Elementary information theory is used to model cybersecurity complexity, where the model assumes that security risk management is a binomial stochastic process. Complexity is shown to increase exponentially with the n...Elementary information theory is used to model cybersecurity complexity, where the model assumes that security risk management is a binomial stochastic process. Complexity is shown to increase exponentially with the number of vulnerabilities in combination with security risk management entropy. However, vulnerabilities can be either local or non-local, where the former is confined to networked elements and the latter results from interactions between elements. Furthermore, interactions involve multiple methods of communication, where each method can contain vulnerabilities specific to that method. Importantly, the number of possible interactions scales quadratically with the number of elements in standard network topologies. Minimizing these interactions can significantly reduce the number of vulnerabilities and the accompanying complexity. Two network configurations that yield sub-quadratic and linear scaling relations are presented.展开更多
Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron...Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.展开更多
In this article the affiliation of Jin-Ke Shen,Nai-Teng Wu,Li-Yuan Wang,Gang Jiang,Jin Li,Gui-Long Liu,Xian-Ming Liu were incorrectly given as:State Key Laboratory of Chemistry and Utilization of Carbon Based Energy R...In this article the affiliation of Jin-Ke Shen,Nai-Teng Wu,Li-Yuan Wang,Gang Jiang,Jin Li,Gui-Long Liu,Xian-Ming Liu were incorrectly given as:State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources,School of Chemical Engineering and Technology,Xinjiang University,Urumqi 830046,China.展开更多
Tin-based metal organic complexes with breakable coordination bonds,multiple active sites,and high theoretical capacity have attracted wide attentiorials for lithium-ion batteries(LIBs).However,the inferior electrical...Tin-based metal organic complexes with breakable coordination bonds,multiple active sites,and high theoretical capacity have attracted wide attentiorials for lithium-ion batteries(LIBs).However,the inferior electrical conductivity and significant volume changes have limited their electrochemical stability and practical application performance.This work proposes a universal doping strategy for the preparation of tin-phthalic acid complexes(Sn-MOF)doped with metal atoms(Al,Cr,Mn,Fe,Co,Ni,Cu,Zn).Metal atoms are uniformly dispersed within Sn-MOF for enhancing electrical conductivity and accommodating appropriate volume expansion,resulting in improved rate capability and cycling stability.Additionally,compared to a series of doped Sn-MOF,Zn-doped Sn-MOF exhibits the most exceptional electrochemical performance with a high reversible capacity of 1131 mAh·g^(-1)and stable cycling performance at a current density of 0.5 A·g^(-1),delivering a capacity of 1065 mAh·g^(-1)after 500 cycles.Zn-doping catalyzes the lithiation reaction between Sn-MOF and Li^(+),promoting their reaction kinetics during the first cycle.Furthermore,the Zn-doped Sn-MOF is inclined to form a thin and stable solid electrolyte interface film to maintain cyclic stability.展开更多
Sn-based metal organic complexes with coordination bonds,multi-active sites,and high theoretical capacity have attracted much attention as promising anodes for lithium ion batteries.However,the low electrical conducti...Sn-based metal organic complexes with coordination bonds,multi-active sites,and high theoretical capacity have attracted much attention as promising anodes for lithium ion batteries.However,the low electrical conductivity and huge volume changes restricted their electrochemical stability and practical utilization.Herein,Snbased anode with superior electrochemical performance,including a high reversible capacity of 1050.1 mAh·g^(-1)at 2 A·g^(-1)and a stable capacity of 1105.5 mAh·g^(-1)after 500 cycles at 1 A·g^(-1),was fabricated via a low-temperature calcination strategy from Sn metal organic complexes.The low-temperature calcination process regulates Sn-O bond and prevents the agglomeration of SnO_(2),generating highly dispersed SnO_(2) decorated metal organic complexes and providing sufficient active sites for ion storage.Ex situ characterizations expound that the undecomposed Sn-based metal organic complexes could be transformed into SnO_(2) during lithiation and delithiation,which enhances the electrical conductivity and induces a strong pseudo-capacitive behavior,accelerating the electrochemical kinetics;the multiple solid electrolyte interface with inflexible LiF and flexible ROCO_(2)Li buffers the volume variation of the electrode,resulting in its high electrochemical stability.This work provides a simple strategy for preparing excellent Sn-based anodes from metal organic complexes and reveals the lithium storage mechanism of the prepared Snbased anode.展开更多
Organic redox compounds are attractive cathode materials in aqueous zinc-ion batteries owing to their low cost,environmental friendliness,multiple-electron-transfer reactions,and resource sustainability.However,the re...Organic redox compounds are attractive cathode materials in aqueous zinc-ion batteries owing to their low cost,environmental friendliness,multiple-electron-transfer reactions,and resource sustainability.However,the realized energy density is constrained by the limited capacity and low voltage.Herein,copper-tetracyanoquinodimethane(CuTCNQ),an organic charge-transfer complex is evaluated as a zinc-ion battery cathode owing to the good electron acceptation ability in the cyano groups that improves the voltage output.Through electrochemical activation,electrolyte optimization,and adoption of graphene-based separator,CuTCNQ-based aqueous zinc-ion batteries deliver much improved rate performance and cycling stability with anti-self-discharge properties.The structural evolution of CuTCNQ during discharge/charge are investigated by ex situ Fourier transform infra-red(FT-IR)spectra,ex situ X-ray photoelectron spectroscopy(XPS),and in situ ultraviolet visible spectroscopy(UV-vis),revealing reversible redox reactions in both cuprous cations(Cu^(+))and organic anions(TCNQ^(x-1)),thus delivering a high voltage output of 1.0 V and excellent discharge capacity of 158 mAh g^(-1).The remarkable electrochemical performance in Zn//CuTCNQ is ascribed to the strong inductive effect of cyano groups in CuTCNQ that elevated the voltage output and the graphene-modified separator that inhibited CuTCNQ dissolution and shuttle effect in aqueous electrolytes.展开更多
Jumong is a legendary figure in Korean mythology.He is depicted as a genius archer,a brilliant mind with horses,a god who rules the rivers and the sky.Jumong is a mythical character who is believed to be of divine des...Jumong is a legendary figure in Korean mythology.He is depicted as a genius archer,a brilliant mind with horses,a god who rules the rivers and the sky.Jumong is a mythical character who is believed to be of divine descent and to possess superhuman abilities that humans cannot match.The myth of Jumong is a very competitive content that can compete on a global scale.However,in order for it to be successful,it is necessary to be able to reinterpret our mythology to suit the times and reproduce it culturally.To this end,the realistic globalization of Korean classical literature should commence with the genre of Korean mythology.This paper presents the educational significance of the Jumong myth as a teaching-learning model,via STEAM(science,technology,engineering,arts,and mathematics),on the theme of Korean mythology.As we enter the era of artificial intelligence(AI)through the 4th Industrial Revolution,the most appropriate teaching and learning method,the convergence class,will provide an opportunity for students living in modern times to discover the cultural archetypes that allow them to recognise themselves as individuals and us as a collective,and to find the roots of the myth to positively renew their identity.Furthermore,it is my hope that they will rediscover and appreciate the representative work of Korean mythology,Gojomong,the eponymous story of Goguryeo.展开更多
A rapid method is applied to analyze conjugated organic ligands bridged binuclear ruthenium complexes by electrospray ionization-tandem mass spectrometry (ESI MSn).Fragmentation pattern be discussed.
A novel Fe/Co metal organic complex nanosheet modified by 1,4-dicarboxybenzene(BDC),i.e.,FeCo@BDC,was prepared,and highly efficient removal performance for trace lead(Ⅱ)(Pb^(2+))was demonstrated in the neutral aqueou...A novel Fe/Co metal organic complex nanosheet modified by 1,4-dicarboxybenzene(BDC),i.e.,FeCo@BDC,was prepared,and highly efficient removal performance for trace lead(Ⅱ)(Pb^(2+))was demonstrated in the neutral aqueous solutions.The removal rates were higher than 95%and the adsorption was equilibrated in 15 min.The isotherms and kinetics for the adsorption Pb^(2+)by the FeCo@BDC adsorbents followed Langmuir model and pseudo-second-order model,respectively.The maximum adsorption capacity was 220.48 mg g^(-1).The FeCo@BDC adsorbents also own a prominent regeneration performance.The prominent performance of in the removal of trace Pb^(2+)makes FeCo@BDC an ideal candidate as commercial adsorbent materials.展开更多
To examine the activation of organic acids on the leaching process of ion-adsorption type rare earth ore（IRE-ore）, the leaching behavior of rare earth（RE） and zeta potential of IRE-ore were investigated in the abs...To examine the activation of organic acids on the leaching process of ion-adsorption type rare earth ore（IRE-ore）, the leaching behavior of rare earth（RE） and zeta potential of IRE-ore were investigated in the absence and presence of carboxylic acids. The results show that all the tested organic acids（acetic acid,malonic acid, citric acid, tartaric acid, succinic acid, and malic acid） can promote RE extraction. At relatively high concentrations of organic acids, the activation efficiency of organic acids on RE extraction is generally consistent with their complexation ability; whereas at their low concentrations, the change of zeta potential on the IRE-ore surface with organic acid concentration and p H has a close association with RE extraction, which indicates that organic acids can impact the surface electrical property of IREore via their adsorption/desorption, and thereby increase/decrease the affinity of RE ions to IRE-ore.Therefore the influence of organic acids on the IRE-ore surface electrical property also plays an important role in RE extraction in addition to their complexation with RE ions.展开更多
The applications of laser-induced breakdown spectroscopy(LIBS) on classifying complex natural organics are relatively limited and their accuracy still requires improvement.In this work,to study the methods on classifi...The applications of laser-induced breakdown spectroscopy(LIBS) on classifying complex natural organics are relatively limited and their accuracy still requires improvement.In this work,to study the methods on classification of complex organics,three kinds of fresh leaves were measured by LIBS.100 spectra from 100 samples of each kind of leaves were measured and then they were divided into a training set and a test set in a ratio of 7:3.Two algorithms of chemometric methods including the partial least squares discriminant analysis(PLS-DA) and principal component analysis Mahalanobis distance(PCA-MD) were used to identify these leaves.By using 23 lines from 16 elements or molecules as input data,these two methods can both classify these three kinds of leaves successfully.The classification accuracies of training sets are both up to 100% by PCA-MD and PLS-DA.The classification accuracies of the test set are 93.3% by PCA-MD and 97.8% by PLS-DA.It means that PLS-DA is better than PCA-MD in classifying plant leaves.Because the components in PLS-DA process are more suitable for classification than those in PCA-MD process.We think that this work can provide a reference for plant traceability using LIBS.展开更多
The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this...The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.展开更多
Atterberg limits and consistency indices are used for classifications of cohesive(fine-grained) soils in relation with compaction and tillage practices. They also provide information for interpreting several soil mech...Atterberg limits and consistency indices are used for classifications of cohesive(fine-grained) soils in relation with compaction and tillage practices. They also provide information for interpreting several soil mechanical and physical properties such as shear strength, compressibility, shrinkage and swelling potentials. Although, several studies have been conducted regarding the land use effects on various soil mechanical properties, little is known about the effects of land use and slope positions on Atterberg limits and consistency indices. This study was conducted to investigate the effects of land use and slope position on selected soil physical and chemical properties, Atterberg limits and consistency indices in hilly region of western Iran. Three land uses including dryland farming, irrigated farming and pasture and four slope positions(i.e., shoulder, backslope, footslope, and toeslope) were used for soil samplings. One hundred eleven soil samples were collected from the surface soil(0-10 cm). Selected physical and chemical properties, liquid limit(LL), plastic limit(PL) and shrinkage limit(SL) were measured using the standard methods; and consistency indices including plastic index(PI), friability index(FI), shrinkage index(SI) and soil activity(A=PI/clay) were calculated. The results showed that irrigated farming significantly increased organic matter content(OM) and OM/clay ratio, and decreased bulk density(ρb) and relative bulk density(ρb-rel) as a result of higher biomass production and plant residues added to the soil compared to other land uses. Except for sand content, OM, ρb, cation exchange capacity(CEC) and calcium carbonate equivalent(CCE), slope position significantly affected soil physical and chemical properties. The highest values of silt, OM/clay and CEC/clay were found in the toeslope position, predominantly induced by soil redistribution within the landscape. The use of complexed(COC)- noncomplexed organic carbon(NCOC) concept indicated that majority of the studied soils were located below the saturation line and the OM in the soils was mainly in the COC form. The LL, PI, FI and A showed significant differences among the land uses; the highest values belonged to the irrigated farming due to high biomass production and plant residues returned to the soils. Furthermore, slope position significantly affected the Atterberg limits and consistency indices except for SL. The highest values of LL, PI, SI and A were observed in the toeslope position probably because of higher OM and CEC/clay due to greater amount of expandable phyllosilicate clays. Overall, soils on the toeslope under irrigated farming with high LL and SI and low values of FI need careful tillage management to avoid soil compaction.展开更多
A novel europium complex, bi(dibenzamide) benzoate europium(Ⅲ) (Eu-DBA-B), was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium complex i...A novel europium complex, bi(dibenzamide) benzoate europium(Ⅲ) (Eu-DBA-B), was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium complex is an electroneutral complex, and it emits very strong red luminescence from (()~5D_1→()~7F_j) (j=0, 1, 2, 3, 4) transitions.展开更多
In this paper,three new polyoxometalates(POM)-based metal–organic complexes constructed from a new semi-rigid organic ligand N,N'-bis(4-pyrimidinecarboxamido)-1,2-cyclohexane(4-bpmah)H_(2)[Cu(4-bpmah)_(2)(SiMo_(1...In this paper,three new polyoxometalates(POM)-based metal–organic complexes constructed from a new semi-rigid organic ligand N,N'-bis(4-pyrimidinecarboxamido)-1,2-cyclohexane(4-bpmah)H_(2)[Cu(4-bpmah)_(2)(SiMo_(12)O_(40))(H_(2)O)_(2)]·2H_(2)O(1),H[Cu(4-bpmah)_(2)(PMo_(12)O_(4)0)(H_(2)O)_(2)]·2H_(2)O(2)and[Cu(4-bpmah)(H_(2)O)_(2)]·[Cu_(2)(TeMo_(6)O_(24))(H_(2)O)_(10)]·4H_(2)O(3)were synthesized by hydrothermal method.Single crystal X-ray analyses showed that complexes 1 and 2 were isostructural,in which the isolated Keggin-type[SiMo1_(2)O_(40)]^(4–)/[PMo_(12)O_(40)]^(3–)anions and[Cu(4-bpmah)_(2)(H_(2)O)2]^(2n+)units were expanded into 3D supramolecular structures through hydrogen bond interactions.In complex 3,the 1D[Cu(4-bpmah)(H_(2)O)_(2)]^(2n+)metal–organic chains and isolated[Cu_(2)(TeMo_(6)O_(24))(H_(2)O)_(10)]^(2n–)units were expanded into a 3D supramolecular framework by the hydrogen bond interactions.In this paper,carbon cloth working electrodes composited by the title complexes(1/CC,2/CC and 3/CC)were prepared and used as electrodes for supercapacitors.The performance of supercapacitors as well as the influence of electrolyte solution and title complexes quality load on the performance of supercapacitors were studied.Furthermore,the electrochemistry and electrocatalytic behaviors of complexes 1–3 bulk-modified carbon paste electrodes(1-CPE,2-CPE and 3-CPE)toward the reduction of KBrO_(3),KNO_(2),Cr(Ⅵ),as well as their sensing behaviors on Cr(Ⅵ)were investigated.展开更多
Based on the strong fluorescence and the highly thermal stability of sodium tris (pyridine dicarboxylato) europate (Na 3Eu(DPA) 3), polymethyl methacrylate (PMMA) composite material incorporated with the complex, P...Based on the strong fluorescence and the highly thermal stability of sodium tris (pyridine dicarboxylato) europate (Na 3Eu(DPA) 3), polymethyl methacrylate (PMMA) composite material incorporated with the complex, PMMA: Na 3Eu(DPA) 3, was prepared at 250 ℃. The fluorescence behavior of PMMA: Na 3Eu(DPA) 3 material was examined. The results show that the composite material keeps the luminescent characteristics of the Eu 3+ chelate after PMMA is incorporated with Na 3Eu(DPA) 3, and strong orange-red emission of the composite was observed. The fluorescence intensity of the composite material increases with the increase of the weight ratio of Na 3Eu(DPA) 3 to PMMA, but the relationship is not linear.展开更多
The reaction of MeCpLnCl·2LiCl·nTHF with 2 equivalent of LiNPh_2 in THF,hexane and toluene mixture solution gives the new complex[Li(DME)_2][(η~5-MeCp)Ln(NPh_2)_3](Ln=La,Pr,Nd)by extraction with DME.They ha...The reaction of MeCpLnCl·2LiCl·nTHF with 2 equivalent of LiNPh_2 in THF,hexane and toluene mixture solution gives the new complex[Li(DME)_2][(η~5-MeCp)Ln(NPh_2)_3](Ln=La,Pr,Nd)by extraction with DME.They have been characterized by elemental analysis,IR and NMR.The La complex crystallizes in the monoclinic space group P2_1/c with α=1.8335(6)nm,b=1.6576(5)nm,c=1.7461(6)nm, β=96.04°,V=5.277 nm^2,Z=4,D_c=1.26g·cm^(-3),R=0.057 and R_w=0.048(1≥2.5σ(I_o))for 3378 reflec- tions.The complex consists of a pair of a cation and an anion.La^(3+) is coordinated by one methylcyclopentadienyl and three diphenylamidos to form six-coordinate pseudotetrahedron with the mean Ln-N and La-C(ring)distances of 0.2459(8)and 0.2843(11)nm,respectively.展开更多
Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of ...Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The influence of the glass contents on the structure of the glass and the erwrgy level of the doped Tb （Ⅲ） ions was analyzed by the emission spectra and IR spectra. The effect of B2O3 on the photolumirwscence properties of rare earth organic complex in silica- based glass was investigated. The IR spectra indicate that the in situ sylthesized rare earth complex molecule was confined to the micropores of the bost and the vibration of the ligands was frozen. When B2O3 was added into the silica host gel, B2O3 had little influence on the noncrystallirw structure of the glass, and BO3 triangle, which had a layer structure different from the silica framework, could form. So the silica network became more inhomogenous, and the luminescence of terbium complexes was quenched with the increase of the B2O23 amount.展开更多
Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and...Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.展开更多
[Pb（HL）（phen）]n （1） and [Cd3L2（phen）]n （2）, where phen = 1,10-phenanthroline and L = 4,4＇-（2-carboxylatopropane-1,3-diyl）dibenzoate, were hydrothermally prepared and fully characterized by X-ray single-cr...[Pb（HL）（phen）]n （1） and [Cd3L2（phen）]n （2）, where phen = 1,10-phenanthroline and L = 4,4＇-（2-carboxylatopropane-1,3-diyl）dibenzoate, were hydrothermally prepared and fully characterized by X-ray single-crystal diffraction, infrared spectroscopy and thermogravimetric analyses. The decomposition temperature of 1 and 2 was measured to be ca. 304 and 416 ℃, respectively. The charge transfer transition based absorption of 1 and 2 was also verified by the powder scattering spectra and theoretical analyses.展开更多
文摘Elementary information theory is used to model cybersecurity complexity, where the model assumes that security risk management is a binomial stochastic process. Complexity is shown to increase exponentially with the number of vulnerabilities in combination with security risk management entropy. However, vulnerabilities can be either local or non-local, where the former is confined to networked elements and the latter results from interactions between elements. Furthermore, interactions involve multiple methods of communication, where each method can contain vulnerabilities specific to that method. Importantly, the number of possible interactions scales quadratically with the number of elements in standard network topologies. Minimizing these interactions can significantly reduce the number of vulnerabilities and the accompanying complexity. Two network configurations that yield sub-quadratic and linear scaling relations are presented.
文摘Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.
文摘In this article the affiliation of Jin-Ke Shen,Nai-Teng Wu,Li-Yuan Wang,Gang Jiang,Jin Li,Gui-Long Liu,Xian-Ming Liu were incorrectly given as:State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources,School of Chemical Engineering and Technology,Xinjiang University,Urumqi 830046,China.
基金support from Natural Science Foundations of Henan Province(Nos.222300420502 and 232300420093)the Program for Science and Technology Innovation Talents in Universities of Henan Province(No.24HASTIT006)the Key Science and Technology Program of Henan Province(No.222102240044)。
文摘Tin-based metal organic complexes with breakable coordination bonds,multiple active sites,and high theoretical capacity have attracted wide attentiorials for lithium-ion batteries(LIBs).However,the inferior electrical conductivity and significant volume changes have limited their electrochemical stability and practical application performance.This work proposes a universal doping strategy for the preparation of tin-phthalic acid complexes(Sn-MOF)doped with metal atoms(Al,Cr,Mn,Fe,Co,Ni,Cu,Zn).Metal atoms are uniformly dispersed within Sn-MOF for enhancing electrical conductivity and accommodating appropriate volume expansion,resulting in improved rate capability and cycling stability.Additionally,compared to a series of doped Sn-MOF,Zn-doped Sn-MOF exhibits the most exceptional electrochemical performance with a high reversible capacity of 1131 mAh·g^(-1)and stable cycling performance at a current density of 0.5 A·g^(-1),delivering a capacity of 1065 mAh·g^(-1)after 500 cycles.Zn-doping catalyzes the lithiation reaction between Sn-MOF and Li^(+),promoting their reaction kinetics during the first cycle.Furthermore,the Zn-doped Sn-MOF is inclined to form a thin and stable solid electrolyte interface film to maintain cyclic stability.
基金financially supported by the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.24HASTIT006)the Natural Science Foundations of China(No.42002040)+2 种基金Natural Science Foundations of Henan Province(No.222300420502)Key Science and Technology Program of Henan Province(No.222102240044)Key Scientific Research Projects in Colleges and Universities of Henan Province(No.21B610010)。
文摘Sn-based metal organic complexes with coordination bonds,multi-active sites,and high theoretical capacity have attracted much attention as promising anodes for lithium ion batteries.However,the low electrical conductivity and huge volume changes restricted their electrochemical stability and practical utilization.Herein,Snbased anode with superior electrochemical performance,including a high reversible capacity of 1050.1 mAh·g^(-1)at 2 A·g^(-1)and a stable capacity of 1105.5 mAh·g^(-1)after 500 cycles at 1 A·g^(-1),was fabricated via a low-temperature calcination strategy from Sn metal organic complexes.The low-temperature calcination process regulates Sn-O bond and prevents the agglomeration of SnO_(2),generating highly dispersed SnO_(2) decorated metal organic complexes and providing sufficient active sites for ion storage.Ex situ characterizations expound that the undecomposed Sn-based metal organic complexes could be transformed into SnO_(2) during lithiation and delithiation,which enhances the electrical conductivity and induces a strong pseudo-capacitive behavior,accelerating the electrochemical kinetics;the multiple solid electrolyte interface with inflexible LiF and flexible ROCO_(2)Li buffers the volume variation of the electrode,resulting in its high electrochemical stability.This work provides a simple strategy for preparing excellent Sn-based anodes from metal organic complexes and reveals the lithium storage mechanism of the prepared Snbased anode.
基金financially supported by the National Natural Science Foundation of China(Nos.52102117,51173170,and 21773216)the joint project from the Henan-Provincial and the China-National Natural Science Foundations(No.U2004208)Key Science and Technology Program of Henan Province(No.202102310212)
文摘Organic redox compounds are attractive cathode materials in aqueous zinc-ion batteries owing to their low cost,environmental friendliness,multiple-electron-transfer reactions,and resource sustainability.However,the realized energy density is constrained by the limited capacity and low voltage.Herein,copper-tetracyanoquinodimethane(CuTCNQ),an organic charge-transfer complex is evaluated as a zinc-ion battery cathode owing to the good electron acceptation ability in the cyano groups that improves the voltage output.Through electrochemical activation,electrolyte optimization,and adoption of graphene-based separator,CuTCNQ-based aqueous zinc-ion batteries deliver much improved rate performance and cycling stability with anti-self-discharge properties.The structural evolution of CuTCNQ during discharge/charge are investigated by ex situ Fourier transform infra-red(FT-IR)spectra,ex situ X-ray photoelectron spectroscopy(XPS),and in situ ultraviolet visible spectroscopy(UV-vis),revealing reversible redox reactions in both cuprous cations(Cu^(+))and organic anions(TCNQ^(x-1)),thus delivering a high voltage output of 1.0 V and excellent discharge capacity of 158 mAh g^(-1).The remarkable electrochemical performance in Zn//CuTCNQ is ascribed to the strong inductive effect of cyano groups in CuTCNQ that elevated the voltage output and the graphene-modified separator that inhibited CuTCNQ dissolution and shuttle effect in aqueous electrolytes.
基金support of the Korea University of Education and Training Center for Convergence Education(2019-2022).
文摘Jumong is a legendary figure in Korean mythology.He is depicted as a genius archer,a brilliant mind with horses,a god who rules the rivers and the sky.Jumong is a mythical character who is believed to be of divine descent and to possess superhuman abilities that humans cannot match.The myth of Jumong is a very competitive content that can compete on a global scale.However,in order for it to be successful,it is necessary to be able to reinterpret our mythology to suit the times and reproduce it culturally.To this end,the realistic globalization of Korean classical literature should commence with the genre of Korean mythology.This paper presents the educational significance of the Jumong myth as a teaching-learning model,via STEAM(science,technology,engineering,arts,and mathematics),on the theme of Korean mythology.As we enter the era of artificial intelligence(AI)through the 4th Industrial Revolution,the most appropriate teaching and learning method,the convergence class,will provide an opportunity for students living in modern times to discover the cultural archetypes that allow them to recognise themselves as individuals and us as a collective,and to find the roots of the myth to positively renew their identity.Furthermore,it is my hope that they will rediscover and appreciate the representative work of Korean mythology,Gojomong,the eponymous story of Goguryeo.
文摘A rapid method is applied to analyze conjugated organic ligands bridged binuclear ruthenium complexes by electrospray ionization-tandem mass spectrometry (ESI MSn).Fragmentation pattern be discussed.
文摘A novel Fe/Co metal organic complex nanosheet modified by 1,4-dicarboxybenzene(BDC),i.e.,FeCo@BDC,was prepared,and highly efficient removal performance for trace lead(Ⅱ)(Pb^(2+))was demonstrated in the neutral aqueous solutions.The removal rates were higher than 95%and the adsorption was equilibrated in 15 min.The isotherms and kinetics for the adsorption Pb^(2+)by the FeCo@BDC adsorbents followed Langmuir model and pseudo-second-order model,respectively.The maximum adsorption capacity was 220.48 mg g^(-1).The FeCo@BDC adsorbents also own a prominent regeneration performance.The prominent performance of in the removal of trace Pb^(2+)makes FeCo@BDC an ideal candidate as commercial adsorbent materials.
基金Project supported by National Natural Science Foundation of China(51604128)
文摘To examine the activation of organic acids on the leaching process of ion-adsorption type rare earth ore（IRE-ore）, the leaching behavior of rare earth（RE） and zeta potential of IRE-ore were investigated in the absence and presence of carboxylic acids. The results show that all the tested organic acids（acetic acid,malonic acid, citric acid, tartaric acid, succinic acid, and malic acid） can promote RE extraction. At relatively high concentrations of organic acids, the activation efficiency of organic acids on RE extraction is generally consistent with their complexation ability; whereas at their low concentrations, the change of zeta potential on the IRE-ore surface with organic acid concentration and p H has a close association with RE extraction, which indicates that organic acids can impact the surface electrical property of IREore via their adsorption/desorption, and thereby increase/decrease the affinity of RE ions to IRE-ore.Therefore the influence of organic acids on the IRE-ore surface electrical property also plays an important role in RE extraction in addition to their complexation with RE ions.
基金supported by the Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.JB190501)Science and Technology Innovation Team of Shaanxi Province(No.2019TD-002)National Natural Science Foundation of China(No.11774277)。
文摘The applications of laser-induced breakdown spectroscopy(LIBS) on classifying complex natural organics are relatively limited and their accuracy still requires improvement.In this work,to study the methods on classification of complex organics,three kinds of fresh leaves were measured by LIBS.100 spectra from 100 samples of each kind of leaves were measured and then they were divided into a training set and a test set in a ratio of 7:3.Two algorithms of chemometric methods including the partial least squares discriminant analysis(PLS-DA) and principal component analysis Mahalanobis distance(PCA-MD) were used to identify these leaves.By using 23 lines from 16 elements or molecules as input data,these two methods can both classify these three kinds of leaves successfully.The classification accuracies of training sets are both up to 100% by PCA-MD and PLS-DA.The classification accuracies of the test set are 93.3% by PCA-MD and 97.8% by PLS-DA.It means that PLS-DA is better than PCA-MD in classifying plant leaves.Because the components in PLS-DA process are more suitable for classification than those in PCA-MD process.We think that this work can provide a reference for plant traceability using LIBS.
基金supported by the National Natural Science Foundation of China(nos.41171198,41403079)the Chongqing Research Program of Basic Research and Frontier Technology(no.cstc2015jcyj A20021)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(no.XDJK2015B035)
文摘The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.
基金Isfahan University of Technology for the financial support of this study
文摘Atterberg limits and consistency indices are used for classifications of cohesive(fine-grained) soils in relation with compaction and tillage practices. They also provide information for interpreting several soil mechanical and physical properties such as shear strength, compressibility, shrinkage and swelling potentials. Although, several studies have been conducted regarding the land use effects on various soil mechanical properties, little is known about the effects of land use and slope positions on Atterberg limits and consistency indices. This study was conducted to investigate the effects of land use and slope position on selected soil physical and chemical properties, Atterberg limits and consistency indices in hilly region of western Iran. Three land uses including dryland farming, irrigated farming and pasture and four slope positions(i.e., shoulder, backslope, footslope, and toeslope) were used for soil samplings. One hundred eleven soil samples were collected from the surface soil(0-10 cm). Selected physical and chemical properties, liquid limit(LL), plastic limit(PL) and shrinkage limit(SL) were measured using the standard methods; and consistency indices including plastic index(PI), friability index(FI), shrinkage index(SI) and soil activity(A=PI/clay) were calculated. The results showed that irrigated farming significantly increased organic matter content(OM) and OM/clay ratio, and decreased bulk density(ρb) and relative bulk density(ρb-rel) as a result of higher biomass production and plant residues added to the soil compared to other land uses. Except for sand content, OM, ρb, cation exchange capacity(CEC) and calcium carbonate equivalent(CCE), slope position significantly affected soil physical and chemical properties. The highest values of silt, OM/clay and CEC/clay were found in the toeslope position, predominantly induced by soil redistribution within the landscape. The use of complexed(COC)- noncomplexed organic carbon(NCOC) concept indicated that majority of the studied soils were located below the saturation line and the OM in the soils was mainly in the COC form. The LL, PI, FI and A showed significant differences among the land uses; the highest values belonged to the irrigated farming due to high biomass production and plant residues returned to the soils. Furthermore, slope position significantly affected the Atterberg limits and consistency indices except for SL. The highest values of LL, PI, SI and A were observed in the toeslope position probably because of higher OM and CEC/clay due to greater amount of expandable phyllosilicate clays. Overall, soils on the toeslope under irrigated farming with high LL and SI and low values of FI need careful tillage management to avoid soil compaction.
文摘A novel europium complex, bi(dibenzamide) benzoate europium(Ⅲ) (Eu-DBA-B), was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium complex is an electroneutral complex, and it emits very strong red luminescence from (()~5D_1→()~7F_j) (j=0, 1, 2, 3, 4) transitions.
基金financially supported by the National Natural Science Foundation of China (Nos. 21971024, 21671025)Liaoning Revitalization Talents Program (No. XLYC1902011)
文摘In this paper,three new polyoxometalates(POM)-based metal–organic complexes constructed from a new semi-rigid organic ligand N,N'-bis(4-pyrimidinecarboxamido)-1,2-cyclohexane(4-bpmah)H_(2)[Cu(4-bpmah)_(2)(SiMo_(12)O_(40))(H_(2)O)_(2)]·2H_(2)O(1),H[Cu(4-bpmah)_(2)(PMo_(12)O_(4)0)(H_(2)O)_(2)]·2H_(2)O(2)and[Cu(4-bpmah)(H_(2)O)_(2)]·[Cu_(2)(TeMo_(6)O_(24))(H_(2)O)_(10)]·4H_(2)O(3)were synthesized by hydrothermal method.Single crystal X-ray analyses showed that complexes 1 and 2 were isostructural,in which the isolated Keggin-type[SiMo1_(2)O_(40)]^(4–)/[PMo_(12)O_(40)]^(3–)anions and[Cu(4-bpmah)_(2)(H_(2)O)2]^(2n+)units were expanded into 3D supramolecular structures through hydrogen bond interactions.In complex 3,the 1D[Cu(4-bpmah)(H_(2)O)_(2)]^(2n+)metal–organic chains and isolated[Cu_(2)(TeMo_(6)O_(24))(H_(2)O)_(10)]^(2n–)units were expanded into a 3D supramolecular framework by the hydrogen bond interactions.In this paper,carbon cloth working electrodes composited by the title complexes(1/CC,2/CC and 3/CC)were prepared and used as electrodes for supercapacitors.The performance of supercapacitors as well as the influence of electrolyte solution and title complexes quality load on the performance of supercapacitors were studied.Furthermore,the electrochemistry and electrocatalytic behaviors of complexes 1–3 bulk-modified carbon paste electrodes(1-CPE,2-CPE and 3-CPE)toward the reduction of KBrO_(3),KNO_(2),Cr(Ⅵ),as well as their sensing behaviors on Cr(Ⅵ)were investigated.
文摘Based on the strong fluorescence and the highly thermal stability of sodium tris (pyridine dicarboxylato) europate (Na 3Eu(DPA) 3), polymethyl methacrylate (PMMA) composite material incorporated with the complex, PMMA: Na 3Eu(DPA) 3, was prepared at 250 ℃. The fluorescence behavior of PMMA: Na 3Eu(DPA) 3 material was examined. The results show that the composite material keeps the luminescent characteristics of the Eu 3+ chelate after PMMA is incorporated with Na 3Eu(DPA) 3, and strong orange-red emission of the composite was observed. The fluorescence intensity of the composite material increases with the increase of the weight ratio of Na 3Eu(DPA) 3 to PMMA, but the relationship is not linear.
文摘The reaction of MeCpLnCl·2LiCl·nTHF with 2 equivalent of LiNPh_2 in THF,hexane and toluene mixture solution gives the new complex[Li(DME)_2][(η~5-MeCp)Ln(NPh_2)_3](Ln=La,Pr,Nd)by extraction with DME.They have been characterized by elemental analysis,IR and NMR.The La complex crystallizes in the monoclinic space group P2_1/c with α=1.8335(6)nm,b=1.6576(5)nm,c=1.7461(6)nm, β=96.04°,V=5.277 nm^2,Z=4,D_c=1.26g·cm^(-3),R=0.057 and R_w=0.048(1≥2.5σ(I_o))for 3378 reflec- tions.The complex consists of a pair of a cation and an anion.La^(3+) is coordinated by one methylcyclopentadienyl and three diphenylamidos to form six-coordinate pseudotetrahedron with the mean Ln-N and La-C(ring)distances of 0.2459(8)and 0.2843(11)nm,respectively.
基金Funded bythe National Natural Science Fundation of China(No.90206047)
文摘Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The influence of the glass contents on the structure of the glass and the erwrgy level of the doped Tb （Ⅲ） ions was analyzed by the emission spectra and IR spectra. The effect of B2O3 on the photolumirwscence properties of rare earth organic complex in silica- based glass was investigated. The IR spectra indicate that the in situ sylthesized rare earth complex molecule was confined to the micropores of the bost and the vibration of the ligands was frozen. When B2O3 was added into the silica host gel, B2O3 had little influence on the noncrystallirw structure of the glass, and BO3 triangle, which had a layer structure different from the silica framework, could form. So the silica network became more inhomogenous, and the luminescence of terbium complexes was quenched with the increase of the B2O23 amount.
基金the National Natural Science Foundation of China(22065038)the Key Project of Natural Science Foundation of Yunnan(KC10110419)+4 种基金the High-Level Talents Introduction in Yunnan Province(C619300A010)the Fund for Excellent Young Scholars of Yunnan(K264202006820)the Program for Excellent Young Talents of Yunnan University and Major Science(C176220200)the International Joint Research Center for Advanced Energy Materials of Yunnan Province(202003AE140001)the Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province(No.2019Z E001-1202002AB080001)for financial support。
文摘Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.
基金supported by the National Natural Science Foundation of China(No.21271033)
文摘[Pb（HL）（phen）]n （1） and [Cd3L2（phen）]n （2）, where phen = 1,10-phenanthroline and L = 4,4＇-（2-carboxylatopropane-1,3-diyl）dibenzoate, were hydrothermally prepared and fully characterized by X-ray single-crystal diffraction, infrared spectroscopy and thermogravimetric analyses. The decomposition temperature of 1 and 2 was measured to be ca. 304 and 416 ℃, respectively. The charge transfer transition based absorption of 1 and 2 was also verified by the powder scattering spectra and theoretical analyses.
