Distributed Construction of Connected Dominating Set in Wireless Ad Hoc Networks

Connected dominating set (CDS) has been proposed as virtual backbone or spine of wireless ad hoc networks. Three distributed approximation algorithms have been proposed in the literature for minimum CDS. In this paper, we first reinvestigate their performances. None of these algorithms have constant approximation factors. Thus these algorithms cannot guarantee to generate a CDS of small size. Their message complexities can be as high as O(n ²), and their time complexities may also be as large as O(n ²) and O(n ³). We then present our own distributed algorithm that outperforms the existing algorithms. This algorithm has an approximation factor of at most 8, O(n) time complexity and O(nlogn) message complexity. By establishing the (nlogn) lower bound on the message complexity of any distributed algorithm for nontrivial CDS, our algorithm is thus message-optimal.     

Multiquark states

The pentaquark state recently discovered has been discussed based on various quark model calculations. Odd parity for the state cannot be ruled out theoretically because the contributions related to nontrivial color structures have not been studied completely. Other multiquark states, especially dibaryons, have been discussed also. A strangeness ?3 NΩ dibaryon has been shown to have a width as small as 12—22 keV and should be detectable in Ω-high-productivity reactions such as at RHIC, COMPAS, and the planned JHF and FAIR projects.     

Subpeaks in the Brillouin loss spectra of distributed fiber-optic sensors

Subpeaks in the Brillouin loss spectra of distributed fiber-optic sensors were observed for what is believed to be the first time and studied. We discovered that the Fourier spectrum of the pulsed signal and the off-resonance oscillation both contributed to subpeaks. The off-resonance oscillation at frequency /v - vB/ is the oscillation in the Brillouin time domain when beat frequency v of the two counterpropagating laser beams does not match local Brillouin frequency vB. This study is important in differentiating the subpeaks from actual strain-temperature peaks.     

Performance analysis of very-small-aperture lasers

The fabrication of very-small-aperture lasers is demonstrated, and their performance is analyzed. Because of strong optical feedback caused by a gold film on the front facet of the laser, its behavior changes: The threshold current decreases, the density of light inside the laser diode and the redshift effect of the spectra are enhanced, and the laser diode's lifetime is shorter than that of common laser diodes with large driving current.     

Developing novel activity-based fluorescent probes that target different classes of proteases

In this article, we report the design and synthesis of a group of novel activity-based probes that target different protease sub-classes based on their substrate specificities, rather than their enzymatic mechanisms. The feasibility of our approach has been demonstrated by using representative members of the different protease sub-classes.     

Characterization of the surface properties of xylan by FT-Raman spectroscopy and wicking technique

Using FT-Raman spectroscopy, column wicking technique and the equations of Washburn as well as van Oss et al., the surface properties of xylan, the main component in hemicelluloses, has been characterized and estimated. Raman spectrum showed that xylan has been structured by acetyl group and methyl-bonded glucurono group. Obtained results show that the surface free energy of xylan is higher in comparison with literature reported values for cellulose because the former has a larger Lifshitz–van der Waals component than the latter. However, xylan has been found to have very smaller polarity and orientation data than that of cellulose.     

Determination of mangiferin, jateorrhizine, palmatine, berberine, cinnamic acid, and cinnamaldehyde in the traditional Chinese medicinal preparation Zi-Shen pill by high-performance liquid chromatography

High-performance liquid chromatography is employed to determine the contents of six marker components such as mangiferin, jateorrhizine, palmatine, berberine, cinnamic acid, and cinnamaldehyde in the traditional Chinese medicinal preparation Zi-Shen pill. The separation is performed on a C(18) column by stepwise gradient elution with water (0.2%, v/v, triethylamine adjusted to pH 4 with phosphoric acid)-methanol-acetonitrile (0.01 min, 98:0:2; 20 min, 80:5:15; 30 min, 65:13:22; and 55 min, 65:13:22) as the mobile phase at a flow rate of 0.9 mL/min, with UV detection at 280 nm. Six regression equations show good linear relationships between the peak area of each marker and concentration. The recoveries of the markers listed are 95.5%, 98.3%, 96.8%, 99.5%, 101.7%, and 102.1%, respectively. The repeatability and reproducibility (relative standard deviation) of the method are less than 2.5% and 3.3%, respectively.     

A simplified approach for evaluation of the polarity parameters for polymer using the K coefficient of the Mark-Houwink-Sakurada equation

Since two solvent polarity parameters, e.g., the Et(30) defined by Reichardt and the pi* defined by Kamlet and Taft, respectively, plotted with the K coefficient of the Mark-Houwink-Sakurada equation, presented good linear fits, this paper suggests applying the extrapolating method in the same way as the Zisman plot to obtain similar polarity parameters for polymers. In order to verify those obtained polarity parameter values for various polymers, literature-reported polarity values determined using other techniques are referenced and indicate that this paper introduced a simplified approach that can be applied to evaluate the polarity parameters for polymers. In this paper, since we observe that various polymers are of interest to present absolutely different slope tendencies, e.g., positive and negative, it is also suggested that polarity properties of polymers may be reinterpreted.     

Preparation of microcapsules containing two-phase core materials

Urea-formaldehyde (UF) microcapsules containing two-phase core materials in which phthalocyanine blue BGS (beta-CuPc) particles were homodispersed in tetrachloroethylene (TCE) were prepared by in situ polymerization. The effects of the various process parameters, including the type of surface modifier, the viscosity of UF prepolymer, the type of water-soluble surfactant, and the concentration of oil-soluble surfactant in the capsule core on the dispersity of beta-CuPc particles in TCE and the properties of the capsule wall and the adsorption of beta-CuPc particles on the internal surface of capsule wall were experimentally investigated. It was shown that using octadecylamine (ODA) to modify beta-CuPc particles resulted in a significant increase of the dispersing extent (DE) and the electrophoresis velocity of the particles in TCE (about 4 and 20 times more than that of unmodified). In addition, the optimal reaction conditions of the synthesis UF prepolymer were obtained by the orthogonal test. On the other hand, as the oil/water interfacial tension of emulsion was big enough, the microcapsule formed. The concentration of Span-80 in TCE was no less than 0.062 mM; the adsorption of beta-CuPc particles on internal surface of wall were restrained. Finally, the microcapsules in which beta-CuPc particles possess reversible response to dc electric field were obtained.     

Effect of surface roughness on determination of bulk tissue optical parameters

Monte Carlo simulations have been conducted to investigate the effect of surface roughness on the inverse determination of bulk optical parameters. Results show that mus, mua, and g can be overestimated by an order of magnitude for thin slab tissue samples with a moderate index mismatch at the interfaces if typical surface roughness is neglected. Measurements of Intralipid samples between glass windows with smooth and rough surfaces have been carried out and agreement was found between the numerical and the experimental data. This study suggests that the surface roughness should be taken into account for both in vitro and in vivo determination of bulk tissue optical parameters.