摘要:
A device for receiving a broadband multi-channel radiofrequency signal includes a radiofrequency analog input stage connected to an intermediate-frequency conversion stage. The conversion stage includes at least one conversion chain having a frequency mixer that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter with a high frequency sampling rate. The intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.
摘要:
The invention relates to a device for receiving a broadband multi-channel radiofrequency signal, consisting of a radiofrequency analog input stage (3) connected to an intermediate-frequency conversion stage (δ), said conversion stage comprising at least one conversion chain (13, 15) comprising a frequency mixer (17, 19) that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter (29, 31) with a high frequency sampling rate, characterized in that the intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.
摘要:
Linearly photopolymerized (LPP) orientation layers for liquid crystals, that is to say liquid crystal orientation layers, are oriented and crosslinked by means of linearly polarized light. The properties of an LPP orientation layer, such as the angle of tilt, surface wetting, voltage holding ratio and anchoring energy, can be adjusted and/or improved by mixing further substances into the starting material for the preparation of the orientation layer.
摘要:
A compound of formula (I): wherein: R1 and R2 together form a benzo ring optionally substituted by halogen or by alkyl, alkoxy, cyano, nitro, hydroxy, amino, alkylamino, dialkylamino or trifluoromethyl, and R3 represents hydrogen,orR1 represents hydrogen, and R2 and R3 together form a benzo ring optionally substituted by halogen or by alkyl, alkoxy, cyano, nitro, hydroxy, amino, alkylamino, dialkylamino or trifluoromethyl,its enantiomers, diastereoisomers, and addition salts thereof with a pharmaceutically acceptable acid or base, and medicaments.
摘要:
A photoactive polymer from the class of polyimides, polyamide acids and esters thereof comprises as a side-chain a photocrosslinkable group of the general formula (I) wherein the broken line indicates the point of linkage to the polyimide main chain and wherein: B is a straight-chain or branched alkyl residue which is optionally substituted, wherein one or more non-adjacent CH2 groups may independently be replaced by a group Q; D represents an oxygen atom or —NR1— wherein R1 represents a hydrogen atom or lower alkyl; and S3 represents a spacer unit. The polymers may be used as orientation layers for liquid crystals and in the construction of unstructured and structured optical elements and multi-layer systems.
摘要:
Compound of formula (I): ##STR1## wherein: n is 0 or 1,A represents a .sigma. bond or alkylene or alkenylene,X represents nitrogen or C--R.sub.2,R.sub.1 represents hydrogen or alkyl,G.sub.1 represents any one of the groups defined in the description.These compounds are useful for treating a living body afflicted with venous insufficiency, and/or migraine, and/or migraine associated with vascular diseases.
摘要:
A compound of formula (I): ##STR1## in which: X represents oxygen or methylene,n represents 1, 2 or 3,R.sub.1 represents hydrogen, aminocarbonyl or hydroxymethyl,R.sub.2 represents: ##STR2## in which R.sub.3 and R.sub.4 are as defined in the description, the isomers thereof and the addition salts thereof with a pharmaceutically acceptable acid or base, and medicinal products containing the same are useful in the treatment of schizophrenia.
摘要:
A diamine compound of formula (I) is proposed as well as polymers, copolymers, polyamic acids, polyamic acid esters, or polyimides based on such compound.
摘要:
A nanocomposite, comprising single-wall and/or multi-wall one-dimensional nanomaterials, and at least one nanooxide of at least one transition metal, said nanooxide filling said nanotubes and covering their walls. A process for preparing such a nanocomposite and an optical limiting device comprising such a nanocomposite in suspension in a medium that is transparent to visible and infrared radiation are disclosed.
摘要:
A novel photoactive copolymer and its use as orientation layers for liquid crystals and in the construction of unstructured and structured optical elements and multilayer systems. The copolymer contains side chains incorporating photoreactive groups and simultaneously side chains of general formula (I) wherein the total number of rings, including the number of rings in optionally present condensed systems is at least two and at most six; wherein the broken line symbolizes the point of linkage to the polymer main chain; and wherein the variables are defined in the disclosure.