竹材液化物碳纤维的电学性能研究

使用万用电表、X射线衍射仪等仪器对竹材液化物碳纤维的电阻率、XRD结构参数等进行测量,初步研究了竹材液化物碳纤维电阻率随炭化温度、炭化时间以及XRD结构参数的变化规律,为进一步探讨其导电机理、导电性能以及将其作为电磁屏蔽材料提供基础数据.     

High pressure processing manipulated buckwheat antioxidant activity,anti-adipogenic properties and starch digestibility

Effect of high pressure processing (HPP) on buckwheat nutritional properties is investigated in this study. The results indicated that the digestion of buckwheat starches of untreated and HPP treated at room temperature (RT) showed an “internal corrosion” pattern. However, an “exocorrosion” digestion behavior was observed for the starches of HPP treated sample at 45 °C, which might be due to the formation of amylose–lipid complexes during the process as revealed by X-ray diffraction (XRD). HPP treatment at 45 °C increased the antioxidant activity of the buckwheat as measured using 1,1′-diphenyl-2-picrylhydrazylvalue (DPPH) and iron chelating capacity (ICC) compared to untreated sample (P < 0.05), which might be associated with the release of bound phenolic compounds. More importantly, this is the first study to investigate the ability of buckwheat extract for inhibiting the formation of fat droplets using a C3H10T1/2 mesenchymal stem cell line, and found that the extract of buckwheat after HPP treatment at 45 °C demonstrated significant anti-adipogenic effects. This study suggested the HPP treatment at an increased temperature (45 °C) achieved a better nutritional value of the buckwheat than both untreated and treated at RT.     

甘蔗渣制取活性炭的试验研究

以甘蔗渣为原料,以ZnCl2为活化剂,采用先活化再炭化的方法制取生物活性炭.通过比较得率和碘值,得到了制取活性炭的优化条件:活化剂ZnCl2浓度为2.0 mol/L,活化剂与甘蔗渣的质量比为5∶1,活化时间为24 h,炭化温度为500 ℃,炭化时间为50 min,以N2作为保护气,流量为2.5 L/min.在上述条件下制得的活性炭的碘值为510 mg/g,得率为35.4%,比表面积为653 m2/g,平均孔径为2.4 nm,孔体积为 7.1×10-2 cm3/g.     

甘蔗渣制取活性炭的强度和稳定性研究

以甘蔗渣为原料,采用ZnCl2活化的方法制取生物活性炭.通过对比得率和碘值,优化了制取活性炭的活化剂浓度、炭化温度和炭化时间,并通过X射线衍射(XRD)、扫描电镜(SEM)和比表面积测定等仪器分析试验,探讨了活性炭制取过程中对强度和吸附稳定性的主要影响因素.结果表明,制取吸附稳定性好、强度高的活性炭优化条件为:活化剂ZnCl2浓度为2.0mol·L-1,活化剂与甘蔗渣的质量比为5:1,活化时间为24 h,炭化温度为500℃,炭化时间为50 min,以N2作为保护气,流量为2.5 L·min-1.在上述条件下制得的活性炭的碘值为510 mg·g-1,得率为35.4%,比表面积为653 m2·g-1,均孔径为2.4 nm,孔体积为7.1×10-2cm3·g-1,可广泛应用于各种水处理领域.     

蒸煮处理对竹纤维化学组成的影响及机理

采用热机械-蒸煮方法制备慈竹纤维,并运用FTIR、x-射线衍射分析技术对蒸煮处理前后慈竹纤维的化学组成、结晶结构进行了研究,此外,还研究了处理前后慈竹化学成分的变化,结果表明:不同蒸煮工艺处理后竹纤维的纤维素较未处理竹材有所上升,而木质素含量有所下降,其中,第2组蒸煮工艺所得纤维素含量提高了19.27%,木质素含量下降了38.85%,运用x-射线衍射测得的纤维素结晶度均有所上升。     

Magnesium-fortified phosphate fertilizers improve nutrient uptake and plant growth without reducing phosphorus availability

Magnesium (Mg) deficiency can significantly limit crop yield and quality. Separate application of straight Mg fertilizer is unattractive because of additional labor costs. Meanwhile, bulk blending Mg with other macronutrient fertilizers is also a suboptimal solution because bulk blended fertilizers often yield poor nutrient distributions. One rapid and economical alternative to alleviating Mg deficiency is to co-granulate macronutrient fertilizers with Mg. However, few commercial products have implemented this approach. One of the barriers hindering the production of Mg-fortified phosphorus (P) fertilizers is the assumption that precipitation of P with Mg will reduce P solubility. In this study, four Mg compounds, anhydrous magnesium sulfate (MgSO₄), magnesium oxide (MgO), anhydrous magnesium chloride (MgCl₂), and dolomite (CaMg(CO₃)₂), were co-granulated with mono-ammonium phosphate (MAP), and their granule strength, Mg and P availabilities, and agronomic effectiveness were evaluated. Results showed that there were no significant differences in P solubility between Mg-fortified MAP and MAP treatments. X-ray diffraction (XRD) indicated that the Mg species after co-granulation were boussingaultite (Mg(NH₄)₂(SO₄)₂·6H₂O), schertelite (Mg(NH₄)₂H₂(PO₄)₂·4H₂O), magnesium hydrogen phosphate (Mg(H₂PO₄)₂), and dolomite (CaMg(CO₃)₂). A pot experiment using an acidic soil demonstrated an average 9.6-fold increase in shoot Mg uptake, 3.0-fold increase in shoot P uptake, and 3.2-fold increase in soybean shoot dry matter in Mg-fortified MAP treatments, compared to those in MAP treatment. The current study provides a simple, effective, and low-cost approach for the addition of Mg to macronutrient fertilizers, to minimize Mg deficiency.     

Fe掺杂SrSnO3陶瓷的制备及其特性的研究

以SrCO3、SnO2和Fe3O4为原料,采用传统固相反应法制备了Fe掺杂SrSnO3陶瓷,并借助XRD和SEM,研究了SrFexSn1-xO3的相结构、形貌及Fe掺杂量对其电性能的影响.XRD图谱表明：未经烧结的样品是混合物,随着烧结次数的增加,样品的收缩增大,成品纯度变高,XRD杂峰减少.Fe掺杂SrSnO3陶瓷中随着Fe含量从0增加到1,烧结温度逐渐降低,从1480℃下降到1200℃,其晶格常数从0.806 9 nm下降到0.773 6 nm,晶体结构没有发生明显改变.SEM图片显示,靶材晶粒随着掺杂量的增加逐渐增大,由2.09μm增加到4.93μm.     

制备方法对Ce0.9Pr0.1O2-δ复合氧化物结构和性能的影响

采用柠檬酸溶胶—凝胶、硝酸盐分解和共沉淀法制备了Ce0.9Pr0.1O2-δ复合氧化物,考察了复合氧化物的CO氧化活性,并进行了XRD、Raman及TPR表征。结果表明:制备方法对复合氧化物的结构、还原性能及CO氧化活性有较大影响;复合氧化物的CO氧化活性与氧空缺的存在有关,复合氧化晶体中氧空缺越多,越有利于CO氧化;CO的氧化活性与还原峰面积的关系不大,而与还原峰温度有关,还原峰温度越低,其氧化活性越高。     

台湾红壤及森林土壤中之氧化铁

本文综合汇整近年来在台湾，应用高梯度磁场分离技术，配合一般化学分析，Ｘ－射线衍射法，磁测分析，电子显微镜观察与电子衍射鉴定，以及铁－５７穆期堡尔谱学分析等方法，研究红壤与森林土壤中，氧化铁的分布及其结构性质之成果回顾；关于氧化铁之分布情形，其研究结果显示：台湾红壤中普遍存在有赤铁矿与针铁矿等氧化铁矿物，而在化育自大屯山更新世纪安山岩母质与澎湖列岛更新世纪玄武岩母质的红壤中，以及兰屿绿岛海边之银白色