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21.
Peikun Wang Dr. Hua Xie Dr. Jianping Guo Zhi Zhao Xiangtao Kong Wenbo Gao Fei Chang Dr. Teng He Prof. Guotao Wu Prof. Dr. Mingshu Chen Prof. Dr. Ling Jiang Prof. Dr. Ping Chen 《Angewandte Chemie (International ed. in English)》2017,56(30):8716-8720
Lithium hydride (LiH) has a strong effect on iron leading to an approximately 3 orders of magnitude increase in catalytic ammonia synthesis. The existence of lithium–iron ternary hydride species at the surface/interface of the catalyst were identified and characterized for the first time by gas-phase optical spectroscopy coupled with mass spectrometry and quantum chemical calculations. The ternary hydride species may serve as centers that readily activate and hydrogenate dinitrogen, forming Fe-(NH2)-Li and LiNH2 moieties—possibly through a redox reaction of dinitrogen and hydridic hydrogen (LiH) that is mediated by iron—showing distinct differences from ammonia formation mediated by conventional iron or ruthenium-based catalysts. Hydrogen-associated activation and conversion of dinitrogen are discussed. 相似文献
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微细光束固化的蒙特卡罗建模 总被引:1,自引:0,他引:1
光固化是光束与光敏树脂之间的光化学反应,其作用过程对光固化加工分辨率有着直接影响.基于光子输运理论,利用蒙特卡罗方法追踪光子往树脂中的运动轨迹,对曝光光束人射、传输过程进行抽样,建立了微细光束固化模型;利用遗传算法并结合光同化实验重构获得了树脂材料的光学参数;利用该崮化模型,模拟计算了微细会聚紫外光束(λ=365 nm)单点曝光同化过程和固化单元点的形状和大小,分析了不同曝光最对固化结果的影响规律,计算结果与实验结果一致.研究表明,该模型可以有效地对微细光束与光敏树脂作用的复杂过程进行仿真,并能对不同入射光和曝光工艺条件下的固化物进行模拟计算,为微细光固化机理的研究和工艺优化提供了基础. 相似文献
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Lijuan Ding Xiangtao Wang Ting Wang Bo Yu Meihua Han Yifei Guo 《Molecules (Basel, Switzerland)》2023,28(1)
Oligoethylene glycol dendron (G2) has been used in drug delivery due to its unique dendritic structure and excellent properties. In order to investigate the effects of lipophilic chains on drug delivery, the amphiphilic hybrid compound G2-C18 is synthesized, and celastrol (CSL) is selected to prepare “core-shell” structured CSL-G2-C18 nanoparticles (NPs) via the antisolvent precipitation method. Meanwhile, CSL-G2 NPs are prepared as the control. The two NPs show similar particle sizes and polydispersity indexes, while their morphologies exhibit dramatic differences. CSL-G2 NPs are solid spherical particles, while G2-C18 NPs are vesicles. The two NPs present ideal stability and similar release tendencies. The in vitro toxicity results show that the cell inhibition effect of CSL-loaded NPs is significantly enhanced when compared with free CSL, and the antitumor effect of CSL-G2-C18 NPs is stronger than that of CSL-G2 NPs. The IC50 value of CSL-G2 NPs and CSL-G2-C18 NPs is enhanced about 2.8-fold and 5-fold when compared with free CSL, respectively. The above results show that lipophilic chain-linking dendritic hybrid nanocarriers promote antitumor activity by affecting the morphology of NPs, which may aid in the selection of carrier designs. 相似文献
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1调查目的《普通高中课程方案(实验)》中强调学生应“具有强健的体魄、顽强的意志,形成积极健康的生活方式和审美情趣,初步具有独立生活的能力、职业意识、创业精神和人生规划能力”[1],《普通高中化学课程标准(实验)》的课程目标中的情感态度与价值观部分也强调“发展化学学习 相似文献
25.
Gao Y Li N Zheng L Bai X Yu L Zhao X Zhang J Zhao M Li Z 《The journal of physical chemistry. B》2007,111(10):2506-2513
The ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) can form nonaqueous microemulsions with benzene by the aid of nonionic surfactant TX-100. The effect of water on ionic liquid-in-oil (IL/O) microemulsions was studied, and it was shown that the addition of small amount of water to the IL microemulsion contributed to the stability of microemulsion and thus increased the amount of solubilized bmimBF4 in the microemulsion. The conductivity measurements also showed that the attractive interactions between IL microdroplets were weakened, that is, the IL/O microemulsion becomes more stable in the present of some water. Fourier transform IR was carried out to analyze the states of the added water, and the result showed that these water molecules mainly behaved as bound water and trapped water, indicating that the water molecules are located in the palisade layers of the IL/O microemulsion. Furthermore, 1H NMR and 19F NMR spectra suggested that the added water molecules built the hydrogen binding network of imidazolium cations and H2O, BF4- anion and H2O, and at the same time the electronegative oxygen atoms of the oxyethylene units of TX-100 and water in the palisade layers, which made the palisade layers more firm and thus increased the stability of the microemulsion. The study can help in further understanding the formation mechanism of microemulsions. In addition, the characteristic solubilization behavior of the added water can provide an aqueous interface film for hydrolysis reactions and therefore may be used as an ideal medium to prepare porous or hollow nanomaterials. 相似文献
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Na Li Quan Cao Yanan Gao Jin Zhang Liqiang Zheng Xiangtao Bai Bin Dong Zhen Li Mingwei Zhao Li Yu 《Chemphyschem》2007,8(15):2211-2217
We demonstrate a novel ionic liquid (IL) microemulsion, consisting of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) and nonionic surfactant Triton X-100 prepared in triethylamine which is used either as an organic solvent or a Lewis base. The effects of small amounts of added water on the microstructure of the IL microemulsion are investigated by various techniques. UV/Vis spectroscopic analysis and FTIR spectra indicate that these water molecules are not solubilized into the IL pools of the microemulsions. 1H NMR spectra further show that the added water binds with triethylamine to form a surrounding OH- base environment. Some of OH- ions enter the palisade layers of the IL microemulsions and a continuous base interface is created. The unique solubilization behavior of water reveals that it is possible to use the triethylamine microemulsions as a template to prepare metal hydroxides as well as metal oxides in the microemulsions, which is not possible when using traditional microemulsions. 相似文献
29.
Guo H Qian H Sun S Sun D Yin H Cai X Liu Z Wu J Jiang T Liu X 《Chemistry Central journal》2011,5(1):1
In this study, hollow mesoporous silica nanoparticles (HMSNs) were synthesized using the sol-gel/emulsion approach and its
potential application in drug delivery was assessed. The HMSNs were characterized, by transmission electron microscopy (TEM),
Scanning Electron Microscopy (SEM), nitrogen adsorption/desorption and Brunauer-Emmett-Teller (BET), to have a mesoporous
layer on its surface, with an average pore diameter of about 2 nm and a surface area of 880 m2/g. Fluorescein isothiocyanate (FITC) loaded into these HMSNs was used as a model platform to assess its efficacy as a drug
delivery tool. Its release kinetic study revealed a sequential release of FITC from the HMSNs for over a period of one week
when soaked in inorganic solution, while a burst release kinetic of the dye was observed just within a few hours of soaking
in organic solution. These FITC-loaded HMSNs was also found capable to be internalized by live human cervical cancer cells
(HeLa), wherein it was quickly released into the cytoplasm within a short period of time after intracellular uptake. We envision
that these HMSNs, with large pores and high efficacy to adsorb chemicals such as the fluorescent dye FITC, could serve as
a delivery vehicle for controlled release of chemicals administered into live cells, opening potential to a diverse range
of applications including drug storage and release as well as metabolic manipulation of cells. 相似文献
30.
Zhengqi Dong Rui Wang Mingyue Wang Zheng Meng Xiaotong Wang Meihua Han Yifei Guo Xiangtao Wang 《Molecules (Basel, Switzerland)》2022,27(3)
Naringenin (NRG) is a natural flavonoid compound abundantly present in citrus fruits and has the potential to treat respiratory disorders. However, the clinical therapeutic effect of NRG is limited by its low bioavailability due to poor solubility. To enhance the solubility, naringenin nanosuspensions (NRG-NSps) were prepared by applying tocopherol polyethylene glycol succinate (TPGS) as the nanocarrier via the media-milling method. The particle size, morphology, and drug-loading content of NRG-NSps were examined, and the stability was evaluated by detecting particle size changes in different physiological media. NRG-NSps exhibited a flaky appearance with a mean diameter of 216.9 nm, and the drug-loading content was 66.7%. NRG-NSps exhibited good storage stability and media stability. NRG-NSps presented a sustainable release profile, and the cumulative drug-release rate approached approximately 95% within 7 d. NRG-NSps improved the antitussive effect significantly compared with the original NRG, the cough frequency was decreased from 22 to 15 times, and the cough incubation period was prolonged from 85.3 to 121.6 s. Besides, NRG-NSps also enhanced expectorant effects significantly, and phenol red secretion was increased from 1.02 to 1.45 μg/mL. These results indicate that NRG-NSps could enhance the bioavailability of NRG significantly and possess a potential clinical application. 相似文献