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Acetone-mediated glucose isomerization over a ZrO_(2)-NC composite catalyst
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作者 Mi Gao Hongquan Fu +2 位作者 Wenhua Zhang Zhicheng Jiang Bi Shi 《Green Energy & Environment》 2026年第2期454-463,共10页
The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen f... The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen fibers were used to anchor Zr^(4+),and a highly dispersed ZrO_(2)-nitrogen-doped carbon(ZrO_(2)-NC)composite catalyst was subsequently fabricated by calcination.For the catalytic glucose-to-fructose isomerization over ZrO_(2)-NC,fructose was obtained in 41.3%yield and 85.3%selectivity in a water-acetone solvent at 120℃ for 10 min.The electron-deficient environment of ZrO_(2)surface during charge transfer from ZrO_(2)-to-NC layer facilitated the preferential adsorption of glucose,which accelerated glucose isomerization and fructose desorption.The amphoteric catalyst triggered both proton transfer on the Bronsted base sites and the intramolecular hydride shift of glucose on the Lewis acid sites of ZrO_(2)-NC in the mixed solvent.The latter isomerization mechanism depended on the presence of acetone,which lowered the energy barrier and increased fructose yield. 展开更多
关键词 Glucose isomerization FRUCTOSE ZrO_(2) ACETONE Adsorption
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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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甲基橙/聚乙烯醇复合薄膜的光致双折射增强研究
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作者 贾文龙 周攀 +1 位作者 杨东旭 朱建华 《四川大学学报(自然科学版)》 北大核心 2026年第1期163-167,共5页
本文研究了环境湿度对甲基橙/聚乙烯醇(MO/PVA)复合薄膜光致双折射的影响。制备了质量分数分别为1%、2%和3%的3种浓度MO/PVA薄膜,并测量了其在60%、50%和40%相对湿度(Relative Humidity,RH)环境下的光致双折射。实验结果表明,随着RH的降... 本文研究了环境湿度对甲基橙/聚乙烯醇(MO/PVA)复合薄膜光致双折射的影响。制备了质量分数分别为1%、2%和3%的3种浓度MO/PVA薄膜,并测量了其在60%、50%和40%相对湿度(Relative Humidity,RH)环境下的光致双折射。实验结果表明,随着RH的降低,样品的光致双折射最大值(Δnmax)逐渐增大。在RH为40%的条件下,质量分数为3%的MO/PVA薄膜表现出最高的Δnmax值,达4.4×10^(-3),该数值显著高于其他文献中报道的甲基橙薄膜的光致双折射水平。基于甲基橙分子的顺反异构与重取向行为,分析了环境湿度调控光致双折射效应的物理机制。研究结果表明,通过优化环境湿度条件,可有效增强样品的光致双折射性能,有望提升偏振全息记录性能,在偏振复用全息存储领域具有重要的应用价值。 展开更多
关键词 偏振全息 光致双折射 甲基橙 异构和重取向 环境湿度
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RP-HPLC法测定甲磺酸沙芬酰胺中的2种异构体杂质
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作者 李旦 徐姁 +2 位作者 张晓 路珊珊 孙春艳 《中国医药工业杂志》 2026年第1期118-121,共4页
建立了反相高效液相色谱法同时测定甲磺酸沙芬酰胺(1)中对氟异构体(2)和对映异构体(3)的含量。采用CHIRALPAK IG-3色谱柱(4.6 mm×250 mm,3μm),以体积比为10∶90的0.05 mol/L碳酸氢铵溶液和甲醇为流动相,在等度洗脱模式下进行分离... 建立了反相高效液相色谱法同时测定甲磺酸沙芬酰胺(1)中对氟异构体(2)和对映异构体(3)的含量。采用CHIRALPAK IG-3色谱柱(4.6 mm×250 mm,3μm),以体积比为10∶90的0.05 mol/L碳酸氢铵溶液和甲醇为流动相,在等度洗脱模式下进行分离。检测波长226 nm,流速0.5 mL/min,柱温15℃。方法学研究显示,2和3分别在0.16~1.62、0.16~1.57μg/mL线性关系良好(r>0.99);检测限均为0.02μg/mL,定量限均为0.16μg/mL。2和3的平均回收率(n=9)分别为102.0%、92.1%,RSD分别为5.9%、4.2%。该方法准确、可靠,灵敏度高,可用于测定1中2种异构体杂质的含量。 展开更多
关键词 甲磺酸沙芬酰胺 抗震颤麻痹药 反相高效液相色谱 手性分离 异构体杂质
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Kinetic mechanism of enzymatic esterification and quantitative profiling of acylglycerol isomer distribution
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作者 Shuo Zou Hongzeng Ai +2 位作者 Yee-Ying Lee Yong Wang Zhen Zhang 《Grain & Oil Science and Technology》 2026年第1期62-70,共9页
Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the k... Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis. 展开更多
关键词 Enzymatic esterification DIACYLGLYCEROL KINETICS Acyl migration ISOMER
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1-丁烯骨架异构化催化剂的研究进展
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作者 金龙 杜改平 陈江波 《合成树脂及塑料》 北大核心 2026年第2期65-70,共6页
综述了1-丁烯骨架异构反应的催化剂类型、反应活性位点及影响因素。1-丁烯骨架异构化催化剂分为卤化物、非卤化物及分子筛催化剂,其中,分子筛催化剂为主流催化剂;在骨架异构反应中,Brönsted酸位点为主要活性位点,而Lewis酸位点几... 综述了1-丁烯骨架异构反应的催化剂类型、反应活性位点及影响因素。1-丁烯骨架异构化催化剂分为卤化物、非卤化物及分子筛催化剂,其中,分子筛催化剂为主流催化剂;在骨架异构反应中,Brönsted酸位点为主要活性位点,而Lewis酸位点几乎不起作用;反应活性和选择性的影响因素包括分子筛的孔道结构、酸位性质及积碳行为,通过调节这些因素能够增大异构化的收率和选择性。 展开更多
关键词 1-丁烯骨架异构化 分子筛催化剂 活性位点 积碳
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Ab initio calculations of isomers in nuclei near the magic number N=50
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作者 S Q Fan Q Yuan +3 位作者 R Z Hu S L Jin J H Hou F R Xu 《Communications in Theoretical Physics》 2026年第2期44-52,共9页
The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nu... The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators andβ-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations. 展开更多
关键词 Ab initio calculations ISOMERISM chiral two-plus three-nucleon force beta decay electromagnetic transitions
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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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Shape polarization and coexistence of high-K three-quasiparticle states in odd-mass N=106 isotones
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作者 Run-Yan Dong Chang-Feng Jiao 《Nuclear Science and Techniques》 2026年第5期315-325,共11页
Three-quasiparticle K-isomeric states in odd-mass N=106 isotones within the A~180 mass region were systematically investigated using configuration-constrained potential energy surface calculations.The calculations suc... Three-quasiparticle K-isomeric states in odd-mass N=106 isotones within the A~180 mass region were systematically investigated using configuration-constrained potential energy surface calculations.The calculations succes sfully reproduced the excitation energies and deformations of the known high-K isomers in nuclei from 175Tm to 181Re.For the nuclei closer to the Z=82 shell closure(^(183)Ir,^(185)Au,and^(187)Tl),predictions of the configurations of the observed and yet-to-be-observed isomers are provided.The results reveal strong shape polarization,where the three-quasiparticle states are driven to larger deformations compared to the often shape-soft or spherical ground states.A particularly rich spectrum of shape coexistence is predicted in^(187)Tl,where several high-K three-quasiparticle configurations with distinct prolate,oblate,and triaxial shapes are found to coexist at similar excitation energies.Notably,the oblate-deformed K^(π)=29/2^(+)configuration at E_(x)=1839 keV was proposed to be responsible for a long-lived isomer.This study provides a comprehensive picture of shape evolution and coexistence in high-K multi-quasiparticle states,offering valuable insights for future experimental studies. 展开更多
关键词 Shape polarization Shape coexistence High-K isomeric state Con-guration-constrained potential energy surface
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Miniaturized bandpass filter with a wide upper stopband using isomeric resonators in a cavity
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作者 Chengyang ZHANG Ying XUE +1 位作者 Qingyuan LU Jianxin CHEN 《ENGINEERING Information Technology & Electronic Engineering》 2026年第1期81-86,共6页
1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(I... 1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023). 展开更多
关键词 bandpass filters bpfs advanced telecommunication systems upper stopband rejection isomeric resonators cavity filters enhancement upper stopband rejection huang miniaturized bandpass filters insertion loss
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生理环境下Val→Mn^(2+)手性对映体异构的DFT研究
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作者 杨静 闫红彦 +5 位作者 姜春旭 赵红迪 孙鸣 吴静 王佐成 戴文娟 《南开大学学报(自然科学版)》 北大核心 2026年第1期33-42,52,共11页
采用M06泛函方法,结合自洽反应场的SMD模型方法,对Val→Mn^(2+)在水液相、1个标准大气压、310.15 K生命体内环境的手性对映体异构机理进行研究.反应通道研究发现:S-Val→Mn^(2+)的对映异构可在3个通道实现,一是α-H以O为桥梁迁移,另一... 采用M06泛函方法,结合自洽反应场的SMD模型方法,对Val→Mn^(2+)在水液相、1个标准大气压、310.15 K生命体内环境的手性对映体异构机理进行研究.反应通道研究发现:S-Val→Mn^(2+)的对映异构可在3个通道实现,一是α-H以O为桥梁迁移,另一个是α-H迁移到O后N原子上的质子再向α-C迁移,再一个是α-H质子迁移到N原子后N原子上的一个H质子向α-C原子迁移.反应的自由能剖面图计算表明,H质子以N原子为桥迁移的反应具有优势,该通道决速步能垒在111.6-115.8 kJ/mol之间.研究结果表明,Val→Mn^(2+)在生命体内的对映体异构十分缓慢,用缬氨酸二价锰配合物为生命体同时补充锰元素和缬氨酸比较安全. 展开更多
关键词 缬氨酸 二价锰 密度泛函理论 溶剂效应 对映异构 自由能垒
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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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