The synthesis of diamond single crystal in the Fe64Ni36-C system with h-BN additive is investigated at pressure 6.5 GPa and temperature range of 1300-1400℃. The color of the obtained diamond crystals translates from ...The synthesis of diamond single crystal in the Fe64Ni36-C system with h-BN additive is investigated at pressure 6.5 GPa and temperature range of 1300-1400℃. The color of the obtained diamond crystals translates from yellow to dark green with increasing the h-BN addition. Fourier-transform infrared (FTIR) results indicate that sp2 hybridization B-N-B and B-N structures generate when the additive content reaches a certain value in the system. The two peaks are located at 745 and 1425cm-1, respectively. Fhrthermore, the FTIR characteristic peak resulting from nitrogen pairs is noticed and it tends to vanish when the h-BN addition reaches 1.1 wt%. Furthermore, Raman peak of the synthesized diamond shifts down to a lower wavenumber with increasing the h-BN ~ddition content in the synthesis system.展开更多
An experiment is conducted to investigate the effects of lubricant10#, which contains extreme pressure additives T304 and T305, on the rolling contact fatigue (RCF) life of the contact pairs of a Si3N4 ceramic ball ...An experiment is conducted to investigate the effects of lubricant10#, which contains extreme pressure additives T304 and T305, on the rolling contact fatigue (RCF) life of the contact pairs of a Si3N4 ceramic ball and a steel rod. The experimental investigation is carried out using a ball-rod RCF test rig. The results show that the extreme pressure additives increase the anti-contact-fatigue performance of ceramic balls; When the content of the additives varies from 1% to 5%, the increasing gradient of the RCF life curve decreases; And the oil sample with 1% T305 additive corresponds to the maximal gradient of the RCF life curve, with the RCF life being increased by about 10.77 times. The fatigue surface of the ceramic ball is analyzed with scanning electron microscope (SEM) and X-ray electron dispersion analysis(EDAX), and the physical model of extreme pressure additives' increasing the RCF life of the ceramic ball is proposed. It is found that the extreme pressure additives form a corrosive film and a transfer film on the surface of the ceramic ball, which decrease the surface tangential stress, and to increase the surface energy is the most effective means for increasing the RCF life.展开更多
The research into the hydrostatic pressure in the crust has been previously conducted from the viewpoint that the hydrostatic pressure is equal to the gravity, based on the fact that the hydrostatic pressure is derive...The research into the hydrostatic pressure in the crust has been previously conducted from the viewpoint that the hydrostatic pressure is equal to the gravity, based on the fact that the hydrostatic pressure is derived mainly from the gravity of its overlying rocks. In this paper, the stress state of any point in the crust is suggested to have been caused by both the gravity and the tectonic force. The author proposes that the hydrostatic pressure is a combination or superposition of two isotropic stresses in the tectonic force and gravity stress fields. The results obtained with a finite element simulation indicate that the additional hydrostatic pressure borne by rocks decreases gradually from the compression zone ( p s c), the shear zone ( p s sh ) to the tensile zone ( p s t), and that the difference in the additional tectonic hydrostatic pressure between these deformed zones tends to increase, following the increase in the absolute value and/or the difference in external forces between different directions. This paper presents the foundation for the research into the tectonic physicochemistry.展开更多
This paper presents some questions to the formula of pressure=depth×specific gravity from the viewpoint that the hydrostatic pressure is equal to the gravity of overlying rocks and the rocks in a static fluid sta...This paper presents some questions to the formula of pressure=depth×specific gravity from the viewpoint that the hydrostatic pressure is equal to the gravity of overlying rocks and the rocks in a static fluid state, which is drawn from the research and analysis of the research field and the corresponding problems of the pressure state in the deep crust and the formation depth of the UHP metamorphic rocks. In this research, the underground rocks are considered as the solid possessing some rheological behaviors to discuss the polysource stress state and to obtain a more reasonable method for the calculation of depths using the model of the unbalanced force solid. It is suggested from this paper that the P/SW method for the calculation of the ultrahigh pressure stemming only from the gravity has obviously overstated the formation depth of the UHP metamorphism. The formation model emphasizing the effect of the gravity, the tectonic force and the metamorphic force of the facies change concludes that such UHP minerals as coesite may have been produced in the inner crust.展开更多
An experimental study of the confining pressure, i.e. additional hydrostatic pressure initiated by the tectonic force is presented. The experimental progress is that the σ 1 is gradually increasing from 0 in a l...An experimental study of the confining pressure, i.e. additional hydrostatic pressure initiated by the tectonic force is presented. The experimental progress is that the σ 1 is gradually increasing from 0 in a limiting movement ( ε 1=0) in the σ 1 direction and the speed rate of the accelerating load is 0.4 MPa·s -1 in the lateral and level directions. When σ 2= σ 3<200 MPa, Δ σ l is nearly lacking, Δ σ l is increasing at a high speed only when the horizontal force reaches 250-380 MPa, and Δ σ l almost ceases to increase at the level force of 380 MPa. It is calculated that the tectonic force can produce the confining pressure which is gradually increasing with σ 2= σ 3 before it reaches 380 MPa in an experiment. It is supposed that the horizontal force is almost all transformed into the confining pressure with the increase of the creep deformation of rocks.展开更多
This paper reports the crystal growth of diamond from the Fe Ni–Carbon system with additive phosphorus at high pressures and high temperatures of 5.4–5.8 GPa and 1280–1360°C. Attributed to the presence of addi...This paper reports the crystal growth of diamond from the Fe Ni–Carbon system with additive phosphorus at high pressures and high temperatures of 5.4–5.8 GPa and 1280–1360°C. Attributed to the presence of additive phosphorus,the pressure and temperature condition, morphology, and color of diamond crystals change obviously. The pressure and temperature condition of diamond growth increases evidently with the increase of additive phosphorus content and results in the moving up of the V-shape region. The surfaces of the diamonds also become coarse as the additive phosphorus added in the growth system. Raman spectra indicate that diamonds grown from the Fe Ni-phosphorus-carbon system have more crystal defects and impurities. This work provides a new way to enrich the doping of diamond and improve the experimental exploration for future material applications.展开更多
Cutting fluid is crucial in ensuring surface quality and machining accuracy during machining.However,traditional mineral oil-based cutting fluids no longer meet modern machining’s health and environmental protection ...Cutting fluid is crucial in ensuring surface quality and machining accuracy during machining.However,traditional mineral oil-based cutting fluids no longer meet modern machining’s health and environmental protection require-ments.As a renewable,pollution-free alternative with excellent processing characteristics,vegetable oil has become an inevitable replacement.However,vegetable oil lacks oxidation stability,extreme pressure,and antiwear proper-ties,which are essential for machining requirements.The physicochemical characteristics of vegetable oils and the improved methods’application mechanism are not fully understood.This study aims to investigate the effects of viscosity,surface tension,and molecular structure of vegetable oil on cooling and lubricating properties.The mechanisms of autoxidation and high-temperature oxidation based on the molecular structure of vegetable oil are also discussed.The study further investigates the application mechanism and performance of chemical modification and antioxidant additives.The study shows that the propionic ester of methyl hydroxy-oleate obtained by epoxidation has an initial oxidation temperature of 175℃.The application mechanism and extreme pressure performance of conventional extreme pressure additives and nanoparticle additives were also investigated to solve the problem of insufficient oxidation resistance and extreme pressure performance of nanobiological lubricants.Finally,the study discusses the future prospects of vegetable oil for chemical modification and nanoparticle addition.The study provides theoretical guidance and technical support for the industrial application and scientific research of vegetable oil in the field of lubrication and cooling.It is expected to promote sustainable development in the manufacturing industry.展开更多
The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong...The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong tectonic movement was an important component of the total pressure that resulted in the formation of the eclogite in the Dabie UHPM zone. The three dimensional tectonic principal stresses and additional tectonic stress induced hydrostatic pressure [ p s=( σ 1+ σ 2+ σ 3)/3] are reconstructed according to the differential stress and the strain ratio ( α ) of the garnet in the minor coesite bearing eclogite of the Yingshan County. Then the gravity induced hydrostatic pressure ( p g) is calculated following the equation p minus p s, where p is estimated to be 2.8 GPa based on the quartz coesite geobarmeter. Therefore, the thickness of the rock column overlying the coesite bearing eclogite in the Ying shan County is determined ≥32 km. This estimation, significantly different from ≥100 km, the previous one obtained solely based on the weight/specific weight ratio (W/SW), offers a proper explanation for the puzzle that no tracer of the addition of mantle derived material has been found in the Dabie UHPM zone during the process of UHPM, although a number of researchers claim that this process took place at the depth of the mantle (≥100 km). It is concluded that attention should be paid to the additional tectonic stress induced hydrostatic pressure in the study of UHPM zones.展开更多
Organic Rankine Cycle(ORC)is a promising technology for converting low or medium temperature heat into power.In order to improve the thermodynamic efficiency of ORC systems,adding a regenerator to the system has been ...Organic Rankine Cycle(ORC)is a promising technology for converting low or medium temperature heat into power.In order to improve the thermodynamic efficiency of ORC systems,adding a regenerator to the system has been widely discussed.However,this needs additional pipes and devices and they will produce additional pressure drop.Considering both the contributions of the regenerator and the power losses caused by additional pressure drop,a theoretical criterion for evaluating the thermodynamic effectiveness of adding a regenerator was proposed by means of mathematic and thermodynamic equations.The core of the criterion is a new concept named Critical Pressure Drop produced by the Regenerator(CPDR).A negative value of CPDR indicates that adding a regenerator will not contribute to the thermodynamic efficiency of ORC systems in any case.An effective regenerator needs a positive value of CPDR,and requires that the value of additional pressure drop produced by introducing the regenerator should be smaller than CPDR.The influences of evaporation temperature,condensation temperature,expander efficiency,regenerator effectiveness and working fluids on CPDR were also examined.It was found that lower evaporation temperature or using working fluids with higher critical temperature tends to reduce the value of CPDR.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 51172089the Natural Science Foundation of Guizhou Province Education Department under Grant No KY[2013]183the Natural Science Foundation of Guizhou Province Science and Technology Agency under Grant Nos LH[2015]7232 and LH[2015]7228
文摘The synthesis of diamond single crystal in the Fe64Ni36-C system with h-BN additive is investigated at pressure 6.5 GPa and temperature range of 1300-1400℃. The color of the obtained diamond crystals translates from yellow to dark green with increasing the h-BN addition. Fourier-transform infrared (FTIR) results indicate that sp2 hybridization B-N-B and B-N structures generate when the additive content reaches a certain value in the system. The two peaks are located at 745 and 1425cm-1, respectively. Fhrthermore, the FTIR characteristic peak resulting from nitrogen pairs is noticed and it tends to vanish when the h-BN addition reaches 1.1 wt%. Furthermore, Raman peak of the synthesized diamond shifts down to a lower wavenumber with increasing the h-BN ~ddition content in the synthesis system.
基金This project is supported by State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences,China(No.0303).
文摘An experiment is conducted to investigate the effects of lubricant10#, which contains extreme pressure additives T304 and T305, on the rolling contact fatigue (RCF) life of the contact pairs of a Si3N4 ceramic ball and a steel rod. The experimental investigation is carried out using a ball-rod RCF test rig. The results show that the extreme pressure additives increase the anti-contact-fatigue performance of ceramic balls; When the content of the additives varies from 1% to 5%, the increasing gradient of the RCF life curve decreases; And the oil sample with 1% T305 additive corresponds to the maximal gradient of the RCF life curve, with the RCF life being increased by about 10.77 times. The fatigue surface of the ceramic ball is analyzed with scanning electron microscope (SEM) and X-ray electron dispersion analysis(EDAX), and the physical model of extreme pressure additives' increasing the RCF life of the ceramic ball is proposed. It is found that the extreme pressure additives form a corrosive film and a transfer film on the surface of the ceramic ball, which decrease the surface tangential stress, and to increase the surface energy is the most effective means for increasing the RCF life.
文摘The research into the hydrostatic pressure in the crust has been previously conducted from the viewpoint that the hydrostatic pressure is equal to the gravity, based on the fact that the hydrostatic pressure is derived mainly from the gravity of its overlying rocks. In this paper, the stress state of any point in the crust is suggested to have been caused by both the gravity and the tectonic force. The author proposes that the hydrostatic pressure is a combination or superposition of two isotropic stresses in the tectonic force and gravity stress fields. The results obtained with a finite element simulation indicate that the additional hydrostatic pressure borne by rocks decreases gradually from the compression zone ( p s c), the shear zone ( p s sh ) to the tensile zone ( p s t), and that the difference in the additional tectonic hydrostatic pressure between these deformed zones tends to increase, following the increase in the absolute value and/or the difference in external forces between different directions. This paper presents the foundation for the research into the tectonic physicochemistry.
文摘This paper presents some questions to the formula of pressure=depth×specific gravity from the viewpoint that the hydrostatic pressure is equal to the gravity of overlying rocks and the rocks in a static fluid state, which is drawn from the research and analysis of the research field and the corresponding problems of the pressure state in the deep crust and the formation depth of the UHP metamorphic rocks. In this research, the underground rocks are considered as the solid possessing some rheological behaviors to discuss the polysource stress state and to obtain a more reasonable method for the calculation of depths using the model of the unbalanced force solid. It is suggested from this paper that the P/SW method for the calculation of the ultrahigh pressure stemming only from the gravity has obviously overstated the formation depth of the UHP metamorphism. The formation model emphasizing the effect of the gravity, the tectonic force and the metamorphic force of the facies change concludes that such UHP minerals as coesite may have been produced in the inner crust.
文摘An experimental study of the confining pressure, i.e. additional hydrostatic pressure initiated by the tectonic force is presented. The experimental progress is that the σ 1 is gradually increasing from 0 in a limiting movement ( ε 1=0) in the σ 1 direction and the speed rate of the accelerating load is 0.4 MPa·s -1 in the lateral and level directions. When σ 2= σ 3<200 MPa, Δ σ l is nearly lacking, Δ σ l is increasing at a high speed only when the horizontal force reaches 250-380 MPa, and Δ σ l almost ceases to increase at the level force of 380 MPa. It is calculated that the tectonic force can produce the confining pressure which is gradually increasing with σ 2= σ 3 before it reaches 380 MPa in an experiment. It is supposed that the horizontal force is almost all transformed into the confining pressure with the increase of the creep deformation of rocks.
基金supported by the Doctoral Fund of Henan Polytechnic University,China(Grant Nos.B2013-013 and B2013-044)the Research Projects of Science and Technology of the Education Department of Henan Province,China(Grant Nos.14B430026 and 12A430010)
文摘This paper reports the crystal growth of diamond from the Fe Ni–Carbon system with additive phosphorus at high pressures and high temperatures of 5.4–5.8 GPa and 1280–1360°C. Attributed to the presence of additive phosphorus,the pressure and temperature condition, morphology, and color of diamond crystals change obviously. The pressure and temperature condition of diamond growth increases evidently with the increase of additive phosphorus content and results in the moving up of the V-shape region. The surfaces of the diamonds also become coarse as the additive phosphorus added in the growth system. Raman spectra indicate that diamonds grown from the Fe Ni-phosphorus-carbon system have more crystal defects and impurities. This work provides a new way to enrich the doping of diamond and improve the experimental exploration for future material applications.
基金Supported by National Key Research and Development Program of China(Grant No.2020YFB2010500)National Natural Science Foundation of China(Grant Nos.51975305,52105457)Shandong Provincial Natural Science Foundation of China(Grant No.ZR2020KE027).
文摘Cutting fluid is crucial in ensuring surface quality and machining accuracy during machining.However,traditional mineral oil-based cutting fluids no longer meet modern machining’s health and environmental protection require-ments.As a renewable,pollution-free alternative with excellent processing characteristics,vegetable oil has become an inevitable replacement.However,vegetable oil lacks oxidation stability,extreme pressure,and antiwear proper-ties,which are essential for machining requirements.The physicochemical characteristics of vegetable oils and the improved methods’application mechanism are not fully understood.This study aims to investigate the effects of viscosity,surface tension,and molecular structure of vegetable oil on cooling and lubricating properties.The mechanisms of autoxidation and high-temperature oxidation based on the molecular structure of vegetable oil are also discussed.The study further investigates the application mechanism and performance of chemical modification and antioxidant additives.The study shows that the propionic ester of methyl hydroxy-oleate obtained by epoxidation has an initial oxidation temperature of 175℃.The application mechanism and extreme pressure performance of conventional extreme pressure additives and nanoparticle additives were also investigated to solve the problem of insufficient oxidation resistance and extreme pressure performance of nanobiological lubricants.Finally,the study discusses the future prospects of vegetable oil for chemical modification and nanoparticle addition.The study provides theoretical guidance and technical support for the industrial application and scientific research of vegetable oil in the field of lubrication and cooling.It is expected to promote sustainable development in the manufacturing industry.
文摘The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong tectonic movement was an important component of the total pressure that resulted in the formation of the eclogite in the Dabie UHPM zone. The three dimensional tectonic principal stresses and additional tectonic stress induced hydrostatic pressure [ p s=( σ 1+ σ 2+ σ 3)/3] are reconstructed according to the differential stress and the strain ratio ( α ) of the garnet in the minor coesite bearing eclogite of the Yingshan County. Then the gravity induced hydrostatic pressure ( p g) is calculated following the equation p minus p s, where p is estimated to be 2.8 GPa based on the quartz coesite geobarmeter. Therefore, the thickness of the rock column overlying the coesite bearing eclogite in the Ying shan County is determined ≥32 km. This estimation, significantly different from ≥100 km, the previous one obtained solely based on the weight/specific weight ratio (W/SW), offers a proper explanation for the puzzle that no tracer of the addition of mantle derived material has been found in the Dabie UHPM zone during the process of UHPM, although a number of researchers claim that this process took place at the depth of the mantle (≥100 km). It is concluded that attention should be paid to the additional tectonic stress induced hydrostatic pressure in the study of UHPM zones.
基金supported by Beijing Municipal Natural Science Foundation(NO.3202006).
文摘Organic Rankine Cycle(ORC)is a promising technology for converting low or medium temperature heat into power.In order to improve the thermodynamic efficiency of ORC systems,adding a regenerator to the system has been widely discussed.However,this needs additional pipes and devices and they will produce additional pressure drop.Considering both the contributions of the regenerator and the power losses caused by additional pressure drop,a theoretical criterion for evaluating the thermodynamic effectiveness of adding a regenerator was proposed by means of mathematic and thermodynamic equations.The core of the criterion is a new concept named Critical Pressure Drop produced by the Regenerator(CPDR).A negative value of CPDR indicates that adding a regenerator will not contribute to the thermodynamic efficiency of ORC systems in any case.An effective regenerator needs a positive value of CPDR,and requires that the value of additional pressure drop produced by introducing the regenerator should be smaller than CPDR.The influences of evaporation temperature,condensation temperature,expander efficiency,regenerator effectiveness and working fluids on CPDR were also examined.It was found that lower evaporation temperature or using working fluids with higher critical temperature tends to reduce the value of CPDR.