春小麦品种墨波成株期抗条锈基因遗传解析

为明确春小麦品种墨波成株期抗条锈性遗传基础,以墨波与感病品种Taichung29(T29)杂交创建F_(2∶3)分离群体,通过青海西宁市和海东市2个试验点2年田间病圃鉴定,应用植物数量性状主基因+多基因混合遗传模型单个分离世代分析方法对墨波/T29 F2群体的抗性遗传效应进行了分析。结果发现群体单株/家系的病害严重度和反应型在2个试验点均未呈现连续性分布,但是在不同区段内,群体株系间又表现出较明显的连续性变异,初步推测,墨波成株期对小麦条锈病抗性具有由主效基因和微效基因共同控制的特征;遗传分析结果表明,墨波的成株期抗条锈性最优遗传模型均为2对主基因遗传,并受微效基因影响,在海东市试验点用反应型数据分析得到的最优遗传模型为C-6模型2MG-EEAD,即2对等显性主基因遗传,在海东市及西宁市试验点用严重度数据分析得到的最优遗传模型均为C-1模型2MG-ADI,即2对主基因加性-显性-上位性遗传。

Dual-band multi-beam reconfigurable terahertz antenna based on graphene frequency selective surface

In this paper,a dual-band graphene-based frequency selective surface(GFSS)is investigated and the operating mechanism of this GFSS is analyzed.By adjusting the bias voltage to control the graphene chemical po-tential between 0 eV and 0.5 eV,the GFSS can achieve four working states:dual-band passband,high-pass lowimpedance,low-pass high-impedance,and band-stop.Based on this GFSS,a hexagonal radome on a broadband omnidirectional monopole antenna is proposed,which can achieve independent 360°six-beam omnidirectional scanning at 1.08 THz and 1.58 THz dual bands.In addition,while increasing the directionality,the peak gains of the dual bands reach 7.44 dBi and 6.67 dBi,respectively.This work provides a simple method for realizing multi-band terahertz multi-beam reconfigurable antennas.

Determination of Cadmium and Lead in Sugarcane by Graphite Furnace Atomic Absorption Spectrometer with Zeeman Correction

[Objective] The aim was to develop a rapid,simple method for determination of cadmium and lead in sugarcane samples by graphite furnace atomic absorption spectrometry.[Method] The method for determination of Cd and Pb in sugarcane by combined graphite furnace atomic absorption spectrometry and microwave digestion was used.[Result] The concentration curve was linear within the range of 0-0.80 μg/L the detection limits of Cd and Pb was 0.015 and 0.030 μg/L,respectively.The precision for elevenfold determination of Cd and of Pb at the 0.40 μg/L level were 1.8% and 2.3%（RSD）,respectively.Recoveries of 96.7%-98.2% for Cd and 104.6%-106.7% for Pb were obtained for two sugarcane samples and one certified reference material.[Conclusion] The proposed method has the advantages of simple operation,high sensitivity,and high efficiency;it was successfully used for determination of Cd and Pb in sugarcane samples.

Magnetic and microwave absorbing properties of M-type barium ferrite/graphene oxide composite microwave absorber

In order to improve the absorbing properties of M- type barium ferrite absorbing materials, M-type barium ferrite/graphene oxide composites with different graphene oxide contents were synthesized by the sol-gel autocombustion method. X-ray diffraction （XRD）, a scanning electronic microscopy （ SEM ）, a physical properties measurement system （PPMS-9）, and a vector network analyzer were used to analyze their structure, surface morphology, magnetic and absorbing properties, respectively. The results show that the absorbing band of the composite absorbing material is widened and the absorbing strength is increased compared with the pure M-type barium ferrite. The sample with the content of doped graphene oxide of 3% has the minimum reflectivity at 10 to 18 GHz frequencies. Hence, the doped graphene oxide effectively improves the absorbing properties of M-type barium ferrite.

Rapid microwave irradiation fast preparation and characterization of few-layer graphenes

Few-layer graphenes were fabricated from expandable graphite by rapid microwave exfoliation. Expandable graphite was irradiated in a domestic microwave in full power for 3 min, then soaked in mixed strong hydrogen nitrate and sulfuric acid with volume ratio of 1：1 for 24 h and re-irradiated, thus few-layer graphene sheets were obtained. Specimens gained from every step were selectively characterized by different techniques, such as SEM, XRD, Raman, AFM, XPS, FTIR and combustion elemental analysis. The results show that expandable graphite with loose, porous and worm-like morphology forms instantaneously in microwave irradiation with crackling sound and sparkles, which manifests physical exfoliation of graphene sheets. Few-layer graphene sheets with a dozen or more layers and average thickness of about 4.7 nm are obtained eventually after sequential treatment of microwave irradiation, mixed acid soaking and second microwave irradiation. The as-prepared few-layer graphenes still have high crystallinity and high purity with traces of oxide groups and without serious unrecoverable oxidation damage.

Low Temperature Plasma CVD Grown Graphene by Microwave Surface-Wave Plasma CVD Using Camphor Precursor

Hydrocarbon precursor such as methane has been widely used to grow graphene films and the methods of growing quality graphene films are dominated by thermal CVD （chemical vapor deposition） system. Graphene films grown by plasma process are generally highly defective which in turns degrade the quality of the films. Here, using a green precursor, camphor we demonstrate a simple and economical method to get high-quality graphene film on copper substrate by micro wave surface-wave plasma CVD at relatively low temperature 550℃. Graphene film grown using camphor shows superior quality than that of the film grown using methane. Results revealed that camphor precursor is a good alternative to hydrocarbon precursors for graphene research.

Tunneling Conductance in d_(x^2-y^2)+id_(xy) Mixed Wave Superconductor Graphene Junctions

Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 ＋ idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio （Δ1/Δ0） of two components for dx2-y2 ＋ idxy mixed wave. The zero bias conductance is nearly 2 and the conductance peak vanishes in doped graphene for a = 0 and Δ1/Δ0 = 1. The conductance increases with increasing the amplitude ratio of two components for α =π/4 and Δ1/Δ0 -- 1. The ZBCP becomes observable wide with 1 〈 EF/Δ0 〈 100 for α= π/4 and Δ1/Δ0 = 1. This property is different from that in normal metal/dx2-y2 wave superconductor graphene junctions.

Engineering graphitic carbon nitride with expanded interlayer distance for boosting photocatalytic hydrogen evolution

Regulating interlayer distance is a crucial factor in the development of two‐dimensional(2D)nanomaterials.A 2D metal‐free photocatalyst,such as graphitic carbon nitride(g‐C3N4),exhibits morphology‐and microstructure‐dependent photocatalytic activity.Herein,we report a straightforward and facile route for the preparation of unique lamellar g‐C3N4,by co‐firing melamine and ammonium chloride via microwave‐assisted heating.Through the decomposition of NH4Cl,the evaporation of NH3 gas can effectively overcome van der Waals forces,expanding the interlayer distance of g‐C3N4,thereby creating a lamellar structure consisting of nanosheets.Compared with bulk g‐C3N4,the NH3‐derived lamellar g‐C3N4 exhibits a larger specific surface area and enhanced optical absorption capability,which increase photocatalytic hydrogen production because of the highly active structure,excellent utilization efficiency of photon energy,and low recombination efficiency of photogenerated charge carriers.This study provides a simple strategy for the regulation of the g‐C3N4 microstructure toward highly efficient photocatalytic applications.

Dependence of Conductance of Corrugated Graphene Quantum Dot on Geometrical Features

Dependence of conductance of corrugated graphene quantum dot(CGQD)on geometrical features includinglength,width,connection and edge is investigated by the first principles calculations.The results demonstrate that theconductance of CGQD with different geometrical features is different from each other.The positions and amplitudesof discrete levels in densities of states and transmission coefficients are sensitive to geometrical features.The I-Vcharacteristics of graphene are modified by size and edge,it is surprise the current does not change monotonously butoscillatory with length.And they are slight change for different connections.

Nonlinear free vibration of graphene platelets reinforced composite corrugated plates

The nonlinear vibration of graphene platelets reinforced composite corrugated(GPRCC)rectangular plates with shallow trapezoidal corrugations is investigated.Since graphene platelets are prone to agglomeration,a multi-layer distribution is adopted here to match the engineering requirements.Firstly,an equivalent composite plate model is obtained,and then nonlinear equations of motion are derived by the von Kármán nonlinear geometric relationship and Hamilton’s principle.Afterwards,the Galerkin method and harmonic balance method are used to obtain an approximate analytical solution.Results show that the unit cell half period,unit cell inclination angle,unit cell height,graphene platelet dispersion pattern and graphene platelet weight fraction and geometry play important roles in the nonlinear vibration of the GPRCC plates.

Bilayered semiconductor graphene nanostructures with periodically arranged hexagonal holes

We present a theoretical study of new nanostructures based on bilayered graphene with periodically arranged hexagonal holes （bilayered graphene antidots）. Our ab initio calculations show that fabrication of hexagonal holes in bigraphene leads to connection of the neighboring edges of the two graphene layers with formation of a hollow carbon nanostructure sheet which displays a wide range of electronic properties （from semiconductor to metallic）, depending on the size of the holes and the distance between them. The results were additionally supported by wave packet dynamical transport calculations based on the numerical solution of the time-dependent Schr/Sdinger equation.

Tunneling conductance in graphene ferromagnet/p wave superconductor junctions

Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of graphene ferromagnet/p wave superconductor junctions. It is found that the conductance spectra are affected by the p wave pairing symmetry. The ferromagnetic exchange energy in the ferromagnet can suppress Andreev retroreflection but enhance the specular Andreev reflection in graphene ferromagnet/p wave superconductor junctions. The conductance decreases with increasing exchange energy Eh for Eh〈Er （the Fermi energy in the ferromagnet region）, but the conductance increases with increasing exchange energy Eh for Eh〉EF.

SAW filter manufacture and piezoelectric materials evaluation based on printed electronics technology

In this paper, the silver nanoparticle ink and ink-jet printing technology are used to manufacture the surface acoustic wave(SAW) filters. The characteristics of three common substrate piezoelectric materials of ST-quartz, Y36°-LiTaO3 and Y128°-LiNbO3 are evaluated. The experimental results show that Y128°-LiNbO3 matches the ink much better than others. The printed SAW filter with Y128°-LiNbO3 as piezoelectric substrate is realized, and its center frequency and bandwidth are 18.4 MHz and 500 kHz, respectively.

A kind of graphene film metamaterial for terahertz absorbers

A kind of functional graphene thin film metamaterial on a metal-plane separated by a thick dielectric layer is designed for terahertz(THz) absorbers.We investigate the properties of the graphene metamaterial with different interlayers in the 0–3 THz range.The simulation results show that the absorption rate reaches up to 99.9% at the frequency of 1.917 THz.Changing the period to 80 μm×18 μm can get a narrow-band high quality factor(Q) absorber.We present a novel theoretical interpretation based on the standing wave field theory,which shows that the coherent superposition of incident and reflection rays produces standing waves,and the field energy is localized inside the thick spacers and dissipates through the metal-planes.

Oscillating Guided Modes in Graphene-Based Asymmetric Waveguides

We investigate the guided modes in monolayer graphene-based waveguides with asymmetric quantum well structure induced by unequal dc voltages. The dispersion relation for the guided modes is obtained analytically, the structures of the guided modes are discussed under three distinct cases. For the cases of the classical motion and the Klein tunneling, the asymmetric structure does not influence the mode structures dramatically compared with that in the symmetric waveguide. But for the mixing case of the former two, the mode structures and the motion characteristics for the electron and the hole exhibit different behaviors at same condition. The results may be helpful for the practical application of graphene-based quantum devices.

Pressure Wave and Fluid Velocity in a Bend-Mode Inkjet Nozzle with Double PZT Actuators

A new concept of bend-mode inkjet nozzle with double PZT (lead zirconate titanate) actuators has been designed and fabricated in the present study. Then the pressure wave and fluid velocity at the nozzle exit have been investigated. The complex pressure behavior inside the channel was solved numerically based on the narrow channel acoustic theory. The two PZTs attached to a rectangular channel were actuated sequentially by setting the waveforms of each PZT to be center-aligned with various pulse widths. As a result, the double PZT actuation is superior to the single PZT actuation in view of strong momentum force and fast dissipation of residual pressure. The maximum fluid velocity at the nozzle exit is observed when the respective pulse widths equal to their optimum pulse widths. The numerical results are supported by the experimental results with the fabricated inkjet device by measuring the speed of meniscus just out of the nozzle.

Excitation of Propagating Plasmons in Semi-Infinite Graphene Layer by Free Space Photons

By investigating the diffraction of plane waves by a semi-infinite solution for propagating surface plasmons in graphene, which can be excited graphene edge. The theoretical results are confirmed by numerical simulations. excite propagating surface plasmons in graphene where the graphene edge plays graphene layer, we present a rigorous by incident plane waves through the Our results reveal a convenient way to an important role.