双脉冲电沉积制备Ni-聚苯胺复合电极及其析氢性能的研究

采用控制双脉冲电位沉积技术制备N i-聚苯胺复合电极。扫描电镜下观察电极表面呈菜花状结构,比表面积约为普通镀N i电极的4~50倍。N i-PAN复合电极的X射线衍射谱图中分别出现了N i和PAN的特征峰。通过测试复合电极在模拟氯碱工业电解液中的阴极极化曲线,研究了N i-PAN电极的析氢性能,结果显示当电流密度为0.10 A/cm2时,析氢过电位较镀N i电极降低约350 mV。复合电极性能稳定,可作为氯碱工业用活性阴极,能显著降低能耗。     

Static and dynamic mechanical properties of flame‐retardant copolyester/nano‐ZnCO3 Composites

Novel phosphorus‐containing copolyester nanocomposites were synthesized by in situ polymerization with 2‐carboxyethyl(phenylphosphinic) acid (CEPPA) and nano‐ZnCO₃. The flame retardancy and static and dynamic mechanical properties of poly(ethylene terephthalate) (PET)/nano‐ZnCO₃ composites and phosphorus‐containing copolyester/nano‐ZnCO₃ composites were evaluated with limiting oxygen index measurements, vertical burning testing (UL‐94), a universal tensile machine, and a dynamic mechanical analysis thermal analyzer. The phosphorus‐containing copolyester nanocomposites had higher limiting oxygen indices (ca. 32%) and a V0 rating according to the UL‐94 test; this indicated that nano‐ZnCO₃ and CEPPA greatly improved the flame retardancy of PET. The static mechanical test results showed that the breaking strength, modulus, and yield stress of the composites tended to increase with increasing nano‐ZnCO₃ content; when 3 wt % nano‐ZnCO₃ was added to PET and the phosphorus‐containing copolyester, the breaking strength of the composites was higher than that of pure PET. Dynamic mechanical analysis indicated that the dynamic storage modulus and loss modulus of the PET composites increased markedly in comparison with those of pure PET. However, the glass‐transition temperatures associated with the peaks of the storage modulus, mechanical loss factor, and loss modulus significantly decreased with the addition of ZnCO₃ and CEPPA. The morphologies of the composites were also investigated with scanning electron microscopy, which revealed that nano‐ZnCO₃ was dispersed homogeneously in the PET and copolyester matrix without the formation of large aggregates. In addition, the interfacial adhesion of nano‐ZnCO₃ and the matrix was perfect, and this might have significantly affected the mechanical properties of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and characterization of bipolar membranes modified using photocatalyst nano‐TiO2 and nano‐ZnO

The nano‐ZnO and nano‐TiO₂ were added into chitosan (CS) anion layer to prepare polyvinyl alcohol (PVA) ‐ sodium alginate (SA)/ TiO₂‐ZnO‐CS (here, PVA:polyvinyl alcohol; SA:sodium alginate) bipolar membrane (BPM), which was characterized using scanning electron microscopy, atomic force microscopy (AFM), thermogravimetric analysis (TG), electric universal testing machine, contact angle measurer, and so on. Experimental results showed that nano‐TiO₂‐ZnO exhibited better photocatalytic property for water splitting at the interlayer of BPM than nano‐TiO₂ or nano‐ZnO. The membrane impedance and voltage drop (IR drop) of the BPM were obviously decreased under the irradiation of high‐pressure mercury lamps. At a current density of 60 mA/cm², the cell voltage of PVA‐SA/TiO₂‐ZnO‐CS BPM‐equipped cell decreased by 1.0 V. And the cell voltages of PVA‐SA/TiO₂‐CS BPM‐equipped cell and PVA‐SA/ZnO‐CS BPM‐equipped cell were only reduced by 0.7 and 0.6 V, respectively. Furthermore, the hydrophilicity, thermal stability, and mechanical properties of the modified BPM were increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

聚乙烯生产技术及其催化剂的研究进展

阐述了当今世界聚乙烯（PE）催化剂，即铬系、钛系、茂金属和非茂金属单活性中心催化剂技术的发展，推动了PE生产过程和产品的技术进步，PE生产工艺和催化剂技术的进步使PE的性能进一步改进，更易于加工成型。新的生产技术主要包括：双峰PE生产技术、反应器新配置技术、冷凝态和超冷凝态技术等。通过对国内PE生产技术进步、催化剂的研发和装置国产化现状分析，指出与国外相比还存在较大差距，对今后我国PE工业的发展提出了建议。     

环锭纺纱全流程机器人自动化生产关键技术

针对环锭纺纱全流程自动化生产工艺与工业机器人的深度集成问题,提出了环锭纺纱生产线布局仿真优化方法,构建了生产线协同调度模型,详细阐述了配棉排包、精梳机自动喂棉卷和筒纱外观检测等关键工艺机器人应用场景,提出了以信息互联互通技术为核心的信息集成管控策略,建立了工艺、生产计划、质量、设备及物流一体化智能管控系统,形成了环锭纺纱生产线全流程智能管理模式,实现了基于纱管的纺纱质量追溯。结果表明：所使用的任务调度方法有效提升了相关工序的生产效率,设计的纺纱工艺机器人打通了配棉排包等工艺流程断点,相关技术应用后企业综合生产效率提升22.65%,运营成本降低40%,形成纺纱行业智能化转型典型案例并已向行业推广。     

Effects of four multi-compound freezing medium on the quality of red drum (Sciaenops ocellatus) during frozen storage

Taking air freezing (AF) as the reference, the effects of four types of multi-compound freezing medium for cryogenic liquid quick-freezing (immersion freezing, IF) on the freezing rate, quality and myofibrillar protein (MP) denaturation of red drum (Sciaenops ocellatus) fillets during frozen storage (−18°C) from days 0 to 90 were studied. Samples were gathered on days 0, 15, 30, 45, 60 and 90 for analysis. The results showed that IF groups (IF-1: 20% ethanol, 30% propylene glycol, 10% sodium chloride aqueous solution; IF-2: 20% ethanol, 20% propylene glycol, 10% glycerol, 10% sodium chloride aqueous solution; IF-3: 20% ethanol, 20% propylene glycol, 10% polyethylene glycol, 10% sodium chloride aqueous solution; IF-4: 20% ethanol, 20% propylene glycol, 5% glycerol, 5% polyethylene glycol, 10% sodium chloride aqueous solution) significantly shortened the time to cross the formation zone of maximum ice crystals while the freezing rate was 6.13 times higher than the AF group after adding 30% propylene glycol as the freezing medium. Furthermore, compared with the AF group, the IF groups significantly reduced losses in the water-holding capacity, the myofibrillar fragmentation index, microstructure damage, texture characteristics, drip loss and water migration (P < 0.05). In addition, the MP of IF groups had higher maximum transition temperatures (T_max1 and T_max2), total sulfhydryl content, Ca²⁺-ATPase activity and relative α-helix content compared with the AF group. In conclusion, IF could significantly increase the freezing rate of red drum fillets, and slow down quality deterioration and denaturation of MP during frozen storage for 90 days (−18°C). In particular, IF-2 (20% ethanol, 20% propylene glycol, 10% glycerol, 10% sodium chloride aqueous solution) was found to be more suitable for the immersion freezing of marine fish among the four multi-compound freezing medium.     

分子光谱成像对玉米粉中微塑料的深度无损表征

目的 采用不同的光谱成像方法对玉米粉中的微塑料进行原位无损表征,并通过化学计量学优化其成像效果。方法 本研究尝试利用光热共振红外光谱成像和共聚焦拉曼光谱成像两种分子光谱技术,结合化学计量学方法对玉米粉中微塑料的存在进行深入表征。结果 采用光热共振红外成像 方法能够快速获取样品中污染物存在信息,但数据完整性和可视化方面受到一定限制。通过对拉曼光谱图像数据降解,应用独立成分分析可以得到玉米粉中微塑料清晰的分布轮廓。此外,光热红外成像能够在低浓度水平上得到污染物的分布图像,但检出率不高（10%）,具有快捷检测特点。拉曼光谱成像受到扫描速度的影响,在低浓度污染样品中检出较少,但在中浓度污染样品得到了30%的检出率,以及中得到了较好的可视化效果。结论 通过分子光谱成像技术串联数据挖掘方法可以实现对粉状食品中微塑料的可视化检测,为食品中微塑料的无损便捷检测提供方法参考。     

健身者营养补充剂的选择

我们应该知道营养补充剂并不是万能的．只有正确地使用才可以起到理想的作用又不会危害人的健康。经常运动的人比一般人消耗更多的体力．因此在合理的饮食之余．服用营养补充剂来补充营养．缓解体力的疲劳显得十分重耍。面对形形色色层出不穷的营养补充剂．如何进行选择？资深营养补充剂营养专家加里何汉为热爱运动的人们推荐了5种可信的营养补充剂。同时也揭穿了5种营养补充剂在宣传上的谎言。我们跟随他起来了解：[编者按]     

印染废水深度处理及回用技术的应用

文章简要介绍了膜分离技术,分析了陶瓷膜技术特点、优点及与各类膜分离技术比较,通过其在实践中的应用,显现其在印染废水深度处理及回用中应用的前景。     

海藻来源藻胆蛋白研究进展

藻胆蛋白是一种天然色素活性蛋白,广泛存在于各种海藻中,是海藻光合作用的重要组成部分,常以藻胆体的形式存在于类囊体膜上,有特定的光吸收峰和荧光发射峰,具有抗氧化、抗肿瘤、抗辐射、增强免疫力等多种生物活性。藻胆蛋白经济价值高,随着新技术的不断出现,其提取纯化工艺和应用开发研究有了新的进展。本文基于藻胆蛋白相关的最新研究,系统综述了藻胆蛋白的来源、结构组成、提取纯化工艺以及藻胆蛋白在食品、化妆品、药品等领域的应用,为藻胆蛋白进一步开发利用提供借鉴。