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Calcium pyroniobate (Ca2Nb2O7) as a kind of lead‐free piezoelectric material has been applied for different fields, but the study of isothermal and non‐isothermal growth behaviors of Ca2Nb2O7 in the molten slag is infrequent. In this paper, the in situ thermal analyzer with a single hot thermocouple technique (SHTT) is used to study the growth behaviors of Ca2Nb2O7 in molten slag. In the isothermal temperatures, the Ca2Nb2O7 presents two kinds of growth morphology, including three dimensional (3D) rhombus growth and fibrous one dimensional (1D) growth. The 3D rhombus is grown under the range of 1608 to 1628 K. When the temperature further decreases to 1593 K, the growth behavior of Ca2Nb2O7 becomes fibrous in 1D. Growth velocity affected by the degree of supercooling may account for the phenomenon of two kinds of growth behaviors in different temperatures. In the non‐isothermal growth process, the cooling rate over 10 K min−1 contributes to multiple crystal nucleuses growth of Ca2Nb2O7. The cooling rate below 5 K min−1 leads to single nuclear growth. This paper provides a control guideline for Ca2Nb2O7 growth. [ABSTRACT FROM AUTHOR]

Growth pattern and electronic and magnetic properties of AgnCr (n = 1–16) clusters have been investigated via density functional theory (DFT) combined with CALYPSO structure search method. The optimized geometry shows that the growth of the global minimum structures of AgnCr clusters have obvious rule. when n > 12, silver atoms grow around an icosahedron which is almost unchanged in each structure. Analyses of electronic properties indicate that the doped Cr atom can only enhance the stability of larger silver clusters. Optical absorption and photoelectron spectra of AgnCr isomers have been predicted and can be used for their structural identification. The icosahedral Ag12Cr cluster with large energy level gap can be seen as a superatom. The adsorption capacity of Cr atom in AgnCr cluster to CO is much higher than that of free Cr atom. The intensity of IR and Ramam spectra can be dramatically enhanced when CO is absorbed on AgnCr cluster that Cr atom is encapsulated by Ag atoms. Moreover, the red shift of IR and Raman spectra of CO adsorbed on these clusters is also very small compared to free CO. Magnetism calculations show that the magnetic moment of AgnCr clusters decreases linearly from n = 6 to 12 and increases linearly from n = 12 to 16. The total magnetic moment of AgnCr cluster is mainly localized on the Cr atom. The change of magnetic moment of Cr atom is related to the charge transfer between Cr and Ag atoms. [ABSTRACT FROM AUTHOR]

The equilibrium geometries, and electronic and magnetic properties of phosphorus, cobalt‐phosphorus, and nickel‐phosphorus (Pn+1, CoPn, and NiPn, n = 1–24) clusters have been investigated by using first principle calculations. The doping with cobalt or nickel atom favors the endohedral structures in which the metal atom is encapsulated inside the phosphorus framework, while geometrical structures are metal‐dependent. The growth pattern behaviors and stabilities are examined from the binding energies, the second‐order energy differences, and the HOMO–LUMO gaps. The doping with Co or Ni atom contributes to strengthening the stability of the phosphorus frame with a marked improvement in the case of Ni atom. The total spin magnetic moment is enhanced with doping with Co atom. In contrast, the magnetic moment is quenched in the case of NiPn. Vertical electron affinities and ionization potentials are also reported and discussed. [ABSTRACT FROM AUTHOR]

Little room remains for further reducing lattice thermal conductivity (κL) which cannot be reduced below the amorphous limit. Further improvements in the thermoelectric (TE) figure of merit should rely on enhancing the TE power factor (PF) with low electrical thermal conductivity (κe). Layered Bi2Te3 exhibits anisotropic TE properties and modulation of its growth behavior can effectively modify the transport of electrons and phonons and thus enhance its TE properties. Herein, Bi2Te3 films are grown by molecular beam epitaxy with the modulation of substrates, seed layer, and thickness. The nanopillars‐dominated film without seed layer changes to nanoplates dominated after the seed layer is predeposited, and the grain size ratio of the (006)/(015) plane increases. The room temperature PF of the stoichiometric Bi2Te3 grown on SiO2 with seed layer reaches 34 μW cm−1 K−2 with a low κe of 0.39 W m−1 K−1. This strategy can be applied in other layered materials with specific growth behavior and properties for nano–micro devices. [ABSTRACT FROM AUTHOR]

The interactive effects of light, nutrient availability and grass competition on seedlings of four tropical dry forest tree species, namely, Indian jujube (Ziziphus mauritiana), arjun (Terminalia arjuna), gum arabic (Acacia nilotica) and catechu (Acacia catechu), were evaluated in an experimental study at Banaras Hindu University, Varanasi, India. Full‐ and reduced‐ (20% of the full) sunlight, no‐nutrient and nutrient supplementation, and presence of grass and no‐grass conditions were taken in a split‐plot design to observe the effects on the plant growth and leaf nutrient parameters. We observed a significant interaction between light and nutrient availability on total dry weight and relative growth rate for the tree seedlings of all the species. Seedling growth was lower in presence of grass under full sunlight condition with/without nutrient addition, and also under reduced sunlight condition with nutrient addition. However, leaf‐N and ‐P concentration showed slight increase following nutrient addition across the species and light conditions. All the species responded positively to nutrient addition irrespective of light and grass conditions. Our study further indicates that nutrient addition under reduced light condition in tropical dry forests may be a possible strategy to ameliorate the negative impact of grasses on tree seedling growth. Overall, a better understanding of tree seedling establishment in the presence of grasses is of utmost importance for the development of management plans that may improve the diversity of tree species in tropical dry forests. [ABSTRACT FROM AUTHOR]

The influence of precursors on the growth of organic films has been studied intensively, but research on their binding energy‐dependent growth behaviors and surface properties has remained an undeveloped field. Herein, we conducted molecular layer deposition of zincone films on two metal oxide substrates, SiO2 and Al2O3, and investigated the binding energy‐dependent growth behaviors and surface properties of the films experimentally. We also performed density functional theory calculations to determine the molecular geometries and surface binding energies of the films on each substrate. We established that the growth and surface characteristics of the films in the initial stages of deposition were strongly influenced by their surface binding energies, which depended on the substrate. [ABSTRACT FROM AUTHOR]

The organic semiconductor 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT) is deposited on a single crystal (0001) Al2O3 (C‐sapphire) by a vacuum thermal evaporation, and effects of the layer thickness and preparation temperature on structural, morphological, optical, and electrical characteristics are investigated with X‐ray diffraction, atomic force microscopy observation, optical absorption measurement, and resistivity measurement with and without light irradiation. The C8‐BTBT layers possess the (001) out‐of‐plane orientation irrespective of the layer thickness and preparation temperature. The C8‐BTBT grains are growing up in direction parallel to the substrate surface keeping almost constant height, and the continuous layer is formed by the coalescence of the C8‐BTBT grains. The grain size of the continuous C8‐BTBT layer increases with raise in preparation temperature. The optical band gap energy could be estimated to be 3.32–3.35 eV regardless of the layer thickness and preparation temperature. The electrical resistivity decreases from 2.1 × 106 to 1.2 × 102 Ω cm with increase in the preparation temperature due to the increase in the grain size, and the light irradiation induce the drastical decrease to 42–28 Ω cm. [ABSTRACT FROM AUTHOR]

Nerve tissue engineering has been one of the promising strategies for regenerative treatment in patients suffering from neural tissue loss, but considerable challenges remain before it is able to progress toward clinical application. It has been demonstrated that transplantation of cells in combination with physically or chemically modified biomaterials provides better environments for neurite outgrowth and further promotes axonal regeneration in animal models of spinal cord injury. In this study, neurons and astrocytes were incorporated into 400-nm, 800-nm, and 1200-nm electrospun Bombyx mori silk fibroin (SF) materials to investigate the effects of scaffold-diameter in regulating and directing cell behaviors. β-III-tubulin immunofluorescence analyses reveal that SF nanofibers with smaller diameters are more favorable to the development and maturation of subventricular zone-derived neuronsthan 1200-nm SF scaffolds. In addition, astrocytes exhibited well-arranged glial fibrillary acidic protein (GFAP) expression on SF scaffolds, and a significant increase in cell-spreading area was observed on 400-nm but not 1200-nm SF scaffolds. Moreover, a significantly enhanced migration efficiency of astrocytes grown on SF scaffolds was verified, which highlights the guiding roles of SF nanofibers to the migratory cells. Overall, our results may provide valuable information to develop effective tissue remodeling substrates and to optimize existing biomaterials for neural tissue engineering applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 2667-2678, 2013. [ABSTRACT FROM AUTHOR]

Various Cu-phthalocyanine (CuPc) films were grown from physical vapor deposition on top of indium-tin-oxide glass substrates by controlling substrate temperature ( T), source temperature ( T), and growth time. From side-view SEM pictures, the growth rates for these CuPc films are estimated and can be categorized into three regions. From the Arrhenius plot of growth rate versus 1/ T, the activation energy E can be obtained. As T = 390 °C, for region (A) with T < 140 °C, the growth of CuPc films is dominated by the adhesion process with E = 810 meV. For region (B) with 140 °C < T < 320 °C, the growth is then limited by the steric character associated with the organic molecular solids with E = 740 meV. For region (C) with T > 320 °C, the re-evaporation of the CuPc adhered molecules from the interface becomes dominant. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A glasshouse experiment was conducted at University Putra Malaysia, Serdang, to study the growth pattern of itchgrass collected from 13 locations. The itchgrass was either associated with crops or found along roadsides in six infested estates located in Johor, Kedah, Pahang, Perak, Perlis and Selangor. Significant differences between populations were observed in all variables except in time to seedling emergence. Cluster analysis of the data classified the populations into three major groups. The first group comprised populations from Johor, Pahang and Perak found in association with banana, cocoa and oil palm plantations, or along the roadsides. The second group comprised populations from Kedah, Perlis and Selangor found in association with maize, upland rice, rubber, sugar cane and tobacco plantations. The third group was a distinct population found only along roadsides at Padang Kartong, Perlis. Principal component analysis was performed to determine the growth characteristics that separated the groups. The results showed that plant height, number of leaves, number of seeds/plant, secondary culm diameter and the weight of 100 intact or dehulled seeds were the most significant characteristics that differentiated the groups. The study provided strong evidence of the existence of three itchgrass groups in Peninsular Malaysia. [ABSTRACT FROM AUTHOR]