Top slag refining for inclusion composition transform control in tire cord steel

Controlling conditions for inclusion plasticization were calculated by FactSage, and the steel/slag reaction equilibration time was determined by pre-equilibrium experiments. Laboratory experiments with different top slags were carried out in 90 rain, and industrial tests were performed based on the results of calculation and laboratory experiments. Scanning electron microscopy （SEM） and energy-dispersive spectroscopy （EDS） were used to determine the morphology and composition of inclusions in tire cord steel. It is found that the shape of in- clusions can be controlled well, and the composition of inclusions varies in the industrial test as the following transformation route： MnO-A1EOa-SiO2→CaO-AIEOa-SiO2→MnO-A1203-SiO2. Inclusion plasticization can be achieved by controlling the binary basicity of top slag （CaO/SiO2 by mass） around 1.0 and the （A1203） content in top slag below 10wt%. Under these controlling conditions in the industrial test, almost all of inclusions in the wire rods achieve plastic deformation.

Morphology, size and distribution of MnS inclusions in non-quenched and tempered steel during heat treatment

This article reports the morphology, size, and distribution evolution of MnS inclusions in non-quenched and tempered steel during heat treatment. The variation of single large-sized MnS inclusions at high temperature was observed in situ using a confocal scanning laser microscope （CSLM）. The slender MnS inclusions first changed to pearl-like slrings. These small-sized pearls subsequently coalesced and became closer together as the temperature increased. Large-sized MnS inclusions in non-quenched and tempered steel samples with different thermal histories were investigated with respect to the evolution of their morphology, size, and distribution. After 30 min of ovulation at 1573 K, the percentage of MnS inclusions larger than 3 μm decreased from 50.5% to 3.0%. After a 3 h making period, Ostwald ripening occurred. Most MnS inclusions moved from the grain bounda- ries to the interior. The present study demonstrates that heat treatment is an effective method of changing the morphology, size, and distribution of MnS inclusions, especially large-sized ones.

Subsurface macro-inclusions and solidified hook character in aluminum-killed deep-drawing steel slabs

Subsurface macro-inclusions and hooks are detrimental to the surface quality of deep-drawing steel sheets. However, little is known about the relationship between macro-inclusions and hooks. Thus, in this work, two ultralow carbon （ULC） steel slabs and two low carbon （LC） aluminum-killed steel slabs were sampled to study the relationship between hooks and subsurface macro-inclusions, which were detected on the cross-sections of steel samples with an area of 56058 mm2 using an automated scanning electron microscopy/energy-disper-sive X-ray spectroscopy system. Results show that subsurface inclusions larger than 200 μm were almost entrapped by hook structures, whereas the location of other inclusions smaller than 200μm had no obvious dependence on the location of solidified hooks. Furthermore, the number density （ND） of subsurface inclusions larger than 200μm decreased from 0.02 to 0 cm-2 in ULC steel as the mean hook depth decreased from 1.57 to 1.01 mm. Similar trends were also observed in LC steel. In addition, the detected inclusions larger than 200μm were concentrated in the region near the slab center （3/8 width-5/8 width）, where hook depths were also larger than those at any other locations. Therefore, minimizing the hook depth is an effective way to reduce inclusion-induced sliver defects in deep-drawing steels.

康柏西普联合PRP治疗视网膜中央静脉阻塞继发早期新生血管性青光眼

目的:对比研究玻璃体腔注射康柏西普联合全视网膜激光光凝(PRP)与单纯全视网膜激光光凝对视网膜中央静脉阻塞(CRVO)继发Ⅰ、Ⅱ期新生血管性青光眼治疗效果的临床观察。方法:采取临床病例对照研究方法。将2014-01/2019-03在我院诊断为CRVO继发Ⅰ、Ⅱ期新生血管性青光眼患者60例60眼,随机分为联合治疗组和单纯治疗组。联合治疗组采用康柏西普联合全视网膜激光光凝治疗;单纯治疗组采用单纯全视网膜激光光凝治疗。观察两组患者治疗前、治疗后1wk,1、3、6、9mo的视力、眼压、虹膜新生血管、房角新生血管的情况,进行统计学分析。结果:不同时间点两组房角及虹膜新生血管数量和视力、眼压有差异(F=154.992、92.519、30.696、82.374,均P<0.001),联合治疗组在治疗开始后1wk的各项指标均出现明显好转,并维持至治疗结束。而单纯治疗组在给予治疗后数据改善程度不及联合治疗组(F=50.870、24.265、13.125、11.829,均P<0.001)。结论:玻璃体腔注射康柏西普联合全视网膜激光光凝治疗CRVO继发Ⅰ、Ⅱ期新生血管性青光眼疗效优于单纯全视网膜激光光凝治疗,效果显著并持续维持。

Fentanyl inhibits glucose-stimulated insulin release from β-cells in rat pancreatic islets

AIM: To explore the effects of fentanyl on insulin release from freshly isolated rat pancreatic islets in static culture.METHODS: Islets were isolated from the pancreas of mature Sprague Dawley rats by common bile duct intraductal collagenase V digestion and were purified by discontinuous Ficoll density gradient centrifugation. The islets were divided into four groups according to the fentanyl concentration: control group (0 ng/mL), group -□(0.3 ng/mL), group□(3.0 ng/mL), and group□(30 ng/mL). In each group, the islets were co-cultured for 48 h with drugs under static conditions with fentanyl alone, fentanyl + 0.1 μg/mL naloxone or fentanyl + 1.0 μg/mL naloxone. Cell viability was assessed by the MTT assay. Insulin release in response to low and high concentrations (2.8 mmol/L and 16.7 mmol/L, respectively) of glucose was investigated and electron microscopy morphological assessment was performed.RESULTS: Low-and high-glucose-stimulated insulin release in the control group was significantly higherthan in groups□and□(62.33 ± 9.67 μIU vs 47.75 ±8.47 μIU, 39.67 ± 6.18 μIU and 125.5 ± 22.04 μIU vs 96.17 ± 14.17 μIU, 75.17 ± 13.57 μIU, respectively, P <0.01) and was lowest in group □(P < 0.01). After adding1 μg/mL naloxone, insulin release in groups □and□wasnot different from the control group. Electron microscopy studies showed that the islets were damaged by 30 ng/mL fentanyl.CONCLUSION: Fentanyl inhibited glucose-stimulated insulin release from rat islets, which could be prevented by naloxone. Higher concentrations of fentanyl significantly damaged β-cells of rat islets.

Desulfurization ability of refining slag with medium basicity

The desulfurization ability of refining slag with relative lower basicity （B） and Al2O3 content （B = 3.5-5.0; 20wt%-25wt% Al2O3） was studied. Firstly, the component activities and sulfide capacity （Cs） of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution （Ls）. Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO （αCaO）, with no deterioration of Cs compared with conventional desulfurization slag. The measured Ls between high-strength low-alloyed （HSLA） steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

Layered niobium carbide enabling excellent kinetics and cycling stability of Li-Mg-B-H hydrogen storage material Layered niobium carbide enabling excellent kinetics

The Li-Mg-B-H composite(2LiBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage material.However,the slow kinetics and poor cycling stability severely restrict its practical applications.In this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the Li-Mg-B-H composite.The milled 2LiH+MgB_(2)composites were initially hydrogenated to obtain the 2LiBH_(4)+MgH_(2)composites.The 2LiBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2LiBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and LiBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2LiBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th cycle.Nb_(2)C keeps stable in the composite and acts as an efficient catalyst for the Li-Mg-B-H composite.It is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the Li-Mg-B-H composite.This work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the Li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.

Ti_(3)AICN MAX for tailoring MgH_(2) hydrogen storage material:from performance to mechanism

Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum carbides or nitrides(MAX) phases,which is environmentally unfriendly.In this work,Ti_(3)AlCN MAX without HFetching was employed directly to observably enhance the kinetics and the cycling stability of MgH_(2).With addition of10 wt% Ti_(3)AlCN,the onset dehydrogenation temperature of MgH2 was dropped from 320 to 205℃,and the rehydrogenation of MgH2 under 6 MPa H2 began at as low as50℃.Furthermore,at 300℃,it could provide 6.2 wt% of hydrogen in 10 min.Upon cycling,the composite underwent an activation process during the initial 40 cycles,with the reversible capacity increased from 4.7 wt% to 6.5 wt%.After that,the capacity showed almost no attenuation for up to 100 cycles.The enhancing effect of Ti_(3)AICN on MgH_(2) was comparable to many MXenes.It was demonstrated that Ti_(3)AICN did not destabilize MgH_(2) but acted as an efficient catalyst for MgH_(2).Ti_(3)AICN was observed to be the active sites for the nucleation and growth of MgH_(2)and might also help in dissociation and recombination of hydrogen molecules.Such two factors are believed to contribute to the improvement of MgH_(2).This study not only provides a promising strategy for improving the hydrogen storage performances of MgH_(2) by using noncorrosive MAX materials,but also adds evidence of nucleation and growth of MgH_(2) on a catalyst.

Improved hydrogen storage properties of LiBH4 confined with activated charcoal by ball milling

In order to enhance the hydrogen storage properties of LiBH4,activated charcoal (AC) was used as the scaffold to confine LiBH4 in this paper.Ball milling was used to prepare LiBH4/AC composites.Experimental results show that dehydrogenation properties of ball-milled LiBH4/AC (LiBH4/AC-BM) are greatly improved compared with that of pristine LiBH4,ball-milled LiBH4 (LiBH4-BM) and hand-milled LiBH4/AC (LiBH4/AC-HM).The onset dehydrogenation temperature of LiBH4 for LiBH4/AC-BM is around 160 ℃,which is 170 ℃ lower than that of pristine LiBH4.At around 400 ℃,LiBH4/AC-BM finishes the dehydrogenation with a hydrogen capacity of 13.6 wt%,which is approximately the theoretical dehydrogenation capacity of pure LiBH4 (13.8 wt%),while the dehydrogenation processes for LiBH4-BM and LiBH4/AC-BM do not finish even when they were heated to 600 ℃.The isothermal dehydriding measurements show that it takes only 15 min for LiBH4/AC-BM to reach a dehydrogenation capacity of 10.1 wt% at 350 ℃,whereas the pristine LiBH4 and the LiBH4/AC-HM release hydrogen less than 1 wt% under the same conditions.The dehydrogenation process and the effect of AC were discussed.

Oxygen transfer phenomenon between slag and molten steel for production of IF steel

FeO-containing slag originated from the basic oxygen furnace to the ladle is a major reoxidation source during the following secondary refining.Ladle slag reduction treatment(slag treatment)is one of the common countermeasures adopted to eliminate the steel contamination by FeO reoxidation.The oxygen transfer phenomenon between molten steel and slag was studied during the industrial production of interstitial-free(IF)steel,the measured and calculated oxygen activities in steel were compared,and the Fe–O equilibrium at the slag–molten steel interface was investigated by thermodynamic analysis.With slag treatment,the oxygen potential is higher in the molten steel than in the pre-deoxidation slag;this causes oxygen transfer from the molten steel to the slag,decreasing the efficiency of slag treatment.Based on this,a two-step slag deoxidation process was optimized.The second step further reduced the FeO content.On the other hand,the CaO/Al2O3(C/A)ratio in the refining slag must be controlled,because it affects the FeO activity and inclusion absorption capacity of the slag.The results suggest that the C/A ratio of 1.2–1.5 and the FeO content of\6%are beneficial to refine IF steel.

Exploiting Pre-Trained Network Embeddings for Recommendations in Social Networks

Recommender systems as one of the most efficient information filtering techniques have been widely studied in recent years. However, traditional recommender systems only utilize user-item rating matrix for recommendations, and the social connections and item sequential patterns are ignored. But in our real life, we always turn to our friends for recommendations, and often select the items that have similar sequential patterns. In order to overcome these challenges, many studies have taken social connections and sequential information into account to enhance recommender systems. Although these existing studies have achieved good results, most of them regard social influence and sequential information as regularization terms, and the deep structure hidden in social networks and rating patterns has not been fully explored. On the other hand, neural network based embedding methods have shown their power in many recommendation tasks with their ability to extract high-level representations from raw data. Motivated by the above observations, we take the advantage of network embedding techniques and propose an embedding-based recommendation method, which is composed of the embedding model and the collaborative filtering model. Specifically, to exploit the deep structure hidden in social networks and rating patterns, a neural network based embedding model is first pre-trained, where the external user and item representations are extracted. Then, we incorporate these extracted factors into a collaborative filtering model by fusing them with latent factors linearly, where our method not only can leverage the external information to enhance recommendation, but also can exploit the advantage of collaborative filtering techniques. Experimental results on two real-world datasets demonstrate the effectiveness of our proposed method and the importance of these external extracted factors.

Hydrogen storage properties of Nb-compounds-catalyzed LiBH4-MgH2

In order to improve the hydrogen storage properties of LiBH4-MgH2 composite, two different kinds of Nb-based catalysts, NbC and NbF5, were added to LiBH4-MgH2 composite by ball milling, and the effect of catalysts on hydrogen storage properties of the modified LiBH4-MgH2 system was investigated. The experimental results show that LiBH4-MgH2 composite is a two-step dehydrogenation process, and Nb-based compounds can remarkably enhance its dehydrogenation kinetics. For the composite without addition of catalysts, the starting decomposition temperature for the first dehydrogenation step is around 320℃, and there is a long period of incubation time（around 220 min） for the occurrence of the second decomposition step even at high temperature of 450℃. It needs more than 10 h to complete the decomposition process and release around 9 wt% H2. After addition of 5 mol% NbF5, the starting decomposition temperature for the first dehydrogenation step is around 150℃, there is no incubation time for the second decomposition step, and it takes around 40 min to complete the second step and reaches a total dehydrogenation capacity of 9.5 wt%. NbF5 has better catalytic effect than NbC. Based on the hydrogenation/dehydrogenation behaviors and structural variation, the mechanism of catalytic effect was discussed.

Qualitatively and quantitatively assessing the aggregation ability of sludge during aerobic granulation process combined XDLVO theory with physicochemical properties

Inexact mechanism of aerobic granulation still impedes optimization and application of aerobic granules. In this study, the extended Derjaguin, Landau, Verwey, and Overbeek（XDLVO） theory and physicochemical properties were combined to assess the aggregation ability of sludge during aerobic granulation process qualitatively and quantitatively. Results show that relative hydrophobicity of sludge and polysaccharide content of extracellular polymeric substances（EPS） increased, while electronegativity of sludge decreased during acclimation phase. After 20 days＇ acclimation, small granules began to form due to high aggregation ability of sludge. Since then, coexisted flocs and granules possessed distinct physicochemical properties during granulation and maturation phase. The relative hydrophobicity decreased while electronegativity increased for flocs, whereas that for granules presented reverse trend. Through analyzing the interaction energy using the XDLVO theory, small granules tended to self-grow rather than self-aggregate or attach of flocs due to poor aggregation ability between flocs and granules during the granulation phase. Besides, remaining flocs were unlikely to self-aggregate owing to poor aggregation ability, low hydrophobicity and high electronegativity.

Microstructure and magnetic performance of Nd–Y–Ce–Fe–B sintered magnets after annealing

Annealing has been widely recognized as a crucial approach to modify the microstructure and enhance the coercivity of Nd–Fe–B magnets. However, in the context of Nd–Y–Ce–Fe–B magnets with multiple rare earths(REs) exhibiting different diffusion behaviors, annealing effects on the magnetic properties become more complicated and remain unknown.

Characteristics and Metallurgical Effects of Medium Basicity Refining Slag on Low Melting Temperature Inclusions

Recently, large sized CaO-Alz 03 inclusions with low melting temperature have been the main reason for lowering mechanical properties of high strength low alloy （HSLA） steel plates. New philosophy, i.e. refining by top slag with relatively low basicity and Al2O3 content, was proposed to control such kind of inclusions. Firstly, the characteristics of refining slag, such as component activities and sulphide capacity （Cs） of CaO-Al2O3-SiO2-MgO slag, were studied through thermodynamic calculation. Then, slag-metal equilibrium experiments were carried out in laboratory to investigate the exact chemical composition of refining slag together with thermodynamic analysis. Finally, industrial trials were done to verify the desulphurization ability and inclusions control in steel refined by the new slag. Thermodynamic calculations indicated that the slags with basicity of 3.5 and Al2O3 content of 200/oo and basicity of 5.0 and Al2O3 content of 20 % or 25 % have high values of CaO activity, sulphide capacity and ratio of MgO activity to Al2O3 activity. Laboratory equilibrium experiments showed that the slag with basicity of about 4.5 and A12 03 content of about 20% is helpful for increasing the melting temperature of inclusions in steel. After introducing such kind of refining slag in industrial trials, the sulphur content in eight heats of steel is below 20 ×l0-6 , which meets the requirement of HSLA steel, and most inclusions distribute in relatively high melting zone （≥1773 K） of CaO- Al2O3-MgO（-SiO2） quasi-ternary diagram. New philosophy of top refining slag is feasible to control low melting point inclusions of CaO-Al2O3 system in HSLA steel.

Desulfurization Behavior and Mechanism of CaO-saturated Slag

To develop a high-efficiency desulfurizer for the production of pipeline steel with the LD-RH-CC process,the desulfurization efficiency and mechanism of CaO-saturated slag were studied using a vacuum-induction furnace and Si-Mo electric resistance furnace.The results show that the desulfurization ability for slag with a small amount of solid CaO was highly enhanced under conditions of satisfied kinetics.The desulfurization reaction of CaO-saturated slag depended on the liquid slag rather than the solid CaO,as sulfur was not detected inside the solid CaO.The desulfurization efficiency of CaO-saturated slag was also influenced by the amount of residual liquid slag and its sulfur absorption ability.The sulfur absorption ability of CaO-CaF2 slag was analyzed to be much higher than that of CaOAl2O3-CaF2-（SiO2）slag.Moreover,the effect of solid CaO on the desulfurization kinetics was evaluated and the application conditions of CaO-saturated slag were discussed.

Formation of Inclusion in Ti–Al Killed Low C–Mn Steel

The formation of inclusion in Ti–Al complex deoxidized C–Mn steel was investigated. When Al content in steel is very low([Al]=0.0005%), for 0.003%【[Ti]【0.007%, the inclusion is the Al2O3–SiO2–MnO–TiOx composite inclusion; for [Ti]≥0.009%, the inclusion is TiOx in the steel. When [Ti]=0.005%, [Al]【0.001%, the inclusion is the Al2O3–SiO2–MnO–TiOx composite inclusion; while [Al]】0.006%, inclusions would be pure Al2O3. The experimental results agree with the thermodynamics conclusions.