湿法磷酸过滤设备和管道结垢原因分析及控制研究

分析湿法磷酸过滤设备与管道结垢的主要原因是氟硅酸钾、钠盐因磷酸液相温度下降而沉积下来。提出采用添加剂,抑制或提前析出氟硅酸钾、钠盐,同时进行了5种添加剂的实验室研究:均有较好的阻垢效果,但最终选择添加剂E(氟硅酸),阻垢率可达70%以上,添加量以0.5g/100g磷矿为宜。     

Reactant induced restructuring and corrosion of germanium-palladium catalysts during hydrogenation reactions

An anomalous rate enhancement with increasing conversion has been observed during the liquid phase hydrogenation of nitrobenzene and crotonaldehyde over Ge/Pd/C catalysts at ambient temperature and atmospheric pressure. Inductive coupled plasma atomic emission spectroscopy and electrochemical measurement of the oxidation state of catalysts during reaction revealed that the bimetallic particles were partially oxidized by the reactants, which resulted in Ge-dissolution and increased exposure of Pd on the surface. It is proposed that the surface and bulk composition of Ge/Pd catalysts are a function of their oxidation state. This behaviour is due to the unusually high mobility of Ge in the Pd lattice and to the good solubility of GeO₂ in polar solvents. The influence of hydrogen transport on the corrosion process and the stability of other X/Pd type bimetallic catalysts during liquid phase hydrogenation are also discussed.     

Significance of Wood Terpenoids in the Resistance of Scots Pine Provenances Against the Old House Borer, Hylotrupes bajulus, and Brown-Rot Fungus, Coniophora puteana

We tested how terpenoid (i.e., monoterpenes and resin acids) composition and concentration in wood affects resistance against wood-borers and decaying fungi. Scots pine (Pinus sylvestris) wood from nine provenances having variable terpenoid profiles was studied against the old house borer, Hylotrupes bajulus, and the decay fungus, Coniophora puteana. Provenances represented a 1200-km N-S transect from Estonia to northern Finland, but they were all cultivated for 7 years in the same nursery field, in central Finland. Mean relative growth rate (MRGR) of small H. hajulus larvae positively correlated with the total monoterpene concentration of wood, and feeding was associated with high proportion of levopimaric+palustric acid in wood. Provenance did not affect the MRGR of small or big larvae, but big larvae consumed more wood and produced more frass on the northern Ylitornio trees than on the southern Rakvere and Ruokolahti trees. Low beta-pinene and total monoterpene concentration and low beta: alpha-pinene ratio in wood were all associated with a high number of eggs. The most northern Muonio provenance was the most favored as an oviposition site, differing significantly from Saaremaa, Tenhola, and Suomussalmi. Wood from Saaremaa, Tenhola, Ruokolahti, and Suomussalmi provenance was most resistant against decay fungus, differing significantly from that of Kinnula provenance. However, decay resistance was not clearly associated with the concentrations of wood terpenoids. These results suggest that monoterpene composition of wood affects resistance against wood-boring Cerambycid beetles, but resistance against wood-decaying fungi is not as clearly associated with wood terpenoids.     

Determination of the solubility parameter of poly(ethylene oxide) at 25°C by gas-liquid chromatography

The solubility parameter of poly(ethylene oxide) at 25°C has been determined using the method developed by DiPaola-Baranyi and Guillet, by the extrapolation of the values of the interaction parameter χ, at high temperatures, ranging from 70°–90°, 90°–110° and 110°–130°C down to 25°C. The values of the solubility parameter obtained, depending on the temperature ranges employed, are 9.8, 9.9 and 10.1, respectively.     

有机锡化合物引发D,L-丙交酯的开环聚合

D,L-丙交酯在有机锡化合物四苯基锡(Ph4Sn)、三正丁基醋酸锡(Bu3SnOAc)、辛酸亚锡(SnOct2)等催化剂引发下开环聚合,得到高分子量的聚D,L-乳酸,讨论了聚合单体D,L-丙交酯纯度、聚合温度、聚合时间、聚合体系真空度以及引发剂有机锡催化剂与聚合单体D,L-丙交酯的比例对聚D,L-乳酸合成的影响,通过红外光谱和核磁共振光谱对聚D,L-乳酸的结构进行了表征。实验结果表明,D,L-丙交酯开环聚合反应的较佳工艺路线是:D,L-丙交酯重结晶5次,聚合温度140℃,聚合时间24 h,聚合体系真空度13.3~133.3 Pa,引发剂有机锡催化剂与单体D,L-丙交酯比例0.2‰~0.5‰,此时聚D,L-乳酸的粘均分子量最高,分别达到32.46×104,33.43×104和41.36×104。     

补强剂和共混工艺对PA/PVC/NBR三元共混弹性体性能的影响

在选择三元共聚尼龙（PA）、聚氯乙烯（PVC）、丁腈橡胶（NBR）为主体材料，制备PA／PVC／NBR（10／30／60）三元共混弹性体的工作基础上，进一步探讨了填料品种和用量，共混温度，加料顺序等因素PA／PVC／NBR三元共混弹性体的影响。试验结果表明：在PA／PVC／NBR（10／30／60）共混体系中，补强型填料的补强效果优于非补强型的填料，6种填料补强效果依次是：快压出炭黑＞半补强炭黑＞白炭黑＞活性重质，CaCO3＞陶土＞滑石粉，快压出炭黑的适宜用量是20－50份。在制备PA／PVC／NBR三元共混物时，适宜的共混温度是122－140℃，并且采用二段法混工艺制得的共混物性能优于采用一段法共混工艺。     

改性BMI微孔轴承保持器材料研究

采用改性双马来酰亚胺树脂制备微孔轴承保持器材料，探讨了制备工艺和最佳工艺参数，得到性能优良的改性双马来酰亚胺微孔轴在保持器材料。     

Electrical and optical study of Cu(In, Ga)Se2 co-evaporated thin films

Co-evaporation technique from three sources was used to prepare Cu(In, Ga)Se₂ polycrystalline thin films for photovoltaic conversion. Their conductivity was studied in the range 20–300 K. The grain boundary scattering mechanism is mainly responsible for the diffusion process in the latter materials. In the low temperature region, we interpret the data in terms of Mott law and the analysis is very consistent with the variable range hopping. However, thermoionic emission is predominant at high temperatures. When the conductivity deviates from the classical grain boundary conduction models, inhomogeneity is then considered and parameters such as the standard deviation and the mean potential barrier height are derived. Transmittance measurements yielded band gap values of 1.07 and 1.64 eV for CuInSe₂ and CuGaSe₂, respectively.     

Nafcillin release from poly(acrylic acid–co–methyl methacrylate) hydrogels

Summary Copolymeric poly(acrylic acid-co-methyl methacrylate) hydrogels for three different compositions: (90/10), (80/20) and (60/40), have been studied. Drug release has been examined as a function of the hydrogel composition by HPLC (High Pressure Liquid Cromatography). The release experiments were carried out at 37 °C. The fraction of available drug release was linear in t^1/2. The values of the diffusional coefficient (0.50<n<1.0) indicate that the nafcillin release mechanism from the hydrogels in study is non-Fickian. The diffusion coefficients for this drug release have been calculated. The molecular diffusion of nafcillin through hydrogels is controlled by the swelling.     

一种耐超高温、耐酸聚合物的制备及性能测试

摘要：为解决常规聚合物无法满足超高温深井酸化压裂的技术要求，本文分别以丙烯酰胺（AM） 甲基丙烯酰氧乙基三甲基氯化铵（DMC）、AM DMC SMA（十八烷基甲基丙烯酸酯）为原料，通过自由基聚合制备出两种耐酸聚合物SY-1和SY-2，并对其结构进行表征及性能测试。结果表明：SY-2红外谱图中720 cm-1为—(CH2)n—的弯曲振动吸收峰，单体成功接枝到聚丙烯酰胺分子链上；热重分析表明，SY-1升温至600℃失重比为98%，SY-2失重比86%，热稳定性得到改善；质量分数为20%盐酸中，SY-2质量分数0.8%：180℃，170s-1流变性能测试，SY-2剪切终点黏度56mPa?s，90℃、120℃、150℃剪切1h，黏度为83.6mPa?s、43.5mPa?s、27.8mPa?s，剪切稳定性分别为85.66%、74.45%、52.01%； 180℃、3MPa条件下，静态酸岩反应速率为8.94?10-5(g/cm2?s)，较常规SY-1反应速率1.69?10-4(g/cm2?s)减小一个量级。且与缓蚀剂、铁离子稳定剂配伍性良好，克服高温酸化压裂技术的应用瓶颈。