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81.
Fei Ding Quanbing Mou Yuan Ma Gaifang Pan Yuanyuan Guo Prof. Gangsheng Tong Prof. Chung Hang Jonathan Choi Prof. Xinyuan Zhu Prof. Chuan Zhang 《Angewandte Chemie (International ed. in English)》2018,57(12):3064-3068
Functional siRNAs are employed as cross‐linkers to direct the self‐assembly of DNA‐grafted polycaprolactone (DNA‐g‐PCL) brushes to form spherical and nanosized hydrogels via nucleic acid hybridization in which small interfering RNAs (siRNAs) are fully embedded and protected for systemic delivery. Owing to the existence of multivalent mutual crosslinking events inside, the crosslinked nanogels with tunable size exhibit not only good thermostability, but also remarkable physiological stability that can resist the enzymatic degradation. As a novel siRNA delivery system with spherical nucleic acid (SNA) architecture, the crosslinked nanogels can assist the delivery of siRNAs into different cells without any transfection agents and achieve the gene silencing effectively both in vitro and in vivo, through which a significant inhibition of tumor growth is realized in the anticancer treatment. 相似文献
82.
Liu D Zhang Y Liu Y Wu J Chen CC Mou CY Chen SH 《The journal of physical chemistry. B》2008,112(14):4309-4312
Small angle neutron scattering (SANS) is used to measure the absolute density of water contained in 1-D cylindrical pores of a silica material MCM-41-S with pore diameters of 19 and 15 A. By being able to suppress the homogeneous nucleation process inside the narrow pore, one can keep water in the liquid state down to at least 160 K. From a combined analysis of SANS data from both H(2)O and D(2)O hydrated samples, we determined the absolute value of the density of 1-D confined water. We found that the average density of water inside the fully hydrated 19 A pore is 8% higher than that of the bulk water at room temperature. The temperature derivative of the density shows a pronounced peak at T(L) = 235 K signaling the crossing of the Widom line at ambient pressure and confirming the existence of a liquid-liquid phase transition at an elevated pressure. Pore size and hydration level dependences of the density are also studied. 相似文献
83.
Jing Cao Tong Mou Bingbao Mei Pengfei Yao Ce Han Xue Gong Ping Song Prof. Zheng Jiang Prof. Thomas Frauenheim Prof. Jianping Xiao Prof. Weilin Xu 《Angewandte Chemie (International ed. in English)》2023,62(43):e202310973
Full understanding to the origin of the catalytic performance of a supported nanocatalyst from the points of view of both the active component and support is significant for the achievement of high performance. Herein, based on a model electrocatalyst of single-iridium-atom-doped iron (Fe)-based layered double hydroxides (LDH) for oxygen evolution reaction (OER), we reveal the first completed origin of the catalytic performance of such supported nanocatalysts. Specially, besides the activity enhancement of Ir sites by LDH support, the stability of surface Fe sites is enhanced by doped Ir sites: DFT calculation shows that the Ir sites can reduce the activity and enhance the stability of the nearby Fe sites; while further finite element simulations indicate, the stability enhancement of distant Fe sites could be attributed to the much low concentration of OER reactant (hydroxyl ions, OH−) around them induced by the much fast consumption of OH− on highly active Ir sites. These new findings about the interaction between the main active components and supports are applicable in principle to other heterogeneous nanocatalysts and provide a completed understanding to the catalytic performance of heterogeneous nanocatalysts. 相似文献
84.
现代飞机普遍采用电传飞行控制系统,飞行控制计算机是该系统的核心。为了提升飞控计算机的可靠性,普遍采用余度技术构建余度飞控计算机,该计算机由多个通道构成,每个通道有一个CPU,互相构成备份。但是,这给飞控计算机的软件调试和测试带来的巨大的困难,因为各个通道的机载软件之间相互同步、通信和交叉监控,必须并行调试和测试,这就造成了机载软件调试和测试的滞后,必须等待真实的飞控计算机开发出来之后才能开展工作。本文提出了一种基于RFM(反射内存)的余度计算机快速原型测试平台设计方法。该平台使用商用货架产品构成余度计算机的多个冗余通道,使用RFM模拟多通道间的通信、同步过程,通过对底层驱动封装实现硬件故障模拟和余度功能模拟,方便实现软件调试和从性能、功能测试,大大提高了开发效率,减少了研制周期。 相似文献
85.
采用尿素溶胶法合成(Y0.95Eu0.05)2O3纳米粉,用超临界干燥技术制备了n-(Y0.95Eu0.05)2O3/SiO2气凝胶介孔组装体。结果表明,当Y^3+:Eu^3+=20:1,均相反应时间为4h,且经680℃、4h灼烧热处理后得到的n-(Y0.95Eu0.05)2O3中,光致发光强度最大(发光峰位于612nm),以Si与2Y摩尔比为1:7的n-(Y0.95Eu0.05)2O3/SiO2气凝胶介孔组装体,经同样条件热616nm)。对产生上述发光强度减弱和峰位红移现象进行讨论。 相似文献
86.
消偏光纤陀螺的理论和实验研究 总被引:7,自引:5,他引:2
本文首次在理论上导出消偏型光纤陀螺的零漂和标度因子表达式,并得出以下两个结论:1)在使用约 40 dB偏振器时,导致陀螺漂移的主要因素是强度误差而并不是振幅误差;2)由光学标度因子与各种器件参量关系表明开环解调时陀螺的线性误差较大.试验样机证明了以上结果,并找出减小漂移的方法. 相似文献
87.
88.
The synergic extraction of uranyl thiocyanate with binary system of 1-phenyl-3-methy1~4-benzoylpyrazolone-5 (PMBP)and tributyl phosphate(TBP)or tetraphenylarsonium chloride [(C6H5)4AsCl] and ternary system of PMBP-TBP-(C6H5 )4AsCl was studied.There was an obvious synergic effect of uranium (VI)from thiocyanate medium in binary and ternary systems.The formation of a ternary extracted complex,(C6H5)4AsUO2.(NCS)A2 TBP,was confirmed by the slope method.A method was first proposed for the calculation of the equilibrium constant of ternary synergic reaction. 相似文献
89.
An ion chromatographic method is described for the purpose of quality control in the process of monochloroacetic acid production. Using 2.5 mM NaOH–10% methanol as eluent, the simultaneous determination of acetic acid, monochloroacetic acid, dichloroacetic acid, and Cl− was obtained in a single run. Monochloroacetic acid and dichloroacetic acid showed good linearity in the range 0.1–20 and 0.15–20 μg/ml and correlation coefficients were 0.9999 and 0.9998, respectively. The detection limits (signal-to-noise ratio 3:1) of monochloroacetic acid and dichloroacetic acid were 17 and 25 ng/ml. This simple, sensitive, and time-saving method can be applied for composition analysis in acetic acid chlorination production. 相似文献
90.