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991.
Progressive failure from a circular hole in glass-fiber-reinforced plastics (GRP) under combined tension/torsion cyclic loading has been investigated. Thin-walled tubular specimens were used. The composition of the specimens was the same as in previous work. As pseudo-crack growth was observed under fatigue loading, leading to the final failure, fracture mechanics methods were applied to characterize the fatigue failure process. The energy release rate was used as a parameter for progressive failure. Fatigue life under combined cyclic loading was estimated on the basis of the relationship between pseudo-crack-growth rate and energy release rate. The prediced S/N lines agree with the experimental results in all except a few cases. 相似文献
992.
The authors fabricated Y-Ba-Cu-O/Au/AlOx/Nb and Y-Ba-Cu-O/AlOx/Nb Josephson tunnel junctions using electron-beam evaporation of Al and Nb films and natural oxidation. Sintered Y-Ba-Cu-O was used as the base electrode. Superconducting Josephson current and hysteresis of the current-voltage characteristics, which are typical features of Josephson tunnel junctions, have been observed at 4.2 K. RF-induced voltage steps at a voltage greater than 0.4 mV have been clearly observed, and RF-induced subharmonic steps have also appeared. The superconducting Josephson current was modulated by the magnetic field 相似文献
993.
Masayuki Okabe 《Computer Methods in Applied Mechanics and Engineering》1983,37(2):151-176
As a nonlinear least-square estimator the modified gradient method is presented interpolating the classical Gauss-Newton and steepest-descent methods in an effective way. Numerical observations are made in detail with some mathematical examinations. 相似文献
994.
Fuzzy sets provide a strong notation for representing real world concepts which are essentially vague. However they have problems caused by the restriction of numerical membership functions, restriction of logical expression, lack of context dependency, etc. These problems relate to the representation of the meaning of a concept. In this article, we propose Conceptual Fuzzy Sets (CFS), a new type of fuzzy sets which conform to Wittgenstein's ideas (Philosophical Investigations, Basil Blackwell, Oxford, 1953) on concept meaning. A CFS is realized as an associative memory, combining a long-term memory and a short-term memory thus reducing the complexity of knowledge representation. In addition to solving the above problems CFS provide simple formula for knowledge representation and the procedure to use this knowledge. We introduce an inductive method for constructing CFS based on neural network learning. the effectiveness of CFS and of the learning method is illustrated through their application to the recognition of facial expressions. © 1995 John Wiley & Sons, Inc. 相似文献
995.
In this paper, a new design scheme of multiloop predictive self‐tuning PID controllers is proposed for multivariable systems. The proposed scheme firstly uses a static pre‐compensator as an approximately decoupling device, in order to roughly reduced the interaction terms of the controlled object. The static matrix pre‐compensator is adjusted by an on‐line estimator. Furthermore, by regarding the approximately decoupled system as a series of single‐input single‐output subsystems, a single‐input single‐output PID controller is designed for each subsystem. The PID parameters are calculated on‐line based on the relationship between the PID control and the generalized predictive control laws. The proposed scheme is numerically evaluated on a simulation example. 相似文献
996.
Hideo Ohno Satoshi Konishi Takanori Nagasaki Toshimasa Kurasawa Hiroji Katsuta Hitoshi Watanabe Toru Matsuo 《Journal of Nuclear Materials》1985,132(3):222-230
The conductivity of a sintered pellet of Li8ZrO6 was measured in dry or wet argon atmosphere by the two-terminal technique with an AC Wheatstone bridge in the temperature range 350–1050 K. The temperature dependence of conductivity multiplied by temperature of Li8ZrO6 in a dry environment had two transition points at 426 and 833 K. The activation energies of conductivity in high, middle and low temperature regions were 103.2, 52.1 and 37.4 kJ/mol, respectively. The activation energies of conductivity agreed well with those obtained by temperature dependence of spin-lattice relaxation time of 7Li with pulsed nuclear magnetic resonance. 相似文献
997.
Cytotoxic cytidine analog, cyclocytidine, and antitumor immunopotentiator, lentinan, offered an opportunity of testing the effect of combined modality of cytocidal agent and immunopotentiator on spontaneous mammary tumors of mice. Lentinan did not improve the therapeutic effect of cyclocytidine; it only prevented the early toxic death of mice due to cyclocytidine in one strain of mice but not in the other strain. 相似文献
998.
An experience with a real-time two-dimensional echocardiographic system was presented. In this report a sagittal plane section, i.e., the section which was parallel to the long axis of the left ventricle was used. The two-dimensional section of the normal heart, mitral stenosis, interventricular septal defect (preoperatively and postoperatively), mitral prosthetic valve, pericardial effusion, and acute myocardial infarction were studied. Easy applicability, quick recording, and non-invasive nature of the procedure, make the indications widened including acutely distressed patients. We conclude that real-time two-dimensional echocardiography is one of the most promising cardiac examinations. 相似文献
999.
Osaka T. Matsubara H. Yamanishi K. Mizutani H. Okabe H. 《IEEE transactions on magnetics》1987,23(3):1935-1936
The read/write characteristics of electroless-plated perpendicular magnetic recording media for flexible disks were studied using commercial VHS and 8-mm VTR ring heads. Excellent results were shown for a medium composed of Co-Ni-Re-P plated on a non-magnetic electroless-plated Ni-P layer. A Ni-P underlayer of only 500 Å greatly improved the read/write characteristics of the disk. Reproduced signals over 300 kFRPI were observed for a system using a VHS head, andD_{50} = 134 kFRPI was obtained using an 8-mm head. 相似文献
1000.
Magnetic nanoparticles have shown promise in the fields of targeted drug delivery, hyperthermia and magnetic resonance imaging (MRI) in cancer therapy. The ability of magnetic nanoparticles to undergo surface modification and the effect of external magnetic field in the dynamics of their movement make them an excellent nanoplatform for cancer destruction. Surgical removal of cancerous or unwanted cells selectively from the interior of an organ or tissue without any collateral damage is a serious problem due to the highly infiltrative nature of cancer. To address this problem in surgery, we have developed a nanosurgeon for the selective removal of target cells using aptamer conjugated magnetic nanoparticles controlled by an externally applied three-dimensional rotational magnetic field. With the help of the nanosurgeon, we were able to perform surgical actions on target cells in in vitro studies. LDH and intracellular calcium release assay confirmed the death of cancer cells due to the action of the nanosurgeon which in turn nullifies the possibility of proliferation by the removed cells. The nanosurgeon will be a useful tool in the medical field for selective surgery and cell manipulation studies. Additionally, this system could be upgraded for the selective removal of complex cancers from diverse tissues by incorporating various target specific ligands on magnetic nanoparticles. 相似文献