Direct Femtosecond Laser Inscription of High-Order Bragg Gratings in Fluoroaluminate Glass Fiber

This letter reports the fabrication of fiber Bragg gratings (FBGs) within in-house fabricated fluoroaluminate (AlF3) glass fibers using femtosecond (fs) laser inscription at 800 nm. The grating strength of the FBGs was investigated for different pulse energies and different orders, and a 3rd-order FBG with Bragg wavelength at 1557 nm was found to have the highest reflectivity of 99.5%. In addition, the reflectivity of the mid-IR grating peaks for different orders was also studied, and a 2nd-order FBG with a reflectivity of 98.8% was obtained at 2864 nm. Finally, the temperature characteristics of a mid-IR FBG were studied between 30 °C and 150 °C, showing a linear wavelength dependence and an excellent stability for the refractive index modulation. Such highly reflectivity FBGs in AlF3 fiber have significant potential for applications in the development of compact all-fiber mid-IR fiber lasers

Experimental observation of topological Fermi arcs in type-II Weyl semimetal MoTe2

Weyl semimetal is a new quantum state of matter [1-12] hosting the condensed matter physics counterpart of relativisticWeyl fermion [13] originally introduced in high energy physics. The Weyl semimetal realized in the TaAs class features multiple Fermi arcs arising from topological surface states [10, 11, 14-16] and exhibits novel quantum phenomena, e.g., chiral anomaly induced negative mag-netoresistance [17-19] and possibly emergent supersymmetry [20]. Recently it was proposed theoretically that a new type (type-II) of Weyl fermion [21], which does not have counterpart in high energy physics due to the breaking of Lorentz invariance, can emerge as topologically-protected touching between electron and hole pockets. Here, we report direct spectroscopic evidence of topological Fermi arcs in the predicted type-II Weyl semimetal MoTe2 [22-24]. The topological surface states are confirmed by directly observing the surface states using bulk-and surface-sensitive angle-resolved photoemission spectroscopy (ARPES), and the quasi-particle interference (QPI) pattern between the two putative Fermi arcs in scanning tunneling microscopy (STM). Our work establishes MoTe2 as the first experimental realization of type-II Weyl semimetal, and opens up new opportunities for probing novel phenomena such as exotic magneto-transport [21] in type-II Weyl semimetals.Comment: submitted on 01/29/2016. Nature Physics, in press. Spectroscopic evidence of the Fermi arcs from two complementary surface sensitive probes - ARPES and STS. A comparison of the calculated band structure for T_d and 1T' phase to identify the topological Fermi arcs in the T_d phase is also included in the supplementary informatio

Limb development genes underlie variation in human fingerprint patterns

Fingerprints are of long-standing practical and cultural interest, but little is known about the mechanisms that underlie their variation. Using genome-wide scans in Han Chinese cohorts, we identified 18 loci associated with fingerprint type across the digits, including a genetic basis for the long-recognized “pattern-block” correlations among the middle three digits. In particular, we identified a variant near EVI1 that alters regulatory activity and established a role for EVI1 in dermatoglyph patterning in mice. Dynamic EVI1 expression during human development supports its role in shaping the limbs and digits, rather than influencing skin patterning directly. Trans-ethnic meta-analysis identified 43 fingerprint-associated loci, with nearby genes being strongly enriched for general limb development pathways. We also found that fingerprint patterns were genetically correlated with hand proportions. Taken together, these findings support the key role of limb development genes in influencing the outcome of fingerprint patterning

The Impact of Remanufactured Products’ Similarity on Purchase Intention of New Products

The remanufacturing industry can realize sustainability by saving resources and protecting the environment. The remanufactured products have a high similarity with the new products, and how they affect consumers’ evaluation of the new products is an important issue. This paper discusses the relationship between the similarity of remanufactured products and consumers’ willingness to purchase new products, with a mediating effect of perceived quality and a moderating effect of brand reputation. The empirical analysis based on 498 valid samples shows our conclusions below. First, the similarity of remanufactured products has a significant negative impact on the purchase intention of new products. Second, the perceived quality of new products plays a partial mediating role between similarity and purchase intention. Third, brand reputation negatively moderates the relationship between the similarity of remanufactured products and the perceived quality of new products. Furthermore, brand reputation also moderates the mediating effect of the similarity of remanufactured products on the purchase intention of new products through the perceived quality of new products. This paper suggests a new perspective for the research of remanufactured products and provides an important reference for the healthy and sustainable development of recycling and remanufacturing industry

Interactive Effects of Soil Water, Nutrients and Clonal Fragmentation on Root Growth of Xerophilic Plant Stipa breviflora

Root traits are often used to predict the ecological adaptations of plants. Water and nutrient availability together with fragment size are likely to affect the adaptative capacity of Stipa breviflora and help plants spread and explore new sites, while the effects of water, nutrients and fragment size on S. breviflora’s root traits have rarely been studied in combination. Here, a standard Taguchi L8(27) array design was conducted with four single factors, water (W), nitrogen (N), phosphorus (P) and fragment size (C), and three interactions (N × P, N × W and P × W). Each of the four factors had two levels (1 = low level and 2 = high level). This study found that water was the most important contributor influencing S. breviflora root growth, followed by N and P, respectively. W2 and P2 additions both promoted root growth, whereas N2 addition significantly inhibited root growth. Though C2 had higher values of total root length, surface area, volume, number of tips and biomass than C1, its root growth rate was lower than C1, and its small size fragment had a higher capacity of root growth under low N addition. These findings suggest that clonal fragmentation may enhance the adaptation of S. breviflora in low nitrogen habitats, and that nitrogen is one of the limiting factors influencing their growth and distribution

Interactive Effects of Soil Water, Nutrients and Clonal Fragmentation on Root Growth of Xerophilic Plant <i>Stipa breviflora</i>

Root traits are often used to predict the ecological adaptations of plants. Water and nutrient availability together with fragment size are likely to affect the adaptative capacity of Stipa breviflora and help plants spread and explore new sites, while the effects of water, nutrients and fragment size on S. breviflora’s root traits have rarely been studied in combination. Here, a standard Taguchi L8(27) array design was conducted with four single factors, water (W), nitrogen (N), phosphorus (P) and fragment size (C), and three interactions (N × P, N × W and P × W). Each of the four factors had two levels (1 = low level and 2 = high level). This study found that water was the most important contributor influencing S. breviflora root growth, followed by N and P, respectively. W2 and P2 additions both promoted root growth, whereas N2 addition significantly inhibited root growth. Though C2 had higher values of total root length, surface area, volume, number of tips and biomass than C1, its root growth rate was lower than C1, and its small size fragment had a higher capacity of root growth under low N addition. These findings suggest that clonal fragmentation may enhance the adaptation of S. breviflora in low nitrogen habitats, and that nitrogen is one of the limiting factors influencing their growth and distribution