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Isolation of Thermally Stable Cellulose Nanocrystals from Spent Coffee Grounds via Phosphoric Acid Hydrolysis 被引量:1
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作者 Brody A.Frost E.Johan Foster 《Journal of Renewable Materials》 SCIE EI 2020年第2期187-203,共17页
As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This ... As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs. 展开更多
关键词 Cellulose nanocrystals phosphoric acid hydrolysis agricultural waste industrial waste spent coffee grounds polymeric nanocomposites renewable cellulosic materials
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Integration of morphology and electronic structure modulation on cobalt phosphide nanosheets to boost photocatalytic hydrogen evolution from ammonia borane hydrolysis 被引量:3
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作者 Chao Wan Yu Liang +5 位作者 Liu Zhou Jindou Huang Jiapei Wang Fengqiu Chen Xiaoli Zhan Dang-guo Cheng 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第2期333-343,共11页
The controllable and safe hydrogen storage technologies are widely recognized as the main bottleneck for the accomplishment of sustainable hydrogen energy.Ammonia borane(AB)has regarded as a competitive candidate for ... The controllable and safe hydrogen storage technologies are widely recognized as the main bottleneck for the accomplishment of sustainable hydrogen energy.Ammonia borane(AB)has regarded as a competitive candidate for chemical hydrogen storage.However,developing efficient yet high-performance catalysts towards hydrogen evolution from AB hydrolysis remains an enormous challenge.Herein,cobalt phosphide nanosheets are synthesized by a facile salt-assisted along with low-temperature phosphidation strategy for simultaneously modulating its morphology and electronic structure,and function as hydrogen evolution photocatalysts.Impressively,the Co_(2)P nanosheets display extraordinary performance with a record high turnover frequency of 44.9 min^(-1),outperforming most of the noble-metal-free catalysts reported to date.This remarkable performance is attributed to its desired nanosheets structure,featuring with high specific surface area,abundant exposed active sites,and short charge diffusion paths.Our findings provide a novel strategy for regulating metal phosphides with desired phase structure and morphology for energy-related applications and beyond. 展开更多
关键词 Ammonia borane Hydrogen generation hydrolysis Cobalt phosphide nanosheets PHOTOCATALYSIS
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Research progress on catalysts for organic sulfur hydrolysis: Review of activity and stability
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作者 Bingning Wang Xianzhe Wang +3 位作者 Song Yang Chao Yang Huiling Fan Ju Shangguan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期203-216,共14页
The removal of organic sulfur through catalytic hydrolysis is a significant area of research in the field of desulfurization.This review provides an overview of recent advancements in catalytic hydrolysis technology o... The removal of organic sulfur through catalytic hydrolysis is a significant area of research in the field of desulfurization.This review provides an overview of recent advancements in catalytic hydrolysis technology of organic sulfur,including the activity,stability,and atmosphere effects of hydrolysis catalysts.The emphasis is on strategies for enhancing hydrolysis activity and anti-oxygen poisoning property of catalysts.Surface modification,metal doping and nitrogen doping have been found to improve the activity of catalysts.Alkaline components modification is the most commonly used method,the formation of oxygen vacancies through metal doping and creation of nitrogen basic sites through nitrogen doping also contribute to the hydrolysis of organic sulfur.The strategies for anti-oxygen poisoning are discussed in a systematic manner.The structural regulation of catalysts is beneficial for the desorption and diffusion of hydrogen sulfide(H_(2)S),thereby effectively inhibiting its oxidation.Nitrogen doping and the addition of electronic promoters such as transition metals can protect active sites and decrease the number of active oxygen species.These methods have been proven to enhance the anti-poisoning performance of catalysts.Additionally,this article summarizes how different atmospheres affect the activity of hydrolysis catalysts.The objective of this review is to pave the way for the development of efficient,stable and widely used catalysts for organic sulfur hydrolysis. 展开更多
关键词 Organic sulfur hydrolysis CATALYSTS ACTIVITY STABILITY
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CAOSA-extracted lignin improves enzymatic hydrolysis of cellulose
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作者 Sen Ma Zheng Li +5 位作者 Jonathan Sperry Xing Tang Yong Sun Lu Lin Jian Liu Xianhai Zeng 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第7期1101-1111,共11页
The conversion of biomass into sugar platform compounds is very important for the biorefinery industry.Pretreatment is essential to the biomass of the sugar platform,however,the lignin obtained by pretreatment,as a ke... The conversion of biomass into sugar platform compounds is very important for the biorefinery industry.Pretreatment is essential to the biomass of the sugar platform,however,the lignin obtained by pretreatment,as a key part of lignocellulose,generally has a passive effect on the enzymatic hydrolysis of cellulose into sugars.In this study,p-TsOH(p-toluenesulfonic acid),DES(Deep eutectic solvent)and CAOSA(cooking with active oxygen and solid alkali)pretreatment ways were used to fraction lignin from bamboo biomass.After CAOSA treatment,the hydrolysis efficiency of the pulp was 95.57%.Moreover,the effect of different treatment methods on lignin properties was studied and the promotion effect of lignin was investigated by adding it to the cellulose enzymatic hydrolysis system.In this work,the results showed that CAOSA-extracted lignin with lower D(1.31-1.25)had a better adsorption effect on the enzyme protein.p-TsOH-extracted lignin with a larger S/G ratio enhanced the inhibition of enzymatic hydrolysis.In addition,the presence of-COOHs in lignin could reduce its inhibitory effect on cellulose saccharification. 展开更多
关键词 Biomass pretreatment CAOSA Cellulose hydrolysis LIGNIN ENZYME
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An efficient and mild recycling of waste melamine formaldehyde foams by alkaline hydrolysis
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作者 Shaodi Wu Ning Zhang +7 位作者 Chizhou Wang Xianglin Hou Jie Zhao Shiyu Jia Jiancheng Zhao Xiaojing Cui Haibo Jin Tiansheng Deng 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第5期919-926,共8页
Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin wastes.Herein,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditi... Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin wastes.Herein,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditions(160℃)in a NaOH–H2O system with ammelide and ammeline as the main degradation products.The alkaline solvent had an obvious corrosion effect for MFF,as indicated by scanning electron microscopy(SEM).The reaction process and products distribution were studied by Fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and ^(13)C nuclear magnetic resonance(NMR).Besides,the MFF degradation products that have the similar chemical structures and bonding performances to those of melamine can be directly used as the raw material for synthesis of melamine urea-formaldehyde resins(MUFs).Moreover,the degradation system demonstrated here showed the high degradation efficiency after reusing for 7 times.The degradation process generated few harmful pollutants and no pre-or post-treatments were required,which proves its feasibility in the safe removal or recovery of waste MFF. 展开更多
关键词 Melamine formaldehyde foam Degradation Alkaline hydrolysis RECYCLING
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Utlra-fast hydrolysis performance of MgH_(2) catalyzed by Ti-Zr-Fe-Mn-Cr-V high-entropy alloys
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作者 Jinting Chen Tingting Xu +7 位作者 Zeyu Zhang Jinghan Zhang Haixiang Huang Bogu Liu Yawei Li Jianguang Yuan Bao Zhang Ying Wu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第11期77-86,共10页
Hydrogen energy is one of the ideal energy alternatives and the upstream of the hydrogen industry chain is hydrogen production,which can be achieved via the reaction of inorganic materials with water,known as hydrolys... Hydrogen energy is one of the ideal energy alternatives and the upstream of the hydrogen industry chain is hydrogen production,which can be achieved via the reaction of inorganic materials with water,known as hydrolysis.Among inorganic materials,the high hydrogen capacity for hydrolysis of MgH_(2)(15.2 wt%)makes it a promising material for hydrogen production via hydrolysis.However,the dense Mg(OH)_(2) passivation layer will block the reaction between MgH_(2) and the solution,resulting in low hydrogen yield and sluggish hydrolysis kinetics.In this work,the hydrogenyield and hydrogen generation rate of MgH_(2) are considerably enhanced by adding Ti-Zr-Fe-Mn-Cr-V high-entropy alloys(HEAs) for the first time.In particular.the MgH_(2)-3 wt% TiZrFe_(1.5)MnCrV_(0.5)(labelled as MgH_(2)-3 wt% Fe_(1.5)) composite releases 1526.70 mL/g H_(2) within 5 min at 40℃,and the final hydrolysis conversion rate reaches 95.62% within 10 min.The mean hydrogen generation rate of the MgH_(2)-3 wt% Fe_(1.5) composite is 289.16 mL/g/min,which is 2.38 times faster than that of pure MgH_(2).Meanwhile,the activation energy of the MgH_(2)-3 wt% Fe_(1.5) composite is calculated to be 12.53 kJ/mol. The density functional theory(DFT) calculation reveals that the addition of HEAs weakens the Mg-H bonds and accelerates the electron transfer between MgH_(2) and HEAs,Combined with the cocktail effect of HEAs as well as the formation of more interfaces and micro protocells,the hydrolysis performance of MgH_(2) is considerably improved.This work provides an appealing prospect for real-time hydrogen supply and offers a new effective strategy for improving the hydrolysis performance of MgH_(2). 展开更多
关键词 Mg-based materials High-entropy alloys hydrolysis Hydrogen generation Cocktail effect CATALYSIS
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In situ formed Mg(BH_(4))_(2) for improving hydrolysis properties of MgH_(2)
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作者 Yongyang Zhu Mili Liu +6 位作者 liming Zeng Yin Wang Daifeng Wu Rui Li Qing Zhou Renheng Tang Fangming Xiao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1204-1214,共11页
The hydrolysis of MgH_(2) delivers high hydrogen capacity(15.2 wt%),which is very attractive for real-time hydrogen supply.However,the formation of a surface passivation Mg(OH)_(2) layer and the large excess of H_(2)O... The hydrolysis of MgH_(2) delivers high hydrogen capacity(15.2 wt%),which is very attractive for real-time hydrogen supply.However,the formation of a surface passivation Mg(OH)_(2) layer and the large excess of H_(2)O required to ensure complete hydrolysis are two key challenges for the MgH_(2) hydrolysis systems.Now,a low-cost method is reported to synthesize MgH_(2)@Mg(BH_(4))_(2) composite via ball-milling MgH_(2) with cheap and widely available B_(2)O_(3)(or B(OH)_(3)).By adding small amounts of B_(2)O_(3),the in-situ formed Mg(BH_(4))_(2) could significantly promote the hydrolysis of MgH_(2).In particular,the MgH_(2)–10 wt%B_(2)O_(3) composite releases 1330.7 mL·g^(−1) H_(2)(close to 80%theoretical hydrogen generation H_(2))in H_(2)O and 1520.4 mL·g^(−1) H_(2)(about 95%)in 0.5 M MgCl_(2) in 60 min at 26℃ with hydrolysis rate of 736.9 mL·g^(−1)·min^(−1) and 960.9 mL·g^(−1)·min^(−1) H_(2) during the first minute of the hydrolysis,respectively.In addition,the MgCl_(2) solution allows repeated use by filtering and exhibits high cycle stability(20 cycles),therefore leading to much reduced capacity loss caused by the excess H_(2)O.We show that by introducing B_(2)O_(3) and recycling the 0.5 M MgCl_(2) solution,the system hydrogen capacity can approach 5.9 wt%,providing a promising hydrogen generation scheme to supply hydrogen to the fuel cells. 展开更多
关键词 hydrolysis MgH_(2) Mg(BH_(4))_(2) Hydrogen generation B_(2)O_(3) MgCl_(2)
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Effects of Dilute Acid-intensified Hydrolysis on Fermentative Biohydrogen Production Capacity of Maize Stalk 被引量:2
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作者 孙学习 李俊峰 +3 位作者 李涛 曾召刚 任保增 樊耀亭 《Agricultural Science & Technology》 CAS 2010年第8期1-3,共3页
[Objective] This study was to explore the effects of dilute acid hydrolysis on fermentative biohydrogen production capacity of maize stalk. [Method] Using maize stalks subjected to mechanical disintegration,steam expl... [Objective] This study was to explore the effects of dilute acid hydrolysis on fermentative biohydrogen production capacity of maize stalk. [Method] Using maize stalks subjected to mechanical disintegration,steam explosion and dilute acid hydrolysis as experimental materials,we measured and analyzed the effects of different treatments and particle size of maize stalk were analyzed. [Result] The optimal fermentative biohydrogen production was found under following parameters:pretreatment of 0.8% dilute H2SO4 following steam explosion,particle size of maize stalk of 0.425-0.850 mm,liquid-solid ratio [0.8% H2SO4 (M):stalk (W)] of 10:1. [Conclusion] Post steam explosion,dilute 0.8% dilute H2SO4 intensified hydrolysis on maize stalk could produce fermentative biohydrogen production capacity. 展开更多
关键词 Maize stalk Dilute acid-intensified hydrolysis Fermentative biohydrogen production
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Preparation and Characterization of Nanometer TiO_2 by Hydrolysis Precipitation Method 被引量:1
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作者 方世杰 徐明霞 +1 位作者 郝俊杰 汪成建 《Transactions of Tianjin University》 EI CAS 2002年第2期79-82,共4页
Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structu... Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structure. Annealed at 500 ℃, nanometer TiO 2 with a specific surface area of 101.39 m 2 ·g -1 and a grain size about 10 nm were obtained(pH=5); and with a specific surface area of 95.48 m 2 ·g -1 and a grain size about 30 nm were obtained(pH=10). The research indicated that crystal phase transformation of rutile at 750 ℃made great promotion in grain size growth. 展开更多
关键词 nanometer Tio 2 hydrolysis precipitation method PH crystal phase transformation
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NMR Spectral Analysis and Hydrolysis Studies of Rebaudioside N, a Minor Steviol Glycoside of <i>Stevia rebaudiana</i>Bertoni 被引量:6
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作者 Venkata Sai Prakash Chaturvedula Steven Chen +1 位作者 Oliver Yu Guohong Mao 《Food and Nutrition Sciences》 2013年第10期1004-1008,共5页
The complete proton and carbon NMR spectral assignments of a diterpene glycoside isolated from the commercial extract of the leaves of Stevia rebaudiana Bertoni, 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β... The complete proton and carbon NMR spectral assignments of a diterpene glycoside isolated from the commercial extract of the leaves of Stevia rebaudiana Bertoni, 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] entkaur-16-en-19-oic acid-[(2-O-α-L-rhamnopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester] (1);also known as rebaudioside N, was achieved by the extensive 1D and 2D NMR (1H and 13C, COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside N using acid and enzymatic studies to identify aglycone and sugar residues in its structure. 展开更多
关键词 STEVIA rebaudiana Diterpene GLYCOSIDE Isolation Structure Elucidation Spectral Data hydrolysis STUDIES
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Wet Oxidation Pretreatment of Poplar Waste for Enhancing Enzymatic Hydrolysis Efficiency 被引量:3
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作者 GuiGan Fang ShanShan Liu +1 位作者 KuiZhong Shen Yan Lin 《Paper And Biomaterials》 2017年第2期8-17,共10页
In this paper, we described the optimization of the wet oxidation pretreatment conditions to enhance enzymatic hydrolysis efficiency, using poplar waste from the stock section of a paper mill as the raw material. We s... In this paper, we described the optimization of the wet oxidation pretreatment conditions to enhance enzymatic hydrolysis efficiency, using poplar waste from the stock section of a paper mill as the raw material. We showed that the optimal conditions of the pretreatment for poplar waste were an initial p H value of 10, a temperature of 195℃, a holding time of 15 min, and an oxygen pressure of 1.2 MPa. In this case, the yield of the obtained solid material produced by the process was 51.7% and the reducing sugar yield was 46.8%. The solid part obtained from the pretreatment process was hydrolyzed by cellulase L-10. The optimal enzymatic conditions were a temperature of 49℃, a duration time of 56 h, an enzyme dosage of 38 FPU/g at a p H value of 4.8, and a solid-to-liquor ratio of 1∶50. The resulting cellulose conversion rate reached 96.4% in terms of the pretreated substances. In addition, a chemical composition analysis of the poplar waste and pretreated material indicated that about 92% of the hemicelluloses and 43% of the lignin in the raw material were degraded and dissolved. In addition, the crystallization decreased from 57.5% to 54.8%. An obvious fibrillation of the fiber pretreated by the wet oxidization process was observed by SEM. Moreover, high-performance liquid chromatography(HPLC) results showed a high xylose content and monosaccharide degradation products in the pretreatment solution. In conclusion, the wet oxidation pretreatment process could efficiently degrade or remove the lignin and hemicellulose, as well as reduce the crystallinity of the lignocellulosic material, which resulted in animprovement of the enzymatic ability and an increase in the cellulose conversion rate. 展开更多
关键词 poplar waste wet oxidation pretreatment enzymatic hydrolysis efficiency cellulase hydrolysis
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Theoretical Studies on Mechanism and Rate Constant of Gas Phase Hydrolysis of Glyoxal Catalyzed by Sulfuric Acid
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作者 黄明强 蔡顺有 +4 位作者 廖颖敏 赵卫雄 胡长进 王振亚 张为俊 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第3期335-343,I0001,I0002,共11页
The gas phase hydration of glyoxal (HCOCHO) in the presence of sulfuric acid (H2SO4) were studied by the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional ... The gas phase hydration of glyoxal (HCOCHO) in the presence of sulfuric acid (H2SO4) were studied by the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional transition state theory (CTST). The mechanism and rate constant of the five different reaction paths are consid- ered corresponding to HCOCHO+H2O, HCOCHO+H2O… H2O, HCOCHO… H2O+H2O, HCOCHO+H2O… H2SO4 and HCOCHO… H2O+H2SOa. Results show that H2SO4 has a strong catalytic ability, which can significantly reduce the energy barrier for the hydration reaction of glyoxal. The energy barrier of hydrolysis of glyoxal in gas phase is lowered to 7.08 kcal/mol from 37.15 kcal/mol relative to pre-reactive complexes at the CCSD(T)/6- 311++G(3df, 3pd)//M06-2X/6-311++G(3df, 3pd) level of theory. The rate constant of the H2SO4 catalyzed hydrolysis of glyoxal is 1.34×10-11 cm3/(molecule.s), about 1013 higher than that involving catalysis by an equal number of water molecules, and is greater than the reaction rate of glyoxal reaction with OH radicals of 1.10×10-11 cm3/(molecule·s) at the room temperature, indicating that the gas phase hydrolysis of glyoxal of H2SO4 catalyst is feasible and could compete with the reaction glyoxal+OH under certain atmospheric condi- tions. This study may provide useful information on understanding the mechanistic features of inorganic acid-catalyzed hydration of glyoxal for the formation of oligomer. 展开更多
关键词 GLYOXAL hydrolysis Sulfuric acid Acid-catalyzed mechanism
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Influence of K + on the Coupling Between ATP Hydrolysis and Proton Transport by the Plasma Membrane H +_ATPase from Soybean Hypocotyls 被引量:1
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作者 邱全胜 《Acta Botanica Sinica》 CSCD 1999年第9期962-966,共5页
The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by th... The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by the plasma membrane H +_ATPase were studied. The results showed that the proton transport activity was increased by 850% in the presence of 100 mmol/L KCl, while ATP hydrolytic activity was only increased by 28.2%. Kinetic studies showed that K m of ATP hydrolysis decreased from 1.14 to 0.7 mmol/L, while V max of ATP hydrolysis increased from 285.7 to 344.8 nmol Pi·mg -1 protein·min -1 in the presence of KCl. Experiments showed that the optimum pH was 6.5 and 6.0 in the presence and absence of KCl, respectively. Further studies revealed that K + could promote the inhibitory effects of hydroxylamines and vanadates on the ATP hydrolytic activity. The above results suggested that K + could regulate the coupling between ATP hydrolysis and proton transport of the plasma membrane H +_ATPase through modulating the structure and function of the kinase and phosphatase domains of the plasma membrane H +_ATPase. 展开更多
关键词 Soybean hypocotyl Plasma membrane H +_ATPase K + ATP hydrolysis Proton transport COUPLING
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STUDY ON HYDROLYSIS RESISTANT POLYCARBONATE POLYURETHANE EPOXY RESIN BLENDS
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作者 陈同蕙 高悦 +1 位作者 黎汉生 张敏莲 《Transactions of Tianjin University》 EI CAS 1998年第2期55-58,共4页
This paper studies the structure and properties of the polycarbonate polyurethane epoxy resin (PCPU EP) blends being resistant to hydrolysis.The samples were analyzed by an infrared spectrome... This paper studies the structure and properties of the polycarbonate polyurethane epoxy resin (PCPU EP) blends being resistant to hydrolysis.The samples were analyzed by an infrared spectrometer,a differential scanning calorimeter,a scanning electron microscope and a dynamic viscoelastometer.The results show that PCPU EP blends have excellent resistance to hydrolysis and mechanical properties at the ratio of PCPU to EP equal to 10/100 (wt/wt). 展开更多
关键词 POLYCARBONATE POLYURETHANE epoxy resin resistance to hydrolysis
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Hydrolysis Mechanism of the NAMI-A-type Antitumor Complex (HL)[trans-RuCl4L(dmso-S)] (L=1-methyl-l,2,4-triazole)
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作者 陈兰美 陈锦灿 +3 位作者 廖思燕 刘江琴 罗辉 郑康成 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第4期383-390,I0003,共9页
The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent ... The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent (Him)[trans-RuC14 (dmso-S)(im)] (NAMI-A, im=imidazole), was investigated using density functional theory combined with the conductor-like polarizable continuum model approach. Tile structural characteristics and the detailed energy profiles for the hydrolysis processes of this complex were obtained. For the first hydrolysis step, complex 1 has slightly higher barrier energies than the reported anticancer drug NAMI-A, and the result is in accordance with the experimental evidence indicating larger half-life for complex 1. For the second hydrolysis step, the formation of cis-diaqua species is thermodynamic preferred to that of trans isomers. In addition, on the basis of the analysis of electronic characteristics of species in the hydrolysis process, the trend in nucleophilic attack abilities of hydrolysis products by pertinent biomolecules is revealed and predicted. 展开更多
关键词 NAMI-A-type complex Anticancer activity hydrolysis Density functional theory Conductor-like polarizable continuum model
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Study on the Technologic Optimization for Hydrolysis of Silver carp By-products
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作者 ZHAOYu-hong KONGBao-hua ZHANGLi-gang 《Journal of Northeast Agricultural University(English Edition)》 CAS 2005年第1期87-90,共4页
The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five le... The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five levels quadratic rotation perpendicular regressive design. The optimum hydrolysis conditions of hydrolyzing the protein of Silver carp by-products were determined to be concentration of enzyme (E/S) 3.33%, pH 8.54, hydrolyzing temperature 58 ℃, reaction time 90 min, concentration of substrate 8%. Nitrogen recovery was more than 75%. 展开更多
关键词 enzymatic hydrolysis Silver carp by-products degree of hydrolysis nitrogen recovery
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Hydrolysis of soy isoflavone conjugates using enzyme may underestimate isoflavone concentrations in tissue
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作者 Hebron C.Chang Myriam Laly +1 位作者 Melody Harrison Thomas M.Badger 《Journal of Nanjing Medical University》 2005年第1期10-14,共5页
Objective:To investigate the differences of using enzymatic hydrolysis and acid hydrolysis for identification and quantification of isoflavone aglycones from biomatrices.Methods:β-glucuronidase/sulfatase isolated fro... Objective:To investigate the differences of using enzymatic hydrolysis and acid hydrolysis for identification and quantification of isoflavone aglycones from biomatrices.Methods:β-glucuronidase/sulfatase isolated from Helix pomatia for routine enzymatic hydrolysis or 6N HCl was used to release glucuronide and sulfate conjugates in the serum,urine and tissue samples.Profiles of soy isoflavones after enzymatic hydrolysis or acid hydrolysis in several tissues of rat fed with diets containing soy protein isolate were also compared using LC/MS and HPLC-ECD.Results:Acid hydrolysis released more aglycone than enzymatic digestion(P<0.05)in liver tissue.The total genistein,daidzein and other metabolites were 20%to 60%lower in samples from enzymatic hydrolysis than in acid hydrolysis.Conclusion:These results indicated that unknown factors in tissues reduced the enzymatic hydrolytic efficiency for releasing isoflavone aglycones even in optimized condition.This would underestimate isoflavone tissue concentrations up to 60%. 展开更多
关键词 isoflavone aglycones enzymatic hydrolysis acid hydrolysis GLUCURONIDE SULFATE CONJUGATES
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Study on Saccharification of Saccharum spontaneum L. by Sulphuric Acid Hydrolysis
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作者 Jianle LIU Changjun BAI +3 位作者 Linling YAN Qinglin JIA Yu ZHANG Hubiao YANG 《Agricultural Biotechnology》 CAS 2014年第6期8-13,共6页
In order to improve the saccharification rate by acid hydrolysis in the technique for production of ethanol from biomass, in this study, Saccharum spontaneum L. was used as the experimental material to investigate the... In order to improve the saccharification rate by acid hydrolysis in the technique for production of ethanol from biomass, in this study, Saccharum spontaneum L. was used as the experimental material to investigate the rules and technological conditions for two-step acid-hydrolysis saccharification by single factor experiment and orthogonal experiment. According to the results, concentrated sulfttric acid hydrolysis was the first step, with the liquid-solid ratio of 42: 1, sulfuric acid concentration of 70%, hydrolysis time of 20 rain, and hydrolysis temperature of 55 ℃ ; dilute sulphuric acid hydrolysis was the second step, with the liquidsolid ratio of 115: 1, sulfuric acid concentration of 5.5%, hydrolysis time of 155 min, and hydrolysis temperature of 100℃. In two-step acid hydrolysis process, the yield of reducing sugar was 48.78%. The results indicated that two-step acid-hydrolysis saccharification required mild conditions, simple operation and low cost, and led to high reducing sugar yield, exhibiting a broad application prospect. 展开更多
关键词 Saccharum spontaneum L. Acid hydrolysis Two-step acid hydrolysis
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Isolation and Purification of Enzymatic Hydrolysates of Yam(Dioscorea opposita Thunb.)Proteins
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作者 MengchenXU Ke DING +1 位作者 Ying LU Tao HAN 《Agricultural Biotechnology》 CAS 2016年第1期19-21,24,共4页
Using yam (Dioscorea opposita Thunb. ) as the experimental material, enzymatic hydrolysates of yam proteins were prepared with alkaline protease, which were then isolated and purified by cellulose DE-52 anion exchan... Using yam (Dioscorea opposita Thunb. ) as the experimental material, enzymatic hydrolysates of yam proteins were prepared with alkaline protease, which were then isolated and purified by cellulose DE-52 anion exchange chromatography Sephadex G-50 gel chromatography. According to the results, four absorp- tion peaks were obtained by cellulose DE-52 anion exchange chromatography, and fractions at each absorption peak were collected. Specifically, the reducing ability of four peaks demonstrated a descending order of peak 2 (P2) 〉 peak I ( P1 ) 〉 peak 3 (P3) 〉 peak 4 (P4). By Sephadex G-50 gel chmmatography, P1 and P2 were isolated and purified with distilled water and Tris-HC1 buffer, and two absorption peaks were obtained, respectively. 展开更多
关键词 Yam proteins Enzymatic hydrolysis Isolation PURIFICATION
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Kinetic Dependences of Two-Stage Dilute Acid and Enzyme Hydrolysis of Paulownia tomentosa
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作者 Greta Radeva Ivo Valchev Stoiko Petrin 《Journal of Chemistry and Chemical Engineering》 2011年第11期985-989,共5页
The sugars potential ofPaulownia tomentosa is estimated by dilute acid pretreatment and cellulase hydrolysis. The kinetics of dilute (1%) sulfuric acid hydrolysis is studied at temperatures of 100 ℃, 120 ℃ and 130... The sugars potential ofPaulownia tomentosa is estimated by dilute acid pretreatment and cellulase hydrolysis. The kinetics of dilute (1%) sulfuric acid hydrolysis is studied at temperatures of 100 ℃, 120 ℃ and 130 ℃, while the kinetics of the subsequent enzyme hydrolysis is examined at a temperature of 50 ℃ and reaction time varied from 60 to 300 min using cellulase complex NS 50013 and β-glucosidase N S 50010. The reducing sugars formation is modeled as a pseudo-homogeneous first order reaction in view of the kinetics of dilute sulfuric acid hydrolysis. The results obtained indicate that the reaction proceeds in an energetically homogeneous system (E = const) providing identical accessibility of the reagent to the hydrolyzing sites (A = const). The enzyme hydrolysis kinetics follows heterogeneous catalytic mechanism. The process is described by an exponential kinetic equation, which is well recognised in case of processes on uniformly inhomogeneous surfaces. The current rate decreases significantly probably because of exhaustion of the available active sites on the surface and steric hindrances due to the presence of lignin. This investigation provides information of importance for the fermentation step of the bio-ethanol production process. 展开更多
关键词 Kinetics dilute sulfuric hydrolysis enzyme hydrolysis paulownia.
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