以太原市主城区作为研究区域,基于兴趣点(Point of Interest, POI)数据,采用核密度分析、局部Getis-OrdGI~*指数等方法,对城市商业空间格局进行了研究,在其现有商业空间格局的基础上借助等值线树法对商业中心进行了识别,并对各类行业的...以太原市主城区作为研究区域,基于兴趣点(Point of Interest, POI)数据,采用核密度分析、局部Getis-OrdGI~*指数等方法,对城市商业空间格局进行了研究,在其现有商业空间格局的基础上借助等值线树法对商业中心进行了识别,并对各类行业的空间分布及集聚特征进行了对比分析。结果表明:太原市主城区商业空间已经形成了以柳巷、朝阳以及亲贤北街商圈为中心向外围扩散的分布格局,体现出汾河以东集中连片、汾河以西零星分散的分布特征;识别出太原市主城区内46个基本商业中心,其中以柳巷、朝阳—双塔、体育路—亲贤北街为主城区三大核心商业中心;各类行业空间聚集表现不同,生活服务类、购物服务类以及餐饮服务类行业分布范围广、集聚程度小,医疗保健类、商务服务类、金融服务类行业分布范围小、集聚程度高。展开更多
Zeolite-confined Fe-site catalysts(ZFCs)have emerged as superior materials for sustainably producing high-value chemicals through CO_(2) hydrogenation,owing to their adaptable framework,customizable composition,and th...Zeolite-confined Fe-site catalysts(ZFCs)have emerged as superior materials for sustainably producing high-value chemicals through CO_(2) hydrogenation,owing to their adaptable framework,customizable composition,and thermal robustness.They excel in activating,adsorbing,and converting CO_(2) with remarkable efficiency and consistency in performance.This has sparked a surge in research interest in recent years.The review delves into the latest advancements in CO_(2) catalytic hydrogenation to olefins,alcohols,aromatics,and other liquid hydrocarbons,examining the synthesis,modification tactics,and the correlation between structure and performance across various ZFCs.Additionally,it underscores the pivotal factors affecting performance and sheds light on the mechanisms behind selectivity control in the CO_(2) hydrogenation process facilitated by ZFCs.To conclude,it presents pressing challenges and strategic recommendations to inspire the development of high-performance,durable ZFCs for CO_(2) hydrogenation applications.展开更多
A new solid high-proton conductor,H7[Ga(H2O)P2W17O61].18H2O,a substituted heteropoly acid with Dawson structure,has been synthesized by the degradation/ion-exchange/freezing method.The product was characterized by pot...A new solid high-proton conductor,H7[Ga(H2O)P2W17O61].18H2O,a substituted heteropoly acid with Dawson structure,has been synthesized by the degradation/ion-exchange/freezing method.The product was characterized by potentiometric titration,chemical analysis,IR,UV,XRD and TG-DTA.Complex impedance measurements show a high conductivity(5.44×10-3 S/cm at 50℃),with an activation energy for proton conduction of 36.04 kJ/mol.The mechanism of proton conduction is the Vehicle mechanism.展开更多
The ruthenium-substituted polyoxometallic acid H6 [Ru(H2O)FeW 11O39 ]·18H2O was synthesized by stepwise acidification and stepwise addition of solutions of the component elements, and an ion-exchange-cooling meth...The ruthenium-substituted polyoxometallic acid H6 [Ru(H2O)FeW 11O39 ]·18H2O was synthesized by stepwise acidification and stepwise addition of solutions of the component elements, and an ion-exchange-cooling method. The product was characterized using inductively coupled plasma spectrometry (ICP), Infrared Spectroscopy (IR), Ultraviolet Spectroscopy (UV), and X-ray diffraction (XRD). The results show that this complex has the Keggin structure. The determination of the thermal stability and proton conductivity of this polyoxometallic acid was carried out by a thermogravimetric-differential thermal analysis (TG-DTA) and electrochemical impedance spectroscopy (EIS).展开更多
Lithium-sulfur(Li-S)batteries have been puzzled by the“shuttle effect”.In the recent years,catalytic materials present a huge potential for solving this problem.However,the exploitation for catalytic activity was st...Lithium-sulfur(Li-S)batteries have been puzzled by the“shuttle effect”.In the recent years,catalytic materials present a huge potential for solving this problem.However,the exploitation for catalytic activity was still challenging in Li-S batteries.In this article,we put forward a single atom catalyst(SAC)of FeN_(4) coupled with Fe_(3)C on the N-doped carbon(FeN_(4)/Fe_(3)C@NC)by one-step pyrolysis method.The FeN_(4) and Fe_(3)C synergistically catalyze the polysulfides conversion when the N-doped carbon provides the high conductive three-dimensional skeleton in Li-S batteries.As a result,the FeN_(4)/Fe_(3)C@NC shows a specific capacity of 1100 mA·h/g at 0.2 C(1 C=1675 mA/g).In addition,the FeN_(4)/Fe_(3)C@NC maintains 99.01%of the pristine specific capacity after 100 cycles at 0.5 C,indicating the improved electrochemical performance in Li-S batteries.This work sheds new lights on the design of engineering catalysts for developing high-performance Li-S batteries.展开更多
Three layered aluminophosphates（UiO-15, APDAP12-150 and APDAP-150） with same topology were crystallized from an initial mixture with a molar Composition of A1203：1.SP2Os：5.5R：227HzO, where R is ethylene- diamine,...Three layered aluminophosphates（UiO-15, APDAP12-150 and APDAP-150） with same topology were crystallized from an initial mixture with a molar Composition of A1203：1.SP2Os：5.5R：227HzO, where R is ethylene- diamine, 1,2-diaminopropane or 1,3-diaminopropane, respectively. The crystallization processes of UiO-15, APDAPI2-150 and APDAP-150 were investigated using solid-state NMR in combination with XRD and other cha- racterization techniques. The evolution of the coordination states of Al and P in the solid products was monitored, and the possible starting points of crystallization（core units） of UiO-15, APDAP12-150 and APDAP-150 were obtained and analyzed. The formation ofa trimer as well as a hexamer of aluminophosphate, a monomer of PO4 and a nonamer containing two three-membered rings is critical for the start of crystallization of UiO-15. The formation of a hexamer and a pentamer is critical for the start of crystallization of APDAP12-150. The formation of an A106 monomer and a pentamer containing a three-membered ring is critical for the start of crystallization ofAPDAP-150. The crystal water played a co-structure-directing role in the formation ofAPDAP-150.展开更多
Using n-propylamine as a template,deioned water and secondary-butanol(butan-2-ol)as solvents,a three-dimensional(3D)open-framework aluminophosphate[C3NH10]·[HAl3P3O13](1)and a two-dimensional layered aluminophosp...Using n-propylamine as a template,deioned water and secondary-butanol(butan-2-ol)as solvents,a three-dimensional(3D)open-framework aluminophosphate[C3NH10]·[HAl3P3O13](1)and a two-dimensional layered aluminophosphate[C3NH10]3·[Al3P4O16](2)were crystallized from the initial mixtures with compositions of Al2O3:2.4 P2O5:5.0 n-propylamine:100 H2O/butan-2-ol,respectively.They are characterized by X-ray powder diffraction(XRD),thermogravimetric(TG),and elemental(CHN)analyses and structurally determined by single-crystal X-ray diffraction analysis.Compound 1 crystallizes in the monoclinic space group P21/c with a=0.85831(13)nm,b=1.7677(3)nm,c=1.04353(12)nm,=123.887(9)°,and V=1.3143(3)nm3.Compound 2 crystallizes in the monoclinic space group P21/c with a=1.1313(2)nm,b=1.4874(3)nm,c=1.8020(6)nm,=125.07(2)°,and V=2.4817(11)nm3.The results show that the properties of solvent have a significant influence on the structure-directing effect of n-propylamine in the crystallization of the open-framework aluminophosphates.展开更多
It is highly desired yet challenged to find an adsorbent with low cost and excellent performance in the removal of organic dyes from aqueous solution. Here we reported that a layered cationic aluminum oxyhydroxide mat...It is highly desired yet challenged to find an adsorbent with low cost and excellent performance in the removal of organic dyes from aqueous solution. Here we reported that a layered cationic aluminum oxyhydroxide material hydrothermally synthesized from the low-cost source materials of AlCl_(3)·6H_(2)O, CaO and H_(2)O, known as JU-111, can meet such criterion in removing methyl orange(MO) and Congo red(CR). JU-111 shows fast adsorption kinetics[especially for CR(15 s)] and high adsorption capacity(MO: >1000 mg/g;CR: >2900 mg/g), surpassing most of the reported adsorbents. Comprehensive characterizations of the adsorption process of MO and CR revealed that both adsorptions were achieved via the anion exchange process. The characteristics of extremely low cost and excellent performance render JU-111 great potential in the practical applications in the removal of anionic dyes.展开更多
The crystallization behavior of the initial mixture with the composition of Al2O3：4.0P2O5：3.0 diethylenetriamine（DETA）：xHF：153H2O was investigated at 180 ℃, where 0≤x≤3. If x≤1.8, three-dimensional openframe...The crystallization behavior of the initial mixture with the composition of Al2O3：4.0P2O5：3.0 diethylenetriamine（DETA）：xHF：153H2O was investigated at 180 ℃, where 0≤x≤3. If x≤1.8, three-dimensional openframework aluminophosphate AIPO-CJ31 was obtained. If 2 ≤x≤3, a chain-like aluminophosphate（1） was obtained. The crystallization process of both compounds was investigated by means of powder X-ray diffraction（XRD） and the concentrations of A1 and P in the liquid product during the crystallization process were analysed by means of induc- tively coupled plasma atomic emission spectroscopy（ICP-AES）. The evolution of the coordination state of A1, P and F during the crystallization was monitored with 27A1, 31p and 19F MAS NMR technique. The influence of the fluoride ions and the source of fluoride ions on the structure-directing effect of DETA was discussed. It was found that the fluoride ions changed the crystallization direction of the initial mixture, i.e., the structure-directing effect of DETA, via altering the distribution or micro-structure of the inorganic fragments.展开更多
Pure silica zeolite has become an important porous material in the chemical industry due to its excellent stability and hydrophobicity. However, there are still some problems in the synthesis process of pure silica ze...Pure silica zeolite has become an important porous material in the chemical industry due to its excellent stability and hydrophobicity. However, there are still some problems in the synthesis process of pure silica zeolite, such as environmental pollution, complex operation and high cost. How to effectively and environmentally synthesize pure silica zeolite still remains a significant challenge. This review summarizes the pure silica zeolitetype frameworks that have been discovered currently, introduces the progresses achieved in the synthesis of pure silica zeolite and prospects the areas for future exploration in the synthesis and development of pure silica zeolite.展开更多
文摘以太原市主城区作为研究区域,基于兴趣点(Point of Interest, POI)数据,采用核密度分析、局部Getis-OrdGI~*指数等方法,对城市商业空间格局进行了研究,在其现有商业空间格局的基础上借助等值线树法对商业中心进行了识别,并对各类行业的空间分布及集聚特征进行了对比分析。结果表明:太原市主城区商业空间已经形成了以柳巷、朝阳以及亲贤北街商圈为中心向外围扩散的分布格局,体现出汾河以东集中连片、汾河以西零星分散的分布特征;识别出太原市主城区内46个基本商业中心,其中以柳巷、朝阳—双塔、体育路—亲贤北街为主城区三大核心商业中心;各类行业空间聚集表现不同,生活服务类、购物服务类以及餐饮服务类行业分布范围广、集聚程度小,医疗保健类、商务服务类、金融服务类行业分布范围小、集聚程度高。
基金the National Natural Science Foundation of China(Nos.U22A20107,U1967215,22078307,22208314,22278379,22238003,and 22002008)the Science and Technology R&D Program Joint Fund Project of Henan Provincial,China(No.222301420001)+3 种基金the Distinguished Young Scholars Innovation Team of Zhengzhou University,China(No.32320275)the Postgraduate Education Reform Project of Henan Province,China(No.2021SJGLX093Y)the National Funded Postdoctoral Researcher Program,China(No.GZC20232382)the Key Research Projects of University in Henan Province,China(No.24A150041).
文摘Zeolite-confined Fe-site catalysts(ZFCs)have emerged as superior materials for sustainably producing high-value chemicals through CO_(2) hydrogenation,owing to their adaptable framework,customizable composition,and thermal robustness.They excel in activating,adsorbing,and converting CO_(2) with remarkable efficiency and consistency in performance.This has sparked a surge in research interest in recent years.The review delves into the latest advancements in CO_(2) catalytic hydrogenation to olefins,alcohols,aromatics,and other liquid hydrocarbons,examining the synthesis,modification tactics,and the correlation between structure and performance across various ZFCs.Additionally,it underscores the pivotal factors affecting performance and sheds light on the mechanisms behind selectivity control in the CO_(2) hydrogenation process facilitated by ZFCs.To conclude,it presents pressing challenges and strategic recommendations to inspire the development of high-performance,durable ZFCs for CO_(2) hydrogenation applications.
基金supported by the National Natural Science Foundation of China(21071124)the Natural Science Foundation of Zhejiang Province(Y4090183)+1 种基金the Foundation of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of Jilin University(2010-16)the Foundation of Key Lab of Polyoxometalates Science of the Ministry of Education of Northeast Normal University(DS-20080102)
文摘A new solid high-proton conductor,H7[Ga(H2O)P2W17O61].18H2O,a substituted heteropoly acid with Dawson structure,has been synthesized by the degradation/ion-exchange/freezing method.The product was characterized by potentiometric titration,chemical analysis,IR,UV,XRD and TG-DTA.Complex impedance measurements show a high conductivity(5.44×10-3 S/cm at 50℃),with an activation energy for proton conduction of 36.04 kJ/mol.The mechanism of proton conduction is the Vehicle mechanism.
基金supported by the National Natural Science Foundation of China (21071124)the Foundation of Jiangxi Educational Committee (GJJ09310)+1 种基金the Foundation of the State Key Laboratory of Inorganic SynthesisPreparative Chemistry of Jilin University (2010-16)
文摘The ruthenium-substituted polyoxometallic acid H6 [Ru(H2O)FeW 11O39 ]·18H2O was synthesized by stepwise acidification and stepwise addition of solutions of the component elements, and an ion-exchange-cooling method. The product was characterized using inductively coupled plasma spectrometry (ICP), Infrared Spectroscopy (IR), Ultraviolet Spectroscopy (UV), and X-ray diffraction (XRD). The results show that this complex has the Keggin structure. The determination of the thermal stability and proton conductivity of this polyoxometallic acid was carried out by a thermogravimetric-differential thermal analysis (TG-DTA) and electrochemical impedance spectroscopy (EIS).
基金National Natural Science Foundation of China(Nos.22109140,21875221,and 22075223)Project of the Distinguished Young Scholars Innovation Team of Zhengzhou University,China(No.32320275).
文摘Lithium-sulfur(Li-S)batteries have been puzzled by the“shuttle effect”.In the recent years,catalytic materials present a huge potential for solving this problem.However,the exploitation for catalytic activity was still challenging in Li-S batteries.In this article,we put forward a single atom catalyst(SAC)of FeN_(4) coupled with Fe_(3)C on the N-doped carbon(FeN_(4)/Fe_(3)C@NC)by one-step pyrolysis method.The FeN_(4) and Fe_(3)C synergistically catalyze the polysulfides conversion when the N-doped carbon provides the high conductive three-dimensional skeleton in Li-S batteries.As a result,the FeN_(4)/Fe_(3)C@NC shows a specific capacity of 1100 mA·h/g at 0.2 C(1 C=1675 mA/g).In addition,the FeN_(4)/Fe_(3)C@NC maintains 99.01%of the pristine specific capacity after 100 cycles at 0.5 C,indicating the improved electrochemical performance in Li-S batteries.This work sheds new lights on the design of engineering catalysts for developing high-performance Li-S batteries.
基金Supported by the National Natural Science Foundation of China（Nos.21571075, 21320102001, 21621001 ） and the National Key Research and Development Program of China（No.2016YFB0701100）.
文摘Three layered aluminophosphates（UiO-15, APDAP12-150 and APDAP-150） with same topology were crystallized from an initial mixture with a molar Composition of A1203：1.SP2Os：5.5R：227HzO, where R is ethylene- diamine, 1,2-diaminopropane or 1,3-diaminopropane, respectively. The crystallization processes of UiO-15, APDAPI2-150 and APDAP-150 were investigated using solid-state NMR in combination with XRD and other cha- racterization techniques. The evolution of the coordination states of Al and P in the solid products was monitored, and the possible starting points of crystallization（core units） of UiO-15, APDAP12-150 and APDAP-150 were obtained and analyzed. The formation ofa trimer as well as a hexamer of aluminophosphate, a monomer of PO4 and a nonamer containing two three-membered rings is critical for the start of crystallization of UiO-15. The formation of a hexamer and a pentamer is critical for the start of crystallization of APDAP12-150. The formation of an A106 monomer and a pentamer containing a three-membered ring is critical for the start of crystallization ofAPDAP-150. The crystal water played a co-structure-directing role in the formation ofAPDAP-150.
基金supported by the National Natural Science Foundation of China(21171063)the Excellent Young Scientists Fund(21222103)+1 种基金the National Basic Research Program of China(2011CB808-703)the Specialized Research Fund for the Doctoral Program of Higher Education
文摘Using n-propylamine as a template,deioned water and secondary-butanol(butan-2-ol)as solvents,a three-dimensional(3D)open-framework aluminophosphate[C3NH10]·[HAl3P3O13](1)and a two-dimensional layered aluminophosphate[C3NH10]3·[Al3P4O16](2)were crystallized from the initial mixtures with compositions of Al2O3:2.4 P2O5:5.0 n-propylamine:100 H2O/butan-2-ol,respectively.They are characterized by X-ray powder diffraction(XRD),thermogravimetric(TG),and elemental(CHN)analyses and structurally determined by single-crystal X-ray diffraction analysis.Compound 1 crystallizes in the monoclinic space group P21/c with a=0.85831(13)nm,b=1.7677(3)nm,c=1.04353(12)nm,=123.887(9)°,and V=1.3143(3)nm3.Compound 2 crystallizes in the monoclinic space group P21/c with a=1.1313(2)nm,b=1.4874(3)nm,c=1.8020(6)nm,=125.07(2)°,and V=2.4817(11)nm3.The results show that the properties of solvent have a significant influence on the structure-directing effect of n-propylamine in the crystallization of the open-framework aluminophosphates.
基金supported by the National Natural Science Foundation of China (Nos.U1967215, 21835002, 21621001)the “111” Project of China (No.B17020).
文摘It is highly desired yet challenged to find an adsorbent with low cost and excellent performance in the removal of organic dyes from aqueous solution. Here we reported that a layered cationic aluminum oxyhydroxide material hydrothermally synthesized from the low-cost source materials of AlCl_(3)·6H_(2)O, CaO and H_(2)O, known as JU-111, can meet such criterion in removing methyl orange(MO) and Congo red(CR). JU-111 shows fast adsorption kinetics[especially for CR(15 s)] and high adsorption capacity(MO: >1000 mg/g;CR: >2900 mg/g), surpassing most of the reported adsorbents. Comprehensive characterizations of the adsorption process of MO and CR revealed that both adsorptions were achieved via the anion exchange process. The characteristics of extremely low cost and excellent performance render JU-111 great potential in the practical applications in the removal of anionic dyes.
基金Supported by the National Natural Science Foundation of China（Nos.21571075, 21320102001, 21621001）, the National Key Research and Development Program of China（No.2016YFB0701100） and the Programme of Introducing Talents of Discipline to Universities（the 111 Project）, China（No.B 17020）.
文摘The crystallization behavior of the initial mixture with the composition of Al2O3：4.0P2O5：3.0 diethylenetriamine（DETA）：xHF：153H2O was investigated at 180 ℃, where 0≤x≤3. If x≤1.8, three-dimensional openframework aluminophosphate AIPO-CJ31 was obtained. If 2 ≤x≤3, a chain-like aluminophosphate（1） was obtained. The crystallization process of both compounds was investigated by means of powder X-ray diffraction（XRD） and the concentrations of A1 and P in the liquid product during the crystallization process were analysed by means of induc- tively coupled plasma atomic emission spectroscopy（ICP-AES）. The evolution of the coordination state of A1, P and F during the crystallization was monitored with 27A1, 31p and 19F MAS NMR technique. The influence of the fluoride ions and the source of fluoride ions on the structure-directing effect of DETA was discussed. It was found that the fluoride ions changed the crystallization direction of the initial mixture, i.e., the structure-directing effect of DETA, via altering the distribution or micro-structure of the inorganic fragments.
基金This work was supported by the National Natural Science Foundation of China (Nos.U1967215,21835002,21621001)the "111" Project of China (No.B17020).
文摘Pure silica zeolite has become an important porous material in the chemical industry due to its excellent stability and hydrophobicity. However, there are still some problems in the synthesis process of pure silica zeolite, such as environmental pollution, complex operation and high cost. How to effectively and environmentally synthesize pure silica zeolite still remains a significant challenge. This review summarizes the pure silica zeolitetype frameworks that have been discovered currently, introduces the progresses achieved in the synthesis of pure silica zeolite and prospects the areas for future exploration in the synthesis and development of pure silica zeolite.
