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991.
Pengfei Li;Shanshan Xue;Lu Sun;Xiaobao Ma;Wenning Liu;Li An;Yichang Liu;Dan Qu;Zaicheng Sun; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(29):2310563
Carbon dots (CDs) have received considerable attention in many application areas owing to their unique optical properties and potential applications; however, the fluorescent mechanism is an obstacle to their applications. Herein, three-color emissive CDs are prepared from single o-phenylenediamine (oPD) by regulating the ratio of ethanol and dimethylformamide (DMF). Fluorescent mechanism of these CDs is proposed as molecular state fluorescence. Reaction intermediates are identified using liquid chromatrography–mass spectroscopy (LC–MS) and 1H nuclear magnetic resonance (NMR) spectra. 1H-Benzo[d]imidazole (BI), 2,3-diaminophenazine (DAP), and 5,14-dihydroquinoxalino[2,3-b] phenazine (DHQP) are proposed to be the fluorophores of blue, green, and red emissive CDs by comparing their optical properties. As per the LC–MS and 1H-NMR analysis, DHQP with red emission tends to form from DAP and oPD in pure ethanol. By adding DMF, BI formation is enhanced and DHQP formation is suppressed. The prepared CDs exhibit green emission with DAP. When the DMF amount is >50%, BI formation is considerably promoted, resulting in DAP formation being suppressed. BI with blue emission then turns into the fluorophore of CDs. This result provides us an improved understanding of the fluorescent mechanism of oPD-based CDs, which guides us in designing the structure and optical properties of CDs. 相似文献
992.
Kehao Tao;Zhilong Wang;An Chen;Yanqiang Han;Jinyun Liu;Xitian Zhang;Jinjin Li; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(42):2402756
In traditional machine learning (ML)-based material design, the defects of low prediction accuracy, overfitting and low generalization ability are mainly caused by the training of a single ML model. Here, a Soft Voting Ensemble Learning (SVEL) approach is proposed to solve the above issues by integrating multiple ML models in the same scene, thus pursuing more stable and reliable prediction. As a case study, SVEL is applied to develop the broad chemical space of novel pyrochlore electrocatalysts with the molecular formula of A2B2O7, to explore promising pyrochlore oxides and accelerate predictions of unknown pyrochlore in the periodic table. The model successfully established the structure-property relationship of pyrochlore, and selected six cost-effective pyrochlore from the periodic table with a high prediction accuracy of 91.7%, all of which showed good electrocatalytic performance. SVEL not only effectively avoids the high costs of experimentation and lengthy computations, but also addresses biases arising from data scarcity in single models. Furthermore, it has significantly reduced the research cycle of pyrochlore by ≈ 22 years, offering broad prospects for accelerating the development of materials genomics. SVEL method is intended to integrate multiple AI models to provide broader model training clues for the AI material design community. 相似文献
993.
Ning Li Siyuan Qiu Qingyuan Du Yi An Yuanmin Chen Yajiao Li Wenhao Wang Daming Wu Xiaoli Wang Jingyao Sun 《Advanced Engineering Materials》2024,26(9):2400054
With the rapid advancement of electronic products, an increasing number of electronic components are being integrated onto chips, leading to a higher power consumption per unit area. Consequently, effective heat dissipation has become increasingly important. To address this heat dissipation challenge, this article introduces and prepares a highly thermally conductive polymer composite based on freeze-drying, coupled with the spatial confining forced network assembly (SCFNA) method. The freeze-drying process is used to create a three-dimensional thermal conductive network. This network provides a well-defined heat path. The SCFNA method enhances the regularity of the thermal conductive network within the matrix. Ultimately, this results in the significant thermal conductivity enhancement of the polymer composite. After freeze-drying, when the mass ratio of hexagonal boron nitride to polyvinyl alcohol is 4:1, the sample prepared by SCFNA presents 72.6% higher thermal conductivity than the one obtained through direct infiltration. This achievement holds significant value for the advancement of polymer composites with high-thermal conductivity and excellent mechanical properties. It can improve the low-dissipation performance of polymer thermal conductive composite systems, meet the needs of high-performance and low-dissipation use of thermal management materials, and reduce the working temperature of electronic chips. 相似文献
994.
Shuai Yuan Changran Hu An Pan Yuedi Ding Xuanhao Wang Zhicheng Qu Junjie Wei Yuheng Liu Cheng Zeng† Jinsong Xia 《半导体学报》2021,42(4):43-52
Lithium niobate on insulator(LNOI)is rising as one of the most promising platforms for integrated photonics due to the high-index-contrast and excellent material properties of lithium niobate,such as wideband transparency from visible to mid-infrared,large electro-optic,piezoelectric,and second-order harmonic coefficients.The fast-developing micro-and nanostructuring techniques on LNOI have enabled various structure,devices,systems,and applications.In this contribution,we review the latest developments in this platform,including ultra-high speed electro-optic modulators,optical frequency combs,opto-electro-mechanical system on chip,second-harmonic generation in periodically poled LN waveguides,and efficient edge coupling for LNOI. 相似文献
995.
Colloidal CdSe nanoplatelets are thin semiconductor materials with atomic flatness surfaces and one-dimensional strong quantum confinement,and hence they own very narrow and anisotropic emission.Here,we present a polydimethylsilox-ane(PDMS)assisted transferring method that can pick up single layer CdSe nanoplatelet films self-assembled on a liquid sur-face and then precisely transfer to a target.By layer-by-layer picking up and transferring,multiple layers of CdSe films can be built up to form CdSe stacks with each single layer having dominant in-plane transition dipole distribution,which both materi-al and energic structures are analogous to traditional multiple quantum wells grown by molecular-beam epitaxy.Additionally,with the great flexibility of colloidal nanoplatelets and this transferring method,CdSe nanoplatelets films can be combined with other materials to form hybrid heterostructures.We transferred a single-layer CdSe film onto WS2 flakes,and precisely stud-ied the fast energy transfer rate with controlled CdSe nanoplatelet orientation and by using a streak camera with a ps time resol-ution. 相似文献
996.
Cuiping Zhou Hao Tang Li Zhang Hong An Yunjin Wu Ding Tang Jianhua Zhou 《Advanced Engineering Materials》2021,23(6):2001355
997.
Georgina To'a Salazar Ziyi Huang Ningyan Zhang Xue-Guang Zhang Zhiqiang An 《工程（英文）》2021,7(11):1541-1551
In analyses of protein families that may serve as drug targets, membrane-associated G-protein-coupled receptors (GPCRs) dominate, followed by ion channels, transporters, and—to a lesser extent—membrane-bound enzymes. However, various challenges put such membrane proteins among key groups of underutilized opportunities for the application of therapeutic antibodies. Antibodies hold the promise of exquisite specificity, as they are able to target even specific conformations of a particular membrane protein, as well as adaptability through engineering into various antibody formats. However, the ease of raising and isolating specific, effective antibodies targeting membrane proteins depends on many factors. In particular, the generation of specific antibodies is easier when targeting larger, simpler, extracellular domains with greater uniqueness of amino acid sequence. The rareness of such ideal conditions is illustrated by the limited number of approved biologics for targeting GPCRs and other complex membrane proteins. Challenges in developing antibodies to complex membrane proteins such as GPCRs, ion channels, transporters, and membrane-bound enzymes can be addressed by the design of the antigen, antibody-generation strategies, lead optimization technologies, and antibody modalities. A better understanding of the membrane proteins being targeted would facilitate mechanism-based drug discovery. This review describes the advantages and challenges of targeting complex membrane proteins with antibodies and discusses the preparation of membrane protein antigens and antibody generation, illustrated by select examples of success. 相似文献
998.
为探究微尺度下的充填不平衡与传统注塑的不同,考虑微尺度下的影响充填不平衡的关键因素包括尺度效应、壁面滑移和对流换热,采用聚甲醛(POM),对H形对称分布的半圆形截面微流道系统进行了充模流动数值模拟实验。通过分析浇口处对称点间温差数据,实验结果表明壁面滑移能有效降低对称点间温度差,对充填不平衡有较明显的改善作用。对流换热使流道内熔体的一部分热量通过模具散失,加剧了充填不平衡,且对流换热系数越小,充填不平衡越明显。随着流道尺寸的减小,壁面滑移越明显,对流换热使对称点间温差变小,有利于改善充填不平衡。 相似文献
999.
Jung Woo Cho Myeong Seop Song In Hyeok Choi Kyoung-June Go Jaewoo Han Tae Yoon Lee Chihwan An Hyung-Jin Choi Changhee Sohn Min Hyuk Park Seung-Hyub Baek Jong Seok Lee Si-Young Choi Seung Chul Chae 《Advanced functional materials》2024,34(24):2314396
The groundbreaking discovery of unconventional ferroelectricity in HfO2 opens exciting prospects for next-generation memory devices. However, the practical implementation, particularly its epitaxial stabilization and a clearer understanding of its intrinsic ferroelectricity has been a significant challenge. The study arouses the potential importance of atomic layer deposition (ALD) for mass production in modern industries, demonstrating its proficiency in achieving epitaxial growth of ferroelectric Hf0.5Zr0.5O2 (HZO) thin films on Yttria-stabilized zirconia (YSZ) substrates. Moreover, with distinct ferroelectric switching currents, the work reveals the ferroelectric characteristics of epitaxial HZO thin films deposited through ALD on YSZ-buffered Si substrates, which aligns well with CMOS technology. Overall, the results pave the way for a scalable synthesis system for ferroelectric HfO2-based materials, hinting at a bright future for low-temperature epitaxial nanoelectronics. 相似文献
1000.
Yi Pan Renbing An Jiulin Bai Xunzhang Yan Shuangshuang Jin 《The Structural Design of Tall and Special Buildings》2019,28(15)
Due to the stable hysteretic behavior, buckling‐restrained braces (BRBs) have been increasingly adopted in reinforced concrete (RC) frame structures to develop a dual structural system (BRB‐RCF). This study proposed an alternative strength‐based design approach that decomposes the dual BRB‐RCF system into two independent RC frame and BRB system using the BRB‐carrying story shear ratio. The design of RC frame is performed in an integrated manner by considering the BRB postyielding force demands. Three RC frames with five, 10, and 15 stories were employed as prototype structures, and seven story shear ratios ranging from 0.1 to 0.7 were used to generate a total of 21 structural modes. The material usage, maximum axial compression ratio of columns, and elastic interstory drift ratio were compared for different story shear ratios. Nonlinear dynamic analysis of the BRB‐RCFs subjected to 12 ground motions were carried out. The seismic response including the maximum interstory drift ratio, hysteretic energy dissipation ratio, and actual BRB‐carrying story shear ratio were systematically assessed for different design story shear ratios. Based on the considerations of material usage and seismic performance, it is suggested that the design BRB‐carrying story shear ratio should be in the range of 0.3 to 0.5. 相似文献