Application of Ceramic Coat Synthesized by In-Situ Combustion Synthesis to BF Tuyere

A novel technology of tuyere protection is introduced. The ceramic coat .is synthesized by using in-situ combustion process as the internal, external, and nose protecting coat of BF tuyeres. It can effectively protect the tuyeres and reduce heat loss by cooling water. The technglogy is quick-acting, easy to use, energy-saving and can make tuyeres have long service life. The feasibility of the application of the tuyere ceramic coat is discussed and the energy-saving effect of the tuyere is compared with that of the tuyeres lined with refractory.

Platinum in-situ catalytic oleylamine combustion removal process for carbon supported platinum nanoparticles

Colloidal synthesis method such as oleylamine(OAm)-stabilized process is of great interest for obtaining uniform and highly dispersed platinum nanoparticle catalysts, yet the ligand may unavoidably inhibit their electro-catalytic performance. Thus, fully removing these ligands is critical to activate catalyst surface. Previous research of OAm removal process pointed that thermal annealing was the most effective way in comparison with other methods such as chemical washing, UV–Ozone irradiation and cyclic voltammetry sweeping, but generally resulting in undesired growth of platinum nanoparticle. Few studies concerning a more efficient ligand removal process have been published yet. In this work we proposed a platinum in-situ catalytic OAm combustion strategy to elucidate the removal mechanism of OAm ligands in thermal process and the key experimental parameters were also optimized. In addition, heat flow signal based on differential scanning calorimetry(DSC) measurement as a sensitive indicator, is suggested to reveal the ligand removal efficiency, which is much more reliable than the traditional spectroscopy.In comparison with commercial Pt/C sample, such a surface clean Pt/C electrocatalyst has shown an enhanced specific activity for oxygen reduction reaction. Our removal strategy and the evaluation method are highly instructive to efficient removal of different organic ligands.

A novel suspension-floating-circulating fluidized combustion technology for coal slurry

A novel suspension-floating-circulating fluidized combustion technology is proposed for burning coal slurry fuel in traditional circulating ftuidized bed boilers （CFBB）. This technology can solve some existing problems in large- capacity CFBB burning coal slurry. The principles of the suspension-floating-circulating fluidized combustion technology were introduced in detail in this paper. A 130 t/h CFBB was retrofitted based on the technology, and the retrofitted system mainly includes a long-distance transport sub-system, a bed-material conveying sub-system with a wind-seal device invented by the authors, a superheater thermoregulation device using a novel temperature regulator, a return loop flu- idization facility, and a pneumatic ash conveying sub-system with sealed pump. The achieved performance of the retro- fitted CFBB shows that the thermal efficiency is 89.83 %, the combustion efficiency is 96.24 %, and the blending proportion of slurry is 94 %.

Synthesis and characterization of SrCe_(0.95)Y_(0.05)O_(3-δ) nano powders by low temperature combustion

Nanosized SrCe0.95Y0.05O3-δ powders with homogeneous composition were synthesized by the low temperature combustion process based on the Pechini method. A polymeric precursor sol was formed by using citric acid and ethylene glycol as the chelating agents of metal ions. The perovskite-type SrCe0.95Y0.05O3-δpowders with uniform shape and smaller than 25 nm in size were obtained through the combustion of the polymeric precursor sol at the existence of nitric acid and ammonium hydroxide. It was found that modulating the quantifies of nitric acid and ammonium hydroxide could control the particle size, and the quantities of residue carbonate ions were also affected by the quantifies of citric acid and ethylene glycol.

The Combustion Synthesis Process of Al-Ti-C System in an Elevated-temperature Al-melt

One of the main disadvantages of combustion synthesis of ceramic/metal composite materials is the relatively high level of porosity present in the products. To synthesize TiC/Al composites with a dense structure, this paper proposes a novel application of an elevated-temperature Al-melt to directly ignite and simultaneously infiltrate Al-Ti-C preform dipped in the melt. The emphasis was placed on the combustion synthesis process and mi-crostructural evolution of the preform in the melt, by a liquid quenching test combined with the measurement of the temperature history of the dipped preform. The results show that the combustion synthesis process of the preform in the elevated-temperature melt involves a series of reactions, and that higher temperature of the melt is favourable for the formation of TiC. The synthesized TiC/Al composites exhibit a dense structure, which is attributed to the infiltration of the melt into the preform.

A New Combustion Process for Nanosized BaCe_(0.95)Y_(0.05)O_(3-δ) Powders

Nanosized BaCe_(0.95)Y_(0.05)O_(3-δ) powders with the homogeneous composition were synthesized by a new combustion process based on the Pechini method. A polymeric precursor sol was formed by use of citric acid and ethylene glycol as the chelating agents of metal ions. The perovskite-type BaCe_(0.95)Y_(0.05)O_(3-δ) powders with uniform shape and smaller than 40 nm in sized were obtained through the combustion of the polymeric precursor sol at the existence of nitric acid and ammonium hydroxide. It was found the particle size could be controlled by modulating the quantities of nitric acid and ammonium hydroxide, the quantities of the residue, carbonate ions were also affected by the quantities of the citric acid and ethylene glycol.

Chromosome analysis of esophageal squamous cell carcinoma cell line KYSE 410-4 by repetitive multicolor fluorescence in situ hybridization

Chromosome aberrations are distinctive features of human malignant tumors. Analysis of chromosomal changes can illuminate the molecular mechanisms underlying the development and progression of cancer. To establish the technique of multicolor fluorescence in situ hybridization （M-FISH） for identifying chromosome aberrations in esophageal carcinoma cell line KYSE 410-4, four pools of 6-color whole-chromosome painting probes have been designed and hybridized on the same metaphase spread by four rounds of repetitive FISH. Repetitive 6-color M-FISH was successfully established and the cytogenetic abnormalities in KYSE 410-4 cells were characterized. Chromosome gains occurred at 2q, 3, 8, 17p, and X. An isochromosome 3q was visualized in the cell line, which might be one intermediate mechanism leading to 3p losses and/or 3q gains. Furthermore, 16 structural arrangements were detected, including four derivative chromosomes. The rearrangement of the centromeric regions accounted for approximately 44% of all rearrangements. The results added a more complete and accurate information of the genetic alterations to the classical cytogenetic description of KYSE 410-4 and provided a detailed cytogenetic background data for appropriate use of the cell line. The established 6-color M-FISH was useful for analyzing chromosomes in the whole genome of human tumors.

Stable CuO/La_(2)Sn_(2)O_(7) catalysts for soot combustion:Study on the monolayer dispersion behavior of CuO over a La_(2)Sn_(2)O_(7) pyrochlore support

To understand the dispersion behavior of metal oxides on composite oxide supports and with the expectation of developing more feasible catalysts for soot oxidation,CuO/La_(2)Sn_(2)O_(7)samples containing varied CuO loadings were fabricated and characterized by different techniques and density functional theory calculations.In these catalysts,a spontaneous dispersion of CuO on the La_(2)Sn_(2)O_(7)pyrochlore support formed,having a monolayer dispersion capacity of 1.90 mmol CuO/100 m^(2) La_(2)Sn_(2)O_(7)surface.When loaded below this capacity,CuO exists in a sub-monolayer or monolayer state.X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,and Bader charge and density of states analyses indicate that there are strong interactions between the sub-monolayer/monolayer CuO and the La_(2)Sn_(2)O_(7)support,mainly through the donation of electrons from Cu to Sn at the B-sites of the structure.In contrast,Cu has negligible interactions with La at the A-sites.This suggests that,in composite oxide supports containing multiple metals,the supported metal oxide interacts preferentially with one kind of metal cation in the support.The Raman,in situ diffuse reflectance infrared Fourier transform spectroscopy,and XPS results confirmed the formation of both O2^(-)and O2^(2-)as the active sites on the surfaces of the CuO/La_(2)Sn_(2)O_(7)catalysts,and the concentration of these active species determines the soot combustion activity.The number of active oxygen anions increased with increase in CuO loading until the monolayer dispersion capacity was reached.Above the monolayer dispersion capacity,microsized CuO crystallites formed,and these had a negative effect on the generation of active surface oxygen sites.In summary,a highly active catalyst can be prepared by covering the surface of the La_(2)Sn_(2)O_(7)support with a CuO monolayer.

MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons

Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.

Mechanism of La2O3 as combustion improver in blast furnace coal injection

La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3＋（CO-）3 that weakens the bridge adhesion of carbon structural units and alters the lattice structures, thus reducing the activation energy of the pulverized coal and accelerating the burning process. Research shows that La2O3 can form the active species La3＋（CO-）3, which weakens the bridge adhesion of carbon structural units and alters the lattice structures of the fixed carbon, hence decreasing the activation energy of the pulverized coal and accelerating the burning process.

JOINING OF Ni_3Al BY PRESSURIZED COMBUSTION SYNTHESIS USING GLEEBLE 1500 TEST SIMULATOR

In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothermic synthesis reaction of a mixture of element Ni and Al poweders pre - compacted as the interlayer material.Effects of the key process parameters, such as the heating rate and joining tem- perature as well as the hold time, on the joint formation and microstructural homogeneity were studied. The feasibility of the addition of Al2O3 particles in the joint interlayer for producing intermetallic -ma- trix composite joints are also explored. Results show that the microstructrual homogeneity in the synthe- sized joint interlayer was significantly influenced by the joining process paramenters.The fully synthesized Ni2Al joints exhibited an average tensile strength of 486MPa at R. T. With the addition of Al2O3 ce- ramic particles in the reactants, joints with reighrced Ni3Al - matrix composite interlayer were ob- tained.

α-Al_2O_3,TiB_2颗粒增强铝基复合材料的XD合成

介绍了α－Ａｌ２Ｏ３， ＴｉＢ２增强自生铝基复合材料 ＸＤ合成工艺，分析了合成反应的热力学及动力学机理．在 Ａｌ－ＴｉＯ２系中未加 Ｂ粉时，生成的增强相是 Ａｌ３Ｔｉ和α－Ａｌ２Ｏ３，通过 Ｂ粉的加入，使 Ａｌ－ＴｉＯ２－Ｂ系中棒状物 Ａｌ３Ｔｉ随 Ｂ／ＴｉＯ２摩尔比的增加而逐渐减少，在 Ｂ／ＴｉＯ２的摩尔比为 ２时，棒状物基本消失．同时分析了升温速率、 Ｂ／ＴｉＯ２摩尔比对燃烧温度、体收缩率的影响．

原位自生WC-Cr_3C_2复相陶瓷增强铁基表面复合材料

采用激光熔覆协同燃烧合成表面涂层技术在铁基材料表面原位生成复相陶瓷涂层。利用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)等方法对涂层的物相组成、显微形貌、组织成分等进行了研究,结果表明涂层主要是由WC、Cr3C2、-σFeCr和Fe2W所组成的复相体系。界面形貌特征表明涂层与基体之间为冶金结合。硬度及摩擦磨损试验表明,涂层的硬度及耐磨性能明显高于基体材料。热震实验结果显示涂层与基体具有良好的结合力。

火驱稠油热采井TP90H-9Cr套管热处理工艺优化试验研究

分析了火驱稠油热采井套管钢种的化学成分特点和技术要求,选择电站锅炉用10Cr9Mo1VNb钢作为火驱稠油热采井套管的替代钢种,并对其原有的热处理工艺进行优化改进。结果表明:经过热轧态直接回火处理的TP90H-9Cr套管材料,其高温强度、抗氧化性能和抗CO_2腐蚀性能满足使用要求;TP90H-9Cr套管的室温组织存在一定程度的轧态组织位相遗传,但通过合金元素的固溶强化、析出强化可使其各项性能指标满足要求。

制备方法对CuO-CeO_2/Al_2O_3/FeCrAl整体催化剂结构、粘附稳定性和催化性能的影响

采用浸渍法、粉末涂覆法、沉积沉淀浸渍法、溶胶高温分解法、原位溶液燃烧法和微乳液法制备了CuO-CeO2/Al2O3/FeCrAl整体催化剂,并运用扫描电镜、X射线衍射、程序升温还原、超声波振动和热振荡等手段研究了制备方法对活性组分的负载及其分布、催化剂结构、粘附稳定性和催化CO优先氧化反应性能的影响.结果表明,溶胶高温分解法、原位溶液燃烧法和微乳液法制备的整体催化剂表现出较好的催化CO优先氧化反应性能和较高的粘附稳定性.

燃烧合成法制备多相内生复合材料NiAl/Cr(Mo)-TiC

在热力学平衡分析的基础上 ,利用多种元素粉末燃烧合成了复杂多相内生复合材料 Ni Al/Cr( Mo) - Ti C,X-射线衍射结果证实 ,合成产物与热力学预测结果相符 .根据热力学基本原理 ,考察了燃烧反应的绝热温度 Tad和瞬时液相量γ.发现 ,随着 Ti C含量的增加反应体系的 Tad和γ提高 ,Ti C含量和瞬时液相量对产物致密度的影响是相辅相成的 .这一复合材料具有较高的屈服强度 ,大大高于其他 Ni

原位引入BN-SiC燃烧合成Si_(3)N_(4)-BN-SiC复合材料

Si_(3)N_(4)-BN-SiC复合材料以其良好的力学性能和抗氧化性能而具有良好的工程应用前景。本研究以Si、Si_(3)N_(4)稀释剂、B_(4)C和Y_(2)O_(3)为原料,采用燃烧合成法成功制备了Si_(3)N_(4)-BN-SiC复合材料。通过Si、B_(4)C和N_(2)气之间的反应,在Si_(3)N_(4)陶瓷中原位引入BN和SiC,制备的Si_(3)N_(4)-BN-SiC复合材料由长棒状的β-Si_(3)N_(4)和空心球形复合材料组成。实验研究了空心球微结构的形成机理,结果表明,生成的SiC、BN颗粒及玻璃相覆盖在原料颗粒上,当原料颗粒反应完全时,形成空心球形微结构。并进一步研究了B4C含量对Si_(3)N_(4)-BN-SiC复合材料力学性能的影响。原位引入SiC和BN在一定程度上可以提高复合材料的力学性能。当B_(4)C添加量为质量分数0~20%时,获得了抗弯强度为28~144 MPa、断裂韧性为0.6~2.3MPa·m^(1/2),杨氏模量为17.4~54.5GPa,孔隙率为37.7%~51.8%的Si_(3)N_(4)-BN-SiC复合材料。

Double perovskite oxides Sr_2Mg_(1-x)Fe_xMoO(6-δ) for catalytic oxidation of methane

The double perovskite oxides Sr2Mg1-xF exMoO6-δ were investigated as catalysts for the methane oxidation.The structural properties of catalysts were characterized in detail by X-ray diffraction,X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.The catalytic property was strongly influenced by the Fe substitution.The relation between catalytic performance and the degree of Fe substitution was examined with regard to the structure and surface characteristics of the mixed oxides.The Fe-containing catalysts exhibited higher activity attributable to the possible（Fe2＋,Mo6＋） and （Fe3＋,Mo5＋）valency pairs,and the highest activity was observed for Sr2Mg0.2Fe0.8MoO6-δ.The enhancement of the catalytic activity may be correlated with the Fe-relating surface lattice oxygen species and was discussed in view of the presence of oxygen vacancies.

Expression of Angiopoietin-1/-2 in the Process of Mouse Embryo Implantation

This study examined the expression and distribution of angiopoietin-1/-2 （Ang-1/-2） in the endometrium of early pregnant mice. The expression of Ang-1/-2 was detected by immunohistochemical staining and in situ hybridization respectively. Computerized image analysis system was used to measure the average optical intensity of Ang-1/-2 in endometria at different time points after gestation. Mice were randomly divided into 5 groups： control group, D2 group （2 days after pregnancy）, D4 group （4 days after pregnancy）, D6 group （6 days after pregnancy） and D8 group （8 days after pregnancy）, each containing 15 mice. The results showed that the expression of Ang-1 and Ang-2 was very different among 4 groups （P〈0.01）. Immunohistochemical staining revealed that Ang-1 was localized in the cytoplasma of stromal cells 2 days after pregnancy （day 2）, and in luminal epithelial cells on day 4. The protein of Ang-2 was mainly expressed in the cytoplasma of glandular epithelia and stromal cells. With gestation time, the positive reactions of Ang-1/-2 were stronger in the endometria of the pregnant mice （P〈0.01）. In situ hybridization showed Ang-I mRNA in stromal cells on day 2. Hybridization signal was localized in both stromal cells and vessel epithelial cells on day 4; Ang-2 mRNA was expressed in stromal cells and glandular epithelia on day 2; high mRNA levels appeared in stromal cells, glandular epithelia and vascular endothelia on day 4; an increasing in mRNA expression of Ang-1/-2 was observed on day 6 and day 8 （P〈0.01）. It is suggested that Ang-1/-2 may play an important role in the cross-talk between blastocyst and maternal endometrium during the process of embryo implantation.

Lag times in toe-to-heel air injection(THAI)operations explain underlying heavy oil production mechanisms

From a time value of revenue point of view,it is preferred that the time between reservoir stimulation and oil production response is small.Heavy oil combustion processes have a lag time between air injection and liquid production,but the common practice in production data analysis uses simultaneous injection and production data when seeking a relationship between them.In this research,the time scales of production for the Kerrobert toe-to-heel air injection(THAI)heavy oil project in Saskatchewan,Canada,is analyzed by using cross correlation analysis,i.e.time delay analysis between air injection and oil production.The results reveal two time scales with respect to production response with two distinctive recovery mechanisms:(1)a short time scale response(nearly instantaneous)where oil production peaks right after air injection(directly after opening production well)reflecting cold heavy oil production mechanisms,and(2)a longer time scale(of order of 100-300 days)response where peak production occurs associated with the collective phenomena of air injection,heat generating reactions,heat transfer,and finally,heated mobilized heavy oil drainage to the production well.This understanding of the two time scales and associated production mechanisms provides a basis for improving the performance of THAI.