摘要:
A cephalosporin derivative represented by the general formula ##STR1## wherein R.sup.1 is a hydrogen atom or a protecting group of the amino group, R.sup.2 is a hydrogen atom or a protecting group of the hydroxyl group, R.sup.3 is a hydrogen atom or a protecting group of the carboxyl group, and R.sup.4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the non-toxic salts thereof are useful as antibacterial agents.
摘要:
Cephalosporin derivatives represented by the general formula ##STR1## Wherein X represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an allyl group, a cycloalkyl group having 5 or 6 carbon atoms or a benzyl group, and the non-toxic salts thereof are disclosed. These compounds are useful as antibacterial agents.
摘要:
A method for the selective methylation of the hydroxy group at the 6-position of erythromycin A derivatives which comprises reacting a compound represented by the formula R-X (wherein R is a 2-alkenyl group, a benzyl group or a substituted benzyl group, and X is a halogen atom), reacting the resulting quaternary salt compound with a methylating agent, and then eliminating R groups of the resulting compound to give 6-O-methylerythromycin A 9-oxime, is disclosed.
摘要:
Disclosed is a method for reducing the dimensions of cameras by arranging the film supplying chamber and the film winding chamber on both sides of the aperture, and by projecting at least one of the external walls defining these chambers into the space behind the photographing lens to avoid interfering with the image forming optical path.
摘要:
A method of producing high purity aluminum-lithium mother alloys essentially free from other alkali metals than lithium, which comprises electrolyzing a mixed molten salts consisting of 34 to 64 wt. % of lithium chloride and 66 to 36 wt. % of potassium chloride, and, optionally, 1 to 20 wt. % of sodium chloride based on a combined weight of the aforesaid two components, using solid aluminum as cathodes, and an .alpha.+.beta. phase aluminum lithium alloy electrode or the alloy coated electrode as a reference electrode, under a current density in the range of 0.005 to 1 A/cm.sup.2, whereby producing aluminum-lithium alloys on the cathode. During electrolyzing, the potential difference between the cathode and the reference electrode is continuously measured and differentiated with respect to time and at the point of a sudden change in the differentiated value, electrolyzing is stopped.
摘要:
An exhaust gas heat recovery system wherein:the system comprises an exhaust gas economizer having of heat transfer sections including a preheating section, an evaporating section and a superheating section, a feed water heater, a steam separation drum, a low pressure steam generator; and a mixed-pressure turbine;a temperature gradient of circulating water and a temperature gradient of exhaust gases are made substantially equal to each other in the preheating section of the exhaust gas economizer to prevent an exhaust gas economizer tube from being corroded by generated sulfuric acid; andlow pressure steam can be effectively utilized by use of the mixed-pressure turbine.
摘要:
In a camera adapted for use with a motor drive unit capable of selectively controlling film winding and rewinding operations, there are provided first and second driving torque input means, the first input means being positioned for continual engagement with a film winding up mechanism, and the second input means being arranged upon setting movement of a manually operated rewinding knob to attain driving engagement with a rewinding shaft and being located outside a film cartridge chamber to insure the protection of the film from fogging. The motor drive unit has a pair of output means connected through respective directionally-responsive clutches to a common motor and arranged upon attachment to the camera to engage the respective input means of the camera and has a single operating member for selectively actuating each of the output means for the film winding and rewinding operation.
摘要:
A photographic camera having a manually and automatically adjustable diaphragm is provided with an electromagnetically operated diaphragm scanning mechanism in combination with a manually operable depth of field pre-viewing device to enable a visual determination of the utilizable zone of sharpness in a reflex viewfinder of the camera regardless of the fact that the camera remains in the run down position. For this purpose, the diaphragm scanning mechanism includes a scanning member and a driving member arranged to establish driving connection therebetwen during the automatic adjustment of the diaphragm. Release means is provided and is responsive to the termination of closing operation of the camera shutter for effecting release of the driving connection, whereby the photographer before cocking the camera is enabled to manipulate the diaphragm followed by the pre-viewing device to read off the range of sharpness in dependence on the manual setting of the diaphragm for use in making a subsequent exposure.
摘要:
A camera equipped with a shutter preselection automatic exposure range and a diaphragm preselection automatic exposure range is automatically switched to the shutter preselection mode when the camera is assembled with a motor drive unit which is set in RUN position, whereby it is insured that a series of successive frame exposures can be made at a predetermined frame frequency.
摘要:
A motor driven photographing control circuit for a double preference type automatic exposure control camera which is used for continuous photographing with a motor drive device attached thereto. When a sum of the shutter time computed by a shutter time computing circuit and the length of time required for a winding operation become longer than a preset photographing cycle in carrying out such continuous photographing, an alarm is displayed giving a warning that photographing in the preset cycle is not possible. Concurrently with this, a stop preference mode of photographing is shifted to a shutter preference mode and the shutter is controlled to be operated at a preset length of time, so that continuous photographing can be accomplished in a set cycle.