碳纳米管的制备及研究

介绍了在直流电弧放电法制备富勒烯过程中，从阴电极表面收集到大量的碳纳米管及巴基葱，产生率达到５０％，并用电子显微镜对其进行了观察和初步研究。     

Engineering practice and economic analysis of ozone oxidation wet denitrification technology

SO₂ and NO emitted from coal-fired power plants have caused serious air pollution in China. In this study, a test system for NO oxidation using O₃ is established. The basic characteristics of NO oxidation and products forms are studied. A separate test system for the combined removal of SO₂ and NO_x is also established, and the absorption characteristics of NO_x are studied. The characteristics of NO oxidation and NO_x absorption were verified in a 35 t·h^-1 industrial boiler wet combined desulfurization and denitrification project. The operating economy of ozone oxidation wet denitrification technology is analyzed. The results show that O₃ has a high rate and strong selectivity for NO oxidation. When O₃ is insufficient, the primary oxidation product is NO₂. When O₃ is present in excess, NO₂ continues to get oxidized to N₂O₅ or NO₃. The removal efficiency of NO₂ in alkaline absorption system is low (only about 15%). NO_x removal efficiency can be improved by oxidizing NO_x to N₂O₅ or NO₃ by increasing ozone ratio. When the molar ratio of O₃/NO is 1.77, the NO_x removal efficiency reaches 90.3%, while the operating cost of removing NO_x per kilogram is 6.06 USD (NO₂).     

Memristor crossbar-based unsupervised image learning

This letter presents a new memristor crossbar array system and demonstrates its applications in image learning. The controlled pulse and image overlay technique are introduced for the programming of memristor crossbars and promising a better performance for noise reduction. The time-slot technique is helpful for improving the processing speed of image. Simulink and numerical simulations have been employed to demonstrate the useful applications of the proposed circuit structure in image learning.     

Exponential Stability of Switched Time-varying Delayed Neural Networks with All Modes Being Unstable

This paper aims to design an appropriate switching law to stabilize the switched neural networks with time-varying delays when all subsystems are unstable. By using the discretized Lyapunov function approach and the extended comparison principle for impulsive systems, the stability of switched delayed neural networks composed full of unstable subsystems is analyzed and a computable sufficient condition is derived in the framework of dwell time. The effectiveness of the proposed results is illustrated by a numerical example.     

HCAA:一种哈希冲突过度的动态解决算法

HASH表作为一种快速查询的数据结构,在防火墙等网络安全应用中得到了广泛的应用。然而,攻击者可能通过一些手段对这些应用发动HASH攻击使其失去响应,从而使某些恶意的数据流能够逃脱网络安全应用的管理和控制。提出一种动态的哈希冲突过度的解决算法—HCAA(Hash Collision-Acceptable Algorithm)算法,该算法在哈希冲突过于集中时通过动态申请HASH表并使用不同哈希函数来对冲突数据流进行处理,使冲突在可接受的范围内。实验结果表明,与已有方法相比,HCAA算法能在使用更少HASH表项的情况下获得更均衡的HASH效果,从而能对数据流进行更快的HASH操作。     

Event‐Based Semiglobal Consensus of Homogenous Linear Multi‐Agent Systems Subject to Input Saturation

In this paper, we consider the semiglobal leader‐following consensus of general linear multi‐agent systems subject to input saturation. First, an event‐triggered control protocol is provided to ensure semiglobal consensus of the multi‐agent systems, in which the agents should continuously monitor the information of their neighbors. Second, a self‐triggered control protocol is proposed to guarantee the semiglobal consensus of the multi‐agent systems, in which the agents only have access to the information of their neighbors in discrete time instants. Moreover, both event‐triggered control protocol and self‐triggered control protocol are proved to be Zeno‐free, that is, the inter‐event times for such two protocols have positive lower bounds. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed event‐based semiglobal consensus protocols.     

Observer-based H∞ fuzzy control for discrete-time Takagi–Sugeno fuzzy mixed delay systems with random packet losses and multiplicative noises

This paper investigates the observer-based H_∞ fuzzy control problem for a class of discrete-time fuzzy mixed delay systems with random communication packet losses and multiplicative noises, where the mixed delays comprise both discrete time-varying and distributed delays. The random packet losses are described by a Bernoulli distributed white sequence that obeys a conditional probability distribution, and the multiplicative disturbances are in the form of a scalar Gaussian white noise with unit variance. In the presence of mixed delays, random packet losses and multiplicative noises, sufficient conditions for the existence of an observer-based fuzzy feedback controller are derived, such that the closed-loop control system is asymptotically mean-square stable and preserves a guaranteed H_∞ performance. Then a linear matrix inequality approach for designing such an observer-based H_∞ fuzzy controller is presented. Finally, a numerical example is provided to illustrate the effectiveness of the developed theoretical results.     

POLYMER DIODES MADE OF ION IMPLANTED POLYACETYLENE FILMS

Polyacetylene films were doped with FeCl3 and implanted with 30 k'eV K+ ions. Physical changes to the films were examined by a series of measurements, which include the four-probe test, infrared ray absorption and 2 MeV He+ particle elastic recoil dettection and Rutherford backscattering. The chemical dopants (Fe+++ and Cl-) were redistributed after the implantation and the different species (K+. Fe+++ and Cl-ions) formed p - n junctions at the implantation depths. The implanted films exhibited desirable Ⅰ-Ⅴ characteristics, with current densities as high as 600 mA/cm- at 3V and back - to - forward ratio of current over 300. The polymer diodes kept their behavior for over 60 days. Discussions on the results were given in detail.