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Understanding the genetic mechanisms of phenotypic variation in hybrids between domestic animals and their wild relatives may aid germplasm innovation. Here, we report the high-quality genome assemblies of a male Pamir argali (O. ammon polii, 2n= 56), a female Tibetan sheep (O. aries, 2n= 54), and a male hybrid of Pamir argali and domestic sheep, and the high-throughput sequencing of 425 ovine animals, including the hybrids of argali and domestic sheep. We detected genomic synteny between Chromosome 2 of sheep and two acrocentric chromosomes of argali. We revealed consistent satellite repeats around the chromosome breakpoints, which could have resulted in chromosome fusion. We observed many more hybrids with karyotype 2n= 54 than with 2n= 55, which could be explained by the selfish centromeres, the possible decreased rate of normal/balanced sperm, and the increased incidence of early pregnancy loss in the aneuploid ewes or rams. We identified genes and variants associated with important morphological and production traits (e.g., body weight, cannon circumference, hip height, and tail length) that show significant variations. We revealed a strong selective signature at the mutation (c.334C > A, p.G112W) in TBXTand confirmed its association with tail length among sheep populations of wide geographic and genetic origins. We produced an intercross population of 110 F2offspring with varied number of vertebrae and validated the causal mutation by whole-genome association analysis. We verified its function using CRISPR-Cas9 genome editing. Our results provide insights into chromosomal speciation and phenotypic evolution and a foundation of genetic variants for the breeding of sheep and other animals.

Hepatocellular carcinoma (HCC) is one of the most prevalent human cancers with high mortality. Long non-coding RNA heart and neural crest derivatives expressed 2 anti-sense 1 (HAND2-AS1) is down-regulated in several cancers including HCC, yet the precise mechanisms how HAND2-AS1 regulates cell survival in HCC remains poorly understood.

Epitaxial GaAs-on-Si is an ideal material system for studying the physics of mismatched heteroepitaxy of a polar semiconductor layer grown on a non-polar substrate like silicon. Understanding and optimization of the initial nucleation of GaAs on silicon is the most crucial step in the success of GaAs/Si heteroepitaxy. Molecular beam epitaxy (MBE) technique has been used to deposit hetero-epitaxial GaAs thin-film on off-angle Si (100) substrate using the three-step growth method. After optimizing the growth parameters of low temperature (LT) buffer layer and high temperature (HT) epilayer, XRD analyses were performed. Characterization results of the GaAs (004) films which were not subjected to annealing, show a full-width half maximum (FWHM) of 760.1 arc sec and a root mean square (RMS) surface roughness of lower than 1 nm for a scanning area of 10 μm × 10 μm.

The effects of annealing on epitaxial graphene on SiC substrates with various conditions are investigated. Results show that high pressure hydrogen atmosphere is more effective to decouple the epitaxial graphene from SiC substrate than that of a relative lower pressure process. Besides, the characteristic 2D-peak of graphene in Raman spectra disappeared with an annealing temperature 1000 °C, which means that the epitaxial graphene layer was decomposed in this condition. The study also shows that the decomposition of graphene can be effectively suppressed by increasing carbon vapor partial pressure through introducing ethylene during high pressure hydrogen annealing at 1000 °C. And the epitaxial graphene is successfully transferred to quasi free standing graphene by the annealing with an appropriate flow of ethylene.

The morphology of the in-situ etching process on Si-face and C-face 4H-SiC, by annealing in a hydrogen environment, is studied by atomic force microscopy (AFM). The uniform step-terrace morphology of both the Si-face and C-face 4H-SiC is achieved with the assistance of carbon/silicon flux. The full width at half maximum (FWHM) of Raman 2D peak for the graphene grown on the uniform step-terrace morphology of the Si-face and C-face is 36.2 and 22 cm-1, respectively.

Exogenous C application can improve the physicochemical properties and fertility of soil. This study was conducted to determine whether the application of biochar (BC) was better than straw for improving soil structure and crop growth. The short‐term effects of exogenous C application on the size distribution of water‐stable aggregates, organic C sequestration, and grain yield of winter wheat (Triticum aestivumL.) were investigated on a silty clay loam soil in the Guanzhong Plain, Northwest China. Biochar and straw were applied at equal C rates: 1, 3, and 10% in straw treatments (Str1.0, Str3.0, and Str10.0, respectively) and 0.8, 2.4, and 8% in BC treatments (BC0.8, BC2.4, and BC8.0, respectively). No‐C treatment (CK) was used as the control. The mass proportion of macroaggregates (>0.25 mm) was increased by 16.9% in BC2.4and 45.8% in BC8.0, and soil organic carbon (SOC) was increased by 13.2 to 155.1% on average in the BC treatments when compared with CK. A small quantity of BC (0.8 and 2.4%) increased microbial biomass C content but decreased dissolved organic C content, while a large quantity of BC (8%) had the reverse effects. Wheat yields were increased by 14.9 and 19.1% in BC0.8and BC2.4, respectively, while they were decreased by 37.3 and 90.1% in Str3.0and Str10.0, respectively, when compared with CK. Moderately heavy soil BC amendment (e.g., applied rate, 2.4%) is beneficial to soil structure improvement and wheat growth and effective for harmless disposal of excess plant residues in the Guanzhong Plain, Northwest China. Core IdeasBiochar addition enhanced macroaggregate formation and microaggregate agglomeration.Biochar particles mostly existed in the macroaggregate (>0.25 mm) fractions.Low and moderate biochar application at 0.8% and 2.4% increased microbial biomass C and wheat yield.Heavy straw application at 3% and 10% inhibited wheat growth and yield increase. Biochar addition enhanced macroaggregate formation and microaggregate agglomeration. Biochar particles mostly existed in the macroaggregate (>0.25 mm) fractions. Low and moderate biochar application at 0.8% and 2.4% increased microbial biomass C and wheat yield. Heavy straw application at 3% and 10% inhibited wheat growth and yield increase.

Sapphire substrate was treated by SiH4 under NH3 atmosphere before GaN growth and nanosize islands SiNx mask was formed on the substrate. Properties of GaN films were investigated by high resolution X-ray diffraction, photoluminescence and transmission electron microscopy. The results indicated that the SiH4 flow rate is an important factor affecting the size and density of SiNx mask besides SiH4 treatment time.The GaN films grown on the SiNx-patterned sapphire substrate revealed an epitaxial lateral overgrowth mode, which affected 3D to 2D growth time and the microstructures of GaN films. The lowest FWHM value of (102) rocking curve was 286 arcsec. as the SiH4 flow rate of 0.5sccm, with the calcultated edge-type dislocations density of 4.28×109cm-2.

A 100μm silicon carbide epilayer with mean doping concentration 6×1014 cm-3 was achieved on 3 inch silicon carbide substrate using a growh rate of 30 μm/h. Hydrogen gas foil rotation was adopted to improve the doping uniformity. The intra-wafer thickness and doping uniformity was 1.83% and 7.51%, respectively. Schottky diodes fabricated on this epilayer presented a breakdown voltage of 10kV. This is the first report of 10kV schottky diodes fabricated on silicon carbide epilayer made in China.

The epitaxial growth of Gallium Nitride (GaN) on 2 inch Si (1 1 1) substrates was investigated, and it was found that by inserting a surface nitridation layer prior to Aluminum Nitride (AlN) nucleation upon substrate, the discoid defects and cracks on the surface were suppressed. Furthermore, compared with the GaN epitaxial layer grown without nitridation, the one with a 30 sec. nitridation layer showed a twice brighter integrated photoluminescence (PL) spectra intensity and a (0 0 2) High-resolution X-ray diffraction (HRXRD) curve width of 13.6 arcminute. The crystalline quality of GaN epitaxial layer became worse when the nitridation time exceeded a critical value, and even more cracks appeared on the surface although no discoid defect appeared anymore.

Heavily P type In0.51Ga0.49As was grown with hole concentration from 3.3E19cm-3 to 4.6E19cm-3. Standard (001) surface Raman backscattering geometry was used to measure samples. Two mode behavior and LO phonon-plasmon-coupled mode (LOPC) were observed obviously. Raman peak of LOPC mode is insensitive to hole concentration. The full width at half maximum (FWHM) of LOPC and the intensity ratio of GaAs-like LO mode and LOPC mode depend on hole concentration. The coupling strength of GaAs-like LO mode and plasmons is weak when hole concentration is very high and Raman peak of LOPC mode is independence with increasing hole concentration.

Recently, electrospinning of nanofibers based on chitosan has been widely studied and numerous chitosan based nanofibers have been prepared, for the enormous possibilities of applications in various areas such as filtration, enzyme immobilization, tissue engineering, wound dressing, drug delivery, and catalysis. Because most of the chitosan based nanofibers are soluble in aqueous solutions and the other properties such as mechanical properties are not suitable for the further applications. It is necessary to improve the properties of chitosan based nanofibers. Various post-processing has been done to the chitosan based nanofibers and many post-processing products have emerged. This article discusses the post-processing of the chitosan based nanofibers involving methods, mechanisms, changes of nanofiber properties, and applications of the post-processing products in details. The post-processing is divided into alkali treatment, crosslinking, and functionalizing.

Yubei area exist thick mud shale, mudstone, gypsum mudstone and high pressure brine formation. In the course of drilling, the problems are most conspicuous which include well bore instability, bit balling and so on. In allusion to complex formation and complex accident, the polyamine form strong inhibitory polyamine collapse prevention drilling fluid on the basis of KCl-polysulfonate drilling fluid system was used in Yubei area. After the analysis on the mechanism of the strong inhibitory polyamine polymer drilling fluid system, the polyamine performance evaluation test made in laboratory shows that the drilling fluid system has good rheological property, high temperature resistance, clay and salt water pollution resistance. This drilling fluid system cooperate with KCl improve the ability of inhibition of drilling fluid, meet the requirements of stabilize borehole wall, which carried on the field test in YB A well has obtained good application effect.

High quality N-polar GaN films were grown by MOCVD on C-face 6H-SiC substrate etched by KOH eutectics at 300°C for 5min. A 50 nm high-temperature AlN buffer layer was used to release the lattice mismatch stress between GaN and SiC substrate. The N-polar GaN films grow on the C-face 6H-SiC substrate etched by KOH eutectics have a high crystalline quality and smooth surface. The full-width-at-half-maximum (FWHM) of (002) and (102) XRD spectra were 347.4 and 501.5 arcsec., respectively. The root-mean-square (RMS) of 3μm×3μm is 0.666 nm. The luminescence property of the N-polar GaN films was studied. The band-edge emission of photoluminescence spectra was at 364.6 nm with weak yellow luminescence near 560 nm. The stress in the films was also calculated from Raman spectra. The results indicated a tensile stress in the N-polar GaN films, which is mainly caused by mismatch of thermal expansion coefficient between GaN and SiC substrate.

AlGaN/InGaN/GaN double heterostructure high electron mobility transistor (HEMT) with In composition from 0.08 to 0.26 were grown by MOCVD. 2DEG density and mobility of different channel In composition were investigated. When In composition below 0.19, 2DEG density increased nearly linearly with In composition, and the mobility decreased a bit. While In composition over 0.19, phase separation became more serious, 2DEG density nearly not changed, and the mobility dropped sharply. A high 2DEG mobility of 1163 cm2/V·s with low sheet resistance of 342Ω/ was obtained with In composition 0.19.

Well KL11-2-1 is a wildcat well that located in KL11-2 structure, where sticking happened in position Ⅳ of Shahejie group, the accident happened again in the same position while drilling the sidetracked well KL11-2-1S on the base of Well KL11-2-1, Analysis reveals that the lithology in the place of the two sticking accidents is rufous mudstone. This kind of mudstone has the character of strong plasticity, swelling with water and very soft, the main reason of sticking is that the mud column pressure can not balance the soft mudstone creep pressure and the creep lead to borehole shrinkage. For solve the problem during drilling in this structure, this paper according to the characteristics of mudstone in this structure builted proper creep equation and creep mechanical computation module of soft mudstone, applied FLAC3D software to compute and analyze the creep characteristics, obtain borehole shrinkage rate plate with different depth and mud density, and the safe mud density that can inhibit the creep which lead to borehole shrinkage is given, the results show that for prevent the sticking accident occurred the safe mud density of the two sticking points of the well KL11-2-1/1S is 1.73 g/cm3 and 1.75 g/cm3.the results make significant sense in guiding the subsequent drill of the structure.

The main lithology of the formation under Permian in Malang sag is basalt, with the characteristic of strong abrasive and low drillability the ROP (rate of penetration) is low. This paper based on drillability experiment of the core from oilfield, established rock drillability model, computed the drillability grade of cone bit and PDC bits, optimized the bit combined with the bit structural features, the result indicates that in the basalt formation under Permian with low ROP the ROP enhanced more than 50% using the recommended bit, the research improved ROP drastically, shorten the drilling cycle, which attained the aim of excellent and fast drilling, and has an important instruction meaning for bit optimization of basalt formation.

The creep of salt layer often leads to tight hole and pipe sticking, while the deviation angle has an important impact on creep rate when drilling directional wells in salt layer. This paper firstly built the creep constitutive model according to the creep property of salt layers, and defined the creep parameters by field data and log data; then built geomechanics model and applied FLAC3D software to simulate the creep of salt layer, so the safe mud density window drilling the salt layers smoothly is obtained. at the same time, at last analyzed the effect of the deviation angle to the drilling in the salt layer, The conclusion is that when the overburden pressure is major principal stress, drilling mud density is certain, the creep rate increases with the increasing of the deviation angle, the safe mud density also increased, the high deviation angle directional well in salt layers is much more risky. The conclude makes great contribution to the optimizing deviation angle, designing well track and reducing the drilling troubles when drilling directional wells in the salt layer.

An excellent organic blue light-emitting diode based on 4,4′-bis(diphenylamino)-quinque(p-phenylene)s (OPP(5)-NPh) with a maximum luminance of up to 5000cd/m2 and a luminanous efficiency of 1.3cd/A was reported. This diode was made by using a wide band-gap hole-blocking layer, F-TBB instead of PBD in the OLED devices. We attribute the good performance to the one trade-off involved in the use of F-TBB to obtain higher luminance is the increased turn-on voltages and slightly decreased device efficiencies.

3-n-Butylphthalide (1) and its analogues, which are the main components in the volatile oil of celery as well as a wide range of umbelliferae and composite plants, have potential applications as hypotensive drugs because of their strong pharmacological activities, such as improving the microcirculatory system of man's brain, improving nervous function deficiency, antiasthma, anticonvulsion, inhibiting platelet aggregation, inhibiting prostaglandin (PG) F2a growth, enhancing blood flow volume, antitumorigenesis, hypotensive activity and so on, so the investigation on the syntheses and applications of them has attracted considerable attention. The significant synthetic methods of 3-n-butylphthalide and its analogues were summarized and discussed in this review and it is expected that it may be valuable for their further development and applications.

Four fluorine-containing X-branched oligophenylenes, X-OPP(5)-Fn, n= 1,2,3 and X-OPP(5)-CF3, have been synthesized and studied as potential hole-blocking materials. These molecular materials exhibit a low HOMO energy level (ca.6.5 eV) and a large energy gap (ca.3.5 eV), indicating that they can be employed as effective hole-blockers in blue-emitting organic EL devices. Four-layer organic EL devices consisting of CuPc as a hole injection layer, α-NPD as a hole-transporting and emitting material, X-OPP(5)-Fnor X-OPP(5)-CF3as a hole-blocker, and Alq3as an electron-transporter sandwiched between indium tin oxide (ITO) and LiF/Al electrodes were fabricated, and their performance was examined and compared with the widely used hole-blocker bathocuproine (BCP), the non-fluorine-containing X-branched analogue X-OPP(5)-Hand the X-branched analogue with one less phenyl ring, X-OPP(3)-F2. The preliminary results show that these new molecular materials, especially X-OPP(5)-F2, are excellent hole-blockers for blue-emitting organic EL devices.

A new catalyst system, CoCl2/tris(2‐(dimethyl amino) ethyl)amine (Me6 TREN), was used to catalyze the polymerization of methyl methacrylate (MMA) successfully through atom transfer radical polymerization mechanism. The control over the polymerization was not ideal, the molecular weight distribution of the resulting polymer (PMMA) was relatively broad (Mw/Mn = 1.63–1.80). To improve its controllability, a small amount of hybrid deactivator (FeBr3/Me6TREN or CuBr2/Me6TREN) was added in the cobalt catalyst system. The results showed that the level of control over the polymerization was significantly improved with the hybrid cobalt–iron (or cobalt–copper) catalyst system; the polydispersity index of the resulting polymer was reduced to a low level (Mw/Mn = 1.15–1.46). Furthermore, with the hybrid cobalt–iron catalyst, the dependence of the propagation rate on the temperature and the copolymerization of methacrylate (MA) with PMMA‐Br as macroinitiator were also investigated. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5207–5216, 2005

A novel series of monodisperse asymmetrically and symmetrically substituted diphenylamino end‐capped oligofluorenes, OF(2)‐NPhR, R= Hor An(An= 9‐anthryl) and OF(n)‐NPh, n= 2–4, has been synthesized by a convergent approach using palladium‐catalyzed Suzuki cross‐coupling. End‐capping of oligofluorenes with diphenylamino group(s) has been shown to offer advantages in terms of lowering their first ionization potentials, enhancing thermal stability, and inducing good amorphous morphological stability. By tuning the number of diphenylamino end‐caps and the chain length, the optimal conjugated length for optical and luminescence properties has been determined. Of all the hitherto reported oligofluorenes capable of serving as non‐doped blue emitters, OF(3)‐NPh, with an optimal conjugated length, exhibits some of the best hole‐transport and blue‐emitting properties. A maximum luminance of 7500 cd m−2and a luminance efficiency up to 1.8 cd A−1have been achieved.

A novel homologous series of highly soluble, multiple alkoxy end-substituted oligophenylenevinylenes (OPV) containing up to six phenyl rings were synthesized. In contrast to the lateral substituted OPVs, our theoretical and experimental evidences have shown that the electron donating groups incorporated at the ends of an oligomer do not affect co-planarity of the π-conjugated system. They can also promote a faster convergence of the HOMO–LUMO energy gap relative to those of unsubstituted OPVs suggesting a shorter effective conjugation length in this series. These end-substituted OPVs containing more than three phenyl-rings exhibit very high fluorescence quantum yields (more than 74%). Multi-layer LEDs using these end-substituted OPVs as emissive layers were fabricated and investigated. We have found that there is a bathochromic shift of the PL and EL maxima with an increase of chain length in this series. All these oligomer-based multi-layer LEDs show very low turn-on-voltage. In addition, the higher homologues of these oligomers suffered from severe interchain interaction leading to a dramatic decrease in the external quantum efficiency; however, this can be alleviated by doping the oligomer into the host matrix.

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