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Coordination polymers based on anthracene-and pyrene-derived ligands:Crystal structure,fluorescent property,and framework isomerization
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作者 HU Youbo LI Donggang +2 位作者 SUN Changhua LU Zhenzhong GU Songjun 《无机化学学报》 北大核心 2025年第8期1681-1688,共8页
Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1.... Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1.5)Cl_(3)]·5H_(2)O}n(2)are framework isomers,which both contain zigzag chains formed by DPA,Zn^(2+),and Cl-.The zigzag chains in 1 are further assembled by C—H…Cl interactions into layers,and these layers exhibit two different orientations,displaying a rare 2D to 3D interpenetration mode.The zigzag chains in 2 are parallelly arranged.{[Zn_(3)(DPA)_(3)Br_(6)]·2DMF·_(1.5)H_(2)O}n(3)is isostructural to 2.3 was obtained using ZnBr_(2)instead of ZnCl_(2).[M(DPA)(formate)_(2)(H_(2)O)_(2)]n[M=Co(4),Cu(5)]are isostructural,contain chain structures formed by DPA,Cu^(2+)/Co^(2+),and for-mate ions,which were formed in situ in the solvothermal reaction.{[Zn(DIP)_(2)Cl]ClO_(4)}n(6)contains a layer structure formed by DIP and Zn^(2+).Free DPA and DIP ligands exhibited high fluorescence at room temperature,and coordina-tion polymers 3 and 6 displayed enhanced fluorescent emissions. 展开更多
关键词 coordination polymer anthracene derivatives pyrene derivatives fluorescence framework isomerization
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Elucidating the catalytic role of lithium(Li)in the glucose-to-fructose isomerization over Li-C_(3)N_(4) catalyst at 60℃ in water
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作者 WANG Yuxuan GUO Fenfen +7 位作者 JIANG Zhicheng TU Youjing ZHANG Xingyu TANG Aoyi WANG Junxia LIANG Yuan YAN Lishi KONG Lingzhao 《燃料化学学报(中英文)》 北大核心 2025年第9期1373-1384,共12页
Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could ... Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could be employed as a starting material to prepare some other functional derivatives for improving the value of biomass resources.The isomerization of glucose to produce fructose is an important intermediate process during numerous high-value-added chemical preparations.Therefore,the development of efficient and selective catalysts for glucose isomerization is of great significance.Currently,glucose isomerase catalysts are limited by the harsh conditions required for microbial activity,which restricts further improvements in fructose yield.Additionally,heterogeneous Bronsted-base and Lewis-acid catalysts commonly employed in chemical isomerization methods often lead to the formation of undesirable by-products,resulting in reduced selectivity toward fructose.This study has demonstrated that lithium-loaded heterogeneous catalysts possess excellent isomerization capabilities under mild conditions.A highly efficient Li-C_(3)N_(4) catalyst was developed,achieving a fructose selectivity of 99.9% and a yield of 42.6% at 60℃ within 1.0 h-comparable to the performance of the enzymatic method.Characterization using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),proton nuclear magnetic resonance(^(1)H NMR),and inductively coupled plasma(ICP)analyses confirmed that lithium was stably incorporated into the g-C_(3)N_(4) framework through the formation of Li-N bonds.Further investigations using CO_(2) temperature-programmed desorption(CO_(2)-TPD),in situ Fourier-transform infrared spectroscopy(FT-IR)and 7Li magic angle spinning nuclear magnetic resonance(^(7)Li MAS NMR)indicated that the isomerization proceeded via a base-catalyzed mechanism.The Li species were found to interact with hydroxyl groups generated through hydrolysis and simultaneously coordinated with nitrogen atoms in the C_(3)N_(4) matrix,resulting in the formation of Li-N_(6)-H_(2)O active sites.These active sites facilitated the deprotonation of glucose to form an enolate intermediate,followed by a proton transfer step that generated fructose.This mechanism not only improved the efficiency of fructose production but also provided valuable insight into the catalytic role of lithium within the isomerization process. 展开更多
关键词 GLUCOSE FRUCTOSE isomerization hydrothermal catalysis Li-C_(3)N_(4)
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19.1%Efficiency PM6:Y6 based ternary organic solar cells enabled by isomerization engineering of A_(2)-A_(1)-D-A_(1)-A_(2)type vip molecules
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作者 Huijuan Ran Bingjie Zhou +6 位作者 Leyi Tang Kehui Wang Jia Yao Bo Xiao Yunfeng Xu Qing Guo Erjun Zhou 《Journal of Energy Chemistry》 2025年第9期577-583,I0015,共8页
In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip mol... In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip molecule is a simple method to increase the amount of promising material,but there are only limited reports,and the structure-property relationships are still unclear.In this work,we synthesized three isomers named BTA5-F-o,BTA5-F-m,and BTA5-F-p,with different fluorine substitution positions,to study the influence of isomerization on the photovoltaic performance.After introducing them as the third components to the classic host system PM6:Y6,all three ternary devices showed improved power conversion efficiency(PCEs)compared to the binary system(PCE of 17.46%).The ternary OSCs based on BTA5-F-o achieved a champion PCE of 19.11%,while BTA5-F-m and BTA5-F-p realized PCEs of 18.65%and 18.45%,respectively.Mechanism studies have shown that the dipole moment of the BTA5-F-o end group is closer to that of the Y6 end group,despite the three isomers with almost identical energy levels and optical properties.It is indicated that the electron attraction ability of BTA5-F-o best matches that of Y6,which leads to the higher charge mobility,less charge recombination,and stronger exciton dissociation and extraction ability in the ternary blend system.This study suggests that rationally adjusting the position of substituents in the terminal group can be an effective way to construct nonfullerene vip acceptors to achieve highly efficient ternary OSCs. 展开更多
关键词 Ternary organic solar cells vip molecules isomerization Nonfullerene acceptors Charge transfer
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Hydrodesulfurization and isomerization performance of model FCC naphtha over sulfided Co(Ni)-Mo/Y catalysts
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作者 Dongyang Liu Guohao Zhang +4 位作者 Xinsheng Kang Wenzhe Wu Liang Zhao Jinsen Gao Chunming Xu 《Chinese Journal of Chemical Engineering》 2025年第1期185-194,共10页
The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with differe... The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with different Ni-Co content were prepared by the incipient wetness impregnation method,the structure and properties were characterized and analyzed using HRTEM,XPS,H_(2)-TPR,and NH_(3)-TPD.The isomerization of 1-hexene and 1-octene as well as the HDS of thiophene were studied by using model FCC naphtha.The incorporation of Ni was found to enhance the number of MoS_(2) stacking layers,thereby improving the degree of sulfurization in Mo and subsequently increasing the desulfurization rate,with a maximum achieved desulfurization rate of 94.7%.When employing a Ni/Co ratio of 3:2,optimal synergy between Ni and Co is achieved,resulting in a greater presence of multi-layer stacked II-Co(Ni)MoS active phases.Additionally,appropriate Brønsted acidity levels are maintained to facilitate efficient olefin isomerization while preserving high HDS activity.As a result,the current isomerization yield stands at 58.2%(mass).These understandings shed light on the development of highly HDS and olefin isomerization catalysts. 展开更多
关键词 HYDRODESULFURIZATION isomerization Co(Ni)-Mo/Y Co(Ni)MoS
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数字化技术在顺(反)式二甘氨酸合铜配合物制备实验中的应用与创新设计
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作者 段雨爱 甘轩羽 +3 位作者 付垚 曹英杰 韩洪亮 马占芳 《大学化学》 2026年第1期373-381,共9页
顺(反)式二甘氨酸合铜制备实验是几何异构配合物制备的经典化学实验。通过引入量子化学计算和颜色识别技术对该实验进行了创新设计,解决了该实验现象易观测而微观机制难理解,以及反应终点不易控制、产率不高等问题。运用量子化学软件Gau... 顺(反)式二甘氨酸合铜制备实验是几何异构配合物制备的经典化学实验。通过引入量子化学计算和颜色识别技术对该实验进行了创新设计,解决了该实验现象易观测而微观机制难理解,以及反应终点不易控制、产率不高等问题。运用量子化学软件Gaussian 09及其可视化工具GaussView,采用密度泛函理论(DFT)对顺、反式二甘氨酸合铜分子的几何结构、能量、偶极矩以及静电势等参数进行计算,使学生初步掌握运用量子化学计算方法求算几何异构配合物分子的思路和方法,进而从微观层面深入理解顺反异构体之间的差异性。同时,基于C++编程语言与OpenCV库,通过机器视觉技术搭建一个颜色识别系统,利用摄像头捕捉反应区域图像,结合HSV颜色空间模型分析溶液颜色变化,实现对顺式二甘氨酸合铜异构化生成反式二甘氨酸合铜反应过程中溶液颜色变化的实时监控及自动识别与判断,精确监测反应终点。将量子化学计算与颜色识别技术有机结合并融入实验教学内容中,有助于学生更为深入地理解分子结构与性质之间的内在联系,大幅提高实验数据的精准度与可信度。同时能有力增强学生的科学思维能力、跨学科综合运用能力,切实提升学生在数智化领域的应用水平。 展开更多
关键词 二甘氨酸合铜 几何异构 密度泛函理论 颜色识别 数智化
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生物炭分散氧化镁催化剂用于葡萄糖异构化为果糖
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作者 高咪 段亚华 +2 位作者 蒋智成 张文华 石碧 《皮革科学与工程》 北大核心 2026年第1期1-9,共9页
【目的】针对金属氧化物因易团聚、活性位点暴露不足导致葡萄糖异构化效率低的问题,构建生物质基载体分散氧化镁,提升催化性能,助力高值糖基化学品制备。【方法】文章利用碱木质素酚羟基与镁离子的静电相互作用和配位作用,经化学交联形... 【目的】针对金属氧化物因易团聚、活性位点暴露不足导致葡萄糖异构化效率低的问题,构建生物质基载体分散氧化镁,提升催化性能,助力高值糖基化学品制备。【方法】文章利用碱木质素酚羟基与镁离子的静电相互作用和配位作用,经化学交联形成三维孔状前驱体,高温煅烧后制得氧化镁-生物炭复合催化剂。【结果】扫描电镜、比表面积与孔隙度等分析结果表明,该催化剂具有丰富的多级孔道结构,氧化镁在生物炭表面高度分散,暴露更多的活性点位,催化效率显著提升。经条件优化,以甲醇为溶剂,葡萄糖质量浓度75 g/L,催化剂用量40 mg,在100°C下反应30 min,果糖收率达34.9%,选择性81.4%。【结论】成功实现了氧化镁的高效分散,且MgO-C催化性能优异,为解决金属氧化物催化剂易团聚的问题提供了有效途径,在糖基化学品的绿色转化中展现出良好的应用前景。 展开更多
关键词 氧化镁 碱木质素 葡萄糖异构化 果糖
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虾青素光异构化机理:实验与量子化学相结合研究
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作者 周乐松 邹晓君 +3 位作者 陈佳玲 肖杰 曹庸 刘晓娟 《食品工业科技》 北大核心 2026年第5期92-100,共9页
为探究虾青素(astaxanthin,AST)的光异构化机理,采用HPLC技术和Q值法分析光催化转化AST的顺式构型种类和含量,通过密度泛函理论对AST构型进行优化与频率分析,计算得到全反式(all-E)和顺式(Z)AST相互转化的热力学、动力学和能量参数。结... 为探究虾青素(astaxanthin,AST)的光异构化机理,采用HPLC技术和Q值法分析光催化转化AST的顺式构型种类和含量,通过密度泛函理论对AST构型进行优化与频率分析,计算得到全反式(all-E)和顺式(Z)AST相互转化的热力学、动力学和能量参数。结果表明,全反式AST在光催化下主要形成9顺式(9-Z)和13顺式(13-Z),13-Z含量(17.72%)显著高于9-Z(13.57%)(P<0.05)。光照后,中性AST分子形成双自由基,双键容易发生扭转。全反式AST的前线轨道能隙差最小,更容易从基态转变为激发态,从而异构为其它构型;根据吉布斯自由能,AST异构体的相对稳定性顺序为:全反式>9-Z>13-Z>15-Z,与实验结果趋势基本相符;全反式AST形成9-Z的活化能高于15-Z和13-Z,单顺式AST转化为多顺式的活化能远高于全反式AST转化为单顺式异构体;13-Z构型生成速率分别约为15-Z和9-Z的4倍和100倍,且相互转化的隧穿效应可以忽略不计,与实验中多顺式异构体难以观察到相吻合,同时阐明实验中出现的13-Z AST比例显著高于9-Z的原因。研究结果揭示了AST可控实现异构体的生成机制,同时为其它类胡萝卜素异构化研究提供理论基础。 展开更多
关键词 虾青素 异构化 量子化学 全反式异构体 顺式异构体
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High-Dimensional Multi-Objective Computation Offloading for MEC in Serial Isomerism Tasks via Flexible Optimization Framework
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作者 Zheng Yao Puqing Chang 《Computers, Materials & Continua》 2026年第1期1160-1177,共18页
As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays... As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays a pivotal role in MEC performance but remains challenging due to complex task topologies,conflicting objectives,and limited resources.This paper addresses high-dimensional multi-objective offloading for serial heterogeneous tasks in MEC.We jointly consider task heterogeneity,high-dimensional objectives,and flexible resource scheduling,modeling the problem as a Many-objective optimization.To solve it,we propose a flexible framework integrating an improved cooperative co-evolutionary algorithm based on decomposition(MOCC/D)and a flexible scheduling strategy.Experimental results on benchmark functions and simulation scenarios show that the proposed method outperforms existing approaches in both convergence and solution quality. 展开更多
关键词 Edge computing offload serial Isomerism applications many-objective optimization flexible resource scheduling
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Noninvasive strategies for metabolic dysfunction-associated steatotic liver disease assessment and referral in Japan
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作者 Yoshihiro Kamada Yoshio Sumida +8 位作者 Hirokazu Takahashi Hiroshi Ishiba Miwa Kawanaka Toshifumi Tada Masato Yoneda Kento Imajo Yuya Seko Hideki Fujii Atsushi Nakajima 《World Journal of Gastroenterology》 2026年第2期18-36,共19页
To establish practical,evidence-based strategies for noninvasive assessment and referral of patients with metabolic dysfunction-associated steatotic liver disease(MASLD)in Japan,we must address the urgent clinical nee... To establish practical,evidence-based strategies for noninvasive assessment and referral of patients with metabolic dysfunction-associated steatotic liver disease(MASLD)in Japan,we must address the urgent clinical need for accurate risk stratification and timely specialist intervention.A panel of 11 Japanese hepatology experts conducted a modified Delphi process to evaluate consensus recommendations regarding the use of noninvasive tests(NITs),including the fibrosis-4 index,enhanced liver fibrosis test,Mac-2-binding protein glycosylation isomer,type IV collagen 7S,cytokeratin-18 fragments,and imaging modalities such as ultrasound elastography and magnetic resonance elastography,for MASLD assessment and clinical referral.Practical algorithms were developed based on current Japanese data and panel consensus.The expert panel validated the utility of NITs as reliable tools for identifying patients with MASLD at risk for advanced fibrosis.Sequential use of NITs improved diagnostic accuracy and referral appropriateness while minimizing unnecessary specialist consultations.The proposed algorithms offer stepwise guidance for primary care physicians,supporting efficient,evidence-based decisionmaking.However,prospective longitudinal studies remain necessary for full prognostic validation of NITs in MASLD management.Noninvasive testing algorithms enable effective risk stratification and referral for MASLD in real-world Japanese practice with anticipated benefit for patient outcomes and healthcare systems.Broader adoption and further validation are warranted. 展开更多
关键词 Fibrosis-4 index Enhanced liver fibrosis test Mac-2-binding protein glycosylation isomer Type 4 collagen 7S Cytokeratin-18 fragment ELASTOGRAPHY
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Selective 3-OH Isomerization of Resibufogenin by Cell Suspension Cultures of Ginkgo biloba 被引量:2
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作者 辛秀兰 谢晓慧 《Journal of Chinese Pharmaceutical Sciences》 CAS 2005年第1期10-12,共3页
Aim To modify the structure of resibufogenin by using Ginkgo bilobasuspension. Methods Young leaves of Ginkgo biloba were differentiated into callus in MS medium withonly 2,4-D as plant growth regulator. The callus wa... Aim To modify the structure of resibufogenin by using Ginkgo bilobasuspension. Methods Young leaves of Ginkgo biloba were differentiated into callus in MS medium withonly 2,4-D as plant growth regulator. The callus was then transferred aseptically to liquid MSmedium exoge-nously supplemented with appropriate concentration of 6-BA, NAA and 2,4-D to establishsuspension cell culture system. Resibufogenin was administered into the well-grown cell cultures andincubated for 4 d. The products dissolved in the liquid phase of the cultures were extracted andpurified by silica gel column chromatography gradiently eluted with petroleum ether and acetonesystem. Results One transformed product was obtained in 40% yield after 4 d incubation, which wasidentified as 3-epi-resibufogenin on the basis of FAB MS, ~1H NMR and ^(13)C NMR spectroscopicanalysis and corresponding data reported in literature. Conclusion G. biloba suspension cultures canbe used as an enzyme system to biotransform resibufogenin, an animal-originated bufadienolide, into3-epi-resibufogenin. 展开更多
关键词 RESIBUFOGENIN isomerization cell suspension cultures ginkgo biloba
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正丁烯骨架异构化催化剂RBIW-400的研发和应用
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作者 王子健 刘洪全 +3 位作者 孔令江 于中伟 李金芝 马爱增 《石油炼制与化工》 北大核心 2026年第1期1-8,共8页
通过筛选模板剂并优化合成条件,在优选的模版剂与SiO_(2)质量比、晶化温度、碱度和晶化时间下,采用水热合成法制备出具有规整宽大薄片状形貌的高硅铝比镁碱沸石;进而,以氢氧化铝粉为黏结剂,开发出RBIW-400正丁烯骨架异构化催化剂,于201... 通过筛选模板剂并优化合成条件,在优选的模版剂与SiO_(2)质量比、晶化温度、碱度和晶化时间下,采用水热合成法制备出具有规整宽大薄片状形貌的高硅铝比镁碱沸石;进而,以氢氧化铝粉为黏结剂,开发出RBIW-400正丁烯骨架异构化催化剂,于2019年在某厂600 kt/a醚后碳四异构化装置上成功进行工业应用。工业应用结果表明,该催化剂具有优异的正丁烯骨架异构化反应活性、目标产物选择性和长时间运行稳定性,达到了国际先进水平,正丁烯转化率可达42.40%,异丁烯选择性可达95.62%。在未来轻烃资源过剩、高价值化工品短缺的背景下,该技术将具有广阔的市场应用前景。 展开更多
关键词 镁碱沸石 异构化 正丁烯 异丁烯 黏结剂 模版剂 晶化
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异构脂肪酸酯的响应面法优化合成及柔润性能
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作者 苏秋萍 李欢玲 +5 位作者 余龙飞 柯烜 黄淋佳 辛锦兰 文武 贾康乐 《精细化工》 北大核心 2026年第2期414-423,共10页
为探索异构脂肪酸酯的绿色合成工艺,以异构脂肪醇与3,5,5-三甲基-1-己酸(异壬酸)为原料、物质的量比为3.05∶1的对甲苯磺酸与亚磷酸为复合催化剂,通过无溶剂法合成了一系列异构脂肪酸酯。采用单因素实验和响应面法优化模型化合物异壬酸... 为探索异构脂肪酸酯的绿色合成工艺,以异构脂肪醇与3,5,5-三甲基-1-己酸(异壬酸)为原料、物质的量比为3.05∶1的对甲苯磺酸与亚磷酸为复合催化剂,通过无溶剂法合成了一系列异构脂肪酸酯。采用单因素实验和响应面法优化模型化合物异壬酸异壬醇酯(ININ)的合成工艺条件。采用FTIR、1HNMR确认了ININ的结构,通过表界面张力、接触角、扩散系数、摩擦系数、相容性等参数的测定,考察了异构脂肪酸酯结构对其润湿铺展、滋润、清洁力的影响。结果表明,在催化剂用量(以异壬酸的质量计,下同)1.44%、醇酸比(异壬醇与异壬酸的物质的量比)1.16∶1.0、反应温度131℃、反应时间4 h的最优条件下,异壬酸的转化率为97.17%。合成的酯均为无色透明无异味,且脂肪酸(正壬酸或异壬酸)的转化率均>95%。多甲基支链化异构脂肪酸酯ININ和异壬酸异十三醇酯的表面张力均<30 mN/m,接触角<50°,扩散速率约40 mm/s,与彩妆成分相容性好,可自发在皮肤上铺展,清爽性与清洁力优于传统矿物油及直链壬酸壬醇酯。皮肤涂抹合成的8种脂肪酸酯,静摩擦系数和动摩擦系数分别减少>59%和>60%,异壬酸2-己基癸醇酯具有相对对称的多条疏水链,滋润性更好。 展开更多
关键词 异构脂肪酸酯 响应面法 润湿 铺展 润滑 日化原料
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Isomerization of linear C5–C7 over Pt loaded on protonated fibrous silica@Y zeolite(Pt/HSi@Y) 被引量:6
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作者 S.Triwahyono A.A.Jalil +2 位作者 S.M.Izan N.S.Jamari N.A.A.Fatah 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第10期163-171,共9页
A novel fibrous silica Y zeolite (HSi@Y) loaded with Pt has been studied based on its ability to produce protonic acid sites originating from molecular hydrogen. The Pt/HSi@Y was prepared using seed assisted crystalli... A novel fibrous silica Y zeolite (HSi@Y) loaded with Pt has been studied based on its ability to produce protonic acid sites originating from molecular hydrogen. The Pt/HSi@Y was prepared using seed assisted crystallization followed by protonation and Pt-loading. The product formed had a spherical morphology with bicontinuous lamellar with a diameter in the range of 500-700 nm. The catalytic activity of the Pt/HSi@Y has been assessed based on light linear alkane (C5-C7) isomerization in a micro-catalytic pulse reactor at 423-623 K. A pyridine IR study confirmed that the introduction of fibrous silica on Y zeolite increased the Lewis acid sites corresponding with the formation of extra-framework Al which led to the generation of more protonic acid sites. A hydrogen adsorbed IR study showed that the protonic acid sites which act as active sites in the isomerization were formed via dissociative-adsorption of molecular hydrogen releasing electrons to the nearby Lewis acid sites. Thus, it is suggested that the presence of Pt and HSi@Y with a high number of Lewis acid as well as weak Bronsted acid sites improved the activity and stability in C5, C6 and C7 isomerization via hydrogen spill-over mechanism. 展开更多
关键词 Pt/HSi@Y FIBROUS silica Y zeolite Acidic sites C5-C7 isomerization
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Modeling of Isomerization of C_8 Aromatics by Online Least Squares Support Vector Machine 被引量:7
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作者 李丽娟 苏宏业 褚建 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第3期437-444,共8页
The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling... The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling of multi-output systems by LS-SVR. The multi-output LS-SVR is derived in detail. To avoid the inversion of large matrix, the recursive algorithm of the parameters is given, which makes the online algorithm of LS-SVR practical. Since the computing time increases with the number of training samples, the sparseness is studied based on the pro-jection of online LS-SVR. The residual of projection less than a threshold is omitted, so that a lot of samples are kept out of the training set and the sparseness is obtained. The standard LS-SVR, nonsparse online LS-SVR and sparse online LS-SVR with different threshold are used for modeling the isomerization of C8 aromatics. The root-mean-square-error (RMSE), number of support vectors and running time of three algorithms are compared and the result indicates that the performance of sparse online LS-SVR is more favorable. 展开更多
关键词 least squares support vector machine multi-variable ONLINE SPARSENESS isomerization
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Hydrocracking diversity in n-dodecane isomerization on Pt/ZSM-22 and Pt/ZSM-23 catalysts and their catalytic performance for hydrodewaxing of lube base oil 被引量:6
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作者 Shan-Bin Gao Zhen Zhao +8 位作者 Xue-Feng Lu Ke-Bin Chi Ai-Jun Duan Yan-Feng Liu Xiang-Bin Meng Ming-Wei Tan Hong-Yue Yu Yu-Ge Shen Meng-Chen Li 《Petroleum Science》 SCIE CAS CSCD 2020年第6期1752-1763,共12页
Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that th... Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock. 展开更多
关键词 isomerization HYDROCRACKING CATALYSTS Pt/ZSM-22 Pt/ZSM-23 DODECANE Lube base oil
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Experimental and kinetic study of n-heptane isomerization on nanoporous Pt-(Re,Sn)/HZSM5-HMS catalysts 被引量:5
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作者 N.Parsafard M.H.Peyrovi M.Rashidzadeh 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第9期1477-1486,共10页
Pt-(Sn,Re)/HZSM5-HMS catalysts were evaluated for n-heptane isomerization at 200–350 ℃.To characterize the catalyst,X-ray diffraction,X-ray fluorescene,Fourier transform infrared spectroscopy,ultraviolet-visible d... Pt-(Sn,Re)/HZSM5-HMS catalysts were evaluated for n-heptane isomerization at 200–350 ℃.To characterize the catalyst,X-ray diffraction,X-ray fluorescene,Fourier transform infrared spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,temperature-programmed reduction of H2,temperature-programmed desorption of NH3,infrared spectroscopy of adsorbed pyridine,H2 chemisorption,nitrogen adsorption-desorption,scanning electron microscopy and thermogravimetric analysis were performed.Kinetics of n-C7 isomerization were investigated under various hydrogen and n-C7 pressures,and the effects of reaction conditions on catalytic performance were studied.The results showed that bi-and trimetallic catalysts exhibit better performance than monometallic catalysts for this reaction.For example,a maximum i-C7 selectivity( 〉74%) and multibranched isomer selectivity(40%) were observed for Pt-Sn/HZSM5-HMS at 200 ℃. 展开更多
关键词 Bimetallic catalyst Trimetallic catalyst n-Heptane isomerization SELECTIVITY Multibranched isomer
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Preparation of Sn-β-zeolite via immobilization of Sn/choline chloride complex for glucose-fructose isomerization reaction 被引量:4
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作者 Asep Bayu Surachai Karnjanakom +2 位作者 Katsuki Kusakabe Abuliti Abudula Guoqing Guan 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第3期426-433,共8页
Well dispersion of tin species in an isolated form is a quite challenge since tin salts are easily hydrolyzed into(hydr)oxides during aqueous stannation of β-zeolite.In this study,immobilization of tin species on h... Well dispersion of tin species in an isolated form is a quite challenge since tin salts are easily hydrolyzed into(hydr)oxides during aqueous stannation of β-zeolite.In this study,immobilization of tin species on high silica commercial β-zeolite by using SnCl_2/Choline chloride(ChCl) complex followed with calcination provided a convenient way to get well dispersed Sn in β-zeolite in the aqueous condition,which was observed based on electron microscopy images,UV visible spectra and X-ray diffraction pattern.The existence of ChCl facilitated tin species to incorporate into zeolite.(1-2)wt%of Sn loaded β-zeolites exhibited good catalytic activity and high selectivity for glucose-fructose isomerization reaction. 展开更多
关键词 Sn-β zeolite IMMOBILIZATION Choline chloride GLUCOSE isomerization FRUCTOSE
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Novel endo-to exo-isomerization of dicyclopentadiene 被引量:5
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作者 Xiang Wen Zhang Kai Jiang +3 位作者 Qiang Jiang Ji Jun Zou Li Wang Zhen Tao Mi 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第6期673-676,共4页
Endo-dicyclopentadiene was isomerized to exo-isomer by thermal treatment at evaluated temperature and pressure. The reaction temperature and pressure are key factors for this novel isomerization. This result may have ... Endo-dicyclopentadiene was isomerized to exo-isomer by thermal treatment at evaluated temperature and pressure. The reaction temperature and pressure are key factors for this novel isomerization. This result may have great potential for practical application. 展开更多
关键词 Endo-dicyclopentadiene Exo-dicyclopentadiene isomerization
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Spiropyran isomerization triggering ESIPT for visualization of pH fluctuations during oxidative stress in living cells 被引量:3
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作者 Jingdong Wang Fangjun Huo +1 位作者 Yongbin Zhang Caixia Yin 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第5期470-474,共5页
Intracellular pH homeostasis is foundation of maintaining normal physiological functions.More and more evidences show that intracellular pH fluctuations were usually associated with many diseases(such as cancer,epilep... Intracellular pH homeostasis is foundation of maintaining normal physiological functions.More and more evidences show that intracellular pH fluctuations were usually associated with many diseases(such as cancer,epilepsy and neurodegenerative diseases).It is very important to develop in situ real-time determination of pH.In recent years,it has been verified that pH can regulate the isomerization process of spiropyran.Thus,we report a pH fluorescent probe BSL,which is a closed loop spiropyran structure by coupling benzothiazole derivatives with indole salts.We utilizes the process of spiropyran isomerization as the trigger of excited state intramolecular proton transfer(ESIPT)effect,and adjust the process of spiropyran isomerization through pH,and then the molecular transformation from enol to ketone(enol:525 nm,ketone:677 nm)through the ESIPT effect.This process achieved accurate measurement of pH.The probe BSL showed sensitive and reversible fluorescence response to pH in vitro.Ultimately,BSL was successfully applied to detect pH fluctuations in cell oxidative stress model. 展开更多
关键词 PH Spiropyran isomerization ESIPT Reversible Oxidative stress
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Isomerization of n-pentane catalyzed by amide-AlCl_(3)-based ionic liquid analogs with various additives 被引量:3
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作者 Pengcheng Hu Jingwei Zheng +2 位作者 Wei Jiang Lijuan Zhong Shufeng Zhou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第1期152-157,共6页
The isomerization of n-pentane to generate high-quality blending components for clean gasoline was catalyzed by several amide-AlCl3-based ionic liquid(IL)analogs with various amides as donor molecules.The catalytic pe... The isomerization of n-pentane to generate high-quality blending components for clean gasoline was catalyzed by several amide-AlCl3-based ionic liquid(IL)analogs with various amides as donor molecules.The catalytic performance of these IL analogs was evaluated in a magnetic agitated autoclave operated in batch mode.IL analog based n-methylacetamide(NMA)-AlCl3 with the amide/AlCl3 molar ratio of 0.65 showed excellent performance toward n-pentane isomerization because 0.65 NMA-1.0 AlCl3 had a low viscosity and bidentate coordination structure.The influences of reaction time,reaction temperature,and stirring speed on the catalytic performance were also investigated.Optimal reaction conditions comprised the reaction time of 1 h,the reaction temperature of 40°C,and the stirring speed of 1500 r·min-1.Under optimal condition,the n-C5 conversion,research octane number(RON)increment,total liquids yield,and isoparaffin yield in isomerized oil were56.80%,13.51,89.90 wt%,and 44.32 wt%,respectively.A new mathematical model was constructed to predict the relationships among RON increment,RON increment/n-C5 conversion ratio,and n-C5 conversion.The new model indicated that an appropriate conversion per pass of n-C5 did not exceed 50%–55%.Various cycloparaffin additives were used to improve the catalytic performance of 0.65 NMA-1.0 AlCl3.The n-C5 conversion increased from 56.80%to 67.32%.The RON increment,total liquids yield,and isoparaffin yield reached 17.83,97.36 wt%,and 63.74 wt%,respectively. 展开更多
关键词 isomerization Ionic liquid analogs N-PENTANE Mathematical model ADDITIVES
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