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41.
This paper proposes an empirical relation, which represents
noise bias condition dependence for a silicon N-channel MOSFET. No matter whether the MOSFET is operated in linear or saturation region, bias condition dependence is found to be well described by a power function of voltage gain. By introducing a device's intrinsic
noise emf vnc(ƒ), which is independent from bias condition, and empirical parameter β, input-referred
noise voltage vni(ƒ) is clarified to be a function of vnc(ƒ), β, and voltage gain
, i.e.
. This relation implies that
noise voltage depends implicitly on bias condition through voltage gain, because transconductance gm and drain-source differential conductance gDS depend on bias condition. If β − 1 value is negligible, vni(ƒ) = vnc(ƒ) is almost independent from bias condition, whereas, if β − 1 value is not negligible, bias condition dependence for vni(ƒ) appears to be observed. The β deviation from unity, which characterizes bias condition dependence, measures the difference between signal amplification and
noise amplification. 相似文献
42.
43.
The aim of this study was to compare endocrine changes and the follicular development in patients receiving pure FSH alone or in association with LH after desensitization with an LH-RH agonist depot. Thirty four cycles were selected for this prospective randomized study. Desensitization was obtained using Goserelin the cycle before the stimulation. Induction of ovulation for IUI was carried out with 225 IU/day of pure FSH or with 225 IU/day of hMG. The number of days and ampules required for follicular maturation were equivalent in the two groups. The same number of follicles were developed, while different, but not significant, pregnancy rates were obtained. Estradiol values at the end of stimulation were significantly lower for FSH group. In conclusion the contemporary administration of LH with FSH does not exert any effect on follicular development, but it seems to facilitate E2 synthesis, probably providing more substrate for the aromatization process. 相似文献
44.
A foundation for economically optimizing the size of a local network area, defined as an area comprising a transit switch and a number of local switches homing on it, is obtained by introducing the concept of an "intra-area traffic ratio." The local network area radius is found to be optimal when the gradient of the intra-area traffic ratio relative to the area radius equals the ratio of the junction cost per kilometer to the cost per circuit for trunks going out of the area. An empirical formula for determining this intra-area traffic ratio is given. 相似文献
45.
Two granite and two concrete core samples were obtained within 500 m from the hypocenter of the Hiroshima atomic bomb, and the depth profile of 152Eu was measured to evaluate the incident neutron spectrum. The granite cores were obtained from a pillar of the Motoyasu Bridge located 101 m from the hypocenter and from a granite rock in the Shirakami Shrine (379 m); the concrete cores were obtained from a gate in the Gokoku Shrine (398 m) and from a pillar top of the Hiroshima bank (250 m). The profiles of the specific activities of the cores were measured to a depth of 40 cm from the surface using low background germanium (Ge) spectrometers. According to the measured depth profiles, relaxation lengths of incident neutrons were derived as 13.6 cm for Motoyasu Bridge pillar (granite), 12.2 cm for Shirakami Shrine core (granite), and 9.6 cm for concrete cores of Gokoku Shrine and Hiroshima Bank. In addition, a comparison of the granite cores in Hiroshima showed good agreement with Nagasaki data. Present results indicates that the depth profile of 152Eu reflects incident neutrons not so high but in the epithermal region. 相似文献
46.
M Urashima G Teoh A Ogata D Chauhan SP Treon Y Sugimoto C Kaihara M Matsuzaki Y Hoshi JA DeCaprio KC Anderson 《Canadian Metallurgical Quarterly》1997,3(11):2173-2179
Loss of p16(INK4A) (p16) expression is frequently associated with the development of epithelial and lymphoid malignancies. However, the frequency and significance of p16 abnormalities in multiple myeloma (MM) and the more aggressive phase of plasma cell leukemia (PCL) have not been well defined. Accordingly, the goal of this study was to define the expression and function of p16 in fresh samples of MM and PCL. We found that p16 protein was highly expressed in primary MM cells, although it was undetectable in fresh samples of PCL. Additionally, p16 protein was also absent in four of four MM-derived cell lines. To determine the mechanism for p16 underexpression in PCL and MM-derived cell lines, we performed PCR analysis to evaluate both gene deletion and the presence of methylation. Interestingly, the p16 gene was present and methylated in all patient PCL cells and MM cell lines, whereas it was unmethylated in patient MM cells and normal B cells. Furthermore, treatment with the demethylating agent 5-deoxyazacytidine or p16 retrofection restored p16 protein expression and induced G1 growth arrest in patient PCL cells and MM cell lines. These results suggest that inactivation of the p16 gene by methylation may be associated with decreased growth control and the development of PCL in a subset of patients with MM. 相似文献
47.
N Yabuki H Sasano M Tobita A Imatani T Hoshi K Kato S Ohara S Asaki T Toyota H Nagura 《Canadian Metallurgical Quarterly》1997,151(3):821-829
Helicobacter pylori (HP) infection, a cause of multifocal atrophic gastritis, is considered an important factor related to the evolution of the human gastric mucosa from normal to intestinal-type adenocarcinoma. We examined cell proliferation and both double and single strand DNA damage in situ in 35 patients undergoing gastrectomy for adenocarcinoma with HP-infected gastric mucosa by immunolocalization of Ki-67, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, and in situ nick translation. We also studied the distribution of intraepithelial neutrophils by elastase immunolocalization. HP infection was confirmed in all cases by serum anti-HP antibodies, ureas testing, and histopathological examination. HP-infected gastric mucosa was classified according to the degree of inflammation and intestinal metaplasia. Ki-67, terminal deoxynucleotidyl transferase-mediated labeling, in situ nick translation, and intraepithelial neutrophil indices all increased with the progression of gastritis and were highest in glands with incomplete intestinal metaplasia. All indices were lowest in gastric glands with complete intestinal metaplasia. Significant positive correlations were observed among these markers. Increased proliferative activity in HP-associated chronic gastritis in response to cell damage or injury was clearly demonstrated, suggesting that both HP-associated toxins and intraepithelial neutrophils are important in HP-related gastric epithelial injury. Increased cell turnover associated with incomplete intestinal metaplasia may result in DNA instability and subsequent development of intestinal-type gastric adenocarcinoma in HP-infected mucosa. 相似文献
48.
The stabilization mechanism by synergetic metal soaps containing complementary colors was previously reported. With increased heating times, the color of heated poly(vinyl chloride) (PVC) films containing Cd/Ba and Zn/Ca synergetic soaps markedly deviated from the polyene color. These color deviations usually decreased the thermal stability of PVC. Discoloration from polyene color to blue appeared especially on PVC films containing Zn/Ca synergetic soap and was concomitant with a marked decrease in thermal stability. The stabilization of PVC containing synergetic metal soaps can be improved by masking or removing the excessive color. In this work, the addition of various masking agents, such as ethylenediaminetetraacetic acid, o-phenanthroline, triethanolamine, urea, N,N′ -dimethylolurea, melamine, stearylamide, and lactams, to PVC containing synergetic metal soaps was investigated. It was shown that these masking agents do markedly slow down the discoloration of PVC. 相似文献
49.
The correlation between molecular interaction and traction properties was investigated using a traction tester and in situ observation of elastohydrodynamic lubrication film with a micro‐Fourier transform infrared spectrometer. The sample oils used were polypropylene glycols (PPGs) with the end‐group of alcohol or ether and a synthetic hydrocarbon oil, poly‐α‐olefin. From the traction tests, it was found that the traction coefficient of PPG was sensitive to the end‐group. PPG with alcohol as the end‐group showed a higher traction coefficient than that with the ether group. In situ observation with a micro‐Fourier transform infrared was performed in order to investigate the molecular interaction of the lubricant oil. It was found that the hydrogen bonding of hydroxyl groups in PPG was strengthened by high pressure in the Hertzian contact region. These results suggest that the rheological properties in the elastohydrodynamic lubrication contact region were affected by the strengthened hydrogen bonding. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
50.
In this article the basic characteristics of a piezoelectric actuator are theoretically analyzed, and the relationship between the thrust force and the weight force are clarified, and verified by the experiments. Various prototypes of plane ultrasonic piezoelectric actuators were experimentally constructed, and the fundamental characteristics mere measured. The vibration mode of the actuators was also analyzed by ANSYS, and compared with the experimental results 相似文献