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Porous organic cages as a novel platform for second harmonic generation

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Science China Chemistry 2024年第11期67卷 3669-3674页

作者： Feng Shui Yunqin Zhang Mao Yi Xiongli Liu Lin Li Shuo Zhang Yongshen Zheng yongtao yao Qiao Zhao Baiyan Li Xianhe Bu School of Materials Science and Engineering National Institute for Advanced Materials TKL of Metal and Molecule-Based Material Chemistry Nankai University National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology

Second harmonic generation(SHG) is one of the most extensively applied nonlinear optical phenomena. Compared to traditional inorganic SHG materials, organic SHG materials, including non-centrosymmetric small molecular crystals and organic polymers, have been extensively explored for SHG optics due to their advantageous properties, including high light-induced damage threshold, ultrafast response speed, high polarization ratio, wide transparency range, and elevated dielectric constant. However,in organic SHG materials, most small molecular crystals often show poor thermal stability(<200 °C) due to their low molecular weight, which is an important obstacle for practical application under high temperatures. On the other hand, the difficulty in the growth of large-size crystals as well as the disorderly array of chromospheres on polymer chains associated with organic polymers have hindered their widespread application in SHG due to the requirements of processability and ***, it is significantly necessary to develop novel organic SHG material with high thermal stability, large-size crystals,excellent processability, high homogeneity, and a well SHG effect. In the contribution, we developed herein porous organic cages(POCs) as a novel platform for SHG optics. Thanks to its inherent macromolecular composition and zero-dimensional discrete structures, POCs can not only solve the instability problem of small molecule crystals but also overcome the drawbacks in growing large-size crystals for organic polymer. The obtained two POCs with chiral asymmetric centers(CPOC-R-5 and CPOCS-7) display advantageous features for SHG optics including well SHG performance, large-size crystal(5 mm×3 mm×1 mm),high thermal stability(≥250 °C), wide transparency window(750–2,000 nm) and high polarization ratio(up to 94.5%). This work thus develops POCs as a new platform toward the construction of organic NLO materials with the potential application in sorts of SHG optics.

关键词： porous organic cages second harmonic generation novel SHG platform high thermal stability large-size single crystal

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仿真模拟主动调节负泊松比力学超材料

复合材料学报 2024年第1期41卷 467-476页

作者：姚永涛丛琳王鸿涛王军哈尔滨工业大学复合材料与结构研究所哈尔滨150080 内蒙动力机械研究所呼和浩特010000

负泊松比材料作为一种新型的超材料,鉴于其优异的力学性能,在航天、航空、工业、医药科学等领域具有广泛的应用前景。为得到性能、结构可主动调节的超材料,首先以负泊松比结构为基础,结合形状记忆智能材料,设计出性能可调控的超材料结... 详细信息

负泊松比材料作为一种新型的超材料,鉴于其优异的力学性能,在航天、航空、工业、医药科学等领域具有广泛的应用前景。为得到性能、结构可主动调节的超材料,首先以负泊松比结构为基础,结合形状记忆智能材料,设计出性能可调控的超材料结构单元模型。然后通过基本梁理论计算,获得宏观结构泊松比正负转变与刚体结构之间的临界参数。其次,通过有限元仿真,确定材料泊松比正负调节与填充单元组合比例及排列方式之间的关系。最后对这种二维结构材料的振动特性和力学性能进行了详细的分析。结果表明:这种材料在调节结构力学性能和振动调控方面表现出优异的性能。调节内部单元的填充形式和排列方式,可以得到不同的力学性能和吸能效果;同时,通过引入形状记忆材料和微结构,使材料表现出优异的宏观结构和刚度智能调节性能。

关键词：力学超材料负泊松比吸能可调节设计有限元仿真

融合思维链和低秩自适应微调的方面情感三元组抽取

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计算机工程 2024年第7期50卷 53-62页

作者：曾碧卿陈鹏飞姚勇涛华南师范大学软件学院广东佛山528225

方面情感三元组抽取(ASTE)任务是方面级情感分析的重要子任务之一,传统的监督学习方法在该任务上取得了SOTA或接近SOTA的效果。然而,随着深度神经网络的发展,生成式大型语言模型(LLM)为该任务带来了更多的可能性。目前大多数工作都是直... 详细信息

方面情感三元组抽取(ASTE)任务是方面级情感分析的重要子任务之一,传统的监督学习方法在该任务上取得了SOTA或接近SOTA的效果。然而,随着深度神经网络的发展,生成式大型语言模型(LLM)为该任务带来了更多的可能性。目前大多数工作都是直接对LLM进行微调,但是忽略了LLM的幻觉现象,导致性能下降。提出一种融合思维链技术和LLM低秩自适应(Lo RA)微调LFC方法,实现生成式的ASTE新范式,以提升任务性能。在LFC中,首先基于思维链技术,通过人工构造少量推理样本,并利用LLM生成具有推理结构的增强数据集。将增强数据集用于微调Chat GLM3-6B模型的学习。在微调过程中,采用Lo RA微调技术提高在低资源环境下适配ASTE任务的效果。实验结果表明,LFC方法相比于最优的基线模型在Res14、Lap14、Res15和Res164个数据集上的F1值分别提升8.37、12.31、11.07和8.43个百分点,该方法不仅能够准确地识别三元组,而且在一定程度上优化了LLM的幻觉现象。

关键词：方面情感三元组抽取大型语言模型低秩自适应微调思维链提示学习

Flexible inorganic piezoelectric functional films and their applications

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Journal of Advanced Ceramics 2023年第3期12卷 433-462页

作者： Liyun Zhen Lijun Lu yongtao yao Jingquan Liu Bin Yang National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiao Tong UniversityShanghai 200240China Department of Micro/Nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150001China

Piezoelectric materials play an increasingly important role in energy harvesters,sensors,and *** and thin piezoelectric films have been demonstrated to provide advanced functionalities and improved ***,the research on flexible inorganic piezoelectric thin films has rarely been systematically ***,we summarize the recent advances in the flexible inorganic piezoelectric thin films,focusing on their structural designs,fabrication techniques,and applications in various practical ***,different fabrication techniques suitable for diverse inorganic piezoelectric nanostructures are reviewed,including sol-gel,hydrothermal,electrospinning,and other techniques,and the integration process with flexible substrates is further *** and industrial applications of the flexible piezoelectric thin films are ***,some existing challenges and future perspectives are discussed.

关键词： inorganic piezoelectric thin films fabrication techniques structural design flexible electronics

Ultrathin, Lightweight, and Flexible CNT Buckypaper Enhanced Using MXenes for Electromagnetic Interference Shielding

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Nano-Micro Letters 2021年第4期13卷 208-220页

作者： Rongliang Yang Xuchun Gui Li yao Qingmei Hu Leilei Yang Hao Zhang yongtao yao Hui Mei Zikang Tang State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-Sen UniversityGuangzhou 510275People’s Republic of China Science and Technology on Thermostructural Composite Materials Laboratory School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072ShaanxiPeople’s Republic of China Instrumental Analysis and Research Center(IARC) Sun Yat-Sen UniversityGuangzhou 510275People’s Republic of China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080People’s Republic of China Institute of Applied Physics and Materials Engineering University of MacaoTaipa 999078MacaoPeople’s Republic of China

Lightweight,flexibility,and low thickness are urgent requirements for next-generation high-performance electromagnetic interference(EMI)shielding materials for catering to the demand for smart and wearable electronic *** several efforts have focused on constructing porous and flexible conductive films or aerogels,few studies have achieved a balance in terms of density,thickness,flexibility,and EMI shielding effectiveness(SE).Herein,an ultrathin,lightweight,and flexible carbon nanotube(CNT)buckypaper enhanced using MXenes(Ti3C2Tx)for high-performance EMI shielding is synthesized through a facile electrophoretic deposition *** obtained Ti3C2Tx@CNT hybrid buckypaper exhibits an outstanding EMI SE of 60.5 dB in the X-band at 100μ*** hybrid buckypaper with an MXene content of 49.4 wt%exhibits an EMI SE of 50.4 dB in the X-band with a thickness of only 15μm,which is 105%higher than that of pristine CNT ***,an average specific SE value of 5.7×10^(4) dB cm^(2) g^(−1) is exhibited in the 5-μm hybrid ***,this assembly process proves promising for the construction of ultrathin,flexible,and high-performance EMI shielding films for application in electronic devices and wireless communications.

关键词： Carbon nanotube MXene Buckypaper Electromagnetic interference shielding

Facile Preparation of TiO_2 Nanoclusters on Graphene Templates for Photodegradation of Organic Compounds

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Journal of Materials Science & Technology 2015年第8期31卷 840-844页

作者： Zaixing Jiang Mingqiang Wang Hao Cheng Jun Li Aslan Husnu Haibao Lv yongtao yao Lu Shao Yudong Huang Mingdong Dong Department of Polymer Science and Technology School of Chemical Engineering and TechnologyHarbin Institute of Technology Interdisciplinary Nanoscience Center(iNANO) Aarhus University Science and Technology on Advanced Composites in Special Environments Laboratory Harbin Institute of Technology

Graphene is the most attractive carbon-based material at present and attracting increasing attention as promising candidates for applications in numerous areas, because of its extraordinary chemical, thermal and mechanical properties. In this paper, we discussed an innovative and simple method to synthesize titanium dioxide （TiO2） nanoclusters, using graphene as a mid-step template not as a component of final product. Using this method, the graphene was firstly fully coated with TiO2 nanoparticles by the thermal decomposition of titanium （IV） isopropoxide in a supercritical carbon dioxide （SC-CO2） at 200 ℃; the developed TiO2/graphene composites then were heated in an oxygen atmosphere. Eventually the TiO2 nanoclusters were obtained. The prepared TiO2 nanoclusters showed irregular features with high surface coverage, providing promises in a wide range of applications, especially for photo-degradation of organic compounds in aqueous solution under the radiation of UV-light.

关键词： Titanium dioxide Graphene Supercritical CO2 Nanocluster

5052铝合金板材渐进成形工艺参数双目标优化及试验验证

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铝加工 2024年第5期 43-48页

作者：姜旭朱冠昱王晓宏谢文强姚永涛黑龙江工程学院工程训练中心哈尔滨150026 黑龙江工程学院机电工程学院哈尔滨150026 哈尔滨工业大学特种环境复合材料技术国家级重点实验室哈尔滨150026

针对金属板材单点渐进成形工艺,选用具有较强成形性能的5052铝合金板材进行研究。基于Abaqus建立单点渐进成形有限元模型,以工具头直径、轴向进给量、板材初始厚度为研究变量,成形后圆锥台结构的最大Mises应力和最大减薄率为优化目标,... 详细信息

针对金属板材单点渐进成形工艺,选用具有较强成形性能的5052铝合金板材进行研究。基于Abaqus建立单点渐进成形有限元模型,以工具头直径、轴向进给量、板材初始厚度为研究变量,成形后圆锥台结构的最大Mises应力和最大减薄率为优化目标,设计了正交试验,并对每组参数进行模拟分析,采用田口分析和方差分析对工艺参数进行优化。优化结果表明,轴向进给量和板材初始厚度是对最大Mises应力影响的显著项,最终的优化工艺参数组合为工具头直径8 mm、轴向进给量0.5 mm、板材初始厚度0.5 mm,该工艺参数分析的圆锥台结构最大Mises为213.35 MPa,最大减薄率为38.32%。通过单点渐进成形试验进行验证,成形后的圆锥台结构表面质量较好,这也表明该工艺参数组合具备实际应用的可行性。

关键词： 5052铝合金渐进成形有限元工艺参数田口法

Effect of Er_(30)Cu_(70) on microstructure and properties of sintered Nd-Fe-B by grain boundary reconstruction

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Journal of Rare Earths 2024年第2期42卷 345-353,I0004页

作者： Kai Wang yongtao Dai Jianqiu Deng Jiang Wang Huaiying Zhou Qingrong yao Weichao Huang Guangxi Key Laboratory of Information Materials Schoolof Materials Science and EngineeringGuilin University of Electronic TechnologyGuilin54004China China Rare Metals and Rare Earth(Guangxi)Jinyuan New Materials Co Ltd.Hezhou542603China

Usually it is generally believed that the Er element forms the Er_(2)Fe_(14)B phase,which will seriously deteriorate the magnetic ***,here we report the balance of corrosion resistance and coercivity in Nd-Fe-B sintered magnets through using simple Er_(30)Cu_(70) additive whose price is much lower than Dy and *** reasonably controlling Er_(30)Cu_(70) addition,the corrosion resistance is improved at the minimum limit of reducing the magnetic *** studying the influence mechanism of Er element,it is found that the main effect of Er elements is to replace the Nd elements at the edge of the main phase grains to form a(Er,Nd)_(2)Fe_(14)B shell with low H_(A),resulting in the reduction of magnetic *** improvement of corrosion resistance mainly comes from the more stable Cu element introduced at the grain *** the same time,the target magnets also show different advantages under different heat treatment *** findings may spur progress towards developing the lowcost permanent magnets that rival the commercial Nd-Fe-B counterpart.

关键词： Er_(30)Cu_(70)alloy Grain boundary reconstruction Magnetic properties Corrosion resistance Heat treatment Rare earths

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高超声速流动与换热数值仿真研究

应用数学和力学 2022年第10期43卷 1105-1112页

作者：王强徐涛姚永涛中北大学能源动力工程学院太原030051 特种环境复合材料技术国家级重点实验室哈尔滨150001

基于有限差分法开发了高超声速流动与换热问题气热耦合仿真求解器,运用该求解器对三种典型高超声速流动与换热问题开展了仿真研究,得到了相应的气动参数、热流密度分布.高超声速后台阶的存在使表面气动参数、热流分布不再连续;随着缝深... 详细信息

基于有限差分法开发了高超声速流动与换热问题气热耦合仿真求解器,运用该求解器对三种典型高超声速流动与换热问题开展了仿真研究,得到了相应的气动参数、热流密度分布.高超声速后台阶的存在使表面气动参数、热流分布不再连续;随着缝深的提高,缝隙局部流速迅速降低,对流换热效应减弱;高超声速无限长圆管绕流中,边界层外部区域气动参数随时间变化不大,边界层内存在较大的温度梯度,壁面温度随时间升高.三个算例的仿真结果均与试验测量值进行了对比,验证了所开发的求解器的计算能力.

关键词：高超声速流动气动热后台阶缝隙非定常气热耦合