According to customs statistics, China’s exports of machinery and electric products in 1996 were worth US$ 48.21 billion, an increase of 9.9 percent over the preceding year, and 8.4 percent higher than the growth rat...According to customs statistics, China’s exports of machinery and electric products in 1996 were worth US$ 48.21 billion, an increase of 9.9 percent over the preceding year, and 8.4 percent higher than the growth rate of the nation’s total exports. The proportion of machinery and electric product exports in the nation’s total foreign trade volume\ increased from 29.5 percent in 1995 to 31.9 percent in 1996, a growth at 2.4 percent.展开更多
A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long peri...A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was investigated.Moreover,a quantitative relationship between the microstructure and tensile yield strength was established.The results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were broken.In IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute atoms.The severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO phase.After MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% respectively.Grain refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP sample.In particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in IZ.This result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate.展开更多
With a long industrial chain and a powerful ability to drive other industries,the automobile manufacturing industry has a prominent strategic position in the national economy.In recent years,many countries have put on...With a long industrial chain and a powerful ability to drive other industries,the automobile manufacturing industry has a prominent strategic position in the national economy.In recent years,many countries have put on their agenda the digitalization of the automobile manufacturing industry,leading to an connected,autonomous,shared,and electric(also known as CASE)①development trend in the industry.As one of the six major automobile industry clusters in China,the Chengdu-Chongqing economic circle has achieved initial results in the digital transformation of the automobile manufacturing industry.However,the region is still faced with some constraints,such as insufficient digital infrastructure,relatively slow development of new automobile products,insufficient innovation ability of the automobile industry,and complex digital transformation of small and medium-sized automobile enterprises(automobile SMEs).This paper intends to construct a framework for the mechanism of action of the digital transformation in the automobile manufacturing industry,analyze the effects of the digital transformation of the automobile manufacturing industry in the Chengdu-Chongqing economic circle,and propose feasible paths for the digital transformation of the automobile manufacturing industry in the region by drawing on domestic and international experience in this regard.The specific paths include:(a)Smoothing the“dual-core”data chain to facilitate the digital transformation of the automobile manufacturing industry;(b)Developing the new energy vehicle(NEV)industry to upgrade the quality of automobile products;(c)Achieving corner overtaking in the digital transformation of the automobile manufacturing industry with digital technology;(d)Jointly building the automobile industrial park to promote the digital transformation of the industry;(e)Addressing problems facing automobile SMEs in digital transformation via targeted policy tools.展开更多
With the rapid development of the market economy, complex changes have occurred in the market environment, and the competition among enterprises has become extremely fierce. The transformation of the structure of the ...With the rapid development of the market economy, complex changes have occurred in the market environment, and the competition among enterprises has become extremely fierce. The transformation of the structure of the market economy has prompted enterprises to seek for new developments and innovations. Under the background of the new economy, enterprises must begin from the perspective of internal management and internal strategic development to ensure quality enterprise operation mechanism innovation. This would help direct enterprise operation and development as well as demonstrate the value of enterprise internal management. In this way, enterprises will be able to array their overall competitiveness. This paper comprises a detailed analysis of the connotation and innovation of enterprise operation mechanism under the economic transformation, with the purpose of investigating the innovation strategy of enterprise operation mechanism under the economic transformation.展开更多
The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade compl...The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore resources.According to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously.展开更多
The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La 3+ were studied by chemical p hase analysis, X-ray diffraction and infrared spectrometry an...The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La 3+ were studied by chemical p hase analysis, X-ray diffraction and infrared spectrometry analysis. The expe rimental results show that phase transformation reactions of FeCO 3, Fe 2O 3 and BaFe 2O 4, barium hexaferrite and γ-Fe 2O 3 take place in the heat tr eatment of gel. While the doping lanthanide ion replace barium ion, an equivalen t quantity of Fe 3+ are reduced to Fe 2+ to maintain the charge equili brium.展开更多
The aged and quenched microstructures of both alloys, Ti-42at-%Al and Ti-45at -%Al,homogenized in the disordered single phase field. were investigated And the results show that the quinched microstructure is a supersa...The aged and quenched microstructures of both alloys, Ti-42at-%Al and Ti-45at -%Al,homogenized in the disordered single phase field. were investigated And the results show that the quinched microstructure is a supersaturated single phase of ordered 22. When the supersaturated phase is aged in the two phase range at 1273 and 1373 K, it will transform to a lamellar microstructure of γ+α2. with a discontinuous decomposition mechanism in Ti-42at-%Al alloy and a semicontinuous decomposition mechanism in T1-45at-%Al alloy. With the methods of quantitative metallograph examination and X-ray diffraction analysis. the relationship between the amount of γ, phase precipitation and the time of isothermal transformation is agreed展开更多
The structure of the solid solution treated and deformed Fe-25Mn-(0-3.11)Al-0.15C alloys was examined by means of metallograph and X-ray diffraction, which has confirmed that Al restrains the γ→ε transformation in ...The structure of the solid solution treated and deformed Fe-25Mn-(0-3.11)Al-0.15C alloys was examined by means of metallograph and X-ray diffraction, which has confirmed that Al restrains the γ→ε transformation in the Fe-Mn alloys. The mechanism on the restraining effect of Al has been discussed on the basis of the efFect of Al upon the stacking fault energy in the Fe-Mn alloys.Aluminium increases thermodynamically the stability of the Fe-Mn austenite and the driving force limit necessitated to be overcome for the γ→ε transformation, because the thermodynamicalcalculation indicates that Al increases the stacking fault energy in the Fe-Mn alloys at 300 K.Al will decrease the number and the size for the ε-martensite nucleus according to the stacking fault mechanism of the ε-martensite nucleation展开更多
<div style="text-align:justify;"> Based on the detailed interpretation of high-accuracy 3D seismic data, the characteristics of regional unconformities, fracture systems, sedimentary filling and paleo-...<div style="text-align:justify;"> Based on the detailed interpretation of high-accuracy 3D seismic data, the characteristics of regional unconformities, fracture systems, sedimentary filling and paleo-stress field in Zhu 1 depression were comprehensively analyzed. The results showed that 2nd episode of Zhu-Qiong movement was an important tectonic transformation that occurred during rifting, basin structure patterns above and below the regional angular unconformity caused by 2nd episode had distinct differences. The orientations of those basin-controlling faults changed from NE, NEE to EW, NWW, which indicated that the paleo-stress field veered from NNW extension clockwise to sub-NS extension and basin structures patterns transformed from NE, NEE strong rifting to sub-EW, NWW weak rifting. The depocenter showed seesaw-like migration from S to N. And the sedimentary systems transformed from semi-deep-deep lacustrine facies to braided river delta facies developed in shore-shallow lacustrine. Combined with its tectonic recombination of periphery plates that period, the mechanism of above tectonic transformation had direct correspondence to the readjustment of the Indian plate and the Pacific plate. The southward subduction of the pro-to-south China Sea is the direct cause of this tectonic transformation. </div>展开更多
Gastric cancer(GC)is a common gastrointestinal tumor.Gastric precancerous lesions(GPL)are the last pathological stage before normal gastric mucosa transforms into GC.However,preventing the transformation from GPL to G...Gastric cancer(GC)is a common gastrointestinal tumor.Gastric precancerous lesions(GPL)are the last pathological stage before normal gastric mucosa transforms into GC.However,preventing the transformation from GPL to GC remains a challenge.Traditional Chinese medicine(TCM)has been used to treat gastric disease for millennia.A series of TCM formulas and active compounds have shown therapeutic effects in both GC and GPL.This article reviews recent progress on the herbal drugs and pharmacological mechanisms of TCM in preventing the transformation from GPL to GC,especially focusing on antiinflammatory,anti-angiogenesis,proliferation,and apoptosis.This review may provide a meaningful reference for the prevention of the transformation from GPL to GC using TCM.展开更多
The high-temperature and high-pressure experiment on natural block rock indicates that dehydration-melting of hydrous biotite (Bi) and partial melting of felsic minerals in garnet-biotite-plagioclase gneiss are mainly...The high-temperature and high-pressure experiment on natural block rock indicates that dehydration-melting of hydrous biotite (Bi) and partial melting of felsic minerals in garnet-biotite-plagioclase gneiss are mainly controlled by temperature, while mineral phase transformation is not only controlled by temperature-pressure conditions but also genetically associated with hydrous mineral dehydration-melting and partial melting of felsic minerals. According to the characteristics of biotite dehydration-melting and garnet transformation reaction, three stages may be distinguished: (1) when the experimental temperature is 700℃, biotite transforms to ilmenite (Ilm) + magnetite (Mt) + H2O and garnet to magnetite (Mt); (2) when the temperature is 730-760℃, biotite is dehydrated and melted and transformed into K2O-rich melt + Ilm + Mt, and garnet, into hypersthene (Hy) + cordierite (Crd); (3) when the temperature is up to or higher than 790℃, biotite is dehydrated and melted and transformed into melt + Hy + Ilm + Mt, and garnet, into the hypersthene (Hy) + spinel (Sp) + cordierite (Crd) assemblage. The melt proportion and its evolutionary characteristics are mainly controlled by dehydration-melting of hydrous minerals and partial melting of felsic minerals besides P-T conditiops: In addition to the traditional solid 4- solid (or fluid) reaction and dehydration-melting reaction, the metamorphic reaction involving melts (reaction between unmelted minerals and melts) is one of the most important reactions in granulite facies metamorphism and its attendant remelting (or regional migmatization). This experiment may provide dependable experimental data for an in-depth study of the genetic mechanism of mineral assemblage evolution and its geological dynamic significance in granulite facies metamorphism of the studied area.展开更多
The phase transformation and deformation mechanism of the alloy based on composition Ti_3Al with addition of Nb,V,Mo have been studied by use of transmission electron microscopy (TEM).It has been shown that the orient...The phase transformation and deformation mechanism of the alloy based on composition Ti_3Al with addition of Nb,V,Mo have been studied by use of transmission electron microscopy (TEM).It has been shown that the orientation relationship of α_2 phase transformed from β phase is:(0001)α_2// (l10)β,[1210]α_2//[111]β.The present dislocation slip systems in α_2 phase are (1100)[0001] and (1100)<1120>.There also exist α_2 twins which have new twin relationship and the twin plane is (2021).展开更多
Cordierite ceramic powders were prepared by solid reaction at low temperatures using gangue as main starting material and adjusting component oxides in formulations. The powders were characterized by XRD, SEM and EDS....Cordierite ceramic powders were prepared by solid reaction at low temperatures using gangue as main starting material and adjusting component oxides in formulations. The powders were characterized by XRD, SEM and EDS. The emphasis was placed on the reaction mechanism and phase transformation of synthesized powders. The results show that cordierite ceramic powders can be synthesized at 1 150 - 1 250 % for 3 - 5 h and its morphology is irregularly granular. The synthesis temperature has an important effect on the phase transformations of powders but the reaction time only has a little effect. The impurities in gangue result in the detected secondary magnesium aluminate spinel and the decreased synthesis temperature.展开更多
The actuation mechanism of TiNi shape memory alloy wires, which were deformed at parent phase followed by a cooling process under constant strain constraint, was investigated. The experimental results show that the tw...The actuation mechanism of TiNi shape memory alloy wires, which were deformed at parent phase followed by a cooling process under constant strain constraint, was investigated. The experimental results show that the two-step reverse martensitic transformation behavior occurs during the heating process, and the temperature range of reverse transformation was obviously widened with the increasing of prestrain. The recovery strain vs temperature curves exhibits an actuation characteristic of linear output recovery strain in a wide temperature range.展开更多
The martensitic transformation,mechanical,and magnetic properties of the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) (x=0.125,0.25,0.375,0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5)[(x=0.125,y=0.125,0.25,0.375,0.5) and (x=0.125...The martensitic transformation,mechanical,and magnetic properties of the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) (x=0.125,0.25,0.375,0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5)[(x=0.125,y=0.125,0.25,0.375,0.5) and (x=0.125,0.25,0.375,y=0.625)]alloys were systematically studied by the first-principles calculations.For the formation energy,the martensite is smaller than the austenite,the Ni–(Co)–Mn–Cu–Ti alloys studied in this work can undergo martensitic transformation.The austenite and non-modulated (NM) martensite always present antiferromagnetic state in the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) (y<0.625) alloys.When y=0.625 in the Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) series,the austenite presents ferromagnetic state while the NM martensite shows antiferromagnetic state.Cu doping can decrease the thermal hysteresis and anisotropy of the Ni–(Co)–Mn–Ti alloy.Increasing Mn and decreasing Ti content can improve the shear resistance and normal stress resistance,but reduce the toughness in the Ni–Mn–Cu–Ti alloy.And the ductility of the Co–Cu co-doping alloy is inferior to that of the Ni–Mn–Cu–Ti and Ni–Co–Mn–Ti alloys.The electronic density of states was studied to reveal the essence of the mechanical and magnetic properties.展开更多
The China National Textiles I/E Corp (Chinatex), one of the foreign trade companies in the country with the biggest import and export value, exported more textiles and expanded its business at home and abroad in 1994,...The China National Textiles I/E Corp (Chinatex), one of the foreign trade companies in the country with the biggest import and export value, exported more textiles and expanded its business at home and abroad in 1994, in spite of the shortage of raw materials and the rise in prices. Chinatex’s import and export value totalled US$2.718 billion last year, a rise of 43.9% over the previous year. The quality of the exports also improved. The company’s Beijing branch exported US$370 million worth of goods, 33.3% more than in the previous year. Its enterprises abroad had a turnover of US$1 billion in 1994.展开更多
The peculiarities of energy dissipation transferred by solitary waves on defects such as freesurface, grain boundary, region with high concentration of vacancies are studied. One of theways of description of the long ...The peculiarities of energy dissipation transferred by solitary waves on defects such as freesurface, grain boundary, region with high concentration of vacancies are studied. One of theways of description of the long range effect taking place at ion implantation in metallic materialsis suggested.展开更多
Blasted(1995)is knitted by Sarah Kane as a huge and intricate net of power,among whose threads every character gets entangled.By deconstructing the configuration of power from two dimensions:body shame,the seen body,w...Blasted(1995)is knitted by Sarah Kane as a huge and intricate net of power,among whose threads every character gets entangled.By deconstructing the configuration of power from two dimensions:body shame,the seen body,we are disclosed how power hierarchy is established.In Blasted,Kane deconstructs the power game by revealing its alienating effect on people,dissolves civilized humans:once stripped off the veneer of civilization,the repressed animality residing in humans would take hold and re⁃duce us to barbarians,still the play hints that humanistic love can function as a alternative to power in ruling the world.展开更多
A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast China. The main findings are as follows:The changes of ...A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast China. The main findings are as follows:The changes of kinetic energy are mainly attributed to the generation due to non-divergent wind. During the early stage of the typhoon landing, there exits only a small quantity of kinetic energy exchanging with the environment. And after it is transformed into an extratropical cyclone, a large amount of kinetic energy is exported from the system toward the environment.The horizontal and vertical flux-divergence terms of eddy available potenlial energy are the prominent sinks in the budgets of eddy kinetic energy. The generations of eddy kinetic energy due to both the barotropic and baroclinic processes are source terms. The former is remarkable during the initial stage. But after the depression is transformed into an extratropical cyclone, the roles of the generation by the barotropic and baroclinic processes are reversed, 1. e. , the latter has become more significant than the former.Diabatic heating is the most dominant heat source. The terms of vertical heat flux by cumulus and large-scale motion are the major sinks. And the latter is prominent after the system is transformed into an extratropical cycfone.展开更多
By analyzing the corrosion of phosphate completion fluid on the P110 steel at 170 °C, the high-temperature corrosion mechanism of phosphate completion fluid was revealed, and a corrosion inhibition method by memb...By analyzing the corrosion of phosphate completion fluid on the P110 steel at 170 °C, the high-temperature corrosion mechanism of phosphate completion fluid was revealed, and a corrosion inhibition method by membrane transformation was proposed and an efficient membrane-forming agent was selected. Scanning electron microscope (SEM) images, X-ray energy spectrum and X-ray diffraction results were used to characterize the microscopic morphology, elemental composition and phase composition of the precipitation membrane on the surface of the test piece. The effect and mechanism of corrosion inhibition by membrane transformation were clarified. The phosphate completion fluid eroded the test piece by high-temperature water vapor and its hydrolyzed products to form a membrane of iron phosphate corrosion product. By changing the corrosion reaction path, the Zn2+ membrane-forming agent could generate KZnPO4 precipitation membrane with high temperature resistance, uniform thickness and tight crystal packing on the surface of the test piece, which could inhibit the corrosion of the test piece, with efficiency up to 69.63%. The Cu2+ membrane-forming agent electrochemically reacted with Fe to precipitate trace elemental Cu on the surface of the test piece, thus forming a protective membrane, which could inhibit metal corrosion, with efficiency up to 96.64%, but the wear resistance was poor. After combining 0.05% Cu2+ and 0.25% Zn2+, a composite protective membrane of KZnPO4 crystal and elemental Cu was formed on the surface of the test piece. The corrosion inhibition efficiency reached 93.03%, which ensured the high corrosion inhibition efficiency and generated a precipitation membrane resistant to temperature and wear.展开更多
文摘According to customs statistics, China’s exports of machinery and electric products in 1996 were worth US$ 48.21 billion, an increase of 9.9 percent over the preceding year, and 8.4 percent higher than the growth rate of the nation’s total exports. The proportion of machinery and electric product exports in the nation’s total foreign trade volume\ increased from 29.5 percent in 1995 to 31.9 percent in 1996, a growth at 2.4 percent.
基金supported by the National Key Research and Development Program of China(2021YFB3501002)State Key Program of National Natural Science Foundation of China(5203405)+3 种基金National Natural Science Foundation of China(51974220,52104383)National Key Research and Development Program of China(2021YFB3700902)Key Research and Development Program of Shaanxi Province(2020ZDLGY13-06,2017ZDXM-GY-037)Shaanxi Province National Science Fund for Distinguished Young Scholars(2022JC-24)。
文摘A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this work.The structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was investigated.Moreover,a quantitative relationship between the microstructure and tensile yield strength was established.The results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were broken.In IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute atoms.The severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO phase.After MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% respectively.Grain refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP sample.In particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in IZ.This result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate.
文摘With a long industrial chain and a powerful ability to drive other industries,the automobile manufacturing industry has a prominent strategic position in the national economy.In recent years,many countries have put on their agenda the digitalization of the automobile manufacturing industry,leading to an connected,autonomous,shared,and electric(also known as CASE)①development trend in the industry.As one of the six major automobile industry clusters in China,the Chengdu-Chongqing economic circle has achieved initial results in the digital transformation of the automobile manufacturing industry.However,the region is still faced with some constraints,such as insufficient digital infrastructure,relatively slow development of new automobile products,insufficient innovation ability of the automobile industry,and complex digital transformation of small and medium-sized automobile enterprises(automobile SMEs).This paper intends to construct a framework for the mechanism of action of the digital transformation in the automobile manufacturing industry,analyze the effects of the digital transformation of the automobile manufacturing industry in the Chengdu-Chongqing economic circle,and propose feasible paths for the digital transformation of the automobile manufacturing industry in the region by drawing on domestic and international experience in this regard.The specific paths include:(a)Smoothing the“dual-core”data chain to facilitate the digital transformation of the automobile manufacturing industry;(b)Developing the new energy vehicle(NEV)industry to upgrade the quality of automobile products;(c)Achieving corner overtaking in the digital transformation of the automobile manufacturing industry with digital technology;(d)Jointly building the automobile industrial park to promote the digital transformation of the industry;(e)Addressing problems facing automobile SMEs in digital transformation via targeted policy tools.
文摘With the rapid development of the market economy, complex changes have occurred in the market environment, and the competition among enterprises has become extremely fierce. The transformation of the structure of the market economy has prompted enterprises to seek for new developments and innovations. Under the background of the new economy, enterprises must begin from the perspective of internal management and internal strategic development to ensure quality enterprise operation mechanism innovation. This would help direct enterprise operation and development as well as demonstrate the value of enterprise internal management. In this way, enterprises will be able to array their overall competitiveness. This paper comprises a detailed analysis of the connotation and innovation of enterprise operation mechanism under the economic transformation, with the purpose of investigating the innovation strategy of enterprise operation mechanism under the economic transformation.
基金financially supported by the National Key Research and Development Program of China (No.2023YFC2909000)the National Natural Science Foundation of China(No.52174240)the Open Foundation of State Key Laboratory of Mineral Processing (No.BGRIMM-KJSKL-2023-15)。
文摘The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore resources.According to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously.
文摘The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La 3+ were studied by chemical p hase analysis, X-ray diffraction and infrared spectrometry analysis. The expe rimental results show that phase transformation reactions of FeCO 3, Fe 2O 3 and BaFe 2O 4, barium hexaferrite and γ-Fe 2O 3 take place in the heat tr eatment of gel. While the doping lanthanide ion replace barium ion, an equivalen t quantity of Fe 3+ are reduced to Fe 2+ to maintain the charge equili brium.
文摘The aged and quenched microstructures of both alloys, Ti-42at-%Al and Ti-45at -%Al,homogenized in the disordered single phase field. were investigated And the results show that the quinched microstructure is a supersaturated single phase of ordered 22. When the supersaturated phase is aged in the two phase range at 1273 and 1373 K, it will transform to a lamellar microstructure of γ+α2. with a discontinuous decomposition mechanism in Ti-42at-%Al alloy and a semicontinuous decomposition mechanism in T1-45at-%Al alloy. With the methods of quantitative metallograph examination and X-ray diffraction analysis. the relationship between the amount of γ, phase precipitation and the time of isothermal transformation is agreed
文摘The structure of the solid solution treated and deformed Fe-25Mn-(0-3.11)Al-0.15C alloys was examined by means of metallograph and X-ray diffraction, which has confirmed that Al restrains the γ→ε transformation in the Fe-Mn alloys. The mechanism on the restraining effect of Al has been discussed on the basis of the efFect of Al upon the stacking fault energy in the Fe-Mn alloys.Aluminium increases thermodynamically the stability of the Fe-Mn austenite and the driving force limit necessitated to be overcome for the γ→ε transformation, because the thermodynamicalcalculation indicates that Al increases the stacking fault energy in the Fe-Mn alloys at 300 K.Al will decrease the number and the size for the ε-martensite nucleus according to the stacking fault mechanism of the ε-martensite nucleation
文摘<div style="text-align:justify;"> Based on the detailed interpretation of high-accuracy 3D seismic data, the characteristics of regional unconformities, fracture systems, sedimentary filling and paleo-stress field in Zhu 1 depression were comprehensively analyzed. The results showed that 2nd episode of Zhu-Qiong movement was an important tectonic transformation that occurred during rifting, basin structure patterns above and below the regional angular unconformity caused by 2nd episode had distinct differences. The orientations of those basin-controlling faults changed from NE, NEE to EW, NWW, which indicated that the paleo-stress field veered from NNW extension clockwise to sub-NS extension and basin structures patterns transformed from NE, NEE strong rifting to sub-EW, NWW weak rifting. The depocenter showed seesaw-like migration from S to N. And the sedimentary systems transformed from semi-deep-deep lacustrine facies to braided river delta facies developed in shore-shallow lacustrine. Combined with its tectonic recombination of periphery plates that period, the mechanism of above tectonic transformation had direct correspondence to the readjustment of the Indian plate and the Pacific plate. The southward subduction of the pro-to-south China Sea is the direct cause of this tectonic transformation. </div>
基金Supported by the National Natural Science Foundation of China,No.81904064Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences,No.CI2021A03804 and No.CI2021A05052Fundamental Research Funds for the Central Public Welfare Research Institutes,No.ZZ14-YQ-023,No.ZXKT21017,and No.ZXKT21024.
文摘Gastric cancer(GC)is a common gastrointestinal tumor.Gastric precancerous lesions(GPL)are the last pathological stage before normal gastric mucosa transforms into GC.However,preventing the transformation from GPL to GC remains a challenge.Traditional Chinese medicine(TCM)has been used to treat gastric disease for millennia.A series of TCM formulas and active compounds have shown therapeutic effects in both GC and GPL.This article reviews recent progress on the herbal drugs and pharmacological mechanisms of TCM in preventing the transformation from GPL to GC,especially focusing on antiinflammatory,anti-angiogenesis,proliferation,and apoptosis.This review may provide a meaningful reference for the prevention of the transformation from GPL to GC using TCM.
基金This study was supported by the Youth Geologist Foundation of the Ministry of Geology and Mineral Resources of China (Grant No. 9603) and the Postdoctoral Science Foundation of the State Education Commission
文摘The high-temperature and high-pressure experiment on natural block rock indicates that dehydration-melting of hydrous biotite (Bi) and partial melting of felsic minerals in garnet-biotite-plagioclase gneiss are mainly controlled by temperature, while mineral phase transformation is not only controlled by temperature-pressure conditions but also genetically associated with hydrous mineral dehydration-melting and partial melting of felsic minerals. According to the characteristics of biotite dehydration-melting and garnet transformation reaction, three stages may be distinguished: (1) when the experimental temperature is 700℃, biotite transforms to ilmenite (Ilm) + magnetite (Mt) + H2O and garnet to magnetite (Mt); (2) when the temperature is 730-760℃, biotite is dehydrated and melted and transformed into K2O-rich melt + Ilm + Mt, and garnet, into hypersthene (Hy) + cordierite (Crd); (3) when the temperature is up to or higher than 790℃, biotite is dehydrated and melted and transformed into melt + Hy + Ilm + Mt, and garnet, into the hypersthene (Hy) + spinel (Sp) + cordierite (Crd) assemblage. The melt proportion and its evolutionary characteristics are mainly controlled by dehydration-melting of hydrous minerals and partial melting of felsic minerals besides P-T conditiops: In addition to the traditional solid 4- solid (or fluid) reaction and dehydration-melting reaction, the metamorphic reaction involving melts (reaction between unmelted minerals and melts) is one of the most important reactions in granulite facies metamorphism and its attendant remelting (or regional migmatization). This experiment may provide dependable experimental data for an in-depth study of the genetic mechanism of mineral assemblage evolution and its geological dynamic significance in granulite facies metamorphism of the studied area.
文摘The phase transformation and deformation mechanism of the alloy based on composition Ti_3Al with addition of Nb,V,Mo have been studied by use of transmission electron microscopy (TEM).It has been shown that the orientation relationship of α_2 phase transformed from β phase is:(0001)α_2// (l10)β,[1210]α_2//[111]β.The present dislocation slip systems in α_2 phase are (1100)[0001] and (1100)<1120>.There also exist α_2 twins which have new twin relationship and the twin plane is (2021).
文摘Cordierite ceramic powders were prepared by solid reaction at low temperatures using gangue as main starting material and adjusting component oxides in formulations. The powders were characterized by XRD, SEM and EDS. The emphasis was placed on the reaction mechanism and phase transformation of synthesized powders. The results show that cordierite ceramic powders can be synthesized at 1 150 - 1 250 % for 3 - 5 h and its morphology is irregularly granular. The synthesis temperature has an important effect on the phase transformations of powders but the reaction time only has a little effect. The impurities in gangue result in the detected secondary magnesium aluminate spinel and the decreased synthesis temperature.
基金FundedbytheNationalNaturalScienceFoundationofChi na (No .5 0 0 710 37)
文摘The actuation mechanism of TiNi shape memory alloy wires, which were deformed at parent phase followed by a cooling process under constant strain constraint, was investigated. The experimental results show that the two-step reverse martensitic transformation behavior occurs during the heating process, and the temperature range of reverse transformation was obviously widened with the increasing of prestrain. The recovery strain vs temperature curves exhibits an actuation characteristic of linear output recovery strain in a wide temperature range.
基金financially supported by the National Natural Science Foundation of China(No.51771044)the Natural Science Foundation of Hebei Province(No.E2019501061)+3 种基金the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(No.22567627H)the Fundamental Research Funds for the Central Universities(No.N2223025)the State Key Lab of Advanced Metals and Materials(No.2022-Z02)Programme of Introducing Talents of Discipline Innovation to Universities 2.0(the 111 Project of China 2.0,No.BP0719037)。
文摘The martensitic transformation,mechanical,and magnetic properties of the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) (x=0.125,0.25,0.375,0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5)[(x=0.125,y=0.125,0.25,0.375,0.5) and (x=0.125,0.25,0.375,y=0.625)]alloys were systematically studied by the first-principles calculations.For the formation energy,the martensite is smaller than the austenite,the Ni–(Co)–Mn–Cu–Ti alloys studied in this work can undergo martensitic transformation.The austenite and non-modulated (NM) martensite always present antiferromagnetic state in the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) (y<0.625) alloys.When y=0.625 in the Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) series,the austenite presents ferromagnetic state while the NM martensite shows antiferromagnetic state.Cu doping can decrease the thermal hysteresis and anisotropy of the Ni–(Co)–Mn–Ti alloy.Increasing Mn and decreasing Ti content can improve the shear resistance and normal stress resistance,but reduce the toughness in the Ni–Mn–Cu–Ti alloy.And the ductility of the Co–Cu co-doping alloy is inferior to that of the Ni–Mn–Cu–Ti and Ni–Co–Mn–Ti alloys.The electronic density of states was studied to reveal the essence of the mechanical and magnetic properties.
文摘The China National Textiles I/E Corp (Chinatex), one of the foreign trade companies in the country with the biggest import and export value, exported more textiles and expanded its business at home and abroad in 1994, in spite of the shortage of raw materials and the rise in prices. Chinatex’s import and export value totalled US$2.718 billion last year, a rise of 43.9% over the previous year. The quality of the exports also improved. The company’s Beijing branch exported US$370 million worth of goods, 33.3% more than in the previous year. Its enterprises abroad had a turnover of US$1 billion in 1994.
文摘The peculiarities of energy dissipation transferred by solitary waves on defects such as freesurface, grain boundary, region with high concentration of vacancies are studied. One of theways of description of the long range effect taking place at ion implantation in metallic materialsis suggested.
文摘Blasted(1995)is knitted by Sarah Kane as a huge and intricate net of power,among whose threads every character gets entangled.By deconstructing the configuration of power from two dimensions:body shame,the seen body,we are disclosed how power hierarchy is established.In Blasted,Kane deconstructs the power game by revealing its alienating effect on people,dissolves civilized humans:once stripped off the veneer of civilization,the repressed animality residing in humans would take hold and re⁃duce us to barbarians,still the play hints that humanistic love can function as a alternative to power in ruling the world.
文摘A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast China. The main findings are as follows:The changes of kinetic energy are mainly attributed to the generation due to non-divergent wind. During the early stage of the typhoon landing, there exits only a small quantity of kinetic energy exchanging with the environment. And after it is transformed into an extratropical cyclone, a large amount of kinetic energy is exported from the system toward the environment.The horizontal and vertical flux-divergence terms of eddy available potenlial energy are the prominent sinks in the budgets of eddy kinetic energy. The generations of eddy kinetic energy due to both the barotropic and baroclinic processes are source terms. The former is remarkable during the initial stage. But after the depression is transformed into an extratropical cyclone, the roles of the generation by the barotropic and baroclinic processes are reversed, 1. e. , the latter has become more significant than the former.Diabatic heating is the most dominant heat source. The terms of vertical heat flux by cumulus and large-scale motion are the major sinks. And the latter is prominent after the system is transformed into an extratropical cycfone.
基金Supported by the National Natural Science Foundation of China(5215000105)Huo Yingdong Education Foundation(171043).
文摘By analyzing the corrosion of phosphate completion fluid on the P110 steel at 170 °C, the high-temperature corrosion mechanism of phosphate completion fluid was revealed, and a corrosion inhibition method by membrane transformation was proposed and an efficient membrane-forming agent was selected. Scanning electron microscope (SEM) images, X-ray energy spectrum and X-ray diffraction results were used to characterize the microscopic morphology, elemental composition and phase composition of the precipitation membrane on the surface of the test piece. The effect and mechanism of corrosion inhibition by membrane transformation were clarified. The phosphate completion fluid eroded the test piece by high-temperature water vapor and its hydrolyzed products to form a membrane of iron phosphate corrosion product. By changing the corrosion reaction path, the Zn2+ membrane-forming agent could generate KZnPO4 precipitation membrane with high temperature resistance, uniform thickness and tight crystal packing on the surface of the test piece, which could inhibit the corrosion of the test piece, with efficiency up to 69.63%. The Cu2+ membrane-forming agent electrochemically reacted with Fe to precipitate trace elemental Cu on the surface of the test piece, thus forming a protective membrane, which could inhibit metal corrosion, with efficiency up to 96.64%, but the wear resistance was poor. After combining 0.05% Cu2+ and 0.25% Zn2+, a composite protective membrane of KZnPO4 crystal and elemental Cu was formed on the surface of the test piece. The corrosion inhibition efficiency reached 93.03%, which ensured the high corrosion inhibition efficiency and generated a precipitation membrane resistant to temperature and wear.