Under the context of carbon neutrality of China,it is urgent to shift our energy supply towards cleaner fuels as well as to reduce the greenhouse gas emission.Currently,coal is the main fossil fuel energy source of Ch...Under the context of carbon neutrality of China,it is urgent to shift our energy supply towards cleaner fuels as well as to reduce the greenhouse gas emission.Currently,coal is the main fossil fuel energy source of China.The country is striving hard to replace it with methane,a cleaner fossil fuel.Although China has rich geological resources of methane as coal bed methane(CBM)reserves,it is quite challenging to utilize them due to low concentration.The CBM is however mainly emitted directly to atmosphere during coal mining,causing waste of the resource and huge contribution to greenhouse effect.The recent work by Yang et al.demonstrated a potential solution to extract low concentration methane selectively from CBM through using MOF materials as sorbents.Such kind of materials and associated separation technology are promising to reduce greenhouse gas emission and promote the methane production capability,which would contribute to carbon neutrality in dual pathways.展开更多
Short-chain perfluorocarboxylic acids(PFCAs) are a class of persistent organic pollutants that are widely used as substitutes for long-chain PFCAs. However, they also pose a non-negligible risk to ecosystems. In this ...Short-chain perfluorocarboxylic acids(PFCAs) are a class of persistent organic pollutants that are widely used as substitutes for long-chain PFCAs. However, they also pose a non-negligible risk to ecosystems. In this study, we demonstrated that a fluorescent metal–organic framework(MOF)(named V-101) constructed from In^(3+)and an aromatic-rich tetratopic carboxylate ligand 5-[2,6-bis(4-carboxyphenyl) pyridin-4-yl] isophthalic acid(H4BCPIA) exhibited highly efficient turn-off and turn-on fluorescence responses toward five short-chain PFCAs in water and methanol, respectively. The limits of detection of V-101 toward five short-chain PFCAs are down to μg/L level, and it showed good anti-interference abilities toward short-chain PFCAs in the presence of common metal ions. The major mechanisms associated with fluorescence responses were molecular collisions and interactions between V-101 and short-chain PFCAs. This work demonstrates that the structure variety of MOFs imparts them with the potential of MOFs in the detection of short-chain PFCAs for pollution control.展开更多
The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH...The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH_4 are considered as promising candidates for the replacement of traditional fossil fuels. However, the technologies for the storage of these gases are still immature. In addition, the release of anthropogenic toxic gases into the atmosphere is a worldwide threat of growing concern. Both in academia and industry, considerable research efforts have been devoted to developing advanced porous materials for the effective and energy-efficient separation, storage, or capture of the related gases. In contrast to conventional inorganic porous materials such as zeolites and activated carbons, metal–organic frameworks(MOFs) are considered as a type of promising materials for gas separation and storage. In this contribution, we review the recent research advance of MOFs in some relevant applications, including CO_2 capture, O_2 purification, separation of light hydrocarbons, separation of noble gases, storage of gases(CH_4,H_2, and C_2 H_2) for energy, and removal of some gaseous air pollutants(NH_3, NO_2, and SO_2). Finally, an outlook regarding the challenges of the future research of MOFs in these directions is given.展开更多
The separation of aromatic/aliphatic hydrocarbon mixtures is a significant process in chemical industry, but challenged in some cases. Compared with conventional separation technologies, pervaporation is quite promisi...The separation of aromatic/aliphatic hydrocarbon mixtures is a significant process in chemical industry, but challenged in some cases. Compared with conventional separation technologies, pervaporation is quite promising in terms of its economical, energy-saving, and eco-friendly advantages. However, this technique has not been used in industry for separating aromatic/aliphatic mixtures yet. One of the main reasons is that the separation performance of existed pervaporation membranes is unsatisfactory. Membrane material is an important factor that affects the separation performance. This review provides an overview on the advances in studying membrane materials for the pervaporation separation of aromatic/aliphatic mixtures over the past decade. Explored pristine polymers and their hybrid materials(as hybrid membranes) are summarized to highlight their nature and separation performance. We anticipate that this review could provide some guidance in the development of new materials for the aromatic/aliphatic pervaporation separation.展开更多
Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP compo...Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework(MOF) as a self-sacrificial template.The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction(HER),particularly representing a low overpotential of 46.3 mV at 10 mA cm^(-2) and Tafel slope of 44.1 mV dec^(-1) in alkaline media.The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process,and enhance the electrical conductivity as well.In addition,the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media,finally improving the durability.This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation.展开更多
Effective monitoring of atmospheric concentrations is vital for assessing the Stockholm Convention's effectiveness on persistent organic pollutants(POPs).This task,particularly challenging in polar regions due to ...Effective monitoring of atmospheric concentrations is vital for assessing the Stockholm Convention's effectiveness on persistent organic pollutants(POPs).This task,particularly challenging in polar regions due to low air concentrations and temperature fluctuations,requires robust sampling techniques.Furthermore,the influence of temperature on the sampling efficiency of polyurethane foam discs remains unclear.Here we employ a flow-through sampling(FTS)column coupled with an active pump to collect air samples at varying temperatures.We delved into breakthrough profiles of key pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorobiphenyls(PCBs),and organochlorine pesticides(OCPs),and examined the temperature-dependent behaviors of the theoretical plate number(N)and breakthrough volume(VB)using frontal chromatography theory.Our findings reveal a significant relationship between temperature dependence coefficients(K_(TN),K_(TV))and compound volatility,with decreasing values as volatility increases.While distinct trends are noted for PAHs,PCBs,and OCPs in KTN,KTV values exhibit similar patterns across all chemicals.Moreover,we establish a binary linear correlation between log(V_(B)/m^(3)),1/(T/K),and N,simplifying breakthrough level estimation by enabling easy conversion between N and VB.Finally,an empirical linear solvation energy relationship incorporating a temperature term is developed,yielding satisfactory results for N at various temperatures.This approach holds the potential to rectify temperature-related effects and loss rates in historical data from long-term monitoring networks,benefiting polar and remote regions.展开更多
The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a...The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework(MOF) BUT-315-a as a C_(2)H_(6)-selective adsorbent for the separation of C2H6/C2H4gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C_(2)H_(6)uptake of 97.5 cm^(3)g^(-1), giving superior high separation potential ΔQ(2226 mmol L^(-1)) for equimolar C_(2)H_(6)/C_(2)H_(4) at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C_(2)H_(6) and the framework. This work highlights a new benchmark material for C_(2)H_(6)/C_(2)H_(4)separation and provides guidance for designing adsorbent for separation applications.展开更多
Given the current global energy and environmental issues resulting from the fast pace of industrialization,the discovery of new functional materials has become increasingly imperative in order to advance science and t...Given the current global energy and environmental issues resulting from the fast pace of industrialization,the discovery of new functional materials has become increasingly imperative in order to advance science and technology and address the associated challenges.The boom in metal–organic frameworks(MOFs)and MOF-derived materials in recent years has stimulated profound interest in exploring their structures and applications.The preparation,characterization,and processing of MOF materials are the basis of their full engagement in industrial implementation.With intensive research in these topics,it is time to promote the practical utilization of MOFs on an industrial scale,such as for green chemical engineering,by taking advantage of their superior functions.Many famous MOFs have already demonstrated superiority over traditional materials in solving real-world problems.This review starts with the basic concept of MOF chemistry and ends with a discussion of the industrial production and exploitation of MOFs in several fields.Its goal is to provide a general scope of application to inspire MOF researchers to convert their focus on academic research to one on practical applications.After the obstacles of cost,scale-up preparation,processability,and stability have been overcome,MOFs and MOF-based devices will gradually enter the factory,become a part of our daily lives,and help to create a future based on green production and green living.展开更多
AIM: To investigate the features of various blood- borne virus infections and co-infection in intravenous drug users (IDUs), and to examine the correlation of T lymphocyte subsets with virus co-infection. METHODS:...AIM: To investigate the features of various blood- borne virus infections and co-infection in intravenous drug users (IDUs), and to examine the correlation of T lymphocyte subsets with virus co-infection. METHODS: Four hundred and six IDUs without any clinical manifestation of hepatitis and 102 healthy persons were enrolled in this study. HBV-DNA and HCV-RNA were detected by fluorescence quantitative PCR. HBsAg, HBeAg, anti-HBc, anti-HCV, HDV-Ag, anti-HGV, anti-HIV, and HCMV-IgM were assayed by enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests. The levels of Th1 and Th2 cytokines were measured by ELISA and radioactive immune assay (RIA). The T lymphocyte subpopulation was detected by using fluorescence immunoassay. The similar indices taken from the healthy persons served as controls. RESULTS: The viral infection rate among IDUs was 36.45% for HBV, 69.7% for HCV, 47.3% for HIV, 2.22% for HDV, 1.97% for HGV, and 3.45% for HCMV. The co- infection rate of blood-borne virus was detected in 255 of 406 (62.81%) IDUs. More than 80% (161/192) of subjects infected with HIV were co-infected with the other viruses, such as HBV, HCV. In contrast, among the controls, the infection rate was 17.65% for HBV and 0% for the other viruses. Our investigation showed that there was a profound decrease in the proportion of CD4/CD8 and the percentage of CD3 and CD4, but not in the percentage of CD8. The levels of PHA-induced cytokines (IFN-γ and IL-4) and serum IL-2 were obviously decreased in IDUs. On the other hand, the level of serum IL-4 was increased. The level of IFN-γ and the percentage of CD4 were continuously decreased when the IDUs were infected with HIV or HIV co-infection. IDUs with HIV and HBV co-infection was 15.1% (29/192). Of those 29 IDU with HIV and HBV co-infection, 51.72% (15/29) and 37.93% (11/29) were HBV-DNA-positive and HBeAg-positive, respectively. But, among IDUs without HIV infection, only 1.68% (2/119) of cases were HBV- DNA-positive.CONCLUSION: HCV, HBV and HIV infections are common in this population of IDU, leading to a high incidence of impaired Thl cytokine levels and CD4 lymphocyte. IDUs with HIV and HBV/HCV co-infection have lower expression of Th1 cytokine with enhancement of the Th2 response. HIV may be causing HBV replication by decreasing Thl function.展开更多
Through an event-related potential(ERP)study, we examined the processing mechanisms of four types of Chinese(Mandarin) relative clauses(RCs),namely subject subject-extracted relative clause(SSR),subject object...Through an event-related potential(ERP)study, we examined the processing mechanisms of four types of Chinese(Mandarin) relative clauses(RCs),namely subject subject-extracted relative clause(SSR),subject object-extracted relative clause(SOR), object subject-extracted relative clause(OSR), and object object-extracted relative clause(OOR) to test the universality and language specificity of RC comprehension processes. The results of this study support a preference for object-extracted RCs modifying both the subject and object of a sentence, i.e.,SORs and OORs. In particular, ERP results showed stronger P600 effects in the RC region for SSRs compared with SORs, which we argue reflects a canonical word order theory. Stronger N400 effects were observed for verbs compared with nouns, reflecting easier understanding for nouns. ERP results from the matrix clause object and the relativizer “de” showed stronger P600 effects in SSRs compared with SORs,suggesting thematic structure effects on syntactic construction and the processing preference of the whole sentence.展开更多
Organic radicals feature versatile unpaired electrons key for photoelectronic and biomedical applications but remain difficult to access in stable concentrated forms.We disclose easy generation of stable,concentrated ...Organic radicals feature versatile unpaired electrons key for photoelectronic and biomedical applications but remain difficult to access in stable concentrated forms.We disclose easy generation of stable,concentrated radicals from various alkynyl phenyl motifs,including 1)sulfur-functionalized alkyne-rich organic linkers in crystalline frameworks;2)the powders of these molecules alone;3)simple diethynylbenzenes.For Zr-based framework,the generation of radical-rich crystalline framework was achieved by thermal annealing in the range of 300-450℃.For terminal alkynes,electron paramagnetic resonance signals(EPR,indicative of free radicals)arise after air exposure or mild heating(e.g,70℃).Further heating(e.g.,150℃for 3 h)raises the radical concentrations up to 3.30 mol kg^(-1).For more stable internal alkynes,transformations into porous radical solids can also be triggered,albeit at higher temperatures(e.g.,250-500℃).The resulted radical-containing solids are porous,stable to air as well as heat(up to 300-450℃)and exhibit photothermal conversion and solar-driven water evaporation capacity.The formation of radicals can be ascribed to extensive alkyne cycliza-tions,forming defects,dangling bonds and the associated radicals stabilized by polycyclicπ-systems.展开更多
Enhancing electrocatalytic water splitting performance by modulating the intrinsic electronic structure is of great importance. Here, porous bimetallic oxide and chalcogenide nanosheets grown on carbon paper denoted a...Enhancing electrocatalytic water splitting performance by modulating the intrinsic electronic structure is of great importance. Here, porous bimetallic oxide and chalcogenide nanosheets grown on carbon paper denoted as NiCo2X4/CP (X = O, S, and Se) are prepared to demonstrate how the anion components affect the electronic structures and thereby disclose the correlation between their intermediates interaction and catalytic activities. The experimental characterization and theoretical calculation demonstrate that Se and S substitution can promote the ratio of Co^(3+)/Co^(2+) and thereby modulate the electronic structure accompanied with the upshift of d band centers, which not only enhance the inner conductivity but also regulate the interaction between the catalyst surface and intermediates, especially for the adsorption of absorbed H and hydroperoxy intermediates towards respective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, a full alkaline electrolyzer using NiCo2Se4/CP and NiCo2S4/CP as cathode and anode delivers a low voltage of 1.51 V at 10 mA·cm^(−2), which is comparable even superior to most transition metal-based electrolyzers.展开更多
Two new metal-organic frameworks(MOFs),[Cu2(H_2O)_2(BCPIA)](BUT-20)and(Me_2NH_2)[In(BCPIA)](BUT-21)were designed and synthesized through the solvothermal reaction between a newly created desymmetric 4-co...Two new metal-organic frameworks(MOFs),[Cu2(H_2O)_2(BCPIA)](BUT-20)and(Me_2NH_2)[In(BCPIA)](BUT-21)were designed and synthesized through the solvothermal reaction between a newly created desymmetric 4-connected ligand,5-(2,6-bis(4-carboxyphenyl)pyridin-4-yl)isophthalic acid(H_4BCPIA)and Cu(NO_3)2 2.5H_2O or In(NO_3)_3·5H_2O,respectively,and characterized by single-crystal and powder Xray diffraction,thermogravimetric analysis,infrared spectroscopy,and elemental analysis.The two MOFs have three-dimensional structures,in which both the BCPIA 4 ligand and metal-containing entities,Cu_2(COO)_4(H_2O)_2 and In(COO)_4 act as 4-connected nodes.However,different linkage configurations of the two metal-containing nodes,quadrilateral Cu_2_TD_2(COO)_4(H_2O)_2and tetrahedral In(COO)_4,lead to distinct structural networks of BUT-20 and 21,with Nbo and Unc topologies,respectively.展开更多
Two primitive metal-organic frameworks(MOFs),Ni L1 and Ni L2,based on Ni_(8)O_(6)-cluster and ditopic pyrazolate linkers,L1(with rigid alkyne arms)and L2(with flexible alkyne chains),were prepared.The proton conductiv...Two primitive metal-organic frameworks(MOFs),Ni L1 and Ni L2,based on Ni_(8)O_(6)-cluster and ditopic pyrazolate linkers,L1(with rigid alkyne arms)and L2(with flexible alkyne chains),were prepared.The proton conductivities of these MOFs in pristine form and imidazole-encapsulated forms,Im@Ni L1 and Im@Ni L2,were measured and compared.Upon introduction of imidazole molecules,the proton conductivity could be increased by 3 to 5 orders of magnitude and reached as high as 1.72×10^(-2)S/cm(at 98%RH and 80℃).Also,whether imidazole molecules were introduced or not,Ni_(8)O_(6)-based MOFs with L2 in general gave better proton conductivity than those with L1 signifying that flexible side arms indeed assist proton conduction probably via establishment of efficient proton-conducting channels along with formation of highly ordered domains of water/imidazole molecules within the network cavities.Beyond the active Ni_(8)O_(6)-cluster,tuning flexibility of linker pendants serves as an alternative approach to regulate/modulate the proton conductivity of MOFs.展开更多
Green synthesis of metal-organic frameworks(MOFs)in water with alleviated environmental influence and reduced cost is an essential step to transfer laboratory MOFs research to industrial application.Switching from the...Green synthesis of metal-organic frameworks(MOFs)in water with alleviated environmental influence and reduced cost is an essential step to transfer laboratory MOFs research to industrial application.Switching from the commonly used organic solvents to pure water encounters challenges of the poor solubility of organic linkers,slow reaction kinetics,and the formation of polymorphic products.So far,a universal MOFs synthetic strategy in water system has yet to be developed.This study reports the seed-aided synthesis of eleven MOFs with diverse compositions and structures while pure water serving as solvent.The corresponding reaction temperature and time of using this new strategy were reduced compared with original synthetic approaches,while the products maintain porous structure and high crystallinity.The success of this strategy relies on the addition of parent MOFs as seeds which could promote crystallization process by skipping the time-consuming induction period and avoiding the formation of polymorphic impurities.展开更多
Despite great progress in concepts and surgical technique,arch replacement remains a challenge for most cardiac surgery centers.The classic Sun’s procedure(total arch replacement using four-branched graft with stente...Despite great progress in concepts and surgical technique,arch replacement remains a challenge for most cardiac surgery centers.The classic Sun’s procedure(total arch replacement using four-branched graft with stented elephant trunk implantation)has achieved good results in arch replacement in cases of type A aortic dissection and become the standard treatment for type A aortic dissection in our center.[1,2]The branch-first technique has been reported by some surgeons.In most cases,the three arch branches were reconstructed under cardiopulmonary bypass(CPB)or deep hypothermia circulatory arrest.We began applying the branch-first Sun’s procedure 1 year ago.131 The three arch branches were bypassed without CPB in most patients.The lowest temperature at circulatory arrest was also elevated.Here we report our early experience with branch-first Sun’s procedure in both elective and emergency settings.展开更多
The illegal usage of antibiotics as veterinary drugs is an increasing threat for human health.The specific sensing of antibiotics with different toxicity levels is of high challenge,and mainly relies on expensive,time...The illegal usage of antibiotics as veterinary drugs is an increasing threat for human health.The specific sensing of antibiotics with different toxicity levels is of high challenge,and mainly relies on expensive,time-consuming,and complex instruments.To realize specific sensing by rapid and handy optical sensors,a metal-organic framework(MOF)based dual sensor system is herein developed using two MOF materials BUT-128 and BUT-129 with high sensing selectivity and sensitivity.BUT-128 and BUT-129 exhibit the lowest limit of detection(LOD)towards chloramphenicol and furazolidone among reported MOF sensors.The corresponding dual sensor system with enriched signal readouts realized specific sensing of the strictly forbidden antibiotics(chloramphenicol and nitrofurans)from other regulated veterinary drugs including thiamphenicol,a structural analog of chloramphenicol.Besides,the strategy of this work is expected to flourish the development of optical sensors with high specificity for environment and food safety purposes.展开更多
Surgical treatment of aortic arch lesions is a challenge for cardiac surgeons because of the complexity of the technique.For high-risk patients who are not suitable to undergo traditional open arch replacement,debranc...Surgical treatment of aortic arch lesions is a challenge for cardiac surgeons because of the complexity of the technique.For high-risk patients who are not suitable to undergo traditional open arch replacement,debranching thoracic endovascular aortic repair (d-TEVAR) is often a good choice.Retrograde type A aortic dissection (RTAD) is a common and fatal complication after d-TEVAR,[1] and thus d-TEVAR is contraindicated in low-risk patients.Herein,we describe a modification of d-TEVAR with an aortoplasty of the ascending aorta using artificial blood vessels and the subsequent use as an anchoring zone to minimize the occurrence of RTAD.展开更多
Photocatalytic CO_(2)reduction to convert solar energy to clean energy remains a critical challenge in exploring efficient catalysts.Herein,a hierarchical structured BiVO4@Au@UiO-66-NH_(2)with high photocatalytic acti...Photocatalytic CO_(2)reduction to convert solar energy to clean energy remains a critical challenge in exploring efficient catalysts.Herein,a hierarchical structured BiVO4@Au@UiO-66-NH_(2)with high photocatalytic activity was fabricated.The theoretical calculations revealed that the metal–organic framework(MOF)with relative higher conduction band(CB)and UiO-66-NH_(2)with relative lower valence band(VB)could absorb full light spectrum,combining Au nanoparticle with suitable Fermi level into a particulate tandem heterojunction.This configuration can not only lower the activation barrier of CO_(2)reduction using the rich active site of MOF,but also improve the selectivity toward CO by optimizing the reaction pathway.Notably,the experimental evaluation proved that BiVO4@Au@UiO-66-NH2 displays a producing rate of 232.7μmol h^(-1)g^(-1)for CO and a selectivity of 97.2%.The investigation reveals that elaborately integrating multiple functional components into such a hier-archical structure enables optimizing crucial processes in photocatalytic CO_(2)conversion and enhancing selectivity via synergistic catalysis.展开更多
This paper studies,under substitutable and cardinal monotone preferences,the lattice structure of the set SePT of many-to-many pairwise-stable matchings.It proves that the selection matchings are increasing functions ...This paper studies,under substitutable and cardinal monotone preferences,the lattice structure of the set SePT of many-to-many pairwise-stable matchings.It proves that the selection matchings are increasing functions on SePT.This fact,along with a few auxiliary results,is then used to prove that SePT is a distributive lattice.The contribution of this paper is not new,but the alternative proof is interesting as it avoids the use of abstract lattice theory.展开更多
基金financial support from the National Natural Science Foundation of China(No.22038001,51621003,22108007)。
文摘Under the context of carbon neutrality of China,it is urgent to shift our energy supply towards cleaner fuels as well as to reduce the greenhouse gas emission.Currently,coal is the main fossil fuel energy source of China.The country is striving hard to replace it with methane,a cleaner fossil fuel.Although China has rich geological resources of methane as coal bed methane(CBM)reserves,it is quite challenging to utilize them due to low concentration.The CBM is however mainly emitted directly to atmosphere during coal mining,causing waste of the resource and huge contribution to greenhouse effect.The recent work by Yang et al.demonstrated a potential solution to extract low concentration methane selectively from CBM through using MOF materials as sorbents.Such kind of materials and associated separation technology are promising to reduce greenhouse gas emission and promote the methane production capability,which would contribute to carbon neutrality in dual pathways.
基金the financial support from the National Natural Science Foundation of China (Nos.22225803 and 22038001)。
文摘Short-chain perfluorocarboxylic acids(PFCAs) are a class of persistent organic pollutants that are widely used as substitutes for long-chain PFCAs. However, they also pose a non-negligible risk to ecosystems. In this study, we demonstrated that a fluorescent metal–organic framework(MOF)(named V-101) constructed from In^(3+)and an aromatic-rich tetratopic carboxylate ligand 5-[2,6-bis(4-carboxyphenyl) pyridin-4-yl] isophthalic acid(H4BCPIA) exhibited highly efficient turn-off and turn-on fluorescence responses toward five short-chain PFCAs in water and methanol, respectively. The limits of detection of V-101 toward five short-chain PFCAs are down to μg/L level, and it showed good anti-interference abilities toward short-chain PFCAs in the presence of common metal ions. The major mechanisms associated with fluorescence responses were molecular collisions and interactions between V-101 and short-chain PFCAs. This work demonstrates that the structure variety of MOFs imparts them with the potential of MOFs in the detection of short-chain PFCAs for pollution control.
基金supported from the Natural Science Foundation of China (Grant Nos. 21771012, 21601008 and 21576006)the National Natural Science Fund for Innovative Research Groups (Grant No. 51621003)the China Postdoctoral Science Foundation (Grant No. 2016M600879)
文摘The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH_4 are considered as promising candidates for the replacement of traditional fossil fuels. However, the technologies for the storage of these gases are still immature. In addition, the release of anthropogenic toxic gases into the atmosphere is a worldwide threat of growing concern. Both in academia and industry, considerable research efforts have been devoted to developing advanced porous materials for the effective and energy-efficient separation, storage, or capture of the related gases. In contrast to conventional inorganic porous materials such as zeolites and activated carbons, metal–organic frameworks(MOFs) are considered as a type of promising materials for gas separation and storage. In this contribution, we review the recent research advance of MOFs in some relevant applications, including CO_2 capture, O_2 purification, separation of light hydrocarbons, separation of noble gases, storage of gases(CH_4,H_2, and C_2 H_2) for energy, and removal of some gaseous air pollutants(NH_3, NO_2, and SO_2). Finally, an outlook regarding the challenges of the future research of MOFs in these directions is given.
基金Supported by the National Natural Science Foundation of China(21406006,21576003)the Science and Technology Program of Beijing Municipal Education Commission(KM201510005010)+1 种基金the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD20150309)the China Postdoctoral Science Foundation funded project(2015M580954)
文摘The separation of aromatic/aliphatic hydrocarbon mixtures is a significant process in chemical industry, but challenged in some cases. Compared with conventional separation technologies, pervaporation is quite promising in terms of its economical, energy-saving, and eco-friendly advantages. However, this technique has not been used in industry for separating aromatic/aliphatic mixtures yet. One of the main reasons is that the separation performance of existed pervaporation membranes is unsatisfactory. Membrane material is an important factor that affects the separation performance. This review provides an overview on the advances in studying membrane materials for the pervaporation separation of aromatic/aliphatic mixtures over the past decade. Explored pristine polymers and their hybrid materials(as hybrid membranes) are summarized to highlight their nature and separation performance. We anticipate that this review could provide some guidance in the development of new materials for the aromatic/aliphatic pervaporation separation.
基金supported by the National Natural Science Foundation of China (nos. 21771012, 22038001, 51621003)。
文摘Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework(MOF) as a self-sacrificial template.The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction(HER),particularly representing a low overpotential of 46.3 mV at 10 mA cm^(-2) and Tafel slope of 44.1 mV dec^(-1) in alkaline media.The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process,and enhance the electrical conductivity as well.In addition,the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media,finally improving the durability.This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation.
基金supported by the National Natural Science Foundation of China(No.21976171,41905115)the CAS Strategic Priority Research Program(XDA23020301)+1 种基金the Guangxi Key Research and Development Program(GuikeAB21220063)the Ministry of Science and Technology of the People's Republic of China(2016YFE0112200),and Guangxi First-class Disciplines(Agricultural Resources and Environment).
文摘Effective monitoring of atmospheric concentrations is vital for assessing the Stockholm Convention's effectiveness on persistent organic pollutants(POPs).This task,particularly challenging in polar regions due to low air concentrations and temperature fluctuations,requires robust sampling techniques.Furthermore,the influence of temperature on the sampling efficiency of polyurethane foam discs remains unclear.Here we employ a flow-through sampling(FTS)column coupled with an active pump to collect air samples at varying temperatures.We delved into breakthrough profiles of key pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorobiphenyls(PCBs),and organochlorine pesticides(OCPs),and examined the temperature-dependent behaviors of the theoretical plate number(N)and breakthrough volume(VB)using frontal chromatography theory.Our findings reveal a significant relationship between temperature dependence coefficients(K_(TN),K_(TV))and compound volatility,with decreasing values as volatility increases.While distinct trends are noted for PAHs,PCBs,and OCPs in KTN,KTV values exhibit similar patterns across all chemicals.Moreover,we establish a binary linear correlation between log(V_(B)/m^(3)),1/(T/K),and N,simplifying breakthrough level estimation by enabling easy conversion between N and VB.Finally,an empirical linear solvation energy relationship incorporating a temperature term is developed,yielding satisfactory results for N at various temperatures.This approach holds the potential to rectify temperature-related effects and loss rates in historical data from long-term monitoring networks,benefiting polar and remote regions.
基金the financial support of the National Natural Science Foundation of China (No. 22038001)。
文摘The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework(MOF) BUT-315-a as a C_(2)H_(6)-selective adsorbent for the separation of C2H6/C2H4gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C_(2)H_(6)uptake of 97.5 cm^(3)g^(-1), giving superior high separation potential ΔQ(2226 mmol L^(-1)) for equimolar C_(2)H_(6)/C_(2)H_(4) at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C_(2)H_(6) and the framework. This work highlights a new benchmark material for C_(2)H_(6)/C_(2)H_(4)separation and provides guidance for designing adsorbent for separation applications.
基金We acknowledge financial support from the National Natural Science Foundation of China(51621003,21771012,and 22038001)the Science&Technology Project of Beijing Municipal Education Committee(KZ201810005004).
文摘Given the current global energy and environmental issues resulting from the fast pace of industrialization,the discovery of new functional materials has become increasingly imperative in order to advance science and technology and address the associated challenges.The boom in metal–organic frameworks(MOFs)and MOF-derived materials in recent years has stimulated profound interest in exploring their structures and applications.The preparation,characterization,and processing of MOF materials are the basis of their full engagement in industrial implementation.With intensive research in these topics,it is time to promote the practical utilization of MOFs on an industrial scale,such as for green chemical engineering,by taking advantage of their superior functions.Many famous MOFs have already demonstrated superiority over traditional materials in solving real-world problems.This review starts with the basic concept of MOF chemistry and ends with a discussion of the industrial production and exploitation of MOFs in several fields.Its goal is to provide a general scope of application to inspire MOF researchers to convert their focus on academic research to one on practical applications.After the obstacles of cost,scale-up preparation,processability,and stability have been overcome,MOFs and MOF-based devices will gradually enter the factory,become a part of our daily lives,and help to create a future based on green production and green living.
基金Supported by the National Natural Sciences Foundation of China, No. 30160083
文摘AIM: To investigate the features of various blood- borne virus infections and co-infection in intravenous drug users (IDUs), and to examine the correlation of T lymphocyte subsets with virus co-infection. METHODS: Four hundred and six IDUs without any clinical manifestation of hepatitis and 102 healthy persons were enrolled in this study. HBV-DNA and HCV-RNA were detected by fluorescence quantitative PCR. HBsAg, HBeAg, anti-HBc, anti-HCV, HDV-Ag, anti-HGV, anti-HIV, and HCMV-IgM were assayed by enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests. The levels of Th1 and Th2 cytokines were measured by ELISA and radioactive immune assay (RIA). The T lymphocyte subpopulation was detected by using fluorescence immunoassay. The similar indices taken from the healthy persons served as controls. RESULTS: The viral infection rate among IDUs was 36.45% for HBV, 69.7% for HCV, 47.3% for HIV, 2.22% for HDV, 1.97% for HGV, and 3.45% for HCMV. The co- infection rate of blood-borne virus was detected in 255 of 406 (62.81%) IDUs. More than 80% (161/192) of subjects infected with HIV were co-infected with the other viruses, such as HBV, HCV. In contrast, among the controls, the infection rate was 17.65% for HBV and 0% for the other viruses. Our investigation showed that there was a profound decrease in the proportion of CD4/CD8 and the percentage of CD3 and CD4, but not in the percentage of CD8. The levels of PHA-induced cytokines (IFN-γ and IL-4) and serum IL-2 were obviously decreased in IDUs. On the other hand, the level of serum IL-4 was increased. The level of IFN-γ and the percentage of CD4 were continuously decreased when the IDUs were infected with HIV or HIV co-infection. IDUs with HIV and HBV co-infection was 15.1% (29/192). Of those 29 IDU with HIV and HBV co-infection, 51.72% (15/29) and 37.93% (11/29) were HBV-DNA-positive and HBeAg-positive, respectively. But, among IDUs without HIV infection, only 1.68% (2/119) of cases were HBV- DNA-positive.CONCLUSION: HCV, HBV and HIV infections are common in this population of IDU, leading to a high incidence of impaired Thl cytokine levels and CD4 lymphocyte. IDUs with HIV and HBV/HCV co-infection have lower expression of Th1 cytokine with enhancement of the Th2 response. HIV may be causing HBV replication by decreasing Thl function.
基金supported by the National Social Science Foundation of China under Grant No.13BYY072
文摘Through an event-related potential(ERP)study, we examined the processing mechanisms of four types of Chinese(Mandarin) relative clauses(RCs),namely subject subject-extracted relative clause(SSR),subject object-extracted relative clause(SOR), object subject-extracted relative clause(OSR), and object object-extracted relative clause(OOR) to test the universality and language specificity of RC comprehension processes. The results of this study support a preference for object-extracted RCs modifying both the subject and object of a sentence, i.e.,SORs and OORs. In particular, ERP results showed stronger P600 effects in the RC region for SSRs compared with SORs, which we argue reflects a canonical word order theory. Stronger N400 effects were observed for verbs compared with nouns, reflecting easier understanding for nouns. ERP results from the matrix clause object and the relativizer “de” showed stronger P600 effects in SSRs compared with SORs,suggesting thematic structure effects on syntactic construction and the processing preference of the whole sentence.
基金fundings by the National Natural Science Foundation of China(22371054,22301045)the Foundation of Basic and Applied Basic Research of Guangdong Province(2020B1515120024,2024A1515012801)+1 种基金Science and Technology Planning Project of Guangdong Province(2021A0505030066,2023A0505050164)Z.X.acknowledges a startup fund from A^(*)STAR(SC25/22-119116).
文摘Organic radicals feature versatile unpaired electrons key for photoelectronic and biomedical applications but remain difficult to access in stable concentrated forms.We disclose easy generation of stable,concentrated radicals from various alkynyl phenyl motifs,including 1)sulfur-functionalized alkyne-rich organic linkers in crystalline frameworks;2)the powders of these molecules alone;3)simple diethynylbenzenes.For Zr-based framework,the generation of radical-rich crystalline framework was achieved by thermal annealing in the range of 300-450℃.For terminal alkynes,electron paramagnetic resonance signals(EPR,indicative of free radicals)arise after air exposure or mild heating(e.g,70℃).Further heating(e.g.,150℃for 3 h)raises the radical concentrations up to 3.30 mol kg^(-1).For more stable internal alkynes,transformations into porous radical solids can also be triggered,albeit at higher temperatures(e.g.,250-500℃).The resulted radical-containing solids are porous,stable to air as well as heat(up to 300-450℃)and exhibit photothermal conversion and solar-driven water evaporation capacity.The formation of radicals can be ascribed to extensive alkyne cycliza-tions,forming defects,dangling bonds and the associated radicals stabilized by polycyclicπ-systems.
基金This work was supported by the National Natural Science Foundation of China(Nos.21771012,21601008)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51621003).
文摘Enhancing electrocatalytic water splitting performance by modulating the intrinsic electronic structure is of great importance. Here, porous bimetallic oxide and chalcogenide nanosheets grown on carbon paper denoted as NiCo2X4/CP (X = O, S, and Se) are prepared to demonstrate how the anion components affect the electronic structures and thereby disclose the correlation between their intermediates interaction and catalytic activities. The experimental characterization and theoretical calculation demonstrate that Se and S substitution can promote the ratio of Co^(3+)/Co^(2+) and thereby modulate the electronic structure accompanied with the upshift of d band centers, which not only enhance the inner conductivity but also regulate the interaction between the catalyst surface and intermediates, especially for the adsorption of absorbed H and hydroperoxy intermediates towards respective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, a full alkaline electrolyzer using NiCo2Se4/CP and NiCo2S4/CP as cathode and anode delivers a low voltage of 1.51 V at 10 mA·cm^(−2), which is comparable even superior to most transition metal-based electrolyzers.
基金financially supported by the NSFC (Nos. 21322601, 21271015, 21406006, and U1407119)Program for New Century Excellent Talents in University (No. NCET-13-0647)
文摘Two new metal-organic frameworks(MOFs),[Cu2(H_2O)_2(BCPIA)](BUT-20)and(Me_2NH_2)[In(BCPIA)](BUT-21)were designed and synthesized through the solvothermal reaction between a newly created desymmetric 4-connected ligand,5-(2,6-bis(4-carboxyphenyl)pyridin-4-yl)isophthalic acid(H_4BCPIA)and Cu(NO_3)2 2.5H_2O or In(NO_3)_3·5H_2O,respectively,and characterized by single-crystal and powder Xray diffraction,thermogravimetric analysis,infrared spectroscopy,and elemental analysis.The two MOFs have three-dimensional structures,in which both the BCPIA 4 ligand and metal-containing entities,Cu_2(COO)_4(H_2O)_2 and In(COO)_4 act as 4-connected nodes.However,different linkage configurations of the two metal-containing nodes,quadrilateral Cu_2_TD_2(COO)_4(H_2O)_2and tetrahedral In(COO)_4,lead to distinct structural networks of BUT-20 and 21,with Nbo and Unc topologies,respectively.
基金the National Natural Science Foundation of China(No.21871061)the Foundation of Basic and Applied Basic Research of Guangdong Province(No.2021A1515010274)+2 种基金the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the Science and Technology Planning Project of Guangdong Province(No.2021A0505030066)the Science and Technology Program of Guangzhou(No.201807010026)。
文摘Two primitive metal-organic frameworks(MOFs),Ni L1 and Ni L2,based on Ni_(8)O_(6)-cluster and ditopic pyrazolate linkers,L1(with rigid alkyne arms)and L2(with flexible alkyne chains),were prepared.The proton conductivities of these MOFs in pristine form and imidazole-encapsulated forms,Im@Ni L1 and Im@Ni L2,were measured and compared.Upon introduction of imidazole molecules,the proton conductivity could be increased by 3 to 5 orders of magnitude and reached as high as 1.72×10^(-2)S/cm(at 98%RH and 80℃).Also,whether imidazole molecules were introduced or not,Ni_(8)O_(6)-based MOFs with L2 in general gave better proton conductivity than those with L1 signifying that flexible side arms indeed assist proton conduction probably via establishment of efficient proton-conducting channels along with formation of highly ordered domains of water/imidazole molecules within the network cavities.Beyond the active Ni_(8)O_(6)-cluster,tuning flexibility of linker pendants serves as an alternative approach to regulate/modulate the proton conductivity of MOFs.
基金financial support from the National Natural Science Foundation of China(Nos.22038001 and 51621003)。
文摘Green synthesis of metal-organic frameworks(MOFs)in water with alleviated environmental influence and reduced cost is an essential step to transfer laboratory MOFs research to industrial application.Switching from the commonly used organic solvents to pure water encounters challenges of the poor solubility of organic linkers,slow reaction kinetics,and the formation of polymorphic products.So far,a universal MOFs synthetic strategy in water system has yet to be developed.This study reports the seed-aided synthesis of eleven MOFs with diverse compositions and structures while pure water serving as solvent.The corresponding reaction temperature and time of using this new strategy were reduced compared with original synthetic approaches,while the products maintain porous structure and high crystallinity.The success of this strategy relies on the addition of parent MOFs as seeds which could promote crystallization process by skipping the time-consuming induction period and avoiding the formation of polymorphic impurities.
文摘Despite great progress in concepts and surgical technique,arch replacement remains a challenge for most cardiac surgery centers.The classic Sun’s procedure(total arch replacement using four-branched graft with stented elephant trunk implantation)has achieved good results in arch replacement in cases of type A aortic dissection and become the standard treatment for type A aortic dissection in our center.[1,2]The branch-first technique has been reported by some surgeons.In most cases,the three arch branches were reconstructed under cardiopulmonary bypass(CPB)or deep hypothermia circulatory arrest.We began applying the branch-first Sun’s procedure 1 year ago.131 The three arch branches were bypassed without CPB in most patients.The lowest temperature at circulatory arrest was also elevated.Here we report our early experience with branch-first Sun’s procedure in both elective and emergency settings.
基金the National Natural Science Foundation of China(Nos.22038001,51621003,and 22108007)the Beijing Nova Program(No.Z211100002121094).
文摘The illegal usage of antibiotics as veterinary drugs is an increasing threat for human health.The specific sensing of antibiotics with different toxicity levels is of high challenge,and mainly relies on expensive,time-consuming,and complex instruments.To realize specific sensing by rapid and handy optical sensors,a metal-organic framework(MOF)based dual sensor system is herein developed using two MOF materials BUT-128 and BUT-129 with high sensing selectivity and sensitivity.BUT-128 and BUT-129 exhibit the lowest limit of detection(LOD)towards chloramphenicol and furazolidone among reported MOF sensors.The corresponding dual sensor system with enriched signal readouts realized specific sensing of the strictly forbidden antibiotics(chloramphenicol and nitrofurans)from other regulated veterinary drugs including thiamphenicol,a structural analog of chloramphenicol.Besides,the strategy of this work is expected to flourish the development of optical sensors with high specificity for environment and food safety purposes.
文摘Surgical treatment of aortic arch lesions is a challenge for cardiac surgeons because of the complexity of the technique.For high-risk patients who are not suitable to undergo traditional open arch replacement,debranching thoracic endovascular aortic repair (d-TEVAR) is often a good choice.Retrograde type A aortic dissection (RTAD) is a common and fatal complication after d-TEVAR,[1] and thus d-TEVAR is contraindicated in low-risk patients.Herein,we describe a modification of d-TEVAR with an aortoplasty of the ascending aorta using artificial blood vessels and the subsequent use as an anchoring zone to minimize the occurrence of RTAD.
基金the National Natural Science Foundation of China(21771012,21606006)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51621003)the Science&Technology Project of Beijing Municipal Education Committee(KZ201810005004)。
文摘Photocatalytic CO_(2)reduction to convert solar energy to clean energy remains a critical challenge in exploring efficient catalysts.Herein,a hierarchical structured BiVO4@Au@UiO-66-NH_(2)with high photocatalytic activity was fabricated.The theoretical calculations revealed that the metal–organic framework(MOF)with relative higher conduction band(CB)and UiO-66-NH_(2)with relative lower valence band(VB)could absorb full light spectrum,combining Au nanoparticle with suitable Fermi level into a particulate tandem heterojunction.This configuration can not only lower the activation barrier of CO_(2)reduction using the rich active site of MOF,but also improve the selectivity toward CO by optimizing the reaction pathway.Notably,the experimental evaluation proved that BiVO4@Au@UiO-66-NH2 displays a producing rate of 232.7μmol h^(-1)g^(-1)for CO and a selectivity of 97.2%.The investigation reveals that elaborately integrating multiple functional components into such a hier-archical structure enables optimizing crucial processes in photocatalytic CO_(2)conversion and enhancing selectivity via synergistic catalysis.
文摘This paper studies,under substitutable and cardinal monotone preferences,the lattice structure of the set SePT of many-to-many pairwise-stable matchings.It proves that the selection matchings are increasing functions on SePT.This fact,along with a few auxiliary results,is then used to prove that SePT is a distributive lattice.The contribution of this paper is not new,but the alternative proof is interesting as it avoids the use of abstract lattice theory.