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931.
With some models of computerized scanners, it is possible to obtain not only axial, but also coronal tomograms. This is feasible because a water bag is not used and limited tilting capacity is built into the gantry. The head is extended and the central ray directed perpendicularly to the base of the skull. The resulting views, orthogonal to the conventional axial views, furnish important complementary information. 相似文献
932.
A drum friction test was conducted on four different ‘flame-resistant’ and one ‘non-flame-resistant’ rubber conveyor belts with a fabric skeleton manufactured in Japan. These test results were compared with those obtained from the other flammability tests, i.e. a small-scale flame test, an oxygen index test and a laboratory-scale gallery test, and both sample and rank correlation coefficients were calculated. As a result, the authors have concluded that fire resistance of belting materials themselves could not be adequately assessed by the results from the drum friction test, which could have some significance only when other combustible materials exist near the drive pulleys or idlers of belt conveyors. 相似文献
933.
Kosaka S. Nakagawa H. Kawamura H. Okada Y. Hamazaki Y. Aoyagi M. Kurosawa I. Shoji A. Takada S. 《IEEE transactions on magnetics》1989,25(2):789-794
The authors describe the design and operation of a Josephson address control unit IC (integrated circuit), which will be used for controlling the instruction sequence of an experimental 4-bit Josephson microcomputer prototype system. The IC is composed of three sets of 7- to 10-bit-wide registers and combinational logic circuits driven by a two-phase monopolar power supply. 593 four-function logic gates have been used in the circuit and fabricated using 2.5-μm NbN/oxide/NbN junction technology with Mo resistors and SiO2 insulation. The operation of the circuit has been successfully tested for all the instructions which control the program sequence of the computer system 相似文献
934.
A new fiber optic baseband analog transmission plan is proposed. It arranges the original signal into a pulse train for driving the laser diode to generate baseband components at the transmitter. The receiver can be just the same as those used in conventional direct linear intensity modulation systems using light emitting diodes (LED). Advantages of this new plan are (i) potentially cheap fibers can be used, since the plan requires neither an extra wide bandwidth nor special light acceptance conditions, (ii) long repeater spacings can be attained, since abundant light can be coupled into fibers using laser diodes and also the simple structures required for fibers are suitable for realizing low transmission losses, and (iii) the transmitter and receiver can be quite simple. Some candidate pulse arranging plans for generating baseband components are investigated. A pulse frequency arranging plan and pulse width arranging plan seem to be promising for efficient picture transmissions. An experiment using pulse frequency arrangement proves the theory developed here to attain a color TV transmission using a 10 km long step index low-loss fiber for a signal to noise ratio of 44 dB. Future improvements are expected by redesigning the transmitter and receiver and also by improving the mode stability of laser diodes. 相似文献
935.
936.
This paper presents a solution method for the reliability optimization problem of series-parallel systems which is formulated as a mixed integer nonlinear programming problem with multiple constraints. In the solution method, the optimal solution is obtained by solving the surrogate dual problem. Surrogate problems with only one constraint which appear in the optimization process are solved by a technique using dynamic programming. Some computational experiences are shown along with the comparison with an existing approach. 相似文献
937.
Rat inflammatory neutrophils induced arachidonic acid release and platelet-activating factor (PAF) production in response to opsonized zymosan (OPZ) dose-dependently. Phospholipase A2 activity also increased dose-dependently, paralleling the increases in arachidonic acid and PAF. The time courses of the activities of phospholipase A2 and acetyltransferase, and the amounts of free arachidonic acid, lyso-PAF, and PAF demonstrated that activation of the enzymes in the remodeling pathway could be required for PAF production in rat neutrophils, which agrees with the documented fact for macrophages. Phospholipase A2 could be a rate-limiting enzyme for PAF production, since an increased lyso-PAF amount or addition of exogenous lyso-PAF reflected the increase in PAF formation in the cells. This phospholipase A2 activity in rat neutrophils could be attributed to cytosolic type phospholipase A2, because the activity was mostly suppressed by a specific antibody to cytosolic phospholipase A2. As previously reported, pretreatment of neutrophils with the acyl-CoA synthetase inhibitor, triacsin C, or the acyltransferase inhibitor, merthiolate, enhanced PAF production as well as arachidonic acid release by the cells in response to OPZ. Triacsin C inhibited arachidonoyl-CoA production and merthiolate suppressed the transacylation of lyso-PAF to 1-alkyl-2-arachidonoyl-GPC. These results suggest that these inhibitors of acylation of lyso-PAF caused accumulation of lyso-PAF, which resulted in enhancement of PAF production when phospholipase A2 and acetyltransferase were activated by OPZ. Thus the activation of cytosolic phospholipase A2 and the acylation of lyso-PAF by such as arachidonic acid could be regulating factors for PAF production in stimulated rat neutrophils. 相似文献
938.
A survey on applications of control technologies in Japanese industries is made based on the inquiry investigation conducted in 1995 by SICE. To the inquiry investigation, 150 engineers from 110 companies responded and gave 148 examples of applications. The survey also makes use of the data of the similar investigation conducted in 1989 by JEMIMA for comparison purpose. Several statistics about characteristics of plants,areas of applications, advantage and disadvantage of each technology, expectations of engineers, etc., are given, which clarifies several features of the future needs for control theory. 相似文献
939.
I Joja T Asakawa A Mitsumori T Nakagawa S Akaki M Yamamoto Y Takeda M Ando Y Hiraki 《Canadian Metallurgical Quarterly》1998,23(1):10-12
Sera from 211 ostriches were tested for the presence of Newcastle disease virus (NDV)-specific antibodies by the virus neutralisation test, the haemagglutination inhibition (HI) test and a recently developed avian paramyxovirus serotype 1 (PMV-1) specific monoclonal antibody blocking ELISA (b-ELISA). The virus neutralisation test was used as the reference for the estimation of the sensitivity and specificity of the b-ELISA and HI tests. Of the 211 sera, 140 contained NDV-specific neutralising antibodies, 130 were positive by the HI test and 122 by the b-ELISA. The sensitivity, specificity and predictive accuracy of the HI and b-ELISA tests relative to the virus neutralisation test were similar. The good agreement between the HI and b-ELISA test (kappa = 0.85) suggested that the two methods are interchangeable. 相似文献
940.
T. Asano D. Feezell R. Koda M.H.M. Reddy D.A. Buell A.S. Huntington E. Hall S. Nakagawa L.A. Coldren 《Photonics Technology Letters, IEEE》2003,15(10):1333-1335
We report, for the first time, InP-based all-epitaxially grown 1.3-/spl mu/m vertical-cavity surface-emitting lasers with lattice-matched Sb-based distributed Bragg reflectors and AlInAs etched apertures. The minimum threshold current and voltage under pulsed operation were 3 mA and 2.0 V, respectively. The thermal impedance was as low as 1.2 K/mW without heat sinking. Implementation of the AlInAs etched aperture was quite effective in improving the injection efficiency and reducing the internal loss, resulting in improved differential efficiency. 相似文献