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We aimed to explore the effects of type-2 diabetes mellitus (T2DM) and hypoglycemic therapy on the salivary microbiome in periodontitis patients and identify the potential salivary micro-biomarker for the early warning of T2DM. Saliva samples were collected from healthy individuals (Health), periodontitis patients (P), T2DM patients, periodontitis patients with T2DM (DAP), and DAP patients treated with Metformin (Met). Samples were determined by16S rRNA gene sequencing. 29 phyla, 322 genera, and 333 species of salivary microbiome were annotated. Compared to the Health group, the P and DAP group showed a significantly higher diversity of saliva microbiota, while the T2DM and Met group had no significant difference in microbial abundance but showed a trend of increasing diversity. Other than well-known periodontitis-inducing pathogens, the proportion of Prevotella copri, Alloprevotella rava, and Ralstonia pickettii, etc. were also significantly increased in periodontitis patients with or without T2DM. After effective glycemic control, the abundance of Prevotella copri, Alloprevotella rava, Ralstonia pickettii, etc. decreased in periodontitis patients with companion T2DM. The accuracies of the classification models in differentiating Health-vs.-P, DAP-vs.-P, and T2DM-vs.-P were 100%, 96.3%, and 98.1%, respectively. Hypoglycemic therapy could reconstruct the saliva microbiota and hence improve the localized conditions of diabetes patients with periodontitis.

The crystal structure and microstructure of Sm 2 (Fe 1 − x Ga x ) 17 ( x = 0−0.12) have been studied by X-ray diffraction and scanning electron microscopy analysis techniques. Results indicate that the alloys have a single phase with Th 2 Zn 17 -type structure for x ⩽ 0.02; when x = 0.05−0.12, two phases, namely Sm 2 (Fe, Ga) 17 and (Ga, Fe)Sm, exist and, the higher the gallium substitution the more (Ga, Fe)Sm phase occurs. The lattice parameters increase with Ga addition. The Curie temperature and saturation magnetization of the nitrides decrease with increasing gallium substitution; however, the anisotropy field reaches a maximum value of 18.4 T for x = 0.02 at room temperature. The hard magnetic properties of the nitrides decrease also except for x = 0.02. The optimum hard magnetic properties obtained are B r = 12.3 kG, i H c = 10.0 kOe and ( BH ) max = 26.2 MG Oe with x = 0.02. The thermomagnetic curves measured of all the nitrides have shown that the onset decomposition temperatures are 760–780 K, which are slightly affected by gallium substitution.

The field dependence of the coercive field for isotropic and aligned Sm2Fe17Nx epoxy resin bonded magnets are investigated. Results indicate that the coercive field of the isotropic magnet is larger than that of the aligned magnet. For small magnetizing fields, the coercive field of the sample magnetized antiparallel to the alignment direction is larger than that of the sample magnetized parallel to the alignment direction of the magnets. When the magnetizing field is large enough, the coercivities obtained after magnetizing the aligned sample in parallel and antiparallel directions are the same. The microstructural parameter derived from the temperature dependence of the coercive field implies that both nucleation and pinning mechanism could be responsible for the magnetic hardening of the Sm2Fe17Nx epoxy resin bonded magnets.

Positive and negative interaction have been found to co-exist in Sm2Fe17Nx and Nd2Fe14B isotropic magnets. The measured positive interaction may come from the interactions from those grains with small deviation angle between its easy axis and the direction of external field, whereas the negative interaction may come from those grains with large deviation angle. The numerical calculations of the magnetostatic fields around a particle indicate that the positive interaction results from the magnetostatic interaction among nearest-particles located in forefront and backfront along their common easy axis of magnetizations and the negative interaction results from the magnetostatic interaction among those particles located in same plane perpendicular to their easy axis of magnetizations. In soft-hard multiphase materials, larger the remanence enhancement is, stronger the negative interparticle interaction becomes. The remanence enhancement in SmFeN materials have also been investigated.

The intrinsic and hard magnetic properties of Sm 2 (Fe 1 − x Al x ) 17 nitrides were investigated. The Curie temperature and saturation magnetization decrease linearly with increasing Al concentration, as also does the anisotropy field at room temperature. The X-ray diffraction patterns have shown that all the samples exist in a nearly single phase with Th 2 Zn 17 -type structure for x up to 0.12. The lattice parameters increase with the substitution of Al for Fe atoms. The hard magnetic properties of the nitrides obtained indicate that the addition of Al has an unfavorable effect. The onset decomposition temperature of all nitrides derived from the thermomagnetic curves is around 750 K, implying that Al substitution could not improve the thermal stability of 2:17 nitrides.

In the present work, hard magnetic behaviours of (Sm1-yPry)2Fe17Nx magnets are investigated. Remanence enhancement is observed when some of the Sm atoms are replaced by Pr atoms in the compounds, which is due to the larger saturation magnetization of (Sm1-yPry)2Fe17Nx than of pure Sm2Fe17Nx. Meanwhile the coercivity of (Sm1-yPry)2Fe17Nx decreases with increasing Pr content in the compounds, which corresponds to the decrease of the anisotropy field in the compounds. In order to obtain a combined good effect on the remanence and the coercivity, the Pr content y should be no more than 0.4 in (Sm1-yPry)2Fe17Nx nitrides.

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The 17CrNiMo6 steel is mainly used for the gear shaft of large modulus in many fields of heavy industry such as mining, transit, hoist, forging and so on [1] . The size of addendum circle and common normal line is changed a lot beyond the tolerance because of the long time of carburizing process and the out-of-step structural stress and thermal stress during the quenching process. And thus the posterior grinding efficiency and quality are influenced. In the paper comparison and analysis of the deformation affected by solid and hollow gear shafts were done and the methods of simulation and practice were both used. The results are as follows: the deformation of gear shaft was small before and after carburizing while that of gear shaft was large before and after quenching because of different cooling velocity, structure and hardness of each position. And the deformation of hollow was much smaller than that of solid. Therefore, if the hollow gear shaft is used, the waste of material will be decreased, and finishing cost will be reduced, and thus the technology of heat treatment will be optimized.