Abstract: An inverted-F antenna comprises a microwave plate, a dielectric substrate, a radiating metal sheet, a ground surface, a shorting metal strip, and a feeding metal strip. The radiating metal sheet comprises a connecting metal sheet, first, second, and third child radiating metal sheets, a matching metal sheet, a slot, a shorting point, and a feeding point. The first child radiating metal sheet is for forming a low frequency operating mode. The second child radiating metal sheet is for forming a high frequency operating mode. The third child radiating metal sheet is for adjusting operating frequency and bandwidth of the second operating mode. The slot, the shorting point, and the feeding point are for adjusting impedance matching. The grounding surface is for increasing the operating bandwidth of the low frequency operating mode. The shorting metal sheet and the feeding metal sheet are for grounding the antenna and signal transmission.

Abstract: An inverted-F antenna comprises a microwave plate, a dielectric substrate, a radiating metal sheet, a ground surface, a shorting metal strip, and a feeding metal strip. The radiating metal sheet comprises a connecting metal sheet, first, second, and third child radiating metal sheets, a matching metal sheet, a slot, a shorting point, and a feeding point. The first child radiating metal sheet is for forming a low frequency operating mode. The second child radiating metal sheet is for forming a high frequency operating mode. The third child radiating metal sheet is for adjusting operating frequency and bandwidth of the second operating mode. The slot, the shorting point, and the feeding point are for adjusting impedance matching. The grounding surface is for increasing the operating bandwidth of the low frequency operating mode. The shorting metal sheet and the feeding metal sheet are for grounding the antenna and signal transmission.

Abstract: A process for the production of white oil includes adding a supercritical fluid (propane, butane or carbon dioxide) to the base oil and hydrogen injected into a reactor for hydrogenation. The base oil and supercritical fluid use high-pressure injector pumps as the feed system. The feed system for hydrogen uses a high-pressure compressor to compress hydrogen from a hydrogen tank to a storage tank, then a mass flow controller is used to steadily feed the hydrogen. A static mixer mounted in line, upstream from the inlet of the reactor mixes the reactant well. Several thermocouples are connected to the reactor, inlet and outlet of said reactor to measure the temperatures of the reaction. The detected data from the thermocouples are transferred to a six-point thermograph. The pressure of the reaction is maintained by a back pressure regulator that is mounted downstream from the outlet of said reactor. After the hydrogenation reaction is complete, the pressure of the fluid in the outlet of the reactor is reduced.

Abstract: The invention discloses a method for depolymerization of a mixture containing polytetrahydrofuran derivatives, including heating the mixture comprising polytetrahydrofuran derivatives at 100-250° C. in the presence of a &bgr;-zeolite catalyst to obtain tetrahydrofuran, whereby the tetrahydrofuran monomer can be recovered from the waste materials in the preparation of polytetramethylene ether glycols.

Abstract: A method of removing spinning and finishing oils from fibers using supercritical carbon dioxide as an extraction media is provided. This process using carbon dioxide to remove oils from fiber surface operates at moderate pressures between 90 and 350 bar and at temperature levels ranghng from 40 to 120° C. The treated fibers have improved strength and elongation properties compared to those treated by conventional scouring. The treated fibers can be directly subjected to the subsequent dyeing processing.

Abstract: A method for preparing polyether glycol is disclosed. An ester end-capped polyalkylene ether and an alcohol are subjected to alcoholysis at a temperature of 35.degree.-150.degree. C. and a pressure of 1-10 atm in the presence of a mixed metal oxide as a catalyst. The mixed metal oxide includes an alkaline earth metal oxide and at least one component selected from alumina, silica, and zinc oxide.

Abstract: A method for preparing ester end-capped polyalkylene ether is disclosed. Cyclic ether monomers are subjected to ring-opening polymerization at a temperature of 10.degree.-80.degree. C. and a pressure of 0-10 atm in the presence of a solid acid of a mixed oxide of group III and group IV elements serving as catalyst and a mixture of acid and acid anhydride serving as molecular weight moidifier. The group III and group IV elements used should have a Ho index of +3.0 to -10.0.

Abstract: Polytetramethylene ether glycols (PTMEG) are fractionated with liquid propane in an extractor under high pressure. Fractions are separated by altering the extraction pressure, which alters the solvent power of the propane. The polydispersities of all extracted PTMEG fractions are generally below 1.3. The addition of a cosolvent, preferably tetrahydrofuran, can effectively lower the initial extraction pressure and increase the efficiency of the extraction.