Introducing functional polar groups into polyolefins can significantly improve the material properties,but there are still challenges in achieving this goal,with the core difficulty being that polar groups are prone t...Introducing functional polar groups into polyolefins can significantly improve the material properties,but there are still challenges in achieving this goal,with the core difficulty being that polar groups are prone to interact with metal active species,affecting the efficiency of the copolymerization.With the rapid advancement in catalyst,a variety of copolymerization strategies are developed aimed at producing more versatile polyolefin materials.Although early transition metal catalysts play an indispensable role in the traditional polyolefin industry,their inherent strong oxophilicity becomes a significant constraint in copolymerization involving polar olefins,limiting their application scope.This review summarizes the progress made in recent years in the efficient copolymerization of non-polar olefins with polar comonomers catalyzed by groups 3 and 4 single-site catalysts.We classify the catalysts into four categories,Sc-,Ti-,Zr-,Hf-,based on the type of metal centers,and provide insights into the influence of catalyst structures and the type of comonomers on the copolymerization behavior.The introduction of polar monomers fundamentally improves the comprehensive performance of the products,greatly broadens the application scope of polyolefin materials,and meets the growing market demand for multifunctional and high-performance materials.展开更多
1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalizat...1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalization of unsymmetric 2-CF_(3)-1,3-enynes.The presence of trifluoromethyl group is determinable for the regioselectivity.When the CF_(3) group was replaced with the methyl or amide group,the regioselectivity decreased to a ratio of 1.3:1 or 1:1.7,respectively.For alkyl substitutedβ-CF_(3)-1,3-enynes,a regiospecificity was obtained.This strategy features excellent regioselectivity,broad substrate scope and high functional group tolerance.Mechanistic studies showed that C–H bond activation is the rate-limiting step.展开更多
Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a promine...Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a prominent component of Paeonia lactiflora Pall.,has demonstrated the ability to restore barrier function in UC mice,but the precise mechanism remains unclear.In this study,we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s.C57BL/6 mice were subjected to random allocation into 7 distinct groups,namely the control group,the 2%dextran sodium sulfate(DSS)group,the paeoniflorin groups(25,50,and 100 mg/kg),the anti-tumor necrosis factor-like ligand 1A(anti-TL1A)antibody group,and the IgG group.We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using Western blot and flow cytometry,respectively.Meanwhile,DR3-overexpressing MNK-3 cells and 2%DSS-induced Rag1^(-/-)mice were used for verification.The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier.Simultaneously,paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines(interleukin-17A,granulocyte-macrophage colony stimulating factor,and interleukin-22).Alternatively,paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage independently of the adaptive immune system.We additionally confirmed that paeoniflorin-conditioned medium(CM)restored the expression of tight junctions in Caco-2 cells via coculture.In conclusion,paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner,and its mechanism is associated with the inhibition of the DR3 signaling pathway.展开更多
In order to study the influences of functionalized groups onto the adsorption of tetracycline,we prepared a series of amino and amino–Fe^（3＋）complex mesoporous silica adsorbents with diverse content of amino and ...In order to study the influences of functionalized groups onto the adsorption of tetracycline,we prepared a series of amino and amino–Fe^（3＋）complex mesoporous silica adsorbents with diverse content of amino and Fe^（3＋）groups（named N,N-SBA15 and Fe-N,N-SBA15）.The resulting mesoporous silica adsorbents were fully characterized by X-ray powder diffraction（XRD）,Fourier transform infrared spectrometer（FTIR）and N2adsorption/desorption isotherms.Furthermore,the effects of functionalized groups on the removal of TC were investigated.The results showed that the periodic ordered structure of SBA-15 was maintained after modification of amino/Fe^（3＋）groups.The functionalized amino groups decreased the adsorption capacity while the coordinated Fe^（3＋）increased the adsorption capacity.The adsorption kinetics of TC fitted pseudo-second-order model well and the equilibrium was achieved quickly.The adsorption isotherms fitted the Langmuir model well and with the Fe^（3＋）content increased from 3.93%to 8.26%,the Q（max）of the adsorbents increased from 102 to 188 mmol/kg.The solution p H affected the adsorption of TC onto amino complex adsorbents slightly while influenced the adsorption onto Fe-amine complex adsorbents greatly.The adsorption of TC on SBA15 and N,N-SBA15 may be related to the formation of outer-sphere surface complexes,while the adsorption of TC onto Fe-N,N-SBA15 was mainly attributed to the inner-sphere surface complexes.This study could offer potential materials that have excellent adsorption behavior for environmental remediation and suggested useful information for the preparing other adsorbents in environmental applications.展开更多
Aliphatic C(sp^(3))-H moieties are ubiquitous in numerous organic compounds.Direct functionalization of inert C(sp^(3))-H bonds is a powerful and straightforward approach for the efficient construction of diverse carb...Aliphatic C(sp^(3))-H moieties are ubiquitous in numerous organic compounds.Direct functionalization of inert C(sp^(3))-H bonds is a powerful and straightforward approach for the efficient construction of diverse carbon-carbon or carbon-heteroatom bonds.Chelating group directed metal-catalyzed remote functionalization of readily available alkenes has emerged as an appealing strategy for rapidly accessing various value-added aliphatic molecules.With the aid of directing groups,variousα-,β-andγ-functionalized alkanes could be synthesized smoothly with excellent regioselectivity.The preferred formation of a stable five-or six-membered metallacycle intermediate terminates the chain-walking at a specific methylene site,which serves as the driving force for excellent site-selective migratory functionalization.This review herein is aimed at summarizing the recent progress on the metal-catalyzed regiodivergent functionalization of unactivated alkenes by merging alkene isomerization and cross-coupling with the assistance of directing auxiliary.Last but not least,the current situations and future directions in this field are highlighted and discussed.展开更多
In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then ...In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then G is isomorphic to M if and only if the set of the orders of the maximal abelian subgoups of G is the same as that of M .展开更多
Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide （4）, and 1,3-alternate p-H-thiacalix[4]arene tetraamide （6） were prepared, and their cry...Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide （4）, and 1,3-alternate p-H-thiacalix[4]arene tetraamide （6） were prepared, and their crystal structures were determined by single-crystal X-ray diffraction method. The steric hindrances posed by tert-butyl groups play an important part in the synthesis and the self-assembly of the two compounds. Compound 6 was synthesized from the corresponding ester, which was obtained by the reaction of acid chloride with ammonia. In the crystal structure, compound 4 presents a highly symmetric molecular structure, while for compound 6, because of absence of tert-butyl groups, it presents a more flexible molecular structure.展开更多
Poly（3-alkyl）pyrroles containing phosphonic acid groups with different alkyl segment lengths were chemical synthesized and the properties were measured by FTIR and UV-Vis spectroscopy. FTIR and UV-Vis results showed...Poly（3-alkyl）pyrroles containing phosphonic acid groups with different alkyl segment lengths were chemical synthesized and the properties were measured by FTIR and UV-Vis spectroscopy. FTIR and UV-Vis results showed that the synthesized polymers were in a low doping level through chemical polymerization. By spin-coating on the surface of substrates, the polymer can be used as a humidity sensor. The change of DC electric current of the polypyrroles varies with the chain length of the alkyl substituents. The capacitance increases with the increase of the humidity and resistance decreases with the increase of humidity. This result is different from that ofpolypyrrole without alkyl substituents due to the influence of the phosphonic acid group. The sensor showed the resistive-type at high relative humidity, and the capacitive- type at the low relative humidity. The sensor exhibited very fast response to the change of environment humidity.展开更多
The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these st...The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these structures are prone to varying degrees of damage,with frequent occurrences of roof leakage and induced rock burst accidents,significantly impacting subsequent mining operations and safe production.To address these issues,this study investigates the surrounding rock deformation patterns during fully mechanized mining face passage through abandoned roadway clusters.Specific countermeasures were systematically summarized according to different occurrence characteristics of abandoned roadways.Through mechanical analysis,the critical unstable width of coal pillars was determined to be approximately 16.1~16.8 m.A three-dimensional numerical model was established based on 17 abandoned roadways with various shapes and occurrences in the working face.Simulation results indicate severe deformation and failure in roof rock layer roadways,while floor roadways exhibit relatively minor damage.Notably,when the distance between abandoned roadways and the coal seam exceeds 8 m,almost no damage occurs.Three technical measures for passing through abandoned roadway group was proposed according to their occurrence characteristics and implemented in engineering practice.Field applications demonstrate limited coal stress variations and weak strata pressure manifestations during the crossing process,ensuring safe passage through abandoned roadway clusters.This achievement enables efficient and safe crossing of abandoned roadway group in fully mechanized mining faces,enhances coal recovery rates,and provides practical engineering references for similar geological conditions.展开更多
Lishiite,(Ca_(2)□)Sr_(3)(CO_(3))_(5),is a new mineral species from Shaxiongdong,Hubei Province,China.It mainly occours as conchoidal crystals and with combination of hexagonal prism and pyramid and is associated with...Lishiite,(Ca_(2)□)Sr_(3)(CO_(3))_(5),is a new mineral species from Shaxiongdong,Hubei Province,China.It mainly occours as conchoidal crystals and with combination of hexagonal prism and pyramid and is associated with calcite,K-feldspar,albite,aegirine,apatite,and ancylite-(Ce)(?)and strontianite etc.Lishiite is brittle with conchiform fracture and has a Mohs hardness of approximately 4 and none cleavages were observed.The Vickers microhardness(VHN10)is 197.42 kg/mm^(2)(range:166.88 kg/mm^(2) to 214.58 kg/mm^(2)),and the calculated density of lishiite is 3.696 g/cm3.Hand specimen of lishiite are yellow-brown.The empirical chemical formula of the lishiite is ^(A)(Ca_(1.18)Sr_(0.25)Na_(0.19□1.38))_(Σ3.00)^( B)[Sr_(2.17)(Ce_(0.42)La_(0.24)Nd_(0.09)Eu_(0.01))_(Σ0.76) Ba_(0.07)]_(Σ3.00)(C_(5.05)O_(15)).As a member of the burbankite group,the general formula of lishiite follows the general formula A_(3)B_(3)(CO_(3))_(5),where A=Na,Ca,or and B=Sr,Ba,REE,or Ca.Its crystal structure is hexagonal(space group P6_(3)mc)with unit cell parameters a=10.4898(5)Å,c=6.4167(5)Å,and V=611.47(6)Å^(3),characterized by layers of AO_(8) and BO_(10) polyhedra connected to[CO_(3)]^(3−)groups.The discovery of lishiite provides new insights into the evolutionary history of rare earth element(REE)carbonate deposit formation.展开更多
基金supported by the National Natural Science Foundation of China(No.U23B6011)。
文摘Introducing functional polar groups into polyolefins can significantly improve the material properties,but there are still challenges in achieving this goal,with the core difficulty being that polar groups are prone to interact with metal active species,affecting the efficiency of the copolymerization.With the rapid advancement in catalyst,a variety of copolymerization strategies are developed aimed at producing more versatile polyolefin materials.Although early transition metal catalysts play an indispensable role in the traditional polyolefin industry,their inherent strong oxophilicity becomes a significant constraint in copolymerization involving polar olefins,limiting their application scope.This review summarizes the progress made in recent years in the efficient copolymerization of non-polar olefins with polar comonomers catalyzed by groups 3 and 4 single-site catalysts.We classify the catalysts into four categories,Sc-,Ti-,Zr-,Hf-,based on the type of metal centers,and provide insights into the influence of catalyst structures and the type of comonomers on the copolymerization behavior.The introduction of polar monomers fundamentally improves the comprehensive performance of the products,greatly broadens the application scope of polyolefin materials,and meets the growing market demand for multifunctional and high-performance materials.
基金supported by National Natural Science Founda:tion of China(22461002,22308061,22305046)Natural Science Foundation(NSF)of Jiangxi Province(20224BAB213011,20242BAB20110,20224BAB213012)+1 种基金High-Level and Highly Demanded Overseas Talent Programs of Jiangxi Province(20232BCJ25050)Gannan Normal University Start-up Fund(BSJJ202109).
文摘1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalization of unsymmetric 2-CF_(3)-1,3-enynes.The presence of trifluoromethyl group is determinable for the regioselectivity.When the CF_(3) group was replaced with the methyl or amide group,the regioselectivity decreased to a ratio of 1.3:1 or 1:1.7,respectively.For alkyl substitutedβ-CF_(3)-1,3-enynes,a regiospecificity was obtained.This strategy features excellent regioselectivity,broad substrate scope and high functional group tolerance.Mechanistic studies showed that C–H bond activation is the rate-limiting step.
基金supported by the National Natural Science Foundation of China(Grant No.:82074092),Natural Science Foundation of Guangdong Province,China(Grant No.:2021A1515012219)Guangzhou University of Chinese Medicine“Double First-Class”and High-level University Discipline Collaborative Innovation Team Project,China(Grant No.:2021xk81) and Graduate Research Innovation Project of Guangzhou University of Chinese Medicine,China.
文摘Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a prominent component of Paeonia lactiflora Pall.,has demonstrated the ability to restore barrier function in UC mice,but the precise mechanism remains unclear.In this study,we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s.C57BL/6 mice were subjected to random allocation into 7 distinct groups,namely the control group,the 2%dextran sodium sulfate(DSS)group,the paeoniflorin groups(25,50,and 100 mg/kg),the anti-tumor necrosis factor-like ligand 1A(anti-TL1A)antibody group,and the IgG group.We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using Western blot and flow cytometry,respectively.Meanwhile,DR3-overexpressing MNK-3 cells and 2%DSS-induced Rag1^(-/-)mice were used for verification.The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier.Simultaneously,paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines(interleukin-17A,granulocyte-macrophage colony stimulating factor,and interleukin-22).Alternatively,paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage independently of the adaptive immune system.We additionally confirmed that paeoniflorin-conditioned medium(CM)restored the expression of tight junctions in Caco-2 cells via coculture.In conclusion,paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner,and its mechanism is associated with the inhibition of the DR3 signaling pathway.
基金supported by Beijing Postdoctoral Science Foundation (No. 21009916007)Beijing Outstanding Talent Project for Excellent Youth Team (No. 2015000026833T0000)+1 种基金the National Science Fund for Distinguished Young Scholars of China (No. 51225805)Natural Science Foundation of China (No. 51678025)
文摘In order to study the influences of functionalized groups onto the adsorption of tetracycline,we prepared a series of amino and amino–Fe^（3＋）complex mesoporous silica adsorbents with diverse content of amino and Fe^（3＋）groups（named N,N-SBA15 and Fe-N,N-SBA15）.The resulting mesoporous silica adsorbents were fully characterized by X-ray powder diffraction（XRD）,Fourier transform infrared spectrometer（FTIR）and N2adsorption/desorption isotherms.Furthermore,the effects of functionalized groups on the removal of TC were investigated.The results showed that the periodic ordered structure of SBA-15 was maintained after modification of amino/Fe^（3＋）groups.The functionalized amino groups decreased the adsorption capacity while the coordinated Fe^（3＋）increased the adsorption capacity.The adsorption kinetics of TC fitted pseudo-second-order model well and the equilibrium was achieved quickly.The adsorption isotherms fitted the Langmuir model well and with the Fe^（3＋）content increased from 3.93%to 8.26%,the Q（max）of the adsorbents increased from 102 to 188 mmol/kg.The solution p H affected the adsorption of TC onto amino complex adsorbents slightly while influenced the adsorption onto Fe-amine complex adsorbents greatly.The adsorption of TC on SBA15 and N,N-SBA15 may be related to the formation of outer-sphere surface complexes,while the adsorption of TC onto Fe-N,N-SBA15 was mainly attributed to the inner-sphere surface complexes.This study could offer potential materials that have excellent adsorption behavior for environmental remediation and suggested useful information for the preparing other adsorbents in environmental applications.
基金the National Natural Science Foundation of China(No.22001116)the Basic and Applied Basic Research Foundation of Guangdong Province(No.2020A1515110816)funds provided by Changzhou University(No.ZMF23020217)。
文摘Aliphatic C(sp^(3))-H moieties are ubiquitous in numerous organic compounds.Direct functionalization of inert C(sp^(3))-H bonds is a powerful and straightforward approach for the efficient construction of diverse carbon-carbon or carbon-heteroatom bonds.Chelating group directed metal-catalyzed remote functionalization of readily available alkenes has emerged as an appealing strategy for rapidly accessing various value-added aliphatic molecules.With the aid of directing groups,variousα-,β-andγ-functionalized alkanes could be synthesized smoothly with excellent regioselectivity.The preferred formation of a stable five-or six-membered metallacycle intermediate terminates the chain-walking at a specific methylene site,which serves as the driving force for excellent site-selective migratory functionalization.This review herein is aimed at summarizing the recent progress on the metal-catalyzed regiodivergent functionalization of unactivated alkenes by merging alkene isomerization and cross-coupling with the assistance of directing auxiliary.Last but not least,the current situations and future directions in this field are highlighted and discussed.
文摘In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then G is isomorphic to M if and only if the set of the orders of the maximal abelian subgoups of G is the same as that of M .
基金Supported by the National Natural Science Foundation of China(20772092)the Hubei Province Natural Science Fund for Distinguished Young Scholars(2007ABB021)
文摘Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide （4）, and 1,3-alternate p-H-thiacalix[4]arene tetraamide （6） were prepared, and their crystal structures were determined by single-crystal X-ray diffraction method. The steric hindrances posed by tert-butyl groups play an important part in the synthesis and the self-assembly of the two compounds. Compound 6 was synthesized from the corresponding ester, which was obtained by the reaction of acid chloride with ammonia. In the crystal structure, compound 4 presents a highly symmetric molecular structure, while for compound 6, because of absence of tert-butyl groups, it presents a more flexible molecular structure.
基金supported by the Fundamental Research Funds for the Central Universities,China(No.GK 200902008)
文摘Poly（3-alkyl）pyrroles containing phosphonic acid groups with different alkyl segment lengths were chemical synthesized and the properties were measured by FTIR and UV-Vis spectroscopy. FTIR and UV-Vis results showed that the synthesized polymers were in a low doping level through chemical polymerization. By spin-coating on the surface of substrates, the polymer can be used as a humidity sensor. The change of DC electric current of the polypyrroles varies with the chain length of the alkyl substituents. The capacitance increases with the increase of the humidity and resistance decreases with the increase of humidity. This result is different from that ofpolypyrrole without alkyl substituents due to the influence of the phosphonic acid group. The sensor showed the resistive-type at high relative humidity, and the capacitive- type at the low relative humidity. The sensor exhibited very fast response to the change of environment humidity.
基金supported by the National Key R&D Program of China(2023YFC3904300)the Taichuangyuan Thick Coal Seam Water Conservation Mining"Scientists+Engineers"Team(2024QCY-KXJ-055)the 111 Project(B21016).
文摘The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these structures are prone to varying degrees of damage,with frequent occurrences of roof leakage and induced rock burst accidents,significantly impacting subsequent mining operations and safe production.To address these issues,this study investigates the surrounding rock deformation patterns during fully mechanized mining face passage through abandoned roadway clusters.Specific countermeasures were systematically summarized according to different occurrence characteristics of abandoned roadways.Through mechanical analysis,the critical unstable width of coal pillars was determined to be approximately 16.1~16.8 m.A three-dimensional numerical model was established based on 17 abandoned roadways with various shapes and occurrences in the working face.Simulation results indicate severe deformation and failure in roof rock layer roadways,while floor roadways exhibit relatively minor damage.Notably,when the distance between abandoned roadways and the coal seam exceeds 8 m,almost no damage occurs.Three technical measures for passing through abandoned roadway group was proposed according to their occurrence characteristics and implemented in engineering practice.Field applications demonstrate limited coal stress variations and weak strata pressure manifestations during the crossing process,ensuring safe passage through abandoned roadway clusters.This achievement enables efficient and safe crossing of abandoned roadway group in fully mechanized mining faces,enhances coal recovery rates,and provides practical engineering references for similar geological conditions.
基金supported by the project China Geological Survey(DD202501026090)the National Key Research and Development Program of China(2024YFC2910102).
文摘Lishiite,(Ca_(2)□)Sr_(3)(CO_(3))_(5),is a new mineral species from Shaxiongdong,Hubei Province,China.It mainly occours as conchoidal crystals and with combination of hexagonal prism and pyramid and is associated with calcite,K-feldspar,albite,aegirine,apatite,and ancylite-(Ce)(?)and strontianite etc.Lishiite is brittle with conchiform fracture and has a Mohs hardness of approximately 4 and none cleavages were observed.The Vickers microhardness(VHN10)is 197.42 kg/mm^(2)(range:166.88 kg/mm^(2) to 214.58 kg/mm^(2)),and the calculated density of lishiite is 3.696 g/cm3.Hand specimen of lishiite are yellow-brown.The empirical chemical formula of the lishiite is ^(A)(Ca_(1.18)Sr_(0.25)Na_(0.19□1.38))_(Σ3.00)^( B)[Sr_(2.17)(Ce_(0.42)La_(0.24)Nd_(0.09)Eu_(0.01))_(Σ0.76) Ba_(0.07)]_(Σ3.00)(C_(5.05)O_(15)).As a member of the burbankite group,the general formula of lishiite follows the general formula A_(3)B_(3)(CO_(3))_(5),where A=Na,Ca,or and B=Sr,Ba,REE,or Ca.Its crystal structure is hexagonal(space group P6_(3)mc)with unit cell parameters a=10.4898(5)Å,c=6.4167(5)Å,and V=611.47(6)Å^(3),characterized by layers of AO_(8) and BO_(10) polyhedra connected to[CO_(3)]^(3−)groups.The discovery of lishiite provides new insights into the evolutionary history of rare earth element(REE)carbonate deposit formation.
