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排序方式: 共有1157条查询结果,搜索用时 15 毫秒
1.
2.
Jagadeesh Babu Sriramoju Murthy Muniyappa Navya Rani Marilingaiah Chetana Sabbanahalli Manjunath Shetty Ravi Mudike Chitrabanu C.P Prasanna D. Shivaramu Nagaraju G Kanchugarakoppal S. Rangappa Ananda Kumar C.S Dinesh Rangappa 《Ceramics International》2021,47(7):10314-10321
Application of brown titanium dioxide (TiO2-x) and its modified composite forms in the photocatalytic decomposition of organic pollutants in the environment is a promising way to provide solutions for environmental redemption. Herein, we report the synthesis of effective and stable TiO2-x nanoparticles with g-C3N4, RGO, and multiwalled carbon nanotubes (CNTs) using a simple hydrothermal method. Among all the as-synthesized samples, excellent photocatalytic degradation activity was observed for RGO-TiO2-x nanocomposite with high rate constants of 0.075 min?1, 0.083 min?1 and 0.093 min?1 for methylene blue, rhodamine-B, and rosebengal dyes under UV–Visible light irradiation, respectively. The altered bandgap (1.8 eV) and the large surface area of RGO-TiO2-x nanocomposite impacts on both absorption of visible light and efficiency of photogenerated charge electron (e?)/hole (h+) pair separation. This resulted in enhanced photocatalytic property of carbon-based TiO2-x nanocomposites. A systematic study on the influence of different carbon nanostructures on the photocatalytic activity of brown TiO2-x is carried out. 相似文献
3.
The nature of pairing mechanism as well as transition temperature of yttrium cuprates is discussed using the strong coupling
theory. An interaction potential has been developed for the layered structure with two conducting CuO2(a–b) layers in a unit cell. The interaction potential properly takes care of electron-electron, electron-phonon and electron-plasmon
interactions. Furthermore, the electron-phonon coupling parameter (λ), the modified Coulomb repulsive parameter (μ*) and the 2D acoustic phonon (plasmon) energy as a function of oxygen deficiency is worked out. Finally, the superconducting
transition temperature (T
c) is then evaluated by using these coupling parameters and obtainedT
c = 95(92)K for Y(Yb)Ba2Cu3O7−δ
superconductors withδ = 0·0. The model parameters estimated from the layered structure approach are consistent with the strong coupling theory.
The result deduced on the variation ofT
c withδ are in fair agreement with the earlier reported data on yttrium cuprates. The analysis of the above results are discussed. 相似文献
4.
5.
We study the mechanical and conformational properties of networks of helical polymers with a combination of Monte Carlo simulations based on the Wang-Landau algorithm and the three-chain model. We find that the stress-strain behavior of these networks has novel features not observed in typical networks made of synthetic polymers. In particular, we find that as these networks are stretched they first strengthen, then soften and finally strengthen again. This non-monotonic behavior of the stress correlates with the one of the helical content and is rationalized by the elongation-induced formation and melting of the helical structure of the polymer. We complement these results with a study of other conformational properties of the polymer strands that clarify the molecular mechanisms behind the mechanical behavior of these networks. Finally, we present a qualitative comparison of some of our results with the theoretical ones recently reported by Kutter and Terentjev. 相似文献
6.
R. Dinesh T. Fujiwara T. Watanabe K. Byrappa M. Yoshimura 《Journal of Materials Science》2006,41(5):1541-1546
A well-crystallized AMO4 (A=Ba, Ca, Sr; M=W, Mo) films have been prepared at room temperature through a simple solution reaction in respective alkaline
solution at higher pH ranging from 12–14. Adopting the corrosion principle for oxidation of metal substrate, these double
oxide films were carried out in presence of chemical driving force without any special apparatus or devices. Hydrogen peroxide
was used to enhance the dissolution rate of metal substrates. The driving force for the film formation and growth were high
concentration of A2+, MO42− ions with high pH conditions. Average grain sizes of 8–10 μm with bipyramidal shaped particle were grown to the thickness
of about 10–14 μm after 3–6 hours treatment. The crystallization of AMO4 was characterized by three-dimensional nucleation. This work demonstrates the possibility of fabrication of functional ceramic
films directly from the aqueous solution in a single step by solution reactions. 相似文献
7.
A signal intensity based maximum-likelihood (ML) target location estimator that uses quantized data is proposed for wireless sensor networks (WSNs). The signal intensity received at local sensors is assumed to be inversely proportional to the square of the distance from the target. The ML estimator and its corresponding Crameacuter-Rao lower bound (CRLB) are derived. Simulation results show that this estimator is much more accurate than the heuristic weighted average methods, and it can reach the CRLB even with a relatively small amount of data. In addition, the optimal design method for quantization thresholds, as well as two heuristic design methods, are presented. The heuristic design methods, which require minimum prior information about the system, prove to be very robust under various situations 相似文献
8.
A quantitative analysis of the effectiveness of laparascopy and endoscopy virtual reality simulators
Shankar Srinivasan Author Vitae Dinesh P. Mital Author VitaeAuthor Vitae 《Computers & Electrical Engineering》2006,32(4):283-298
The increasing use of virtual reality (VR) simulators in surgical training makes it imperative that definitive studies be performed to assess their training effectiveness. Indeed in this paper we report the meta-analysis of the efficacy of virtual reality simulators in (1) the transference of skills from the simulator training environment to the operating room and (2) their ability to discriminate between the experience levels of its users. The task completion time and the error score were the two study outcomes collated and analyzed in this meta-analysis. Sixteen studies were identified from a computer-based literature search (1996-2004). The meta-analysis of the random-effects model (because of the heterogeneity of the data) revealed that training on virtual reality simulators did lessen the time taken to complete a given surgical task as also clearly differentiate between the experienced and the novice trainees. Meta-analytic studies such as the one reported here would be very helpful in the planning and setting up of surgical training programs and for the establishment of reference ‘learning curves’ for a specific simulator and surgical task. If any such programs already exist they can then indicate the improvements to be made in the simulator used such as providing for more variety in their case scenarios based on the state and/or rate of learning of the trainee. 相似文献
9.
Dinesh Kalyanasundaram Shinnosuke Inoue Jong-Hoon Kim Hyun-Boo Lee Zenko Kawabata Woon-Hong Yeo Gerard A. Cangelosi Kieseok Oh Dayong Gao Kyong-Hoon Lee Jae-Hyun Chung 《Microfluidics and nanofluidics》2012,13(2):217-225
Simple, high-yield concentration of DNA is important for high-throughput genetic analysis and disease diagnosis. Glass-based microfilters are popular but the process requires centrifugation steps with cumbersome chemical processes. As an alternative, a concentration method using an electric field has been explored previously, but with limited efficiency. In this paper, electric field-induced concentration and capture of DNA are studied by using high-aspect-ratio microtips coated with a gold layer. The microtips are immersed longitudinally into a solution of 100???L containing ??-phage DNA. After DNA concentration using an electric field, the microtips are withdrawn from the solution. Under AC- and biased AC fields, DNA is concentrated by electrophoresis (EP), dielectrophoresis (DEP), and electroosmotic flow (EOF). To reduce capillary effects in the withdrawal process, the microtips are coated with positively charged poly-l-lysine (PLL). The pattern of captured DNA is analyzed by fluorescence microscopy. DEP attracts DNA molecules at the edges of microtips, where the highest gradient of electric field exists. EP attracts DNA onto the surface of microtips following the vectors of an electric field. EOF generates vortexes that deliver DNA onto microtips. Using this method, 85% of DNA is captured on the PLL-coated microtips after three sequential captures. The concentration mechanism can potentially facilitate rapid and simple preparation of DNA for downstream analysis. 相似文献
10.
Usha Varshney R. J. Churchill H. P. Groger A. I. Kingon 《Journal of Superconductivity》1989,2(2):293-304
Recent advances in the fabrication of high-T
c
superconducting thick films demand processing techniques which can eliminate film/substrate interdifiusion that occurs during subsequent post-annealing heat treatment after the film is deposited, thereby limiting the application of the thick films for devices. The present study evaluates laser annealing techniques for plasma-deposited Y-Ba-Cu-O thick films using a high-energy CO2 laser (10.6m) in a continuous wave mode. The results are compared with those obtained by conventional furnace annealing techniques necessary for post-heat treatment of as-deposited superconducting thick films. The high-T
c
superconducting phase is recovered by cationic diffusion during subsequent post-annealing heat treatment. Crystallographic phases and microstructural characterization have been performed using XRD, SEM, and EPMA analytical techniques. The significance of the technology lies in the elimination of film/substrate interdiffusion problems, thereby resulting in high-quality superconducting thick films. The technology will significantly reduce the post-annealing times usually required by conventional furnace annealing techniques. 相似文献