Electrical conductivity in iodine-doped ethyl cellulose

The electrical conductivity of solution-grown ethyl cellulose (EC) films, 5–30 μm thick, has been studied in the sandwich configuration (metal–EC–metal) as a function of iodine concentration from 0.5 to 5.0 wt% ratio. The studies were conducted in the temperature range 333–383 K, while the field was varied over the range (3.0–5.5) × 10⁴V/cm. Aluminium was used as the lower electrode, while the upper electrode was of Al, Ag, Cu, Au or Sn. Certain transient effects such as a large burst of current immediately after the application of field were observed. An attempt was made to identify the nature of the current by comparing the observed dependence on electric field, electrode material and temperature with the respective characteristic features of the existing theories of electrical conduction. The results show that the electrical conduction follows Ohm's law at lower fields, while at higher fields, space-charge limited current (SCLC) was observed. It was also found that Richardson–Schottky emission was responsible, to some extent, for the transport of charge carriers in the polymer. The conductivity of the films increased on doping with iodine. The dopant molecules are considered to act as additional trapping centes and provide links between the polymer molecules in the amorphous region, thus resulting in the formation of charge transfer complexes.     

2021年混合云科技将如何发展?

很少有企业能预料到2020年出现的巨大变化.2020年出现的新冠肺炎疫情打乱了整个世界的节奏,迫使企业迅速调整其技术基础设施,让员工能远程开展工作的同时做好更长远的规划,以应对前所未有的不确定性.对很多企业而言,重新改造IT基础设施是其生存下去的关键.     

Leading One Detection Hyperbolic CORDIC with Enhanced Range of Convergence

This paper focuses on developing an area efficient hyperbolic Coordinate Rotation Digital Computer (CORDIC) algorithm with performance improvement. The algorithm eliminates the need of scale factor calculation in the Range of Convergence (ROC). At the same time the range of convergence offered is higher than the conventional CORDIC ROC in the hyperbolic rotation mode. Being the only kind of algorithm in hyperbolic rotation with sign sequence μ?=?1 always, one complete operation requires just 5 iterations. Thus the pipelined implementation has 5 stages which provides a 50% increase in throughput in comparison to conventional CORDIC. As far as the area improvement is considered, 16-bit processor can be realized using 56% less number of full adders required by Flat-CORDIC. The x and y datapath are based on series expansion of hyperbolic functions. The complete algorithm design along with pipelined architecture implementation is detailed.     

Yield-oriented computer-aided defect diagnosis

Any good yield-oriented defect strategy must have two main components-(a) the ability to perform rapid defect diagnosis for yield learning, and (b) the ability to efficiently extract defect parameters from the manufacturing line. In this work, an inductive fault analysis (IFA)-based defect methodology is investigated to see if it meets the above requirements. Using an SRAM test vehicle as an example, the research analyzes whether computer-generated mappings between defect types and tester fail data can provide sufficient resolution for both, defect diagnosis and defect parameter characterization     

Structural Stabilization and Piezoelectric Enhancement in Epitaxial (Ti1−xMgx)0.25Al0.75N(0001) Layers

Epitaxial (Ti_1?xMg_x)_0.25Al_0.75N(0001)/Al₂O₃(0001) layers are used as a model system to explore how Fermi‐level engineering facilitates structural stabilization of a host matrix despite the intentional introduction of local bonding instabilities that enhance the piezoelectric response. The destabilizing octahedral bonding preference of Ti dopants and the preferred 0.67 nitrogen‐to‐Mg ratio for Mg dopants deteriorate the wurtzite AlN matrix for both Ti‐rich (x < 0.2) and Mg‐rich (x ≥ 0.9) alloys. Conversely, x = 0.5 leads to a stability peak with a minimum in the lattice constant ratio c/a, which is caused by a Fermi‐level shift into the bandgap and a trend toward nondirectional ionic bonding, leading to a maximum in the expected piezoelectric stress constant e₃₃. The refractive index and the subgap absorption decrease with x, the optical bandgap increases, and the elastic constant along the hexagonal axis C₃₃ = 270 ± 14 GPa remains composition independent, leading to an expected piezoelectric constant d₃₃ = 6.4 pC N^?1 at x = 0.5, which is 50% larger than for the pure AlN matrix. Thus, contrary to the typical anticorrelation between stability and electromechanical coupling, the (Ti_1?xMg_x)_0.25Al_0.75N system exhibits simultaneous maxima in the structural stability and the piezoelectric response at x = 0.5.     

A 243-GHz F/sub t/ and 208-GHz F/sub max/, 90-nm SOI CMOS SoC technology with low-power mm-wave digital and RF circuit capability

A 90-nm silicon-on-insulator (SOI) CMOS system on-chip integrates high-performance FETs with 243-GHz F/sub t/, 208-GHz F/sub max/, 1.45-mS//spl mu/m gm, and sub 1.1-dB NFmin up to 26 GHz. Inductor Q of 20, VNCAP of 1.8-fF//spl mu/m/sup 2/, varactor with a tuning range as high as 25:1, and a low-loss microstrip. Transmission lines were successfully integrated without extra masks and processing steps. SOI and its low parasitic junction capacitance enables this high level of performance and will expand the use of CMOS for millimeter-wave applications.     

Combined computer-aided approach for the facilities design problem and estimation of the distribution parameter in the case of multigoal optimization

The multigoal facilities design problem, a case of quadratic assignment problem, deals with the problem of optimum assignment of n facilities to n locations, optimizing multigoal cost objectives. These objectives are classified into two categories, conflicting and congruent. Conflicting objectives aim at minimization of total flow cost and maximization of total closeness rating, whereas congruent objectives aim at maximization of distance weighted cost of several attributes, vis. flow, closeness rating, etc. The technique available for dealing with the congruent objective optimization does not consider the weightage to these attributes. The optimality of a suboptimal solution should also be checked at all levels of weightages in order to arrive at a correct solution, with the help of estimation of the distribution parameter, in the case of the multigoal facilities design problem.

This paper presents a combined computer-aided approach which determines the solution of the multigoal facilities design problem at different weightages to attributes, finds the parameter of distribution viz. mean, median, mode, standard deviation, checks the optimality of solution, plots the histogram and gives the nature of distribution.     

Climate Change Impact Assessment on Blue and Green Water by Coupling of Representative CMIP5 Climate Models with Physical Based Hydrological Model

Water Resources Management - Climatic changes have altered hydrological and climatic parameters worldwide, and climate projections suggest that such alterations will continue. In order to maintain...