摘要:
The invention relates to cholesteric organic polymers which contain, in the side groups, both mesogens, at least some of which are optically active, and chromophoric groups.
摘要:
The invention relates to optical elements based on helical liquid-crystalline substances, having reflection bands of linear-polarized light, and to a process for preparing the same. The optical elements of this invention contain only one optically effective component based on helical liquid-crystalline substances. They reflect light incident perpendicular to the surface in a linear-polarized manner parallel to the direction of incidence of the incident light. The process for preparing the optical elements comprises illuminating a helical liquid-crystalline substance which contains at least one photoisomerizable substance with linear-polarized light in such a manner that this substance is subsequently aligned so that it exhibits at least one reflection band of linear-polarized light on illumination. Suitable helical liquid-crystalline substances are in particular organopolysiloxanes. The optical elements are suitable, for example, for data storage.
摘要:
The invention relates to optical elements based on liquid-crystalline substances, and to a process for the production thereof. The optical elements based on liquid-crystalline substances are ones which exhibit no birefringence in a defined direction of incidence, optical elements in which no birefringence occurs perpendicularly to the surface being excepted. The process for preparing the optical elements comprises illuminating a liquid-crystalline substance with unpolarized light of suitable wavelength at a defined angle in such a way that, after illumination, the director of this substance is aligned parallel to the direction of the illuminating light on passing through said substance.
摘要:
A device for pulling a single crystal from a melt having a widened portion between an upper and a lower neck portion including a pulling device having a pulling device cable drum configured to wind a pulling cable, the pulling cable configured to pull the single crystal and a supporting device configured to relieve the upper neck portion of a weight of the single crystal.
摘要:
Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ≧450 mm and a length of ≧800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ≧70 mm is present between a heat shield surrounding the single crystal and the melt surface.
摘要:
An SOI wafer is constructed from a carrier wafer and a monocrystalline silicon layer having a thickness of less than 500 nm, an excess of interstitial silicon atoms prevailing in the entire volume of the silicon layer. The SOI wafers may be prepared by Czochralski silicon single crystal growth, the condition v/G
摘要翻译:SOI晶片由载体晶片和厚度小于500nm的单晶硅层构成,在硅层的整个体积中存在过量的间隙硅原子。 可以通过Czochralski硅单晶生长制备SOI晶片,在整个晶体截面处在结晶前沿满足条件v / G <(v / G)crit = 1.3×10 -3 cm 2 /(K·min) ,结果是在所生成的硅单晶中存在过量的间隙硅原子; 从该硅单晶分离至少一个施主晶片,将施主晶片与载体晶片的接合以及施主晶片的厚度的减小,结果是厚度小于500nm的硅层与 载体晶片残留。
摘要:
Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ≧450 mm and a length of ≧800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ≧70 mm is present between a heat shield surrounding the single crystal and the melt surface.
摘要:
The present invention relates to an excavator having an undercarriage, a superstructure and an internal combustion engine for the drive of the excavator arranged in or at the superstructure, with at least one fuel tank for the supply of the internal combustion engine with fuel being arranged in or/and at the undercarriage of the excavator.
摘要:
An SOI wafer is constructed from a carrier wafer and a monocrystalline silicon layer having a thickness of less than 500 nm, an excess of interstitial silicon atoms prevailing in the entire volume of the silicon layer. The SOI wafers may be prepared by Czochralski silicon single crystal growth, the condition v/G
摘要翻译:SOI晶片由载体晶片和厚度小于500nm的单晶硅层构成,在硅层的整个体积中存在过量的间隙硅原子。 SOI晶片可以通过Czochralski硅单晶生长制备,条件v / G <(V / G) SUB> = 1.3×10 -3 cm 2 在整个晶体截面上在结晶前沿实现/SUP>/(K.min),结果产生的硅单晶中存在过量的间隙硅原子; 从该硅单晶分离至少一个施主晶片,将施主晶片与载体晶片的接合以及施主晶片的厚度减小,结果是厚度小于500nm的硅层与 载体晶片残留。
摘要:
Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ≧450 mm and a length of ≧800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ≧70 mm is present between a heat shield surrounding the single crystal and the melt surface.