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Meccanica - Based on the classification ability of a convolutional neural network (CNN), this paper proposes a structural damage detection method in which a CNN is used to classify the location and... 相似文献
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Nonlinear Dynamics - Aiming to isolate disturbance vibration for heavy machines with low frequency, a novel hydro-pneumatic vibration isolator with high-static and low-dynamic (HSLD) stiffness is... 相似文献
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采用基于密度泛函理论的第一性原理赝势平面波方法,对稀土元素La,Y单掺杂和La和Y共掺杂GaN的晶格常数、电子结构及光学性质进行了计算与分析.计算结果表明:掺杂改变了GaN的能带结构,未掺杂和Y掺杂形成导带底和价带顶位于G点的直接带隙半导体,而La掺杂和La和Y共掺杂形成导带底位于G点,价带顶位于Q点的间接带隙半导体.可以通过掺杂元素来调制GaN的禁带宽度和带隙类型,掺杂均提高GaN在低能区的静态介电常数、反射率、折射率,使光子的跃迁强度增大,说明稀土元素La,Y掺杂可有效调制GaN的光电性质. 相似文献
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ABSTRACTThe stable configurations, electronic structures and catalytic activities of single-atom metal catalyst anchored silicon-doped graphene sheets (3Si-graphene-M, M?=?Ni and Pd) are investigated by using density functional theory calculations. Firstly, the adsorption stability and electronic property of different gas reactants (O2, CO, 2CO, CO/O2) on 3Si-graphene-M substrates are comparably analysed. It is found that the coadsorption of O2/CO or 2CO molecules is more stable than that of the isolated O2 or CO molecule. Meanwhile, the adsorbed species on 3Si-graphene-Ni sheet are more stable than those on the 3Si-graphene-Pd sheet. Secondly, the possible CO oxidation reactions on the 3Si-graphene-M are investigated through Eley–Rideal (ER), Langmuir–Hinshelwood (LH) and new termolecular Eley–Rideal (TER) mechanisms. Compared with the LH and TER mechanisms, the interaction between 2CO and O2 molecules (O2?+?CO → CO3, CO3?+?CO → 2CO2) through ER reactions (< 0.2?eV) are an energetically more favourable. These results provide important reference for understanding the catalytic mechanism for CO oxidation on graphene-based catalyst. 相似文献
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We demonstrate a harmonically pumped femtosecond optical parametric oscillator(OPO)laser using a frequency-doubled mode-locked Yb:KGW laser at a repetition rate of 75.5 MHz as the pump laser.Based on a bismuth borate nonlinear crystal,repetition rates up to 1.13 GHz are realized,which is 15 times that of the pump laser.The signal wavelength is tunable from 700 nm to 887 nm.The maximum power of the signal is 207 m W at the central wavelength of 750 nm and the shortest pulse duration is 117 fs at 780 nm.The beam quality(M^2 factor)in the horizontal and vertical directions of the output beam are 1.077 and 1.141,respectively. 相似文献
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Development of an LC‐MS/MS method for determining the pharmacokinetics of clonidine following oral administration of Zhenju antihypertensive compound 下载免费PDF全文
Jing Qin Limin Wang Lihong Wu Jun Chen Teng Shen Yongji Li Limei Han Jianxin Wang 《Biomedical chromatography : BMC》2015,29(7):1068-1075
Zhenju antihypertensive compound (ZJAHC) is a combined Chinese–Western medicine formula including clonidine (CLO), hydrochlorothiazide (HCT), rutin, Chrysanthemum indicum extract and pearl powder. Compared with CLO preparations, ZJAHC shows improved activities and decreased adverse effects. It is believed that the side effects of CLO are caused by its high peak plasma concentration. Hence, study of the influence of ZJAHC on the pharmacokinetic behaviors of clonidine seems essential. In present study, the plasma concentrations of CLO were determined with a liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method. The MS/MS transitions monitored for clonidine and internal standard were 230.2 → 213.1 and 152.2 → 110.2, respectively. The analyte was quantified in a single run within 3 min. The pharmacokinetic study showed that the area under the plasma concentration–time curve of CLO in ZJAHC (60 µg/kg CLO) was similar to that of CLO‐HCT‐high (120 µg/kg CLO) but the peak concentration was much lower than that in CLO‐HCT‐high. ZJAHC could enhance the bioavailability without greatly increasing peak concentration of clonidine. This comprehensive effect of enhancing the bioavailability and avoiding the high peak plasma concentration for CLO might mainly result from the co‐contribution of Western medicine and traditional Chinese medicine (TCM), while the effect of TCM was stronger than that of Western medicine. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Yaogang Hu Peng Teng Wenyang Gao Xiaobing Zuo Lukasz Wojtas Randy W. Larsen Shengqian Ma Jianfeng Cai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2501-2507
Foldamers offer an attractive opportunity for the design of novel molecules that mimic the structures and functions of proteins and enzymes including biocatalysis and biomolecular recognition. Herein we report a new class of nonnatural helical sulfono‐γ‐AApeptide foldamers of varying lengths. The crystal structure of the sulfono‐γ‐AApeptide monomer S6 illustrates the intrinsic folding propensity of sulfono‐γ‐AApeptides, which likely originates from the bulkiness of tertiary sulfonamide moiety. The two‐dimensional solution NMR spectroscopy data for the longest sequence S1 demonstrates a 10/16 right‐handed helical structure. Optical analysis using circular dichroism further supports well‐ defined helical conformation of sulfono‐γ‐AApeptides in solution containing as few as five building blocks. Future development of sulfono‐γ‐AApeptides may lead to new foldamers with discrete functions, enabling expanded application in chemical biology and biomedical sciences. 相似文献
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Tianyu Gong Longhai Guo Jun Ye Lifan He Teng Qiu Xiaoyu Li 《Journal of polymer science. Part A, Polymer chemistry》2021,59(16):1807-1820
The implementation of covalent adaptable networks (CANs) in general resin system is becoming attractive. In this work, we propose a simple post-curing strategy based on the core-shell structured acrylate latex for the achievement on both the improved general performance and the CANs characteristics in latex films. The building to the CANs was relied on the introduction of 4,4′-diaminophenyl disulfide as the curing agent, which cured the acetoacetoxy decorated shell polymer through the ketoamine reaction. The metathesis reaction of aromatic disulfides in the crosslinking segments enabled the thermally induced dynamic behavior of the network as revealed in the stress relaxation tests by comparison with other diamine crosslinking agents without the incorporation of disulfide. The synergism of the dynamic crosslinking of the shell polymer and static crosslinking in the core polymer contributed to the improved mechanical strength (15 MPa, strain% = 250%) and the suppressed water adsorption (~1% in 24 h of soaking) of the latex film, which exhibited above 90% of recovery in both strength and strain from a cut-off film damage within 1 h at 80°C. Moreover, the cured latex film could be recycled, and 75% of the mechanical performance was regained after three fragmentation-hot-pressing cycles. These, in addition with the feasible and environmental friendly characteristics, suggest a sustainable paradigm toward the smart thermosetting latex polymers. 相似文献