Studies of the mineralogy and sulfur isotope composition of sediment-hosted hydrothermal sulfide minerals in cores are important for understanding the seafloor mineralization environment and material source and recons...Studies of the mineralogy and sulfur isotope composition of sediment-hosted hydrothermal sulfide minerals in cores are important for understanding the seafloor mineralization environment and material source and reconstructing the hydrothermal history.However,the source of ore-forming materials and the history of hydrothermal activity in the southern Okinawa Trough(SOT)remain unclear.Here,the mineralogy and sulfur isotope characteristics of sulfides from gravity core HOBAB4-S2,collected between the Yonaguni Knoll IV hydrothermal field(HF)and the Tangyin HF,was investigated.Enrichments in Zn(up to 321×10^(-6)),Cu(up to73.7×10^(-6)),and Pb(up to 160×10^(-6))and the presence of pyrite,galena,pyrrhotite and minor sphalerite and chalcopyrite provide evidence for the input of hydrothermal materials into the sediments.The pyrite morphologies include disseminated cubic,pentagonal dodecahedron,and framboidal forms.Except for minor framboidal pyrite,euhedral pyrite from core HOBAB4-S2 is mainly of hydrothermal origin with Co/Ni ratios>1 and S/Fe atomic ratios<2 in the Cu-Zn-Pb-rich layers.The occurrences of hexagonal pyrrhotite,high-Co(up to0.17%)pyrite and high-Fe sphalerite indicate that the hydrothermal precipitates formed at medium-high temperatures and low-sulfur fugacity(f S_(2))environments.The δ^(34) S values of sulfides(0.21‰–3.45‰)with low-f S_(2) mineral assemblages(e.g.,pyrrhotite±high-Fe sphalerite)in the core are significantly lower than those of magmatic rocks and seawater,indicating possible incorporation of previously formed biogenic sulfur in the sediment.Combined with the age model of the core,it is suggested that hydrothermal activity likely began in the Tangyin HF before AD 1445–1483 and that at least three active episodes may have occurred since then.展开更多
Metal oxide thin-films transistors(TFTs)produced from solution-based printing techniques can lead to large-area electronics with low cost.However,the performance of current printed devices is inferior to those from va...Metal oxide thin-films transistors(TFTs)produced from solution-based printing techniques can lead to large-area electronics with low cost.However,the performance of current printed devices is inferior to those from vacuum-based methods due to poor film uniformity induced by the“coffeering”effect.Here,we report a novel approach to print highperformance indium tin oxide(ITO)-based TFTs and logic inverters by taking advantage of such notorious effect.ITO has high electrical conductivity and is generally used as an electrode material.However,by reducing the film thickness down to nanometers scale,the carrier concentration of ITO can be effectively reduced to enable new applications as active channels in transistors.The ultrathin(~10-nm-thick)ITO film in the center of the coffee-ring worked as semiconducting channels,while the thick ITO ridges(>18-nm-thick)served as the contact electrodes.The fully inkjet-printed ITO TFTs exhibited a high saturation mobility of 34.9 cm2 V^(−1) s^(−1) and a low subthreshold swing of 105 mV dec^(−1).In addition,the devices exhibited excellent electrical stability under positive bias illumination stress(PBIS,ΔV_(th)=0.31 V)and negative bias illuminaiton stress(NBIS,ΔV_(th)=−0.29 V)after 10,000 s voltage bias tests.More remarkably,fully printed n-type metal–oxide–semiconductor(NMOS)inverter based on ITO TFTs exhibited an extremely high gain of 181 at a low-supply voltage of 3 V,promising for advanced electronics applications.展开更多
Hydrothermal precipitates associated with active vents in the eastern Manus Basin, an actively opening back-arc basin in the Bismarck Sea, Papua New Guinea, are among the most Cu-rich on the modern seafloor. The volca...Hydrothermal precipitates associated with active vents in the eastern Manus Basin, an actively opening back-arc basin in the Bismarck Sea, Papua New Guinea, are among the most Cu-rich on the modern seafloor. The volcanic rocks associated with this mineralization may be insufficiently enriched in Cu to account for the Cu content of the sulfides by simple leaching. The PACMANUS hydrothermal field lies in the eastern portion of the eastern Manus Basin. Mass balance modeling of the PACMANUS hydrothermal system indicates that simple leaching of a stationary reaction zone (0.144 km^3) by hydrothermal fluids cannot yield the Cu found in associated sulfide deposits because unacceptably high leaching, transportation and precipitation efficiencies are required to derive the Cu in sulfides by leaching processes. With 100% leaching, transport and precipitating efficiency, 0.166 km^3 of volcanic rocks would need to be leached to account for the Cu budget of hydrothermal sulfide deposits. The key requirement for forming metal-rich magmatic fluids is a large amount of metals available to enter the exsolved vapor phase. Magmas generated in the eastern Manus Basin inherently have high fO2 because of metasomatism of the mantle source by oxidized materials from the subducted slab, leading to copper enrichment in the magma chamber. Moreover, the presence of Cu in gas-rich melt inclusi on bubbles in Pual Ridge andesite is evidence that degassing and partitioning of Cu into the magmatic volatile phase has occurred in the eastern Manus Basin. Numerical mass balance modeling indicates that approximately 0.236 Mt Cu was potentially transferred to the hydrothermal system per cubic kilometer magma. Magmatic degassing seems to play a more significant role than leaching.展开更多
Continuous drug monitoring is a promising alternative to current therapeutic drug monitoring strategies and has a strong potential to reshape our understanding of pharmacokinetic variability and to improve individuali...Continuous drug monitoring is a promising alternative to current therapeutic drug monitoring strategies and has a strong potential to reshape our understanding of pharmacokinetic variability and to improve individualised therapy.This review highlights recent advances in biosensing technologies that support continuous drug monitoring in real time.We focus primarily on aptamer-based biosensors,wearable and implantable devices.Emphasis is given to the approaches employed in constructing biosensors.We pay attention to sensors’biocompatibility,calibration performance,long-term characteristics stability and measurement quality.Last,we discuss the current challenges and issues to be addressed in continuous drug monitoring to make it a promising,future tool for individualised therapy.The ongoing efforts are expected to result in fully integrated implantable drug biosensing technology.Thus,we may anticipate an era of advanced healthcare in which wearable and implantable biochips will automatically adjust drug dosing in response to patient health conditions,thus enabling the management of diseases and enhancing individualised therapy.展开更多
We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division mul...We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.展开更多
Cryoablation(CRA)and microwave ablation(MWA)are two main local treatments for hepatocellular carcinoma(HCC).However,which one is more curative and suitable for combining with immunotherapy is still controversial.Herei...Cryoablation(CRA)and microwave ablation(MWA)are two main local treatments for hepatocellular carcinoma(HCC).However,which one is more curative and suitable for combining with immunotherapy is still controversial.Herein,CRA induced higher tumoral PD-L1 expression and more T cells infiltration,but less PD-L1^(high)CD11b^(+)myeloid cells infiltration than MWA in HCC.Furthermore,CRA had better curative effect than MWA for anti-PD-L1 combination therapy in mouse models.Mechanistically,anti-PD-L1 antibody facilitated infiltration of CD8^(+)T cells by enhancing the secretion of CXCL9 from cDC1 cells after CRA therapy.On the other hand,anti-PD-L1 antibody promoted the infiltration of NK cells to eliminate PD-L1^(high)CD11b^(+)myeloid cells by antibody-dependent cell-mediated cytotoxicity(ADCC)effect after CRA therapy.Both aspects relieved the immunosuppressive microenvironment after CRA therapy.Notably,the wild-type PD-L1 Avelumab(Bavencio),compared to the mutant PD-L1 atezolizumab(Tecentriq),was better at inducing the ADCC effect to target PD-L1^(high)CD11b^(+)myeloid cells.Collectively,our study uncovered the novel insights that CRA showed superior curative effect than MWA in combining with anti-PD-L1 antibody by strengthening CTL/NK cell immune responses,which provided a strong rationale for combining CRA and PD-L1 blockade in the clinical treatment for HCC.展开更多
The terahertz photonics technique has bright application prospects in future sixth-generation(6G)broadband communication.In this study,we have experimentally demonstrated a photonics-assisted record-breaking net bit r...The terahertz photonics technique has bright application prospects in future sixth-generation(6G)broadband communication.In this study,we have experimentally demonstrated a photonics-assisted record-breaking net bit rate of 417 Gbit/s per wavelength signals delivery in a fiber-wireless converged communication system supported by advanced digital-signalprocessing(DSP)algorithms and a polarization multiplexing-based multiple-input multiple-output(MIMO)scheme.In the experiment,up to 60 GBaud(480 Gbit/s)polarization-division-multiplexing 16-ary quadrature-amplitude-modulation(PDM16QAM)signals are transmitted over 20 km fibers and 3 m wireless 2×2 MIMO links at 318 GHz with the bit error rate(BER)under 1.56×10^(−2).It is the first demonstration to our knowledge of signals delivery exceeding 400 Gbit/s per wavelength in a photonics-assisted fiber-wireless converged 2×2 MIMO communication system.展开更多
To understand the relation between different nanostructures and thermal properties, a simple yet effective model is in demand for characterizing the underlying phonons and electrons scattering mechanisms. Herein, we m...To understand the relation between different nanostructures and thermal properties, a simple yet effective model is in demand for characterizing the underlying phonons and electrons scattering mechanisms. Herein, we make a systematic review on the newly developed thermal reffusivity theory. Like electrical resistivity which has been historically used as a theory for analyzing structural domain size and defect levels of metals, the thermal reffusivity can also uncover phonon behavior, structure defects and domain size of materials. We highlight that this new theory can be used for not only metals, but also nonmetals, even for amorphous materials. From the thermal reffusivity against temperature curves, the Debye temperature of the material and the ideal thermal diffusivity of single perfect crystal can be evaluated. From the residual thermal reffusivity at the 0 K limit, the structural thermal domain (STD) size of crystalline and amorphous materials can be obtained. The difference of white hair and normal black hair from heat conduction perspective is reported for the first time. Loss of melanin results in a worse thermal protection and a larger STD size in the white hair. By reviewing the different variation of thermal reffusivity against decreasing temperature profiles, we conclude that they reflected the structural connection in the materials. Ultimately, the future application of thermal reffusivity theory in studying 2D materials and amorphous materials is discussed.展开更多
We experimentally built a photonics-aided long-distance large-capacity millimeter-wave wireless transmission system and demonstrated a delivery of 40 Gbit/s W-band 16-ary quadrature amplitude modulation(QAM)signal ove...We experimentally built a photonics-aided long-distance large-capacity millimeter-wave wireless transmission system and demonstrated a delivery of 40 Gbit/s W-band 16-ary quadrature amplitude modulation(QAM)signal over 4600 m wireless distance at 88.5 GHz.Advanced offline digital signal processing algorithms are proposed and employed for signal recovery,which makes the bit-error ratio under 2.4×10^(−2).To the best of our knowledge,this is the first field-trial demonstration of>4 km W-band 16QAM signal transmission,and the result achieves a record-breaking product of wireless transmission capacity and distance,i.e.,184(Gbit/s)·km,for high-speed and long-distance W-band wireless communication.展开更多
Liquid fuel intermediates could be produced via aldol condensation reaction between furfural or 5-hydroxymethylfurfural(HMF)and acetone.It was found that iron-modified MCM-41 zeolite can be an effective Lewis acid cat...Liquid fuel intermediates could be produced via aldol condensation reaction between furfural or 5-hydroxymethylfurfural(HMF)and acetone.It was found that iron-modified MCM-41 zeolite can be an effective Lewis acid catalyst for C-C bond formation via aldol condensation of furfural or HMF with acetone.The 4-(2-furyl)-3-buten-2-one and 1,5-di-2-furanyl-1,4-pentadien-3-one(FAc and F_(2)Ac),or 1,5-di-2-furanyl-1,4-pentadien-3-one and 1,5-bis[(5-hydroxlmethyl)-2-furanyl]-1,4-pentadien-3-one(HAc and H_(2)Ac),as two main condensation products of furfural with acetone or HMF with acetone,were observed.After 24 h at 160℃,86.9%conversion of furfural with 60.0%yield of the FAc as well as 7.5%yield of the F_(2)Ac and 88.9%conversion of the HMF with 41.1%yield of the HAc as well as 3.5%yield of the H_(2)Ac were achieved.Although furfural or HMF conversion was almost same after 24 h at 160℃,iron-modified MCM-41 zeolite catalyst displayed an enhanced selectivity to condensation products of furfural with acetone.In addition,catalysts showed an improved selectivity to the F_(2)Ac and H_(2)Ac at higher reaction temperature.The reusability and regeneration studies showed that iron-modified MCM-41 zeolite catalyst could not be reused directly,but could be regenerated by calcination in air,and the catalytic perfor-mance of regenerated catalyst was acceptable.展开更多
基金The National Natural Science Foundation of China under contract No.91958213the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDB42020402+3 种基金the National Programma on Global Change and AirSea Interaction under contract No.GASI-GEOGE-02the International Partnership Program of the Chinese Academy of Sciences under contract No.133137KYSB20170003the Special Fund for the Taishan Scholar Program of Shandong Province under contract No.ts201511061the National Key Basic Research Program of China under contract No.2013CB429700。
文摘Studies of the mineralogy and sulfur isotope composition of sediment-hosted hydrothermal sulfide minerals in cores are important for understanding the seafloor mineralization environment and material source and reconstructing the hydrothermal history.However,the source of ore-forming materials and the history of hydrothermal activity in the southern Okinawa Trough(SOT)remain unclear.Here,the mineralogy and sulfur isotope characteristics of sulfides from gravity core HOBAB4-S2,collected between the Yonaguni Knoll IV hydrothermal field(HF)and the Tangyin HF,was investigated.Enrichments in Zn(up to 321×10^(-6)),Cu(up to73.7×10^(-6)),and Pb(up to 160×10^(-6))and the presence of pyrite,galena,pyrrhotite and minor sphalerite and chalcopyrite provide evidence for the input of hydrothermal materials into the sediments.The pyrite morphologies include disseminated cubic,pentagonal dodecahedron,and framboidal forms.Except for minor framboidal pyrite,euhedral pyrite from core HOBAB4-S2 is mainly of hydrothermal origin with Co/Ni ratios>1 and S/Fe atomic ratios<2 in the Cu-Zn-Pb-rich layers.The occurrences of hexagonal pyrrhotite,high-Co(up to0.17%)pyrite and high-Fe sphalerite indicate that the hydrothermal precipitates formed at medium-high temperatures and low-sulfur fugacity(f S_(2))environments.The δ^(34) S values of sulfides(0.21‰–3.45‰)with low-f S_(2) mineral assemblages(e.g.,pyrrhotite±high-Fe sphalerite)in the core are significantly lower than those of magmatic rocks and seawater,indicating possible incorporation of previously formed biogenic sulfur in the sediment.Combined with the age model of the core,it is suggested that hydrothermal activity likely began in the Tangyin HF before AD 1445–1483 and that at least three active episodes may have occurred since then.
基金This research was financially supported under the Westlake Multidisciplinary Research Initiative Center(MRIC)Seed Fund(Grant No.MRIC20200101).
文摘Metal oxide thin-films transistors(TFTs)produced from solution-based printing techniques can lead to large-area electronics with low cost.However,the performance of current printed devices is inferior to those from vacuum-based methods due to poor film uniformity induced by the“coffeering”effect.Here,we report a novel approach to print highperformance indium tin oxide(ITO)-based TFTs and logic inverters by taking advantage of such notorious effect.ITO has high electrical conductivity and is generally used as an electrode material.However,by reducing the film thickness down to nanometers scale,the carrier concentration of ITO can be effectively reduced to enable new applications as active channels in transistors.The ultrathin(~10-nm-thick)ITO film in the center of the coffee-ring worked as semiconducting channels,while the thick ITO ridges(>18-nm-thick)served as the contact electrodes.The fully inkjet-printed ITO TFTs exhibited a high saturation mobility of 34.9 cm2 V^(−1) s^(−1) and a low subthreshold swing of 105 mV dec^(−1).In addition,the devices exhibited excellent electrical stability under positive bias illumination stress(PBIS,ΔV_(th)=0.31 V)and negative bias illuminaiton stress(NBIS,ΔV_(th)=−0.29 V)after 10,000 s voltage bias tests.More remarkably,fully printed n-type metal–oxide–semiconductor(NMOS)inverter based on ITO TFTs exhibited an extremely high gain of 181 at a low-supply voltage of 3 V,promising for advanced electronics applications.
基金The National Natural Science Foundation of China under contract Nos 41706052,41476044 and 41325021the National Program on Global Change and Air-Sea Interaction under contract No.GASI-GEOGE-02+11 种基金the National Basic Research Program(973 Program)of China under contract No.2013CB429700the International Partnership Program of Chinese Academy of Sciences under contract No.133137KYSB20170003the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11030302the Special Fund for the Taishan Scholar Program of Shandong Province under contract No.ts201511061the National Special Fund for the 13th Five Year Plan of COMRA under contract No.DY135-G2-1-02the AoShan Talents Program supported by Qingdao National Laboratory for Marine Science and Technology under contract No.2015ASTP-0S17the Innovative Talent Promotion Program under contract No.2012RA2191the Science and Technology Development Program of Shandong Province under contract No.2013GRC31502the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology under contract No.2015ASKJ03the National High Level Talent Special Support ProgramCAS/SAFEA International Partnership Program for Creative Research TeamsQingdao Collaborative Innovation Center of Marine Science and Technology
文摘Hydrothermal precipitates associated with active vents in the eastern Manus Basin, an actively opening back-arc basin in the Bismarck Sea, Papua New Guinea, are among the most Cu-rich on the modern seafloor. The volcanic rocks associated with this mineralization may be insufficiently enriched in Cu to account for the Cu content of the sulfides by simple leaching. The PACMANUS hydrothermal field lies in the eastern portion of the eastern Manus Basin. Mass balance modeling of the PACMANUS hydrothermal system indicates that simple leaching of a stationary reaction zone (0.144 km^3) by hydrothermal fluids cannot yield the Cu found in associated sulfide deposits because unacceptably high leaching, transportation and precipitation efficiencies are required to derive the Cu in sulfides by leaching processes. With 100% leaching, transport and precipitating efficiency, 0.166 km^3 of volcanic rocks would need to be leached to account for the Cu budget of hydrothermal sulfide deposits. The key requirement for forming metal-rich magmatic fluids is a large amount of metals available to enter the exsolved vapor phase. Magmas generated in the eastern Manus Basin inherently have high fO2 because of metasomatism of the mantle source by oxidized materials from the subducted slab, leading to copper enrichment in the magma chamber. Moreover, the presence of Cu in gas-rich melt inclusi on bubbles in Pual Ridge andesite is evidence that degassing and partitioning of Cu into the magmatic volatile phase has occurred in the eastern Manus Basin. Numerical mass balance modeling indicates that approximately 0.236 Mt Cu was potentially transferred to the hydrothermal system per cubic kilometer magma. Magmatic degassing seems to play a more significant role than leaching.
基金supported by the start-up funds from Westlake University to CenBRAIN lab and Bright Dream Joint Institute for Intelligent Robotics.
文摘Continuous drug monitoring is a promising alternative to current therapeutic drug monitoring strategies and has a strong potential to reshape our understanding of pharmacokinetic variability and to improve individualised therapy.This review highlights recent advances in biosensing technologies that support continuous drug monitoring in real time.We focus primarily on aptamer-based biosensors,wearable and implantable devices.Emphasis is given to the approaches employed in constructing biosensors.We pay attention to sensors’biocompatibility,calibration performance,long-term characteristics stability and measurement quality.Last,we discuss the current challenges and issues to be addressed in continuous drug monitoring to make it a promising,future tool for individualised therapy.The ongoing efforts are expected to result in fully integrated implantable drug biosensing technology.Thus,we may anticipate an era of advanced healthcare in which wearable and implantable biochips will automatically adjust drug dosing in response to patient health conditions,thus enabling the management of diseases and enhancing individualised therapy.
基金supported by the National Key R&D Program of China(No.2018YFB1800905)the National Natural Science Foundation of China(Nos.61935005,61720106015,61835002,and 62127802)。
文摘We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.
基金supported by the National Natural Science Foundation of China(Nos.81971719,82172036,and 82102169)the major scientific and technological project of Guangdong Province(No.2020B0101130016,China)+2 种基金the major programme for tackling key problems of Guangzhou city(No.202103000021,China)General project of China Postdoctoral Foundation(No.2021M693646,China)Guangdong Province joint training postgraduate demonstration base project(No.80000-18842217,China)。
文摘Cryoablation(CRA)and microwave ablation(MWA)are two main local treatments for hepatocellular carcinoma(HCC).However,which one is more curative and suitable for combining with immunotherapy is still controversial.Herein,CRA induced higher tumoral PD-L1 expression and more T cells infiltration,but less PD-L1^(high)CD11b^(+)myeloid cells infiltration than MWA in HCC.Furthermore,CRA had better curative effect than MWA for anti-PD-L1 combination therapy in mouse models.Mechanistically,anti-PD-L1 antibody facilitated infiltration of CD8^(+)T cells by enhancing the secretion of CXCL9 from cDC1 cells after CRA therapy.On the other hand,anti-PD-L1 antibody promoted the infiltration of NK cells to eliminate PD-L1^(high)CD11b^(+)myeloid cells by antibody-dependent cell-mediated cytotoxicity(ADCC)effect after CRA therapy.Both aspects relieved the immunosuppressive microenvironment after CRA therapy.Notably,the wild-type PD-L1 Avelumab(Bavencio),compared to the mutant PD-L1 atezolizumab(Tecentriq),was better at inducing the ADCC effect to target PD-L1^(high)CD11b^(+)myeloid cells.Collectively,our study uncovered the novel insights that CRA showed superior curative effect than MWA in combining with anti-PD-L1 antibody by strengthening CTL/NK cell immune responses,which provided a strong rationale for combining CRA and PD-L1 blockade in the clinical treatment for HCC.
基金partially supported by the National Natural Science Foundation of China(Nos.61935005,61835002,and62127802)。
文摘The terahertz photonics technique has bright application prospects in future sixth-generation(6G)broadband communication.In this study,we have experimentally demonstrated a photonics-assisted record-breaking net bit rate of 417 Gbit/s per wavelength signals delivery in a fiber-wireless converged communication system supported by advanced digital-signalprocessing(DSP)algorithms and a polarization multiplexing-based multiple-input multiple-output(MIMO)scheme.In the experiment,up to 60 GBaud(480 Gbit/s)polarization-division-multiplexing 16-ary quadrature-amplitude-modulation(PDM16QAM)signals are transmitted over 20 km fibers and 3 m wireless 2×2 MIMO links at 318 GHz with the bit error rate(BER)under 1.56×10^(−2).It is the first demonstration to our knowledge of signals delivery exceeding 400 Gbit/s per wavelength in a photonics-assisted fiber-wireless converged 2×2 MIMO communication system.
文摘To understand the relation between different nanostructures and thermal properties, a simple yet effective model is in demand for characterizing the underlying phonons and electrons scattering mechanisms. Herein, we make a systematic review on the newly developed thermal reffusivity theory. Like electrical resistivity which has been historically used as a theory for analyzing structural domain size and defect levels of metals, the thermal reffusivity can also uncover phonon behavior, structure defects and domain size of materials. We highlight that this new theory can be used for not only metals, but also nonmetals, even for amorphous materials. From the thermal reffusivity against temperature curves, the Debye temperature of the material and the ideal thermal diffusivity of single perfect crystal can be evaluated. From the residual thermal reffusivity at the 0 K limit, the structural thermal domain (STD) size of crystalline and amorphous materials can be obtained. The difference of white hair and normal black hair from heat conduction perspective is reported for the first time. Loss of melanin results in a worse thermal protection and a larger STD size in the white hair. By reviewing the different variation of thermal reffusivity against decreasing temperature profiles, we conclude that they reflected the structural connection in the materials. Ultimately, the future application of thermal reffusivity theory in studying 2D materials and amorphous materials is discussed.
基金partially supported by the National Key R&D Program of China(No.2018YFB1800905)the National Natural Science Foundation of China(Nos.61935005,91938202,61720106015,61835002,62127802,and 61805043).
文摘We experimentally built a photonics-aided long-distance large-capacity millimeter-wave wireless transmission system and demonstrated a delivery of 40 Gbit/s W-band 16-ary quadrature amplitude modulation(QAM)signal over 4600 m wireless distance at 88.5 GHz.Advanced offline digital signal processing algorithms are proposed and employed for signal recovery,which makes the bit-error ratio under 2.4×10^(−2).To the best of our knowledge,this is the first field-trial demonstration of>4 km W-band 16QAM signal transmission,and the result achieves a record-breaking product of wireless transmission capacity and distance,i.e.,184(Gbit/s)·km,for high-speed and long-distance W-band wireless communication.
基金supported by National Key R&D Program of China(No.2018YFB1501601)National Natural Science Foundation of China(No.51676178)Transformational Technologies for Clean Energy and Demonstration,and Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA 21060101).
文摘Liquid fuel intermediates could be produced via aldol condensation reaction between furfural or 5-hydroxymethylfurfural(HMF)and acetone.It was found that iron-modified MCM-41 zeolite can be an effective Lewis acid catalyst for C-C bond formation via aldol condensation of furfural or HMF with acetone.The 4-(2-furyl)-3-buten-2-one and 1,5-di-2-furanyl-1,4-pentadien-3-one(FAc and F_(2)Ac),or 1,5-di-2-furanyl-1,4-pentadien-3-one and 1,5-bis[(5-hydroxlmethyl)-2-furanyl]-1,4-pentadien-3-one(HAc and H_(2)Ac),as two main condensation products of furfural with acetone or HMF with acetone,were observed.After 24 h at 160℃,86.9%conversion of furfural with 60.0%yield of the FAc as well as 7.5%yield of the F_(2)Ac and 88.9%conversion of the HMF with 41.1%yield of the HAc as well as 3.5%yield of the H_(2)Ac were achieved.Although furfural or HMF conversion was almost same after 24 h at 160℃,iron-modified MCM-41 zeolite catalyst displayed an enhanced selectivity to condensation products of furfural with acetone.In addition,catalysts showed an improved selectivity to the F_(2)Ac and H_(2)Ac at higher reaction temperature.The reusability and regeneration studies showed that iron-modified MCM-41 zeolite catalyst could not be reused directly,but could be regenerated by calcination in air,and the catalytic perfor-mance of regenerated catalyst was acceptable.