摘要:
A dielectric element for positioning on an examination subject for locally influencing the B1 field distribution during magnetic resonance data acquisition contains a relaxation agent bound to mutually separated particles. The relaxation agent incorporates a paramagnetic substance. In a corresponding method for acquiring magnetic resonance data from an examination subject, such a dielectric element is positioned on the examination subject for locally influencing the B1 field distribution, by homogenizing the B1 field of a magnetic resonance apparatus.
摘要:
A dielectric element is formed of a dielectric material exhibiting a magnetic resonance relaxation time, with a relaxation agent incorporated in the dielectric material that reduces the relaxation time of the dielectric material. The dielectric element is adapted for placement on a subject while magnetic resonance data are acquired from the subject, and locally influences the B1 field distribution in the subject during the acquisition of magnetic resonance data.
摘要:
A brake device is provided with an actuator which is operated by a pressure medium, used to apply and release a vehicle brake, especially a brake of a rail vehicle, includes an actuating piston which defines two pressure chambers. One pressure chamber impinges upon the vehicle brake in an applied position and the other pressure chamber impinges upon the vehicle brake in a release position. The two pressure chambers are connected to each other by a line with an overflow valve which opens at least during part of the transition phases—between the release position and open position—and which is otherwise closed.
摘要:
Epoxy resin mixtures for the production of prepregs and composites contain the following components: a phosphorus-modified epoxy resin with an epoxy value of 0.02 to 1 mol/100 g, made up of structural units derived from (a) polyepoxy compounds with at least two epoxy groups per molecule, and (b) phosphinic acid anhydrides, phosphonic acid anhydrides, or phosphonic acid half-esters; an amine-substituted aromatic sulfonic acid amide or hydrazide as a hardener; an amino hardening accelerator.
摘要:
Prepregs can be prepared by impregnating reinforcement materials such as glass, carbon or plastic (in the form of fibers or nonwoven or woven materials) with a solution of a polyepoxy resin and a polyamine as a hardener and subsequent drying. For the manufacture of storage-stable prepregs based on polyepoxy resins, 1,3,5-tris(3-amino-4-alkylphenyl-2,4,6-trioxo-hexahydrotriazine with a C.sub.1 - to C.sub.4 alkyl radical is used as the hardener. The new method leads to storage-stable prepregs and assures that composite materials, especially circuit boards, manufactured therefrom meet the requirements for these materials.
摘要:
A brake device of a rail vehicle includes at least one spring-loaded cylinder having a pressure port and at least one service brake cylinder having a pressure port configured to receive a service brake pressure. Further included is a control valve arrangement having at least three ports, wherein a first port is connected to the pressure port of the spring-loaded cylinder and the control valve arrangement is configured to connect the first port to one of the following: (1) a second port configured to receive a pressure derived from a first pressure reservoir; and (2) a third port.
摘要:
Epoxy resin mixtures for prepregs and composites Epoxy resin mixtures for preparing prepregs and composites contain the following components: a phosphorus-modified epoxy resin with an epoxy value of 0.02 to 1 mol/100 g, made up of structural units derived from (a) polyepoxy compounds with at least two epoxy groups per molecule and (b) phosphinic acid anhydrides, phosphonic acid anhydrides, or phosphonic acid half-esters; a glycidyl group-free compound with phenolic OH groups in the form of bisphenol-A, bisphenol-F, or a high-molecular phenoxy resin obtained through the condensation of bisphenol-A or bisphenol-F with epichlorohydrin; an aromatic polyamine used as a hardening agent.
摘要:
The present invention relates to phosphorus-modified epoxy resins having an epoxy number from 0 to 1 mol/100 g, comprising structural units which are derived from (A) polyepoxy compounds having at least two epoxy groups per molecule, and (B) phosphinic and/or phosphonic anhydrides. The invention further provides a process for preparing these phosphorus-modified epoxy resins and provides for the use of the resins in producing moldings, coatings or laminates.
摘要:
Epoxy resin mixtures to produce prepregs and composites contain the following components: a phosphorus-modified epoxy resin with an epoxy value of 0.02 to 1 mol/100 g, made up of structural units derived from (a) polyepoxy compounds with at least two epoxy groups per molecule and (b) phosphinic acid anhydrides, phosphonic acid anhydrides or phosphonic acid half-esters; dicyandiamide and/or an aminobenzoic acid derivative as the hardener; an amino hardening accelerator.
摘要:
Reaction resin mixtures which can be economically processed provide inflammable molded materials with excellent mechanical properties and high dimensional stability under heat when they contain the following constituents: (A) a phosphorus-free polyfunctional epoxide; (B) an epoxy-group-containing phosphorus compound; (C) a polyfunctional isocyanate; (D) a curing catalyst; and, if required, (E) filler material.