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Titratable Acidity and Alkalinity of Red Soil Surfaces
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作者 SHAOZONG-CHEN HEQUN 《Pedosphere》 SCIE CAS CSCD 1993年第2期107-117,共11页
The surfaces of red soils have an apparent amphotenc character, carrying titratable acidity and titratable alkalinity simultaneously. The titratable acidity arises from deprotonation of hydroxyl groups of hydrous oxid... The surfaces of red soils have an apparent amphotenc character, carrying titratable acidity and titratable alkalinity simultaneously. The titratable acidity arises from deprotonation of hydroxyl groups of hydrous oxide-type surfaces and dissociation of weak-acid functional groups of soil organic matter, while the titratable alkalinity is derived from release of hydroxyl groups of hydrous oxide-type surfaces. The titratable acidity and titratable alkalinity mainly depended on the composition and content of iron and aluminum oxides in the soils. The results showed that the titratable acidity and titratable alkalinity were in significantly positive correlation not only with the content of amorphous aluminum oxide(Alo) and iron oxide(Feo) extracted with acid ammonium oxalate solution, free iron ox-ide(Fed) extracted with sodium dithionite-citrate-bicarbonate (DCB) and clays, but also with the zero point of charge (ZPC) of the samples. Organic matter made an important contribution to the titratable acidity. The titratable alkalinity was closely correlated with the amount of fluoride ions adsorbed. The titratable acidity and titratable alkalinity of red soils were influenced by parent materials, being in the order of red soil derived from basalt > that from tuff > that from granite. The titratable acidity and titratable alkalinity were closely related with origination of the variable charges of red soils, and to a certain extent were responsible for variable negative and positive charges of the soils. 展开更多
关键词 fluoride adsorption red soil titratable acidity titratable alkalinity variable charge
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Effect of Saline Water on Soil Acidity, Alkalinity and Nutrients Leaching in Sandy Loamy Soil in Rwamagana Bella Flower Farm, Rwanda
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作者 Abel Mwubahaman Wali Umaru Garba +3 位作者 Hussein Bizimana Jean de Dieu Bazimenyera Eric Derrick Bugenimana Jean Nepomuscene Nsengiyumva 《Agricultural Sciences》 2024年第1期15-35,共21页
The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific consideration... The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K<sup>+</sup>), Magnesium (Mg2<sup>+</sup>), Sulphur (S), CN ratio and Sodium (Na<sup>+</sup>) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels. 展开更多
关键词 NUTRIENTS LEACHING Saline Water Soil acidity Soil alkalinity
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Use of Alkaline Slag and Crop Residue Biochars to Promote Base Saturation and Reduce Acidity of an Acidic Ultisol 被引量:6
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作者 M.M.MASUD LI Jiu-Yu XU Ren-Kou 《Pedosphere》 SCIE CAS CSCD 2014年第6期791-798,共8页
This investigation was conducted by using alkaline slag and crop straw biochars to reduce acidity of an acidic Ultisol through incubation and pot experiments with lime as a comparison. The soil was amended with differ... This investigation was conducted by using alkaline slag and crop straw biochars to reduce acidity of an acidic Ultisol through incubation and pot experiments with lime as a comparison. The soil was amended with different liming materials: lime(1 g kg-1),alkaline slag(2 and 4 g kg-1), peanut straw biochar(10 and 20 g kg-1), canola straw biochar(10 and 20 g kg-1) and combinations of alkaline slag(2 g kg-1) and biochars(10 g kg-1) in the incubation study. A pot experiment was also conducted to observe the soybean growth responses to the above treatments. The results showed that all the liming materials increased soil p H and decreased soil exchangeable acidity. The higher the rates of alkaline slag, biochars, and alkaline slag combined with biochars, the greater the increase in soil p H and the reduction in soil exchangeable acidity. All the amendments increased the levels of one or more soil exchangeable base cations. The lime treatment increased soil exchangeable Ca2+, the alkaline slag treatment increased exchangeable Ca2+and Mg2+levels, and the biochars and combined applications of alkaline slag with biochars increased soil exchangeable Ca2+, Mg2+and K+and soil available P. The amendments enhanced the uptake of one or more nutrients of N, P, K, Ca and Mg by soybean in the pot experiment. Of the different amendments, the combined application of alkaline slag with crop straw biochars was the best choice for increasing base saturation and reducing soil acidity of the acidic Ultisol. The combined application of alkaline slag with biochars led to the greatest reduction in soil acidity, increased soil Ca, Mg, K and P levels, and enhanced the uptake of Ca, Mg, K and P by soybean plants. 展开更多
关键词 alkaline amendment exchangeable acidity exchangeable base cation soil pH soybean growth
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Alleviation of Soil Acidity and Aluminium Phytotoxicityin Acid Soils by Using Alkaline-Stabilized Biosolids 被引量:6
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作者 LUOYONGMING P.CHRISTIE 《Pedosphere》 SCIE CAS CSCD 2002年第2期185-188,共4页
A pot experiment was catried out to study alleviation of soil acidity and Al toxicity by applying analkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acidsandy lo... A pot experiment was catried out to study alleviation of soil acidity and Al toxicity by applying analkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acidsandy loam (pH 4.5). Barley (Hondeum vulgare L. cv. Forrester) was used as a test crop and was grownin the sewage sludge-amended (33.5 t sludge DM ha-1) and unamended soils. The results showed that thealka1ine biosloids increased soil pH from 5.7 to 6.9 for the clay sandy loam and from 4.5 to 6.0 for the sandyloam. The sludge product decreased KCl-extractable Al from 0.1 to 0.0 cmol kg-1 for the former soil andfrom 4.0 to 0.1 cmol kg-1 for the latter soil. As a result, barley plants grew much better and grain yieldincreased greatly in the amended treatments compared with the unamended controls. These observationsindicate that alkaline-stabilised biosolids can be used as a liming material for remedying Al phytotoxicity instrongly acid soils by increasing soil pH and lowering Al bioavailability. 展开更多
关键词 alkaline biosolids phytotoxicity soil acidity soil remediation
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Flotation separation of chalcopyrite from pyrite using mineral fulvic acid as selective depressant under weakly alkaline conditions 被引量:5
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作者 Zhi-hao SHEN Shu-ming WEN +1 位作者 Jia-mei HAO Qi-cheng FENG 《Transactions of Nonferrous Metals Society of China》 2025年第1期313-325,共13页
Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger in... Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite. 展开更多
关键词 mineral fulvic acid CHALCOPYRITE PYRITE flotation separation
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Ethylenediamine tetramethylenephosphonic acid as a selective collector for the improved separation of chalcopyrite against pyrite at low alkalinity 被引量:4
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作者 Jianjun Wang Gaogui Jing +3 位作者 Renji Zheng Zijie Huang Wei Sun Zhiyong Gao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第7期873-882,共10页
Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment a... Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment and associated precious metals recovery. Therefore, in this study, the green and odourless ethylenediamine tetramethylenephosphonic acid(EDTMPA) was introduced as a novel chalcopyrite collector. Flotation results from the binary mineral mixture and real ore demonstrated that EDTMPA could realize the selective separation of chalcopyrite from pyrite relative to ethyl xanthate(EX) without any depressants within the wide p H range of 6.0–11.0, and might replace the traditional high-alkaline lime process. Electrochemical and Fourier transform infrared spectra measurements indicated that the difference in adsorption performance of EDTMPA on chalcopyrite and pyrite was larger than that of EX, suggesting a better selectivity for EDTMPA. Density functional theory calculations demonstrated that there were stronger chemical bonds between P—O groups of EDTMPA and the Fe/Cu atoms on chalcopyrite in the form of a stable six-membered ring. Crystal chemistry calculations further revealed that the activity of metal atoms of chalcopyrite was higher than that of pyrite. Therefore, these basic theoretical results and practical application provide a guidance for the industrial application of EDTMPA in chalcopyrite flotation. 展开更多
关键词 CHALCOPYRITE PYRITE Flotation Ethylenediamine tetramethylenephosphonic acid COLLECTOR
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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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Continuous-flow synthesis of pentaerythritol:Alkalinity release of sodium solvation cage to control aldol and Cannizzaro reactions
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作者 Zhengguang Wang Xin Qu +6 位作者 Xingke Yuan Zhanpeng Gao Niu Hu Jiansheng Wei Wenpeng Li Zhirong Yang Jingtao Wang 《Chinese Journal of Chemical Engineering》 2025年第3期23-29,共7页
Continuous-flow upgrading of pentaerythritol synthesis technology via base-catalyzed aldol and Cannizzaro reactions of formaldehyde and acetaldehyde faces the challenge of effectively controlling the critical side rea... Continuous-flow upgrading of pentaerythritol synthesis technology via base-catalyzed aldol and Cannizzaro reactions of formaldehyde and acetaldehyde faces the challenge of effectively controlling the critical side reaction of hydroxymethyl acetaldehyde(HA)to the acrolein intermediate.Here,we first identified the forms of industrial formaldehyde as methane diol that easily converts to the alkaline formaldehyde under alkaline(NaOH)environment.The carbonyl group of alkaline formaldehyde induces deprotonation of acetaldehyde instead of the recognized base-hydroxyl group-induced deprotonation,and it needs to overcome only 18.31 kcal·mol^(-1)(1 kcal=4.186 kJ)energy barrier to form key intermediates of HA.The sodium solvation cage formed by NaOH hexa-coordinated formaldehyde effectively inhibits the alkalinity,thus contributing to a high energy barrier(46.21 kcal·mol^(-1))to unwanted acrolein formation.In addition,the solvation cage gradually opens to increase the alkalinity with the consumption of formaldehyde,thus facilitating the subsequent Cannizzaro reaction(to overcome 11.77 kcal·mol^(-1)).In comparison,strong alkalinity promotes the formation of acrolein(36.65 kcal·mol^(-1))to initiate the acetal side reaction,while weak alkalinity reduces the possibility of the Cannizzaro reaction(to overcome 20.44 kcal·mol^(-1)).This theoretically reveals the importance of the segmented feeding of weak and strong bases to successively control the aldol reaction and Cannizzaro reaction,and the combination of Na_(2)CO_(3) or HCOONa with NaOH improves the pentaerythritol yield by 7%to 13%compared to that of NaOH alone(70%yield)within 1 min at a throughput of 155.7 ml·min^(-1). 展开更多
关键词 alkaline formaldehyde Sodium solvation cage Aldol reaction Cannizzaro reaction CONTINUOUS-FLOW PENTAERYTHRITOL
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Vacuum ammonia stripping from liquid digestate:Effects of pH,alkalinity,temperature,negative pressure and process optimization
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作者 Qiuhong Chen Donghai Yang +3 位作者 Xiang Chen Xiankai Wang Bin Dong Xiaohu Dai 《Journal of Environmental Sciences》 2025年第3期638-650,共13页
High ammonia-nitrogen digestate has become a key bottleneck limiting the anaerobic digestion of organic solid waste.Vacuum ammonia stripping can simultaneously remove and recover ammonia nitrogen,which has attracted a... High ammonia-nitrogen digestate has become a key bottleneck limiting the anaerobic digestion of organic solid waste.Vacuum ammonia stripping can simultaneously remove and recover ammonia nitrogen,which has attracted a lot of attention in recent years.To investigate the parameter effects on the efficiency and mass transfer,five combination conditions(53℃ 15 kPa,60°C 20 kPa,65°C 25 kPa,72°C 35 kPa,and 81°C 50 kPa)were conducted for ammonia stripping of sludge digestate.The results showed that 80%of ammonia nitrogen was stripped in 45 min for all experimental groups,but the ammonia transfer coefficient varied under different conditions,which increased with the rising of boiling point temperature,and reached the maximum value(39.0 mm/hr)at 81°C 50 kPa.The ammonia nitrogen removal efficiency was more than 80%for 30 min vacuum stripping after adjusting the initial pH to above 9.5,and adjustment of the initial alkalinity also affects the pH value of liquid digestate.It was found that pH and alkalinity are the key factors influencing the ammonia nitrogen dissociation and removal efficiency,while temperature and vacuum mainly affect the ammonia nitrogen mass transfer and removal velocity.In terms of the mechanism of vacuum ammonia stripping,it underwent alkalinity destruction,pH enhancement,ammonia nitrogen dissociation,and free ammonia removal.In this study,two-stage experiments of alkalinity destruction and ammonia removal were also carried out,which showed that the two-stage configuration was beneficial for ammonia removal.It provides a theoretical basis and practical technology for the vacuum ammonia stripping from liquid digestate of organic solid waste. 展开更多
关键词 Liquid digestate Vacuum ammonia stripping alkalinity Mass transfer Process optimization
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Facile modification using organic acid molecules to neutralize residual alkaline compounds for stabilizing LiNi_(0.9)5Co_(0.04)Mn_(0.01)O_(2) cathode material
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作者 Chao Zhao Xiangshao Yin +7 位作者 Yuanyuan Huang Xinyu Zhang Weihong Jiang Zhuo Zhou Wenhui Tu Xianshu Wang Ding Wang Jianguo Duan 《Energy Materials and Devices》 2025年第1期84-94,83,共12页
The presence of residual alkaline compounds in the ultrahigh-nickel layered oxide cathodes(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x≥_(0.9))aggravates structural degradation,increases surface reactivity,and promotes slurry gel... The presence of residual alkaline compounds in the ultrahigh-nickel layered oxide cathodes(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x≥_(0.9))aggravates structural degradation,increases surface reactivity,and promotes slurry gelation,leading to the capacity decay of batteries with these cathodes and complicating their manufacturing.Traditional approaches for addressing this issue,including direct removal,coverage,and utilization,are complex and require surface regeneration.Herein,we propose neutralizing residual alkaline compounds with 3-thiopheneboronic acid(3-TBA)to improve the performance of LiNi_(0.9)5Co_(0.04)Mn_(0.01)O_(2)(NCM)cathode material,a facile strategy that does not require any post-treatment.The suggested reaction yields a uniform and thin organic-modified layer on the surface of the NCM cathode,improving its chemical stability toward the electrolyte,as demonstrated by multiple characterization methods.The modified NCM cathode exhibited impressive cyclic and rate performances,achieving a capacity retention of 83.34%after 200 cycles at 1.0 C and a specific capacity of 162.00 mAh·g^(−1) at 10.0 C.Most importantly,the proposed approach can efficiently suppress unfavorable phase transitions,severe electrolyte degradation,and CO_(2) gas evolution,improving the application potential of ultrahigh-nickel layered oxide cathode materials. 展开更多
关键词 lithium-ion battery ultrahigh-nickel layered oxide cathode residual alkaline compounds organic molecule NEUTRALIZATION
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Alkaline-free oxidation of ethylene glycol into glycolic acid over PdNi/NF in an asymmetric electrolytic cell
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作者 Jia Cheng Yang Xiang +1 位作者 Xun Huang Zidong Wei 《Chinese Journal of Chemical Engineering》 2025年第10期79-86,共8页
Electrocatalytic oxidation of surplus ethylene glycol(EG)to high-value glycolic acid(GA)represents a promising approach for sustainable resource utilization,though critical challenges persist in developing durable ele... Electrocatalytic oxidation of surplus ethylene glycol(EG)to high-value glycolic acid(GA)represents a promising approach for sustainable resource utilization,though critical challenges persist in developing durable electrocatalysts and achieving effective recovery of the free acid product from its salt derivatives in alkaline electrolytes.In this work,a PdNi/NF catalyst was rationally synthesized via a one-step electrodeposition method.Systematic characterization revealed that the electron transfer from Ni to Pd modulates *OH adsorption to accelerate EG oxidation reaction(EGOR)while preventing Pd deactivation through oxidation.The optimized system demonstrated exceptional alkaline performance with a glycolic acid Faraday efficiencyof 95%and a current density of 666 mA·cm^(-2).When implemented in an asymmetric EGOR||HER flowcell configuration where only the cathodic electrolyte contains alkaline,the system demonstrated exceptional operational stability by sustaining 70 mA·cm^(-2) current density at a low cell voltage of 0.9 V in neutral media for over 100 h,with product glycolic acid requiring no further acidification.This investigation provides a practical framework for designing efficientelectrocatalytic systems that simplifiesproduct separation steps. 展开更多
关键词 Ethylene glycol Glycolic acid PdNi Separation Asymmetric reactor
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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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Effects of urease on strongly alkaline sodium-based dispersive soils from check dams under acidic conditions
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作者 Guanzhou Ren Minqiang Meng +4 位作者 Henghui Fan Yuan Gao Yuyang Ji Shuai Pang Xingyao Li 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第11期7397-7409,共13页
This study explores the adaptation of microbial enzymatic techniques,which were originally developed to eliminate amino impurities in alcoholic beverages,for stabilizing strongly alkaline sodium-based dispersive soils... This study explores the adaptation of microbial enzymatic techniques,which were originally developed to eliminate amino impurities in alcoholic beverages,for stabilizing strongly alkaline sodium-based dispersive soils from check dams.Employing acid urease from Lactobacillus reuteri(L.reuteri)and a control group using soybean-derived urease,this research aimed to modify soil alkalinity through biomineralization.Ultraviolet(UV)mutagenesis optimized L.reuteri strains for biomass and activity.Solution experiments were conducted to assess the effects of pH,temperature,and storage duration on urease activity and to evaluate the calcium carbonate production and crystal morphology of the two ureases under varying calcium ion concentrations.Dispersivity identificationtests and tensile strength evaluations were conducted to analyze the disparities in the modifieddispersive soil treated with the two types of ureases.The results showed that soybean urease should be stored under low-temperature conditions and a neutral pH,whereas acid urease from L.reuteri can be stored at room temperature across a range of pH levels.Both urease treatments effectively reduced soil dispersivity and improved tensile strength significantly(up to 94%and 177%,respectively),with acid urease from L.reuteri resulting in superior soil strengthening and ammonia regulation.These findingssuggest that treating alkaline dispersive soils with acid urease is an efficientand eco-friendly method. 展开更多
关键词 acidic conditions UREASE Lactobacillus reuteri(L.reuteri) Dispersive soil DISPERSIVITY STRENGTH
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Lysophosphatidic acid signaling:Transmembrane modulators in the central nervous system
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作者 Alexandra Polyzou Alexandros Κ.Tsiouris +2 位作者 Charalampos Labrakakis Britta J.Eickholt George Leondaritis 《Neural Regeneration Research》 2026年第3期1104-1105,共2页
Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,includi... Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,including cerebrospinal fluid,varies significantly(Figure 1Α;Yung et al.,2014).LPA actually corresponds to a variety of lipid species that include different stereoisomers with either saturated or unsaturated fatty acids bearing likely differentiated biological activities(Figure 1Α;Yung et al.,2014;Hernández-Araiza et al.,2018). 展开更多
关键词 transmembrane modulators cerebrospinal fluidvaries variety lipid species lysophosphatidic acid biological fluidsincluding lysophosphatidic acid lpa saturated unsaturated fatty acids pleiotropic lipid agonist
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Saturated Alcohols Electrocatalytic Oxidations on Ni-Co Bimetal Oxide Featuring Balanced B-and L-Acidic Active Sites
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作者 Junqing Ma Wenshu Luo +9 位作者 Xunlu Wang Xu Yu Jiacheng Jayden Wang Huashuai Hu Hanxiao Du Jianrong Zeng Wei Chen Minghui Yang Jiacheng Wang Xiangzhi Cui 《Nano-Micro Letters》 2026年第2期105-123,共19页
Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electro... Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts. 展开更多
关键词 Solid-acid electrocatalyst Alcohol oxidation reaction Bronsted acid sites Lewis acid sites C_(1)-C_(6)saturated alcohols
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Short-chain fatty acids mediate enteric and central nervous system homeostasis in Parkinson’s disease:Innovative therapies and their translation 被引量:1
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作者 Shimin Pang Zhili Ren +1 位作者 Hui Ding Piu Chan 《Neural Regeneration Research》 2026年第3期938-956,共19页
Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’... Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease. 展开更多
关键词 ALPHA-SYNUCLEIN blood-brain barrier blood circulation central nervous system ENDOCRINE enteric nervous system glial cell gut-brain axis gut microbiota intestinal barrier neuron Parkinson’s disease short chain fatty acids vagus nerve
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Oleanolic acid inhibits mitochondrial fission by improving mitochondrial dysfunction and reducing atherosclerosis via regulating AMPK/Drp1 pathway:An in vivo and in vitro study
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作者 Jin-Zhou Xie Wei-Jia Cui +1 位作者 Wei-Tian Zhong Liang Ning 《Asian Pacific Journal of Tropical Biomedicine》 2026年第1期24-39,共16页
Objective:To investigate effect of oleanolic acid(OA)on atherosclerosis and its related mechanisms.Methods:Human umbilical vein endothelial cells(HUVECs)were injured by oxidized low-density lipoprotein for 24 h and tr... Objective:To investigate effect of oleanolic acid(OA)on atherosclerosis and its related mechanisms.Methods:Human umbilical vein endothelial cells(HUVECs)were injured by oxidized low-density lipoprotein for 24 h and treated with OA,and the levels of cell proliferation,migration,adhesion,and apoptosis were evaluated by BrdU staining,scratch healing assay,monocyte-endothelial cell adhesion assay and flow cytometry.The mice were fed with a high-fat diet to induce an atherosclerosis model,and treated with OA by gastric gavage.The mice were divided into the control group,the model group,and the OA administration group.The blood lipid and plaque formation in mice were detected.In addition,oxidative stress and mitochondrial structure and function changes in cells and mice were evaluated by transmission electron microscopy,JC-1 fluorescent probe,and Western blotting assays.The expression levels of proteins in the AMPK/Drp1 pathway were examined through Western blot.Results:OA markedly increased cell viability and migration rate of HUVECs,and decreased the adhesion rate of THP-1 cells and the apoptosis rate.OA significantly reduced serum lipid levels,such as total cholesterol and triglyceride,in mice and inhibited plaque formation in the aorta.OA also significantly increased the content of superoxide dismutase and catalase,alleviated mitochondrial damage,such as mitochondrial swelling and mitochondrial cristae reduction,reduced the number of mitochondria,increased adenosine triphosphate content,and significantly reduced p-Drp1(Ser616)/Drp1,MFF and FIS1 levels,increased p-AMPK/AMPK levels,activated AMPK,and then regulated DRP1 activity.Conclusions:OA activates AMPK,which in turn regulates the activity of DRP1 to restore normal mitochondrial dynamics and reduce atherosclerosis. 展开更多
关键词 Oleanolic acid AMPK/Drp1 pathway MITOCHONDRIA ATHEROSCLEROSIS Oxidative stress Endothelial cells
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Polysialic acid-Siglec immune checkpoints of microglia and macrophages:Perspectives for therapeutic intervention
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作者 Hauke Thiesler Herbert Hildebrandt 《Neural Regeneration Research》 2026年第2期661-662,共2页
Microglia are the resident macrophages of the central nervous system.They act as the first line of defense against pathogens and play essential roles in neuroinflammation and tissue repair after brain insult or in neu... Microglia are the resident macrophages of the central nervous system.They act as the first line of defense against pathogens and play essential roles in neuroinflammation and tissue repair after brain insult or in neurodegenerative and demyelinating diseases(Borst et al.,2021).Together with infiltrating monocyte-derived macrophages,microglia also play a critical role for brain tumor development,since immunosuppressive interactions between tumor cells and tumor-associated microglia and macrophages(TAM)are linked to malignant progression.This mechanism is of particular relevance in glioblastoma(GB),the deadliest form of brain cancer with a median overall survival of less than 15 months(Khan et al.,2023).Therefore,targeting microglia and macrophage activation is a promising strategy for therapeutic interference in brain disease. 展开更多
关键词 therapeutic intervention central nervous system immune checkpoints neurodegenerative demyelinating diseases borst MACROPHAGES polysialic acid SIGLEC MICROGLIA
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Potential role of astrocyte on gamma-aminobutyric acid tone regulation during developmental period
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作者 Erva Ozkan Wuhyun Koh 《Neural Regeneration Research》 2026年第3期1118-1119,共2页
The early developmental period is a critical window during which brain cells mature and contribute to both brain development and later life functions.Gamma-aminobutyric acid(GABA),recognized as a major neurotransmitte... The early developmental period is a critical window during which brain cells mature and contribute to both brain development and later life functions.Gamma-aminobutyric acid(GABA),recognized as a major neurotransmitter,plays a crucial role in coordinating synapse formation,neuronal proliferation,and migration during this time. 展开更多
关键词 early developmental period developmental period brain cells neuronal proliferation synapse formation gamma aminobutyric acid ASTROCYTE GABA
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