Evolution of Nonmetallic Inclusion during Steelmaking Process of Cold Heading Steel SWRCH35K

In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS and the image processing software Image-Pro-Plus6.0 were employed to analyze the chemical composition, morphology, quantity and size of non-metal inclusions in the steel samples. The results show that from BOF tapping to continuous casting tundish, the composition of inclusions in SWRCH35K steel changes from Al2O3 →MgO·Al2O3 →CaO-MgO-Al2O3-CaS, and the typical morphology of the inclusions in the steel gradually changes from irregular blocks and clusters to spherical. The number of inclusions in the BOF argon blowing station is the largest, 213#/mm2, while the number of inclusions at the end of LF refining is the least, about 12#/mm2, and there are basically no inclusions above 5 μm. In addition, LF calcium treatment will adversely affect the size and quantity control of inclusions in steel. In order to effectively reduce the large-size calcium-containing spherical oxide inclusions in cold heading steel, it is necessary to find a technical method that can replace LF calcium treatment to solve the problem of molten steel continuous casting.

Clinical Performance of ADNEX (The Assessment of Different NEoplasias in the adneXa) Model in Early Diagnosis and Staging of Benign and Malignant Ovarian Tumors

Objective: To investigate the clinical value of ADNEX model in early diagnosis and staging of benign and malignant ovarian tumors. Method: 136 cases of ovarian cancer patients treated in our hospital were retrospectively analyzed using the ADNEX risk model and MRI data. The accuracy of the two diagnostic methods was compared with the results of pathological examination as gold standard. Results: For qualitative assessment, the accuracy and sensitivity of the ADNEX model were 78.70% and 93%, while the accuracy and sensitivity of MRI examination were 80.1%, and 90.7%, respectively. The diagnostic values of the two methods were not statistically different (P > 0.05). For ovarian tumor staging, the ADNEX model was significantly less accurate and specific for staging borderline tumor than MRI examination, although it had significantly higher sensitivity (P 0.05). Conclusion: ADNEX risk model has certain diagnostic and predictive value to distinguish benign from malignant ovarian tumors. It is useful to detect and exclude ovarian tumor. However, for early diagnosis, it is not accurate enough and further study is needed to validate this usefulness.

Effect of MnO on Mineral Composition of CaO-SiO₂-MgO-Al₂O₃-Cr₂O₃System

The chromium leaching from stainless steel slag highly depends on the occurrence of chromium. The effect of MnO on the mineral composition of stainless steel slag was investigated through CaO-SiO2-MgO-Al2O3-Cr2O3 synthetic slags. The experiments were performed in a conductive furnace, and the samples collected during tests were analyzed using X-ray Diffrac-tion (XRD) and Scanning Electron Microscope (SEM) equipped Energy Dispersive Spectroscopy (EDS). The results show that the addition of MnO significantly reduces the solidus temperature of oxide systems from 1204oC to 950oC, promotes the spinel precipitation and increases the size of spinel crystals. The fraction of chromium contained in non-spinel mineral phases decreases and the amount of larnite dissolved into spinel phase slightly reduces with the content of MnO increasing. In addition, the amorphous phase forms when the content of MnO is up to 6 wt%. Hence, the addition of MnO is beneficial to suppress chromium leaching from slag.

Alternately aligned 2D heterostructures enabled by dspacing accessible,highly periodic accordion-like graphene oxide frameworks

Two-dimensional(2D)heterostructures hold great promise in designing integrated materials,while the current synthesis strategies still confront challenges for multilayer heterostructure construction and scale-up production.Here we report a generalized host-guest strategy based on nonexfoliated layered graphene oxide(LGO)to construct graphene-based heterostructures that consist of multilayered,alternately aligned graphene and metal oxide nanosheets.The 2D-aligned GOs and open interlayer spaces make LGO an ideal platform to create periodic 2D host frameworks.Polyetheramine oligomers covalently bond the adjacent GOs.The extended chain conformation endows the resulting accordionlike GO frameworks with high structural stability,periodicity and enlarged interlayer space.Owing to the high affinity of the open and well-arranged 2D channels toward guest precursors,a variety of high-quality heterostructures can be synthesized.Furthermore,a variety of exfoliated,ultrathin metal oxide nanosheets can also be prepared by removing the graphene skeleton.The flexible interlayer chemistry presented in this study paves a way toward the synthesis of a large family of graphene-inorganic/organic 2D heterostructures.