Self‐Healing Reduced Graphene Oxide Films by Supersonic Kinetic Spraying

The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide (r‐GO) suspension. The r‐GO flakes are used as received, which are pre‐annealed and pre‐hydrazine‐treated, and do not undergo any post‐treatment. A part of the considerable kinetic energy of the r‐GO flakes entrained by the supersonic jet is used in stretching the flakes upon impact with the substrate. The resulting “frozen elastic strains” heal the defects (topological defects, namely Stone‐Wales defect and C₂ vacancies) in the r‐GO flakes, which is reflected in the reduced ratio of the intensities of the D and G bands in the deposited film. The defects can also be regenerated by annealing.     

A Supermolecular Photosensitizer with Excellent Anticancer Performance in Photodynamic Therapy

A supermolecular photosensitizer with excellent anticancer behavior when used for photodynamic therapy (PDT) is fabricated by the incorporation of zinc phthalocyanines (ZnPc) into the gallery of a layered double hydroxide (LDH). The composite material possesses uniform particle size (hydrodynamic diameter ～120 nm), and the host–guest and guest–guest interactions result in a high dispersion of ZnPc in a monomeric state in the interlayer region of the LDH matrix, with high singlet oxygen production efficiency. In vitro tests performed with HepG2 cells reveal a satisfactory PDT effectiveness of the ZnPc(1.5%)/LDH composite photosensitizer: a cellular damage as high as 85.7% is achieved with a rather low dosage of ZnPc (10 μg/mL). An extraordinarily high specific efficacy is demonstrated (31.59 μg^?1 (J/cm²)^?1), which is over 185.5% enhancement compared with the previously reported photosensitizers under similar test conditions. Furthermore, an in vivo study of the ZnPc(1.5%)/LDH demonstrates excellent PDT performance with an ultra‐low dose (0.3 mg/kg) and a low optical fluence rate (54 J/cm²). In addition, the ZnPc/LDH photosensitizer displays high stability, good biocompatibility, and low cytotoxicity, which would guarantee its practical application. Therefore, this work provides a facile approach for design and fabrication of inorganic–organic supermolecular materials with greatly enhanced anticancer behavior.     

Spectral Efficiency Evaluation for MRC Diversity Schemes Over Generalized Rician Fading Channels

In this paper, closed-form expressions for the capacities per unit bandwidth for generalized Rician fading channels are derived for power and rate adaptation, constant transmit power, channel inversion with fixed rate, and truncated channel inversion adaptation policies. The closed-form solutions are derived for the single antenna reception (without diversity combining) and maximal-ratio combining (MRC) diversity cases. Truncated channel inversion adaptation policy is the best policy for the single antenna reception case, while the channel inversion with fixed rate policy is the best policy for the MRC diversity case. Constant transmit power policy provides the lowest spectral efficiency as compared to the other policies with and without diversity.     

Polynomial-Based Interpolation Filters—Part I: Filter Synthesis

This paper introduces a generalized design method for polynomial-based interpolation filters. These filters can be implemented by using a modified Farrow structure, where the fixed finite impulse response (FIR) sub-filters possess either symmetrical or anti-symmetrical impulse responses. In the proposed approach, the piecewise polynomial impulse response of the interpolation filter is optimized directly in the frequency domain using either the minimax or least mean square criterion subject to the given time domain constraints. The length of the impulse response and the degree of the approximating polynomial in polynomial intervals can be arbitrarily selected. The optimization in the frequency domain makes the proposed design scheme more suitable for various digital signal processing applications and enables one to synthesize interpolation filters for arbitrary desired and weighting functions. Most importantly, the interpolation filters can be optimized in a manner similar to that of conventional linear-phase FIR filters.     

WLAN-GPRS Tight Coupling Based Interworking Architecture with Vertical Handoff Support

There have been parallel technological developments in wireless local network (WLAN) and cellular wide area network (WAN) technologies. This is evidenced by the boom in fast WLANs enabled devices, the spread of 2.5 G networks and the increasing emergence 3 G communication networks, applications and terminals. The prospects of integrating WLAN and cellular WAN technologies with support for seamless handoffs between the two heterogeneous have changed the mentality of researchers from considering WLAN technology as a threat to the future of wide area cellular networks to accepting the technology as a complementary solution. A number of architectures for interworking the two different network types have been proposed mainly based on the loose coupling interworking approach recommended by the ETSI. One of the main weaknesses anticipated with loose coupling architecture is excessive handoff latency, which may lead to data loss, traffic congestion and handoff failure. In this paper an architecture for interworking WLAN and the GPRS networks, based on the ETSI tight coupling approach, is proposed. Fredson Alfred Phiri holds a Master of Engineering Science (MEngSc) degree obtained from Multimedia University, Malaysia in 2005 and a Bachelor of Science degree in Electrical Engineering from the University of Malawi where he graduated in 2001. Mr. Phiri is currently working as a lecturer at the Polytechnic of Namibia (Namibia’s University of Science and Technology) where he also chairs the Electronics and Telecommunications (E-TEL) Research Group. He has previously worked as a lecturer at the University of Malawi, as a Telecommunications Engineer at Technocentre (Malawi), and as a Telecommunication Technician at the Malawi Telecommunications Limited (MTL). Mr. Phiri’s research interests include Integration of Mobile Data Networks, Network Programming and Powerline Communication. M.B.R. Murthy has obtained his B.E. (Electrical) from Andhra University, College of Engineering, Waltair, India, M.Sc (Engg) in Communication Systems from Regional Engineering College-Rourkela, India and PhD from Karnatak University, Dharwad, India. He has over 32 years of academic experience teaching under graduates and graduate students. He has vast research experience and has 43 publications in reputed journals and international conferences. He is a senior member at IEEE. He had six years of teaching and research experience at Multi Media University Malaysia. Currently he is Professor ECE and Dean PG engineering and R&D in GEC Gudlavalleru, India.     

EACLE : Energy-Aware Clustering Scheme with Transmission Power Control for Sensor Networks

In this paper, we propose a new energy efficient clustering scheme with transmission power control named “EACLE” (Energy-Aware CLustering scheme with transmission power control for sEnsor networks) for wireless sensor networks, which are composed of the following three components; “EACLE clustering” is a distributed clustering method by means of transmission power control, “EACLE routing” builds a tree rooted at a sink node and sets the paths from sensor nodes taking energy saving into consideration, and “EACLE transmission timing control” changes the transmission timing with different levels of transmission power to avoid packet collisions and facilitates packet binding. With an indoor wireless channel model which we obtained from channel measurement campaigns in rooms and corridors and an energy consumption model which we obtained from a measurement of a chipset, we performed computer simulations to investigate the performance of EACLE in a realistic environment. Our simulation results indicate that EACLE outperforms a conventional scheme such as EAD (Energy-Aware Data-centric routing) in terms of communication success rate and energy consumption. Furthermore, we fully discuss the impact of transmission power and timing control on the performance of EACLE.     

Modified SMC method of blind multiuser detection for DS-CDMA systems over fading channels

This paper presents the application of sequential Monte Carlo (SMC) methodology for blind detection in wireless direct sequence code division multiple access (DS-CDMA) systems over fading channels. It is known that the conventional SMC method requires a high-computational complexity that grows exponentially with the number of active users. This paper proposes a solution to this problem by employing Cholesky factorization to decompose the observed data into separate components for each user and then the parameters of each user are estimated with the SMC inference method under the decision feedback framework. Based on these concepts, an efficient blind decision feedback SMC (DF-SMC) receiver is developed for differentially encoded DS-CDMA systems. Simulation results demonstrate the promising performance of the proposed receiver for both flat fading and frequency-selective fading channels.     

LightSheer半导体激光脱毛的疗效评价

目的:评价LightSheer半导体激光脱毛的治疗效果。方法:运用LightSheer半导体激光脱毛系统,对97名患者共113个部位进行脱毛治疗,波长800nm,能量密度24-40J/cm2,脉冲宽度30ms,分别对治疗一次、二次及三次后的有效性进行分级评价。结果:97名患者共113个部位一次治疗后均出现毛发再生减少、再生延迟,再生毛发细小、浅淡。随着治疗次数的增加有效性分级提高。二次治疗后,60%以上可达到3级(毛发减少40-59%);三次治疗后,80%以上可达到3级。腋窝和唇毛部位约50%可达到4级(毛发减少60-79%)。结论:LightSheer半导体激光脱毛系统对亚洲人是安全和有效的,80%的患者经三次治疗后毛发可减少近60%,但要达到更好的疗效需更多次治疗。     

光子晶体光纤中群速度失配对脉冲俘获的影响

基于耦合非线性薛定谔方程,研究了超短脉冲在光子晶体光纤中传输时的俘获特性,得到了群速度失配的大小对脉冲俘获率的影响规律.研究表明,随着群速度失配量值的减小,俘获率将逐渐增大,群速度失配量值在10-6～10-7(fs/nm)数量级之间时,俘获率变化较快,但当群速度失配的大小减小到10-8(fs/nm)数量级后,俘获率变化缓慢,并趋近于最大俘获率值.     

断言技术在SOC验证中的应用

主要阐述了基于断言技术新硬件验证平台用于实时监测设计描述是否违反了设计目标,提出了OVA的特点及应用,并以LCD controller的sharp接口时序为实例讲解了该方法的优点。