An improved seed growth method for accurate stereo matching in disparity space

Matching is a classical problem in stereo vision. To solve the matching problem that components cannot continue growing on the occlusions region and repetitive patterns, an improved seed growth method is proposed. The method obtains a set of interesting points defined as initial seeds from a rectified image. Through global optimization the seeds and their neighbors can be selected in- to a match table. Finally the components grow with the matching points and create a semi-dense map under the maximum similar subset according to the principle of the unique constraint. Experimental results show that the proposed method in the grown process can rectify some errors in matching. The semi-dense map has a good performance in the occlusions region and repetitive patterns. This algorithm is faster and more accurate than the traditional seed growing method.

Vertical Bridgman Seeded Growth of Cd_(1-x)Zn_xTe Crystals

The method of vertical Bridgman seeded growth of Cdi.Zn.Te crystals was studied. This method ispromising in obtaining large size single crystals and improving the crystal structure. However, some prob-lems such as seeded growth failurc exist at present.(111)-oriented Cd_(0.96)Zn_(0.04)Te single crystal substrateswith size greater than 15×15 mm￣2 arc obtained. The FWHM ranges from 18 to 66 arc.sec and theresistivity is greater than 10￣6 obmem.

Effect of Wood Vinegar on Seed Germination and Water Implantation of Corn

To analyze the effect of wood vinegar on seed germination and seedling growth, the seeds of corn are dipped in wood vinegar of different densities. The results showed that significant effects were found through all the treatments on the seed germination rate, the seed germinating energy and the germinating index. The regress CUBICS curves were developed to describe the relation. The reasonable parameters range was obtained. At the same time, the corn was cultivated by wood vinegar of different densities, aiming to study the effect of wood vinegar on biomass. It showed that all treatments had obvious effects on the seedling length and dry weight aboveground, the chlorophyll and dry weight underground were not included. The research results could be used to direct the wood vinegar deeply refining process and product development.

Some Aspects of Yield Physiology Research in Soybean

The paper reviews the factors and mechanisms involved in the regulation of seed growth,discusses the roles of source sink relationship in yield formation and effects of climate change and canopy photosynthesis on groth and yield in soybean.

Effects of imidacloprid and thiamethoxam as seed treatments on the early seedling characteristics and aphid-resistance of oilseed rape

Seed treatments with the neonicotinoid insecticides imidacloprid and thiamethoxam were evaluated to determine whether the chemicals at effective concentrations for aphid control would influence the germination and early growth of oilseed rape,Brassica napus.Treatment with imidacloprid or thiamethoxam did not affect the cumulative germination rate,but significantly inhibited establishment potential by suppressing root system development in the cotyledon stage.However,these alterations in seedling development in the thiamethoxam-treated seeds appeared not to be detrimental as leaves developed;in contrast,for the seedlings with imidacloprid as seed treatment agent,a significantly decreased shoot/root ratio was still evident at the late two-leaf stage.After two leaves developed,chlorophyll content per leaf in the thiamethoxam treatment was significantly higher than that of the control,while chlorophyll content per leaf in the imidacloprid treatment remained close to that in the control.Most other parameters,i.e.,height,leaf area,weight of stem,leaf or root,and other growth indexes,between the treatments and the control showed no significant difference.Additionally,it was found that storage time of the treated seeds had a significant effect on cumulative germination rate.Treatment 30 d before planting significantly reduced germination relative to that of the control.All of the plants treated with neonicotinoids were shown to have significant anti-aphid characteristics that persisted until the end of the trial.

ENDOGENOUS INHIBITORS IN SEED OF FRAXINUS MANDSHURICA RUPR AND THEIR EFFECT ON GERMINATION AND REGENERATION

Bioassay and GC-MS determination indicated that inhibitors of seeds of Fraxinus mandshurica Rupr were distributed mainly in zones of β-inhibitors (including ABA) and of high and low Rf value. The inhibitory activity of outer seed coat of the dormant seed (control treatment) was higher than that of seeds with only the inner coat attached e.g. ABA was 114 and 54ng/g fresh weight respectively. The inhibitory effect of No. 12 zone was even higher than ABA. The inhibitory activity of all the zones decreased after stratification (St) and burying (AO) treatment, especially that of the outer seed coat, whose ABA content decreased to 7(St) and 11(AO) ng / g(fw). However, the decrease in inhibition of root growth lagged bchind'thc decrease in germination. It is concluded that burial is advantageous to regeneration. Inhibitors of the outer seed coat and seeds were mostly destroyed under the adverse conditions of natural dissemination (Di treatment) indicating that Di was not conducive to regeneration. MS analysis revealed that the largest peaks of No. 6, 7 and 12 zones were linoleic acid, olcic acid and 17-C, 18-C, and 20-C long chain fatty acids. Several coumarins were found in No. 6 and 7 zones, and cadincncs, farncsol and scsquitcrpcncs were found in No. 6 and 12 zones having common bioorigins with ABA.

Engineering miniature gold nanorods with tailorable plasmonic wavelength in NIR region via ternary surfactants mediated growth

Plasmonic nanoparticles are endowed profound capability for sensing,biomedicine,and cancer therapy.However,the inaccessibly adjustable wavelength in near infrared(NIR)region window and size limit for the particles penetration in tumor strongly hinder their developments.Miniature gold nanorods(mini-Au NRs)with diameter less than 12 nm can effectively address this challenge due to the tiny size and tailorable NIR absorption.Herein,we adopt ternary surfactants(hexadecyl trimethyl ammonium bromide(CTAB),sodium oleate(NaOL),and sodium salicylate(NaSal))mediated growth strategy to precisely synthesize miniature Au NRs under micelle space-confinement.Importantly,the selectively dense accumulation of ternary surfactants can efficiently improve the micellar stacking parameters(p)and lower micellar free energy(F),further tends to achieve the formation of Au NRs with tiny diameter and high purity.Compared with that of conventional methods,the purity of mini-Au NRs up to 100%can be dramatically improved via varying the relative concentration of ternary surfactants.The diameter of Au NRs can be dynamically controlled to 6,8,and 11 nm through regulating the concentration of silver nitrate and the mole ratio of ternary surfactants.Such ternary surfactants system is favorable for the aging of tiny Au NRs,and further enables the aspect ratio-tunable in the region from 2.70 to 7.32,as well as tailorable plasmonic wavelength in wide NIR window from 700 to 1,147 nm.Therefore,our findings shed a light on the precise preparation of small sized plasmonic nanoparticles and pave the way to applications in biomedicine,imaging,and cancer therapy.

Preparation of Core-shell Structured Particles and Their Nucleation in Polyester:I. Preparation of Monodisperse SiO_2/PS Core-shell Composite Particles

To enhance the nucleation and crystallization properties of polyester (e.g., polyethylene terephthalate, PET), core-shell structured particles are used to improve these properties by controlling the inorganic dispersion properties in the polymers. In the paper, monodisperse particles of silica/polystyrene (PS) are prepared with both dispersion and emulsion polymerization techniques. The monodisperse silicon dioxide particles are first prepared with the seed growth method and modified by the coupling agents. Silica is properly modified with KH-570, and its size deviation is 3.0% or so. The modified silica then reacts with the mixture of ethanol, water medium, and monomer of styrene under dispersion polymerization. Results show that the dispersion polymerization technique is more suitable for monodisperse core-shell SiO2/PS particles than that of the emulsion. The morphology and molecular structure of the core-shell particles are investigated with the transmission electron microscope (TEM), and fourier transform infra-red spectroscopy (FTIR). The results show that the modified silica particles are successfully encapsulated with polystyrene. The average number of silica particles encapsulated into each polystyrene sphere decreases when the size of silica particles increases from 50 nm to 600 nm, and will approach one when the silica is greater than 380nm in size. The mass ratio for silica/PS particles in emulsion polymerization is 4.7/1, lower than that of 6.8/1 for dispersion polymerization, which is the first reported optimized data for preparing the similar monodisperse composite particles. Thus, the PS shell in the former is thinner than that in the latter.

KLN晶体生长与蓝光SHG特性

In this paper,ferroelectric tetragonal tungsten bronze type potassium lithium niobate(KLN)crystal with a size of 20mm×8mm×43mm was grown from a melt with a composition of 32mol% K 2CO 3,24mol% Li 2CO 3 and 44mol% Nb 2O 5 by the top seeded solution growth (TSSG)method.The KLN crystal as grown along [110]axis has a perfect crystal melt interface dominated by {110} and {210} facets.Lattice constants were measured by X ray diffraction (XRD) analysis performed on {001}and {110}natural faces of single crystal samples.The anisotropic thermal expansion behavior of the crystal was also studied along [001] and [110] axes,respectively by using a Shimadzu TMA 50 thermomechnical analyzer.For the purpose of crystal poling,the dependence of crystal capacitance vs.temperature in both heating and cooling cycles was measured and the ferroelectric Curie temperature was determined to be 514℃.The crystal was poled at 506℃ with a dc field of about 250 V/cm along the c axis of the sample,for a time corresponding to about 1.5 h/cm.The blue second harmonic generation (SHG)characteristics of the KLN crystal were investigated by using a 3900s Ti∶sapphire CW tunable laser.Blue laser light at wavelength 432nm was obtained by the non critical phase matching (NCPM)SHG at room temperature.Based on the wavelength and temperature tuning curves for the NCPM SHG,the wavelength acceptance and temperature acceptance of this KLN crystal were measured.The crystal property homogeneity along the <110>growth axis was also studied by measuring the room temperature NCPM wavelength at different growth positions.

Combining the Curvature and Ligand Effects for Regioselective Growth on Au Nano-bipyramids

We demonstrate the regioselective growth of Au on Au nanobipyramids,either with etching of the tips,uniform coating except the tips,or forming a single island on the axial tip or an island on the equatorial corner.Importantly,the regioselectivity not only arises from the local curvature,as suggested by the recent literature,but also critically depends on the extent of ligand coverage on the seed surface.It is important to consider the competitive growth together with the curvature−ligand interplay:when there are insufficient ligands,they bind preferentially to the sharp tip for high surface energy,so that the remaining growth materials are diverted elsewhere;when the bipyramid is fully covered by ligands,the growth then selectively occurs at the tips because of the larger gaps among the ligands there.Our results demonstrate the great potentials in the rational design and synthesis when constructing sophisticated hybrid structures for functional nanomaterials.

Nucleation and Growth Mechanisms for Pd-Pt Bimetallic Nanodendrites and Their Electrocatalytic Properties

In a seed-mediated synthesis, nanocrystal growth is often described by assuming the absence of homogeneous nucleation in the solution. Here we provide new insights into the nucleation and growth mechanisms underlying the formation of bimetallic nanodendrites that are characterized by a dense array of Pt branches anchored to a Pd nanocrystal core. These nanostructures can be easily prepared by a one-step, seeded growth method that involves the reduction of K2PtCl4 by L-ascorbic acid in the presence of 9-nm truncated octahedral Pd seeds in an aqueous solution. Transmission electron microscopy (TEM) and high-resolution TEM analyses revealed that both homogeneous and heterogeneous nucleation of Pt occurred at the very early stages of the synthesis and the Pt branches grew through oriented attachment of small Pt particles that had been formed via homogeneous nucleation. These new findings contradict the generally accepted mechanism for seeded growth that only involves heterogeneous nucleation and simple growth via atomic addition. We have also investigated the electrocatalytic properties of the Pd-Pt nanodendrites for the oxygen reduction and formic acid oxidation reactions by conducting a comparative study with foam-like Pt nanostructures prepared in the absence of Pd seeds under otherwise identical conditions.

Seeded growth of Ti-46Al-8Nb polysynthetically twinned crystals with an ultra-high elongation

Large size polysynthetically twinned crystals of Ti-46 Al-8 Nb alloy with a parallel lamellar microstructure were successfully prepared using a Ti-43 Al-3 Si seed by our new operation.A large amount of columnar B2 phase paralleling to the growth direction was found in the final lamellar microstructure.Higher growth rate(>30 mm/h)led to the failure of seeding process.Based on these results,a new mechanism is proposed to describe the seeding process of the hypo-peritectic Ti Al alloys.The peritecticαphase is suggested to directly nucleate from the melt,and then act as nucleus for transformedαphase in the subsequentβtoαtransformation.At the higher growth rate,the appearance ofβphase secondary dendrites and homogeneous nucleation lead to the failure of seeding process.High Nb addition leads to a large amount of residualβphase,and theseβdendrites finally evolve into B2 phase.The room temperature tensile elongation was measured to be 11.9-18.5%for Ti-46 Al-8 Nb PST crystals,which is the highest ever reported value for Ti Al based alloys.

Cooperative interactions among CTA^＋, Br^-and Ag^＋ during seeded growth of gold nanorods

We have carried out a comprehensive study on the formation mechanism of Au nanorods （AuNRs） in binary surfactant mixtures composed of quaternary ammonium halide and sodium oleate （NaOL）. We identify the cetyltrimethyl ammonium （CTA）-Br-Ag^＋ complex as the key ingredient in directing the anisotropic growth of AuNRs. Based on the improved understanding of the cooperative interactions among CTA^＋, Br^- and Ag^＋, we further demonstrate that AgBr, which is readily solubilized by the cetyltrimethyl ammonium bromide （CTAB） or cetyltrimethyl ammonium chloride （CTAC） micelles, can be employed as the combined source of Ag^＋ and Br^- for the preparation of AuNRs. The growth of high-quality AuNRs can be completed within 15 min under extremely low bromide content （0.1 mM）.

Ag^＋-assisted heterogeneous growth of concave Pd@Au nanocubes for surface enhanced Raman scattering （SERS）

AgNO3 is often used in the preparation of Au nanostructures since Ag-based substances （AgBS） can selectively be adsorbed on Au（100） and significantly modulate the growth of Au nanocrystals. High-index-faceted Au nanostructures have demonstrated excellent performance in catalysis and surface enhanced Raman scattering （SERS）, thus attracting the interest of many researchers in the past several decades. Herein, high-index-faceted Pd@Au concave nanocubes （CNCs） were prepared using AgBS as growth-directing agents in the heterogeneous growth of Au on Pd nanocubes （NCs）. During the growth of Pd@Au CNCs, Au atoms are initially deposited on the Pd{100} facets leading to the formation of thin Au shells, and then AgBS are quickly adsorbed on the formed Au（100）, favoring the growth along 〈111〉 and the formation of Pd@Au CNCs. Transmission electron microscopy （TEM）, high resolution transmission electron microscopy （HRTEM）, energy dispersive spectroscopy （EDS）, high angle annular dark field （HAADF）, and scanning transmission electron microscopy EDS （STEM- EDS） were used to systematically investigate the growth of Pd@Au CNCs. We also demonstrated that the high-index-faceted Pd@Au CNCs exhibited excellent SERS performances.

Steady-state solution growth of microcrystalline silicon on nanocrystalline seed layers on glass

The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented.This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, which are prepared in a preceding process step. Scanning electron microscopy and atomic force microscopy investigations reveal details about the seed layer surfaces, which consist of small hillocks, as well as about Sn inclusions and gaps along the glass substrate after solution growth. The successful growth of continuous microcrystalline Si layers with grain sizes up to several ten micrometers shows the feasibility of the process and makes it interesting for photovoltaics.