ZSD顶燃式热风炉的改造

ZSD顶燃式热风炉在引进初期能够提高风温,但长时间的生产实践暴露出许多缺陷。通过从炉内结构、燃烧器、耐火材料配置三个方面进行改造,弥补了其缺陷,消除了重大安全隐患,大幅度提高了风温。     

Evaluation of isotopic boron (11B) for the fabrication of low activation Mg11B2 superconductor for next generation fusion magnets

In this study, we analyze the properties of boron isotope (¹¹B)-rich powders from three different sources, that is, American, Cambridge, and Pavezyum, to fabricate the bulk Mg¹¹B₂ superconductors and evaluate their superconducting properties. While ¹¹B-rich powder is an essential precursor to fabricate Mg¹¹B₂ superconductors for fusion magnet applications, the properties of the ¹¹B powder turned out to be critical to determine the quality of the final superconducting product. Therefore, appropriate control of processing conditions is needed to comply with the requirements of the nuclear fusion application. Analysis of the B isotope ratio by accelerator mass spectroscopy and neutron transmission revealed that all three types of powder are enriched with ¹¹B to better than 99 at % quality. In addition, Pavezyum's ¹¹B shows the lowest crystallinity and smallest crystalline domain size as evidenced by the high-resolution X-ray diffractometer and scanning electron microscopy. The chemical states of the boron isotope investigated with near edge X-ray absorption fine structure spectroscopy and X-ray photoemission spectroscopy also reveals that Pavezyum boron has amorphous structure. Mg¹¹B₂ bulks and multi-filamentary (12-filament) wires have been manufactured, sintered at different temperatures and characterized via the transport critical current density. The wire with Pavezyum ¹¹B shows three times higher current carrying capacity at a particular magnetic field compared to the wire using Cambridge ¹¹B and hence, Pavezyum ¹¹B boron has the potential for manufacturing fusion grade Mg¹¹B₂ based magnets. The results of this study demonstrated that Boron powders with higher purity, smaller grain size and lower crystallinity are critical for improving the superconducting and electronic properties of Mg¹¹B₂ samples fabricated from the powder. Thus, the low-neutron-activation Mg¹¹B₂ is possibly an affordable and technically viable candidate to replace NbTi superconductors in the low field poloidal field and correction coils for the next-generation fusion reactors.     

日本线材及其制品发展研究(待续)

对近年来日本线材及其制品的生产和进出口情况进行统计分析 ,结果显示 ,日本线材年产量基本不变 ,普通钢线材和特殊钢线材产量变化呈互补性 ;金属制品年产量 1998年急挫后有所回升 ,不同品种有不同的变化规律 ,低碳钢丝、PC钢丝、钢丝绳等产量下降 ,钢帘线和高碳镀锌钢丝等产量增加 ;制品产量与线材产量之比略有下降 ,但仍处于较高水平 ;线材进口呈下降趋势 ,出口呈增加趋势 ;金属制品进口呈增加趋势 ,出口量波动较大 ,总出口量远大于进口量。日本对中国的线材出口远大于进口 ,但出口呈下降趋势 ;对中国的金属制品进口远大于出口 ,呈增加趋势 ,并对产生这一结果的原因进行分析     

Influence of Ca2PbO4 on Phase Formation and Electrical Properties of (Bi,Pb)2Sr2Ca2Cu3O10/Ag Superconducting Composites

(Bi,Pb)₂Sr₂Ca₂Cu₃O₁₀ (Bi2223) precursor powders with large and small amounts of Ca₂PbO₄ phase were prepared and used to make superconductor/silver composite tapes. The melting behavior of the powders and tapes was examined by differential thermal analysis (DTA). The influence of Ca₂PbO₄ on the formation and microstructure of Bi2223, and electrical properties of the tapes, was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and critical current measurements. It was found that the melting onset temperature ( T _m,onset) of precursor powders and composite tapes was strongly dependent on the amount of Ca₂PbO₄. Tapes with a small amount of Ca₂PbO₄ had a higher T _m,onset and a higher optimum sintering temperature compared with tapes with a large amount of Ca₂PbO₄. Also because of the higher sintering temperature, the total sintering time required for the former tapes was drastically shortened compared with the latter ones (250 vs 110 h). Furthermore, the microstructure and the current-carrying capacity of the tapes were significantly improved by reducing the Ca₂PbO₄ content of the precursor powders. These results are of practical significance for the commercialization of Bi-based high-temperature superconductors.     

A facile route to carbon-coated SnO2 nanoparticles combined with a new binder for enhanced cyclability of Li-ion rechargeable batteries

Carbon-coated SnO₂ nanoparticles were prepared by a novel facile route using commercial SnO₂ nanoparticles treated with concentrated sulfuric acid in the presence of sucrose at room temperature and ambient pressure. The key features of this method are the simple procedure, low energy consumption, and inexpensive and non-toxic source materials. As-prepared core/shell nanoparticles were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The electrochemical measurements showed that the carbon-coated SnO₂ nanoparticles with 10% carbon and using carboxymethyl cellulose (CMC) as a binder displayed the best electrochemical performance with the highest specific capacity of 502 mAh g⁻¹ after 50 cycles at a current density of 100 mA g⁻¹. In addition, owing to the water solvability of CMC, the usage of CMC as binder makes the whole electrode fabrication process cheaper and more environmental friendly.     

富钾绿肥籽粒苋对夏烟烟叶品质的影响研究

富钾绿肥籽粒苋D881、No.12于4月中旬播种，6月初压青，含钾量达6．3％，从土壤中吸收钾素358－510kg/hm^2供烟株吸收利用；D881处理的烟叶（C3F）含钾量2年试验均较对照增加0．35个百分点以上。烟叶评吸质量与对照差异不明显，但烟叶香吃味、燃烧性得分明显高于春烟。籽粒苋压青还田后第2年土壤速效磷、速效钾含量有较明显的增加；籽粒苋D881在烟草上有一定推广价值，但利用方式还有待于进一步完善。     

营养保健型挂面工艺研究

试验在挂面中添加枸杞籽汁,制得具有降血糖功效的营养保健型挂面,并通过正交试验研究确定了枸杞降血糖营养挂面的最佳工艺配方。试验结果表明:枸杞浆用5%的β-环糊精包埋2 d后,以30%的用量加入面粉,再分别添加3%的食盐和0.2%的海藻酸钠改善品质,可制得风味独特、降低血糖,并能较长时间保持色泽、品质不变的营养保健型挂面。     

The protective effects of garlic oil on acute ethanol‐induced oxidative stress in the liver of mice

BACKGROUND: Alcoholic liver disease is so serious that no effective therapies have been developed up to now. This study was conducted to elucidate the effects of garlic oil (GO) on acute ethanol‐induced liver injury. Male Kun‐Ming mice were orally administered GO (50, 100 or 200 mg kg^?1) for 30 days and then ethanol (4.8 g kg^?1). At 16 h after ethanol treatment the mice were sacrificed. Subsequent serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride (TG) levels, hepatic malondialdehyde (MDA) and glutathione (GSH) levels and antioxidant enzyme activities were measured. Histopathological examination of mouse liver sections was performed by Sudan III staining. RESULTS: GO pretreatment significantly inhibited acute ethanol‐induced increase in ALT, AST, TG and MDA and decrease in GSH in a dose‐dependent manner. In the three GO groups the level of GSH increased by 10.3%, 15.8% (P < 0.05) and 25.5% (P < 0.01) respectively compared with that in the ethanol group. The activities of superoxide dismutase, catalase and glutathione reductase were increased markedly in the 200 mg kg^?1 GO group (P < 0.01). Histopathological examination showed fewer fat droplets in liver sections of GO‐pretreated mice. CONCLUSION: GO may have protective effects against acute ethanol‐induced liver injury through restoration of the GSH level and enhancement of the activities of antioxidant enzymes. Copyright © 2008 Society of Chemical Industry     

薤白多糖的酶法修饰及其抗氧化活性

为探讨薤白多糖酶法修饰的最佳条件,以及酶法修饰提高薤白多糖活性的可能性,采用α-淀粉酶对醇沉法得到的薤白多糖和柱层析纯化的3种分级薤白多糖进行酶法修饰,以O2-·清除率为响应值,应用响应面分析法对α-淀粉酶修饰薤白多糖的工艺进行优化,用邻苯三酚自氧化法测定修饰产物的抗氧化活性。结果表明,对修饰多糖抗氧化活性的影响因素从大到小依次为:加酶量、酶解温度、酶解p H;α-淀粉酶修饰薤白多糖的最优工艺条件为:加酶量263U/g,酶解温度45℃、酶解p H 5.8,在此条件下O2-·清除率预测值为80.13%,验证值为80.16%,结果重现性好,可用于实际预测。抗氧化试验表明,酶法修饰能提高薤白多糖的抗氧化活性。     

胶质芽孢杆菌胞外多糖的制备及流变学特性

以实验室保藏的胶质芽孢杆菌SM-01为研究对象,研究了其胞外多糖(EPS)在5 L发酵罐中的发酵过程及制备方法,并对EPS溶液的流变学特性进行了研究,主要分析了质量浓度、剪切速率、剪切时间、温度、pH、无机盐、外加多糖等对其黏度的影响。结果表明,发酵液中EPS的最大产量为23.46 g/L,经离心、醇沉、冷冻干燥后EPS的回收率为76.7%;EPS溶液是典型的非牛顿流体;溶液黏度随着质量浓度的增加而快速增大;25～100℃范围内EPS黏度变化不大;EPS溶液黏度受pH影响较大,其黏度值在pH 7时达到最大,pH>12时溶液成弱凝胶状;加入NaCl、KCl、MgCl2、CaCl2等无机盐后溶液黏度显著下降,Fe3+、Pb2+等高价阳离子使EPS沉淀;EPS与海藻酸钠、黄原胶、瓜尔胶、槐豆胶、阿拉伯胶均有协效性。