一种植物油中苯并（a）芘含量测定的固相萃取前处理方法

为了建立一种准确性高、成本低的植物油中苯并(a)芘测定的样品前处理方法，基于GB 5009.7—2016以自制氧化铝柱为固相萃取柱，采用单因素试验对称样量、洗脱剂量、洗脱流速、吸附剂存放时间、吸附剂量这5个影响植物油中苯并（a）芘洗脱的因素进行研究，优化前处理条件，并对测定方法进行考察。结果表明：优化的前处理条件为称样量0.100 0 g、洗脱剂量120 mL、吸附剂（氧化铝）量22 g、洗脱流速1滴/2 s、吸附剂存放时间少于12周；方法检出限为0.2 μg/L，样品加标回收率为94.23%～100.00%，RSD为1.20%～7.36%；同一样品测定结果与SGS测定值接近，相对平均偏差为2.36%～3.50%。说明本试验方法测定结果准确，可应用于油脂企业植物油中痕量苯并（a）芘的测定。     

Synthesis and characterization of SrFeOx hetero-film resistance-switching device with low operation voltage

As a critical topological phase transition material, SrFeO_x could play an essential role in the field of resistive memory. How to implement resistance-switching more softly and ensure the stability of materials has always been a relevant research hotspot. Regulating the oxygen environment during the deposition process of the films can effectively control the stoichiometry of the functional layer and then improve the resistance-switching characteristics of the device. In this paper, a SrFeO_x hetero-film was prepared by oxygen pretreatment on the SrRuO₃ surface before SrFeO_x deposition, and the as-assembled micrometer-scale device exhibits a low set operating voltage of 0.6 V and favorable cycling characteristics. The SrFeO_x hetero-film reveals a vertical brownmillerite superlattice-like structure with ～20 nm perovskite buffer layer, which benefits the connection and rupture of conductive filament. Additionally, XPS and UV–vis were used to analyze the bonding energy and band gap of SrFeO_x hetero-film, and offers the experimental basis for the explanation of the conductive mechanism. Therefore, the device based on SrFeO_x hetero-film with low operation voltage provides a reference for low power consumption research on topological phase transition material.     

Phosphoric Acid-assisted Pretreatment Strategy for the Rational Synthesis of Lignin-derived Hierarchical Porous Carbon Toward High-performance Supercapacitors

In this article, a facile two-step activation method, coupled with phosphoric acid (H₃PO₄)-assisted pretreatment and followed KOH activation, was reported for constructing hierarchical porous carbon (HPC) materials derived from lignin. The introduction of H₃PO₄, cross-linked with lignin sources generated phosphate (and/or polyphosphate) ester groups throughout the lignin structure, which endowed the pre-activated intermediate char (IC) with a hierarchical porous structure. Such phosphate esters contributed to the multi-scale pore structure within the pre-activated IC, which was beneficial for the uniform distribution and impregnation of subsequent KOH activators, thus leading to the formation of HPC materials. The as-prepared HPC exhibited a large specific surface area (SSA) of 1345.1 m²/g, which ensures the accessibility of the ion diffusion pathways. The supercapacitors integrated with HPC delivered a high specific capacitance of 241 F/g (in a three-electrode system) and outstanding rate capability with an 80.9% capacitance retention from 0.5 A/g to an ultra-high current density of 50 A/g.     

燃煤电厂软土层地基预处理方案和施工探究

本文阐述了预处理的重要性,揭示了当前施工中存在的问题,并对软土层地基处理提出了具体的方案。     

功能性海带面包生产工艺的研究

该研究将海带进行处理后添加到面包中,通过对生产工艺进行研究,以期得到功能性的海带面包。以面包感官评价得分为考察指标,考察高压蒸煮温度、蒸煮时间、海带粒径3个因素对面包品质的影响,确定海带最佳预处理工艺条件为:高压蒸煮温度125℃、蒸煮时间20 min、海带粉碎粒度40目<φ<60目;采用正交试验分析法,确定海带面包的最佳生产配方为:食盐添加量为1.5%、海带粉添加量为8%、酵母添加量为2.0%、改良剂添加量为0.8%。此条件下,海带面包的体积膨松,组织气孔细密,口感柔软,具有海带清香味。     

二氧化氯结合加热法处理蛋源对液蛋产品特性的影响

通过优化二氧化氯结合加热法处理新鲜鸡蛋提高其杀菌效率,缩短其消毒时间,并对蛋液的理化及功能性质进行分析。结果表明,最佳蛋源前处理方法为浓度为125 mg/L的二氧化氯溶液浸泡5 min后,65℃热水冲洗120 s,对蛋壳表面的微生物的杀菌率达到99.9%。前处理方法对蛋液起泡性、泡沫稳定性、挥发性盐基氮没有显著影响;经前处理后的蛋液储存8周后,菌落总数、起泡性和挥发性盐基氮均明显优于对照组。该方法可以有效延长液蛋制品的保质期。     

废旧毛涤黏混纺面料脱色预处理工艺研究

以废旧毛涤黏混纺面料为研究对象,首先对面料进行清洁与消毒,然后对其组分进行定性、定量分析,最后通过单因素法优化,得出最佳的溶胀工艺为:m_(废旧面料)∶m_(DMSO)=1∶10,溶胀时间40 min,溶胀温度90℃。在该工艺下对织物进行溶胀处理,得到织物的质量损失率为3.06%,K/S值为16.906。     

生物酶预处理对烟梗浆料纤维特性的影响

通过采用生物酶对烟梗浆料进行预处理,对比分析了生物酶预处理对烟梗浆料纤维特性的影响。结果表明,相同打浆度下,酶预处理组纤维平均长度、粗度、细小纤维含量和扭结指数均高于对照组。烟梗浆料扫描电子显微镜(SEM)分析表明,酶预处理有促使纤维纹孔打开、破坏细胞结构的可能;红外光谱表明,酶预处理后烟梗浆料中的纤维素相对含量增加,而烟碱类物质相对含量减少,溶出增加;X射线衍射仪(XRD)分析表明,酶预处理可提高烟梗浆料纤维素的结晶度,相对于对照样的26. 19%,酶预处理样纤维素结晶度为28. 15%,增加了7. 51%;热重分析表明生物酶预处理会提高烟梗浆料的热稳定性。     

离子色谱-电导法检测酱油中氯化钠的含量

该研究采用灰化预处理+离子色谱-电导法检测酱油中食盐的含量，并与莫尔法、电位滴定法进行比较。结果表明，莫尔法存在滴定过量问题，电位滴定法对温度等外界环境条件和仪器操作要求苛刻，而离子色谱-电导法具有操作简便快速并具有较好的准确度和精密度。实验结果表明，氯化钠含量处于11.56～11.61 g/100 mL之间，回收率实验结果为96.00%～102.10%，相对标准偏差为0.089%。干扰实验对结果无明显影响，且能同时测定多种离子，可用于成品酱油中氯化钠含量的检验。