Showing papers by "Mitsubishi published in 1991"

Dispersion of fillers and the electrical conductivity of polymer blends filled with carbon black

Abstract: Dispersion state of carbon black(CB) was studied in polymer blends which are incompatible with each other. It was found that CB distributes unevenly in each component of the polymer blend. There are two types of distribution. (1) One is almost predominantly distributed in one phase of the blend matrix, and in this phase fillers are relatively homogeneously distributed in the same manner as a single polymer composite. (2) In the second, the filler distribution concentrates at interface of two polymers. As long as the viscosities of two polymers are comparable, interfacial energy is the main factor determining uneven distribution of fillers in polymer blend matrices. This heterogeneous dispersion of conductive fillers has much effect on the electrical conductivity of CB filled polymer blends. The electrical conductivity of CB filled polymer blends is determined by two factors. One is concentration of CB in the filler rich phase and the other is phase continuity of this phase. These double percolations affect conductivity of conductive particle filled polymer blends.

The use of stable isotopes for food web analysis

Abstract: General aspects in isotope biogeochemistry was summarized with emphasis on delta 15N and delta 13C contents in plants and animals in natural ecosystems. In the estuary, the variation of isotope ratios were principally governed by the mixing of land-derived organic matter, marine phytoplankton, and seagrasses. A clear cut linear relationship between animal delta 15N and its trophic level was obtained in the Antarctic food chain system. Several current efforts to use the stable isotopes for food web analysis were demonstrated for some terrestrial and marine systems as well as human food web.

Method for forming a thin layer on a semiconductor substrate and apparatus therefor

Abstract: A method and apparatus for manufacturing a semiconductor device having a thin layer of material formed on a semiconductor substrate with a much improved interface between them are disclosed. A silicon substrate is heated up to a temperature around 300° C. in the presence of ozone gas under exposure to UV light. Through this process, organic contaminants that might be present on the surface of the silicon substrate are dissipated by oxidation, and a thin oxide film is formed on the substrate surface on the other. The silicon substrate with the thin oxide film coated thereon is then heated up to temperatures of 200°-700° C. in the presence of HCl gas under illumination to UV light to strip the oxide film off the substrate surface, thereby exposing the cleaned substrate surface. Finally, HCl cleaned surface of the silicon substrate is coated with a thin layer of material such as monocrystalline silicon without exposing the cleaned substrate surface. The method provides a semiconductor with the thin layer of material formed thereon having a well-controlled, well organized interface between them.

Calculation of critical loading condition with nose curve using homotopy continuation method

Abstract: A new method is presented for calculating the nose curves and critical loading conditions of power systems. The nose curve (PV curve), which donates the relationship between total load and system voltages, is calculated by a new approach based on the homotopy continuation method. The critical loading condition, which might be called the bifurcation point, is also calculated precisely as the final point of the nose curve. This method does not require an exhausting cut-and-try process or a rough-approximation process. It is based on the conventional Newton-Raphson load flow calculation, but it overcomes the numerical difficulties associated with the singularity of the Jacobian matrix. The results of applying the proposed method to the IEEE 118-bus system and to other large practical systems (e.g., a 496-bus system) verify its robustness and feasibility. >

Rescue of thymocytes and T cell hybridomas from glucocorticoid‐induced apoptosis by stimulation via the T cell receptor/CD3 complex: a possible in vitro model for positive selection of the T cell repertoire

Abstract: Positive and negative selection events are involved in determining useful T cell clones to mature in the thymus. Accumulating evidence suggests that immature self-reactive thymocytes undergo apoptotic death (negative selection) upon stimulation via the T cell receptors (TcR). A similar phenomenon of activation-induced death has been reported in T cell hybridomas. On the other hand, little is known about the mechanism of the positive selection. Apoptosis in rodent thymocytes or T cell hybridomas is also known to be induced by glucocorticoids in vitro at concentrations within the physiologic range. We report here that the TcR/CD3-mediated stimulation and glucocorticoids mutually inhibit the apoptosis in T cell hybridomas. The production of interleukin 2 by the rescued cells indicated that the TcR/CD3-mediated signal was transduced into the cells. Thymocytes were also rescued from glucocorticoid-induced apoptosis by the stimulation with antibodies to TcR/CD3 molecules. The rescue of thymocytes, however, was observed only at a narrow concentration range of each of the antibodies, suggesting that the proper stimulation via the TcR/CD3 is required for the rescue. If thymocytes in situ are differentially stimulated according to the affinity of the TcR towards self, only the thymocytes whose TcR have proper affinity towards self may be rescued from glucocorticoid-induced apoptosis. Therefore, we propose a hypothesis that the positive selection of the T cell repertoire is based on the inhibition of glucocorticoid-induced apoptosis in immature thymocytes bearing TcR with proper affinity for self by the TcR-mediated signals in situ. Furthermore, the selection may be influenced by the peak level of glucocorticoid concentration, since the proper concentration range of the anti-TcR/CD3 antibody for the rescue was variable depending on the glucocorticoid concentration.

Semiconductor device having an interlayer insulating film of high crack resistance

Abstract: A method of manufacturing a semiconductor device having a flat surface and an interlayer insulating film having superior crack resistance is disclosed. A first silicon oxide film having a superior crack resistance is formed on a semiconductor substrate so as to cover the surface of a stepped pattern. A second silicon oxide film having a superior step coverage is deposited on the above-mentioned first silicon oxide film so as to fill the recessed portions of said stepped pattern and to cover said stepped pattern. The above-described second silicon oxide film is etched to a prescribed thickness. A third silicon oxide film superior in filling of recesses is placed into the recessed portions existing on the surface of the above-described second silicon oxide film after its etching. A fourth silicon oxide film is formed on said semiconductor substrate including the above-described second silicon oxide film and third silicon oxide film.

Antenna selecting diversity receiving apparatus

Abstract: The apparatus is used in a TDM system with a linear modulating wave (BPSK, QPSK or 16 QAM) and has an integrating circuit 15 which integrates the signals from antennas 11, 12 for respective predetermined time periods prior to the start point of each TDM time slot allotted to the receiver 14 in order to select which antenna should be used during that time slot. The selection may be effected by a comparator 17 which compares the integrated signal from one antenna with that from the other previously integrated and retained in a sample and hold circuit 16. A further comprator (19) may be provided operative during an allotted time slot for repeatedly comparing the integrated signal with a reference so that changeover between antennas is effected if the integrated value is below the reference, (Figs 10, 11). In an alternative embodiment, (Figs 12, 13), prior to an allotted time slot, the signal from each antenna 11, 12 is integrated for multiple respective predetermined time periods, and from the integrated values a prediction of the signal level during the time slot is made for each antenna. The antenna to be used during the time slot is selected in dependence on the predicted levels.

Semiconductor pressure sensor

Abstract: PURPOSE:To obtain a semiconductor pressure sensor in which a residual stress produced in the manufacture is reduced and which can measure an accurate pressure. CONSTITUTION:In a semiconductor pressure sensor, a pressure sensor chip 1, a pedestal 5, leads 8, wirings 9 and a die pad 7 are integrally sealed with a case except the front surface of a diaphragm 2 of a semiconductor pressure sensor chip 1 and a rear surface of the pad 7. The ratio of the thickness of the pedestal 5 to that of the chip 1 is set to 7.5 or less, and the ratio of the diameter of the case opening of the surface of the diaphragm 2 to that of the diaphragm 2 is set to 1 or more. According to this invention, a thermal stress generated in the chip 1 can be freely reduced to a desired value, and the sensor of necessary accuracy can be obtained. The sensor can be manufactured by a flow of general-purpose IC manufacturing steps, and the sensor having a low cost and high quality, can be obtained.

A 10-b 70-MS/s CMOS D/A converter

Abstract: A 10-b 70-MS/s CMOS D/A converter fabricated in a 1- mu m CMOS technology is described. An integral linearity error caused by error distributions of current sources is reduced by a new switching sequence called hierarchical symmetrical switching. A differential linearity error caused by an off-axis drain-source implantation is reduced by the layout technique of current sources. The D/A converter is fabricated by using a single-polycide double-metal standard digital process. Both the integral and the differential linearity errors are less than +or-0.5 LSB. The settling time to +or-0.1 % is less than 14 ns. The worst-case glitch energy is approximately 60 pV-s. This D/A converter has a single power supply of 5 V and dissipates 170 mW at 70 MS/s. The chip size is 2.02 mm*1.87 mm. >

Home bus system

Abstract: A home bus system is to perform concentrated monitoring and control of electric appliances positioned in a house as well as alerting users by monitoring outputs from security sensors positioned in places of consideration in the house. The appliances, and the occurrence of emergencies sensed by the security sensors, appear on the screen of a visual controller in the form of pictographs. Data about the pictographs are stored in a memory such as a graphic ROM, and once stored data are read from the memory to be displayed on the screen.

An alternatively processed mRNA generated from human hepatocyte growth factor gene.

Abstract: We recently reported the isolation and sequencing of cDNA for human hepatocyte growth factor (hHGF) [Miyazawa, K., Tsubouchi, H., Naka, D., Takahashi, K., Okigaki, M., Arakaki, N., Nakayama, H., Hirono, S., Sakiyama, O., Takahashi, K., Gohda, E., Daikuhara, Y. & Kitamura, N. (1989) Biochem. Biophys. Res. Commun. 163, 967–973]. In the present study, we report the sequence of another cDNA clone for a shorter form of hHGF mRNA. Comparison of the sequence with that of the hHGF cDNA revealed that the two sequences are identical in their 5′ ends up to 865 nucleotides downstream from the translation-initiation site, then completely diverge from each other. By Northern blot analysis, the hHGF-related 1.5-kb mRNA, which corresponded to the newly isolated cDNA variant, was identified in human placenta. Sequence analysis of a human genomic HGF clone showed that the diverged 3′-terminal portion of the mRNA is generated by alternative RNA-processing events utilizing a specific exon. The mRNA could encode a short hHGF molecule of 290 amino acids corresponding to the N-terminal portion of hHGF which consists of 728 amino acids. In order to examine the effect of the predicted translation product on hepatocyte growth, an expression plasmid for the cDNA variant was constructed and transfected into Cos cells. Immunoblotting analysis showed that the transfected Cos cells produced a protein of about 33 kDa. The protein product did not stimulate DNA synthesis by rat hepatocytes in primary culture.

Pattern representation model training apparatus

Abstract: Disclosed is an Hidden Markov Model (HMM) training apparatus in which a capacity for discriminating between models is taken into consideration so as to allow a high level of recognition accuracy to be obtained. A probability of a vector sequence appearing from HMMs is computed with respect to an input vector and continuous mixture density HMMs. Through this computation, the nearest different-category HMM, with which the maximum probability is obtained and which belongs to a category different from that of a training vector sequence of a known category, is selected. The respective central vectors of continuous densities constituting the output probability densities of the same-category HMM belonging to the same category as that of the training vector sequence and the nearest different-category HMM are moved on the basis of the vector sequence.

Air conditioning apparatus

Abstract: An air conditioning apparatus comprises an air conditioner provided with an air inlet port opening to a room, a heat exchanger and a blower, a duct box connected to the air conditioner directly or through a duct, a blow-off casing provided on the duct box to project into the room and having an air outlet opening to the room, and a fan disposed on a lower portion of the blow-off casing, wherein a conical partition wall is provided between the air outlet and the fan to diffuse conditioning air in the radial direction while turning into the horizontal direction, a plurality of ring-like louvers are provided in the air outlet into the form of multiple stages, the fan is rotatable forward and backward and includes an outer rotor motor and a plurality of blades fixedly attached to an outer peripheral surface of an outer rotor of the motor, the air outlet and fan are disposed within a recess provided on the ceiling or wall surface, an oscillating mechanism is provided to oscillate the fan or both of the fan and air outlet integrally, and a start/stop switch is provided for starting and stopping the fan in synchronism with the start and stop of a conditioning air generator

Semiconductor integrated circuit device having a memory and an operational unit integrated therein

Abstract: A semiconductor integrated circuit device includes a memory cell array for storing data to be processed, and an operational unit for effecting a predetermined operation on the data read from the memory cell array. The memory cell array has first and second regions for storing first and second data words of first and second groups. The first data words and second data words each include a plurality of data bits. The first region includes a plurality of bit arrays for storing data bits of the same digit in the first data words, and the second region includes a plurality of bit arrays for storing data bite of the same digit in the second data words. The bit arrays of the first and second groups are arranged alternately in the order of digits of the data words. The bit arrays storing the data bits of the same digit form one subarray. The data bits in one data word are stored in the same positions of the bit arrays. The operational unit includes operational circuits each corresponding to one of the subarrays. Each operational circuit effects the predetermined operation on the data read from the two bit arrays in the corresponding subarray. Each bit array has selectors responsive to external addresses to select one column from each bit array and connect this column to a corresponding operational circuit.

Electrode for secondary battery

Abstract: An electrode for secondary batteries, in which an alkali metal of an active material is carried by a carrier, whose principal component is the carbonaceous material of the multilayer structure comprising a surface layer and the nucleous enveloped therein and satisfies the following conditions: (1) a true density ς is not less than 1.80 g/cm3; (2) in Raman spectroscopic analysis using the argon ion laser beam of 5145 A in its wavelength, peaks P?A? and PB exist within the ranges of 1580-1620 cm?-1? and 1350-1370 cm-1 respectively, and the ratio R = I?B?/IA of the intensity IB of PB to the intensity IA of PA is not less than 0.4.

MCI-9042, a new antiplatelet agent is a selective S2-serotonergic receptor antagonist.

Abstract: MCI-9042, (+/-)-1-[2-[2-(3-methoxyphenyl)ethyl]phenoxy]-3- (dimethylamino)-2-propyl hydrogen succinate hydrochloride inhibited platelet aggregation induced by collagen and secondary aggregation by ADP or epinephrine at 10(-6) M level in platelets of various species. The antiplatelet effect of MCI-9042 was potentiated in aggregation induced by a combination of serotonin with collagen. IC50 value of human platelet aggregation by the serotonin plus collagen was 1.0 x 10(-7) M. MCI-9042 inhibited serotonin release accompanied with collagen-induced platelet aggregation, while it did not affect serotonin uptake into platelet. MCI-9042 also potently inhibited the S2-serotonergic receptor-mediated contraction of rat caudal artery by serotonin in a competitive manner with a Ki value of 1.79 x 10(-8) M, while S1 receptor- or adrenergic receptor-mediated vasoconstriction was inhibited more weakly. Platelet adhesiveness, c-AMP level in platelets and the conversion of arachidonic acid to thromboxane A2 were not influenced by MCI-9042. These results suggest that MCI-9042 is a selective S2-serotonergic receptor antagonist, exhibiting the inhibition of S2-serotonergic potentiated platelet aggregation and the suppression of blood vessel constriction mediated by S2-serotonergic receptor.

Development and migration of Purkinje cells in the mouse cerebellar primordium.

Abstract: The mode of Purkinje cell migration in the mouse cerebellar primordium was examined immunohistochemically, by marking Purkinje cells with anti-spot 35 antibody and labeling them with 5′-bromodeoxyuridine. The cells migrated radially from the neuroepithelium of the fourth ventricle towards the cortical surface between the 13th and 17th days (E13–E17) of gestation. Regional differences in the migratory process were evident: the final settlement of the Purkinje cells proceeded earlier in the lateral and posterior parts of the primordium, exhibiting latero-medial and posteroventral-anterodorsal diminishing sequences. To elucidate the factors involved in the migration, the arrangement of radial glial fibers, and expression of the cell adhesion molecule, tenascin, were examined immunohistochemically with the monoclonal antibody 1D11, a marker for both immature and mature astroglia, and an anti-tenascin antibody. At E14, 1D11-immunopositive fibers were seen to extend from the ventricle to the pial surface, and the cell bodies of immature glia migrated after E15 towards the cortex, shortening the radial processes whose end-feet were attached to the pia mater. Tenascin, which possesses a neuron-glial adhesiveness, was also expressed on the radial fibers during the migration of the Purkinje cells. The fibers were closely apposed to the migratory Purkinje cells, and their arrangement and orientation accorded with the migratory direction of the Purkinje cells. Further, changes in the molecular species of antigens detected by both the 1D11 and anti-tenascin antibodies were observed by immunoblotting analysis during the course of cerebellar development. These findings suggest that the arrangement of radial glia and expression of adhesion molecules may be involved in the control and guidance of Purkinje cell migration.

Excimer laser device

Abstract: At least the opposing surface portions of the main electrodes of an excimer laser device are covered with materials which are resistive to chemical etching than nickel. The etching resistive material may be a platinum based alloy containing rhodium, ruthenium, iridium, or osmium; a nickel based alloy containing gold, platinum, rhodium, ruthenium, iridium, or osmium; or rhodium, ruthenium, iridium, or osmium. Thus, an excimer laser device is realized by which the lives of the electrodes and the laser gas are prolonged.

Method of fabricating semiconductor device having sidewall spacers and oblique implantation

Abstract: First, a low-concentration impurity layer is formed by obliquely implanting an n-type impurity at a prescribed angle with respect to the surface of a p-type semiconductor substrate, using a gate electrode formed on the semiconductor substrate as a mask. Thereafter a sidewall spacer is formed on the sidewall of the gate electrode, and then a medium-concentration impurity layer is formed by obliquely implanting an n-type impurity to the surface of the semiconductor substrate. Thereafter a high-concentration impurity layer is formed by substantially perpendicularly implanting an n-type impurity with respect to the surface of the semiconductor substrate. According to this method, the low-concentration impurity layer in source and drain regions having triple diffusion structures can be accurately overlapped with the gate electrode, with no requirement for heat treatment for thermal diffusion.

Parallel data processing system combining a SIMD unit with a MIMD unit and sharing a common bus, memory, and system controller

Abstract: There are SIMD type parallel data processing systems having a single instruction stream and multiple data streams and MIMD type parallel data processing systems having multiple instruction and data streams in the parallel data processing field for performing high-speed data processing. They have both merits and demerits and each have their suitable application fields. Because of this, it is extremely difficult to cover a wide range of application fields with either one of the systems. Then, a SIMD type parallel processing unit (50) and a MIMD type parallel data processing unit (51) are connected to each other by a common bus (41) and a memory (42), and a system controller (43) is provided to allow each of the parallel data processing units to perform its suitable processings, thus making it possible to apply the optimum parallel processing system to a wide range of application fields. That is, simple processings of a large volume of data are allocated to the SIMD type parallel data processing unit, while complex processings of a small volume of data are allocated to the MIMD type parallel data processing unit, whereby processings which have been difficult for a conventional computer to accomplish within an effective time, such as large-scale and complex processings of images, can be performed within a practical time at a high speed.

Navigation system using satellite signals

Abstract: The navigation system using GPS signals from satellites first checks whether or not there are four or more satellites in radio range of the moving body. If so, the position calculation section performs an ordinary three-dimensional positioning operation to provide an accurate fix of the moving body. When the number of satellites within the radio range is three or less, the two-dimensional positioning operation is carried out, which comprises reading the previous altitude data from the altitude storage section; calculating the atmospheric pressure deviation from the atmospheric pressure sensor output as caused by the movement of the body; calculating the altitude deviation from the previous altitude data and the atmospheric pressure deviation; calculating the current altitude from the altitude deviation and the previous altitude data; and then calculating the two-dimensional position data from the GPS signals and the current altitude data. This method produces no errors which would otherwise be caused by changes in the altitude of the moving body but provides accurate two-dimensional fix data of the body.

Charge accumulation on insulating spacers for HVDC GIS

Abstract: A capacitive probe measurement that can be used to quantify the charge density on solid insulators is introduced. Studies performed in the development of a +or-125 kV high-voltage DC (HVDC) gas-insulated converter station and +or- 500 kV HVDC switchgear (HVDC-GIS) are reviewed. The properties and mechanisms of surface charging, the optimum design of the spacer and its breakdown characteristics are summarized. Problems associated with capacitive probe measurement of surface charge and a practical solution to obtain the charge distribution on the spacer are presented. >

Neuronal survival factor from bovine brain is identical to neuron-specific enolase.

Abstract: Neuronal survival factors in the central nervous system were investigated by using a primary culture of embryonic rat neocortical neurons. Bovine hippocampus was homogenized, and the supernatant from high-speed centrif-ugation was used as the starting material. At the step of DE-52 ion-exchange chromatography, neuronal survival activity was recovered in two fractions, fraction 14 (F14) and fraction 23 (F23). Antisera to the crude F14 and F23 fractions were raised in rabbits. These two antisera completely inhibited the neurotrophic activity of both fractions. Western blotting analysis revealed that anti-F14 antiserum recognized mainly a 30-kDa protein in F14 and anti-F23 antiserum recognized mainly a 44-kDa protein in F23. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis of F23, the 44-kDa protein was cut out from the gel and partial amino acid sequences of the protein fragments were determined. A GenBank data bank indicated that the amino acid sequence of the fragment was identical to that of neuron-specific enolase (NSE). In our assay system, commercially available NSE itself possessed neuronal survival activity for the cultured neocortical neurons. The effects of NSE and F23 were inhibited completely by anti-NSE polyclonal antibody. Furthermore, highly purified NSE supported the survival of cultured neurons in a dose-dependent manner, and the neurotrophic effect was inhibited by monoclonal antibody to the NSE. These results strongly suggest that NSE is one of the neuronal survival factors in the central nervous system.

Semiconductor memory device having block write function

Abstract: A color data transferring circuit, a color data storing circuit, and a block selecting circuit 1020 are provided separately from an input/output buffer circuit, in order to transmit data stored in a color register to a memory cell block. In a block write mode, data applied to a data input/output terminal is stored in the color data storing circuit through color register and the color data transferring circuit. One block selecting gate is selected in response to a block selecting signal from a block decoder, and data stored in each storage element in the color data storing circuit is transmitted to a corresponding memory cell block. Input/output buffer circuit performs normal data writing only through a sense amplifier +I/O block. A semiconductor memory device capable of easily extending the number of bits of block write with a simple circuit configuration is implemented.