过氧化氢/臭氧-曝气生物滤池深度处理造纸废水生化出水

本研究采用过氧化氢/臭氧-曝气生物滤池组合工艺处理造纸废水生化出水,通过实验确定了优化操作参数,并对组合工艺的处理性能进行了探究。结果表明,组合工艺的优化操作条件为：pH值（7.3~8.4）、过氧化氢/臭氧投加量=113/60 mg/mg、氧化时间25 min、曝气生物滤池水力停留时间2.5 h、曝气生物滤池气水比3∶1。在优化操作条件下,过氧化氢/臭氧氧化后废水的生物处理适宜性显著提高;废水经组合工艺处理后,出水COD_Cr<20 mg/L、色度<10倍,达到企业废水回用水质要求。     

响应面法优化O3/H2O2组合工艺处理制浆中段废水的研究

本研究为提高臭氧（O₃）氧化处理制浆中段废水的COD去除率,以广西某造纸厂制浆中段废水为研究对象,采用O₃/H₂O₂组合工艺对其进行高级氧化处理。分别探究了废水初始pH值、O₃用量、H₂O₂用量、反应时间和搅拌速度等影响因素对废水色度和COD去除效果的影响。为提高最优工艺参数的精确度,对O₃/H₂O₂组合工艺参数进行响应面优化法分析。结果表明,在废水初始pH值=8、H₂O₂用量为1.0 mL/L、O₃用量为480 mg/L的工艺条件下,废水色度为85.7倍,色度去除率为99.3%;COD_Cr达208.2 mg/L,COD_Cr去除率为84.5%。     

Protective effect of whey protein hydrolysates on H2O2-induced PC12 cells oxidative stress via a mitochondria-mediated pathway

Whey protein hydrolysates (WPHs) were prepared with pepsin and trypsin. A PC12 cell model was built to observe the protective effect of WPHs against H₂O₂-induced oxidative stress. The results indicated that WPHs reduced apoptosis by 14% and increased antioxidant enzyme activities. Flow cytometry was used to assess the accumulation of reactive oxygen species (ROS), Ca²⁺ levels and the mitochondrial membrane potential (MMP). The results showed that WPHs suppressed ROS elevation and Ca²⁺ levels and stabilised MMP by 16%. The anti-apoptosis/pro-apoptosis proteins Bcl-2/Bax and poly (ADP-ribose) polymerase (PARP) were investigated by Western-blot analysis, which indicated that WPHs increased the expression of Bcl-2 while inhibiting the expression of Bax and the degradation of PARP. WPHs also blocked Caspase-3 activation by 62%. The results demonstrate that WPHs can significantly protect PC12 cells against oxidative stress via a mitochondria-mediated pathway. These findings indicate the potential benefits of WPHs as valuable food antioxidative additives.     

Free radical scavenging activity and comparative proteomic analysis of antioxidative protein against H2O2-induced oxidative stress in neuronal cells

Artemisia annua was enzymatically hydrolyzed by five proteases and seven carbohydrases. All enzymatic extracts scavenged DPPH, hydroxyl and alkyl radicals. Especially, the Protamex among the various proteases and Maltogenase among the various carbohydrases extracts exhibited the highest scavenging activity on hydroxyl radical. The extracts of A. annua clearly reduced neuronal cell death from H₂O₂-induced damage. In addition, a proteomic analysis, two-dimensional electrophoresis (2-DE) and matrix assisted laser desorption ionisation-time of flight/time of flight (MALDI-TOF/TOF) was used to identify the proteins of the neuronal cells whose expressions were or were not altered by the treatment of the Maltogenase extracts which showed the highest hydroxyl radical scavenging activity among all enzymatic extracts for 24 h. The protein characterisation revealed that translation elongation factor Tu (EF-Tu), Immunoglobulin E (IgE) and voltage-dependent anion channel 1 (VDAC-1) were involved in the cell survival effects against H₂O₂-induced apoptosis. These results suggest that EF-Tu, IgE and VDAC-1 have an important role in the reduction of neuronal apoptosis by oxidative stress, and the enzymatic extracts of A. annua shows potent antioxidative activities by regulating EF-Tu, IgE and VDAC-1.     

Essential rosemary oil protects testicular cells against DNA-damaging effects of H2O2 and DMNQ

Rosemary oil (RO) is popular in the Mediterranean region as a culinary additive which has the ability to protect delicate organs such as liver, brain and heart. We examined the effect of RO consumption on resistance of rat testicular cells (TCs) against DNA-damaging effects of the oxidative agents H₂O₂ and DMNQ and on the activity of the antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). DNA lesions were detected by conventional and modified comet assay and the activities of GSH-Px and SOD were measured spectrophotometrically. Since TCs represent a mixture of haploid, diploid and tetraploid cells, we used flow cytometry for their differentiation and calculation of DNA-damaging effects of H₂O₂ and DMNQ in cells of different ploidy. The results showed that the oxidative DNA lesions were significantly reduced in TCs from rats administered RO; however, the activity of antioxidant enzymes did not differ in TCs from control and RO-supplemented rats.     

牡丹花蕊醇提物对H2O2诱导HUVEC细胞损伤的保护作用

采用高效液相色谱分析牡丹花蕊醇提物的主要成分,并通过H_2O_2诱导HUVEC细胞建立损伤模型,研究牡丹花蕊醇提物对其保护作用。结果表明:牡丹花蕊醇提物主要成分为芦丁、槲皮素和芍药苷3种单体,含量分别为44.25%,15.50%,17.00%;牡丹花蕊醇提物能够降低细胞及其培养液中MDA含量,提高细胞内SOD和GPX活性以及GSH的含量。牡丹花蕊醇提物能够提高HUVEC细胞的抗氧化能力。     

Transfer process limited models for CO2 perception in CO2 hydrate desserts

A CO₂ hydrate dessert is a carbonated frozen dessert in which CO₂ hydrates replace some or all of the ice. When a CO₂ hydrate dessert is eaten, CO₂ perception is very strong due to formation and bursting of bubbles in the mouth as well as dissolution of CO₂ leading to nociceptor stimulation. A preliminary sensory panel indicated that a CO₂ hydrate dessert could be perceived as more carbonated than a freshly opened soda. However, it was also found that a CO₂ hydrate dessert must have a significantly higher CO₂ concentration than is typical in carbonated beverages (including champagne), just to have moderate perception of carbonation. In this work, heat transfer limited and mass transfer limited models for CO₂ hydrate dissociation are compared and the implications for CO₂ perception are discussed. It is suggested that the mass transfer limited model is most applicable to the case of eating CO₂ hydrate desserts. According to this model, a thin ice shell limits the rate of CO₂ hydrate dissociation. After dissociation, CO₂ gas is dissolved in the available aqueous phase. In a CO₂ hydrate there is much more CO₂ present than could be dissolved in the water that is present, so a large fraction of the CO₂ in the dessert may be lost with the breath of the consumer.     

TPA/TiO2-SiO2的制备及在地沟油预酯化工艺中的应用

以钛酸丁酯和硅酸乙酯为原料制备TiO₂-SiO₂,以磷钨酸(TPA)为活性组分,通过浸渍法制备TPA/TiO₂-SiO₂,用于高酸值地沟油中的预酯化研究。TPA/TiO₂-SiO₂表征结果表明,TPA/TiO₂-SiO₂具有较好的热稳定性、内部存在孔结构、具有较大的比表面积。以地沟油的酸值变化率为指标,通过单因素试验和正交试验,确定最佳工艺条件：TPA负载量为40%,载体焙烧温度为600 ℃,催化剂用量为5 wt%,反应时间为5 h,醇油质量比为0.8:1。在此条件下,FFAs的转化率可以达到98%。     

MoS2/g-C3N4复合纳米催化剂光催化深度处理造纸废水研究

本研究采用N-甲基吡咯烷酮复合MoS₂与g-C₃N₄,制得MoS₂/g-C₃N₄复合纳米催化剂。采用X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、光致发光光谱仪（PL）和扫描电子显微镜（SEM）对复合纳米催化剂进行表征,并利用MoS₂/g-C₃N₄复合纳米催化剂光催化深度处理造纸废水。结果表明,少量MoS₂与g-C₃N₄复合可提高复合光催化剂的光催化活性,反应时间180 min、pH值5、1.5% MoS₂/g-C₃N₄复合纳米催化剂投加量为2 g/L时,对造纸废水的COD_Cr去除率和色度去除率最高,分别达到63.4%和83.2%。MoS₂/g-C₃N₄的光催化活性有所增强是由于MoS₂与g-C₃N₄的能带结构匹配,降低了光生电子-空穴的复合几率,从而提高了催化剂的光催化活性。     

NaOH-H2O2溶剂体系下玉米秸秆的组分分离规律研究

研究了NaOH-H2O2组成的碱溶剂体系对玉米秸秆的溶解规律,并结合酸沉、醇析方法分离出了3种主要成分,研究了过氧化氢浓度、pH、液固比、温度、时间对玉米秸秆组分分离过程的影响。结果表明:碱溶剂处理后的剩余固体物质是纤维素和不溶物,滤液经酸沉后的固体为木质素,酸沉后的滤液调pH后醇析所得的固体为半纤维素。试验确定了分离过程的最佳工艺条件:过氧化氢浓度5%,pH=12,反应时间3 h,溶解温度60℃,液固比30 m L/g。在此条件下,纤维素回收率84.2%,木质素回收率为66.6%,半纤维素回收率96.7%,滤液经4次循环使用,纤维素回收率82.7%,木质素回收率67.6%,半纤维素回收率97.4%。碱处理及酸沉、醇析后剩余固体的结构分析证明了此方法的可行性。     

Comprehensive Evaluation and Prediction of the Effectiveness of H2O2-assisted Na2CO3 Pretreatment of Corn Stover Using Multivariate Analysis

In this study, multivariate analysis methods, including a principal component analysis (PCA) and partial least square (PLS) analysis, were applied to reveal the inner relationship of the key variables in the process of H₂O₂-assisted Na₂CO₃ (HSC) pretreatment of corn stover. A total of 120 pretreatment experiments were implemented at the lab scale under different conditions by varying the particle size of the corn stover and process variables. The results showed that the Na₂CO₃ dosage and pretreatment temperature had a strong influence on lignin removal, whereas pulp refining instrument (PFI) refining and Na₂CO₃ dosage played positive roles in the final total sugar yield. Furthermore, it was found that pretreatment conditions had a more significant impact on the amelioration of pretreatment effectiveness compared with the properties of raw corn stover. In addition, a prediction of the effectiveness of the corn stover HSC pretreatment based on a PLS analysis was conducted for the first time, and the test results of the predictability based on additional pretreatment experiments proved that the developed PLS model achieved a good predictive performance (particularly for the final total sugar yield), indicating that the developed PLS model can be used to predict the effectiveness of HSC pretreatment. Therefore, multivariate analysis can be potentially used to monitor and control the pretreatment process in future large-scale biorefinery applications.     

纳米Ag@TiO2、Fe@TiO2和Zn@TiO2的抑菌活性比较研究

探索常见金属离子掺杂对抑菌片的抑菌性能的影响,为新型纳米TiO₂抑菌片的制备与改善提供技术基础。选择固定质量分数的Ag⁺、Zn²⁺和Fe³⁺掺杂TiO₂,通过抑菌圈、MIC与MBC方法综合评价其抑菌性能,对微观结构进行表征分析,探讨抑菌性能差异的原因。结果表明:抑菌性能大小顺序为Ag@TiO₂> Zn@TiO₂> Fe@TiO₂,Zn@TiO2 的抑菌活性较好但抑菌稳定性差Ag@TiO2对大肠杆菌和金黄色葡萄球菌的MIC、MBC均是10、20 mg/L,Zn@TiO₂对大肠杆菌和金黄色葡萄球菌的MIC、MBC均是30、50 mg/L。表征发现抑菌活性强弱主要归因于纳米TiO₂表面与金属离子共同产生的活性位点数量及稳定性,与孔结构或表面宫能团的关联不大。     

Prolonged storage of ‘Aledo’ table grapes in a slightly CO2 enriched atmosphere in combination with generators of SO2

The quality of late-harvested (early December) ‘Aledo’ table grapes, during storage at 2±1 °C followed by a period of 4 days at 20 °C in a slightly CO₂ enriched atmosphere in combination with generators of SO₂ in cardboard boxes, was evaluated. The changes in different biochemical parameters indicative of grape quality, such as weight, texture, colour, sugars, organic acids and fungal attacks, was determined. The best quality maintenance was achieved by combining the use of generators of SO₂ with a slightly CO₂ enriched atmosphere. The rates of weight, texture and colour losses were slowed, and both fungal attack and the rachis drying were delayed. During storage at 2 °C, the levels of glucose, fructose and sucrose remained unchanged under all the tested conditions, while levels of tartaric and citric acids showed a sharp increase. However, a slightly CO₂ enriched atmosphere, SO₂ microgenerators and their combination extended the storage period of late-harvested ‘Aledo’ table grapes without relatively affecting their organoleptic characteristics.     

铜铁氧体-纳米纤维素磁性复合材料的制备、表征及催化还原对硝基酚性能

采用一锅溶剂热法,分别以三氯化铁(FeCl_3)、二氯化铜(CuCl_2)、醋酸钠(NaAc)、聚乙二醇(PEG6000)、纳米纤维素晶体(CNC)作为铁源、铜源、碱源、表面活性剂和载体,在CNC表面原位合成了铜铁氧体-纳米纤维素(CuFe_2O_4-CNC)磁性复合材料,并根据其对于对硝基酚催化还原性能的好坏作为标准优化其制备工艺。另外,通过电感耦合等离子体原子发射光谱(ICP-AES)、透射电子显微镜(TEM)、傅里叶红外光谱仪(FT-IR)、X射线衍射仪(XRD)、比表面积分析仪(BET)、振动样品磁强计(VSM)、同步热分析仪(TG-DSC)和紫外-分光光度计(UV-Vis)对制备的复合材料进行结构及性能表征。结果表明,所制备的CuFe_2O_4-CNC磁性复合材料为单一尖晶石结构,磁性复合材料尺寸约10 nm,最大饱和磁化强度Ms为171.56 kA/m,且为典型的超顺磁性材料;在反应温度为200℃、反应时间为8 h的条件下制备的CuFe_2O_4-CNC磁性复合材料具有较高的比表面积和较好的催化还原对硝基酚性能。     

Al2O3负载ZnO催化臭氧氧化处理造纸废水的研究

将ZnO负载在Al₂O₃上,制备用于催化臭氧降解造纸废水中有机物的催化剂（Al₂O₃@ZnO）;采用场发射扫描电子显微镜（SEM）和X射线衍射仪（XRD）对Al₂O₃@ZnO催化剂进行物相分析;研究了造纸废水的初始pH值、反应时间和催化剂用量对Al₂O₃@ZnO催化臭氧氧化处理造纸废水效果的影响;并进行了自由基捕集剂叔丁醇实验,以探讨降解造纸废水中有机物的主要因素。结果表明,本研究成功制备了具有良好催化性能的Al₂O₃@ZnO催化剂;在造纸废水初始pH值为11、催化剂用量为2.0 g/L、反应时间为60 min的条件下,Al₂O₃@ZnO催化剂对造纸废水中COD_Cr的去除率可达到84.6％,与单独使用臭氧氧化方法相比,COD_Cr去除率明显提高,且COD_Cr的动力学降解反应遵循准一级动力学方程;叔丁醇的实验结果表明,在Al₂O₃@ZnO催化臭氧氧化处理造纸废水有机物的过程中,羟基自由基是降解废水有机物的主要因素。     

纳米TiO2胶体光催化-磁絮凝回收深度处理造纸废水

以纳米TiO₂(Nano-TiO₂)为光催剂、Fe₃O₄/SiO₂(FS)为磁性絮凝剂,提出了一种通过调节p H值来实现Nano-TiO₂磁絮凝回收及解絮凝释放的回收再利用系统;研究了FS/Nano-TiO₂质量比和相同质量比下Nano-TiO₂浓度对系统絮凝性能的影响,考察了造纸废水预处理方式对Nano-TiO₂光催化-磁絮凝回收循环光降解性能的影响。结果表明,FS/Nano-TiO₂质量比越大或相同质量比下Nano-TiO₂浓度越高,两者形成的FS/Nano-TiO₂絮凝体的沉降速率越快,越有利于Nano-TiO₂的磁絮凝回收;经浓度为0.6 g/L Nano-TiO₂絮凝处理后的造纸废水(SBR-T)在光催化降解180 min后,其COD_Cr、固体悬浮物、...     

KH-550改性纳米Al2O3增强芳纶纸性能的研究

采用不同用量的硅烷偶联剂(KH-550)对纳米Al_2O_3表面进行改性研究,采用红外光谱和粒度仪对改性前后纳米Al_2O_3进行表征;并考察了改性纳米Al_2O_3的用量对芳纶纸抗张强度、介电强度和紧度等性能的影响。结果表明,KH-550能够成功地对纳米Al_2O_3进行改性,并且有助于芳纶纸性能的增强。随着KH-550用量的增加,改性后的纳米Al_2O_3粒径有所减小;纳米Al_2O_3与KH-550最佳配比为5 g∶15 m L,改性纳米Al_2O_3用量为6%时,芳纶纸的抗张指数和介电强度分别提高了58.3%和37.0%,但纸张的紧度变化不明显。     

不同季节工况下变转速NH3/CO2复叠制冷系统性能研究

目的：研究在不同季节工况、蒸发温度为25 ℃条件下,高温压缩机转速对NH₃/CO₂复叠制冷系统性能的影响。方法：建立NH₃/CO₂复叠制冷系统模型并验证其可靠性,计算分析高温压缩机转速与系统高温蒸发温度、高温排气温度、中间温度、高温压缩机功率、制冷量、性能系数的变化关系。结果：仿真模型对制冷量的预测与理论值的相对误差小于14.1%。高温压缩机转速从2 300 r/min增至3 300 r/min,春季、夏季、秋季、冬季工况下的制冷量分别提升了31.7%,41.7%,33.9%,25.2%,且在低转速范围内冬季制冷量最高;高温压缩机功率呈两段式上升趋势,提升了40%～45%。结论：存在使得性能系数最大的最佳高温压缩机转速。基于系统对不同季节工况的适应性问题,提出了变转速NH₃/CO₂复叠制冷系统方案,与定转速系统相比每年可减少19.9%耗电量。     

改性TiO2的制备及其在壁纸中的应用研究

以纳米TiO_2 (P25)为改性对象,通过简单的一步水热法制备了具有可见光催化活性的N掺杂改性P25光催化剂 (N-P25),借助X射线衍射仪、紫外-可见光谱仪和扫描电子显微镜对N-P25的结构进行表征;再将其涂布于壁纸上,通过对壁纸物理性能和光催化降解甲醛性能的综合对比选择最佳涂布工艺。结果表明,N-P25仍为混晶结构,但对可见光的响应得到提升。在最佳涂布工艺条件下,N-P25涂布量1. 5g/m~2的壁纸在日光灯照射6 h后,对甲醛的降解率可达87%;且对不同初始浓度甲醛的光催化降解符合LH一级反应动力学规律。