein,flexible aramid nanofibers@polypyrrole(ANF@PPy)films with high stability were easily achieved by the in-situ growth of PPy on the surface of ANF and the subsequent pressured-filtration film-forming process.When the amount of pyrrole(Py)monomer is 40μL,the ANF@PPy(AP40)film exhibited excellent EMI shielding performance with shielding effectiveness(SE)of 41.69 dB,tensile strength of 96.01 MPa,and fracture strain of 21.95%at the thickness of 75.76μm.Particularly,the anticipated EMI shielding performance can be maintained even after being heated at 200℃in air,soaked in 3.5%NaCl solution,repeated folding for one million times,or burned directly,indicating superior environmental durability in harsh conditions.Therefore,it is believed that the ANF@PPy films with high stability offer a facile solution for practical protection for high-performance EMI shielding applications.

关键词： in-situ growth of polypyrrole(PPy)on aramid nanofibers(ANF) electromagnetic interference(EMI)shielding films high stability water-resistance thermal mechanical properties

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Organic polystyrene and inorganic silica double shell protected lead halide perovskite nanocrystals with high emission efficiency and superior stability

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Nano Research 2023年第7期16卷 10507-10514页

作者： Shujian Wang Dejian Chen Kunyuan Xu Jie Hu Decai Huang Maochun Hong Haomiao Zhu University of Science and Technology of China Hefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of Nanomaterials Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Research Center of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China

The practical application of all-inorganic semiconductor lead halide perovskite nanocrystals(LHP NCs)has been limited by their poor stability.Recently,a lot of research on core-shell structure has been done to improve the stability of perovskite NCs,but the effect was far from the application requirements.Herein,we,for the first time,report a convenient approach to synthesize organic-inorganic double shell CsPbBr_(3)@SiO_(2)@polystyrene(PS)NCs with an inter-core of CsPbBr_(3),the intermediate layer of SiO_(2)shell,and outmost PS shell.Particularly,the CsPbBr_(3)@SiO_(2)@PS NCs maintained more than 90%of their initial photoluminescence(PL)intensity under one month's ultraviolet lamp irradiation or in 85℃ and 85%relative humidity(RH)condition.The white-light-emitting-diodes(WLEDs)were fabricated by encapsulating commercial InGaN chip with CsPbBr_(3)@SiO_(2)@PS NCs and K2SiF6:Mn^(4+)(KSF:Mn^(4+))phosphor with a luminous efficacy of~100 lm/W at 20 mA current and a color gamut of 128%of the National Television Standards Committee(NTSC)standard.In addition,these WLEDs still maintain 91%of the initial luminous efficacy after 1200 h of continuous lighting.These results demonstrated that double shell-protected CsPbBr_(3)perovskite NCs have great potential in the field of WLEDs.

关键词： core-shell structure organic polystyrene(PS)inorganic SiO_(2)double shell CsPbBr_(3)@SiO_(2)@PS nanocrystals(NCs) high stability

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Application Layer Multicast Model with Low Delay and high stability

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Journal of Donghua University(English Edition) 2023年第1期40卷 74-79页

作者：廖小飞宣益亮宿轩策李德敏 College of Information Sciences and Technology Donghua UniversityShanghai 201620China Engineering Research Center of Digitized Textile&Fashion Technology Ministry of EducationDonghua UniversityShanghai 201620China

As an alternative of Internet protocol(IP)multicast,application layer multicast(ALM)is widely used with the advantage of simplicity and flexibility.However,the existing problems of large transmission delay and poor stability limit the application and development.In this article,to solve these problems,an ALM model based on node potential(NP)and topological index(TI)is proposed.The proposed model considers the factors of node capability and node distance in constructing and maintaining multicast tree to reduce transmission delay and increase stability,and thus it improves the application level in real-time multimedia multicast.The computer simulations prove that the proposed model reduces the ALM transmission delay,increases multicast tree stability effectively,and improves the ALM performance,and therefore it is suitable to apply in large-scale real-time multimedia environment.

关键词： application layer multicast(ALM) high stability low delay node potential(NP) topological index(TI)

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基于准二维钙钛矿的高稳定电阻随机存储器

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Science China Materials 2024年第3期67卷 879-886页

作者：陈享潘孝鑫蒋博闻危家昀龙研汤杰李晓庆张军段金霞桃李马国坤王浩 Institute of Microelectronics and Integrated Circuits School of MicroelectronicsHubei UniversityWuhan 430062China Hubei Yangtze Memory Laboratories Wuhan 430205China

电阻式随机存储器(RRAM)一直被视为新兴存储器技术中具有挑战性的替代品.近年来,人们发现基于有机-无机杂化卤化物钙钛矿的RRAM具有优异的存储特性.本研究利用简单的一步旋涂策略,在空气中不使用反溶剂,制备出了具有准二维钙钛矿活性层... 详细信息

电阻式随机存储器(RRAM)一直被视为新兴存储器技术中具有挑战性的替代品.近年来,人们发现基于有机-无机杂化卤化物钙钛矿的RRAM具有优异的存储特性.本研究利用简单的一步旋涂策略,在空气中不使用反溶剂,制备出了具有准二维钙钛矿活性层的Al/(PEA)_(2)-MAPb_(2)I_(3)Br_(4)/SnO_(2)/氧化铟锡(ITO)非易失性RRAM,该器件表现出了出色且高度稳定的双极性电阻切换特性.此外,该器件表现出约为10~4的开/关比,低SET电压(约0.8 V),并且具有相对稳定的耐久性(大于1000次循环).高阻态和低阻态的传导机制分别是空间电荷限流传导和欧姆传导.此外,由于苯乙胺分子的疏水性,该器件在40%湿度下放置90天依然表现出显著的阻变特性.因此,这种高性能、稳定的RRAM为未来存储器的商业化提供了可能性.

关键词： resistive random access memory organic-inorganic hybrid quasi-two-dimensional high stability

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A high-power high-stability Q-switched green laser with intracavity frequency doubling using a diode-pumped composite ceramic Nd:YAG laser

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Chinese Physics B 2012年第9期21卷 315-320页

作者：王与烨徐德刚刘长明王卫鹏姚建铨 Institute of Laser and Optoelectronics College of Precision Instrument and Optoelectronics EngineeringTianjin University Key Laboratory of Optoelectronics Information Science and Technology Tianjin UniversityMinistry of Education

We successfully obtain a high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd：YAG in a straight piano-concave cavity. The temperature distribution in composite ceramic Nd：YAG crystal is numerically analyzed and compared with that of conventional Nd：YAG crystal. By using a composite ceramic Nd：YAG rod and a type-II high gray track resistance KTP （HGTR-KTP） crystal, a green laser with an average output power of 165 W is obtained at a repetition rate of 25 kHz, with a diode-to-green optical conversion of 14.68%, and a pulse width of 162 ns. To the best of our knowledge, both the output power and optical-to-optical efficiency are the highest values for green laser systems with intracavity frequency doubling of this novel composite ceramic Nd：YAG laser to date. The power fluctuation at around 160 W is lower than 0.3% in 2.5 hours.

关键词： high-average-power green laser high stability composite ceramic Nd：YAG rod

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Novel photoelectric material of perovskite-like(CH_(3))_(3)SPbI_(3) nanorod arrays with high stability

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Journal of Energy Chemistry 2021年第8期30卷 581-588,I0012页

作者： Ruiyuan Hu Chuangye Ge Liang Chu Yifei Feng Shanshan Xiao Yuhui Ma Wei Liu Xing'ao Li Mohammad Khaja Nazeeruddin Institute of Advanced Materials&New Energy Technology Engineering Laboratory of Jiangsu Province&School of Materials Science and Engineering&School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Hoffmann Institute of Advanced Materials Shenzhen PolytechnicShenzhen 518055China Group for Molecular Engineering of Functional Materials EPFL Valais WallisCH-1951 SionSwitzerland

Organometallic halide perovskite materials make great achievements in optoelectronic fields,especially in solar cells,in which the organic cations contain amine components.However,the amine with NàH bonds is easily hydrolyzed with moisture in the air,weakening the perovskite materials stability.It is desirable to develop other non-amine stable perovskite materials.In this work,sulfur-based perovskite-like(CH_(3))_(3)SPbI_(3) nanorod arrays were fabricated by a solution-processed method,which can be indexed hexagonal crystal structure in the space group P63 mc.The binding force is exceptionally strong between the non-amine(CH_(3))_(3) S+and[PbI_(6)]_(4)-octahedral,leading to high stability of(CH_(3))_(3)SPbI_(3).The(CH_(3))_(3)SPbI_(3) nanorod arrays can keep the morphology and crystal structure in an ambient atmosphere over 60 days.In addition,the(CH_(3))_(3)SPbI_(3) nanorod arrays can offer direct charge transfer channels,which show excellent optoelectronic properties.The(CH_(3))_(3)SPbI_(3) nanorod arrays-based solar cells with VOx hole transfer layers achieved a power conversion efficiency of 2.07%with negligible hysteresis.And the(CH_(3))_(3)SPbI_(3) nanorod arrays were also effectively applied in photodetectors with interdigitated gold electrodes.This work demonstrates that sulfur-based perovskite-like(CH_(3))_(3)SPbI_(3) is a novel promising stable compound with great potential for practical optoelectronic applications.

关键词： Perovskite solar cells high stability (CH_(3))_(3)SPbI_(3) nanorod arrays Photodetectors

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Excellent Terahertz shielding performance of ultrathin flexible Cu/graphene nanolayered composites with high stability

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Journal of Materials Science & Technology 2020年第17期52卷 136-144页

作者： Shengyue Hou Wenle Ma Guanghao Li Yi Zhang Yunyun Ji Fei Fan Yi Huang National Institute for Advanced Materials Tianjin Key Laboratory of Metal and Molecule Based Material ChemistryKey Laboratory of Functional Polymer MaterialsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Materials Science and EngineeringNankai UniversityTianjin 300350China Beijing Institute of Aeronautical Materials Beijing 100095China Institute of Modern Optics Nankai UniversityTianjin 300350China

Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high shielding effectiveness(SE),good flexibility and stability are highly desirable.Herein,an ultrathin flexible copper/graphene(Cu/Gr)nanolayered composite are prepared,which can reach the average EMI SE of 60.95 dB at 0.1–1.0 THz with a thickness of only 160 nm,indicating that more than 99.9999%of the THz wave power can be shielded.Furthermore,the Cu/Gr nanolayered composite also exhibits excellent oxidation resistance,with a 93.09%maintenance rate for EMI SE value after heating at 120℃for 3 h in air,far higher than that of the bare Cu film(62.15%).Besides,the Cu/Gr nanolayered composite exhibits good mechanical flexibility and flexural fatigue resistance.The EMI SE value of the Cu/Gr nanolayered composite shows a maintenance rate of 98.87%even after 1500 times bending cycles,obviously higher than that of multilayer Cu film(93.07%).These results demonstrate that the ultrathin flexible Cu/Gr nanolayered composites with excellent shielding performance and good stability have a broad application prospect in THz shielding for wearable devices and next generation mobile communication equipment.

关键词： Terahertz shielding Ultrathin flexible Cu/grapheme nano composites high stability

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1-Methyl-3-octylimidazolium Polyoxomolybdate Ionic Liquid with Low Melting Point and high stability:Preparation and Photocatalytic Activity

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Chemical Research in Chinese Universities 2011年第2期27卷 177-180页

作者： DONG Tao XU Yan-qing CHEN Fa-wang CHI Ying-nan HU Chang-wen State Key Laboratory of Explosion Science and Technology Department of ChemistryInstitute for Chemical Physics Beo＇ing Institute of Technology Beijing 100081 P R. China

The polyoxometalate（POM）-imidazole ionic liquid（IL） [C8mim]2[Mo6O19]（C8mim=1-methyl-3-octylimi- dazolium） with a low melting point of 82.6 °C was successfully prepared and characterized by FTIR, XPS, NMR, TG and so on. The polyoxomolybdate-based IL has high stability, and its decomposing temperature reaches 321 °C, which is higher than that of 1-alkyl-3-methylimidazolium halides IL. Further photocatalytic performances of the IL were measured via degrading dye rhodamine B（RB） in aqueous solution under the UV light irradiation. The experiments show that the conversion of RB reaches 80.5% after 90 min under UV-light and the degradation efficiency depends on the pH value of the solution, irradiation time and the dosage of the IL and so on.

关键词： Ionic liquid Polyoxomolybdate Low melting point high stability Photocatalytic activity

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