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排序方式: 共有1394条查询结果,搜索用时 15 毫秒
1.
Wan-Li He Meng-Die Yu Ya-Jie Pang Hao Ren Jun-Liang Ma Cheng Shi 《Liquid crystals》2019,46(2):249-256
A composite system of Fe3O4 nanoparticle-doped chiral nematic liquid crystals (N*LC) with flexible display performance was proposed. Fe3O4 nanoparticle and the nanoparticle-doped N*LC composite were detailed prepared and investigated. The influence of nanoparticle doping amount and chiral compound content on the magnetic performance as well as electrical performance of the flexible device had been studied in detail. The most suitable N*LC composites for magnetic-driven display had been found. With the characteristics of simple preparation, good stability and high resolution, the Fe3O4 nanoparticle-doped N*LCs had promising applications for power-free magnetic-driven flexible LC paper or display board. 相似文献
2.
YOU Mingqing 《力学与实践》2019,41(4):436
偏心转子惯性力引起的底座运动受到地面摩擦的影响,与光滑情形的理论结果存在定性差异。转子逆时针匀速旋转的惯性力若小于构件总重,则底座随摩擦因子增加而出现连续、一次停顿和两次停顿的振动及完全静止的4种状态。因惯性力对正压力及摩擦力的影响,底座在连续及一次停顿的振动时右向位移较大;而底座跳起时如``蛤蟆夯'则整体向左移动。 相似文献
3.
Xiaoyu Ding Dr. Zhenghui Pan Na Liu Linge Li Xianshu Wang Guoguang Xu Jie Yang Jin Yang Nengsheng Yu Meinan Liu Prof. Wanfei Li Prof. Yuegang Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(15):3775-3780
Flexible lithium/sulfur (Li/S) batteries are promising to meet the emerging power demand for flexible electronic devices. The key challenge for a flexible Li/S battery is to design a cathode with excellent electrochemical performance and mechanical flexibility. In this work, a flexible strap-like Li/S battery based on a S@carbon nanotube/Pt@carbon nanotube hybrid film cathode was designed. It delivers a specific capacity of 1145 mAh g−1 at the first cycle and retains a specific capacity of 822 mAh g−1 after 100 cycles. Moreover, the flexible Li/S battery retains stabile specific capacity and Coulombic efficiency even under severe bending conditions. As a demonstration of practical applications, an LED array is shown stably powered by the flexible Li/S battery under flattened and bent states. We also use the strap-like flexible Li/S battery as a real strap for a watch, which at the same time provides a reliable power supply to the watch. 相似文献
4.
Xiaofeng Zheng Xinyu Zhao Jie Huang Hao Yang Qinghui Wang Yuhang Liu Peiwei Gong Laijin Tian Hongping Xiao Zhe Liu 《应用有机金属化学》2020,34(12):e5981
The low-cost, high specific surface area and porosity, controlled pore size, and chemical properties of metal–organic framework (MOF) materials have attracted much attention in the exploration of proton conduction. The method of chemically modifying MOF structures or introducing conductive medium into the holes can effectively improve the proton conductivities of the materials. Here, the structural tunability of ionic liquid (IL) and flexible MOF (fle-MOF) materials are matched to give full play to the conductivity of IL, the framework support, and the microporous effect of MOFs, which achieves the synergistic effect of performance and expands the temperature range of proton transfer. Three kinds of CS/IL@fle-MOF membranes were prepared by combining three fle-MOFs with 1-carboxymethyl-3-methylimidazole (CMMIM) in different proportions to obtain 15 pieces of membranes. The comparative analyses show that CS/IL@fle-MOF membranes have excellent proton conduction performance at a wider temperature range (263–353 K) and lower relative humidity (75% RH). Among them, the proton conductivities of CS/CMMIM@MIL-88A-25% and CS/CMMIM@MIL-88B-125% are up to 1.33 and 1.42 S cm−1 at 75% RH and 353 K, respectively; whereas those of CS/CMMIM@MIL-53(Fe)-75% and CS/CMMIM@MIL-88B-125% reach up to 2.1 × 10−3 and 1.28 × 10−3 S cm−1 at 75% RH and 263 K, respectively. The Ea of CS/CMMIM@fle-MOFs is in the range of 0.1–0.5 eV, suggesting that the proton transport follows predominantly the typical Grotthuss transfer mechanism. The results of this study indicate that the CS/CMMIM@fle-MOF membranes combinations offer great potential for the design of composite porous proton-conducting materials. 相似文献
5.
两端铰接的细长柔性圆柱体涡激振动响应特性数值研究 总被引:1,自引:0,他引:1
目前细长柔性圆柱体涡激振动响应的研究方法主要包括实验方法、计算流体动力学方法以及半经验模型方法. 鉴于实验方法研究成本较高、计算流体动力学方法计算时间较长,本文基于尾流振子模型对线性剪切来流下两端铰接的细长柔性圆柱体涡激振动响应特性进行了半经验模型方法研究. 先建立了柔性圆柱体结构振子以及尾流振子之间的耦合模型,紧接着基于二阶精度中心差分格式对耦合模型先离散后迭代进行求解. 对不同剪切参数下柔性圆柱体涡激振动响应的振动波长、振动频率、振动位移以及响应频率随时间的变化特性等参数进行了分析. 分析结果表明:圆柱体的涡激振动响应由驻波和行波混合组成. 当无量纲弯曲刚度较小时,在圆柱体两端附近,驻波占主导;而在圆柱体中间段附近,行波占主导. 当无量纲弯曲刚度较大时,在圆柱体整个长度区间上均为驻波占主导. 随着剪切参数的增大,振动位移以及振动波长均逐渐减小,而振动频率和频率带宽均逐渐增大. 相似文献
6.
Two different order reduction methods of the deterministic and stochastic systems are discussed in this paper. First, the transient proper orthogonal
decomposition (T-POD) method is introduced based on the high-dimensional nonlinear dynamic system. The optimal order reduction conditions of the T-POD
method are provided by analyzing the rotor-bearing system with pedestal looseness fault at both ends. The efficiency of the T-POD method is verified via comparing with the results of the original system. Second, the polynomial dimensional
decomposition (PDD) method is applied to the 2 DOFs spring system considering
the uncertain stiffness to study the amplitude-frequency response. The numerical
results obtained by the PDD method agree well with the Monte Carlo simulation
(MCS) method. The results of the PDD method can approximate to MCS better
with the increasing of the polynomial order. Meanwhile, the Uniform-Legendre
polynomials can eliminate perturbation of the PDD method to a certain extent
via comparing it with the Gaussian-Hermite polynomials. 相似文献
7.
Green solvent approach for printable large deformation thermoplastic elastomer based piezoresistive sensors and their suitability for biomedical applications 下载免费PDF全文
Bruna F. Gonçalves Pedro Costa Juliana Oliveira Sylvie Ribeiro Vitor Correia Gabriela Botelho Senentxu Lanceros‐Mendez 《Journal of Polymer Science.Polymer Physics》2016,54(20):2092-2103
Composites based on biocompatible thermoplastic elastomer styrene‐ethylene/butylene‐styrene (SEBS) as matrix and multi‐walled carbon nanotubes (MWCNT) as nanofillers show excellent mechanical and piezoresistive properties from low to large deformations. The MWCNT/SEBS composites have been prepared following a green solvent approach, to extend their range of applicability to biomedical applications. The obtained composites with 2, 4, and 5 wt % MWCNT content provide suitable piezoresistive response up to 80% deformation with a piezoresistive sensibility near 2.7, depending on the applied strain and MWCNT content. Composite sensors were also developed by spray and screen printing and integrated with an electronic data acquisition system with RF communication. The possibility to accurately control the composites properties and performance by varying MWCNT content, viscosity, and mechanical properties of the polymer matrix, shows the large potential of the system for the development of large deformation printable piezoresistive sensors. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2092–2103 相似文献
8.
9.
María Elena Snchez-Vergara Citlalli Rios Omar Jimnez-Sandoval Roberto Salcedo 《Molecules (Basel, Switzerland)》2020,25(24)
The structure formed by cobalt phthalocyanine (CoPc) and cobalt octaethylporphyrin (CoOEP) with electron-acceptor tetracyano-π-quinodimethane (TCNQ), was studied by Density Functional Theory (DFT) methods. According to theoretical calculations, both cobalt systems can establish dispersion forces related to TCNQ and also in both cases the link between them is built by means of hydrogen bonds. Based on the results of these DFT calculations, we developed experimental work: the organic semiconductors were doped, and the thermal evaporation technique was used to prepare semiconductor thin films of such compounds. The structure of the films was studied by FTIR and Raman spectroscopy. The optical properties of the CoPc-TCNQ and CoOEP-TCNQ films were investigated by means of UV-Vis measurements. The results obtained were used to estimate the type of transitions and the optical bandgap. The results were compared to the previously calculated theoretical bandgap. The CoOEP-TCNQ film presented the smallest theoretical and experimental bandgap. Finally, the electrical properties of the organic semiconductors were evaluated from a PET (polyethylene terephthalate)/indium tin oxide (ITO)/cobalt macrocycle-TCNQ/silver (Ag) device we prepared. The CoOEP-TCNQ-based device showed an ohmic behavior. The device manufactured from CoPc-TCNQ also showed an ohmic behavior at low voltages, but significantly changed to SCLC (space-charge limited conductivity) at high voltage values. 相似文献
10.
De-Hui Guan Xiao-Xue Wang Ma-Lin Li Fei Li Li-Jun Zheng Prof. Xiao-Lei Huang Prof. Ji-Jing Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(44):19686-19692
A photoinduced flexible Li-CO2 battery with well-designed, hierarchical porous, and free-standing In2S3@CNT/SS (ICS) as a bifunctional photoelectrode to accelerate both the CO2 reduction and evolution reactions (CDRR and CDER) is presented. The photoinduced Li-CO2 battery achieved a record-high discharge voltage of 3.14 V, surpassing the thermodynamic limit of 2.80 V, and an ultra-low charge voltage of 3.20 V, achieving a round trip efficiency of 98.1 %, which is the highest value ever reported (<80 %) so far. These excellent properties can be ascribed to the hierarchical porous and free-standing structure of ICS, as well as the key role of photogenerated electrons and holes during discharging and charging processes. A mechanism is proposed for pre-activating CO2 by reducing In3+ to In+ under light illumination. The mechanism of the bifunctional light-assisted process provides insight into photoinduced Li-CO2 batteries and contributes to resolving the major setbacks of the system. 相似文献