Abstract: A sample to be measured is placed in a medium solution between two circular magnets to ensure that the sample to be measured is levitated in a set circular area between the two circular magnets, and a levitation position of the sample to be measured in the magnetic field is measured. The density of the sample is calculated according to formula (I): ? s = ? m + ? m - ? s g ? ? 0 ? ( B r ? ? B z ? r + B z ? ? B z ? z ) . Compared to the prior art, the method of the present disclosure provides a novel method for measuring a density of a substance, in which the involved device is easy to operate and has low cost, and the measurement results are easy to observe and have high accuracy.

Abstract: The present invention relates to the field of chemical synthesis, particularly to a method of synthesizing levorotatory p-hydroxyphenylglycine compounds, which eliminates the subsequent processes of resolution, racemization processings, etc., simplifies operational steps; and acids with small organic molecule are chosen as catalyst in the second step, which not only is conducive to the realization of a industrialized production, but also makes the ee value of the end products be 88.1˜98.0% by determining the catalyst, the reaction solvent, the reactive substance, the reaction temperature, and the reaction duration; non-aqueous solvent is used in the second step, to avoid the discharging of phenol-containing waste water, thus environmental pollution is reduced.

Abstract: The present invention relates to the field of chemical synthesis, particularly to a method of synthesizing levorotatory p-hydroxyphenylglycine compounds, which eliminates the subsequent processes of resolution, racemization processings, etc., simplifies operational steps; and acids with small organic molecule are chosen as catalyst in the second step, which not only is conducive to the realization of a industrialized production, but also makes the ee value of the end products be 88.1˜98.0% by determining the catalyst, the reaction solvent, the reactive substance, the reaction temperature, and the reaction duration; non-aqueous solvent is used in the second step, to avoid the discharging of phenol-containing waste water, thus environmental pollution is reduced.

Abstract: A method of welding together a motor vehicle structural assembly is available. The vehicle structural assembly includes a boxed member including an outboard wall, a top wall, a bottom wall and an inboard wall spaced from the outboard wall. The inboard wall has an opening therein. The motor vehicle structural assembly also includes a cylindrical support including a first end and a shoulder spaced from the first end at least the distance the boxed member inboard wall is spaced from the boxed member outboard wall. The method comprises spinning the support and advancing the support through the inboard wall opening so that the support first end is friction welded to the outboard wall and so that the support shoulder is friction welded to the inboard wall.