In the field of Raman spectroscopy detection,the quest for a non–noble metal,recyclable,and highly sensitive detection substrate is of utmost importance.In this work,a new crystalline and noble metal–free substrate ...In the field of Raman spectroscopy detection,the quest for a non–noble metal,recyclable,and highly sensitive detection substrate is of utmost importance.In this work,a new crystalline and noble metal–free substrate of[Bi(DMF)_(8)][PMo_(12)O_(40)](Bi–PMo_(12))is designed,which is composed of[PMo_(12)O_(40)]^(3−)and solvated[Bi(DMF)_(8)]^(3+)cations.Mechanistic studies have revealed that Raman scattering quenching phenomenon arises from two main factors.Firstly,it arises from the absorption of the scattered light due to the transition of a single electron in the reduced state of MoV between 4d orbitals.Secondly,after the interaction between the substrate and hydrazine,the surface undergoes varying degrees of roughening,leading to an impact on the scattered light intensity.These two effects collectively contribute to the detection of low concentrations of N_(2)H_(4).As a result,Bi–PMo_(12)opens up a novel Raman scattering quenching mechanism to realize the detection of reduced N_(2)H_(4)small molecules.A remarkably low detection limit of 4.5×10^(−9)ppm for N_(2)H_(4)is achieved on the Bi–PMo_(12)substrate.This detection has a lower concentration than the currently known SERS detection of N_(2)H_(4).Moreover,Bi–PMo_(12)can be recovered and reused through recrystallization,achieving a recovery rate of up to ca.51%.This study reveals the underlying potential of crystalline polyoxometalate materials in the field of Raman detection,thus opening up new avenues for highly sensitive analysis using Raman techniques.展开更多
The separation of rare earths is difficult due to their similar properties and the complex characteristics of associated vein o res.Complexation-ultrafiltration(CUF)and shear induced o rderly dissociation coupling wit...The separation of rare earths is difficult due to their similar properties and the complex characteristics of associated vein o res.Complexation-ultrafiltration(CUF)and shear induced o rderly dissociation coupling with ultrafiltration(SIODUF)were used to separate metal ions(M,M=La(Ⅲ),Ce(Ⅳ)and Ca(Ⅱ))from simulated bastnaesite leaching solution using acidic phosphonic chitosan(aPCS)and rotating disk membrane.Effect of simultaneous removal of metallic ions was investigated by CUF,and suitable conditions were obtained for C/M 10.0(mass ratio of complexant to metal ions)and pH 5.0.The shear stabilities of aPCS-M complexes were explored at different pH values and the results show that the complexes can dissociate at a certain rotational speed,the critical one.The critical s hear rates of aPCS-La,aPCS-Ce and aPCS-Ca complexes at pH 5.0 were calculated as 1.42×10^(5).1.69×10^(5) and 9.75×10^(4) s^(-1),respectively.The order of complexes shear stability is aPCS-Ca aPCS-La<aPCS-Ce.The high selective separation of M and regeneration of aPCS were achieved by SIODUF in the light of the difference of aPCSM complexes shear stabilities.The separation coefficientsβLa/Ce andβCa/La reach 31.2 and 53.9,respectively.展开更多
Biofabrication,also known as bioprinting,has been widely used in the field of biomedicine.The three most important factors in biofabrication are 3D bioprinter,biomaterials to be printed(bioinks),and the printing objec...Biofabrication,also known as bioprinting,has been widely used in the field of biomedicine.The three most important factors in biofabrication are 3D bioprinter,biomaterials to be printed(bioinks),and the printing object(application).This review provides a detailed introduction to the latest research progress in these aspects.In particularly,the bioinks for bioprinting require strict biocompatible requirements.Four typical materials,i.e.metal/alloys,ceramics,polymers,and their composites,were introduced in detail,and their printing process and application scenarios were summarized,respectively.There are many applications of biofabrication in clinical practice.The application of biofabrication in skeletal system,skin and soft tissue,cardiovascular system,digestive system,respiratory system,urinary system,nervous system,plastic surgery and medical aesthetics were briefly introduced.The applications of biofabrication has a wide range of clinical need.Biofabrication is an innovative technology that is expected to further promote the clinical precision treatments.展开更多
Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resu...Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resulting in its much lower sodium storage performance than hard carbon. We propose a novel preoxidation strategy to introduce additional oxygen atoms into the low-cost soft carbon precursor pitch to fabricate a defect-rich and large-interlayer spacing hard carbon anode(HPP-1100). Compared with the direct pyrolysis of pitch carbon, the sodium storage capacity of HPP-1100 is significantly improved from 120.3 m Ah/g to 306.7 m Ah/g, with an excellent rate and cycling capability(116.5 m Ah/g at 10 C). Moreover, when assorted with an O_(3)-Na(NiFeMn)1/3O_(2)cathode, the full cell delivers a high reversible capacity of 274.0 m Ah/g at 0.1 C with superb cycle life. This work provides a new solution for realizing the application of low-cost pitch anodes in Na-ion batteries.展开更多
Nitrogen-doped lignin-based carbon microspheres are synthesized using 3-aminophenol as a nitrogen source by the hydrothermal method.The structural change and the effect on the electrochemical properties are systematic...Nitrogen-doped lignin-based carbon microspheres are synthesized using 3-aminophenol as a nitrogen source by the hydrothermal method.The structural change and the effect on the electrochemical properties are systematically investigated. Nitrogen-doped lignin-based carbon microspheres represent well-developed spherical morphology with many active sites, ultramicroporous(< 0.7 nm) structure, and large interlayer spacing. Consistent with the obtained physical structures and properties, the nitrogen-doped carbon microspheres exhibit fast sodium ion adsorption/intercalation kinetic process and excellent electrochemical performance. For example, a reversible specific capacity of 374 m Ah g^(-1) at 25 m A g^(-1) with high initial coulombic efficiency of 85% and high capacitance retention of 90% after 300 cycles at 100 m A g^(-1) and stable charge/discharge behavior at different current density is obtained. The additional defects and abundant ultramicroporous structure can enhance sloping capacity, and large interlayer spacing is considered to be the reason for improving plateau capacity.展开更多
The ether electrolytes usually outperform ester electrolytes by evaluating sodium-ion batteries(SIBs)rate performance,which is a near-unanimous conclusion of previous studies based on an essential configuration of the...The ether electrolytes usually outperform ester electrolytes by evaluating sodium-ion batteries(SIBs)rate performance,which is a near-unanimous conclusion of previous studies based on an essential configuration of the half-cell test.However,here we find that contrary to consensus,the ester electrolyte shows better Na storage capability than the ether electrolyte in full cells.An in-depth analysis of three-electrode,symmetric cell,and in situ XRD tests indicates that traditional half-cell test results are unreliable due to interference from Na electrodes.In particular,Na electrodes show a huge stability difference in ester and ether electrolytes,and ester electrolytes suffer more severe interference than ether electrolytes,resulting in the belief that esters are far inferior to ether electrolytes.More seriously,the more accurate three-electrode test would also suffer from Na electrode interference.Thus,a“corrected half-cell test”protocol is developed to shield the Na electrode interference,revealing the very close super rate capability of hard carbon in ester and ether electrolytes.This work breaks the inherent perception that the kinetic properties of ester electrolytes are inferior to ethers in sodium-ion batteries,reveals the pitfalls of half-cell tests,and proposes a new test protocol for reliable results,greatly accelerating the commercialization of sodium-ion batteries.展开更多
The present study aims to investigate the gastroprotective effect of Brucea javanica oil emulsion(BJOE) in animals. Gastroprotective potential of BJOE was studied on absolute ethanol,aspirin, reserpine and restraint p...The present study aims to investigate the gastroprotective effect of Brucea javanica oil emulsion(BJOE) in animals. Gastroprotective potential of BJOE was studied on absolute ethanol,aspirin, reserpine and restraint plus water immersion-induced gastric ulcers in mice as well as glacial acetic acid(GAA) and pyloric ligation(PL)-induced gastric ulcers in rats. Except for ulcer scores, total acidity as well as pepsin activity as for the PL-induced gastric ulcer model and ulcer incidence as for the GAA-induced gastric ulcer model were also determined. Histopathological evaluation as for aspirin, reserpine, PL-induced models was conducted. Results showed that BJOE significantly(P < 0.05) reduced ulcer index in the mouse and rat models in a dose-dependent manner. It had significant(P < 0.05) suppressive effect on total activity of gastric juice as well in PL-induced model. Histopathological examination for the stomach samples confirmed the findings in the aspirin, reserpine or PLinduced gastric lesion models, which showed relatively complete mucosa structure and less inflammation. It is concluded that BJOE could be effective on gastric ulcer in rodents and its gastroprotective activity might be related to antioxidant, anti-inflammatory ability and promote gastric mucus secreted. The results may provide beneficial basis for increasing BJOE's clinical indication in future.展开更多
Reasonable construction of sulfur host with high conductivity,large sulfur storage gap,strong chemical adsorption,and fast oxidation–reduction kinetics of polysulfide is very significant for its practical use in lith...Reasonable construction of sulfur host with high conductivity,large sulfur storage gap,strong chemical adsorption,and fast oxidation–reduction kinetics of polysulfide is very significant for its practical use in lithium-sulfur batteries(LSBs).In this paper,the surface modification of MIL-88A(Fe)is carried out by Dawson-type polyoxometalate(POM),and a hollow capsule shell material with P_(2)W_(18),Fe_(3)O_(4),and C components is synthesized by the subsequent carbonization process.When applied as the sulfur host,the hollow capsule shell material can efficiently improve the conductivity of sulfur electrode and restrain the volumetric change of active sulfur while charging and discharging.On this foundation,electrochemical analysis and density functional theory(DFT)calculation show that the P_(2)W_(18)on the outer layer of the capsule shell have effective electrocatalytic activity and potent chemical bond on the lithium polysulfides(LiPSs),which is helpful to block the shuttle effect.Therefore,the as-assembled LSBs display the outstanding specific capacity and prominent cycle stability.Specifically,it delivers an excellent reversible capacity of 1063 mAh/g after 100 cycles of charge–discharge at a rate of 0.5 C,accounting for a preservation by 96%in comparison to that of the initial cycle.Moreover,even after 2000 cycles at 1 C,the reversible specific capacity of 585 mAh/g can still be maintained with an average decay rate of only 0.021%.展开更多
Polyoxometalates (POMs) are important inorganic photochromic materials to be potentially applied in photo-induced switch,energy storage,and even the detection of light.However,due to the limited sensitivity of POMs,it...Polyoxometalates (POMs) are important inorganic photochromic materials to be potentially applied in photo-induced switch,energy storage,and even the detection of light.However,due to the limited sensitivity of POMs,it is difficult to realize the photochromic response to weak visible light.In this paper,by the coordination of solvated Pb(Ⅱ),a new structure-defined chain-like polyoxomolybdate complex of[(Pb(DMF)_(4))^(3)(P_(2)Mo_(18)O_(62))_(2)]n(Pb_(3)Mo_(18) ,DMF=dimethylformamide) has been demonstrated by a facile solvent-diffusion approach.By virtue of interactions between Pb(DMF)_(4) and polyoxoanions,Pb_(3)Mo_(18) shows an ultrasensitive photochromic response to weak visible lights and forms the reduced’heteropoly blue’species through ligand-to-metal charge transfer (LMCT) process.A new mechanism is firstly proposed here that the 6s orbital lone electron pair on Pb(II) can effectively stabilize the generated hole of oxygen atoms as a result of O→Mo charge transfer.Through the proposed mechanism,the LMCT barrier is drastically lowered and allows the coloration to be occurred even upon weak visible light.Also,because the conductivity of Pb_(3)Mo_(18) enhances with the increase of reduction extent,its electrochemical impedance signals are proportionally response to irradiation intensity.Especially,for the first time,the polyoxomolybdate composite can be used to detect weak visible light,in which the optical signal can be converted into electrical signal output.Moreover,Pb_(3)Mo_(18) can be drip-coated on the surface of the screen printed chip electrode,which is facile to the detection of light by portable devices compatible with computers,mobile phones and other electronic equipment.This work not only highlights a new approach to the molecular design of photochromic POMs by the coordination of metal ions with the effect of inert electron pair,but also lays a foundation to extend the application of POMs as light signal sensors.展开更多
The study aims to investigate the effects of(-)-Linarinic acid(LA) and one of its derivatives(LAd) on brain injury induced by ischemia. Malonaldehyde(MDA) is determined as an index for lipid peroxidation both in vitro...The study aims to investigate the effects of(-)-Linarinic acid(LA) and one of its derivatives(LAd) on brain injury induced by ischemia. Malonaldehyde(MDA) is determined as an index for lipid peroxidation both in vitro and vivo. Mice were pre-treated with LA and LAd for 3 d.Thereafter, they were induced to have incomplete cerebral ischemia with both bilateral carotid artery occlusion and hypotension(BCAOH). In the first part of the in vivo experiment, mice were divided into four groups: sham(control), ischemia, ischemia + LA(200 mg/kg, i.g.) and ischemia + LAd(200 mg/kg, i.g.). In the second part, the dose-response of LAd was investigated at 100, 200 and 400 mg/kg i.g., respectively. A modified neurological severity score was developed for evaluating behavioral deficits of the mice with ischemia. Brains of the mice were excised in order to determinate MDA after ischemia for 6 h. Survival time, survival rate, neurological injury score and MDA level in brains were observed. Results were: 1) The data in vitro showed that both LA and LAd could inhibit the generation of MDA. IC50 values obtained by Probit analysis were 2.9 mM for LAd and 4.88 mM for LA;2) BCAOH could significantly shorten the survival span, reduce the survival rate and cause neurological deficits,which were associated with high level of lipid hydroperoxide production in cerebral tissues;3) LAd decreased lipid peroxidation and improved the neurological outcome more than LA.It is concluded that LAd offers a better neuroprotection than LA against brain damage caused by cerebral ischemia.展开更多
Cerebral ischemia is due to the formation of blood clots or embolisms in the brain arteries,which leads to local brain tissue necrosis and neural cell apoptosis.Recent studies have shown that microRNA(miRNA)plays an i...Cerebral ischemia is due to the formation of blood clots or embolisms in the brain arteries,which leads to local brain tissue necrosis and neural cell apoptosis.Recent studies have shown that microRNA(miRNA)plays an important regulatory role in the pathological process of ischemic injury.The aim of this study is to investigate the role and the mechanism of miR-21-3p and drosophila mothers against decapentaplegic 2(SMAD2)in cerebral ischemic reperfusion injured(CIRI)neural cells.The CIRI model was established by oxygen-glucose deprivation and recovery process for N2a cells.The cell viability and the apoptotic was evaluated by MTT assay and the Flow Cytometer,respectively.The expression of miR-21-3p and SMAD2 mRNA was detected by real-time fluorescence quantitative PCR(qRT-PCR),and the expression of SMAD2 and apoptotic-related proteins were detected by Western Blotting.Our results showed that miR-21-3p is down-regulated,and SMAD2 is up-regulated in CIRI.Overexpression of miR-21-3p inhibits the apoptosis of neural cells in CIRI.miR-21-3p targets SMAD2 and inhibits SMAD2 expression.Overexpression of SMAD2 eliminates the protective effect of over-expression of miR-21-3p on neural cells in CIRI.Token together,this study provides a theoretical basis for the mechanism of ischemic reperfusion injury in neural cells and a new molecular target for ischemic stroke therapy.展开更多
China's splendid achievements and fast development attract the attention of the whole world. The rising of the great power shock the rest countries. More and more people want to know what is happening in this coun...China's splendid achievements and fast development attract the attention of the whole world. The rising of the great power shock the rest countries. More and more people want to know what is happening in this country and what effect it will bring to the world. At the same time, Chinese people have gradually realized the importance of exchanging information with other countries. Under this motivation, the translation of Chinese materials into English becomes necessary and essential. It is an effective way to present China comprehensively. Among all these materials, Government Work Report is one of the most remarkable ones. The translation of it plays a key role to present the image of China to the world. But, compared with State of the Union address, the translation of Government Work Report contains some problems from the perspective of foreignization and domestication theory. This essay will discuss the differences between these two texts at the lexical, syntactic, and discourse level from the angle of foreignization and domestication theory, and give some suggestions to the translation of Government Work Report.展开更多
The rapid migration and separation of photoinduced carriers is a key factor influencing photocatalytic efficiency.Constructing an S-scheme heterojunction is a strategic technique to enhance the separation of photogene...The rapid migration and separation of photoinduced carriers is a key factor influencing photocatalytic efficiency.Constructing an S-scheme heterojunction is a strategic technique to enhance the separation of photogenerated carriers and boost overall catalytic activity.Herein,a simple physical stirring technique was adopted to successfully fabricate a novel NiCo_(2)S_(4)/CoTiO_(3) S-scheme heterojunction photocatalyst.Upon exposure to light,the NiCo_(2)S_(4)/CoTiO_(3)-10 specimen demonstrated an outstanding hydrogen evolution rate of 2037.76μmol·g^(-1)·h^(-1),exceeding twice the rate observed for the pristine NiCo_(2)S_(4)(833.72μmol·g^(–1)·h^(–1)).The experimental outcomes reveal that the incorporation of CoTiO_(3) significantly enhances the charge separation and transfer within the system.Concurrently,the formation of the S-scheme mechanism facilitates the separation of carriers while maintaining high redox capabilities.This work introduces an innovative approach to forming S-scheme heterojunctions based on bimetallic sulfides,thereby offering new prospects for the efficient utilization of solar energy.展开更多
Contamination with Aspergillus flavus,which produces carcinogenic metabolites,during the post-harvest storage of agricultural products seriously endangers human health and safety.In this study,the efficacy of short-te...Contamination with Aspergillus flavus,which produces carcinogenic metabolites,during the post-harvest storage of agricultural products seriously endangers human health and safety.In this study,the efficacy of short-term electron beam irradiation processing with high sterilization efficiency,no contamination and no additives was evaluated for the prevention and control of A.flavus.The effects of irradiation on Aspergillus growth were determined based on analyses of physical and chemical indexes,morphology,mycelial growth,spore germination rates,mycelial dry weights,and toxin-producing ability.The effects of irradiation on the cell membrane and cell wall of A.flavus were investigated based on assays of the chitin content,chitinase activity,protein concentration,and malondialdehyde content.Damage to the antioxidant system was determined by the hydrogen peroxide content,catalase activity,superoxide dismutase activity,superoxide anion radical scavenging activity and rates of 1,1-diphenyl-2-trinitrophenylhydrazine inhibition.The inhibitory effect of irradiation on peanut invasion by A.flavus was verified.After irradiation,the thallus morphology was destroyed,mycelial growth was inhibited,and the spore germination rate,mycelial dry weight,and toxin-producing ability of A.flavus were reduced.Chitinase activity and the malondialdehyde content increased,while the chitin and total protein contents decreased.Catalase activity,superoxide dismutase activity,superoxide anion radical scavenging activity,and the rate of 1,1-diphenyl-2-trinitrophenylhydrazine inhibition decreased,while the hydrogen peroxide content increased after irradiation.These findings suggested that electron beam irradiation can effectively inhibit the normal growth and toxin production of A.flavus.Irradiation increased cell membrane permeability and decreased the integrity of the cell wall.The antioxidant system was damaged to some extent.Compared with that in unirradiated A.flavus,high-dose electron beam irradiation effectively inhibited growth.As a means of postharvest control,electron beam irradiation may have wide applications in the agricultural industry.展开更多
基金the financial support from the National Natural Science Foundation of China(No.21971085)the Natural Science Foundation of Shandong Province(No.ZR2021MB008)。
文摘In the field of Raman spectroscopy detection,the quest for a non–noble metal,recyclable,and highly sensitive detection substrate is of utmost importance.In this work,a new crystalline and noble metal–free substrate of[Bi(DMF)_(8)][PMo_(12)O_(40)](Bi–PMo_(12))is designed,which is composed of[PMo_(12)O_(40)]^(3−)and solvated[Bi(DMF)_(8)]^(3+)cations.Mechanistic studies have revealed that Raman scattering quenching phenomenon arises from two main factors.Firstly,it arises from the absorption of the scattered light due to the transition of a single electron in the reduced state of MoV between 4d orbitals.Secondly,after the interaction between the substrate and hydrazine,the surface undergoes varying degrees of roughening,leading to an impact on the scattered light intensity.These two effects collectively contribute to the detection of low concentrations of N_(2)H_(4).As a result,Bi–PMo_(12)opens up a novel Raman scattering quenching mechanism to realize the detection of reduced N_(2)H_(4)small molecules.A remarkably low detection limit of 4.5×10^(−9)ppm for N_(2)H_(4)is achieved on the Bi–PMo_(12)substrate.This detection has a lower concentration than the currently known SERS detection of N_(2)H_(4).Moreover,Bi–PMo_(12)can be recovered and reused through recrystallization,achieving a recovery rate of up to ca.51%.This study reveals the underlying potential of crystalline polyoxometalate materials in the field of Raman detection,thus opening up new avenues for highly sensitive analysis using Raman techniques.
基金Project supported by the National Natural Science Foundation of China(22178392)the Fundamental Research Funds for the Central Universities of Central South University,China(2022ZZTS0493)。
文摘The separation of rare earths is difficult due to their similar properties and the complex characteristics of associated vein o res.Complexation-ultrafiltration(CUF)and shear induced o rderly dissociation coupling with ultrafiltration(SIODUF)were used to separate metal ions(M,M=La(Ⅲ),Ce(Ⅳ)and Ca(Ⅱ))from simulated bastnaesite leaching solution using acidic phosphonic chitosan(aPCS)and rotating disk membrane.Effect of simultaneous removal of metallic ions was investigated by CUF,and suitable conditions were obtained for C/M 10.0(mass ratio of complexant to metal ions)and pH 5.0.The shear stabilities of aPCS-M complexes were explored at different pH values and the results show that the complexes can dissociate at a certain rotational speed,the critical one.The critical s hear rates of aPCS-La,aPCS-Ce and aPCS-Ca complexes at pH 5.0 were calculated as 1.42×10^(5).1.69×10^(5) and 9.75×10^(4) s^(-1),respectively.The order of complexes shear stability is aPCS-Ca aPCS-La<aPCS-Ce.The high selective separation of M and regeneration of aPCS were achieved by SIODUF in the light of the difference of aPCSM complexes shear stabilities.The separation coefficientsβLa/Ce andβCa/La reach 31.2 and 53.9,respectively.
基金supported by National Key Research and Development Program of China(Grant Nos.2023YFC2411300,2023YFB4605800)National Natural Science Foundation of China(Grant No.32471474)+2 种基金Sichuan Science and Technology Program(Grant Nos.2024YFHZ0125,2022NSFSC1405)China Postdoctoral Science Foundation(Grant No.2022M722268)Research and Develop Program,West China Hospital of Stomatology Sichuan University(Grant No.RD-03-202406).
文摘Biofabrication,also known as bioprinting,has been widely used in the field of biomedicine.The three most important factors in biofabrication are 3D bioprinter,biomaterials to be printed(bioinks),and the printing object(application).This review provides a detailed introduction to the latest research progress in these aspects.In particularly,the bioinks for bioprinting require strict biocompatible requirements.Four typical materials,i.e.metal/alloys,ceramics,polymers,and their composites,were introduced in detail,and their printing process and application scenarios were summarized,respectively.There are many applications of biofabrication in clinical practice.The application of biofabrication in skeletal system,skin and soft tissue,cardiovascular system,digestive system,respiratory system,urinary system,nervous system,plastic surgery and medical aesthetics were briefly introduced.The applications of biofabrication has a wide range of clinical need.Biofabrication is an innovative technology that is expected to further promote the clinical precision treatments.
基金supported by the National Natural Science Foundation of China (No. 22179094)。
文摘Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resulting in its much lower sodium storage performance than hard carbon. We propose a novel preoxidation strategy to introduce additional oxygen atoms into the low-cost soft carbon precursor pitch to fabricate a defect-rich and large-interlayer spacing hard carbon anode(HPP-1100). Compared with the direct pyrolysis of pitch carbon, the sodium storage capacity of HPP-1100 is significantly improved from 120.3 m Ah/g to 306.7 m Ah/g, with an excellent rate and cycling capability(116.5 m Ah/g at 10 C). Moreover, when assorted with an O_(3)-Na(NiFeMn)1/3O_(2)cathode, the full cell delivers a high reversible capacity of 274.0 m Ah/g at 0.1 C with superb cycle life. This work provides a new solution for realizing the application of low-cost pitch anodes in Na-ion batteries.
基金the support of the National Natural Science Foundation of China(51603147)Tianjin application foundation and advanced technology research plan project(15ZCZDGX00270 and 14RCHZGX00859)。
文摘Nitrogen-doped lignin-based carbon microspheres are synthesized using 3-aminophenol as a nitrogen source by the hydrothermal method.The structural change and the effect on the electrochemical properties are systematically investigated. Nitrogen-doped lignin-based carbon microspheres represent well-developed spherical morphology with many active sites, ultramicroporous(< 0.7 nm) structure, and large interlayer spacing. Consistent with the obtained physical structures and properties, the nitrogen-doped carbon microspheres exhibit fast sodium ion adsorption/intercalation kinetic process and excellent electrochemical performance. For example, a reversible specific capacity of 374 m Ah g^(-1) at 25 m A g^(-1) with high initial coulombic efficiency of 85% and high capacitance retention of 90% after 300 cycles at 100 m A g^(-1) and stable charge/discharge behavior at different current density is obtained. The additional defects and abundant ultramicroporous structure can enhance sloping capacity, and large interlayer spacing is considered to be the reason for improving plateau capacity.
基金supported by the National Natural Science Foundation of China(22179094)the Tianjin Research Program of Application Foundation and Advanced Technology of China(15ZCZDGX00270)
文摘The ether electrolytes usually outperform ester electrolytes by evaluating sodium-ion batteries(SIBs)rate performance,which is a near-unanimous conclusion of previous studies based on an essential configuration of the half-cell test.However,here we find that contrary to consensus,the ester electrolyte shows better Na storage capability than the ether electrolyte in full cells.An in-depth analysis of three-electrode,symmetric cell,and in situ XRD tests indicates that traditional half-cell test results are unreliable due to interference from Na electrodes.In particular,Na electrodes show a huge stability difference in ester and ether electrolytes,and ester electrolytes suffer more severe interference than ether electrolytes,resulting in the belief that esters are far inferior to ether electrolytes.More seriously,the more accurate three-electrode test would also suffer from Na electrode interference.Thus,a“corrected half-cell test”protocol is developed to shield the Na electrode interference,revealing the very close super rate capability of hard carbon in ester and ether electrolytes.This work breaks the inherent perception that the kinetic properties of ester electrolytes are inferior to ethers in sodium-ion batteries,reveals the pitfalls of half-cell tests,and proposes a new test protocol for reliable results,greatly accelerating the commercialization of sodium-ion batteries.
文摘The present study aims to investigate the gastroprotective effect of Brucea javanica oil emulsion(BJOE) in animals. Gastroprotective potential of BJOE was studied on absolute ethanol,aspirin, reserpine and restraint plus water immersion-induced gastric ulcers in mice as well as glacial acetic acid(GAA) and pyloric ligation(PL)-induced gastric ulcers in rats. Except for ulcer scores, total acidity as well as pepsin activity as for the PL-induced gastric ulcer model and ulcer incidence as for the GAA-induced gastric ulcer model were also determined. Histopathological evaluation as for aspirin, reserpine, PL-induced models was conducted. Results showed that BJOE significantly(P < 0.05) reduced ulcer index in the mouse and rat models in a dose-dependent manner. It had significant(P < 0.05) suppressive effect on total activity of gastric juice as well in PL-induced model. Histopathological examination for the stomach samples confirmed the findings in the aspirin, reserpine or PLinduced gastric lesion models, which showed relatively complete mucosa structure and less inflammation. It is concluded that BJOE could be effective on gastric ulcer in rodents and its gastroprotective activity might be related to antioxidant, anti-inflammatory ability and promote gastric mucus secreted. The results may provide beneficial basis for increasing BJOE's clinical indication in future.
基金the financial support from the National Natural Science Foundation of China (No. 21971085)the Natural Science Foundation of Shandong Province (No. ZR2019MB004, China)
文摘Reasonable construction of sulfur host with high conductivity,large sulfur storage gap,strong chemical adsorption,and fast oxidation–reduction kinetics of polysulfide is very significant for its practical use in lithium-sulfur batteries(LSBs).In this paper,the surface modification of MIL-88A(Fe)is carried out by Dawson-type polyoxometalate(POM),and a hollow capsule shell material with P_(2)W_(18),Fe_(3)O_(4),and C components is synthesized by the subsequent carbonization process.When applied as the sulfur host,the hollow capsule shell material can efficiently improve the conductivity of sulfur electrode and restrain the volumetric change of active sulfur while charging and discharging.On this foundation,electrochemical analysis and density functional theory(DFT)calculation show that the P_(2)W_(18)on the outer layer of the capsule shell have effective electrocatalytic activity and potent chemical bond on the lithium polysulfides(LiPSs),which is helpful to block the shuttle effect.Therefore,the as-assembled LSBs display the outstanding specific capacity and prominent cycle stability.Specifically,it delivers an excellent reversible capacity of 1063 mAh/g after 100 cycles of charge–discharge at a rate of 0.5 C,accounting for a preservation by 96%in comparison to that of the initial cycle.Moreover,even after 2000 cycles at 1 C,the reversible specific capacity of 585 mAh/g can still be maintained with an average decay rate of only 0.021%.
基金the financial support from the National Natural Science Foundation of China (No. 21971085)the Natural Science Foundation of Shandong Province (No. ZR2019MB004)。
文摘Polyoxometalates (POMs) are important inorganic photochromic materials to be potentially applied in photo-induced switch,energy storage,and even the detection of light.However,due to the limited sensitivity of POMs,it is difficult to realize the photochromic response to weak visible light.In this paper,by the coordination of solvated Pb(Ⅱ),a new structure-defined chain-like polyoxomolybdate complex of[(Pb(DMF)_(4))^(3)(P_(2)Mo_(18)O_(62))_(2)]n(Pb_(3)Mo_(18) ,DMF=dimethylformamide) has been demonstrated by a facile solvent-diffusion approach.By virtue of interactions between Pb(DMF)_(4) and polyoxoanions,Pb_(3)Mo_(18) shows an ultrasensitive photochromic response to weak visible lights and forms the reduced’heteropoly blue’species through ligand-to-metal charge transfer (LMCT) process.A new mechanism is firstly proposed here that the 6s orbital lone electron pair on Pb(II) can effectively stabilize the generated hole of oxygen atoms as a result of O→Mo charge transfer.Through the proposed mechanism,the LMCT barrier is drastically lowered and allows the coloration to be occurred even upon weak visible light.Also,because the conductivity of Pb_(3)Mo_(18) enhances with the increase of reduction extent,its electrochemical impedance signals are proportionally response to irradiation intensity.Especially,for the first time,the polyoxomolybdate composite can be used to detect weak visible light,in which the optical signal can be converted into electrical signal output.Moreover,Pb_(3)Mo_(18) can be drip-coated on the surface of the screen printed chip electrode,which is facile to the detection of light by portable devices compatible with computers,mobile phones and other electronic equipment.This work not only highlights a new approach to the molecular design of photochromic POMs by the coordination of metal ions with the effect of inert electron pair,but also lays a foundation to extend the application of POMs as light signal sensors.
基金supported partly by a grant from Natural Science Foundation of China (30973613)
文摘The study aims to investigate the effects of(-)-Linarinic acid(LA) and one of its derivatives(LAd) on brain injury induced by ischemia. Malonaldehyde(MDA) is determined as an index for lipid peroxidation both in vitro and vivo. Mice were pre-treated with LA and LAd for 3 d.Thereafter, they were induced to have incomplete cerebral ischemia with both bilateral carotid artery occlusion and hypotension(BCAOH). In the first part of the in vivo experiment, mice were divided into four groups: sham(control), ischemia, ischemia + LA(200 mg/kg, i.g.) and ischemia + LAd(200 mg/kg, i.g.). In the second part, the dose-response of LAd was investigated at 100, 200 and 400 mg/kg i.g., respectively. A modified neurological severity score was developed for evaluating behavioral deficits of the mice with ischemia. Brains of the mice were excised in order to determinate MDA after ischemia for 6 h. Survival time, survival rate, neurological injury score and MDA level in brains were observed. Results were: 1) The data in vitro showed that both LA and LAd could inhibit the generation of MDA. IC50 values obtained by Probit analysis were 2.9 mM for LAd and 4.88 mM for LA;2) BCAOH could significantly shorten the survival span, reduce the survival rate and cause neurological deficits,which were associated with high level of lipid hydroperoxide production in cerebral tissues;3) LAd decreased lipid peroxidation and improved the neurological outcome more than LA.It is concluded that LAd offers a better neuroprotection than LA against brain damage caused by cerebral ischemia.
文摘Cerebral ischemia is due to the formation of blood clots or embolisms in the brain arteries,which leads to local brain tissue necrosis and neural cell apoptosis.Recent studies have shown that microRNA(miRNA)plays an important regulatory role in the pathological process of ischemic injury.The aim of this study is to investigate the role and the mechanism of miR-21-3p and drosophila mothers against decapentaplegic 2(SMAD2)in cerebral ischemic reperfusion injured(CIRI)neural cells.The CIRI model was established by oxygen-glucose deprivation and recovery process for N2a cells.The cell viability and the apoptotic was evaluated by MTT assay and the Flow Cytometer,respectively.The expression of miR-21-3p and SMAD2 mRNA was detected by real-time fluorescence quantitative PCR(qRT-PCR),and the expression of SMAD2 and apoptotic-related proteins were detected by Western Blotting.Our results showed that miR-21-3p is down-regulated,and SMAD2 is up-regulated in CIRI.Overexpression of miR-21-3p inhibits the apoptosis of neural cells in CIRI.miR-21-3p targets SMAD2 and inhibits SMAD2 expression.Overexpression of SMAD2 eliminates the protective effect of over-expression of miR-21-3p on neural cells in CIRI.Token together,this study provides a theoretical basis for the mechanism of ischemic reperfusion injury in neural cells and a new molecular target for ischemic stroke therapy.
文摘China's splendid achievements and fast development attract the attention of the whole world. The rising of the great power shock the rest countries. More and more people want to know what is happening in this country and what effect it will bring to the world. At the same time, Chinese people have gradually realized the importance of exchanging information with other countries. Under this motivation, the translation of Chinese materials into English becomes necessary and essential. It is an effective way to present China comprehensively. Among all these materials, Government Work Report is one of the most remarkable ones. The translation of it plays a key role to present the image of China to the world. But, compared with State of the Union address, the translation of Government Work Report contains some problems from the perspective of foreignization and domestication theory. This essay will discuss the differences between these two texts at the lexical, syntactic, and discourse level from the angle of foreignization and domestication theory, and give some suggestions to the translation of Government Work Report.
基金supported by the Fundamental Research Funds for the Central Universities of the North Minzu University(Grant No.2023ZRLG20)。
文摘The rapid migration and separation of photoinduced carriers is a key factor influencing photocatalytic efficiency.Constructing an S-scheme heterojunction is a strategic technique to enhance the separation of photogenerated carriers and boost overall catalytic activity.Herein,a simple physical stirring technique was adopted to successfully fabricate a novel NiCo_(2)S_(4)/CoTiO_(3) S-scheme heterojunction photocatalyst.Upon exposure to light,the NiCo_(2)S_(4)/CoTiO_(3)-10 specimen demonstrated an outstanding hydrogen evolution rate of 2037.76μmol·g^(-1)·h^(-1),exceeding twice the rate observed for the pristine NiCo_(2)S_(4)(833.72μmol·g^(–1)·h^(–1)).The experimental outcomes reveal that the incorporation of CoTiO_(3) significantly enhances the charge separation and transfer within the system.Concurrently,the formation of the S-scheme mechanism facilitates the separation of carriers while maintaining high redox capabilities.This work introduces an innovative approach to forming S-scheme heterojunctions based on bimetallic sulfides,thereby offering new prospects for the efficient utilization of solar energy.
基金supported by The National Natural Science Foundation of China(No.31860458)The Natural Science Foundation of Guangxi Province(No.2017JJA130645Y).
文摘Contamination with Aspergillus flavus,which produces carcinogenic metabolites,during the post-harvest storage of agricultural products seriously endangers human health and safety.In this study,the efficacy of short-term electron beam irradiation processing with high sterilization efficiency,no contamination and no additives was evaluated for the prevention and control of A.flavus.The effects of irradiation on Aspergillus growth were determined based on analyses of physical and chemical indexes,morphology,mycelial growth,spore germination rates,mycelial dry weights,and toxin-producing ability.The effects of irradiation on the cell membrane and cell wall of A.flavus were investigated based on assays of the chitin content,chitinase activity,protein concentration,and malondialdehyde content.Damage to the antioxidant system was determined by the hydrogen peroxide content,catalase activity,superoxide dismutase activity,superoxide anion radical scavenging activity and rates of 1,1-diphenyl-2-trinitrophenylhydrazine inhibition.The inhibitory effect of irradiation on peanut invasion by A.flavus was verified.After irradiation,the thallus morphology was destroyed,mycelial growth was inhibited,and the spore germination rate,mycelial dry weight,and toxin-producing ability of A.flavus were reduced.Chitinase activity and the malondialdehyde content increased,while the chitin and total protein contents decreased.Catalase activity,superoxide dismutase activity,superoxide anion radical scavenging activity,and the rate of 1,1-diphenyl-2-trinitrophenylhydrazine inhibition decreased,while the hydrogen peroxide content increased after irradiation.These findings suggested that electron beam irradiation can effectively inhibit the normal growth and toxin production of A.flavus.Irradiation increased cell membrane permeability and decreased the integrity of the cell wall.The antioxidant system was damaged to some extent.Compared with that in unirradiated A.flavus,high-dose electron beam irradiation effectively inhibited growth.As a means of postharvest control,electron beam irradiation may have wide applications in the agricultural industry.
