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Mold flux, which plays an important role in continuous casting, occurs when liquid slag on top of the molten steel infiltrates the gap between the shell and mold. During this process, a liquid slag film forms on the shell side, whereas a solid slag film forms on the mold side. The behavior of the slag film between the shell and mold has a significant effect on the sequence casting and quality of the slab surface. To investigate the in-mold behavior and heat transfer of slag film, researchers have simulated the formation of slag film in the laboratory. Measurements and theoretical calculations have been performed to study the heat transfer of slag film. In this paper, the experimental methods used to simulate the formation of slag film were described and the research related to heat transfer in slag film was summarized, including the interfacial thermal resistance, the thermal conductivity of the mold flux, radiative heat transfer, and optical properties of the slag film. The issues related to the formation and heat transfer of slag film were also identified, that require further investigation. The results of recent studies indicate that the hot thermocouple technique could be applied to observe the formation of slag film, and the copper-finger dig test could be used to obtain samples for investigations related to the microstructure of solid slag film. The interfacial heat resistance is reported to be between 0.0002 and 0.002 m2·K·W-1. The thermal conductivity of mold flux at 800℃ ranges from 1.0-2.0 m2·K·W-1, and increases with increased temperature. Crystals in the solid slag film not only increase the interfacial heat resistance, but also decrease the radiative heat flux by reducing the reflectivity of slag film. Furthermore, due to the resulting change in optical properties, the addition of transition metal oxides and fine particles dispersed in slag film may also influence the radiative heat transfer through slag film.

Solidification of micro-alloyed steels under different cooling processes was simulated by confocal laser scanning micros-copy (CLSM), and the change of the sample surface was in-situ observed. The correlation between the change of the sample surface and the precipitation of secondary phases was discussed. It is found that some small reliefs appear on the sample surface during liquid steel solidification. The appearing temperature and the distribution of reliefs are consistent with the results of the theoretical calculation of secondary phase precipitation and the characterization of transmission electron microscopy (TEM). The precipitation of secondary phases can be indirectly characterized by in-situ observations of surface reliefs, which will be helpful to analyze the effect of secondary phases on the evolution of the matrix.

In order to eliminate the hazard effects of the leaching of fluorine in mold fluxes,this paper introduces a mold flux with high Al2O3 content. The effects of Al2O3 content on the concentration of F- ions and the pH value of leaching water were investigated,and the dependence of Al2O3 on the structure of mold fluxes was analyzed by X-ray photoelectron spectroscopy(XPS). When the mass fraction of Al2O3 is 4%,the concentration of F- ions in leaching water is about 22.8 to 35.4 mg·L-1,and the pH range is between 4.0 and 9.5. The F- concentration and the pH range initially reduces and then slightly rises again as the Al2O3 content increases from 4% to 34%. The XPS spectra show that the Al-F bond forms in the mold flux when the Al2O3 content increases. This can restrain the dissolution of fluorine in water. Controlling the content of Al2O3 between 16% and 34%,the F- concentration in leaching water is about 4.0 to 10.0 mg·L-1,and the pH range is between 6.5 and 7.5. This is helpful to reduce the hazard effects of the leaching of fluorine in mold fluxes.

Due to the [Al] reaction with the CaO-SiO2-based mold flux used in the high-Al steels continuous casting processes, decreasing the SiO2 content is decreased and the Al2O3 content in mold flux is increased, thus converting the original CaO-SiO2-based mold flux into a CaO-SiO2-Al2O3-based mold flux. This conversion of the mold fluxes can cause the problem of high-Al steels continuous casting. Hence, study on the structural characteristics of the CaO-SiO2-Al2O3- based mold flux can provide fundamental data to design optimum fluxes for high Al-containing steels. In this paper, the structural characteristics of the CaO-SiO2-based and CaO-SiO2-Al2O3-based flux were studied by Raman spectroscopy. The results have shown that, the CaO-SiO2-based flux was the silicate structure whose main micro-structure units were Q0, Q1, Q2 and Q3. The network breakers prefer to depolymerize the silicate network in CaO-SiO2-Al2O3-based flux. While the CaO-SiO2-Al2O3-based flux with low SiO2 content, the [AlO4] tetrahedron was entered the silicate network and the melt converted into the aluminosilicates structure, the formation of Al-O-Al linkages and Si-O-Al linkages increased the degree of disorder of network. The results of Li2O replace Na2O and CaO replace MgO have shown that the ions will influence the formation of [AlO4] tetrahedron linkages. CaF2 replace CaO shown that the polymerization degree of mold slag decreased first, and then increased with the content of CaF2 more than 13 mol%. So, the influences of the ions type and the ions content on the structure were both need considered while designing the CaO-SiO2-Al2O3-based flux.

Objective: To explore the relationship between the standard uptake value (SUV) of 18F-fluorine-2-deoxyglucose (18F-FDG) and the expression of estrogen receptor (ER) in duct carcinoma of breast, as well as their correlation., Methods: From March 2004 to November 2006, PET/CT scans were performed to 41 patients (female, mean age (55.2 +/- 9.55) years) with duct carcinoma of breast. All of the diagnoses were proved by pathology and immunohistochemical ER assays. The SUVs were calculated., Results: ER positive patients comprised 43.9% of the 41 patients. The mean age of ER positive patients was (60.20 +/- 9.34) years, older than the ER negative patients ((50.32 +/- 9.33) years, P = 0.012). The SUV in the ER positive patients (2.76 +/- 1.34) was significantly less than in the ER negative patients (5.84 +/- 2.90, P = 0 004). The receiver operating characteristic (ROC) by FDG SUV for ER demonstrated that the area under curves reached 0.801 +/- 0.075, with significant implications on the expression of estrogen receptor (P = 0.002); The cut point of FDG SUV for ER was 3.135, with sensitivity of 72.2% and specificity of 73.9%., Conclusion: 18F-FDG SUV is significantly correlated with the expression of ER. We propose 3.135 as a threshold of SUV for the indication of expression of ER in duct carcinoma of breast.

Objective: To investigate the biological character of new agent 153Sm-citrate-nano-Hydroxyapatite (nano-HA) in vitro and in vivo, and to explore a new radiopharmaceutical for the target therapy of bone metastasis cancer., Methods: The nano-HA was synthesized by collosol-gelatum method, and evaluated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). 153Sm was produced at a high specific activity and excellent radionuclidic purity, with which nano-HA was labeled by citrate transfer ligands in the best environment. By adopting the independent variable method, we also studied the optimally labeled condition and stability of 153Sm-citrate-nano-HA in vitro. And 153Sm-citrate-nano-HA was injected into normal rabbits for radio scanning performed. The cancer cell SMMC-7721 and MCF-7 cell lines were divided into two groups, and treated with nano-HA, 153Sm-citrate and 153Sm-citrate-nano-HA in vitro respectively, of which the cell survival rate was measured by MTT methods., Results: Through the detections of TEM, XRD showed that nano-HA consisted of needle-like microcrystals. The label rate of 153Sm-citrate-nano-HA was more than 95%, and extremely stable in vitro. The radio scanning of normal rabbits showed the skeletal system to be clear, and other systems, for example liver, spleen and kidney, could also be seen. The cell culture experiments in vitro indicated that 153Sm-citrate-nano-HA strongly inhibited the proliferation of SMMC-7721 and MCF-7 cells. 153Sm-citrate-nano-HA's half effective inhibition concentrations were 1.89 mg/L and 0.094 mg/L respectively; nano-HA's half effective inhibition concentrations were 3. 31 mg/L and 0.52 mg/L respectively; 153Sm-citrate's half effective inhibition concentrations were 4. 32 mg/L and 0. 67 mg/L respectively., Conclusions: Sm-citrate-nano-HA shows fine biological properties, and is well worth for further researched and prepared as a promising potential radiopharmaceutical in nuclidic treatment for cancer bone metastases.