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Stability of K-struvite in High Temperature and Acid-base Environment
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作者 LIU Jun YANG Qile +1 位作者 GUO Yuchen YANG Yuanquan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第5期1213-1220,共8页
K-struvite was prepared by precipitation method,and the stability of K-struvite in high temperature and acid-base environment were investigated by X-ray diffraction(XRD),thermogravimetric analysis(TG/DSC),and infrared... K-struvite was prepared by precipitation method,and the stability of K-struvite in high temperature and acid-base environment were investigated by X-ray diffraction(XRD),thermogravimetric analysis(TG/DSC),and infrared spectroscopy(FT-IR).The results show that K-struvite decomposes from 50 to 110℃,and the mass loss begins at 50℃before being completely destroyed at 110℃,then further heating at temperature above 500℃leading to complete loss of the binding water in K-struvite.Moreover,K-struvite is more stable in alkaline environments than acidic environment. 展开更多
关键词 K-struvite temperature magnesium potassium phosphate cement acid-base environment
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Comparative Study on the Acid-Base Indicator Properties of Natural Dye, Turmeric Rhizome (Curcuma longa) and Synthetic Dyes
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作者 Genevive Chinyere Onuegbu Onyekachi Onyinyechi Nnorom Gerald Okwuchi Onyedika 《Journal of Textile Science and Technology》 2023年第1期20-29,共10页
Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60&deg;C. It was ground into powder and soaked in hot ... Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60&deg;C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment. 展开更多
关键词 Turmeric Rhizome EXTRACTION acid-base Indicator Methyl Orange PHENOLPHTHALEIN
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Application of Amino Acid-Based Surfactant in Dishwasher Detergent
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作者 Gao Chunfang Ren Jing Wang Ting 《China Detergent & Cosmetics》 2023年第1期60-68,共9页
The application of amino acid-based surfactant in dishwasher detergent was studied in this paper. The foam and oil-removing performance of amino acid surfactants in alkaline condition were test to discuss feasibility ... The application of amino acid-based surfactant in dishwasher detergent was studied in this paper. The foam and oil-removing performance of amino acid surfactants in alkaline condition were test to discuss feasibility of amino acid-based surfactant from natural origin as the alternative to traditional nonionic surfactants from petroleum origin in dishwasher detergent. Comparative study was conducted through using various amino acid-based surfactants and nonionic surfactants respectively, together with enzymes and peroxide to formulate dishwasher detergents, and their application properties such as foam performance and detergency were also evaluated when washing different tableware in automatic dishwasher. The results showed that among all tested amino acid surfactants, glutamate surfactants showed low foaming and high oil-removing ability in alkaline condition, and excellent decontamination ability in dishwashing tests. 展开更多
关键词 amino acid-based surfactant dishwasher detergent foam Interfacial tension oil-removing rate
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Oxidative esterification of acetol with methanol to methyl pyruvate over hydroxyapatite supported gold catalyst: Essential roles of acid-base properties 被引量:3
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作者 Yan Wan Congcong Zheng +6 位作者 Xianchi Lei Mengqi Zhuang Jinhan Lin Wenda Hu Jing dongLin Shaolong Wan Yong Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第11期1810-1819,共10页
Acetol is a major light oxygenate and readily produced from staged or fast pyrolysis of lignocellulose biomass. Herein we report that acetol can be selectively converted to methyl pyruvate, an important fine chemical,... Acetol is a major light oxygenate and readily produced from staged or fast pyrolysis of lignocellulose biomass. Herein we report that acetol can be selectively converted to methyl pyruvate, an important fine chemical, through oxidative esterification over Au-based catalysts. Detailed experimental studies showed that Au on amphoteric supports with appropriate strength and balanced ratio of acid and base sites can facilitate the desired oxidative-esterification pathway without accelerating undesired aldol-condensation or Cannizzaro reactions. In particular, hydroxyapatite (with a Ca/P ratio of 1.62) supported Au achieved 87% selectivity to methyl pyruvate at an acetol conversion of 62%. 展开更多
关键词 ACETOL acid-base properties GOLD HYDROXYAPATITE Methyl pyruvate
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Hepatic encephalopathy complicated with hyponatremia and acid-base disturbance and its prognosis 被引量:3
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作者 Ren Chengshan Wang Lei +13 位作者 Zhao Xiaoyan Yang Shiming Zhang Yanqi Wang Xiwen Bo Jianying Zhang Pengbin Guo Hong Ling Xianlong Li Yihui Da Siping Xie Xia Ren Wei Li Chunhua Qian Guisheng 《Journal of Medical Colleges of PLA(China)》 CAS 2012年第3期143-160,共18页
Objective:To improve the diagnosis and therapeutic effect of occurrence and development of hyponatremia and disorder of acid-base balance among patients with hepatic encephalopathy(HE) by elucidating the regularity an... Objective:To improve the diagnosis and therapeutic effect of occurrence and development of hyponatremia and disorder of acid-base balance among patients with hepatic encephalopathy(HE) by elucidating the regularity and mechanism,as well as its influence on prognosis.Methods:327 HE patients admitted to our hospital from January 1990 to June 2010 were enrolled.Meanwhile 316 patients hospitalized in the medical department of the same hospital were chosen as the control group.Patients in both groups were given the same methods to measure arterial blood gas parameters(pH value,PaCO2,[HCO3-],TCO2,BE and SaO2),blood biochemistry([Na+],[K+],[Cl-]),liver function,kidney function and blood glucose,serum sodium,and thereupon tocalculate the anion gap(AG) and the potential [HCO3-],and acid-base balance disorder.Results:Among the 327 HE patients,hyponatremia was found in 188 cases(57.4%),of whom 132 patients died(70.2%).While among the 316 patients in control group,68 presented with hyponatremia(21.5%),and 19 died(27.9%).The incidence and mortality were significantly different between the two groups(P<0.001).All the 327 patients presented with different degrees of acid-base balance disorder and 178 died(54.4%),in whom 164(50.2%) belonged to simple acid-base balance disorder and 74(45.1%) died,136(41.6%) were dual acid-base balance disorder and 80(58.8%) died,27(8.2%) were triple acid-base disturbance and 24(88.9%) died.Whereas in the control group only 83 patients(26.2%) were recognized as simple and dual acid-base balance disorder,and 18(21.7%) died.There was higher incidence of acid-base balance disorder and mortality rate in HE group than control one(P<0.001).Conclusion:Hyponatremia is valuable to judge HE patients' prognosis.The key parameters in the judgment and evaluation on acid-base balance disorder among HE patients are the change of pH values and serum electrolyte values.When pH value ≤ 7.30 or > 7.55,it generally suggests a poor prognosis. 展开更多
关键词 Hepatic Encephalopathy HYPONATREMIA acid-base Disturbance PROGNOSIS Blood gas parameters
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Two Dehydroabietic Acid-based Arylamines: Synthesis, Crystal Structure and Fluorescent Properties 被引量:2
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作者 高宏 宋杰 +1 位作者 商士斌 宋湛谦 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第3期396-402,共7页
Two dehydroabietic acid-based arylamines have been synthesized and characterized by FTIR, 1H NMR, 13C NMR, MS spectra and elemental analysis. Their spatial structures were determined by X-ray diffraction analysis. UV-... Two dehydroabietic acid-based arylamines have been synthesized and characterized by FTIR, 1H NMR, 13C NMR, MS spectra and elemental analysis. Their spatial structures were determined by X-ray diffraction analysis. UV-Vis absorption and fluorescence spectral characteristics of these compounds in methanol were investigated. Their fluorescence emission spectra in different polarity solvents were further evaluated. Fluorescent properties and structural relationship of the compounds showed that fluorescence intensity and quantum yield inversely increase with the non-coplanar degree. In addition, the solvent polarity has different effects on the fluorescence emission spectra of two compounds. 展开更多
关键词 dehydroabietic acid-based arylamine SYNTHESIS crystal structure fluorescent property
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Determination of pKa values of alendronate sodium in aqueous solution by piecewise linear regression based on acid-base potentiometric titration 被引量:2
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作者 Jing Ke Hanfei Dou +3 位作者 Ximin Zhang Dushimabararezi Serge Uhagaze Xiali Ding Yuming Dong 《Journal of Pharmaceutical Analysis》 SCIE CAS 2016年第6期404-409,共6页
As a mono-sodium salt form of alendronic acid,alendronate sodium presents multi-level ionization for the dissociation of its four hydroxyl groups.The dissociation constants of alendronate sodium were determined in thi... As a mono-sodium salt form of alendronic acid,alendronate sodium presents multi-level ionization for the dissociation of its four hydroxyl groups.The dissociation constants of alendronate sodium were determined in this work by studying the piecewise linear relationship between volume of titrant and p H value based on acidbase potentiometric titration reaction.The distribution curves of alendronate sodium were drawn according to the determined p Ka values.There were 4 dissociation constants(pKa_1=2.43,pKa_2=7.55,pKa_3=10.80,pKa_4=11.99,respectively) of alendronate sodium,and 12 existing forms,of which 4 could be ignored,existing in different p H environments. 展开更多
关键词 Dissociation CONSTANTS ALENDRONATE SODIUM Distribution curve Piecewise linear regression acid-base POTENTIOMETRIC TITRATION
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In situ spectroscopic insights into the redox and acid-base properties of ceria catalysts 被引量:1
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作者 Xiang Wang Meijun Li Zili Wu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第12期2122-2140,共19页
Cerium oxide(ceria)plays an important and fascinating role in heterogeneous catalysis as illustrated by its versatile use as a catalyst,a catalyst support,or a promotor in various oxidation and reduction reactions.Cen... Cerium oxide(ceria)plays an important and fascinating role in heterogeneous catalysis as illustrated by its versatile use as a catalyst,a catalyst support,or a promotor in various oxidation and reduction reactions.Central to these reactions is the rich defect chemistry,facile redox capability,and unusual acid-base properties of ceria.Understanding the unique redox and acid-base properties of ceria is essential to build the structure-catalysis relationship so that improved catalytic functions can be achieved for ceria-based materials.Among the characterization toolbox,spectroscopic approach indisputably stands out for its unparalleled power in offering chemical insights into the surface properties of ceria at atomic and molecular level.In this review,we summarize advances in revealing the redox and acid-base properties of ceria via a variety of spectroscopic methods including optical,X-ray,neutron,electronic and nuclear spectroscopy.Both direct spectroscopy characterization and its coupling with probe molecules are analyzed to illustrate how the nature,strength and density of different surface sites are influenced by the pretreatment,the morphology and size of ceria nanoparticles.Further directions in taking advantage of in situ/operando spectroscopy for better understanding the catalysis of ceria-based materials are proposed in the summary and outlook section. 展开更多
关键词 CERIA Redox acid-base Defects Spectroscopy CATALYSIS
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Acid-base characterization of foursulfide minerals 被引量:1
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作者 Lin Yuhuan(Research Center for Eco-Environmentai Sciences, Chinese Academy of Sciences, Beijing 100085, China)George W. Bailey(Environmental Research Laboratory Office of Research and Development, U. S. Environmental Protection Agency, Athens, Georgia 306 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1994年第2期215-223,共9页
The amphoteric properties of four sulfide minerals were characterized byacidimetric-alkalimetric titration. Chalcocite, galena, and sphalerite were found to bediprotic acids, while pyrite was determined to be a tripro... The amphoteric properties of four sulfide minerals were characterized byacidimetric-alkalimetric titration. Chalcocite, galena, and sphalerite were found to bediprotic acids, while pyrite was determined to be a triprotic acid. Intrinsic acidity con-stants for the four minerals are as follows: chalcocite-pK_(a1)=5.25, pK_(a2)=9.68;galena- pK_(a1)=5.26, pK_(a2)=9.62; sphalente- pK_(a1)= 5.08, pK_(a2)= 9.13;and pyrite - pK_(a1) = 3.50,pK_(a2)=5.32, pK_(a3)=9.81. 展开更多
关键词 acid-base titration CHALCOCITE GALENA pynte sphalerite.
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Studies on synthesis and property of novel acid-base proton exchange membranes 被引量:1
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作者 Yong Fang Liang Hai Yan Pan Xiu Ling Zhu Yao Xia Zhang Xi Gao Jian 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第5期609-612,共4页
Sulfonated poly(phthalazinone)s (SPPENK, SPPESK and SPPBEK) were prepared by direct polymerization reaction from sulfonated monomers. The novel acid-base membranes were composed of sulfonated polymers as the acidi... Sulfonated poly(phthalazinone)s (SPPENK, SPPESK and SPPBEK) were prepared by direct polymerization reaction from sulfonated monomers. The novel acid-base membranes were composed of sulfonated polymers as the acidic compounds, and polyetherimide (PEI) as the basic compounds, casting from their N-methylpyrrolidone (NMP) solution directly onto clean glass plates at 60 ℃ aiming at enhancing membrane toughness and other relative properties. The resulted acid-base composite membranes had excellent resistance to swelling, thermo-stability, hydrolysis resistance and oxidative resistance properties with highly ion-exchange capacity (IEC). 展开更多
关键词 acid-base composite membrane PEM STABILITY SULFONATION
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Prospects for nucleic acid-based therapeutics against hepatitis C virus 被引量:1
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作者 Chang Ho Lee Ji Hyun Kim Seong-Wook Lee 《World Journal of Gastroenterology》 SCIE CAS 2013年第47期8949-8962,共14页
In this review,we discuss recent advances in nucleic acid-based therapeutic technologies that target hepatitis C virus(HCV)infection.Because the HCV genome is present exclusively in RNA form during replication,various... In this review,we discuss recent advances in nucleic acid-based therapeutic technologies that target hepatitis C virus(HCV)infection.Because the HCV genome is present exclusively in RNA form during replication,various nucleic acid-based therapeutic approaches targeting the HCV genome,such as ribozymes,aptamers,siRNAs,and antisense oligonucleotides,have been suggested as potential tools against HCV.Nucleic acids are potentially immunogenic and typically require a delivery tool to be utilized as therapeutics.These limitations have hampered the clinical development of nucleic acid-based therapeutics.However,despite these limitations,nucleic acid-based therapeutics has clinical value due to their great specificity,easy and large-scale synthesis with chemical methods,and pharmaceutical flexibility.Moreover,nucleic acid therapeutics are expected to broaden the range of targetable molecules essential for the HCV replication cycle,and therefore they may prove to be more effective than existing therapeutics,such as interferon-αand ribavirin combination therapy.This review focuses on the current status and future prospects of ribozymes,aptamers,siRNAs,and antisense oligonucleotides as therapeutic reagents against HCV. 展开更多
关键词 Hepatitis C virus Nucleic acid-based THERAPEUTICS RIBOZYME APTAMER siRNA ANTISENSE OLIGONUCLEOTIDE
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Non-covalent Bonded 3D Supramolecular Architectures Based on Acid-base Adducts 被引量:3
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作者 李卫东 方旭 +1 位作者 乔瑞 陈水生 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第1期46-54,共9页
Two novel acid-base adducts,[H2L1^2+](Hpbda)2(1,L1 = 1,4-di(lH-imidazol-4-yl)benzene,H2pbda = 1,4-benzenedicarboxylic acid) and[H2L2^2+](NO3)2(2,L2 = l,4-di(l-carboxymethyl-imidazol-4-yl)benzene),have be... Two novel acid-base adducts,[H2L1^2+](Hpbda)2(1,L1 = 1,4-di(lH-imidazol-4-yl)benzene,H2pbda = 1,4-benzenedicarboxylic acid) and[H2L2^2+](NO3)2(2,L2 = l,4-di(l-carboxymethyl-imidazol-4-yl)benzene),have been prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy and elemental analysis.Compound 1 crystallizes in monoclinic,space group P21/n with a = 5.3525(11),b = 9.1471(19),c = 19.314(4) ?,β = 92.342(3)°,V= 944.8(3) A°3,Z = 2,C16H16N6O(10),Mr = 452.35,Dc = 1.590 g/cm^3,μ = 0.135 mm^-1,S = 1.058,F(000) = 468,the final R = 0.0661 and wR = 0.1887 for 2298 observed reflections(I〉 2σ(I)).Compound 2 crystallizes in monoclinic,space group P21/c with a = 9.6923(10),b = 17.2950(17),c = 7.1880(7) ?,β =94.801(2)°,V= 1200.7(2)A°3,Z = 2,C(28)H(22)N4O8,Mr = 542.50,Dc = 1.501 g/cm^3,μ = 0.112 mm^-1,S= 1.060,F(000) = 564,the final R = 0.0394 and wR = 0.1017 for 2768 observed reflections(I 〉2σ(I)).In the title compounds,both of L1 and L2 ligands act as weak base to accept protons to exhibit diprotonated H2L1^2+ and H2L2^2+ form,which can effectively employ as hydrogen bonding donors to combine anion moieties to form binary adducts respectively.In the crystal packing diagram of two polymers,there exist extensive noncovalent interactions including charge-transfer interactions,C(N)-H…π and N-H…O,C-H…O,O-H…O hydrogen bonding interactions between co-crystal moieties which consolidate the structures of supramolecular polymers,thus generating three-dimensional(3D) frameworks. 展开更多
关键词 synthesis acid-base adducts crystal structure noncovalent interactions
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Acid-base cooperativity of heterogeneous catalyst containing acidic framework and sterically hindered base for aldol condensation 被引量:1
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作者 Hua Li Shu Tao Xu +1 位作者 Xiao Bing Lu Wei Ping Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第9期1051-1054,共4页
A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesi... A bifunctional heterogeneous catalyst containing two mutually incompatible acidic and basic sites, which exhibits cooperative catalytic behavior in the aldol condensation of acetone and various aldehydes, was synthesized by postgrafting of 1,5,7- triazabicyclo[4.4.0] dec-5-ene (TBD, a sterically hindered organic base) onto AI-MCM-41 molecular sieve. 2009 Xiao Bing Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. 展开更多
关键词 Bifunctional catalyst acid-base cooperative catalysis Mesoporous material Aldol reaction
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The Roles of Key Electrolytes in Balancing Blood Acid-Base and Nutrient in Broiler Chickens Reared under Tropical Conditions 被引量:2
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作者 Ibukun Olukorede Popoola Oluwabukola Rashidat Popoola +2 位作者 Matthew Oluwatobi Ojeniyi Oluwaseyi Olamide Olajide Eustace Ayemere Iyayi 《Natural Science》 2020年第1期4-11,共8页
The loss of electrolyte balance in diets of broiler chickens has resulted in a serious distur-bance of blood acid-base balance, coupled with elevated body temperature. The body losses carbon dioxide (CO2) and bicarbon... The loss of electrolyte balance in diets of broiler chickens has resulted in a serious distur-bance of blood acid-base balance, coupled with elevated body temperature. The body losses carbon dioxide (CO2) and bicarbonate (HCO3), resulting in respiratory alkalosis or acidosis. Under tropical conditions of high environmental temperatures, the balance of electrolytes in feeds must be set much higher as to maintain equal metabolic and digestive efficiency. However, information on the ideal dietary electrolyte balance (DEB) that could effectively correct acid-base imbalance in broiler chickens under severe heat stress condition is scanty. Therefore, the effects of varying electrolyte balance in diets on haematology, blood glucose and serum inorganic elements were assessed in broiler chickens at starter (0 - 21 d) and finisher (22 - 35 d) phases, under temperature-humidity index of 24.97 - 35.19. One day-old Arbor Acre chicks (n = 300) were procured and randomly allotted to diets supplemented with potassium chloride and sodium bicarbonate, to balance monovalent ions (sodium, potassium and chloride) at 210 (T1), 240 (T2), 270 (T3), 300 (T4), 330 (T5) and 360 (T6) mEq/kg DEB, in a completely randomised design. On days 21 and 35, blood (5 mL) samples were collected from birds in each replicate whose weights were closest to the mean class weight for haematology and serum biochemical indices using standard procedures. Data were analysed using descriptive statistics and ANOVA at α = 0.05. Different levels of DEB did not significantly affect (P > 0.05) haematology and blood glucose at starter phase. However, at finisher phase, heterophil: lymphocyte of birds on 270 and 240 mEq/kg DEB were lower (P < 0.05) compared to other dietary treatments. Blood acid-base balance was relatively enhanced in birds on aggregate DEB level of 360 mEq/kg with reduced chloride ion and relatively lower incidence of hemodilution with respect to high haemoglobin levels as this level is advantageous in balancing blood acid to base ratio in broiler chickens reared under severe environmental temperatures higher than 43?C ± 5?C as against some previous opinions that did not take into consideration, the inherent dietary electrolyte balance in feedstuff, other functional mono or divalent ions, and the severity of environmental factors. 展开更多
关键词 BLOOD acid-base Monovalent Ions BROILERS BLOOD GLUCOSE Heat Stress Serum MINERALS
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Facile synthesis of metal-organic frameworks embedded in interconnected macroporous polymer as a dual acid-base bifunctional catalyst for efficient conversion of cellulose to 5-hydroxymethylfurfural 被引量:1
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作者 Yanan Wei Yunlei Zhang +4 位作者 Bing Li Wen Guan Changhao Yan Xin Li Yongsheng Yan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第4期169-181,共13页
5-Hydroxymethylfurfural(5-HMF),as a key platform compound for the conversion of biomass to various biomass-derived chemicals and biofuels,has been attracted extensive attention.In this research,using Pickering high in... 5-Hydroxymethylfurfural(5-HMF),as a key platform compound for the conversion of biomass to various biomass-derived chemicals and biofuels,has been attracted extensive attention.In this research,using Pickering high internal phase emulsions(Pickering HIPEs)as template and functional metal-organic frameworks(MOFs,UiO-66-SO;H and UiO-66-NH;)/Tween 85 as co-stabilizers to synthesis the dual acid-base bifunctional macroporous polymer catalyst by one-pot process,which has excellent catalytic activity in the cascade reaction of converting cellulose to 5-HMF.The effects of the emulsion parameters including the amount of surfactant(ranging from 0.5%to 2.0%(mass)),the internal phase volume fraction(ranging from 75%to 90%)and the acid/base Pickering particles mass ratio(ranging from 0:6 to 6:0)on the morphology and catalytic performance of solid catalyst were systematically researched.The results of catalytic experiments suggested that the connected large pore size of catalyst can effectively improve the cellulose conversion,and the synergistic effect of acid and base active sites can effectively improve the 5-HMF yield.The highest 5-HMF yield,about 40.5%,can be obtained by using polymer/MOFs composite as catalyst(Poly-P12,the pore size of(53.3±11.3)μm,the acid density of 1.99 mmol·g^(-1)and the base density of 1.13 mol·g^(-1))under the optimal reaction conditions(130℃,3 h).Herein,the polymer/MOFs composite with open-cell structure was prepared by the Pickering HIPEs templating method,which provided a favorable experimental basis and theoretical reference for achieving efficient production of high addedvalue product from abundant biomass. 展开更多
关键词 Catalyst Biomass HYDROLYSIS 5-HYDROXYMETHYLFURFURAL Pickering high internal phase emulsions templated polymer acid-base bifunctional site
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Acid-base buffer effect of fulvic acid and barium fulvate from weathered coal 被引量:1
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作者 GUO Xiao-feng LI Xi-feng 《Journal of Coal Science & Engineering(China)》 2009年第4期415-419,共5页
The acid-base buffer characteristics of fulvic acid (FA) and barium fulvate (BaFA)were analyzed. Each share of the sample or model agents (phthalic acid and salicylic acid)were separately mixed into a series of shares... The acid-base buffer characteristics of fulvic acid (FA) and barium fulvate (BaFA)were analyzed. Each share of the sample or model agents (phthalic acid and salicylic acid)were separately mixed into a series of shares of dilute solutions of HCI or NaOH with a series of concentration. The original pH values of the solutions were arranged from 2 to 13.Final balanced pH of each share was measured. The pH changes show that FA and BaFApossess buffer ability, whereas the model agents do not. The tendency of balanced pHvalues was 5.4 for FA and 7.4 for BaFA, whereas the original pH was 4.0-8.5; balancedpH changed little. At room temperature, the maximum buffer capacities were as follows:18.11 mmol hydroxyl per gram FA, 11.25 mmol hydroxyl per gram BaFA, 1.19 mmol protonper gram FA, and 1.45 mmol proton per gram BaFA. Mathematics analysis shows thatlogarithm of buffer capacities of FA and BaFA is linearly dependent on original pH. Compared with BaFA and model agents, it is concluded that FA buffer capacity against hydroxylrelies not only on its acidic groups, BaFA buffer capacity against hydroxyl does not rely onits acidic groups, and FA buffer capacity against proton is not related with its carboxyl andphenolic hydroxyl group. The pH values of FA-water solutions with different concentrationsfrom 1 to 10 grams per liter were measured. Their pH values were slightly affected by itsconcentration. Thus, FA possesses a much stronger buffer ability against water dilutionthan common buffer agent. All the pH values of FA water solutions were very nearby 5.4,just the same as the balanced pH tendency for adding FA. 展开更多
关键词 acid-base buffer fulvic acid barium fulvate weathered coal pH value
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Has Stewart approach improved our ability to diagnose acid-base disorders in critically ill patients? 被引量:2
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作者 Fabio D Masevicius Arnaldo Dubin 《World Journal of Critical Care Medicine》 2015年第1期62-70,共9页
The Stewart approach-the application of basic physicalchemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that p H is determined ... The Stewart approach-the application of basic physicalchemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that p H is determined by three independent variables, which change primarily and independently of one other. In blood plasma in vivo these variables are:(1) the PCO2;(2) the strong ion difference(SID)-the difference between the sums of all the strong(i.e., fully dissociated, chemically nonreacting) cations and all the strong anions; and(3) the nonvolatile weak acids(Atot). Accordingly, the p H and the bicarbonate levels(dependent variables) are only altered when one or more of the independent variables change. Moreover, the source of H+ is the dissociation of water to maintain electroneutrality when the independent variables are modified. The basic principles of the Stewart approach in blood, however, have been challenged in different ways. First, the presumed independent variables are actually interdependent as occurs in situations such as:(1) the Hamburger effect(a chloride shift when CO2 is added to venous blood from the tissues);(2) the loss of Donnan equilibrium(a chloride shift from the interstitium to the intravascular compartment to balance the decrease of Atot secondary to capillary leak; and(3) the compensatory response to a primary disturbance in either independent variable. Second, the concept of water dissociation in response to changes in SID is controversial and lacks experimental evidence. In addition, the Stewart approach is not better than the conventional method for understanding acid-base disorders such as hyperchloremic metabolic acidosis secondary to a chloride-rich-fluid load. Finally, several attempts were performed to demonstrate the clinical superiority of the Stewart approach. These studies, however, have severe methodological drawbacks. In contrast, the largest study on this issue indicated the interchangeability of the Stewart and conventional methods. Although the introduction of the Stewart approach was a new insight into acid-base physiology, the method has not significantly improved our ability to understand, diagnose, and treat acid-base alterations in critically ill patients. 展开更多
关键词 acid-base metabolism STEWART approach Base excess BICARBONATE Anion GAP STRONG ION difference STRONG ION GAP
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Double Acid-Base Extraction of Silicic Acid from Quartz Sand 被引量:1
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作者 Laksmita Prima Santi Djoko Mulyanto Didiek Hadjar Goenadi 《Journal of Minerals and Materials Characterization and Engineering》 2017年第6期362-373,共12页
Silica is becoming more attractive as plant nutrient for non-graminae crops particularly in relation with drought-stress tolerant. Many efforts have been conducted to obtain an efficient technique to produce silica fe... Silica is becoming more attractive as plant nutrient for non-graminae crops particularly in relation with drought-stress tolerant. Many efforts have been conducted to obtain an efficient technique to produce silica fertilizer worldwide, but the results are varying considerably due to various factors including raw material and extraction technique. This study was carried out to develop an efficient extraction technique for ortho-silicic acid (OSA-H4SiO4) from a Bangka-Belitung quartz sand by employing acid-base dissolution method. A 325-mesh size quartz sand was boiled in HCl solution at various concentrations. The optimum concentration was then used in the following experiment at several different volumes of solution. The sand obtained from optimum concentration and volume of HCl solution was then reacted with different amounts of NaOH (s), and heated until a wet mixture was obtained. As a reference the best extraction conditions were applied to a natural zeolite sample. All OSA analyses were done in triplicates with spectrophotometric method. Supporting evidences were collected from x-ray diffraction and scanning-electron-microscopy analyses of the treated samples. The yield of quartz sand-originated OSA was 183 g·kg-1 and significantly increased linearly with increasing weight of NaOH (R2 = 0.99**), whereas that from zeolite was only 104.2 g·kg-1 at 80 g NaOH. XRD and SEM data confirmed the evidences that the acid-base extraction disrupted the quartz mineral structure and as a consequence releasing more water soluble OSA. 展开更多
关键词 Ortho-Silicic ACID Bangka-Belitung QUARTZ SAND acid-base DISSOLUTION Pre-Washed
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Water,electrolytes,and acid-base alterations in human immunodeficiency virus infected patients 被引量:1
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作者 Carlos G Musso waldo H Belloso Richard J Glassock 《World Journal of Nephrology》 2016年第1期33-42,共10页
The clinical spectrum of human immunodeficiency virus (HIV) infection associated disease has changed significantly over the past decade, mainly due to the wide availability and improvement of combination antiretrovi... The clinical spectrum of human immunodeficiency virus (HIV) infection associated disease has changed significantly over the past decade, mainly due to the wide availability and improvement of combination antiretroviral therapy regiments. Serious complications associated with profound immunodeficiency are nowa-days fortunately rare in patients with adequate access to care and treatment. However, HIV infected patients, and particularly those with acquired immune defciency syndrome, are predisposed to a host of different water, electrolyte, and acid-base disorders (sometimes with opposite characteristics), since they have a modified renal physiology (reduced free water clearance, and relatively increased fractional excretion of calcium and magnesium) and they are also exposed to infectious, inflammatory, endocrinological, oncological variables which promote clinical conditions (such as fever,tachypnea, vomiting, diarrhea, polyuria, and delirium), and may require a variety of medical interventions (antiviral medication, antibiotics, antineoplastic agents), whose combination predispose them to undermine their homeostatic capability. As many of these disturbances may remain clinically silent until reaching an advanced condition, high awareness is advisable, particularly in patients with late diagnosis, concomitant inflammatory conditions and opportunistic diseases. These disorders contribute to both morbidity and mortality in HIV infected patients. 展开更多
关键词 Human immunodeficiency virus Acquired immune defciency syndrome SALT WATER POTASSIUM acid-base
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Acid-base alternation diagenesis and its influence on shale reservoirs in the Permian Lucaogou Formation, Jimusar Sag, Junggar Basin, NW China 被引量:2
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作者 WANG Jian ZHOU Lu +3 位作者 LIU Jin ZHANG Xinji ZHANG Fan ZHANG Baozhen 《Petroleum Exploration and Development》 2020年第5期962-976,共15页
The diagenesis and diagenetic facies of shale reservoirs in Lucaogou Formation of Jimusar Sag were studied by means of microscopic observation and identification of ordinary thin sections and cast thin sections,X-ray ... The diagenesis and diagenetic facies of shale reservoirs in Lucaogou Formation of Jimusar Sag were studied by means of microscopic observation and identification of ordinary thin sections and cast thin sections,X-ray diffraction,scanning electron microscope and electron probe tests.The results show that alkaline and acidic diagenetic processes occurred alternately during the deposition of Permian Lucaogou Formation in Jimusar Sag.The evolution of porosity in the shale reservoirs was influenced by compaction and alternate alkaline and acidic diagenetic processes jointly,and has gone through three stages,namely,stage of porosity reduction and increase caused by alkaline compaction,stage of porosity increase caused by acid dissolution,and stage of porosity increase and reduction caused by alkaline dissolution.Correspondingly,three secondary pore zones developed in Lucaogou Formation.The shale reservoirs are divided into three diagenetic facies:tuff residual intergranular pore-dissolution pore facies,tuff organic micrite dolomite mixed pore facies,and micrite alga-dolomite intercrystalline pore facies.With wide distribution,good pore structure and high oil content,the first two facies are diagenetic facies of favorable reservoirs in Lucaogou Formation.The research results provide a basis for better understanding and exploration and development of the Lucaogou Formation shale reservoirs. 展开更多
关键词 acid-base alternation diagenesis porosity evolution shale oil shale reservoir Permian Lucaogou Formation Jimusar Sag Junggar Basin
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