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991.
聚合物基底上纳米银颗粒薄膜的制备工艺相对简单,成本较低,且该薄膜具有成为高敏感性压阻应力/应变传感材料的潜力。本文采用银镜制备法在聚酰亚胺(PI)和聚乙烯(PE)上合成了纳米银颗粒薄膜,系统研究了该薄膜制备工艺、结构特性、材料性能之间的关系。实验考察了材料“浸泡”时间及聚合物材料前处理等因素对材料表面吸附纳米颗粒含量的影响,研究了 “浸泡”时间对纳米银颗粒粒径大小、颗粒含量及分布的影响,并探讨了不同聚合物基体的颗粒特性对薄膜二维导电渗滤,压阻特性及拉伸性能的影响。研究表明,增加“浸泡”时间能够增加纳米银颗粒粒径大小,提高银颗粒的含量及分布均匀性;在相同的制备条件下,PI基底较PE基底对纳米银颗粒具有更加优异的吸附效果;在PI 和PE基底上的纳米银颗粒薄膜均表现出显著的压阻性能,且电阻对应变的敏感性随应变的增大及银颗粒含量的减少而显著提高。 相似文献
993.
Granular Matter - Frustration arises for a broad class of physical systems where confinement (geometric) or the presence of a perturbation (kinematic) prevents equilibration to a minimum energy... 相似文献
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Maxim K. Rabchinskii Vladimir V. Shnitov Dina Yu. Stolyarova Sergei A. Ryzhkov Marina V. Baidakova Eugenia Yu. Lobanova 《Fullerenes, Nanotubes and Carbon Nanostructures》2020,28(3):221-225
AbstractThe one-step method for graphene oxide (GO) simultaneous reduction and carboxylation via ultraviolet irradiation in the inert atmosphere has been reported. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) data revealed that the proposed approach allows to obtain reduced graphene oxide (rGO) films, containing up to 10 at.% of carboxyl groups. The carboxyl groups concentration can be tuned within the range of 3 to 10 at.% by controlling the oxidation degree of the irradiated GO via the preliminary low-temperature air heating. Furthermore, no carboxylation effect is observed in the case of irradiation of the completely reduced GO films. This coincides with our previous results, validating the proposed model of GO carboxylation based on photoinduced conversion of basal-plane hydroxyl groups and ketones into carboxyl ones. Despite a different degree of carboxylation, all the obtained samples demonstrate almost complete elimination of basal plane groups and restoration of the graphene flakes aromatic structure. This fact is emphasized by the sheet resistance measurements, demonstrating that the obtained C-xy graphene exhibits high electrical conductivity. As a net result, the material obtained by the presented method shows promising applications in the manufacturing of biosensor transducers owing to both its conductive nature and presence of carboxyl groups, playing the role of the anchoring points for biomolecules. 相似文献
998.
Zhigang Ren Xinmei Chen Liangjie Hong Xiaoxiong Zhao Guangying Cui Ang Li Yang Liu Lina Zhou Ranran Sun Shen Shen Juan Li Jiamin Lou Heqi Zhou Junmei Wang Guowang Xu Zujiang Yu Yujun Song Xinhua Chen 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(2)
Hepatocellular carcinoma (HCC) is the third leading cause of cancer‐related death worldwide. The prognosis of HCC remains very poor; thus, an effective treatment remains urgent. Herein, a type of nanomedicine is developed by conjugating Fe@Fe3O4 nanoparticles with ginsenoside Rg3 (NpRg3), which achieves an excellent coupling effect. In the dimethylnitrosamine‐induced HCC model, NpRg3 application significantly prolongs the survival of HCC mice. Further research indicates that NpRg3 application significantly inhibits HCC development and eliminates HCC metastasis to the lung. Notably, NpRg3 application delays HCC‐induced ileocecal morphology and gut microbial alterations more than 12 weeks during HCC progression. NpRg3 administration elevates the abundance of Bacteroidetes and Verrucomicrobia, but decreases Firmicutes. Twenty‐nine predicted microbial gene functions are enriched, while seven gene functions are reduced after NpRg3 administration. Moreover, the metabolomics profile presents a significant progression during HCC development, but NpRg3 administration corrects tumor‐dominant metabolomics. NpRg3 administration decreases 3‐indolepropionic acid and urea, but elevates free fatty acids. Importantly, NpRg3 application remodels the unbalanced correlation networks between gut microbiota and metabolism during HCC therapy. In conclusion, nanoparticle conjugation of ginsenoside Rg3 inhibits HCC development and metastasis via the remodeling of unbalanced gut microbiota and metabolism in vivo, providing an antitumor therapy strategy. 相似文献
999.
Yu‐Jung Lin Chun‐Chieh Chen Dang Nguyen Huei‐Rou Su Kun‐Ju Lin Hsin‐Lung Chen Yu‐Jung Hu Po‐Liang Lai Hsing‐Wen Sung 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(23)
Nitric oxide (NO) is a potent tumor‐cell radiosensitizer but it can be readily scavenged by hemoglobin (Hb) in vivo. A biomimetic incubator that can generate and deliver NO in a scavenger (Hb)‐free environment to enhance its radiosensitizing effect to maximize its efficacy in radiotherapy is proposed. This NO incubator comprises a poly(lactic‐co‐glycolic acid) (PLGA) hollow microsphere (HM) that contains an NO donor (NONOate) and a surfactant molecule (sodium caprate, SC) in its aqueous core. In acidic tumorous environments, the PLGA shell of the HM allows the penetration of protons from the outside, activating the hydrolytic cleavage of NONOate, spontaneously generating NO bubbles, which are immediately trapped/stabilized by SC. The SC‐stabilized NO bubbles in the HM are then squeezed through the spaces of its PLGA matrices by the elevated internal pressure. Upon leaving the HM, the entrapped NO molecules may passively diffuse through their SC‐stabilized/protected layer gradually to the tumor site, having a long‐lasting radiosensitizing effect and inhibiting tumor growth. The entire process of NO generation and delivery is conducted in a scavenger (Hb)‐free environment, mimicking the development of young ovoviviparous fish inside their mothers' bodies in the absence of predators before birth. 相似文献
1000.
Guihua Liu Dan Luo Rui Gao Yongfeng Hu Aiping Yu Zhongwei Chen 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(37)
The practical application of lithium–sulfur (Li–S) batteries is hindered by the “shuttle” of lithium polysulfides (LiPS) and sluggish Li–S kinetics issues. Herein, a synergistic strategy combining mesoporous architecture design and defect engineering is proposed to synthesize multifunctional defective 3D ordered mesoporous cobalt sulfide (3DOM N‐Co9S8?x) to address the shuttling and sluggish reaction kinetics of polysulfide in Li–S batteries. The unique 3DOM design provides abundant voids for sulfur storage and enlarged active interfaces that reduce electron/ion diffusion pathways. Meanwhile, X‐ray absorption spectroscopy shows that the surface defect engineering tunes the CoS4 tetrahedra to CoS6 octahedra on Co9S8, endowing abundance of S vacancies on the Co9S8 octahedral sites. The ever‐increasing S vacancies over the course of electrochemical process further promotes the chemical trapping of LiPS and its conversion kinetics, rendering fast and durable Li–S chemistry. Benefiting from these features, the as‐developed 3DOM N‐Co9S8?x/S cathode delivers high areal capacity, superb rate capability, and excellent cyclic stability with ultralow capacity fading rate under raised sulfur loading and low electrolyte content. This design strategy promotes the development of practically viable Li–S batteries and sheds lights on the material engineering in related energy storage application. 相似文献