Abstract: A digital FM demodulator utilizes delay lines as the timing reference and incorporates the concept of delta-sigma analog-to-digital conversion to implement the function of time-to-digital conversion. The FM demodulator is constructed from delay lines, a multiplexer, a phase detector, a charge pump circuit, a quantizer and a digital integrator. The modulated signal on an intermediate frequency carrier passes through the delay lines and is then phase-compared with the original modulation signal. The comparison produces a pulse which is converted into a voltage and stored in a capacitor by way of the charge pump circuit. The voltage having been accumulated and quantized, a new delayed output signal is acquired to compare its phase with the input signal. Meanwhile, the phase difference between input signal and delayed signal is used to select a delay for the delayed signal for the next cycle. The phase difference is continuously evaluated and adjusted to produce zero phase difference.

Abstract: A thin-disc piezoelectric actuating ultrasonic motor includes a stator made up of a commercially available piezoelectric element that includes a piezoelectric ceramic membrane bonded on a metal plate to form a concentric disk. An ultrasonic motor driving mechanism induces mechanical vibration in the piezoelectric element by extension and shrinkage of the metal back plate, upon application of single phase AC power. There are two propagating directions in the induced mechanical vibrating wave. One is a radial component, and the other is a transverse component. The outer edge of the piezoelectric element thus forms traveling waves in different directions. These traveling waves may be used to provide a torque so as to drive the rotor to rotate.

Abstract: Keywords: computer assisted test, test assessment, test collection, distant learning. The main problem with the network test base system is that there are neither sufficiently many nor good enough test items. To satisfy these two points, there must be more test item resources and a mechanism for assessing test items to determine whether a test item should stay in the test base. The present invention provides a method for automation of dynamic test item collection and assessment, which allows teacher and students to contribute test items to the test base and each independently managed test base can share test items. This can make the test base rapidly grow and expand the size of a test base. The more independent the student are, the higher the applicability of this method is.

Abstract: A hand operated bicycle gear transmission device. The device includes a handle bar fixing base, a cover fixing base, a rubber cover, a positioning plate, positioning protuberances, saucer shaped springs, a circular fixing hole for a steel cable head, a steel cable guide groove and a stroke compensating device. The device utilizes cooperative function of positioning recessed slots formed around a rigid positioning plate. The positioning protuberances are provided at the rear of the cover fixing base and the saucer shaped springs are adjacent to the positioning plate to provide mutual engagement force therebetween so as to achieve an excellent positioning effect of gear transmission even under the worst riding environment. As a result, the device can be conveniently operable with a small applied force to perform speed change smoothly, the device having a simplified and easy looking appearance constructed with a small number of components, and being able to easily be assembled and repaired.

Abstract: The invention is a frequency stabilized passive Q-switch laser, which has the advantages of small volume, simple structure, no need for high power voltage, etc. It has been a long time that timing jitter in conventional lasers is so large that they can not be applied to fields such as distance measurement. This invention utilizes an optical external modulation method to stabilize the repetition rate of the passive Q-switch, and thus to decrease its timing jitter. At the same time, the repetition rate of the Q-switch laser can be controlled by the same technology to meet various application needs.

Abstract: A xerographic photoreceptor primarily formed by amorphous silicon material is disclosed, wherein the xerographic photoreccptor is a photosensitive drum used in copying and manufactured by the plasma enhanced low pressure chemical vapor deposition system. Such a drum has a higher resolution, and a longer lifetime. In this structure, an Al2O3 oxidization layer is grown on an aluminum substrate. Then a n type hydrogenated amorphous silicon blocking layer is grown on the aluminum substrate with Al2O3 oxidization layer. Then an intrinsic hydrogenated amorphous silicon charge generating transmission layer is grown on the n type hydrogenated amorphous silicon blocking layer. Finally a hydrogenated amorphous carbon surface protecting layer is grown on the intrinsic hydrogenated amorphous silicon charge generation transport layer for forming a xerographic photoreceptor with a multiple layer structure.

Abstract: The present invention relates to a dielectric composition which can be densified at a temperature no higher than 1000° C. and can provide ceramic products with a dielectric constant of 20 to 45 and a quality constant of 1000 to 1300 at 7 GHz. The dielectric composition comprises 20-90 vol % borosilicate glass and 10-80 vol % TiO2 ceramic. Multilayered microwave dielectric ceramic elements can be prepared by mixing the composition of the present invention with an organic solvent, a polymer binder and a plasticizer, forming a green sheet from the mixture by tape casting, screen-printing and laminating the green sheet, and then cofiring the multilayer ceramic laminate with a high electrical conductivity metal, such as Ag and Cu.

Abstract: A CMOS pulse shrinking delay element with deep subnanosecond resolution applicable to a Time-to-Digital Converter (TDC) can control its pulse shrinking or expanding capability be adjusting the dimension ratio between internal adjacent elements. This eliminates the need in prior CMOS pulse shrinking delay elements to adjust an external bias voltage or continuously calibrate the element in order to control pulse shrinking or expanding capabilities, facilitates simplification of circuits using the delay element, permits more precise design and control of the pulse shrinking or expanding capabilities of every element in a TDC circuit, and in practice reduces single shot errors in a cyclic TDC utilizing the pulse shrinking delay element to on the order of ten picoseconds, resulting in a TDC having extremely fine resolution, excellent accuracy, low power consumption, and low sensitivity to supply voltage and ambient temperature variations.

Abstract: The invention provides a set of two PCR primers designed based on a DNA sequence of a gene encoding malic acid dehydrogenase and a specific DNA of Salmonella typhimurium. The invention provides also a DNA probe specific for the above-mentioned PCR primers. Finally, a PCR method using above-mentioned primers is provided for the rapid and specific detection of Salmonella typhimurium in food and clinical specimens such as human fecal specimens. Said PCR method comprises further a Southern hybridization assay for detecting PCR products. The whole process could be shortened from 5-7 days for BAM method to 1-2 days.

Abstract: A frequency synthesizer using a multiphase reference signal source consists of three portions: a basic phase locked loop including a variable frequency oscillator, a loop filter, a phase detector, and a frequency divider; a generating circuit including a multiphase reference signal source for providing a reference signal to the basic phase locked loop; and a frequency discriminator and phase modulator. The frequency discriminator facilitates detection of whether the main loop of the frequency synthesizer is approaching a phase locking state for a proper change of the loop bandwidth. The phase modulator is employed to change the output phase of the reference signal source in order to speed up phase locking and make it applicable to creating signals with a rapid frequency switching speed, frequency tuning capability, and fine channel resolution.

Abstract: A structure and producing method of a three-electrode capacitive pressure sensor can integrate and produce sensor capacitor and reference capacitor in the same pressure sensor cavity. This dual capacitor integration structure can cancel off environment interference of the same mode by differentiated circuit. Avoiding connection between upper and lower electrode plates can be achieved through the existence of a third electrode plate. In working pressure interval from 25 psi to 40 psi, the sensitivity of said three-electrode capacitive sensor is a 0.21 pF/psi, while the sensitivity of an ordinary planar connection pressure sensor is 0.05 pF/psi. The merits of said three-electrode capacitive pressure sensor include trivial production procedure and connection with planar and high sensitivity.

Abstract: The present invention relates to the structure and fabrication process of a high-gain monocrystal Silicon Carbide phototransistor applicable at high temperature. In view of the optical gain and applicable temperature of the conventional n-p-n type Silicon Carbide phototransistor are too low for practical usage, the present invention utilizes a newly developed n-i-p-i-n structure to strengthen the intrinsic properties of the element, in order to enhance optical gain of the phototransistor for being able to operate at high temperature steadily.

Abstract: The invention concerns a process for producing aquafuel by replacing conventional inflexible carbon bars with thin, flexible and tough carbon fiber bundles as consumptive electrodes which thereby can be sustainedly fed and can produce aquafuel continuously. Such carbon fiber bundle electrodes can be prepared by pultrusion, and electrodes may be further carbonized or graphitized in order to increase the conductivity and gas productivity thereof.

Abstract: A process for preparing an optically active (S)-&agr;-aryl propionic acid, by hydrolyzing a racemic thioester of &agr;-aryl propionic acid at various temperature in different aqueous organic solvents in the presence of an (S)-stereoselective lipase to form an (S)-&agr;-aryl propionic acid product, while the unreacted (R)-thioester of &agr;-aryl propionic acid can be converted to the corresponding (S)-thioester of &agr;-aryl propionic acid via a racemization reaction by adding a base as the catalyst in the solution and then hydrolyzing by the lipase described as above so that the (S)-&agr;-aryl propionic acid can be obtained theoretically at a conversion of 100% and with high optical purity.

Abstract: Provided a process for producing a refractory metal by chemical vapor deposition of a bilayer-stacked tungsten metal by depositing a bilayer-stacked tungsten metal in a same chamber in the manner of not breaking the vacuum therein. Firstly, a layer of amorphous-like tungsten is deposited to increase thermal stability and to prevent diffusion of fluorine atom. Next, a nitridizing treatment is performed thereon to promote further the barrier property and thermal stability of the amorphous-like tungsten. Finally, conventional selective chemical vapor deposited tungsten having low is deposited on the amorphous-like tungsten. Through the deposition of bilayer tungsten according to the process of the invention, thermal stability of conventional selective chemical vapor deposited tungsten can be increased greatly.

Abstract: A method of producing high coercivity FePt—Si3N4 granular composite thin films for magnetic recording media is invented. The method includes magnetron co-sputtering of FePt and Si3N4 targets at controlled sputtering power and sputtering argon gas pressure to form a selective composition of granular FePt—Si3N4 thin film on a low temperature substrate, then post-annealed in vacuum at selective time period and temperature. Two kinds of FePt targets can be used. One is the FePt alloy target. The other one is a composite target consisting of an iron disk overlaid with small Pt pieces. This arrangement provides a wide range of effective target compositions and therefore film compositions. FePt—Si3N4 films were deposited on natural oxidized silicon wafer or quartz glass substrate at room temperature. The as-deposited film has soft magnetic properties and granular structure with soft magnetic &ggr;-FePt particles dispersed in amorphous Si3N4 matrix.

Abstract: The invention relates to a novel one-step process for preparation of phenol by oxidation of benzene with hydrogen peroxide catalyzed by molecular sieves doped with copper ions. With proper solvent, a phenol yield around 15-35%, selectivity close to 100% and phenol/Cu TON around 100 could be achieved. These results show that the inventive process is of great economical value for further development in large scale production of phenol.

Abstract: The invention relates a process for fabricating crystalline metal oxide materials comprising tin oxide, zirconia, or titania in form as powder, monolith gel or film by first forming a metal oxide material containing —OH surface group through a sol-gel process, and then treating them with [SiRm]nXzHy compound which reacts with the —OH group to form —OSiRm surface group, and heating the thus-treated oxide material at a high temperature to crystallize them into a crystalline metal oxide material with high crystallinity, small crystal size (<100 Å) and high surface area (>100 m2/g).

Abstract: The invention relates to a ROM with four-phase dynamic circuits, featuring at a concept of four-phase operation by fusing and combining pseudo-domino dynamic circuits as well as skill of HS-PDCMOS dynamic circuits. Meanwhile, the invention has improved HS-PDCMOS concept circuit for use in a ROM. Analysis and simulation reveal that the invention is advantageous not only in keeping a compact circuit area but also in evaluation speed and in reducing power dissipation for a ROM.

Abstract: A liquid phase deposition method for growing a titanium dioxide on the gallium arsenide substrate is disclosed. Wherein the solution of hexafluorotitanic acid (H.sub.2 TiF.sub.6) is added with nitric acid (HNO.sub.3) and boric acid (H.sub.3 BO.sub.3) or only added with a nitric acid. Thus a titanium dioxide film is grown on the gallium arsenide substrate which is the most important material of semiconductor. The refractive index will achieve to a value of 2.5. The growth rate can be exactly controlled by the concentration of the nitric acid. The present invention has the advantages of lower cost and low growing temperature. Not only the industrial necessity is satisfied, but also the disadvantages from other growing process having a high cost and expensive equipment is avoided. Thus, the present invention is potentially used in the process of integrated circuits, such as being used in the memory structure with a higher dielectric constant.