排序方式: 共有74条查询结果,搜索用时 15 毫秒
71.
Parul Rungta Volodymyr Tsyalkovsky Christopher F. Huebner Yuriy P. Bandera Stephen H. Foulger 《Synthetic Metals》2010,160(23-24):2486-2493
An electron-transporting monomer was synthesized that was structurally and energetically similar to the small molecule 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD). The monomer was copolymerized with 2-(9H-carbazol-9-yl)ethyl 2-methylacrylate and the resulting copolymer was utilized in organic light emitting devices which employed fluorescent coumarin 6 (C6) or phosphorescent tris(2-phenylpyridine)iridium(III) [Ir(ppy)3] emitters. The copolymer devices exhibited a mean luminance of ca. 400 and 3552 cd/m2 with the C6 and Ir(ppy)3 emitters, respectively, that was stable with thermal aging at temperatures ranging from 23 °C to 130 °C. Comparable poly(9-vinyl-9H-carbazole)/tBu-PBD blend devices exhibited more pronounced variations in performance with thermal aging. 相似文献
72.
The samples of tin (Sn) modified NASICON (Na3Zr2Si2PO12) type solid electrolyte are prepared and their electrical properties are investigated. The two modified compositions of NASICON in which zirconium (Zr) atoms are replaced by Sn atoms i.e., Na3ZrSnSi2PO12 (NASN) and Na3Sn2Si2PO12 (NASN2), are prepared by solid state reaction technique. The structural studies show variation in the lattice parameters a and c which enhance the bottle neck size. The FT-IR results also confirm structural modification (stretching of bond lengths) on addition of Sn. The electrical studies show when one atom of Zr is replaced by one atom of Sn (NASN), both DC and AC electrical conductivities increase as compared to unmodified NASICON material while for replacement of both the Zr atoms by Sn atoms (NASN2), the electrical conductivity decreases. 相似文献
73.
A series of dialkyl diphosphate gemini surfactants has been synthesized using C18 as hydrophobic chains and phosphate as head groups. Three flexible spacers have been used. In the present study, an attempt has also been made to synthesize mono octadecyl phosphate (MOP) at 35°C, which was used as an intermediate in the synthesis of geminis. This long chain of MOP has been effectively converted to gemini surfactants and subsequently converted to their disodium salts. The effect of reaction variables like temperature, duration, molar ratios of reactants, catalyst and spacer on the yield of dialkyl diphosphate gemini surfactant has also been reported. The MOP, gemini surfactants and disodium salt of gemini surfactants were characterized using FT‐IR and 1H‐NMR. Surface active and physico‐chemical properties of synthesized gemini surfactants and their monomer were also determined. The results revealed that the yield of dialkyl diphosphate gemini surfactants ranged from 80 to 90%. Among all synthesized dialkyl diphosphate gemini surfactants D, S‐1,6‐GSOD had maximum anionic content, i.e. 80.7%, showed highest foaming ability and superior dispersing ability, whereas D, S‐1,8‐GSOD showed low cmc values, i.e. 0.00012 mM/L; minimum surface tension and interfacial tension, i.e. 39.1 and 36.3 mN/m, respectively. 相似文献
74.
Anuradha Banerjee Sachin Kumar Gupta Parul Gupta Abu Sufian Ashutosh Srivastava Manoj Kumar 《International Journal of Communication Systems》2023,36(14):e5555
UAVs are capable of providing significant potential to IoT devices through sensors, cameras, GPS systems, and so forth. Therefore, the smart UAV-IoT collaborative system has become a current hot research topic. However, other concerns require in-depth investigation and study, such as resource allocation, security, privacy preservation, trajectory optimization, intelligent decision-making, energy harvesting, and so forth. Here, we suggest a task-scheduling method that splits IoT devices into distinct clusters based on physical proximity and saves time and energy. Cluster heads can apply an auto regressive moving average (ARMA) model to predict intelligently the timestamp of the arrival of the next task and associated estimated payments. Based on the overall expected payment, a cluster head can smartly advise the UAV about its time of next arrival. According to the findings of the simulation, the proposed ETTS algorithm significantly outperforms Task TSIE and TDMA-WS in terms of energy use (67%) and delays (36%). 相似文献