摘要:
The present invention relates to a process for preparation of polyolefin/inorganic component nanocomposite by in-situ polymerization, in which, a clay is first organically modified and then silica or titanium dioxide nanometer particles are incorporated into the layers of crystal sheets of the clay by sol-gel method. And a metallocene catalyst is then loaded on the above-mentioned material and a finished catalyst is obtained. The said catalyst is used for in-situ polymerization of ethylene or propylene, and polyolefin/clay nanocomposite is finally obtained. The process for preparation of the catalyst according to the present invention is simple, and the mechanical properties of the nanocomposite are high. For example, the Young's modulus and the tensile strength thereof are in the ranges of 700-2600 Mpa, and 20-55 MPa respectively.
摘要:
The present invention relates to a method and an equipment for controlling the mobile station to switch between different wireless communication systems and belongs to the technical field of data transmission in the wireless communication systems. In order to resolve the problem that there are no means in the prior art to effectively control the mobile station to switch between different wireless communication systems at specified position, the present invention uses different network identifications to distinguish different wireless communication systems, and a set of wireless transceiver modules is mounted on the mobile station to associate with wireless communication system, and a set of independent receiving modules is mounted to receive the switch command from the ground sending device, the ground sending device sends the switch command when the mobile station passes the switching point; after receiving this switch command, the mobile station modifies its network identification according to the network identification comprised in the switch command for the target switching wireless communication system, and cuts off the link with the current wireless communication system and establishes the link with the target switching wireless communication system. This solution could realize the controlled switching for the mobile station between multiple overlapping wireless communication systems, and reduce the rate of wrong switching.
摘要:
A radio frequency unit and an integrated antenna are provided. The radio frequency unit includes a duplexer, a power amplifier circuit board, and a transceiver circuit board. The duplexer connects to the power amplifier circuit board and the transceiver circuit board. The power amplifier circuit board connects to the transceiver circuit board. The power amplifier circuit board and the transceiver circuit board are respectively located at two end portions of the duplexer. The power amplifier circuit board and the transceiver circuit board are projected onto the same plane along a direction being vertical to the power amplifier circuit board with their projections on the same plane non-overlapped each other.
摘要:
A radio frequency unit and an integrated antenna are provided. The radio frequency unit includes a duplexer, a power amplifier circuit board, and a transceiver circuit board. The duplexer connects to the power amplifier circuit board and the transceiver circuit board. The power amplifier circuit board connects to the transceiver circuit board. The power amplifier circuit board and the transceiver circuit board are respectively located at two end portions of the duplexer. The power amplifier circuit board and the transceiver circuit board are projected onto the same plane along a direction being vertical to the power amplifier circuit board with their projections on the same plane non-overlapped each other.
摘要:
The present invention relates to a method for preparing a carbon nanotube material, comprising the steps of: (a) preparing a modified montmorillonite by an ion exchange reaction comprising the substeps of: i) acidifying an alkylamine with equal mole of a concentrated HCl; ii) mixing the resulting acidified alkylamine with a montmorillonite dispersion in 1:1˜2 volume ratio of the acidified alkylamine to the montmorillonite dispersion; and iii) precipitating, filtering and pulverizing to obtain a modified montmorillonite; (b) preparing a catalyst by a hydrogenation reduction method, comprising the substeps of: i) mixing an aqueous solution of nickel nitrate and an alumina-silica hybrid in a weight ratio of 35-45 parts of nickel to 55-65 parts of alumina-silica hydrid, wherein the alumina-silica hydrid contains 10 wt % of alumina and has a particle size of 10-30 μm; ii) drying and calcining the resulting product; and iii) reducing the product with a reducing gas containing hydrogen to produce a nickel-supported catalyst; (c) preparing a polyolefin mixture of a polyolefin, the modified montmorillonite prepared in step a) and the catalyst prepared in step b) in a mixer in the weight ratio of 75˜97.5:0˜20:0˜5 provided that the amounts of the modified montmorillonite and the catalyst are not both 0; and (d) preparing and purifying a nanotube, comprising the substeps of: i) placing the polyolefin mixture obtained in step (c) in a crucible and heating the temperature inside crucible up to 550° C.˜650° C., wherein the heating time begins from the burning of the polymer and ends when no flame can be observed and cooling the polyolefin mixture to obtain a mixture of carbon nanotube, nickel catalyst and montmorillonite; ii) adding a hydrofluoric acid with a concentration of 20-50% to the mixture, mixing, and separating to obtain a carbon powder; and iii) adding a mixture of a concentrated sulfuric acid and a concentrated nitric acid, refluxing, and separating to obtain a purified carbon nanotube. The carbon source material used in the present invention was polyolefin or recovered polyolefin whose price was low and whose source was abundant. The manufacturing facilities involved for preparing supported catalyst and modified montmorillonite were simple. The mixer used was that of the conventional fabricating equipment for polymeric materials while the facilities used for synthesizing carbon nanotube material were porcelain crucible and common flame. The method could simultaneously solve the problem of recovery and utilization of waste plastics.
摘要:
A dual-channel hot standby system and a method for carrying out dual-channel hot standby, the system comprises a hot standby status management layer including two hot standby management units, an application processing layer including two application processors, and a data communication layer including two communicators; the hot standby status management layer is used for controlling the setting and switching between a active status and a standby status of the two application processors, monitoring the working status of the data communication layer, and carrying out synchronization of the control cycles for the two channels of the system; wherein one of the hot standby management units controls one of the application processors, and together constitute a channel of the system therewith; the data communication layer is used for receiving data from outside, and forwarding the data to the application processing layer. The present invention avoids the occurrence of “dual-channel-active” or “dual-channel-standby” status; ensures synchronization of the control cycles of two channels; reduces the time of the system for responding to breakdowns; meets the real-time requirements; enhances the reliability and availability of the system; and ensures a seamless switching between active and standby statuses.
摘要:
The present invention discloses a calculation method of movement authority for communications-based train control system, comprising: handling a route information for a train, and determining a searching range of the train according to the route information; initializing the limit of movement authority with the end position of the searching range; searching for static obstacles within the searching range, and successively determining whether each static obstacle meets the safety requirements for train operating, if not, setting the position of the last static obstacle within the searching range as the limit of the movement authority; if so, modifying the limit of movement authority as the end of route having been matched; searching for dynamic obstacles within the searching range, and determining whether there is a train, if so, modifying the end of movement authority as the beginning point of the track section where the train is occupying; if there is no dynamic obstacle within the searching range, modifying the final end of movement authority as the position of the last static obstacle within the searching range. In accordance with the present invention, it is possible to increase line capacity and improve traffic fluidity for rail transit.
摘要:
A radio frequency unit and an integrated antenna are provided. The radio frequency unit includes a duplexer, a power amplifier circuit board, and a transceiver circuit board. The duplexer connects to the power amplifier circuit board and the transceiver circuit board. The power amplifier circuit board connects to the transceiver circuit board. The power amplifier circuit board and the transceiver circuit board are respectively located at two end portions of the duplexer. The power amplifier circuit board and the transceiver circuit board are projected onto the same plane along a direction being vertical to the power amplifier circuit board with their projections on the same plane non-overlapped each other.
摘要:
The present invention provides a method for preparing a carbon nanotube material. In the present invention, a mixture of polyolefin and modified montmorillonite is used as the carbon source. Under the action of a catalyst, a carbon nanotube is synthesized in air. The present invention can address the problem of “white pollution” caused by waste plastics, such as waste polyolefin polymers.
摘要:
A radio frequency unit and an integrated antenna are provided. The radio frequency unit includes a duplexer, a power amplifier circuit board, and a transceiver circuit board. The duplexer connects to the power amplifier circuit board and the transceiver circuit board. The power amplifier circuit board connects to the transceiver circuit board. The power amplifier circuit board and the transceiver circuit board are respectively located at two end portions of the duplexer. The power amplifier circuit board and the transceiver circuit board are projected onto the same plane along a direction being vertical to the power amplifier circuit board with their projections on the same plane non-overlapped each other.