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Characterization of the acidity and basicity of green solvents by NMR techniques
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作者 Kemeng Shi Christian Marcus Pedersen +3 位作者 Hui Chang Jing Shi Yingxiong Wang Yan Qiao 《Magnetic Resonance Letters》 2021年第1期81-88,共8页
The acidity and basicity of the solvents can influence the reaction outcome notably,and hence the precise measurement of pH is important for reaction.However,not all the pH values of organic solvents can be determined... The acidity and basicity of the solvents can influence the reaction outcome notably,and hence the precise measurement of pH is important for reaction.However,not all the pH values of organic solvents can be determined with a classic pH meter straightly.In this research,the acidity and basicity of environmentally friendly green solvents,such as ZnCl_(2) molten salt hydrate,ionic liquids(ILs)and deep eutectic solvents(DESs),were characterized by 31P and 1 H NMR spectroscopy using trimethylphosphine oxide(TMPO)and pyrrole as probe molecules at 298 K.For the ZnCl_(2) molten salt hydrate,the acidic strength of the ZnCl_(2) molten salt hydrate increased with the concentration of ZnCl_(2).By using the ^(1)H-pyrrole NMR approach,it was found that the base strength of amino acid-based ILs follows the order:[Ch][Lys]>[Ch][His]. 展开更多
关键词 Green solvents acidity basicity ^(31)P-TMPO NMR ^(1)H-pyrrole NMR
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Activation of adult endogenous neurogenesis by a hyaluronic acid collagen gel containing basic fibroblast growth factor promotes remodeling and functional recovery of the injured cerebral cortex 被引量:1
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作者 Yan Li Peng Hao +6 位作者 Hongmei Duan Fei Hao Wen Zhao Yudan Gao Zhaoyang Yang Kwok-Fai So Xiaoguang Li 《Neural Regeneration Research》 SCIE CAS 2025年第10期2923-2937,共15页
The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate ne... The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate neurogenesis and reconstruct cortical layers II to VI in non-neurogenic regions,such as the cortex,remains unknown.In this study,we implanted a hyaluronic acid collagen gel loaded with basic fibroblast growth factor into the motor cortex immediately following traumatic injury.Our findings reveal that this gel effectively stimulated the proliferation and migration of endogenous neural stem/progenitor cells,as well as their differentiation into mature and functionally integrated neurons.Importantly,these new neurons reconstructed the architecture of cortical layers II to VI,integrated into the existing neural circuitry,and ultimately led to improved brain function.These findings offer novel insight into potential clinical treatments for traumatic cerebral cortex injuries. 展开更多
关键词 adult endogenous neurogenesis basic fibroblast growth factor-hyaluronic acid collagen gel cortical remodeling functional recovery migration motor cortex injury neural circuits neural stem cells newborn neurons proliferation
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Relative Basicity of Trioctylamine to Carboxylic Acid in Selected Organic Diluents 被引量:1
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作者 单欣昌 秦炜 戴猷元 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第6期747-750,共4页
The relative basicity of trioctylamine (TOA), pKa,BS, in protic polar diluent (1-octanol), non-protic polar diluent [methyl iso-butyl ketone (MIBK)] and inert diluent (CCl4) were determined for 11 mono-carboxy... The relative basicity of trioctylamine (TOA), pKa,BS, in protic polar diluent (1-octanol), non-protic polar diluent [methyl iso-butyl ketone (MIBK)] and inert diluent (CCl4) were determined for 11 mono-carboxylic acids, and the dependence of PKa,BS on the nature of solute and diluent type was discussed. The results show that pKa,BS determined by half neutralization with the solute carboxylic acid is in the order of 1-octanol〉MIBK〉CCl4 for a fixed TOA concentration, and it increases with increasing acidity and hydrophobicity of the carboxylic acid. Compared with two parameters of the solute extracted (acidity and hydrophobicity), pKa,BS is more sensitive to hydrophobicity of the acid. A mathematic equation representing relationship between the apparent extraction equilibrium (K11) and the system properties (PKa,BS and pKa) was proposed: 1g K11 = 2pKa,BS=pKa. It is proved that the extraction equilibrium of mono-carboxylic acids can be predicted by the above equation with reasonable accuracy. 展开更多
关键词 relative basicity trioctylamine (TOA) mono-carboxylic acid extraction equilibrium
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Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope
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作者 Qiang Liu Xiang Li +3 位作者 Shen Du Ming Gao Yanbin Yin Jiongming Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期102-110,共9页
During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest... During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels. 展开更多
关键词 mold flux low basicity BUBBLES three-dimensional X-ray microscope VISCOSITY
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Basicity of volcanic ash determining the degradation of thermal barrier coatings at elevated temperatures 被引量:1
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作者 Xiang Song Yiqian Guo +3 位作者 Qianyong Zhu Zhengfu Guo Shiteng Zhao Hongbo Guo 《Journal of Materials Science & Technology》 2025年第29期283-293,共11页
Volcanic ashes are posing increasingly severer threats to the aviation safety.As the operation temperature of the turbine engine elevates,molten volcanic ash leads to the degradation of the thermal barrier coatings(TB... Volcanic ashes are posing increasingly severer threats to the aviation safety.As the operation temperature of the turbine engine elevates,molten volcanic ash leads to the degradation of the thermal barrier coatings(TBCs)and eventually catastrophic engine failure.However,the physical and chemical properties of volcanic ashes vary due to the distinct chemical compositions,rendering it extremely challenging to evaluate the effects of each ash material on the failure of TBC.Here,we proposed a new metric termed Basicity to investigate the influence of chemical composition on the melting temperature and viscosity of volcanic ashes.Artificial CaO-MgO-Al_(2)O_(3)-SiO_(2) materials(CMAS)were synthesized to simulate the wetting,spreading and corrosion behavior of volcanic ashes at 1300 ℃ on(Gd_(0.9)Yb_(0.1))2Zr_(2)O_(7)(GYbZ),a model TBC material.Our results reveal that the synthetic CMAS does not fully capture the damage caused by volcanic ash due to the difference in compositions.The viscosity and characteristic temperatures decrease as the Basicity value increases,indicating its significant impact on the fusion properties of ashes.Notably,distinct from CMAS,the unexpected presence of Fe_(2)O_(3) in volcanic ashes promotes the formation of garnet phase,conversely impedes the formation of apatite dense layer.These findings provide valuable insights into the corrosion mechanisms caused by TBC and strategies for TBC protection against volcanic ashes. 展开更多
关键词 Volcanic ash basicity Thermal barrier coatings(TBC) Wetting behavior Corrosion mechanism
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On using an aerosol thermodynamic model to calculate aerosol acidity of coarse particles 被引量:1
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作者 Zhengyang Fang Shuwei Dong +10 位作者 Chengpeng Huang Shiguo Jia Fu Wang Haoming Liu He Meng Lan Luo Yizhu Chen Huanhuan Zhang Rui Li Yujiao Zhu Mingjin Tang 《Journal of Environmental Sciences》 2025年第2期46-56,共11页
Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should b... Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should be incorporated when thermodynamicmodels are employed to estimate the acidity of coarse particles.In this work,field measurements were conducted at a coastal city in northern China across three seasons,and covered wide ranges of temperature,relative humidity and NH_(3) concentrations.We examined the performance of different modes of ISORROPIA-II(a widely used aerosol thermodynamic model)in estimating aerosol acidity of coarse and fine particles.The M0 mode,which incorporates gas-phase data and runs the model in the forward mode,provided reasonable estimation of aerosol acidity for coarse and fine particles.Compared to M0,the M1 mode,which runs the model in the forward mode but does not include gas-phase data,may capture the general trend of aerosol acidity but underestimates pH for both coarse and fine particles;M2,which runs the model in the reverse mode,results in large errors in estimated aerosol pH for both coarse and fine particles and should not be used for aerosol acidity calculations.However,M1 significantly underestimates liquid water contents for both fine and coarse particles,while M2 provides reliable estimation of liquid water contents.In summary,our work highlights the importance of incorporating gas-aerosol partitioning when estimating coarse particle acidity,and thus may help improve our understanding of acidity of coarse particles. 展开更多
关键词 Aerosol acidity Coarse particles Thermodynamic model Aerosol liquid water ISORROPIA-II Gas-aerosol partitioning
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Influence of bulk-phase acidity,organic fraction,and dissolved oxygen on the photosensitized renoxification of nitrate in NaNO_(3)/humic acid mixtures
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作者 Qiong Li Wenkai Huang +2 位作者 Xinyuan Wu Yu Liu Hongbo Fu 《Journal of Environmental Sciences》 2025年第11期197-205,共9页
Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence... Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence of various environmental factors and aerosol properties on reactive nitrogen production remains largely unclear.In this work,we employed NaNO_(3)/humic acid(HA)as a model nitrate photosensitization system to investigate the crucial roles of aerosol acidity,organic fraction,and dissolved oxygen in the production of HONO,NO_(2),and NO_(2)^(-).The presence of HA at 10 mg/L resulted in a remarkable increase in HONO production rates by approximately 2–3 times and NO_(2)^(-) concentration by 3–6 times across a pH range of 5.2 to 2.0.Meanwhile,the molar fraction of gaseous HONO in total N(Ⅲ)production increased from4%to 69%as bulk-phase pH decreased from 5.2 to 2.0.The higher organic fraction(i.e.,20 and 50 mg/L HA concentration)instead inhibited HONO and NO_(2) release.The presence of dissolved oxygen was found to be adverse for reactive nitrogen production.This suggests that the HA photosensitizer promoted the secondary conversion of NO_(2) to HONO mainly via reduced ketyl radical intermediates,while superoxide radical formation might exert a negative effect.Our findings provide comprehensive insights into reactive nitrogen production from photosensitized nitrate photolysis mediated by various external and internal factors,potentially accounting for discrepancies between field observations and model simulations. 展开更多
关键词 Nitrate photolysis HONO Humic acid PHOTOSENSITIZATION Aerosol acidity Organic fraction
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Properties evaluation of DRI smelting slag for molten iron production:viscosity and sulfide capacity dependence on binary basicity
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作者 Wen-guo Liu Zhuo-gang Pang +1 位作者 Jian-lu Zheng Hai-bin Zuo 《Journal of Iron and Steel Research International》 2025年第11期4095-4107,共13页
The properties of direct reduced iron(DRI)smelting slag are important in the DRI melting process for molten iron production to ensure the slag-iron separation and quality of molten iron.The influence of binary basicit... The properties of direct reduced iron(DRI)smelting slag are important in the DRI melting process for molten iron production to ensure the slag-iron separation and quality of molten iron.The influence of binary basicity on the viscosity and sulfide capacity of CaO-SiO_(2)-MgO-Al_(2)O_(3)-FeO slag was investigated by the high-temperature experiments,structural analysis and thermodynamic calculation.The viscosity of the slag decreased rapidly with an increase in basicity from 0.4 to 0.8,and this trend became slow as the basicity further increased to 1.2.For the acidic slag with basicity of 0.4 and 0.6,the viscosity at 1500℃ was higher than 0.6 Pa s,which was harmful for the fluidity of slag melt.The slags with basicity of 0.8,1.0 and 1.2 at 1500℃ showed the low viscosity of less than 0.6 Pa s.For the basic slag with basicity of 1.0 and 1.2,the rapid precipitation of melilite led to the abrupt increase behavior of the viscosity,and the acidic slag showed the gentle temperature-viscosity curves.The Raman analysis revealed that the conversion from Q^(3) to Q^(2),Q^(1) and Q^(0) mainly occurred with the basicity increasing from 0.4 to 0.8,and the conversion from Q^(2) to Q^(1) and Q^(0) was dominant with further increase in basicity to 1.2,decreasing the degree of polymerization.The sulfide capacity was improved with the increasing basicity due to the increase in O^(2-)ions,and CaS could be formed dominantly for S^(2-)stabilization in present slag.The sulfur partition ratio was derived from sulfide capacity,and the values of sulfur partition ratio at basicity of 0.4 and 0.6 were much smaller than those at basicity of 0.8,1.0 and 1.2,indicating a weak desulfurization ability of the slag with a low basicity. 展开更多
关键词 Direct reduced iron Smelting slag basicity Sulfide capacity VISCOSITY
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The determination of acidity of the dilute solutions of weak multibasic organic acids
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作者 Elene Kvaratskhelia Ramaz Kvaratskhelia 《Journal of Biomedical Science and Engineering》 2010年第5期484-487,共4页
The new theoretical method for the accurate determination of acidity of dilute solutions of weak multibasic organic acids (which are widely used in medicine, pharmacology, various branches of industry and participate ... The new theoretical method for the accurate determination of acidity of dilute solutions of weak multibasic organic acids (which are widely used in medicine, pharmacology, various branches of industry and participate in important biological processes in living organisms) is suggested. The concepts of the contributions of the separate dissociation steps to the [H+] value, xm, are used for an analysis of complex equilibria of the processes of dissociation of these acids. The cases of weak dibasic and tribasic organic acids with the “overlapping” dissociation equilibria and a general case of weak multibasic acids, HnA, are considered. From the conditions of equality of the concentrations of various ionized and non-ionized forms in the dilute solutions of weak multibasic organic acids the areas of dominance of these forms in connection with the corresponding xm values are formulated. 展开更多
关键词 Dibasic acidS Tribasic acidS Hydrogen IONS CONCENTRATION EQUATIONS
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BASICITY ON ZEOLITE NAX AFTER WATER HANDLING STUDIED BY TPD OF ORGANIC ACID
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作者 Ming SU Ke Yi TAO Ling Ping ZHOU He Xuan LI(Department of Chemistry, Nankai University, Tianjin. 300071) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第8期741-742,共2页
In this paper the effect of ion-exchange simplified as water handling on basic zeolitewas studied.It was foond that the interaction between chemisorbed water and Na+-O2- couplewould increase the total number of basic ... In this paper the effect of ion-exchange simplified as water handling on basic zeolitewas studied.It was foond that the interaction between chemisorbed water and Na+-O2- couplewould increase the total number of basic sites, while weaken the intensity of each basic sites.Theprocess can be explained by the adsorb model of organic acid on NaX presented before. 展开更多
关键词 TPD basicity ON ZEOLITE NAX AFTER WATER HANDLING STUDIED BY TPD OF ORGANIC acid
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Selective separation of vanadium from the high-acidity leaching liquor through chelating extraction by the ketoxime extractant
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作者 Xile Tian Fancheng Meng +7 位作者 Xianglan Zhang Yongchao Wang Yahui Liu Jian Zhang Shuai Zhao Desheng Chen Lina Wang Tao Qi 《Chinese Journal of Chemical Engineering》 2025年第11期262-272,共11页
The high-acidity vanadium-containing solution contains high concentrations of iron and aluminum with pH around 0.5,the ketoxime extractant with the active ingredient of 2-hydroxy-5-nonylacetophenone oxime(HNAO,HL) was... The high-acidity vanadium-containing solution contains high concentrations of iron and aluminum with pH around 0.5,the ketoxime extractant with the active ingredient of 2-hydroxy-5-nonylacetophenone oxime(HNAO,HL) was proposed to extract vanadium from the solution.Under the phase ratio(O/A)of 1:2,HNAO concentration of 0.542 mol·L^(-1) at 25℃ for 10 min,99.06% of vanadium was extracted after a three-stage countercurrent extraction,while the extraction of impurities was less than 1%,with the separation coefficients of vanadium from iron and aluminum were 137050 and 43197,respectively.The antioxidant properties of the extractant were studied.At 25℃,the extractant basically did not undergo oxidative degradation.Besides,about 91.2% of the loaded vanadium was effectively stripped using 2.5 mol·L^(-1)Na_(2)CO_(3) solution.The extraction mechanism of vanadium was investigated through the slope analysis method,the spectral characterizations and density functional theory calculations.It has been observed that VO_(2)^(+) substitutes the H atom on the phenolic hydroxyl and coordinates with the N atom on the oxime and the O atom on the phenolic hydroxyl to form of a six-membered ring,and the extraction complexes were determined to be VO_(2)(H_(2)O)L and VO_(2)L. 展开更多
关键词 VANADIUM Solvent extraction High acidity Ketoxime extractant CHELATING
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Effect of slag basicity on semi-molten smelting process of saprolitic and limonitic laterite ores
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作者 Yu-xiao XUE Jian-bo ZHAO +1 位作者 Zhi-xiong YOU Xue-wei LV 《Transactions of Nonferrous Metals Society of China》 2025年第5期1679-1690,共12页
The semi-molten smelting process of a mixture of saprolitic and limonitic laterite ores was systematically investigated and the effect of slag basicity was deeply analyzed.The results indicate that the slag system can... The semi-molten smelting process of a mixture of saprolitic and limonitic laterite ores was systematically investigated and the effect of slag basicity was deeply analyzed.The results indicate that the slag system can be located in the liquidus region of low melting-point diopside(CaMgSi_(2)O_(6))when slag basicity is kept at 0.3 and limonitic laterite mass fraction is not less than 10%.When the reduction temperature,C/O mass ratio,limonitic laterite mass fraction and slag basicity are kept at the optimum values of 1300℃,0.86,20%and 0.3,respectively,ferronickel products with grades 6.42%Ni and 86.99%Fe are prepared.The recovery rates of Ni and Fe reach 88.60%and 72.25%,respectively. 展开更多
关键词 ferronickel saprolitic laterite ore limonitic laterite ore slag basicity semi-molten smelting process
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Basicity regulation of Ni-rich layered oxide cathodes for all-solid-state Li-ion batteries
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作者 Xiao-Zhong Fan Jin-Hao Zhang +6 位作者 Xiao-He Zhou Jin-Xiu Chen Yan-Qin Shi Gulnur Kalimuldina Fang Wang Ayaulym Belgibayeva Long Kong 《Journal of Energy Chemistry》 2025年第6期454-460,I0011,共8页
Ni-rich layered oxide cathode materials such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)face poor interfacial stability and serious side reactions with sulfide solid-state electrolytes.This problem is thought to be exa... Ni-rich layered oxide cathode materials such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)face poor interfacial stability and serious side reactions with sulfide solid-state electrolytes.This problem is thought to be exacerbated by the gradually accumulated basicity of the surface with the Ni content increasing.Herein,the acidic Li_(3)PO_(4)coating layer on NCM811 particles is introduced by ball-milling approach to neutralize the basicity and aggrandize the interfacial stability.The tailored surface structure and components of NCM811 not only suppress the direct contact of cathode particles with sulfide solid-state electrolyte,but also facilitate electrochemical dynamics by driving the Li+migration across the interface and promoting the electron exchange.Thus,cells with Li_(3)PO_(4)coating layer yield 101.3 mAh g^(-1)specific capacity at 2.0 C and highly reversed discharging capacity after suffering from harsh work conditions.Additionally,the stable coating layer broadens the electrochemical windows of cells,delivering long cycle stability(>100 cycles 0.5 C).This contribution highlights the importance of basicity regulation of Ni-rich layered oxide cathode and offers a low-cost and effective approach to design the interfacial structures for the development of all solid-state batteries. 展开更多
关键词 basicity regulation Cathode coating Interfacial stability Ni-rich layered oxide cathode All-solid-state lithium battery
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Origin of Brönsted acidity in germanosilicates from neighboring Ge-hydroxyl groups
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作者 Kun Lu Qian Liu +11 位作者 Liyu Chen Jilong Wang Zhenxuan Yuan Xiao Kong Yunxing Bai Jingang Jiang Yejun Guan Sicong Ma Hao Xu Weixin Huang Zhipan Liu Peng Wu 《Chinese Journal of Catalysis》 2025年第10期110-122,共13页
Constructing new Brönsted acid sites within zeolitic materials holds paramount importance for the advancement of solid-acid catalysis.Zeo-type germanosilicates,a class of metallosilicates with a neutral framework... Constructing new Brönsted acid sites within zeolitic materials holds paramount importance for the advancement of solid-acid catalysis.Zeo-type germanosilicates,a class of metallosilicates with a neutral framework composed of tetravalent Ge and Si oxygen tetrahedrons,are conventionally considered not to generate Brönsted acid sites.Herein,we disclose an abnormal phenomenon with Ge-rich IWW-type germanosilicate(IWW-A)as an example that Ge-enriched germanosilicates are featured by mild Brönsted acidity.Using the art-of-state density functional theory calculation,19F magic angle spinning nuclear magnetic resonance,microcalorimetric and ammonia infrared mass spectrometry-temperature-programmed desorption characterizations,the nature of germanosilicate's Brönsted acidity has been demonstrated to be closely related to the neighboring framework Ge-hydroxyl pairs.Besides,the contribution of Ge-OH groups to Brönsted acidity and the role of Ge-pair structure for maintaining mild acid strength have been elucidated.In catalytic cracking of n-hexane and methanol-to-olefins reaction,the IWW-A germanosilicate exhibit high light olefins selectivity,good recyclability and low carbon deposition,outperforming the benchmark zeolite catalyst,ZSM-5 aluminosilicate. 展开更多
关键词 Germanosilicates IWW Brönsted acidity Framework Ge-hydroxyl Alkane cracking Methanol-to-olefins
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Syntheses,structures,and catalytic performances of complexes with 4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid ligands
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作者 LING Weizhong LIN Jingyi +3 位作者 ZHU Jianglin LIANG Yuyi DAI Shanshan LI Yu 《无机化学学报》 北大核心 2026年第1期152-160,共9页
Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(... Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid),phen(1,10-phenanthroline),bpb(1,4-bis(pyrid-4-yl)benzene),bpa(bis(4-pyridyl)amine),and copper,nickel and cadmium chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and singlecrystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three complexes crystallize in the monoclinic P21/n,tetragonal I42d,and orthorhombic P21212 space groups.The complexes exhibit molecular dimers(1)or 2D metal-organic networks(2 and 3).The catalytic performances in the Knoevenagel reaction of these complexes were investigated.Complex 1 exhibits an effective catalytic activity and excellent reusability as a heterogeneous catalyst in the Knoevenagel reaction at room temperature.CCDC:2463800,1;2463801,2;2463802,3. 展开更多
关键词 COMPLEX dicarboxylic acid catalytic properties Knoevenagel reaction
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The study on citric acid-modified HUSY catalyzed alkylation of phenol with cyclohexanol
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作者 HUA Canhao WU Jingfeng +2 位作者 ZHU Lingjun XU Guangwen WANG Shurong 《燃料化学学报(中英文)》 北大核心 2026年第3期58-70,共13页
Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylat... Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylation-hydrogenation processes.This study systematically evaluates the catalytic performance of various zeolites(Hβ,HZSM-5,MCM-41 and HUSY)in the alkylation reaction of phenol with cyclohexanol.Characterization results demonstrate that HUSY zeolite showed superior catalytic activity compared to other zeolites,attributable to its favorable pore architecture and well-balanced acid site distribution that synergistically facilitate molecular diffusion and catalytic transformations.To further enhance the catalytic properties,HUSY zeolite was modified with citric acid at various concentrations and compared with those treated with NaOH and oxalic acid.The results revealed that citric acid treatment preserved the crystallinity of the zeolite while modulating its acid distribution and pore structure.All modified zeolites enhanced phenol alkylation activity.Notably,the HUSY-0.5M catalyst,which exhibited the highest medium-strong acid to total acid ratio,achieved superior catalytic performance,80.4%conversion of phenol and 99.6%selectivity for alkylation products.The catalyst also exhibited high activity in the alkylation of various lignin-derived compounds,demonstrating its broad applicability.This work provides a new strategy for the valorization of lignin-derived phenols into high-value fuel precursors through alkylation. 展开更多
关键词 citric acid modification HUSY phenolic alkylation aviation fuel
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Influence of the distance between Brønsted acid sites and Mo sites in Mo/HZSM-5 on the mechanism of methane dehydroaromatization performance
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作者 WANG Ce WEI Lihong +2 位作者 ZHANG Qinghao ZHANG Hongxiang SUN Yuewen 《燃料化学学报(中英文)》 北大核心 2026年第4期68-81,共14页
Methane dehydroaromatization(MDA)presents a promising carbon-neutral pathway for benzene,toluene,and xylene(BTX)production,alternative to petroleumderived routes.Elucidating the regulatory mechanisms of Brønsted ... Methane dehydroaromatization(MDA)presents a promising carbon-neutral pathway for benzene,toluene,and xylene(BTX)production,alternative to petroleumderived routes.Elucidating the regulatory mechanisms of Brønsted acid site(BAS)strength on reaction pathways,alongside the spatial proximity effects between BAS and Mo active sites in bifunctional synergy,remains a critical scientific challenge in catalyst design.This study systematically tunes both BAS strength(via isomorphous metal substitution)and Mo-BAS spatial proximity in zeolites,integrating MDA catalytic evaluations with density functional theory(DFT)calculations to dissect their individual contributions.Strongly acidic BAS catalysts(compared to moderately acidic Fe/Ga-substituted counterparts)exhibit superior performance,evidenced by enhanced aromatic yields.Conversely,weakly acidic Bsubstituted zeolites demonstrate optimal mono-/bifunctional synergy,outperforming moderate-acid systems.DFT results reveal that acid strength dictates C−H activation mechanisms by modulating the energy barriers of rate-determining steps.While Al-zeolites deliver the highest activity,B-substituted systems display unique potential for mechanistic investigations.Spatial proximity analysis indicates that micrometer-scale Mo-BAS distances hinder effective synergy due to exceeding electron interaction and mass transfer limits,whereas nanometer-scale proximity enhances activity(via accelerated intermediate transport)and suppresses coke formation.These findings establish a theoretical framework for rationalizing zeolite catalyst optimization through BAS property engineering and spatial control of Mo-BAS cooperation,providing actionable guidelines for designing next-generation MDA catalysts. 展开更多
关键词 methane dehydroaromatization Brønsted acid catalytic mechanism ZEOLITE
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Photocatalytic Radical-Mediated Synthesis of Unnaturalα-Amino Acids from Heteroaryl Aldehydes
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作者 Ren Ke Zhang Guanglu +3 位作者 Niu Yifan Wang Xiaomeng Chen Canyu Jiang Min 《有机化学》 北大核心 2026年第1期215-224,共10页
Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehyde... Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehydes via acyl radical intermediates is reported.This method exhibits exceptional functional group tolerance and enables late-stage diversification of peptides and carbonyl-group derivatization.Mechanistic studies confirm a radical-based pathway,while applications in peptide modification highlight its utility in bioorganic chemistry. 展开更多
关键词 PHOTOCATALYTIC non-natural amino acids heteroaryl aldehydes acyl radical electron paramagnetic resonance
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Integrated Transcriptomic and Metabolomic Analysis Reveals the Adaptive Mechanism of Penicillium digitatum under Modified Atmosphere Packaging Based on Amino Acid Metabolism
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作者 HAO Shanshan WANG Zhengli +3 位作者 XU Huihui JI Nana GUO Yanyin Abbas AQLEEM 《食品科学》 北大核心 2026年第6期129-144,共16页
This study employed integrated multi-omics approaches to elucidate,from the perspective of amino acid metabolism,the adaptive mechanism of Penicillium digitatum under modified atmosphere packaging(MAP)conditions.Compa... This study employed integrated multi-omics approaches to elucidate,from the perspective of amino acid metabolism,the adaptive mechanism of Penicillium digitatum under modified atmosphere packaging(MAP)conditions.Comparative analysis of natural air(Air),controlled atmosphere(CA),and MAP treatments revealed that MAP upregulated the expression of the hercynylcysteine S-oxide synthase(HCSOS),aldehyde dehydrogenase(ALDH),and monoamine oxidase(MAO)genes,thereby enhancing histidine-derived ergothioneine and methionine levels,and subsequently boosting glutathione-mediated redox homeostasis.Meanwhile,MAP induced the expression of the dihydroxyacid dehydratase(DHAD),saccharopine dehydrogenase(SDH),and arginosuccinate lyase(ASL)genes,redirecting valine,lysine,and arginine into the tricarboxylic acid(TCA)cycle to fuel ATP production.MAP also enhanced ASL-mediated arginine degradation and urea cycle activity,reducing arginine accumulation when compared to CA treatment.In contrast,while MAP induced upregulated expression of the pyrroline-5-carboxylate dehydrogenase(P5CDH)and D-amino acid oxidase(DAAO)genes,CA treatment promoted proline accumulation,reflecting stress-specific metabolic flexibility.Collectively,these findings demonstrate that MAP triggers transcriptional reprogramming of amino acid metabolism to coordinate oxidative defense,energy generation,and osmotic balance.By modulating these metabolic pathways and regulatory genes under MAP conditions,fungal adaptability can be disrupted.Hence,this study provides a promising strategy for suppressing green mold development,extending the postharvest shelf life,and improving the quality of fruits and vegetables. 展开更多
关键词 amino acid metabolism multi-omics Penicillium digitatum modified atmosphere packaging postharvest pathology
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Efficient leaching and separation of iron,aluminum,and calcium from carbon-rich components in coal gasification fine slag using organic acids
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作者 NAN Tianhao ZHOU Anning +4 位作者 HAN Rui HAN Chunmeng CHEN Heng ZHANG Ningning LI Bingying 《燃料化学学报(中英文)》 北大核心 2026年第4期1-16,共16页
The efficient extraction and separation of valuable metal elements from coal gasification fine slag(CGFS)are crucial for the comprehensive high-value utilization of its constituents.This study focused on the carbon-ri... The efficient extraction and separation of valuable metal elements from coal gasification fine slag(CGFS)are crucial for the comprehensive high-value utilization of its constituents.This study focused on the carbon-rich components of CGFS(CGFS-H)and systematically investigates the selective leaching behavior of Fe^(3+),Al^(3+)and Ca^(2+)using three organic acid extractants,i.e.,citric acid,tartaric acid,and tetrasodium iminodisuccinate.Additionally,the stepwise leaching of iron,aluminum and calcium from CGFS-H is explored.The selective dissolution mechanisms of these metals by different organic acids are elucidated through X-ray diffraction(XRD),X-ray fluorescence(XRF),and scanning electron microscopy(SEM)analyses.The results indicate that tetrasodium iminodisuccinate exhibits the highest leaching selectivity for Fe^(3+),while tartaric acid demonstrateds a comparable affinity for both Fe^(3+)and Al^(3+).In contrast citric acid shows superior selectivity toward Ca^(2+).The leaching yield of Fe^(3+),Al^(3+)and Ca^(2+)after sequential leaching with the three organic acids were 79.8%,65.08%and 78.6%,respectively.These findings confirm that effective and selective separation of Fe^(3+),Al^(3+)and Ca^(2+)from CGFS-H can be achieved via optimized organic acid-based leaching strategies.This advancement provides a critical foundation for developing Ca/Fe/Al hydrotalcite materials using CGFS-H as a sustainable feedstock,thereby facilitating the transformation of waste residue into high-value functional materials and promoting resourceefficient utilization of coal gasification fine slag. 展开更多
关键词 coal gasification fine slag carbon-rich components organic acids LEACHING stepwise extraction
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