Changes in particle size distribution, mineral yield and strength of coke samples from various locations of two Chinese blast furnaces as well as deadman porosity were investigated in the present ...study for an in-depth understanding about the blast furnace hearth phenomenon. It was found that the percentage of <10 mm coke fines varied from 20% to 49% in majority of the hearth-level regions. The average size of hearth coke was about 20 mm–31 mm. Compared with the feed coke, the hearth coke size was observed to decrease by 43%–63%. The average size of hearth coke particles of a 2800 m3 blast furnace in diameter direction distributed in “M-shape” in majority of the hearth-level regions while that of a 5500 m3 blast furnace distributed in inversed “V-shape”. The hearth coke mass was 1.43–2.21 times of the feed coke under the same conditions. The M10 of hearth coke with size larger than 40 mm after drum test was about 11%–18% and the M40 was 75%–79%. The M10 increased with the increasing distance to the tuyere level while the M40 decreased with the distance. Due to the catalytic effect of hot metal on coke graphitization, the M10 of hearth coke in the lower part was increased by 63.6% compared with the coke in the upper part. The average porosity of the edge, the middle and the center areas was 0.334, 0.299 and 0.250, respectively. The average porosity of deadman decreased with the increase of distance to the center line of the taphole and the increasing distance to the furnace wall.
Polymer semiconductors (PSCs) are a desirable class of materials for next-generation electronics. However, the conformational complexity associated with macromolecules, as well as the presence of ...unique inter- and intrachain interactions, make it challenging to control the morphology of PSCs. Previously, it has been reported that beyond a certain molecular weight, thin-film charge carrier mobility typically drops due to reduced crystallinity and increased entanglement. Here, the use of an insulating secondary matrix polymer, polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS), is shown to induce molecular ordering of PSCs across multiple length scales. Aggregation-induced molecular ordering in SEBS/PSC hybrid films is strongly correlated to the molecular weight of the semiconducting component. The higher the molecular weight of PSC used to blend with SEBS, the greater the observed improvement in polymer aggregation and orientation. This leads to a 5-fold increase of charge carrier mobility, from 0.3 to 1.5 cm2 V–1 s–1 (P-97k), in field-effect transistors (FETs) with only 30 wt % of the semiconducting polymer in SEBS. Moreover, mobility can be further elevated to 2 cm2 V–1 s–1 using an extensional flow-driven solution shearing deposition method. The findings here on using a secondary polymer matrix to dramatically improve the molecular organization and charge transport of a high-molecular-weight PSC are a useful morphological control strategy. It can also be carried out using nonhalogenated solvents, such as p-xylene, which are more environmentally benign and industrially relevant than commonly used chlorinated solvents.
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IJS, KILJ, NUK, PNG, UL, UM
In this paper, the residual thickness of carbon brick, residual carbon brick and skull of a Chinese 2800 m3 blast furnace hearth were studied in detail and the formation mechanism of skull and ...brittle layer were proposed. The results show that the remaining thickness of carbon brick is highly inhomogeneous in the height and circumferential direction. In the circumferential direction, the sidewall erosion in the range of 3.6 m under the taphole is more serious. In the height direction, the carbon brick at the distance of 1.0–2.0 m below the central line of the taphole is more obvious. The erosion of hearth bottom is “mumps face+ bowl” type erosion. The minerals of the hot surface of carbon brick used for more than nine years are mainly composed of KAlSiO4, KAlSi2O6, Zn2SiO4 and ZnO as well as a small amount of ZnS, KCl and ZnAl2O4. Micro cracks resulted from the KAlSiO4, KAlSi2O6, Zn2SiO4 and ZnAl2O4 are the inducement of formation of brittle layer. The main reason for the formation of macro cracks and brittle layer in carbon brick is the continuous accumulation of ZnO in micro cracks. The brittle layer mainly occurs in the region where the temperature of carbon brick is lower than 950°C. The skull above the central line of the taphole is mainly composed of Ca2Al2SiO7, Ca2MgSi2O7, CaTiO3 and KAlSiO4. The skull below the central line of the taphole is primarily comprised of Ca2Al2SiO7, Ca2MgSi2O7, CaS, Fe and Fe3Si. The blast furnace slag phase in the skull below the central line of taphole is derived from the blast furnace slag that penetrates into the deadman coke. The blast furnace slag can be present below the central line of the taphole and adhere to the hot surface of the carbon brick to isolate the direct contact between the molten iron and carbon brick.
Stretchable polymer semiconductors (PSCs) have seen great advancements alongside the development of soft electronics. But it remains a challenge to simultaneously achieve high charge carrier mobility ...and stretchability. Herein, we report the finding that stretchable PSC thin films (<100-nm-thick) with high stretchability tend to exhibit multi-modal energy dissipation mechanisms and have a large relative stretchability (rS) defined by the ratio of the entropic energy dissipation to the enthalpic energy dissipation under strain. They effectively recovered the original molecular ordering, as well as electrical performance, after strain was released. The highest rS value with a model polymer (P4) exhibited an average charge carrier mobility of 0.2 cm
V
s
under 100% biaxial strain, while PSCs with low rS values showed irreversible morphology changes and rapid degradation of electrical performance under strain. These results suggest rS can be used as a parameter to compare the reliability and reversibility of stretchable PSC thin films.
Conjugated, borole-linked polymers have been self-assembled based on boronate ester formation between a fluorene-2,7-diboronic acid and 1,2,4,5-tetrahydroxybenzene. Readily soluble polymers with ...molecular weights approaching 60 000 have been generated with materials exhibiting extended conjugation over approximately 3−5 borole linkages. Emission from these polymers reaches into the visible (blue) range, representing a novel class of blue-emitting materials.
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IJS, KILJ, NUK, PNG, UL, UM
Both high gain and transconductance at low operating voltages are essential for practical applications of organic field-effect transistors (OFETs). Here, we describe the significance of the ...double-layer capacitance effect in polar rubbery dielectrics, even when present in a very low ion concentration and conductivity. We observed that this effect can greatly enhance the OFET transconductance when driven at low voltages. Specifically, when the polar elastomer poly(vinylidene fluoride-co-hexafluoropropylene) (e-PVDF-HFP) was used as the dielectric layer, despite a thickness of several micrometers, we obtained a transconductance per channel width 30 times higher than that measured for the same organic semiconductors fabricated on a semicrystalline PVDF-HFP with a similar thickness. After a series of detailed experimental investigations, we attribute the above observation to the double-layer capacitance effect, even though the ionic conductivity is as low as 10(-10) S/cm. Different from previously reported OFETs with double-layer capacitance effects, our devices showed unprecedented high bias-stress stability in air and even in water.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The increased use of copper radioisotopes in radiopharmaceutical applications has created a need for bifunctional chelators (BFCs) that form stable radiocopper complexes and allow covalent attachment ...to biological molecules. The chelators most commonly utilized for labeling copper radionuclides to biomolecules are analogues of 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA); however, recent reports have communicated the instability of the radio-Cu(II)-TETA complexes in vivo. A class of bicyclic tetraazamacrocycles, the ethylene “cross-bridged” cyclam (CB-cyclam) derivatives, form highly kinetically stable complexes with Cu(II) and therefore may be less susceptible to transchelation than their nonbridged analogues in vivo. Herein we report results on the relative biological stabilities and identification of the resulting radiolabeled metabolites of a series of 64Cu-labeled macrocyclic complexes. Metabolism studies in normal rat liver have revealed that the 64Cu complex of 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo6.6.2hexadecane (64Cu-CB-TE2A) resulted in significantly lower values of protein-associated 64Cu than 64Cu-TETA 13 ± 6% vs 75 ± 9% at 4 h. A similar trend was observed for the corresponding cyclen derivatives, with the 64Cu complex of 4,10-bis(carboxymethyl)-1,4,7,10-tetraazabicyclo5.5.2tetradecane (64Cu-CB-DO2A) undergoing less transchelation than the 64Cu complex of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (64Cu-DOTA) 61 ± 14% vs 90.3 ± 0.5% protein associated 64Cu at 4 h. These data indicate that the structurally reinforcing cross-bridge enhances in vivo stability by reducing metal loss to protein in both the cyclam and cyclen cross-bridged 64Cu complexes and that 64Cu-CB-TE2A is superior to 64Cu-CB-DO2A in that regard. These findings further suggest that a bifunctional chelator derivative of CB-TE2A is a highly desirable alternative for labeling copper radionuclides to biological molecules for diagnostic imaging and targeted radiotherapy.
The design of polymer semiconductors possessing high charge transport performance, coupled with good ductility, remains a challenge. Understanding the distribution and behavior of both crystalline ...domains and amorphous regions in conjugated polymer films, upon an applied stress, shall provide general guiding principles to design stretchable organic semiconductors. Structure–property relationships (especially in both side chain and backbone engineering) are investigated for a series of poly(tetrathienoacene‐diketopyrrolopyrrole) polymers. It is observed that the fused thiophene diketopyrrolopyrrole‐based polymer, when incorporated with branched side chains and an additional thiophene spacer in the backbone, exhibits improved mechanical endurance and, in addition, does not show crack propagation until 40% strain. Furthermore, this polymer exhibits a hole mobility of 0.1 cm2 V−1 s−1 even at 100% strain or after recovered from strain, which reveals prominent continuity and viscoelasticity of the polymer thin film. It is also observed that the molecular packing orientations (either edge‐on or face‐on) significantly affect the mechanical compliance of the polymer films. The improved stretchability of the polymers is attributed to both the presence of soft amorphous regions and the intrinsic packing arrangement of its crystalline domains.
Stretchable polymer electronics are regarded as the next generation of soft electronic devices. Structure–property relationships of conjugated poly(tetrathienoacene‐diketopyrrolopyrrole) polymers with molecular structure modification are demonstrated. The physical, electrical, and morphological properties of conjugated polymers are characterized to elucidate how the thin film behavior under various stretching conditions.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The paper examined the changes in microstructure and inorganic elements in their true mineral forms of the coke samples from various hearth locations using X-ray diffraction (XRD) and scanning ...electron microscopy-energy dispersive spectroscopy (SEM-EDS) after the blow out and cool down of a 2800 m3 industrial blast furnace. The results illustrate that all deadman coke samples from fines to lumps were confirmed to be highly graphitized. Furthermore, the deadman coke was filled up with the accumulated KAlSiO4 during its descent process and the blast furnace slag which consisted of Ca2MgSi2O7–Ca2Al2SiO7 system and Ca2ZnSi2O7 phases. Besides the slag phases, the iron was also observed in the deadman coke soaked in the iron layer. Those cause that the mass of the deadman coke is about 1.62–2.82 times larger than that of the feed coke under the same conditions. Thus it may make the deadman which was designed to float sit on the hearth bottom as the permeation of the slag and the liquid iron into the deadman coke was not taken into consideration during the design process. We concluded that the slag phase below the taphole level is primarily derived from the blast furnace slag. Moreover, the deadman coke carrying final slag may come in contact with the hearth bottom and react with ceramic pad or carbon brick with a sitting deadman, thereby it results in degrading the hearth lining. Meanwhile, the slag phases below the taphole level can provide the material for the formation of skull to protect the hearth lining.
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