温度对黑豆皮活性成分、抗氧化和抗肿瘤活性的影响

在不同温度下用蒸馏水浸提黑豆皮,测定了黑豆皮提取物中总黄酮、总酚、花青素、碳水化合物、蛋白质、糖醛酸等6种活性成分的含量,并体外评估了其抗氧化活性和抗肿瘤活性.结果表明,90℃浸提时,黑豆皮提取物中的总黄酮、总酚、蛋白质、糖醛酸含量最高,分别为(11.555±0.160)％、(1.454±0.070)％、(13.096±0.600)％、(21.587±1.570)％;花青素含量在80℃浸提时达到最高,为(0.199±0.003)％;而碳水化合物的含量则在100℃浸提时达到最高,为(65.566±1.448)％.随着黑豆皮提取物浓度的增加,其总还原能力和对DPPH自由基的清除能力逐渐增强且呈线性关系;黑豆皮提取物具有抑制肿瘤细胞增殖的作用,能够有效抑制人胃腺癌细胞株(BGC-823)、宫颈癌细胞株(HeLa)和人大细胞肺癌细胞株(NCI-H460)的增殖且呈浓度依赖关系.表明黑豆皮提取物具有成为功能性保健品的潜能,为其产业化开发奠定了重要基础.     

Chemical durability and surface alteration of lanthanide zirconates (A2Zr2O7: A = La-Yb)

Chemical durability of lanthanide zirconates (A₂Zr₂O₇) (A = La-Yb) under near-field environments is important for evaluating their application as potential nuclear waste forms. In this work, A₂Zr₂O₇ (A = La-Yb) are synthesized by spark plasma sintering with controlled microstructure and their chemical durability are evaluated in a nitric acid solution (pH = 1). Scanning transmission electron microscopy analysis reveals an amorphous passivation film either enriched with Zr or lanthanide. The complex chemistry of the passivation films can be correlated with a transition in corrosion mechanisms from a preferential release of lanthanide in La₂Zr₂O₇ to a preferential release of Zr in Er₂Zr₂O₇ and Yb₂Zr₂O₇. These results suggest a dominant mechanism of incongruent dissolution and surface reorganization for the formation of passivation films. Strong correlations are identified between the leaching rates and cation ionic size, ionic potential, electronegativity differences between A-site cation and Zr, and bonding valence sum of oxygen, suggesting important impacts of structural and bonding characteristics in controlling chemical durability of lanthanide zirconates.     

大木作术语的物外之意——以四川穿斗民居为例

对四川穿斗民居的田野调查发现,工匠使用的术语存在一物多名、多物同名、异物类名等现象.在梳理田野调查、已有文献大木作术语的基础上,通过设计和施工阶段术语的不同作用,分析具体营造中工匠的思维与意识.同时从术语的角度,就穿斗结构以及术语的重名、异名现象提出新的认识.     

Meticulously tailoring phase boundary in KNN-based ceramics to enhance piezoelectricity and temperature stability

Although KNN-based ceramics with high electrical properties are obtained through a variety of strategies, the temperature sensitivity is still one of the key technical bottlenecks hindering practical applications. Here, we use a new strategy, meticulously tailoring phase boundary, to refine the ferroelectric boundary of KNN-based ceramics, leading to high piezoelectricity companied with improving temperature stability. The highest d₃₃ value in this system reaches 501 pC/N with a T_C ∼ 240°C, whereas a large strain of ∼0.134% can be kept with 10% lower deterioration until 100°C. The origin of high piezoelectricity is mainly attributed to the well-preserved multiphase coexistence and the appearance of nanodomains, which greatly facilitate the polarization rotation. Instead of the changed intrinsic thermal insensitivity, the precision phase boundary engineering plays an important role in strengthening the temperature stability of electric-induced strain. This work provides a simple and effective method to obtain both high electrical properties and excellent thermal stability in KNN-based ceramics, which is expected to promote the practical applications in the future.     

表面离子印迹聚合物金属离子吸附材料研究进展

离子印迹聚合物吸附材料对模板离子具有强识别能力，对其可实现高选择吸附，因而离子印迹技术常用于制备高选择性吸附材料。但传统方法制备的离子印迹吸附材料，因识别位点容易被包埋导致其吸附容量小、吸附-脱附速率低，而表面离子印迹技术则是采用模板离子和聚合单体直接在载体表面或附近区域构筑选择性识别位点，所有活性位点均暴露，从而有效地解决了上述问题。本文从技术原理与合成原料、制备工艺方法以及载体材料类型等方面对表面印迹聚合物吸附材料近期研究进展情况进行了概述。针对相关研究现状，从载体材料、功能单体、目标离子等角度分析和讨论了表面离子印迹聚合物吸附材料当前发展中的不足及其所面临的挑战，并对表面离子印迹技术发展趋势和前景进行了展望。     

泸州大气污染特征、成因及其防治对策研究

以2020年泸州市大气自动监测数据为对象，应用相关分析开展大气污染成因及污染防治对策研究。成果表明，泸州市区主要污染源为O₃和PM_2.5;在冬季全市及各站点PM_2.5与NO₂、CO显著相关，PM_2.5与SO₂、SO₂与CO、CO与NO₂俱低度相关；在夏季全市及各站点O₃与NO₂显著相关；泸州大气环境主要受工业污染源和机动车污染源共同影响；在不利天气下，通过多污染源综合控制工业污染源、机动车、秸秆燃烧等方式以减轻大气污染。