Modelling of migration and accumulation of elements Au and Ag in rocks under temperatures of350-450℃ and a confining pressure of 300 MPa and axial pressure of 100-150 MPa is conducted. It is found thatthe contents of...Modelling of migration and accumulation of elements Au and Ag in rocks under temperatures of350-450℃ and a confining pressure of 300 MPa and axial pressure of 100-150 MPa is conducted. It is found thatthe contents of gold and silver get higher in metallic sulphides such as pyrite, chalcopyrite and sphalerite as well asin quartz and muscovite, and get lower in chlorite, biotite, sericite, albite and calcite, showing that tectono-dynamicsis one of the important factors for petrogenesis and metallogenesis.展开更多
Decreasing the risks and geohazards associated with drilling engineering in high-temperature high-pressure(HTHP) geologic settings begins with the implementation of pre-drilling prediction techniques(PPTs). To improve...Decreasing the risks and geohazards associated with drilling engineering in high-temperature high-pressure(HTHP) geologic settings begins with the implementation of pre-drilling prediction techniques(PPTs). To improve the accuracy of geopressure prediction in HTHP hydrocarbon reservoirs offshore Hainan Island, we made a comprehensive summary of current PPTs to identify existing problems and challenges by analyzing the global distribution of HTHP hydrocarbon reservoirs, the research status of PPTs, and the geologic setting and its HTHP formation mechanism. Our research results indicate that the HTHP formation mechanism in the study area is caused by multiple factors, including rapid loading, diapir intrusions, hydrocarbon generation, and the thermal expansion of pore fluids. Due to this multi-factor interaction, a cloud of HTHP hydrocarbon reservoirs has developed in the Ying-Qiong Basin, but only traditional PPTs have been implemented, based on the assumption of conditions that do not conform to the actual geologic environment, e.g., Bellotti's law and Eaton's law. In this paper, we focus on these issues, identify some challenges and solutions, and call for further PPT research to address the drawbacks of previous works and meet the challenges associated with the deepwater technology gap. In this way, we hope to contribute to the improved accuracy of geopressure prediction prior to drilling and provide support for future HTHP drilling offshore Hainan Island.展开更多
Pyrite tailings are the main cause of acid mine wastewater.We propose an idea to more effectively use pyrite,and it is modified by exploiting the reducibility of metal represented by Al under high-pressure and high-te...Pyrite tailings are the main cause of acid mine wastewater.We propose an idea to more effectively use pyrite,and it is modified by exploiting the reducibility of metal represented by Al under high-pressure and high-temperature(HPHT)conditions.Upon increasing the Al addition,the conductivity of pyrite is effectively improved,which is nearly 734 times higher than that of unmodified pyrite at room temperature.First-principles calculations are used to determine the influence of a high pressure on the pyrite lattice.The high pressure increases the thermal stability of pyrite,reduces pyrite to highconductivity Fe7S8(pyrrhotite)by Al.Through hardness and density tests the influence of Al addition on the hardness and toughness of samples is explored.Finally we discuss the possibility of using other metal-reducing agents to improve the properties of pyrite.展开更多
The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus ar...The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus are reported in this paper.The reactions are proposed to simulate the interactions between melts from the asthenospheric mantle and the lithospheric mantle.The starting melt in the experiments was made from the alkaline basalt occurring in Fuxin,Liaoning Province,and the orthopyroxenes were separated from the mantle xenoliths in Damaping,Hebei Province.The results show that clinopyroxenes were formed in all the reactions between the alkaline basaltic melt and orthopyroxenes under the studied P–T conditions.The formation of clinopyroxene in the reaction zone is mainly controlled by dissolution–crystallization,and the chemical compositions of the reacted melt are primarily infl uenced by the diff usion eff ect.Temperature is the most important parameter controlling the reactions between the melt and orthopyroxenes,which has a direct impact on the melting of orthopyroxenes and the diff usion of chemical components in the melt.Temperature also directly controls the chemical compositions of the newly formed clinopyroxenes in the reaction zone and the reacted melt.The formation of clinopyroxenes from the reactions between the alkaline basaltic melt and orthopyroxenes can result in an increase of CaO and Al_(2)O_(3) contents in the rocks containing this mineral.Therefore,the reactions between the alkaline basaltic melt from the asthenospheric mantle and orthopyroxenes from the lithospheric mantle can lead to the evolution of lithospheric mantle in the North China Craton from refractory to fertile with relatively high CaO and Al 2 O 3 contents.In addition,the reacted melts in some runs were transformed from the starting alkaline basaltic into tholeiitic after reactions,indicating that tholeiitic magma could be generated from alkaline basaltic one via reactions between the latter and orthopyroxene.展开更多
CO_(2) drilling is a promising underbalance drilling technology with great advantages,such as lower cutting force,intense cooling and excellent lubrication.However,in the underbalance drilling,the mechanism of the cou...CO_(2) drilling is a promising underbalance drilling technology with great advantages,such as lower cutting force,intense cooling and excellent lubrication.However,in the underbalance drilling,the mechanism of the coupling CO_(2) jet and polycrystalline-diamond-compact(PDC)cutter are still unclear.Whereby,we established a coupled smoothed particle hydrodynamics/finite element method(SPH/FEM)model to simulate the composite rock-breaking of high-pressure CO_(2) jet&PDC cutter.Combined with the experimental research results,the mechanism of composite rock-breaking is studied from the perspectives of rock stress field,cutting force and jet field.The results show that the composite rock-breaking can effectively relieve the influence of vibration and shock on PDC cutter.Meanwhile,the high-pressure CO_(2) jet has a positive effect on carrying rock debris,which can effectively reduce the temperature rising and the thermal wear of the PDC cutter.In addition,the effects of CO_(2) jet parameters on composite rock-breaking were studied,such as jet impact velocity,nozzle diameter,jet injection angle and impact distance.The studies show that when the impact velocity of the CO_(2) jet is greater than 250 m/s,the CO_(2) jet could quickly break the rock.It is found that the optimal range of nozzle diameter is 1.5–2.5 mm,the best injection angle of CO_(2) jet is 60,the optimal impact distance is 10 times the nozzle diameter.The above studies could provide theoretical supports and technical guidance for composite rock-breaking,which is useful for the CO_(2) underbalance drilling and drill bit design.展开更多
A new structural phase of MgV2O6 was obtained by a high-pressure,high-temperature(HPHT) synthesis method.The new phase was investigated by the Rietveld analysis of X-ray powder diffraction data,showing space group Pbc...A new structural phase of MgV2O6 was obtained by a high-pressure,high-temperature(HPHT) synthesis method.The new phase was investigated by the Rietveld analysis of X-ray powder diffraction data,showing space group Pbcn(No.60) symmetry and a = 13.6113(6) (1 = 0.1 nm),b = 5.5809(1) ,c = 4.8566(3) ,V = 368.93(2) 3(Z = 4).High pressure behavior was studied by Raman spectroscopy at room temperature.Under 22.5 GPa,there was no sign of a structural phase transition in the spectra,demonstrating stability of the HPHT phase up to the highest pressure.展开更多
The solubility of Au in silicate melts and fluids governs the enrichment and migration of Au during the formation of magmatic-hydrothermal Au deposits.Large Au deposits require vast amounts of Au to migrate from the u...The solubility of Au in silicate melts and fluids governs the enrichment and migration of Au during the formation of magmatic-hydrothermal Au deposits.Large Au deposits require vast amounts of Au to migrate from the upper mantle-lower crust to the shallow crust,and high Au solubility in magma and hydrothermal fluid facilitates the formation of Au-rich magma and fluid in the crust and mantle source and efficient transport.This paper reviews recent high-pressure and high-temperature experimental studies on Au species in magmas and hydrothermal fluids,the partitioning behavior of Au between silicate melts and fluids,and the effects of temperature,pressure,oxygen fugacity,sulfur fugacity,silicate melt composition,and volatiles(H2O,CO2,chlorine,and sulfur)on the solubility of Au in magma.We show that the solubility of Au in magma is largely controlled by the volatiles in the magma:the higher the content of reduced sulfur(S2-and HS-)in the magma,the higher the solubility of Au.Under high-temperature,high-pressure,H2O-rich,and intermediate oxygen fugacity conditions,magma can dissolve more reduced sulfur species,thus enhancing the ability of the magma to transport Au.If the ore-forming elements of the Au deposits in the North China Craton originate from mantle-derived magmas and fluids,we can conclude,in terms of massive Au migration,that these deep Au-rich magmas might have been generated under H2 O-rich and moderately oxidized conditions(S2-coexists with S6+).The big mantle wedge beneath East Asia was metasomatized by melts and fluids from the dehydration of the Early Cretaceous paleo-Pacific stagnant slab,which not only caused thinning of the North China Craton,but also created physicochemical conditions favorable for massive Au migration.展开更多
The pure-silica hollow-core fiber(HCF) has excellent thermostabilities that can benefit a lot of high-temperature sensing applications.The air-core microstructure of the HCF provides an inherent gas container, which c...The pure-silica hollow-core fiber(HCF) has excellent thermostabilities that can benefit a lot of high-temperature sensing applications.The air-core microstructure of the HCF provides an inherent gas container, which can be a good candidate for gas or gas pressure sensing.This paper reviews our continuous efforts to design, fabricate, and characterize the hightemperature and high-pressure sensors with HCFs, aiming at improving the sensing performances such as dynamic range,sensitivity, and linearity.With the breakthrough advances in novel anti-resonant HCFs, sensing of high temperature and high pressure with HCFs will continuously progress and find increasing applications.展开更多
Due to the important scientific significance of the interaction between alkaline feldspar and high-temperature and high-pressure fluids. We have conducted a series of autoclave experiments of feldspar dissolution and ...Due to the important scientific significance of the interaction between alkaline feldspar and high-temperature and high-pressure fluids. We have conducted a series of autoclave experiments of feldspar dissolution and secondary mineral precipitation in conditions of 250–500℃, 8-50 MPa, and pH = 3.0 and 5.5. Based on the interaction experiments between alkaline feldspar and fluid of high-temperatures and high-pressures, we get the main results as follows:(1) The law that people have grasped below the critical point about the influence of temperature, pressure, and pH value on the alkaline feldspar dissolution behavior is still held above the critical point.(2) Due to the experimental techniques of autoclave flip 180°—sharp quenching and based on electron microprobe analysis of mineral new formed, theoretical analysis has determined that the new altered minerals distributed on the island dissolution surface of feldspar are products of precipitation on a feldspar surface after saturation of the relative ion concentration in water fluid.展开更多
In order to constrain the crustal wave velocity structure in the southern Tibetan crust and provide insight into the contribution of crustal composition, geothermal gradient and partial melting to the velocity structu...In order to constrain the crustal wave velocity structure in the southern Tibetan crust and provide insight into the contribution of crustal composition, geothermal gradient and partial melting to the velocity structure, which is characterized by low average crustal velocities and widespread presence of low-velocity zone(s), the authors model the crustal velocity and density as functions of depth corresponding to various heat flow values in light of velocity measurements at high temperature and high pressure. The modeled velocity and density are regarded as comparison standards. The comparison of the standards with seismic observations in southern Tibet implies that the predominantly felsic composition at high heat flow cannot explain the observed velocity structure there. Hence, the authors are in favor of attributing low average crustal velocities and low-velocity zone(s) observed in southern Tibet mainly to partial melting. Modeling based on the experimental results suggests that a melting percentage of 7-12 could account for the low-velocity zone(s).展开更多
From the perspective of high-temperature applications,materials with excellent high-temperature mechanical properties are always desirable.The present work demonstrates that the binder-free nanopolycrystalline WC cera...From the perspective of high-temperature applications,materials with excellent high-temperature mechanical properties are always desirable.The present work demonstrates that the binder-free nanopolycrystalline WC ceramic with an average grain size of 103 nm obtained by high-pressure and hightemperature sintering exhibits excellent mechanical properties at both room temperature and high temperature up to 1000℃.Specifically,the binder-free nanopolycrystalline WC ceramic still maintains a considerably high Vicker hardness H_(V)of 23.4 GPa at 1000℃,which is only 22%lower than the room temperature H_(V).This outstanding thermo-mechanical stability is superior to that of typical technical ceramics,e.g.SiC,Si_(3)N_(4),Al_(2)O_(3),etc.Nanocrystalline grains with many dislocations,numerous low-energy,highly stableΣ2 grain boundaries,and a relatively low thermal expansion coefficient,are responsible for the observed outstanding high-temperature mechanical properties.展开更多
The compressional sound velocity VP for enstatite of polycrystalline specimens were measured at pressures from 40 to 140 GPa using the optical analytical techniques under shock loading. The dependence of VP (in km/s) ...The compressional sound velocity VP for enstatite of polycrystalline specimens were measured at pressures from 40 to 140 GPa using the optical analytical techniques under shock loading. The dependence of VP (in km/s) on Hugoniot pressure (P, in GPa) can be described by lnVP= 3.079-0.691 ln(P) + 0.094(lnP)2. VP satisfies Birch’s law: VP= 4.068 + 1.677p, where p is corresponding density, which indicated that enstatite is stable throughout the conditions of the lower mantle. The wave velocity P is 0.5% lower and the wave velocity S is 2% higher than that of PREM respectively. We concluded that the lower mantle is mainly composed of perovskite-(Mg1-x, Fex) SiO3 and only a small amount of (Mg1-x, Fex) O is allowed in it.展开更多
The thermal equation of state of a natural kyanite has been investigated with a DIA-type,cubic-anvil apparatus(SAM85)combined with an energy-dispersive synchrotron X-ray radiation technique up to 8.55 GPa and 1273 K.N...The thermal equation of state of a natural kyanite has been investigated with a DIA-type,cubic-anvil apparatus(SAM85)combined with an energy-dispersive synchrotron X-ray radiation technique up to 8.55 GPa and 1273 K.No phase transition was observed in the studied pressure-temperature(P-T)range.The Le Bail full profile refinement technique was used to derive the unit-cell parameters.By fixing the bulk modulus K 0 as 196 GPa and its pressure derivative K0 as 4,our P-V(volume)-T data were fitted to the high temperature BircheMurnaghan equation of state.The obtained parameters for the kyanite are:V_(0)=294.05(9)Å^(3),a=2.53(11)×10^(-5)K^(-1) and(K/T)P=-0.021(8)GPa∙K^(-1).These parameters have been combined with other experimentally-measured thermodynamic data for the relevant phases to calculate the P-T locus of the reaction kyanite¼stishoviteþcorundum.With this thermodynamically constrained phase boundary,previous high-pressure phase equi-librium experimental studies with the multi-anvil press have been evaluated.展开更多
The core-mantle differentiation process is one of the most significant events in the Earth’s early history,which profoundly affects the Earth’s internal structure.According to the simple core-mantle differentiation ...The core-mantle differentiation process is one of the most significant events in the Earth’s early history,which profoundly affects the Earth’s internal structure.According to the simple core-mantle differentiation mechanism,elements such as iron and nickel should be extracted from silicate to form an iron-rich proto-core,and the residual silicate materials form the proto-mantle.However,the composition of the lower mantle and the core remains controversial,which largely affects the partition of elements,thus the referred differentiation process of the Earth.In recent years,many experimental studies on the partition coefficient of siderophile elements between metal and silicate under high-temperature and high-pressure conditions have put forward new ideas on the issues around Earth’s core-mantle differentiation.Meanwhile,some researchers suggested that the redox state of the Earth’s mantle changes during its formation and evolution,and many isotope geochemistry studies support that some enstatite chondrites have a common nebular precursor as the Earth.These new studies bring dispute on the Earth’s building materials,which dominates the core-mantle differentiation process and largely affects the partitioning behaviors of elements during the core-mantle differentiation.This chapter aims to review recent experimental studies on the siderophile element geochemistry and discussions on the Earth’s building blocks.展开更多
Epidote is a typical hydrous mineral in subduction zones.Here,we report a synchrotron-based single-crystal X-ray diffraction(XRD)study of natural epidote[Ca1.97Al2.15Fe0.84(SiO4)(Si2O7)O(OH)]under simultaneously high ...Epidote is a typical hydrous mineral in subduction zones.Here,we report a synchrotron-based single-crystal X-ray diffraction(XRD)study of natural epidote[Ca1.97Al2.15Fe0.84(SiO4)(Si2O7)O(OH)]under simultaneously high pressure-temperature(high P-T)conditions to~17.7 GPa and 700 K.No phase transition occurs over this P-T range.Using the third-order Birch-Murnaghan equation of state(EoS),we fitted the pressure-volume-temperature(P-V-T)data and obtained the zero-pressure bulk modulus K_(0)=138(2)GPa,its pressure derivative K'_(0)=3.0(3),the temperature derivative of the bulk modulus((∂K/∂T)P=-0.004(1)GPa/K),and the thermal expansion coefficient at 300 K(α_(0)=3.8(5)×10^(-5)K^(-1)),as the zero-pressure unit-cell volume V_(0)was fixed at 465.2(2)Å^(3)(obtained by a single-crystal XRD experiment at ambient conditions).This study reveals that the bulk moduli of epidote show nonlinear compositional dependence.By discussing the stabilization of epidote and comparing its density with those of other hydrous minerals,we find that epidote,as a significant water transporter in subduction zones,may maintain a metastable state to~14 GPa along the coldest subducting slab geotherm and promote slab subduction into the upper mantle while favoring slab stagnation above the 410 km discontinuity.Furthermore,the water released from epidote near 410 km may potentially affect the properties of the 410 km seismic discontinuity.展开更多
The double perovskite Ca2CrSbO6 exhibits a ferromagnetic long-range order below Tc=13 K and a saturation magnetization of 2.35µB at 2 K.In this study,the polycrystalline Ca2CrSbO6 is synthesized under high pressu...The double perovskite Ca2CrSbO6 exhibits a ferromagnetic long-range order below Tc=13 K and a saturation magnetization of 2.35µB at 2 K.In this study,the polycrystalline Ca2CrSbO6 is synthesized under high pressure and high temperature,and the critical behavior of the ferromagnetic material as well as the effects of the magnetic behavior due to the isovalent substitution of Sr2+for Ca2+is investigated.Also studied are the ferromagnetic criticality of the double perovskite Ca2CrSbO6 at the ferromagnetic transition temperature Tc≈12.6 K from the isotherms of magnetization M(H)via an iteration process and the Kouvel–Fisher method.The critical exponents associated with the transition are determined as follows:β=0.322,γ=1.241,andδ=4.84.The magnetization data in the vicinity of Tc can be scaled into two universal curves in the plot of M/|ε|βversus H/|ε|β+γ,whereε=T/Tc−1.The obtainedβandγvalues are consistent with the predicted values from a three-dimensional Ising model.The effects of Sr substitution on the double perovskite Ca2CrSbO6 are taken into consideration.As the Sr content increases,the(Ca2−xSrx)CrSbO6 polycrystal shows a continuous switch from ferromagnetic to antiferromagnetic behavior.展开更多
Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fu...Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fusion reactor.Today the more innovative version of this apparatus that is known as an ITER(international thermonuclear experimental reactor)shows a way toward MCF(magnetic confinement fusion)of hot plasma goal by satisfying Lawson’s Criteria to some degree of achievement.However,since this fusion driven reactor of hot plasma needs to operate at almost 150 million Celsius,the internal material of this reactor is a matter of concern for scientists that are involved with its fabrication.Uniqueness of nanomaterials from the point of view of physical and chemical properties is suggested as a possible potential application for this special and innovative reactor for a nuclear fusion device.Convergence of nanotechnology in study of new generation of materials of this kind can shape the path for various technological developments and a large variety of disciplines,including MCF driven plasma of hot fusion as well.This short TM(technical memorandum)written by these two authors will cover this aspect of technology in a holistic way and the more granular level is left to the reader of this TM to investigate further.展开更多
Here we present an insight into the genesis of Himalayan granulitic lower crust based on the experimental studies on the dehydration melting of natural biotite-plagioclase gneiss performed at the temperatures of 770-9...Here we present an insight into the genesis of Himalayan granulitic lower crust based on the experimental studies on the dehydration melting of natural biotite-plagioclase gneiss performed at the temperatures of 770-980°C and the pressures of 1.0-1.4 GPa. The experiments produce peraluminous granitic melt and residual phase assemblage (Pl+Qz+Gat+Bio+Opx±Cpx+Ilm/Rut±Kfs). The residual mineral assemblage is similar to those of granu-lites observed at the eastern and western Himalayan syntax-ises, and the chemical compositions of characteristic minerals-garnet and pyroxene in the residual phase and the granu-lite are identical. Additionally, the modeled wave velocities of the residual phase assemblage are comparable well with those of the top part of lower crust beneath Himalayas. Hence, we suggest that (1) the top part of lower crust beneath Himalayas is probably made up of garnet-bearing intermediate granulite; (2) the formations of granulite and leucogranites in Himalayas are interrelated as the展开更多
It is generally accepted that carbonates can be subducted to the mantle depths,where they are reduced with iron metal to produce a diamond.In this work,we found that this is not always the case.The mantle carbonates f...It is generally accepted that carbonates can be subducted to the mantle depths,where they are reduced with iron metal to produce a diamond.In this work,we found that this is not always the case.The mantle carbonates from inclusions in diamonds show a wide range of cation compositions(Mg,Fe,Ca,Na,and K).Here we studied the reaction kinetics of these carbonates with iron metal at 6-6.5 GPa and 1000-1500℃.We found that the reduction of carbonate with Fe produces C-bearing species(Fe,Fe-C melt,Fe_(3)C,F e_(7)C_(3),C)and wüistite containing Na_(2)O,CaO,and MgO.The reaction rate constants(k=△x^(2)/2t)are log-linear relative to 1/T and their temperature dependences are determined to be k_(MgcO_(3))(m^(2)/s)=4.37×10^(-3)exp[-251(kJ/mol)/RT]k_(caMg(CO_(3))2)(m^(2)/s)=1.48×10^(-3)exp[-264(kJ/mol)/RT]k_(cacO_(3))(m^(2)/s)=3.06×10^(-5)exp[-245(kJ/mol)/RT]and k_(Na_(2)cO_(3))(m^(2)/s)=1.88×10^(-10)exp[-155(kJ/mol)/RT].According to obtained results at least,45-70 vol%of carbonates preserve during subduction down to the 660-km discontinuity if no melting occurs.The slab stagnation and warming,subsequent carbonate melting,and infiltration into the mantle saturated with iron metal are accompanied by a reduction of carbonate melt with Fe.The established sequence of reactivity of carbonates:FeCO_(3)≥MgCO_(3)>CaMg(CO_(3))2>CaCO_(3)>>Na_(2)CO_(3),where K_(2)CO_(3)does not react at all with iron metal,implies that during reduction carbonate melt with Fe evolves toward alkali-rich.The above conclusions are consistent with the findings of carbonates in inclusions in diamonds from the lower mantle and high concentrations of alkalis,particularly K,in mantle carbonatite melts entrapped by diamonds from kimberlites and placers worldwide.展开更多
Based on the results of melting experiments on the whole rock of chondrite, the differentiation mechanism of the core, the mantle and the crust of the early Earth was discussed in Ref. [1]. In order to investigate the...Based on the results of melting experiments on the whole rock of chondrite, the differentiation mechanism of the core, the mantle and the crust of the early Earth was discussed in Ref. [1]. In order to investigate the geochemical behaviour of metal-sulfide in the melting-process of the original Earth matter and the formation of the core, further melting experiments were carried out on metal-rich phase of Jilin chondrite under high pressure.展开更多
文摘Modelling of migration and accumulation of elements Au and Ag in rocks under temperatures of350-450℃ and a confining pressure of 300 MPa and axial pressure of 100-150 MPa is conducted. It is found thatthe contents of gold and silver get higher in metallic sulphides such as pyrite, chalcopyrite and sphalerite as well asin quartz and muscovite, and get lower in chlorite, biotite, sericite, albite and calcite, showing that tectono-dynamicsis one of the important factors for petrogenesis and metallogenesis.
基金funded by the National Basic Research Program of China (No. 2015CB251201)the NSFC-Shandong Joint Fund for Marine Science Research Centers (No. U1606401)+3 种基金the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology (No. 2016ASKJ13)the Major National Science and Technology Programs (No. 016ZX05024-001-002)the Natural Science Foundation of Hainan (No. ZDYF2016215)Key Science and Technology Foundation of Sanya (Nos. 2017PT13, 2017PT2014)
文摘Decreasing the risks and geohazards associated with drilling engineering in high-temperature high-pressure(HTHP) geologic settings begins with the implementation of pre-drilling prediction techniques(PPTs). To improve the accuracy of geopressure prediction in HTHP hydrocarbon reservoirs offshore Hainan Island, we made a comprehensive summary of current PPTs to identify existing problems and challenges by analyzing the global distribution of HTHP hydrocarbon reservoirs, the research status of PPTs, and the geologic setting and its HTHP formation mechanism. Our research results indicate that the HTHP formation mechanism in the study area is caused by multiple factors, including rapid loading, diapir intrusions, hydrocarbon generation, and the thermal expansion of pore fluids. Due to this multi-factor interaction, a cloud of HTHP hydrocarbon reservoirs has developed in the Ying-Qiong Basin, but only traditional PPTs have been implemented, based on the assumption of conditions that do not conform to the actual geologic environment, e.g., Bellotti's law and Eaton's law. In this paper, we focus on these issues, identify some challenges and solutions, and call for further PPT research to address the drawbacks of previous works and meet the challenges associated with the deepwater technology gap. In this way, we hope to contribute to the improved accuracy of geopressure prediction prior to drilling and provide support for future HTHP drilling offshore Hainan Island.
基金supported by the National Natural Science Foundation of China(Grant No.51171070)the Project of Jilin Science and Technology Development Plan(Grant No.20170101045JC)+1 种基金the Natural Science Foundation of Chongqing,China(Grant No.cstc2019jcyj-msxmX0391)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN201901405)。
文摘Pyrite tailings are the main cause of acid mine wastewater.We propose an idea to more effectively use pyrite,and it is modified by exploiting the reducibility of metal represented by Al under high-pressure and high-temperature(HPHT)conditions.Upon increasing the Al addition,the conductivity of pyrite is effectively improved,which is nearly 734 times higher than that of unmodified pyrite at room temperature.First-principles calculations are used to determine the influence of a high pressure on the pyrite lattice.The high pressure increases the thermal stability of pyrite,reduces pyrite to highconductivity Fe7S8(pyrrhotite)by Al.Through hardness and density tests the influence of Al addition on the hardness and toughness of samples is explored.Finally we discuss the possibility of using other metal-reducing agents to improve the properties of pyrite.
基金supported by the National Natural Science Foundation of China(Nos.41472065 and 42073059).
文摘The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus are reported in this paper.The reactions are proposed to simulate the interactions between melts from the asthenospheric mantle and the lithospheric mantle.The starting melt in the experiments was made from the alkaline basalt occurring in Fuxin,Liaoning Province,and the orthopyroxenes were separated from the mantle xenoliths in Damaping,Hebei Province.The results show that clinopyroxenes were formed in all the reactions between the alkaline basaltic melt and orthopyroxenes under the studied P–T conditions.The formation of clinopyroxene in the reaction zone is mainly controlled by dissolution–crystallization,and the chemical compositions of the reacted melt are primarily infl uenced by the diff usion eff ect.Temperature is the most important parameter controlling the reactions between the melt and orthopyroxenes,which has a direct impact on the melting of orthopyroxenes and the diff usion of chemical components in the melt.Temperature also directly controls the chemical compositions of the newly formed clinopyroxenes in the reaction zone and the reacted melt.The formation of clinopyroxenes from the reactions between the alkaline basaltic melt and orthopyroxenes can result in an increase of CaO and Al_(2)O_(3) contents in the rocks containing this mineral.Therefore,the reactions between the alkaline basaltic melt from the asthenospheric mantle and orthopyroxenes from the lithospheric mantle can lead to the evolution of lithospheric mantle in the North China Craton from refractory to fertile with relatively high CaO and Al 2 O 3 contents.In addition,the reacted melts in some runs were transformed from the starting alkaline basaltic into tholeiitic after reactions,indicating that tholeiitic magma could be generated from alkaline basaltic one via reactions between the latter and orthopyroxene.
基金This work was supported by the National Natural Science Foundation of China(No.52004236)Sichuan Science and Technology Program(No.2021JDRC0114)+4 种基金the Starting Project of Southwest Petroleum University(No.2019QHZ009)the China Postdoctoral Science Foundation(No.2020M673285)the Open Project Program of Key Laboratory of Groundwater Resources and Environment(Jilin University)Ministry of Education(No.202005009KF)the Chinese Scholarship Council(CSC)funding(No.202008515107).
文摘CO_(2) drilling is a promising underbalance drilling technology with great advantages,such as lower cutting force,intense cooling and excellent lubrication.However,in the underbalance drilling,the mechanism of the coupling CO_(2) jet and polycrystalline-diamond-compact(PDC)cutter are still unclear.Whereby,we established a coupled smoothed particle hydrodynamics/finite element method(SPH/FEM)model to simulate the composite rock-breaking of high-pressure CO_(2) jet&PDC cutter.Combined with the experimental research results,the mechanism of composite rock-breaking is studied from the perspectives of rock stress field,cutting force and jet field.The results show that the composite rock-breaking can effectively relieve the influence of vibration and shock on PDC cutter.Meanwhile,the high-pressure CO_(2) jet has a positive effect on carrying rock debris,which can effectively reduce the temperature rising and the thermal wear of the PDC cutter.In addition,the effects of CO_(2) jet parameters on composite rock-breaking were studied,such as jet impact velocity,nozzle diameter,jet injection angle and impact distance.The studies show that when the impact velocity of the CO_(2) jet is greater than 250 m/s,the CO_(2) jet could quickly break the rock.It is found that the optimal range of nozzle diameter is 1.5–2.5 mm,the best injection angle of CO_(2) jet is 60,the optimal impact distance is 10 times the nozzle diameter.The above studies could provide theoretical supports and technical guidance for composite rock-breaking,which is useful for the CO_(2) underbalance drilling and drill bit design.
基金supported by the National Natural Science Foundation of China (Grant No. 51172091)the Program for New Century Excellent Talents in University
文摘A new structural phase of MgV2O6 was obtained by a high-pressure,high-temperature(HPHT) synthesis method.The new phase was investigated by the Rietveld analysis of X-ray powder diffraction data,showing space group Pbcn(No.60) symmetry and a = 13.6113(6) (1 = 0.1 nm),b = 5.5809(1) ,c = 4.8566(3) ,V = 368.93(2) 3(Z = 4).High pressure behavior was studied by Raman spectroscopy at room temperature.Under 22.5 GPa,there was no sign of a structural phase transition in the spectra,demonstrating stability of the HPHT phase up to the highest pressure.
基金Project of China(Grant No.2016YFC0600104),the National Natural Science Foundation of China(Grant No.41573053)the Youth Innovation Promotion Association CAS(Grant No.2019344)。
文摘The solubility of Au in silicate melts and fluids governs the enrichment and migration of Au during the formation of magmatic-hydrothermal Au deposits.Large Au deposits require vast amounts of Au to migrate from the upper mantle-lower crust to the shallow crust,and high Au solubility in magma and hydrothermal fluid facilitates the formation of Au-rich magma and fluid in the crust and mantle source and efficient transport.This paper reviews recent high-pressure and high-temperature experimental studies on Au species in magmas and hydrothermal fluids,the partitioning behavior of Au between silicate melts and fluids,and the effects of temperature,pressure,oxygen fugacity,sulfur fugacity,silicate melt composition,and volatiles(H2O,CO2,chlorine,and sulfur)on the solubility of Au in magma.We show that the solubility of Au in magma is largely controlled by the volatiles in the magma:the higher the content of reduced sulfur(S2-and HS-)in the magma,the higher the solubility of Au.Under high-temperature,high-pressure,H2O-rich,and intermediate oxygen fugacity conditions,magma can dissolve more reduced sulfur species,thus enhancing the ability of the magma to transport Au.If the ore-forming elements of the Au deposits in the North China Craton originate from mantle-derived magmas and fluids,we can conclude,in terms of massive Au migration,that these deep Au-rich magmas might have been generated under H2 O-rich and moderately oxidized conditions(S2-coexists with S6+).The big mantle wedge beneath East Asia was metasomatized by melts and fluids from the dehydration of the Early Cretaceous paleo-Pacific stagnant slab,which not only caused thinning of the North China Craton,but also created physicochemical conditions favorable for massive Au migration.
基金supported by the National Natural Science Foundation of China (NSFC)(Nos.61875128 and 61635007)China Postdoctoral Science Foundation (No.2020M683184)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2021B1515020030)Department of Science and Technology of Guangdong Province (No.2019TQ05X113)Shenzhen Science and Technology Program(No.RCYX20200714114538160)。
文摘The pure-silica hollow-core fiber(HCF) has excellent thermostabilities that can benefit a lot of high-temperature sensing applications.The air-core microstructure of the HCF provides an inherent gas container, which can be a good candidate for gas or gas pressure sensing.This paper reviews our continuous efforts to design, fabricate, and characterize the hightemperature and high-pressure sensors with HCFs, aiming at improving the sensing performances such as dynamic range,sensitivity, and linearity.With the breakthrough advances in novel anti-resonant HCFs, sensing of high temperature and high pressure with HCFs will continuously progress and find increasing applications.
基金financed by the Fund from the Ministry of Science and Technology of People’s Republic of China under the grant number XDB18000000Major State Research Development Program of China under Grant Nos.2016YFC0601101 and 2016YFC0600109
文摘Due to the important scientific significance of the interaction between alkaline feldspar and high-temperature and high-pressure fluids. We have conducted a series of autoclave experiments of feldspar dissolution and secondary mineral precipitation in conditions of 250–500℃, 8-50 MPa, and pH = 3.0 and 5.5. Based on the interaction experiments between alkaline feldspar and fluid of high-temperatures and high-pressures, we get the main results as follows:(1) The law that people have grasped below the critical point about the influence of temperature, pressure, and pH value on the alkaline feldspar dissolution behavior is still held above the critical point.(2) Due to the experimental techniques of autoclave flip 180°—sharp quenching and based on electron microprobe analysis of mineral new formed, theoretical analysis has determined that the new altered minerals distributed on the island dissolution surface of feldspar are products of precipitation on a feldspar surface after saturation of the relative ion concentration in water fluid.
基金supported by the Key Basic Research and Development Program of China(G19980407000)the National Natural Science Foundation of China(40072062)+1 种基金the Foundation of the Open Laboratory of Tectonophysics,China Seismological Bureauthe Post-Doctoral Grant of Ministry of Education,China.
文摘In order to constrain the crustal wave velocity structure in the southern Tibetan crust and provide insight into the contribution of crustal composition, geothermal gradient and partial melting to the velocity structure, which is characterized by low average crustal velocities and widespread presence of low-velocity zone(s), the authors model the crustal velocity and density as functions of depth corresponding to various heat flow values in light of velocity measurements at high temperature and high pressure. The modeled velocity and density are regarded as comparison standards. The comparison of the standards with seismic observations in southern Tibet implies that the predominantly felsic composition at high heat flow cannot explain the observed velocity structure there. Hence, the authors are in favor of attributing low average crustal velocities and low-velocity zone(s) observed in southern Tibet mainly to partial melting. Modeling based on the experimental results suggests that a melting percentage of 7-12 could account for the low-velocity zone(s).
基金supported by the National Key R&D Program of China(Grant No.2018YFA0305900)the Natural Science Basic Research Program of Shaanxi Province(Grant No.2020JQ870)+2 种基金the National Natural Science Foundation of China(Nos.52090020,U20A20238,51772260,91963203,51525205)NSF for Distinguished Young Scholars of Hebei Province of China(E2018203349)the China Postdoctoral Science Foundation(2017M620097)。
文摘From the perspective of high-temperature applications,materials with excellent high-temperature mechanical properties are always desirable.The present work demonstrates that the binder-free nanopolycrystalline WC ceramic with an average grain size of 103 nm obtained by high-pressure and hightemperature sintering exhibits excellent mechanical properties at both room temperature and high temperature up to 1000℃.Specifically,the binder-free nanopolycrystalline WC ceramic still maintains a considerably high Vicker hardness H_(V)of 23.4 GPa at 1000℃,which is only 22%lower than the room temperature H_(V).This outstanding thermo-mechanical stability is superior to that of typical technical ceramics,e.g.SiC,Si_(3)N_(4),Al_(2)O_(3),etc.Nanocrystalline grains with many dislocations,numerous low-energy,highly stableΣ2 grain boundaries,and a relatively low thermal expansion coefficient,are responsible for the observed outstanding high-temperature mechanical properties.
文摘The compressional sound velocity VP for enstatite of polycrystalline specimens were measured at pressures from 40 to 140 GPa using the optical analytical techniques under shock loading. The dependence of VP (in km/s) on Hugoniot pressure (P, in GPa) can be described by lnVP= 3.079-0.691 ln(P) + 0.094(lnP)2. VP satisfies Birch’s law: VP= 4.068 + 1.677p, where p is corresponding density, which indicated that enstatite is stable throughout the conditions of the lower mantle. The wave velocity P is 0.5% lower and the wave velocity S is 2% higher than that of PREM respectively. We concluded that the lower mantle is mainly composed of perovskite-(Mg1-x, Fex) SiO3 and only a small amount of (Mg1-x, Fex) O is allowed in it.
基金This work is financially supported by the Natural Science Foundation of China(Grant No.41273072)by the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB18030602).
文摘The thermal equation of state of a natural kyanite has been investigated with a DIA-type,cubic-anvil apparatus(SAM85)combined with an energy-dispersive synchrotron X-ray radiation technique up to 8.55 GPa and 1273 K.No phase transition was observed in the studied pressure-temperature(P-T)range.The Le Bail full profile refinement technique was used to derive the unit-cell parameters.By fixing the bulk modulus K 0 as 196 GPa and its pressure derivative K0 as 4,our P-V(volume)-T data were fitted to the high temperature BircheMurnaghan equation of state.The obtained parameters for the kyanite are:V_(0)=294.05(9)Å^(3),a=2.53(11)×10^(-5)K^(-1) and(K/T)P=-0.021(8)GPa∙K^(-1).These parameters have been combined with other experimentally-measured thermodynamic data for the relevant phases to calculate the P-T locus of the reaction kyanite¼stishoviteþcorundum.With this thermodynamically constrained phase boundary,previous high-pressure phase equi-librium experimental studies with the multi-anvil press have been evaluated.
基金financially supported by the National Natural Science Foundation of China(NSFC Nos.41773052 and 41973058)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB 41000000)+1 种基金the key research program of frontier sciences of Chinese Academy of Sciences(ZDBS-SSWJSC007-10)preresearch project on Civil Aerospace Technologies by CNSA(D020201)。
文摘The core-mantle differentiation process is one of the most significant events in the Earth’s early history,which profoundly affects the Earth’s internal structure.According to the simple core-mantle differentiation mechanism,elements such as iron and nickel should be extracted from silicate to form an iron-rich proto-core,and the residual silicate materials form the proto-mantle.However,the composition of the lower mantle and the core remains controversial,which largely affects the partition of elements,thus the referred differentiation process of the Earth.In recent years,many experimental studies on the partition coefficient of siderophile elements between metal and silicate under high-temperature and high-pressure conditions have put forward new ideas on the issues around Earth’s core-mantle differentiation.Meanwhile,some researchers suggested that the redox state of the Earth’s mantle changes during its formation and evolution,and many isotope geochemistry studies support that some enstatite chondrites have a common nebular precursor as the Earth.These new studies bring dispute on the Earth’s building materials,which dominates the core-mantle differentiation process and largely affects the partitioning behaviors of elements during the core-mantle differentiation.This chapter aims to review recent experimental studies on the siderophile element geochemistry and discussions on the Earth’s building blocks.
基金the National Natural Science Foundation of China(Grant Nos.41772043 and 41802043)the CAS"Light of West China"Program(2017 and 2019),the Youth Innovation Promotion Association CAS(Dawei Fan,2018434)+4 种基金the Innovation and Entrepreneurship Funding of High-Level Overseas Talents of Guizhou Province(Dawei Fan,[2019]10)GeoSoilEnviroCARS(The University of Chicago,Sector 13)Advanced Photon Source(APS),Argonne National Laboratory.GeoSoilEnviroCARS is supported by the National Science Foundation(EAR-0622171)the Department of Energy(DE-FG02-94ER14466)under Contract No.DE-AC02-06CH11357the Advanced Photon Source,a U.S.Department of Energy(DOE)Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DE-AC02-06CH11357.
文摘Epidote is a typical hydrous mineral in subduction zones.Here,we report a synchrotron-based single-crystal X-ray diffraction(XRD)study of natural epidote[Ca1.97Al2.15Fe0.84(SiO4)(Si2O7)O(OH)]under simultaneously high pressure-temperature(high P-T)conditions to~17.7 GPa and 700 K.No phase transition occurs over this P-T range.Using the third-order Birch-Murnaghan equation of state(EoS),we fitted the pressure-volume-temperature(P-V-T)data and obtained the zero-pressure bulk modulus K_(0)=138(2)GPa,its pressure derivative K'_(0)=3.0(3),the temperature derivative of the bulk modulus((∂K/∂T)P=-0.004(1)GPa/K),and the thermal expansion coefficient at 300 K(α_(0)=3.8(5)×10^(-5)K^(-1)),as the zero-pressure unit-cell volume V_(0)was fixed at 465.2(2)Å^(3)(obtained by a single-crystal XRD experiment at ambient conditions).This study reveals that the bulk moduli of epidote show nonlinear compositional dependence.By discussing the stabilization of epidote and comparing its density with those of other hydrous minerals,we find that epidote,as a significant water transporter in subduction zones,may maintain a metastable state to~14 GPa along the coldest subducting slab geotherm and promote slab subduction into the upper mantle while favoring slab stagnation above the 410 km discontinuity.Furthermore,the water released from epidote near 410 km may potentially affect the properties of the 410 km seismic discontinuity.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0305700 and 2018YFA0305800)the National Natural Science Foundation of China(Grant Nos.11574377,11888101,11834016,11874400,11904272,and 11704292)Jiao and Sun were sponsored by the China Postdoctoral Science Foundation and the Postdoctoral Innovative Talent Program.
文摘The double perovskite Ca2CrSbO6 exhibits a ferromagnetic long-range order below Tc=13 K and a saturation magnetization of 2.35µB at 2 K.In this study,the polycrystalline Ca2CrSbO6 is synthesized under high pressure and high temperature,and the critical behavior of the ferromagnetic material as well as the effects of the magnetic behavior due to the isovalent substitution of Sr2+for Ca2+is investigated.Also studied are the ferromagnetic criticality of the double perovskite Ca2CrSbO6 at the ferromagnetic transition temperature Tc≈12.6 K from the isotherms of magnetization M(H)via an iteration process and the Kouvel–Fisher method.The critical exponents associated with the transition are determined as follows:β=0.322,γ=1.241,andδ=4.84.The magnetization data in the vicinity of Tc can be scaled into two universal curves in the plot of M/|ε|βversus H/|ε|β+γ,whereε=T/Tc−1.The obtainedβandγvalues are consistent with the predicted values from a three-dimensional Ising model.The effects of Sr substitution on the double perovskite Ca2CrSbO6 are taken into consideration.As the Sr content increases,the(Ca2−xSrx)CrSbO6 polycrystal shows a continuous switch from ferromagnetic to antiferromagnetic behavior.
文摘Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fusion reactor.Today the more innovative version of this apparatus that is known as an ITER(international thermonuclear experimental reactor)shows a way toward MCF(magnetic confinement fusion)of hot plasma goal by satisfying Lawson’s Criteria to some degree of achievement.However,since this fusion driven reactor of hot plasma needs to operate at almost 150 million Celsius,the internal material of this reactor is a matter of concern for scientists that are involved with its fabrication.Uniqueness of nanomaterials from the point of view of physical and chemical properties is suggested as a possible potential application for this special and innovative reactor for a nuclear fusion device.Convergence of nanotechnology in study of new generation of materials of this kind can shape the path for various technological developments and a large variety of disciplines,including MCF driven plasma of hot fusion as well.This short TM(technical memorandum)written by these two authors will cover this aspect of technology in a holistic way and the more granular level is left to the reader of this TM to investigate further.
基金The work wassponsored by the Key Basic Research and Development Program (Grant No. G1998040800) the National Natural Science Foundation of China (Grant No. 40072062)+1 种基金 a grant form GeoForschungsZentrum in Germany for International Cooperation the F
文摘Here we present an insight into the genesis of Himalayan granulitic lower crust based on the experimental studies on the dehydration melting of natural biotite-plagioclase gneiss performed at the temperatures of 770-980°C and the pressures of 1.0-1.4 GPa. The experiments produce peraluminous granitic melt and residual phase assemblage (Pl+Qz+Gat+Bio+Opx±Cpx+Ilm/Rut±Kfs). The residual mineral assemblage is similar to those of granu-lites observed at the eastern and western Himalayan syntax-ises, and the chemical compositions of characteristic minerals-garnet and pyroxene in the residual phase and the granu-lite are identical. Additionally, the modeled wave velocities of the residual phase assemblage are comparable well with those of the top part of lower crust beneath Himalayas. Hence, we suggest that (1) the top part of lower crust beneath Himalayas is probably made up of garnet-bearing intermediate granulite; (2) the formations of granulite and leucogranites in Himalayas are interrelated as the
基金Russian Science Foundation(project No 21-17-00024).
文摘It is generally accepted that carbonates can be subducted to the mantle depths,where they are reduced with iron metal to produce a diamond.In this work,we found that this is not always the case.The mantle carbonates from inclusions in diamonds show a wide range of cation compositions(Mg,Fe,Ca,Na,and K).Here we studied the reaction kinetics of these carbonates with iron metal at 6-6.5 GPa and 1000-1500℃.We found that the reduction of carbonate with Fe produces C-bearing species(Fe,Fe-C melt,Fe_(3)C,F e_(7)C_(3),C)and wüistite containing Na_(2)O,CaO,and MgO.The reaction rate constants(k=△x^(2)/2t)are log-linear relative to 1/T and their temperature dependences are determined to be k_(MgcO_(3))(m^(2)/s)=4.37×10^(-3)exp[-251(kJ/mol)/RT]k_(caMg(CO_(3))2)(m^(2)/s)=1.48×10^(-3)exp[-264(kJ/mol)/RT]k_(cacO_(3))(m^(2)/s)=3.06×10^(-5)exp[-245(kJ/mol)/RT]and k_(Na_(2)cO_(3))(m^(2)/s)=1.88×10^(-10)exp[-155(kJ/mol)/RT].According to obtained results at least,45-70 vol%of carbonates preserve during subduction down to the 660-km discontinuity if no melting occurs.The slab stagnation and warming,subsequent carbonate melting,and infiltration into the mantle saturated with iron metal are accompanied by a reduction of carbonate melt with Fe.The established sequence of reactivity of carbonates:FeCO_(3)≥MgCO_(3)>CaMg(CO_(3))2>CaCO_(3)>>Na_(2)CO_(3),where K_(2)CO_(3)does not react at all with iron metal,implies that during reduction carbonate melt with Fe evolves toward alkali-rich.The above conclusions are consistent with the findings of carbonates in inclusions in diamonds from the lower mantle and high concentrations of alkalis,particularly K,in mantle carbonatite melts entrapped by diamonds from kimberlites and placers worldwide.
基金Project supported by the National Natural Science Foundation of China.
文摘Based on the results of melting experiments on the whole rock of chondrite, the differentiation mechanism of the core, the mantle and the crust of the early Earth was discussed in Ref. [1]. In order to investigate the geochemical behaviour of metal-sulfide in the melting-process of the original Earth matter and the formation of the core, further melting experiments were carried out on metal-rich phase of Jilin chondrite under high pressure.