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81.
高分子半导电材料的研制 总被引:1,自引:0,他引:1
在以氯丁橡胶为骨架材料的高分子半导电材料配方中,并用10~30质量份(简称份,以下同)氯化聚乙烯以改善材料的物理机械和耐热性能以及加工工艺;为降低生产成本,填充30~40份的活化硫化胶粉;导电物质选用具有一定协同效应的导电炉黑和导电石墨并用,并用量在40~70份;由此配制的高分子半导电材料具有较好的物理机械、加工和导电性能。混炼时,在满足工艺性能的同时,尽量缩短混炼时间、增加交联密度,同时尽量使导电物质均匀分散。 相似文献
82.
This paper reviews the current status and research trends of two types of ceramic based resistive sensors, thermistors and gas sensors. The issues and challenges associated with their development for high temperature applications are examined and discussed. Worldwide research efforts in ceramic based resistive sensors, devoted mostly to resolve the issues of selectivity and stability, are also reviewed. These efforts tend to integrate the results obtained from both empirical and basic science approaches, and focus on various stages of sensor development, including development of new material systems, sensor fabrication and manufacturing techniques, and smart sensor arrays. 相似文献
83.
84.
ZnO nanofibers were electro‐spun from a solution containing poly 4‐vinyl phenol and Zn acetate dihydrate. The calcination process of the ZnO/PVP composite nanofibers brought forth a random network of polycrystalline würtzite ZnO nanofibers of 30 nm to 70 nm in diameter. The electrical properties of the ZnO nanofibers were governed by the grain boundaries. To investigate possible applications of the ZnO nanofibers, their CO and NO2 gas sensing responses are demonstrated. In particular, the SnO2‐deposited ZnO nanofibers exhibit a remarkable gas sensing response to NO2 gas as low as 400 ppb. Oxide nanofibers emerge as a new proposition for oxide‐based gas sensors. 相似文献
85.
Huang Zhu Jiuhong Deng Minjia Yuan Xiao Rong Xi Xiang Fangxue Du Xianglin Luo Chong Cheng Li Qiu 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(18):2206911
The external-stimulation-induced reactive-oxygen-species (ROS) generation has attracted increasing attention in therapeutics for malignant tumors. However, engineering a nanoplatform that integrates with efficient biocatalytic ROS generation, ultrasound-amplified ROS production, and simultaneous relief of tumor hypoxia is still a great challenge. Here, we create new semiconducting titanate-supported Ru clusterzymes (RuNC/BTO) for ultrasound-amplified biocatalytic tumor nanotherapies. The morphology and chemical/electronic structure analysis prove that the biocatalyst consists of Ru nanoclusters that are tightly stabilized by Ru-O coordination on BaTiO3. The peroxidase (POD)- and halogenperoxidase-like biocatalysis reveals that the RuNC/BTO can produce abundant •O2− radicals. Notably, the RuNC/BTO exhibits the highest turnover number (63.29 × 10−3 s−1) among the state-of-the-art POD-mimics. Moreover, the catalase-like activity of the RuNC/BTO facilitates the decomposition of H2O2 to produce O2 for relieving the hypoxia of the tumor and amplifying the ROS level via ultrasound irradiation. Finally, the systematic cellular and animal experiments have validated that the multi-modal strategy presents superior tumor cell-killing effects and suppression abilities. We believe that this work will offer an effective clusterzyme that can adapt to the tumor microenvironment-specific catalytic therapy and also provide a new pathway for engineering high-performance ROS production materials across broad therapeutics and biomedical fields. 相似文献
86.
Ling Li Zhen Yang Shoujun Zhu Liangcan He Wenpei Fan Wei Tang Jianhua Zou Zheyu Shen Mingru Zhang Longguang Tang Yunlu Dai Gang Niu Shuo Hu Xiaoyuan Chen 《Advanced materials (Deerfield Beach, Fla.)》2019,31(21)
The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR‐associated protein 9 (Cas9) genome‐editing system has shown great potential in biomedical applications. Although physical approaches, viruses, and some nonviral vectors have been employed for CRISPR/Cas9 delivery and induce some promising genome‐editing efficacy, precise genome editing remains challenging and has not been reported yet. Herein, second near‐infrared window (NIR‐II) imaging‐guided NIR‐light‐triggered remote control of the CRISPR/Cas9 genome‐editing strategy is reported based on a rationally designed semiconducting polymer brush (SPPF). SPPF can not only be a vector to deliver CRISPR/Cas9 cassettes but also controls the endolysosomal escape and payloads release through photothermal conversion under laser irradiation. Upon laser exposure, the nanocomplex of SPPF and CRISPR/Cas9 cassettes induces effective site‐specific precise genome editing both in vitro and in vivo with minimal toxicity. Besides, NIR‐II imaging based on SPPF can also be applied to monitor the in vivo distribution of the genome‐editing system and guide laser irradiation in real time. Thus, this study offers a typical paradigm for NIR‐II imaging‐guided NIR‐light‐triggered remote control of the CRISPR/Cas9 system for precise genome editing. This strategy may open an avenue for CRISPR/Cas9 genome‐editing‐based precise gene therapy in the near future. 相似文献
87.
ZHOU Dongxiang CHEN Yong LIU Huan DENG Chuanyi GONG Shuping ZHANG Daoli 《武汉理工大学学报(材料科学英文版)》2006,21(2):44-46
The constitution and firing-technology of Ni paste were experimentally investigated. The experimental resalts show that the contact resistance could be lowered by adding glass powder and Boron powder, respectively used as adhesive and antioxidant when the content of Ni powder is higher than 65wt% . By firing at 810 ℃ , Ni paste obtained could form a good ohmic contact to PTC ceramics, as shown by SEM iamges. In addition, we compared the electrical properties of PTCR ceramics measured with various electrodes and found that fired- Ni contact is superior to contacts made by fired-Al and sputtered-Ni. 相似文献
88.
Dual‐Peak Absorbing Semiconducting Copolymer Nanoparticles for First and Second Near‐Infrared Window Photothermal Therapy: A Comparative Study
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Yuyan Jiang Jingchao Li Xu Zhen Chen Xie Kanyi Pu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(14)
Near‐infrared (NIR) light is widely used for noninvasive optical diagnosis and phototherapy. However, current research focuses on the first NIR window (NIR‐I, 650–950 nm), while the second NIR window (NIR‐II, 1000–1700 nm) is far less exploited. The development of the first organic photothermal nanoagent (SPNI‐II) with dual‐peak absorption in both NIR windows and its utilization in photothermal therapy (PTT) are reported herein. Such a nanoagent comprises a semiconducting copolymer with two distinct segments that respectively and identically absorb NIR light at 808 and 1064 nm. With the photothermal conversion efficiency of 43.4% at 1064 nm generally higher than other inorganic nanomaterials, SPNI‐II enables superior deep‐tissue heating at 1064 nm over that at 808 nm at their respective safety limits. Model deep‐tissue cancer PTT at a tissue depth of 5 mm validates the enhanced antitumor effect of SPNI‐II when shifting laser irradiation from the NIR‐I to the NIR‐II window. The good biodistribution and facile synthesis of SPNI‐II also allow it to be doped with an NIR dye for fluorescence‐imaging‐guided NIR‐II PTT through systemic administration. Thus, this study paves the way for the development of new polymeric nanomaterials to advance phototherapy. 相似文献
89.
Phase‐Engineered PtSe2‐Layered Films by a Plasma‐Assisted Selenization Process toward All PtSe2‐Based Field Effect Transistor to Highly Sensitive,Flexible, and Wide‐Spectrum Photoresponse Photodetectors
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Teng‐Yu Su Henry Medina Yu‐Ze Chen Sheng‐Wen Wang Shao‐Shin Lee Yu‐Chuan Shih Chia‐Wei Chen Hao‐Chung Kuo Feng‐Chuan Chuang Yu‐Lun Chueh 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(19)
The formation of PtSe2‐layered films is reported in a large area by the direct plasma‐assisted selenization of Pt films at a low temperature, where temperatures, as low as 100 °C at the applied plasma power of 400 W can be achieved. As the thickness of the Pt film exceeds 5 nm, the PtSe2‐layered film (five monolayers) exhibits a metallic behavior. A clear p‐type semiconducting behavior of the PtSe2‐layered film (≈trilayers) is observed with the average field effective mobility of 0.7 cm2 V?1 s?1 from back‐gated transistor measurements as the thickness of the Pt film reaches below 2.5 nm. A full PtSe2 field effect transistor is demonstrated where the thinner PtSe2, exhibiting a semiconducting behavior, is used as the channel material, and the thicker PtSe2, exhibiting a metallic behavior, is used as an electrode, yielding an ohmic contact. Furthermore, photodetectors using a few PtSe2‐layered films as an adsorption layer synthesized at the low temperature on a flexible substrate exhibit a wide range of absorption and photoresponse with the highest photocurrent of 9 µA under the laser wavelength of 408 nm. In addition, the device can maintain a high photoresponse under a large bending stress and 1000 bending cycles. 相似文献
90.
Dafei Yuan Evan Plunkett Phong H. Nguyen Dakota Rawlings My Linh Le Rene Kroon Christian Müller Rachel A. Segalman Michael L. Chabinyc 《Advanced functional materials》2023,33(29):2300934
The interactions between counterions and electronic carriers in electrically doped semiconducting polymers are important for delocalization of charge carriers, electronic conductivity, and thermal stability. The introduction of a dianions in semiconducting polymers leads to double doping where there is one counterion for two charge carriers. Double doping minimizes structural distortions, but changes the electrostatic interactions between the carriers and counterions. Polymeric ionic liquids (PIL) with croconate dianions are helpful to investigate the role of the counterion in p-type semiconducting polymers. PILs prevent diffusion of the cation into the semiconducting polymers during ion exchange. The redox-active croconate dianions undergo ion exchange with doped semiconducting polymers depending on their ionization energy. Croconate dianions are found to reduce doped films of poly(3-hexyl thiophene), but undergo ion exchange with a polythiophene with tetraethylene glycol side chains, P(g42T-T), that has a lower ionization energy. The croconate dianion maintains crystalline order in P(g42T-T) and leads to a lower activation energy for the electrical conductivity than PF6− counterions. The control of the doping level with croconate allows optimization of the thermoelectric performance of the semiconducting polymer. The thermal stability of the doped films of P(g42T-T) is found to depend strongly on the nature of the counterion. 相似文献