Electronic energy and electron transfer processes in photoexcited donor–acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units

Lee, K. J.,Woo, J. H.,Kim, E.,Xiao, Y.,Su, X.,Mazur, L. M.,Attias, A.-J.,Fages, F.,Cregut, O.,Barsella, A.,Mathevet, F.,Mager, L.,Wu, J. W.,D'Alé,o, A.,Ribierre, J.-C. The Royal Society of Chemistry 2016 Physical chemistry chemical physics Vol.18 No.11

<P>We investigate the photophysical properties of organic donor-acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units linked by a non-conjugated flexible bridge in solution using complementary optical spectroscopy techniques. When these molecules are diluted in dichloromethane solution, energy transfer from the triphenylene to the perylene diimide excited moieties is evidenced by time-resolved fluorescence measurements resulting in a quenching of the emission from the triphenylene moieties. Simultaneously, another quenching process that affects the emission from both donor and acceptor units is observed. Solution ultrafast transient absorption measurements provide evidence of photo-induced charge transfer from either the donor or the acceptor depending upon the excitation. Overall, the analysis of the detailed time-resolved spectroscopic measurements carried out in the dyad and triad systems as well as in the triphenylene and perylene diimide units alone provides useful information both to better understand the relations between energy and charge transfer processes with molecular structures, and for the design of future functional dyad and triad architectures based on donor and acceptor moieties for organic optoelectronic applications.</P>

Quantitative Trait Loci Mapping for Porcine Backfat Thickness

Wu, X.L.,Lee, C.,Jiang, J.,Peng, Y.L.,Yan, H.F.,Yang, S.L.,Xiao, B.N.,Liu, X.C.,Shi, Q.S. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.7

A partial genome scan using porcine microsatellites was carried out to detect quantitative trait loci (QTL) for backfat thickness (BFT) in a pig reference population. This population carried QTL on chromosomes 1, 13 and 18. The QTL on chromosome 1 was located between marker loci S0113 and SW1301. The QTL corresponded to very low density lipoprotein receptor gene (VLDLR) in location and in biological effects, suggesting that VLDLR might be a candidate gene. The QTL found on chromosome 13 was found between marker loci SWR1941 and SW864, but significance for the marker-trait association was inconsistent by using data with different generations. The QTL on chromosome 18 was discovered between markers S0062 and S0117, and it was in proximity of the regions where IGFBP3 and GHRHR were located. The porcine obese gene might be also a candidate gene for the QTL on chromosome 18. In order to understand genetic architecture of BFT better, fine mapping and positional comparative candidate gene analyses are necessary.

Structure and Magnetic Properties of Cr₂O₃/CrO₂ Nanoparticles Prepared by Reactive Laser Ablation and Oxidation under High Pressure of Oxygen

P. Z. Si,X. L. Wang,X. F. Xiao,H. J. Chen,X. Y. Liu,L. Jiang,J. J. Liu,Z. W. Jiao,H. L. Ge 한국자기학회 2015 Journal of Magnetics Vol.20 No.3

Cr₂O₃ nanoparticles were prepared via one-step reactive laser ablation of Cr in oxygen. The metastable CrO₂ phase was obtained through the subsequent oxidation of Cr₂O₃ nanoparticles under O₂ with gas pressures of up to 40 MPa. The as-prepared Cr₂O₃ nanoparticles are spherical or rectangular in shape with sizes ranging from 20 nm to 50 nm. High oxygen pressure annealing is effective in producing meta-stable CrO₂ from as-dried Cr₂O₃ nanoparticles, and the Cr₂O₃ nanoparticles exhibit a weak ferromagnetic behavior with an exchange bias of up to 11 mT that can be ascribed to the interfacial exchange coupling between uncompensated surface spins and the antiferromagnetic core. The Cr₂O₃/CrO₂ nanoparticles exhibit an enhanced saturation magnetization and a reduced exchange bias with an increasing faction of CrO₂ due to the elimination of uncompensated surface spins over the Cr₂O₃ nanoparticles when exposed to a high pressure of O₂ and/or possible phase segregation that results in a smaller grain size for both Cr₂O₃ and CrO₂.

Cytokine mRNA Expression in the Small Intestine of Weanling Pigs Fed Diets Supplemented with Specialized Protein or Peptide Sources

Zhao, J.,Harper, A.F.,Webb, K.E. Jr.,Kuehn, L.A.,Gilbert, E.,Xiao, X.,Wong, E.A. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.12

Cytokines play a central role in the mucosal immune response and are involved in regulation of nutrient absorption, metabolism and animal growth. This study investigated the effect of diet manipulation with specialized protein or peptide sources on expression of cytokine (IL-1, IL-6, IL-10, and TNF-${\alpha}$) mRNA abundance in different intestinal regions and at different ages post-weaning in piglets. A total of 48 (17 days of age, $6.16{\pm}0.34kg\;BW$) weanling pigs were fed either a corn-soy/whey protein basal diet, the basal diet supplemented with spray-dried plasma protein (SDPP), or the basal diet supplemented with $Peptiva^{(R)}$, a hydrolyzed marine plant protein. A fourth treatment group was fed the SDPP diet, but the feed intake level was limited (SDPP-LF). Pigs were killed at 3 and 10 d, and intestinal cytokine mRNA was measured by real-time PCR using the relative quantification method. The SDPP-LF group exhibited an increased TNF-${\alpha}$ mRNA abundance compared with the ad libitum SDPP group (p<0.05). The TNF-${\alpha}$ and IL-10 mRNA abundance increased from the proximal to distal part of the intestine, and the mRNA abundance was greater (p<0.01) in the distal intestine as compared with the proximal and middle intestine. The cytokines IL-1-${\beta}$, IL-10 and TNF-${\alpha}$ mRNA abundance also increased from d3 to d10 postweaning (p<0.01). In summary, restricted feeding increased the TNF-${\alpha}$ mRNA abundance in the small intestine, however neither SDPP nor peptide supplementation affected cytokine mRNA expression. Abundance of mRNA for most cytokines examined in this study increased with age post-weaning, suggesting that during 10 d after weaning the mucosal immune system is still under development.

Buckling of axially graded columns with varying power-law gradients

X.-F. Li,L. Lu,Y. Huang,B.J. Xiao 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.4

This paper studies the static stability of an axially graded column with the power-law gradient varying along the axial direction. For a nonhomogeneous column with one end linked to a rotational spring and loaded by a compressive force, respectively, an Euler problem is analyzed by solving a boundary value problem of an ordinary differential equation with varying coefficients. Buckling loads through the characteristic equation with the aid of the Bessel functions are exactly given. An alternative way to approximately determine buckling loads through the integral equation method is also presented. By comparing approximate buckling loads with the exact ones, the approximate solution is simple in form and enough accurate for varying power-law gradients. The influences of the gradient index and the rotational spring stiffness on the critical forces are elucidated. The critical force and mode shapes at buckling are presented in graph. The critical force given here may be used as a benchmark to check the accuracy and effectiveness of numerical solutions. The approximate solution provides a feasible approach to calculating the buckling loads and to assessing the loss of stability of columns in engineering.

A New On-Line Parameters Identification Method for IPMSMs Using Current Derivative Measurement

M.X. Bui,D. Xiao,M.F. Rahman 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The d- and q- axis inductances of an IPMSM, especially Lq, vary with magnitude of the current of each axis due to the magnetic saturation. The existing on-line methods using recursive algorithms fail to estimate the change of the machine inductances during zero speed and fast transient operations. This paper proposes a new on-line method to estimate machine inductances using measurements of current derivatives and the DC-bus voltage of the inverter during each PWM cycle. In addition, the stator resistance and permanent magnet flux linkage, which vary with the operating temperature, are identified by using the recursive least square (RLS) technique. Extensive simulation and experimental studies were conducted to verify the robustness and effectiveness of the proposed on-line parameter identification method which estimates all four electrical parameters of the IPMSM.

Experimental Investigation on the Characteristics of a Solar Cell under Different Illumination Intensities and Shading Areas

W. B. Xiao,F. Y. Hu,X. D. He,H. M. Zhang,H. M. Wu 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.11

The characteristics of a solar cell, the short-circuit current (Isc), the open-circuit voltage (Voc), the maximum power point (Vm, Im), the fill factor (FF) and the photoelectric conversion efficiency () under different illumination intensities and shading areas have been experimentally investigated. The work factor ! is given by ! = (1 − A/A0) × S/S0, where A0 is the total solar cell area, A the shading area, S0 the benchmark reference irradiation level, and S the new level of the irradiation, is introduced to take the light intensity and shading area into account. The results show that Isc and Im increase on an approximately linear increasing way with !, but Voc and Vm approach the saturation levels. The reason is that the current is a linear function of !, and the relationship of the voltage to ! is logarithmic. We also found Isc (Vm) to depend more on ! than Im (Voc). In addition, we observed that tended to increase linearly with !, but FF tended to converge to saturation. The reason for the behavior of is the reduction in the contact resistance and in the electron-hole recombination with increasing !. However, FF is mainly determined by Voc. The improvement in the solar cell performance with increasing ! results from an increase in the current, but not in the voltage or the fill factor.