摘要:
A process for producing polyacrylonitrile-base precursor fibers for production of carbon fibers, which comprises spinning a spinning dope containing 10 to 25 wt % of a polyacrylonitrile-base polymer having an intrinsic viscosity of 2.0 to 10.0 by extruding the spinning dope from a spinneret by a wet spinning or a dry wet spinning method, drying and heat-treating fibers obtained by the spinning, and then steam drawing the resulting fibers, wherein the linear extrusion rate of the polyacrylonitrile-base polymer from the spinneret is 2 to 15 m/min. Carbon fibers which are produced by stabilizing-carbonizing treatment of the polyacrylonitrile-base precursor fibers and which have a strand tensile modulus of 320 to 380 GPa and a conduction electron density of 3.0×1019 to 7.0×1019 spins/g as determined by electron spin resonance.
摘要翻译:一种制造用于生产碳纤维的聚丙烯腈基前体纤维的方法,其包括通过将纺丝原液从喷丝头挤出而纺丝纺丝原液,该纺丝原液含有10-25重量%的特性粘度为2.0至10.0的聚丙烯腈基聚合物 湿式纺丝或干式湿式纺丝方法,通过纺丝得到的纤维的干燥和热处理,然后对所得纤维进行蒸汽拉伸,其中来自喷丝板的聚丙烯腈基聚合物的线性挤出速率为2〜15m / min 。 通过使聚丙烯腈类前体纤维进行稳定碳化处理而得到的碳纤维,其股线拉伸模量为320〜380GPa,导电电子密度为3.0×1019〜7.0×1019,通过电子自旋测定 谐振。
摘要:
A process for producing polyacrylonitrile-base precursor fibers for production of carbon fibers, which comprises spinning a spinning dope containing 10 to 25 wt % of a polyacrylonitrile-base polymer having an intrinsic viscosity of 2.0 to 10.0 by extruding the spinning dope from a spinneret by a wet spinning or a dry wet spinning method, drying and heat-treating fibers obtained by the spinning, and then steam drawing the resulting fibers, wherein the linear extrusion rate of the polyacrylonitrile-base polymer from the spinneret is 2 to 15 m/min. Carbon fibers which are produced by stabilizing-carbonizing treatment of the polyacrylonitrile-base precursor fibers and which have a strand tensile modulus of 320 to 380 GPa and a conduction electron density of 3.0×1019 to 7.0×1019 spins/g as determined by electron spin resonance.
摘要翻译:一种制造用于生产碳纤维的聚丙烯腈基前体纤维的方法,其包括通过将纺丝原液从喷丝头挤出而纺丝纺丝原液,该纺丝原液含有10-25重量%的特性粘度为2.0至10.0的聚丙烯腈基聚合物 湿式纺丝或干式湿式纺丝方法,通过纺丝得到的纤维的干燥和热处理,然后对所得纤维进行蒸汽拉伸,其中来自喷丝板的聚丙烯腈基聚合物的线性挤出速率为2〜15m / min 。 通过使聚丙烯腈类前体纤维进行稳定碳化处理而得到的碳纤维,其股线拉伸模量为320〜380GPa,导电电子密度为3.0×1019〜7.0×1019,通过电子自旋测定 谐振。
摘要:
A process for producing polyacrylonitrile-base precursor fibers for production of carbon fibers, which comprises spinning a spinning dope containing 10 to 25 wt % of a polyacrylonitrile-base polymer having an intrinsic viscosity of 2.0 to 10.0 by extruding the spinning dope from a spinneret by a wet spinning or a dry wet spinning method, drying and heat-treating fibers obtained by the spinning, and then steam drawing the resulting fibers, wherein the linear extrusion rate of the polyacrylonitrile-base polymer from the spinneret is 2 to 15 m/min.
摘要翻译:一种制造用于生产碳纤维的聚丙烯腈基前体纤维的方法,其包括通过将纺丝原液从喷丝头挤出而纺丝纺丝原液,该纺丝原液含有10-25重量%的特性粘度为2.0至10.0的聚丙烯腈基聚合物 湿式纺丝或干式湿式纺丝方法,通过纺丝得到的纤维的干燥和热处理,然后对所得纤维进行蒸汽拉伸,其中来自喷丝板的聚丙烯腈基聚合物的线性挤出速率为2〜15m / min 。
摘要:
Compounds of formula (I): ##STR1## (wherein R.sup.1 and R.sup.2 are hydroxy, alkoxy, aryloxy or acyloxy or R.sup.2 is hydrogen, R.sup.3 is hydrogen or alkyl and R.sup.4 and R.sup.5 are hydrogen or various organic substituents) have valuable antidepressant activity and may be used in the treatment of mental depression.
摘要:
A Costas loop carrier wave reproducing circuit includes a first differential amplifier circuit, a second differential amplifier circuit, a multiplying circuit, a first square circuit, a second circuit, and a double-balanced differential amplifier circuit. The first differential amplifier circuit obtains an inphase output from an inphase demodulated signal obtained by performing synchronous detection of a component inphase with a four-phase modulated wave. The second differential amplifier circuit obtains an orthogonal output from an orthogonal demodulated signal obtained by performing synchronous detection of an orthogonal component of the four-phase modulated wave. The multiplying circuit multiplies outputs from the first and second differential amplifier circuits. The first square circuit obtains a square output of an output from the first differential amplifier circuit. The second square circuit obtains a square output of an output from the second differential amplifier circuit. The double-balanced differential amplifier circuit obtains an output difference between the first and second square circuits and outputting a product of the output difference and an output from the multiplying circuit as a PLL control signal.
摘要:
New 4-anilinopyrimidine derivatives of formula (I): ##STR1## (wherein: R.sup.1 and R.sup.2 are the same or different and each represents a C.sub.1 -C.sub.6 alkyl group or R.sup.1 and R.sup.2 together represent a C.sub.3 -C.sub.5 alkylene group;R.sup.3 represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group;n is 0, 1 or 2; andR.sup.4 represents a C.sub.1 -C.sub.6 alkyl group, a C.sub.1 -C.sub.6 alkoxy group, a C.sub.1 -C.sub.6 haloalkyl group, a halogen atom, a nitro group, a C.sub.1 -C.sub.6 alkanesulphonyl group, a cyano group, a carboxy group or a C.sub.2 -C.sub.7 alkoxycarbonyl group and, when n is 2, the two groups represented by R.sup.4 may be the same or different or they may together represent a methylenedioxy group)and pharmaceutically acceptable acid addition salts thereof have been found to have strong antidepressant activity, with low toxicity and very few side-effects. The compounds may be formulated in conventional pharmaceutical compositions for administration by various routes and may be prepared by reacting a 4-halopyrimidine with aniline or an aniline derivative.
摘要:
A fire and smoke damper for installation in a duct which includes a plate rotatably mounted within the duct and having means enclosing the periphery of the plate and biased outwardly to engage the duct wall when the damper is in the closed position.