Developing a chiral material as versatile and universal chiral stationary phase(CSP) for chiral separation in diverse chromatographic techniques simultaneously is of great significance.In this study,we demonstrated fo...Developing a chiral material as versatile and universal chiral stationary phase(CSP) for chiral separation in diverse chromatographic techniques simultaneously is of great significance.In this study,we demonstrated for the first time that a chiral metal-organic cage(MOC),[Zn_(6)M_(4)],as a universal chiral recognition material for both multi-mode high-performance liquid chromatography(HPLC) and capillary gas chromatography(GC) enantioseparation.Two novel HPLC CSPs with different bonding arms(CSP-A with a cationic imidazolium bonding arm and CSP-B with an alkyl chain bonding arm) were prepared by clicking of functionalized chiral MOC [Zn_(6)M_(4)] onto thiolated silica via thiol-ene click chemistry.Meanwhile,a capillary GC column statically coated with the chiral MOC [Zn_(6)M_(4)] was also fabricated.The results showed that the chiral MOC exhibits excellent enantioselectivity not only in normal phase HPLC(NP-HPLC) and reversed phase(RP-HPLC) but also in GC,and various racemates were well separated,including alcohols,diols,esters,ketones,ethers,amines,and epoxides.Importantly,CSP-A and CSP-B are complementary to commercially available Chiralcel OD-H and Chiralpak AD-H columns in enantioseparation,which can separate some racemates that could not be or could not well be separated by the two widely used commercial columns,suggesting the great potential of the two prepared CSPs in enantioseparation.This work reveals that the chiral MOC is potential versatile chiral recognition materials for both HPLC and GC,and also paves the way to expand the potential applications of MOCs.展开更多
Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial c...Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.展开更多
Integration of single-atom catalysts(SACs) onto metal-organic frameworks(MOFs) with porous channels has garnered significant interest in the field of CO_(2) reduction.However,MOFs are usually bulky can impede the diff...Integration of single-atom catalysts(SACs) onto metal-organic frameworks(MOFs) with porous channels has garnered significant interest in the field of CO_(2) reduction.However,MOFs are usually bulky can impede the diffusion of intermediates with substrates and maximizing catalytic site utilization remains a challenge.In this study,we utilized firstly the post-synthetic single-atom chelation sites on zirconiumbased metal-organic cages(Zr-MOCs) to anchor cobalt(Co) atom to synthesize single-dispersible Zr T^(-1)-NH_(2)-IS-Co molecular cages for CO_(2) photoreduction.Experimental results demonstrate that Zr T^(-1)-NH_(2)-ISCo exhibits impressive catalytic performance,achieving syngas yields of up to 30.9 mmol g^(-1)h^(-1),ranking among the highest values of reported crystalline porous catalysts.Mechanistic insights reveal the newly introduced metal serving as the catalytic site and ^(*)COOH acts as a crucial intermediate in the CO_(2) reduction process.Furthermore,the successful synthesis of Zr T^(-1)-NH_(2)-IS-Ni and Zr T^(-1)-NH_(2)-IS-Mn show the universality of the modification strategies,with their CO_(2) catalytic activity surpassing that of Zr T^(-1)-NH_(2).展开更多
We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptiona...We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions.展开更多
The potent antibacterial activity of silver nanoparticles is primarily attributed to the release of silver ions,which disrupt cell membranes and inactivate essential enzymes through Ag−S bonding formation.[Objective]T...The potent antibacterial activity of silver nanoparticles is primarily attributed to the release of silver ions,which disrupt cell membranes and inactivate essential enzymes through Ag−S bonding formation.[Objective]To explore silver ion immobilization to minimize silver release.[Methods]A macrocyclic cryptand with nitrogen bridgeheads was prepared and subsequently chelated with silver ions to produce Cage silver(I),which was then coordinated with different ratios of sulfonated chitosan(SCS)to form SCS/Cage Ag(I)complexes(SCA1,SCA2,and SCA3).The antioxidant activities of the complexes were assessed by reducing power and 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical and hydrogen peroxide scavenging assays.The antibacterial activities of the complexes were evaluated based on the minimum inhibitory concentrations(MICs)and minimum bactericidal concentrations(MBCs)against Staphylococcus aureus ATCC 6538 and Escherichia coli O157:H7 and the inhibition rate on biofilm formation.[Results]Cage silver(I)exhibited strong antibacterial activity,with the MIC of 0.015 mg/mL and MBC of 0.031 mg/mL against S.aureus ATCC 6538,and the MIC of 0.031 mg/mL and MBC of 0.120 mg/mL against E.coli O157:H7.Significant antioxidant properties of Cage silver(I)were also observed,as demonstrated by the DPPH free radical scavenging rates of 42.2%and 53.1%at 326 nm and 517 nm,respectively.Cage silver(I)exhibited the highest antibacterial and antioxidant activities,followed by SCA1,SCA2,SCA3,and SCS,because the content of silver ions in Cage silver(I)was 10-fold higher than that in SCA1.The antibacterial and antioxidant activities of SCA1 were better than those of Cage silver(I),which further indicated that the sulfonic groups of SCS may intensely coordinate with silver ions to exert synergistic effects.[Conclusion]Combining the merits of silver ions and SCS improves the bioavailability of the agent at microbicidal concentrations,minimizes the accumulation in the environment,and reduces treatment costs.The method developed herein offers a sustainable approach to enhance microbial control while minimizing the impact on the environment.展开更多
This research develops a gravity-based index of public school competition from private schools within local markets. Proponents of educational reform often call for policies to increase competition between schools. A ...This research develops a gravity-based index of public school competition from private schools within local markets. Proponents of educational reform often call for policies to increase competition between schools. A major hurdle for researchers examining this issue is to determine a workable definition of “competition” by which they can measure the degree of competition within local markets. This study addresses this challenge by developing a school competition index for public schools in the Jackson metropolitan area of Mississippi, USA that considers the enrollments in public schools and the enrollments in their neighboring private schools, as well as the distances between them. The school competition index reveals the degree of competition for each public school based on its spatial location relative to peer private schools operating within its service area. This methodology can be useful for evaluating competition in other markets and redefining the traditional market structure.展开更多
Porous organic cages(POCs)with permanent porosity and excellent host–vip property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testifie...Porous organic cages(POCs)with permanent porosity and excellent host–vip property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testified in a practical battery.Herein,we design and fabricate a quasi-solid-state electrolyte(QSSE)based on a POC to enable the stable operation of Li-metal batteries(LMBs).Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC,the resulting POC-based QSSE exhibits a high Li+transference number of 0.67 and a high ionic conductivity of 1.25×10^(−4) S cm^(−1) with a low activation energy of 0.17 eV.These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h.As a proof of concept,the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85%capacity retention after 1000 cycles.Therefore,our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems,such as Na and K batteries.展开更多
Herein,we report the synthesis and third-order nonlinear optical(NLO)properties of a novel cage-based 2D metal-organic framework constructed from Ti_(4)L_(6)(L4-=embonate)cage combined with Mg^(2+)and tris[4-(1H-imida...Herein,we report the synthesis and third-order nonlinear optical(NLO)properties of a novel cage-based 2D metal-organic framework constructed from Ti_(4)L_(6)(L4-=embonate)cage combined with Mg^(2+)and tris[4-(1H-imidazol-1-yl)phenyl]amine(tipa)ligand,whose molecular formula is(Me_(2)CH_(2))_(2)[Mg_(3)(Ti_(4)L_(6))(tipa)(H_(2)O)_(12)](PTC‑378).The Ti_(4)L_(6)tetrahedral cages serve as robust building units,while the Mg^(2+)ions and tipa ligands provide structural stability and tunable optical properties.The resulting PTC‑378 film exhibited intriguing third-order NLO property,which was systematically investigated using Z-scan techniques.Our results demonstrate that the synergistic interaction between Ti_(4)L_(6)cages andπ-conjugated ligands significantly enhances the NLO performance of the materials.CCDC:2453909.展开更多
Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strate-gies to manage biofouling in marine fish aquaculture.The coastal area in the Yellow Sea is a ke...Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strate-gies to manage biofouling in marine fish aquaculture.The coastal area in the Yellow Sea is a key area for cage aquaculture in China;however,this region faces significant challenges from biofouling organisms.Here,we employed an experimental approach in a filed mesocosm in a net cage aquaculture area in the Yellow Sea,with weekly monitoring of changes in macrofouling species on mesh nets and in the seawater,to assess the utility of water eDNA metabarcoding for identifying macrofoulers.We compared the temporal variation patterns in the composition and diversity of macrofouling communities identified through morphological method as well as COI and 18S rRNA metabarcoding.The results showed that metabarcoding detected the majority of macrofoulers identified through morphological method(64%),and revealed additional species that were overlooked by traditional monitoring approach.Furthermore,the changes in diversity and community composition over sampling dates in COI data were generally consistent with those in morphological identification,although a temporal lag existed between these two approaches.A notable shift in the fouling community occurred at the end of June with the appearance of Ectopleura crocea and Caprella sp.,marking a pivotal change in its structure.Future research could focus on developing targeted primers for these key fouling species,which would enhance the efficiency of monitoring efforts.展开更多
In recent years,stimulus-responsive metal-organic cages(MOCs)have attracted significant attention due to their dynamic structures and properties,which greatly enhance the structural diversity and functional adaptabili...In recent years,stimulus-responsive metal-organic cages(MOCs)have attracted significant attention due to their dynamic structures and properties,which greatly enhance the structural diversity and functional adaptability of these supramolecular assemblies.Among various external stimuli,light stands out as a straightforward and efficient means of modulating MOCs through the incorporation of photoresponsive units,such as azobenzene,thereby enabling precise photoresponsive behavior.Substantial progress has been made in the development of azobenzene-containing MOCs,underscoring their research significance and broad application potential across multiple fields.Given these advancements,it is timely to provide a comprehensive summary of the latest progress in azophenyl-based MOCs.This review will highlight key developments and explore their functional applications.展开更多
Background:Previously,a chronic social defeat stress(CSDS)model has been widely-adopted for assessing depressive-like behaviors in animals.However,there is still room for improvement in the CSDS model to safeguard stu...Background:Previously,a chronic social defeat stress(CSDS)model has been widely-adopted for assessing depressive-like behaviors in animals.However,there is still room for improvement in the CSDS model to safeguard study accuracy and the wel-fare of lab rodents.Our study team developed a novel,standardized apparatus to induce CSDS in rodents and assessed the model's practical adaptability.Methods:An innovative CSDS cage apparatus and water bottle was designed.To evaluate the effectiveness of the newly developed tools,a variety of animal models,including the tail suspension test(TST),sucrose preference test,forced swimming test(FST),novelty-suppressed feeding test,female urine sniffing test,and open field test(OFT),were adopted to assess depressive-like behaviors in mice.Fluoxetine treat-ment was also administered to observe the reversal effect,as part of the validation.Results:The CSDS cage apparatus resulted in the manifestation of depressive-like behaviors in the model mice.Significant reductions in sucrose preference and urine sniffing time were observed,while the OFT revealed decreased central zone total distance,residence time,and frequency of entry.Moreover,increased immobility was found in the FST and TST.Fluoxetine treatment was found to successfully reverse the modeling effect.Conclusion:The CSDS cage apparatus was validated for enhanced usability and ad-dressed the previous challenges of water bottle leakage and lab rodent welfare is-sues.The consistent results from multiple behavioral tests also supported real-world application of the apparatus,offering researchers a promising alternative to conven-tional rodent cages.展开更多
The desensitization of nitramine explosives while maintaining energetic performance is challenging.A highly efficient desensitizer is the key to solving the antinomy.This study focuses on using porous organic cages(PO...The desensitization of nitramine explosives while maintaining energetic performance is challenging.A highly efficient desensitizer is the key to solving the antinomy.This study focuses on using porous organic cages(POCs),specifically CC3 and RCC3,to desensitize RDX.By coating 0.1 wt%–5 wt%of POCs on RDX particles,a series of composite energetic materials were prepared.Characterization results show that POCs change the surface morphology of RDX,and there are interfacial interactions between them.The RDX@POCs composites exhibit enhanced stabilities in terms of heat,impact,friction,and electrostatic spark.For the RDX@RCC3-5%composite,the impact sensitivity(E_(IS)),friction sensitivity(E_(FS)),and electrostatic sensitivity(EES)were significantly reduced by 66.7%,68.8%,and 56.5%,respectively,while the detonation velocity decreased by merely 3.1%.These findings indicate that POCs,especially RCC3,are promising desensitizers for nitramine explosives,and their desensitization mechanisms likely involve barrier and buffering effects.The distinct desensitization behavior of RDX@RCC3 highlights the effectiveness of POCs in reducing the sensitivity of RDX without significantly compromising its energetic properties.展开更多
Intramolecular[2+2]photocycloaddition is a reliable way to synthesize high-strained cyclobutylcontaining structures for high-value chemicals.Here we propose a photosensitized dimer of methyl cyclopentadiene(DMCPD)intr...Intramolecular[2+2]photocycloaddition is a reliable way to synthesize high-strained cyclobutylcontaining structures for high-value chemicals.Here we propose a photosensitized dimer of methyl cyclopentadiene(DMCPD)intramolecular[2+2]cycloaddition to synthesize an intriguing liquid caged fuel,namely 3,8-dimethylpentacyclic[5.3.0.0^(2,5).0^(3,9).0^(4.8)]decane(MPCD),with two four-membered rings,four five-membered rings and two methyl branched chains.The reaction conditions are optimized to obtain a high DMCPD conversion of 80.95%as well as a high MPCD selectivity of 74.19%.Based on the quenching experiment and low-temperature phosphorescence test,intramolecular[2+2]photocycloaddition complies with the Dexter triplet-energy-transfer mechanism,which is essentially double electron exchange between excited photosensitizer and DMCPD.Through kinetic studies,the reaction order(α=1)and the reaction kinetic equation related to light intensity and DMCPD concentration are obtained.MPCD has excellent physicochemical properties,with a high density of 0.964 g·cm^(-3),high net heat of combustion of 42.63 MJ·kg^(-1),relatively low kinetic viscosity of 25.03 mm^(2)·s^(-1)at(20℃),and high specific impulse of 328.19 s.展开更多
Selective separation of phenanthrene(PHE)from aromatic isomer mixtures poses a significant challenge in industry due to the similar physical properties of PHE and its isomer anthracene(ANT).Herein,we report the self-a...Selective separation of phenanthrene(PHE)from aromatic isomer mixtures poses a significant challenge in industry due to the similar physical properties of PHE and its isomer anthracene(ANT).Herein,we report the self-assembly of a water-soluble Pd_(2)L_(2) cage 1 with a large hydrophobic cavity,formed from novel macrocyclic ligands(L)and cis-Pd(Ⅱ).Cage 1 can selectively encapsulate PHE instead of ANT.Based on host-vip recognition followed by extraction,we achieve a remarkable 99%purity of PHE separation from an equimolar mixture of PHE and ANT using cage 1 in aqueous solution.Importantly,the separation performance of PHE using cage 1 remains unaffected even after five extraction cycles,demonstrating its robustness.This work highlights the potential of supramolecular cages for efficient and cost-effective PHE separation from the isomer ANT in aqueous solutions using such promising host-vip strategy.展开更多
Covalent organic cages(COCs)are three-dimensional organic molecules with permanent cavities,known for their ordered pore structures,excellent processability,and modular design.They have shown significant potential in ...Covalent organic cages(COCs)are three-dimensional organic molecules with permanent cavities,known for their ordered pore structures,excellent processability,and modular design.They have shown significant potential in applications such as gas adsorption,molecular separation,and catalysis.Introducing chiral elements into COCs results in chiral COCs with confined chiral cavities,which endows them with unique chiral functions and expands their application prospects.This review summarizes the research progress on chiral covalent organic cages,focusing on strategies for incorporating chiral elements,the structures and synthesis methods of representative chiral COCs,and advancements in their chiral functions.Additionally,we provide perspectives on future research directions.We hope this review will inspire further interest and creativity among researchers in the field of chiral molecular cages,leading to the development of materials with unique structures and functions.展开更多
The structural synthesis and property exploration of organometallic cages have always attracted widespread attention from chemists.Nevertheless,the achievement on photothermal property enhancement and their applicatio...The structural synthesis and property exploration of organometallic cages have always attracted widespread attention from chemists.Nevertheless,the achievement on photothermal property enhancement and their application in solar-driven water evaporation via structural modulation remain scarce.Here,four organometallic cages 1,2,3 and 4 with different functional sites are synthesized via reasonably selecting different building units E1,E2,E3 and E4 based on a tetradentate pyridyl ligand L1.These complexes are characterized by single-crystal X-ray diffraction analysis,nuclear magnetic resonance(NMR)spectroscopy and ESI-TOF-MS analysis.Notably,they exhibit different near-infrared(NIR)photothermal conversion properties due to variations in their size,conjugated area,and electron-withdrawing characteristic of halogen atoms in building units.Compound 4 shows the optimal photothermal performance among this series,with notably enhanced near-infrared absorption and the highest photothermal conversion efficiency.The radical effect of the building unit plays an important role in photothermal conversion ability,as evidenced by the significant EPR signal changes.Therefore,compound 4 is used to construct new membrane 1',achieving a solar power-induced water steam generation rate of 1.92 kg·m^(-2).h^(−1),demonstrating its suitability for the collection of fresh water through desalination and wastewater treatment.This research provides a new strategy for synthesizing and optimizing photothermal conversion property of half sandwich organometallic cages.展开更多
基金supported by the National Natural Science Foundation of China (Nos.22064020,22364022,and 22174125)the Applied Basic Research Foundation of Yunnan Province (Nos.202101AT070101 and 202201AT070029)。
文摘Developing a chiral material as versatile and universal chiral stationary phase(CSP) for chiral separation in diverse chromatographic techniques simultaneously is of great significance.In this study,we demonstrated for the first time that a chiral metal-organic cage(MOC),[Zn_(6)M_(4)],as a universal chiral recognition material for both multi-mode high-performance liquid chromatography(HPLC) and capillary gas chromatography(GC) enantioseparation.Two novel HPLC CSPs with different bonding arms(CSP-A with a cationic imidazolium bonding arm and CSP-B with an alkyl chain bonding arm) were prepared by clicking of functionalized chiral MOC [Zn_(6)M_(4)] onto thiolated silica via thiol-ene click chemistry.Meanwhile,a capillary GC column statically coated with the chiral MOC [Zn_(6)M_(4)] was also fabricated.The results showed that the chiral MOC exhibits excellent enantioselectivity not only in normal phase HPLC(NP-HPLC) and reversed phase(RP-HPLC) but also in GC,and various racemates were well separated,including alcohols,diols,esters,ketones,ethers,amines,and epoxides.Importantly,CSP-A and CSP-B are complementary to commercially available Chiralcel OD-H and Chiralpak AD-H columns in enantioseparation,which can separate some racemates that could not be or could not well be separated by the two widely used commercial columns,suggesting the great potential of the two prepared CSPs in enantioseparation.This work reveals that the chiral MOC is potential versatile chiral recognition materials for both HPLC and GC,and also paves the way to expand the potential applications of MOCs.
基金financially supported by the Ten-thousand Talents Programthe K. C. Wong Pioneer Talent Program+3 种基金China Three Gorges Corporation (WWKY-2021–0027)Inner Mongolia Science and Technology Plan (2021ZD0033)the National Natural Science Foundation of China (52202121)funded by China Petroleum&Chemical Corporation (123091)
文摘Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.
基金financially supported by the NSFC of China (Nos.22175033,22371033,22371032)Jilin Provincial Department of Science and Technology (No.20230508108RC)+1 种基金the Fundamental Research Funds for the Central Universities Excellent Youth Team Program (No.2412023YQ001)the Postdoctoral Fellowship Program of CPSF (No.GZC20230939)。
文摘Integration of single-atom catalysts(SACs) onto metal-organic frameworks(MOFs) with porous channels has garnered significant interest in the field of CO_(2) reduction.However,MOFs are usually bulky can impede the diffusion of intermediates with substrates and maximizing catalytic site utilization remains a challenge.In this study,we utilized firstly the post-synthetic single-atom chelation sites on zirconiumbased metal-organic cages(Zr-MOCs) to anchor cobalt(Co) atom to synthesize single-dispersible Zr T^(-1)-NH_(2)-IS-Co molecular cages for CO_(2) photoreduction.Experimental results demonstrate that Zr T^(-1)-NH_(2)-ISCo exhibits impressive catalytic performance,achieving syngas yields of up to 30.9 mmol g^(-1)h^(-1),ranking among the highest values of reported crystalline porous catalysts.Mechanistic insights reveal the newly introduced metal serving as the catalytic site and ^(*)COOH acts as a crucial intermediate in the CO_(2) reduction process.Furthermore,the successful synthesis of Zr T^(-1)-NH_(2)-IS-Ni and Zr T^(-1)-NH_(2)-IS-Mn show the universality of the modification strategies,with their CO_(2) catalytic activity surpassing that of Zr T^(-1)-NH_(2).
基金supported by the Natural Science Foundation of China(Grant Nos.T2325013,52288102,52090024,12034009,12474004,and 12304036)the National Key R&D Program of China Grant No.2023YFA1610000+1 种基金the Fundamental Research Funds for the Central Universitiesthe Program for Jilin University and Sun Yat-sen University.
文摘We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions.
文摘The potent antibacterial activity of silver nanoparticles is primarily attributed to the release of silver ions,which disrupt cell membranes and inactivate essential enzymes through Ag−S bonding formation.[Objective]To explore silver ion immobilization to minimize silver release.[Methods]A macrocyclic cryptand with nitrogen bridgeheads was prepared and subsequently chelated with silver ions to produce Cage silver(I),which was then coordinated with different ratios of sulfonated chitosan(SCS)to form SCS/Cage Ag(I)complexes(SCA1,SCA2,and SCA3).The antioxidant activities of the complexes were assessed by reducing power and 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical and hydrogen peroxide scavenging assays.The antibacterial activities of the complexes were evaluated based on the minimum inhibitory concentrations(MICs)and minimum bactericidal concentrations(MBCs)against Staphylococcus aureus ATCC 6538 and Escherichia coli O157:H7 and the inhibition rate on biofilm formation.[Results]Cage silver(I)exhibited strong antibacterial activity,with the MIC of 0.015 mg/mL and MBC of 0.031 mg/mL against S.aureus ATCC 6538,and the MIC of 0.031 mg/mL and MBC of 0.120 mg/mL against E.coli O157:H7.Significant antioxidant properties of Cage silver(I)were also observed,as demonstrated by the DPPH free radical scavenging rates of 42.2%and 53.1%at 326 nm and 517 nm,respectively.Cage silver(I)exhibited the highest antibacterial and antioxidant activities,followed by SCA1,SCA2,SCA3,and SCS,because the content of silver ions in Cage silver(I)was 10-fold higher than that in SCA1.The antibacterial and antioxidant activities of SCA1 were better than those of Cage silver(I),which further indicated that the sulfonic groups of SCS may intensely coordinate with silver ions to exert synergistic effects.[Conclusion]Combining the merits of silver ions and SCS improves the bioavailability of the agent at microbicidal concentrations,minimizes the accumulation in the environment,and reduces treatment costs.The method developed herein offers a sustainable approach to enhance microbial control while minimizing the impact on the environment.
文摘This research develops a gravity-based index of public school competition from private schools within local markets. Proponents of educational reform often call for policies to increase competition between schools. A major hurdle for researchers examining this issue is to determine a workable definition of “competition” by which they can measure the degree of competition within local markets. This study addresses this challenge by developing a school competition index for public schools in the Jackson metropolitan area of Mississippi, USA that considers the enrollments in public schools and the enrollments in their neighboring private schools, as well as the distances between them. The school competition index reveals the degree of competition for each public school based on its spatial location relative to peer private schools operating within its service area. This methodology can be useful for evaluating competition in other markets and redefining the traditional market structure.
基金supported by the National Natural Science Foundation of China(No.92372123)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515012057,2022B1515020005,2023B1515130004)Guangzhou Basic and Applied Basic Research Foundation(No.202201011342).
文摘Porous organic cages(POCs)with permanent porosity and excellent host–vip property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testified in a practical battery.Herein,we design and fabricate a quasi-solid-state electrolyte(QSSE)based on a POC to enable the stable operation of Li-metal batteries(LMBs).Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC,the resulting POC-based QSSE exhibits a high Li+transference number of 0.67 and a high ionic conductivity of 1.25×10^(−4) S cm^(−1) with a low activation energy of 0.17 eV.These allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 h.As a proof of concept,the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85%capacity retention after 1000 cycles.Therefore,our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems,such as Na and K batteries.
文摘Herein,we report the synthesis and third-order nonlinear optical(NLO)properties of a novel cage-based 2D metal-organic framework constructed from Ti_(4)L_(6)(L4-=embonate)cage combined with Mg^(2+)and tris[4-(1H-imidazol-1-yl)phenyl]amine(tipa)ligand,whose molecular formula is(Me_(2)CH_(2))_(2)[Mg_(3)(Ti_(4)L_(6))(tipa)(H_(2)O)_(12)](PTC‑378).The Ti_(4)L_(6)tetrahedral cages serve as robust building units,while the Mg^(2+)ions and tipa ligands provide structural stability and tunable optical properties.The resulting PTC‑378 film exhibited intriguing third-order NLO property,which was systematically investigated using Z-scan techniques.Our results demonstrate that the synergistic interaction between Ti_(4)L_(6)cages andπ-conjugated ligands significantly enhances the NLO performance of the materials.CCDC:2453909.
基金supported by grants from the National Key Research and Development Program of China(No.2023YFD2401103)the Fundamental Research Funds for the Central Universities.
文摘Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strate-gies to manage biofouling in marine fish aquaculture.The coastal area in the Yellow Sea is a key area for cage aquaculture in China;however,this region faces significant challenges from biofouling organisms.Here,we employed an experimental approach in a filed mesocosm in a net cage aquaculture area in the Yellow Sea,with weekly monitoring of changes in macrofouling species on mesh nets and in the seawater,to assess the utility of water eDNA metabarcoding for identifying macrofoulers.We compared the temporal variation patterns in the composition and diversity of macrofouling communities identified through morphological method as well as COI and 18S rRNA metabarcoding.The results showed that metabarcoding detected the majority of macrofoulers identified through morphological method(64%),and revealed additional species that were overlooked by traditional monitoring approach.Furthermore,the changes in diversity and community composition over sampling dates in COI data were generally consistent with those in morphological identification,although a temporal lag existed between these two approaches.A notable shift in the fouling community occurred at the end of June with the appearance of Ectopleura crocea and Caprella sp.,marking a pivotal change in its structure.Future research could focus on developing targeted primers for these key fouling species,which would enhance the efficiency of monitoring efforts.
基金supported by the National Nature Science Foundation of China(No.22401096)the Fundamental Research Funds for the Central Universities(East China Normal University)。
文摘In recent years,stimulus-responsive metal-organic cages(MOCs)have attracted significant attention due to their dynamic structures and properties,which greatly enhance the structural diversity and functional adaptability of these supramolecular assemblies.Among various external stimuli,light stands out as a straightforward and efficient means of modulating MOCs through the incorporation of photoresponsive units,such as azobenzene,thereby enabling precise photoresponsive behavior.Substantial progress has been made in the development of azobenzene-containing MOCs,underscoring their research significance and broad application potential across multiple fields.Given these advancements,it is timely to provide a comprehensive summary of the latest progress in azophenyl-based MOCs.This review will highlight key developments and explore their functional applications.
基金National Natural Science Foundation of China,Grant/Award Number:82204958 and 82305065Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2020ZD17+2 种基金Traditional Chinese Medicine Emotional Disease and Brain Steady State Regulation Innovation Team,Grant/Award Number:2023KJ191Medical and Health Science and Technology Development Plan Project of Shandong Province,Grant/Award Number:202105010467Traditional Chinese Medicine Science and Technology Project of Shandong Province,Grant/Award Number:Q-2022059。
文摘Background:Previously,a chronic social defeat stress(CSDS)model has been widely-adopted for assessing depressive-like behaviors in animals.However,there is still room for improvement in the CSDS model to safeguard study accuracy and the wel-fare of lab rodents.Our study team developed a novel,standardized apparatus to induce CSDS in rodents and assessed the model's practical adaptability.Methods:An innovative CSDS cage apparatus and water bottle was designed.To evaluate the effectiveness of the newly developed tools,a variety of animal models,including the tail suspension test(TST),sucrose preference test,forced swimming test(FST),novelty-suppressed feeding test,female urine sniffing test,and open field test(OFT),were adopted to assess depressive-like behaviors in mice.Fluoxetine treat-ment was also administered to observe the reversal effect,as part of the validation.Results:The CSDS cage apparatus resulted in the manifestation of depressive-like behaviors in the model mice.Significant reductions in sucrose preference and urine sniffing time were observed,while the OFT revealed decreased central zone total distance,residence time,and frequency of entry.Moreover,increased immobility was found in the FST and TST.Fluoxetine treatment was found to successfully reverse the modeling effect.Conclusion:The CSDS cage apparatus was validated for enhanced usability and ad-dressed the previous challenges of water bottle leakage and lab rodent welfare is-sues.The consistent results from multiple behavioral tests also supported real-world application of the apparatus,offering researchers a promising alternative to conven-tional rodent cages.
文摘The desensitization of nitramine explosives while maintaining energetic performance is challenging.A highly efficient desensitizer is the key to solving the antinomy.This study focuses on using porous organic cages(POCs),specifically CC3 and RCC3,to desensitize RDX.By coating 0.1 wt%–5 wt%of POCs on RDX particles,a series of composite energetic materials were prepared.Characterization results show that POCs change the surface morphology of RDX,and there are interfacial interactions between them.The RDX@POCs composites exhibit enhanced stabilities in terms of heat,impact,friction,and electrostatic spark.For the RDX@RCC3-5%composite,the impact sensitivity(E_(IS)),friction sensitivity(E_(FS)),and electrostatic sensitivity(EES)were significantly reduced by 66.7%,68.8%,and 56.5%,respectively,while the detonation velocity decreased by merely 3.1%.These findings indicate that POCs,especially RCC3,are promising desensitizers for nitramine explosives,and their desensitization mechanisms likely involve barrier and buffering effects.The distinct desensitization behavior of RDX@RCC3 highlights the effectiveness of POCs in reducing the sensitivity of RDX without significantly compromising its energetic properties.
基金support from the National Natural Science Foundation of China(22222808,22408272,U24A20547)the China National Postdoctoral Program for Innovative Talents(BX20240251)+3 种基金the Natural Science Foundation of Tianjin(24JCQNJC01820)the China Postdoctoral Science Foundation(2023M742592)the Aeronautical Science Foundation of China(2023Z073048003)the Haihe Laboratory of Sustainable Chemical Transformations。
文摘Intramolecular[2+2]photocycloaddition is a reliable way to synthesize high-strained cyclobutylcontaining structures for high-value chemicals.Here we propose a photosensitized dimer of methyl cyclopentadiene(DMCPD)intramolecular[2+2]cycloaddition to synthesize an intriguing liquid caged fuel,namely 3,8-dimethylpentacyclic[5.3.0.0^(2,5).0^(3,9).0^(4.8)]decane(MPCD),with two four-membered rings,four five-membered rings and two methyl branched chains.The reaction conditions are optimized to obtain a high DMCPD conversion of 80.95%as well as a high MPCD selectivity of 74.19%.Based on the quenching experiment and low-temperature phosphorescence test,intramolecular[2+2]photocycloaddition complies with the Dexter triplet-energy-transfer mechanism,which is essentially double electron exchange between excited photosensitizer and DMCPD.Through kinetic studies,the reaction order(α=1)and the reaction kinetic equation related to light intensity and DMCPD concentration are obtained.MPCD has excellent physicochemical properties,with a high density of 0.964 g·cm^(-3),high net heat of combustion of 42.63 MJ·kg^(-1),relatively low kinetic viscosity of 25.03 mm^(2)·s^(-1)at(20℃),and high specific impulse of 328.19 s.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1503300 and 2021YFA1500400)the National Natural Science Foundation of China(Nos.22171262,21825107 and 22171264)the Science Foundation of Fujian Province(Nos.2021J01516 and 2021J02016)。
文摘Selective separation of phenanthrene(PHE)from aromatic isomer mixtures poses a significant challenge in industry due to the similar physical properties of PHE and its isomer anthracene(ANT).Herein,we report the self-assembly of a water-soluble Pd_(2)L_(2) cage 1 with a large hydrophobic cavity,formed from novel macrocyclic ligands(L)and cis-Pd(Ⅱ).Cage 1 can selectively encapsulate PHE instead of ANT.Based on host-vip recognition followed by extraction,we achieve a remarkable 99%purity of PHE separation from an equimolar mixture of PHE and ANT using cage 1 in aqueous solution.Importantly,the separation performance of PHE using cage 1 remains unaffected even after five extraction cycles,demonstrating its robustness.This work highlights the potential of supramolecular cages for efficient and cost-effective PHE separation from the isomer ANT in aqueous solutions using such promising host-vip strategy.
基金supported by the National Natural Science Foundation of China(Grant Nos.22271164 and U20A20259 and 22371147)the Fundamental Research Funds for the Central Universities,the NCC Fund(Grant No.NCC2020FH04)+1 种基金the Tianshan Innovation Team Plan of Xinjiang Uygur Autonomous Region(Grant No.2023D14002)Nankai University(NKU).
文摘Covalent organic cages(COCs)are three-dimensional organic molecules with permanent cavities,known for their ordered pore structures,excellent processability,and modular design.They have shown significant potential in applications such as gas adsorption,molecular separation,and catalysis.Introducing chiral elements into COCs results in chiral COCs with confined chiral cavities,which endows them with unique chiral functions and expands their application prospects.This review summarizes the research progress on chiral covalent organic cages,focusing on strategies for incorporating chiral elements,the structures and synthesis methods of representative chiral COCs,and advancements in their chiral functions.Additionally,we provide perspectives on future research directions.We hope this review will inspire further interest and creativity among researchers in the field of chiral molecular cages,leading to the development of materials with unique structures and functions.
基金the National Natural Science Foundation of China(No.22471113)the Natural Science Foundation for Excellent Young Scholars of Henan Province(No.242300421139)the Sci-ence and Technology Innovation Talent Program of the University in Henan Province(25HASTIT001).
文摘The structural synthesis and property exploration of organometallic cages have always attracted widespread attention from chemists.Nevertheless,the achievement on photothermal property enhancement and their application in solar-driven water evaporation via structural modulation remain scarce.Here,four organometallic cages 1,2,3 and 4 with different functional sites are synthesized via reasonably selecting different building units E1,E2,E3 and E4 based on a tetradentate pyridyl ligand L1.These complexes are characterized by single-crystal X-ray diffraction analysis,nuclear magnetic resonance(NMR)spectroscopy and ESI-TOF-MS analysis.Notably,they exhibit different near-infrared(NIR)photothermal conversion properties due to variations in their size,conjugated area,and electron-withdrawing characteristic of halogen atoms in building units.Compound 4 shows the optimal photothermal performance among this series,with notably enhanced near-infrared absorption and the highest photothermal conversion efficiency.The radical effect of the building unit plays an important role in photothermal conversion ability,as evidenced by the significant EPR signal changes.Therefore,compound 4 is used to construct new membrane 1',achieving a solar power-induced water steam generation rate of 1.92 kg·m^(-2).h^(−1),demonstrating its suitability for the collection of fresh water through desalination and wastewater treatment.This research provides a new strategy for synthesizing and optimizing photothermal conversion property of half sandwich organometallic cages.
