Based on a set of equations established by Duan et al. (1992, 1996) for a geofluid system H2O-CO2-CH4(-N2), a formula is obtained to calculate the heat changes. Combining the geological T-P conditions (geothermal grad...Based on a set of equations established by Duan et al. (1992, 1996) for a geofluid system H2O-CO2-CH4(-N2), a formula is obtained to calculate the heat changes. Combining the geological T-P conditions (geothermal gradients and lithostatic and hydrostatic pressures), the enthalpy of some typical geofluids is figured out. Then the principles of heat transfer of deep-derived supercritical fluids are discussed. The result shows that deep-derived geofluids can bring a large amount of thermal heat and release most heat to the shallow surroundings as they move up, because the molar enthalpies vary very greatly from the deep to shallow, increasing with the increases of T and P. Generally, more than tens of kilojoules heat per molar can be released. Furthermore, the molar enthalpy is affected by the compositions of the geofluids, and the molar enthalpy of CO2, CH4, or N2 is greater than that of H2O, being twice, more than twice, and about 140% of H2O, respectively. Finally, a case study is conducted by investigating a source rock sequence affected hydrothermally by magmatic fluids in the Huimin depression of Shengli Oilfield. The thermal heat calculated theoretically of the fluids related to a diabase intrusion is quite large, which can increase the temperature near the diabase to about 300℃, and that can, to some extent, account for the abnormal rise of the vitrinite reflectance, with the highest of about 3.8% (Ro).展开更多
A new one-dimensional Mg（Ⅱ） coordination polymer, [Mg（L）（phen）（H2O）]（1）, has been hydrothermally synthesized by using 3,5-dinitro-salicylic acid（H2L） and 1,10-phenanthroline（phen）. It crystallizes in mo...A new one-dimensional Mg（Ⅱ） coordination polymer, [Mg（L）（phen）（H2O）]（1）, has been hydrothermally synthesized by using 3,5-dinitro-salicylic acid（H2L） and 1,10-phenanthroline（phen）. It crystallizes in monoclinic, space group C2/c with a = 33.038（7）, b = 6.6481（13）, c = 22.750（5） A, β = 126.99（3）°, V = 3991.1（14） A3, Z = 8, C19H12 MgN4O8, Mr = 448.64, Dc = 1.493 g/cm3, F（000） = 1840, μ（Mo Ka） = 0.146 mm-1, R = 0.0559 and w R = 0.0975. In 1, each L anion bridges two Mg（Ⅱ） atoms to give one-dimensional zigzag chains with the Mg…Mg separation of 5.34 ？, which are extended by π-π stacking interactions between 1,10-phenanthroline ligands into a two-dimensional supramolecular layer. Moreover, the O–H…O hydrogen-bonding interactions further stabilize the layer structure of 1. The luminescent property was also studied for 1 in solid state at room temperature. In addition, natural bond orbital（NBO） analysis was performed by the B3LYP/LANL2 DZ method in Gaussian 09 Program. The calculation results show obvious covalent interaction between the coordinated atoms and Mg（Ⅱ） ion.展开更多
A novel complex,[Mn(2-NCP)(H2BTC)(H2O)]n(1,1,3,5-H3BTC=1,3,5-benzenetricarboxylic acid,2-HNCP=2-(2-carboxyphenyl)-1 H-imidazo(4,5-f)-(1,10)phenanthroline),was hydrothermally synthesized and structurally characterized ...A novel complex,[Mn(2-NCP)(H2BTC)(H2O)]n(1,1,3,5-H3BTC=1,3,5-benzenetricarboxylic acid,2-HNCP=2-(2-carboxyphenyl)-1 H-imidazo(4,5-f)-(1,10)phenanthroline),was hydrothermally synthesized and structurally characterized by elemental analysis,IR,XRD and single-crystal X-ray diffraction.Structural analyses reveal that complex 1 exhibits a(6,6)-connected topology network with a Schl?fli symbol of(63).The adjacent 2 D layers are further stacked via strong hydrogen-bonding interactions,giving a 3 D supramolecular framework.In addition,the structure of complex 1 was calculated by the B3LYP/LANL2 DZ method by Gaussian program.The results from natural bond orbital(NBO)analysis shows obvious covalent interaction between the coordinated atoms and Mn(Ⅱ)ion.展开更多
A new Cd（Ⅱ） coordination polymer, [Cd（L）2（H2O）]n（1）, has been hydrothermally synthesized by using 1-（1 H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）naphthalen-2-ol（HL）,(3-（4-（carboxymethoxy）phenyl）acrylic...A new Cd（Ⅱ） coordination polymer, [Cd（L）2（H2O）]n（1）, has been hydrothermally synthesized by using 1-（1 H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）naphthalen-2-ol（HL）,(3-（4-（carboxymethoxy）phenyl）acrylic acid and Cd（NO3）·4 H2O. It crystallizes in monoclinic, space group P21/c with a = 19.41（2）, b = 11.078（12）, c = 20.09（2） ?, β = 116.824（17）o, V = 3855（7） ?3, Z = 4, C46H28CdN8O3, Mr = 853.17, Dc = 1.470 g/cm3, F（000） = 1728, μ（Mo Ka） = 0.621 mm-1, R = 0.0338 and wR = 0.0890. 1 shows a one-dimensional（1 D） zigzag chain structure. The neighboring chains are extended into a two-dimensional（2 D） layer structure by π-π interactions between adjacent L ligands. In addition, Natural Bond Orbital（NBO） analysis was performed by the B3LYP/LANL2DZ method in Gaussian 09 Program. The calculation results show the obvious covalent interaction between the coordinated atoms and Cd（Ⅱ） ion.展开更多
Combining with electrospray ionization(ESI)mass spectrometry,infrared photodissociation(IRPD)spectroscopy is a powerful method to study structures of cluster ions in the gas phase.In this paper,infrared photodissociat...Combining with electrospray ionization(ESI)mass spectrometry,infrared photodissociation(IRPD)spectroscopy is a powerful method to study structures of cluster ions in the gas phase.In this paper,infrared photodissociation spectrum of Pro_4H~+in the range of 2700–3600 cm 1was obtained experimentally.Both theoretically predicted spectra of the two most stable isomers of Pro4^(-1)and Pro4^(-2)obtained at the level of M062X/6-31+G(d,p)are in good consistent with the experimental results.The two isomers have similar structures and close energies.Both of them only consist of zwitterionic units,indicating the strong salt-bridged interactions inside the clusters.And the calculated collision cross section(ccs)of Pro4-1 is found to be very close to the experimental result previously reported.展开更多
As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this r...As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is summarized.Specifically,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical calculations.The applications of these materials as electrodes are then featured for various SCs.Finally,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.展开更多
The title compound [2-（2,6-dioxacyclohexyl）-5-methoxylphenols]2 was synthesized by the reaction of 2-hydroxyl-3-methoxylbenzaldehyde and 1,3-propanediol in the presence of DMF-DMS adduct and characterized by IR spec...The title compound [2-（2,6-dioxacyclohexyl）-5-methoxylphenols]2 was synthesized by the reaction of 2-hydroxyl-3-methoxylbenzaldehyde and 1,3-propanediol in the presence of DMF-DMS adduct and characterized by IR spectrum, UV-Vis spectrum and X-ray crystallography. The title compound belongs to monoclinic, space group P21 with a = 9.8967（10）, b = 8.2240（9）, c = 13.3654（14） A^°, β= 90.016（2）°, C11H14O4, Mr = 210.22, V = 1087.8（2）A^°3, Z = 4, Dc = 1.284 Mg/m^3, F（000） = 448,μ = 0.098 mm^-1, the final R = 0.0300 and wR = 0.0761 for 2070 observed reflections with I 〉 2σ（I）. The molecules are connected via intermolecular O-H…O hydrogen bonds into a 2D network structure. Moreover, theoretical investigations of the title compound with HF/6-31G（d） method were performed, and its stability, frontier molecular orbital composition and Mulliken charge distribution were also discussed. The compound is a bis-molecule. The two molecules stay together and could not be separated. Two crystallographically independent molecules exist in an asymmetric unit. The bond lengths and bond angles of the two molecules are slightly different with each other.展开更多
A coordination polymer [Mn2（ctpt）2（aic）2]n （1, ctpt = 2-（4-chloro-phenyl）-1H- 1,3,7,8-tetraaza-cyclopenta[l]phenanthrene, H2aic = 5-amino-isophthalic acid） was hydrother- mally designed and synthesized. The co...A coordination polymer [Mn2（ctpt）2（aic）2]n （1, ctpt = 2-（4-chloro-phenyl）-1H- 1,3,7,8-tetraaza-cyclopenta[l]phenanthrene, H2aic = 5-amino-isophthalic acid） was hydrother- mally designed and synthesized. The complex was characterized by elemental analysis, IR spectro- scopy, single-crystal X-ray diffraction, and thermogravimetric analysis （TGA）. Each Mn（II） atom is linked by the aic ligands with neighbor Mn（II） atoms, forming an infinite one-dimensional （1D） double-chain structure. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 18.23（1）, b = 17.27（1）, c = 16.69（1） ？, V = 4814.0（7） ？3, C27H16ClMnN5O4, Mr = 564.84, Dc = 1.559 g/cm3, μ（MoKα） = 0.706 mm-1, F（000） = 2296, Z = 8, the final R = 0.0487 and wR = 0.1269 （I 〉 2σ（I））. The 1D chain structure of complex 1 is stable below 458 ℃. In addition, to elucidate the essential electronic characters of this complex, theoretical calculation analysis of 1 was performed by the PBE0/LANL2DZ method in Gaussian 03 Program.展开更多
The title adduct imidazolium 3,5-dinitrobenzoate has been synthesized in aqueous solution and characterized by elemental analyses, IR spectrum and X-ray crystallography. The title compound belongs to monoclinic, space...The title adduct imidazolium 3,5-dinitrobenzoate has been synthesized in aqueous solution and characterized by elemental analyses, IR spectrum and X-ray crystallography. The title compound belongs to monoclinic, space group P21/n with a = 7.5540（9）, b = 21.333（2）, c = 7.7823（9）A, β = 102.741（2）^o, C10H8N4O6, Mr = 280.20, V= 1223.3（2）A^3, Z = 4, Dc = 1.521 g/cm^3, F（000） = 576, p = 0.129 mm^-1, the final R = 0.0433 and wR = 0.1092 for 2001 observed reflections with I 〉 2a（I）. The structural analysis indicates the component ions are linked by N-H...O hydrogen bonds into an infinite one-dimensional C2^2 （8） chain parallel to the [1 0 -1] direction. Moreover, the theoretical investigations of the title compound with HF/6-31G（d） method were performed, and its stability, frontier molecular orbital composition and Mulliken charge distribution were also discussed.展开更多
Because of its high mobility and difficult capture,gaseous arsenic pollution control has become the focus of arsenic pollution control.It mainly exists in the form of highly toxic As_(2)O_(3)in the flue gas.Therefore,...Because of its high mobility and difficult capture,gaseous arsenic pollution control has become the focus of arsenic pollution control.It mainly exists in the form of highly toxic As_(2)O_(3)in the flue gas.Therefore,removing gaseous As_(2)O_(3)from flue gas is of great practical significance for arsenic pollution control.Stabilizing gaseous As_(2)O_(3)on the surface of adsorbents by physical or chemical adsorption is an effective way to reduce the content of arsenic in the flue gas and alleviate arsenic pollution.Over the past few decades,various adsorbents have been developed to capture gaseous As_(2)O_(3)in the flue gas,and their adsorption mechanisms have been studied in detail.Thus,it is necessary to review the strategies of arsenic removal from flue gas by adsorption,which can inspire further research.Based on summarizing the morphological distribution of gaseous As_(2)O_(3)in the flue gas,this review further summarizes the removal of gaseous As_(2)O_(3)by several adsorbents and the effect of temperature and the main components of the flue gas on arsenic adsorption.In addition,the mechanism of arsenic removal based on adsorption in the flue gas is discussed in depth through theoretical calculations,which is the particular focus of this review.Finally,prospects based on the present research state of arsenic removal by adsorption are proposed to provide ideas for developing effective and stable adsorbents for arsenic removal from flue gas.展开更多
The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents(DESs) on the aqueous solubility of curcumin(C...The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents(DESs) on the aqueous solubility of curcumin(CUR) via experiment and theoretical calculation. Choline chloride-based DESs with polyols 1,2-propanediol(1,2-PDO), 1,3-propanediol, ethylene glycol, and glycerol as hydrogen bond donors were prepared and used as co-solvents. The CUR aqueous solubility increased with increasing the DESs content at temperature of 303.15-318.15 K, especially in aqueous ChCl/1,2-PDO(mole ratio 1:4) solutions. The positive apparent molar volume values and reduced density gradient analysis confirmed the existence of strong interactions between CUR and solvent. The van der Waals interactions and hydrogen bonding coexisted in DESs monomer retained the stability of DESs structure after introducing CUR. Moreover,the lower interaction energy of DESs…CUR system than that of the counterpart DESs further proved the strong interaction between CUR and DESs. The lowest interaction energy of ChCl/1,2-PDO…CUR system indicated that this system was the most stable and ChCl/1,2-PDO was promising for CUR dissolution.This work provides efficient solvents for utilizing curcumin, contributing to a deep insight into the interactions between DES and CUR at the molecular level, and the role of DESs on enhancing drugs solubility.展开更多
Solvothermal reactions of Ca(NO), Sr(NO)with thiophene-2,5-dicarboxylic in DMF afforded two new inorganic-organic hybrid frameworks, [M(TDC)(DMF)]n(M = Ca(1), Sr(2), TDC = thiophene-2,5-dicarboxylic, DMF = N,N?-dimeth...Solvothermal reactions of Ca(NO), Sr(NO)with thiophene-2,5-dicarboxylic in DMF afforded two new inorganic-organic hybrid frameworks, [M(TDC)(DMF)]n(M = Ca(1), Sr(2), TDC = thiophene-2,5-dicarboxylic, DMF = N,N?-dimethylformamide), which have been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis and IR spectra. Both compounds feature three-dimensional(3D) frameworks based on the versatile coordinated modes(μ-η~2:η~2, μ-η~2:η~1, μ-η~2:η~1) of carboxylic groups in tdc ligands. C–H···S hydrogen bonds and C–H···π interactions contribute to the stabilization of the structures. They exhibit weaker packing force compared with their literature isomers. Consequently, blue and blue/green luminescence of two compounds has been observed. Their luminescence mechanism can be ascribed to ligand-to-metal charge transfer(LMCT) compared with the ligand-centered luminescence in their isomers. Electronic structural calculations illustrate that under the condition of weaker packing forces, larger gaps can be achieved, which facilitate the LMCT. This work suggests that the introduction of S-heteroatom can result in more electrons rich in the metal centers, thus giving rise to metal-involved luminescence.展开更多
Polymer‐stabilized Au nano clusters （NCs） with mean diameters of 2–10 nm exhibit unique catalytic properties. Several studies have shown that the key factors affecting the catalytic activity of poly‐mer‐stabiliz...Polymer‐stabilized Au nano clusters （NCs） with mean diameters of 2–10 nm exhibit unique catalytic properties. Several studies have shown that the key factors affecting the catalytic activity of poly‐mer‐stabilized Au NCs are control of the Au NC size, appropriate selection of polymers and optimi‐zation of the reaction conditions. This is because polymer‐stabilized Au NCs exhibit a clear size effect in several catalytic reactions, and the catalytic activity differs with the type of polymer used and the reaction conditions. In order to elucidate the reason underlying the catalytic activity of the polymer‐stabilized Au NCs, much attention is being devoted to the interplay of theoretical calcula‐tions and experiments in catalysis by polymer stabilized Au NCs. The present article mainly summa‐rizes our progress in understanding this interplay in polymer‐stabilized Au NC catalysis.展开更多
This study investigates the intersystem crossing(ISC)mechanism in donor-acceptor(D-A)type distyryl-BODIPY photosensitizers,including previously reported M1(benzene donor),M2,M3(phenothiazine donors),and newly predicte...This study investigates the intersystem crossing(ISC)mechanism in donor-acceptor(D-A)type distyryl-BODIPY photosensitizers,including previously reported M1(benzene donor),M2,M3(phenothiazine donors),and newly predicted M4(triphenylamine donor),M5-M7(nitrogen-containing aliphatic rings with thiophene donors).Using computational chemistry,we analyzed their geometric configurations,spectral properties,spin-orbit coupling,and electron-hole orbitals.We found that S_(2) is a charge transfer singlet state(^(1)CT),T2is a locally excited triplet state(^(3)LE),and the S_(2)→T_(2)transition is the main ISC pathway in M2-M7,following the ^(1)CT→^(3)LE mechanism.M5-M7 show near-vertical dihedral angles between donor and acceptor in the S_(2) state relative to M2-M4,facilitating charge transfer.The strain energies in the nitrogen-containing rings of M5-M7 affect oxidation potentials and ISC.M5,with the highest strain energy,shows the lowest oxidation potential,smaller△_(ES2-T2),highest SOC,and fastest kisc,making it the most efficient predicted singlet oxygen producer.This research clarifies the structure-performance relationships of near-infrared D-A type distyryl-BODIPY photosensitizers and provides a theoretical foundation for developing heavy-atom-free photosensitizers with tuned fluorescence quantum yield and singlet oxygen quantum yield.展开更多
It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization appli...It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization applications of nano gold catalysts. In this work, some theoretical works on CO adsorp‐tion, O2 adsorption, atomic oxygen adsorption, formation of surface gold oxide films, reaction mechanisms of CO oxidation involving O2 reaction with CO and O2 dissociation before reacting with CO on gold surfaces and Au/metal oxide were summarized, and the influences of coordination number, charge transfer and relativity of gold on CO oxidation reaction were briefly reviewed. It was found that CO reaction mechanism depended on the systems with or without oxide and the strong relativistic effects might play an important role in CO oxidation reaction on gold catalysts. In particular, the relativistic effects are related to the unique behaviors of CO adsorption, O adsorption, O2 activation on gold surfaces, effects of coordination number and the wide gap between the chem‐ical inertness of bulk gold and high catalytic activity of nano gold. The present work helps us to understand the CO oxidation reaction mechanism on gold catalysts and the influence of relativistic effects on gold catalysis.展开更多
The use of a shaped liner driven by electromagnetic force is a new means of forming jets. To study the mechanism of jet formation driven by electromagnetic force, we considered the current skin effect and the characte...The use of a shaped liner driven by electromagnetic force is a new means of forming jets. To study the mechanism of jet formation driven by electromagnetic force, we considered the current skin effect and the characteristics of electromagnetic loading and established a coupling model of "ElectriceMagnetic eForce" and the theoretical model of jet formation under electromagnetic force. The jet formation and penetration of conical and trumpet liners have been calculated. Then, a numerical simulation of liner collapse under electromagnetic force, jet generation, and the stretching motion were performed using an ANSYS multiphysics processor. The calculated jet velocity, jet shape, and depth of penetration were consistent with the experimental results, with a relative error of less than 10%. In addition, we calculated the jet formation of different curvature trumpet liners driven by the same loading condition and obtained the influence rule of the curvature of the liner on jet formation. Results show that the theoretical model and the ANSYS multiphysics numerical method can effectively calculate the jet formation of liners driven by electromagnetic force, and in a certain range, the greater the curvature of the liner is, the greater the jet velocity is.展开更多
To further verify the feasibility of newly designed reinforced bamboo scrimber composite(RBSC)beams used in building construction,the bonding properties between steel bar and bamboo scrimber were investigated by anti-...To further verify the feasibility of newly designed reinforced bamboo scrimber composite(RBSC)beams used in building construction,the bonding properties between steel bar and bamboo scrimber were investigated by anti-pulling tests.Results indicated that the anti-pulling mechanical properties were significantly correlated to the diameter,thread form and buried depth of steel bar,forming density of bamboo scrimber as well as the heat treatment of bamboo bundle.There were two failure modes for anti-pulling tests:the tensile fracture and pulling out of steel bar.Both the ultimate load and average shear strength of anti-pulling specimen could be increased greatly with the ribbed bar,high forming density of bamboo scrimber and un-heated bamboo bundle.Furthermore,a theoretical calculation model of the bonding interface between steel bar and bamboo scrimber was developed.Based on the theoretical calculation model,the change laws of normal stress of bamboo scrimber,and shear stress of glue layer along the buried depth of steel bar were revealed.This study is beneficial for the safety application of RBSC beams in building construction.展开更多
Methyl 2-furoate(FAME2)is a model for the potential renewable biofuel of dimethyl furan-2,5-dicarboxylate,with the development of its new synthesis method.The potential energy surfaces of H-abstractions and OHaddition...Methyl 2-furoate(FAME2)is a model for the potential renewable biofuel of dimethyl furan-2,5-dicarboxylate,with the development of its new synthesis method.The potential energy surfaces of H-abstractions and OHadditions between FAME2 and hydroxyl radical(OH)were studied using CCSD(T)/CBS//M062X/ccpVTZ.The subsequent isomerization and decomposition reactions were also determined for the primary radicals produced.The results showed that H-abstraction on the branched methyl group was the dominant channel and that the OH-addition reactions on the furan ring had a significant pressure dependency.The rate coefficients presented here provide important kinetic data to support future improvement of the combustion mechanism of FAME2,and present a sound basis for further research into practical fuels.展开更多
Trans-sobrerol （Sob） and 8-p-menthen-1,2-diol （Limo-diol） are the primary products in the atmospheric oxidation of α-pinene and limonene, respectively. Because of their low volatility, they associate more likely ...Trans-sobrerol （Sob） and 8-p-menthen-1,2-diol （Limo-diol） are the primary products in the atmospheric oxidation of α-pinene and limonene, respectively. Because of their low volatility, they associate more likely to the liquid particles in the atmosphere, where they are subject to the aqueous phase oxidation by the atmospheric oxidants. In this work, through experimental and theoretical study, we first provide the rate constants of Sob and Limo-diol reacting with hydroxyl radical （.OH） in aqueous solution at room temperature of 3044-3 K and 1 atm pressure, which are （3.05±0.5）×10 9 and （4.57±0.2）×10 9 L/（mol.s）, respectively. Quantum chemistry calculations have also been employed to demonstrate the solvent effect on the rate constants in aqueous phase and the calculated results agree well with the measurements. Some reaction products have been identified based on liquid chromatography combined with mass spectroscopy and theoretical calculations.展开更多
The deep understanding of 4f-correlated electron motion behavior is experimentally limited due to similar physicochemical properties of rare earth elements(REEs).While the solvent extraction behavior originating from ...The deep understanding of 4f-correlated electron motion behavior is experimentally limited due to similar physicochemical properties of rare earth elements(REEs).While the solvent extraction behavior originating from the continuous occupation of 4f electrons along the lanthanide family provides a particular platform to probe the 4f electrons motion behavior and its correlations to their versatile functions.Herein,the complexation between REEs and the prototypical extractant of diethyl phosphoric acid(DEP)was substantially studied based on quantum mechanical calculation.The results firstly show that the average bond lengths between Ln and six coordinated oxygen atoms are consistent with lanthanide contraction phenomenon,and gadolinium break effect is also obviously observed.Secondly,the"tetrad effect"is figured out based on the subtle discrepancy of 4f electrons occupation,namely La-Nd,Sm-Eu,Gd-Dy and Ho-Lu.Specifically,the main composition is 4f5d6p for La-Nd,while the discrepancy is due to the increasing electrons in the 5d shell,while it is 4f5d for Pm-Eu.For Gd-Dy,their 4f orbitals accept little electrons and the donating electrons flow into 6s5d subshells due to the half-filled stability and the enhancement of shielding effect.The electrons donate into 5d6p subshells due to multiply electrons occupation of 4f orbitals for Ho-Lu.These detailed analyses obviously clarify the"tetrad effect"along the lanthanide family due to the different variation of 4f orbital occupation.It is expected that these microscopic understandings provide important guidance for the separation of REEs and the design of new extractants.展开更多
基金supported by the Major State Basic Research Development Program of China(G1999043309)the National Natural Science Foundation of China grant 49973001.
文摘Based on a set of equations established by Duan et al. (1992, 1996) for a geofluid system H2O-CO2-CH4(-N2), a formula is obtained to calculate the heat changes. Combining the geological T-P conditions (geothermal gradients and lithostatic and hydrostatic pressures), the enthalpy of some typical geofluids is figured out. Then the principles of heat transfer of deep-derived supercritical fluids are discussed. The result shows that deep-derived geofluids can bring a large amount of thermal heat and release most heat to the shallow surroundings as they move up, because the molar enthalpies vary very greatly from the deep to shallow, increasing with the increases of T and P. Generally, more than tens of kilojoules heat per molar can be released. Furthermore, the molar enthalpy is affected by the compositions of the geofluids, and the molar enthalpy of CO2, CH4, or N2 is greater than that of H2O, being twice, more than twice, and about 140% of H2O, respectively. Finally, a case study is conducted by investigating a source rock sequence affected hydrothermally by magmatic fluids in the Huimin depression of Shengli Oilfield. The thermal heat calculated theoretically of the fluids related to a diabase intrusion is quite large, which can increase the temperature near the diabase to about 300℃, and that can, to some extent, account for the abnormal rise of the vitrinite reflectance, with the highest of about 3.8% (Ro).
基金Supported by the Science and Technology Development Projects of Jilin Province(No.20150101007JC)
文摘A new one-dimensional Mg（Ⅱ） coordination polymer, [Mg（L）（phen）（H2O）]（1）, has been hydrothermally synthesized by using 3,5-dinitro-salicylic acid（H2L） and 1,10-phenanthroline（phen）. It crystallizes in monoclinic, space group C2/c with a = 33.038（7）, b = 6.6481（13）, c = 22.750（5） A, β = 126.99（3）°, V = 3991.1（14） A3, Z = 8, C19H12 MgN4O8, Mr = 448.64, Dc = 1.493 g/cm3, F（000） = 1840, μ（Mo Ka） = 0.146 mm-1, R = 0.0559 and w R = 0.0975. In 1, each L anion bridges two Mg（Ⅱ） atoms to give one-dimensional zigzag chains with the Mg…Mg separation of 5.34 ？, which are extended by π-π stacking interactions between 1,10-phenanthroline ligands into a two-dimensional supramolecular layer. Moreover, the O–H…O hydrogen-bonding interactions further stabilize the layer structure of 1. The luminescent property was also studied for 1 in solid state at room temperature. In addition, natural bond orbital（NBO） analysis was performed by the B3LYP/LANL2 DZ method in Gaussian 09 Program. The calculation results show obvious covalent interaction between the coordinated atoms and Mg（Ⅱ） ion.
基金supported by the National Natural Science Foundation of China(No.21576112)the Project of Department of Science&Technology of Jilin Province(No.20180623042TC)+3 种基金Natural Science Foundation Project of Jilin Province(No.20170520143JH)the China Postdoctoral Science Foundation(No.2017M611732)the Science and Technology Research Projects of the Education Department of Jilin Province(No.JJKH20180791KJ)the Science and Technology Development Plan of Siping City(2017056)
文摘A novel complex,[Mn(2-NCP)(H2BTC)(H2O)]n(1,1,3,5-H3BTC=1,3,5-benzenetricarboxylic acid,2-HNCP=2-(2-carboxyphenyl)-1 H-imidazo(4,5-f)-(1,10)phenanthroline),was hydrothermally synthesized and structurally characterized by elemental analysis,IR,XRD and single-crystal X-ray diffraction.Structural analyses reveal that complex 1 exhibits a(6,6)-connected topology network with a Schl?fli symbol of(63).The adjacent 2 D layers are further stacked via strong hydrogen-bonding interactions,giving a 3 D supramolecular framework.In addition,the structure of complex 1 was calculated by the B3LYP/LANL2 DZ method by Gaussian program.The results from natural bond orbital(NBO)analysis shows obvious covalent interaction between the coordinated atoms and Mn(Ⅱ)ion.
基金Supported by the National Natural Science Foundation of China(No.21607051)
文摘A new Cd（Ⅱ） coordination polymer, [Cd（L）2（H2O）]n（1）, has been hydrothermally synthesized by using 1-（1 H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）naphthalen-2-ol（HL）,(3-（4-（carboxymethoxy）phenyl）acrylic acid and Cd（NO3）·4 H2O. It crystallizes in monoclinic, space group P21/c with a = 19.41（2）, b = 11.078（12）, c = 20.09（2） ?, β = 116.824（17）o, V = 3855（7） ?3, Z = 4, C46H28CdN8O3, Mr = 853.17, Dc = 1.470 g/cm3, F（000） = 1728, μ（Mo Ka） = 0.621 mm-1, R = 0.0338 and wR = 0.0890. 1 shows a one-dimensional（1 D） zigzag chain structure. The neighboring chains are extended into a two-dimensional（2 D） layer structure by π-π interactions between adjacent L ligands. In addition, Natural Bond Orbital（NBO） analysis was performed by the B3LYP/LANL2DZ method in Gaussian 09 Program. The calculation results show the obvious covalent interaction between the coordinated atoms and Cd（Ⅱ） ion.
基金Financial support from the National Natural Science Foundation of China(Nos.21172121,21475065)the Fundamental Research Funds for the Central Universities
文摘Combining with electrospray ionization(ESI)mass spectrometry,infrared photodissociation(IRPD)spectroscopy is a powerful method to study structures of cluster ions in the gas phase.In this paper,infrared photodissociation spectrum of Pro_4H~+in the range of 2700–3600 cm 1was obtained experimentally.Both theoretically predicted spectra of the two most stable isomers of Pro4^(-1)and Pro4^(-2)obtained at the level of M062X/6-31+G(d,p)are in good consistent with the experimental results.The two isomers have similar structures and close energies.Both of them only consist of zwitterionic units,indicating the strong salt-bridged interactions inside the clusters.And the calculated collision cross section(ccs)of Pro4-1 is found to be very close to the experimental result previously reported.
基金financial support from the National Natural Science Foundation of China(21676036)the Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0580)the Graduate Research and Innovation Foundation of Chongqing(CYS-20040)。
文摘As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is summarized.Specifically,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical calculations.The applications of these materials as electrodes are then featured for various SCs.Finally,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.
基金Supported by the Postgraduate Foundation of Taishan University (No. Y07-2-16)
文摘The title compound [2-（2,6-dioxacyclohexyl）-5-methoxylphenols]2 was synthesized by the reaction of 2-hydroxyl-3-methoxylbenzaldehyde and 1,3-propanediol in the presence of DMF-DMS adduct and characterized by IR spectrum, UV-Vis spectrum and X-ray crystallography. The title compound belongs to monoclinic, space group P21 with a = 9.8967（10）, b = 8.2240（9）, c = 13.3654（14） A^°, β= 90.016（2）°, C11H14O4, Mr = 210.22, V = 1087.8（2）A^°3, Z = 4, Dc = 1.284 Mg/m^3, F（000） = 448,μ = 0.098 mm^-1, the final R = 0.0300 and wR = 0.0761 for 2070 observed reflections with I 〉 2σ（I）. The molecules are connected via intermolecular O-H…O hydrogen bonds into a 2D network structure. Moreover, theoretical investigations of the title compound with HF/6-31G（d） method were performed, and its stability, frontier molecular orbital composition and Mulliken charge distribution were also discussed. The compound is a bis-molecule. The two molecules stay together and could not be separated. Two crystallographically independent molecules exist in an asymmetric unit. The bond lengths and bond angles of the two molecules are slightly different with each other.
基金supported by the National Natural Science Foundation of China(No.21406085)
文摘A coordination polymer [Mn2（ctpt）2（aic）2]n （1, ctpt = 2-（4-chloro-phenyl）-1H- 1,3,7,8-tetraaza-cyclopenta[l]phenanthrene, H2aic = 5-amino-isophthalic acid） was hydrother- mally designed and synthesized. The complex was characterized by elemental analysis, IR spectro- scopy, single-crystal X-ray diffraction, and thermogravimetric analysis （TGA）. Each Mn（II） atom is linked by the aic ligands with neighbor Mn（II） atoms, forming an infinite one-dimensional （1D） double-chain structure. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 18.23（1）, b = 17.27（1）, c = 16.69（1） ？, V = 4814.0（7） ？3, C27H16ClMnN5O4, Mr = 564.84, Dc = 1.559 g/cm3, μ（MoKα） = 0.706 mm-1, F（000） = 2296, Z = 8, the final R = 0.0487 and wR = 0.1269 （I 〉 2σ（I））. The 1D chain structure of complex 1 is stable below 458 ℃. In addition, to elucidate the essential electronic characters of this complex, theoretical calculation analysis of 1 was performed by the PBE0/LANL2DZ method in Gaussian 03 Program.
基金Basic Research Foundation for Natural Science of Henan University (No. 04YBRW053)
文摘The title adduct imidazolium 3,5-dinitrobenzoate has been synthesized in aqueous solution and characterized by elemental analyses, IR spectrum and X-ray crystallography. The title compound belongs to monoclinic, space group P21/n with a = 7.5540（9）, b = 21.333（2）, c = 7.7823（9）A, β = 102.741（2）^o, C10H8N4O6, Mr = 280.20, V= 1223.3（2）A^3, Z = 4, Dc = 1.521 g/cm^3, F（000） = 576, p = 0.129 mm^-1, the final R = 0.0433 and wR = 0.1092 for 2001 observed reflections with I 〉 2a（I）. The structural analysis indicates the component ions are linked by N-H...O hydrogen bonds into an infinite one-dimensional C2^2 （8） chain parallel to the [1 0 -1] direction. Moreover, the theoretical investigations of the title compound with HF/6-31G（d） method were performed, and its stability, frontier molecular orbital composition and Mulliken charge distribution were also discussed.
基金supported by the National Science Fund for Excellent Young Scholars of China (No.52022111)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.52121004)+1 种基金the Hunan High Tech Industry Science and Technology Innovation Leading Plan Project (No.2020SK2006)the Huxiang Youth Talent Support Program (No.2020RC3012)。
文摘Because of its high mobility and difficult capture,gaseous arsenic pollution control has become the focus of arsenic pollution control.It mainly exists in the form of highly toxic As_(2)O_(3)in the flue gas.Therefore,removing gaseous As_(2)O_(3)from flue gas is of great practical significance for arsenic pollution control.Stabilizing gaseous As_(2)O_(3)on the surface of adsorbents by physical or chemical adsorption is an effective way to reduce the content of arsenic in the flue gas and alleviate arsenic pollution.Over the past few decades,various adsorbents have been developed to capture gaseous As_(2)O_(3)in the flue gas,and their adsorption mechanisms have been studied in detail.Thus,it is necessary to review the strategies of arsenic removal from flue gas by adsorption,which can inspire further research.Based on summarizing the morphological distribution of gaseous As_(2)O_(3)in the flue gas,this review further summarizes the removal of gaseous As_(2)O_(3)by several adsorbents and the effect of temperature and the main components of the flue gas on arsenic adsorption.In addition,the mechanism of arsenic removal based on adsorption in the flue gas is discussed in depth through theoretical calculations,which is the particular focus of this review.Finally,prospects based on the present research state of arsenic removal by adsorption are proposed to provide ideas for developing effective and stable adsorbents for arsenic removal from flue gas.
基金financially supported by the National Natural Science Foundation of China (21905069, U21A20307, 22208073)the Shenzhen Science and Technology Innovation Committee (ZDSYS20190902093220279, KQTD20170809110344233, GXWD20201230155427003-20200821181245001, GXWD20201230155427003-202008211 81809001, ZX20200151)the Department of Science and Technology of Guangdong Province (2020A1515110879)。
文摘The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents(DESs) on the aqueous solubility of curcumin(CUR) via experiment and theoretical calculation. Choline chloride-based DESs with polyols 1,2-propanediol(1,2-PDO), 1,3-propanediol, ethylene glycol, and glycerol as hydrogen bond donors were prepared and used as co-solvents. The CUR aqueous solubility increased with increasing the DESs content at temperature of 303.15-318.15 K, especially in aqueous ChCl/1,2-PDO(mole ratio 1:4) solutions. The positive apparent molar volume values and reduced density gradient analysis confirmed the existence of strong interactions between CUR and solvent. The van der Waals interactions and hydrogen bonding coexisted in DESs monomer retained the stability of DESs structure after introducing CUR. Moreover,the lower interaction energy of DESs…CUR system than that of the counterpart DESs further proved the strong interaction between CUR and DESs. The lowest interaction energy of ChCl/1,2-PDO…CUR system indicated that this system was the most stable and ChCl/1,2-PDO was promising for CUR dissolution.This work provides efficient solvents for utilizing curcumin, contributing to a deep insight into the interactions between DES and CUR at the molecular level, and the role of DESs on enhancing drugs solubility.
基金supported by the Science and Technology Funding Project of Fujian Provincial Department of Transportation(No.201337)
文摘Solvothermal reactions of Ca(NO), Sr(NO)with thiophene-2,5-dicarboxylic in DMF afforded two new inorganic-organic hybrid frameworks, [M(TDC)(DMF)]n(M = Ca(1), Sr(2), TDC = thiophene-2,5-dicarboxylic, DMF = N,N?-dimethylformamide), which have been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis and IR spectra. Both compounds feature three-dimensional(3D) frameworks based on the versatile coordinated modes(μ-η~2:η~2, μ-η~2:η~1, μ-η~2:η~1) of carboxylic groups in tdc ligands. C–H···S hydrogen bonds and C–H···π interactions contribute to the stabilization of the structures. They exhibit weaker packing force compared with their literature isomers. Consequently, blue and blue/green luminescence of two compounds has been observed. Their luminescence mechanism can be ascribed to ligand-to-metal charge transfer(LMCT) compared with the ligand-centered luminescence in their isomers. Electronic structural calculations illustrate that under the condition of weaker packing forces, larger gaps can be achieved, which facilitate the LMCT. This work suggests that the introduction of S-heteroatom can result in more electrons rich in the metal centers, thus giving rise to metal-involved luminescence.
基金supported by Japan Science and Technology Agency (JST)Advanced Low Carbon Technology Research and Development Program (ALCA)Core Research for Evolutional Science and Technology (CREST)
文摘Polymer‐stabilized Au nano clusters （NCs） with mean diameters of 2–10 nm exhibit unique catalytic properties. Several studies have shown that the key factors affecting the catalytic activity of poly‐mer‐stabilized Au NCs are control of the Au NC size, appropriate selection of polymers and optimi‐zation of the reaction conditions. This is because polymer‐stabilized Au NCs exhibit a clear size effect in several catalytic reactions, and the catalytic activity differs with the type of polymer used and the reaction conditions. In order to elucidate the reason underlying the catalytic activity of the polymer‐stabilized Au NCs, much attention is being devoted to the interplay of theoretical calcula‐tions and experiments in catalysis by polymer stabilized Au NCs. The present article mainly summa‐rizes our progress in understanding this interplay in polymer‐stabilized Au NC catalysis.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.DUT20RC(3)076)Natural Science Foundation of Liaoning Province(No.2020-MS293)。
文摘This study investigates the intersystem crossing(ISC)mechanism in donor-acceptor(D-A)type distyryl-BODIPY photosensitizers,including previously reported M1(benzene donor),M2,M3(phenothiazine donors),and newly predicted M4(triphenylamine donor),M5-M7(nitrogen-containing aliphatic rings with thiophene donors).Using computational chemistry,we analyzed their geometric configurations,spectral properties,spin-orbit coupling,and electron-hole orbitals.We found that S_(2) is a charge transfer singlet state(^(1)CT),T2is a locally excited triplet state(^(3)LE),and the S_(2)→T_(2)transition is the main ISC pathway in M2-M7,following the ^(1)CT→^(3)LE mechanism.M5-M7 show near-vertical dihedral angles between donor and acceptor in the S_(2) state relative to M2-M4,facilitating charge transfer.The strain energies in the nitrogen-containing rings of M5-M7 affect oxidation potentials and ISC.M5,with the highest strain energy,shows the lowest oxidation potential,smaller△_(ES2-T2),highest SOC,and fastest kisc,making it the most efficient predicted singlet oxygen producer.This research clarifies the structure-performance relationships of near-infrared D-A type distyryl-BODIPY photosensitizers and provides a theoretical foundation for developing heavy-atom-free photosensitizers with tuned fluorescence quantum yield and singlet oxygen quantum yield.
基金supported by the National Natural Science Foundation of China (21103165)
文摘It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization applications of nano gold catalysts. In this work, some theoretical works on CO adsorp‐tion, O2 adsorption, atomic oxygen adsorption, formation of surface gold oxide films, reaction mechanisms of CO oxidation involving O2 reaction with CO and O2 dissociation before reacting with CO on gold surfaces and Au/metal oxide were summarized, and the influences of coordination number, charge transfer and relativity of gold on CO oxidation reaction were briefly reviewed. It was found that CO reaction mechanism depended on the systems with or without oxide and the strong relativistic effects might play an important role in CO oxidation reaction on gold catalysts. In particular, the relativistic effects are related to the unique behaviors of CO adsorption, O adsorption, O2 activation on gold surfaces, effects of coordination number and the wide gap between the chem‐ical inertness of bulk gold and high catalytic activity of nano gold. The present work helps us to understand the CO oxidation reaction mechanism on gold catalysts and the influence of relativistic effects on gold catalysis.
基金supported by the Natural Science Funds for Distinguished Young Scholar (Grant No. 11602110)Jiangsu Province Graduate Research and Practice Innovation Program (No.KY CX180471)。
文摘The use of a shaped liner driven by electromagnetic force is a new means of forming jets. To study the mechanism of jet formation driven by electromagnetic force, we considered the current skin effect and the characteristics of electromagnetic loading and established a coupling model of "ElectriceMagnetic eForce" and the theoretical model of jet formation under electromagnetic force. The jet formation and penetration of conical and trumpet liners have been calculated. Then, a numerical simulation of liner collapse under electromagnetic force, jet generation, and the stretching motion were performed using an ANSYS multiphysics processor. The calculated jet velocity, jet shape, and depth of penetration were consistent with the experimental results, with a relative error of less than 10%. In addition, we calculated the jet formation of different curvature trumpet liners driven by the same loading condition and obtained the influence rule of the curvature of the liner on jet formation. Results show that the theoretical model and the ANSYS multiphysics numerical method can effectively calculate the jet formation of liners driven by electromagnetic force, and in a certain range, the greater the curvature of the liner is, the greater the jet velocity is.
基金supported by the National Key Research and Development Program of China(2016YFC0701505).
文摘To further verify the feasibility of newly designed reinforced bamboo scrimber composite(RBSC)beams used in building construction,the bonding properties between steel bar and bamboo scrimber were investigated by anti-pulling tests.Results indicated that the anti-pulling mechanical properties were significantly correlated to the diameter,thread form and buried depth of steel bar,forming density of bamboo scrimber as well as the heat treatment of bamboo bundle.There were two failure modes for anti-pulling tests:the tensile fracture and pulling out of steel bar.Both the ultimate load and average shear strength of anti-pulling specimen could be increased greatly with the ribbed bar,high forming density of bamboo scrimber and un-heated bamboo bundle.Furthermore,a theoretical calculation model of the bonding interface between steel bar and bamboo scrimber was developed.Based on the theoretical calculation model,the change laws of normal stress of bamboo scrimber,and shear stress of glue layer along the buried depth of steel bar were revealed.This study is beneficial for the safety application of RBSC beams in building construction.
基金This work was supported by the National Natural Science Foundation of China(No.51776045,No.51676176 and No.51976207)the Project was also sponsored by the Scientific Research Foundation of Guangxi University(No.XGZ170074)the Foundation of State Key Laboratory of Coal Combustion(No.FSKLCCA1908).The numerical calculations in this work were performed on the supercomputing system in the Supercomputing Center of the University of Science and Technology of China.
文摘Methyl 2-furoate(FAME2)is a model for the potential renewable biofuel of dimethyl furan-2,5-dicarboxylate,with the development of its new synthesis method.The potential energy surfaces of H-abstractions and OHadditions between FAME2 and hydroxyl radical(OH)were studied using CCSD(T)/CBS//M062X/ccpVTZ.The subsequent isomerization and decomposition reactions were also determined for the primary radicals produced.The results showed that H-abstraction on the branched methyl group was the dominant channel and that the OH-addition reactions on the furan ring had a significant pressure dependency.The rate coefficients presented here provide important kinetic data to support future improvement of the combustion mechanism of FAME2,and present a sound basis for further research into practical fuels.
基金This work was supported by the National Natural Science Foundation of China （No.21177041 and No.21107026）, the Fundamental Research Funds for the Central Universities （No.2013ZZ0073）, and the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry.
文摘Trans-sobrerol （Sob） and 8-p-menthen-1,2-diol （Limo-diol） are the primary products in the atmospheric oxidation of α-pinene and limonene, respectively. Because of their low volatility, they associate more likely to the liquid particles in the atmosphere, where they are subject to the aqueous phase oxidation by the atmospheric oxidants. In this work, through experimental and theoretical study, we first provide the rate constants of Sob and Limo-diol reacting with hydroxyl radical （.OH） in aqueous solution at room temperature of 3044-3 K and 1 atm pressure, which are （3.05±0.5）×10 9 and （4.57±0.2）×10 9 L/（mol.s）, respectively. Quantum chemistry calculations have also been employed to demonstrate the solvent effect on the rate constants in aqueous phase and the calculated results agree well with the measurements. Some reaction products have been identified based on liquid chromatography combined with mass spectroscopy and theoretical calculations.
基金Project supported by the National Key Research and Development Project of China(2019YFC0605003)the StrategicPriority Research Program of Chinese Academy of Sciences(XDA02030100)。
文摘The deep understanding of 4f-correlated electron motion behavior is experimentally limited due to similar physicochemical properties of rare earth elements(REEs).While the solvent extraction behavior originating from the continuous occupation of 4f electrons along the lanthanide family provides a particular platform to probe the 4f electrons motion behavior and its correlations to their versatile functions.Herein,the complexation between REEs and the prototypical extractant of diethyl phosphoric acid(DEP)was substantially studied based on quantum mechanical calculation.The results firstly show that the average bond lengths between Ln and six coordinated oxygen atoms are consistent with lanthanide contraction phenomenon,and gadolinium break effect is also obviously observed.Secondly,the"tetrad effect"is figured out based on the subtle discrepancy of 4f electrons occupation,namely La-Nd,Sm-Eu,Gd-Dy and Ho-Lu.Specifically,the main composition is 4f5d6p for La-Nd,while the discrepancy is due to the increasing electrons in the 5d shell,while it is 4f5d for Pm-Eu.For Gd-Dy,their 4f orbitals accept little electrons and the donating electrons flow into 6s5d subshells due to the half-filled stability and the enhancement of shielding effect.The electrons donate into 5d6p subshells due to multiply electrons occupation of 4f orbitals for Ho-Lu.These detailed analyses obviously clarify the"tetrad effect"along the lanthanide family due to the different variation of 4f orbital occupation.It is expected that these microscopic understandings provide important guidance for the separation of REEs and the design of new extractants.
