摘要:
[Problems] Addition of an organic acid such as a dicarboxylic acid to a soldering flux in order to improve wettability causes a reaction with copper oxide to form a metallic soap of copper having a green color. Although this metallic soap of copper is not corrosive and does not decrease reliability, its external appearance is impossible to distinguish it from verdigris which is indicative of corrosion. There is need for a soldering flux which does not form a metallic soap of copper.[Means for Solving the Problems] Addition of a tetrazole or a tetrazole derivative to a soldering flux can prevent carboxyl groups from reacting exclusively with copper ions, thereby suppressing the formation of a metallic soap of copper having a green color. Among tetrazoles and tetrazole derivatives, 5-phenyl-1H-tetrazole and its derivatives which have hydrogen as a substituent in the 1-position and a phenyl, group which strongly attracts electron in the 5-position are effective at improving soldering since they result in an increased polarity in the solvent.
摘要:
An apparatus includes a vector unit to process a vector data, a cache memory which includes a plurality of cache lines to store a plurality of divisional data being sent from a main memory, each of the divisional data of vector data having been divided according to a capacity of a cache line, and a cache controller to send all of the divisional data as the vector data to the vector unit after the cache lines have stored all of the divisional data including the vector data.
摘要:
A soldering flux which is suitable as a no-clean post flux in flow soldering and which can prevent the formation of whiskers which tends to occur when soldering electronic parts to a printed circuit board using a lead-free solder (such as Sn-3.0Ag-0.5Cu) having a higher Sn content and a higher melting point than the eutectic solder contains, in addition to a rosin as a base resin and an activator, 0.2-4 mass % of at least one compound selected from acid phosphate esters and derivatives thereof. The formation of whiskers can be more effectively prevented by carrying out soldering in a nitrogen atmosphere.
摘要:
A corneal surgical apparatus, which can smoothly incise the cornea (particularly the Bowman's membrane at the cutting start) while ensuring the cutting ability of the blade with a simple arrangement. After a suction unit is fixed to a periphery of the cornea of patient's eye, the cornea projecting from an opening portion provided in the suction unit is applanated substantially flatly, and the applanated cornea is incised in a layered form by a blade. The blade is moved such that any point on the blade depicts an arcuate locus of the same shape.
摘要:
A transparent display panel such as an electroluminescent panel is overlapped on a part of a conventional instrument panel for use in an automobile. The overlapped display panel displays additional information such as navigation maps when required and is turned off under a normal driving condition. When the overlapped transparent display panel is turned off, the conventional instrument panel displays information such as a vehicle speed, an engine speed so and so forth. In this situation, overall luminance on the combined display panel is made uniform throughout a whole surface including the area where the transparent display panel is overlapped. To realize the uniformity of luminance, brightness of back lamps for illuminating the instrument panel is adjusted or a filter having an adequate transparency is used. The combined display panel may be also made by combining a non-transparent display panel with a conventional instrument panel. A filter may be used in this case to attain an overall uniform luminance on the combined display panel.
摘要:
A multiprocessor system includes a plurality of nodes interconnected by a network. Each of the nodes includes a job identification number generator for generating a job identification number, a controller for issuing an instruction and associating the instruction with the job identification number, and a data transfer unit for transferring data according to the instruction. The data transfer unit includes an error detector for detecting an error and for generating an error signal. The error detector associates the error signal with the job identification number.
摘要:
An image processing apparatus containing a first bus, a second bus, a CPU connected to the first bus, a plurality of bus user units respectively connected to the second bus, a bus control unit connected with each of the plurality of bus user units and the CPU, and a bus connect/isolate gate unit connected with the first and second buses and the bus control unit. Each of the plurality of bus user units and the CPU contains a bus request signal sending unit for sending a bus request signal to the bus control unit when each of the plurality of bus user units and the CPU has a demand to use the second bus. The bus connect/isolate gate unit can isolate the first bus from the second bus, or connect the first bus with the second bus, under control of the bus control unit. The bus control unit receives the bus request signal from each of the plurality of bus user units and the CPU, determines one of the plurality of bus user units and the CPU, which sends the bus request signal to the bus control unit, as an acknowledged unit, sends an acknowledge signal to the acknowledged unit, makes the bus connect/isolate gate connect the first bus with the second bus when the CPU is the acknowledged unit, and makes the bus connect/isolate gate isolate the first bus from the second bus when the CPU is not the acknowledged unit.
摘要:
An antiferroelectric liquid crystal compound of the following formulae: ##STR1## wherein R.sup.1 and R.sup.2 each is an alkyl group of C.sub.4 - C.sub.18, Rf is CF.sub.3 or C.sub.2 F.sub.5, X is O, COO, or a single bond, and * shows an optically active carbon atom.
摘要:
A liquid crystal compound represented by the following formula; ##STR1## wherein R.sup.1 and R.sup.2 each represents an alkyl group having 3-20 carbon atoms, and X represents a group ##STR2## or --O--, or a single bond, and a liquid crystal composition exhibiting optically tristable states comprising the liquid crystal compound represented by the above formula and an antiferroelectric liquid crystal compound.