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991.
Observation of Mode Patterns for High Purity Mode Operation in the Submillimeter Wave Gyrotron FU VA
T. Idehara I. Ogawa S. Maeda R. Pavlichendko S. Mitsudo D. Wagner M. Thumm 《International Journal of Infrared and Millimeter Waves》2002,23(7):973-980
Operation tests of a cavity designed for high purity mode operation of the submillimeter wave gyrotron FU VA has been carried out successfully. The observed emission patterns of several cavity modes appear very pure and are compared with calculated results. High purity mode operation has the advantage of making the conversion to Gaussian-like beams more efficient. 相似文献
992.
993.
Shoji Suehiro Takeshi Yamada Hajime Inagaki Thein Kyu Shunji Nomura Hiromichi Kawai 《Journal of Polymer Science.Polymer Physics》1979,17(5):763-790
The dynamic mechanical and birefringence behavior of three kinds of test specimens, prepared from a low-density polyethylene by different heat treatments, was investigated over the frequency range 0.008 to 4.3 Hz at various temperatures from 20 to 80°C. Reduction of both kinds of data to the common reference temperature of 50°C revealed rather broad frequency dispersions, corresponding to the α dispersion, with activation energies for the mechanical and optical relaxation processes of around 25 kcal/mole for all specimens. An annealed specimen was further investigated by dynamic x-ray diffraction to determine the dispersions of crystal orientation and of lattice deformation. The mechanical and birefringence dispersions are associated with the dispersion of crystal orientation and with the relatively elastic nature of the lattice deformation. Thus, the mechanical dispersion could be assigned to an α1 mechanism arising from rotation of crystallites within the spherulites, i.e., a type of grain-boundary phenomena, but not to an α2 mechanism resulting from a crystal disordering transition or premelting. Combining dynamic birefringence with dynamic crystal orientation, the mechanical α dispersion is further discussed in terms of dynamic orientation behavior of noncrystalline chain segments in order to elucidate the nature of the grain-boundary phenomena in detail in relation to the dynamic deformation mechanism of the spherulitic crystalline texture, i.e., reorientation of “crystal grains” within orienting lamellae due to intralamellar shearing resulting from the paracrystalline nature of the lamellae. A mechanical model characterizing the grain-boundary relaxation in association with the reorientation of the crystal grain is also proposed. 相似文献
994.
995.
Shigeru Maeda Kosuke Kumeda Mitsuru Maeda Shiro Higashi Toshio Takeshita 《应用有机金属化学》1987,1(4):363-370
An arsenic-resistant blue-green alga, Nostoc sp., was screened from an arsenic-polluted environment. The effects of the culture conditions on the growth and the arsenic bioaccumulation were investigated. In five culture media tested, Microcystis aeruginosa medium was found to be optimum for the growth. The effects of the concentration of five nutrients (P, Co, Fe, Mo and N) in the MA medium on arsenic bioaccumulation by the Nostoc sp. were also investigated. From the experimental results, the authors proposed a new culture medium which was designed for effective arsenic bioaccumulation by the Nostoc sp. The new medium was named the Modified MA medium (abbreviated as MMA). Removal of arsenic from an aqueous phase by means of arsenic bioaccumulation by the Nostoc sp. was investigated. When arsenic-polluted water was enriched with the nutrients of MMA, the arsenic level was found to be effectively lowered by the Nostoc sp. to 0.05 ppm. 相似文献
996.
S. Krishna Prasad Yoji Maeda Shankar D. S. Rao Anitha S. Nagamani Uma S. Hiremath C. V. Yelamaggad 《Liquid crystals》2003,30(11):1277-1283
The phase behaviour of two achiral bent core banana-shaped compounds, the hexyloxy (compound I) and decyloxy (compound II) members of the 1,3-phenylene bis[N-(2-hydroxy-4-n-alkoxybenzylidene)-4'-aminobenzoate] series was investigated under hydrostatic pressures up to 300 MPa using high pressure differential thermal analysis and light transmission methods. The reversible transition sequence crystal (Cr1)-B1 phase-isotropic liquid (I), observed at room pressure for compound I, remains in the pressure region up to c 70 MPa. At higher pressures a pressure-induced crystalline phase (Cri) appears between the Cr1 and B1 phases, its temperature region becoming wider with increasing pressure. The temperature vs. pressure phase diagram shows a triple point of 72.9 MPa and 160.3°C for the Cr1, Cri and B1 phases, indicating the lower limit of pressure for the Cri phase. In compound II the reversible transition sequence crystal (Cr1)-B2 phase-I is seen over the whole pressure region, and the temperature range of the B2 phase remains unaltered. It is concluded that both the B1 and B2 banana phases are stable over the whole pressure region studied. 相似文献
997.
998.
Thin-film 850-nm vertical-cavity surface-emitting lasers (VCSELs) were improved in light output power by designing both the reflectivity of the distributed Bragg reflector on the light-emitting side and also the degree of de-tuning between the photoluminescence peak and the etalon wavelength. Thin-film VCSELs, which were fabricated on A1N substrates by a functional layer transfer technique, are attractive components for the hybrid integration of optoelectronic devices. Their maximum output power was 2.8 mW and their slope efficiency was 0.40 W/A for the 15μm diameter VCSEL devices that we studied. Uniform spontaneous emission over the entire mesa area, and a single transverse laser mode up to 1.3 times the threshold current were confirmed by observing the near-field images. 相似文献
999.
Energy levels in 50V up to 4.3 MeV have been studied using the 49Ti(3He, d)50V and 51V(d,t)50V reactions with 3He particles of 22 MeV and deuterons of 19.5 MeV incident energy. More than eighty levels are seen, with angular distributions taken for forty-one levels in the (3He, d) reaction and for the ten lowest levels in the (d, t) reaction. The angular distributions are compared with the distorted-wave Born approximation (DWBA) to extract the l-values of the transferred nucleons and obtain the spectroscopic strengths. In the stripping reaction, a small amount of l = 0 and l = 2 strength is seen, indicating the presence of s and d proton holes in the g.s. of 49Ti. The results are compared with a recent shell-model calculation based on an configuration, and show qualitative agreement. 相似文献
1000.