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1.
Katsumi Katoh Shunsuke Ito Yuji Ogata Jun-ichi Kasamatsu Hiroshi Miya Masaaki Yamamoto Yuji Wada 《Journal of Thermal Analysis and Calorimetry》2010,99(1):159-164
In order to prevent the spontaneous ignition of nitrocellulose (NC), NC is stabilized by washing with industrial water in
its synthesis process. However, there is a possibility that the components in industrial water contribute to the thermal stability
of NC. In this way, the purpose of this study is to clarify the effect of industrial water components on the thermal stability
of NC. In experiments, a heat flux calorimeter was used to observe the thermal behavior of NC with the residue of vaporized
industrial water. The induction period of heat release of NC with 2-mass% residues was approximately 2–5 h shorter than that
of NC alone whose induction period was observed at 7 h. Those results indicate that the residue destabilized NC. On the other
hand, when the additive amount of the residue was increased, the induction period gradually increased as well. Based upon
these results, we assume that inorganic salts contributing to stabilization and destabilization competitively coexist in the
industrial water components. The same thermal analysis was performed on NC with CaCO3, CaSO4, CaCl, ZnSO4, NaCl, and CuCl. Those salts are predicted to exist in the industrial water. In the results, the induction period of NC with
2-mass% CaCO3 was approximately 15-h longer than that of NC alone, while the induction period with the inorganic salts CaSO4, CaCl, ZnSO4, NaCl, and CuCl was 4–5-h shorter. Therefore, when the industrial water components accumulate in NC, the destabilization
by inorganic salts such as CaSO4, CaCl, ZnSO4, NaCl, and CuCl and the stabilization by compounds such as CaCO3 are thought to countervail against each other. 相似文献
2.
W. Sato H. Ueno A. Taniguchi Y. Itsuki Y. Kasamatsu A. Shinohara K. Asahi Y. Ohkubo 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(3):665-668
The time-differential perturbed angular correlation (TDPAC) method was applied to a study on the behavior of 140Ce atoms implanted in highly oriented pyrolytic graphite (HOPG). Exponential-type gradual attenuation of the directional anisotropy
of the relevant γ-ray cascade was observed in the perturbation patterns. From temperature dependence of the relaxation rate,
a thermally activated dynamic motion of the probe atoms was suggested. 相似文献
3.
Shinichi Suzuki Yasuhiro Suzuki Hikoto Ohta Masaaki Kasamatsu Toshio Nakanishi 《Analytical sciences》2005,21(7):775-778
Thirteen arsenous acid samples of known origins and refining methods were collected. Each sample was subjected to quantitative analysis of any impurity elements present using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The trace elements selected were Sn, Sb and Bi for the reasons that they were considered not to be changed by their circumstances and that they showed high sensitivity to SR-XRF. These results obtained by both methods were compared and the correlation between these two methods was determined. The quantification of trace impurities obtained by SR-XRF using As as an internal standard showed good agreement with the results obtained by ICP-AES. The discrimination of refining method became possible by the comparison of these impurities' contents measured with non-destructive SR-XRF using several arsenous acid particles. 相似文献
4.
We propose a laser-diode-pumped Yb:YAG laser as a novel practical fiber amplifier pump source, and describe its first successful
application of high-output-power operation (850 mW=+29.3 dB m) of an Er3+,Yb3+-codoped fiber amplifier at 1.55 μm. We have developed both bulk and microchip Yb:YAG lasers and obtained 3.3 W and 2.7 W,
respectively, in the cw mode at room temperature. Laser-diode-pumped Yb:YAG lasers are shown to have a potential applicability
to such fiber amplifiers as Pr3+-doped amplifiers and Tm3+-doped amplifiers, as well as Er3+,Yb3+-codoped fiber amplifiers.
Received: 12 August 1999 / Revised version: 3 September 1999 / Published online: 20 October 1999 相似文献
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The 59Co and 55Mn NMR frequencies ν in Co2MnZ (Z = Si, Ge, Sn and Ga) were measured as a function of temperature T and pressure P by the cw method. The ν/ν4.2 value decreased faster for 59Co than for 55Mn with increasing T/TC especially in Co2MnGa, for which ∂ν/∂P was positive at 0°C in contrast to the results in other alloys. 相似文献
7.
A. Toyoshima K. Ooe S. Miyashita M. Asai M. F. Attallah N. Goto N. S. Gupta H. Haba M. Huang J. Kanaya Y. Kaneya Y. Kasamatsu Y. Kitatsuji Y. Kitayama K. Koga Y. Komori T. Koyama J. V. Kratz H. V. Lerum Y. Oshimi V. Pershina D. Sato T. K. Sato Y. Shigekawa A. Shinohara A. Tanaka K. Tsukada S. Tsuto T. Yokokita A. Yokoyama J. P. Omtvedt Y. Nagame M. Schädel 《Journal of Radioanalytical and Nuclear Chemistry》2015,303(2):1169-1172
8.
Tetracarboxylic dianhydrides were synthesized from hydrogenated trimellitic anhydride (HTA) and some diols to obtain novel poly(ester imide)s (PEsIs). The HTA-derived tetracarboxylic dianhydrides showed much higher reactivity with various diamines than conventional cycloaliphatic tetracarboxylic dianhydrides and led to PEsI precursors with high molecular weights (Mw). The results can be explained in terms of a spacer effect. The PEsI films were essentially colorless regardless of diol and diamine components owing to inhibited charge-transfer interactions. The HTA-derived PEsIs also exhibited excellent combined properties: relatively high glass transition temperatures (Tg), relatively low water absorption (WA), and relatively low dielectric constants. The outstanding processability (thermoplasticity and solubility) observed for the HTA-derived PEsIs was discussed on the basis of a non-planar/bent structure at the HTA-based imide units. The use of a fluorene-containing diol component was effective for enhancing Tg’s by restricted internal rotation and for reducing WA by a decreased imide group content. On the other hand, the use of 4,4′-biphenol as another diol gave rise to a prominent toughening effect without sacrificing other target properties. One of the HTA-derived PEsI systems can be a promising candidate as plastic substrates because of its excellent combined properties: a high Tg close to 300 °C, high optical transparency, significant toughness (elongation at break > 100%), and good thermo- and solution-processability. 相似文献
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Hyperfine fields at sp impurities in ferromagnetic CsCl type compounds GdZn and GdCd have been measured by NMR method. The
impurity hyperfine fields are always negative, indicating the negative polarization of s-like conduction electrons at impurities
on the Zn(Cd) sites, and are smaller at the beginning and end of each sp series. This trend of the hyperfine fields is similar
to that in Gd metal and is qualitatively understood by the Daniel-Friedel mechanism. 相似文献