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Ceratovacuna lanigera Zehntner is a major leaf pest of sugarcane. Widely distributed, it affects both the yield and quality of sugarcane in China. This study aimed to assess real yield and sugar yield losses, and the effect of C. lanigera damage on emergence of newly planted and ratoon cane under current production levels. Field experiments were carried out from 2014 to 2016 in Yunnan Province China. At maturity, plants were harvested and weighed to determine yield, and the effect on sugarcane quality and sucrose content analyzed. Real yield decreased by average of 46,185 kg hm−2 (range: 37,545–61,845 kg hm−2) in damaged versus undamaged areas, with an average yield loss rate of 35.9% (28.5–45.7%). Juice yield decreased by an average of 3.01% (2.4–4.13%) and sucrose content by 6.38% (5.48–8.16%). Juice brix decreased by an average of 7.66°BX (6.95–9.05°BX) and juice gravity purity by 12.35% (8.43–19.97%). In contrast, the reducing sugar content increased by an average of 1.21% (1.01–1.3%). Emergence rates of newly planted cane decreased by an average of 26.0% (24.7–27.3%). The emergence number of ratoon cane decreased by 66,834 hm2 (57,429–76,238 hm−2) and relative emergence loss rates of ratoon cane decreased by an average of 57.8% (57.6–58.0%). These findings confirm that C. lanigera damage severely affects sugarcane yield and quality in Yunnan Province. The results will help the implementation of effective control measures, thereby supporting sustainable development of the Chinese sugar industry.
The numerical simulations for cycloidal propellers based on five aerofoils with different thickness are presented in this paper. The CFD simulation is based on sliding mesh and URANS. The results of CFD simulation indicates that all test cases share similar flow pattern. There are leading edge vortex and trailing-edge vortex due to blade dynamic stall. Interaction between the vortices shed from upstream blade and the downstream blade can be observed. There is variation of blade relative inflow velocity due to downwash in the cycloidal rotor cage. These factors result in large fluctuations of the aerodynamics forces on the blade. The comparison of the forces and flow pattern indicates that the thickness and leading edge radius of the aerofoil can significantly influent the flow pattern and hence the performance of the cycloidal propeller.
Reciprocal space mapping using synchrotron-based x-ray diffraction has been used to study the effects of strain and strain relaxation in (111) oriented thin films of In2O3 on cubic Y-stabilized ZrO2 over a range of epilayer thicknesses between 35 and 420 nm. Maps around the epilayer (1026) reflection show that the 35-nm film is highly strained with a lateral periodicity close to that of the substrate, while the 420-nm film is almost completely relaxed. Analysis of the map for the former sample leads to an estimate of 0.31 for the Poisson ratio for In2O3. The mosaic spread deduced from transverse scans through the epilayer (444) and (666) reflections increases from 0.1° for the 35-nm-thick film to 0.3° for the 420-nm-thick film. These changes are discussed in relation to the morphological changes observed by atomic force microscopy.
N-doped Cu2O thin films have been deposited on glass substrate by reactive magnetron sputtering method under various N2/O2 flow ratios from 0 to 1.0. The structural and electronic properties of Cu2O:N films were investigated by X-ray diffraction (XRD), four-point probe and Hall effect measurements. XRD pattern showed that crystalline structures of all the samples retained single phase of Cu2O with the increase of N2/O2 flow ratio from 0 to 1.0. However, the crystalline quality of Cu2O:N films reduced with the increase of the N2/O2 flow ratio. The phenomenon of peak shift of Cu2O(1 1 1) implied that N atoms have been doped into Cu2O film. The square resistance of Cu2O:N films linearly decreased from 28.1 to 1.5 (104 Ω/☐) with the increase of N2/O2 flow ratio from 0.2 to 0.6 initially, and then it changed slowly with the increase of N2/O2 flow ratio from 0.8 to 1.0. Hole density of Cu2O:N films with various N2/O2 flow ratios from 0 to 0.6 was measured using the Van der Pauw method. All the samples are p-type, and the hole density of Cu2O:N films was enhanced from 1.2 × 1016 cm−3 to 3.1 × 1019 cm−3 with the increase of N2/O2 flow ratio from 0 to 0.6. The experimental results demonstrated that N doping was an effective method to enhance hole density of p-type Cu2O film.
AgSbTe2 is the critical component in both LAST-m and TAGS-x system, which are two state-of-the-art mid-temperature thermoelectric bulk nanocomposites. By adjusting the Ag2Te/Sb2Te3 ratio, Sb2Te3 and Ag2Te precipitated samples were obtained with x = 0.68 to 0.74 and x = 0.84 to 0.90 (x as in (Ag2Te)x/2(Sb2Te3)1-x/2), respectively. The single phased AgSbTe2 was obtained with the x value of 0.78 and 0.81, which is consistent of the previous results on the phase diagram of (Ag2Te)x(Sb2Te3)1-x system. Comparing the effect of the two different precipitates, Ag2Te are much effective for the improvements of thermoelectric properties in AgSbTe2 nanocomposites. Utilizing the high-resolution transmission electron microscopy, Ag2Te was observed as nanodots and nano-lamellae embedded in the AgSbTe2 matrix, which can be related to the energy filtering effect for the increase of Seebeck coefficient. The relationship among the composition, microstructure and thermoelectric properties was systematically studied. It can be noticed that the thermoelectric properties of AgSbTe2 system are very sensitive to the composition, especially at low temperature. The maximum figure of merit ZT value of 1.53 was obtained at 500 K for Ag0.84Sb1.16Te2.16 with 40% increase comparing with the single phased sample.
PbTe-based materials are promising for efficient heat energy to electricity conversion. We present studies of the thermoelectric properties of the PbTe-SrTe system. X-ray diffraction patterns reveal that all the samples crystallize in the rock salt structure without noticeable secondary phase. Na2Te doping of the PbTe-SrTe materials resulting in a positive sign Hall coefficient indicating p-type conduction. Lattice thermal conductivity is significantly decreased with the insertion of SrTe in PbTe lattice. The ZT ∼ 1.3 of these materials is derived from their very low thermal conductivities and reasonably high power factor at 800 K.
The Iron Project is an international consortium dedicated to the computation of atomic data for astrophysical applications. Although the project has been mainly concerned with ions in the iron group, the earlier papers gave priority to calculations of $A$-values and electron impact collision strengths for infrared transitions. In the present report we include a compilation of these data which will become useful in the spectral modelling of planetary nebulae.
An intermediate temperature solid oxide fuel cell (SOFC) electrolyte film of La0.8Sr 0.2Ga0.8Mg0.2O2.8 (LSGM) was fabricated using a plasma spray process. The microstructure and phase were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the thermal sprayed LSGM film was investigated using electrochemical impedance spectroscopy (EIS). The study indicates that thermal spray can deposit a dense LSGM layer. It was found that the rapid cooling in the thermal process led to an amorphous or poor crystalline LSGM deposited layer. This amorphous structure has a significant effect on the performance of the cell. Crystallization of the deposited LSGM layer was observed during annealing between 500–600 °C. After annealing at 800 °C, the ionic conductivity of the sprayed LSGM layer can reach the same level as that of the sintered LSGM.
Ruthenium sulfide samples were prepared by flowing pure hydrogen sulfide into an aqueous solution of ruthenium chloride followed by further sulfidation in hydrogen sulfide. The final products were characterized by X-ray diffraction and crystallite-sizes were estimated from line broadening. The specific surface areas of catalysts were measured using the multipoint BET method and compositions were determined by thermogravimetric analysis. Ruthenium sulfide loaded gas diffusion electrodes were fabricated by a spraying technique and their electrochemical behavior studied. The electrochemical oxidation of hydrogen was investigated in a three -electrode cell using a ruthenium sulfide loaded gas diffusion electrode as the working electrode with humidified hydrogen containing small amounts of carbon monoxide. Results on the activity and the effects of carbon monoxide with reference to a standard platinum electrode measured at the same conditions show that ruthenium sulfide has a lower activity for hydrogen oxidation but is not susceptible to CO poisoning.
Tin oxide films were deposited on sapphire and silicon substrates using reactive femtosecond pulsed laser deposition at temperatures ranging from room temperature to 700°C. The effect of electrical discharge and background oxygen pressure on the thin film microstructure was studied. The microstructure of the films was characterized by transmission electron microscopy and x-ray diffraction. SnO2 films fabricated consist of different textures in microstructures that depend on the deposition conditions and substrate surface structures. For instance, films deposited on the (1012) sapphire (R-cut) are amorphous if deposited at room temperature, whereas films deposited at 700°C were epitaxial, single crystalline. Discharge and oxygen pressure had a strong effect on the ion/neutral ratio of the ablated plasma plume of SnO2.
Transuranic nuclear wastes being disposed of in the Waste Isolation Pilot Plant (WIPP) contain large amounts of organic material that may decay producing substantial quantities of undesirable CO2. Because of this possibility a MgO backfill has been included in the repository design. In addition to scavenging CO2, the backfill may also hydrate forming Mg(OH)2. Backfill hydration may provide a sink that may sorb much, or all, of the brine that enters the repository. The key to understanding the full implications of including the MgO backfill lies in knowing the rates of the various processes that may operate as the repository ages and evolves. Both carbonation and hydration reactions were found to occur rapidly enough to have beneficial impacts on repository performance.
Recent calculations of electron and proton impact excitation rates in Ne VI are used to derive the intensity ratios of lines in the ~402–1006 Å wavelength range as a function of electron temperature (Te) and density (Ne). These results are presented in the form of ratio-ratio diagrams, which should in principle allow both Ne and Te to be deduced for the Ne VI line emitting region of a plasma. Electron temperatures and densities derived from ratio-ratio diagrams involving the 562.7, 997.4, 999.6 and 1006.1 Å lines, in conjunction with observational data for a sunspot obtained with the Harvard S-0555 spectrometer on board Skylab, are found to be compatible, and in good agreement with plasma parameters determined using other methods. This provides some support for the diagnostic calculations presented in this paper, and hence the atomic data used in their derivation. However agreement between theory and observation is very poor for other Ne VI lines in the sunspot spectrum, and for most transitions observed in S-0555 active region and flare data, which is probably due to blending with lines from N III, Mg VI and Mg VII. The application of the calculations to non-solar EUV sources is discussed.
An apparatus design is described. It is for detecting VHE gamma ray point sources by means of the atmospheric Cerenkov technique. Obviously, the improvement of flux sensitivity and discrimination between gamma ray and isotropic proton showers is still a key problem. Of course, it is necessary to set up more observatories and to track an object continuously with several facilities. With this in mind, we decided to develop an experiment for observing VHE gamma ray sources in China. As a first step, we will set up an apparatus which consists of three 1.5 m diameter searchlight morrors at Xinglong station of Beijing Observatory, Xinglong county, Hebei province (40°. 4N, 117°.5E, altitude 940 m). The observation will start in 1988. Then, the second apparatus will be set up at Delingha station of Purple Mountain Observatory, Delingha county, Qinghai porvince (37°.22N, altitude 3204 m). Both the sites are far from air and light pollution, and have suitable meteological condition for Cerenkov light detection as well as quite convenient facilities for transportation. Some probable technical improvements are also discussed in this paper.
High Resolution electron microscope observations of the effect of water vapour and the electron beam on high temperature superconductors indicate that the effects are very similar. Water vapour leads to the decomposition into a barium compound which in the microscope is barium oxide (presumably barium carbonate in air) which takes the form of whiskers on the surface and the green and brown phases. The electron beam first produces a true surface amorphous phase which on prelonged irradiation develops a barium oxide surface coating. Different from the results of ion beam damage, we have not seen any evidence for preferential formation of the amorphous phase at grain boundaries. These results indicate that as the oxygen content of the material is reduced, the barium cations become more mobile and can therefore diffuse out to the surface.
Electron microscopical analysis of brown powders of composition YBa2Cu3O6.5 produced by oil quenching and conventionally produced orthorhombic GdBa2Cu3O7-δ show in both cases clear evidence for site exchange both between the different heavy metals and the heavy metals and the copper sites. For instance, the brown powder is a mixture of phases which are based upon two trigonal phases, both with a=0.536 and c=0.666 nm, one with the Y atoms stacked on the (111) planes of the parent perovskite structure and the second where the Y atoms of this structure have interchanged with one of the copper sites. The GdBa2Cu3O7-δ, material shows numerous planar defects on (001) planes which can be understood as copper rich regions with additional copper planes in the Ba or Gd sites. These results, together with earlier reports of order-disorder in YBa2Cu3O7-δ, strongly indicate that there exist ordering energies in these materials which may be important with respect to the current indications of the important of grain boundary phases in degrading the performance of some superconductors.
We have investigated the structure and composition of La2CuO4 (both pure and Sr-doped) and Nd(Ba2−xNdx)Cu3O7 using powder neutron diffraction. In La2−xSrxCuO4, Tc reacnes its maximum at x=0.15, after which vacancies are introduced in the 2D planes and superconductivity is destroyed. Superconductivity in La2CuO4 is not bulk. No evidence for nonstoichlometry in this material can be observed. In the Nd(Ba2−xNdx)Cu3O7 system, Tc is a complex function of oxygen ordering and electronic effects.
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