Efficient photodegradation of phenol assisted by persulfate under visible light irradiation via a nitrogen-doped titanium-carbon composite

To realize the utilization of visible light and improve the photocatalytic efficiency of organic pollutant degradation in wastewater, a nitrogen-doped titanium-carbon composite (N-TiO₂/AC) prepared by sol-gel methods was applied in the photodegradation of phenol assisted by persulfate under visible light irradiation (named N-TiO₂/AC/PS/VIS). The results show that a synergistic effect exists between visible-light photocatalysis and persulfate activation. Compared with TiO₂/PS/VIS, the phenol degradation rate was found to be observably improved by 65% in the N-TiO₂/AC/PS/VIS system. This significant increase in degradation rate was mainly attributed to the following two factors: 1) The N and C doping can change the crystal structure of TiO₂, which extends the TiO₂ absorption wavelength range to the visible light region. 2) As an electron acceptor, PS can not only prevent electrons and holes from recombining with each other but can also generate strong oxidizing radicals such as ∙SO₄^– and ∙OH to accelerate the reaction dynamics. The process of phenol degradation was found to be consistent with the Langmuir pseudo-first-order kinetic model with an apparent rate constant k of 1.73 min^–1. The N-TiO₂/AC/PS/VIS process was proven to be a facile method for pollutant degradation with high pH adaptability, excellent visible-light utilization and good application prospects.     

2＋2×0.32ST超高强度钢丝帘线在半钢子午线轮胎带束层中的应用

研究2+2×0.32ST钢丝帘线替代2+2×0.35HT钢丝帘线在半钢子午线轮胎带束层中的应用。结果表明:与2+2×0.35HT钢丝帘线相比,2+2×0.32ST钢丝帘线的强度更高、直径更小、耐疲劳性能更好;在轮胎带束层中用2+2×0.32ST钢丝帘线替代2+2×0.35HT钢丝帘线后,工艺性能良好,成品轮胎的充气外缘尺寸变化不大,强度性能、高速性能、耐久性能和耐水压性能均能满足设计和国家标准要求,滚动阻力降低,同时有效减小了轮胎中的钢丝帘线和胶料用量,降低了生产成本。     

环境空气质量标准指引家居场景空气质量标准制定

我国的空气质量标准采用了发达国家和地区在环境空气质量标准制修订方面等的丰富经验,世界卫生组织(WHO)从保护人群健康出发,根据现有科研资料提出的标准和判断,从人的健康角度考虑,也作为标准依据的参考,在2021年对空气污染物浓度限值进行了调整,做了最新的跟踪比较.综述空气污染物对健康的影响,介绍WHO环境空气质量准则,从标准的历史沿袭、标准分级、控制污染物种类、标准限值四个部分对各国空气质量标准进行比较,得到污染物控制的理论基础和数值依据,并借鉴GB/T 18883《室内空气质量标准》,对我国家居场景室内空气质量标准的制定提供参考.     

含多端口能量路由器的多能互补系统故障保护功能测试研究

针对某区域用电负荷存在严重的季节性过载现象,以及可再生能源存在功率波动大、稳定性较差的问题,研制了多能(含水电、光伏、储能)、多端口的能量路由器装置及其能量管理系统.综合考虑当地多场景运行,解决了季节性过载问题,实现了能量的合理配置与利用.首先,对比分析选定能量路由器各端口变换器的拓扑结构;然后,对多场景下的工作模式进行介绍;最后,对含能量路由器的多能互补系统进行故障保护功能测试.测试结果表明,该系统具有较好的故障保护功能,有效实现了不同场景下的工作模式切换,直流母线电压稳定以及上层功率指令跟踪等功能,解决了当地用电负荷季节性过载和可再生能源功率波动较大的问题.     

粗粒料三轴试验橡皮膜嵌入量数值模拟

在粗粒料三轴试验中,橡皮膜嵌入量可造成显著的体积变形量测误差。本文针对颗粒材料的接触特点,利用Nagata Patch方法重建颗粒表面,基于重建曲面进行接触状态的判断和接触几何信息的计算,开发了高效的颗粒接触算法。该法采用dual mortar有限元方法处理颗粒与橡皮膜间的接触模拟,针对橡皮膜变形较大的特点,采用更新坐标的大变形计算格式,并根据重建的颗粒表面对颗粒-橡皮膜的距离进行几何修正,实现了颗粒-橡皮膜接触的精细化模拟,可较好地模拟计算“柔性”橡皮膜嵌入颗粒孔隙的过程。进行了Kramer钢球试验以及粗颗粒料和标准粗砂三轴试验橡皮膜嵌入过程的模拟计算,计算结果符合一般规律,与相应的试验结果吻合较好,验证了本文方法对于粗粒料膜嵌入问题的适用性。     

Implications from γ-globulin adsorption onto cation exchangers fabricated by sequential alginate grafting and sulfonation

Our previous work proved that high adsorption capacity and uptake rate of lysozyme were achieved on alginate(Alg)-grafted re sin with an ionic capacity(IC) of 240 mmol·L~(-1)(Alg-FF-240).Moreover,the salt-tolerant feature of Alg-FF-230 was improved by using sequential alginate grafting and sulfonation strategy.Inspired by the enhanced adsorption performance of lysozyme,we have herein proposed to investigate the static and dynamic adsorption behaviors of γ-globulin on a series of Alg-grafted resins with different grafting densities and sulfonation degrees.The adsorption ca pacity of γ-globulin decreased with increa sing alginate-grafting density(IC) from 160 to 230 mmol·L~(-1) at 0 mmol·L~(-1) NaCl because of the steric hindrance caused by the alginate-grafting layer.Effects of ionic strength(IS) indicated that the adsorption capacities of the resins with the IC value of 230-370 mmol·L~(-1) were much higher than CM Sepharose FF at 50-100 mmol·L~(-1) NaCl,and the uptake rate of Alg-FF-230 was about twice as much as that of CM Sepharose FF.This work demonstrated the important effects of alginate-grafting layer and IS in γ-globulin adsorption behavior,which would be helpful in the design of Alggrafted resins and the selection of proper IS condition for protein purification.     

Characterization of wet microalgal cells pretreated with steam for lipid extraction

Steam pretreatment was employed to disrupt microalgal cells for lipids extraction.Effects of steam pre-treatment on microstructure of microalgal cells were investigated through scanning electron microscopy(SEM) and transmission electron microscopy (TEM).Effect of treatment on lipid extraction was also stud-ied.Microalgal cell walls were distorted after steam pretreatment due to the hydrolysis of organic macro-molecules contained in cell wall.Maximum curvature was increased from 1.88 × 10-6 m-1 to 1.43 × 10-7 m-1 after treatment with the steam at 130 ℃.The fractal dimension of microalgal cells increased from 1.25 to 1.30 after pretreatment for 15 min,and further increased to 1.47 when the pre-treatment time was increased to 60 min.Increased steam pretreatment temperature and time enhanced the hydrolysis of organic macromolecules,and finally destroyed microalgal cell walls at pretreatment temperature of 130 ℃ and pretreatment time of 60 min.Lipid extracted from wet microalgal was signif-icantly increased (2.1-fold) after pretreatment.     

覆膜滤料用聚四氟乙烯微孔膜的制备及其性能研究

针对市场上常用4种SSG范围的聚四氟乙烯(polytetrafluoroethylene,简称PTFE)树脂原料,采用双向拉伸法制备PTFE微孔膜,分析微孔膜性能的差异,并确定最适用于覆膜滤料用PTFE树脂原料.分析了不同分子量PTFE树脂原料的相对标准密度(SSG)、粒径、挤出压力和含水率等参数,采用不同分子量树脂原料来制备PTFE微孔膜,并表征PTFE微孔膜力学、厚度、结晶度、孔径、孔隙率和透气性能.研究表明:SSG的大小会影响PTFE微孔膜的力学性能(最大力、断裂伸长率)和孔结构(孔径、孔隙率),随SSG的增大呈现先上升后下降的趋势,在2.170～2.189范围内达到最优;结晶度与SSG的大小成正相关,而微孔膜透气性能主要与其孔结构有关,与孔径和孔隙率的变化趋势具有一致性.得出结论:PTFE树脂原料SSG分布在2.170～2.189范围时,制备的PTFE微孔膜最适用于覆膜滤料领域.     

HPLC法分析40%氟噻草胺·吡氟酰草胺·异丙隆悬浮剂含量

[目的]采用HPLC建立检测40%氟噻草胺·吡氟酰草胺·异丙隆悬浮剂含量的方法。[方法]采用高效液相色谱法,以0.1%磷酸水溶液-乙腈为流动相梯度洗脱,使用Extend C18柱和DAD检测器,对试样中的氟噻草胺、吡氟酰草胺和异丙隆进行测定,外标法定量。[结果]该分析方法氟噻草胺、吡氟酰草胺和异丙隆线性相关系数分别为0.9999、0.9999和0.9998,变异系数分别为0.73%、0.84%和0.57%,平均回收率分别为101.09%、100.91%和101.12%。[结论]该方法的操作简单,精密度、准确度和灵敏度均满足要求,可用于40%氟噻草胺·吡氟酰草胺·异丙隆悬浮剂含量检测。     

高固含量丙烯酸酯乳液压敏胶的制备及性能

以丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)、丙烯酸羟乙酯(HEA)为共聚单体,以烯丙氧基脂肪醇聚氧乙烯醚硫酸铵(SR-10)和烷基聚氧乙烯醚琥珀酸单酯磺酸二钠(A-102)作为环保型复合乳化剂,通过无种子半连续乳液聚合工艺制备了固含量高达62％的丙烯酸酯乳液压敏胶.考察了硬单体MMA用量对乳液压敏胶性能的影响.结果表明,当MMA用量为10％(以单体总质量计,下同)时,高固含量丙烯酸酯乳液压敏胶玻璃化转变温度(Tg)为–32.6℃,初始热分解温度为337℃,水接触角为108°,环形初粘力为(9.53±0.389)N/25 mm,180°剥离强度为(10.08±0.056)N/25 mm,持粘力超过72 h;与未添加MMA的高固含量乳液相比,添加10％MMA后乳液黏度从361 mPa·s降至155 mPa·s,平均粒径从375 nm降至350 nm,粒径分布指数(PDI)从0.144增至0.214.