微波辅助固体酸催化废弃油脂合成生物柴油工艺的优化

以废弃油脂为原料,采用微波辐射辅助固体酸催化合成生物柴油。考察反应温度、微波功率、微波加热时间、醇油摩尔比及催化剂的用量对生物柴油产率的影响,并采用响应面法建立二次回归模型对合成工艺进行了优化。分析结果显示,在反应温度为82℃、反应时间为93 min、醇油摩尔比7∶1、催化剂的用量为3.2%时,生物柴油的产率可达到94.58%,与在相同工艺条件下未经微波处理的产率提高了32.47%。     

微波辐射四氯化锡催化无溶剂合成7-羟基-4-甲基香豆素

以间苯二酚和乙酰乙酸乙酯为原料,以五水四氯化锡为催化剂,采用微波辐射技术,无溶剂合成7-羟基-4-甲基香豆素。探索了不同反应条件对产率的影响。结果表明:当n(间苯二酚)∶n(乙酰乙酸乙酯)为1∶0.8,反应温度为115℃,五水四氯化锡为2.6 g(间苯二酚为0.15 mol),辐射时间为16 min,辐射功率为500 W时,产率可达80.6%。     

微波消解ICP-AES法测定润滑油中的铁,镍,铜,锌,硼,磷

通过微波消解处理润滑油,ICP法测定润滑油中铁,镍,铜,锌,硼等元素,通过正交实验进行微波消解条件优化,并进行了精密度实验,标准样品的回收率为98%以上,相对标准偏差小于1%。     

无溶剂下微波辐射合成阿魏酸

以香草醛为反应底物,丙二酸为试剂,醋酸铵为催化剂,采用微波辐射技术,经Knoevenagel-Doebner反应,在无溶剂条件下合成了阿魏酸。研究了酸、醛和醋酸铵用量,微波功率和辐射时间对阿魏酸收率的影响。得到较佳工艺条件为:40 mmol香草醛、48 mmol丙二酸、4.8 mmol醋酸铵,微波功率400 W,辐射15 min。在此条件下产率为86.9%,阿魏酸的质量分数超过98%。     

微波用于高粘原油脱水的研究

文章分析了微波破乳的机理,并以脱水率为考查依据,采用正交设计的方法对影响稠油微波脱水的主要因素,即原油含水量、微波辐射时间、微波功率进行了系统研究。结果表明,原油含水量为影响稠油微波脱水的主要因素,含水量越高,脱水率越大。另外,微波辐射时间与辐射功率对脱水率也存在着一定的影响。对于实验所用的稠油,当微波辐射功率为420 W,辐射时间为120 s,原油含水量为80%时,稠油脱水率最高,达到93.88%。     

4-甲氧基二苯甲酰甲烷合成新方法研究

研究了微波辐射合成4-甲氧基二苯甲酰甲烷。得到优化合成条件为:n(对甲氧基苯乙酮):n(苯甲酸乙酯):n(氨基钠)=1:15:4,微波辐射功率320W,反应时间为45min,与传统加热法相比,反应时间从7h减少到45min,收率从61.4%增加到77.4%。其结构经元素分析、IR和1HNMR确证。     

微波辐射合成1,3-二苯基-4-甲酰基吡唑

在微波辐射下,以苯肼和苯乙酮为原料,经脱水和Vislmeier环合反应,简便、高效地合成1,3-二苯基-4-甲酰基吡唑,并对微波辐射下的原料配比、反应温度和辐射时间等反应条件进行优化。     

微波辐射下无溶剂催化合成环己酮1,2-丙二醇缩酮

在微波辐射下,以硫酸氢钾为催化剂,不用溶剂,合成了环己酮1,2-丙二醇缩酮。考察了酮醇物质的量比、催化剂用量、微波功率和辐射时间对产品收率的影响。结果表明,硫酸氢钾有着良好的催化活性,在环己酮用量0.2 mol,n(环己酮)∶n(1,2-丙二醇)=1∶1.4,催化剂用量为反应物总质量的1.25%,微波功率450 W,辐射时间10 min条件下,环己酮1,2-丙二醇缩酮收率可达79.2%,催化剂重复使用4次仍保持较高活性。     

微波辐照下聚硅氧烷微乳液的制备及动力学研究

以八甲基环四硅氧烷(D4)为原料,十二烷基苯磺酸(DBSA)为催化剂,十二烷基苯磺酸钠(SDBS)和聚乙二醇辛基苯基醚(OP-10)为复配乳化剂,在微波辐照下制备聚硅氧烷微乳液。讨论了反应条件对微乳液制备的影响,结果表明,反应温度80℃,D4、DBSA、SDBS和OP-10分别为微乳液质量的15%,3%,4%和1%时微乳液的流体力学半径最小。进一步研究了反应条件对反应动力学的影响,结果表明,温度越高,催化剂用量越大,D4转化速率越快,但最终的平衡转化率接近。     

Positron Annihilation Investigation of Embrittlement Behavior in Chinese RPV Steels after Fe-Ion IrradiationEI北大核心CSCD

The reactor pressure vessel (RPV) is the key component in the nuclear power plant, which is considered irreplaceable and can be the life-limiting feature of the operation of nuclear power plant if its mechanical properties degrade sufficiently. High temperature gas-cooled reactor (HTGR) has perfect inherent safety, which is intended to be one of the fourth generation advanced nuclear reactors. However, HTGR has different service temperature with pressurized water reactor (PWR), that the service temperature of HTGR is 250 degrees C and that of PWR is 290 degrees C. So the irradiation behaviour of RPV in HTGR is expected to be investigated. In this wok, 3 MeV Fe-ion irradiation was performed on Chinese A508-3 reactor pressure vessel steel which is employed by high-temperature gas-cooled reactors and pure Fe under room temperature (about 25 degrees C) and high temperature (250 degrees C). The ion doses were 0.1, 0.5 and 1.0 dpa for both room temperature irradiation and high temperature irradiation. SRIM modeling was performed before irradiation experiments to guide the experimental details. Positron annihilation Doppler broadening (PADB) spectroscopy experiments and nano-indentation tests (to study embrittlement behavior) were conducted for characterization. It is found that after both room temperature irradiation and high temperature irradiation, the densities of defects in the reactor pressure vessel steel and pure Fe increase, and the type of defects could be vacancy-type and solute cluster type from PADB results. The vacancy-type defect density under high temperature irradiation is lower than that under room temperature irradiation. That is because high temperature can recover the defects formed during irradiation. The hardness test results show that for both the reactor pressure vessel steel and pure Fe, the irradiation hardening increases with increasing dose. Compared to room temperature irradiation, high temperature irradiation can produce more solute clusters and fewer vacancy-type defects in the reactor pressure vessel steel. So the irradiation hardening of the reactor pressure vessel steel might be caused mainly by the formation of solute clusters.