Abstract: The present disclosure provides an optimizer for a photovoltaic system, a control method for an optimizer, and an optimizer parallel arrangement thereof. In the method, a DC bus voltage output by the optimizer is acquired; and the optimizer is controlled to switch among an MPPT mode, a limited power mode and a fast shutdown mode based on the DC bus voltage.

Abstract: The present invention discloses a silty marine natural gas hydrate gravel stimulation mining method and a mining device. The mining method appropriately relaxes the sand retention accuracy of a wellbore, so that the fine sand and muddy components of the stratum can flow into the wellbore, and after a certain period of production, the coarse gravels are injected into the extra-pipe stratum of the production well to fill the deficit caused by the production of the fine components of the stratum and the hydrates, and then the well is opened for production. The method achieves the triple objectives of improving the productivity of the silty reservoir, preventing the large-area deficit in the stratum and extending the effective period of the sand retention of the wellbore, by way of the alternation of the rounds of the gravel injection and the hydrate reservoir fluid extraction.

Abstract: A bearing system includes a first bearing, the first bearing being annular in shape and defining a ring aperture, the first bearing including a first surface and a second surface, a second bearing being substantially the same in construction to the first bearing, a first surface of the second bearing contacting a second surface of the first bearing, wherein each of the bearings is constructed of nylon MDS.

Abstract: A rapid shutdown device and a photovoltaic system are provided. The photovoltaic system includes an inverter and multiple serially-connected photovoltaic elements. The rapid shutdown device includes a switching circuit, a control circuit, a communication circuit and an auxiliary power circuit. The switching circuit includes a first switch and a second switch. A first terminal of the first switch is electrically connected with the positive terminal of a first photovoltaic element. A second terminal of the first switch is electrically connected with the negative terminal of a second photovoltaic element. A first terminal of the second switch is electrically connected with the negative terminal of the first photovoltaic element. The communication circuit receives a command signal from the inverter and transmits it to the control circuit. The control circuit controls the first switch and the second switch to turn on or turn off according to the command signal.

Abstract: The present invention discloses a silty marine natural gas hydrate gravel stimulation mining method and a mining device. The mining method appropriately relaxes the sand retention accuracy of a wellbore, so that the fine sand and muddy components of the stratum can flow into the wellbore, and after a certain period of production, the coarse gravels are injected into the extra-pipe stratum of the production well to fill the deficit caused by the production of the fine components of the stratum and the hydrates, and then the well is opened for production. The method achieves the triple objectives of improving the productivity of the silty reservoir, preventing the large-area deficit in the stratum and extending the effective period of the sand retention of the wellbore, by way of the alternation of the rounds of the gravel injection and the hydrate reservoir fluid extraction.

Abstract: A stem coupling for a hydrant includes: an upper portion defining an upper portion length from a center of a plurality of break-away features defined in the stem coupling to a first end of the stem coupling; and a lower portion defining an lower portion length from the center of the plurality of break-away features defined in the stem coupling to a second end of the stem coupling distal from the first end of the stem coupling, the lower portion length equaling at least two times the upper portion length.

Abstract: The present disclosure provides an optimizer for a photovoltaic system, a control method for an optimizer, and an optimizer parallel arrangement thereof. In the method, a DC bus voltage output by the optimizer is acquired; and the optimizer is controlled to switch among an MPPT mode, a limited power mode and a fast shutdown mode based on the DC bus voltage.

Abstract: A nozzle cap assembly includes a nozzle cap housing configured to mount on a hydrant, the nozzle cap housing defining an upper rim and a lower rim, the nozzle cap housing defining an interior cavity extending inward from the upper rim toward the lower rim, the nozzle cap housing defining an antenna mounting portion extending from the upper rim toward the lower rim; an antenna cover mounted on the nozzle cap housing, the antenna cover positioned over at least a portion of the antenna mounting portion, the antenna cover defining an inner cover surface facing the antenna mounting portion, an antenna cover cavity at least partially defined between the inner cover surface and the antenna mounting portion; and an antenna assembly positioned in the antenna cover cavity, the antenna assembly secured to the inner cover surface.

Abstract: A nozzle cap assembly includes a nozzle cap including a base, the base defining a top end and a bottom end; and a nut positioned opposite from the bottom end; an enclosure positioned between the top end of the base and the nut, the enclosure defining a cavity within the enclosure; at least one antenna positioned within the cavity.

Abstract: A nozzle cap assembly can include a nozzle cap housing configured to mount on a hydrant, a nozzle cap cover mounted on the nozzle cap housing, an antenna cover positioned on the nozzle cap housing and secured by the nozzle cap cover, the nozzle cap housing, the antenna cover, and the nozzle cap cover can define an antenna cover cavity, and an antenna assembly can be positioned in the antenna cover cavity.

Abstract: An antenna assembly includes a curved printed circuit board (PCB) configured to mount around a curved surface. The curved PCB can include an outward-facing first side and an inward-facing second side with a plurality of antenna structures disposed on one of the first side and second side of the PCB. The plurality of antenna structures can be configured to provide directional radiation in at least one frequency band.

Abstract: A stem coupling for a hydrant includes: an upper portion defining an upper portion length from a center of a plurality of break-away features defined in the stem coupling to a first end of the stem coupling; and a lower portion defining an lower portion length from the center of the plurality of break-away features defined in the stem coupling to a second end of the stem coupling distal from the first end of the stem coupling, the lower portion length equaling at least two times the upper portion length.

Abstract: An antenna assembly includes a curved printed circuit board (PCB) configured to mount around a curved surface. The curved PCB can include an outward-facing first side and an inward-facing second side with a plurality of antenna structures disposed on one of the first side and second side of the PCB. The plurality of antenna structures can be configured to provide directional radiation in at least one frequency band.

Abstract: A nozzle cap assembly can include a nozzle cap housing configured to mount on a hydrant, a nozzle cap cover mounted on the nozzle cap housing, an antenna cover positioned on the nozzle cap housing and secured by the nozzle cap cover, the nozzle cap housing, the antenna cover, and the nozzle cap cover can define an antenna cover cavity, and an antenna assembly can be positioned in the antenna cover cavity.

Abstract: A stereo projection apparatus includes a polarized beam splitter assembly for splitting a projecting light beam; a polarization state transforming assembly for adjusting the polarization state of the transmitted light beam or the polarization state of the first and second reflective beam; a light path direction adjustment assembly for adjusting a travel direction of the transmitted light beam or a travel direction of the first and the second reflective light beam; a light beam size adjustment assembly for adjusting a coverage range of the transmitted light beam or a coverage range of the first and the second reflective light beam; and a light modulator for modulating the adjusted transmitted light beam, first reflective light beam and second reflective light beam.

Abstract: The present disclosure provides a photovoltaic power generation system and a shut-down device. The photovoltaic power generation system comprises: a photovoltaic array, an inverter, and a shut-down device electrically connected between the photovoltaic array and the inverter, wherein the inverter generates a first control signal when the inverter is turned off or fails; and the shut-down device receives the first control signal, to disconnect the photovoltaic array from the inverter. The photovoltaic power generation system according to the present disclosure has higher safety and reliability.

Abstract: A stereo projection apparatus includes a polarized beam splitter assembly for splitting a projecting light beam into a transmitted light beam, a first reflective light beam and a second reflective light beam; a polarization state transforming assembly for adjusting the polarization state of the transmitted light beam or the polarization state of the first reflective light beam and second reflective beam; a light path direction adjustment assembly for adjusting a travel direction of the transmitted light beam or a travel direction of the first reflective light beam and the second reflective light beam; a light beam size adjustment assembly for adjusting a coverage range of the transmitted light beam or a coverage range of the first reflective light beam and the second reflective light beam; and a light modulator for modulating the adjusted transmitted light beam, first reflective light beam and second reflective light beam to left-circularly polarized light and right-circularly polarized light in accordance wi

Abstract: The present invention relates to inhibitors of 11-? hydroxyl steroid dehydrogenase type 1, antagonists of the mineralocorticoid receptor (MR), and pharmaceutical compositions thereof. The compounds of the invention can be useful in the treatment of various diseases associated with expression or activity of 11-? hydroxyl steroid dehydrogenase type 1 and/or diseases associated with aldosterone excess.

Abstract: The present invention relates to inhibitors of 11-? hydroxyl steroid dehydrogenase type 1, antagonists of the mineralocorticoid receptor (MR), and pharmaceutical compositions thereof. The compounds of the invention can be useful in the treatment of various diseases associated with expression or activity of 11-? hydroxyl steroid dehydrogenase type 1 and/or diseases associated with aldosterone excess.

Abstract: The present invention relates to inhibitors of 11-? hydroxyl steroid dehydrogenase type 1, antagonists of the mineralocorticoid receptor (MR), and pharmaceutical compositions thereof. The compounds of the invention can be useful in the treatment of various diseases associated with expression or activity of 11-? hydroxyl steroid dehydrogenase type 1 and/or diseases associated with aldosterone excess.