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基于DFT和GCMC方法的MgCl_(2)水合盐储热材料吸水特性的数值模拟
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作者 钱增辉 朱传勇 +2 位作者 段欣悦 姜枭 巩亮 《工程热物理学报》 北大核心 2025年第4期1329-1336,共8页
MgCl_(2)水合盐被视为最具前景的中低温储热材料之一。研究MgCl_(2)水合盐储热材料微尺度下孔隙内的水分子吸附规律,揭示内在传质机理,对高效热化学储热系统的设计具有重要价值。本文基于DFT方法,研究了水分子在MgCl_(2)晶体表面吸附稳... MgCl_(2)水合盐被视为最具前景的中低温储热材料之一。研究MgCl_(2)水合盐储热材料微尺度下孔隙内的水分子吸附规律,揭示内在传质机理,对高效热化学储热系统的设计具有重要价值。本文基于DFT方法,研究了水分子在MgCl_(2)晶体表面吸附稳定后的分子几何构型,揭示了其可能的吸附位点。研究结果表明:水分子的吸附破坏了MgCl_(2)表面晶体规则的原子排列,这可能为后续进一步吸附和潮解创造了条件。此外,基于GCMC方法,研究了不同温度下,不同尺寸MgCl_(2)孔隙内水分子的吸附等温曲线和水分子浓度分布,结果表明:温度和孔隙尺寸对MgCl_(2)的吸水性有着明显的影响,当温度大于473 K时,孔隙的大小不再影响其吸水性能。 展开更多
关键词 热化学储能 mgcl2水合盐 DTF 水分子吸附
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MgCl_(2)及MgSO_(4)胁迫对紫花苜蓿幼苗生理的影响 被引量:1
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作者 魏晓娜 张晨 沈迎芳 《草原与草坪》 2025年第2期239-245,共7页
【目的】探索MgCl_(2)、MgSO_(4)胁迫对紫花苜蓿生理的影响。【方法】以中苜1号紫花苜蓿幼苗为试验材料,设置200 mmol/L MgCl_(2)、MgSO_(4)模拟中性盐胁迫,研究中苜1号在盐胁迫0、3、6、24 h的生理变化趋势。【结果】随着胁迫时间的延... 【目的】探索MgCl_(2)、MgSO_(4)胁迫对紫花苜蓿生理的影响。【方法】以中苜1号紫花苜蓿幼苗为试验材料,设置200 mmol/L MgCl_(2)、MgSO_(4)模拟中性盐胁迫,研究中苜1号在盐胁迫0、3、6、24 h的生理变化趋势。【结果】随着胁迫时间的延长,MgCl_(2)胁迫下中苜1号幼苗叶绿素(Chl)、丙二醛(MDA)、可溶性糖(SS)、可溶性蛋白(SP)含量及过氧化物酶(POD)活性均呈现先上升后下降的趋势。其中,胁迫3 h时,幼苗内Chl、MDA和SP含量达到最大值,均与CK间存在显著性差异,分别比CK上升了57.06%、56.77%和138.95%,胁迫6 h时,幼苗内SS含量和POD活性达到最大值,均与CK间存在显著性差异,分别比CK上升了352.13%和86.41%;在MgSO_(4)胁迫下苜蓿叶片内SS、SP含量和POD活性均呈现先上升后下降的趋势,其中,胁迫3 h时,幼苗内SP和POD活性达到最大值,幼苗内SP含量与CK间存在显著性差异,而POD含量与CK间差异不显著,与CK相比,分别上升了115.88%和15.48%,胁迫6 h时,幼苗内SS含量达到最大值,与CK间存在显著性差异,SS含量上升了1175.64%,而CC和MDA的含量呈现逐渐上升的趋势,在胁迫24 h,Chl和MDA含量达到最大值,均与CK间存在显性差异,分别比CK上升了251.72%和382.71%。利用隶属函数法对两种盐胁迫下中苜1号幼苗内不同生理指标进行综合评价得出,中苜1号紫花苜蓿MgCl_(2)胁迫的平均隶属函数值为0.51,MgSO_(4)胁迫的平均隶属函数值为0.49。【结论】中苜1号幼苗对两种盐的耐受性由强到弱为MgCl_(2)>MgSO_(4)。 展开更多
关键词 紫花苜蓿 mgcl_(2) MgSO_(4) 生理指标 隶属函数 耐盐性
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Efficient removal of Al(Ⅲ)and P507 from high concentration MgCl_(2)solution based on in-situ reaction strategy 被引量:1
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作者 Qiang WANG Meng WANG +3 位作者 Zong-yu FENG Yong-qi ZHANG Xiao-wei HUANG Xiang-xin XUE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期3042-3053,共12页
For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high conce... For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high concentration MgCl_(2)solution at different pH values and Al/P molar ratios was investigated.The results showed that P507 formed organic complexes of Al_(x)(OH)_y^(Z+)-P507 at pH of 2.0-4.0.At pH of 4.0-5.0,Al(Ⅲ)precipitated and transferred into Al(OH)_(3)with a flocculent amorphous morphology.Active sites on the Al(OH)_(3)surface enhanced the removal efficiency of P507.At pH of 6.0-6.5,Al(Ⅲ)and Mg(Ⅱ)formed layered crystalline Al(OH)_(3)and MgAl_(2)(OH)_(8with)small pore channels and fewer active sites,resulting in a reduced removal efficiency of P507.When the Al/P molar ratio exceeded 13 and the pH was between 4.0 and 5.0,the removal rates of both Al(Ⅲ)and P507 were higher than98%,while the concentration loss of Mg(Ⅱ)was only 0.2%-0.9%. 展开更多
关键词 in-situ removal AL(III) P507 mgcl_(2)solution pH Al/P molar ratio
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MgCl_(2)胁迫对紫花苜蓿萌发期和苗期生长的影响及耐盐指标筛选
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作者 魏晓娜 张晨 +1 位作者 祁乐萍 沈迎芳 《河南农业科学》 北大核心 2025年第9期43-52,共10页
设置不同浓度(0、40、80、120、160、200 mmol/L)MgCl_(2)溶液,研究MgCl_(2)胁迫对紫花苜蓿种子萌发和幼苗生长、生理指标的影响,并采用灰色关联度分析法筛选耐盐指标,以期为紫花苜蓿响应MgCl_(2)胁迫的应答机制研究及盐碱地治理提供一... 设置不同浓度(0、40、80、120、160、200 mmol/L)MgCl_(2)溶液,研究MgCl_(2)胁迫对紫花苜蓿种子萌发和幼苗生长、生理指标的影响,并采用灰色关联度分析法筛选耐盐指标,以期为紫花苜蓿响应MgCl_(2)胁迫的应答机制研究及盐碱地治理提供一定的理论基础。结果表明,随着MgCl_(2)浓度增加、处理时间延长,紫花苜蓿种子萌发、幼苗生长受到的抑制程度越来越大,在MgCl_(2)浓度为200 mmol/L时,种子不萌发,盐害指数为1.0。紫花苜蓿种子萌发指标中与耐盐性关联较大的指标是鲜质量、发芽率和发芽指数,关联度分别为0.948、0.927和0.927;苗期生长、生理指标中与耐盐性关联较大的指标是叶绿素含量、超氧化物歧化酶(SOD)活性和过氧化氢酶(CAT)活性,关联度分别为0.941、0.920和0.917。综上,紫花苜蓿萌发期和苗期的主要耐盐指标分别为鲜质量、发芽率、发芽指数和叶绿素含量、SOD活性、CAT活性。 展开更多
关键词 紫花苜蓿 mgcl_(2) 种子萌发 幼苗生长 耐盐指标
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四乙氧基硅烷对MgCl_(2)载体型Z-N催化剂催化乙烯聚合的影响
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作者 任合刚 高晶杰 刘智博 《合成树脂及塑料》 北大核心 2025年第1期28-31,共4页
以四乙氧基硅烷为内给电子体,制备了MgCl_(2)载体型Ziegler-Natta催化剂,考察了四乙氧基硅烷用量对催化剂催化乙烯聚合性能的影响,同时考察了n(Al)∶n(Ti)、聚合温度、氢气分压和1-己烯用量对催化剂性能的影响,并研究了所制聚乙烯的性... 以四乙氧基硅烷为内给电子体,制备了MgCl_(2)载体型Ziegler-Natta催化剂,考察了四乙氧基硅烷用量对催化剂催化乙烯聚合性能的影响,同时考察了n(Al)∶n(Ti)、聚合温度、氢气分压和1-己烯用量对催化剂性能的影响,并研究了所制聚乙烯的性能。结果表明:四乙氧基硅烷可增大催化剂的比表面积,提高催化剂活性,减少聚乙烯颗粒的细粉含量;聚合条件的改变能调控催化剂活性、聚乙烯颗粒形态和熔体流动速率;当n(Al)∶n(Ti)为50、聚合温度为80℃、氢气分压为0.25MPa时,催化剂活性达28265g/g,聚乙烯的堆密度为0.326g/cm^(3),粒径为75~750μm的聚乙烯颗粒质量分数为99.32%。 展开更多
关键词 乙烯聚合 氯化镁载体 齐格勒-纳塔催化剂 四乙氧基硅烷 活性
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Copper and iron extraction from chalcopyrite by NaCl@MgCl_(2)@urea:Synthesis of CuFe_(2)O_(4) electrodes for supercapacitors
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作者 POLAT Safa MOHAMMED Mariem MASHRAH Muwafaq 《Journal of Central South University》 2025年第1期82-93,共12页
This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitor... This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage. 展开更多
关键词 COPPER IRON NACL mgcl_(2) UREA thiourea CHALCOPYRITE supercapacitor copper ferrite
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Electrochemical evaluation of Fe^(2+)ions in MgCl_(2)−NaCl−KCl melt
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作者 Jia ZHAO Zhao-ting LIU Gui-min LU 《Transactions of Nonferrous Metals Society of China》 2025年第5期1704-1712,共9页
A comprehensive electrochemical assessment of Fe^(2+)behavior in a MgCl_(2)−NaCl−KCl melt was reported,involving cyclic voltammetry(CV),square wave voltammetry(SWV),and chronoamperometry(CA)analyses.Reduction of Fe^(2... A comprehensive electrochemical assessment of Fe^(2+)behavior in a MgCl_(2)−NaCl−KCl melt was reported,involving cyclic voltammetry(CV),square wave voltammetry(SWV),and chronoamperometry(CA)analyses.Reduction of Fe^(2+)in MgCl_(2)−NaCl−KCl was observed to occur in a single step involving two electrons,exhibiting quasi-reversible behavior.The diffusion coefficient of Fe^(2+)(5.75×10^(-5)cm^(2)/s)in this system was experimentally determined at 973 K,with an associated diffusion activation energy of 25.06 kJ/mol in the range of 973−1048 K,and an estimated standard rate constant for Fe^(2+)/Fe of around 1×10^(-3)cm/s.The nucleation of Fe on the tungsten electrode in the MgCl_(2)−NaCl−KCl molten salt is insensitive to temperature and overpotential.It is found that the nucleation mode is related to the concentration of Fe^(2+)surrounding the electrode and evolves from an instantaneous to a progressive process,accompanied by a deterioration of magnesium electrolysis due to Fe impurities. 展开更多
关键词 Fe^(2+) mgcl_(2)−NaCl−KCl melt electrochemical reduction kinetic properties nucleation mechanism
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Thermoelectric Performance of CuInSe_(2)‑ZnSe Solid Solution
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作者 Chengwei Sun Wang Li +6 位作者 Chengjun Li Yingchao Wei Wenyuan Ma Xin Li Qinghui Jiang Yubo Luo Junyou Yang 《Acta Metallurgica Sinica(English Letters)》 2025年第5期823-830,共8页
CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high therma... CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high thermal conductivity of CuInSe_(2) limits the enhancement of its thermoelectric performance.Herein,we investigate the thermoelectric performance of N-type CuInSe_(2) materials by incorporating ZnSe through a solid solution strategy.A series of(CuInSe_(2))_(1-x)(ZnSe)_(x)(x=0.0,0.2,0.4,0.6,0.8,1.0)samples were synthesized,forming continuous solid solutions,while introducing minor porosity.ZnSe solid solution effectively reduces the lattice thermal conductivity of the CuInSe_(2) matrix at near-room temperatures,but has a weaker effect at higher temperatures.Due to the intrinsic low carrier concentration of the system,resulting in high resistivity,the maximum figure of merit(ZT)of(CuInSe_(2))0.8(ZnSe)0.2 reaches 0.08 at 773 K.Despite the relatively low ZT,the solid solution strategy proves effective in reducing the lattice thermal conductivity near-room temperature and offers potential for cost-effective thermoelectric materials. 展开更多
关键词 THERMOELECTRIC CuInSe_(2) ZNSE Solid solution
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Hydrogen production from dry reforming of methane,using CO_(2)previously chemisorbed in the Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution
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作者 Yocelin B.González-González Fernando Plascencia-Hernández +1 位作者 Rubén Mendoza-Cruz Heriberto Pfeiffer 《Journal of Environmental Sciences》 2025年第3期535-550,共16页
Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)ca... Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials. 展开更多
关键词 Dry reforming of methane(DRM) CO_(2)chemisorption H_(2)production Solid solution Li_(6)ZnO_(4)
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Engineering surface and subsurface oxygen vacancies of Ce_(x)Zr_(1-x)O_(2) solid solution for enhanced total toluene oxidation
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作者 Yang Yu Mingjia Zhang +5 位作者 Huangang Shi Jifa Qu Yongheng Xiong Wenyi Tan Xinlei Ge Qijie Jin 《Journal of Environmental Sciences》 2025年第12期39-49,共11页
Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surf... Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surface and subsurface oxygen vacancies on the performance and mechanisms of catalysts.Herein,a series of zirconium doping on CeO_(2) samples(CeO_(2),Ce_(0.95)Zr_(0.05)O_(2),and Ce_(0.8)5Zr_(0.15)O_(2))with various surface-to-subsurface oxygen vacancies ratios have been synthesized and applied in toluene catalytic oxidation.The obtained Ce_(0.95)Zr_(0.05)O_(2) exhibits an excellent catalytic performance with a 90%toluene conversion at 295℃,which is 68℃lower than that of CeO_(2).Additionally,the obtained Ce_(0.95)Zr_(0.05)O_(2)catalyst also exhibited good catalytic stability and water resistance.The XRD and HRTEM results show that Zr ions are incorporated into CeO_(2) lattice,forming Ce_(x)Zr_(1-x)O_(2) solid solution.Temperature-programmed experiments reveal that Ce_(0.95)Zr_(0.05)O_(2) shows excellent lowtemperature reducibility and abundant surface oxygen species.In-situ DRIFTS tests were used to probe the reaction mechanism,and the function of Zr doping in promoting the activation of oxygen was further determined.Density functional theory(DFT)calculations indicate that the vacancy formation energy and O_(2) adsorption energy are both lower on Ce_(0.95)Zr_(0.05)O_(2),confirming the reason for its superior catalytic performance. 展开更多
关键词 Ce_(x)Zr_(1-x)O_(2)solid solution Toluene oxidation Surface oxygen species DFT calculations
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Effect of B_(2)O_(3) and Na_(2)B_(4)O_(7) on phosphorus enrichment in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2) solid solutions
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作者 Xin Ping Fang Zhang +2 位作者 Jun Peng Hong-tao Chang Shuang Liu 《Journal of Iron and Steel Research International》 2025年第6期1502-1513,共12页
To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solu... To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solution were comparatively analyzed through theoretical calculations and experimental investigations.The results indicate that the optimum reaction temperature between B_(2)O_(3)and C_(2)S–C_(3)P is 800℃.The phase compositions of C_(2)S–C_(3)P equilibrium system with 5 wt.%B_(2)O_(3)at 800℃ included Ca_(3)(PO_(4))_(2),CaSiO_(3)and Ca11B_(2)Si_(4)O_(22),among which the content of Ca_(3)(PO_(4))_(2)was the highest.For C_(2)S–C_(3)P with 5 wt.%Na_(2)B_(4)O_(7)equilibrium system,Ca_(3)(PO_(4))_(2),CaSiO_(3),Ca11B_(2)Si_(4)O_(22)and Na_(2)Ca_(2)P_(2)O_(8)were independent at 390–690℃.Ca_(3)(PO_(4))_(2)and Ca_(2)SiO_(4)precipitated in the solid solution when the addition of B_(2)O_(3)was more than 6 wt.%,and the content of Ca_(3)(PO_(4))_(2)raised with the increase in the addition of B_(2)O_(3).The main phases in the C_(2)S–C_(3)P solid solution with Na_(2)B_(4)O_(7)were(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],Ca_(2)SiO_(4)and Na_(3)Ca_(6)(PO_(4))_(5)at 650℃.And when the addition of Na_(2)B_(4)O_(7)exceeded 6 wt.%,the content of Na_(3)Ca_(6)(PO_(4))_(5)increased significantly.There was no precipitation of Ca_(3)(PO_(4))_(2)or boron-containing phase in the samples with Na_(2)B_(4)O_(7),but a small proportion of Ca_(3)(PO_(4))_(2)transformed into(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],and Ca^(2+)was partially replaced by Na^(+)to generate Na_(3)Ca_(6)(PO_(4))_(5).As a result,the temperature for Na_(2)B_(4)O_(7)to enrich the phosphorus-containing phase in C_(2)S–C_(3)P solid solution was lower than that for B_(2)O_(3).However,the grade of the phosphorus-containing phase for Na_(2)B_(4)O_(7)was lower than that for B_(2)O_(3). 展开更多
关键词 B_(2)O_(3) Na_(2)B_(4)O_(7) Ca_(2)SiO_(4)-Ca_(3)(PO_(4))_(2)solid solution Phosphorus enrichment
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Low-dose X-ray induced long afterglow NIR luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions
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作者 Tingting Zhao Wenzhi Sun +4 位作者 Shuya Wang Wei Meng Chunqing Fu Xiaoyan Fu Hongwu Zhang 《Journal of Rare Earths》 2025年第2期246-252,I0001,共8页
The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd... The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials. 展开更多
关键词 Zn_(1-x)Cd_(x)Ga_(2)O_(4):1%Cr^(3+) Phosphors Solid solutions X-ray induced long afterglow luminescence Rare earths
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CaCl_(2)和MgCl_(2)及其复合溶液制备α-半水石膏 被引量:2
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作者 胡成 刘梦 +4 位作者 向玮衡 陈平 王能 卢冠举 周金兰 《无机盐工业》 CAS CSCD 北大核心 2024年第7期112-117,共6页
为提高磷石膏的利用率和附加值,采用常压水热合成法以磷石膏为主要原材料制备α-半水石膏材料,主要研究不同质量分数的CaCl_(2)、MgCl_(2)及其复合溶液对磷石膏常压水热制备α-半水石膏脱水速率、物相组成和微晶形貌的影响。研究发现,... 为提高磷石膏的利用率和附加值,采用常压水热合成法以磷石膏为主要原材料制备α-半水石膏材料,主要研究不同质量分数的CaCl_(2)、MgCl_(2)及其复合溶液对磷石膏常压水热制备α-半水石膏脱水速率、物相组成和微晶形貌的影响。研究发现,磷石膏在95℃的CaCl_(2)溶液、MgCl_(2)溶液及CaCl_(2)-MgCl_(2)复合溶液中均可脱水转晶生成α-半水石膏。在CaCl_(2)溶液和MgCl_(2)溶液中,随着盐溶液浓度的增加,α-半水石膏的生成速率加快,其中经质量分数为35%的CaCl_(2)溶液反应4 h后或质量分数为25%的MgCl_(2)溶液反应1 h后,磷石膏可完全反应成α-半水石膏。在CaCl_(2)-MgCl_(2)复合溶液中,随着MgCl_(2)溶液浓度的增加,磷石膏的脱水转化速率逐渐加快,当CaCl_(2)质量分数≤19%和MgCl_(2)质量分数≥11%时,磷石膏水热反应1 h即可形成颗粒分布较为完整的α-半水石膏。 展开更多
关键词 磷石膏 CaCl_(2) mgcl_(2) 复合溶液 Α-半水石膏
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褐煤腐植酸的超临界CO_(2)萃取及增效作用机制 被引量:1
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作者 樊玉萍 金伟 +3 位作者 马晓敏 付元鹏 董宪姝 朱本康 《煤炭学报》 北大核心 2025年第5期2679-2691,共13页
超临界CO_(2)(ScCO_(2))萃取技术是煤炭中可溶性有机质提取的有效途径之一,其强大的溶解及萃取能力可改变煤样形貌特征及孔隙结构。以内蒙古某地褐煤及用10%过氧化氢溶液预处理后的褐煤为原料,以乙醇为共溶剂,进行褐煤的ScCO_(2)萃取腐... 超临界CO_(2)(ScCO_(2))萃取技术是煤炭中可溶性有机质提取的有效途径之一,其强大的溶解及萃取能力可改变煤样形貌特征及孔隙结构。以内蒙古某地褐煤及用10%过氧化氢溶液预处理后的褐煤为原料,以乙醇为共溶剂,进行褐煤的ScCO_(2)萃取腐植类物质实验。利用ICP-MS电感耦合等离子体质谱仪、傅里叶红外光谱仪、扫描电子显微镜、紫外-可见分光光度计等对腐植类产物进行分析;利用扫描电子显微镜、比表面积及孔径分析仪等探究在ScCO_(2)萃取过程中煤样的形貌特征及孔隙的变化,揭示ScCO_(2)萃取技术对腐植类物质提取的作用机制。研究结果表明,过氧化氢溶液预处理后的煤样会让有乙醇共溶的ScCO_(2)更有效地渗透到褐煤的孔隙中,与黄腐酸官能团之间通过氢键等作用发生相互作用,使得黄腐酸从褐煤基质中大量溶解到超临界流体中,萃取后的煤样整体疏松孔隙更多有利于后续腐植酸的提取。萃取出的黄腐酸溶液中Mg、P、K和Fe等植物营养必需元素的离子质量浓度大幅度提高,分别为21432.77、148.83、8823.84、415.12μg/L。萃取后的煤样具有最大的总孔容为0.0179 cm^(3)/g及比表面积为3.3743 m^(2)/g,以其为原料制备出的腐植酸产率高(49.38%)、O/C高(0.74)、N/C高(0.12)、含硫量低(1.11%)、富含羰基和羧基、芳香度低、分子量较小、表面多孔粗糙。这表明ScCO_(2)萃取技术对黄腐酸及腐植酸的有效提取及品质提高具有重要启示作用。 展开更多
关键词 褐煤 ScCO_(2)萃取 黄腐酸溶液 腐植酸 作用机制
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SrCl_(2)-KCl-MgCl_(2)熔体中氯化镁的电化学行为和镁锶共沉积机理 被引量:1
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作者 赵佳 闫艺航 +3 位作者 张皓 高华阳 张烨 路贵民 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第7期2381-2392,共12页
采用循环伏安法、方波伏安法、开路电位等电化学手段评估SrCl_(2)-KCl共晶体系中MgCl_(2)的电化学行为和Mg、Sr共沉积机理。在SrCl_(2)-KCl体系中,Mg(Ⅱ)在钨电极的还原属于一步两电子的准可逆过程;Mg、Sr的电化学共沉积过程形成两种Mg... 采用循环伏安法、方波伏安法、开路电位等电化学手段评估SrCl_(2)-KCl共晶体系中MgCl_(2)的电化学行为和Mg、Sr共沉积机理。在SrCl_(2)-KCl体系中,Mg(Ⅱ)在钨电极的还原属于一步两电子的准可逆过程;Mg、Sr的电化学共沉积过程形成两种Mg-Sr金属间化合物。基于计时电流法探索共沉积过程的成核类型随过电位的演变关系,结果显示,电极表面的成核模式依赖于基体材料和电极反应产物。所有过电位下对应的前期成核归因于Mg(Ⅱ)的还原。当Mg和Sr共同沉积时,首先是Mg(Ⅱ)在电极表面还原,形成Mg核,随后同时进行Sr(Ⅱ)在Mg表面欠电位沉积和Mg的沉积。此外,随着SrCl_(2)-KCl体系中MgCl_(2)浓度的增加,Mg-Sr共沉积过程中的电流密度相应增加。 展开更多
关键词 氯化镁 电化学行为 扩散系数 成核机理 共沉积
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MgCl_(2)·6H_(2)O溶液对方镁石-镁铝尖晶石耐火材料性能的影响
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作者 王鑫 韩兵强 +2 位作者 苗正 陈俊峰 鄢文 《硅酸盐通报》 CAS 北大核心 2024年第2期719-726,共8页
以电熔镁砂和电熔镁铝尖晶石为原料,以18°Be’、24°Be’、30°Be’三种不同浓度的MgCl_(2)·6H_(2)O溶液和酚醛树脂为结合剂,制备方镁石-镁铝尖晶石耐火材料。以酚醛树脂为对照组,通过研究MgCl_(2)·6H_(2)O溶液... 以电熔镁砂和电熔镁铝尖晶石为原料,以18°Be’、24°Be’、30°Be’三种不同浓度的MgCl_(2)·6H_(2)O溶液和酚醛树脂为结合剂,制备方镁石-镁铝尖晶石耐火材料。以酚醛树脂为对照组,通过研究MgCl_(2)·6H_(2)O溶液对材料常温抗折强度、常温耐压强度、烧结性能、抗热震性能的影响,探明MgCl_(2)·6H_(2)O溶液对材料的作用机理。结果表明,在常温下MgCl_(2)·6H_(2)O溶液能与镁砂反应生成氯氧镁水泥(MOC),MOC在微观下表现为交错互锁的晶须结构,使得耐火材料在干燥后具有非常高的机械强度。当热处理温度为1 700℃、溶液浓度为24°Be’时,材料的常温耐压强度达到79.1 MPa,相较于酚醛树脂提高了58.2%;当热处理温度为1 700℃、溶液浓度为18°Be’时,材料的显气孔率达到16.8%,相较于酚醛树脂降低了13.4%。MgCl_(2)·6H_(2)O溶液浓度的增加有利于提高材料的断裂韧性。MOC和Mg(OH)_(2)在烧成过程中会分解产生活性MgO,促进材料的烧结。此外,分解产生的活性MgO呈类球状,它们分散填充在镁砂颗粒内部裂隙处,形成微孔结构,有利于减缓热震时的热应力冲击。 展开更多
关键词 mgcl_(2)·6H_(2)O溶液 方镁石-镁铝尖晶石 氯氧镁水泥 类球状MgO 烧结致密化 抗热震性能
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MEA+BEA+DEEA的CO_(2)吸收-解吸特性实验研究
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作者 魏燕 张楠 +2 位作者 史焕聪 金晶 韩鹏飞 《上海理工大学学报》 北大核心 2025年第2期194-201,208,共9页
乙醇胺(MEA)+2-丁基乙醇胺(BEA)溶液体系中存在对CO_(2)吸收的协同效应,这种协同效应可以同时促进CO_(2)的吸收和解吸。将MEA+BEA二元胺体系扩展至MEA+BEA+二乙氨基乙醇胺(DEEA)三元胺体系,在实验室规模的间歇式吸收-解吸反应器和再循... 乙醇胺(MEA)+2-丁基乙醇胺(BEA)溶液体系中存在对CO_(2)吸收的协同效应,这种协同效应可以同时促进CO_(2)的吸收和解吸。将MEA+BEA二元胺体系扩展至MEA+BEA+二乙氨基乙醇胺(DEEA)三元胺体系,在实验室规模的间歇式吸收-解吸反应器和再循环过程的实验系统中,研究了浓度(0.1~0.5 mol/L) MEA+2.0 mol/L BEA+2.0 mol/L DEEA溶液的CO_(2)吸收-解吸性能,与2.0 mol/L BEA+2.0 mol/L DEEA溶液进行比较,并进一步采用CO_(2)吸收和解吸参数对协同效应进行分析。结果表明,MEA+仲胺(RR'NH)+叔胺(RR'R''N)的协同效应使MEA+BEA+DEEA在CO_(2)吸收和解吸方面均优于BEA+DEEA,与传统的MEA增强吸收但降低解吸的效果不同,MEA、BEA、DEEA的最佳浓度分别为0.1、2.0、2.0 mol/L。 展开更多
关键词 CO_(2)吸收和解吸 协同效应 混合胺溶液 吸收和解吸参数
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铝矾土合成Al_(2)O_(3)-MgAl_(2)O_(4)复合材料的烧结性和力学性能研究
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作者 王晓军 玄松桐 +2 位作者 王燕锋 苏廷龙 田玉明 《材料导报》 北大核心 2025年第15期87-91,共5页
Al_(2)O_(3)-MgAl_(2)O_(4)复合材料因具有优异的性能,可被应用在一些特殊的高温行业中,从而引起了人们的广泛关注。本工作选取铝矾土生料和氧化镁为原料,采用固相烧结工艺在1 350~1 450℃保温2 h后,获得了Al_(2)O_(3)-MgAl_(2)O_(4)复... Al_(2)O_(3)-MgAl_(2)O_(4)复合材料因具有优异的性能,可被应用在一些特殊的高温行业中,从而引起了人们的广泛关注。本工作选取铝矾土生料和氧化镁为原料,采用固相烧结工艺在1 350~1 450℃保温2 h后,获得了Al_(2)O_(3)-MgAl_(2)O_(4)复合陶瓷材料,研究了MgAl_(2)O_(4)的含量和烧结温度对其致密性和力学性能的影响。研究发现:经1 400℃烧结保温2 h后的样品的致密性和力学性能较好,烧结温度升高至1 450℃时,样品的致密性和力学性能降低。经1 400℃烧结得到的样品中,当MgAl_(2)O_(4)与Al_(2)O_(3)+MgAl_(2)O_(4)的质量比达到35∶100时,样品的性能最佳:显气孔率最小,为0.64%,抗折强度最大,为132.11 MPa。 展开更多
关键词 复合材料 镁铝尖晶石 离子扩散 力学性能 固溶体
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致密砂岩气藏CO_(2)增能压裂的碳埋存机理
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作者 赵金省 严繁 +3 位作者 肖元相 张庆祝 章思鹏 李攀 《天然气工业》 北大核心 2025年第8期77-87,共11页
在“双碳”目标背景下,致密砂岩气藏CO_(2)增能压裂技术兼具提高压裂液返排效率、补充地层能量及实现CO_(2)埋存的双重作用,揭示CO_(2)增能压裂的碳埋存机理具有重要理论意义和指导作用。为此,通过室内实验研究,结合核磁共振、启动压力... 在“双碳”目标背景下,致密砂岩气藏CO_(2)增能压裂技术兼具提高压裂液返排效率、补充地层能量及实现CO_(2)埋存的双重作用,揭示CO_(2)增能压裂的碳埋存机理具有重要理论意义和指导作用。为此,通过室内实验研究,结合核磁共振、启动压力梯度测试、X射线衍射等手段,系统评价了致密砂岩气藏CO_(2)增能压裂的碳埋存效果,分析了不同压力下CO_(2)埋存率的变化规律,阐明了束缚埋存与溶解固化埋存的作用机理,指出了裂缝闭合滞留的关键影响因素,最后明确了CO_(2)增能压裂过程中的碳埋存规律。研究结果表明:①CO_(2)增能压裂以束缚碳埋存为主,压力高于超临界压力时,束缚碳埋存率可达60%以上,且受启动压力梯度显著影响,梯度越大,CO_(2)埋存率越高;②溶解固化碳埋存率介于5%~30%,在超临界压力附近达到峰值(10%~30%),其效果受矿物成分控制,方解石、白云石及黏土矿物易被溶蚀并生成高岭石等沉淀,进而改变储层孔喉结构;③裂缝闭合滞留碳埋存率主要受闭合压力主导,液体返排率与铺砂浓度次之,支撑剂类型影响最小。结论认为,CO_(2)增能压裂在致密砂岩气藏中可实现高效碳埋存,研究成果为优化CO_(2)增能压裂工艺及预测碳埋存效果提供了理论依据,对推动低碳油气开发具有重要指导价值。 展开更多
关键词 致密砂岩气藏 CO_(2)增能压裂 CO_(2)埋存 束缚碳埋存 溶解固化碳埋存 孔喉分布 启动压力梯度 核磁共振
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新的(2+1)维Boussinesq方程的孤立子解
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作者 郭学军 曹玉雷 《山东大学学报(理学版)》 北大核心 2025年第5期33-39,共7页
研究(2+1)维的Boussinesq方程,该系统是Boussinesq方程的一个多维推广版本。利用Hirota的双线性方法构造(2+1)维Boussinesq方程的孤立子解,并分析孤立子解的局部特征,给出了孤立子解的动力学行为。此外,在特殊参数限制下得到了共振的孤... 研究(2+1)维的Boussinesq方程,该系统是Boussinesq方程的一个多维推广版本。利用Hirota的双线性方法构造(2+1)维Boussinesq方程的孤立子解,并分析孤立子解的局部特征,给出了孤立子解的动力学行为。此外,在特殊参数限制下得到了共振的孤立子解。由于共振碰撞,孤立子解呈现“V”型,不再是传统的交叉型。更高阶的共振孤立子解的动力学行为更加复杂多样,由基本的共振孤立子叠加而成。 展开更多
关键词 (2+1)-维Boussinesq方程 双线性方法 孤立子解 动力学
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