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Strong metal-support interactions between highly dispersed Cu^(+) species and ceria via mix-MOF pyrolysis toward promoted water-gas shift reaction
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作者 Xiao-Chen Sun Xing-Chi Li +7 位作者 Ze-Wei Xie Chen-Yue Yuan De-Jiu Wang Qian Zhang Xiao-Yu Guo Hao Dong Hai-Chao Liu Ya-Wen Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期475-483,共9页
The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported catalysts.Here,we report a synthetic strategy to upgrade Cu-CeO_(2)i... The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported catalysts.Here,we report a synthetic strategy to upgrade Cu-CeO_(2)interfacial interaction by the pyrolysis of mixed metal-organic framework(MOF)structure.The obtained highly dispersed Cu/CeO_(2)-MOF catalyst via this strategy was used to catalyze water-gas shift reaction(WGSR),which exhibited high activity of 40.5μmolCOgcat^(-1).s^(-1)at 300℃and high stability of about 120 h.Based on comprehensive studies of electronic structure,pyrolysis strategy has significant effect on enhancing metal-support interaction and then stabilizing interfacial Cu^(+)species under reaction conditions.Abundant Cu^(+)species and generated oxygen vacancies over Cu/CeO_(2)-MOF catalyst played a key role in CO molecule activation and H2O molecule dissociation,respectively.Both collaborated closely and then promoted WGSR catalytic performance in comparison with traditio nal supported catalysts.This study shall offer a robust approach to harvest highly dispersed catalysts with finely-tuned metal-support interactions for stabilizing the most interfacial active metal species in diverse heterogeneous catalytic reactions. 展开更多
关键词 Cu-based catalyst MOF derivative water-gas shift reaction Metal-support interaction
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Alternation and Evolution of the Fables of Pre-Qin Scholars Along With the Contextual Changes
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作者 ZHANG Pei LIU Tianchang 《Cultural and Religious Studies》 2023年第4期199-201,共3页
The fables of Pre-Qin scholars occupied an important position in the history of the development of Chinese culture,thoughts,and literature,hence had profound and extensive influence on later generations.As a kind of c... The fables of Pre-Qin scholars occupied an important position in the history of the development of Chinese culture,thoughts,and literature,hence had profound and extensive influence on later generations.As a kind of carrier of thoughts,the fables of the Pre-Qin scholars were not immutable and frozen,for they have been influenced by various aspects in the process of transmitting and recognizing.This article attempts to study the evolution of the function,expression,and connotation of the fables of the Pre-Qin scholars. 展开更多
关键词 fables Pre-Qin scholars alternation EVOLUTION
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Alternative splicing of the PECTINESTERASE gene encoding a cell wall-degrading enzyme affects postharvest softening in grape
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作者 Hainan Liu Maosong Pei +5 位作者 Charles Ampomah-Dwamena Yaxin Shang Yihe Yu Tonglu Wei Qiaofang Shi Dalong Guo 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期863-875,共13页
The firmness of table grape berries is a crucial quality parameter. Despite extensive research on postharvest fruit softening, its precise molecular mechanisms remain elusive. To enhance our comprehension of the under... The firmness of table grape berries is a crucial quality parameter. Despite extensive research on postharvest fruit softening, its precise molecular mechanisms remain elusive. To enhance our comprehension of the underlying molecular factors, we initially identified differentially expressed genes(DEGs) by comparing the transcriptomes of folic acid(FA)-treated and water-treated(CK) berries at different time points. We then analyzed the sequences to detect alternatively spliced(AS) genes associated with postharvest softening. A total of 2,559 DEGs were identified and categorized into four subclusters based on their expression patterns, with subcluster-4 genes exhibiting higher expression in the CK group compared with the FA treatment group. There were 1,045 AS-associated genes specific to FA-treated berries and 1,042 in the CK-treated berries, respectively. Gene Ontology(GO) annotation indicated that the AS-associated genes in CK-treated berries were predominantly enriched in cell wall metabolic processes,particularly cell wall degradation processes. Through a comparison between treatment-associated AS genes and subcluster-4 DEGs, we identified eight genes, including Pectinesterase 2(VvPE2, Vitvi15g00704), which encodes a cell wall-degrading enzyme and was predicted to undergo an A3SS event. The reverse transcription polymerase chain reaction further confirmed the presence of a truncated transcript variant of VvPE2 in the FA-treated berries.Our study provides a comprehensive analysis of AS events in postharvest grape berries using transcriptome sequencing and underscores the pivotal role of VvPE2 during the postharvest storage of grape berries. 展开更多
关键词 GRAPE postharvest softening folic acid alternative splicing Pectinesterase 2 alternative 3'splice site(A3SS)
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Alternate cotton-peanut intercropping:a new approach to increasing productivity and minimizing environmental impact
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作者 CHI Baojie DONG Hezhong 《Journal of Cotton Research》 CAS 2024年第1期101-103,共3页
Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in... Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in the alternate cotton-peanut intercropping,specifically focusing on its yield benefits,environmental impacts,and the underlying mechanisms.In addition,we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment,pest management options,and the mechanisms of root-canopy interactions.This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production. 展开更多
关键词 Cotton PEANUT alternate intercropping PRODUCTIVITY
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Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading
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作者 Praveen Huded M Suresh R Dash 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期359-376,共18页
Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone regions.Pile foundations have experienced failures in past earthquakes due to liquefaction.Research on pile found... Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone regions.Pile foundations have experienced failures in past earthquakes due to liquefaction.Research on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil profiles.However,in natural occurrence,it may occur in alternative layers of liquefiable and non-liquefiable soil.However,the experimental and/or numerical studies on the layered effect on pile foundations have not been widely addressed in the literature.Most of the design codes across the world do not explicitly mention the effect of sandwiched non-liquefiable soil layers on the pile response.In the present study,the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied numerically.This study found that the kinematic bending moment is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ignored.Therefore,ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach. 展开更多
关键词 pile foundation LIQUEFACTION alternately layered soil fixity effect layered effect
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Wetting alternating with partial drying during grain filling increases lysine biosynthesis in inferior rice grain
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作者 Yi Jiang Wenli Tao +2 位作者 Weiyang Zhang Zhiqin Wang Jianchang Yang 《The Crop Journal》 SCIE CSCD 2024年第1期262-270,共9页
Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breedin... Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG. 展开更多
关键词 BRASSINOSTEROIDS Inferior grain Lysine biosynthesis Rice Wetting alternating with partial drying
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2,3,5,4’-Tetrahydroxystilbene-2-O-b-D-Glucoside modulates CHEK2 and CCND1 alternative splicing to inhibit MCF-7 cells proliferation
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作者 Hui Shen You-Zhi Zhang +5 位作者 Peng-Yu Wang Shuo Zhang Huan Pan Bei-Bei Liu Long-Sheng Xu Jian-Fen Shen 《Traditional Medicine Research》 2024年第1期33-46,共14页
Background:In our previous study,we observed a synergistic effect of 2,3,5,4’-Tetrahydroxystilbene-2-O-b-D-glucoside combined with adriamycin to induce apoptosis in MCF-7 breast cancer cells.However,the underlying me... Background:In our previous study,we observed a synergistic effect of 2,3,5,4’-Tetrahydroxystilbene-2-O-b-D-glucoside combined with adriamycin to induce apoptosis in MCF-7 breast cancer cells.However,the underlying mechanisms of epigenetic modifications,such as alternative splicing,have not been explored.In this study,we aimed to investigate the mechanism by which THSG inhibits MCF-7 cell proliferation using full-length transcriptome sequencing.Methods:First,cell viability was examined using the methyl thiazolyl tetrazolium method and full-length transcriptome sequencing was performed to identify genes and pathways.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used to identify the principal pathways and targets of THSG.Flow cytometry analysis of cell cycle distribution was performed.Meanwhile,the analysis of alternative splicing and domains of the key proteins was conducted.Quantitative polymerase chain reaction and western blotting were performed for verification.Results:THSG showed significant cytotoxic activity in MCF-7 cells.Full-length transcriptome sequencing revealed differential alternative splicing with 173 upregulated and 263 downregulated genes.Further analysis identified distinct differential expression of genes(CHEK2-211 and CCND1-201)involved in the cell cycle in the THSG-treated group.Subsequently,alternative splicing types of CHEK2(mutually exclusive exon)and CCND1(intron retention).We found that THSG downregulated mRNA expression,as confirmed by quantitative polymerase chain reaction analysis.Interestingly,protein structural analysis revealed that THSG treatment led to the generation of CHK2-211,which was the result of a mutation in the amino acid residues(GLU-150,ASN-151)of the CHEK2 domain(VAL-150,GLY-151).and CyclinD1-201 were obtained when an amino acid(ASP-267)in the domain was lost in CyclinD1.Moreover,molecular docking analysis demonstrated that the domains of key proteins could bind THSG more effectively,with no difference in affinity.Western blotting confirmed that THSG inhibited the expression of CHK2 and CyclinD1.Conclusion:THSG modulated the alternative splicing of CHEK2 and CCND1 by inducing G0/G1 cell cycle arrest,consequently suppressing MCF-7 cell proliferation. 展开更多
关键词 THSG breast cancer full-length transcriptome sequencing alternative splicing
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Suppression of stimulated Brillouin and Raman scatterings using an alternating frequency laser and transverse magnetic fields
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作者 程瑞锦 李晓旬 +11 位作者 王清 刘德基 黄卓明 吕帅宇 周远志 张舒童 李雪铭 陈祖杰 王强 刘占军 曹莉华 郑春阳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期545-553,共9页
A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allow... A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allows the laser frequency to change discretely and alternately over time. The suppression of SBS is significant as long as the AF difference is greater than the linear growth rate of SBS or the alternating time of the laser frequency is shorter than the linear growth time of SBS. However, the AF laser proves ineffective in suppressing SRS, which usually has a much higher linear growth rate than SBS. To remedy that, a transverse magnetic field is included to suppress the SRS instability. The electrons trapped in the electron plasma waves(EPWs) of SRS can be accelerated by the surfatron mechanism in a transverse magnetic field and eventually detrapped. While continuously extracting energy from EPWs, the EPWs are dissipated and the kinetic inflation of SRS is suppressed. The one-dimensional particle-in-cell simulation results show that both SBS and SRS can be effectively suppressed by combining the AF laser with a transverse magnetic field with tens of Tesla. The total reflectivity can be dramatically reduced by more than one order of magnitude. These results provide a potential reference for controlling SBS and SRS under the related parameters of inertial confinement fusion. 展开更多
关键词 stimulated Brillouin scattering stimulated Raman scattering alternating frequency laser transverse magnetic field
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Workshop “Navigating the Transition: Standards Powering the Journey of Alternative Fuel Infrastructure”
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《China Standardization》 2024年第2期67-67,共1页
April 18, Brussels, Belgium In light of recent significant regulatory changes within the European Union impacting the transport sector, such as the Alternative Fuels Infrastructure Regulation(AFIR), Re Fuel EU and Fue... April 18, Brussels, Belgium In light of recent significant regulatory changes within the European Union impacting the transport sector, such as the Alternative Fuels Infrastructure Regulation(AFIR), Re Fuel EU and Fuel EU Maritime, the role of European standardization becomes increasingly critical in facilitating the transition towards the deployment of alternative fuels. 展开更多
关键词 TRANSITION alternATIVE MARITIME
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Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift
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作者 吴明兴 谢楷 +3 位作者 刘艳 徐晗 张宝 田得阳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期519-530,共12页
A non-contact low-frequency(LF)method of diagnosing the plasma surrounding a scaled model in a shock tube is proposed.This method utilizes the phase shift occurring after the transmission of an LF alternating magnetic... A non-contact low-frequency(LF)method of diagnosing the plasma surrounding a scaled model in a shock tube is proposed.This method utilizes the phase shift occurring after the transmission of an LF alternating magnetic field through the plasma to directly measure the ratio of the plasma loop average electron density to collision frequency.An equivalent circuit model is used to analyze the relationship of the phase shift of the magnetic field component of LF electromagnetic waves with the plasma electron density and collision frequency.The applicable range of the LF method on a given plasma scale is analyzed.The upper diagnostic limit for the ratio of the electron density(unit:m^(-3))to collision frequency(unit:Hz)exceeds 1×10^(11),enabling an electron density to exceed 1×10^(20)m^(-3)and a collision frequency to be less than 1 GHz.In this work,the feasibility of using the LF phase shift to implement the plasma diagnosis is also assessed.Diagnosis experiments on shock tube equipment are conducted by using both the electrostatic probe method and LF method.By comparing the diagnostic results of the two methods,the inversion results are relatively consistent with each other,thereby preliminarily verifying the feasibility of the LF method.The ratio of the electron density to the collision frequency has a relatively uniform distribution during the plasma stabilization.The LF diagnostic path is a loop around the model,which is suitable for diagnosing the plasma that surrounds the model.Finally,the causes of diagnostic discrepancy between the two methods are analyzed.The proposed method provides a new avenue for diagnosing high-density enveloping plasma. 展开更多
关键词 low-frequency alternating magnetic field phase shift shock-tube plasma diagnosis electron density collision frequency
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Use of Topical Complementary and Alternative Medicines (CAM) in Diabetic Septic Foot Disease in Makkah Region, Western of Saudi Arabia, an Exploratory Study
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作者 Mohamed Elamin Salih Hatim Alrizqi +5 位作者 Mohammed Hussain Abdullah Alshumrani Ismail Alhasani Ali Alkhamisi Hamzah Alsayed Fahad Alqarni 《Journal of Biosciences and Medicines》 2024年第3期245-258,共14页
Diabetes is a chronic condition that is significantly impacted daily by environment. At least one in five Saudis, suffer from diabetes. “Diabetes is a pandemic of unprecedented magnitude spiraling out of control” (B... Diabetes is a chronic condition that is significantly impacted daily by environment. At least one in five Saudis, suffer from diabetes. “Diabetes is a pandemic of unprecedented magnitude spiraling out of control” (Boulton). Saudi Arabia ranks the second highest in the Middle East, and is the seventh in the world for the prevalence of diabetes (WHO). Diabetes mellitus (DM) has been found to be related to high mortality, morbidity accompanied by poor general health and lower quality of life. Current Saudi diabetes patients’ behaviors, practices, and beliefs regarding foot health problems such as ulcers, are not well investigated. Diabetic patients frequently utilize natural remedies and Herbs for self-medication as a part of complementary and alternative Medicine. Aim of study: To explore the widespread use of the alternative remedies in the local communities of the Western Saudi Arabia, the drives behind using and to focus on the potential adverse effects following their usage. Method: A descriptive, cross-sectional study of 386 diabetic patients with feet problems in Makkah Region, West of Saudi Arabia during the period April - June 2023. Results: Out of the 531 participants, only 386 participants reported diabetic foot disorder (DFD). Most of the participant were above 65 years of age group (24.61 %). Male (52.08%) more than female (47.92%) in the research group. All of the participants had diabetic foot disorders at least once. The prevalence of complementary and alternative medicines (CAM) use among them was 67.88%, as solitary or in combination with hospital medicines. Honey headed the list followed by myrrh and black seeds. Acquaintances advice (59.54%) was the most reason for using the alternative medicine. 60.30% of Diabetic foot patient complained of adverse effects during CAM remedies use. Conclusion: Consumption of CAM remedies among diabetic patients for Diabetic Foot Disorder (DFD) is common. Honey headed the list followed by myrrh and black seeds. Additional wide-scale research is required to establish their actual efficacy, safety and potential adverse out-comes and to generalize the outcomes. 展开更多
关键词 Diabetic Foot Ulcer Diabetes Complementary and alternative Medicine CAM West of Saudi Arabia
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Molecular targets and mechanisms of different aberrant alternative splicing in metastatic liver cancer
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作者 De-Yi Geng Qing-Shan Chen +7 位作者 Wan-Xian Chen Lin-Sa Zhou Xiao-Sha Han Qi-Hu Xie Geng-Hong Guo Xue-Fen Chen Jia-Sheng Chen Xiao-Ping Zhong 《World Journal of Clinical Oncology》 2024年第4期531-539,共9页
Metastasis remains a major challenge in the successful management of malignant diseases.The liver is a major site of metastatic disease and a leading cause of death from gastrointestinal malignancies such as colon,sto... Metastasis remains a major challenge in the successful management of malignant diseases.The liver is a major site of metastatic disease and a leading cause of death from gastrointestinal malignancies such as colon,stomach,and pancreatic cancers,as well as melanoma,breast cancer,and sarcoma.As an important factor that influences the development of metastatic liver cancer,alternative splicing drives the diversity of RNA transcripts and protein subtypes,which may provide potential to broaden the target space.In particular,the dysfunction of splicing factors and abnormal expression of splicing variants are associated with the occurrence,progression,aggressiveness,and drug resistance of cancers caused by the selective splicing of specific genes.This review is the first to provide a detailed summary of the normal splicing process and alterations that occur during metastatic liver cancer.It will cover the role of alternative splicing in the mechanisms of metastatic liver cancer by examining splicing factor changes,abnormal splicing,and the contribution of hypoxia to these changes during metastasis. 展开更多
关键词 alternative splicing CARCINOMA HEPATOCELLULAR Metastasic Liver neoplasms PROGNOSIS
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Effects of 4f Electron Characteristics and Alternation Valence of Rare Earths on Photosynthesis: Regulating Distribution of Energy and Activities of Spinach Chloroplast 被引量:7
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作者 刘晓晴 苏明玉 +3 位作者 刘超 张易 司文会 洪法水 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第4期495-501,共7页
Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, ... Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order: Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement. 展开更多
关键词 4f electron characteristic and alternation valence SPINACH CHLOROPLAST energy transfer and distribution photochemical activity rare earths
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Dissipative particle dynamics simulation of wettability alternation phenomena in the chemical flooding process 被引量:4
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作者 Xiaobo Li Yuewu Liu +1 位作者 Jianfei Tang Shujiao Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第5期583-587,共5页
Wettability alternation phenomena is considered one of the most important enhanced oil recovery (EOR) mechanisms in the chemical flooding process and induced by the adsorption of surfactant on the rock surface. Thes... Wettability alternation phenomena is considered one of the most important enhanced oil recovery (EOR) mechanisms in the chemical flooding process and induced by the adsorption of surfactant on the rock surface. These phenomena are studied by a mesoscopic method named as dissipative particle dynamics (DPD). Both the alteration phenomena of water-wet to oil-wet and that of oil-wet to water-wet are simulated based on reasonable definition of interaction parameters between beads. The wetting hysteresis phenomenon and the process of oil-drops detachment from rock surfaces with different wettability are simulated by adding long-range external forces on the fluid particles. The simulation results show that, the oil drop is liable to spread on the oil-wetting surface and move in the form of liquid film flow, whereas it is likely to move as a whole on the waterwetting surface. There are the same phenomena occuring in wettability-alternated cases. The results also show that DPD method provides a feasible approach to the problems of seepage flow with physicochemical phenomena and can be used to study the mechanism of EOR of chemical flooding. 展开更多
关键词 Wettability alternation Dissipative particledynamics - Enhanced oil recovery Chemical flooding -Mesoscopic mechanics
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Effects of CeO_2 on structure and properties of Ni-Mn-K/bauxite catalysts for water-gas shift reaction 被引量:3
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作者 江莉龙 叶炳火 魏可镁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第3期352-356,共5页
Multiple-metal catalysts (Ni-Mn-Ce-K/bauxite) for Water-Gas Shift (WGS) reaction were prepared by impregnation, and the catalytic structure and properties were investigated by N2 physical, XRD, H2-TPR, and CO-TPD.... Multiple-metal catalysts (Ni-Mn-Ce-K/bauxite) for Water-Gas Shift (WGS) reaction were prepared by impregnation, and the catalytic structure and properties were investigated by N2 physical, XRD, H2-TPR, and CO-TPD. The results indicated that the addition of 7.5% CeO2 improved the activity of the WGS reaction obviously, and also increased the specific surface area and pore volume of the catalysts. The addition of CeO2 decreases the reduction temperature, enhanced the adsorption and activation of H2O2, and improved the adsorption content of CO. Besides, active sites were not changed and the number of active sites on catalysts did not increase obviously. 展开更多
关键词 IMPREGNATED water-gas shift BAUXITE CEO2 rare earths
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Copper Promoted Au/ZnO-CuO Catalysts for Low Temperature Water-gas Shift Reaction 被引量:2
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作者 LIAN Hong-lei JIA Ming-jun +2 位作者 PAN Wei-cheng ZHANG Wen-xiang JIANG Da-zhen 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第1期99-102,共4页
Various copper promoted Au/ZnO-CuO catalysts with different atomic ratios of Cu to Zn prepared by means of co-precipitation were tested for the low temperature water-gas shift(WGS) reaction. The catalytic activity o... Various copper promoted Au/ZnO-CuO catalysts with different atomic ratios of Cu to Zn prepared by means of co-precipitation were tested for the low temperature water-gas shift(WGS) reaction. The catalytic activity of the catalyst depends largely on the ratio of Cu to Zn. The addition of an appropriate amount of copper can considerably improve both the catalytic activity and the stability of the catalyst in comparison with those of copper-free Au/ZnO cata- lysts. The enhanced reducibility of copper oxide in the Au/ZnO-CuO ternary-component catalysts, which was confirmed by H2-TPR, may be related to the high activity and stability of the catalyst for the low temperature WGS reaction. 展开更多
关键词 water-gas shift reaction ZNO CUO GOLD
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Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application 被引量:2
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作者 智科端 刘全生 +2 位作者 赵瑞岗 何润霞 张利峰 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第4期538-543,共6页
Cu-Ce-La mixed oxides were prepared by three precipitation methods (coprecipitation, homogeneous precipitation, and deposition precipitation) with variable precipitators and characterized using X-ray diffraction, BE... Cu-Ce-La mixed oxides were prepared by three precipitation methods (coprecipitation, homogeneous precipitation, and deposition precipitation) with variable precipitators and characterized using X-ray diffraction, BET, temperature-programmed reduction, and catalytic reaction for the water-gas shift. The Cu-Ce-La mixed oxide prepared by coprecipitation method with NaOH as precipitator presented the highest activity and thermal stability. Copper ion substituted quadrevalent ceria entered CeO2 (111) framework was in favor of activity and thermal stability of catalyst. The crystallinity of fresh catalysts increased with the reduction process. La^3+ or Ce^4+ substituted copper ion entered the CeO2 framework during reduction process. The coexistence of surface copper oxide (crystalline) and pure bulk crystalline copper oxide both contributed to the high activity and thermal stability of Cu-Ce-La mixes oxide catalyst. 展开更多
关键词 Cu-Ce-La mixed oxide water-gas shift reaction PRECIPITATION precipitator rare earths
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Codon evolution in double-stranded organelle DNA: strong regulation of homonucleotides and their analog alternations 被引量:2
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作者 Kenji Sorimachi 《Natural Science》 2010年第8期846-854,共9页
In our previous study, complete single DNA strands which were obtained from nuclei, chloroplasts and plant mitochondria obeyed Chargaff’s second parity rule, although those which were obtained from animal mitochondri... In our previous study, complete single DNA strands which were obtained from nuclei, chloroplasts and plant mitochondria obeyed Chargaff’s second parity rule, although those which were obtained from animal mitochondria deviated from the rule. On the other hand, plant mitochondria obeyed another different rule after their classification. Complete single DNA strand sequences obtained from chloroplasts, plant mitochondria, and animal mitochondria, were divided into the coding and non-coding regions. The non-coding region, which was the complementary coding region on the reverse strand, was incorporated as a coding region in the forward strand. When the nucleotide contents of the coding region or non-coding regions were plotted against the composition of the four nucleotides in the complete single DNA strand, it was determined that chloroplast and plant mitochondrial DNA obeyed Chargaff’s second parity rule in both the coding and non-coding regions. However, animal mitochondrial DNA deviated from this rule. In chloroplast and plant mitochondrial DNA, which obey Chargaff’s second parity rule, the lines of regression for G (purine) and C (pyrimidine) intersected with regression lines for A (purine) and T (pyrimidines), respectively, at around 0.250 in all cases. On the other hand, in animal mitochondrial DNA, which deviates from Chargaff’s second parity rule, only regression lines due to the content of homonucleotides or their analogs in the coding or non-coding region against those in the complete single DNA strand intersected at around 0.250 at the horizontal axis. Conversely, the intersection of the two lines of regression (G and A or C and T) against the contents of heteronucleotides or their analogs shifted from 0.25 in both coding and non-coding regions. Nucleotide alternations in chloroplasts and plant mitochondria are strictly regulated, not only by the proportion of homonucleotides and their analogs, but also by the heteronucleotides and their analogs. They are strictly regulated in animal mitochondria only by the content of homonucleotides and their analogs. 展开更多
关键词 CODON EVOLUTION in DOUBLE-STRANDED organelle DNA: STRONG REGULATION of homonucleotides and their ANALOG alternations
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Effects of the partial replacement of La by M(M=Ce,Ca and Sr) in La_(2-x)M_xCuO_4 perovskites on catalysis of the water-gas shift reaction 被引量:1
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作者 S.S.Maluf E.M.Assaf 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2010年第6期567-574,共8页
The performance of La2-x M x CuO4 perovskites (where M=Ce,Ca or Sr) as catalysts for the water-gas shift reaction was investigated at 290℃ and 360℃.The catalysts were characterized by EDS,XRD,N2 adsorption-desorpt... The performance of La2-x M x CuO4 perovskites (where M=Ce,Ca or Sr) as catalysts for the water-gas shift reaction was investigated at 290℃ and 360℃.The catalysts were characterized by EDS,XRD,N2 adsorption-desorption,XPS and XANES.The XRD results showed that all the perovskites exhibited a single phase (the presence of perovskite structure),suggesting the incorporation of metals in the perovskite structure.The XPS and XANES results showed the presence of Cu2+ on the surface.The perovskites that exhibited the best catalytic performance were La 2 x Ce x CuO 4 perovskites,with CO conversions of 85% 90%.Moreover,these perovskites have higher surface areas and larger amounts of Cu on the surface.And Ce has a higher filled energy level than the other metals,increasing the energy of the valence band of Ce and providing more electrons for the reaction.Besides,the La1.80Ca0.20CuO4 perovskite showed a good catalytic performance. 展开更多
关键词 perovskites water-gas shift reaction LANTHANUM copper calcium CERIUM STRONTIUM
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Effects of ZrO_2 Content on Structure and Performance of Cu/CeO_2-ZrO_2 Catalysts for Water-Gas Shift Reaction 被引量:1
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作者 郑云弟 林性贻 +3 位作者 郑起 詹瑛瑛 李达林 魏可镁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第6期685-689,共5页
Cu/CeO2-ZrO2 catalysts for water-gas shift (WGS) reaction were prepared with co-precipitation method, and the influence of ZrO2 content on the catalytic structure and properties was investigated by the techniques of... Cu/CeO2-ZrO2 catalysts for water-gas shift (WGS) reaction were prepared with co-precipitation method, and the influence of ZrO2 content on the catalytic structure and properties was investigated by the techniques of N2 physical adsorption analysis, XRD and H2-TPR. The results indicate that the BET surface areas of the catalysts are increased in varying degrees due to the presence of ZrO2. With increasing ZrO2 content, the pore size distribution is centered on 1.9 nm. ZrO2 can efficiently restrain the growth of Cu crystal particles. The appropriate amount of ZrO2 in the Cu/CeO2 catalysts can help the catalyst keep better copper dispersion in the WGS reaction, which can lead to both higher catalytic activity and better thermal stability. When ZrO2 content is 10% (atom fraction), Cu/CeO2-Zr02 catalyst reaches a CO conversion rate of 73.7% at the reaction temperature of 200℃. 展开更多
关键词 water-gas shift Cu/CeO2-ZrO2 catalyst rare earths
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