We probe the universality of acceleration scale a_(0) in Milgrom's modified Newtonian dynamics(MOND)using the recently released rotation curve data from SPARC galaxies.We divide the SPARC data into different subsamples according to the morphological types of galaxies,and fit the rotation curve data of each subsample with the theoretical prediction of MOND.MOND involves an arbitrary interpolation function which connects the Newtonian region and the MOND region.Here we consider five different interpolation functions that are widely discussed in the literature.It is shown that the best-fitting a_(0) significantly depends on the interpolation functions.For a specific interpolation function, a_(0) also depends on the morphological types of galaxies,implying that a_(0) may be not a universal constant.Introducing a dipole correction to a_(0) can significantly improve the fits.The dipole directions for four of the five interpolation functions point towards an approximately consistent direction,but a_(0) still varies for different interpolation functions.
The hardfacing alloys with different concentrations of titanium were deposited on carbon steel substrates by shielded metal arc welding, and the effect of titanium content on the microstructure characteristics of the hardfacing alloys was investigated. The wear resistance test of the hardfacing alloys was carried out by using a slurry rubber wheel abrasion test machine, and the wear behaviour was also studied. The results indicate that the addition of titanium can effectively promote the precipitation of the complex carbides of Nb and Ti due to the prior precipitation of titanium carbide which acts as nucleation sites for complex carbides. With the increase of titanium content, the wear resistance of the hardfacing alloys is increased gradually resulting from the refinement of microstructure and dispersive distribution of fine carbide precipitates. And the wear mechanism is mainly minimum plastic deformation with interrupted grooves due to the strengthening and protecting effects of carbide precipitates.
Glycogen storage disease(GSD)is a rare autosomal recessive disease by abnormal accumulation of intracellular glycogen.1 Mutations in genes encoding G-6-P or G-6-Pase lead to dysfunction of the body's glycogen metabolism.Without adequate metabolic treatment,patients with GSD can die during infancy or childhood from severe hypoglycemia and acidosis.The patient's symptoms generally achieve remission during adolescence,except in rare cases when cirrhosis of the liver or myopathy occurs.Once GSD is identified in adults,the patients are often accompanied by many complications,such as fasting hypoglycemia.
Maohui YinLei ChangPing JiangZhiyong YangZhonglin ZhangWanyu ZhangZhisu Liu
