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排序方式: 共有8471条查询结果,搜索用时 203 毫秒
1.
Song Zi-Long Zhu Yun Liu Jing-Rui Guo Shu-Ke Gu Yu-Cheng Han Xinya Dong Hong-Qiang Sun Qi Zhang Wei-Hua Zhang Ming-Zhi 《Molecular diversity》2021,25(1):205-221
Molecular Diversity - Based on the strategy of diversity-oriented synthesis and the structures of natural product pimprinine and streptochlorin, two series of novel pimprinine derivatives... 相似文献
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磷酸酯类前药与原药相比,不仅能够提高药物靶向性、稳定性和生物利用度,减少药物毒副作用,还能掩蔽药物不适气味、提高水溶性从而改善给药途径。含羟基药物的磷酸酯化是该类药物前药设计的重要方法之一。本文根据中心磷原子的价态和化合物结构进行分类,综述了各种P(Ⅴ)四配位分子、P(Ⅲ)三配位分子和H-亚磷酸酯类化合物作为磷酸酯化试剂在磷酸酯类前药合成方法中的研究进展,并阐述了这些磷酸酯类药物的应用,最后总结了各类磷酸酯化试剂的优势与局限,并结合连续流反应技术应用案例展望了其发展趋势。 相似文献
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Song Zhang Luke A. Galuska Xiaodan Gu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(7):1108-1129
Thin films with a nanometer-scale thickness are of great interest to both scientific and industrial communities due to their numerous applications and unique behaviors different from the bulk. However, the understanding of thin-film mechanics is still greatly hampered due to their intrinsic fragility and the lack of commercially available experimental instruments. In this review, we first discuss the progression of thin-film mechanical testing methods based on the supporting substrate: film-on-solid substrate method, film-on-water tensile tests, and water-assisted free-standing tensile tests. By comparing past studies on a model polymer, polystyrene, the effect of different substrates and confinement effect on the thin-film mechanics is evaluated. These techniques have generated fruitful scientific knowledge in the field of organic semiconductors for the understanding of structure–mechanical property relationships. We end this review by providing our perspective for their bright prospects in much broader applications and materials of interest. 相似文献
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We reported a chalcogenide glass-based rib waveguide fabricated using photolithography and dry etching method. A commercial software(COMSOL Multiphysics) was used to optimize the waveguide structure and the distribution of the fundamental modes in the waveguide based on the complete vector finite component. We further employed thermal annealing to optimize the surface and sidewalls of the rib waveguides. It was found that the optimal annealing temperature for Ge As Se S films is 220℃, and the roughness of the films could be significantly reduced by annealing. The zero-dispersion wavelength(ZDW) could be shifted to a short wavelength around ~2.1 μm via waveguide structural optimization, which promotes supercontinuum generation with a short wavelength pump laser source. The insertion loss of the waveguides with cross-sectional areas of 4.0 μm×3.5 μm and 6.0 μm×3.5 μm was measured using lens fiber and the cut-back method. The propagation loss of the 220℃ annealed waveguides could be as low as 1.9 d B/cm at 1550 nm. 相似文献
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Qingbing Xia Zeheng Lin Weihong Lai Yongfei Wang Cheng Ma Zichao Yan Qinfen Gu Weifeng Wei Jia‐Zhao Wang Zhiqiang Zhang Hua Kun Liu Shi Xue Dou Shu‐Lei Chou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14263-14266
Two‐dimensional (2D) superlattices offer promising technological opportunities in tuning the intercalation chemistry of metal ions. Now, well‐ordered 2D superlattices of monolayer titania and carbon with tunable interlayer‐spacing are synthesized by a molecularly mediated thermally induced approach. The 2D superlattices are vertically encapsulated in hollow carbon nanospheres, which are embedded with TiO2 quantum dots, forming a 0D‐2D‐3D multi‐dimensional architecture. The multi‐dimensional architecture with the 2D superlattices encapsulated inside exhibits a near zero‐strain characteristic and enriched electrochemical reactivity, achieving a highly efficient Na+ storage performance with exceptional rate capability and superior long‐term cyclability. 相似文献
8.
Dake Hu Tianqi Zhao Xiaofan Ping Husong Zheng Lei Xing Xiaozhi Liu Jingying Zheng Lifei Sun Lin Gu Chenggang Tao Dong Wang Liying Jiao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):7051-7055
Two‐dimensional (2D) PtSe2 shows the most prominent layer‐dependent electrical properties among various 2D materials and high catalytic activity for hydrogen evolution reaction (HER), and therefore, it is an ideal material for exploring the structure–activity correlations in 2D systems. Here, starting with the synthesis of single‐crystalline 2D PtSe2 with a controlled number of layers and probing the HER catalytic activity of individual flakes in micro electrochemical cells, we investigated the layer‐dependent HER catalytic activity of 2D PtSe2 from both theoretical and experimental perspectives. We clearly demonstrated how the number of layers affects the number of active sites, the electronic structures, and electrical properties of 2D PtSe2 flakes and thus alters their catalytic performance for HER. Our results also highlight the importance of efficient electron transfer in achieving optimum activity for ultrathin electrocatalysts. Our studies greatly enrich our understanding of the structure–activity correlations for 2D catalysts and provide new insight for the design and synthesis of ultrathin catalysts with high activity. 相似文献
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Nan Gan Xuan Wang Huili Ma Anqi Lv He Wang Qian Wang Mingxing Gu Suzhi Cai Yanyun Zhang Lishun Fu Meng Zhang Chaomin Dong Wei Yao Huifang Shi Zhongfu An Wei Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14278-14283
Provided here is evidence showing that the stacking between triplet chromophores plays a critical role in ultralong organic phosphorescence (UOP) generation within a crystal. By varying the structure of a functional unit, and different on‐off UOP behavior was observed for each structure. Remarkably, 24CPhCz, having the strongest intermolecular interaction between carbazole units exhibited the most impressive UOP with a long lifetime of 1.06 s and a phosphorescence quantum yield of 2.5 %. 34CPhCz showed dual‐emission UOP and thermally activated delayed fluorescence (TADF) with a moderately decreased phosphorescence lifetime of 770 ms, while 35CPhCz only displayed TADF owing to the absence of strong electronic coupling between triplet chromophores. This study provides an explanation for UOP generation in crystal and new guidelines for obtaining UOP materials. 相似文献
10.
Lin Yung-Sen Shie Bing-Shiun Lai Yan-Hong Chen Jui-Hung Gu Zhi-Wei Chen Hsiang Lin Chia-Feng 《Journal of Solid State Electrochemistry》2019,23(2):441-453
Journal of Solid State Electrochemistry - Lithium ionic intercalation and conduction performance of tantalum oxides films improved by adding with iron oxides using an atmospheric pressure plasma... 相似文献