Abstract: An AC/DC converter includes: a charge accumulation unit including first and second capacitors connected in series; a switching unit including a switch unit; a control unit; a switch drive unit; and first current and second current detection units. The switch unit includes first and second switching elements connected in series. The switching unit switches between charging and non-charging of each of the first and second capacitors. The switch drive unit causes the first and second switching elements to perform an ON/OFF operation exclusively to each other. A current detector of the first current detection unit is disposed between a rectifier circuit and the switch unit. The control unit detects a current flowing through the switch unit on the basis of based on a difference value between a detection value of a first current detected by the first current detection unit and a detection value of a second current detected by the second current detection unit.

Abstract: To provide a light-emitting element with an improved reliability, a light-emitting element with a high current efficiency (or a high quantum efficiency), and a novel dibenzo[f,h]quinoxaline derivative that is favorably used in a light-emitting element which is one embodiment of the present invention. A light-emitting element includes an EL layer between an anode and a cathode. The EL layer includes a light-emitting layer; the light-emitting layer contains a first organic compound having an electron-transport property and a hole-transport property, a second organic compound having a hole-transport property, and a light-emitting substance; the combination of the first organic compound and the second organic compound forms an exciplex; the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound; and a difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is less than or equal to 0.4 eV.

Abstract: Provided are a heterocyclic compound which emits blue light and is represented by General Formula (G1) below, and a light-emitting element, a light-emitting device, an electronic device and a lighting device which are formed using the heterocyclic compound represented by General Formula (G1) below. The use of the heterocyclic compound represented by General Formula (G1) makes it possible to provide a light-emitting element which has high emission efficiency, and also a light-emitting device, an electronic device and a lighting device which have reduced power consumption.

Abstract: A novel organic compound is provided. That is, a novel organic compound that is effective in improving element characteristics and reliability is provided. The organic compound includes an anthracene skeleton and a carbazole skeleton, and is represented by the following general formula (G1). (In the formula, Ar represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and when the arylene group has substituents, the substituents may be bonded to each other to form a ring. Furthermore, Cz represents a substituted or unsubstituted carbazole skeleton. Furthermore, each of R1 to R9 and R11 to R17 independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Furthermore, at least one of the following pairs may form a fused ring: R12 and R13; R14 and R15; R15 and R16; or R16 and R17.

Abstract: A DC power supply device includes a booster circuit generating boosted voltage obtained by boosting DC voltage output from a rectifier circuit and applying the boosted voltage to an inverter circuit, a control unit controlling operation of the booster circuit, and a current detection unit detecting current flowing into and from the inverter circuit. The booster circuit includes a charge accumulation unit including first and second capacitors connected in series and first and second switching elements connected in series. The booster circuit includes a switching unit including backflow prevention elements for preventing backflow of charges from the charge accumulation unit and a current detection unit detecting current flowing into and from the booster circuit. The control unit determines whether to continue driving of an electric motor based on each of detection values of the current detection units.

Abstract: A novel organic compound is provided. That is, a novel organic compound that is effective in improving element characteristics and reliability is provided. The organic compound includes an anthracene skeleton and a carbazole skeleton, and is represented by the following general formula (G1). (In the formula, Ar represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and when the arylene group has substituents, the substituents may be bonded to each other to form a ring. Furthermore, Cz represents a substituted or unsubstituted carbazole skeleton. Furthermore, each of R1 to R9 and R11 to R17 independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Furthermore, at least one of the following pairs may form a fused ring: R12 and R13; R14 and R15; R15 and R16; or R16 and R17.

Abstract: To provide a light-emitting element with an improved reliability, a light-emitting element with a high current efficiency (or a high quantum efficiency), and a novel dibenzo[f,h]quinoxaline derivative that is favorably used in a light-emitting element which is one embodiment of the present invention. A light-emitting element includes an EL layer between an anode and a cathode. The EL layer includes a light-emitting layer; the light-emitting layer contains a first organic compound having an electron-transport property and a hole-transport property, a second organic compound having a hole-transport property, and a light-emitting substance; the combination of the first organic compound and the second organic compound forms an exciplex; the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound; and a difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is less than or equal to 0.4 eV.

Abstract: A handpiece-type high-frequency vibration cutting device includes a housing (10); a vibration device (21); a holding member (11); a tool (12); and a controller (20) to control the operations of the vibration device (21). The controller (20) controls the vibration of the tool (12) due to the vibration device (21) such that the vibration is burst oscillation in which vibration and stop of vibration are repeated. The controller (20) also controls the entire burst frequency f1 of the tool (12) to be included in the range of 1 to 8 [Hz], one cycle of the burst frequency f1 including a burst period with the holding member (11) vibrating and a stop period with the tool (12) not vibrating. The controller (20) also controls the vibration frequency f2 of the tool (12) during the burst period such that the vibration frequency f2 is in the range of 20 to 60 [kHz].

Abstract: A method for manufacturing a compound semiconductor substrate comprises: a step to form an SiC (silicon carbide) layer on a Si (silicon) substrate, a step to form a LT (Low Temperature)-AlN (aluminum nitride) layer with a thickness of 12 nanometers or more and 100 nanometers or less on the SiC layer at 700 degrees Celsius or more and 1000 degrees Celsius or less, a step to form a HT (High Temperature)-AlN layer on the LT-AlN layer at a temperature higher than the temperature at which the LT-AlN layer was formed, a step to form an Al (aluminum) nitride semiconductor layer on the HT-AlN layer, a step to form a GaN (gallium nitride) layer on the Al nitride semiconductor layer, and a step to form an Al nitride semiconductor layer on the GaN layer.

Abstract: A direct current power supply device includes a rectifier circuit that rectifies alternating current power supplied from an alternating current power supply and converts the alternating current power into direct current power, a charge storage unit that includes a function of storing a charge, a charger that charges the charge storage unit, and a heat sink. The charger includes a positive-side switching element, a negative-side switching element, a positive-side backflow prevention diode, and a negative-side backflow prevention diode. The positive-side switching element, the negative-side switching element, the positive-side backflow prevention diode, and the negative-side backflow prevention diode are discrete semiconductor elements. The negative-side backflow prevention diode is a full mold package element. The positive-side switching element, the negative-side switching element, and the positive-side backflow prevention diode are elements that are not full mold packages.

Abstract: A vibration type removal apparatus 2 includes a housing 10, a holding member 11, a tool 12, a control device 20, a vibration device 21, and a cooling pump 22. The control device 20 drives the cooling pump 22, and cooling water supplied from the cooling pump 22 passes through a flow path 25 in the housing 10, and is sprayed toward the tool 12 from a distal end of the flow path 25. In this state, the tool 12 is inserted between a hard tissue HT and a soft tissue ST, the vibration device 21 is operated, and the tool 12 is vibrated. Due to the vibration of the tool 12, a surface of the hard tissue HT which adheres to the soft tissue ST is cut, and the hard tissue HT is peeled and removed from the soft tissue ST.

Abstract: A DC power supply device includes: a rectifier circuit; a reactor connected at one end to one output terminal of the rectifier circuit; a charging unit including a first and second switching element connected in series between another end of the reactor and another output terminal of the rectifier circuit, the charging unit configured to charge a first and second capacitor connected in series between output terminals to which a load is connected; and a control unit that controls the charging unit. The control unit sets, based on the timing at which the zero-crossing occurs, a dead time in which both the and second switching element are off, and when states of the first and second switching element at a time of occurrence of the zero-crossing match a predetermined set of states, reverses the states of the first switching element and the second switching element.

Abstract: A compound semiconductor substrate includes a SiC (silicon carbide) layer, a AlN (aluminum nitride) buffer layer formed on the SiC layer, an Al (aluminum) nitride semiconductor layer formed on the AlN buffer layer, a composite layer formed on the Al nitride semiconductor layer, a GaN (gallium nitride) layer as an electron transition layer formed on the composite layer, and an Al nitride semiconductor layer as a barrier layer formed on the GaN layer. The composite layer includes C—GaN layers stacked in a vertical direction, and an AlN layer formed between the C—GaN layers.

Abstract: Provided are a heterocyclic compound which emits blue light and is represented by General Formula (G1) below, and a light-emitting element, a light-emitting device, an electronic device and a lighting device which are formed using the heterocyclic compound represented by General Formula (G1) below. The use of the heterocyclic compound represented by General Formula (G1) makes it possible to provide a light-emitting element which has high emission efficiency, and also a light-emitting device, an electronic device and a lighting device which have reduced power consumption.

Abstract: A compound semiconductor substrate that can improve in-plane uniformity of current-voltage characteristics in the vertical direction is provided. A compound semiconductor substrate includes a center and an edge which is 71.2 millimeters away from the center when viewed in a plane. When a film thickness of the GaN layer at the center of the compound semiconductor substrate is W1 and a film thickness of the CaN layer at the edge is W2, film thickness error ?W represented by ?W (%)=W1?W2|*100/W1 is greater than 0 and 8% or less. The average carbon concentration in the depth direction at a center of the CaN layer is 3*1018 pieces/cm3 or more and 5*1020 pieces/cm3 or less. When a carbon concentration at a center position of the depth direction at the center of the GaN layer is concentration C1 and a carbon concentration at a center position of the depth direction at the edge of the GaN layer is concentration C2, concentration error ?C represented by ?C (%)=|C1?C2*100/C1 is 0 or more and 50% or less.

Abstract: Provided are a heterocyclic compound which emits blue light and is represented by General Formula (G1) below, and a light-emitting element, a light-emitting device, an electronic device and a lighting device which are formed using the heterocyclic compound represented by General Formula (G1) below. The use of the heterocyclic compound represented by General Formula (G1) makes it possible to provide a light-emitting element which has high emission efficiency, and also a light-emitting device, an electronic device and a lighting device which have reduced power consumption.

Abstract: A highly efficient light-emitting element capable of providing a plurality of emission colors is provided, which does not easily deteriorate and can minimize a decrease in external quantum efficiency even when a light-emitting layer has a stacked structure. A light-emitting device, an electronic device, and a lighting device which have low power consumption and long lifetime are provided. A light-emitting element includes a plurality of light-emitting layers stacked between a pair of electrodes. The light-emitting layers each contain a host material and a guest material. The guest materials of the light-emitting layers are substances which have different HOMO levels but have substantially the same LUMO levels and emit light of different colors. A light-emitting device, an electronic device, and a lighting device are fabricated using the light-emitting element.

Abstract: A novel compound for a host material is provided. A compound for a host material that is capable of increasing the lifetime of a light-emitting device is provided. A light-emitting device with a long lifetime is provided. A material whose thermophysical properties such as a glass transition temperature are high is provided. An anthracene compound for a host material represented by General Formula (G1) below is provided. (Note that in General Formula (G1), R1 to R7 each independently represent hydrogen or an aryl group having 1 to 25 carbon atoms.

Abstract: A novel organic compound is provided. That is, a novel organic compound that is effective in improving the element characteristics and reliability is provided. The organic compound has a benzofuroquinoxaline skeleton or a benzothienoquinoxaline skeleton. The organic compound is represented by General Formula (G1). In the formula, Q represents O or S, and each of R1 to R8 independently represents any of hydrogen, a halogeno group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms. At least one of R1 to R8 includes a substituted or unsubstituted condensed aromatic or heteroaromatic ring having 3 to 24 carbon atoms.

Abstract: A novel organic compound is provided. That is, a novel organic compound that is effective in improving the element characteristics and reliability is provided. The organic compound has a benzofuroquinoxaline skeleton or a benzothienoquinoxaline skeleton. The organic compound is represented by General Formula (G1). In the formula, Q represents O or S, and each of R1 to R8 independently represents any of hydrogen, a halogeno group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms. At least one of R1 to R8 includes a substituted or unsubstituted condensed aromatic or heteroaromatic ring having 3 to 24 carbon atoms.