Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compo...Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compose the target, of which the productivity was 59%, UV was 267.50, 218.00, 220.50 nm, FTIR was 6291, 34158.6, 2850.2, 1708.2;1457.3;1370.4, 1224.2, 1144.0, 760.5 cm﹣1, fluorescence value λmax = 257, 591.1, 593.7, 590.3, 591.0, 591.5, XRD λ/nm is 3.6974, 4.186, 12.0762, 15.4747, 1H-NMRδ = 0.782, 1.193, 1.483 - 1.586, 1.959 - 2.184, 2.479, 3.116, 3.970 - 3.981, 5.231 - 5.753, 6.537 - 7.300. Finally it was ascertained through XRD as double-coordinated polycrystal compound.展开更多
Phenol is an important raw material.The pre-sent industrial method of a multistep and indirect syn-thesis of phenol from benzene has the disadvantages of a long synthetic route,large consumption of raw ma-terial and s...Phenol is an important raw material.The pre-sent industrial method of a multistep and indirect syn-thesis of phenol from benzene has the disadvantages of a long synthetic route,large consumption of raw ma-terial and serious environment pollution.The direct oxidization of benzene to phenol under mild conditions is being sought for researches[1~3].The reaction-con-trolled phase-transfer catalyst[4-6]developed recently is a kind of environmentally friendly catalyst.The re-action-controlled phase-transfer catalyst can be recov-ered,like a heterogeneous catalyst,but also acts as a homogeneous catalyst.The reaction-controlled phase-transfer catalyst possesses the above advantages and it is significant to design and synthesize such a catalyst,but there have been few reports concerning the prepa-ration of this kind of catalysts.展开更多
A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the pr...A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.展开更多
A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with h...A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.展开更多
A highly effective and mild protocol for ring opening of epoxides with NH4SCN in the presence of catalytic amount of a multi- site phase-transfer catalyst, α,α＇,α＂-N-hexakis（triethylammoniummethylene chloride）-...A highly effective and mild protocol for ring opening of epoxides with NH4SCN in the presence of catalytic amount of a multi- site phase-transfer catalyst, α,α＇,α＂-N-hexakis（triethylammoniummethylene chloride）-melamine, is developed. A variety of ^-hydroxy thiocyanates as important intermediates in agricultural and pharmaceutical chemistry were obtained in high yields with excellent regioselectivity and in short reaction times. 2009 Ali Reza Kiasat. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxida...A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.展开更多
Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylatio...Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system （IL-hase） could also be recycled after the extraction of products with ether.展开更多
Chiral phase-transfer catalysts, derived from cinchona alkaloids and Fréchet dendritic wedges up to generation two, have been synthesized. These chiral dendritic molecules have been used as PTCs in the epoxidatio...Chiral phase-transfer catalysts, derived from cinchona alkaloids and Fréchet dendritic wedges up to generation two, have been synthesized. These chiral dendritic molecules have been used as PTCs in the epoxidation of α, β-enones, showing a moderate level of asymmetric induction.展开更多
A new series of chiral phase-transfer catalysts 7a-7h were designed and synthesized from L-proline with moderate to good yields.＇The catalytic activity of 7a-Th for the asymmetric alkylation of glycine Schiff bases w...A new series of chiral phase-transfer catalysts 7a-7h were designed and synthesized from L-proline with moderate to good yields.＇The catalytic activity of 7a-Th for the asymmetric alkylation of glycine Schiff bases was evaluated, and some interesting relationships between structure and catalytic activity were revealed.展开更多
A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the...A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.展开更多
Using 4-Dialkylaminopyridinium salt as a thermal stable phase-transfer catalyst (PTC), the excellent results were obtained in the halogen-exchange fluorination.
针对500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行过程中存在馈源接收机安装及更换时设备精密且拆装过程复杂、馈源舱内安装空间狭小、馈源舱停靠平台处安装空间有限、连接螺栓数量多、...针对500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行过程中存在馈源接收机安装及更换时设备精密且拆装过程复杂、馈源舱内安装空间狭小、馈源舱停靠平台处安装空间有限、连接螺栓数量多、下平台尺寸重量大且安装精度要求高、更换时间长和运输困难等问题,提出FAST运行维护作业机器人总体技术解决方案。通过机器人总体技术需求分析、机器人总体技术设计、机器人关键技术研究及仿真分析,该方案可满足馈源接收机拆装过程中定位、识别、拆装和运输等应用需求,减小运行维护的时间成本和经济成本,确保FAST运行维护的安全,提高使用效率,延长FAST的全年观测时间,从而促进天文成果的产出。展开更多
为保障500 m口径球面射电望远镜(FAST)的安全稳定运行,提出基于实时信息数据的三维可视化监测方法。融合三维静态/动态建模、多源数据实时处理、Ansys仿真分析等关键技术,构建FAST高保真数字孪生模型,基于LightningChart图形库开发图形...为保障500 m口径球面射电望远镜(FAST)的安全稳定运行,提出基于实时信息数据的三维可视化监测方法。融合三维静态/动态建模、多源数据实时处理、Ansys仿真分析等关键技术,构建FAST高保真数字孪生模型,基于LightningChart图形库开发图形用户界面(graphical user interface,GUI)系统,实现设备异常信号的秒级可视化预警,故障响应时间显著缩短。该方法为大型射电望远镜及其阵列实施基于数字孪生的可视化监测提供参考。展开更多
非量测相机以价格低、体积小、使用灵活等优势被广泛应用于高精度测量工作中,但相机标定结果对测量精度影响较大,针对现有相机标定方法存在着精度不够或标定效率不高等问题,文章提出一种联合加速分割检测特征(features from accelerated...非量测相机以价格低、体积小、使用灵活等优势被广泛应用于高精度测量工作中,但相机标定结果对测量精度影响较大,针对现有相机标定方法存在着精度不够或标定效率不高等问题,文章提出一种联合加速分割检测特征(features from accelerated segment test,FAST)算法和双像光束法平差的相机标定方法。首先利用FAST算法对像片标志点自动提取,利用直接线性变换方法解得相机内、外参数初值;然后基于固定基线长度约束的双像光束法平差模型解算相机相关参数,并通过分类阈值方法提高模型收敛效率。结果表明:该方法相较于普通双像光束法平差的精度有所提升,其标定后的中误差达到0.0064 mm,且实现了相机标定流程的半自动化,提高了作业效率,有望应用于实际场景的相机标定作业。展开更多
文摘Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compose the target, of which the productivity was 59%, UV was 267.50, 218.00, 220.50 nm, FTIR was 6291, 34158.6, 2850.2, 1708.2;1457.3;1370.4, 1224.2, 1144.0, 760.5 cm﹣1, fluorescence value λmax = 257, 591.1, 593.7, 590.3, 591.0, 591.5, XRD λ/nm is 3.6974, 4.186, 12.0762, 15.4747, 1H-NMRδ = 0.782, 1.193, 1.483 - 1.586, 1.959 - 2.184, 2.479, 3.116, 3.970 - 3.981, 5.231 - 5.753, 6.537 - 7.300. Finally it was ascertained through XRD as double-coordinated polycrystal compound.
文摘Phenol is an important raw material.The pre-sent industrial method of a multistep and indirect syn-thesis of phenol from benzene has the disadvantages of a long synthetic route,large consumption of raw ma-terial and serious environment pollution.The direct oxidization of benzene to phenol under mild conditions is being sought for researches[1~3].The reaction-con-trolled phase-transfer catalyst[4-6]developed recently is a kind of environmentally friendly catalyst.The re-action-controlled phase-transfer catalyst can be recov-ered,like a heterogeneous catalyst,but also acts as a homogeneous catalyst.The reaction-controlled phase-transfer catalyst possesses the above advantages and it is significant to design and synthesize such a catalyst,but there have been few reports concerning the prepa-ration of this kind of catalysts.
文摘A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.
基金supported by the Talent Foundation of Anhui Science and Technology University (No. ZRC2014401)
文摘A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.
基金the partial support of this work by Shahid Chamran Research Council
文摘A highly effective and mild protocol for ring opening of epoxides with NH4SCN in the presence of catalytic amount of a multi- site phase-transfer catalyst, α,α＇,α＂-N-hexakis（triethylammoniummethylene chloride）-melamine, is developed. A variety of ^-hydroxy thiocyanates as important intermediates in agricultural and pharmaceutical chemistry were obtained in high yields with excellent regioselectivity and in short reaction times. 2009 Ali Reza Kiasat. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.
文摘Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system （IL-hase） could also be recycled after the extraction of products with ether.
文摘Chiral phase-transfer catalysts, derived from cinchona alkaloids and Fréchet dendritic wedges up to generation two, have been synthesized. These chiral dendritic molecules have been used as PTCs in the epoxidation of α, β-enones, showing a moderate level of asymmetric induction.
基金National Natural Science Foundation of China (Grant No. 20802004)
文摘A new series of chiral phase-transfer catalysts 7a-7h were designed and synthesized from L-proline with moderate to good yields.＇The catalytic activity of 7a-Th for the asymmetric alkylation of glycine Schiff bases was evaluated, and some interesting relationships between structure and catalytic activity were revealed.
文摘A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.
基金the Natural Science Foundation of Zhejiang Province (No. 299024).
文摘Using 4-Dialkylaminopyridinium salt as a thermal stable phase-transfer catalyst (PTC), the excellent results were obtained in the halogen-exchange fluorination.
文摘针对500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行过程中存在馈源接收机安装及更换时设备精密且拆装过程复杂、馈源舱内安装空间狭小、馈源舱停靠平台处安装空间有限、连接螺栓数量多、下平台尺寸重量大且安装精度要求高、更换时间长和运输困难等问题,提出FAST运行维护作业机器人总体技术解决方案。通过机器人总体技术需求分析、机器人总体技术设计、机器人关键技术研究及仿真分析,该方案可满足馈源接收机拆装过程中定位、识别、拆装和运输等应用需求,减小运行维护的时间成本和经济成本,确保FAST运行维护的安全,提高使用效率,延长FAST的全年观测时间,从而促进天文成果的产出。
文摘为保障500 m口径球面射电望远镜(FAST)的安全稳定运行,提出基于实时信息数据的三维可视化监测方法。融合三维静态/动态建模、多源数据实时处理、Ansys仿真分析等关键技术,构建FAST高保真数字孪生模型,基于LightningChart图形库开发图形用户界面(graphical user interface,GUI)系统,实现设备异常信号的秒级可视化预警,故障响应时间显著缩短。该方法为大型射电望远镜及其阵列实施基于数字孪生的可视化监测提供参考。
