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991.
Number of groups in neutron-constant libraries for calculating nuclear fields and neutron parameters
Translated from Atomnaya énergiya, Vol. 79, No. 1, pp. 76–78, July, 1995. 相似文献
992.
993.
利用平板型热管纺丝装置对普通高速纺丝机进行技术改造,并一步法生产出充分结晶的PET纤维(FCY)。该纤维可直接用于织造,调节热管温度、热管安装位置可获得满足后道工序不同需要的FCY。 相似文献
994.
Dr. P. Bošnjakovié Dipl.-Ing. B. Djokié 《Electrical Engineering (Archiv fur Elektrotechnik)》1992,75(2):131-135
Contents This paper analyzes a problem of phase shifting and deseribes a novel method for electronic reactive energy measurement. The proposed measurement structure, composed of an integrator as a phase shifting circuit and a frequency controlled analog-to-pulse-rate converter, provides for the measurement completely in accordance with IEC definition of reactive energy, which is performed with simple but high performance metering device.
Die Blindverbrauchsmessung anhand eines netzsynchronisierten Analog-Frequenz-Wandlers
Übersicht In diesem Artikel wird das Problem der Phasenverschiebung analysiert und eine neue Meßmethode für elektronische Blindverbrauschsmessung aufgezeigt. Die vorgeschlagene Strucktur, bestehend aus einem Integrator als Phasenschieber und netzkontrolliertem Analog-Frequenz-Wandler, ermöglicht die Verwirklichung eines einfachen aber präzisen Elektrizitätszählers zur Messung der Blindenergie, dessen Arbeitsprinzip mit den IEC Empfehlungen vollkommen übereinstimmt.相似文献
995.
Single-channel properties of a delayed rectifier voltage-gated K+ channel (I-type) were investigated in peripheral myelinated axons from Xenopus laevis. Channels activated between -60 and -40 mV with a potential of half-maximal activation, E50, at -47.5 mV. Averaged single-channel currents activated with a time delay at all membrane potentials tested. Time to half-maximal activation decreased from 80 to 1.6 msec between -60 and +40 mV. The channel inactivated monoexponentially with a time constant of 10.9 sec at -40 mV. The time constant of deactivation was 126 msec at -80 mV and 16.9 msec at -110 mV. In symmetrical 105 mM K+, the single-channel conductance (gamma) was 22 and 13 pS at negative and positive membrane potentials, respectively, at 13-15 degrees C. In Na+ -rich solution with 2.5 mM extracellular K+ gamma was 7 pS and the reversal potential was negative to -80 mV, indicating a high selectivity for K+ over Na+. gamma depended on extracellular K+ concentration (KD = 19.6 mM) and temperature (Q10 = 1.45). External tetraethylammonium (TEA) reduced the apparent single-channel amplitude at all potentials tested with a half-maximal inhibiting concentration (IC50) of 0.6 mM. Open probability of the channel, but not single-channel current amplitude was decreased by extracellular dendrotoxin (DTX, IC50 = 6.8 nM). mast cell degranulating peptide (MCDP, IC50 = 41.9 microM). In Ringer solution the membrane potential of macroscopic I-channel patches was about -65 mV and depolarized under TEA and DTX. It is concluded that besides their activation during action potentials, I-channels may also stabilize the resting membrane potential. 相似文献
996.
Wavelength-tunable add/drop optical filter 总被引:4,自引:0,他引:4
B. Glance 《Photonics Technology Letters, IEEE》1996,8(2):245-247
A new type of add/drop optical filter discretely tunable along equally spaced channels is presented. This device may have very useful applications in WDM optical networks. 相似文献
997.
A test method useful in determining the effects of polymer additives upon water carry-over (WCO) in water quenched, cast film extrusion is presented. Data from this test is obtained on film specimens based in a Spherilene process HDPE resin individually doped with 250 and 500 ppm of six various primary and secondary antioxidants and acid scavengers. Water contact angles and film surface tension data is also presented. The WCO test is reproducible and data may be applied to commercial production. Different additives that carry out the same function in the polymer may have greatly varying WCO properties; these differences are not detected by equilibrium goniometry. 相似文献
998.
D. A. Ivashintsov D. V. Stefanishin A. B. Veksler 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1995,29(4):227-234
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 30–35, April, 1995. 相似文献
999.
Presence of weldlines introduces an element of uncertainty to the performance of injection molded parts. Weldlines are particularly problematic in reinforced plastics because, unlike molecular orientation in neat polymers, the flow induced fiber orientation does not relax. This paper deals with the structure and mechanical behavior of weldlines in glass fiber reinforced nylon 66, a plastic known for excellent fiber-matrix adhesion. Two molds were used to generate weldlines: a double gated tensile sample shaped cavity in which the weldline is formed by a head-on collision of melt fronts flowing in opposite directions and a film gated rectangular plaque with a circular insert in which the weldline formation behind the insert is followed by additional flow. In both cases the weldline zone is several millimetres wide: in the plane where the melts fronts have met fibers are oriented parallel to this plane (random-in-plane in the double-gated cavity and unidirectional in the cavity with insert). The transition zone between the weldline plane and the rest of the sample is characterized by an increased presence of microvoids. Weldline tensile depends little on the fiber concentration and on the sample shape or thickness: values close to the matrix strength are found: in samples without weldlines strength increases with the fiber content. However, in instrumented impact penetration test during which the material is subjected to multiaxial loading, the weldline effect appears negligible. 相似文献
1000.
Summary Stability of a twisted and axially compressed elastic rod is analysed using the Euler method of adjacent equilibrium configuration. The constitutive equations of the rod are assumed in the form that takes into account both shear of the cross-sections and compressibility of the rod axis. It is shown that bifurcation points of the non-linear system of equations describing equilibrium are determined from the linearized system of equations. The influence of shear and compressibility on the critical values of twisting couple and compressive force is obtained. Moreover, the bifurcation pattern is examined by using the Liapunov-Schmidt method. 相似文献