微波作用下的乙酸乙酯合成反应动力学

为揭示微波辐射效应对非均相酯化反应动力学的影响,研究了微波加热催化合成乙酸乙酯的酯化反应动力学,并与常规动力学作了对比.在自制微波功率连续可调、红外测温已校正的反应装置中,重复测定了反应温度为60,65,70和75℃时的正、逆反应速率常数,得到了Arrhenius方程参数.微波加热下的反应活化能为51.719 kJ/mol,指前因子为582.9:常规水浴加热下的反应活化能为48.581 kJ/mol,指前因子为169.2.研究结果表明,在研究的反应温度范围内,微波改变了反应动力学,加快了反应速率,存在微波非热效应,但并不改变反应平衡常数.     

两步法合成环氧树脂的反应动力学

论述了两步法合成环氧树脂的反应动力学。结果表明,在季铵盐存在下,双酚A与环氧氯丙烷的开环反应为二级反应,而第二步的闭环反应为一级反应。计算了各步反应的活化能,探讨了闭环反应的机理。     

硅烷封端聚氨酯热熔胶反应动力学的研究

采用自制聚酯A与甲苯二异氰酸酯(TDI)进行反应,合成了聚氨酯(PU)预聚体,再与3-N(苯基)氨基丙基三甲氧基硅烷进行封端反应,合成了硅烷封端聚氨酯热熔胶(SPUR)。通过化学分析法分别研究了PU预聚体和SPUR的反应动力学。结果表明,聚酯A与TDI的预聚反应为二级反应,反应活化能Ea为33.82kJ/mol,75℃下反应速率常数k为0.00732g/(mol.min),反应末期由于粘度增大和支化反应,偏离了二级反应;PU预聚体与3-N(苯基)氨基丙基三甲氧基硅烷的反应也为二级反应,反应速率常数k为0.0827g/(mol.min),反应速率快,可在室温下快速反应。     

一氯丙酮制备新方法

本文采用了二氯丙醇脱氯化氢的全新工艺来制备一氯丙酮,考察了活性组分、载体、反应空速和反应温度对反应活性的影响,并对工艺条件进行了优化:采用NdCl3/活性炭为催化剂,反应温度控制在180℃,反应空速为0.8h-1,反应转化率为44.5%,选择性为97.4%,反应副产氯化氢,无废水,符合现今清洁生产的要求。     

高含量一氯丙酮制备新方法

文章采用了二氯丙醇脱氯化氢的全新工艺来制备一氯丙酮,考察了活性组分、载体、反应空速和反应温度对反应活性的影响,并对工艺条件进行了优化:采用ZnCl2/活性炭为催化剂,反应温度控制在180℃,反应空速为0.8 h-1,反应转化率为43.8%,选择性为97.3%,反应副产氯化氢,工艺符合现今清洁生产的要求。     

α-异佛尔酮异构化反应研究

以α-异佛尔酮为原料,4A分子筛为催化剂,通过异构化反应制备β-异佛尔酮,考察了温度和催化剂用量对反应的影响,并对反应进行了热力学研究.实验结果表明:该反应的最佳反应温度为210℃,催化剂用量为反应原料的10％,反应时间为6h.a-异佛尔酮异构化生成β-异佛尔酮反应的焓变为55.4 kJ/mol.     

碱性条件下NaY分子筛水热交换反应的研究

对碱性条件下的分子筛离子水热交换反应进行了研究。结果表明,离子交换反应为吸热反应,交换反应等温线为d型,交换反应为一级反应,表观活化能Ea为10．05kJ／mol。     

分子内还原Heck反应合成7-溴-1-茚满酮

研究了标题化合物的合成新方法,即以邻溴苯甲酸为原料,经取代反应、氧化还原反应、格氏反应以及分子内还原Heck反应合成了目标化合物。探讨了分子内还原Heck反应中反应溶剂、反应温度、反应时间及催化剂种类等条件对产率的影响。最终确定了以四氢呋喃为溶剂、Pd(dppf)Cl_2为催化剂、60℃反应6 h的最佳反应条件,产率可达83%。     

2,3-二氯吡啶催化加氢动力学研究

采用液相还原法制备了Pd/C催化剂,在压力0.6 MPa、温度303～323 K、转速800 r/min的条件下应用于2,3-二氯吡啶催化加氢反应动力学研究,建立了动力学反应模型,对动力学参数进行了估值。其中3-氯吡啶催化加氢反应为2.1级反应,反应速度方程为：■,活化能44.14 kJ/mol, 2-氯吡啶催化加氢反应为1级反应,反应速率方程为：■,活化能72.28 kJ/mol, 2,3-二氯吡啶催化剂加氢反应为3级反应,反应速度方程为：■,活化能81.13 kJ/mol。     

2-(2-溴-9-苯基-9H-芴-9-基)吡啶的合成研究

以2-溴吡啶为初始原料,经格氏反应、亲核取代反应和傅克反应合成了2-(2-溴-9-苯基-9H-芴-9-基)吡啶,总收率为46.3%,通过1H NMR、13C NMR、 MS和IR表征了化合物的结构;研究了傅克反应中反应温度和反应时间对目标化合物收率的影响,得出优化反应条件:反应温度为5℃,反应时间为5h,优化条件下,傅克反应的收率为71.1%。     

RHEOLOGICAL BEHAVIOR OF LOW-RANK COAL-WATER SLURRIES

The rheological behavior of low-rank coal-water slurries was studied using a Brookfleld Rheolog viscometer. A Sarpy Creek subbituminous coal from Montana, with particle sizes ranging from 0.044 mm to 0.223 mm, was used. The solids concentration in the slurry varied from 15 to 65 weight % and the temperature was maintained constant at 82°F. The rheological behavior of the slurry made from as received coal was compared with that of the slurry made from hot water dried coal

Coal-water slurries, made from both as received and hot water dried coal exhibited pseudoplastic behavior. The shear stress was found to be related to the shear rate by the power law model. As expected, the apparent viscosity was found to increase sharply with solids loading. It was also observed that the apparent viscosities of the slurries made from hot water dried coal were lower than those made from as received coal.     

Naegeli茶螺烷合成方法的改进

对Naegeli报道的以β-紫罗兰酮为原料经乙酸异丙烯酯酯交换、硼氢化钠还原成逆紫罗兰醇再环化合成茶螺烷的方法进行了改进,改进后的合成方法反应副产物巨豆三烯含量从15%降至4%,反应时间明显缩短,茶螺烷的收率从75%提高至84.5%。     

磷石膏基矿井充填材料制备及其性能研究

为实现磷石膏的资源化利用,制备了以原状磷石膏为主要原料、赤泥为碱性激发剂的矿井充填材料,并分析了高效减水剂掺量、水泥掺量、赤泥掺量对其性能的影响。实验结果表明,水灰质量比为0.2,聚羧酸盐减水剂掺量为0.5%（质量分数）时,浆料的初始流动度约为230 mm,满足充填材料性能要求;水泥掺量从0增加到10%时,28 d抗压强度从2.03 MPa提升至10.75 MPa,初始流动度从180 mm增加到235 mm,强度保持率从0.39提升至1,表明水泥掺量直接影响充填材料的强度、流动性及耐水性能;赤泥掺量从0增加到5%时,28 d抗压强度提升了50%,强度保持率从0.82提升至1,激发作用明显,对材料的流动性有相反的影响。     

用硬填料回收催化热油泵密封油的试验研究

在回收催化热油泵密封油的试验中,用硬填料作为密封油和介质的隔离装置。介绍了硬填料密封的基本结构及密封原理,给出了比压计算式。试验结果是较理想的。     

RHEOLOGICAL BEHAVIOR OF LOW-RANK COAL-WATER SLURRIES

The rheological behavior of low-rank coal-water slurries was studied using a Brookfleld Rheolog viscometer. A Sarpy Creek subbituminous coal from Montana, with particle sizes ranging from 0.044 mm to 0.223 mm, was used. The solids concentration in the slurry varied from 15 to 65 weight % and the temperature was maintained constant at 82°F. The rheological behavior of the slurry made from as received coal was compared with that of the slurry made from hot water dried coal

Coal-water slurries, made from both as received and hot water dried coal exhibited pseudoplastic behavior. The shear stress was found to be related to the shear rate by the power law model. As expected, the apparent viscosity was found to increase sharply with solids loading. It was also observed that the apparent viscosities of the slurries made from hot water dried coal were lower than those made from as received coal.     

膜技术在糖蜜酒精废液处理中的应用

研究了用膜直接过滤和逐层过滤的方法对糖蜜酒精废水进行了处理,结果表明：糖蜜废水原液直接过滤0.45μm的微滤膜时有902.5mg/L的COD被过滤掉;在0.22μm到10000Da分子量之间总共截留了1164mg/L COD的污染物。小于10000Da分子量的污染物COD的总量为6903.8mg/L。经过0.45μm和0.22μm的微滤膜时渗滤液由混浊变得澄清,颜色由黑褐色直接变为浅褐色。再经过140000Da分子量超滤膜后,糖蜜废水已经完全澄清。从140000Da超滤膜逐级过滤后出水,糖蜜废水的颜色为淡的黄褐色、水质澄清。     

Effectiveness of different phosphatic fertilizers measured using labelled superphosphate and phosphorus taken up by plants

The agronomic effectiveness of three P fertilizers (diamonium phosphate, rock phosphate and compost) was studied in a greenhouse experiment using wheat. A radioisotopic method, using triple superphosphate labelled with³²P, was used to evaluate the P in dried tops that was derived from i) the soil, ii) labelled superphosphate and iii) the fertilizer being studied.The ratio between P uptake from each fertilizer and P uptake from the soil was used to compare the effectiveness of the different fertilizers. P derived from diammonium phosphate was greater than P derived from the soil, except in one soil. P derived from rock phosphate was always lower than P derived from the soil. The effectiveness of compost depended on soil type. Compost can produce two kind of effects: i) a direct P contribution and ii) an indirect effect improving P uptake from the soil. The radioisotopic method can be used to study the effectiveness of fertilizers even when there are no differences in yield.     

纤维素酶对豆粕异黄酮提取的影响

在常规的醇提工艺前用不同微生物来源的纤维素酶对豆粕进行预处理，研究结果发现：细菌纤维素酶能使异黄酮的提取率提高1.4倍，产物以糖苷型异黄酮为主，与直接醇提得到的产物组成相类似；来自黑曲霉的纤维素酶对大豆异黄酮的提取率没有影响，但能将糖苷型异黄酮转化为苷元型异黄酮；里氏木霉纤维素酶能使醇提液中大豆异黄酮的提取率提高1.6倍，并能把以糖苷型为主的异黄酮转化为具有更高生理活性的苷元型异黄酮。里氏木霉纤维素酶的最适用量为15 FPIU·(g豆粕)-1，酶作用时间为36 h。采用弱极性的大孔树脂精制苷元型异黄酮，效果较好。     

堇青石基体化学气相沉积碳化硅薄膜及其性能表征

采用等温等压化学气相沉积技术,分别以CH3SiCl3-H2和SiCl4-CH4-H2为气源,在沉积温度1100和1000℃、压力101 kPa条件下,制备了SiC薄膜. 利用SEM和XRD、显微拉曼光谱、EDAX元素分析、HRTEM等测试技术对沉积薄膜的结构和组成进行了表征. 结果表明,1100℃时,以CH3SiCl3-H2为气源沉积得到纯净的SiC薄膜,以b-SiC (111)面择优定向生长,由微米级的金字塔锥形结构组成,硅含量随着沉积温度降低而增加;以SiCl4-CH4-H2为气源沉积得到非晶态碳掺杂的SiC薄膜,碳含量随着沉积温度降低而增加. 此外,以CH3SiCl3-H2为气源沉积的SiC颗粒平均粒径均比以SiCl4-CH4-H2为气源的粒径大. 前者SiC薄膜的方块电阻在kW级以上,且随着沉积温度的下降急剧升高;后者1100℃时制备的薄膜的方块电阻在kW级以上,且随着沉积温度的降低而急剧下降,1000℃时降低到W级.     

USE OF IRON-IMPREGNATED GRANULAR ACTIVATED CARBON FOR CO-ADSORPTIVE REMOVAL OF PHENOL AND CYANIDE: INSIGHT INTO EQUILIBRIUM AND KINETICS

In the present study, the effect of iron impregnation on granular activated carbon (GAC) for removal of multicomponents from synthetic wastewater was studied. It was observed that percentage removal of phenol and cyanide increased from 72.89% to 91.82% and from 75.99% to 95.57% respectively. A decrease in equilibrium time from 33 to 27 h and a decrease in optimum adsorbent dose from 30 to 10 g/L were also observed. Equilibrium modeling using two single-component isotherms and four multicomponent isotherms was performed, and it was found that extended Langmuir and extended Freundlich isotherm fits best to the adsorption of phenol and cyanide, respectively. Kinetic modeling using contact time studies was done to reveal the nature of adsorption and it was found that the rate-limiting step was a chemical adsorption process.