Abstract: In a semiconductor light-emitting device, on an n-GaAs substrate are stacked an n-GaAs buffer layer, an n-cladding layer, an undoped active layer, a p-cladding layer, a p-intermediate band gap layer and a p-current diffusion layer. Further, a first electrode is formed under the n-GaAs substrate, and a second electrode is formed on the grown-layer side. In this process, a region of the p-intermediate band gap layer just under the second electrode is removed, the p-current diffusion layer is stacked in the removal region on the p-cladding layer, and a junction plane of the p-current diffusion layer and the p-cladding layer becomes high in resistance due to an energy band structure of type II. This semiconductor light-emitting device is capable of reducing ineffective currents with a simple construction and taking out light effectively to outside, thus enhancing the emission intensity.

Abstract: A sensitizer for tumor treatment has a structure such that a lipophilic group and a hydrophilic group are bound to one and the same carbon atom in a compound containing a xanthene dye structure. It is important that the lipophilic group and hydrophilic group are bound to one and the same carbon atom; if they are separated from each other, no sufficient effect is obtained. Thus, the sensitizer possesses both lipophilicity and hydrophilicity. This sensitizer has a function of promoting acoustic cavitation and a function of revealing an antitumor effect and is an agent highly accumulable in tumor tissues. Thus, this sensitizer is highly selective for tumor tissues and enables the treatment of malignant tumor using ultrasound.

Abstract: The semiconductor light emitting element of the present invention includes: a compound semiconductor substrate having a first conductivity type; a light emitting layer; a compound semiconductor interface layer having a second conductivity type and not containing Al; and a current diffusion layer having the second conductivity type and being made of a compound semiconductor not containing Al.

Abstract: The present invention provides an advantageous method for producing an optically active chrysanthemic acid. Disclosed is a method for producing an optically active chrysanthemic acid whose trans isomer ratio and optical purity are improved, which comprises reacting chrysanthemic acid having a trans isomer ratio of not less than 50% and an optical purity of not less than 10% e.e. with an optically active organic amine to optically resolve said chrysanthemic acid.

Abstract: There is provided a semiconductor light emitting device having improved adhesion of an electrode by reducing defects in a crystal surface. An n-type AlGaInP lower clad layer 12, an AlGaInP active layer 13, a p-type AlGaInP upper clad layer 14, a p-type AlGaInP intermediate layer 15 whose lattice matching rate &Dgr;a/a with GaAs is −3.3%, a p-type AlGaInP current diffusion layer 16 and a p-type electrode 17 are laminated on an n-type GaAs substrate 11 and an n-type electrode 18 is provided on the n-type GaAs substrate 11. Thus, the number of crystal defects in the crystal surface can be reduced to 20 or less per one LED by setting the value of the lattice matching rate &Dgr;a/a of the intermediate layer 15 to be −3.3%, which is lower than −2.5%. As a result, adhesion of the p-type electrode 17 formed on the current diffusion layer 16 is improved and thereby the yield of LED can be enhanced.

Abstract: The semiconductor light emitting element of the present invention includes: a compound semiconductor substrate having a first conductivity type; a light emitting layer; a compound semiconductor interface layer having a second conductivity type and not containing Al; and a current diffusion layer having the second conductivity type and being made of a compound semiconductor not containing Al.

Abstract: An ultrasonic manipulation apparatus has a plurality of ultrasonic wave oscillators arranged in two dimensions to trap, fix or move particles to an optional position in the solution or perform cell fusion by using a gradient force obtained by superposing one over another the gradient force fields generated by ultrasonic waves produced by a plurality of ultrasonic wave oscillators. The ultrasonic wave oscillators, functioning independently of one another, can emit ultrasonic waves with optional intensities and phases, and by using an external force produced by superposed gradient force fields generated by ultrasonic waves, particles are handled easily.

Abstract: In monitoring a network in which nodes such as a host, a hub, rooter, etc. are interconnected, each node is indicated by an icon, and the connection between the nodes is indicated by a line. A node to be regarded is positioned in the center of the map as a root, and a node directly connected to the root is arranged as a node at the second hierarchical level on the circumference of the circle with the root centered. The node connected to the node at the second hierarchical level is arranged as a node at the third hierarchical level on the circumference of the concentric circle, with the root centered, having a larger radius than the node at the second hierarchical level. Similarly, the network configuration is assumed to be a hierarchical structure with the root centered, and an icon indicating an object at a higher hierarchical level is arranged on the circumference of a concentric circle having a larger radius.

Abstract: A semiconductor light-emitting device includes: a semiconductor substrate of a first conductive type, and a multilayered structure formed on the semiconductor substrate. The multilayered structure includes a first cladding layer of the first conductive type, an undoped active layer, a second cladding layer of a second conductive type, and a current diffusing layer of the second conductive type which are subsequently deposited. An undoped spacer layer is provided between the undoped active layer and the second cladding layer.

Abstract: A semiconductor light-emitting device includes: a semiconductor substrate of a first conductive type, and a multilayered structure formed on the semiconductor substrate. The multilayered structure includes a first cladding layer of the first conductive type, an undoped active layer, a second cladding layer of a second conductive type, and a current diffusing layer of the second conductive type which are subsequently deposited. An undoped spacer layer is provided between the undoped active layer and the second cladding layer.

Abstract: A semiconductor laser device includes a substrate having one of p- and n-conductivity types, and a current constrictive layer formed on a surface of the substrate and having the other type of conductivity. The current constrictive layer has a through-channel extending to the surface of the substrate for defining a current path in a direction perpendicular to the surface of the substrate. The through-channel is of a belt-like pattern extending in a direction perpendicular to end surfaces of the substrate. A third cladding layer having the one type of conductivity is filled in the through-channel, a surface of the third cladding layer being flush with a surface of a current constrictive layer. A first cladding layer, an active layer, and a second cladding layer which constitute a double heterostructure are formed over the third cladding layer and current constrictive layer.

Abstract: A method for producing a semiconductor laser device includes the steps of: forming window layers on either one of a top surface of an internal structure or a reverse surface of a substrate and on light-emitting end facets of the internal structure; forming a reflection film on the light-emitting end facets; removing the window layer formed on either one of the top surface or the reverse surface by using an etchant which hardly etches the reflection film; and forming electrodes on the surface from which the window layer is removed by etching and on the other surface. Another method for producing a semiconductor laser device includes the steps of: forming window layers on light-emitting end facets of the bars; inserting the bars into an apparatus having openings for forming electrodes and a supporting portion for preventing a positional shift between the bars and the openings, and forming the electrodes on the top surfaces and the reverse surfaces of the bars; and cutting the bars into the chips.

Abstract: A semiconductor laser device includes a substrate having one of p- and n-conductivity types, and a current constrictive layer formed on a surface of the substrate and having the other type of conductivity. The current constrictive layer has a through-channel extending to the surface of the substrate for defining a current path in a direction perpendicular to the surface of the substrate. The through-channel is of a belt-like pattern extending in a direction perpendicular to end surfaces of the substrate. A third cladding layer having the one type of conductivity is filled in the through-channel, a surface of the third cladding layer being flush with a surface of a current constrictive layer. A first cladding layer, an active layer, and a second cladding layer which constitute a double heterostructure are formed over the third cladding layer and current constrictive layer.

Abstract: A method for producing a semiconductor laser device includes the steps of: forming window layers on either one of a top surface of an internal structure or a reverse surface of a substrate and on light-emitting end facets of the internal structure; forming a reflection film on the light-emitting end facets; removing the window layer formed on either one of the top surface or the reverse surface by using an etchant which hardly etches the reflection film; and forming electrodes on the surface from which the window layer is removed by etching and on the other surface. Another method for producing a semiconductor laser device includes the steps of: forming window layers on light-emitting end facets of the bars; inserting the bars into an apparatus having openings for forming electrodes and a supporting portion for preventing a positional shift between the bars and the openings, and forming the electrodes on the top surfaces and the reverse surfaces of the bars; and cutting the bars into the chips.

Abstract: A semiconductor light emitting device which allows part of an active layer to generate light by supplying current to the part of the active layer is disclosed. The semiconductor light emitting device includes: a semiconductor substrate having upper and lower surfaces, the upper surface having a stepped portion, the stepped portion dividing the upper surface into at least a first area and a second area; a current confining layer, formed on the upper surface of the substrate, the current confining layer being discontinuous at the stepped portion, the current flowing through an area between the first area and the second area of the substrate; a multilayer structure formed on the current confining layer, the multilayer structure including the active layer; a first electrode which covers only part of an upper surface of the multilayer structure; and a second electrode formed over the lower surface of the substrate.

Abstract: A surface electrode on a surface of a LED has a pad, and further, at least first-order branches linearly extending from the pad, second-order branches diverged and linearly extending from the first-order branches, and third-order branches diverged and linearly extending from the second-order branches. The pad out of the surface electrode is not in electrical contact with a underlying semiconductor layer, whereas the surface electrode and the semiconductor layer are in electrical contact with each other at ends of the highest-order branches. Also, the semiconductor layer is provided along a pattern of the surface electrode in a mesa shape. Thus, ineffective light emission underneath the surface electrode is relatively reduced so that external quantum efficiency can be improved, and moreover even shorter-wavelength light can be allowed to go out at high efficiency by omitting a current diffusion layer.

Abstract: A semiconductor laser device is disclosed which emits laser light from a facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on the facet, wherein a film containing sulfur is provided between the facet and the protective film.

Abstract: The present invention provides an aldol condensation dehydration catalyst, a process for preparing the same comprising reacting an aluminium salt with at least one magnesium compound selected from the group consisting of magnesium oxide and magnesium hydroxide to support thereon an aluminium compound and heating said supported product at a temperature in the range from 350.degree. to 700.degree. C., and a process for preparing an aldol condensation dehydrate by using the process.

Abstract: Magnesium.aluminium complex compound useful for aldol condensation dehydration is prepared by allowing a solution of magnesium salts and a solution of aluminium salts to react with ammonia and then heating the thus obtained precipitate at a temperature of 400.degree.-700.degree. C.

Abstract: A semiconductor laser device is provided which is constituted by semiconductor materials so as to emit laser light from a cavity end facet, the laser light being excited in a waveguide within an active layer sandwiched between a pair of cladding layers, wherein a window layer made of a semiconductor material having a band gap greater than that of the active layer is formed on the cavity end facet from which the laser light is emitted, so as to have a thickness sufficient to prevent local generation of crystal defects by lattice mismatching between the semiconductor material of the window layer and the semiconductor materials at the cavity end facet. There is also provided a method for producing such a semiconductor laser device with high efficiency.