摘要:
Process for synthesizing a chemical, in particular an agriculturally or pharmaceutically active compound, including: a first step comprising reacting a carboxylic acid halide with a vinyl ether to prepare a halogenated precursor of an alkenone; a second step comprising eliminating hydrogen halide from such precursor to form an alkenone, preferably by thermolysis under specific conditions; and a third step which uses the formed alkenone as a building block to synthesize the chemical. First step may be done in a liquid reaction medium comprising an alkenone or a halogenated alkenone precursor, or in a liquid reaction medium in turbulent state, specifically by creation of gas bubbles of the carboxylic acid halide herein. Second step may include a flash thermolysis, vacuum thermolysis, thermolysis under stripping with inert gas, and/or a thermolysis at a temperature from >90° C. to 120° C. Third step preferably comprises reacting the alkenone with a nitrogen-containing compound.
摘要:
Systems and methods for selecting an action associated with a power state transition of a head-mounted display (HMD) in the form of eyeglasses are disclosed. A signal may be received from a sensor on a nose bridge of the eyeglasses indicating if the HMD is in use. Based on the received signal, a first powers state for the HMD may be determined. Responsive to the determined first power state, an action associated with a power state transition of the HMD from an existing power state to the first power state may be selected. The action may be selected from among a plurality of actions associated with a plurality of state transitions. Also, the action may be a sequence of functions performed by the HMD including modifying an operating state of a primary processing component of the HMD and a detector of the HMD configured to image an environment.
摘要:
A process for the manufacture of a cyclic compound of formula (I) which comprises (a) adding an acid halide of formula R1—C(O)—X, to a vinyl ether of formula (II): CH2═CH—OR2, to produce an addition product, and (b) reacting the addition product with a compound of formula (III): Y-A-Z; wherein R1 is a halogenated alkyl group; wherein X is fluorine, chlorine, or bromine; wherein R2 is an alkyl group, an aralkyl group, or an aryl group; wherein Z and Y designate independently carbon or a heteroatom; and wherein A is a linking group between Z and Y comprising 0, 1, 2 or 3 atoms in the cycle.
摘要:
A method includes generating a light pattern using a display panel and forming a virtual image from the light pattern utilizing one or more optical components. The virtual image is viewable from a viewing location. The method also includes receiving external light from a real-world environment incident on an optical sensor. The real-world environment is viewable from the viewing location. Further, the method includes obtaining an image of the real-world environment from the received external light, identifying a background feature in the image of the real-world environment over which the virtual image is overlaid, and extracting one or more visual characteristics of the background feature. Additionally, the method includes comparing the one or more visual characteristics to an upper threshold value and a lower threshold value and controlling the generation of the light pattern based on the comparison.
摘要:
Systems and methods for selecting an action associated with a power state transition of a head-mounted display (HMD) in the form of eyeglasses are disclosed. A signal may be received from a sensor on a nose bridge of the eyeglasses indicating if the HMD is in use. Based on the received signal, a first powers state for the HMD may be determined. Responsive to the determined first power state, an action associated with a power state transition of the HMD from an existing power state to the first power state may be selected. The action may be selected from among a plurality of actions associated with a plurality of state transitions. Also, the action may be a sequence of functions performed by the HMD including modifying an operating state of a primary processing component of the HMD and a detector of the HMD configured to image an environment.
摘要:
A process for preparing a halogenated precursor of an alkenone, which comprises reacting a carboxylic acid halide with a vinyl ether in a liquid reaction medium under turbulent conditions and a process for preparing an alkenone, by eliminating hydrogen halide from said precursor to form the alkenone.
摘要:
Process for preparing an alkenone, which comprises (a) reacting a carboxylic acid halide with a vinyl ether by introducing vinyl ether into a liquid reaction medium containing carboxylic acid halide to form a halogenated precursor of the alkenone and (b) eliminating hydrogen halide from said precursor to form the alkenone.
摘要:
Carbonyl fluoride, which can also be used as an etching gas, can be prepared by photochemical oxidation of chlorodifluoromethane or trifluoromethane with light, for example with light of a wavelength ≧280 nm in the presence of chlorine.
摘要:
Inorganic and organic compounds containing fluorine can be produced, for example, from corresponding chlorine-containing compounds by chlorine/fluorine exchange using fluorinating agents. Monocyclic or bicyclic compounds containing at least two nitrogen atoms, at least one of which is incorporated into the ring system, can be used as catalysts or fluorinating agents for chlorine/fluorine exchange reactions to produce sulfurylchlorofluoride, sulfurylfluoride or a carboxylic acid fluoride. It is likewise possible to carry out HF addition to unsaturated carbon-carbon bonds or chlorine/fluorine exchange at carbon atoms. For example, monochloro or dichloro malonic acid esters can be converted to difluoro malonic acid esters. Work-up of the reaction mixture can be simplified by using suitable solvents which force the reaction mixture to exist in two phases.
摘要:
A process for producing a compound containing an acylated nitrogen atom in which the adduct compound formed from an N-protonated cation and a chloride, bromide or iodide anion or the free nitrogen base is reacted with an acyl halide, preferably an acyl chloride, in the presence of an acid that drives off the released hydrogen chloride (HCl), hydrogen bromide (HBr) or hydrogen iodide (HI).