氨吸收制冷装置运行总结

简述了氨吸收制冷工艺原理,分析了系统运行中出现磨损、泄漏、腐蚀和结垢问题的原因,认为设计问题是磨损和泄漏的原因,铵根离子、溶解氧、钙离子、粘泥、氯离子和硫酸根离子是造成腐蚀和结垢的原因。通过更改叶轮尺寸、密封形式、循环水流程,装置改造后运行稳定,具有节能、环保、易操作、节省投资的特点。     

乙二醇生产技术的发展及比较分析

石油路线乙二醇生产技术主要有非催化水合法、催化水合法、乙二醇和碳酸二甲酯联产法等,非石油路线乙二醇生产技术主要有氧化偶联法、甲醛甲醇合成法、草酸二酯法等;综述了国内外乙二醇生产技术的发展应用情况及研究进展,对不同的乙二醇生产技术进行了比较分析,并提出煤制乙二醇技术的发展方向。     

固体酸催化合成2-乙酰噻吩

制备了磷酸/活性白土、FeCl3/活性白土、Fe(III)树脂、SO42-/Fe2O3等固体酸催化剂,并考察了其对噻吩与乙酸酐反应合成2-乙酰噻吩的催化性能。结果表明,磷酸/活性白土的催化效果较好。在适宜的反应条件下,以磷酸/活性白土为催化剂,合成2-乙酰噻吩的收率达到90%,选择性高于99%。催化剂重复使用4次后,活性有一定的下降。     

丙烯酸酯低聚物的制备及其改性PUA乳液

以丙烯酸丁酯(BA)、乙酸乙烯酯(VAc)、丙烯酸羟乙酯(HEA)、丙烯酸(AA)等为主要原料合成了丙烯酸酯低聚物,以该低聚物为改性剂,制备了丙烯酸酯改性水性聚氨酯乳液(PUA)。考察了低聚物中单体组成、引发剂种类及用量、合成PUA时低聚物加入方式对PUA性能的影响。通过傅里叶变换红外光谱、偏光显微镜照片和热重曲线研究了乳液微观结构和耐热性能,通过气相色谱测定了单体残留量。结果表明:当低聚物中单体组成为BA,VAc,HEA,AA,所用引发剂为偶氮二异丁腈(用量为单体总质量的1.17%),将低聚物与异氰酸酯基单体同时加入反应时,可得到综合性能好、单体残留量极低的水性PUA,其初黏性可达13号球,持黏性为45 min,且乳液稳定。     

KOH／SBA-15负载型固体碱催化剂的合成、表征及催化性能

采用后合成法制备出固体碱催化剂KOH／SBA-15,利用X射线衍射法（XRD）、N2吸附-脱附（BET）、透射电镜（TEM）、化学吸附剂表面碱性测定（COz—TPD）等对其进行表征。考察了其在大豆油酯交换反应制备生物柴油中的催化性能。结果表明,在相同反应条件下,与CaO／SBA-15和MgO／SBA-15相比,KOH／SBA-15在催化活性和孔扩散上都具有较大的优越性,催化制备生物柴油产率最高（83．56％）。     

浅谈汕头市××污水厂的节能降耗的技术研究

随着城镇污水处理规模的增加,污水厂的能耗也越来越引起重视。文章根据汕头市××污水厂实际情况分析,结合国内外污水厂运行中的经验,从电量、维修费用,人工分配、药剂投加量以及优化管理等方面研究节能降耗技术。     

煤浆浓度提高对气化装置的影响及经济性评价

介绍了煤浆浓度提高对多喷嘴水煤浆加压气化装置的影响。通过对提浓前、后煤浆浓度、黏度、添加剂消耗、有效气成分、炉温等各工艺参数的变化进行对比,进而对有效气产量、甲醇产量、比氧耗等影响作进一步分析。在此基础上,对煤浆提浓后对经济效益的影响进行了评价,为进一步优化工艺控制、提高经济效益提供依据。     

Thermo-mechanical properties of MWCNT-g-poly (l-lactide)/poly (l-lactide) nanocomposites

The thermo-mechanical properties of poly (l-lactide) (PLLA) biodegradable polymer reinforced with PLLA grafted from multiwalled carbon nanotubes (MWCNT-g-PLLA)s are characterized. The crystallinity of PLLA polymer matrix affected by MWCNT-g-PLLAs is illuminated. For this purpose, the PLLA chains are covalently grafted from the sidewall of aminated MWCNTs. Then, the MWCNT-g-PLLAs/PLLA composite films are prepared by solution casting using chloroform as solvent. It is found that the MWCNT-g-PLLAs well dispersed in PLLA matrix. The mechanical properties of PLLA enhanced gradually with the increasing concentrations of MWCNT-g-PLLAs up to 2 wt%. The MWCNT-g-PLLAs increase the glass transition temperature (T _g) and melting point of PLLA as revealed by the curves from differential scanning calorimeter (DSC). In addition, the dynamic mechanical analysis (DMA) results show that the T _g and Young modulus of PLLA increase with the increment in the concentrations of MWCNT-g-PLLAs. Due to the homogenous dispersion of MWCNT-g-PLLAs and the van der Walls force between grafted PLLA chains on the sidewall of MWCNTs and the PLLA matrix chains, the chain stiffness in amorphous phase of PLLA increases. In addition, the MWCNT-g-PLLAs as heterogeneous nucleation agents increase the crystallinity of PLLA.     

Studies on Interaction of Polysaccharide-Templated Silver Nanoparticles with Bovine Serum Albumin

In the present work, the interaction between bovine serum albumin (BSA) and as-synthesized silver nanoparticles (Oc-AgNPs) by using 4-acetamido-TEMPO-oxidized curdlan (Oc), as a reducing and stabilizing agent, was studied through fluorescence quenching method, ultraviolet visible spectrum (UV–Vis), and circular dichroism measurement. The results presented clearly indicate that the intrinsic fluorescence of BSA molecule was effectively quenched after the interaction with Oc-AgNPs by a static mechanism, which is further confirmed by UV–Vis analysis. The apparent binding constant (K), number of binding sites (n), and dissociation equilibrium constant (K_D) were calculated to be 7.5 × 10⁵ M^?1, 1.03, and 3.0 ± 0.6 μM, respectively. Furthermore, a conformational change of BSA was also observed when the Oc-AgNPs–BSA interactant formed.     

连续纤维增强热塑性复合材料制备与熔融浸渍机理研究

介绍了4种连续纤维增强热塑性复合材料制备技术及这些方法的优缺点,针对具有工业化前景的熔融浸渍法,根据流体力学理论和Darcy定律,建立了基于物性参数、工艺参数和结构参数的连续纤维束熔融浸渍模型,并对模型进行了求解;结合理论研究和实验研究,分析了物性参数、工艺参数和结构参数对纤维浸渍效果的影响。分析结果表明,聚合物黏度和模具结构参数是影响纤维浸渍效果的关键参数。