戊二醛铬复鞣对猪正面服装坯革性能及微观结构的影响

本文进行了戊二醛铬结合复鞣的一系列对比试验和复鞣坯革的感观鉴定,并用扫描电镜观察了复鞣坯革的纤维结构,为合理选择戊二醛用量和改善猪皮服装革质量提供了科学依据。     

数控机床主轴电机伺服驱动系统研究

针对CAK3665数控机床主轴电机,在分析数控机床主轴电机的工作原理、数学模型及控制策略的基础上,设计一套伺服控制系统。对控制系统进行仿真研究,结果表明,控制系统具有对故障的快速反应能力,并能完成控制要求,所设计系统具有可行性。     

异养硝化菌株W1的分离和表征(英文)

In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gram-negative, rod-shaped, and identified preliminarily as Alcaligenes sp. according to its morphological and physiological properties and its 16S rRNA gene sequence analysis. In the high concentration ammonium medium (400 mg·L 1 4 NH -N), the effects of C source, N source, C/N ratio and initial pH of medium on ammonium removal were investigated in order to determine the optimal condition for strain W1. The maximum ammonium removal was around 95% in 4 days in an improved medium. The production of N 2 gas was examined in a closed system that was full of pure oxygen at the beginning. N 2 gas was detected in the system after 4 days of cultivation, which further testified that strain W1 has heterotrophic nitrification and aerobic denitrification abilities simultaneously.     

缩放管内插双扭带复合强化传热的数值模拟(英文)

The paper presents a 3D numerical simulation of turbulent heat transfer and flow characteristics in converging-diverging tubes(CDs) and converging-diverging tubes equipped with twin counter-swirling twisted tapes(CDTs).The effects of Reynolds number(Re 10000-20000),pitch length(P 11.25,22.5 mm),rib height(e 0.5,0.8,1.1 mm),pitch ratio(δ1:8,5:4,8︰1),gap distance between twin twisted tapes(b 0.5,4.5,8.5 mm) and tape number(n 2,3,4,5,6) on Nusselt number(Nu),friction factor(f) and thermal enhancement factor(η) are investigated under uniform heat flux conditions,using water as working fluid.In order to illustrate the heat transfer and fluid flow mechanisms,flow structures in CDs and CDTs are presented.The obtained results reveal that all geometric parameters have important effects on the thermal performance of CD and CDT,and both CD and CDT show better thermal performance than plain tube at the constant pumping power.It is also found that the increases in the Nusselt number and friction factor for CDT are,respectively,up to 6.3%-35.7% and 1.75-5.3 times of the corresponding bare CD.All CDTs have good thermal performance with η greater than 1 which indicates that the compound heat transfer technique of CDT is commendable for the maximum enhanced heat transfer rate.     

Physicochemical characteristics,antioxidant capacity and thermodynamic properties of purple-fleshed potatos dried by radio frequency energy

Abstract

The impacts of using radio frequency (RF) energy to dry purple-fleshed potatoes were investigated and compared to infrared radiation (IR) and microwave (MW) drying techniques. The gelatinization rate, color, flavor, morphological, and structural characteristics, thermodynamic properties, as well as antioxidant capacity were examined. The results indicated that the drying time of RF (70?min) and MW (21?min) were shorter than IR (105?min). The gelatinization ratio of MW, RF, and IR were 94.4?±?2.0, 88.3?±?1.4, and 64.5?±?1.1%, respectively. The degree of crystallization of purple-fleshed potato powder decreased with all three drying methods. RF-dried potatoes were able to retain higher polyphenols (loss rate: 4.3%), total anthocyanin (3.7%), and total flavonoid content (35.1%), whereas IR showed the lowest retention. The content of polyphenols also decreased significantly. Furthermore, after RF heating, the scavenging of free radicals was higher compared to MW and IR.     

Solution‐reprocessable microporous polymeric adsorbents for carbon dioxide capture

Solution‐processable microporous polymers are promising materials for CO₂ capture because of their low synthetic cost and high processability. In this work, we for the first time systematically evaluate the feasibility of two microporous polymers, namely PIM‐1 and its hydrolyzed form hPIM‐1, as adsorbent materials for postcombustion CO₂ capture. By conducting ternary CO₂/N₂/H₂O breakthrough experiments, PIM‐1 demonstrates several promising features: moderate CO₂ working capacity, low water vapor uptake capacity, good moisture resistance, and easy regeneration process. In addition, we have pioneeringly studied the multiple‐cycle CO₂ adsorption–desorption induced relaxation effect on soft PIM‐1 polymers. Through a simple dissolution–precipitation approach, PIM‐1 can restore its BET surface area, CO₂ uptake capacity, and pore‐size distribution. The solution reprocessability of PIM‐1 demonstrated in this study distinguishes it from other rigid adsorbents and thus offers a new insight for the future design of economically‐viable and facilely regenerable adsorbents. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3376–3389, 2018     

蚕沙基多孔炭表面氧化改性对农药噻虫嗪吸附及缓控释影响

选用桑蚕废弃物蚕沙为炭源,通过炭化活化的方式获得了一种高比表面的中微双孔道生物炭材料SCSE,并采用不同氧化剂对其表面氧化处理以调控材料孔径和表面积对农药噻虫嗪分子的吸附作用力,以实现SCSE材料对农药噻虫嗪的缓控释,并系统研究了氧化改性后材料的比表面积、孔径和表面基团性质的变化对材料吸附噻虫嗪的热力学和动力学平衡以及噻虫嗪的释放动力学等性能的影响。结果表明：SCSE孔隙结构发达,其BET比表面和孔容分别为1290.95 m²/g和0.690 cm³/g;在室温下,该材料对噻虫嗪分子的吸附容量达到560 mg/g。噻虫嗪在四种SCSE上的释放动力学可分为快速持续释放过程和慢速释放过程两个过程,其中快速持续释放过程的释放动力学常数约是慢速释放过程的29～34倍;其中硝酸改性后的SCSE-HN对噻虫嗪的释放比例最大,释放速度最快。本实验所获得的四种SCSE材料对噻虫嗪的释放均表现出长效释放效力。按照一般农作物的需药量,该吸附剂只要按照0.5 g/（d·m²）的投入量便能很好地对农作物进行长效的虫害防治（>40 d）。     

ABS阻燃与抑烟性的研究

对ABS树脂的阻燃、抑烟性等性能进行了研究和探讨。实验结果表明,采用共混、添加复合阻燃剂、抑烟剂的方法可以有效地获得阻燃、抑烟性及其他性能皆优的ABS树脂体系。     

Preparation of Iron Oxide Particle-Decorated Lignin-Based Carbon Nanofibers as Electrode Material for Pseudocapacitor

Iron oxide particle-decorated lignin-based carbon nanofibers (IO-LCNFs) were fabricated from organic mixtures containing acetic acid lignin (AAL) together with ferric acetylacetonate (Fe(acac)₃) via electrospinning followed by stabilization in air and carbonization in nitrogen. After the addition of Fe(acac)₃, IO-LCNFs showed different morphologies: Non-fused IO-LCNFs were obtained with diameters of 400–500 nm; iron oxide nanoparticles with diameters of 30–60 nm were exposed outside and well-distributed when sufficient amounts of Fe(acac)₃ were added. These carbon nanofibers were then used as electrode material for pseudocapacitor. It was found that the iron oxide particles enhanced the resulting electrochemical properties via reversible redox reactions. IO-LCNFs made from the composite nanofibers with mass ratio of AAL/Fe(acac)₃ of 80/20 [i.e., IO-LCNFs (80/20)] exhibited the highest specific capacitance, 72.1 F g^?1, at current density of 500 mA g^?1.     

不同氨氮含量对厌氧颗粒污泥理化特性的影响

通过序批式试验,研究了氨氮含量变化对厌氧颗粒污泥去除有机物及氨氮效能的影响,并通过紫外可见光谱（UV-Vis）、三维荧光光谱（EEM）、傅里叶红外光谱（FTIR）对厌氧颗粒污泥的溶解性微生物产物（SMP）、疏松胞外聚合物（LB-EPS）及紧密胞外聚合物（TB-EPS）进行了分析。结果表明,当进水氨氮浓度增加到1000 mg·L^-1时,厌氧颗粒污泥对COD去除率由对照组的94.19%下降至93.33%,其对COD去除影响不明显;但NH₄⁺-N去除率由40.6%降至7.9%,去除效率明显降低。UV-Vis谱图分析表明,LB-EPS与TB-EPS在205～210 nm处出现了吸收峰,表明其中均含有苯环与双键结构,且随着氨氮浓度的增大,吸收带出现了红移。EEM谱图分析表明,随着氨氮浓度的增大,SMP中芳香蛋白吸收峰强度降低,而在E_X/E_M为370～390/420～450 nm处的类胡敏酸吸附峰增强;对于LB-EPS而言,辅酶F₄₂₀吸收峰消失,表明高氨氮浓度对产甲烷菌的活性产生了抑制作用;同时TB-EPS类蛋白荧光峰发生了红移。而由LB-EPS的FTIR谱图可知,氨氮浓度为1000 mg·L^-1时,LB-EPS中存在较多的羧酸。通过利用UV-Vis、FTIR、EEM谱图可对厌氧颗粒污泥的SMP、LB-EPS、TB-EPS进行较为全面的分析,从而为指导厌氧反应器的运行提供科学借鉴。