摘要:
Described herein are novel poly(aryl ethers) based on 2,5-di-t-butylhydroquinone. These poly(aryl ethers) have excellent high temperature, oxidative and chemical resistance, as well as good melt-fabricability.
摘要:
The present invention provides for a reflectron time-of-flight mass spectrometer in which there exists a curved field in a portion of the reflectron that takes into account acceleration and deceleration fields in upstream (from the ion source down to the reflectron) and downstream (from the reflectron down to the ion detector) regions, which are always present in any TOF-MS. The reflectron includes a decelerating section and a correcting section, with curved electric fields in the correcting and/or decelerating sections of the reflectron being considered. Moreover, analytic expressions are provided for calculating the profiles of the curved electric field in the second (correcting) section of the reflectron, which expressions are valid for arbitrary electric field distributions in the upstream and downstream regions as well as in the first (deceleration) section of the reflectron. These profiles will depend on the electric field distributions in the upstream and downstream regions and in the first (deceleration) section of the reflectron.
摘要:
A method of operation of an ion trap mass spectrometer which isolates a first group of ions having a mass-to-charge ratio range is disclosed. The method includes producing ions from a plurality of atoms or molecules; trapping the ions in an ion trap by applying a trapping voltage to a ring electrode; applying an excitation voltage to a pair of end-cap electrodes; employing as the excitation voltage a first broadband excitation waveform and a second broadband excitation waveform, with the first waveform exciting the ions excluding substantially all of the first group and also excluding substantially all of a second group of ions having a range of mass-to-charge ratios about the first group's mass-to-charge ratio range, and the second waveform exciting the second group; applying the first waveform in order to eject the ions excluding substantially all of the first and second groups; and applying the second waveform in order to successively eject the second group of ions, according to the mass-to-charge ratios thereof, excluding substantially all of the first group of ions, thereby isolating the first group of ions. In another embodiment, the excitation voltage is a broadband excitation waveform having first, second, and third excitation portions, with the first and third portions exciting the ions excluding substantially all of the first group and also excluding substantially all of the second group, and the second portion exciting the second group. Associated apparatus is also disclosed.
摘要:
A reflectron capable of focusing an entire mass range of product ions at substantially the same focal point, comprising a plurality of lens plates, each having an opening therein, for generating a non-linear electric field in the reflectron. To generate the non-linear electric field, the voltage applied to each successive lens plate increases non-linearly with respect to its adjacent lens plate. The voltage of the first lens plate having the opening through which the ions first enter the reflectron is set to a low potential and the voltage being applied to each successive lens plate increases in a non-linear manner with the largest voltage being applied to the lens plate furthest from the first lens plate. This non-linear voltage application, to generate the non-linear electric field, can be achieved by coupling a potentiometer between each lens plate and adjusting each potentiometer accordingly. Alternatively, to generate the non-linear electric field, the lens plates may be unequally spaced and an equal voltage may be applied to each lens plate.
摘要:
Featured is a quadrupole ion trap mass spectrometer having a compact configuration with a low voltage fundamental RF and using supplemental RF to a very low qejec value so as to yield a device characterized as having a high mass range. In more particular embodiments, such a quadrupole ion trap mass spectrometer is configured and arranged so as to a mass range on the order of 1,000 to 2,500 Da. Also featured are methods embodying the use of such a quadrupole ion trap mass spectrometer.
摘要:
A method of producing a sealed, liquid filled spherical object for use in a golf ball core comprising the steps of;(a) providing a hollow spherical object;(b) injecting a flowable material into said spherical object wherein said injecting produces an aperture in said spherical object;(c) sealing said aperture with a radiation curable polymer; and(d) exposing said radiation curable polymer to radiation in an amount and for a time sufficient to cure said polymer.
摘要:
Described herein are resinous compositions comprising a particular cycloaliphatic epoxy resin and the adduct of these epoxy resins with an aromatic active hydrogen-containing compound. These compositions afford unreinforced castings with higher heat deflection temperatures, faster cure rates, and reduced water uptake than similar compositions containing epoxy adducts made from aliphatic polyols.