Abstract: An Alternate Current (AC) white Light-Emitting Diode (LED) device is provided, which belongs to the technical field of white LED manufacturing. The problem to be solved by the present invention is to low-costly overcome a series of deficiencies such as the stroboflash of an AC driven LED, and the heat dissipation difficulty caused by an integrated packaging of multiple LEDs. A white LED unit includes an LED chip and a light emitting material that can emit light when being excited by the LED chip. The luminous lifetime of the light emitting material is 1˜100 ms. The LED chip only comprises one PN junction. The light emitted by the LED chip is mixed with the light emitted by the light emitting material to form white light. The white LED unit is driven by AC with a frequency not more than 100 Hz. The white LED device of prevent invention uses the single PN junction chip, rather than the prior integrated packaged AC multi-LED chip.

Abstract: Disclosed is an alternating current dimming drive circuit for an LED, comprising a rectification unit and N stages of LED direct current drive circuits. In the ith stage of LED direct current drive circuit, a first end of the ith voltage sampling unit and an input end of the ith LED light source module directly or indirectly receive the output voltage of the rectification unit; a voltage division end of the ith voltage sampling unit is connected to a second input end of the ith switch unit; and a first input end of the ith switch unit is connected to an output end of the ith LED light source module, and an output end of the ith switch unit, a second end of the ith voltage sampling unit and a second output end of the rectification unit are grounded. When the ith switch unit is switched on, the first to the ith LED light source modules emit light.

Abstract: Disclosed are an alternating current rectifying circuit and an alternating current rectifying method for driving an LED module.

Abstract: Disclosed are an alternating current rectifying circuit and an alternating current rectifying method for driving an LED module.

Abstract: The present disclosure discloses a multipath current source switching device, including a switching control unit, N current paths, and N loads. Each current path is formed by a constant current source circuit and a switching circuit. One terminal of a first load is coupled to a load power supply, and the other terminal of the first load is coupled to an output terminal of a constant current source circuit of a first current path and one terminal of a second load; one terminal of an ith load is coupled to the other terminal of an (i?1)th load and an output terminal of a constant current source circuit of an ith current path; and the switching control unit controls an output current of a corresponding constant current source circuit through a corresponding switching circuit.

Abstract: An Alternate Current (AC) white Light-Emitting Diode (LED) device is provided, which belongs to the technical field of white LED manufacturing. The problem to be solved by the present invention is to low-costly overcome a series of deficiencies such as the stroboflash of an AC driven LED, and the heat dissipation difficulty caused by an integrated packaging of multiple LEDs. A white LED unit includes an LED chip and a light emitting material that can emit light when being excited by the LED chip. The luminous lifetime of the light emitting material is 1-100 ms. The LED chip only comprises one PN junction. The light emitted by the LED chip is mixed with the light emitted by the light emitting material to form white light. The white LED unit is driven by AC with a frequency not more than 100 Hz. The white LED device of prevent invention uses the single PN junction chip, rather than the prior integrated packaged AC multi-LED chip.

Abstract: Disclosed is an alternating current dimming drive circuit for an LED, comprising a rectification unit and N stages of LED direct current drive circuits. In the ith stage of LED direct current drive circuit, a first end of the ith voltage sampling unit and an input end of the ith LED light source module directly or indirectly receive the output voltage of the rectification unit; a voltage division end of the ith voltage sampling unit is connected to a second input end of the ith switch unit; and a first input end of the ith switch unit is connected to an output end of the ith LED light source module, and an output end of the ith switch unit, a second end of the ith voltage sampling unit and a second output end of the rectification unit are grounded. When the ith switch unit is switched on, the first to the ith LED light source modules emit light.

Abstract: The present invention discloses a white LED light emitting device driven directly by constant current in manner of being supplied with alternating current. N parallel branches, consisting of LED modules and constant current units which are in series connection with the LED modules, are connected to an output terminal of a rectification circuit, and by setting the current value, the turning-off voltage, and the turning-on voltage of the constant current unit of each branch, the periodic flickers generated due to changes in the voltage of the alternating current can be avoided. Because the current of each branch is constant, the changes in junction temperatures do not result in the current changing in LED, and the reliability is improved. Along with the increase of the number of the branches, the driving current waveform approximates a sine wave, and the power factor and the efficiency of the light emitting device are improved.

Abstract: A polymerization catalyst system and polymerization processes using the catalyst systems are disclosed. The polymerization catalyst systems may include a) a first catalyst compound, and b) a second catalyst compound, wherein the first catalyst compound comprises a biphenyl phenol compound having essentially no hydrogen response.

Abstract: Provided is a method for making a polyolefin comprising contacting one or more olefins in a reactor containing a catalyst; polymerizing the one or more olefins to produce an olefin polymer characterized by a first melt flow ratio (MFR) and a first haze; and altering the reaction temperature in the reactor to shift the first MFR to a MFR that is different than the first MFR and to shift the first haze to a haze that is different than the first haze.

Abstract: A catalyst composition that includes a support material having an improved particle-size distribution is provided. Processes for producing polyolefin composition also are provided. Polymers and films also are provided. An example of a catalyst composition is a supported multi-transition-metal catalyst composition that includes: (a) at least two catalyst components selected from the group consisting of: a nonmetallocene catalyst component and a metallocene catalyst component; (b) a support material that has a D50 of less than about 30 microns and a particle size distribution having a D90/D10 ratio of less than about 6; and (c) an activator.

Abstract: A process for polymerizing olefin(s) utilizing a cyclic bridged metallocene catalyst system to produce polymers with improved properties is provided. The catalyst system may include a cyclic bridged metallocene, LA(R?SiR?)LBZrQ2, activated by an activator, the activator comprising aluminoxane, a modified aluminoxane, or a mixture thereof, and supported by a support, where: LA and LB are independently an unsubstituted or a substituted cyclopentadienyl ligand bonded to Zr and defined by the formula (C5H4-dRd), where R is hydrogen, a hydrocarbyl substituent, a substituted hydrocarbyl substituent, or a heteroatom substituent, and where d is 0, 1, 2, 3 or 4; LA and LB are connected to one another with a cyclic silicon bridge, R?SiR?, where R? are independently hydrocarbyl or substituted hydrocarbyl substituents that are connected with each other to form a silacycle ring; and each Q is a labile hydrocarbyl or a substituted hydrocarbyl ligand.

Abstract: A network switching method, device and system for mobile multimedia services are provided. The method includes: detecting signal strength of media stream data of a first network, and when the signal strength of the media stream data of the first network is smaller than a first preset value, receiving media stream data of a second network in parallel; and buffering the media stream data of the second network, decoding the buffered media stream data of the second network, and playing the decoded media stream data of the second network. The device includes a first communication module, a detecting module, a switching module, a second communication module, a processing module and a playing module. The system includes a first network, a second network and a terminal. Through the method, device and system, the time delay in the process of switching the serving network is reduced, and the service interruption caused by the network switching when the terminal performs multimedia services is prevented.

Abstract: Olefin polymerization catalyst systems including a high molecular weight catalyst compound and a low molecular weight catalyst compound, and methods of making same are provided. High molecular weight catalysts include metallocene catalysts and low molecular weight catalysts include non-metallocene compounds including biphenyl phenol compounds. Generally catalyst systems may include less than about 5.0 mol % of the high molecular weight catalyst compound relative to said low molecular weight catalyst. Methods for olefin polymerization including the aforementioned catalyst systems, and polyolefins and products made therefrom.

Abstract: An Alternate Current (AC) white Light-Emitting Diode (LED) device is provided, which belongs to the technical field of white LED manufacturing. The problem to be solved by the present invention is to low-costly overcome a series of deficiencies such as the stroboflash of an AC driven LED, and the heat dissipation difficulty caused by an integrated packaging of multiple LEDs. A white LED unit includes an LED chip and a light emitting material that can emit light when being excited by the LED chip. The luminous lifetime of the light emitting material is 1-100 ms. The LED chip only comprises one PN junction. The light emitted by the LED chip is mixed with the light emitted by the light emitting material to form white light. The white LED unit is driven by AC with a frequency not more than 100 Hz. The white LED device of prevent invention uses the single PN junction chip, rather than the prior integrated packaged AC multi-LED chip.

Abstract: A polymerization catalyst system and polymerization processes using the catalyst systems are disclosed. The polymerization catalyst systems may include a) a first catalyst compound, and b) a second catalyst compound, wherein the first catalyst compound includes an oxadiazole-containing compound. In some embodiments, the oxadiazole-containing compound has essentially no hydrogen response, thus allowing better and/or tailored control of product properties when producing polymers using the catalyst system.

Abstract: Bimodal polyethylene compositions and methods for making the same are provided. In at least one specific embodiment, the bimodal polyethylene composition can include a high molecular weight component having a weight average molecular weight (Mw) of from about 400,000 to about 950,000. The bimodal polyethylene composition can also include a low molecular weight component having a weight average molecular weight (Mw) of from about 3,000 to about 100,000. The high molecular weight component can be present in an amount ranging from about 25 wt % to about 40 wt % of the bimodal polyethylene composition. The bimodal polyethylene composition can also have a percent die swell of less than about 80%.

Abstract: Polyethylene compositions having improved properties are provided. In one aspect, a polyethylene composition having a long chain branching index (g?avg) of 0.5 to 0.9; a Melt Flow Rate (MFR) of greater than (49.011×MI(?0.4304)), where MI is Melt Index; and a weight average molecular weight to number average molecular weight (Mw/Mn) of less than or equal to 4.6 is provided.

Abstract: A polymerization catalyst system and polymerization processes using the catalyst systems are disclosed. The polymerization catalyst systems may include a) a first catalyst compound, and b) a second catalyst compound, wherein the first catalyst compound comprises a biphenyl phenol compound having essentially no hydrogen response.

Abstract: Provided is a method for making a polyolefin comprising contacting one or more olefins in a reactor containing a catalyst; polymerizing the one or more olefins to produce an olefin polymer characterized by a first melt flow ratio (MFR) and a first haze; and altering the reaction temperature in the reactor to shift the first MFR to a MFR that is different than the first MFR and to shift the first haze to a haze that is different than the first haze.