High Efficiency White Organic Light‐Emitting Devices Incorporating Yellow Phosphorescent Platinum(II) Complex and Composite Blue Host

A new class of charge neutral, strongly luminescent cyclometalated platinum(II) complexes supported by dianionic tetradentate ligand are synthesized. One of these platinum(II) complexes, Y‐Pt , displays a high photoluminescence quantum yield of 86% and electroluminescence efficacy (η_power) of up to 52 lm W^?1, and is utilized as a yellow phosphorescent dopant in the fabrication of white organic light‐emitting devices (WOLEDs). WOLEDs based on conventional structures with yellow emission from Y‐Pt in combination with blue emission from bis(4,6‐difluorophenyl‐pyridinato‐N,C²′) (picolinate) iridium(III) (FIrpic) show a total η_power of up to 31 lm W^?1. A two‐fold increase in η_power by utilizing a modified WOLED structure comprising of a composite blue host is realized. With this modified device structure, the total η_power and driving voltage at a luminance of 1000 cd m^?2 can be improved to 61 lm W^?1 and 7.5 V (i.e., 10 V for control devices). The performance improvement is attributed to an effectively broaden exciton formation‐recombination zone and alleviation of localized exciton accumulation within the FIrpic‐doped composite host for reduced triplet‐triplet annihilation, yielding blue light‐emission with enhanced intensity. The modified device structure can also adopt a higher concentration of Y‐Pt towards its optimal value, leading to WOLEDs with high efficiency.     

Third-Person Effect and Internet Pornography: The Influence of Collectivism and Internet Self-Efficacy

Within the context of Internet pornography, a survey of both U.S. and South Korean college students ( N = 232) examined the influence of individualism-collectivism and media self-efficacy on the third-person effect. Two findings emerged: First, this study demonstrates the third-person effect of the Internet for the first time within Western culture. Participants perceived that Internet pornography's negative effect was greater on others than themselves, and this third-person perception predicted support for Internet censorship. Second, although prior research failed to support conjecture that culture shapes third-person perception, these data show culture as an important antecedent; collectivism diminished third-person perception and subsequent support for Internet pornography censorship. The impact of Internet self-efficacy was not substantial. The influence of collectivism on the third-person effect generally and public perceptions of Internet pornography in particular signals its import to scholars interested in social policy and social influence.     

Passive gyrotron cavity loading and frequency shift

Measurements of change in Q and frequency shift are presented for the penultimate cavity in a 3-cavity gyroklystron under conditions where the cavity does not oscillate. This allowed detailed comparisons to be made with linearized theory, over a wide range of beam currents and DC magnetic fields. The theory was formulated to take into account the effects of cut-off beam tunnels on the effective length of the cavity, the geometrical beam filling factor, the effect of a spread in beam pitch angle, and the effect of the cavity RF magnetic fields. Best fits between the data and the theoretical curves for change in Q and frequency shift were obtained for beam values in good agreement with those predicted from a modified Herrmannsfeldt code. Calculations of oscillation starting currents for TE₀₁, TE₀₁₁, TE₀₁₂, and TE rectangular₀₁₃ cavities as a function of the cavity detuning parameter show that serious errors can occur if one neglects the cavity RF magnetic fields.     

Uplink PID power control technique for TDMA‐based cellular radio systems

The efficient management of wireless resource is essential to the success of wireless systems. While power control is traditionally considered to be a means to counteract the detrimental effects of channel fading, it is also a flexible mechanism that achieves high link quality, high bandwidth utilization, and low power consumption, which are mainly driven in cellular radio systems. Once the power control algorithm provides a lower outage probability, the SUs experienced adequate link quality need not to competitively increase their transmission power. Spontaneously, the systems with lower power consumption and better bandwidth efficiency are achieved. In this paper, a novel power control based on the proportional‐integration‐derivative (PID) controller is proposed, and its performance with an autonomous closed‐loop uplink power control model under the time division multiple access (TDMA) systems is presented. Computer simulation is used to illustrate the performance of the proposed power control algorithm in a cellular radio system with Rayleigh fading channels. The results show that our proposed power control algorithm is remarkably superior to several previous power control methods, especially in a short power control period. Copyright © 2006 John Wiley & Sons, Ltd.     

Understanding the Third-Person Perception: Evidence From a Meta-Analysis

The third-person effect hypothesis has generated a vibrant research area. The expansion of this literature poses need for a systematic synthesis of the empirical evidence and assessment of the viability of various theoretical accounts. For this purpose, a meta-analysis is conducted on all published empirical studies of the perceptual component. This analysis covers 60 papers, 106 studies, and 372 effect sizes. Results from a series of multilevel models show that the third-person perception is robust and not influenced by variations in research procedures. Desirability of presumed message influence, vulnerability of referent others, referent others depicted as being similar to self, and others being likely audience of the media content in question are significant moderators. A vote counting analysis is conducted on 124 self–other comparisons in 29 studies from 13 additional papers that do not have the necessary statistical information. Further analyses are conducted to detect and estimate potential publication bias. Based on the empirical synthesis, the paper evaluates several explanatory factors and offers suggestions for future research.     

The Third-Person effect in perceptions of the influence of television violence

This study examines the third-person effect (the belief that others are more affected by media messages than oneself) for two different effects of televised violence, mean world perceptions and aggression, using attribution theory as an explanatory framework. In telephone interviews with a random sample of 253 community residents, third-person effects, as predicted, were observed for both aggression and mean world perceptions, but were larger for the more socially undesirable influence on aggression and for more distant others (in the U.S. rather than the local community). In addition, those who compared themselves favorably with others perceived a larger third-person effect for aggression. The study also explores the role of other factors in the third-person effect, including demographics and liking for and exposure to televised violence.     

Effect of etch holes on the capacitance and pull-in voltage in MEMS tunable capacitors

Microelectromechanical systems (MEMS) tunable capacitors, switches or actuators are widely applied in wireless communication systems. In the fabrication process etch holes are used to release the sacrificial layer with relatively large structures, which obviously affects the performance of devices. However, most researchers neglect this effect during their designing of the capacitors, switches or actuators. This article presents the theoretical calculation of the capacitance of tunable capacitors with etch holes, and analyses the deviation of the capacitance and pull-in voltage with different parameters such as the length of the plates w, the length of the etch holes w _h, the air gap between the two plates d, and the number of the etch holes. To validate the theory in this article, a tunable capacitor was fabricated by surface micromachined technology. The theoretical results compare well with the experimental results.     

Third-person effects on publication of a holocaust-denial advertisement

We examine the potential of third-person effects to influence editorial behavior. Two studies investigated college students' judgments about a controversial advertisement and its suitability for publication in their college newspaper. The advertisement in question, printed in many college newspapers in the early 1990s, claimed that the Nazi campaign against the Jews in the World War II was an exaggeration. Study 1 confirmed a correlation between students' third-person effect perceptions and opposition to publishing the advertisement. Jewish students produced larger third-person effects and were significantly less willing to print the advertisement. These results suggest that those with interests at stake perceived the message as especially likely to influence others, and thus dangerous. However, a closer inspection of the data, followed up experimentally in study 2, suggests that both third-person effects and publication decisions were primarily a function of variance in subjects' perceived impact of the message on themselves, not on others. We discuss the implications of these findings for future research.     

Invertibility of 2-D linear systems

The concept ofL-delay invertibility is extended for generalized 2-D linear systems. A method based on the left inverse of the transfer function matrix of the model and the realization theory for finding a whole class of generalized or regular inverse systems is presented. Necessary and sufficient conditions for the (d ₁,d ₂)-delay invertibility of the regular 2-D linear systems are established.     

Positive Column Plasma in a Neon Discharge at Medium Pressures†

The present paper concentrates on the experimental investigation of the behaviour of steady-state plasma columns in a neon discharge for a pressure range of 2-32 mm Hg. The electron temperature T _e, the electron concentration across the centre-line tube n _o, the electron radial distribution n(r), the axial electric field E and the ionic current density at the discharge tube walls are determined. The experimental results are compared to the theoretical data obtained in the model proposed by Kagan and Ljagushchenko (1964 a, b). For our experimental conditions a good agreement is obtained between theory and experiment.     

Placing and maintaining a core node in wirelessad hoc networks

Wireless ad hoc networks are characterized by several performance metrics, such as bandwidth, transport, delay, power, etc. These networks are examined by constructing a tree network. A core node is usually chosen to be the median or center of the multicast tree network with a tendency to minimize a performance metric, such as delay or transport. In this paper, we present a new efficient strategy for constructing and maintaining a core node in a multicast tree for wireless ad hoc networks undergoing dynamic changes, based on local information. The new core (centdian) function is defined by a convex combination signifying total transport and delay metrics. We provide two bounds of O(d) and O(d+l) time for maintaining the centdian using local updates, where l is the hop count between the new center and the new centdian, and d is the diameter of the tree network. We also show an O(n log n) time solution for finding the centdian in the Euclidian complete network. Finally, an extensive simulation for the construction algorithm and the maintenance algorithm is presented along with an interesting observation. Copyright © 2009 John Wiley & Sons, Ltd.     

Dissecting movie performance across multiple distribution channels: An elastic justification theory perspective

The recent emergence of multiple channels such as Internet protocol television (IPTV) and online video-on-demand (VOD) has transformed sequential movie distribution structures into simultaneous ones. We analyze the drivers of movie performance success in terms of box office, IPTV, and online VOD services amid these changed market conditions. We use elastic justification theory and consider diverse consumer risks to explain how movie consumers exhibit different behaviors for different movie channels when facing different degrees and types of risk. We classify the antecedents of movie selection into justifiable (risk-hedging) factors such as viewer rating, scenario familiarity, star power, and country of origin and unjustifiable (tempting and appealing) factors, including expert rating and genre. By considering various types and degrees of risk in each channel based on elastic justification theory, this study offers insights that should lead to more effective movie distribution across channels. This study is a first step toward paving the way for advanced movie distribution strategies for producers and distributors.     

Energy-Based Micromechanics Analysis on Fatigue Crack Propagation Behavior in Sn-Ag Eutectic Solder

Sn-Ag-eutectic-based solders are replacing Sn-Pb eutectic solders in the electronics industry. The current paper extends the recently developed approach based on phase transformation theory, micromechanics, and fracture mechanics to treat fatigue crack nucleation and propagation for steels and alloys to predict fatigue crack propagation in solder alloys. To verify the proposed method, fatigue experiments were conducted on Sn-3.5Ag solder alloys. Finite element analysis is performed to predict the stress intensity factor range ΔK and the required energy U to increase the crack by a unit area. Unified creep-plasticity theory and a cohesive zone model are incorporated to predict the creep and hysteresis effects on fatigue crack propagation in solder and the interfacial behavior between the solder alloy and the intermetallic layer, respectively. With U determined numerically, the predicted fatigue crack propagation rate using phase transformation theory is compared with experimental data for Sn-3.5Ag and Sn-37Pb eutectic solders. Reasonable agreement between theoretical predictions and experimental results is obtained.     

Problem Solving and Communicative Action: A Situational Theory of Problem Solving

This article introduces the situational theory of problem solving (theory of problem solving) as an extended and generalized version of the situational theory of publics (theory of publics). The theory of problem solving introduces a new concept, communicative action in problem solving, as its dependent variable. To explain communicative action, the theory of problem solving refines the independent variables of the theory of publics: problem recognition, constraint recognition, involvement recognition, and referent criterion. Finally, it introduces a new variable: situational motivation in problem solving. The new motivational variable mediates the effects of antecedent perceptual variables on communicative behavior. We report the supporting evidence for theoretical propositions of the new theory based on structural equation modeling (SEM) testing using survey data.     

A new internet of things group search optimizer

The development of the Internet of Things brings new opportunities and challenges for sensor networks. The scale of sensor networks tends to be larger. And the fusion rules need to be intelligent. In this paper, we propose a new Internet of Things group search optimizer (ITGSO) to solve intelligent information fusion problems in the high‐dimensional multi‐sensor networks. ITGSO is inspired by the latest research achievement about leader decision in Nature and works about social coordination, which mainly consists of three parts: basic group search optimizer, binary group search optimizer, and social decision model. With ITGSO, we need less time to obtain minimum Bayes cost than particle swarm optimization. And information of uncertain social intelligent problems can be fused. In this paper, we give the theoretical basic of ITGSO and proved its validity via mathematical analysis and simulation results. Copyright © 2014 John Wiley & Sons, Ltd.     

Theoretical study of the structural,elastic and thermodynamic properties of chalcopyrite ZnGeP2

The structural, elastic, and thermodynamic properties of ZnGeP₂ with chalcopyrite structure are investigated using the pseudo-potentials plane wave method based on the density functional theory with the generalized gradient approximation. The lattice parameters (a, c and u) are directly calculated and agree well with previous experimental and theoretical results. The obtained negative formation enthalpy shows that ZnGeP₂ crystal has strong structural stability. We have also calculated the bulk modulus B and the elastic parameters (C₁₁, C₁₂, C₁₃, C₃₃, C₄₄, and C₆₆) which have not been measured yet. The accuracy and reliability of the calculated elastic constants of ZnGeP₂ crystal are discussed. In addition, the pressure and temperature dependencies of the lattice parameters, bulk modulus, Debye temperature, Grüneisen parameter, entropy, volume thermal expansion coefficient, and specific heat capacity are obtained in the ranges of 0–20 GPa and 0–1200 K using the quasi-harmonic Debye model. To our knowledge this is the first quantitative theoretical prediction of the thermodynamic properties for ZnGeP₂ compound and still awaits experimental confirmations.     

Long-term structural relaxation and photoinduced degradation in a-Si: H

The effect of heating-illumination cycling on the electrical properties of a-Si: H fabricated in a glow discharge was investigated. Comparison of experimental and theoretical results shows that photostimulated degradation of a-Si: H (the Staebler-Wronski effect) may occur due to long-term degradation of structural defects generated by preliminary heating. Fiz. Tekh. Poluprovodn. 32, 1272–1276 (October 1998)     

Appearance of negative resistance in p-n junction structures in a microwave field

The results of theoretical and experimental investigations of the appearance of negative differential resistance in p-n junction diode structures in the presence of a high level of microwave power are presented. The theoretical analysis of the influence of a high level of microwave power on the form of the current-voltage characteristic of a diode takes into account the variation of the constant component of the current flowing through the p-n structure due to the heating of the free charge carriers and the rectifier effect. Fiz. Tekh. Poluprovodn. 32, 1399–1402 (November 1998)     

应变Si/(101)Si1-xGex的谷间声子散射机制

Inter valley scattering has a great impact on carrier mobility of strained Si materials,so based on Fermi’s golden rule and the theory of Boltzmann collision term approximation,inter valley phonon scattering mechanism of electrons in nano scale strained Si（101） materials is established under the influence of both energy and stress. It shows that inter valley phonon f₂,f₃,g₃ scattering rates decrease markedly in nano scale strained Si（101） materials with increasing stress.The quantized models can provide valuable references to the understanding of strained Si materials and the research on electron carrier mobility.     

Single Crystal Microwires of p‐DTS(FBTTh2)2 and Their Use in the Fabrication of Field‐Effect Transistors and Photodetectors

Single crystal microwires of a well‐studied organic semiconductor used in organic solar cells, namely p‐DTS(FBTTh₂)₂, are prepared via a self‐assembly method in solution. The high level of intermolecular organization in the single crystals facilitates migration of charges, relative to solution‐processed films, and provides insight into the intrinsic charge transport properties of p‐DTS(FBTTh₂)₂. Field‐effect transistors based on the microwires can achieve hole mobilities on the order of ≈1.8 cm² V^?1 s^?1. Furthermore, these microwires show photoresponsive electrical characteristics and can act as photoswitches, with switch ratios over 1000. These experimental results are interpreted using theoretical simulations using an atomistic density functional theory approach. Based on the lattice organization, intermolecular couplings and reorganization energies are calculated, and hole mobilities for comparison with experimental measurements are further estimated. These results demonstrate a unique example of the optoelectronic applications of p‐DTS(FBTTh₂)₂ microwires.