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排序方式: 共有692条查询结果,搜索用时 15 毫秒
681.
Xiaolong Zhang Mohammad Abul Hashem Xiaolin Chen Hua Tan 《Theoretical and Computational Fluid Dynamics》2018,32(6):753-764
Circulating tumor cells (CTCs) are potential indicators of cancer. Detection of CTCs is important for diagnosing cancer at an early stage and predicting the effectiveness of cancer treatment. Among various devices, deformation-based CTC microchips have shown a strong promise for CTC detection. This type of devices involves a process where CTCs are trapped while allowing more deformable blood cells to squeeze through the filtration geometry at the specified operating pressure. For designing a reliable CTC microchip, in-depth understanding of the cell passing process through the deformation-based microfluidic device is of high value to the device performance enhancement. In this paper, the CTC squeezing process through a microfluidic filtering channel is studied with a non-Newtonian CTC model employed to account for shear-thinning properties of the cell. Detailed microscopic multiphase flow characteristics regarding the filtering process are discussed including the pressure signatures, flow details, cell deformation, and viscosity variation. Critical pressure for the non-Newtonian CTC at different flow rates is analyzed as it plays a crucial role in the device operation in ensuring a successful passing event. Our study provides insights into the non-Newtonian cell squeezing process, which can guide in the design and optimization of next-generation deformation-based CTC microfilters. 相似文献
682.
Haiyang Wang Miaomiao Liang Xiaolong Zhang Dong Duan Wenyu Shi Yanyan Song Zhanbo Sun 《Ionics》2018,24(7):2063-2072
The CeO2 nanorod framework was synthesized via a facile-dealloying method coupled with calcination treatment for supercapacitors. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) characterizations identified the cubic phase and nanorod morphology of the synthesized sample. Their electrochemical performance was also evaluated by cyclic voltammetry, galvanostatic charge-discharge tests, and cycling performances. The results show that CeO2 nanorod framework possesses high-specific capacitance and superior charge/discharge stability, which are mainly ascribed to its high-Brunauer-Emmett-Tellar surface area (110.6 m2 g?1). Notably, the CeO2//AC (Active Carbon) asymmetric supercapacitor device exhibits excellent cycling stability with capacity retention of 133.6% after cycling for 30,000 cycles. 相似文献
683.
甲醛不仅用作工业化学品,也是调节人体生理活动的必要代谢产物。但是,人体从外环境过量的摄入甲醛或者内环境甲醛代谢的不平衡,会造成器官癌变和老年痴呆等重大疾病。有机小分子荧光探针以其高灵敏度、高选择性、可视化和原位检测等特点,使其在生物体内外甲醛检测和生物成像领域具有应用优势,同时也为实际产品中甲醛的痕量检测提供一种新方法。近五年来,甲醛荧光探针得到了快速的发展。本文主要从甲醛荧光探针的反应类型、生物体中甲醛的荧光成像以及在实际样品(商品)检测应用三个方面,介绍有机小分子荧光探针对甲醛的识别和应用。最后总结指出,不同类型的有机小分子荧光探针在不断开发、结构优化和光学性能提升及满足辅助生物医学方向长期性研究的同时,也能拓展应用范围,达到短期内对实际产品中甲醛快速(原位)检测的目的。 相似文献
684.
Prof. Qi Lei Yaqian Sun Junda Huang Wei Liu Xiaolong Zhan Wenxiang Yin Sishi Guo Dr. Anna Sinelshchikova Prof. C. Jeffrey Brinker Prof. Zhiyuan He Prof. Jimin Guo Prof. Stefan Wuttke Prof. Wei Zhu 《Angewandte Chemie (International ed. in English)》2023,62(22):e202217374
To increase the red blood cell (RBC) cryopreservation efficiency by metal–organic frameworks (MOFs), a dimensional reduction approach has been proposed. Namely, 3D MOF nanoparticles are progressively reduced to 2D ultra-thin metal–organic layers (MOLs). We found that 2D MOLs are beneficial for enhanced interactions of the interfacial hydrogen-bonded water network and increased utilization of inner ordered structures, due to the higher surface-to-volume ratio. Specifically, a series of hafnium (Hf)-based 2D MOLs with different thicknesses (monolayer to stacked multilayers) and densities of hydrogen bonding sites have been synthesized. Both ice recrystallization inhibition activity (IRI) and RBCs cryopreservation assay confirm the pronounced better IRI activity and excellent cell recovery efficiency (up to ≈63 % at a very low concentration of 0.7 mg mL−1) of thin-layered Hf-MOLs compared to their 3D counterparts, thereby verifying the dimensional reduction strategy to improved cryoprotectant behaviors. 相似文献
685.
Run Shi Yonghuang Wu Zeqin Xin Jing Guo Zonglin Li Bochen Zhao Ruixuan Peng Chenyu Li Enze Wang Bolun Wang Xiaolong Zhang Prof. Chun Cheng Prof. Kai Liu 《Angewandte Chemie (International ed. in English)》2023,62(16):e202301421
The study of VO2 flourishes due to its rich competing phases induced by slight stoichiometry variations. However, the vague mechanism of stoichiometry manipulation makes the precise phase engineering of VO2 still challenging. Here, stoichiometry manipulation of single-crystal VO2 beams in liquid-assisted growth is systematically studied. Contrary to previous experience, oxygen-rich VO2 phases are abnormally synthesized under a reduced oxygen concentration, revealing the important function of liquid V2O5 precursor: It submerges VO2 crystals and stabilizes their stoichiometric phase (M1) by isolating them from the reactive atmosphere, while the uncovered crystals are oxidized by the growth atmosphere. By varying the thickness of liquid V2O5 precursor and thus the exposure time of VO2 to the atmosphere, various VO2 phases (M1, T, and M2) can be selectively stabilized. Furthermore, this liquid precursor-guided growth can be used to spatially manages multiphase structures in single VO2 beams, enriching their deformation modes for actuation applications. 相似文献
686.
Dr. Zhiqiang Wei Weiqin Zheng Xiaolong Wan Prof. Dr. Jinbo Hu 《Angewandte Chemie (International ed. in English)》2023,62(37):e202308816
Molecules containing a difluoromethyl group or a propargylic stereocenter are widely used in pharmaceuticals and agrochemicals, and 1,2-functionalization of olefins is an important method for introducing the two groups into molecules simultaneously. The construction of the propargylic stereocenter with terminal alkynes usually requires bases. However, difluoromethylating agents with high reduction potentials often decompose in the presence of bases because of their acidities, and those with low reduction potentials are stable but difficult to undergo the desired single electron transfer (SET) reduction. Using the linear relationship between reduction potential differences (ΔE) and Hammett substituent constants (σ) of difluoromethyl aryl sulfones, we solved the dilemma between acidities and reduction potentials of difluoromethylating agents. Herein, we report the first enantioselective difluoromethylation-alkynylation of olefins with difluoromethyl 4-chlorophenyl sulfone with high enantioselectivity (>90 % ee). We also extended this asymmetric fluoroalkylation-alkynylation reaction with other fluoroalkyl sulfones, which enabled efficient installation of trifluoromethyl, difluoroalkyl, difluorobenzyl, (benzenesulfonyl)-difluoromethyl and monofluoromethyl groups into products. 相似文献
687.
Zhiteng Wang Prof. Qingwen Tian Hao Zhang Prof. Huidong Xie Yachao Du Lei Liu Xiaolong Feng Adel Najar Xiaodong Ren Prof. Shengzhong Liu 《Angewandte Chemie (International ed. in English)》2023,62(30):e202305815
Halide-related surface defects on inorganic halide perovskite not only induce charge recombination but also severely limit the long-term stability of perovskite solar cells. Herein, adopting density functional theory calculation, we verify that iodine interstitials (Ii) has a low formation energy similar to that of the iodine vacancy (VI) and is also readily formed on the surface of all-inorganic perovskite, and it is regarded to function as an electron trap. We screen a specific 2,6-diaminopyridine (2,6-DAPy) passivator, which, with the aid of the combined effects from halogen-Npyridine and coordination bonds, not only successfully eliminates the Ii and dissociative I2 but also passivates the abundant VI. Furthermore, the two symmetric neighboring -NH2 groups interact with adjacent halides of the octahedral cluster by forming hydrogen bonds, which further promotes the adsorption of 2,6-DAPy molecules onto the perovskite surface. Such synergetic effects can significantly passivate harmful iodine-related defects and undercoordinated Pb2+, prolong carrier lifetimes and facilitate the interfacial hole transfer. Consequently, these merits enhance the power-conversion efficiency (PCE) from 19.6 % to 21.8 %, the highest value for this type of solar cells, just as importantly, the 2,6-DAPy-treated CsPbI3−xBrx films show better environmental stability. 相似文献
688.
Aluminescent Ag-based metal-organic framework(1) has been synthesized and its structure has been characterized. Compound 1 was fabricated using the Ag+ and bbimb2‒ ligands and manifestes a rare LON topology. Compound 1 is selective not only in detecting traces of Fe3+ and 2,4,6-trinitrophenol(TNP) via luminescence quenching, but also demonstrates high selectivity in the presence of other competitors. Compound 1’s Ksv values towards Fe3+ can reach as high as 9.3×103 L/mol, which is higher than those of several other MOF materials. It is also a recyclable luminous sensor with the potential to be utilized for detecting TNP. Hence, based on its characteristics, compound 1 can be regarded as a prospective luminescence sensor for detecting Fe3+ and TNP. 相似文献
689.
Xiaolong Liu Dr. Kang Wang Ang Ren Tongjin Zhang Shizhe Ren Prof. Jiannian Yao Prof. Haiyun Dong Prof. Yong Sheng Zhao 《Angewandte Chemie (International ed. in English)》2023,62(40):e202309386
Stimulated Raman scattering offers an alternative strategy to explore continuous-wave (c.w.) organic lasers, which, however, still suffers from the limitation of inadequate Raman gain in organic material systems. Here we propose a metal-linking approach to enhance the Raman gain of organic molecules. Self-assembled microcrystals of the metal linked organic dimers exhibit large Raman gain, therefore allowing for c.w. Raman lasing. Furthermore, broadband tunable Raman lasing is achieved in the organic dimer microcrystals by adjusting excitation wavelengths. This work advances the understanding of Raman gain in organic molecules, paving a way for the design of c.w. organic lasers. 相似文献
690.
Yang Qian Lai Mingyang Liu Dawei Zhang Junyuan Zhang Yang Liu Changyu Xu Xiaolong Jia Jianbo 《Journal of Solid State Electrochemistry》2023,27(3):585-595
Journal of Solid State Electrochemistry - A low-cost dual-chamber microbial fuel cell (MFC) was constructed as a biosensor for the rapid determination of biochemical oxygen demand (BOD) in domestic... 相似文献