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221.
An ultraviolet laser diode system stabilized to an external Fabry–Perot cavity by using the resonant optical feedback method
is described. Both wide continuous sweep with fast response and drift compensation for long term operation are realized simultaneously
by performing feedforward control along with feedback control of the system parameters. By utilizing the capability of synchronized
sweep realized by the feedforward control, the modulation of the output frequency, due to dither for lock-in feedback control
of the system parameters, is almost perfectly canceled. The method described here is useful for developing diode laser systems
for practical use with such features as small short term fluctuation, long-term operability and fast continuous sweep.
PACS 42.55.Px; 42.60.By; 32.80.Pj 相似文献
222.
In this paper, we discuss the generalization of the Hecke's integration formula for the Epstein zeta functions. We treat the Epstein zeta function as an Eisenstein series come from a degenerate principal series. For the Epstein zeta function of degree two, Siegel considered the Hecke's formula as the constant term of a certain Fourier expansion of the Epstein zeta function and obtained the other Fourier coefficients as the Dedekind zeta functions with Grössencharacters of a real quadratic field. We generalize this Siegel's Fourier expansion to more general Eisenstein series with harmonic polynomials. Then we obtain the Dedekind zeta functions with Grössencharacters for arbitrary number fields. 相似文献
223.
Kozo Mochiji Michihiro Hashinokuchi Kousuke Moritani Noriaki Toyoda 《Rapid communications in mass spectrometry : RCM》2009,23(5):648-652
In the secondary ion mass spectrometry (SIMS) of organic substances, the molecular weight of the intact ions currently detectable is at best only as high as 1000 Da, which for all practical purposes prevents the technique from being applied to biomaterials of higher mass. We have developed SIMS instrumentation in which the primary ions were argon cluster ions having a kinetic energy per atom, controlled down to 1 eV. On applying this instrumentation to several peptides and proteins, the signal intensity of fragment ions was decreased by a factor of 102 when the kinetic energy per atom was decreased below 5 eV; moreover, intact ions of insulin (molecular weight (MW): 5808) and cytochrome C (MW: 12 327) were detected without using any matrix. These results indicate that fragmentation can be substantially suppressed without sacrificing the sputter yield of intact ions when the kinetic energy per atom is decreased to the level of the target's dissociation energy. This principle is fully applicable to other biomolecules, and it can thus be expected to contribute to applications of SIMS to biomaterials in the future. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
224.
Hideo ASAKAWA Masataka SASABE Ryuunosuke MIYAZAKI Haruo MATSUDA Fumio FUKAI Kazuki HANADA Hisashi HIRANO Seiichi TAKASAKI 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(5):181-187
Ferritin is an iron-storage protein and its serum level is known to increase in the patient of with inflammation and malignant tumor. To further elucidate the difference between ferritins from normal human liver tissue and that of cancer cells, their sialic acids were analyzed. The Western blot analysis and the cytochemical staining using anti-NeuGc antiserum indicated that ferritins from the human hepatocarcinoma tissue and malignant K562 cells contain NeuGc, but that from the normal liver does not. The result was also confirmed by HPLC analysis and MALDI-TOF/MS analysis of sialic acids which were derivatized by the DMB method. It was also shown that the sialic acid content in hepatocarcinoma ferritin was much higher than that in the normal liver ferritin. These results suggest that normal and cancerous liver ferritins are qualitatively and quantitatively different in sialylation. In addition, K562 cells were shown to express NeuGc even if the cells were cultured in serum-free media which lack NeuGc. This is of interest from the current concept that expression of NeuGc in human cells is due to uptake and utilization of exogenous NeuGc. 相似文献
225.
Xiaoqing Zhang Masahiko Shimoda Akinobu Toyoda 《Journal of Polymer Science.Polymer Physics》1994,32(8):1399-1406
The molecular motion of crosslinked polyepichlorohydrin (PECH) is studied qualitatively by NMR techniques. The results of temperature dependence of 1H T2 and T1 indicate that the crosslinking (crosslink density < 3%) restricts molecular motions of the polymer even far above its Tg. The 1H T1 minimum, corresponding to the large-scale chain-motion of crosslinked PECH, shifts to higher temperatures with increasing crosslink density. 1H T2 data also show that the crosslinking hinders free chain motions of the polymer above its Tg. The 13C T1 relaxation time is sensitive to such motional changes as well. 13C linewidths of crosslinked PECHs vary with the crosslink density in both the swollen state and the solid state. The mechanism of 13C linewidth broadening of crosslinked polymers is discussed in detail. In the case of PECH, the linewidth broadening is caused by changing molecular environment due to crosslinking (such as presence of various chemical shift structures and freezing effects in conformational environment as chain mobility decreases), rather than increasing correlation times, which shorten the relaxation time (T2) of polymer chains. © 1994 John Wiley & Sons, Inc. 相似文献
226.
Itsuo Mori Yoshikazu Fujita Minako Toyoda Miyoko Hamada Masao Akagi 《Fresenius' Journal of Analytical Chemistry》1992,343(12):902-904
Summary A simple and sensitive determination of cobalt(II) is based on its fluorescence reaction with p-hydroxy-2-anilinopyridine and hydrogen peroxide. The relative standard deviation is 2.5% (n=5). An application to pharmaceutical preparations is recommended.The application of diarylamine compounds in analytical chemistry. IV.-Part III see ref. [1] 相似文献
227.
Kimitoshi Fukudome Toshimitsu Suetsugu Takuya Ueshin Ryo Idegami Kazuki Takeya 《Applied Acoustics》2007,68(8):864-884
This paper proposes a method for the fast measurement of head related impulse responses (HRIRs) for all azimuthal directions using the continuous measurement method with a subject sitting on a servo-swiveled chair (SSC). The subject faces all azimuthal directions with a constant angular speed as the SSC rotates and hears corresponding spatial sounds. In our continuous measurement method, we use a maximum length sequence (MLS) as the excitation signal, record binaural signals using tiny microphones placed in the subject’s ear canal around 5 mm from the entrance, and feed them, along with the MLS signal, into a PC so that HRIRs can be extracted for all azimuthal directions and discrete elevations. In this paper, the underlying principles behind the method are described and conditions for successful implementation are examined through numerical simulations. Further, the validity of the proposed method is verified using a physical realization and empirical measurements. 相似文献
228.
Masaru Nishiguchi Yoshihiro Ueno Michisato Toyoda Mitsutoshi Setou 《Journal of mass spectrometry : JMS》2009,44(5):594-604
A new multi‐turn ion optical system ‘IRIS’ has been designed for use with a high‐performance time‐of‐flight (TOF) mass spectrometer, which satisfies the new design concepts of time focusing and phase space stability. It has an elliptical flight path composed of four toroidal electric sectors, with a flight path length for one lap of 0.974 m. Dimensions and voltages of sector electrodes have been optimized to satisfy theoretical requirements by simulations using surface charge method. Generally, multi‐turn instruments require an injection and ejection system to inject and eject ions. On the basis of this ion optical study, we have designed an injection and ejection ion optical system, which achieves time focusing for the total system. Furthermore, we have designed novel field‐adjusting electrodes (FAEs) for the perforated sectors in the injection and ejection systems, which accurately correct the electric potential around the perforated sector's hole. We have also used simulations to evaluate mass resolving power and ion transmissions for various lap numbers or flight path lengths. Through these we have confirmed that mass resolving powers of over 100 000 can be achieved with reasonable ion transmissions for a given set of initial conditions. Usually a multi‐turn TOF mass spectrometer with a closed optic axis has mass range limitations from overtaking ions. To solve this problem, a TOF segmentation method is proposed that identifies all peaks in a TOF spectrum, including those from overtaking ions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
229.
Masahisa Okada Yasusei Yamada Pin Jin Masato Tazawa Kazuki Yoshimura 《Applied Surface Science》2007,254(1):156-159
Nitridation of TiO2 films is performed by the simultaneous irradiation of low-energy N2+ and H2+ ions under substrate-heating condition. Spectroscopic observations of the resultant films clarify the formation of nitrogen-substituted TiO2 (TiO2−xNx) with large N fractions and the agglomeration of undesirable oxynitride species attributed to the deep states in the band gap. We find that the addition of a thin TiO2 cap layer on the ion-irradiated films improves the nitrogen bonding structure and distribution near the surfaces, leading to a good photocatalytic performance even in the visible region. 相似文献
230.
Stereoselective synthesis of the pentacyclic key intermediate 22 for (-)-lemonomycin (1) has been accomplished using the Ugi 4-CC reaction with our novel isocyanide 8, a cross-metathesis of 13 and allylsilane and a subsequent intramolecular Hosomi-Sakurai type reaction. 相似文献