Non-hydrostatic stress plays a significant role in shaping the properties of materials under compression.High-pressure effects such as yielding deformation,phase transitions,and volume contraction can alter the pressu...Non-hydrostatic stress plays a significant role in shaping the properties of materials under compression.High-pressure effects such as yielding deformation,phase transitions,and volume contraction can alter the pressure distribution within the pressure chamber.However,due to the inherent size limitation of the diamond anvil cell(DAC),in situ high-pressure studies usually assume a hydrostatic environment,equaling the pressure of samples to a pressure calibrator inside the chamber.Accurately imaging pressure distribution within the DAC chamber remains challenging,particularly as the material undergoes phase transitions.Here,we present a method for mapping pressure distribution with high spatial resolution using wide-field optically detected magnetic resonance(ODMR)of nanodiamonds.The pressure gradients during the highpressure transition of zinc oxide(ZnO)were compared using both the multiple rubies technique and wide-field ODMR.The latter technique demonstrated superior spatial resolution,easier operation,and more detailed information.These results highlight the potential of wide-field ODMR as a powerful tool for precise pressure sensing,particularly in studies involving non-hydrostatic pressure conditions.展开更多
Objective： To investigate the expression of cyclooxygenase-2 （COX-2） and p16 proteins in non-Hodgkin＇s lymphomas （NHL） and their relationship with the genesis and progress of it. Methods： The expression of COX-...Objective： To investigate the expression of cyclooxygenase-2 （COX-2） and p16 proteins in non-Hodgkin＇s lymphomas （NHL） and their relationship with the genesis and progress of it. Methods： The expression of COX-2 and p16 protein were studied in the lymph nodes tissue from 60 NHL patients and 10 control patients with non-malignant diseases by flow cytometry. Results： Positive rate of COX-2 protein expression in NHL tissues （63.3%, 38/60） was higher than that in normal lymphaden tissues （0, 0/10）. The difference was significant between the two groups （P 〈 0.01）. Expression of COX-2 protein was related with the clinical stage of NHL. In stage Ⅰ ＋ Ⅱ patients, it was significantly lower （35.0% ± 54.6%） than that in stage Ⅲ ＋ Ⅳ patients （84.6% ±87.5%） （P 〈 0.01）. In different sex, age, tumor malignant degree, IPI grade, extranodal involvement and B symptoms groups, the differences of COX-2 expression were not statistically significant （P 〉 0.05）. Positive rate of p16 protein expression （41.7%, 25/60） in NHL＇ was statistically lower than that in normal lymphomas （100%, 10/10） （P 〈 0.01）. Expression of p16 protein was related to malignant degree of NHL. The positive rates of p16 protein in low malignant degree tissues （64.7%, 11/17） was higher than that in high malignant degree tissues （14.3%, 2/14） （P 〈 0.05）. Positive rates of p16 protein of NHL tissues in different sex, age, IPI grade, extranodal involvement, clinical stages and B symptoms were not statistically significant （P 〉 0.05）. The p16 protein expression in COX-2 positive patients was 47.4% （18/38）, and in negative patients it was 31.8% （7/22）. There was no statistically difference between them （P 〉 0.05）. Correlation analysis revealed there was no correlation between expression of COX-2 and p16 protein. Conclusion： Both COX-2 and p16 protein may all have relationship with the genesis and progress of NHL. The expression of COX-2 protein in NHL may be a poor prognostic indicator. COX-2 and p16 protein probably have different mechanisms in the genesis and progress of NHL. Their relationship is firstly put forward in this article and needed further studying.展开更多
Searching for new carbon allotropes with superior properties has been a longstanding interest in material sciences and condensed matter physics.Here we identify a novel superhard carbon phase with an 18-atom trigonal ...Searching for new carbon allotropes with superior properties has been a longstanding interest in material sciences and condensed matter physics.Here we identify a novel superhard carbon phase with an 18-atom trigonal unit cell in a full-sp^(3) bonding network,termed tri-C_(18) carbon,by first-principles calculations.Its structural stability has been verified by total energy,phonon spectra,elastic constants,and molecular dynamics simulations.Furthermore,tri-C_(18) carbon has a high bulk modulus of 400 GPa and Vickers hardness of 79.0 GPa,comparable to those of diamond.Meanwhile,the simulated x-ray diffraction pattern of tri-C_(18) carbon matches well with the previously unexplained diffraction peaks found in chimney soot,indicating the possible presence of tri-C_(18) carbon.Remarkably,electronic band structure calculations reveal that tri-C_(18) carbon has a wide indirect bandgap of 6.32 eV,larger than that of cubic diamond,indicating its great potential in electronic or optoelectronic devices working in the deep ultraviolet region.展开更多
As one promising carbon-based material,sp^(3)-hybrid carbon nitride has been predicted with various novel physicochemical properties.However,the synthesis of sp^(3)-hybrid carbon nitride is still limited by the nanaos...As one promising carbon-based material,sp^(3)-hybrid carbon nitride has been predicted with various novel physicochemical properties.However,the synthesis of sp^(3)-hybrid carbon nitride is still limited by the nanaoscale,low crystallinity,complex source,and expensive instruments.Herein,we have presented a facile approach to the sp^(3)-hybrid carbon nitride nano/micro-crystals with microwave-assisted confining growth and liquid exfoliation.Actually,the carbon nitride nano/micro-crystals can spontaneously emerge and grow in the microwave-assisted polymerization of citric acid and urea,and the liquid exfoliation can break the bulk disorder polymer to retrieve the highly crystalline carbon nitride nano/micro-crystals.The obtained carbon nitride nano/micro-crystals present superior blue light absorption strength and surprising photoluminescence quantum yields of 57.96% in ethanol and 18.05%in solid state.The experimental characterizations and density functional theory calculations reveal that the interface-trapped localized exciton may contribute to the excellent intrinsic light emission capability of carbon nitride nano/micro-crystals and the interparticle staggered stacking will prevent the aggregation-caused-quenching partially.Finally,the carbon nitride nano/micro-crystals are demonstrated to be potentially useful as the phosphor medium in light-emitting-diode for interrupting blue light-induced eye damage.This work paves new light on the synthesis strategy of sp^(3)-hybrid carbon nitride materials and thus may push forward the development of multiple carbon nitride research.展开更多
The discovery of each new allotropic manifestation of carbon has substantially propelled contemporary scientific research and applications,as vividly exemplified by the explosive progressions within the realms of full...The discovery of each new allotropic manifestation of carbon has substantially propelled contemporary scientific research and applications,as vividly exemplified by the explosive progressions within the realms of fullerene,carbon nanotube,graphene,and diamond sciences over recent decades.Here,using state-of-the-art first-principles calculations,we predict a new type of twodimensional carbon network,dubbed fullerphene,by replacing each C atom in graphene with a fullerene(C_(60)).Its high energetic stability is tied to the symmetric cycloaddition of the double bonds between each C_(60) superatom with each of its three neighbors.A kinetic pathway is also proposed for the selective fabrication of fullerphene on Cu(111)or Rh(111),upon exploiting its enhanced stability over other competing C_(60) assemblies and significantly lowered kinetic barrier in seed growing,as strategically supported by a recent experimental advance.Further investigations on fullerphene reveal an array of desirable characteristics,including a substantial band gap of∼2 eV,Dirac states for the conduction electrons,and flat bands for the valence electrons.These findings represent a distinctly new and significant advance in both fullerene and graphene sciences.展开更多
Humidity sensors have attracted considerable attention for their capability for real-time,continuous monitoring of critical physiological information,thus offering valuable insights into human health.Two-dimensional h...Humidity sensors have attracted considerable attention for their capability for real-time,continuous monitoring of critical physiological information,thus offering valuable insights into human health.Two-dimensional hexagonal boron nitride(h-BN)has emerged as an attractive material for humidity sensing due to its high specific surface area and excellent chemical stability.However,the low hydrophilicity of h-BN limits its ability to adsorb water molecules,resulting in reduced sensitivity and slow response times.Herein,capacitive humidity sensors consisted of aminefunctionalized h-BN nanosheets have been developed.The introduction of amine groups modulates the hydrophilicity of pristine h-BN by forming hydrogen bonds,promoting interactions with water molecules.The h-BN-based sensor shows significantly improved performance,including high sensitivity(124,136 pF/%RH),large response(5,268,192%),and rapid response and recovery time(2.39 s/1.77 s).These findings demonstrate that amine functionalization can effectively enhance both water adsorption capacity and sensor performance,providing a promising approach for highly sensitive and responsive humidity sensors.展开更多
Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications.However,most of luminescent materials usually undergo emission quenching under external stimuli.Herein,we demonstra...Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications.However,most of luminescent materials usually undergo emission quenching under external stimuli.Herein,we demonstrate for the first time that the photoluminescence of carbon dots(CDs)confined within sodium hydroxide can be enhanced when high pressure is applied.They exhibit a 1.6-fold fluorescence enhancement compared with pristine CDs.Importantly,the enhanced fluorescence intensity can be retained after the release of pressure to ambient conditions.A combination of experimental analysis and theoretical simulations indicates that such an enhanced emission is mainly attributed to the strong confinement resulting from the sodium hydroxide matrix,which can separate the CDs spatially and restrict the nonradiative pathway.These results provide a rational strategy for manipulating the optical properties of CDs with enhanced and retainable photoluminescence(PL)performance,thus opening up a venue for designing luminescent CDs-based materials.展开更多
Humidity sensors with high sensitivity,rapid response,and facile fabrication process for contactless sensing applications have received considerable attention in recent years.Herein,humidity sensors based on hexagonal...Humidity sensors with high sensitivity,rapid response,and facile fabrication process for contactless sensing applications have received considerable attention in recent years.Herein,humidity sensors based on hexagonal boron nitride(h-BN)nanosheets that are synthesized by a facile ultrasonic process have been fabricated,which display an ultrahigh sensitivity of 28,384%at 85%relative humidity(RH),rapid response/recovery time(3.0/5.5 s),and long-term stability in a wide humidity detection range(11%-85%RH),superior to most of the reported humidity sensors.The high sensitivity can be ascribed to the massive hydrophilic functional groups absorbed on the h-BN nanosheet surface.Benefiting from the high humidity sensing performances,contactless Morse code messaging and human writing and speech recognition have been demonstrated.This work demonstrates the great potential of the high-performance h-BN nanosheet-based humidity sensors for future contactless sensing devices.展开更多
Recent experiments have demonstrated Rabi-oscillations, superradiant pulses and stimulated emission from negatively-charged nitrogen-vacancy(NV;) center spins in microwave resonators. These phenomena witness the kind ...Recent experiments have demonstrated Rabi-oscillations, superradiant pulses and stimulated emission from negatively-charged nitrogen-vacancy(NV;) center spins in microwave resonators. These phenomena witness the kind of collective and strong coupling which has been the prerequisite for observation of superradiant lasing in the optical frequency regime. In this article, we investigate the possibility to employ coherence, present in both the collective NV-spin ensemble and the microwave field, to achieve a superradiant maser. Our calculations show that a superradiant maser with a linewidth below millihertz can be achieved with moderate kilohertz incoherent pumping of over 10;spins at room temperature. We show that the superradiant masing prevails in the presence of inhomogeneous broadening, and we present numerical and analytical studies of the dependence of the phenomenon on the various physical parameters.展开更多
基金supported by the National Key R&D Program of China(Grant No.2024YFE0105200)the National Natural Science Foundation of China(Grant Nos.62422408,12374016,12174348,62271450,62027816,12422413,and 62475242).
文摘Non-hydrostatic stress plays a significant role in shaping the properties of materials under compression.High-pressure effects such as yielding deformation,phase transitions,and volume contraction can alter the pressure distribution within the pressure chamber.However,due to the inherent size limitation of the diamond anvil cell(DAC),in situ high-pressure studies usually assume a hydrostatic environment,equaling the pressure of samples to a pressure calibrator inside the chamber.Accurately imaging pressure distribution within the DAC chamber remains challenging,particularly as the material undergoes phase transitions.Here,we present a method for mapping pressure distribution with high spatial resolution using wide-field optically detected magnetic resonance(ODMR)of nanodiamonds.The pressure gradients during the highpressure transition of zinc oxide(ZnO)were compared using both the multiple rubies technique and wide-field ODMR.The latter technique demonstrated superior spatial resolution,easier operation,and more detailed information.These results highlight the potential of wide-field ODMR as a powerful tool for precise pressure sensing,particularly in studies involving non-hydrostatic pressure conditions.
文摘Objective： To investigate the expression of cyclooxygenase-2 （COX-2） and p16 proteins in non-Hodgkin＇s lymphomas （NHL） and their relationship with the genesis and progress of it. Methods： The expression of COX-2 and p16 protein were studied in the lymph nodes tissue from 60 NHL patients and 10 control patients with non-malignant diseases by flow cytometry. Results： Positive rate of COX-2 protein expression in NHL tissues （63.3%, 38/60） was higher than that in normal lymphaden tissues （0, 0/10）. The difference was significant between the two groups （P 〈 0.01）. Expression of COX-2 protein was related with the clinical stage of NHL. In stage Ⅰ ＋ Ⅱ patients, it was significantly lower （35.0% ± 54.6%） than that in stage Ⅲ ＋ Ⅳ patients （84.6% ±87.5%） （P 〈 0.01）. In different sex, age, tumor malignant degree, IPI grade, extranodal involvement and B symptoms groups, the differences of COX-2 expression were not statistically significant （P 〉 0.05）. Positive rate of p16 protein expression （41.7%, 25/60） in NHL＇ was statistically lower than that in normal lymphomas （100%, 10/10） （P 〈 0.01）. Expression of p16 protein was related to malignant degree of NHL. The positive rates of p16 protein in low malignant degree tissues （64.7%, 11/17） was higher than that in high malignant degree tissues （14.3%, 2/14） （P 〈 0.05）. Positive rates of p16 protein of NHL tissues in different sex, age, IPI grade, extranodal involvement, clinical stages and B symptoms were not statistically significant （P 〉 0.05）. The p16 protein expression in COX-2 positive patients was 47.4% （18/38）, and in negative patients it was 31.8% （7/22）. There was no statistically difference between them （P 〉 0.05）. Correlation analysis revealed there was no correlation between expression of COX-2 and p16 protein. Conclusion： Both COX-2 and p16 protein may all have relationship with the genesis and progress of NHL. The expression of COX-2 protein in NHL may be a poor prognostic indicator. COX-2 and p16 protein probably have different mechanisms in the genesis and progress of NHL. Their relationship is firstly put forward in this article and needed further studying.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11804307,U1804155,and U1604263)the China Postdoctoral Science Foundation(Grant Nos.2018M630830 and 2019T120631).
文摘Searching for new carbon allotropes with superior properties has been a longstanding interest in material sciences and condensed matter physics.Here we identify a novel superhard carbon phase with an 18-atom trigonal unit cell in a full-sp^(3) bonding network,termed tri-C_(18) carbon,by first-principles calculations.Its structural stability has been verified by total energy,phonon spectra,elastic constants,and molecular dynamics simulations.Furthermore,tri-C_(18) carbon has a high bulk modulus of 400 GPa and Vickers hardness of 79.0 GPa,comparable to those of diamond.Meanwhile,the simulated x-ray diffraction pattern of tri-C_(18) carbon matches well with the previously unexplained diffraction peaks found in chimney soot,indicating the possible presence of tri-C_(18) carbon.Remarkably,electronic band structure calculations reveal that tri-C_(18) carbon has a wide indirect bandgap of 6.32 eV,larger than that of cubic diamond,indicating its great potential in electronic or optoelectronic devices working in the deep ultraviolet region.
基金the National Natural Science Foundation of China(12074348,12261141661,62204223,52072345,and 12174348)the China Postdoctoral Science Foundation(2022TQ0307)the Natural Science Foundation of Henan Province(242300421179 and 222102310664).
文摘As one promising carbon-based material,sp^(3)-hybrid carbon nitride has been predicted with various novel physicochemical properties.However,the synthesis of sp^(3)-hybrid carbon nitride is still limited by the nanaoscale,low crystallinity,complex source,and expensive instruments.Herein,we have presented a facile approach to the sp^(3)-hybrid carbon nitride nano/micro-crystals with microwave-assisted confining growth and liquid exfoliation.Actually,the carbon nitride nano/micro-crystals can spontaneously emerge and grow in the microwave-assisted polymerization of citric acid and urea,and the liquid exfoliation can break the bulk disorder polymer to retrieve the highly crystalline carbon nitride nano/micro-crystals.The obtained carbon nitride nano/micro-crystals present superior blue light absorption strength and surprising photoluminescence quantum yields of 57.96% in ethanol and 18.05%in solid state.The experimental characterizations and density functional theory calculations reveal that the interface-trapped localized exciton may contribute to the excellent intrinsic light emission capability of carbon nitride nano/micro-crystals and the interparticle staggered stacking will prevent the aggregation-caused-quenching partially.Finally,the carbon nitride nano/micro-crystals are demonstrated to be potentially useful as the phosphor medium in light-emitting-diode for interrupting blue light-induced eye damage.This work paves new light on the synthesis strategy of sp^(3)-hybrid carbon nitride materials and thus may push forward the development of multiple carbon nitride research.
基金supported by the National Natural Science Foundation of China(Grant Nos.U23A2072,12204421,12074345,and 12174349).
文摘The discovery of each new allotropic manifestation of carbon has substantially propelled contemporary scientific research and applications,as vividly exemplified by the explosive progressions within the realms of fullerene,carbon nanotube,graphene,and diamond sciences over recent decades.Here,using state-of-the-art first-principles calculations,we predict a new type of twodimensional carbon network,dubbed fullerphene,by replacing each C atom in graphene with a fullerene(C_(60)).Its high energetic stability is tied to the symmetric cycloaddition of the double bonds between each C_(60) superatom with each of its three neighbors.A kinetic pathway is also proposed for the selective fabrication of fullerphene on Cu(111)or Rh(111),upon exploiting its enhanced stability over other competing C_(60) assemblies and significantly lowered kinetic barrier in seed growing,as strategically supported by a recent experimental advance.Further investigations on fullerphene reveal an array of desirable characteristics,including a substantial band gap of∼2 eV,Dirac states for the conduction electrons,and flat bands for the valence electrons.These findings represent a distinctly new and significant advance in both fullerene and graphene sciences.
基金supported by the National Key Research and Development Program of China(No.2024YFE0105200)the National Natural Science Foundation of China(Nos.62422408,12374016,12174348,and 62027816).
文摘Humidity sensors have attracted considerable attention for their capability for real-time,continuous monitoring of critical physiological information,thus offering valuable insights into human health.Two-dimensional hexagonal boron nitride(h-BN)has emerged as an attractive material for humidity sensing due to its high specific surface area and excellent chemical stability.However,the low hydrophilicity of h-BN limits its ability to adsorb water molecules,resulting in reduced sensitivity and slow response times.Herein,capacitive humidity sensors consisted of aminefunctionalized h-BN nanosheets have been developed.The introduction of amine groups modulates the hydrophilicity of pristine h-BN by forming hydrogen bonds,promoting interactions with water molecules.The h-BN-based sensor shows significantly improved performance,including high sensitivity(124,136 pF/%RH),large response(5,268,192%),and rapid response and recovery time(2.39 s/1.77 s).These findings demonstrate that amine functionalization can effectively enhance both water adsorption capacity and sensor performance,providing a promising approach for highly sensitive and responsive humidity sensors.
基金the National Natural Science Foundation of China(Nos.11804307,12074348,U2004168,62027816 and U1804155)the China Postdoctoral Science Foundation(Nos.2018M630830,2019T120631 and 2020M682310)the Natural Science Foundation of Henan Province(Nos.212300410410 and 212300410078).
文摘Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications.However,most of luminescent materials usually undergo emission quenching under external stimuli.Herein,we demonstrate for the first time that the photoluminescence of carbon dots(CDs)confined within sodium hydroxide can be enhanced when high pressure is applied.They exhibit a 1.6-fold fluorescence enhancement compared with pristine CDs.Importantly,the enhanced fluorescence intensity can be retained after the release of pressure to ambient conditions.A combination of experimental analysis and theoretical simulations indicates that such an enhanced emission is mainly attributed to the strong confinement resulting from the sodium hydroxide matrix,which can separate the CDs spatially and restrict the nonradiative pathway.These results provide a rational strategy for manipulating the optical properties of CDs with enhanced and retainable photoluminescence(PL)performance,thus opening up a venue for designing luminescent CDs-based materials.
基金This work was supported by the National Natural Science Foundation of China(Nos.12174348,U21A2070,and 62027816)the Young Elite Scientists Sponsorship Program by CAST(No.2021QNRC001)+1 种基金the Natural Science Foundation of Henan Province(No.212300410410)the China Postdoctoral Science Foundation(Nos.2018M630830 and 2019T120631).
文摘Humidity sensors with high sensitivity,rapid response,and facile fabrication process for contactless sensing applications have received considerable attention in recent years.Herein,humidity sensors based on hexagonal boron nitride(h-BN)nanosheets that are synthesized by a facile ultrasonic process have been fabricated,which display an ultrahigh sensitivity of 28,384%at 85%relative humidity(RH),rapid response/recovery time(3.0/5.5 s),and long-term stability in a wide humidity detection range(11%-85%RH),superior to most of the reported humidity sensors.The high sensitivity can be ascribed to the massive hydrophilic functional groups absorbed on the h-BN nanosheet surface.Benefiting from the high humidity sensing performances,contactless Morse code messaging and human writing and speech recognition have been demonstrated.This work demonstrates the great potential of the high-performance h-BN nanosheet-based humidity sensors for future contactless sensing devices.
基金supported by the National Natural Science Foundation of China (Grant Nos. 12004344, and 62027816)the Danish National Research Foundation through the Center of Excellence for Complex Quantum Systems (Grant No. DNRF156)。
文摘Recent experiments have demonstrated Rabi-oscillations, superradiant pulses and stimulated emission from negatively-charged nitrogen-vacancy(NV;) center spins in microwave resonators. These phenomena witness the kind of collective and strong coupling which has been the prerequisite for observation of superradiant lasing in the optical frequency regime. In this article, we investigate the possibility to employ coherence, present in both the collective NV-spin ensemble and the microwave field, to achieve a superradiant maser. Our calculations show that a superradiant maser with a linewidth below millihertz can be achieved with moderate kilohertz incoherent pumping of over 10;spins at room temperature. We show that the superradiant masing prevails in the presence of inhomogeneous broadening, and we present numerical and analytical studies of the dependence of the phenomenon on the various physical parameters.
