Unifying Energetic Disorder from Charge Transport and Band Bending in Organic Semiconductors

Characterizing the density of states (DOS) width accurately is critical in understanding the charge‐transport properties of organic semiconducting materials as broader DOS distributions lead to an inferior transport. From a morphological standpoint, the relative densities of ordered and disordered regions are known to affect charge‐transport properties in films; however, a comparison between molecular structures showing quantifiable ordered and disordered regions at an atomic level and its impact on DOS widths and charge‐transport properties has yet to be made. In this work, for the first time, the DOS distribution widths of two model conjugated polymer systems are characterized using three different techniques. A quantitative correlation between energetic disorder from band‐bending measurements and charge transport is established, providing direct experimental evidence that charge‐carrier mobility in disordered materials is compromised due to the relaxation of carriers into the tail states of the DOS. Distinction and quantification of ordered and disordered regions of thin films at an atomic level is achieved using solid‐state NMR spectroscopy. An ability to compare solid‐state film morphologies of organic semiconducting polymers to energetic disorder, and in turn charge transport, can provide useful guidelines for applications of organic conjugated polymers in pertinent devices.     

Scientometrics of Indian organic chemistry research

Making use of scientometric techniques, the paper attempts to assess the performance of Indian organic chemistry research during the 70s and 80s. Identifies the significant work and its impact using mainstream connectivity, surrogate measures of quality and relative impact indicators. It is observed that the organic chemistry research performed in India during the later period (80s) has improved slightly as compared to the previous period (70s).     

Industrial research in India as viewed throughResearch & Industry

The paper examines the bibliometric characteristics of industrial research activity of India. The study reveals that public-funded R&D is the major contributor of research papers, inResearch & Industry while the contribution of in-house R&D centres is lacking. Among the two industrial sectors (Chemical and Engineering), much of the R&D activity, as reflected by published papers, has been in chemical and allied industries. However, there appears to be a significant change in emphasis during the decade studied, namely a decrease in R&D activity in engineering industries with a corresponding increase in miscellaneous industries. There is a significant increase in exploratory research. R&D and industry interface is found inadequate. Multiplicity of authorship is gradually increasing. Indian Industrial research is heavily dependent on foreign and non-patent literature.     

Reliability assessment of restructured power systems using reliability network equivalent and pseudo-sequential simulation techniques

This paper presents a technique to evaluate reliability of a restructured power system with a bilateral market. The proposed technique is based on the combination of the reliability network equivalent and pseudo-sequential simulation approaches. The reliability network equivalent techniques have been implemented in the Monte Carlo simulation procedure to reduce the computational burden of the analysis. Pseudo-sequential simulation has been used to increase the computational efficiency of the non-sequential simulation method and to model the chronological aspects of market trading and system operation. Multi-state Markov models for generation and transmission systems are proposed and implemented in the simulation. A new load shedding scheme is proposed during generation inadequacy and network congestion to minimize the load curtailment. The IEEE reliability test system (RTS) is used to illustrate the technique.     

Bibliometric study of world literature on patents

Some bibiliometric characteristics of the literature on patents have been studied. The period considered is 1900 to 1980. Data have been analysed into the types of publications, i.e.books, conference proceedings, reports, journals, etc. and grouped under four broad categories. Language-wise distribution of the publication data has been done to find out the pattern of distribution in different languages. Journal-wise distribution of articles has been studied to find out the pattern of authorship as well as the most prolific authors. The growth of the literature on patents was found exponential in nature. It follows Bradford's law, with the ‘core’ comprising nine journals containing 33% of the literature.     

Fabrication,characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate nanoparticles

Polyurethane (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and/or dielectric barium titanate nanoparticles fabricated by the surface-initiated-polymerization approach were investigated. The polymer matrix incorporated with different nanoparticles shows different presenting status surrounding the nanoparticles, i.e., chemical bonding, physical entanglement and bulk polymer chain. The nanoparticles have a different effect on the thermal stability of the polymer nanocomposites. By embedding different functional nanoparticles, unique physical properties were observed, such as enlarged coercivity and larger dielectric constant (real permittivity). The synergistic effect of the binary nanoparticle reinforced PU nanocomposite was explored. The addition of the iron oxide nanoparticles does have some effect on the permittivity. However, little difference was observed in the magnetic properties and permeability after the introduction of the dielectric barium titanate nanoparticle into Fe₂O₃/PU nanocomposites. The permeability and permittivity of γ-Fe₂O₃ and BaTiO₃ nanoparticle reinforced PU nanocomposites were investigated with frequencies ranging from 10 MHz to 1 GHz. The predicted microwave properties from Bruggeman’s equation were consistent with the measured data, except for the real permittivity of Fe₂O₃/BaTiO₃/PU. The volume average method (VAM) usually used for fiber-reinforced composites with reinforcements in the thickness direction was applied in this nanocomposite system. The predicted real permittivity by VAM was found to be in better agreement with the measured data than that predicted by Bruggeman’s equation.     

Bicom3工艺技术满足先进应用系统需求

第三代(3G)无线基站、自动测试与测量以及便携式计算设备等先进应用系统都需要高性能的模拟组件。各家公司都在利用先进的工艺技术以满足这种需求,比如最新推出的第三代完全介质隔离互补双极工艺BiCom3。 BiCom3是一种硅-锗(SiGe)工艺,是为极高速精密模拟集成电路开发的。这是以硅(Si)为基底,然后再添加锗(Ge)的一种工艺。用锗来掺杂基底大大提高了     

蜂窝基站中的模拟技术发展趋势

目前，移动计算与通信设备已很普遍，数字电子技术正是支持这一发展的驱动力，不过模拟电子技术发展也同样重要，二者缺一不可。