Abstract: A depolarizer includes a second birefringent plate having a thickness which continuously changes in a direction of an optical axis of the second birefringent plate; and a third birefringent plate having a thickness which continuously changes in a direction of 45 degree with respect to an optical axis of the third birefringent plate; wherein the second birefringent plate is stuck on the third birefringent plate so that a reduction direction of the thickness of the second birefringent plate and a reduction direction of the thickness of the third birefringent plate are opposite to each other.

Abstract: Plane diffraction grating 13 is formed of a material having an appropriate linear expansion coefficient and a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of members other than plane diffraction grating 13 is cancelled out or reduced by a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of plane diffraction grating 13. The same principle is used to deal with the effect on the wavelength of the diffracted light that may be caused by changes in the layout of individual members on account of thermal expansion or shrinkage of substrate 10a that fix them.

Abstract: In a four-stage type monochromator, there is provided a returning reflector 6 for making the dispersing direction of the wavelength of light 13e and 13h incident on and emergent from a plane diffraction grating 4 is reversed before and after its reflection. Angles of incident and emergent light at a time when the light is spectrally separated by the diffraction grating 4 are made identical.

Abstract: In the present invention, in a drill rod for a boring machine, a rod outside diameter is large so as to be approximately equal to a bore diameter, external threads are provided at one end and internal threads are provided at the other end, and at least one small-diameter portion is formed near an internally threaded portion. This step tube rod can reduce a bore bend.

Abstract: A pressure control valve automatically controllable of a set value of a pressure circuit by pilot operation without using an electrical signal, is provided. A pressure control valve include a valve body (30) opposing to a seat surface of a relief port (A) connected to a pressure circuit (46) and a spring (32) biasing the valve body (30) onto the seat surface, for flowing out a part of the fluid within the pressure circuit (46) to hold the fluid pressure in the pressure circuit (46) at a predetermined set pressure when the fluid pressure in the pressure circuit (46) is higher than or equal to the set pressure. A pilot piston (40) is arranged movably in expansion and contraction direction of the spring (32) at an end portion of the spring (32) remote from the valve body (30), the pilot piston (40) moves in a direction for compressing the spring (32) when a predetermined pressure of a pilot fluid is input.

Abstract: Provided is a downhole percussion drill, which is installed at an end portion of a drillstring and performs drilling by giving impact blows to a drill bit at the bottomhole, which includes a hydraulic hammering mechanism 7 which uses oil having high lubricating ability as a driving medium, a hydraulic pump 8 which pressurizes the oil, and a downhole motor 9 which drives the hydraulic pump 8.

Abstract: An optical spectrum analyzer comprises a refractive grating which extracts a specific wavelength of light which is incident to be measured and outputs as a component light, an optical detector which measures optical intensity of the component light, a container in which the refractive grating and the optical detector are provided, a gas filling port and a gas exhaust port, for performing a replacement of air with a gas, which are provided in the container, are provided. By doing this, the optical spectrum analyzer which can measure level of the light to be measured having a specific wavelength accurately without causing the absorption of the specific wavelength by an OH group.

Abstract: A monochromator including: a concave mirror which converts incident light into parallel light and emits the parallel light, a plane diffraction grating for diffracting the parallel light emitted from the concave mirror, first reflection means which reflects first light diffracted by the plane diffraction grating and causes the diffracted light to enter the plane diffraction grating as second incident light, second reflection means which reflects second diffracted light and causes the reflected light to enter the plane diffraction grating as third incident light, and an exit slit disposed in the vicinity of a focal point such that third diffracted light is reflected by the first reflection means, to thereby enter the plane diffraction grating as fourth incident light and such that fourth diffracted light is converged at the focal point by the concave mirror, to thereby enable extraction of light having a specific wavelength.

Abstract: A spectroscope having a high spectroscopic characteristic capable of eliminating a polarization dependence on an arbitrary polarization state of an incident light, and measuring a spectrum having a true central wavelength of the light. The spectroscope comprises: a depolarizer comprising: a first plate a thickness of which continuously changes in a direction of 45 degrees with a first optical axis; and a second plate a thickness of which continuously changes, and which is stuck on the first plate; wherein an angle between the first optical axis and a second optical axis of the second plate, is 45 degrees, and a first reduction direction of the thickness of the first plate and a second reduction direction of the thickness of the second plate is opposite to each other; and a spectroscopic device a dispersion direction of which intersects orthogonally with the first reduction direction.

Abstract: A depolarizing plate comprising a first rectangular wedge plate that has a first crystallographic optical axis in a diagonal direction of the rectangle and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said first crystallographic optical axis and a second rectangular wedge plate that has a second crystallographic optical axis in a diagonal direction of the rectangle crossing said first crystallographic optical axis at right angles and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said second crystallographic optical axis, the two wedge plates being joined in such a position that said first crystallographic optical axis crosses said second crystallographic optical axis at right angles, wherein the slope formed by the joint of said wedge plates is rotated about the optical axis of an incident ray of light.

Abstract: In a four-stage type monochromator, there is provided a returning reflector 6 for making the dispersing direction of the wavelength of light 13e and 13h incident on and emergent from a plane diffraction grating 4 is reversed before and after its reflection. Angles of incident and emergent light at a time when the light is spectrally separated by the diffraction grating 4 are made identical.

Abstract: Plane diffraction grating 13 is formed of a material having an appropriate linear expansion coefficient and a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of members other than plane diffraction grating 13 is cancelled out or reduced by a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of plane diffraction grating 13. The same principle is used to deal with the effect on the wavelength of the diffracted light that may be caused by changes in the layout of individual members on account of thermal expansion or shrinkage of substrate 10a that fix them.

Abstract: A damper pressure control apparatus for a hydraulic rock drill is automatically adjustable of damper pressure to be applied to a damping piston depending upon a thrust of a rock drill body and makes damping function and floating function effective even when thrust of hydraulic rock drill is varied. The damper control apparatus is thus provided damper pressure control means for controlling the damper pressure (DPpr) to be applied to a damping piston (16, 17) from a hydraulic pressure source (21) based on the frontward thrust (F1) acting on the hydraulic rock drill body 1.

Abstract: A damper pressure control apparatus for a hydraulic rock drill is automatically adjustable of damper pressure to be applied to a damping piston depending upon a thrust of a rock drill body and makes damping function and floating function effective even when thrust of hydraulic rock drill is varied. The damper control apparatus is thus provides a damper pressure control for controlling the damper pressure (DPpr) to be applied to a damping piston (16, 17) from a hydraulic pressure source (21) based on the frontward thrust (F1) acting on the hydraulic rock drill body 1.

Abstract: This invention provides a pressure control valve 20 including a valve plug 30 facing a seat As at a relief port A that communicates with a pressure circuit 46, and a spring 32 pressing the valve plug 30 against the seat, and when the fluid pressure in the pressure circuit surpasses the force of the spring 32 for the valve plug, the pressure control valve discharges part of the fluid to keep the interior of the pressure circuit at a specified setting pressure. In the pressure control valve, at one end of the spring for the valve plug which is remote from the valve plug there is provided a pilot piston 40 freely movable in the expansion and compression direction of the spring for the valve plug. There is also provided a spring for adjustment 38c urging the pilot piston 40 toward the valve plug side. The pilot piston 40 is so structured as to move in a direction of going away from the valve plug when supplied with a pilot fluid under a specified pressure Ppi.

Abstract: The present invention relates to a double pass monochromator that improves wavelength resolution and reduces the actual length thereof. A return reflection means 7 that reverses the direction of dispersion of the wavelength of the second pass light 1c, 1f emitted and incident on a diffraction grating 4 during the reflection. In addition, the angles of the incident and emitted light during separation of spectral components by the diffraction grating are identical during the first and second diffraction.

Abstract: The present invention relates to an agent for enhancing and stabilizing the activity of Bifidus factor, containing at least one member selected from the group consisting of ascorbic acid, hyposulfurous acid and acetic anhydride as the effective ingredient, and by preparing the agent singly or in combination with Bifidus factor as a food and drink type or as a composition of pharmaceutical type, intestinal microflora can be ameliorated. The agent can be used as a selective medium for assaying the number of bifidobacteria.

Abstract: The present invention relates to a buffer mechanism of a hydraulic impact apparatus of a rock drill, and the like, and the buffer mechanism reduces damage by buffering the reflected energy from a shank rod (2), and enables to apply impact by advancing a bit so as to contact the rock even when a rock drill main body (1) cannot advance to a predetermined position for lack of thrust before the next application of impact after the rock drill main body once retracted, thereby to improve the efficiency of impact application. In a rock drill including an impact mechanism for applying impact to the shank rod (2), and a chuck driver bush (13) for transmitting thrust to the shank rod (2) to be applied to an object to be crushed, a front damping piston (4) having thrust smaller than thrust of the rock drill main body (1), and a rear damping piston (5) having thrust larger than the thrust of the rock drill main body (1) are provided at the rear of the chuck driver bush (13).

Abstract: A method for fermenting diacetyl and acetoin with a lactic acid bacterium by adding one or more additives selected from ferroporphyrin, heme protein, an animal tissue containing ferroporphyrin and blood and metal salts to a culture substrate containing a sugar source which a lactic acid bacterium can use, inoculating the lactic acid bacterium into the substrate and then aerobically culturing the bacterium with shaking or under aeration. A culture solution containing high concentrations of diacetyl and acetoin obtained by the present invention or its diacetyl concentrate is used to increase or improve the flavor of foods such as oils and fats, e.g., butter, margarine, cheeses, shortening, etc., confectionery, creams and the like.