AIM To clarify the mechanisms of HOX transcript antisense intergenic RNA(HOTAIR) in gastric cancer(GC) migration and invasion.METHODS Quantitative real-time polymerase chain reaction(qp CR) was used to detect the expr...AIM To clarify the mechanisms of HOX transcript antisense intergenic RNA(HOTAIR) in gastric cancer(GC) migration and invasion.METHODS Quantitative real-time polymerase chain reaction(qp CR) was used to detect the expression level of HOTAIR in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve(AUCROC) was constructed to evaluate the diagnostic value of HOTAIR. Wound-healing assay and Transwell assay were performed to detect the biological effects of HOTAIR in GC cells. qp CR,western blot and immunohistochemistry were used to evaluate the m RNA and protein expression of E-cadherin. RNAbinding protein immunoprecipitation was used for the analysis of EZH2 interactions with HOTAIR. Chromatin immunoprecipitation assay was performed to investigate direct interactions between EZH2 and E-cadherin.RESULTS The expression of HOTAIR was up-regulated in GC tumorous tissues compared with the para-tumorous tissues(p < 0.001). Its over-expression was correlated with tumor-node-metastasis(TNM) stage(p = 0.024),tumor invasion(p = 0.018),lymph node metastasis(p = 0.023),and poor prognosis(p < 0.001). Multivariate Cox regression analysis confirmed expression of HOTAIR as an independent predictor of overall survival(p = 0.033),together with TNM stage(p = 0.002) and lymph node metastasis(p = 0.002). The AUCROC was up to 0.709(95%CI: 0.623-0.785,p < 0.001). Knockdown of HOTAIR by si RNA in GC cells suppressed the migration and invasion of GC cells. Significantly negative correlation between HOTAIR and E-cadherin was found in GC tissues and cell lines,and HOTAIR contributed to the regulation of E-cadherin through binding to EZH2 with the E-cadherin promoter. CONCLUSION HOTAIR may play a pivotal role in tumor cell migration and invasion. It can be used as a potential diagnostic and prognostic biomarker for GC.展开更多
Red bayberry(Morella rubra)is an evergreen fruit tree found in southern China whose whole-genome sequence has recently been published.We updated the linkage map of the species by adding 118 SSR markers and the females...Red bayberry(Morella rubra)is an evergreen fruit tree found in southern China whose whole-genome sequence has recently been published.We updated the linkage map of the species by adding 118 SSR markers and the femalespecific marker MrFT2_BD-SEX.The integrated map included eight linkage groups and spanned 491 cM.Eleven sexassociated markers were identified,six of which were located in linkage group 8,in agreement with the previously reported location of the sex-determining region.The MrFT2_BD-SEX marker was genotyped in 203 cultivated accessions.Among the females of the accessions,we found two female-specific alleles,designated W-b(151 bp)and W-d(129 bp).We previously found that‘Dongkui’,a female cultivar,could produce viable pollen(we refer to such plants‘Dongkui-male’)and serve as the paternal parent in crosses.The genotypes of the MrFT2_BD-SEX marker were W-b/Z in‘Biqi’and W-d/Z in‘Dongkui-male’.The progeny of a cross between these parents produced a 3:1 female(W-)to male(ZZ)ratio and the expected 1:1:1:1 ratio of W-b/W-d:W-b/Z:W-d/Z:Z/Z.In addition,the flowering and fruiting phenotypes of all the F1 progeny fit their genotypes.Our results confirm the existence of ZW sex determination and show that the female phenotype is controlled by a single dominant locus(W)in a small genomic region(59 kb and less than 3.3 cM).Furthermore,we have produced a homozygous“super female”(WW)that should produce all-female offspring in the F2 generation,providing a foundation for commercial use and presenting great potential for use in modern breeding programs.展开更多
This paper reports a piezoelectric nanogenerator(NG) with a thickness of approximately 80 μm for miniaturized self-powered acceleration sensors. To deposit the piezoelectric zinc oxide(ZnO) thin film, a magnetron spu...This paper reports a piezoelectric nanogenerator(NG) with a thickness of approximately 80 μm for miniaturized self-powered acceleration sensors. To deposit the piezoelectric zinc oxide(ZnO) thin film, a magnetron sputtering machine was used. Polymethyl methacrylate(PMMA) and aluminum-doped zinc oxide(AZO) were used as the insulating layer and the top electrode of the NG, respectively. The experimental results show that the ZnO thin films annealed at 150℃ exhibited the highest crystallinity among the prepared films and an optical band gap of 3.24 eV. The NG fabricated with an AZO/PMMA/ZnO/stainless steel configuration exhibited a higher output voltage than the device with an AZO/ZnO/PMMA/stainless steel configuration. In addition, the annealing temperature affected the open-circuit voltage of the NGs;the output voltage reached 3.81 V when the annealing temperature was 150℃. The open-circuit voltage of the prepared self-powered accelerometer increased linearly with acceleration. In addition, the small NG-based accelerometer, which exhibited excellent fatigue resistance, can be used for acceleration measurements of small and lightweight devices.展开更多
The giant Dahutang tungsten(W)deposit has a total reserve of more than 1.31 Mt WO3.Veinlet-disseminated scheelite and vein type wolframite mineralization are developed in this deposit,which are related to Late Mesozoi...The giant Dahutang tungsten(W)deposit has a total reserve of more than 1.31 Mt WO3.Veinlet-disseminated scheelite and vein type wolframite mineralization are developed in this deposit,which are related to Late Mesozoic biotite granite.Four major types of alterations,which include albitization,potassic-alteration,and greisenization,and overprinted silicification developed in contact zone.The mass balance calculate of the four alteration types were used to further understanding of the mineralization process.The fresh porphyritic biotite granite has high Nb,Ta,and W,but low Ca and Sr while the Jiuling granodiorite has high Ca and Sr,but low Nb,Ta,and W concentrations.The altered porphyritic biotite granite indicated that the Nb,Ta,and W were leached out from the fresh porphyritic biotite granite,especially by sodic alteration.The low Ca and Sr contents of the altered Neoproterozoic Jiuling granodiorite indicate that Ca and Sr had been leached out from the fresh granodiorite by the fluid from Mesozoic porphyritic biotite granites.The metal W of the Dahutang deposit was mainly derived from the fluid exsolution from the melt and alteration of W-bearing granites.This study of alteration presents a new hydrothermal circulation model to understand tungsten mineralization in the Dahutang deposit.展开更多
To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a nov...To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.展开更多
Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a ...Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a green bio-based flame-retardant system to fabricate polyurethane foam composite with durable flame retardancy,smoke suppression,and thermal insulation property.In this system,the green bio-based polyol(VED)with good reactivity and compatibility plays a role of flame retardant and EG acts as a synergistic filler.As a result,the LOI value of foam composite increased to 30.5 vol.%and it achieved a V-0 rating in the UL-94 vertical burning test.Additionally,the peak heat release rate(pHRR)and the total smoke production(TSP)decreased by 66.1%and 63.4%,respectively.Furthermore,the foam composite maintained durable flame retardancy after accelerated thermal aging test,whose thermal-insulating property was maintained even after being treated in high-humidity environment with 85%R.H.for a week.This work provides a facile strategy for durable flame retardancy and long-term thermal insulation performance,and creates opportunities for the practical applications of bio-based foam composites.展开更多
The purpose of this study was to investigate the effects of Zr interlayer on the structure and mechanical properties of TiAlN films, which were deposited on the M2 high-speed steel substrates by means of plasma-enhanc...The purpose of this study was to investigate the effects of Zr interlayer on the structure and mechanical properties of TiAlN films, which were deposited on the M2 high-speed steel substrates by means of plasma-enhanced magnetron sputtering. The result shows that the crystal orientation of Zr/TiAlN films is similar to that of single-layered TiAlN films, but the difference is that AlN(111) of Zr/TiAlN films disappears completely. With respect to Zr interlayer, the texture coefficient of Zr/TiAlN films is approximately 1. Zr/TiAlN films exhibit a compact isometric structure, which is distinctly different from the columnar structure existing in the single-layered TiAlN films and Ti/TiAlN films. The hardness and H3/E*2 of Zr/TiAlN films are, respectively, enhanced to be 36.6 GPa and 0.147. With a few cracks emerging around the indention, the adhesion strength of TiAlN films is obviously advanced by adding Zr metal interlayer.展开更多
Protective materials that possess superelasticity and multifunctionality over a broad temperature range are urgently needed in various advanced applications.However,under harsh work conditions,the performance of curre...Protective materials that possess superelasticity and multifunctionality over a broad temperature range are urgently needed in various advanced applications.However,under harsh work conditions,the performance of current materials may largely deteriorate to lose protective functionality.Herein,we report a bidirectionally oriented multi-walled carbon nanotubes(MWCNTs)-reinforced chitosan carbon aerogel(CS-MWCNT)that possesses superelasticity,high electromagnetic interference shielding,thermal insulation,and infrared stealth at both low temperatures(such as liquid nitrogen)and high temperatures(such as alcohol flames).Highly oriented lamellar arch structures combined with an MWCNTs-reinforced carbon skeleton act as elastic segments to disperse the stress during compression and endow CS-MWCNT with the ability to recover to almost the original size after being compressed at−196-500℃.The lamellar structures make CS-MWCNT thermally insulating and infrared stealth with a low thermal conductivity of~0.03 W/(m·K).Furthermore,a high electromagnetic interference(EMI)shielding effect of 64 dB is realized via an absorption-dominant EMI shielding mechanism derived from the successive inherently conductive carbon lamella,and the EMI shielding performance is largely maintained after treatment under extreme conditions like low temperature,high temperature,as well as cyclic compression.This work provides a new strategy for the development of temperature-invariant multifunctional aerogels for harsh environment applications.展开更多
Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demon...Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave absorber.In this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high temper-atures.Meanwhile,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon fibers.Consequently,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption performances.Typically,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 mm.This work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.展开更多
An SnO2-decorated graphene/polyaniline （GSP） nanocomposite with homogeneous structure was prepared and adopted to achieve high electrochemical performance for supercapacitor electrode. Graphene sheets were decorated...An SnO2-decorated graphene/polyaniline （GSP） nanocomposite with homogeneous structure was prepared and adopted to achieve high electrochemical performance for supercapacitor electrode. Graphene sheets were decorated with tin dioxide （SnO2） particles, which effectively hinder the restacking of graphene nanosheets, and then were used as substrates for an in-situ polymerization of aniline monomers. The GSP nanocomposite was characterized by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared, UV-Visible and X-ray photoelectron spectroscopy. The results revealed that polyaniline nanorods were orderly and vertically aligned on the SnO2-decorated graphene nanosheets via π-π stacking effect between basal planes of graphene nanosheets and phenyl group of polyaniline. The GSP nanocomposite exhibited an excellent specific capacitance of 429 F g^-1 at a current density of 1 A g^-1, excellent cycling stability and rate capability, which suggested a promising application for supercapacitor.展开更多
A new method for characterizing fiber bending flexibility was developed by worm-like chain model proposed by Kratky-Porod,[1]which was first introduced to the pulp and paper field in this study.For the three types of ...A new method for characterizing fiber bending flexibility was developed by worm-like chain model proposed by Kratky-Porod,[1]which was first introduced to the pulp and paper field in this study.For the three types of pulps,the experimental results were compared with the KP chain model,and the resulting determination coefficients were all above 0.95,which proved that the model was feasible to be applied to these three fibers.The relation between fiber bending rigidity and that of cellulosic chains inside was discussed to deduce the fiber bending flexibility.The flexibility of an individual fiber can be approximated as the contribution of that of all the cellulose chains inside.By this method,the fiber flexibility values were determined to be in the range of 0.6×10^(11)-3.5×10^(11)N^(-1)·m^(-2),which was comparable to that of the conventional methods recorded in the literature.展开更多
基金Supported by the Shandong Provincial Natural Science Foundation of China,No.ZR2016HQ08Shandong Province Medical Science and Technology Development Projects of China,No.2016WS0151the Jining Municipal Project on Science and Technology Development of China,No.2013jnwk58
文摘AIM To clarify the mechanisms of HOX transcript antisense intergenic RNA(HOTAIR) in gastric cancer(GC) migration and invasion.METHODS Quantitative real-time polymerase chain reaction(qp CR) was used to detect the expression level of HOTAIR in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve(AUCROC) was constructed to evaluate the diagnostic value of HOTAIR. Wound-healing assay and Transwell assay were performed to detect the biological effects of HOTAIR in GC cells. qp CR,western blot and immunohistochemistry were used to evaluate the m RNA and protein expression of E-cadherin. RNAbinding protein immunoprecipitation was used for the analysis of EZH2 interactions with HOTAIR. Chromatin immunoprecipitation assay was performed to investigate direct interactions between EZH2 and E-cadherin.RESULTS The expression of HOTAIR was up-regulated in GC tumorous tissues compared with the para-tumorous tissues(p < 0.001). Its over-expression was correlated with tumor-node-metastasis(TNM) stage(p = 0.024),tumor invasion(p = 0.018),lymph node metastasis(p = 0.023),and poor prognosis(p < 0.001). Multivariate Cox regression analysis confirmed expression of HOTAIR as an independent predictor of overall survival(p = 0.033),together with TNM stage(p = 0.002) and lymph node metastasis(p = 0.002). The AUCROC was up to 0.709(95%CI: 0.623-0.785,p < 0.001). Knockdown of HOTAIR by si RNA in GC cells suppressed the migration and invasion of GC cells. Significantly negative correlation between HOTAIR and E-cadherin was found in GC tissues and cell lines,and HOTAIR contributed to the regulation of E-cadherin through binding to EZH2 with the E-cadherin promoter. CONCLUSION HOTAIR may play a pivotal role in tumor cell migration and invasion. It can be used as a potential diagnostic and prognostic biomarker for GC.
基金support from the Natural Science Foundation of China(31972364)Yuyao Forestry Technology Extension Center.H.M.J.was supported by the National Natural Science Foundation of China(31901985).Z.S.G.,Y.J.,C.Y.C.were funded by a Ningbo Science and Technology Research Grant(contract no 2016C10021).
文摘Red bayberry(Morella rubra)is an evergreen fruit tree found in southern China whose whole-genome sequence has recently been published.We updated the linkage map of the species by adding 118 SSR markers and the femalespecific marker MrFT2_BD-SEX.The integrated map included eight linkage groups and spanned 491 cM.Eleven sexassociated markers were identified,six of which were located in linkage group 8,in agreement with the previously reported location of the sex-determining region.The MrFT2_BD-SEX marker was genotyped in 203 cultivated accessions.Among the females of the accessions,we found two female-specific alleles,designated W-b(151 bp)and W-d(129 bp).We previously found that‘Dongkui’,a female cultivar,could produce viable pollen(we refer to such plants‘Dongkui-male’)and serve as the paternal parent in crosses.The genotypes of the MrFT2_BD-SEX marker were W-b/Z in‘Biqi’and W-d/Z in‘Dongkui-male’.The progeny of a cross between these parents produced a 3:1 female(W-)to male(ZZ)ratio and the expected 1:1:1:1 ratio of W-b/W-d:W-b/Z:W-d/Z:Z/Z.In addition,the flowering and fruiting phenotypes of all the F1 progeny fit their genotypes.Our results confirm the existence of ZW sex determination and show that the female phenotype is controlled by a single dominant locus(W)in a small genomic region(59 kb and less than 3.3 cM).Furthermore,we have produced a homozygous“super female”(WW)that should produce all-female offspring in the F2 generation,providing a foundation for commercial use and presenting great potential for use in modern breeding programs.
基金supported by the National Natural Science Foundation of China (No. 61671017)Key Project of Excellent Youth Talent Support Program in Colleges and Universities of Anhui Province (No. gxyqZD2018004)+1 种基金Provincial Natural Science Foundation of Anhui Higher Education Institution of China (No. KJ2016A787)Anhui Provincial Natural Science Foundation of China (No. 1508085ME72)
文摘This paper reports a piezoelectric nanogenerator(NG) with a thickness of approximately 80 μm for miniaturized self-powered acceleration sensors. To deposit the piezoelectric zinc oxide(ZnO) thin film, a magnetron sputtering machine was used. Polymethyl methacrylate(PMMA) and aluminum-doped zinc oxide(AZO) were used as the insulating layer and the top electrode of the NG, respectively. The experimental results show that the ZnO thin films annealed at 150℃ exhibited the highest crystallinity among the prepared films and an optical band gap of 3.24 eV. The NG fabricated with an AZO/PMMA/ZnO/stainless steel configuration exhibited a higher output voltage than the device with an AZO/ZnO/PMMA/stainless steel configuration. In addition, the annealing temperature affected the open-circuit voltage of the NGs;the output voltage reached 3.81 V when the annealing temperature was 150℃. The open-circuit voltage of the prepared self-powered accelerometer increased linearly with acceleration. In addition, the small NG-based accelerometer, which exhibited excellent fatigue resistance, can be used for acceleration measurements of small and lightweight devices.
基金This research is jointly funded by the Project of China Geological Survey(DD20190186 and 12120114034501)National Natural Science Foundation of China(42062006 and 41962007).
文摘The giant Dahutang tungsten(W)deposit has a total reserve of more than 1.31 Mt WO3.Veinlet-disseminated scheelite and vein type wolframite mineralization are developed in this deposit,which are related to Late Mesozoic biotite granite.Four major types of alterations,which include albitization,potassic-alteration,and greisenization,and overprinted silicification developed in contact zone.The mass balance calculate of the four alteration types were used to further understanding of the mineralization process.The fresh porphyritic biotite granite has high Nb,Ta,and W,but low Ca and Sr while the Jiuling granodiorite has high Ca and Sr,but low Nb,Ta,and W concentrations.The altered porphyritic biotite granite indicated that the Nb,Ta,and W were leached out from the fresh porphyritic biotite granite,especially by sodic alteration.The low Ca and Sr contents of the altered Neoproterozoic Jiuling granodiorite indicate that Ca and Sr had been leached out from the fresh granodiorite by the fluid from Mesozoic porphyritic biotite granites.The metal W of the Dahutang deposit was mainly derived from the fluid exsolution from the melt and alteration of W-bearing granites.This study of alteration presents a new hydrothermal circulation model to understand tungsten mineralization in the Dahutang deposit.
基金financially supported by the National Natural Science Foundation of China(51827803,51320105011,51790504,and 51721091)the Young Elite Scientists Sponsorship Program by CASTFundamental Research Funds for the Central Universities。
文摘To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.
基金supported by the National Natural Science Foundation of China(Nos.22175123,52122302,and 51991351)the 111 Project(No.B20001)Fundamental Research Funds for the Central Universities,and Open and Innovative Fund of Hubei Three Gorges Laboratory(Nos.2022LF2021 and SC213011).
文摘Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a green bio-based flame-retardant system to fabricate polyurethane foam composite with durable flame retardancy,smoke suppression,and thermal insulation property.In this system,the green bio-based polyol(VED)with good reactivity and compatibility plays a role of flame retardant and EG acts as a synergistic filler.As a result,the LOI value of foam composite increased to 30.5 vol.%and it achieved a V-0 rating in the UL-94 vertical burning test.Additionally,the peak heat release rate(pHRR)and the total smoke production(TSP)decreased by 66.1%and 63.4%,respectively.Furthermore,the foam composite maintained durable flame retardancy after accelerated thermal aging test,whose thermal-insulating property was maintained even after being treated in high-humidity environment with 85%R.H.for a week.This work provides a facile strategy for durable flame retardancy and long-term thermal insulation performance,and creates opportunities for the practical applications of bio-based foam composites.
基金financially supported by the Ministry of Industry and Information Technology of China(No.2012ZX04003011)the National Natural Science Foundation of China(No.51275323)
文摘The purpose of this study was to investigate the effects of Zr interlayer on the structure and mechanical properties of TiAlN films, which were deposited on the M2 high-speed steel substrates by means of plasma-enhanced magnetron sputtering. The result shows that the crystal orientation of Zr/TiAlN films is similar to that of single-layered TiAlN films, but the difference is that AlN(111) of Zr/TiAlN films disappears completely. With respect to Zr interlayer, the texture coefficient of Zr/TiAlN films is approximately 1. Zr/TiAlN films exhibit a compact isometric structure, which is distinctly different from the columnar structure existing in the single-layered TiAlN films and Ti/TiAlN films. The hardness and H3/E*2 of Zr/TiAlN films are, respectively, enhanced to be 36.6 GPa and 0.147. With a few cracks emerging around the indention, the adhesion strength of TiAlN films is obviously advanced by adding Zr metal interlayer.
基金the National Natural Science Foundation of China(Nos.52122302,51991351,22175123,and 51790504)Fundamental Research Funds for the Central Universities,Young Elite Scientists Sponsorship Program by CAST,and financial support by the 111 project(No.B20001)is sincerely acknowledged。
文摘Protective materials that possess superelasticity and multifunctionality over a broad temperature range are urgently needed in various advanced applications.However,under harsh work conditions,the performance of current materials may largely deteriorate to lose protective functionality.Herein,we report a bidirectionally oriented multi-walled carbon nanotubes(MWCNTs)-reinforced chitosan carbon aerogel(CS-MWCNT)that possesses superelasticity,high electromagnetic interference shielding,thermal insulation,and infrared stealth at both low temperatures(such as liquid nitrogen)and high temperatures(such as alcohol flames).Highly oriented lamellar arch structures combined with an MWCNTs-reinforced carbon skeleton act as elastic segments to disperse the stress during compression and endow CS-MWCNT with the ability to recover to almost the original size after being compressed at−196-500℃.The lamellar structures make CS-MWCNT thermally insulating and infrared stealth with a low thermal conductivity of~0.03 W/(m·K).Furthermore,a high electromagnetic interference(EMI)shielding effect of 64 dB is realized via an absorption-dominant EMI shielding mechanism derived from the successive inherently conductive carbon lamella,and the EMI shielding performance is largely maintained after treatment under extreme conditions like low temperature,high temperature,as well as cyclic compression.This work provides a new strategy for the development of temperature-invariant multifunctional aerogels for harsh environment applications.
基金supported by the National Natural Science Foun-dation of China(Nos.52122302,51991351,and 51790504)Funda-mental Research Funds for the Central Universities,Young Elite Sci-entists Sponsorship Program by CAST.Financial support by the 111 Project(No.B20001)is sincerely acknowledged.
文摘Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave absorber.In this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high temper-atures.Meanwhile,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon fibers.Consequently,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption performances.Typically,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 mm.This work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.
基金financial support of the National Natural Science Foundation of China(No.51272045)the Foundation for Development of Science and Technology of Fuzhou University(2014-XQ-2)
文摘An SnO2-decorated graphene/polyaniline （GSP） nanocomposite with homogeneous structure was prepared and adopted to achieve high electrochemical performance for supercapacitor electrode. Graphene sheets were decorated with tin dioxide （SnO2） particles, which effectively hinder the restacking of graphene nanosheets, and then were used as substrates for an in-situ polymerization of aniline monomers. The GSP nanocomposite was characterized by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared, UV-Visible and X-ray photoelectron spectroscopy. The results revealed that polyaniline nanorods were orderly and vertically aligned on the SnO2-decorated graphene nanosheets via π-π stacking effect between basal planes of graphene nanosheets and phenyl group of polyaniline. The GSP nanocomposite exhibited an excellent specific capacitance of 429 F g^-1 at a current density of 1 A g^-1, excellent cycling stability and rate capability, which suggested a promising application for supercapacitor.
基金financially supported by the National Natural Science Foundation of China (No. 21534002)National Key R&D Program of China (No. 2019YFC1520402)
文摘A new method for characterizing fiber bending flexibility was developed by worm-like chain model proposed by Kratky-Porod,[1]which was first introduced to the pulp and paper field in this study.For the three types of pulps,the experimental results were compared with the KP chain model,and the resulting determination coefficients were all above 0.95,which proved that the model was feasible to be applied to these three fibers.The relation between fiber bending rigidity and that of cellulosic chains inside was discussed to deduce the fiber bending flexibility.The flexibility of an individual fiber can be approximated as the contribution of that of all the cellulose chains inside.By this method,the fiber flexibility values were determined to be in the range of 0.6×10^(11)-3.5×10^(11)N^(-1)·m^(-2),which was comparable to that of the conventional methods recorded in the literature.
