摘要:
An improved and highly efficient method for the preparation of 2-R(R=alkyl, aryl, H) pyrroles from nitrites (RCN, R=alkyl, aryl) is described using Lewis acid activated donor-acceptor cyclopropanes to react with aliphatic, aromatic, branched, α,β-unsaturated, or otherwise functionalized nitrites in a cascade [3+2] dipolar cycloaddition, dehydration and tautomerization sequence.
摘要:
A waveguide assembly for operation over a range of temperatures includes a waveguide body and a plurality of restraining strips coupled to the waveguide body. The waveguide body includes a pre-curved narrow sidewall of material having a first coefficient of thermal expansion (CTE). The restraining strips are coupled to the waveguide body at first and second lateral points on either side of the pre-curved narrow sidewall laterally and are spaced apart along the length of the waveguide body, and are made from a material having a second CTE much less than the first CTE. Thus, when the temperature of the waveguide assembly changes, the restraining strips maintain a substantially constant lateral distance between said first and second lateral points over the range of temperatures such that as the length of the waveguide varies with temperature, the curvature of the pre-curved narrow sidewall also changes, causing the effective large dimension of the waveguide assembly to vary such that the combination of said changes results in a constant phase length for said waveguide body.
摘要:
A photocathode as a source of electron beams, having a substrate of optically transmissive diamond and a photoemitter. A photocathode with a single emitting region provides a single electron beam; a photocathode with multiple emitting regions provides multiple electron beams. The photoemitter is positioned on the side of the diamond substrate opposite the surface on which the illumination is incident, and has an irradiation region at the contact with the optically transmissive diamond, and an emission region opposite the irradiation region, these regions being defined by the path of the illumination. The diamond substrate at the irradiation region/emission region interface conducts heat away from this focused region of illumination on the photocathode. Alternately, a diamond film is used for heat conduction, while another material is used as a substrate to provide structural support. The thermal conductivity of diamond is at least three orders of magnitude greater than that of fused silica, which is an alternative substrate material for photocathodes. This allows for efficient conduction of heat away from the irradiation region/emission region interface, and therefore allows higher currents to be achieved from the photocathode. This, in turn, permits higher throughput rates in applications including electron beam lithography.
摘要:
A display apparatus is provided. The display apparatus includes a light source. The display apparatus includes a display target configured to receive light from the light source. The display target displays an image using at least a portion of the light received from the light source. The display apparatus includes a first reflective structure configured to reduce an outgoing angle of at least a portion of the light from the light source. The display apparatus includes a second reflective structure configured to longitudinally translate at least a portion of the light from at least one of the light source and the first reflective structure toward the display target.
摘要:
This invention points to biological molecules and/or sequences that can be used as target for designing drug for treating cancer. This invention also points to biological sequences that can be used to target those molecules as a mean to treat cancer.
摘要:
A microwave filter has a housing defining an inner cavity. A first resonator is positioned in a first portion of the inner cavity. A second resonator is positioned in a second portion of the inner cavity. A third resonator is positioned in a third portion of the inner cavity. The first resonator and the third resonator are cross-coupled via an iris. The second resonator is elongated and is coupled to the first resonator and the third resonator. The resulting microwave filter has a frequency response having a transmission zero in the lower stopband. A high-pass filter is realized without the use of a cross-coupling probe.
摘要:
A portable computing device is disclosed. The portable computing device can take many forms such as a laptop computer, a tablet computer, and so on. The portable computing device can include at least a single piece housing. The single piece housing including a plurality of steps. The plurality of mounting steps is formed by at least removing a preselected amount of housing material at predetermined locations on the interior surface. At least some of the mounting steps are used to mount at least some of the plurality of internal operating components to the housing.
摘要:
A multi-mode base station and an operating method and a wireless communication system thereof are provided. The multi-mode base station includes: at least two protocol processing modules, vested in at least two modes respectively, and adapted to process data and/or signaling of the mode according to the protocol corresponding to the mode; and an interface processing module, adapted to distinguish the mode of the data and/or the signaling while receiving the data and/or the signaling, and distribute the data and/or the signaling to the protocol processing module corresponding to the mode. Thus, the reconfiguration of the multi-mode base station can be performed more conveniently and quickly.