Anomalous thermoelectric effects of ZrTe5_{5} in and beyond the quantum limit

Thermoelectric effects are more sensitive and promising probes to topological properties of emergent materials, but much less addressed compared to other physical properties. Zirconium pentatelluride (ZrTe$_{5}$) has inspired active investigations recently because of its multiple topological nature. We study the thermoelectric effects of ZrTe$_{5}$ in a magnetic field and find several anomalous behaviors. The Nernst response has a steplike profile near zero field when the charge carriers are electrons only, suggesting the anomalous Nernst effect arising from a nontrivial profile of Berry curvature. Both the thermopower and Nernst signal exhibit exotic peaks in the strong-field quantum limit. At higher magnetic fields, the Nernst signal has a sign reversal at a critical field where the thermopower approaches to zero. We propose that these anomalous behaviors can be attributed to the Landau index inversion, which is resulted from the competition of the $\sqrt{B}$ dependence of the Dirac-type Landau bands and linear-$B$ dependence of the Zeeman energy ($B$ is the magnetic field). Our understanding to the anomalous thermoelectric properties in ZrTe$_{5}$ opens a new avenue for exploring Dirac physics in topological materials.Comment: 6 pages, 4 figure

Requirement-oriented core technological components’ identification based on SAO analysis

© 2017, Akadémiai Kiadó, Budapest, Hungary. Technologies play an important role in the survival and development of enterprises. Understanding and monitoring the core technological components (e.g., technology process, operation method, function) of a technology is an important issue for researchers to develop R&D policy and manage product competitiveness. However, it is difficult to identify core technological components from a mass of terms, and we may experience some difficulties with describing complete technical details and understanding the terms-based results. This paper proposes a Subject-Action-Object (SAO)-based method, in which (1) a syntax-based approach is constructed to extract the SAO structures describing the function, relationship and operation in specified topics; (2) a systematic method is built to extract and screen technological components from SAOs; and (3) we propose a “relevance indicator” to calculate the relevance of the technological components to requirements, and finally identify core technological components based on this indicator. Based on the considerations for requirements and novelty, the core technological components identified have great market potential and can be useful in monitoring and forecasting new technologies. An empirical study of graphene is performed to demonstrate the proposed method. The resulting knowledge may hold interest for R&D management and corporate technology strategies in practice

Spectral properties, generation order parameters and luminosities for spin-powered X-ray pulsars

We show the spectral properties of 15 spin-powered X-ray pulsars, and the correlation between the average power-law photon index and spin-down rate. Generation order parameters (GOPs) based on polar-cap models are introduced to characterize the X-ray pulsars. We calculate three definitions of generation order parameters due to the different effects of magnetic and electric fields on photon absorption during cascade processes, and study the relations between the GOPs and spectral properties of X-ray pulsars. There exists a possible correlation between the photon index and GOP in our pulsar sample. Furthermore, we present a method due to the concept of GOPs to estimate the non-thermal X-ray luminosity for spin-powered pulsars. Then X-ray luminosity is calculated in the context of our polar-cap accelerator model which is well consistent with the most observed X-ray pulsar data. The ratio between X-ray luminosity estimated by our method and the pulsar's spin-down power is well consistent with the $L_{\rm X}\sim 10^{-3}L_{\rm sd}$ feature.Comment: 20 pages, 8 figures, 1 table, revised version for the publication in Ap

Effects of a short-term feed restriction on growth performance, blood metabolites and hepatic IGF-1 levels in growing rabbits

[EN] A total of 144 weaned hybrid HYLA rabbits (40-day-old) were randomly divided into 4 groups, to investigate the effects of the intensity of one week’s feed restriction on short- and medium-term growth performance, blood metabolites and hepatic IGF-1 in growing rabbits. Restricted groups were fed with 30% (Group L30), 50% (Group L50) 70% (Group L70) of ad libitum feeding for 1 wk and then fed ad libitum until the end of the experiment (75 d of age). The control group (Group AL) was fed ad libitum throughout the experiment. Total feed intake (–15.8%) and feed conversion ratio (–13.2%) were lower in the L50 than in the AL group (P0.05) for these parameters. Total weight gain did not significantly differ among the 4 experimental groups (38.5 g/d; P>0.05). At the end of the feed restriction period, the total serum protein level (P=0.01) was higher in restricted rabbits than AL rabbits (P0.05) throughout the experiment. In conclusion, a short-term feed restriction improves feed conversion ratio in a lasting way, transiently alters serum protein and IFG-1 levels and leads to compensatory growth in growing rabbits.This work was supported by the Special Public Welfare Industry (Agriculture) Research Program of China (Grant No. 201303144) and the Fundamental Research Funds for the Central Universities (Grant No. XDJK2013C096).Lu, J.; Shen, Y.; He, Z.; Dai, X.; Wang, D.; Zhang, J.; Li, H. (2017). Effects of a short-term feed restriction on growth performance, blood metabolites and hepatic IGF-1 levels in growing rabbits. World Rabbit Science. 25(3):233-239. https://doi.org/10.4995/wrs.2017.6478SWORD233239253Bruss, M. L. (1997). Lipids and Ketones. Clinical Biochemistry of Domestic Animals, 83-115. doi:10.1016/b978-012396305-5/50005-1Cabaraux J.F., Kerrour M., van Eenaeme C., Dufrasne I., Istasse L., Hornick J.L. 2003. Different modes of food restriction and compensatory growth in double-muscled Belgian Blue bulls: plasma metabolites and hormones. Anim. Sci., 77: 205-214.Oliveira, M. C. de, Silva, R. P. da, Araújo, L. S., Silva, V. R. da, Bento, E. A., & Silva, D. M. da. (2012). Effect of feed restriction on performance of growing rabbits. Revista Brasileira de Zootecnia, 41(6), 1463-1467. doi:10.1590/s1516-35982012000600021Di Meo C., Bovera F., Marono S., Vella N., Nizza A. 2007. Effect of feed restriction on performance and feed digestibility in rabbits. Ital. J. Anim. Sci., 6: 765-767.Ebeid T., Tůmová E., Volek Z. 2012. Effects of a one week intensive feed restriction in the growing rabbit: Part 1 – Performance and blood biochemical parameters. In: Proceedings 10th World Rabbit Congress, September 3-6, Sharm El-Sheikh, Egypt, 607-611.Gidenne T., Murr S., Travel A., Corrent E., Foubert C., Bebin K., Mevel L., Rebours G., Renouf B. 2009c. Effets du niveau de rationnement et du mode de distribution de l'aliment sur les performances et les troubles digestifs post-sevrage du lapereau. Premiers résultats d'une étude concertée du réseau GEC. Cuniculture Magazine. 36:65-72.Guyton A.C., Hall J.E. 2006. In: Textbook of Medical Physiology. 11th Edition. Philadelphia, Pa: Elsevier Saunders, 918-930.Kronfeld, D. S., Donoghue, S., Copp, R. L., Stearns, F. M., & Engle, R. H. (1982). Nutritional Status of Dairy Cows Indicated by Analysis of Blood. Journal of Dairy Science, 65(10), 1925-1933. doi:10.3168/jds.s0022-0302(82)82440-5Licois D. 2004. Domestic rabbit enteropathies. In: Proceedings 8th World Rabbit Congress, September 7-10. Puebla, Mexico, 385-403. Rajman M., Jurani M., Lamosova D., Macajova M., Sedlackov

Dynamics of Fluctuations of Localized Waves

We follow the temporal evolution of mesoscopic intensity fluctuations and correlation in strongly localized samples. We find an initial burst in relative transmission fluctuations in random one dimensional (1D) samples due to fluctuations in the arrival time of ballistic transmission. Relative fluctuations subsequently rise, then drop to a minimum at a time t_m, after which they increase rapidly in 1D simulations and quasi-1D (Q1D) measurements. For t > 3t_m, results in 1D and Q1D samples converge towards predictions of a dynamic single parameter scaling model. These results reflect the changing number of modes participating appreciably in transmission as the impact of longer lived modes grows with time delay

Control effect analysis for arch auxiliary system on long term deflection of long span prestressed concrete continuous beam bridge

In order to explore the control effect of arch assisted system on long-term deflection of long-span PC continuous girder bridge, an evaluation framework of long-term deflection control effect is proposed. Firstly, the functional relationship between long-term deflection and structural parameters is fitted based on the measured data, and the deflection prediction model is established; Secondly, based on the calculation method of bending stiffness of inversion theory, the evaluation framework of long-term deflection control effect based on the analogy stiffness method is proposed; Finally, based on the engineering example, under the premise of equal load sharing ratio, the above frame is applied to carry out parameter analysis. The results show that the deflection prediction model based on the measured data has good correlation, and the established evaluation framework can quantitatively evaluate the control effect of arch auxiliary system on long-term deflection

Dimensional crossover and anomalous magnetoresistivity in single crystals NaxCoO2Na_xCoO_2

The in-plane ($\rho_{ab}$) and c-axis ($\rho_c$) resistivities, and the magnetoresistivity of single crystals $Na_xCoO_2$ with x = 0.7, 0.5 and 0.3 were studied systematically. $\rho_{ab}(T)$ shows similar temperature dependence between $Na_{0.3}CoO_2$ and $Na_{0.7}CoO_2$, while $\rho_c(T)$ is quite different. A dimensional crossover from two to three occurs with decreasing Na concentration from 0.7 to 0.3. The angular dependence of in-plane magnetoresistivity for 0.5 sample shows a \emph{"d-wave-like"} symmetry at 2K, while the \emph{"p-wave-like"} symmetry at 20 K. These results give an evidence for existence of a \emph{spin ordering orientation} below 20 K turned by external field, like the stripes in cuprates.Comment: 4 pages, 3 figure