Broadband dual-polarized patch antennas fed by capacitively coupledfeed and slot-coupled feed

Designs of broadband dual-polarized patch antennas fed by promising feed structures of a capacitively coupled feed and a slot-coupled feed (antenna A), two capacitively coupled feeds of a 180° phase shift and a slot-coupled feed (antenna B), and two capacitively coupled feeds of a 180° phase shift and two slot-coupled feeds (antenna C) are proposed and experimentally studied. The first two feed designs are for the excitation of a single-element broadband patch antenna, while the last design is for a two-element broadband patch antenna. These proposed patch antennas have a thick air substrate, and the 10 dB return-loss impedance bandwidths obtained for the two polarizations are all greater than 13%. High isolation (<-30 dB for antenna A, <-32 dB for antenna B, <-35 dB for antenna C) between the two feeding ports for the entire impedance bandwidth of the proposed antennas can be obtained. Also, improved cross-polarization levels (>20 dB) in both E and H plane patterns for the two polarizations of antennas B and C are achieved     

InGaN/GaN MQW p–n junction photodetectors

InGaN/GaN multiquantum well (MQW) p–n junction photodetectors with semi-transparent Ni/Au electrodes were fabricated and characterized. It was found that the fabricated InGaN/GaN MQW p–n junction photodetectors exhibit a 20 V breakdown voltage and a 3.5 V forward 20 mA turn on voltage. It was also found that the photocurrent to dark current contrast ratio is higher than 10⁵ when a 0.4 V reverse bias was applied to the InGaN/GaN MQW p–n junction photodetectors. Furthermore, it was found that the maximum responsivity was 1.28 and 1.76 A/W with a 0.1 and 3 V applied reverse bias, respectively.     

Fabrication and properties of PLZT ceramics from spray-dried aqueous solution

PLZT ceramics with the composition of 9/62/38 (La/Zr/Ti) were fabricated from spraydried aqueous solution. Complete crystallization of the spray-dried powder is achieved after 1 hr calcination at 650‡ C as compared to 800‡ C, 1 hr for conventional mixedoxide method. Sintering environment plays an important role in the densification of PLZT ceramics. Densities of the atmosphere sintered samples are much higher than those of normal sintered ones. PLZT ceramics derived from spray-dried powders have properties comparable to those derived from sol-gel ones. The spray-dried method presents a less expensive and more effective approach in the synthesis of PLZT ceramics.     

Rheology of concentrated solutions of hyperbranched polyesters

The solution rheology of different generations of hyperbranched polyesters in N‐methyl‐2‐pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amidoamine) (PAMAM) dendrimers in ethylenediamine were compared with those of the hyperbranched polyesters in NMP. Both types of dendritic polymers have relative viscosities that are exponential functions of their molar fraction in solution. The slopes of these relative viscosity curves show a linear relationship with respect to the generation number. PAMAM dendrimers have the greater slopes for each generation, reflecting their relatively larger intrinsic viscosity values.     

Fullerene Derivatives Attenuate Bronchoconstriction Induced by Xanthine-Xanthine Oxidase

The intratracheal instillation of xanthine-xanthine oxidase caused a marked decrease in dynamic respiratory compliance, indicating airway constriction. The constriction was significantly attenuated by fullerenol-1, but not by other agents or receptor antagonists.     

Structural evolution of matrix phase for liquid phase sintered 93W-4.9Ni-2.1Fe

The structure of the matrix of a two phase heavy alloy, 93W-4.9Ni-2.1Fe (wt%), was characterized. The matrix phase was not the expected face centred cubic Ni-Fe-W solid solution with a large grain size reported in the literature. Instead, an amorphous phase containing fine grained crystals as well as intermetallic compounds having different compositions were found. The partition of tungsten from the matrix toward the tungsten phase resulted in formation of different phases in the matrix. Under furnace cooling, the matrix phase was composed of an amorphous phase for the matrix phase remote from the tungsten grain-matrix interfaces, and a strained FeNi intermetallic phase near the interfaces. For specimens solution treated at temperatures between 1000–1400 °C followed by water quenching, an intermetallic phase rich in tungsten, (Ni, Fe) W, evolved and surrounded the tungsten grains in clusters. The relative abundance of this intermetallic phase was highest for a solution treatment temperature of 1400 °C, indicating that the formation of this phase was a result of supersaturation of tungsten in the matrix phase and retarded partition of tungsten from the matrix phase to tungsten grains under a rapid cooling condition.     

A drag-link drive of mechanical presses for precision drawing

The augmented Lagrange multiplier method has been used to synthesize the dimensions of a drag-link drive of mechanical presses for precision drawing. The objective functions include the maximum normal force on the guide, mean mechanical advantage, variance of the drawing velocity, etc. The constraints include the working velocity for drawing, variance of the working velocity for precision drawing, time ratio, etc. Based on the concept of kinematic coefficients, a method is proposed to provide suitable initial guesses of the optimization. The drag-link drive thus synthesized has performance superior to an existing press for precision drawing.     

A new look at software piracy: Soft lifting primes an inauthentic sense of self,prompting further unethical behavior

Soft lifting refers to the process whereby a legally licensed software program is installed or copied in violation of its licensing agreement. Previous research on this pervasive kind of unethical computer use has mainly focused on the determinants of this unethical act, which are rooted in personal, economic, technological, cultural, socio-political, or legal domains. However, little is known about the symbolic power that soft lifting has on the sense of self. Based on recent advances in behavioral priming, we hypothesized that soft lifting can influence the signals one sends to oneself; more specifically, soft lifting may prime individuals to experience an inauthentic sense of self, which, in turn, prompts further unethical behavior. In Study 1, we showed that participants, primed with the memory of a recent soft lifting experience, cheated more than participants recalling a recent experience of purchasing authentic software or than control participants. Moreover, feelings of inauthenticity mediated the priming effect of soft lifting on dishonest behavior. In Study 2, participants primed with soft lifting showed a greater willingness to purchase a wide range of counterfeit products over authentic products. Besides those antecedents or correlates of soft lifting already identified in the literature, educators should pay more attention to the negative impact of soft lifting on the self-images of users, which may go beyond computer-related behaviors. Priming may provide a new direction for HCI researchers to examine the impact of computer-use-related factors on users' perceptions, motivations, and behaviors.