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Fabrication and Properties of a New Reactive Diluent for Cationic UV Curing
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作者 吴正森 黄笔武 +1 位作者 LIU Yuansheng SHEN Han 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期1053-1060,共8页
The reactive diluent prepared by siloxane modified Trimethylene oxide can improve the performance of the UV curing system.Therefore,1,7-bis[(3-ethyl-3-methoxyoxacylobutane)propyl]octadecylosiloxane(BEMOPOMTS)was synth... The reactive diluent prepared by siloxane modified Trimethylene oxide can improve the performance of the UV curing system.Therefore,1,7-bis[(3-ethyl-3-methoxyoxacylobutane)propyl]octadecylosiloxane(BEMOPOMTS)was synthesized from diethyl carbonate,trimethylopropanes,allyl bromide,and 1,1,3,3,5,5,7,7-octadecylosiloxane as the main raw materials.BEMOPOMTS can be used as reactive diluents in the field of cationic UV curing.It has good thermal stability,and the addition of BEMOPOMTS significantly improves the tensile strength and elongation at break of epoxy resin.Compared with the pure epoxy resin,adding 20%BEMOPOMTS increased the elastic modulus by 25%to 677 MPa. 展开更多
关键词 UV curing cation curing reactive diluent SILOXANE
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Cationic ordering transition in oxygen-redox layered oxide cathodes
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作者 Xinyan Li Ang Gao +10 位作者 Qinghua Zhang Hao Yu Pengxiang Ji Dongdong Xiao Xuefeng Wang Dong Su Xiaohui Rong Xiqian Yu Hong Li Yong-Sheng Hu Lin Gu 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期197-206,共10页
Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na... Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na-ion cathodes.Here,we reveal the correlation between cationic ordering transition and OR degradation in ribbon-ordered P3-Na_(0.6)Li_(0.2)Mn_(0.8)O_(2) via in situ structural analysis.Comparing two different voltage windows,the OR capacity can be improved approximately twofold when suppressing the in-plane cationic ordering transition.We find that the intralayer cationic migration is promoted by electrochemical reduction from Mn^(4+)to Jahn–Teller Mn^(3+)and the concomitant NaO_(6) stacking transformation from triangular prisms to octahedra,resulting in the loss of ribbon ordering and electrochemical decay.First-principles calculations reveal that Mn^(4+)/Mn^(3+)charge ordering and alignment of the degenerate eg orbital induce lattice-level collective Jahn–Teller distortion,which favors intralayer Mn-ion migration and thereby accelerates OR degradation.These findings unravel the relationship between in-plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR-active layered oxide cathodes. 展开更多
关键词 cationic ordering layered oxide cathodes oxygen redox sodium-ion batteries
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Enabling an Inorganic-Rich Interface via Cationic Surfactant for High-Performance Lithium Metal Batteries
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作者 Zejun Sun Jinlin Yang +18 位作者 Hongfei Xu Chonglai Jiang Yuxiang Niu Xu Lian Yuan Liu Ruiqi Su Dayu Liu Yu Long Meng Wang Jingyu Mao Haotian Yang Baihua Cui Yukun Xiao Ganwen Chen Qi Zhang Zhenxiang Xing Jisheng Pan Gang Wu Wei Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期1-17,共17页
An anion-rich electric double layer(EDL)region is favorable for fabricating an inorganic-rich solid-electrolyte interphase(SEI)towards stable lithium metal anode in ester electrolyte.Herein,cetyltrimethylammonium brom... An anion-rich electric double layer(EDL)region is favorable for fabricating an inorganic-rich solid-electrolyte interphase(SEI)towards stable lithium metal anode in ester electrolyte.Herein,cetyltrimethylammonium bromide(CTAB),a cationic surfactant,is adopted to draw more anions into EDL by ionic interactions that shield the repelling force on anions during lithium plating.In situ electrochemical surface-enhanced Raman spectroscopy results combined with molecular dynamics simulations validate the enrichment of NO_(3)^(−)/FSI−anions in the EDL region due to the positively charged CTA^(+).In-depth analysis of SEI structure by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry results confirmed the formation of the inorganic-rich SEI,which helps improve the kinetics of Li^(+)transfer,lower the charge transfer activation energy,and homogenize Li deposition.As a result,the Li||Li symmetric cell in the designed electrolyte displays a prolongated cycling time from 500 to 1300 h compared to that in the blank electrolyte at 0.5 mA cm^(-2) with a capacity of 1 mAh cm^(-2).Moreover,Li||LiFePO_(4) and Li||LiCoO_(2) with a high cathode mass loading of>10 mg cm^(-2) can be stably cycled over 180 cycles. 展开更多
关键词 cationic surfactant Lithium nitrate additive Solid-electrolyte interphase Electric double layer Lithium metal batteries
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A novel cationic collector for silicon removal from collophane using reverse flotation under acidic conditions 被引量:2
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作者 Zhongxian Wu Dongping Tao +2 位作者 Youjun Tao Man Jiang Patrick Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1038-1047,共10页
We analyzed a novel cationic collector using chemical plant byproducts,such as cetyltrimethylammonium bromide(CTAB)and dibutyl phthalate(DBP).Our aim is to establish a highly effective and economical process for the r... We analyzed a novel cationic collector using chemical plant byproducts,such as cetyltrimethylammonium bromide(CTAB)and dibutyl phthalate(DBP).Our aim is to establish a highly effective and economical process for the removal of quartz from collophane.A microflotation test with a 25 mg·L^(−1)collector at pH value of 6-10 demonstrates a considerable difference in the floatability of pure quartz and fluorapatite.Flotation tests for a collophane sample subjected to the first reverse flotation for magnesium removal demonstrates that a rough flotation process(using a 0.4 kg·t−1 new collector at pH=6)results in a collophane concentrate with 29.33wt%P_(2)O_(5)grade and 12.66wt%SiO2 at a 79.69wt%P_(2)O_(5)recovery,providing desirable results.Mechanism studies using Fourier transform infrared spectroscopy,zeta potential,and contact angle measurements show that the adsorption capacity of the new collector for quartz is higher than that for fluorapatite.The synergistic effect of DBP increases the difference in hydrophobicity between quartz and fluorapatite.The maximum defoaming rate of the novel cationic collector reaches 142.8 mL·min−1.This is considerably higher than that of a conventional cationic collector. 展开更多
关键词 cationic collector collophane DEFOAMING QUARTZ reverse flotation
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One-step crosslinking preparation of tannic acid particles for the adsorption and separation of cationic dyes
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作者 Yujia Cui Zhiqiang Tan +2 位作者 Yanan Wang Shuxian Shi Xiaonong Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第5期309-318,共10页
In this study,a new tannic acid adsorbent(ethylene glycol diglycidyl ether crosslinked tannic acid,TAEGDE)for adsorptive removal of dyes from water was prepared using EGDE as a cross-linking agent.The resultant TA-EGD... In this study,a new tannic acid adsorbent(ethylene glycol diglycidyl ether crosslinked tannic acid,TAEGDE)for adsorptive removal of dyes from water was prepared using EGDE as a cross-linking agent.The resultant TA-EGDE was in particulate form with rough surface morphology and a diameter ranging from 10 to 30μm.The adsorption performance of the TA-EGDE was evaluated in a flow-through mode using water samples contaminated with methylene blue(MB)and two-component mixed dyes,respectively.The TA-EGDE provided adsorption capacity up to 721.8 mg·g^(-1)at 65°C for MB.It showed a high removal efficiency(99%)of MB(50 mg·L^(-1))from the water sample and could recovery 90%of the adsorbed MB by eluting with acidic ethanol aqueous solution.The excellent adsorption of MB and neutral red on the TA-EGDE may be the result of the synergy of electrostatic interaction andπ-πinteraction.Furthermore,the TA-EGDE could separate dyes from water samples contaminated with twocomponent mixed dyes with a separation coefficient ranging from 1.8 to 36.5.The anionic TA-EGDE would be an effective adsorbent to remove and recycle dyes from the contaminated water. 展开更多
关键词 Tannic acid Water treatment cationic dyes ADSORPTION Recovery Dyes separation
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Divalent nitrogen-rich cationic salts with great gas production capacities
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作者 Hao Gu Cheng-chuang Li +3 位作者 Chang-hao Dai Dong-xu Chen Hong-wei Yang Guang-bin Cheng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第4期54-68,共15页
Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction f... Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction from the readily available reactant.Their energetic salts with high nitrogen content were proved to be rare examples of divalent monocyclic/fused cyclic cationic salts according to the single crystal analyses.The structure of intermediate B was also identified and verified by its trivalent cation crystal 17.5H_2O indirectly.Energetic compounds 2-8 and 10-17 were fully characterized by NMR spectroscopy,infrared spectroscopy,differential scanning calorimetry,elemental analysis.These energetic salts exhibit good thermal stability with decomposition temperatures ranged from 182℃to 245℃.The sensitivity of compounds 2,6,10 and 14 is similar or superior to that of RDX while the others were much more insensitive to mechanical stimulate.Furthermore,detonation velocity of 10(8843 m/s)surpass that of RDX(D=8795 m/s).Considering the high gas production volume(≥808 L/kg)of 2,4,10and 12,constant-volume combustion experiments were conduct to evaluate their gas production capacities specifically.These compounds possess much higher maximum gas-production pressures(P_(max):7.88-10.08 MPa)than the commonly used reagent guanidine nitrate(GN:P_(max)=4.20 MPa),which indicate their strong gas production capacity. 展开更多
关键词 Fused cyclic compound TRIAZOLE Divalent cation Gas production Energetic materials
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Cation effects in electrocatalytic reduction reactions:Recent advances
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作者 Qinghui Ren Liang Xu +4 位作者 Mengyu Lv Zhiyuan Zhang Zhenhua Li Mingfei Shao Xue Duan 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第8期16-32,共17页
Electrocatalytic reduction reactions,powered by clean energy sources such as solar energy and wind,offer a sustainable method for converting inexpensive feedstocks(e.g.,CO_(2),N2/NOx,organics,and O_(2))into high-value... Electrocatalytic reduction reactions,powered by clean energy sources such as solar energy and wind,offer a sustainable method for converting inexpensive feedstocks(e.g.,CO_(2),N2/NOx,organics,and O_(2))into high-value-added chemicals or fuels.The design and modification of electrocatalysts have been widely implemented to improve their performance in these reactions.However,bottle-necks are encountered,making it challenging to further improve performance through catalyst development alone.Recently,cations in the electrolyte have emerged as critical factors for tuning both the activity and product selectivity of reduction reactions.This review summarizes recent advances in understanding the role of cation effects in electrocatalytic reduction reactions.First,we introduce the mechanisms underlying cation effects.We then provide a comprehensive overview of their application in electroreduction reactions.Characterization techniques and theoretical calcula-tion methods for studying cation effects are also discussed.Finally,we address remaining challeng-es and future perspectives in this field.We hope that this review offers fundamental insights and design guidance for utilizing cation effects,thereby advancing their development. 展开更多
关键词 ELECTROCATALYSIS Reduction reaction cation effect MECHANISM APPLIcation
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Waste acid recovery utilizing monovalent cation permselective membranes through selective electrodialysis
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作者 Yanran Zhu Yue Zhou +4 位作者 Qian Chen Rongqiang Fu Zhaoming Liu Liang Ge Tongwen Xu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期45-57,共13页
Selective electrodialysis(SED)has surfaced as a highly promising membrane separation technique in the realm of acid recovery owing to its ability to effectively separate monovalent ions through the utilization of a po... Selective electrodialysis(SED)has surfaced as a highly promising membrane separation technique in the realm of acid recovery owing to its ability to effectively separate monovalent ions through the utilization of a potential difference.However,the current SED process is limited by conventional commercial monovalent cation permselective membranes(MCPMs).This study systematically investigates the use of an independently developed MCPM in the SED process for acid recovery.Various factors such as current density,volume ratio,initial ion concentration,and waste acid systems are considered.The independently developed MCPM offers several advantages over the commercial monovalent selective cation-exchange membrane(CIMS),including higher recovered acid concentration,better ion flux ratio,improved acid recovery efficiency,increased recovered acid purity,and higher current efficiency.The SED process with the MCPM achieves a recovered acid of 95.9%and a concentration of 2.3 mol·L^(–1) in the HCl/FeCl_(2) system,when a current density of 20 mA·cm^(-2) and a volume ratio of 1:2 are applied.Similarly,in the H_(2)SO_(4)/FeSO_(4) system,a purity of over 99%and a concentration of 2.1 mol·L^(–1) can be achieved in the recovered acid.This study thoroughly examines the impact of operation conditions on acid recovery performance in the SED process.The independently developed MCPM demonstrates outstanding acid recovery performance,highlighting its potential for future commercial utilization. 展开更多
关键词 Selective electrodialysis WASTEWATER Monovalent cation permselective membranes SEPARATION RECOVERY
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Exploring the Cation Regulation Mechanism for Interfacial Water Involved in the Hydrogen Evolution Reaction by In Situ Raman Spectroscopy
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作者 Xueqiu You Dongao Zhang +4 位作者 Xia‑Guang Zhang Xiangyu Li Jing‑Hua Tian Yao‑Hui Wang Jian‑Feng Li 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期303-312,共10页
Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.U... Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.Unfortunately,investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.Here,the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry,in situ core-shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques.Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction.When comparing the different cation electrolyte systems at a given potential,the frequency of the interfacial water peak increases in the specified order:Li+<Na^(+)<K^(+)<Ca^(2+)<Sr^(2+).The structure of interfacial water was optimized by adjusting the radius,valence,and concentration of cation to form the two-H down structure.This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance.Therefore,local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure. 展开更多
关键词 In situ Raman Interfacial water Hydrogen evolution reaction cationS
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Atomically Adjustable Rhodium Catalyst Synthesis with Outstanding Mass Activity via Surface-Li mi ted Cation Exchange
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作者 Hak Hyeon Lee Dong Su Kim +3 位作者 Swagotom Sarker Ji Hoon Choi Ho Seong Lee Hyung Koun Cho 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期83-92,共10页
Rh has been widely studied as a catalyst for the promising hydrazine oxidation reaction that can replace oxygen evolution reactions for boosting hydrogen production from hydrazine-containing wastewater.Despite Rh bein... Rh has been widely studied as a catalyst for the promising hydrazine oxidation reaction that can replace oxygen evolution reactions for boosting hydrogen production from hydrazine-containing wastewater.Despite Rh being expensive,only a few studies have examined its electrocatalytic mass activity.Herein,surface-limited cation exchange and electrochemical activation processes are designed to remarkably enhance the mass activity of Rh.Rh atoms were readily replaced at the Ni sites on the surface of NiOOH electrodes by cation exchange,and the resulting RhOOH compounds were activated by the electrochemical reduction process.The cation exchange-derived Rh catalysts exhibited particle sizes not exceeding 2 nm without agglomeration,indicating a decrease in the number of inactive inner Rh atoms.Consequently,an improved mass activity of 30 A mg_(Rh)^(-1)was achieved at 0.4 V versus reversible hydrogen electrode.Furthermore,the two-electrode system employing the same CE-derived Rh electrodes achieved overall hydrazine splitting over 36 h at a stable low voltage.The proposed surface-limited CE process is an effective method for reducing inactive atoms of expensive noble metal catalysts. 展开更多
关键词 cation exchange synthesis electrochemical metallization hydrazine oxidation reaction mass activity rhodium catalyst
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Enhancing selectivity in acidic CO_(2)electrolysis:Cation effects and catalyst innovation
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作者 Zichao Huang Tinghui Yang +4 位作者 Yingbing Zhang Chaoqun Guan Wenke Gui Min Kuang Jianping Yang 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第8期61-80,共20页
The electrochemical reduction of CO_(2)(eCO_(2)R)under ambient conditions is crucial for reducing carbon emissions and achieving carbon neutrality.Despite progress with alkaline and neutral elec-trolytes,their efficie... The electrochemical reduction of CO_(2)(eCO_(2)R)under ambient conditions is crucial for reducing carbon emissions and achieving carbon neutrality.Despite progress with alkaline and neutral elec-trolytes,their efficiency is limited by(bi)carbonates formation.Acidic media have emerged as a solution,addressing the(bi)carbonates challenge but introducing the issue of the hydrogen evolu-tion reaction(HER),which reduces CO_(2)conversion efficiency in acidic environments.This review focuses on enhancing the selectivity of acidic CO_(2)electrolysis.It commences with an overview of the latest advancements in acidic CO_(2)electrolysis,focusing on product selectivity and electrocatalytic activity enhancements.It then delves into the critical factors shaping selectivity in acidic CO_(2)elec-trolysis,with a special emphasis on the influence of cations and catalyst design.Finally,the research challenges and personal perspectives of acidic CO_(2)electrolysis are suggested. 展开更多
关键词 ACIDIC CO_(2)electrolysis High selectivity cation effects Catalyst design Competitive HER
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Identification of Mulberry Bacterial Blight Caused by Klebsiella oxytoca in Bazhong,Sichuan,China
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作者 Yuan Huang Jia Wei +8 位作者 Peigang Liu Yan Zhu Tianbao Lin Zhiqiang Lv Yijun Li Mei Zong Yun Zhou Junshan Gao Zilong Xu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第8期1995-2008,共14页
To provide a scientific basis for controlling mulberry bacterial blight in Bazhong,Sichuan,China(BSC),this study aimed to isolate and purify pathogenic bacteria from diseased branches of mulberry trees in the region a... To provide a scientific basis for controlling mulberry bacterial blight in Bazhong,Sichuan,China(BSC),this study aimed to isolate and purify pathogenic bacteria from diseased branches of mulberry trees in the region and to clarify their taxonomic status using morphological observation,physiological and biochemical detection,molecular-level identification,and the construction of a phylogenetic tree.A total of 218 bacterial strains were isolated from samples of diseased mulberry branches.Of these,7 strains were identified as pathogenic bacteria based on pathogenicity tests conducted in accordance with Koch’s postulates.Preliminary findings from the analysis of the 16S rRNA sequence indicated that the 7 pathogenic bacteria are members of Klebsiella spp.Morphological observation revealed that the pathogenic bacteria were oval-shaped and had capsules but no spores.They could secrete pectinase,cellulase,and protease and were able to utilize D-glucose,D-mannose,D-maltose,and D-Cellobiose.The 7 strains of pathogenic bacteria exhibited the highest homology with Klebsiella oxytoca.This study identifies Klebsiella oxytoca as the causative agent of mulberry bacterial blight in BSC,laying the foundation for the prevention and control of this pathogen and further investigation into its pathogenic mechanism. 展开更多
关键词 MULBERRY bacterial blight pathogenic identification Klebsiella spp. Klebsiella oxytoca
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Application of Transgenic Technology in Identification for Gene Function on Grasses
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作者 Lijun Zhang Ying Liu +1 位作者 Yushou Ma Xinyou Wang Qinghai 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第8期1913-1941,共29页
Perennial grasses have developed intricate mechanisms to adapt to diverse environments,enabling their resistance to various biotic and abiotic stressors.These mechanisms arise from strong natural selection that contri... Perennial grasses have developed intricate mechanisms to adapt to diverse environments,enabling their resistance to various biotic and abiotic stressors.These mechanisms arise from strong natural selection that contributes to enhancing the adaptation of forage plants to various stress conditions.Methods such as antisense RNA technology,CRISPR/Cas9 screening,virus-induced gene silencing,and transgenic technology,are commonly utilized for investigating the stress response functionalities of grass genes in both warm-season and cool-season varieties.This review focuses on the functional identification of stress-resistance genes and regulatory elements in grasses.It synthesizes recent studies on mining functional genes,regulatory genes,and protein kinase-like signaling factors involved in stress responses in grasses.Additionally,the review outlines future research directions,providing theoretical support and references for further exploration of(i)molecular mechanisms underlying grass stress responses,(ii)cultivation and domestication of herbage,(iii)development of high-yield varieties resistant to stress,and(iv)mechanisms and breeding strategies for stress resistance in grasses. 展开更多
关键词 Grasses regulatory genes protein kinase-like signaling factors gene function identification resistance breeding
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Flotation of low-grade bauxite using organosilicon cationic collector and starch depressant 被引量:7
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作者 余新阳 王浩林 +2 位作者 王强强 冯博 钟宏 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第4期1112-1117,共6页
The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated.... The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated. The results show that both diaspore and aluminosilicate minerals float readily with organosilicon cationic collector TAS101 at pH values of 4 to 10. Starch has a strong depression effect for diaspore in the alkaline pH region but has little influence on the flotation of aluminosilicate minerals. It is possible to separate diaspore from aluminosilicate minerals using the organosilicon cationic collector and starch depressant. Further studies of bauxite ore flotation were also conducted, and the reverse flotation separation process was adopted. The concentrates with the mass ratio of Al2O3 to SiO2 of 9.58 and Al2O3 recovery of 83.34% are obtained from natural bauxite ore with the mass ratio of Al2O3 to SiO2 of 6.1 at pH value of 11 using the organosilicon cationic collector and starch depressant. 展开更多
关键词 BAUXITE reverse flotation organosilicon cationic collector starch depressant
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Comparative studies on flotation of aluminosilicate minerals with Gemini cationic surfactants BDDA and EDDA 被引量:7
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作者 黄志强 钟宏 +2 位作者 王帅 夏柳荫 刘广义 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第10期3055-3062,共8页
Gemini quaternary ammonium salt surfactants, butane-a, co-bis(dimethyl dodeculammonium bromide) (BDDA) ethane-a, fl-bis(dimethyl dodeculammonium bromide) (EDDA) were adopted to comparatively study the flotatio... Gemini quaternary ammonium salt surfactants, butane-a, co-bis(dimethyl dodeculammonium bromide) (BDDA) ethane-a, fl-bis(dimethyl dodeculammonium bromide) (EDDA) were adopted to comparatively study the flotation behaviors of kaolinite, pyrophyllite and illite. It was found that three silicate minerals all exhibited good floatability with Gemini cationic surfactants as collectors over a wide pH range, while BDDA showed a stronger collecting power than EDDA. FTIR spectra and zeta potential analysis indicated that the mechanism of adsorption of Gemini collector molecules on three silicate minerals surfaces was almost identical for the electronic attraction and hydrogen bonds effect. The theoretically obtained results of density functional theory (DFT) at B3LYP/6-31G (d) level demonstrated the stronger collecting power of BDDA presented in the floatation test and zeta potential measurement. 展开更多
关键词 aluminosilicate minerals Gemini cationic surfactants reverse flotation adsorption mechanism
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Rheological Behavior of Aqueous Solutions of Cationic Guar in Presence of Oppositely Charged Surfactant 被引量:1
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作者 李化真 杨海洋 +2 位作者 谢永军 李化玉 何平笙 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第4期491-496,I0002,共7页
The cationic guar (CG) is synthesized and the rheological behavior of aqueous solutions of CG in the presence of sodium dodecyl sulfate (SDS) is studied in detail. The steady viscosity measurements show that the z... The cationic guar (CG) is synthesized and the rheological behavior of aqueous solutions of CG in the presence of sodium dodecyl sulfate (SDS) is studied in detail. The steady viscosity measurements show that the zero shear viscosity enhancement can be almost 3 orders of magnitude as the concentration of SDS increases from 0 to 0.043%. The gel-like formation is observed as the concentration of SDS is greater than 0.016%. The oscillatory rheological measurements of CG solutions in the presence of SDS show that the crossover modulus is almost independent of the concentration of SDS whereas the apparent relaxation time increases swiftly upon increasing the concentration of SDS. The experimental results indicate that the strength rather than the number of the cross-links is greatly affected by SDS molecules. The mechanism concerning the effect of SDS upon the rheology of CG solutions can be coined by the two-stage model. Before the formation of cross-links at the critical concentration, the electrostatic interaction between SDS and cationic site of CG chains plays a key role and the SDS molecules bind to CG chains through the electrostatic interaction. After the formation of cross-links at the concentration greater than the critical concentration, the cooperative hydrophobic interaction become dominant and SDS molecules bind to the cross-links through the hydrophobic interaction. The theological behavior of aqueous solutions of CG in the presence of SDS is chiefly determined by the micelle-like cross-links between CG chains. In fact, the flow activation energy of CG solution, obtained from the temperature dependence of the apparent relaxation time, falls in the range of transferring a hydrophobic tail of SDS from the micelle to an aqueous environment. 展开更多
关键词 cationic guar Sodium dodecyl sulfate Rheological behavior Relaxation time Zero-shear viscosity
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In vitro investigation of RGD-modified stabilized cationic liposomes as non-viral vehicle for siRNA delivery 被引量:2
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作者 杨世进 杨丽娟 +2 位作者 姜娟 王坚成 张强 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第2期97-105,共9页
In this study, the novel RGD-modified stabilized cationic liposomes were developed as the delivery vehicle for siRNA targeting human MDR1 gene. The complex of cationic liposomes and siRNA, RGD-Lipo-siRNA, was prepared... In this study, the novel RGD-modified stabilized cationic liposomes were developed as the delivery vehicle for siRNA targeting human MDR1 gene. The complex of cationic liposomes and siRNA, RGD-Lipo-siRNA, was prepared with a narrow size distribution below 200 nm. It was shown that the encapsulated siRNA in the liposomes could be effectively protected from serum degradation. Also, enhanced cell binding and intracellular uptake of siRNA in the doxorubicin-resistant human ova- rian cancer cell lines SKOV3/A were found in RGD-Lipo-siRNA preparation as compared to that of unmodified cationic lipsomes (Lipo-siRNA). Using the post-insertion method for RGD modification, lysosome release of siRNA in pRGD-Lipo-siRNA was improved. From flow cytometry, significant increase of doxorubicin accumulation was observed in the SKOV3/A cells treated with pRGD-Lipo-siRNA targeting human MDR1 gene. In vitro cytotoxicity assay showed that the significant cell growth inhibition was achieved in the SKOV3/A cells after treating with the combined use of siRNA and doxorubicin. In conclusions, postinserted RGD modified lipoplex, pRGD-Lipo-siRNA, was successfully used for siRNA transfection and achieved drug resistance reversal in human ovarian cancer SKOV3/A (doxorubicin-resistant) cells. It suggested that this liposomes might be a potential vehicle for siRNA delivery in vivo. 展开更多
关键词 SIRNA cationic liposomes DC-Chol RGD modification
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Degradation Mechanism of Cationic Red X-GRL by Ozonation 被引量:14
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作者 Wei Rong ZHAO Xin Hua XU +1 位作者 Hui Xiang SHI Da Hui WANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第12期1309-1312,共4页
The degradation mechanism of Cationic Red X-GRL was investigated when the intermediates, the nitrate ion and the pH were analyzed in the ozonation. The degradation of the Cationic Red X-GRL includes the de-auxochrome... The degradation mechanism of Cationic Red X-GRL was investigated when the intermediates, the nitrate ion and the pH were analyzed in the ozonation. The degradation of the Cationic Red X-GRL includes the de-auxochrome stage, the decolour stage, and the decomposition of fragment stage. During the degradation process, among the six nitrogen atoms of Cationic Red X-GRL, one is transferred into a nitrate ion, one becomes the form of an amine compound, and the rest four are transformed into two molecules of nitrogen. In the course of the ozonation of Cationic Red X-GRL, the direct attack of ozone is the main decolour effect. 展开更多
关键词 OZONATION cationic Red X-GRL MECHANISM INTERMEDIATES DYE decolourization.
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Studies on a Cationically Modified Quaternary Ammonium Salt of Lignin 被引量:18
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作者 YANG Ai-li JIANG Wen-ju 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第4期479-482,共4页
A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin( noted as QL), with the monomer was carried out by grafting copolymerization. The products were characterized by Fourier Tr... A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin( noted as QL), with the monomer was carried out by grafting copolymerization. The products were characterized by Fourier Transform Infrared spectroscopy( FTIR). The experimental results indicate that the yield of the monomer was 99.06%, and the conversion of the monomer and the grafting yield of QL were 93.69% and 185.78%, respectively. The feasibility of QL as the flocculant to be applied in color removal of five artificial dyes, erioehrome black T(dye A), gongo red(dye B ), direct fast black G (dye C ), cuprofix blue green B (dye D ), and acid black ATT (dye E ) was examined. Results show that OL exhihits the favorable flocculation nerformance and high stability. 展开更多
关键词 Quaternary ammonium salt of lignin(QL) cationic monomer Grafting copolymerization FLOCCULATION
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Synthesis and Surface Activity of Novel Triazole-based Cationic Gemini Surfactants 被引量:10
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作者 Ling Guang QIU An Jian XIE Yu Hua SHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第6期653-656,共4页
The synthesis and surfactant activities of two new cationic gemini surfactants containing triazole compound as spacer were described. Their critical micelle concentrations (CMC), which are 1.8×10-4 mol/L and 3.9... The synthesis and surfactant activities of two new cationic gemini surfactants containing triazole compound as spacer were described. Their critical micelle concentrations (CMC), which are 1.8×10-4 mol/L and 3.9×10-4 mol/L respectively, are much lower than that of conventional surfactant cetyltrimethyl ammonium chloride (CTAC). In addition, compared with some gemini surfactants containing phenylene, xylylene and stilbenyl as spacer, this new kind of surfactants has good solubility in water at room temperature because of containing more hydrophilic groups or atoms in molecules. 展开更多
关键词 Gemini surfactant cationic surfactant critical micelle concentration TRIAZOLE synthesis.
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