Ultrahigh pressure generation at high temperatures is technologically challenging for large sample volumes.In this study,we successfully generated pressures of 37.3-40.4 GPa at 1900-2100 K in a Walker-type large-volum...Ultrahigh pressure generation at high temperatures is technologically challenging for large sample volumes.In this study,we successfully generated pressures of 37.3-40.4 GPa at 1900-2100 K in a Walker-type large-volume press(LVP).Expansion of the pressure range at high temperatures was achieved by adapting newly designed ZK01F tungsten carbide(WC)anvils with tapered surfaces and using cell assemblies with an^(-1) mm^(3) sample volume and hard materials,as well as by applying certain adjustments to the apparatus.The pressure efficiencies of the different types of WC anvils and cell assemblies were also studied.Using the above-mentioned techniques,we successfully synthesized and characterized bulk samples of nearly pure sp3-hybridized ultrahard amorphous carbon,core-shell nanocrystals with high Néel temperatures,as well as large-sized single crystals of lower-mantle minerals.The developed LVP techniques presented here could enable the exploration of the chemical and physical properties of novel materials and Earth’s interior.展开更多
The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature a...The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature and a high temperature of 1900 K∼60within a millimeter-sized sample volume in a Kawai-type LVP(KLVP)using hard tungsten carbide(WC)and newly designed assem-blies.The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe_(2)O_(3) pressure standard upon compression.The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils.Our study has enabled the routine gener-ation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs.This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs,but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.展开更多
Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challeng...Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challenging and thereby causes relatively large pressure uncertainties in deformation experiments,resulting in the synthesis of complex multiphase materials.Here,pressure generations of three types of deformation assemblies were well calibrated in a Walker-type largevolume press(LVP)by electrical resistance measurements combined with finite element simulations(FESs).Hard Al_(2)O_(3) or diamond pistons in shear and uniaxial deformation assemblies significantly increase the efficiency of pressure generation compared with the conventional quasi-hydrostatic assembly.The uniaxial deformation assembly using flat diamond pistons possesses the highest efficiency in these deformation assemblies.This finding is further confirmed by stress distribution analysis based on FESs.With this deformation assembly,we found shear can effectively promote the transformation of C60 into diamond under high pressure and realized the synthesis of phase-pure diamond at relatively moderate pressure and temperature conditions.The present developed techniques will help improve pressure efficiencies in LVP and explore the new physical and chemical properties of materials under deformation in both science and technology.展开更多
Pressure allows the precise tuning of a fundamental parameter, the interatomic distance, which controls the electronic structure and virtually all interatomic interactions that determine material properties. Hence, pr...Pressure allows the precise tuning of a fundamental parameter, the interatomic distance, which controls the electronic structure and virtually all interatomic interactions that determine material properties. Hence, pressure tuning is an effective tool in the search for new materials with enhanced properties. To realize pressure tuning on matter, large-volume press （LVP） apparatuses have been widely used not only to synthesize novel materials but also to implement the in situ measurement of physical properties. Herein, we introduce the LVP apparatuses, including belt-type, cubic anvil, and 6-8 type multi-anvil, that will be constructed at the Synergetic Extreme Condition User Facility （SECUF） at Jilin University. Typically, cell volumes of 1000 mm3 can be obtained at 20 GPa in a belt-type apparatus that is significantly larger than that obtained in a 6-8 type multi-anvil apparatus at the same pressure. Furthermore, the in situ measurement of physical prop- erties, including thermological, electrical, and mechanical behaviors, is coupled to these LVP apparatuses. Some typical results of both synthetic experiments and in situ measurements obtained from the LVP apparatuses are also reviewed.展开更多
The clinical application of tumor vaccines is hindered by challenges such as timeconsuming and costly production processes.In this context,in situ cancer vaccines represent a promising strategy by leveraging endogenou...The clinical application of tumor vaccines is hindered by challenges such as timeconsuming and costly production processes.In this context,in situ cancer vaccines represent a promising strategy by leveraging endogenous tumor antigens to elicit robust antitumor T cell responses.Herein,a photoactivatable tumor-targeting in situ nanovaccine,Lipo-D8-6,was constructed using cRGD-functionalized liposomes that co-encapsulated the photosensitizer chlorin e6 and a cleavable immunoadjuvant conjugate D8,allowing light-triggered synchronous activation of three therapeutic modules.Upon near-infrared light irradiation,Lipo-D8-6 generates reactive oxygen species that exert direct cytotoxicity on tumor cells and induce immunogenic cell death,while concurrently cleaving the responsive linker within D8 to achieve the controlled release of R848.In vivo biodistribution analysis confirmed the superior intratumoral accumulation of Lipo-D8-6,facilitating precise treatment.In a large-volume tumor model,the nanovaccine exhibited pronounced antitumor efficacy,accompanied by enhanced tumor infiltration of CD8t T cells.Overall,this work provides a simplified and effective approach for developing in situ nanovaccines that enable synergistic photodynamic immunotherapy with precise spatiotemporal control over immune activation.展开更多
Neutron diffraction techniques of large-volume samples at high pressure using compact opposed-anvil cells are developed at a reactor neutron source, China＇s Mianyang research reactor. We achieve a high-pressure condi...Neutron diffraction techniques of large-volume samples at high pressure using compact opposed-anvil cells are developed at a reactor neutron source, China＇s Mianyang research reactor. We achieve a high-pressure condition of in situ neutron diffraction by means of a newly designed large-volume opposed-anvil cell. This pressure calibration is based on resistance measurements of bismuth and the neutron diffraction of iron. Pressure calibration experiments are performed at room temperature for a new cell using the tungsten carbide anvils with a tapered angle of 30°, Φ4.5 mm culet diameter and the metal-nonmetal composite gasket with a thickness of 2 mm. Transitions in Bi（Ⅰ–Ⅱ 2.55 GPa, Ⅱ–V 7.7 GPa） are observed at 100 and 300 kN, respectively, by resistance measurements.The pressure measurement results of neutron diffraction are consistent with resistance measurements of bismuth.As a result, pressures up to about 7.7 GPa can routinely and stably be achieved using this apparatus, with the sample volume of 9 mm^3.展开更多
Tight gas reservoirs are often characterized by pronounced heterogeneity and poor continuity,resulting in wide variability in production enhancement and net present value(NPV)for different geological parameter combina...Tight gas reservoirs are often characterized by pronounced heterogeneity and poor continuity,resulting in wide variability in production enhancement and net present value(NPV)for different geological parameter combinations(see e.g.,the Ordos Basin).The conditions governing geological adaptability remain insufficiently defined.To address these challenges,this study integrates large-volume hydraulic fracturing,numerical production simulation,and economic evaluation to elucidate the mechanisms by which large-scale fracturing enhances fracture parameters in tight gas formations.The analysis reveals that,for identical proppant and fluid volumes,increasing the fracturing injection rate leads to longer and taller fractures.Over the same production period,this results in a more rapid decline in average reservoir pressure and a higher cumulative gas output.Through simulations conducted at varying injection rates across 11 production wells in the target block,the study demonstrates that large-volume fracturing can effectively connect otherwise isolated tight gas pockets,enlarge the drainage area,and substantially boost individual well production.A comparative assessment of simulation outcomes and economic performance shows that large-volume fracturing significantly improves gas recovery and NPV compared to conventional smaller-scale treatments.The study identifies the key geological indicators that influence differences in production enhancement and economic returns between small-and large-volume fracturing strategies.Based on these findings,a decision matrix is developed(utilizing a trapezoidal membership function)to evaluate the geological suitability of large-volume fracturing in tight gas reservoirs.This matrix is applied to the 11 target wells,with the evaluation results aligning well with those obtained from numerical simulations.展开更多
The paper shows selected aspects of the microclimate change inside the selected type of the large-volume buildings--sacral buildings and for comparison--in the residential apartment buildings, caused by the heat emitt...The paper shows selected aspects of the microclimate change inside the selected type of the large-volume buildings--sacral buildings and for comparison--in the residential apartment buildings, caused by the heat emitted by people. Microclimate parameters such as air temperature or air relative humidity change because of heat emission from people staying inside there. Exemplary methods and results of research conducted in the existing sacral buildings and in the residential apartment buildings are shown. It is based on author＇s research, whose novelty is the research of the human heat emission in case of a big number of people staying inside a large-volume building. It can be useful for sacral buildings and other large-volume buildings design and for a microclimate shaping. In some large-volume buildings as the sacral buildings with a big number of people staying inside at the same time heat emitted from people significantly influences on a microclimate. Human heat streams can be useful as a part of the heat balance of the room.展开更多
To enhance the mechanical properties of Mo alloys prepared through laser powder bed fusion(LPBF),a hot isostatic pressing(HIP)treatment was used.Results show that following HIP treatment,the porosity decreases from 0....To enhance the mechanical properties of Mo alloys prepared through laser powder bed fusion(LPBF),a hot isostatic pressing(HIP)treatment was used.Results show that following HIP treatment,the porosity decreases from 0.27%to 0.22%,enabling the elements Mo and Ti to diffuse fully and to distribute more uniformly,and to forming a substantial number of low-angle grain boundaries.The tensile strength soars from 286±32 MPa to 598±22 MPa,while the elongation increases from 0.08%±0.02%to 0.18%±0.02%,without notable alterations in grain morphology during the tensile deformation.HIP treatment eliminates the molten pool boundaries,which are the primary source for premature failure in LPBFed Mo alloys.Consequently,HIP treatment emerges as a novel and effective approach for strengthening the mechanical properties of LPBFed Mo alloys,offering a fresh perspective on producing high-performance Mo-based alloys.展开更多
Hot isostatic pressing (HIP) temperature has a significant impact on the service performance of powder metallurgy titanium alloys. In this study, a high-temperature titanium alloy, Ti-6.5Al-3.5Mo-1.5Zr-0.3Si, was prep...Hot isostatic pressing (HIP) temperature has a significant impact on the service performance of powder metallurgy titanium alloys. In this study, a high-temperature titanium alloy, Ti-6.5Al-3.5Mo-1.5Zr-0.3Si, was prepared under different HIP temperatures (880–1000℃), and the microstructural evolution and mechanical properties were systematically investigated. The results demonstrated that the HIPed alloys were predominantly composed of more than 80 vol.% α phase and a small amount of β phase, and their phase compositions were basically unaffected by the HIP temperatures. Under the typical single-temperature-maintained HIP (STM-HIP) regime, the microstructure of alloy significantly coarsened as the HIP temperature increased, and the alloy strength exhibited an obvious linear negative correlation with the HIP temperature. On the basis of Hall–Petch relation, the prediction model of grain size was established, and the mathematical equation between HIP temperature and grain size (d=M(T_(HIP-N)^(-2))) was deduced. Furthermore, a possible evolution mechanism of microstructure was proposed, which could be divided into the decomposition of initial α′ martensite for as-received powder, formation of the globular α grains in prior particle boundaries (PPBs) region, and precipitation of the platelet α grains in non-PPBs region. For these alloys prepared by the dual-temperature-maintained HIP (DTM-HIP) regime, although their tensile properties were comparable to that of alloy prepared by STM-HIP regime with same high-temperature holding stage, higher proportion of globular α grains occurred due to more recrystallization nucleation during the low-temperature holding stage, which probably provided a solution for improving the dynamic service performance of HIPed alloys.展开更多
To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,t...To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,thereby improving both microstructure uniformity and mechanical properties of sintered bodies.The results indicate that WIP reduces defects in MEX greens,thus decreasing the dimensions and numbers of defects,modifying shapes of pores within sintered bodies,while preserving surface quality and shape characteristics.Compared with WC-9Co prepared via MEX followed by debinding and sintering(DS),the hardness of WC-9Co prepared using MEX-WIP-DS does not change significantly,ranging HV_(30)1494-1508,the transverse rupture strength increases by up to 49.3%,reaching 2998-3514 MPa,and the fracture toughness remains high,ranging 14.8-17.0 MPa·m^(1/2).The mechanical properties surpass comparable cemented carbides fabricated through other AM methods and are comparable to those produced by powder metallurgy.The integration of green WIP into MEX-DS broadens the MEX processing window,and improves the overall mechanical properties of MEX AM WC-Co cemented carbides.展开更多
OBJECTIVE:To assess the efficacy and safety of the Qingyanyin formulated granules(轻燕饮配方颗粒,QYY),press needles(PN),and their combined application in addressing abdominal obesity(AO).This trial aims to offer a mor...OBJECTIVE:To assess the efficacy and safety of the Qingyanyin formulated granules(轻燕饮配方颗粒,QYY),press needles(PN),and their combined application in addressing abdominal obesity(AO).This trial aims to offer a more scientifically grounded therapeutic regimen for clinical interventions.METHODS:From March 2021 to July 2021,a multicenter,triple-blind,randomized 2×2 factorial design clinical trial was conducted across 7 centers in 4 major cities within China's mainland.The trial participants were patients diagnosed with AO.The trial followed a 1∶1∶1∶1 random allocation ratio,assigning participants to one of four groups:QYY placebo plus simulated press needles(SPN)(placebo+SPN),QYY plus SPN(QYY+SPN),QYY placebo plus PN(placebo+PN),and QYY plus PN(QYY+PN).The trial participants received treatment for 12 weeks.Observe the changes in waist circumference,body weight,body mass index(BMI),Beck Depression Inventory(BDI),Beck Anxiety Inventory(BAI)scores,and Pittsburgh Sleep Quality Index(PSQI)before and after treatment.RESULTS:The QYY+PN group exhibited significant improvements in waist circumference compared to placebo+PN[Difference=-1.59,95%CI(-3.03,-0.16)]and placebo+SPN groups[Difference=-2.01,95%CI(-3.46,-0.57)].QYY+PN demonstrated a significant advantage over placebo+SPN[Difference=-2.01,95%CI(-3.46,-0.57)],and no statistically significant interaction was observed between the two interventions(P>0.05).In terms of weight and BMI improvements,the QYY+PN,QYY+SPN,and the PN+placebo groups all experienced trending greater reductions in weight compared to the placebo group.In terms of the total scores of PSQI,BAI,and BDI,all four groups exhibited improvements compared to the baseline.Specifically,concerning the change in total PSQI scores,the QYY+PN group exhibited a greater reduction;Regarding the change in total BAI scores,the PN+placebo group demonstrated a greater decrease;As for the change in total BDI scores,the QYY+SPN group displayed a greater reduction.CONCLUSION:This study confirmed that QYY+PN can effectively reduce the waist circumference of patients with AO.Furthermore,the combined approach offers greater benefits than either treatment alone,all without any reported serious adverse events.展开更多
To investigate the effect of microstructure evolution on corrosion behavior and strengthening mechanism of Mg-1Zn-1Ca(wt.%)alloys,as-cast Mg-1Zn-1Ca alloys were performed by equal channel angular pressing(ECAP)with 1 ...To investigate the effect of microstructure evolution on corrosion behavior and strengthening mechanism of Mg-1Zn-1Ca(wt.%)alloys,as-cast Mg-1Zn-1Ca alloys were performed by equal channel angular pressing(ECAP)with 1 and 4 passes.The corrosion behavior and mechanical properties of alloys were investigated by optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),electrochemical tests,immersion tests and tensile tests.The results showed that mechanical properties improved after ECAP 1 pass;however,the corrosion resistance deteriorated due to high-density dislocations and fragmented secondary phases by ECAP.In contrast,synchronous improvement in the mechanical properties and corrosion resistance was achieved though grain refinement after ECAP 4 passes;fine grains led to a significant improvement in the yield strength,ultimate tensile strength,elongation,and corrosion rate of 103 MPa,223 MPa,30.5%,and 1.5843 mm/a,respectively.The enhanced corrosion resistance was attributed to the formation of dense corrosion product films by finer grains and the barrier effect by high-density grain boundaries.These results indicated that Mg-1Zn-1Ca alloy has a promising potential for application in biomedical materials.展开更多
The microstructure,micro-hardness,and tensile properties of interface between hot isostatic pressing densified low alloy steel and Inconel 690 cladding were investigated during the aging process at 600℃.The results s...The microstructure,micro-hardness,and tensile properties of interface between hot isostatic pressing densified low alloy steel and Inconel 690 cladding were investigated during the aging process at 600℃.The results show that the interface region can be divided into four zones from base metal to deposited metal:carbon-depleted zone(CDZ),partial melting zone(PMZ),planar growth zone(PGZ),and brownish feature zone(BFZ).Dimensions of these zones do not significantly change during aging.However,type I carbides noticeably increase in size in the PMZ,and precipitates clearly occur in the PGZ.The main reason for their growth and occurrence is continuous carbon migration.The highest micro-hardness appears in the PGZ and BFZ regions,which is related to carbon accumulation and precipitates in these regions.Tensile failure occurs on the base metal side due to the high strength mismatch between these two materials.The CDZ,composed of only ferrite,has lower strength and fractures at the boundary between CDZ and base metal.The ultimate tensile strength decreases by only 50 MPa after aging for 1500 h,and the interface region maintains high strength without significant deformation.展开更多
Find It What did people use years ago to print things?Each year,the world produces millions of pounds of paper.A lot goes into the trash.Recycling means waste can be used again.To recycle paper,you usually need specia...Find It What did people use years ago to print things?Each year,the world produces millions of pounds of paper.A lot goes into the trash.Recycling means waste can be used again.To recycle paper,you usually need special tools and machines.But what if you could recycle paper by yourself?You could turn used paper into writing paper.展开更多
In this study,we developed an in-situ hot-pressing sintering(HPS)device that can be coupled to a lab-oratory X-ray microscope,offering laboratory-available observation of the morphology evolution.With the help of this...In this study,we developed an in-situ hot-pressing sintering(HPS)device that can be coupled to a lab-oratory X-ray microscope,offering laboratory-available observation of the morphology evolution.With the help of this device,in-situ three-dimensional(3D)visualizations of the microstructural evolution of 7055 aluminum alloys during the HPS process were conducted.The 3D results revealed that the twodimensional(2D)methods usually underestimated sintering neck width and exhibited significant standard deviation in statistical analysis.Benefiting from the precise microstructure characterization of the insitu 3D methods,the diffusion activation energy for the sintering of 7055 alloys was calculated,and the quantitative relationship between the sintering temperature and the sintering process was constructed.Moreover,it was experimentally found an accelerative effect of satellite particles on the sintering process,and its mechanisms were discussed.The satellite particles enhanced the curvature near the sintering neck and thus increased the sintering driving stress,promoting the densification process.These findings provide new insights for optimizing sintering processes.展开更多
Pure titanium fabricated by powder metallurgy generally encounters problems including low relative density and low strength,which limits its application performance.This work proposed a multi-step pressing(MSP)techniq...Pure titanium fabricated by powder metallurgy generally encounters problems including low relative density and low strength,which limits its application performance.This work proposed a multi-step pressing(MSP)technique for developing highstrength pure titanium.The MSP processes of spherical Ti powders of 15–53μm,53–105μm,and 75–180μm were systematically investigated through multi-particle fnite element method(MPFEM)compared with conventional one-step pressing(OSP)technique.The relative density,phase constitution,microstructure,and compressive mechanical properties of the sintered bulk pure titanium were characterized.Simulation results demonstrate that the MSP technique signifcantly increases the relative density of green compacts by 3.2%,3.3%,and 5.2%,respectively,compared with OSP technique.Experimental results indicate the relative density of the sintered specimens prepared by MSP spherical powders increases by 5.4%,4.5%,and 4.5%,respectively,compared to OSP,and the yield strength improves by 16%,13%,and 18%.For the sintered specimens prepared by MSP irregular powder of 15–53μm,the relative density increases by 6.0%and the yield strength increases by 15%.The enhancement of relative density and yield strength is mainly because the MSP technique mitigates stress concentration between powder particles.Compared to spherical powder,irregular powder exhibits stronger mechanical interlocking owing to the greater propensity for displacement and deformation,which facilitates mutual wedging and interlocking,resulting in superior strength performance.展开更多
Press hardening with manganese-boron steels is a prominent manufacturing technique that allows for reduced weight and expense in automotive construction,while providing enhanced crash performance.Nevertheless,the deve...Press hardening with manganese-boron steels is a prominent manufacturing technique that allows for reduced weight and expense in automotive construction,while providing enhanced crash performance.Nevertheless,the development of a loosely attached oxide layer during press hardening and following additional processing of the layer presents a significant risk to the dimensional precision of the completed product.Here,we develop a new preprocessing approach to address the scale spallation issue by introducing trace amounts of silicate and tungstate into the rinsing solution following pickling.We demonstrate that the pre-deposited membrane promotes the formation of a noticeably thinner,more continuous and stickier oxide scale at high temperatures,enabling the direct application of automobile painting onto the scale.Our research provides an economical remedy to the troublesome scale flaking issue without requiring any modifications to the existing production line,and conveys a thorough comprehension of the mechanism by which the preprocessed membrane resists high-temperature oxidation.展开更多
A novel Al-alloyed press-hardening steel(PHS)was developed,which exhibits excellent tensile,bending and antioxidation properties.Al is a ferrite-forming element that can hinder the formation of cementite and enhance t...A novel Al-alloyed press-hardening steel(PHS)was developed,which exhibits excellent tensile,bending and antioxidation properties.Al is a ferrite-forming element that can hinder the formation of cementite and enhance the stability of austenite.The incorporation of Al not only induces the formation of ferrite within martensitic matrix but also enhances the stability of retained austenite(RA).The microstructure of novel steel consists of martensite,ferrite,and RA after press hardening.Investigations into the role of Al in RA development were supported by thermo-kinetic calculations.The simultaneous introduction of ferrite and RA into the martensitic matrix via tailored chemical compositions significantly enhances the elongation and bending toughness of the novel PHS.Additionally,Al can form a dense Al oxide at the bottom of oxide layer,resulting in the improved antioxidant properties.Compared to 22MnB5 steel,it is an exciting discovery as there is a significant improvement in total elongation and bending toughness of novel PHS without compromising strength.The novel PHS,with its exceptional balance of strength and ductility,will play a crucial role in reducing weight when it replaces the existing class 22MnB5 PHS in different structural components of vehicle bodies.展开更多
基金supported by the National Key Research and Development Program of China(2022YFB3706600 and 2023YFA1406200)the National Natural Science Founda-tion of China(42272041,52302043,12304015,41902034,and 12011530063)+1 种基金the Jilin University High-level Innovation Team Foundation,China(2021TD-05)the National Major Science Facility Synergetic Extreme Condition User Facility Achievement Transformation Platform Construction(2021FGWCXNLJSKJ01).
文摘Ultrahigh pressure generation at high temperatures is technologically challenging for large sample volumes.In this study,we successfully generated pressures of 37.3-40.4 GPa at 1900-2100 K in a Walker-type large-volume press(LVP).Expansion of the pressure range at high temperatures was achieved by adapting newly designed ZK01F tungsten carbide(WC)anvils with tapered surfaces and using cell assemblies with an^(-1) mm^(3) sample volume and hard materials,as well as by applying certain adjustments to the apparatus.The pressure efficiencies of the different types of WC anvils and cell assemblies were also studied.Using the above-mentioned techniques,we successfully synthesized and characterized bulk samples of nearly pure sp3-hybridized ultrahard amorphous carbon,core-shell nanocrystals with high Néel temperatures,as well as large-sized single crystals of lower-mantle minerals.The developed LVP techniques presented here could enable the exploration of the chemical and physical properties of novel materials and Earth’s interior.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(Grant Nos.42272041 and 52302043)+2 种基金the National Natural Science Foundation of China(Grant No.U23A20561)the Jilin University High-level Innovation Team Foundation(Grant No.2021TD–05)the Shanghai Synchrotron Radiation Facility(Grant Nos.2024-SSRF-PT-510031 and 505511).
文摘The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature and a high temperature of 1900 K∼60within a millimeter-sized sample volume in a Kawai-type LVP(KLVP)using hard tungsten carbide(WC)and newly designed assem-blies.The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe_(2)O_(3) pressure standard upon compression.The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils.Our study has enabled the routine gener-ation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs.This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs,but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.
基金the National Natural Science Foundation of China(Grant Nos.42272041,41902034,52302043,12304015,52302043,and 12011530063)the National Major Science Facility Synergetic Extreme Condition User Facility Achievement Transformation Platform Construction(Grant No.2021FGWCXNLJSKJ01)+2 种基金the China Postdoctoral Science Foundation(Grant Nos.2022M720054 and 2023T160257)the National Key Research and Development Program of China(Grant No.2022YFB3706602)the Jilin Univer-sity High-level Innovation Team Foundation,China(Grant No.2021TD-05).
文摘Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challenging and thereby causes relatively large pressure uncertainties in deformation experiments,resulting in the synthesis of complex multiphase materials.Here,pressure generations of three types of deformation assemblies were well calibrated in a Walker-type largevolume press(LVP)by electrical resistance measurements combined with finite element simulations(FESs).Hard Al_(2)O_(3) or diamond pistons in shear and uniaxial deformation assemblies significantly increase the efficiency of pressure generation compared with the conventional quasi-hydrostatic assembly.The uniaxial deformation assembly using flat diamond pistons possesses the highest efficiency in these deformation assemblies.This finding is further confirmed by stress distribution analysis based on FESs.With this deformation assembly,we found shear can effectively promote the transformation of C60 into diamond under high pressure and realized the synthesis of phase-pure diamond at relatively moderate pressure and temperature conditions.The present developed techniques will help improve pressure efficiencies in LVP and explore the new physical and chemical properties of materials under deformation in both science and technology.
文摘Pressure allows the precise tuning of a fundamental parameter, the interatomic distance, which controls the electronic structure and virtually all interatomic interactions that determine material properties. Hence, pressure tuning is an effective tool in the search for new materials with enhanced properties. To realize pressure tuning on matter, large-volume press （LVP） apparatuses have been widely used not only to synthesize novel materials but also to implement the in situ measurement of physical properties. Herein, we introduce the LVP apparatuses, including belt-type, cubic anvil, and 6-8 type multi-anvil, that will be constructed at the Synergetic Extreme Condition User Facility （SECUF） at Jilin University. Typically, cell volumes of 1000 mm3 can be obtained at 20 GPa in a belt-type apparatus that is significantly larger than that obtained in a 6-8 type multi-anvil apparatus at the same pressure. Furthermore, the in situ measurement of physical prop- erties, including thermological, electrical, and mechanical behaviors, is coupled to these LVP apparatuses. Some typical results of both synthetic experiments and in situ measurements obtained from the LVP apparatuses are also reviewed.
基金supported by National Natural Science Foundation of China(22090011)Liaoning Binhai Laboratory(LBLB-2023-03)Fundamental Research Funds for the Central Universities(DUT22LAB608).
文摘The clinical application of tumor vaccines is hindered by challenges such as timeconsuming and costly production processes.In this context,in situ cancer vaccines represent a promising strategy by leveraging endogenous tumor antigens to elicit robust antitumor T cell responses.Herein,a photoactivatable tumor-targeting in situ nanovaccine,Lipo-D8-6,was constructed using cRGD-functionalized liposomes that co-encapsulated the photosensitizer chlorin e6 and a cleavable immunoadjuvant conjugate D8,allowing light-triggered synchronous activation of three therapeutic modules.Upon near-infrared light irradiation,Lipo-D8-6 generates reactive oxygen species that exert direct cytotoxicity on tumor cells and induce immunogenic cell death,while concurrently cleaving the responsive linker within D8 to achieve the controlled release of R848.In vivo biodistribution analysis confirmed the superior intratumoral accumulation of Lipo-D8-6,facilitating precise treatment.In a large-volume tumor model,the nanovaccine exhibited pronounced antitumor efficacy,accompanied by enhanced tumor infiltration of CD8t T cells.Overall,this work provides a simplified and effective approach for developing in situ nanovaccines that enable synergistic photodynamic immunotherapy with precise spatiotemporal control over immune activation.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0401503the Science Challenge Project under Grant No TZ2016001the National Natural Science Foundation of China under Grant No 11427810
文摘Neutron diffraction techniques of large-volume samples at high pressure using compact opposed-anvil cells are developed at a reactor neutron source, China＇s Mianyang research reactor. We achieve a high-pressure condition of in situ neutron diffraction by means of a newly designed large-volume opposed-anvil cell. This pressure calibration is based on resistance measurements of bismuth and the neutron diffraction of iron. Pressure calibration experiments are performed at room temperature for a new cell using the tungsten carbide anvils with a tapered angle of 30°, Φ4.5 mm culet diameter and the metal-nonmetal composite gasket with a thickness of 2 mm. Transitions in Bi（Ⅰ–Ⅱ 2.55 GPa, Ⅱ–V 7.7 GPa） are observed at 100 and 300 kN, respectively, by resistance measurements.The pressure measurement results of neutron diffraction are consistent with resistance measurements of bismuth.As a result, pressures up to about 7.7 GPa can routinely and stably be achieved using this apparatus, with the sample volume of 9 mm^3.
基金open fund of Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University)YQZC202404.
文摘Tight gas reservoirs are often characterized by pronounced heterogeneity and poor continuity,resulting in wide variability in production enhancement and net present value(NPV)for different geological parameter combinations(see e.g.,the Ordos Basin).The conditions governing geological adaptability remain insufficiently defined.To address these challenges,this study integrates large-volume hydraulic fracturing,numerical production simulation,and economic evaluation to elucidate the mechanisms by which large-scale fracturing enhances fracture parameters in tight gas formations.The analysis reveals that,for identical proppant and fluid volumes,increasing the fracturing injection rate leads to longer and taller fractures.Over the same production period,this results in a more rapid decline in average reservoir pressure and a higher cumulative gas output.Through simulations conducted at varying injection rates across 11 production wells in the target block,the study demonstrates that large-volume fracturing can effectively connect otherwise isolated tight gas pockets,enlarge the drainage area,and substantially boost individual well production.A comparative assessment of simulation outcomes and economic performance shows that large-volume fracturing significantly improves gas recovery and NPV compared to conventional smaller-scale treatments.The study identifies the key geological indicators that influence differences in production enhancement and economic returns between small-and large-volume fracturing strategies.Based on these findings,a decision matrix is developed(utilizing a trapezoidal membership function)to evaluate the geological suitability of large-volume fracturing in tight gas reservoirs.This matrix is applied to the 11 target wells,with the evaluation results aligning well with those obtained from numerical simulations.
文摘The paper shows selected aspects of the microclimate change inside the selected type of the large-volume buildings--sacral buildings and for comparison--in the residential apartment buildings, caused by the heat emitted by people. Microclimate parameters such as air temperature or air relative humidity change because of heat emission from people staying inside there. Exemplary methods and results of research conducted in the existing sacral buildings and in the residential apartment buildings are shown. It is based on author＇s research, whose novelty is the research of the human heat emission in case of a big number of people staying inside a large-volume building. It can be useful for sacral buildings and other large-volume buildings design and for a microclimate shaping. In some large-volume buildings as the sacral buildings with a big number of people staying inside at the same time heat emitted from people significantly influences on a microclimate. Human heat streams can be useful as a part of the heat balance of the room.
基金National Natural Science Foundation of China(52105385)Stable Support Plan Program of Shenzhen Natural Science Fund(20220810132537001)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2022A1515010781)Joint Fund of Henan Province Science and Technology R&D Program(225200810002)Fundamental Research Funds of Henan Academy of Sciences(240621041)。
文摘To enhance the mechanical properties of Mo alloys prepared through laser powder bed fusion(LPBF),a hot isostatic pressing(HIP)treatment was used.Results show that following HIP treatment,the porosity decreases from 0.27%to 0.22%,enabling the elements Mo and Ti to diffuse fully and to distribute more uniformly,and to forming a substantial number of low-angle grain boundaries.The tensile strength soars from 286±32 MPa to 598±22 MPa,while the elongation increases from 0.08%±0.02%to 0.18%±0.02%,without notable alterations in grain morphology during the tensile deformation.HIP treatment eliminates the molten pool boundaries,which are the primary source for premature failure in LPBFed Mo alloys.Consequently,HIP treatment emerges as a novel and effective approach for strengthening the mechanical properties of LPBFed Mo alloys,offering a fresh perspective on producing high-performance Mo-based alloys.
基金support from CAS Project for Young Scientists in Basic Research(YSBR-025)and the Technology Innovation(RCJJ-145-24-39)R.P.Guo acknowledges the financial support from the National Natural Science Foundation of China(No.52401104)+1 种基金the Fundamental Research Program of Shanxi Province(No.202203021221072)the China Postdoctoral Science Foundation(No.2024M753298).
文摘Hot isostatic pressing (HIP) temperature has a significant impact on the service performance of powder metallurgy titanium alloys. In this study, a high-temperature titanium alloy, Ti-6.5Al-3.5Mo-1.5Zr-0.3Si, was prepared under different HIP temperatures (880–1000℃), and the microstructural evolution and mechanical properties were systematically investigated. The results demonstrated that the HIPed alloys were predominantly composed of more than 80 vol.% α phase and a small amount of β phase, and their phase compositions were basically unaffected by the HIP temperatures. Under the typical single-temperature-maintained HIP (STM-HIP) regime, the microstructure of alloy significantly coarsened as the HIP temperature increased, and the alloy strength exhibited an obvious linear negative correlation with the HIP temperature. On the basis of Hall–Petch relation, the prediction model of grain size was established, and the mathematical equation between HIP temperature and grain size (d=M(T_(HIP-N)^(-2))) was deduced. Furthermore, a possible evolution mechanism of microstructure was proposed, which could be divided into the decomposition of initial α′ martensite for as-received powder, formation of the globular α grains in prior particle boundaries (PPBs) region, and precipitation of the platelet α grains in non-PPBs region. For these alloys prepared by the dual-temperature-maintained HIP (DTM-HIP) regime, although their tensile properties were comparable to that of alloy prepared by STM-HIP regime with same high-temperature holding stage, higher proportion of globular α grains occurred due to more recrystallization nucleation during the low-temperature holding stage, which probably provided a solution for improving the dynamic service performance of HIPed alloys.
基金supported by the Key Project of Chinese Academy of Engineering(No.2019-XZ-11)the General Project of Chinese Academy of Engineering(No.2023-XY-18)+1 种基金the Open Fund of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials of China(No.HKDNM201907)the Independent Project of State Key Laboratory of Powder Metallurgy,China。
文摘To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,thereby improving both microstructure uniformity and mechanical properties of sintered bodies.The results indicate that WIP reduces defects in MEX greens,thus decreasing the dimensions and numbers of defects,modifying shapes of pores within sintered bodies,while preserving surface quality and shape characteristics.Compared with WC-9Co prepared via MEX followed by debinding and sintering(DS),the hardness of WC-9Co prepared using MEX-WIP-DS does not change significantly,ranging HV_(30)1494-1508,the transverse rupture strength increases by up to 49.3%,reaching 2998-3514 MPa,and the fracture toughness remains high,ranging 14.8-17.0 MPa·m^(1/2).The mechanical properties surpass comparable cemented carbides fabricated through other AM methods and are comparable to those produced by powder metallurgy.The integration of green WIP into MEX-DS broadens the MEX processing window,and improves the overall mechanical properties of MEX AM WC-Co cemented carbides.
基金National Key Research and Development Project:Clinical Evaluation of the Interventional Techniques for Abdominal Obesity(No.2019YFC1710102)。
文摘OBJECTIVE:To assess the efficacy and safety of the Qingyanyin formulated granules(轻燕饮配方颗粒,QYY),press needles(PN),and their combined application in addressing abdominal obesity(AO).This trial aims to offer a more scientifically grounded therapeutic regimen for clinical interventions.METHODS:From March 2021 to July 2021,a multicenter,triple-blind,randomized 2×2 factorial design clinical trial was conducted across 7 centers in 4 major cities within China's mainland.The trial participants were patients diagnosed with AO.The trial followed a 1∶1∶1∶1 random allocation ratio,assigning participants to one of four groups:QYY placebo plus simulated press needles(SPN)(placebo+SPN),QYY plus SPN(QYY+SPN),QYY placebo plus PN(placebo+PN),and QYY plus PN(QYY+PN).The trial participants received treatment for 12 weeks.Observe the changes in waist circumference,body weight,body mass index(BMI),Beck Depression Inventory(BDI),Beck Anxiety Inventory(BAI)scores,and Pittsburgh Sleep Quality Index(PSQI)before and after treatment.RESULTS:The QYY+PN group exhibited significant improvements in waist circumference compared to placebo+PN[Difference=-1.59,95%CI(-3.03,-0.16)]and placebo+SPN groups[Difference=-2.01,95%CI(-3.46,-0.57)].QYY+PN demonstrated a significant advantage over placebo+SPN[Difference=-2.01,95%CI(-3.46,-0.57)],and no statistically significant interaction was observed between the two interventions(P>0.05).In terms of weight and BMI improvements,the QYY+PN,QYY+SPN,and the PN+placebo groups all experienced trending greater reductions in weight compared to the placebo group.In terms of the total scores of PSQI,BAI,and BDI,all four groups exhibited improvements compared to the baseline.Specifically,concerning the change in total PSQI scores,the QYY+PN group exhibited a greater reduction;Regarding the change in total BAI scores,the PN+placebo group demonstrated a greater decrease;As for the change in total BDI scores,the QYY+SPN group displayed a greater reduction.CONCLUSION:This study confirmed that QYY+PN can effectively reduce the waist circumference of patients with AO.Furthermore,the combined approach offers greater benefits than either treatment alone,all without any reported serious adverse events.
基金financially supported by the National Natural Science Foundation of China(No.52374395)the Natural Science Foundation of Shanxi Province,China(Nos.20210302123135,202303021221143)+5 种基金the Scientific and Technological Achievements Transformation Guidance Special Project of Shanxi Province,China(Nos.202104021301022,202204021301009)the Central Government Guided Local Science and Technology Development Projects,China(No.YDZJSX20231B003)the Ministry of Science and Higher Education of the Russian Federation for financial support under the Megagrant(No.075-15-2022-1133)the National Research Foundation(NRF)grant funded by the Ministry of Science and ICT of Korea through the Research Institute of Advanced Materials(No.2015R1A2A1A01006795)the China Postdoctoral Science Foundation(No.2022M710541)the Research Project supported by Shanxi Scholarship Council of China(No.2022-038)。
文摘To investigate the effect of microstructure evolution on corrosion behavior and strengthening mechanism of Mg-1Zn-1Ca(wt.%)alloys,as-cast Mg-1Zn-1Ca alloys were performed by equal channel angular pressing(ECAP)with 1 and 4 passes.The corrosion behavior and mechanical properties of alloys were investigated by optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),electrochemical tests,immersion tests and tensile tests.The results showed that mechanical properties improved after ECAP 1 pass;however,the corrosion resistance deteriorated due to high-density dislocations and fragmented secondary phases by ECAP.In contrast,synchronous improvement in the mechanical properties and corrosion resistance was achieved though grain refinement after ECAP 4 passes;fine grains led to a significant improvement in the yield strength,ultimate tensile strength,elongation,and corrosion rate of 103 MPa,223 MPa,30.5%,and 1.5843 mm/a,respectively.The enhanced corrosion resistance was attributed to the formation of dense corrosion product films by finer grains and the barrier effect by high-density grain boundaries.These results indicated that Mg-1Zn-1Ca alloy has a promising potential for application in biomedical materials.
基金Major Scientific and Technological Project of Gansu(22ZD6GA008)Excellent Doctorate Project of Gansu(23JRRA806)National Natural Science Foundation of China(52175325,51961024,52071170)。
文摘The microstructure,micro-hardness,and tensile properties of interface between hot isostatic pressing densified low alloy steel and Inconel 690 cladding were investigated during the aging process at 600℃.The results show that the interface region can be divided into four zones from base metal to deposited metal:carbon-depleted zone(CDZ),partial melting zone(PMZ),planar growth zone(PGZ),and brownish feature zone(BFZ).Dimensions of these zones do not significantly change during aging.However,type I carbides noticeably increase in size in the PMZ,and precipitates clearly occur in the PGZ.The main reason for their growth and occurrence is continuous carbon migration.The highest micro-hardness appears in the PGZ and BFZ regions,which is related to carbon accumulation and precipitates in these regions.Tensile failure occurs on the base metal side due to the high strength mismatch between these two materials.The CDZ,composed of only ferrite,has lower strength and fractures at the boundary between CDZ and base metal.The ultimate tensile strength decreases by only 50 MPa after aging for 1500 h,and the interface region maintains high strength without significant deformation.
文摘Find It What did people use years ago to print things?Each year,the world produces millions of pounds of paper.A lot goes into the trash.Recycling means waste can be used again.To recycle paper,you usually need special tools and machines.But what if you could recycle paper by yourself?You could turn used paper into writing paper.
基金supported by the National Key Research&Development Plan(No.2021YFA1600702)the National Natural Science Foundation of China(Nos.92263201,52301155,and 52001161).
文摘In this study,we developed an in-situ hot-pressing sintering(HPS)device that can be coupled to a lab-oratory X-ray microscope,offering laboratory-available observation of the morphology evolution.With the help of this device,in-situ three-dimensional(3D)visualizations of the microstructural evolution of 7055 aluminum alloys during the HPS process were conducted.The 3D results revealed that the twodimensional(2D)methods usually underestimated sintering neck width and exhibited significant standard deviation in statistical analysis.Benefiting from the precise microstructure characterization of the insitu 3D methods,the diffusion activation energy for the sintering of 7055 alloys was calculated,and the quantitative relationship between the sintering temperature and the sintering process was constructed.Moreover,it was experimentally found an accelerative effect of satellite particles on the sintering process,and its mechanisms were discussed.The satellite particles enhanced the curvature near the sintering neck and thus increased the sintering driving stress,promoting the densification process.These findings provide new insights for optimizing sintering processes.
基金supports from the National Natural Science Foundation of China(No.52404382)the Key Research and Development Project of Shaanxi Province(No.2023-YBGY-090).
文摘Pure titanium fabricated by powder metallurgy generally encounters problems including low relative density and low strength,which limits its application performance.This work proposed a multi-step pressing(MSP)technique for developing highstrength pure titanium.The MSP processes of spherical Ti powders of 15–53μm,53–105μm,and 75–180μm were systematically investigated through multi-particle fnite element method(MPFEM)compared with conventional one-step pressing(OSP)technique.The relative density,phase constitution,microstructure,and compressive mechanical properties of the sintered bulk pure titanium were characterized.Simulation results demonstrate that the MSP technique signifcantly increases the relative density of green compacts by 3.2%,3.3%,and 5.2%,respectively,compared with OSP technique.Experimental results indicate the relative density of the sintered specimens prepared by MSP spherical powders increases by 5.4%,4.5%,and 4.5%,respectively,compared to OSP,and the yield strength improves by 16%,13%,and 18%.For the sintered specimens prepared by MSP irregular powder of 15–53μm,the relative density increases by 6.0%and the yield strength increases by 15%.The enhancement of relative density and yield strength is mainly because the MSP technique mitigates stress concentration between powder particles.Compared to spherical powder,irregular powder exhibits stronger mechanical interlocking owing to the greater propensity for displacement and deformation,which facilitates mutual wedging and interlocking,resulting in superior strength performance.
基金supported by the Liaoning Youth Science Foundation Project B Category(Contract No.2025010041-JH6/1010)the National Natural Science Foundation of China(Grant No.52471103).
文摘Press hardening with manganese-boron steels is a prominent manufacturing technique that allows for reduced weight and expense in automotive construction,while providing enhanced crash performance.Nevertheless,the development of a loosely attached oxide layer during press hardening and following additional processing of the layer presents a significant risk to the dimensional precision of the completed product.Here,we develop a new preprocessing approach to address the scale spallation issue by introducing trace amounts of silicate and tungstate into the rinsing solution following pickling.We demonstrate that the pre-deposited membrane promotes the formation of a noticeably thinner,more continuous and stickier oxide scale at high temperatures,enabling the direct application of automobile painting onto the scale.Our research provides an economical remedy to the troublesome scale flaking issue without requiring any modifications to the existing production line,and conveys a thorough comprehension of the mechanism by which the preprocessed membrane resists high-temperature oxidation.
基金supported by the Fundamental Research Funds for the Central Universities(N2107001)the National Natural Science Foundation of China(52001060).
文摘A novel Al-alloyed press-hardening steel(PHS)was developed,which exhibits excellent tensile,bending and antioxidation properties.Al is a ferrite-forming element that can hinder the formation of cementite and enhance the stability of austenite.The incorporation of Al not only induces the formation of ferrite within martensitic matrix but also enhances the stability of retained austenite(RA).The microstructure of novel steel consists of martensite,ferrite,and RA after press hardening.Investigations into the role of Al in RA development were supported by thermo-kinetic calculations.The simultaneous introduction of ferrite and RA into the martensitic matrix via tailored chemical compositions significantly enhances the elongation and bending toughness of the novel PHS.Additionally,Al can form a dense Al oxide at the bottom of oxide layer,resulting in the improved antioxidant properties.Compared to 22MnB5 steel,it is an exciting discovery as there is a significant improvement in total elongation and bending toughness of novel PHS without compromising strength.The novel PHS,with its exceptional balance of strength and ductility,will play a crucial role in reducing weight when it replaces the existing class 22MnB5 PHS in different structural components of vehicle bodies.
