Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale b...Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale but low accuracy, incompetence in the acquirement of nano-upgraded single-cell liquid. Flow cytometry has been widely used in large-scale single-cell detection, while precise single-cell isolation relies on both a precision operating platform and a microscope, which is not only extremely inefficient, but also not conducive to couple with modern analytical instruments. Herein, we develop a modular single-cell pipette(m SCP) microfluidic chip with high efficiency and strong applicability for accurate direct capture of single viable cell from cell suspensions into nanoliter droplets(30-1000 n L). The m SCP is used as a sampling platform for the detection of Cd Te quantum dots in single cells with electrothermal atomic absorption spectrometry(ETAAS) for the first time. It also ensures precise single-cell sampling and detection by inductively coupled plasma mass spectrometry(ICP-MS).展开更多
A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temper...A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temperatures and pressures,a high-temperature and high-pressure reactor,gas chromatograph,and other related experimental equipment were used to perform methane dissolution experiments,and a single surfactant sodium oleate(NaOA)and n-hexane demonstrated superior results.The single-factor experiments of temperature,pressure,and NaOA addition were performed and fitted via a response surface analysis.The optimal conditions for methane solubility were as follows:temperature of 34C,pressure of 4.5 MPa,NaOA addition of 85 g/L,and time of 1 h.The optimal effect of the surfactant-polyalkane system in dissolving methane was achieved with 32.31 mL/100 mL.Meanwhile,the change in the surface structure of coal before and after washing with the system was compared using scanning electron microscopy.The results indicated that the gas after washing with the surfactant-polyalkane system dissolved,and the surface pore structure of the coal changed.Moreover,the specific surface area and pore size of the coal surface increased after washing.Hence,the desorption of gas from the coal surface into the system becomes easy,thereby reducing the gas content in the coal sample.展开更多
The preparation of silver nanoparticles(AgNPs)with microbe or plant tissues as bio-template offers green approach,while it suffers from low harvest and purification is needed.Herein,we propose a facile protocol for on...The preparation of silver nanoparticles(AgNPs)with microbe or plant tissues as bio-template offers green approach,while it suffers from low harvest and purification is needed.Herein,we propose a facile protocol for one-pot preparation of AgNPs using M13 phage as bio-template by simply mixing AgN03 solution with alkali M13 phage.In the obtained AgNPs-M13 phage composite,Cr(Ⅲ)selectively coordinates with the amino residues on phage surface and leads to the aggregation of AgNPs through the bridging of M13 phages.This makes it feasible for colorimetric sensing of Cr(Ⅲ)by measuring the absorbance ratio of AgNPs at 600 and 405 nm,which provides a LOD of 14 nmol/L.The composite also showed favorable bactericidal activity for both Gram-positive and Gram-negative bacteria,making it a promising candidate as antibacterial film in chromium-containing dental alloys and meanwhile serve as a sensing probe for monitoring the corrosion of the dental alloys.展开更多
In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.P...In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.Plasma synthesized organosilicon(SiOxCyHz)thin films with water contact angle over 160°and sliding angle below 5°,were able to be achieved.FTIR and XPS analysis indicates a large number of hydrocarbon compositions were polymerized in the thin films enduing the latter very-low surface free energy.SEM shows the SH films display micro-nanostructure and with high degree of averaged surface roughness 190 nm evaluated by AFM analysis.From experiments under controlled low-temperature and moisture conditions,the prepared SH surface exhibits good anti-icing effects.Significantly prolonging freezing time was achievable on the SH thin films for both static and sliding water droplets.This investigation demonstrates the anti-icing potentials of SH surface prepared through low-cost simple atmospheric-pressure plasma polymerization process.展开更多
With the release of China Education Modernization 2035,education modernization has become a national strategic goal.In this context,Chongqing Energy Vocational College is actively exploring the“four integration and f...With the release of China Education Modernization 2035,education modernization has become a national strategic goal.In this context,Chongqing Energy Vocational College is actively exploring the“four integration and four innovation”specialized and creative integration talent cultivation mode,aiming at cultivating high-quality talents with innovative spirit and practical skills.This paper analyzes the status quo and challenges of talent cultivation in higher vocational education,puts forward the main practices of innovation-driven,creation and research,cross-border integration,and innovative practice,and has achieved remarkable results.Additionally,it summarizes the experience revelation and provides a reference for other higher vocational colleges and universities.展开更多
Curriculum ideology and politics is an effective method to reform innovation and entrepreneurship education in the new era.Students in higher education institutions have high expectations and recognition of the integr...Curriculum ideology and politics is an effective method to reform innovation and entrepreneurship education in the new era.Students in higher education institutions have high expectations and recognition of the integration of innovation and entrepreneurship education with civics education.However,currently,the phenomena of poor integration,mechanical application,and confusion between innovation and entrepreneurship education and civics education exist.This paper reconstructs the curriculum standards of innovation and entrepreneurship education from the perspective of curriculum ideology and politics,deeply integrates ideological and political elements into teaching objectives,design,and evaluation,reshapes teaching modules,improves teaching methods,and perfects the multiple evaluation and assessment system,so as to enhance the innovation spirit,creative consciousness,and entrepreneurial ability of higher vocational students.展开更多
Detecting and identifying rare tumor cells circulating among the vast number of blood cells is challenging.Current identification methods neither maintain cellular viability nor determine cell lines when the disease i...Detecting and identifying rare tumor cells circulating among the vast number of blood cells is challenging.Current identification methods neither maintain cellular viability nor determine cell lines when the disease is undiagnosed.Herein,we demonstrate the identification of tumor cells using machine learning-assisted access resistance cytometry(ML-ARC).Unlike the single-peak current transients induced by the access of red blood cells at the orifice of a nanopipette,doublet and multiple transients were recorded when the cell line changed from white blood cells to tumor cells.Results from scanning ion conductance microscopy and finite element simulation demonstrated that these fingerprints are closely related to the physicochemical properties of the cell membrane.To better understand the transient features,five parameters describing peak shape and amplitude were extracted for comparison,machine learning training,and testing.After training,we achieved cell identification in mixed cell samples and the blood samples from breast cancer patients using ML-ARC.This work presents a novel platform for label-free cell identification of tumor cells in complex biological samples.展开更多
Iodine ion is one of the most indispensable anions in living organisms,particularly being an important substance for the synthesis of thyroid hormones.Curcumin is a yellow-orange polyphenol compound derived from the r...Iodine ion is one of the most indispensable anions in living organisms,particularly being an important substance for the synthesis of thyroid hormones.Curcumin is a yellow-orange polyphenol compound derived from the rhizome of Curcuma longa L.,which has been commonly used as a spice and natural coloring agent,food additives,cosmetics as well as Chinese medicine.However,excess curcumin may cause DNA inactivation,lead to a decrease in intracellular ATP levels,and trigger the tissue necrosis.Therefore,quantitative detection of iodine and curcumin is of great significance in the fields of food and life sciences.Herein,we develop nitrogen-doped fluorescent carbon dots(NCDs)as a multi-mechanism detection for iodide and curcumin in actual complex biological and food samples,which was prepared by a one-step solid-phase synthesis using tartaric acid and urea as precursors without adding any other reagents.An assembled NCDs-Hg^(2+) fluorescence-enhanced sensor for the quantitative detection of I^(-) was established based on a fluorescence“turn-off-on”mechanism in a linear range of 0.3-15μM with a detection limit of 69.4 nM and successfully quantified trace amounts of I^(-) in water samples and urine sample.Meanwhile,the as-synthesized NCDs also can be used as a fluorescent quenched sensor for curcumin detection based on the synergistic internal filtration effect(IFE)and static quenching,achieving a good linear range of 0.1-20μM with a satisfactory detection limit of 29.8 nM.These results indicate that carbon dots are potential sensing materials for iodine and curcumin detection for the good of our health.展开更多
Aggregation-induced emission luminogens(AIEgens)exhibit efficient cytotoxic reactive oxygen species(ROS)generation capability and unique light-up features in the aggregated state,which have been well explored in image...Aggregation-induced emission luminogens(AIEgens)exhibit efficient cytotoxic reactive oxygen species(ROS)generation capability and unique light-up features in the aggregated state,which have been well explored in image-guided photodynamic therapy(PDT).However,the limited penetration depth of light in tissue severely hinders AIEgens as a candidate for primary or adjunctive therapy for clinical applications.Coincidentally,microwaves(MWs)show a distinct advantage for deeper penetration depth in tissues than light.Herein,for the first time,we report AIEgen-mediated microwave dynamic therapy(MWDT)for cancer treatment.We found that two AIEgens(TPEPy-I and TPEPy-PF6)served as a new type of microwave(MW)sensitizers to produce ROS,including singlet oxygen(1O2),resulting in efficient destructions of cancer cells.The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and live/dead assays reveal that the two AIEgens when activated by MW irradiation can effectively kill cancer cells with average IC-50 values of 2.73 and 3.22μM,respectively.Overall,the ability of the two AIEgens to be activated by MW not only overcomes the limitations of conventional PDT,but also helps to improve existing MW ablation therapy by reducing the MW dose required to achieve the same therapeutic outcome,thus reducing the occurrence of side-effects of MW radiation.展开更多
Atomic force microscopy technology is gradually spreading to almost all aspects,including food science and technology,since it was first invented in 1986.In this study,this powerful instrument was applied to image nan...Atomic force microscopy technology is gradually spreading to almost all aspects,including food science and technology,since it was first invented in 1986.In this study,this powerful instrument was applied to image nanostructures of three water absorbents-original konjac powder,konjac powder grafted with acrylic acid using^(60)Coγ-irradiation and regenerated grafted powder.Water absorption capacities and the rates of the three absorbents were also determined in this work.Original konjac powder could only absorb 60 times(w/w)of water,while 270 times for the grafted absorbent and 360 times for the regenerated absorbent.The initial water absorption rates in both tap and distilled water were high,but the rate decreased steeply as time elapsed.After 20 min,the absorbent was close to saturated status.These physical properties were in accordance with the nanostructures of these three water absorbents.展开更多
Two-dimensional(2D)graphitic carbon nitride(g-C_(3)N_(4))possesses a unique geometric configuration featuring a superimposed heterocyclic sp2 carbon and nitrogen framework.Its fluorescence may be attributed to π-π^(...Two-dimensional(2D)graphitic carbon nitride(g-C_(3)N_(4))possesses a unique geometric configuration featuring a superimposed heterocyclic sp2 carbon and nitrogen framework.Its fluorescence may be attributed to π-π^(*),lone pair(LP)-π^(*),or LP-δ^(*)transitions.So far,the manipulation of its fluorescence emissions is largely unexploited and remains challenging.Herein,for the first time,rare-earth doping into the backbone structure of a g-C_(3)N_(4) framework under microwave agitation endows unprecedented fluorescence nature,with the emergence of two exceptional new fluorescence emissions in the 450-700 nm range.With terbium-doped g-C_(3)N_(4):Tb as a representative,these emissions exhibit distinctive features,that is,very sharp fluorescence peaks with narrow full width at half maximum(FWHM)(peak width at half-height)of<12 nm,quantumyields of 2.3±0.0% and 7.6±0.1% for the new emissions at λ_(ex)/λ_(em)=290/490 nm,and 290/545 nm,respectively;and a large Stokes shift of>200 nm.These features of g-C_(3)N_(4):Tb are most advantageous for applications in various fields,as demonstrated by(1)tracking biodistribution of g-C_(3)N_(4) in vivo with mass spectrometric imaging where the doped terbium serves as a tag,(2)a biometrics study facilitating the identification of an individual through fingerprint,and(3)anti-counterfeiting with g-C_(3)N_(4)∶Tb as a dual-functional marker to facilitate fluorescence and mass spectrometric imaging.展开更多
基金financial support of the National Natural Science Foundation of China (Nos. 21727811,21922402)the Fundamental Research Funds for the Central Universities (Nos. N2005003, N2105017)+1 种基金the Liaoning Revitalization Talents Program (No. XLYC1802016)Scientific Research Funding Project of the Education Department of Liaoning (No. LJKZ0007)。
文摘Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale but low accuracy, incompetence in the acquirement of nano-upgraded single-cell liquid. Flow cytometry has been widely used in large-scale single-cell detection, while precise single-cell isolation relies on both a precision operating platform and a microscope, which is not only extremely inefficient, but also not conducive to couple with modern analytical instruments. Herein, we develop a modular single-cell pipette(m SCP) microfluidic chip with high efficiency and strong applicability for accurate direct capture of single viable cell from cell suspensions into nanoliter droplets(30-1000 n L). The m SCP is used as a sampling platform for the detection of Cd Te quantum dots in single cells with electrothermal atomic absorption spectrometry(ETAAS) for the first time. It also ensures precise single-cell sampling and detection by inductively coupled plasma mass spectrometry(ICP-MS).
基金the financial support of project No.FRFIC-20-01 and No.FRF-IC-19-013the Fundamental Research Funds for the Central Universities,China project No.51974015,No.51904292,and No.51474017+5 种基金the National Natural Science Foundation of China,China project No.2018YFC0810600the National Key Research and Development Program of China,China project No.2017CXNL02the Fundamental Research Funds for the Central Universities(China University of Mining and Technology),China project No.BK20180655the Natural Science Foundation of Jiangsu Province,China project No.WS2018B03the State Key Laboratory Cultivation Base for Gas Geology and Gas Control(Henan Polytechnic University),China and project No.E21724the Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines of China(Hunan University of Science and Technology),China.
文摘A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temperatures and pressures,a high-temperature and high-pressure reactor,gas chromatograph,and other related experimental equipment were used to perform methane dissolution experiments,and a single surfactant sodium oleate(NaOA)and n-hexane demonstrated superior results.The single-factor experiments of temperature,pressure,and NaOA addition were performed and fitted via a response surface analysis.The optimal conditions for methane solubility were as follows:temperature of 34C,pressure of 4.5 MPa,NaOA addition of 85 g/L,and time of 1 h.The optimal effect of the surfactant-polyalkane system in dissolving methane was achieved with 32.31 mL/100 mL.Meanwhile,the change in the surface structure of coal before and after washing with the system was compared using scanning electron microscopy.The results indicated that the gas after washing with the surfactant-polyalkane system dissolved,and the surface pore structure of the coal changed.Moreover,the specific surface area and pore size of the coal surface increased after washing.Hence,the desorption of gas from the coal surface into the system becomes easy,thereby reducing the gas content in the coal sample.
基金Financial support from the National Natural Science Foundation of China (Nos.21874014,21727811,21675019,21605161)the Fundamental Research Funds for the Central Universities (No. N180505021)
文摘The preparation of silver nanoparticles(AgNPs)with microbe or plant tissues as bio-template offers green approach,while it suffers from low harvest and purification is needed.Herein,we propose a facile protocol for one-pot preparation of AgNPs using M13 phage as bio-template by simply mixing AgN03 solution with alkali M13 phage.In the obtained AgNPs-M13 phage composite,Cr(Ⅲ)selectively coordinates with the amino residues on phage surface and leads to the aggregation of AgNPs through the bridging of M13 phages.This makes it feasible for colorimetric sensing of Cr(Ⅲ)by measuring the absorbance ratio of AgNPs at 600 and 405 nm,which provides a LOD of 14 nmol/L.The composite also showed favorable bactericidal activity for both Gram-positive and Gram-negative bacteria,making it a promising candidate as antibacterial film in chromium-containing dental alloys and meanwhile serve as a sensing probe for monitoring the corrosion of the dental alloys.
基金partly supported by the State Key Laboratory of Advanced Electromagnetic Engineering and Technology(No.AEET 2018KF003)National Natural Science Foundation of China(Nos.51637002,11405144)+3 种基金the Fundamental Research Funds for the Central Universities(Nos.2018CDXYTW0031,20720150022)the Construction Committee of Chongqing(No.2018-1-3-6)the International Science&Technology Cooperation Program of China(No.2015DFR70390)the Natural Science Foundation of Hunan Province(No.2018JJ3587)
文摘In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.Plasma synthesized organosilicon(SiOxCyHz)thin films with water contact angle over 160°and sliding angle below 5°,were able to be achieved.FTIR and XPS analysis indicates a large number of hydrocarbon compositions were polymerized in the thin films enduing the latter very-low surface free energy.SEM shows the SH films display micro-nanostructure and with high degree of averaged surface roughness 190 nm evaluated by AFM analysis.From experiments under controlled low-temperature and moisture conditions,the prepared SH surface exhibits good anti-icing effects.Significantly prolonging freezing time was achievable on the SH thin films for both static and sliding water droplets.This investigation demonstrates the anti-icing potentials of SH surface prepared through low-cost simple atmospheric-pressure plasma polymerization process.
文摘With the release of China Education Modernization 2035,education modernization has become a national strategic goal.In this context,Chongqing Energy Vocational College is actively exploring the“four integration and four innovation”specialized and creative integration talent cultivation mode,aiming at cultivating high-quality talents with innovative spirit and practical skills.This paper analyzes the status quo and challenges of talent cultivation in higher vocational education,puts forward the main practices of innovation-driven,creation and research,cross-border integration,and innovative practice,and has achieved remarkable results.Additionally,it summarizes the experience revelation and provides a reference for other higher vocational colleges and universities.
基金A School-Level Educational Reform Project"The Reform and Practice Study in Higher Vocational Institutions Under the Perspective of Curriculum Thinking and Government-Case Study of Chongqing Energy College"(Grant Number:2021J03002)。
文摘Curriculum ideology and politics is an effective method to reform innovation and entrepreneurship education in the new era.Students in higher education institutions have high expectations and recognition of the integration of innovation and entrepreneurship education with civics education.However,currently,the phenomena of poor integration,mechanical application,and confusion between innovation and entrepreneurship education and civics education exist.This paper reconstructs the curriculum standards of innovation and entrepreneurship education from the perspective of curriculum ideology and politics,deeply integrates ideological and political elements into teaching objectives,design,and evaluation,reshapes teaching modules,improves teaching methods,and perfects the multiple evaluation and assessment system,so as to enhance the innovation spirit,creative consciousness,and entrepreneurial ability of higher vocational students.
基金supported financially by the National Natural Science Foundation of China[grant nos.21790390,21790391,and 22134002(L.M.)22125406,21790053,and 22074149(P.Y.)],the Natural Science Foundation of Beijing(grant no.JQ19009)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB30000000)the CAS Project for Young Scientists in Basic Research(grant no.YSBR-050)the Postdoctoral Science Foundation of China(grant no.2022M710011)the Youth Fund from the National Natural Science Foundation of China(grant no.22304012).
文摘Detecting and identifying rare tumor cells circulating among the vast number of blood cells is challenging.Current identification methods neither maintain cellular viability nor determine cell lines when the disease is undiagnosed.Herein,we demonstrate the identification of tumor cells using machine learning-assisted access resistance cytometry(ML-ARC).Unlike the single-peak current transients induced by the access of red blood cells at the orifice of a nanopipette,doublet and multiple transients were recorded when the cell line changed from white blood cells to tumor cells.Results from scanning ion conductance microscopy and finite element simulation demonstrated that these fingerprints are closely related to the physicochemical properties of the cell membrane.To better understand the transient features,five parameters describing peak shape and amplitude were extracted for comparison,machine learning training,and testing.After training,we achieved cell identification in mixed cell samples and the blood samples from breast cancer patients using ML-ARC.This work presents a novel platform for label-free cell identification of tumor cells in complex biological samples.
基金Financial supports from the XingLiao Talent Project Grants(No.XLYC1902076)the University of Science and Technology Liaoning Talent Project Grants(No.601010302)are highly appreciated.
文摘Iodine ion is one of the most indispensable anions in living organisms,particularly being an important substance for the synthesis of thyroid hormones.Curcumin is a yellow-orange polyphenol compound derived from the rhizome of Curcuma longa L.,which has been commonly used as a spice and natural coloring agent,food additives,cosmetics as well as Chinese medicine.However,excess curcumin may cause DNA inactivation,lead to a decrease in intracellular ATP levels,and trigger the tissue necrosis.Therefore,quantitative detection of iodine and curcumin is of great significance in the fields of food and life sciences.Herein,we develop nitrogen-doped fluorescent carbon dots(NCDs)as a multi-mechanism detection for iodide and curcumin in actual complex biological and food samples,which was prepared by a one-step solid-phase synthesis using tartaric acid and urea as precursors without adding any other reagents.An assembled NCDs-Hg^(2+) fluorescence-enhanced sensor for the quantitative detection of I^(-) was established based on a fluorescence“turn-off-on”mechanism in a linear range of 0.3-15μM with a detection limit of 69.4 nM and successfully quantified trace amounts of I^(-) in water samples and urine sample.Meanwhile,the as-synthesized NCDs also can be used as a fluorescent quenched sensor for curcumin detection based on the synergistic internal filtration effect(IFE)and static quenching,achieving a good linear range of 0.1-20μM with a satisfactory detection limit of 29.8 nM.These results indicate that carbon dots are potential sensing materials for iodine and curcumin detection for the good of our health.
基金We would like to acknowledge the supports from Guangxi Jialouyuan Medical Inc.,Solgro,and the distinguished award from UT Arlington,the Pencis award,as well as the supports from the China Scholarship Council(201906155012)the National Natural Science Foundation of China(22071065,21772045)+2 种基金the Natural Science Foundation of Guangdong Province(2018B030311008)and the Technology Program of Guangzhou(201904010414)e would also like to acknowledge Dr.Kytai Nguyen for helping with DLS measurements and Alexios Papadimitratos for ESR measurements.LL would like to acknowledge support by the Welch Foundation grant number AT-1877-20180324 and the UT Dallas-NRUF Collaborative Biomedical Research Award(CoBRA).
文摘Aggregation-induced emission luminogens(AIEgens)exhibit efficient cytotoxic reactive oxygen species(ROS)generation capability and unique light-up features in the aggregated state,which have been well explored in image-guided photodynamic therapy(PDT).However,the limited penetration depth of light in tissue severely hinders AIEgens as a candidate for primary or adjunctive therapy for clinical applications.Coincidentally,microwaves(MWs)show a distinct advantage for deeper penetration depth in tissues than light.Herein,for the first time,we report AIEgen-mediated microwave dynamic therapy(MWDT)for cancer treatment.We found that two AIEgens(TPEPy-I and TPEPy-PF6)served as a new type of microwave(MW)sensitizers to produce ROS,including singlet oxygen(1O2),resulting in efficient destructions of cancer cells.The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and live/dead assays reveal that the two AIEgens when activated by MW irradiation can effectively kill cancer cells with average IC-50 values of 2.73 and 3.22μM,respectively.Overall,the ability of the two AIEgens to be activated by MW not only overcomes the limitations of conventional PDT,but also helps to improve existing MW ablation therapy by reducing the MW dose required to achieve the same therapeutic outcome,thus reducing the occurrence of side-effects of MW radiation.
文摘Atomic force microscopy technology is gradually spreading to almost all aspects,including food science and technology,since it was first invented in 1986.In this study,this powerful instrument was applied to image nanostructures of three water absorbents-original konjac powder,konjac powder grafted with acrylic acid using^(60)Coγ-irradiation and regenerated grafted powder.Water absorption capacities and the rates of the three absorbents were also determined in this work.Original konjac powder could only absorb 60 times(w/w)of water,while 270 times for the grafted absorbent and 360 times for the regenerated absorbent.The initial water absorption rates in both tap and distilled water were high,but the rate decreased steeply as time elapsed.After 20 min,the absorbent was close to saturated status.These physical properties were in accordance with the nanostructures of these three water absorbents.
基金the financial support of the National Natural Science Foundation of China(nos.22074011,21922402,and 21727811)the Fundamental Research Funds for the Central Universities(nos.N2005003 and N2005017)+1 种基金the Liaoning Revitalization Talents Program(no.XLYC1802016)the Liaoning Innovative Talents Program in Colleges and Universities(no.ZX20200088).
文摘Two-dimensional(2D)graphitic carbon nitride(g-C_(3)N_(4))possesses a unique geometric configuration featuring a superimposed heterocyclic sp2 carbon and nitrogen framework.Its fluorescence may be attributed to π-π^(*),lone pair(LP)-π^(*),or LP-δ^(*)transitions.So far,the manipulation of its fluorescence emissions is largely unexploited and remains challenging.Herein,for the first time,rare-earth doping into the backbone structure of a g-C_(3)N_(4) framework under microwave agitation endows unprecedented fluorescence nature,with the emergence of two exceptional new fluorescence emissions in the 450-700 nm range.With terbium-doped g-C_(3)N_(4):Tb as a representative,these emissions exhibit distinctive features,that is,very sharp fluorescence peaks with narrow full width at half maximum(FWHM)(peak width at half-height)of<12 nm,quantumyields of 2.3±0.0% and 7.6±0.1% for the new emissions at λ_(ex)/λ_(em)=290/490 nm,and 290/545 nm,respectively;and a large Stokes shift of>200 nm.These features of g-C_(3)N_(4):Tb are most advantageous for applications in various fields,as demonstrated by(1)tracking biodistribution of g-C_(3)N_(4) in vivo with mass spectrometric imaging where the doped terbium serves as a tag,(2)a biometrics study facilitating the identification of an individual through fingerprint,and(3)anti-counterfeiting with g-C_(3)N_(4)∶Tb as a dual-functional marker to facilitate fluorescence and mass spectrometric imaging.
