摘要:
Molten metal is fed to a caster in a continuous casting operation through a distributor that divides the molten metal into four streams flowing in circulating patterns from the central axis of the caster. Each stream sweeps first along the longer side wall of the caster toward the corner, then back along the shorter side wall toward the center line. The result is a higher degree of fragmentation of metal crystals as they form, and a better distribution of the fragments across the caster cross section, as well as a more even temperature distribution.
摘要:
A robot fork calibration method and system is provided. At least three non-linear arranged lower sensors are provided on a bottom surface of the fork to detect distances to a fixed detection point. The fixed detection point and a horizontal plane of the detection point define a reference coordinate system. Spatial coordinates of the lower sensors in the reference coordinate system are calculated and a plane equation as well as a tilted angle of the fork are obtained according to the spatial coordinates. Therefore, the height of the fork can be calibrated according to the Z axis coordinates of the lower sensors and the levelness of the fork can be calibrated according to the tilted angle.
摘要:
A method for fabricating ultra-short T-gates on heterojunction field effect transistors (HFETs) comprising the steps of (a) providing a coating of three layers of resists, with polymethylmethacrylate (PMMA) with high molecular weight on the bottom, polydimethylglutarimide (PMGI) in the middle, and PMMA with low molecular weight on the top; (b) in a first exposure, exposing and developing the layers with a dose of a developer that is high enough to allow the developer to break the top PMMA but low to avoid contributing significantly to the overall dose received in the bottom PMMA layer; and (c) in a second exposure, using an exposure and developing process to define 0.03-0.05 um openings in the bottom PMMA layer.
摘要:
Oxygen toxicity is one of the major risk factors in the development of the chronic lung disease or bronchopulmonary dysplasia in premature infants. Using proteomic analysis, we discovered mitochondrial aldehyde dehydrogenase (mtALDH or ALDH2) was down-regulated in neonatal rat lung after hyperoxic exposure. To study the role of mtALDH in hyperoxic lung injury, we overexpressed mtALDH in human lung epithelial cells (A549) and found that mtALDH significantly reduced hyperoxia-induced cell death. Compared to control cells (Neo-A549), the necrotic cell death in mtALDH overexpressing cells (mtALDH-A549) decreased from 25.3% to 6.5%, 50.5% to 9.1% and 52.4% to 15.06% after 24-, 48- and 72-hour hyperoxic exposure, respectively. The levels of intracellular and mitochondria-derived reactive oxygen species (ROS) in mtALDH-A549 cells after hyperoxic exposure were significantly lowered compared to Neo-A549 cells. mtALDH overexpression significantly stimulated extracellular signal regulated kinase (ERK) phosphorylation under normoxic and hyperoxic conditions. Inhibition of ERK phosphorylation partially eliminated the protective effect of mtALDH in hyperoxia-induced cell death, suggesting ERK activation by mtALDH conferred cellular resistance to hyperoxia. mtALDH overexpression augmented Akt phosphorylation and maintained the total Akt level in mtALDH-A549 cells under normoxic and hyperoxic conditions. Inhibition of PI3K activation by LY294002 in mtALDH-A549 cells significantly increased necrotic cell death after hyperoxic exposure, indicating that PI3K/Akt activation by mtALDH played an important role in cell survival after hyperoxia. Taken together, these data demonstrate that mtALDH overexpression attenuates hyperoxia-induced cell death in lung epithelial cells through reduction of ROS, activation of ERK/MAPK and PI3K/Akt cell survival signaling pathways.
摘要:
The present invention concerns a submerged entry nozzle for use in the continuous casting of liquid metal. The nozzle comprises a central bore and a plurality of pairs of discharge outlets. The cross-sectional area of the central bore decreases between pairs of discharge outlets, such that ratio of height to width of any outlet is one or less.
摘要:
A planar 2×2 switch is provided for controllably coupling first and second input channels to first and second output channels. The switch includes a first reflector that is movable between a first position and a second position. When the first reflector is in its second position, it reflects light from the first input channel to the second output channel and reflects light from the second input channel to the first output channel. When the first reflection is in its first position, it does not affect the optical beams in the switch. Instead, these beams are reflected by a second reflector which has two reflective surfaces. The second reflector reflects light from the first input channel to the first output channel and reflects light from the second input channel to the second output channel. Switches having a larger number of input and output channels are also provided.
摘要:
A system and method are proposed for identifying multimedia files in a first database which are related to a textual term specified by a user. The textual term is used to search a second database of multimedia files, each of which is associated with a portion of text. The “second database” is usually composed of files from the databases of a very large number of servers connected via the internet. The multimedia files identified in the search are ones for which the corresponding associated text is relevant to the textual term. The identified multimedia files are used to generate a classifier engine. The classifier engine is then applied to the first database of multimedia files, thereby retrieving multimedia files in the first database which are relevant to the textual term. The user can optionally specify whether the retrieved multimedia files are relevant or not, and this permits a feedback process to improve the classifier engine.
摘要:
A pseudomorphic-high-electron-mobility-transistor (PHEMT) includes a substrate, a low-temperature-grown (LTG) GaAs gate-insulator layer disposed on the substrate, and a gate electrode disposed on the gate-insulator layer.
摘要:
A tundish impact pad for use in the continuous casting of molten metal is described that includes a base plate having an upper impact surface surrounded, at least in part, by a sidewall defining passageways. The impact pad is adapted to receive and deflect an incoming stream of molten metal, and permit outflow of the deflected stream through the passageways and the open top surface of the pad. Vaulted-stepped features surrounding the passageways and/or weir-like walls assist in directing the outflow. The division and distribution of the outflow facilitates the development of plug flow in the molten metal between the impact pad and the tundish outlet.
摘要:
A motion detector generates a field motion detection signal from information contained in adjacent fields of a two-to-one interlaced format video signal. The motion detector comprises an input for receiving the video signal from a source, a first delay for delaying the video signal at the input by one field period less one half of one scanning line period and for providing a first delayed output, a second delay for delaying the video signal at the input by one field period plus one half of one scanning line period and for providing a second delayed output, a first subtraction circuit for subtracting the first delayed output from the video signal to provide a first difference, a second subtraction circuit for subtracting the second delayed output from the video signal to provide a second difference, and a comparison circuit for comparing the first difference with the second difference and for putting out a selected one thereof having a lesser absolute magnitude as the field motion detection signal. A film mode sequence pattern interruption detector using the motion detector is also disclosed.