[en] The formation of boride phases is studied in the production of Al-B master alloys, which involves chemical reactions of KBF₄ and aluminum melts. Boron is reduced from KBF₄ and reacts with aluminum to form AlB₁₂ and AlB₂ depending on processing conditions. AlB₁₂ forms at the Al/flux interface and subsequently reacts with aluminum to form AlB₂ in a slow process while moving away from the Al/flux interface. In designed experiments, aluminum reacted with KBF₄ droplets producing dense AlB₁₂ shells trapping KAlF₄ salt inside at high temperatures. In comparison, the majority of individual AlB₂ particles is located near the Al/flux interface inside the aluminum matrix in a circular shape. Meanwhile, a uniform dispersion of AlB₂ particles in the aluminum matrix is also observed away from the Al/flux interface. It is revealed that boron, after being reduced from KBF₄ by aluminum, has a high tendency to build up at the Al/flux interface, forming AlB₁₂ and subsequently transforming to AlB₂. - Graphical abstract: The following figure demonstrates the phase relationships of AlB₂-Al-Flux system. - Highlights: • Boron builds up at the flux/Al interface resulting in the formation of AlB₁₂. • Metastable AlB₁₂ transforms to AlB₂. • Interfacial energies play critical roles in the dispersion of AlB₁₂ and AlB₂. • Interfacial energies: AlB₁₂/Al > Al/flux > AlB₁₂/flux > AlB₂/flux > AlB₂/Al. • AlB₂ has the lowest interfacial energy with aluminum.

[en] Titanium tri-aluminide (Al₃Ti) particles were dispersed homogeneously into a castable aluminium alloy matrix by the aluminothermic reduction of hexafluorotitanate (K₂TiF₆) under different conditions. Al₃Ti particles in different morphologies and sizes were produced by changing the fabrication conditions, such as composition of the flux, the temperature and holding time. The coarsening and growth of the Al₃Ti particulates are principally affected by other elements present in the flux during fabrication. The effects of the temperature and holding time, alloying elements and the composition of flux on the dispersion of the reinforcement were examined by using SEM and X-ray diffraction techniques. The observed results are explained in terms of the different growth behaviour of the Al₃Ti particles under different conditions. The dispersion of the Al₃Ti particles and the Al/Al₃Ti interfacial bonding are explained by the solidification of aluminium

[en] The principal uranium minerals found in the Tono area are as follows:(10 Tetravalent uranium minerals: uraninite, coffinite. (2) Hexavalent uranium minerals: autunite, uranocircite. There are minerals absorbing uranium: zeolite, montmorillonite, carbonaceous matter. Uranium minerals are usually accompanied by pyrite. Uranium in the deposits is supplied from surrounding source rocks, mostly from granite and transported by circulating ground-water

[en] For the commissioning of the WWER nuclear island ventilation system, the fixed flow orifice plate is used for the air volume adjustment, and the on-site operation is heavy and time-consuming. By analyzing the principle of the aperture mechanism, a ventilation flow orifice plate aperture adjuster is developed. The test results show that the regulator realizes the function of changing the diameter of the line to adjust the air volume, and has the characteristics of easy installation and high precision. The device is used for the system commissioning, avoiding the repeated changes of the fixed-diameter orifice plates, which is beneficial to improve the commissioning efficiency, and also provides reference for the design of other stack-type ventilation systems. (authors)

[en] The robust optimum design was made for a structural design with uncertainties based on the experimental design method. By changing the weighting factors in objective function, the robust design was done in a broad sense and in a narrow sense by a truss design problem with large uncertainties. The validity of the robust design in a broad sense was clarified through the reliability analysis by Monte Carlo simulation, but there is no effectiveness to the robust structural design in a narrow sense. And, a comparison between structural robust design and structural optimum design with uncertainties is made too. Through the reliability analysis by Monte Carlo simulation, the structures designed by the two methods show the same reliability, but the robust design has the merit of controlling the structural response's variations effectively

[en] In summary form only

[en] The upper member of the Nadang Formation is the main ore-bearing horizon of the Tunlin deposit in Shiwandashan Basin, Guangxi Province, Based on the theories of sequence stratigraphy and sandstone uranium mineralization, this article studies the ore-bearing bodies in the upper member of the Nadang Formation by comparing small strata for the first time, summarizes the uranium mineralization characteristics of the Tunlin deposit, provides guidance for the search for the same type of uranium mineralization in the basin. The sedimentary microfacies, lithologic characteristics, spatial distribution characteristics and epigenetic alteration of the third layer in the upper member of Nadang Formation are analyzed in detail. Uranium mineralization mainly occurs in the delta front estuary bar sand body at the bottom of the third layer of the upper member of Nadang Formation. Its lithology is fine-grained Feldspar Quartz Sandstone, rich in carbon dust and pyrite. The ore body occurs in the transition zone between red sandstone and gray sandstone for plate-like and layered. (authors)

[en] The conditions of seism, geology, hydrography, environment protection and communications of the site of Liaoning nuclear power plant are briefly described and certain evaluations are made. It proves the safety and reliability of the site

[en] The activities of PPO in pear juice were measured when it received different dosage of ⁶⁰Co γ-rays irradiation, different pH, and the combination of radiation and pH condition. The results showed that, radiation treatment and decreasing the pH value can inhibit the PPO's activity. Combination treatment of 3 kGy γ-irradiation and pH 3.1 can lower the activity of PPO about 92%. (authors)

[en] Objective: To quantitatively assess brain maturation and prognosis in premature infants on conventional MRI using total maturation score (TMS). Methods: Nineteen cases of sequelae of white matter damage (WMD group )and 21 cases of matched controls (control group) in premature infants confirmed by MRI examinations were included in the study. All cases underwent conventional MR imaging approximately during the perinatal period after birth. Brain development was quantitatively assessed using Childs AM's validated scoring system of TMS by two sophisticated radiology physicians. Interobserver agreement and reliability was evaluated by using intraclass correlation (ICC). Linear regression analysis between TMS and postmenstrual age (PMA) was made(Y: TMS, X: PMA). Independent-sample t test of the two groups' TMS was made. Results: Sixteen of 19 cases revealed MRI abnormalities. Lesions showing T₁ and T₂ shortening tended to occur in clusters or a linear pattern in the deep white matter of the centrum semiovale, periventricular white matter. Diffusion-weighted MR image (DWI) showed 3 cases with greater lesions and 4 cases with new lesions in corpus callosum. There was no abnormality in control group on MRI and DWI. The average numbers of TMS between the two observers were 7.13±2.27, 7.13±2.21. Interobservcer agreement was found to be high (ICC=0.990, P<0.05). Positive correlation was demonstrated between TMS and PMA in MRI(r²=0.6401,0.5156 respectively, P<0.01) of the WMD group and the control group. Linear regression equation showing positive correlation between TMS and PMA were Y=0.733X-19.421, Y=0.846X-21.835 (P<0.05). TMS of the two groups (average numbers are 6.32±1.73, 7.86±2.48 respectively) were statistically significantly different (t=2.26, P<0.05). Myelination (average numbers are 1.95±0.71, 2.52±0.75) appeared to be significantly different (t=2.50, P<0.05), which delayed in babies with SWMD group. Cortical infolding (average numbers are 2.26±0.87, 2.90±1.09) appeared to be different (t=2.04, P<0.05) without clinical significance. Germinal matrix distribution (average numbers are 1.00±0.01, 1.14±0.36 respectively) and bands of migrating glial cells (1.11±0.46, 1.29±0.78 respectively) showed no statistical difference between WMD group and control group (t=1.83, t=0.88, P>0.05). Conclusion: Conventional MRI is able to quantify the brain maturation and prognosis of premature infants using TMS. (authors)