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By using first-principles calculations, we demonstrate the influence of proximity effect on the band structures of heterostructures formed by graphene stacking on a two dimensional (2D) topological insulator (TI) 1T'-MX2. The interlayer distance d between graphene and TI decreases with the enhancement of the intrinsic lattice anisotropy of 1T'-MX2, which determines different strength of the interlayer proximity interaction. The bandgap can be opened by the proximity exchange. The weak anisotropic symmetry of heterostructure (large d) only results in a small band gap (∼50 meV) in graphene/MoTe2. However, a large energy gap (up to ∼200 meV) can be obtained in graphene/MoS2, which is attributed to the inter-intralayer charge transfer due to the strong proximity interaction of the hetero-interface (small d). In addition, the 1T'-MX2 of heterostructure still possesses the topological feature of Z 2 = 1, since the graphene has a negligible effect on the band structure of the system.

The sound field in a vault with two open ends is studied and its sound pressure distribution is compared with that in an enclosure and a long space. The accuracy of estimation on this kind of space by the classic Sabine Formula, the modified Sabine Formula and the ray tracing method are compared through numerical simulations and experiments. It is found that the sound field in this type of non-close space is not uniform, SPL declines faster near the openings, and RT values have a large span when the source is not at the center. Non-exponential decay is also found in this open vault, and the reason and precondition of its occurrence are discussed.

The properties of ZnO quantum dots (QDs) synthesized by the sol–gel process are reported. The primary focus is on investigating the origin of the visible emission from ZnO QDs by the annealing process. The X-ray diffraction results show that ZnO QDs have hexagonal wurtzite structure and the QD diameter estimated from Debye–Scherrer formula is 8.9 nm, which has a good agreement with the results from transmission electron microscopy images and the theoretical calculation based on the Potential Morphing Method. The room-temperature photoluminescence spectra reveal that the ultraviolet excitation band has a red shift. Meanwhile, the main band of the visible emission shifts to the green luminescence band from the yellow luminescence one with the increase of the annealing temperature. A lot of oxygen atoms enter into Zn vacancies and form oxygen antisites with increasing temperature. That is probably the reason for the change of the visible emission band.

VO 2 thin film synthesized by a novel sputtering oxidation coupling (SOC) method has been successfully fabricated. The experimental results show that the optimum oxidation time is 285 s and the thin film exhibits a good metal-insulator transition (MIT) approximately at 340 K. The corresponding structures and surface compositions of the films have been characterized by X-ray diffractometer and X-ray photoelectron spectroscopy separately.

Cu 2+ -doped ZnS quantum dots were synthesized by a chemical precipitation method in water/ethanol solution. The quantum dots obtained were characterized by X-ray diffraction, transmission electron microscopy and spectroscopy techniques including X-ray photoelectron spectroscopy. The [S 2- ]/ [Zn 2+ ] ratios have an effect on the photoluminescence of both aqueous solutions and powders of Cu 2+ -doped ZnS quantum dots. For aqueous samples, a green luminescence centre is observed in the spectrum of sample 1 with [S 2- ]/[Zn 2 +] = 1:2 and a blue one for sample 2 with [S 2- ]/[Zn 2+ ] = 1:1. For powders, only the green emission is the main luminescence centre, and the integrated intensity in the blue emission region of sample 1 is stronger than that of sample 2. Compared with the spectrum of CuS powders, the X-ray-induced Auger electron spectrum of Cu L 3 M 45 M 45 in ZnS quantum dots shows a unique spectral characteristic. The 3d level of the Cu 2+ ion is split into two different energy levels at 334.0 and 347.2 eV, respectively.

The kinetics Monte Carlo (KMC) simulation and the rate equation method were used to study the influence of the anisotropic surface migration on the submonolayer growth mechanism. Simulations show that the influence of the migration anisotropy tends to saturate when the migration anisotropy exceeds 100. There is good agreement between the KMC simulation and the adjusted rate-equation. The researches show that it is significant to define a new parameter: effective diffusion rate. The effective diffusion rate is not only determined by the temperature and the hopping barrier, but is also by the anisotropy. The effective surface diffusion rate will decrease with the increase of the surface migration anisotropy.

The authors theoretically investigate a triple-barrier ferromagnetic resonant-tunneling diode composing nonmagnetic couple wells and three GaMnN magnetic barriers, in which two kinds of antiparallel configurations are formed by changing the relative orientation of magnetization in the barriers. Based on a two-band model, the achievement of large magnetocurrents in the resonant bias regime is proposed under an optimal magnetization configuration. The magnetocurrents in both antiparallel configurations of triple-barrier system are much higher than that in double-barrier structure.

The density functional calculation with the generalized gradient approximation is applied to study the structural, electronic and vibrational properties of PbnSn clusters up to n = 9 . It is found that ringlike structures are the lowest-energy configuration for n ⩽ 3 . However, at the beginning of n = 4 , three-dimensional spheroid structures are prevailed. The supercluster structures based on Pb2S2 and Pb3S3 bridges are dominant for the larger PbnSn with n ⩾ 3 . In addition, we discussed the size dependence of binding energies, gaps between highest-occupied and lowest-unoccupied molecular orbitals, second-order difference of total energies, and the IR spectra of PbnSn clusters.

We present a self-consistent analysis of the Curie temperature ( T c ) modulation in Mn δ -doped GaAs/Be-doped AlGaAs heterostructures. Considering the influences of both Mn dopants and Hartree potential, we solve simultaneously the Schrodinger and Poisson equations for different Mn δ -doping positions ( d s ) and uncompensated Mn atom concentration ( N Mn ). Under low dopant concentration ( N Mn 4 × 10 15 / m 2 ), the peak position of the two-dimensional hole gas envelope function is fixed at 4 nm distance away from the heterointerface, which is independent of delta-doping position. Further increasing the effective Mn concentration will lead to the remarkable shift of the envelope function. T c of the heterostructure can be enhanced up to 1.6 times under optimized calculational parameters. Our theoretical results agree well with experimental results available for this system.

Methanol catalytic oxidation over VOx/Al2O3, VOx/ZrO2 and VOx/MgO catalysts has been studied by solid-state nuclear magnetic resonance (NMR) spectroscopy. It was found that stronger acid sites in VOx/Al2O3 result in almostthe same selectivities fordimethoxymethane, paraformaldehyde and formic acid, and weaker acid sites in VOx/ZrO2 favor the formation of paraformaldehyde, while the VOx/MgO catalyst with the base support shows high selectivity for formate. Supporting VOx species on gamma-Al2O3 and ZrO2 leads to the formation of Bronsted acid sites as revealed by the adsorption of probe molecules. The acid strength of Bronsted acid sites on the VOx/Al2O3 catalyst is found to be stronger than that of the VOx/ZrO2 catalyst which has the acid strength similar to zeolite HZSM-5's. The proposed bridging hydroxyl models accounting for the Bronsted acid sites formation were also confirmed by quantum chemical calculation. (c) 2007 Elsevier B.V. All rights reserved.

The kinetic Monte Carlo simulations were used to study the nucleation and growth mechanism of GaAs. The Ehrlich–Schwoebel (ES) barrier has an important effect on the growth mechanism. It was shown that the island density mainly depends on the growth temperature: low island density for high temperature, and high island density for low temperature. The islands in the second layer appear at small surface coverage for the high ES barrier or low temperature, while the islands appear at large surface coverage for the low ES barrier or high temperature. In GaAs epitaxial growth the critical size has its original meaning only for the low temperature and the high ES barrier. The single value of the critical size has to be replaced by two sizes in the two different directions because of the anisotropic surface migration.

Silicon carbide nanotubes (SiCNTs) were directly synthesized by chemical vapor deposition (CVD) in the paper. Methyltrichlorosilane (MTS) was selected as the SiC gaseous source and, ferrocence and thiophene as the catalyst and the cocatalyst, respectively. The influences of reaction temperature, contents of catalyst and cocatalyst, and content of gaseous source on the morphologies of the products were investigated, respectively. The products were identified by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX), respectively. The synthesis of SiCNTs by CVD suggested a condition-dependent process. Novel SiCNTs, with 20 approximately 80 nm in outer diameter and 15 approximately 35 nm in inner diameter, respectively, were observed. The wall structure similar to that of carbon nanotubes was not found for the SiCNTs.

Solid-state NMR spectroscopy was used to study the conversion of methanol to aromatics (MTA) over silver exchanged HZSM-5 zeolites. It is the silver oxide rather than silver cation that plays a crucial role for the MTA reaction. The aromatic products (mainly toluene and benzene) are formed at the expense of the small alkanes (mainly propane and isobutane). AgZSM-5 zeolite calcined in air shows much higher activity and selectivity for the MTA conversion compared with AgZSM-5 zeolite calcined in vacuum or HZSM-5 zeolite. A possible reaction mechanism is proposed for the MTA conversion on the AgZSM-5 zeolite.

WFIKKN2 may play a role in the regulation of muscle growth and development, but to date there have been no reports on the effect of variation in WFIKKN2 on growth and carcass traits in livestock. In this study, the effect of variation in ovine WFIKKN2 was investigated in 800 New Zealand Romney lambs (395 male and 405 female), with five previously described variants (A to E) being identified. Variation in ovine WFIKKN2 was not found to affect various growth traits in the female lambs, but the presence of variant B was associated (P B was associated (P WFIKKN2 may have a differential effect on growth in male and female lambs and hence that the gene may be expressed in, or act in, a gender-specific fashion.

Raman spectroscopy was employed to study the evolution of host lattice recrystallization in Mn + -implanted GaAs both prior to and following irradiation with Ga, As and H ions. The additional irradiation stimulates the regrowth of the host lattice after a thermal anneal of 920 °C. A competitive process between post-implantation-induced damage and recovery in the crystallization process of amorphous GaAs was observed. At a As + fluence level exceeding 8 × 10 15 cm −2 , the self-implantation-enhanced recovery of the crystal dominates the regrowth stage. The vacancy supersaturation produced during additional irradiation is mainly responsible for the enhancement of recrystallization in Mn + -implanted GaAs.

The acidity of mesoporous MoO(x)/ZrO2 and WO(x)/ZrO2 materials was studied in detail by multinuclear solid-state NMR techniques as well as DFT quantum chemical calculations. The 1H MAS NMR experiments clearly revealed the presence of two different types of strong Brønsted acid sites on both MoO(x)/ZrO2 and WO(x)/ZrO2 mesoporous materials, which were able to prontonate adsorbed pyrine-d5 (resulting in 1H NMR signals at chemical shifts in the range 16-19 ppm) as well as adsorbed trimethylphosphine (giving rise to 31P NMR signal at ca. 0 ppm). The 13C NMR of adsorbed 2-(13)C-acetone indicated that the average Brønsted acid strength of the two mesoporous materials was stronger than that of zeolite HZSM-5 but still weaker than that of 100% H2SO4, which was in good agreement with theoretical predictions. The quantum chemical calculations revealed the detailed structures of the two distinct types of Brønsted acid sites formed on the mesoporous MoO(x)/ZrO2 and WO(x)/ZrO2. The existence of both monomer and oligomer Mo (or W) species containing a Mo-OH-Zr (or W-OH-Zr) bridging OH group was confirmed with the former having an acid strength close to zeolite HZSM-5, with the latter having an acid strength similar to sulfated zirconia. On the basis of our NMR experimental and theoretical calculation results, a possible mechanism was proposed for the formation of acid sites on these mesoporous materials.

The structure and acidity of sulfonic group functionalized mesoporous materials with MSU structure were characterized in detail using multinuclear NMR technique in combination with other approaches such as XRD, N2 adsorption and desorption, as well as density function theory (DFT) calculation. Our experimental and theoretical calculation results indicate that functionalized MSU–SO3H materials with well-ordered mesostructure have been successfully synthesized and the materials have acid strength slightly weaker than that of microporous zeolite HZSM-5, which may be helpful for the understanding of some acid-catalyzed reactions, such as alkylation and esterification, occurring on sulfonic-functionalized mesoporous materials.

Raman spectroscopy was used to study the evolution of host lattice recrystallization in high-fluence N + -implanted GaAs. A high-fluence of N + ions (>10 15 cm −2 ) was introduced into semi-insulating GaAs by the combinatorial implantation method. Subsequent thermal annealing at 800 °C was carried out to re-grow the implantation-induced amorphous layers. The dependence of Raman parameters on N contents was systematically observed for each recrystallized cell. The volume of the newly formed crystallites with original orientation decreases with increasing fluences, whereas that of crystallites of other orientations increases after high-fluence implantation and annealing. The correlation length L , representing the size of crystalline regions with preserved translational symmetry, was determined by fitting the LO phonon signal with spatial correlation model. For 10 16 cm −2 implantation, the recrystallized layer consists of nano-meter-sized crystallites (∼30 nm). The dimension of the recrystallized crystallites decreases with increasing N + fluences, in good agreement with the model.

Atomic nitrogen and oxygen were deposited on beta-Mo(2)C through dissociative adsorption of NO. Reflectance absorbance infrared spectroscopy (RAIRS), thermal desorption, and synchrotron X-ray photoelectron spectroscopy (XPS) measurements were used to investigate the interplay between atomic nitrogen, carbon, and oxygen in the 400-1250 K region. The combination of the high resolution and high surface sensitivity offered by the synchrotron XPS technique was used to show that atomic nitrogen displaces interstitial carbon onto the carbide surface. Thermal desorption measurements show that the burnoff of the displaced carbon occurs at approximately 890 K. The incorporation of nitrogen into interstitial sites inhibits oxygen dissolution into the bulk. RAIRS spectroscopy was used to identify surface oxo, terminal oxygen, species formed from O(2) and NO on beta-Mo(2)C.

The photoluminescence properties of CdSe quantum dots with different radii are studied in this paper. The FWHM of photoluminescence of different quantum dots are nearly the same, which reveals that the nucleation centers are formed only at the beginning of chemical reaction and the size fluctuation does not increase with the increase of the reaction time. Thermal treatment and light illumination will reduce the photoluminescence efficiency and make a blue shift remarkably, which results from the change of surface states of CdSe quantum dots.

In this paper, we report the fabrication of ferromagnetic semiconductor on GaN substrates by high-dose Cr ion implantation. Both magnetic and optical properties for Cr + -implanted GaN were studied by photoluminescence and superconducting quantum interference device. The results of photoluminescence reveal that the implanted chromium incorporates substitutionally on Ga site and forms deep acceptor level in GaN. The materials show ferromagnetic-like order up to 300 K as indicated by temperature-dependent magnetization measurement. The M vs. T curve also implies the presence of different components to the magnetization in Cr + -implanted GaN.

The gene encoding the high glycine/tyrosine keratin-associated protein 20-2 (KAP20-2) gene has been described in humans, but has not been identified in any livestock species. A search for similar sequences in the caprine genome using the human KAP20-2 gene (KRTAP20-2) revealed a homologous sequence on chromosome 1. Three different banding patterns representing distinct sequences (A–C) in Longdong cashmere goats were identified using polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) analysis. These sequences shared high sequence similarity with the human and mouse KRTAP20-2 sequences, suggesting that A–C are caprine variants of the human and mouse genes. Four single nucleotide polymorphisms (SNPs) were identified, and three of them were non-synonymous. KRTAP20-2 was found to be expressed in secondary hair follicles, but not in heart, liver, lung, kidney, spleen, or longissimus dorsi muscle. The presence of A was associated with increased cashmere fibre weight, while the presence of B was associated with a decrease in cashmere fibre weight and curly fibre length. Goats with genotype AA had a higher cashmere fibre weight and a higher curly fibre length than those with genotypes AB or BB. These results indicate that caprine KRTAP20-2 variation may have value as a genetic marker for improving cashmere fibre weight.

Using first-principles calculations, we report on charge injection induced switching between ferromagnetic (FM) and antiferromagnetic (AFM) in a 2H- monolayer. monolayers doped with different transition metals (TM)—Fe and Mn—initially demonstrate FM and AFM magnetic ground state, respectively. Once the injected charge approaches e/unit, the systems respectively tend to AFM and FM states, due to the modulation effect of the exchange splitting of spins via injected charge. The interesting switch between FM and AFM can be explained by the competition between FM double-exchange and AFM super-exchange interaction. In contrast, the / heterojunction, because of the direct bonding between dopant TM atoms, remains in the AFM state even under charge injection. These findings point toward the possible development of spintronic switch devices using charge injection in TM doped materials, which could be pivotal to information storage and spintronic applications.

Keratin-associated proteins (KAPs) are structural components of wool and hair fibers. To date, eight high glycine/tyrosine KAP (HGT-KAP) families have been identified in humans, but only three have been identified in sheep. In this study, the putative ovine homolog of the human KAP22-1 gene (KRTAP22-1) was amplified using primers designed based on a human KRTAP22-1 sequence. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) was used to screen for variation in KRTAP22-1 in 390 Merino × Southdown-cross lambs and 75 New Zealand (NZ) Romney sheep. Three PCR-SSCP banding patterns were detected and DNA sequencing revealed that the banding patterns represented three different nucleotide sequences (A–C). Two single nucleotide polymorphisms (SNPs) were identified in these sequences. Variant B was most common with a frequency of 81.3% in NZ Romney sheep, while in the Merino × Southdown-cross lambs, A was more common with a frequency of 51.8%. The presence of B was found to be associated with increased wool yield and decreased mean fiber curvature (MFC). Sheep of genotype BB or AB had a higher wool yield than those of genotype AA. These results suggest that ovine KRTAP22-1 variation may be useful when developing breeding programs based on increasing wool yield, or decreasing wool curvature.

Investigations on the variation present at the male-specific Y chromosome region provide strong information to understand the origin and evolution of domestic sheep. One SNP OY1 (g.88A>G) in the upstream region of SRY gene, and the microsatellite SRYM18 locus within ovine Y chromosome were analyzed in one hundred and forty five samples collected from eleven breeds in China. SNP OY1 was analyzed using PCR-SSCP method and sequencing. Two different PCR-SSCP patterns represented two specific sequences with sequence analysis revealing SNP-OY1 (g.88A>G) were observed, while SNP A-OY1 showed the most common frequency (82.8%). Sequencing of the SRYM18 region revealed one novel size fragment (A2) with different repetitive units. Seven haplotypes (H4, H5, H6, H7, H8, H9 and H12) and two novel haplotypes (Ha and Hb) were established using combined genotype analysis. H6 showed the highest frequency (43.4%) across all breeds, and H8 showed the second frequency (24.1%). Ha was only found in one breed (Tan), while Hb was present in three breeds (Gansu alpine, White Suffolk and Duolang). Our findings reveal one novel allele in SRYM18 region and two novel male haplotypes of domestic sheep in China.

A single nucleotide polymorphism (SNP) may have an impact on phenotype, but it may also be influenced by multiple SNPs within a gene; hence, the haplotype or phase of multiple SNPs needs to be known. Various methods for haplotyping SNPs have been proposed, but a simple and cost-effective method is currently unavailable. Here we describe a haplotyping approach using two simple techniques: polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) and haplotype-specific PCR. In this approach, individual regions of a gene are analyzed by PCR-SSCP to identify variation that defines sub-haplotypes, and then extended haplotypes are assembled from the sub-haplotypes either directly or with the additional use of haplotype-specific PCR amplification. We demonstrate the utility of this approach by haplotyping ovine FABP4 across two variable regions that contain seven SNPs and one indel. The simplicity of this approach makes it suitable for large-scale studies and/or diagnostic screening.

This experiment was conducted to identify some aspects of secondary follicle (SF) characteristics of Hexi cashmere goats at five different growing stages in one year in order and discover the expression pattern of Hoxc13 in a SF cycling to provide morphological basis for studying the growth of cashmere. Ten cashmere goats of one-year old (5 males, 5 females) were included in this study. The density and activity of SF were observed and measured by making paraffin sections, the ultra-structural features of SF were studied under transmission electron microscopy (TEM) by making ultra-thin sections, and the expression of Hoxc13 was investigated through the immunohistochemistry method. The average diameter of SF had the smallest value in the anagen stage, and significant difference (P 0.05) was found between the anagen stage and other stages. The density of SF increased gradually through the different growing stages, and significant difference was found between the anagen and procatagen stages (P 0.05). With an increase in time (months), the percentage of SF activity increased, and significant difference in the percentage of SF activity was found between the telogen and anagen stages (P 0.05). At the telogen stage, the layers of connective tissue sheath (CTS) of SF were unclear, hemidesmosomes between the outer root sheath (ORS) and basement membrane disappeared, and dead cells were found at the top of the SF. The rudiments of new SF were found in the proanagen stage, CTS was thickened, and the cells of ORS were stretched out like fingers. At the anagen stage, the structure of SF was integral, and the inner root sheath (IRS) consisted of three concentric layers (Helen, Huxley, and Cuticle layers). The cells of Huxley's layer degenerated gradually, and pseudopodia were formed on the cells of ORS in the procatagen stage. At the catagen stage, the ORS was separated from the IRS, and IRS disappeared. Huxley's layer was absent in the inactive SF while, the ORS was present in the active SF. Hoxc 13 was expressed in the epidermis and sebaceous gland o, ORS, IRS, hair shaft of SF in the skin. Hoxc13 was expressed weakly during procatagen, catagen, and telogen stage, while with an increase in proanagen and anagen stage, significant difference was found between them. These findings demonstrated the ultra-structural features of SF could provide the useful activity criteria, and Hoxc13 associated with the SF activity.

WFIKKN2 may play a role in the regulation of muscle growth and development through its interaction with growth and differentiation factor 8 (GDF8) and growth and differentiation factor 11 (GDF11), but to date research into the function of the protein has been focused on mice, even though the WFIKKN2 gene (WFIKKN2) was first identified in humans in 2001. In this study two regions (intron 1 and the 3' UTR) of ovine WFIKKN2 were investigated, using Polymerase Chain Reaction-Single Stranded Conformational Polymorphism (PCR-SSCP). Two different PCR-SSCP patterns, representing two unique DNA sequences (designated a and b) were detected in a 399-bp amplicon derived from the 3' UTR, with sequence analysis revealing one single nucleotide polymorphism (SNP). In a 421-bp amplicon from intron 1, five different PCR-SSCP patterns (designated A-E) were observed and twelve SNPs were detected. Either one or two different sequences were detected in individual sheep and all the sequences identified shared homology with the WFIKKN2 sequences from cattle and other animal species, suggesting that these sequences represent variants of the ovine WFIKKN2 gene. In intron 1 of 487 sheep from eight breeds, variants B and C were the most common, followed by A, D and E. These results indicate that ovine WFIKKN2 is polymorphic and suggest that further analysis is required to see if variation in the gene is associated with variation in growth and muscle traits in sheep.

Cadmium sulfide (CdS) quantum dots (QDs) prepared by a convenient chemical method have been characterized using absorption, fluorescence, and photoluminescence excitation techniques. The photoluminescence excitation studies show that there is an electron transfer from the surface adsorbate (thiourea) to CdS QDs in aqueous solution. The excitation band with peak maximum at 5.8 eV is assigned to the electronic transitions in the chemisorbed thiourea, whereas the excitation band between 3.45 and 3.7 eV corresponds to the band-to-band transition within the nanocrystalline CdS host. The absorption spectroscopy of the CdS QD solutions shows a strong absorption peak which is generated from thiourea. The band-edge fluorescence of the CdS QDs has also been investigated. It is shown that the fluorescence property of the CdS QDs can be enhanced by adding cadmium chloride (CdCl2) solution.

The processes of HS-DNA immobilization and colloidal gold amplification of DNA hybridization signals were monitored by quartz crystal microbalance (QCM) in real time. The QCM detection was carried out in three cases: (1) Quiescent mode under open conditions; (2) Quiescent mode under sealed conditions; and (3) Flowing mode under sealed conditions. It was demonstrated that the stability of the QCM detection was greatly improved with the flowing mode under sealed conditions in comparison with those under the other two conditions. An increase of the frequency shift under flowing mode was found to be 57.6% in the HS-DNA immobilization process and 91.5% in the nanogold amplification process relative to the quiescent mode. The flowing mode can improve not only the stability but also the sensitivity of QCM detection.

The specific heat of a spin-one Heisenberg antiferromagnetic chain with transverse and longitudinal single-ion anisotropies in the presence of an applied magnetic field is explored on the basis of the Schwinger boson mean-field theory. The specific heat as functions of temperature, the anisotropy as well as the applied field are discussed, respectively. The results indicate that new features of the specific heat as a function of temperature at the transverse single-ion anisotropy are very different from those obtained at longitudinal single-ion anisotropy in an applied transverse field.

Raman measurements were performed on ZnO single crystals before and after implantation with N+, O+, Si+, and Ga+ ions. It is found that the broad Raman band at 576 cm−1 appears in all spectra of implanted ZnO, independent of the ion species, and thus it is attributed to disorder-activated Raman scattering. Two extra peaks at 275 and 510 cm−1 are observed only in Raman spectrum of N+-implanted ZnO. The dependence of intensity on doses indicates that the origin of these two modes is different from that of 576 cm−1 peak. We assign the additional modes to N+-related local vibrational modes.

The importance of sheep’s wool in making textiles has inspired extensive research into its structure and the underlying genetics since the 1960s. Wool keratin-associated proteins (KAPs) are a key structural component of the wool fibre. The characterisation of the genes encoding these proteins has progressed rapidly with advances in the nucleotide and protein sequencing. This review describes our knowledge of ovine KAPs, their categorisation into families, polymorphism in the proteins and genes, the clustering and chromosomal location of the genes, some characteristics of gene expression and some potential effects of the KAPs on wool traits. The extent and nature of genetic variation in wool KAP genes and its association with fibre characteristics, provides an opportunity for the development of gene-markers for selective breeding of sheep to produce better wool with properties highly matched to specific end-uses.

Acceleration of neutral particles is of great importance in many areas, such as controlled chemical reactions, atomic nanofabrication, and atom optics. Recent experimental studies have shown that pulsed lasers can be used to push neutral Rydberg atoms forward [Nature 461, 1261 (2009)10.1038/nature08481; Nat. Photonics 6, 386 (2012)10.1038/nphoton.2012.87]. Our simulation shows that pulsed lasers can also be used to pull Rydberg atoms back toward a light source. In particular, we proposed a method of using two laser pulses on a neutral atom, then selective operations on the neutral atom (pushing or pulling) can be performed by adjusting the delay time between the two laser pulses.

This experiment conducted to identify a periodic change of ultrastructures of secondary follicle characteristics during a whole year, reveal the molecule regulation of growth of cashmere. A total of 10 cashmere goats of 1-year old were studied. The paraffin section and ultrathin slices of skin were made each month in a whole year, observed, photographed, and analyzed under light microscope and transmission electron microscope after stained. Following the development of down fiber, the ultrastructures of secondary follicle of Hexi cashmere goat showed a periodic change within a year. There were five different periods during a down fiber cycle. It was observed that the stage of telogen, proanagen, anagen, procatagen, and catagen was in January and February, March and April, May to August, September and October, and November and December, respectively. The key change observed in secondary follicle under transmission electron microscope was inner root sheath. This study illustrated the five different stage of secondary follicle of Hexi Cashmere goat within a whole growth cycle, and has provided more detailed information about the research field of Hexi cashmere goat. Choosing the suitable time to harvest the cashmere may get the profit maximization.

The photoluminescence properties of a ZnO nanobelt are investigated. Both the band-edge emission and the green-yellow emission bands have a series of eigenmodes. The theoretical results demonstrate that in the band-edge emission region the photoluminescence modes are determined by the polariton modes. In the green-yellow band there is no coupling between the photons and excitons and the photoluminescence modes are determined by the transverse Fabry-Perot modes. The photoluminescence spectra at different spots confirm that the Fabry-Perot modes are determined by the transverse size. Furthermore, the fitting results show in the waveband in the ultraviolet and visible band the quality-factor Q of the cavity is decreased from 280 to 70 with the increase of the wavelength.

[Eu(bpy) 2 ] 3+ (bpy: 2, 2'-bipyridine) was encapsulated in HMS, MCM-41 and SBA-15, respectively. Effect of dispersion degree of Eu 3+ species and mesoporous structure on the photoluminescence efficiency was investigated.

Ferromagnetic/MoS2 junctions are significant building blocks for spintronics. Our first-principle calculations show that magnetic anisotropy energy (MAE) and the direction of magnetization in the Fe/MoS2 system can be tailored by injecting charge or strain engineering. We demonstrate that these two approaches have a significant influence on the magnitude of the MAE. The hybridization between Fe 3 d and Mo 4 d electrons changes the occupation of d orbitals around the Fermi level, which leads to the strong dependence of MAE on the external charge injection or strain. MAE increases up to ten times higher than that of the neutral system when injecting charge. More intriguing is that the biaxial strain can affect the easy-axis switching in Fe/MoS2, while the process does not occur in the single Fe monolayer.

Solid-state NMR spectroscopy and density functional theory (DFT) calculations were employed to study the structure and properties, especially the solid acidity, of molybdenum oxide supported on tin oxide. As demonstrated by solid-state NMR experiments, Mo species are mainly dispersed on the surface of SnO(2) support rather than significantly dissolved into the SnO(2) structure and Bronsted as well as Lewis acid sites are present on the MoO(3)/SnO(2) catalyst. Acid strength of the supported metal oxide is stronger than those of zeolites, e.g., HY and HZSM-5, though the concentration of acid sites is relatively lower. The DFT calculated (13)C chemical shift for acetone adsorbed on MoO(3)/SnO(2) is in good agreement with the experimental value, which confirms our proposed structure of -Mo-(OH)-Sn- for the Bronsted acid site. Reducibility of the supported metal oxide is also demonstrated by solid-state NMR experiments and an active oxidation center of this catalyst is proposed as well.

To better control drug delivery rate, a simple and effective approach has been developed for controlled drug delivery carrier system through one-step surface modification of the ibuprofen-impregnated silica MCM-41 with 1, 1, 1, 3, 3, 3-hexamethyldisilazane (HMDS). The 29Si MAS NMR characterization demonstrated that different contents of trimethylsilyl (TMS) groups were successfully grafted onto the samples modified with different silylation times. The results obtained from in vitro tests exhibited that the introduction of TMS groups greatly retarded the ibuprofen release rate. Even after in vitro test for 48 h, only 75% of the impregnated ibuprofen could be released from the modified sample with TMS groups content of 14.5% (related to the total silicon atoms). However, the release of ibuprofen could be completed just after about 1 h from the pure silica MCM-41 under the same release conditions. Furthermore, the release rate of ibuprofen could be well modulated by changing the grafted content of TMS groups, and was found to decrease with increasing grafted amount of TMS groups.