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排序方式: 共有2743条查询结果,搜索用时 15 毫秒
971.
Yamaguchi T. Morimoto T. Akeura K. Tada K. Nakano Y. 《Photonics Technology Letters, IEEE》1994,6(12):1442-1444
We propose a novel quantum well (QW) structure with two or four thin barriers inserted in which effective width of the well is mass-dependent. It is very useful for polarization-independent optical modulation. Incorporation of tensile strain is also discussed for further improvement of the polarization insensitivity. Fabrication of a modulator with lattice-matched QW's results in 6-V switching voltage with more than -10-dB extinction (--30 dB maximum) for both TE and TM modes over 29-nm wavelength range. Compared with the quasiparabolic QW, this new quantum well has better fabrication tolerance, wider wavelength range of operation, and higher yield 相似文献
972.
Kikkawa Sho Yamaguchi Takami Tanishita Kazuo Sugawara Motoaki 《IEEE transactions on bio-medical engineering》1987,(5):388-391
It is shown that time-varying velocity produces frequency modulation of the backscattered signal in ultrasonic Doppler flowmeters. Further, for blood flow in the ascending aorta, it is estimated that the spectrum of the backscattered signal would have a very wide bandwidth in the acceleration phase. 相似文献
973.
974.
Iwai T. Ohara S. Yamada H. Yamaguchi Y. Imanishi K. Jeshin K. 《Electron Devices, IEEE Transactions on》1998,45(6):1196-1200
This paper reports on a matching technique of the source and load impedance focused on a phase distortion of InGaP/GaAs HBT power amplifiers to simultaneously achieve a high efficiency and a high linearity performance. Load-pull measurements were done to maximize power added efficiency (PAE) and source pull measurements to minimize the phase distortion and adjacent channel leakage power (ACP). Our HBT exhibited a high PAE of 60.7% and an ACP at a 50 kHz offset frequency of -51 dBc for 1.5 GHz π/4-shift QPSK modulated signal with an output power (Pcut) of 31 dBm under a supply voltage of 3.5 V 相似文献
975.
K Yamaguchi M Mori A Kawai K Asano T Takasugi A Umeda T Kawashiro T Yokoyama 《Canadian Metallurgical Quarterly》1993,74(2):643-649
We systematically investigated the quantitative importance of pH and O2 saturation (SO2) of hemoglobin on the solubility coefficients (alpha) for six inert gases: sulfur hexafluoride, N2, ethane, cyclopropane, halothane, and diethyl ether. Measurements of alpha were made at 37 degrees C with SO2 of 0-1.0 and pH of 7.2-7.7 by use of whole blood obtained from three healthy subjects. No significant dependence of alpha on pH was demonstrated for sulfur hexafluoride, N2, halothane, or diethyl ether, but an appreciable augmentation of alpha with increasing pH was found for ethane and cyclopropane. No alpha value obtained for oxygenated blood differed statistically from that for deoxygenated blood. In addition to the basic findings on the effects of pH on alpha values of ethane and cyclopropane with the multiple inert gas elimination technique (data obtained from 22 patients with either interstitial pneumonia or chronic obstructive pulmonary disease), we also found that dependence of alpha on blood pH exerted no significant influence on the recovery of ventilation-perfusion distribution in the lung. We concluded that: 1) pH plays an appreciable role in determining gas solubilities in blood, 2) SO2 is not a decisive factor for gas solubilities in blood, and 3) the influence of various pH values in pulmonary capillaries on inert gas exchange is negligible. 相似文献
976.
N Shimojo Y Kohno T Katsuki K Honma K Yamaguchi H Tsunoo T Takahashi S Kaminogawa H Niimi 《Canadian Metallurgical Quarterly》1997,39(4):416-421
Juvenile absence epilepsy (JAE) is a common subtype of idiopathic generalized epilepsy (IGE). Hereditary factors play a major role in its etiology. The important function of glutamate receptors (GluRs) in excitatory neurotransmission, synaptic plasticity, and neurodevelopment suggests their involvement in epileptogenesis. A tetranucleotide repeat polymorphism in the non-coding region of the kainate-selective GluR5 receptor gene (GRIK1) on chromosome 21q22.1 provides the tool to investigate this candidate gene. The present association and linkage study tested the hypothesis that allelic variants of GRIK1 confer genetic susceptibility to the pathogenesis of JAE. Our family-based association analysis using the haplotype-based haplotype relative risk statistic revealed an association of JAE with the nine-repeat containing allele of the GRIK1 tetranucleotide polymorphism (chi2 = 8.31, df = 1, P = 0.004). Supportive evidence for linkage to a JAE related IGE spectrum (Zmax = 1.67 at GRIK1) under an autosomal dominant mode of inheritance and significant allele sharing (P < 0.05) among the affected family members suggest that allelic variants of GRIK1 contribute a major genetic determinant to the pathogenesis of JAE-related phenotypes. 相似文献
977.
E Otsuji T Yamaguchi N Yamaoka T Kotani H Tsurumi K Kitamura N Yamaguchi T Takahashi 《Canadian Metallurgical Quarterly》1993,53(3):168-174
Much recent research has been directed toward the use of monoclonal antibodies (MoAbs) for the immunodetection of solid tumors. In pancreatic cancer, conventional immunoscintigraphy using intact MoAbs remains disappointing. In this study, 125I-labeled F(ab')2 fragments produced by pepsin digestion of MoAb A7 were injected intravenously into nude mice bearing human pancreatic cancer, HPC-YS, xenografts that have previously been shown to react specifically with MoAb A7. The tumor tissue/blood ratio of 125I-labeled F(ab')2 fragments of MoAb A7 increased with time and was much higher than those for normal tissues. Moreover, the tumor tissue/blood ratio of 125I-labeled F(ab')2 fragments was greater than that of intact MoAb A7, although the F(ab')2 accumulation was less than that of intact MoAb A7 in the tumor. These results suggest that F(ab')2 fragments of MoAb A7 may be suitable carriers of radionuclides for immunodetection of human pancreatic cancer. 相似文献
978.
T Yamamura S Tsukikawa O Akaishi K Tanaka H Matsuoka A Hanai H Oikawa T Ozasa K Kikuchi H Matsuzaki S Yamaguchi 《Canadian Metallurgical Quarterly》1997,40(12):1425-1429
PURPOSE: It frequently is observed that widely varying prognoses are given for patients with the same extent of liver metastases from colorectal cancer, even though the same treatment is performed on these patients. One of the reasons for this variance is that prognostic factors for these patients have not been defined. This study was designed to elucidate which clinicopathologic factors were the most important in the prognosis of 73 patients with unresectable synchronous liver metastasis from colorectal cancer. METHODS: Univariate and multivariate analysis of 11 clinicopathologic factors were performed using the Cox proportional hazard model. Survival curves were generated using the Kaplan-Meier method. RESULTS: Extent of liver metastases was the most significant variable in this survival analysis, although the extent of lymph node metastases of the primary lesion also was significant. However, the method of treatment was not a significant determinant in the survival for patients with unresectable liver metastases. Median survival of patients with H1, H2, and H3 was 13, 12, and 6 months, respectively, and there was a significant difference between survival curves for patients with H1 and patients with H3. Median survival of patients with n0, n1, and n2 was 13, 7, and 7 months respectively, and there was a significant difference between survival curves for patients with n0 and patients with n2. Median survival of 6 patients with H1 and n0 and of 17 patients with H3 and n2 was 28 and 4 months, respectively. There was a significant difference in survival curves between these two groups. CONCLUSION: Longevity of patients with unresectable synchronous liver metastases from colorectal cancer is affected adversely by the presence of nodal metastases and extent of liver metastases. This should be considered in the planning treatment. 相似文献
979.
Seismic PSA was carried out for a typical liquid metal cooled fast breeder reactor (LMFBR) in order to study the rationalized seismic design, maintaining and/or improving safety during seismic event. The seismic sequence quantification identifies the dominant structures, systems and components (SSCs) to the seismic core damage frequency (CDF). The sensitivity analyses by reducing or increasing the seismic capacity for SSCs are used to examine the optimized seismic design in view of safety and economical aspects. The LMFBR-specific risk-significant SSCs are reactor coolant boundary, decay heat removal coolant path and reactor control rod, which are different from those of light water reactors (LWRs). The electrical power supply system has a minor contribution to the seismic CDF. The sensitivity study shows that passive safety features of LMFBRs are important to maintain and/or enhance seismic capacity. The passive safety includes the decay heat removal capability via natural circulation and safety measures without depending on the support systems such as alternating current (AC) electrical power, for example. On the course of seismic sequence quantification, a methodology to evaluate the probability of seismic-induced multiple failure has been developed and applied to the decay heat removal function. The results suggest the multiplicity of the triply redundant system is to be considered for the significant components such as the decay heat removal path when one considers the difference in the seismic response. 相似文献
980.
H Ueda K Yoshikawa T Hashimoto T Yamaguchi T Dousei A Moriguchi M Taniguchi S Taketani K Kawano T Tsujimura 《Canadian Metallurgical Quarterly》1996,93(2):120-125
Although the overall survival rates for patients with metastatic non-small cell lung cancer have not changed in the past two decades, meta-analytic studies have confirmed that a modest increase in mean survival time can be gained with platinum-based combination chemotherapy. With appropriate selection of patients, chemotherapy will have symptomatic benefits in more than 60% of patients, and concerns regarding the costs of chemotherapy will be lessened by the observation that in some instances chemotherapy is less costly than best supportive care. Until the end of the 1980s, apart from the few active agents and their analogues no new drugs became available, but in the past 5 years several new agents have shown promising results and are now being included in combination programs. Large-scale comparative studies, looking for the combination with the best therapeutic index, are awaited with great interest. The number of patients with non-small cell lung cancer is so great that even modest improvements in therapy will have a great impact on survival rates. 相似文献