摘要:
A heterodyne communication system uses coherent data modulation that is resistant to phase noise. In particular, a pilot tone and reference clock signal are transmitted along with the modulated data to form the basis of an electrical demodulation local oscillator at the receiver. The pilot tone and/or reference clock signal carry phase noise which is correlated with the phase noise in the data signal. At the receiver, the local oscillator is generated from the pilot tone and reference clock signal in a manner so that the local oscillator also has phase noise which is correlated with the phase noise in the data signal. Thus, the two noise components can be used to cancel each other during demodulation of the data signal using the local oscillator.
摘要:
A transmitter subsystem generates an optical signal which contains multiple subbands of information. The subbands have different polarizations. For example, in one approach, two or more optical transmitters generate optical signals which have different polarizations. An optical combiner optically combines the optical signals into a composite optical signal for transmission across an optical fiber. In another approach, a single optical transmitter generates an optical signal with multiple subbands. The polarization of the subbands is varied, for example by using a birefringent crystal. In another aspect of the invention, each optical transmitter generates an optical signal containing both a lower optical sideband and an upper optical sideband (i.e., a double sideband optical signal). An optical filter selects the upper optical sideband of one optical signal and the lower optical sideband of another optical signal to produce a composite optical signal.
摘要:
A novel, salt-free monoamphopropionate amphoteric surfactant is prepared in yields of from 75% to 80%, from a reaction comprising an imidazoline and a mixture of acrylic acid and sodium acrylate in an aqueous medium. The acrylic acid/sodium acrylate mixture is comprised of the two components in a range of molar ratios of from about 1:6 to about 1:3, respectively, and by replacing methyl acrylate, the reaction does away with the production of methanol which is an unwanted, hazardous and toxic byproduct. The imidazoline reacts in amounts in excess of 90% resulting in the highly pure yields and any left over unreacted acrylic acid can be easily removed by treating it with sodium bisulfate.
摘要:
According to the invention, an improved class of amphoteric surfactant having improved surfactant properties characterized as mild and environmentally safe has been provided comprising compounds of the formula: ##STR1## The amphoteric surfactant of the subject invention have at least two hydrophobic moieties and at least two hydrophilic groups per molecule and are useful as emulsifiers, detergents, dispersants and solubilizing agents.
摘要:
A method for preparing a collagen from a chromium-containing tanned leather waste is disclosed. The method includes acid dechromation, obtaining a collagen aggregate, and converting the collagen aggregate to the collagen. The method also includes a reaction in a supercritical carbon dioxide reactor.
摘要:
A confined pulsed laser deposition method and apparatus that includes an ablative coating between a transparent confinement layer and a backing plane, and a laser beam directed through the confinement layer to ablate the coating at generally ambient temperature and pressure, and using laser induced pressure to synthesize metaphase from the ablative coating. For example, diamond phase carbon can be synthesized from a graphite coating. The laser beam can be directed through a focus lens to control the final spot size, or through a beam diffuser to make the intensity more uniform. An XYZ-stage can position a desired target area of the ablative coating to be irradiated by the laser beam. The laser beam can have an intensity of less than about 6 GW/cm2, or less than about 4 GW/cm2. The laser beam can have an excitation wavelength of about 568 nm.
摘要翻译:一种限制脉冲激光沉积方法和装置,其包括透明约束层和背衬平面之间的烧蚀涂层,以及引导通过约束层的激光束,以在一般环境温度和压力下烧蚀涂层,并且使用激光诱导压力合成 烧蚀涂层的中期。 例如,可以由石墨涂层合成金相碳。 激光束可以被引导通过聚焦透镜来控制最终光斑尺寸,或者通过光束漫射器使得强度更均匀。 XYZ级可以定位由激光束照射的烧蚀涂层的期望目标区域。 激光束可以具有小于约6GW / cm 2或小于约4GW / cm 2的强度。 激光束可以具有约568nm的激发波长。
摘要:
Provided, among other things, is a multiplex assay comprising: conducting a fluorescence-developing assay on microtabs having at least one surface that shows plasmonic enhancement, wherein a plurality of the microtabs have unique probes affixed to their plasmonically enhanced surfaces; and measuring the fluorescence associated with the substrates and identifying the correlated probe by for the microtab. The microtabs can be, for example, MTPs that send a unique identifier, and the correlated probe can be identified by querying the MTPs for their identifier.
摘要:
Provided is a resonance converting apparatus. The resonance converting apparatus preferably includes a resonant circuit, a bridge-type converter, and a synchronous rectification circuit. In which the resonant circuit has a transformer. The bridge-type converter connects with a primary side of the transformer, and operates open or close according to a switching signal. The synchronous rectification circuit further includes a pair of rectification transistors and driving circuits. The driving circuits correspondingly connect with channels to the rectification transistors, and respectively examine the current passing through the rectification transistors. A sensing signal is then generated. In accordance with the switching signal and the sensing signal, a driving signal is generated for driving the rectification transistor. Consequently the apparatus can raise the efficiency of the resonance converting apparatus.
摘要:
A property of a layer is measured by: (1) focusing a heating beam on a region (also called “heated region”) of a conductive layer (2) modulating the power of the heating beam at a predetermined frequency that is selected to be sufficiently low to ensure that at any time the temperature of an optically absorbing layer is approximately equal to (e.g., within 90% of) a temperature of the optically absorbing layer when heated by an unmodulated beam, and (3) measuring the power of another beam that is (a) reflected by the heated region, and (b) modulated in phase with modulation of the heating beam. The measurement in act (3) can be used directly as a measure of the resistance (per unit area) of a conductive pad formed by patterning the conductive layer. Change in measurement across regions indicates a corresponding change in resistance of the layer.
摘要:
According to the invention, an improved class of amphoteric surfactant having improved surfactant properties characterized as mild and environmentally safe has been provided comprising compounds of the formula: ##STR1## The amphoteric surfactant of the subject invention have at least two hydrophobic moieties and at least two hydrophilic groups per molecule and are useful as emulsifiers, detergents, dispersants and solubilizing agents.