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1.
Extensive creep cavitation in Ti, Nb and Cu containing precipitation hardened austenitic steels was found to limit the usefulness of deformation resistance to increase long-term creep rupture strength. The steels were microalloyed with boron and cerium that resulted in increase in creep rupture strength and ductility of the steels significantly. Grain boundary sliding and creep cavity nucleation and growth in the steels were suppressed greatly on microalloying. Auger spectroscopic analysis revealed the segregation of boron instead of sulfur on cavity surface and the absence of sulfur contamination of grain boundary upon the microalloying. Suppression of creep cavitation through the control of trace elements segregation along with the precipitation hardening increased the creep rupture strength of austenitic stainless steels. 相似文献
2.
Shozo Takata Masami Ogawa Peter Bertok Junro Ootsuka Katsumori Matushima Toshio Sata 《Robotics and Computer》1985,2(1):33-40
In this paper, a real-time monitoring system of tool breakage, which measures the cutting torque from the spindle motor current, is described. The system uses an auto-regressive (AR)-model which is adapted for the measured signal using the Kalman filtering technique. The tool breakage is detected by monitoring the residual, that is, the deviation of the observed signal from the estimated value obtained by the AR-model. Additional processing of the residual is introduced to discriminate the signature of tool breakage from the effect caused by the marked change in the cutting condition. To reduce the computation time, the fast calculation algorithm is adopted for estimating the coefficient vector of the AR-model. The monitoring experiment has proven the effectiveness of the system in a milling operation. 相似文献
3.
A. Giordana O. J. Glembocki E. R. Glaser D. K. Gaskill C. S. Kyono M. E. Twigg M. Fatemi B. Tadayon S. Tadayon 《Journal of Electronic Materials》1993,22(12):1391-1393
The results from an in-depth characterization of as-grown and annealed low-temperature GaAs layers deposited at less than
260°C are presented. The layers, amorphous as grown, became crystalline after annealing. The crystallization was documented
by several characterization techniques including photoreflectance, Raman spectroscopy, photoluminescence, transmission electron
microscopy, and double-crystal x-ray diffraction. The n-type conductivity of the annealed films was exploited for the construction
of a diode structure. 相似文献
4.
To improve diagnostic sensitivity for detecting low-level asbestos exposure (AEx) in patients, a new method was developed using an analytical transmission electron microscope (ATEM) for specimens of transbronchial lung biopsy (TBLB). The TBLB specimens from 28 patients were examined and the results were: 1) In cases with long-term AEx, the present method detected a large amount of asbestos fibers (AF) as well as asbestos bodies (AB) showing a good agreement with the results of light microscope (LM) which detected definite amounts of ferruginous bodies (FB). 2) In cases with short-term or suspected AEx, the LM failed to detect FB in some cases, but an appreciable amount of AF was detected using the present method, and AEx was disclosed through a second close interview. 3) Neither AB nor AF were detected in most of the cases without any dust exposure. Although small amounts of chrysotile fibers were observed in some cases, this might simply reflect the exposure level of urban dwellers. These results show that the ATEM applied to the TBLB specimens promises to confirm low-level AEx in such small specimens even if the patients were unaware of their past AEx. 相似文献
5.
Kyono C.S. Binari S.C. Kruppa W. Ikossi-Anastasiou K. Hier H.S. 《Electronics letters》1992,28(15):1388-1390
A seven monolayer AlAs layer was used as an etch stop at the emitter-base heterojunction of an Npn In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As HBT. The etch-stop HBTs displayed higher DC gain and similar microwave performance when compared to devices without the AlAs layer.<> 相似文献
6.
Masami Taguchi Junro TanakaToru Bundo Rei ItouKenta Shirai 《Journal of power sources》2011,196(1):470-474
The control of the growth of a Pb-based alloy grid is very important for extending the life of a lead-acid battery. In this study, the creep behavior of pure Pb was investigated in air, in a highly concentrated H2SO4 solution, and in a highly concentrated H2SO4 solution with the intermittent electrifying to the specimen electrode, which simulated the discharge-charge process of the lead-acid battery, in order to obtain the fundamental knowledge about the growth of the Pb-based alloy grid. The growth or the creep of pure Pb in the stress range of 4.0-6.0 MPa was advanced by a dislocation creep mechanism. The creep rate in a 4.5 kmol m−3 H2SO4 solution was also accelerated by the electrifying to the electrode. This suggests that the acceleration of the creep rate is closely related to the release of dislocations near the specimen surface by the electrifying. 相似文献
7.
Quantitative proteome analysis has become a versatile tool to understand biological functions. Although stable isotope labeling is the most reliable method for quantitative mass spectrometry, preparation of isotope-labeled compounds is time-consuming and expensive. Simple label-free approaches have been introduced, but intensity-based quantitation without standards is not generally accepted as reliable, especially for small molecules. We have developed a novel label-free quantitative proteome analysis using pseudo internal standards (PISs). This idea was derived from northern blotting analysis, in which housekeeping genes are used as standards to normalize and compare target gene expression levels in different samples. In many proteomics studies, most proteins do not change their expression levels under different conditions, and therefore, these proteins can be employed as pseudo internal standards. This new approach is simple and does not require additional standards or labeling reagents. The PIS method represents a novel approach for mass spectrometry-based comprehensive quantitatitation and may also be applicable to quantitative metabolome analysis. 相似文献
8.
Type 347 austenitic stainless steel (18Cr-12Ni-Nb) was alloyed with copper (3 wt pct), boron (0.01 to 0.06 wt pct), and cerium
(0.01 wt pct) with an aim to increase the creep rupture strength of the steel through the improved deformation and cavitation
resistance. Short-term creep rupture strength was found to increase with the addition of copper in the 347 steel, but the
long-term strength was inferior. Extensive creep cavitation deprived the steel of the beneficial effect of creep deformation
resistance induced by nano-size copper particles. Boron and cerium additions in the copper-containing steel increased its
creep rupture strength and ductility, which were more for higher boron content. Creep deformation, grain boundary sliding,
and creep cavity nucleation and growth in the steel were found to be suppressed by microalloying the copper-containing steel
with boron and cerium, and the suppression was more for higher boron content. An auger electron spectroscopic study revealed
the segregation of boron instead of sulfur on the cavity surface of the boron- and cerium-microalloyed steel. Cerium acted
as a scavenger for soluble sulfur in the steels through the precipitation of cerium sulfide (CeS). This inhibited the segregation
of sulfur and facilitated the segregation of boron on cavity surface. Boron segregation on the nucleated cavity surface reduced
its growth rate. Microalloying the copper-containing 347 steel with boron and cerium thus enabled to use the full extent of
creep deformation resistance rendered by copper nano-size particle by increase in creep rupture strength and ductility. 相似文献
9.
Paulsen R.E. Kyono C.S. Wang Y. Klein K.M. Lim I.-S. Tinkler S. Bellamak B. Odle D.W. Zhou Z. Dahl P. Giovanetto M. Makwana J. Patel S. Reno C. Lenahan P.M. Billman C.A. 《Electron Devices, IEEE Transactions on》1998,45(3):655-664
Process integration is approached from a built-in reliability perspective in order to develop a pre-metal inter-level dielectric (ILDO) module which may be integrated into a submicron CMOS process with embedded nonvolatile memory. The approach involves developing a fundamental understanding of the process parameters that modulate parasitics and impact reliability. The benefit of such an approach is a relatively simple process integration while achieving a highly manufacturable and reliable process. Several ILDO films have been characterized to understand the physical and chemical composition, process parameter dependencies, and gettering properties in order to define a process window from which to integrate the most manufacturable process 相似文献
10.
Kaoru Ogawa‐Mitsuhashi Koji Sagane Junro Kuromitsu Hiroshi Takagi Kappei Tsukahara 《Yeast (Chichester, England)》2009,26(11):587-593
L ‐Azetidine‐2‐carboxylic acid (AZC) is a toxic four‐membered ring analogue of L ‐proline that is transported into cells by proline transporters. AZC and L ‐proline in the cells are competitively incorporated into nascent proteins. When AZC is present in a minimum medium, misfolded proteins are synthesized in the cells, thereby inhibiting cell growth. The MPR1 gene has been isolated from the budding yeast Saccharomyces cerevisiae Σ1278b as a multicopy suppressor of AZC‐induced growth inhibition. MPR1 encodes a novel acetyltransferase that detoxifies AZC via N‐acetylation. Since MPR1 is absent in the laboratory strain of S. cerevisiae S288C, it could be a positive selection marker that confers AZC resistance in the S288C background strains. To examine the usefulness of MPR1, we constructed some plasmid vectors that harboured MPR1 under the control of various promoters and introduced them into the S288C‐derived strains. The expression of MPR1 conferred AZC resistance that was largely dependent on the expression level of MPR1. In an additional experiment, the galactose‐inducible MPR1 and ppr1+, the fission yeast Schizosaccharomyces pombe homologue of MPR1, were used for gene disruption by homologous recombination, and here AZC‐resistant colonies were also successfully selected. We concluded that our MPR1–AZC system provides a powerful tool for yeast transformation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献