Lake Karakir (system of lakes) is located in the north west of Bukhara Oasis, it consists of 3 small lakes—a large karakir, a small karakir and an aquarium. The total area of the lake is 26.5 - 27.2 thousand hectares...Lake Karakir (system of lakes) is located in the north west of Bukhara Oasis, it consists of 3 small lakes—a large karakir, a small karakir and an aquarium. The total area of the lake is 26.5 - 27.2 thousand hectares. As a result of the research carried out in Lake karakir, 16 families of high water plants, 34 species belonging to 24 categories were identified. The study was carried out mainly on a large spruce and an aquarium. Phragmites australis (Cav.) Trin. ex Steud. (Cav.) Trin. ex Steud. as the dominant species of high water plants, Typha angustifolia L., T. laxmannii Lepech., T. minima Funck. like species are most common.展开更多
Fe-based sulfates are ideal cathode candidates for sodium-ion batteries(SIBs) owing to their high operating voltage and low cost but suffer from the nature of poor power performance. Herein, a hierarchical porous Na2F...Fe-based sulfates are ideal cathode candidates for sodium-ion batteries(SIBs) owing to their high operating voltage and low cost but suffer from the nature of poor power performance. Herein, a hierarchical porous Na2Fe(SO4)2@reduced graphene oxide/carbon dot(Na2Fe(SO4)2@rGO/C) with low carbon content(4.12 wt%) was synthesized via a facile homogeneous strategy benefiting for engineering application,which delivers excellent sodium storage performance(high voltage plateau of 3.75 V, 85 m Ah g-1 and330 Wh kg-1 at 0.05 C;5805 W kg-1 at 10 C) and high Na+diffusion coefficient(1.19 × 10-12 cm2 s-1).Moreover, the midpoint voltage of assembled full cell could reach 3.0 V. The electron transfer and reaction kinetics are effectively boosted since the nanoscale Na2Fe(SO4)2 is supported by a robust crosslinked carbon matrix with rGO sheets and carbon dots. The slight rGO sheets sufficiently enhance the electron transfer like a current collecter and restrain the aggregation, as well as ensure smooth ion channels. Meanwhile, the carbon dots in the whole space connect with Na2Fe(SO4)2 and help rGO to promote the conductivity of the electrode. Ex-situ X-ray powder diffraction and X-ray photoelectron spectrometry analysis confirm the high reversibility of this sodiation/desodiation process.展开更多
A series of MnM/palygorskite(PG)(M=La,W,Mo,Sb,Mg)catalysts was prepared by the wetness co-impregnation method for low-temperature selective catalytic reduction(SCR)of NO with NH_3.Conversion efficiency followed the or...A series of MnM/palygorskite(PG)(M=La,W,Mo,Sb,Mg)catalysts was prepared by the wetness co-impregnation method for low-temperature selective catalytic reduction(SCR)of NO with NH_3.Conversion efficiency followed the order Sb>Mo>La>W>Mg.A combination of various physico-chemical techniques was used to investigate the influence of Sb-modified Mn/PG catalysts.MnSb_(0.156)/PG catalyst showed highest NO conversion at low temperatures in the presence of SO_(2) which reveals that addition of Sb oxides effectively enhances the SCR activity of catalysts.A SO_(2) step-wise study showed that MnSb_(0.156)/PG catalyst displays higher durable resistance to SO_(2) than Mn/PG catalyst,where the sulfating of active phase is greatly inhibited after Sb doping.Scanning electron microscopy and X-ray diffraction results showed that Sb loading enhances the dispersion of Mn oxides on the carrier surface.According to the results of characterization analyses,it is suggested that the main reason for the deactivation of Mn/PG is the formation of manganese sulfates which cause the permanent deactivation of Mn-based catalysts.For Sb-doped Mn/PG catalyst,SO_(x) ad-species formed were mainly combined with SbO_(x) rather than MnO_(x).This preferential interaction between SbO_(x) and SO_(2) effectively shields the MnO_(x) as active species from being sulfated by SO_(2) resulting in the improvement of SO_(2) tolerance on Sb-added catalyst.Multiple information support that,owing to the addition of Sb,original formed MnO_(x) crystallite has been completely transformed into highly dispersed amorphous phase accounting for higher SCR activity.展开更多
Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by th...Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by the conventional hydrothermal method.Both two compounds endow short ultraviolet(UV)absorption edges(281 nm and 278 nm,respectively)and large birefringence(0.171@546 nm and 0.174@546 nm,respectively),which means that they are promising short-wave UV optical materials.Interestingly,though both of the two compounds exhibit similar 1D chained structures,and possess the same functional moieties including SbO4 seesaws and SO4 tetrahedral groups,they exhibit significantly opposite macroscopic symmetries,i.e.,compound 1 crystallizes in a centrosymmetric(CS)manner(P2_(1)/n)and compound 2 in a noncentrosymmetric(NCS)manner(P2_(1)2_(1)2_(1)),due to the size of cations[r(Rb+)=1.56 A˚,r(Cs+)=1.67 A˚]affects the orientation of SCALP of the adjacent Sb^(3+).展开更多
文摘Lake Karakir (system of lakes) is located in the north west of Bukhara Oasis, it consists of 3 small lakes—a large karakir, a small karakir and an aquarium. The total area of the lake is 26.5 - 27.2 thousand hectares. As a result of the research carried out in Lake karakir, 16 families of high water plants, 34 species belonging to 24 categories were identified. The study was carried out mainly on a large spruce and an aquarium. Phragmites australis (Cav.) Trin. ex Steud. (Cav.) Trin. ex Steud. as the dominant species of high water plants, Typha angustifolia L., T. laxmannii Lepech., T. minima Funck. like species are most common.
基金the National Natural Science Foundation of China(Nos.21771164,U1804129 and 21671205)Postdoctoral Research Grant in Henan Province(001702055)+1 种基金Center of Advanced Analysis&Gene Sequencing of Zhengzhou Universitythe Zhongyuan Youth Talent support program in Henan province。
文摘Fe-based sulfates are ideal cathode candidates for sodium-ion batteries(SIBs) owing to their high operating voltage and low cost but suffer from the nature of poor power performance. Herein, a hierarchical porous Na2Fe(SO4)2@reduced graphene oxide/carbon dot(Na2Fe(SO4)2@rGO/C) with low carbon content(4.12 wt%) was synthesized via a facile homogeneous strategy benefiting for engineering application,which delivers excellent sodium storage performance(high voltage plateau of 3.75 V, 85 m Ah g-1 and330 Wh kg-1 at 0.05 C;5805 W kg-1 at 10 C) and high Na+diffusion coefficient(1.19 × 10-12 cm2 s-1).Moreover, the midpoint voltage of assembled full cell could reach 3.0 V. The electron transfer and reaction kinetics are effectively boosted since the nanoscale Na2Fe(SO4)2 is supported by a robust crosslinked carbon matrix with rGO sheets and carbon dots. The slight rGO sheets sufficiently enhance the electron transfer like a current collecter and restrain the aggregation, as well as ensure smooth ion channels. Meanwhile, the carbon dots in the whole space connect with Na2Fe(SO4)2 and help rGO to promote the conductivity of the electrode. Ex-situ X-ray powder diffraction and X-ray photoelectron spectrometry analysis confirm the high reversibility of this sodiation/desodiation process.
基金supported by the National Natural Science Foundation of China(No.51872070)。
文摘A series of MnM/palygorskite(PG)(M=La,W,Mo,Sb,Mg)catalysts was prepared by the wetness co-impregnation method for low-temperature selective catalytic reduction(SCR)of NO with NH_3.Conversion efficiency followed the order Sb>Mo>La>W>Mg.A combination of various physico-chemical techniques was used to investigate the influence of Sb-modified Mn/PG catalysts.MnSb_(0.156)/PG catalyst showed highest NO conversion at low temperatures in the presence of SO_(2) which reveals that addition of Sb oxides effectively enhances the SCR activity of catalysts.A SO_(2) step-wise study showed that MnSb_(0.156)/PG catalyst displays higher durable resistance to SO_(2) than Mn/PG catalyst,where the sulfating of active phase is greatly inhibited after Sb doping.Scanning electron microscopy and X-ray diffraction results showed that Sb loading enhances the dispersion of Mn oxides on the carrier surface.According to the results of characterization analyses,it is suggested that the main reason for the deactivation of Mn/PG is the formation of manganese sulfates which cause the permanent deactivation of Mn-based catalysts.For Sb-doped Mn/PG catalyst,SO_(x) ad-species formed were mainly combined with SbO_(x) rather than MnO_(x).This preferential interaction between SbO_(x) and SO_(2) effectively shields the MnO_(x) as active species from being sulfated by SO_(2) resulting in the improvement of SO_(2) tolerance on Sb-added catalyst.Multiple information support that,owing to the addition of Sb,original formed MnO_(x) crystallite has been completely transformed into highly dispersed amorphous phase accounting for higher SCR activity.
基金the National Natural Science Foundation of China(Nos.22122106,22071158,21971171)the Fundamental Research Funds from Sichuan University(No.2021SCUNL101).
文摘Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by the conventional hydrothermal method.Both two compounds endow short ultraviolet(UV)absorption edges(281 nm and 278 nm,respectively)and large birefringence(0.171@546 nm and 0.174@546 nm,respectively),which means that they are promising short-wave UV optical materials.Interestingly,though both of the two compounds exhibit similar 1D chained structures,and possess the same functional moieties including SbO4 seesaws and SO4 tetrahedral groups,they exhibit significantly opposite macroscopic symmetries,i.e.,compound 1 crystallizes in a centrosymmetric(CS)manner(P2_(1)/n)and compound 2 in a noncentrosymmetric(NCS)manner(P2_(1)2_(1)2_(1)),due to the size of cations[r(Rb+)=1.56 A˚,r(Cs+)=1.67 A˚]affects the orientation of SCALP of the adjacent Sb^(3+).
