In the Large Helical Device(LHD),diborane(B2H6)is used as a standard boron source for boronization,which is assisted by helium glow discharges.In 2019,a new Impurity Powder Dropper(IPD)system was installed and is unde...In the Large Helical Device(LHD),diborane(B2H6)is used as a standard boron source for boronization,which is assisted by helium glow discharges.In 2019,a new Impurity Powder Dropper(IPD)system was installed and is under evaluation as a real-time wall conditioning technique.In the LHD,which is a large-sized heliotron device,an additional helium(He)glow discharge cleaning(GDC)after boronization was operated for a reduction in hydrogen recycling from the coated boron layers.This operational time of 3 h was determined by spectroscopic data during glow discharges.A flat hydrogen profile is obtained on the top surface of the coated boron on the specimen exposed to boronization.The results suggest a reduction in hydrogen at the top surface by He-GDC.Trapped oxygen in coated boron was obtained by boronization,and the coated boron,which has boron-oxide,on the first wall by B-IPD was also shown.Considering the difference in coating areas between B2H6 boronization and B-IPD operation,it would be most effective to use the IPD and B2H6 boronization coating together for optimized wall conditioning.展开更多
Boronization with carborane (C2B10H12) by ICRF has been applied routinely to the walls of HT-7 super-conducting tokamak for the reduction of impurity influx, especially carbon and oxygen. Significant suppression of me...Boronization with carborane (C2B10H12) by ICRF has been applied routinely to the walls of HT-7 super-conducting tokamak for the reduction of impurity influx, especially carbon and oxygen. Significant suppression of metallic impurities and radiating power fraction are achieved. The improved confinement for both particle and energy is observed in full range of operation parameters. Energy balance analysis shows that electron heat diffusion coefficient is strongly reduced. Measurements by Langmuir probes at the edge plasma show that the poloidal velocity shear after boronization is changed to a profile favoring to good confinement. The main emphasis of this paper is to describe effects of boronization on aspects of the enhanced plasma performance.展开更多
The TEM observation on the single-side thinned specimens was made of the nucleation and growth of boride during boronization for steel 20 and the influence of prior room temperature deformation.The results of X-ray di...The TEM observation on the single-side thinned specimens was made of the nucleation and growth of boride during boronization for steel 20 and the influence of prior room temperature deformation.The results of X-ray diffraction and electron probe microstructure analysis show that only Fe_2B formed in the surface layer of specimens at the beginning of boronization;the atomic concentration of B in the surface layer increased with the increase of deformation monotonously;and the segregation of B atoms in the dislocation cells hindered the recovery and recrystallization of the deformed structure of the matrix and accelerated the nucleation and growth of boride in the surface layer.展开更多
The electrolytic coatings of boron and RE-boron on medium carbon steel are carried out in molten salt mix- tures respectively.The brittleness of both coatings has been measured by using sound-emission with the method ...The electrolytic coatings of boron and RE-boron on medium carbon steel are carried out in molten salt mix- tures respectively.The brittleness of both coatings has been measured by using sound-emission with the method of three point bending.Results show that the brittleness of electrolytic boronization coating can be obviously de- creased by addition of RE elements.Meanwhile,the shape of crack and the solid solubility of RE in boride and α-Fe phase are determined,and the effect of RE on the lattice constant of Fe_2B is discussed.From these experi- ments,the authors explain the cause of the brittleness decreasing of electrolytic boronization coating.展开更多
Heterogeneous metal-catalyzed chemical conversions with a recyclable catalyst are very ideal and challenging for sustainable organic synthesis.A new bipyridyl-Mo(IV)-carbon nitride(CN-K/Mo-Bpy)was prepared by supporti...Heterogeneous metal-catalyzed chemical conversions with a recyclable catalyst are very ideal and challenging for sustainable organic synthesis.A new bipyridyl-Mo(IV)-carbon nitride(CN-K/Mo-Bpy)was prepared by supporting molybdenum complex on C_(3)N_(4)-K and characterized by FT-IR,XRD,SEM,XPS and ICP-OES.Heterogeneous CN–Mo-Bpy catalyst can be applied to the direct amination of nitroarenes and arylboronic acid,thus constructing various valuable diarylamines in high to excellent yields with a wide substrate scope and good functional group tolerance.It is worth noting that this heterogeneous catalyst has high chemical stability and can be recycled for at least five times without reducing its activity.展开更多
Magnetostrictive Fe-Ga alloys have captivated substantial focus in biomedical applications because of their exceptional transition efficiency and favorable cytocompatibility.Nevertheless,Fe-Ga alloys always exhibit fr...Magnetostrictive Fe-Ga alloys have captivated substantial focus in biomedical applications because of their exceptional transition efficiency and favorable cytocompatibility.Nevertheless,Fe-Ga alloys always exhibit frustrating magnetostriction coefficients when presented in bulk dimensions.It is well-established that the magnetostrictive performance of Fe-Ga alloys is intimately linked to their phase and crystal structures.In this study,various concentrations of boron(B)were doped into Fe_(81)Ga_(19) alloys via the laser-beam powder bed fusion(LPBF)technique to tailor the crystal and phase structures,thereby improving the magnetostrictive performance.The results revealed the capacity for quick solidification of the LPBF process in expediting the solid solution of B element,which increased both lattice distortion and dislocations within the Fe-Ga matrix.These factors contributed to an elevation in the density of the modified-D0_(3) phase structure.Moreover,the prepared Fe-Ga-B alloys also exhibited a(001)preferred grain orientation caused by the high thermal gradients during the LPBF process.As a result,a maximum magnetostriction coefficient of 105 ppm was achieved in the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy.In alternating magnetic fields,all the LPBF-prepared alloys showed good dynamic magnetostriction response without visible hysteresis,while the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy presented a notable enhancement of~30%in magnetostriction coefficient when compared with the Fe_(81)Ga_(19) alloy.Moreover.the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy exhibited favorable biocompatibility and osteogenesis,as confirmed by increased alkaline phosphatase(ALP)activity and the formation of mineralized nodules.These findings suggest that the B-doped Fe-Ga alloys combined with the LPBF technique hold promise for the development of bulk magnetostrictive alloys that are applicable for bone repair applications.展开更多
The microstructure design for thermal conduction pathways in polymeric electrical encapsulation materials is essential to meet the stringent requirements for efficient thermal management and thermal runaway safety in ...The microstructure design for thermal conduction pathways in polymeric electrical encapsulation materials is essential to meet the stringent requirements for efficient thermal management and thermal runaway safety in modern electronic devices.Hence,a composite with three-dimensional network(Ho/U-BNNS/WPU)is developed by simultaneously incorporating magnetically modified boron nitride nanosheets(M@BNNS)and non-magnetic organo-grafted BNNS(U-BNNS)into waterborne polyurethane(WPU)to synchronous molding under a horizontal magnetic field.The results indicate that the continuous in-plane pathways formed by M@BNNS aligned along the magnetic field direction,combined with the bridging structure established by U-BNNS,enable Ho/U-BNNS/WPU to exhibit exceptional in-plane(λ//)and through-plane thermal conductivities(λ_(⊥)).In particular,with the addition of 30 wt%M@BNNS and 5 wt%U-BNNS,theλ//andλ_(⊥)of composites reach 11.47 and 2.88 W m^(-1) K^(-1),respectively,which representing a 194.2%improvement inλ_(⊥)compared to the composites with a single orientation of M@BNNS.Meanwhile,Ho/U-BNNS/WPU exhibits distinguished thermal management capabilities as thermal interface materials for LED and chips.The composites also demonstrate excellent flame retardancy,with a peak heat release and total heat release reduced by 58.9%and 36.9%,respectively,compared to WPU.Thus,this work offers new insights into the thermally conductive structural design and efficient flame-retardant systems of polymer composites,presenting broad application potential in electronic packaging fields.展开更多
Lowering the synthesis temperature of boron nitride nanotubes(BNNTs)is crucial for their development.The primary reason for adopting a high temperature is to enable the effective activation of highmelting-point solid ...Lowering the synthesis temperature of boron nitride nanotubes(BNNTs)is crucial for their development.The primary reason for adopting a high temperature is to enable the effective activation of highmelting-point solid boron.In this study,we developed a novel approach for efficiently activating boron by introducing alkali metal compounds into the conventional MgO–B system.This approach can be adopted to form various low-melting-point AM–Mg–B–O growth systems.These growth systems have improved catalytic capability and reactivity even under low-temperature conditions,facilitating the synthesis of BNNTs at temperatures as low as 850℃.In addition,molecular dynamics simulations based on density functional theory theoretically demonstrate that the systems maintain a liquid state at low temperatures and interact with N atoms to form BN chains.These findings offer novel insights into the design of boron activation and are expected to facilitate research on the low-temperature synthesis of BNNTs.展开更多
Hard carbon (HC) has been considered as promising anode material for sodium-ion batteries (SIBs).The optimization of hard carbon’s microstructure and solid electrolyte interface (SEI) property are demonstrated effect...Hard carbon (HC) has been considered as promising anode material for sodium-ion batteries (SIBs).The optimization of hard carbon’s microstructure and solid electrolyte interface (SEI) property are demonstrated effective in enhancing the Na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly desirable.Herein,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more Na+storage sites.In-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy (FTIR/EIS) and X-ray photoelectron spectroscopy (XPS) analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI,which leads to facilitated charge transfer and excellent rate performance.As a result,the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling performance.In general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced Na+storage performance.展开更多
Thermally activated delayed fluorescence(TADF)materials driven by a through-space charge transfer(TSCT)mechanism have garnered wide interest.However,access of TSCT-TADF molecules with longwavelength emission remains a...Thermally activated delayed fluorescence(TADF)materials driven by a through-space charge transfer(TSCT)mechanism have garnered wide interest.However,access of TSCT-TADF molecules with longwavelength emission remains a formidable challenge.In this study,we introduce a novel V-type DA-D-A’emitter,Trz-mCzCbCz,by using a carborane scaffold.This design strategically incorporates carbazole(Cz)and 2,4,6-triphenyl-1,3,5-triazine(Trz)as donor and acceptor moieties,respectively.Theoretical calculations alongside experimental validations affirm the typical TSCT-TADF characteristics of this luminogen.Owing to the unique structural and electronic attributes of carboranes,Trz-mCzCbCz exhibits an orange-red emission,markedly diverging from the traditional blue-to-green emissions observed in classical Cz and Trz-based TADF molecules.Moreover,bright emission in aggregates was observed for Trz-mCzCbCz with absolute photoluminescence quantum yield(PLQY)of up to 88.8%.As such,we have successfully fabricated five organic light-emitting diodes(OLEDs)by utilizing Trz-mCzCbCz as the emitting layer.It is important to note that both the reverse intersystem crossing process and the TADF properties are profoundly influenced by host materials.The fabricated OLED devices reached a maximum external quantum efficiency(EQE)of 12.7%,with an emission peak at 592 nm.This represents the highest recorded efficiency for TSCT-TADF OLEDs employing carborane derivatives as emitting layers.展开更多
The increase in the utilization of infrared heat detection technology in military applications necessitates research on composites with improved thermal transmission performance and microwave absorption capabilities.T...The increase in the utilization of infrared heat detection technology in military applications necessitates research on composites with improved thermal transmission performance and microwave absorption capabilities.This study satisfactorily fabricated a series of MoS_(2)/BN-xyz composites(which were characterized by the weight ratio of MoS_(2)to BN,denoted by xy:z)through chemical vapor depos-ition,which resulted in their improved thermal stability and thermal transmission performance.The results show that the remaining mass of MoS_(2)/BN-101 was as high as 69.25wt%at 800℃under air atmosphere,and a temperature difference of 31.7℃was maintained between the surface temperature and the heating source at a heating temperature of 200℃.Furthermore,MoS_(2)/BN-301 exhibited an im-pressive minimum reflection loss value of-32.21 dB at 4.0 mm and a wide effective attenuation bandwidth ranging from 9.32 to 18.00 GHz(8.68 GHz).Therefore,these simplified synthesized MoS_(2)/BN-xyz composites demonstrate great potential as highly efficient con-tenders for the enhancement of microwave absorption performance and thermal conductance.展开更多
The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the a...The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the amount of acid-impregnated slag dosed on the compressive strength and water resistance of LR-MOC.The results showed that the magnesium element in the boron mud could be maximally leached under the conditions of 1:1 concentration of hydrochloric acid at room temperature,liquid-solid ratio of 2.5 mL·g^(-1),and reaction time of 5 h,and the main products were amorphous SiO_(2) as well as a small amount of magnesium olivine which had not been completely reacted.The LR-MOC prepared using the acid-soaked mixture could reach a softening coefficient of 0.85 for 28 d of water immersion when the molar ratio of MgO/MgCl_(2) was 2.2,the amount of water added was 0 g,and the acid-soaked slag dosing was 40 wt%,which also led to an appreciable late-strength,with an increase of 19.4%in compressive strength at 28 d compared to that at 7 d.Unlike previous studies,LR-MOC prepared in this way has a final strength phase that is not the more easily hydrolysed 3-phase but the lath-like 5-phase.For this phenomenon,we analyzed the mechanism and found that,during the acid leaching process,a part of amorphous SiO_(2) dissolved in the acid leaching solution formed a silica sol,in which Mg^(2+)played a bridging role to make the silica sol more stable.With the addition and hydrolysis of MgO,the silica sol gel coagulation slows down,providing a capping layer to inhibit the hydrolysis of the 5-phase crystals and providing some strength after coagulation.The amorphous SiO_(2) in the other part of the acid-impregnated slag generated M-S-H gel with Mg^(2+)and OH-,which synergised with the dense structure composed of interlocking crystals to improve the water resistance of LR-MOC.展开更多
Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron...Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.展开更多
Silica-based ramming mixes are widely used as lining materials in coreless induction furnaces,which serve as the main equipment for iron and steel in foundry industry.The service life of linings made from silica-based...Silica-based ramming mixes are widely used as lining materials in coreless induction furnaces,which serve as the main equipment for iron and steel in foundry industry.The service life of linings made from silica-based ramming mixes depends on the properties of quartzite raw materials.In this paper,quartzites from three regions were selected as raw materials,with boron oxide and boron phosphate as sintering aids.By comparing and testing performance such as the phase composition,permanent linear change,bulk density,apparent porosity,and slag resistance,the effects of raw material characteristics and sintering aids on the performance of the silica-based ramming mixes were investigated.The results showed that boron oxidecontaining ramming mixes prepared from quartzite with a fast phase transition showed lower strength and greater expansion as well as lower slag penetration index.For boron phosphate as a sintering aid,ramming mixes made from quartzites with medium and slow phase transition rates had an approaching slag penetration index comparable to those containing boron oxide,although their strength was lower than the latter.According to the melting requirements of stainless steel,boron phosphate can replace boron oxide as a sintering aid for silica-based ramming mixes.Regarding practical applications for linings of coreless induction furnaces,the selection of quartzite as the raw material for silica-based ramming mixes shall be comprehensively considered from multiple aspects.展开更多
Boron neutron capture therapy(BNCT)has emerged as a promising treatment for cancers,offering a unique approach to selectively target tumor cells while sparing healthy tissues.Despite its clinical utility,the widesprea...Boron neutron capture therapy(BNCT)has emerged as a promising treatment for cancers,offering a unique approach to selectively target tumor cells while sparing healthy tissues.Despite its clinical utility,the widespread use of fructose-BPA(F-BPA)has been hampered by its limited ability to penetrate the blood-brain barrier(BBB)and potential risks for patients with certain complications such as diabetes,hyperuricemia,and gout,particularly with substantial dosages.Herein,a series of novel BPA derivatives were synthesized.After the primary screening,geniposide-BPA(G-BPA)and salidroside-BPA(S-BPA)exhibited high water solubility,low cytotoxicity and safe profiles for intravenous injection.Furthermore,both G-BPA and S-BPA had demonstrated superior efficacy in vitro against the 4T1 cell line compared with F-BPA.Notably,S-BPA displayed optimal BBB penetration capability,as evidenced by in vitro BBB models and glioblastoma models in vivo,surpassing all other BPA derivative candidates.Meanwhile,GBPA also exhibited enhanced performance relative to the clinical drug F-BPA.In brief,G-BPA and S-BPA,as novel BPA derivatives,demonstrated notable safety profiles and remarkable boron delivery capabilities,thereby offering promising therapeutic options for BNCT in the clinic.展开更多
Lacustrine dolomite is paid increasing attention to uncover the diagenetic water condition of paleo-lake and“dolomite problem”.Here,a dolomite nodule from the Qingshankou Formation in the Songliao Basin was analyzed...Lacustrine dolomite is paid increasing attention to uncover the diagenetic water condition of paleo-lake and“dolomite problem”.Here,a dolomite nodule from the Qingshankou Formation in the Songliao Basin was analyzed to explore the salinity,alkalinity,and redox conditions of the diagenetic water.Multiple proxies,including bulk boron(B)content,B isotope composition(δ^(11)B_(bul)),boron to gallium weight ratio(B/Ga)and carbonate oxygen isotope composition(δ^(18)O_(carb)),were used to determine the diagenetic water to be brackish-fresh.Through numerical simulation,we calculated the B contents,δ^(11)B values and B/Ga in detritus(e.g.,clay,quartz and feldspar)and dolomite as two endmembers,confirming the intense interference of clay minerals onδ^(11)B_(bul).By using the fittedδ^(11)B of dolomite endmember(20.6‰),we calculated the p H value of the diagenetic water to be 8.2.The negativeδ^(11)B value of detritus endmember(-12.9‰)might be related to the terrestrial weathering.The indicative nature of strontium to barium weight ratio(Sr/Ba)was discussed to deny its applicability as a proxy of salinity in carbonate system.High Sr/Ba ratio in this dolomite nodule indicates a sulfate-poor water condition,consistent with the iron-manganese(Fe-Mn)reduction environments reflected by the Mn/Fe molar ratio.The positive carbonate carbon isotopes(δ^(13)C_(carb),4.5‰-9.4‰)indicate that methanogenesis dominated the formation of dolomite,coinciding with the weak sulfate reduction reaction in sulfate-poor water.The growth of dolomite nodule might be related to the microbial activities of methanogen and iron reducing bacteria,which had not only maintained the salinity,p H,and redox status of the diagenetic water,but also led to a ferricmethane transition zone(FMTZ).This research depicts a scenario about the diagenetic water environment of lacustrine dolomite formed in brackish-fresh water,which is different from that occurred in sulfate-rich condition.展开更多
Although the demand of ^(10)B separation has arisen in the 1930s,^(10)B/^(11)B are among the most difficult isotopes to separate due to the extremely similar relative atomic mass.Herein,we report an efficient separati...Although the demand of ^(10)B separation has arisen in the 1930s,^(10)B/^(11)B are among the most difficult isotopes to separate due to the extremely similar relative atomic mass.Herein,we report an efficient separation of ^(10)B isotopologue by engineering amino-galloyl synergistic materials via a selective adsorption and isotope exchange reaction,achieving a record-high single-stage separation factor of 1.048 with ^(10)B abundance up to 21.42%.^(11)B MAS NMR results and DFT calculations reveal that the galloyl groups exhibit inherent high affinity for B(OH)4-,forming tetrahedral sp^(3) B-galloyl complexes.The relatively higher ^(10)B–O bond energy of ^(10)B-galloyl complexes facilitates the isotope exchange between11B in B-galloyl complexes and ^(10)B in B(OH)_(3).Flowthrough dynamic separation in fixed-bed demonstrates the feasibility and potential of large-scale deployment of this method in real-world,suggesting a promising avenue for the exploitation of more efficient enrichment of ^(10)B for the sustainable nuclear energy and biomedical research.展开更多
Organic structure directingagents(OSDAs),suchas tetrapropylammonium(TPA)cations,serve as crucial templates for the formation of zeolite frameworks.These organic molecules interact with inorganic species,guiding the as...Organic structure directingagents(OSDAs),suchas tetrapropylammonium(TPA)cations,serve as crucial templates for the formation of zeolite frameworks.These organic molecules interact with inorganic species,guiding the assembly of the zeolite structure.In this study,we inves-tigate the complex interplay between boron species and TPA cations during the crystallization of[B,Al]-ZSM-5 zeolites.Two-dimensional(2D)11B-{1H}cross-polarization heteronuclear correlation(CP-HECTOR)NMRexperiments elucidate distinct interactions between two boron species,B(IV)-1 and B(IV)-2,and the propyl chain of the TPAs.Amorphous B(IV)-1 species exhibit a strong preference for proximity to the nitrogen cation center of the OSDAs,while framework B(IV)-2 species engage with components situated at greater distances from the cation center.Moreover,13C-{11B}symmetry-based resonance-echo saturation-pulse double-resonance(S-RESPDOR)experiments revealed that framework boron species preferentially occupy the straight channels of the MFI structure,as evidenced by their interaction with specificmethyl groups on the TPAmolecules.This observation provides valuable insights into the crystallization mechanism of boron-based zeolites,suggesting that the conformation and orientation of the OSDA molecules play a critical role in determining the location of boron atoms within the zeolite framework.展开更多
Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials.In this article,both the iterative Boltzmann tran...Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials.In this article,both the iterative Boltzmann transport equation solution and the two-temperature model were employed to investigate the efficacy of targeted phonon excitation applied to hexagonal boron nitride(hBN).The results indicate significant modifications to hBN's thermal conductivity,achieving increases of up to 30.1%as well as decreases of up to 59.8%.These findings validate the reliability of the strategy,expand its scope of applicability,and establish it as a powerful tool for tailoring thermal properties across a wider range of fields.展开更多
The integration of boronizing and austempering termed boro-austempering treatment is a new processing route for preparing high strength bainitic steel with high surface hardness and high corrosion resistance.The micro...The integration of boronizing and austempering termed boro-austempering treatment is a new processing route for preparing high strength bainitic steel with high surface hardness and high corrosion resistance.The microstructure and properties of a medium-carbon bainitic steel prepared by boro-austempering treatment were characterized and analyzed.The results show that a single Fe_(2)B layer on bainite substrate was obtained with surface hardness of~1400 HV,and the critical load for adhesive failure of borided layer reached 73.6 N.The silicon-rich α-Fe phase in transition zone was clarified as ferrite,which was formed at the beginning stage of cooling process from boronizing to low-temperature bainite transformation.Moreover,the relative potential differences between Fe_(2)B and bainite matrix,and ferrite and bainite matrix were 75 and 92 mV,respectively,with bainite matrix acting as active anode,indicating that the corrosion resistances of Fe2B and ferrite were better than that of bainite.展开更多
基金supported by NIFS budgets,KOBF031,ULFF004,KUHR032partly supported by JSPS KAKENHI 18K04999+2 种基金JSPS-CAS Bilateral Joint Research Projects,“Control of wall recycling on metallic plasma-facing materials in fusion reactor”2019-2022,(No.GJHZ201984)the Chinese Academy of Sciences President’s International Fellowship Initiative Grant No.2024VMB0003 in FY2023the U.S.Department Of Energy under Contract No.DE-AC02-09CH11466 with Princeton University。
文摘In the Large Helical Device(LHD),diborane(B2H6)is used as a standard boron source for boronization,which is assisted by helium glow discharges.In 2019,a new Impurity Powder Dropper(IPD)system was installed and is under evaluation as a real-time wall conditioning technique.In the LHD,which is a large-sized heliotron device,an additional helium(He)glow discharge cleaning(GDC)after boronization was operated for a reduction in hydrogen recycling from the coated boron layers.This operational time of 3 h was determined by spectroscopic data during glow discharges.A flat hydrogen profile is obtained on the top surface of the coated boron on the specimen exposed to boronization.The results suggest a reduction in hydrogen at the top surface by He-GDC.Trapped oxygen in coated boron was obtained by boronization,and the coated boron,which has boron-oxide,on the first wall by B-IPD was also shown.Considering the difference in coating areas between B2H6 boronization and B-IPD operation,it would be most effective to use the IPD and B2H6 boronization coating together for optimized wall conditioning.
基金This work was supported by National Natural Science Foundation of China Grant No.10175069.
文摘Boronization with carborane (C2B10H12) by ICRF has been applied routinely to the walls of HT-7 super-conducting tokamak for the reduction of impurity influx, especially carbon and oxygen. Significant suppression of metallic impurities and radiating power fraction are achieved. The improved confinement for both particle and energy is observed in full range of operation parameters. Energy balance analysis shows that electron heat diffusion coefficient is strongly reduced. Measurements by Langmuir probes at the edge plasma show that the poloidal velocity shear after boronization is changed to a profile favoring to good confinement. The main emphasis of this paper is to describe effects of boronization on aspects of the enhanced plasma performance.
文摘The TEM observation on the single-side thinned specimens was made of the nucleation and growth of boride during boronization for steel 20 and the influence of prior room temperature deformation.The results of X-ray diffraction and electron probe microstructure analysis show that only Fe_2B formed in the surface layer of specimens at the beginning of boronization;the atomic concentration of B in the surface layer increased with the increase of deformation monotonously;and the segregation of B atoms in the dislocation cells hindered the recovery and recrystallization of the deformed structure of the matrix and accelerated the nucleation and growth of boride in the surface layer.
文摘The electrolytic coatings of boron and RE-boron on medium carbon steel are carried out in molten salt mix- tures respectively.The brittleness of both coatings has been measured by using sound-emission with the method of three point bending.Results show that the brittleness of electrolytic boronization coating can be obviously de- creased by addition of RE elements.Meanwhile,the shape of crack and the solid solubility of RE in boride and α-Fe phase are determined,and the effect of RE on the lattice constant of Fe_2B is discussed.From these experi- ments,the authors explain the cause of the brittleness decreasing of electrolytic boronization coating.
基金support for this work by Hebei Education Department(No.JZX2024004)Central Guidance on Local Science and Technology Development Fund of Hebei Province(No.236Z1404G)+3 种基金the National Natural Science Foundation of China(Nos.22301060 and 21272053)China Postdoctoral Science Foundation(No.2023M730914)the Natural Science Foundation of Hebei Province(Biopharmaceutical Joint Fund No.B2022206008)Project of Science and Technology Department of Hebei Province(No.22567622H)。
文摘Heterogeneous metal-catalyzed chemical conversions with a recyclable catalyst are very ideal and challenging for sustainable organic synthesis.A new bipyridyl-Mo(IV)-carbon nitride(CN-K/Mo-Bpy)was prepared by supporting molybdenum complex on C_(3)N_(4)-K and characterized by FT-IR,XRD,SEM,XPS and ICP-OES.Heterogeneous CN–Mo-Bpy catalyst can be applied to the direct amination of nitroarenes and arylboronic acid,thus constructing various valuable diarylamines in high to excellent yields with a wide substrate scope and good functional group tolerance.It is worth noting that this heterogeneous catalyst has high chemical stability and can be recycled for at least five times without reducing its activity.
基金supported by the National Natural Science Foundation of China(Nos.52275395,51935014,and 82072084)the Science and Technology Innovation Program of Hunan Province(No.2023RC3046)+4 种基金the Young Elite Scientists Sponsorship Program byCAST(No.2020QNRC002)the NationalKeyResearchand Development Program of China(No.2023YFB4605800)the Central South University Innovation-Driven Research Programme(No.2023CXQD023)the Jiangxi Provincial Natural Science Foundation of China(No.20224ACB204013)the Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University.
文摘Magnetostrictive Fe-Ga alloys have captivated substantial focus in biomedical applications because of their exceptional transition efficiency and favorable cytocompatibility.Nevertheless,Fe-Ga alloys always exhibit frustrating magnetostriction coefficients when presented in bulk dimensions.It is well-established that the magnetostrictive performance of Fe-Ga alloys is intimately linked to their phase and crystal structures.In this study,various concentrations of boron(B)were doped into Fe_(81)Ga_(19) alloys via the laser-beam powder bed fusion(LPBF)technique to tailor the crystal and phase structures,thereby improving the magnetostrictive performance.The results revealed the capacity for quick solidification of the LPBF process in expediting the solid solution of B element,which increased both lattice distortion and dislocations within the Fe-Ga matrix.These factors contributed to an elevation in the density of the modified-D0_(3) phase structure.Moreover,the prepared Fe-Ga-B alloys also exhibited a(001)preferred grain orientation caused by the high thermal gradients during the LPBF process.As a result,a maximum magnetostriction coefficient of 105 ppm was achieved in the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy.In alternating magnetic fields,all the LPBF-prepared alloys showed good dynamic magnetostriction response without visible hysteresis,while the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy presented a notable enhancement of~30%in magnetostriction coefficient when compared with the Fe_(81)Ga_(19) alloy.Moreover.the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy exhibited favorable biocompatibility and osteogenesis,as confirmed by increased alkaline phosphatase(ALP)activity and the formation of mineralized nodules.These findings suggest that the B-doped Fe-Ga alloys combined with the LPBF technique hold promise for the development of bulk magnetostrictive alloys that are applicable for bone repair applications.
基金support from the National Natural Science Foundation of China(22268025,52473083,and 22475176)Key Research and Development Program of Yunnan Province(202403AP140036)+2 种基金Natural Science Basic Research Program of Shaanxi(2024JC-TBZC-04)Applied Basic Research Program of Yunnan Province(202201AT070115 and 202201BE070001-031)supported by the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57).
文摘The microstructure design for thermal conduction pathways in polymeric electrical encapsulation materials is essential to meet the stringent requirements for efficient thermal management and thermal runaway safety in modern electronic devices.Hence,a composite with three-dimensional network(Ho/U-BNNS/WPU)is developed by simultaneously incorporating magnetically modified boron nitride nanosheets(M@BNNS)and non-magnetic organo-grafted BNNS(U-BNNS)into waterborne polyurethane(WPU)to synchronous molding under a horizontal magnetic field.The results indicate that the continuous in-plane pathways formed by M@BNNS aligned along the magnetic field direction,combined with the bridging structure established by U-BNNS,enable Ho/U-BNNS/WPU to exhibit exceptional in-plane(λ//)and through-plane thermal conductivities(λ_(⊥)).In particular,with the addition of 30 wt%M@BNNS and 5 wt%U-BNNS,theλ//andλ_(⊥)of composites reach 11.47 and 2.88 W m^(-1) K^(-1),respectively,which representing a 194.2%improvement inλ_(⊥)compared to the composites with a single orientation of M@BNNS.Meanwhile,Ho/U-BNNS/WPU exhibits distinguished thermal management capabilities as thermal interface materials for LED and chips.The composites also demonstrate excellent flame retardancy,with a peak heat release and total heat release reduced by 58.9%and 36.9%,respectively,compared to WPU.Thus,this work offers new insights into the thermally conductive structural design and efficient flame-retardant systems of polymer composites,presenting broad application potential in electronic packaging fields.
基金supported by the National Natural Science Foundation of China(No.51972162)the Fundamental Research Funds for the Central Universities(No.2024300440).
文摘Lowering the synthesis temperature of boron nitride nanotubes(BNNTs)is crucial for their development.The primary reason for adopting a high temperature is to enable the effective activation of highmelting-point solid boron.In this study,we developed a novel approach for efficiently activating boron by introducing alkali metal compounds into the conventional MgO–B system.This approach can be adopted to form various low-melting-point AM–Mg–B–O growth systems.These growth systems have improved catalytic capability and reactivity even under low-temperature conditions,facilitating the synthesis of BNNTs at temperatures as low as 850℃.In addition,molecular dynamics simulations based on density functional theory theoretically demonstrate that the systems maintain a liquid state at low temperatures and interact with N atoms to form BN chains.These findings offer novel insights into the design of boron activation and are expected to facilitate research on the low-temperature synthesis of BNNTs.
基金National Key Research and Development Program of China (2022YFE0206300)National Natural Science Foundation of China (U21A2081,22075074, 22209047)+3 种基金Guangdong Basic and Applied Basic Research Foundation (2024A1515011620)Hunan Provincial Natural Science Foundation of China (2024JJ5068)Foundation of Yuelushan Center for Industrial Innovation (2023YCII0119)Student Innovation Training Program (S202410532594,S202410532357)。
文摘Hard carbon (HC) has been considered as promising anode material for sodium-ion batteries (SIBs).The optimization of hard carbon’s microstructure and solid electrolyte interface (SEI) property are demonstrated effective in enhancing the Na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly desirable.Herein,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more Na+storage sites.In-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy (FTIR/EIS) and X-ray photoelectron spectroscopy (XPS) analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI,which leads to facilitated charge transfer and excellent rate performance.As a result,the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling performance.In general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced Na+storage performance.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BZ2022007)the National Natural Science Foundation of China(No.92261202)+1 种基金the Ministry of Science and Technology of the People’s Republic of China(No.2021YFE0114800)the Ministry of Science and Higher Education of the Russian Federation(No.075-15-2021-1027).
文摘Thermally activated delayed fluorescence(TADF)materials driven by a through-space charge transfer(TSCT)mechanism have garnered wide interest.However,access of TSCT-TADF molecules with longwavelength emission remains a formidable challenge.In this study,we introduce a novel V-type DA-D-A’emitter,Trz-mCzCbCz,by using a carborane scaffold.This design strategically incorporates carbazole(Cz)and 2,4,6-triphenyl-1,3,5-triazine(Trz)as donor and acceptor moieties,respectively.Theoretical calculations alongside experimental validations affirm the typical TSCT-TADF characteristics of this luminogen.Owing to the unique structural and electronic attributes of carboranes,Trz-mCzCbCz exhibits an orange-red emission,markedly diverging from the traditional blue-to-green emissions observed in classical Cz and Trz-based TADF molecules.Moreover,bright emission in aggregates was observed for Trz-mCzCbCz with absolute photoluminescence quantum yield(PLQY)of up to 88.8%.As such,we have successfully fabricated five organic light-emitting diodes(OLEDs)by utilizing Trz-mCzCbCz as the emitting layer.It is important to note that both the reverse intersystem crossing process and the TADF properties are profoundly influenced by host materials.The fabricated OLED devices reached a maximum external quantum efficiency(EQE)of 12.7%,with an emission peak at 592 nm.This represents the highest recorded efficiency for TSCT-TADF OLEDs employing carborane derivatives as emitting layers.
基金supported by the Science and Technology Department of Qinghai Province,China(No.2022-ZJ-932Q).
文摘The increase in the utilization of infrared heat detection technology in military applications necessitates research on composites with improved thermal transmission performance and microwave absorption capabilities.This study satisfactorily fabricated a series of MoS_(2)/BN-xyz composites(which were characterized by the weight ratio of MoS_(2)to BN,denoted by xy:z)through chemical vapor depos-ition,which resulted in their improved thermal stability and thermal transmission performance.The results show that the remaining mass of MoS_(2)/BN-101 was as high as 69.25wt%at 800℃under air atmosphere,and a temperature difference of 31.7℃was maintained between the surface temperature and the heating source at a heating temperature of 200℃.Furthermore,MoS_(2)/BN-301 exhibited an im-pressive minimum reflection loss value of-32.21 dB at 4.0 mm and a wide effective attenuation bandwidth ranging from 9.32 to 18.00 GHz(8.68 GHz).Therefore,these simplified synthesized MoS_(2)/BN-xyz composites demonstrate great potential as highly efficient con-tenders for the enhancement of microwave absorption performance and thermal conductance.
基金Funded by Provincial Basic Research Projects(No.LJKMZ20220947)。
文摘The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the amount of acid-impregnated slag dosed on the compressive strength and water resistance of LR-MOC.The results showed that the magnesium element in the boron mud could be maximally leached under the conditions of 1:1 concentration of hydrochloric acid at room temperature,liquid-solid ratio of 2.5 mL·g^(-1),and reaction time of 5 h,and the main products were amorphous SiO_(2) as well as a small amount of magnesium olivine which had not been completely reacted.The LR-MOC prepared using the acid-soaked mixture could reach a softening coefficient of 0.85 for 28 d of water immersion when the molar ratio of MgO/MgCl_(2) was 2.2,the amount of water added was 0 g,and the acid-soaked slag dosing was 40 wt%,which also led to an appreciable late-strength,with an increase of 19.4%in compressive strength at 28 d compared to that at 7 d.Unlike previous studies,LR-MOC prepared in this way has a final strength phase that is not the more easily hydrolysed 3-phase but the lath-like 5-phase.For this phenomenon,we analyzed the mechanism and found that,during the acid leaching process,a part of amorphous SiO_(2) dissolved in the acid leaching solution formed a silica sol,in which Mg^(2+)played a bridging role to make the silica sol more stable.With the addition and hydrolysis of MgO,the silica sol gel coagulation slows down,providing a capping layer to inhibit the hydrolysis of the 5-phase crystals and providing some strength after coagulation.The amorphous SiO_(2) in the other part of the acid-impregnated slag generated M-S-H gel with Mg^(2+)and OH-,which synergised with the dense structure composed of interlocking crystals to improve the water resistance of LR-MOC.
文摘Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.
基金grateful to Hubei Province Science and Technology Innovation Talent Plan,and Science and Technology Service Talent Special Project(2023DJC124)for the support on this work.
文摘Silica-based ramming mixes are widely used as lining materials in coreless induction furnaces,which serve as the main equipment for iron and steel in foundry industry.The service life of linings made from silica-based ramming mixes depends on the properties of quartzite raw materials.In this paper,quartzites from three regions were selected as raw materials,with boron oxide and boron phosphate as sintering aids.By comparing and testing performance such as the phase composition,permanent linear change,bulk density,apparent porosity,and slag resistance,the effects of raw material characteristics and sintering aids on the performance of the silica-based ramming mixes were investigated.The results showed that boron oxidecontaining ramming mixes prepared from quartzite with a fast phase transition showed lower strength and greater expansion as well as lower slag penetration index.For boron phosphate as a sintering aid,ramming mixes made from quartzites with medium and slow phase transition rates had an approaching slag penetration index comparable to those containing boron oxide,although their strength was lower than the latter.According to the melting requirements of stainless steel,boron phosphate can replace boron oxide as a sintering aid for silica-based ramming mixes.Regarding practical applications for linings of coreless induction furnaces,the selection of quartzite as the raw material for silica-based ramming mixes shall be comprehensively considered from multiple aspects.
基金supported by Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120065)National Natural Science Foundation of China(Nos.82202339,32271420,82202307)+3 种基金China Postdoctoral Science Foundation(Nos.2022M711527,2021M701640)Science Fund for Creative Research Groups of Nature Science Foundation of Hebei Province(No.B2021201038)National High-End Foreign Expert Recruitment Plan(No.G2022003007L)Natural Science Foundation of Hebei Province(No.B2023201108).
文摘Boron neutron capture therapy(BNCT)has emerged as a promising treatment for cancers,offering a unique approach to selectively target tumor cells while sparing healthy tissues.Despite its clinical utility,the widespread use of fructose-BPA(F-BPA)has been hampered by its limited ability to penetrate the blood-brain barrier(BBB)and potential risks for patients with certain complications such as diabetes,hyperuricemia,and gout,particularly with substantial dosages.Herein,a series of novel BPA derivatives were synthesized.After the primary screening,geniposide-BPA(G-BPA)and salidroside-BPA(S-BPA)exhibited high water solubility,low cytotoxicity and safe profiles for intravenous injection.Furthermore,both G-BPA and S-BPA had demonstrated superior efficacy in vitro against the 4T1 cell line compared with F-BPA.Notably,S-BPA displayed optimal BBB penetration capability,as evidenced by in vitro BBB models and glioblastoma models in vivo,surpassing all other BPA derivative candidates.Meanwhile,GBPA also exhibited enhanced performance relative to the clinical drug F-BPA.In brief,G-BPA and S-BPA,as novel BPA derivatives,demonstrated notable safety profiles and remarkable boron delivery capabilities,thereby offering promising therapeutic options for BNCT in the clinic.
基金financially supported by the National Natural Science Foundation of China(Nos.42372162,U22B6004)the Scientific Research and Technology Development Program of CNPC(Nos.2021DJ0102,2021DJ1808)。
文摘Lacustrine dolomite is paid increasing attention to uncover the diagenetic water condition of paleo-lake and“dolomite problem”.Here,a dolomite nodule from the Qingshankou Formation in the Songliao Basin was analyzed to explore the salinity,alkalinity,and redox conditions of the diagenetic water.Multiple proxies,including bulk boron(B)content,B isotope composition(δ^(11)B_(bul)),boron to gallium weight ratio(B/Ga)and carbonate oxygen isotope composition(δ^(18)O_(carb)),were used to determine the diagenetic water to be brackish-fresh.Through numerical simulation,we calculated the B contents,δ^(11)B values and B/Ga in detritus(e.g.,clay,quartz and feldspar)and dolomite as two endmembers,confirming the intense interference of clay minerals onδ^(11)B_(bul).By using the fittedδ^(11)B of dolomite endmember(20.6‰),we calculated the p H value of the diagenetic water to be 8.2.The negativeδ^(11)B value of detritus endmember(-12.9‰)might be related to the terrestrial weathering.The indicative nature of strontium to barium weight ratio(Sr/Ba)was discussed to deny its applicability as a proxy of salinity in carbonate system.High Sr/Ba ratio in this dolomite nodule indicates a sulfate-poor water condition,consistent with the iron-manganese(Fe-Mn)reduction environments reflected by the Mn/Fe molar ratio.The positive carbonate carbon isotopes(δ^(13)C_(carb),4.5‰-9.4‰)indicate that methanogenesis dominated the formation of dolomite,coinciding with the weak sulfate reduction reaction in sulfate-poor water.The growth of dolomite nodule might be related to the microbial activities of methanogen and iron reducing bacteria,which had not only maintained the salinity,p H,and redox status of the diagenetic water,but also led to a ferricmethane transition zone(FMTZ).This research depicts a scenario about the diagenetic water environment of lacustrine dolomite formed in brackish-fresh water,which is different from that occurred in sulfate-rich condition.
基金supported by the National Natural Science Foundation of China(Nos.22108181,22178233)the Fund of Science and Technology on Reactor Fuel and Materials Laboratory(No.6142A06190601)+6 种基金the National Excellent Young Scientists Fund(No.00308054A1045)the National Key R&D Program of China(No.2022YFA0912800)the Talents Program of Sichuan ProvinceDouble First Class University Plan of Sichuan Universitythe State Key Laboratory of Polymer Materials Engineering(No.sklpme 2020–03–01)the Tianfu Emei Program of Sichuan Province(No.2022EC02–00073-CG)Ministry of Education Key Laboratory of Leather Chemistry and Engineering(Sichuan University)。
文摘Although the demand of ^(10)B separation has arisen in the 1930s,^(10)B/^(11)B are among the most difficult isotopes to separate due to the extremely similar relative atomic mass.Herein,we report an efficient separation of ^(10)B isotopologue by engineering amino-galloyl synergistic materials via a selective adsorption and isotope exchange reaction,achieving a record-high single-stage separation factor of 1.048 with ^(10)B abundance up to 21.42%.^(11)B MAS NMR results and DFT calculations reveal that the galloyl groups exhibit inherent high affinity for B(OH)4-,forming tetrahedral sp^(3) B-galloyl complexes.The relatively higher ^(10)B–O bond energy of ^(10)B-galloyl complexes facilitates the isotope exchange between11B in B-galloyl complexes and ^(10)B in B(OH)_(3).Flowthrough dynamic separation in fixed-bed demonstrates the feasibility and potential of large-scale deployment of this method in real-world,suggesting a promising avenue for the exploitation of more efficient enrichment of ^(10)B for the sustainable nuclear energy and biomedical research.
基金supported by the National Energy R&D Center of Petroleum Refining Technology(RIPP,SINOPEC),the National Natural Science Foundation of China(Grants 22161132028,22172177,22225205,22372191 and 22372178)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0540000)+2 种基金the International Partnership Program of the Chinese Academy of Sciences(314GJH2022022FN)Natural Science Foundation of Hubei Province(2021CFA021)Hubei International Scientific and Technological Cooperation Program(2024EHA043)and Base(SH2303).
文摘Organic structure directingagents(OSDAs),suchas tetrapropylammonium(TPA)cations,serve as crucial templates for the formation of zeolite frameworks.These organic molecules interact with inorganic species,guiding the assembly of the zeolite structure.In this study,we inves-tigate the complex interplay between boron species and TPA cations during the crystallization of[B,Al]-ZSM-5 zeolites.Two-dimensional(2D)11B-{1H}cross-polarization heteronuclear correlation(CP-HECTOR)NMRexperiments elucidate distinct interactions between two boron species,B(IV)-1 and B(IV)-2,and the propyl chain of the TPAs.Amorphous B(IV)-1 species exhibit a strong preference for proximity to the nitrogen cation center of the OSDAs,while framework B(IV)-2 species engage with components situated at greater distances from the cation center.Moreover,13C-{11B}symmetry-based resonance-echo saturation-pulse double-resonance(S-RESPDOR)experiments revealed that framework boron species preferentially occupy the straight channels of the MFI structure,as evidenced by their interaction with specificmethyl groups on the TPAmolecules.This observation provides valuable insights into the crystallization mechanism of boron-based zeolites,suggesting that the conformation and orientation of the OSDA molecules play a critical role in determining the location of boron atoms within the zeolite framework.
基金supported by the National Key Research and Development Project of China(Grant No.2018YFE0127800)。
文摘Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials.In this article,both the iterative Boltzmann transport equation solution and the two-temperature model were employed to investigate the efficacy of targeted phonon excitation applied to hexagonal boron nitride(hBN).The results indicate significant modifications to hBN's thermal conductivity,achieving increases of up to 30.1%as well as decreases of up to 59.8%.These findings validate the reliability of the strategy,expand its scope of applicability,and establish it as a powerful tool for tailoring thermal properties across a wider range of fields.
基金supported by the National Natural Science Foundation of China(Nos.52274392 and 52104381)Natural Science Foundation of Hubei Province(No.2023AFB023)Knowledge Innovation Program of Wuhan-Basi Research(No.2023010201010133).
文摘The integration of boronizing and austempering termed boro-austempering treatment is a new processing route for preparing high strength bainitic steel with high surface hardness and high corrosion resistance.The microstructure and properties of a medium-carbon bainitic steel prepared by boro-austempering treatment were characterized and analyzed.The results show that a single Fe_(2)B layer on bainite substrate was obtained with surface hardness of~1400 HV,and the critical load for adhesive failure of borided layer reached 73.6 N.The silicon-rich α-Fe phase in transition zone was clarified as ferrite,which was formed at the beginning stage of cooling process from boronizing to low-temperature bainite transformation.Moreover,the relative potential differences between Fe_(2)B and bainite matrix,and ferrite and bainite matrix were 75 and 92 mV,respectively,with bainite matrix acting as active anode,indicating that the corrosion resistances of Fe2B and ferrite were better than that of bainite.
