摘要:
A sample container (2) for NMR measurements defines a volume (V) of sample substance. The sample container (2) has a first interface (G1) towards an environment (1) and a second interface (G2) towards the sample substance (3). A susceptibility jump at the second interface G2 is sufficiently large that the maximum value of |B′G2/B0| within the volume (V) is at least 0.5 ppm. The geometry of the sample container (2) is selected in such a fashion that, when a homogeneous magnetic field B0 has been applied, a location-dependent relative field change F is present in the volume (V), which is larger than 20 ppb at least at one point in a center partial volume (V1) and a first residual field (R1) in the center partial volume (V1) is smaller than 1.6 ppb. A second residual field (R2a) in the lower partial volume (V2a) is smaller than 30 ppb.
摘要:
A sample container (2) for NMR measurements defines a volume (V) of sample substance. The sample container (2) has a first interface (G1) towards an environment (1) and a second interface (G2) towards the sample substance (3). A susceptibility jump at the second interface G2 is sufficiently large that the maximum value of |B′G2/B0| within the volume (V) is at least 0.5 ppm. The geometry of the sample container (2) is selected in such a fashion that, when a homogeneous magnetic field B0 has been applied, a location-dependent relative field change F is present in the volume (V), which is larger than 20 ppb at least at one point in a center partial volume (V1) and a first residual field (R1) in the center partial volume (V1) is smaller than 1.6 ppb. A second residual field (R2a) in the lower partial volume (V2a) is smaller than 30 ppb.
摘要:
A fully automatic, parameter free MR interpretation system is based on human logic emulation. Information is derived mainly from an MR spectrum with maximum confidence and in a similar way as a human expert. This is achieved by the combination of different expert systems that interpret certain MR spectral features as well as features from a proposed structure. The expert systems are dynamically linked to each other and the analysis is performed iteratively in all directions in a way that the expert systems can utilize all of the interpretations of all expert systems at all times. The expert system may generate not just a single result but rather lists of probability weighted hypotheses.
摘要:
A nuclear magnetic resonance (NMR) spectrometer probe head having one or more drive units, one or more transmission units and one or more drive shafts which are coupled to adjustment rods and a means for directly mounting and fastening the drive unit, transmission unit, and drive shaft to the lower portion of the probe head during operation of the NMR spectrometer, which increases user comfort and freedom of motion below the magnet. The probe head also having an actuator for remote control adjustment of electrical and/or mechanical units, e.g. trimmer capacitors, variable resistors, and adjustable inductors within the probe head. The probe head is characterized in that the amount of space needed for the actuator is minimized, access to the region below the magnet is optimized, and installation of the actuator is simplified because the actuator is an integral part of the NMR-probe head within an NMR-spectrometer.
摘要:
A fully automatic, parameter free MR interpretation system is based on human logic emulation. Information is derived mainly from an MR spectrum with maximum confidence and in a similar way as a human expert. This is achieved by the combination of different expert systems that interpret certain MR spectral features as well as features from a proposed structure. The expert systems are dynamically linked to each other and the analysis is performed iteratively in all directions in a way that the expert systems can utilize all of the interpretations of all expert systems at all times. The expert system may generate not just a single result but rather lists of probability weighted hypotheses.
摘要:
An NMR spectrometer comprising an NMR magnet system (27) disposed in a helium tank of a cryostat and an NMR probe head (11) disposed in a room temperature bore of the cryostat, which contains a cooled RF resonator (9) for receiving NMR signals from a sample to be investigated, and a cooled pre-amplifier (10), wherein the NMR probe head (11) is cooled by a common multi-stage compressor-operated refrigerator (2), wherein the refrigerator (2) comprises a cold head and several heat exchangers (5, 6) at different temperature levels, wherein the refrigerator (2) is disposed at a spatial separation from the cryostat in a separate, evacuated and thermally insulated housing (1) and wherein at least one cooling circuit with cooling lines, which are thermally insulated by a transfer line (13, 14) is disposed between the housing (1) containing the heat exchangers (5, 6) and the NMR probe head (11), is characterized in that additional cooling lines to an LN2 tank (18) or radiation shield (21) disposed in the cryostat and surrounding the helium tank are provided, and the refrigerator (2) also cools the LN2 tank (18) or the radiation shield (21). The inventive NMR spectrometer comprises a simple and inexpensive device for matching the holding time of LN2 to that of LHe through cooling the LN2 tank using the refrigerator provided for cooling the NMR probe head and without great expense.
摘要:
In a temperature-control device for samples, in particular for NMR spectroscopy, comprising a vessel (20) provided with an opening (19) for receiving a measuring sample (1), an inlet opening (10) for introduction of the fluid, an outlet opening (15) for the outflow of the fluid and a flow channel (18) through which at least a partial flow of the fluid is guided past the sample (1), as direct fluid flow, from the bottom to the top, there is provided at least one by-pass channel (17) which is arranged in such a way that an additional partial fluid flow can be guided past the upper area of the said sample (1) in the form of a by-pass fluid flow (7). This enables also the upper area of the sample (1) to be temperature-controlled in an efficient way so as to minimize the temperature gradient in the sample (1). The temperature-control device may comprise, in the upper area of the sample (1), a heat-exchanger system (14) which concentrates the direct fluid flow ( 8), after it has been combined with the by-pass fluid flow (8), around the sample (1). One achieves in this manner efficient temperature control of the upper section of the sample by the fluid flow, without any disturbing thermal obstacles.
摘要:
An NMR (nuclear magnetic resonance) apparatus has a magnet system disposed in a cryostat (1), the cryostat having at least one nitrogen tank (3b) for receiving liquid nitrogen (5b) and a room temperature bore (7) for receiving an NMR probehead (8), wherein part(s) of the probehead or the overall probehead can be cooled to cryogenic temperatures by supplying liquid nitrogen (5b) via a supply line (14). The nitrogen tank (3b) of the cryostat (1) is connected to the NMR probehead (8) by means of a supply line (14) in such a fashion that liquid nitrogen (5b) is removed from the nitrogen tank (3b) and guided to the NMR probehead (8). The overall apparatus is therefore more compact, the operating comfort of the apparatus is increased, and the costs for acquisition, operation and maintenance are considerably reduced compared to previous comparable devices.
摘要:
A transport device for conveying an object to be transported (18) between an input point (A) and a supply point (Z), where the object to be transported (18) can be supplied to an RT tube (4) of a cryostat (1), wherein the input point (A) is both horizontally and also vertically spaced apart from the supply point (Z), wherein a transport tube (14) is provided for pneumatically conveying the object to be transported within the transport tube (14) from a first transfer point (B) to a second transfer point (C), is characterized in that the transport tube (14) is vertically arranged, a first transport container (TB1) and a second transport container (TB2) are provided for receiving the object to be transported (18), a first transfer device is disposed between the input point (A) and the first transfer point (B), and a second transfer device is provided between the second transfer point (C) and the supply point (Z).
摘要:
A sample tube for an NMR probe head, which extends along a z axis and has an internal cavity that extends in an axial direction of the z axis, is open to the outside at the axially upper end, is closed at the axially lower end and contains a liquid NMR sample substance during operation, wherein the cross-sectional surface of this cavity extending perpendicularly to the z axis and parallel to the xy coordinate plane has an elongated shape in the direction of the x axis with maximum dimensions a in the y direction and b in the x direction, wherein a