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The present study investigated the dry matter yield (DMY) and arbuscular mycorrhizal (AM) colonization (internal hyphae, arbuscules, and vesicles) of two genotypes of zoysia grass (Zoysia japonica strain Aso and cv. Asagake) at three rates (10, 20 and 40 g N/m2/year) of application of digested slurry (DS) or mineral fertilizer. Soil chemical properties (available phosphorus concentration, pH and electrical conductivity (EC)) were also measured as factors associated with AM colonization. The fertilizer type (DS v. mineral fertilizer) had an effect on DMY depending on the plant genotypes but had little or no effect on AM colonization, and soil chemical properties, indicating that DS can be used as a substitute for mineral fertilizer; however, it is necessary to apply it taking into account the ratio of inorganic nitrogen (N). However, heavy DS application decreased colonization by internal hyphae. Furthermore, even at the lowest rate, the continuous application of DS decreased colonization by arbuscules and vesicles in both genotypes, which were associated with decreasing soil pH and increasing EC. The results suggest that zoysia grass should be fertilized with DS at a rate of <10 g N/m2/year in order to achieve a continuous association with AM fungi, although this range of N application is sub-optimal for zoysia grass production.
A backend processor has been constracted which is a pipeline for calculating the gravitational force exerted on one particle from the rest in an astrophysical many-body system (Sugimoto et al. '90). The first version of the processor, GRAPE-1 (GRAvity PipE), was designed with 8 bits floating point format for use in collision-free systems (Ito et al. '90). It is in operation at the speed of 120M flops equivalent.
Diverse environmental conditions surrounding preimplantation embryos, including available nutrients, affect their metabolism and development in both short- and long-term manner. Thioredoxin-interacting protein (TXNIP) is a possible marker for preimplantation stress that is implicated in in vitro fertilization- (IVF) induced long-term DOHaD effects. B vitamins, as participants in one-carbon metabolism, may affect preimplantation embryos by epigenetic alterations of metabolically and developmentally important genes. In vitro-produced bovine embryos were cultured with or without Roswell Park Memorial Institute 1640 vitamin mixture, containing B vitamins and B vitamin-like substances, from day 3 after IVF and we evaluated blastocyst development and TXNIP messenger RNA (mRNA) expression in the blastocysts by reverse transcription-quantitative polymerase chain reaction. The degree of trimethylation of histone H3 lysine 27 (H3K27me3) at TXNIP promoter was examined semi-quantitatively by chromatin immunoprecipitation polymerase chain reaction. Total H3K27me3 were also compared between the groups by Western blot analysis. The vitamin treatment significantly increased the rates of blastocyst development (P<0.05) and their hatching (P<0.001) from the zona pellucida by day 8. The mRNA expression of TXNIP was lower (P<0.01) in blastocysts in the vitamin-mixture-treated group concomitant with higher (P<0.05) level of H3K27me3 of its promoter compared with the control group. The total H3K27me3 in the vitamin-mixture-treated group was also higher (P<0.01) than that in the control group. The epigenetic control of genes related to important metabolic processes during the periconceptional period by nutritional conditions in utero and/or in vitro may have possible implication for the developmental programming during this period that may impact the welfare and production traits of farm animals.
This report of Commission 35, as in past reports, consists of some details of only a few selected topics. This is necessary because a survey of the entire field of stellar formation, structure, stability, evolution, pulsation, and explosions for the three year period from mid-1981 to mid-1984 would be excessively long. Our topics here, in order from the most massive stellar classes to the least are: Massive Stars (R.M. Humphreys), Rotation in Late Type Stars (W. Benz), Helioseismology (J. Christensen-Dalsgaard), Planetary Nebula Central Stars (E.M. Sion), Pulsations in Hot Degenerate Dwarf Stars (A.N. Cox and S.D. Kawaler), and White Dwarfs (V. Weidemann). There is some overlap in the reviewing of these last three reports because the topics are very closely related. Concentration in this dying stage of stellar evolution seems appropriate because of the great current interest in these matters.
The electronic band structures of monolayer molybdenum dichalcogenides, MoS2, MoSe2, and MoTe2 under either uniaxial or biaxial strain are calculated using first-principles calculation with the GW method. The imposed uniaxial strain is in the zigzag direction in the honeycomb lattice whereas the imposed biaxial strain is in the zigzag and armchair directions. It is found that the band gaps of these dichalcogenides almost linearly increase with the decrease of the magnitude of compressive strain, reach their maxima at some compressive strain, and then decrease almost linearly with the increase of tensile strain. It is also found their maximum band gaps are direct bandgaps.
For realizing the proof of mass production capablity or a move toward a GW/a production, 16%-efficiency project has been started setting the target of each parameter as V∝: 0.685 V/cell, FF: 0.735 and Jsc: 31.8mA/cm2. Up to FY2008, the target of each parameter independently has been achieved expect the efficiency. All of our research by adjusting the two resistance (Rsh and Rs) in the monolithically integrated 30cm×30cm-sized circuits. To improve the FF, double buffer structure with CBD-Zn(O,S,OH)x and MOCVD-ZnO is proposed and the thickness is adjusted by optimizing the Rs and the Rsh. As the result, FF of over 0.7 has been achieved for the first time in our CIS R&D since FY 1993.
Preparation processing to obtain 124 single phase films has been studied by MOCVD. The YBCO thin films which were fabricated on MgO(100) and SrTiO3(100) substrates, respectively, were obtained under both conditions of Ts(temperature of susceptor)=800°C and Po2(oxygen partial pressure)=17.5torr. It was found that the oriented peaks of 124 c-axis and of 123 a-axis were more prominent than others at the composition ratio(Y/Ba/Cu=l.0/2.7/4.7), using the MgO(100) substrates. The 123 a-axis oriented grain was observed by using SEM and TEM. We have obtained thin films which were dominant in the 124 phase on the SrTiO3(100) substrates. The film surface morphology on the SrTiO3(100) substrate was smoother than that on the MgO(100) substrate. The origin of a-axis oriented grain growth was explained by the surface step(about 10 À) on MgO(100).
The electrical properties associated with diamond charged particle- and photo-detectors were studied using charged particle-induced conductivity (CPIC) and photo-induced conductivity (PIC). The collection distance d, the product of the excess carrier mobility μ excess carrier lifetime T and electric field E, was used to characterize the diamonds. X-ray diffraction, Raman spectroscopy, photoluminescence, SEM and TEM were performed on CVD diamond detectors to investigate the limitations of the electrical properties. Correlations were found between the electrical properties and the material characterizations.
Two complementary techniques are used to study the electrical transport properties related to the use of diamonds as materials for ionizing radiation detectors. Transient photoconductivity using soft x-rays is used to probe the first few microns of the material, while ionizing particle-excited conductivity is used to probe the entire bulk of the material (1 millimeter). Both techniques measure the mean drift distance of free carriers, or the collection distance d. In addition, transient photoconductivity is able to extract the lifetimes and mobilities of the excited carriers. The collection distance measured by the two methods are in agreement, suggesting the material is homogeneous. At an applied field of 10 kV/cm, d is 25 to 30 microns, and, up to a field of 25 kV/cm, d has not saturated. The lifetime varies between 100 and 600 ps, and the mobility varies between 1000 and 4000 cm2/V-s, the range due to natural variations from sample to sample. The primary defects limiting the lifetime are believed to be nitrogen impurities and dislocations.
We synthesized the highly ordered mesoporous thin films with alkyltrimethyl-ammonium (CnTMA+). The arrangement of mesopores was depend on the Si/surfactant ratio. The hexagonal(P6mm) arrangement was observed, when Surfactant/Si ratio was 1/10. Increasing the Surfactant/Si ratio to 1.6/10, the cubic (Pm3n) arrangements were observed. A steel vessel for the measurement of the nitrogen adsorption isotherms of thin film on the substrate was designed. It was found that mesopore arrangements in the film is more regular than that in the powder samples prepared by the same acidic synthesis conditions.
The electrical properties associated with carrier mobility, μ, and lifetime, τ, have been investigated for the chemical vapor deposited (CVD) diamond films using charged particle-induced conductivity and time resolved transient photo-induced conductivity. The collection distance, d, the average distance which electron and hole depart when driven by an applied electric field E, was measured by both methods. The collection distance is related to the carrier mobility and lifetime by d = μEτ Our measurements show that the collection distance increases linearly with sample thickness for CVD diamond films. The collection distance at the growth side of the CVD diamond film is comparable to that of single crystal natural type IIa diamond; at the substrate side of the film, the collection distance is near zero. No saturation of the collection distance is observed for film thickness up to 500 microns.
Diamond is suitable for use as an ionizing particle detector for high rate, high radiation, and/or chemically harsh environments. A sampling calorimeter, a detector measuring the total energy of an incident particle, consisting of 20 alternating layers of diamond and tungsten has been constructed and tested. The diamond for the detector layers was grown by chemical vapor deposition with an averaged thickness of 500 μm. The active area of each layer was 3×3 cm2 with ohmic contacts on opposite faces forming a metal-insulator-metal structure. The calorimeter was tested with electrons of energies up to 5.0 GeV. The response of the diamond/tungsten calorimeter was found to be linear as a function of incident energy. A direct comparison of diamond/tungsten and silicon/tungsten calorimeters was made.
A 32 Mbit chain FeRAM™ stack with 0.20μm minimum feature size was etched with two subsequent lithography/RIE steps: in mask step 1 the platinum/SRO (strontium ruthenium oxide) top electrode and the PZT (lead zirconate titanate) layer, in mask step 2 the bottom electrode together with the Ir/IrO2 diffusion barrier were etched. The stack was etched with various chlorine based chemistries. High temperature etching processes were applied to suppress residues by the formation of volatile etching byproducts resulting in a highly anisotropic etching profile and low redeposition.
Profile angles of 75° for step 1 and 80° for step 2 could be achieved. For the thin SRO-layer a separate etching recipe was developed to avoid surface roughening caused by micromasking. The influence of etching temperature and different gas chemistries on the etching behavior was evaluated. Reliable end point detection and good uniformity of the individual etching processes were obtained, both being crucial for the application of a multi-step recipe. The ferroelectric properties of the capacitor were confirmed by hysteresis measurements. This demonstrates that the ferroelectric properties were conserved during RIE etch processes at high temperature.
High quality Bi2O3 based Er-doped films for planar waveguide amplifier have been deposited by sputtering from sintered targets. It was found that both the amount of residual water and the Er concentration in films mainly affected a lifetime of the fluorescence at 1530nm. By optimizing these parameters, we have obtained films with a lifetime over 3msec, as the same as that of bulk glass prepared by the melting method.
For high density FeRAM devices small cell sizes are essential. The combination of the capacitor on plug (COP) structure with the Chain FeRAM™ cell design is used to develop a 32Mb FeRAM. Based on a 0.2 μm standard CMOS process a silicide capped polysilicon plug is used to contact the bottom electrode of the ferroelectric capacitor to the transistor. The barrier contact to the plug is formed by IrO2/Ir and a sputter deposited PZT (40/60) is used as ferroelectric material. The function of SrRuO3 (SRO) layers at the electrode/PZT interfaces is described in more detail. Double sided SRO results in slightly lower coercive voltage and imprint behavior compared to capacitors without SRO. Double sided SRO is essential to achieve excellent fatigue behavior measured up to 1×1011 switching cycles.
SiC thin films were formed on Si (111) at growth temperatures of 750–1000 °C using the molecular ion beam technique, with a precursor of methylsilicenium ions (SiCH3+). The chemical bindings and surface structures of SiC thin films were analyzed by Raman spectroscopy and reflection high-energy electron diffraction. As a result, 3C-SiC (111) was grown on Si (111) substrates without carbonized treatments.
Selective heteroepitaxial growth of α-Al2O3 thin films on a NiO layer was investigated using an electron-beam assisted pulsed laser deposition process. The epitaxial NiO layer was grown on an ultrasmooth sapphire (α-Al2O3 single crystal) (0001) substrate. The α-Al2O3 thin film could be grown epitaxially only in the electron-beam irradiated region of the epitaxial NiO layer at 300°C, while the amorphous Al2O3 film was grown in the non-irradiated region. The homoepitaxial growth of α-Al2O3 thin films could not be attained on the sapphire (0001) substrate at 300°C. This indicates that the electron-beam irradiation enhances heteroepitaxial growth of the α-Al2O3 thin films on the NiO layer at 300°C. When we annealed the epitaxial Al2O3/NiO bilayer film at 350°C in a hydrogen atmosphere, we could reduce only the NiO layer to an epitaxial Ni metal layer, allowing the fabrication of epitaxial Al2O3/Ni (insulator/metal structure) films. The fabricated Al2O3/Ni bilayer films exhibited a very smooth surface.
In this study, the pn hetero-interface between Zn(O,S,OH)x buffer and Cu(InGa)(SSe)2 (CIGSS) surface layers is discussed in order to achieve the fill factor (FF) over 0.73 and the circuit efficiency of 16 % on aperture area of over 800 cm2. Two resistances, i.e. shunt resistance (Rsh) and series resistance (Rs), in the circuits are employed as a yardstick to evaluate the interface quality. Since there are no realistic yardsticks on the Rs, the difference between Voc and optimum-power voltage (Vop) (i.e. Voc-Vop [V/cell]) is applied as a simple tool to evaluate the Rs. It is emphasized that it is important to reduce the Rs mainly correlated to the buffer deposition process and, as a result, the interface quality. We consider the Rs is dependent on the remaining Zn(OH)2 concentration in the Zn(O,S,OH)x buffer deposited by a chemical-bath deposition (CBD) technique. As an approach to make the Rs minimize and the Rsh maximize simultaneously, adjusting the thickness of a CBD-Zn(O,S,OH)x buffer layer and a non-doped ZnO layer deposited by a metal-organic chemical vapor deposition (MOCVD) technique has been effective to reduce the remaining Zn(OH)2 concentration. Determining the optimized deposition procedure to achieve the FF over 0.700 consistently, the circuit efficiency of 15.3 % with aperture area of 856 cm2 and the FF of 0.717 has been achieved.