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Alkali-metal-modified ZSM-5 zeolites for improvement of catalytic dehydration of lactic acid to acrylic acid 被引量:8
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作者 袁川 刘华彦 +3 位作者 张泽凯 卢晗锋 朱秋莲 陈银飞 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第11期1861-1866,共6页
Various ZSM-5 zeolites modified with alkali metals (Li, Na, K, Rb, and Cs) were prepared using ion exchange. The catalysts were used to enhance the catalytic dehydration of lactic acid (LA) to acrylic acid (AA).... Various ZSM-5 zeolites modified with alkali metals (Li, Na, K, Rb, and Cs) were prepared using ion exchange. The catalysts were used to enhance the catalytic dehydration of lactic acid (LA) to acrylic acid (AA). The effects of cationic species on the structures and surface acid-base distributions of the ZSM-5 zeolites were investigated. The important factors that affect the catalytic performance were also identified. The modified ZSM-5 catalysts were characterized using X-ray diffraction, tempera- ture-programmed desorptions of NH3 and CO2, pyridine adsorption spectroscopy, and N2 adsorption to determine the crystal phase structures, surface acidities and basicities, nature of acid sites, specific surface areas, and pore volumes. The results show that the acid-base sites that are adjusted by alkali-metal species, particularly weak acid-base sites, are mainly responsible for the formation of AA. The KZSM-5 catalyst, in particular, significantly improved LA conversion and AA selectivity because of the synergistic effect of weak acid-base sites. The reaction was conducted at different reaction temperatures and liquid hourly space velocities (LHSVs) to understand the catalyst selectivity for AA and trends in byproduct formation. Approximately 98% LA conversion and 77% AA selectivity were achieved using the KZSM-5 catalyst under the optimum conditions (40 wt% LA aqueous solution, 365 ℃, and LHSV 2 h-1). 展开更多
关键词 ZSM-5 zeolite alkali metal Lactic acid Acrylic acid Dehydration
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Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure 被引量:1
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作者 Ming Li Da-Hao Yuan +2 位作者 Zhi Yang Teng-Xiang Luw Xiao-Biao Zou 《World Journal of Clinical Cases》 SCIE 2024年第18期3461-3467,共7页
BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.Howeve... BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF. 展开更多
关键词 Serum cystatin C Monocyte/high-density lipoprotein-C ratio Uric acid Coronary heart disease Heart failure Risk stratification
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Humic Acid Effects on Reducing Corn Leaf Burn Caused by Foliar Spray of Urea-Ammonium Nitrate at Different Humic Acid/Urea-Ammonium Nitrate Ratios
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作者 Xinhua Yin 《Open Journal of Soil Science》 2024年第3期180-189,共10页
Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on c... Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season. 展开更多
关键词 Humic acid Urea-Ammonium Nitrate CORN Leaf Burn N rate ratio
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Calcium-Magnesium Ca/Mg Ratios and Their Agronomic Implications for the Optimization of Phosphate Fertilization in Rainfed Rice Farming on Acidic Ferralsol in the Forest Zone of Ivory Coast
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作者 Fernand G. Yao Brahima Kone +7 位作者 Franck M. L. Bahan Kouadio Amani Jean L. Essehi Mamadou B. Ouattara Konan E. B. Dibi Brou Kouame François Lompo Albert Yao-Kouame 《Open Journal of Soil Science》 2024年第1期81-96,共16页
This study is a contribution to improving rice productivity on acidic plateau soils of the tropical rainforest zone. It is based on taking into account the cationic balances of the soil in order to optimize the phosph... This study is a contribution to improving rice productivity on acidic plateau soils of the tropical rainforest zone. It is based on taking into account the cationic balances of the soil in order to optimize the phosphorus (P) nutrition of rice on these acidic soils, where this nutrient constitutes a limiting factor for agricultural production. Three (3) pot trials were conducted in Adiopodoumé in the forested south of Côte d’Ivoire. The interactive effects of calcium carbonate (0, 25, 50 and 75 kg Ca ha<sup>−1</sup>) and magnesium sulfate (0, 25, 50 and 75 kg Mg ha<sup>−1</sup>) were evaluated on the response of NERICA 5 rice at doses 0, 25, 50 and 75 kg P ha<sup>−1</sup> of natural phosphate from Togo, applied only once at the start of the experiment. Additional fertilizers of nitrogen (N) (100 kg N ha<sup>−1</sup>) and potassium (K) (50 kg KCl ha<sup>−1</sup>) were added to each of the tests in a split-plot device. The test results revealed a paddy production potential of approximately 3 to 5 t⋅ha<sup>−1</sup> for NERICA 5 on an acidic soil, under the effect of the interaction of P, Ca and Mg. The quadratic response of rice yield to the doses of these fertilizers would be more dependent on their balance, itself influenced by Ca nutrition. For the sustainability and maintenance of rice production in agro-ecology studied, it was recommended doses of 38 kg Ca ha<sup>−1</sup>, 34 kg Mg ha<sup>−1</sup> in a Ca/Mg ratio (1/1) with intakes of 41 kg P ha<sup>−1</sup>, overall in a ratio 1/1/1 (P/Ca/Mg) more favorable to the availability of free iron considered a guiding element of mineral nutrition. Thus, these promising results should be confirmed in a real environment for better management of the fertilization of rice cultivated on acidic plateau soils in Côte d’Ivoire. 展开更多
关键词 Soil acidity Ca/Mg ratios Phosphate Fertilization Rice Growing Ivory Coast
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PREPARATION OF HOLLOW LATEX PARTICLES BY ALKALI-ACID TREATMENT
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作者 郝冬梅 王新灵 +3 位作者 朱卫华 唐小真 刘成岑 施凯 《Journal of Shanghai Jiaotong university(Science)》 EI 2001年第1期10-15,共6页
Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methac... Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage). 展开更多
关键词 seeded emulsion polymerization hollow polymer particles alkali treatment acid treatment MORPHOLOGY
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Bifunctional Mn-doped CoSe_(2) nanonetworks electrode for hybrid alkali/acid electrolytic H_(2) generation and glycerol upgrading
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作者 Linfeng Fan Yaxin Ji +5 位作者 Genxiang Wang Zhifang Zhang Luocai Yi Kai Chen Xi Liu Zhenhai Wen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第9期424-431,I0012,共9页
Electrolytic water splitting,as a promising route to hydrogen(H_(2))production,is still confronted with the sluggish anodic oxygen evolution reaction(OER)and its less value-added O2 production.Herein,we report a bifun... Electrolytic water splitting,as a promising route to hydrogen(H_(2))production,is still confronted with the sluggish anodic oxygen evolution reaction(OER)and its less value-added O2 production.Herein,we report a bifunctional electrode fabricated by in situ growth of Mn-doped CoSe_(2)nanonetworks on carbon fiber cloth(Mn-CoSe_(2)/CFC),which shows attractive electrocatalytic properties toward glycerol oxidation reaction(GOR)in alkali and hydrogen evolution reaction(HER)in acid.A flow alkali/acid hybrid electrolytic cell(fA/A-hEC)was then developed by coupling anodic GOR with cathodic HER with the Mn-CoSe_(2)/CFC bifunctional electrode.Such fA/A-hEC enables a rather low voltage of 0.54 V to achieve 10 mA cm^(-2),and maintain long-term electrolysis stability over 300-h operation at 100 mA cm^(-2)with Faraday efficiencies of over 99%for H_(2)and 90%for formate production.The designed bifunctional electrode in such innovative fA/A-hEC device provides insightful guidance for coupling energy-efficient hydrogen production with biomass upgradation. 展开更多
关键词 Mn-doped CoSe_(2)nanonetworks Glycerol upgrading electrooxidation Hydrogen production Bifunctional electrocatalytic electrode Hybrid flow alkali/acid electrolyzer
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Preparation of Conjugated Linoleic Acid of High Purity and Its Apparent Kinetic Characteristics During Formation 被引量:4
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作者 唐向阳 郭诤 张根旺 《Transactions of Tianjin University》 EI CAS 2002年第1期27-32,共6页
Conjugated linoleic acid (CLA) is a fatty acid with physiological activities and potential application prospect. This paper focuses on the method of synthesis of conjugated linoleic acid of high purity and the process... Conjugated linoleic acid (CLA) is a fatty acid with physiological activities and potential application prospect. This paper focuses on the method of synthesis of conjugated linoleic acid of high purity and the process line and conditions for its purification that can be used in large scale production. CLA of more than 95% purity was prepared by means of urea adduct purification and conjugation using safflower oil as material. The total recovery of the product adds up to more than 48%. The reactive kinetics about linoleic acid from sunflower oil converted into CLA was investigated, and its apparent kinetic model was also established, which can be used as a base for industrial designs. 展开更多
关键词 linoleic acid conjugated linoleic acid PREPAratioN apparent kinetics urea adduct alkali catalyzed conjugation safflower oil
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Effects of alkaline additives on the formation of lactic acid in sorbitol hydrogenolysis over Ni/C catalyst 被引量:1
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作者 张俊杰 路芳 +2 位作者 于维强 卢锐 徐杰 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第1期177-183,共7页
Lactic acid is produced as a major byproduct during sorbitol hydrogenolysis under alkaline conditions.We investigated the effects of two different alkaline additives,Ca(OH)2 and La(OH)3,on lactic acid formation du... Lactic acid is produced as a major byproduct during sorbitol hydrogenolysis under alkaline conditions.We investigated the effects of two different alkaline additives,Ca(OH)2 and La(OH)3,on lactic acid formation during sorbitol hydrogenolysis over Ni/C catalyst.In the case of Ca(OH)2,the selectivity of lactic acid was 8.9%.In contrast,the inclusion of La(OH)3 resulted in a sorbitol conversion of 99% with only trace quantities of lactic acid being detected.In addition,the total selectivity towards the C2 and C4 products increased from 20.0% to 24.5% going from Ca(OH)2 to La(OH)3.These results therefore indicated that La(OH)3 could be used as an efficient alkaline additive to enhance the conversion of sorbitol.Pyruvic aldehyde,which is formed as an intermediate during sorbitol hydrogenolysis,can be converted to both 1,2-propylene glycol and lactic acid by hydrogenation and rearrangement reactions,respectively.Notably,these two reactions are competitive.When Ca(OH)2 was used as an additive for sorbitol hydrogenolysis,both the hydrogenation and rearrangement reactions occurred.In contrast,the use of La(OH)3 favored the hydrogenation reaction,with only trace quantities of lactic acid being formed. 展开更多
关键词 Lactic acid alkali SORBITOL Catalytic hydrogenolysis Nickel catalyst
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Noninvasive assessment of liver fibrosis with combined serum aminotransferase/platelet ratio index and hyaluronic acid in patients with chronic hepatitis B 被引量:14
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作者 You-Xiang Zhang Wen-Juan Wu +3 位作者 Yun-Zhi Zhang Yan-Ling Feng Xin-Xi Zhou Qi Pan 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第46期7117-7121,共5页
AIM: To construct a noninvasive assessment model consisting of routine laboratory data to predict significant fibrosis and cirrhosis in patients with chronic hepatitis B (CHB). METHODS: A total of 137 consecutive ... AIM: To construct a noninvasive assessment model consisting of routine laboratory data to predict significant fibrosis and cirrhosis in patients with chronic hepatitis B (CHB). METHODS: A total of 137 consecutive patients with CriB who underwent percutaneous liver biopsy were retrospectively analyzed. These patients were divided into two groups according to their aminotransferase (ALT) level. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), the likelihood ratio (LR) of aminotransferase/platelet ratio index (APRI) ≥ 1.5 or 〈 1.5 in combination with different hyaluronic acid (HA) cut-off points were calculated for the presence of moderate to severe fibrosis/cirrhosis (fibrosis stages 2 and 4) and no to mild fibrosis/cirrhosis (fibrosis stages 0 and 1). RESULTS: The APRI correlated with fibrosis stage in CriB patients. The APRI ≥1.5 in combination with a cut-off HA cut-off point 〉 300 ng/mL could detect moderate to severe fibrosis (stages 2-4) in Crib patients. The PPV was 93.7%, the specificity was 98.9%. The APRI 〈 1.5 in combination with different HA cut-off points could not detect no to mild fibrosis in CHB patients. CONCLUSION: The APRI ≥ 1.5 in combination with a HA cut-off point 〉 300 ng/mL can detect moderate to severe fibrosis (stages 2-4) in Crib patients. 展开更多
关键词 Noninvasive assessment Liver fibrosis Chronic hepatitis B Aminotransferase/platelet ratio index Hyaluronic acid
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Effect of Starch/Polylactic Acid Ratio on the Interdependence of Two-Phase and the Properties of Composites 被引量:3
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作者 左迎峰 GU Jiyou +3 位作者 CAO Jun WEI Shuangying TAN Haiyan 张彦华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第5期1108-1114,共7页
Starch/polylactic acid(PLA) composites were prepared by melt extrusion, with corn starch and PLA as raw materials, glycerol as the plasticizer. Effects of starch/PLA ratio on the interdependence of two-phase and other... Starch/polylactic acid(PLA) composites were prepared by melt extrusion, with corn starch and PLA as raw materials, glycerol as the plasticizer. Effects of starch/PLA ratio on the interdependence of two-phase and other properties of the composites were studied. The combination of results of TGA with SEM indicated that the interdependence between starch and PLA was increased gradually as the starch/PLA ratio reduced. DSC results showed that the glass transition temperature(Tg), melting temperature(Tm) and degree of crystallinity of PLA in composites were increased gradually, whereas the cold crystallization temperature(Tc) was gradually decreased as the starch/PLA ratio reduced. The rheological properties of composites were closely related with the interdependence of two-phase, with reducing starch/PLA proportion, the interdependence was increased, and then the strain for storage modulus was firstl reduced and then gradually increased. Frequency scanning showed that the storage modulus and complex viscosity were decreased with reducing starch content. As the starch/PLA ratio reduced, the matrix phase PLA was increased, so that the strength of composites was increased gradually, whereas water absorption rate was decreased gradually. 展开更多
关键词 corn starch polylactic acid mixing ratio interdependence of two-phase PROPERTIES
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Effect of Altering Linoleic Acid and Linolenic Acid Dietary Ratios on the Performance and Tissue Fatty Acid Profiles of Prawn, Macrobrachium rosenbergii (de Man 1879) Post Larvae 被引量:11
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作者 A. M. A. S. Goda M. M. Habashy +5 位作者 M. A. Hanafy R. A. Mohamed H. A. Mabrouk T. M. El-Afifi S. A.Nada K. A. Mohamed 《Journal of Agricultural Science and Technology(B)》 2011年第7期1032-1044,共13页
A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid (LA; 18:2n-6) and linolenic acid ratios (LNA; 18:3n-3) on growth induces, feed utilization and tissue fatty acid pr... A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid (LA; 18:2n-6) and linolenic acid ratios (LNA; 18:3n-3) on growth induces, feed utilization and tissue fatty acid profile of freshwater prawn, Macrobrachium rosenbergii post-larvae (PL). The experiment was conducted in cubic indoor fiberglass tanks, each holding 700 L in triplicate. Post-larvae with an average weight of 20.8 ± 0.20 mg were stocked at 80 PL m2. Five experimental isocaloric (15.06 MJ kgl digestible energy), and isonitrogenous (30.45% digestible protein) diets were formulated by blending of soybean oil and linseed oil to containing five dietary LA/LNA ratios (7.80, 2.75, 1.28, 0.65 and 0.30). The highest survival values were recorded for prawn PL fed diet containing 0.65 LA/LAN ratios. Growth indices of PL significantly increased (P 〈 0.05) with decreased dietary LA/LAN ratios to 0.65. The same trend was observed for the highest (P ≤ 0.05) protein efficiency ratio, protein productive value, fat retention, energy retention and best feed conversion ratio. The total whole tissue polyunsaturated fatty acid composition of M. rosenbergii PL was dominated by LA followed by LAN. Post larvae fed the diets containing higher LA/LNA ratios showed a higher tissue LA/LNA ratio. The obtained findings revealed that fatty acid patterns ofM. rosenbergii PL were influenced by fatty acid profiles of diets. The diet containing 0.65 LA/LNA ratio is recommended to obtaining optimum growth performance and feed utilization for M. rosenbergii PL. 展开更多
关键词 Fatty acids linoleic linolenic Macrobrachium rosenbergii dietary ratio.
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Determination of Hf–Sr–Nd isotopic ratios by MC-ICP-MS using rapid acid digestion after flux-free fusion in geological materials 被引量:4
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作者 Zhian Bao Chunlei Zong +3 位作者 Linru Fang Honglin Yuan Kaiyun Chen Mengning Dai 《Acta Geochimica》 EI CAS CSCD 2018年第2期244-256,共13页
In this study, we established a rapid acid digestion for determining Hf-Sr-Nd isotopic ratios of geological samples by using MC-ICP-MS. Conditions of 1600 ℃ for 1 min and 1400 ℃ for 1 min were adopted for fusing int... In this study, we established a rapid acid digestion for determining Hf-Sr-Nd isotopic ratios of geological samples by using MC-ICP-MS. Conditions of 1600 ℃ for 1 min and 1400 ℃ for 1 min were adopted for fusing intrusive rocks and extrusive rocks, respectively. The rapid acid digestion technique is superior in digestion time compared with high-pressure PTFE bomb method. The procedural blanks of the method were also lower than that flux fusion. Replicate analyses of international certified reference materials (CRMs) indicate that isotopic ratios of ^176Hf/^177Hf, ^87Sr/^86Sr and 143Nd/144Nd agree well with previously published data. The external reproducibility (2SD, n = 5) of ten CRMs are ±0.000030 for ^87Sr/^86Sr, ± 0.000030 for ^143Nd/^144Nd, and ±0.000018 for ^176Hf/^177Hf. 展开更多
关键词 Certified reference material Flux-free fusion Hf-Sr-Nd isotopic ratio Procedural blank Rapid acid digestion
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Influence of Ca/P ratio on the catalytic performance of hydroxyapatite for decarboxylation of itaconic acid to methacrylic acid 被引量:2
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作者 Shutong Pang Hualiang An +1 位作者 Xinqiang Zhao Yanji Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第1期402-408,共7页
Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid... Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid.In view of the problems existing in the researches on this route such as use of noble metal catalyst,harsh reaction conditions and low desired-product yield,we prepared a series of hydroxyapatite catalysts with different Ca/P molar ratios and evaluated their catalytic performance.The results showed that the hydroxyapatite catalyst with a Ca/P molar ratio of 1.58 had the best catalytic activity.The highest yield of MAA up to 61.2%was achieved with basically complete conversion of itaconic acid under the suitable reaction conditions of 1 equivalent of NaOH,2 MPa of N_(2),250℃,and 2 h.On this basis,a reaction network for the decarboxylation of itaconic acid to methacrylic acid catalyzed by hydroxyapatite was established.With the aid of catalyst characterization using X-ray powder diffraction,NH3/CO2 temperature-programmed desorption,N_(2)physisorption,inductively coupled plasma optical emission spectrometry,and scanning electron microscopy,we found that the distribution of surface acid sites and basic sites,crystal growth orientation,texture properties and morphology of hydroxyapatite varied with the Ca/P molar ratio.Furthermore,the change of the crystal growth orientation and its influence on the surface acidity and alkalinity were clarified. 展开更多
关键词 Biomass-derived itaconic acid Methacrylic acid Hydroxyapatite catalyst Ca/P ratio Decarboxylation reaction
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Branched-chain amino acids to tyrosine ratio value as a potential prognostic factor for hepatocellular carcinoma 被引量:10
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作者 Toru Ishikawa 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第17期2005-2008,共4页
The prognosis of hepatocellular carcinoma(HCC) depends on tumor extension as well as hepatic function.Hepatic functional reserve is recognized as a factor affecting survival in the treatment of HCC;the ChildPugh class... The prognosis of hepatocellular carcinoma(HCC) depends on tumor extension as well as hepatic function.Hepatic functional reserve is recognized as a factor affecting survival in the treatment of HCC;the ChildPugh classif ication system is the most extensively used method for assessing hepatic functional reserve in patients with chronic liver disease,using serum albumin level to achieve accurate assessment of the status of protein metabolism.However,insuff icient attention has been given to the status of amino acid(AA) metabolism in chronic liver disease and HCC.Fischer's ratio is the molar ratio of branched-chain AAs(BCAAs:leucine,valine,isoleucine) to aromatic AAs(phenylalanine,tyrosine) and is important for assessing liver metabolism,hepatic functional reserve and the severity of liver dysfunction.Although this ratio is diff icult to determine in clinical situations,BCAAs/tyrosine molar concentration ratio(BTR) has been proposed as a simpler substitute.BTR correlates with various liver function examinations,including markers of hepatic f ibrosis,hepatic blood flow and hepatocyte function,and can thus be considered as reflecting the degree of hepatic impairment.This manuscript examines the literature to clarify whether BTR can serve as a prognostic factor for treatment of HCC. 展开更多
关键词 Branched-chain amino acids to tyrosine ratio Fischer's ratio Prognostic factor Hepatocellular carcinoma
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Preparation of Cs-Rb-V series sulphuric acid catalyst 被引量:1
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作者 陈振兴 杨刚 叶华 《中国有色金属学会会刊:英文版》 CSCD 2001年第4期595-598,共4页
Cs Rb V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali metal salts. The results show that the conversion of SO 2 on catalyst prepared... Cs Rb V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali metal salts. The results show that the conversion of SO 2 on catalyst prepared directly with carbonized mother liquor could reach to 24.8% at 410?℃. If n (Na)/ n (V) was adjusted properly, the conversion of SO 2 could be increased to 35.6% at 410?℃. Refined carbonized mother liquor could make the catalytic activity even higher at low temperature, the conversion of SO 2 could be increased to 36.65% at 410?℃. The catalyst was examined with differential thermal analysis. It was found that both endothermic peaks and exothermic peaks of catalyst shifted forward obviously and the catalyst possessed higher activity at low temperature. 展开更多
关键词 sulphuric acid catalyst sulphur dioxide alkali metal element low temperature activity PROMOTER
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A Bifunctional Brønsted Acidic Deep Eutectic Solvent to Dissolve and Catalyze the Depolymerization of Alkali Lignin 被引量:2
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作者 Lifen Li Zhigang Wu +4 位作者 Xuedong Xi Baoyu Liu Yan Cao Hailong Xu Yingcheng Hu 《Journal of Renewable Materials》 SCIE EI 2021年第2期219-235,共17页
Lignin is an abundant renewable macromolecular material in nature,and degradation of lignin to improve its hydroxyl content is the key to its efficient use.Alkali lignin(AL)was treated with Brønsted acidic deep e... Lignin is an abundant renewable macromolecular material in nature,and degradation of lignin to improve its hydroxyl content is the key to its efficient use.Alkali lignin(AL)was treated with Brønsted acidic deep eutectic solvent(DES)based on choline chloride and p-toluenesulfonic acid at mild reaction temperature,the structure of the lignin before and after degradation,as well as the composition of small molecules of lignin were analyzed in order to investigate the chemical structure changes of lignin with DES treatment,and the degradation mechanism of lignin in this acidic DES was elucidated in this work.FTIR and NMR analyses demonstrated the selective cleavage of the lignin ether linkages in the degradation process,which was in line with the increased content of phenolic hydroxyl species.XPS revealed that the O/C atomic ratio of the regenerated lignin was lower than that of the AL sample,revealing that the lignin underwent decarbonylation during the DES treatment.Regenerated lignin with low molecular weight and narrow polydispersity index was obtained,and the average molecular weight(Mw)decreased from 17680 g/mol to 2792 g/mol(130°C,3 h)according to GPC analysis.The lignin-degraded products were mainly G-type phenolics and ketones,and small number of aldehydes were also generated,the possible degradation pathway of lignin in this acidic DES was proposed. 展开更多
关键词 alkali lignin DEPOLYMERIZATION Brønsted acidic deep eutectic solvent structural analysis
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Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid 被引量:1
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作者 Li Hua LIU Zhi Qiang LIU Zhu Qing GONG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第11期1523-1526,共4页
The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the... The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and roe and rNsAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers. 展开更多
关键词 Diethyldiallylammonium chloride (DEDAAC) acrylamide (AM) acrylic acid (AA) copolymerization reactivity ratios.
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Preparation of activated carbon from sunflower straw through H_(3)PO_(4) activation and its application for acid fuchsin dye adsorption 被引量:1
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作者 Wen-de Zhao Li-ping Chen Yan Jiao 《Water Science and Engineering》 EI CAS CSCD 2023年第2期192-202,共11页
With the development circular economy, the use of agricultural waste to prepare biomass materials to remove pollutants has become a research hotspot. In this study, sunflower straw activated carbon (SSAC) was prepared... With the development circular economy, the use of agricultural waste to prepare biomass materials to remove pollutants has become a research hotspot. In this study, sunflower straw activated carbon (SSAC) was prepared by the one-step activation method, with sunflower straw (SS) used as the raw material and H3PO4 used as the activator. Four types of SSAC were prepared with impregnation ratios (weight of SS to weight of H3PO4) of 1:1, 1:2, 1:3, and 1:5, corresponding to SSAC1, SSAC2, SSAC3, and SSAC4, respectively. The adsorption process of acid fuchsin (AF) in water using the four types of SSAC was studied. The results showed that the impregnation ratio significantly affected the structure of the materials. The increase in the impregnation ratio increased the specific surface area and pore volume of SSAC and improved the adsorption capacity of AF. However, an impregnation ratio that was too large led to a decrease in specific surface area. SSAC3, with an impregnation ratio of 1:3, had the largest specific surface area (1 794.01 m2/g), and SSAC4, with an impregnation ratio of 1:5, exhibited the smallest microporosity (0.052 7 cm3/g) and the largest pore volume (2.549 cm3/g). The adsorption kinetics of AF using the four types of SSAC agreed with the quasi-second-order adsorption kinetic model. The Langmuir isotherm model was suitable to describe SSAC3 and SSAC4, and the Freundlich isotherm model was appropriate to describe SSAC1 and SSAC2. The result of thermodynamics showed that the adsorption process was spontaneous and endothermic. At 303 K, SSAC4 showed a removal rate of 97.73% for 200-mg/L AF with a maximum adsorption capacity of 2 763.36 mg/g, the highest among the four types of SSAC. This study showed that SAAC prepared by the H3PO4-based one-step activation method is a green and efficient carbon material and has significant application potential for the treatment of dye-containing wastewater. 展开更多
关键词 acid fuchsin Activated carbon Adsorption Sunflower straw Phosphoric acid activation Impregnation ratio
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Adaptive strategy of Nitraria sibirica to transient salt,alkali and osmotic stresses via the alteration of Na+/K+fluxes around root tips 被引量:1
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作者 Xindi Mei Ting Dai Yingbai Shen 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第2期425-432,共8页
Nitraria sibirica Pall.is an important shrub with a strong salt-alkali tolerance,but the mechanism underlying this tolerance remains obscure.In this study,N.sibirica,with salt-sensitive Vigna radiata(Linn.)Wilczek as ... Nitraria sibirica Pall.is an important shrub with a strong salt-alkali tolerance,but the mechanism underlying this tolerance remains obscure.In this study,N.sibirica,with salt-sensitive Vigna radiata(Linn.)Wilczek as the control,was subjected to transient salt stress(100 mM NaCl),alkali stress(50 mM Na_(2)CO_(3)),and osmotic stress(175 mM mannitol).The ionic fluxes of Na^(+)and K^(+)in the root apical region were measured.Results show that,under salt and alkali stress,N.sibirica roots exhibited higher capacities to limit Na+influx and reduce K+efflux,thereby resulting in lower Na^(+)/K^(+)ratios compared with V.radiata roots.Alkali stress induced stronger Na^(+)influx and K+efflux in the root salt stress treatment;Na^(+)influx was mainly observed in the root cap,while K^(+)efflux was mainly observed in the elongation zone.While under osmotic stress,N.sibirica roots showed stronger Na+efflux and weaker K+efflux than V.radiata roots.Na+efflux was mainly observed in the root elongation zone,while K+efflux was in the root cap.These results reveal the ionic strategy of N.sibirica in response to transient salt,alkali,and osmotic stresses through the regulation of Na+/K+flux homeostasis. 展开更多
关键词 Nirtaria sibirica Na^(+)/K^(+)fl uxes Na^(+)/K^(+)ratios Salt stress alkali stress Osmotic stress
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Beneficial n-3 polyunsaturated fatty acid levels and n6:n3 ratios after 4-week EPA + DHA supplementation associated with reduced CRP: A pilot study in healthy young adults 被引量:1
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作者 Jodi McDaniel Emily Ickes Christopher Holloman 《Modern Research in Inflammation》 2013年第4期59-68,共10页
Chronic systemic inflammation is associated with many conditions of aging such as atherosclerosis. Lowering high n-6:n-3 polyunsaturated fatty acid (PUFA) ratios are commonly found in Western diets aids in preventing ... Chronic systemic inflammation is associated with many conditions of aging such as atherosclerosis. Lowering high n-6:n-3 polyunsaturated fatty acid (PUFA) ratios are commonly found in Western diets aids in preventing inflammatory-related diseases. However, it is not clear whether dietary interventions designed to alter n-6:n-3 PUFA ratios can reduce systemic inflammation in younger adults. Studies that evaluate PUFA intake often use subjective data from food frequency questionnaires or food records rather than more precise physiological measures of PUFAs (e.g. plasma levels). Therefore, the purpose of this pilot study that analyzed data from the experimental parent study of younger adults (n = 18), was to determine whether plasma PUFA levels were associated with levels of C-reactive protein (CRP), an inflammatory marker, and if supplementation with n-3 PUFAs was correlated with rising n-3 PUFA concentrations in plasma and decreasing n-6:n-3 ratios. In the parent study, participants received daily either placebo or n-3 PUFA softgels (1.6 g eicosapentaenoic acid [EPA] and 1.2 g docosahexaenoic acid [DHA]). EPA and DHA are the biologically active components in fish oil. Measures included blood for PUFA quantification at baseline and four weeks later, when blister wounds were created and wound fluid and saliva were collected. The saliva samples were used to measure CRP in the present study. We report that CRP was significantly and negatively correlated with total n-3 PUFAs (tau-β = ?0.373, p = 0.031) and positively correlated with n-6:n-3 ratios (tau-β = 0.320, p = 0.063). Those consuming EPA + DHA supplements had significantly higher concentrations of total n-3 PUFAs and significantly lower n-6:n-3 ratios (p The present study has shown that beneficial levels of n-3 PUFAs and n-6:n3 ratios were achieved with 4-weeks of EPA + DHA supplementation and were associated with reduced CRP in young adults. EPA + DHA supplementation for some young adults may help prevent inflammatory conditions later in life. 展开更多
关键词 n-6:n-3 Polyunsaturated FATTY acid ratios n-3 DIETARY Supplementation Inflammation CRP
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