The higher vocational education has the dual attributes of higher education and vocational education, with vocational education development pace continues to accelerate, the establishment of vocational schools and sch...The higher vocational education has the dual attributes of higher education and vocational education, with vocational education development pace continues to accelerate, the establishment of vocational schools and school-enterprise cooperation corporate long-term mechanism must be addressed now become a good core issues as soon as possible, to achieve effective implementation of internships, we must achieve five-win of social, school, business, students and parents, to a certain extent, for the regional industry economic development.展开更多
The development mechanism and mode and the new technical characteristics of the modern cutting technology are studied and analyzed. It is presented that to speed up the development of cutting technology and fully use ...The development mechanism and mode and the new technical characteristics of the modern cutting technology are studied and analyzed. It is presented that to speed up the development of cutting technology and fully use the good-quality technical resource of cutting tool have the significant meaning for construction of powerful manufacturing industry of China.展开更多
To study the penetration mechanism of cement-based slurry in intersected fractures during grouting and the related pressure distribution,we have used two different variants of cement,namely,basic cement slurry and fas...To study the penetration mechanism of cement-based slurry in intersected fractures during grouting and the related pressure distribution,we have used two different variants of cement,namely,basic cement slurry and fast-setting cement slurry.The influence of a retarder,time-varying viscosity,fracture width and location of injection hole is also considered.A finite element software is used to implement two and three-dimensional numerical models for grouting of intersected fractures in hydrostatic conditions.Results show that there are significant differences in the diffusion morphology and pressure distribution depending on the considered cement slurry.Retarder can effectively slow down the rising rate of injection pressure and extend the diffusion distance of grout.The influence of the branch fracture is more important when basic cement slurry is considered,indicating that the change of grout pressure is correlated with the slurry viscosity.The faster the viscosity increases,the less evident is the effect.展开更多
Hypoxia is a common pathological process in various clinical diseases and is characterized by abnormal changes in metabolism, function, and morphological structure of tissues resulting from insufficient oxygen supply ...Hypoxia is a common pathological process in various clinical diseases and is characterized by abnormal changes in metabolism, function, and morphological structure of tissues resulting from insufficient oxygen supply or oxygen barriers in tissues. In particular, hypoxia in vital organs such as the brain and heart is an important cause of death;. The prevention of tissue hypoxia and the展开更多
The propagation mechanism of steady cellular detonations in curved channels is investigated numerically with a detailed chemical reaction mechanism, The numerical results demonstrate that as the radius of the curvatur...The propagation mechanism of steady cellular detonations in curved channels is investigated numerically with a detailed chemical reaction mechanism, The numerical results demonstrate that as the radius of the curvature decreases, detonation fails near the inner wall due to the strong expansion effect. As the radius of the curvature increases, the detonation front near the inner wall can sustain an underdriven detonation. In the case where deto- nation fails, a transverse detonation downstream forms and re-initiates the quenched detonation as it propagates toward the inner wall. Two kinds of propagation modes exist as the detonation is propagating in the curved channel. One is that the detonation fails first, and then a following transverse detonation initiates the quenched detonation and this process repeats itself. The other one is that without detonation failure and re-initiation, a steady detonation exists which consists of an underdriven detonation front near the inner wall subject to the diffraction and an overdriven detonation near the outer wall subject to the compression.展开更多
A robust iterative method suitable for the numerical simulation of high angle-of-attack vortex flows is established based upon the multiple line-vortex model(MLVM).With symmetric or asymmetric positions of sep- aratio...A robust iterative method suitable for the numerical simulation of high angle-of-attack vortex flows is established based upon the multiple line-vortex model(MLVM).With symmetric or asymmetric positions of sep- aration lines given,the first converged solution at an angle of attack as high as 60 degree is obtained by means of the present method.Numerical experiments for a tangent-ogive forebody indicate the viscous onset mechanism of asymmetric vortex flows over a body of revolution at high angles of attack and zero sideslip.展开更多
ESR measurements using spin trapping technique were carried out for β-carotene-halobenzene system under UV light irradiation.The ESR spectra observed in the presence and in the absence of β-carotene are markedly dif...ESR measurements using spin trapping technique were carried out for β-carotene-halobenzene system under UV light irradiation.The ESR spectra observed in the presence and in the absence of β-carotene are markedly different.The possible scheme of β-carotene interacting with halogen atom was proposed.展开更多
The question of possible teleconnections between the middle latitude general circulation and the Indian south-west monsoon was investigated in this paper. Within the framework of a simple model it was shown that there...The question of possible teleconnections between the middle latitude general circulation and the Indian south-west monsoon was investigated in this paper. Within the framework of a simple model it was shown that there can exist such an interaction via the ultra-long Rossby waves.展开更多
In the presence of alkali nitrite and carbonate,some nitrobenzenes subs- tituted by strongly electron withdrawing group undergo a self condensation in an aprotic polar sotvent to give symmetrical disubstituted dipheny...In the presence of alkali nitrite and carbonate,some nitrobenzenes subs- tituted by strongly electron withdrawing group undergo a self condensation in an aprotic polar sotvent to give symmetrical disubstituted diphenyl ethers in good yields.A possible mechanism is discussed,the nucteophilic aromatic substitution S_NAr and S_(Ru)Ar may occur simultaneously.展开更多
For the superconductors(Rb_xK_(1-x))_3C_(60)(x=0.1),according to BCS theory and assuming that the virtual phonon acting on electron-pair is corresponding to the intrasolecular vibration in the bnckminnterfullerene C_(...For the superconductors(Rb_xK_(1-x))_3C_(60)(x=0.1),according to BCS theory and assuming that the virtual phonon acting on electron-pair is corresponding to the intrasolecular vibration in the bnckminnterfullerene C_(60),a linear relationship of the superconducting transition temperature T_c with x has been derived,which is in agreement with the experimentals,展开更多
When criminal suspects are being investigated for criminal responsibil- ity, they are the most vulnerable to infringement by public power. Thus, they need more special attention and protection. It is the in- evitable ...When criminal suspects are being investigated for criminal responsibil- ity, they are the most vulnerable to infringement by public power. Thus, they need more special attention and protection. It is the in- evitable requirement of the modern democratic rule of law, and also the inevitable historic choice of respecting and protecting human rights.展开更多
Based on the particularities of gas outbursts,i.e.,low gas bearing capacity and low gas pressure in the "Three Soft" coal seam in western Henan,we applied the theories of plate tectonics and regional structu...Based on the particularities of gas outbursts,i.e.,low gas bearing capacity and low gas pressure in the "Three Soft" coal seam in western Henan,we applied the theories of plate tectonics and regional structural evolution to investigate the mechanism of this seam and its impact on the coal seam gas formation.Our investigation revealed that coal and gas outbursts are distributed in a strip in a NW direction,with a number of high-penetration mines scattered towards the south side and low-gas mines largely located on the north side.We analyzed the statistics of 38 gas explosions and the rock-coal sturdiness number coefficient f of 167 sampling sites in the region and found the gas outburst mechanism that features a "low indicator outburst phenomenon".The mechanism is characterized by structural coal as its core,a low gas bearing capacity,low gas pressure and sturdiness coefficient f mostly less than 0.3.Our research results provide a theoretical foundation for effective control of gas disasters.展开更多
[Mg(H2O)6](NTO)2·2H2O Was prepared by adding magnesium carbonate hydroxide to the aqueous solution of 3-nitro-1,2,4-triazol-5-one(NTO).Its thermal decomposition mechanism was studied by DSC,TG/DTGand IR.The...[Mg(H2O)6](NTO)2·2H2O Was prepared by adding magnesium carbonate hydroxide to the aqueous solution of 3-nitro-1,2,4-triazol-5-one(NTO).Its thermal decomposition mechanism was studied by DSC,TG/DTGand IR.The quantum chemical calculation on the title complex as a structure unit with the experimental geometry as atartmg values was carried out at B3LYP level with 6-31G basis set.The results show that the bonds between the coordinate waters and the Mgatom have certain extent covalent character.The net charges on nitrogen atoms of the NTO ring appear to be negative while the nitrogen atom on the nitro group(—NO2)appears to be positive which indicates—NO2 will lost first when the complex is heated to some uniform temperature and this result is in agreement with that of the thermal decomposition experiment.展开更多
Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted...Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted based on the research site conditions. The geological conditions, dumping operation, and waste particle size distribution were investigated in the Heidaigou open pit mine. Particle size distribution, dumping height, dumping volume, and floor inclination were varied to examine their effects on a single pile formation. The design of blasting can be modified to make the particle size of waste smaller. The volume of the bucket does not have a pronounced effect on dumping pile repose angle, capacity of dumping pile, and dumping area stability. The smaller the floor inclination, the better it is. Two measures are proposed to increase the kinetic force of friction between waste material and floor surface. The interval distance, dumping volume and dumping height were also varied to examine the interaction between the formations of multiple piles. The dumping width should be decided through optimization efficiency of bulldozer and dumping device in bucket wheel excavator-belt-stacker dumping operation and dragline dumping operation. Moreover, the volume of the bucket does not have a pronounced interaction effect. In the dumping operation, the work amount of bulldozer decreases as dumping pile increases. The design of the dumping operation must consider the total efficiency of ground leveling operation and forming dumping the area.展开更多
Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and or...Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and orientations of the stress can be classified into three types. The corresponding physical conditions for each type of the loop are deduced based on the principle of minimal energy. The equation of the critical stress is derived, which can judge whether the loops show hysteresis or not. Numerical calculations suggest that except for the magnitude of the mechanical stress, the relative orientation of the stress is also an important factor to tune the exchange bias effect.展开更多
In this study,the texture evolutions of two Mg materials during tension are explored.In-situ X-ray synchrotron and Visco-Plastic SelfConsistent(VPSC) modeling are employed to investigate the different deformation mode...In this study,the texture evolutions of two Mg materials during tension are explored.In-situ X-ray synchrotron and Visco-Plastic SelfConsistent(VPSC) modeling are employed to investigate the different deformation modes between pure Mg and Mg-15Gd(wt.%) alloy.These two materials with a strong extrusion texture show large different slip/twinning activity behaviors during tensile deformation.The basal(a) slip has the highest contribution to the initial stage of plastic deformation for pure Mg.During the subsequent plastic deformation,the prismatic slip is dominant due to the strong ED//(100) fiber texture.In contrast,the deformation behavior of Mg-15Gd alloy is more complex.Twinning and basal slip are dominant at the early stage of plastic deformation,but further deformation results in the increased activation of prismatic and pyramidal slips.In comparison to pure Mg,the ratios of the critical resolved shear stress(CRSS) between non-basal slip and basal slip of the Mg-15Gd alloy are much lower.展开更多
In recent years, many countries implement the TBT in the export trade practice of agricultural products, which has greatly positive influence on the Chinese agricultural products export enterprise. On the basis of gre...In recent years, many countries implement the TBT in the export trade practice of agricultural products, which has greatly positive influence on the Chinese agricultural products export enterprise. On the basis of green technical innovation concept, the paper had determined the enterprise green technical innovation motivation mechanism, analyzed the influence of TBT on green technical innovation of the enterprise, and integrated Chinese reality to analyze the influence of TBT on green technical innovation of Chinese agricultural enterprise. Finally, based on the above analysis, the paper proposed corresponding suggestions to the Chinese government.展开更多
The understanding of the geotechnical problems and failure mechanisms of stone structures of Sakakini palace (1897 after century) entails a comprehensive study on the mechanical behaviour of the stones and other const...The understanding of the geotechnical problems and failure mechanisms of stone structures of Sakakini palace (1897 after century) entails a comprehensive study on the mechanical behaviour of the stones and other construction materials. In addition to micro analysis, geological and geomorphologic interests, several investigations on stone deterioration and engineering geology were performed, First phase included more sophisticated techniques, which provided additional information on particular aspects of site deterioration and it included laser induced breakdown spectroscopy (LIBs), electron probe micro analysis, micro XRD and XRF analyses, scanning electron microscope analysis coupled with EDX probing, transmission electron microscopy and grain size distribution analysis, permeability and pore size distribution of stone, mortars, core binders and other construction materials. Second phase included the determination of mechanical properties of building stones, such as compressive strength, modulus of elasticity, tensile strength, and shear strength. To arrive at reliable values for these properties, a suitable number of samples should be extracted, prepared for testing, and properly tested. The test results are then analyzed to establish the investigated stone properties. The testing program includes extracting seven cylindrical cores from the basement stone walls of Sakakini’s mansion in down townCairo. The cores are extracted using rotary cylindrical diamond blade coring machine. The top and bottom surfaces of every core were prepared to be flat circular surfaces perpendicular to the vertical axis of the core. Because the palace is museum and attractive places for the tourists, core sampling could be carried out only at a limited number of locations under official permission. For the purpose, cylindrical specimens with a diameter of 42 - 44 mm and height of 90 - 100 mm, prepared by the use of a core drilling machine and some collected blocks from the archaeological site under investtigation were taken to determine the bulk structure, physical, short and long-term mechanical properties of the stone and other construction materials in the laboratory. A number of specimens prepared from these blocks were employed for testing. Furthermore, limitation due to the number of blocks was overcome by the determination of the in situ characteristics of the stones by Schmidt hammer tests, geo-tomographic investigations and rock mass classification on some stone rock structures where testing has been permitted. The objectives of the study are to provide a characterization of micro structures and the mechanical properties of the stones of Sakakini’s Mansion;describe the required testing plan;describe the test results and conclude the values of the basic mechanical properties of the building stones. The following sections provide detailed descriptions of the steps taken to achieve the objectives of the study. The purpose of the present research is to provide recommendations regarding the strengthening and the safety of architectural heritage under long and short-term loading. For this purpose, a set of experimental tests and of advanced numerical analyses are to be carried out.展开更多
Objective:To investigate the influencing mechanism of Jin-Shui-Liu-Jun-Jian and Acupoint Application combined therapy on hemorheology, inflammatory factors and pulmonary functions in patients with chronic bronchitis, ...Objective:To investigate the influencing mechanism of Jin-Shui-Liu-Jun-Jian and Acupoint Application combined therapy on hemorheology, inflammatory factors and pulmonary functions in patients with chronic bronchitis, thus to offer relevant help for clinical therapies on patients with chronic bronchitis. Methods:120 cases of patients with chronic bronchitis treated in our hospital were selected and randomly divided to be the therapeutic group and the control group, 60 cases each. Patients in control group were provided some basic treatments, such as spasmolysis, anti-inflammation, asthma relieving, oxygen inhalation and dissolve phlegm. For therapeutic group on this basis, Jin-Shui-Liu-Jun-Jian and Acupoint Application combined therapy was provided. Hemorheology, inflammatory factors and pulmonary functions in the two groups of patients were detected before and after treatment. Results:Differences of hemorheology indexes, inflammatory factors and pulmonary function relevant indexes between the two groups of patients with chronic bronchitis before treatment showed no statistical significance (P>0.05). Compared with prior treatment, hemorheology relevant indexes [whole blood high shear viscosity (WHV), whole blood low shear viscosity (WLV), packed cell volume (PCV), plasma viscosity (PV) and red cell assembling index (RCAI)], inflammatory factors [IL-8 (interleukin-8) and TNF-α(tumor necrosis factor-α)] were significantly decreased and pulmonary function relevant indexes [forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), peak expiratory flow (PEF), maximal voluntary ventilation (MVV) and expiratory flow rate when exhale vital capacity was 0.50], inflammatory factors (IL-4, IL-2) were significantly increased in the two groups of patients with chronic bronchitis after relevant treatments;The differences between the groups showed statistical significance (P<0.05). After combined therapy provided, pulmonary function relevant indexes (FVC, FEV1.0, PEF, MVV and V0.50) and inflammatory factors (IL-4, IL-2) in therapeutic group were significantly higher than control group after basic therapy. Hemorheology relevant indexes (WHV, WLV, PV, PCV and RCAI) and inflammatory factors (IL-8 and TNF-α) in therapeutic group were significantly lower than control group;Differences between the two groups showed statistical significance (P<0.05). Conclusions: Combination of Jin-Shui-Liu-Jun-Jian and Acupoint Application significantly improved the levels of hemorheology, inflammatory factors and pulmonary functions in patients with chronic bronchitis. It has a great important clinical significance on therapies for patients with chronic bronchitis.展开更多
文摘The higher vocational education has the dual attributes of higher education and vocational education, with vocational education development pace continues to accelerate, the establishment of vocational schools and school-enterprise cooperation corporate long-term mechanism must be addressed now become a good core issues as soon as possible, to achieve effective implementation of internships, we must achieve five-win of social, school, business, students and parents, to a certain extent, for the regional industry economic development.
文摘The development mechanism and mode and the new technical characteristics of the modern cutting technology are studied and analyzed. It is presented that to speed up the development of cutting technology and fully use the good-quality technical resource of cutting tool have the significant meaning for construction of powerful manufacturing industry of China.
基金by the Joint Funds of National Natural Science Foundation of China[Grant No.U1706223]the National Key Research and Development Project(Grant No.2016YFC0801600)+1 种基金the General Program of National Natural Science Foundation[Grant No.51779133]the General Program of Shandong Province Natural Science Foundation[Grant No.ZR2018MEE047].
文摘To study the penetration mechanism of cement-based slurry in intersected fractures during grouting and the related pressure distribution,we have used two different variants of cement,namely,basic cement slurry and fast-setting cement slurry.The influence of a retarder,time-varying viscosity,fracture width and location of injection hole is also considered.A finite element software is used to implement two and three-dimensional numerical models for grouting of intersected fractures in hydrostatic conditions.Results show that there are significant differences in the diffusion morphology and pressure distribution depending on the considered cement slurry.Retarder can effectively slow down the rising rate of injection pressure and extend the diffusion distance of grout.The influence of the branch fracture is more important when basic cement slurry is considered,indicating that the change of grout pressure is correlated with the slurry viscosity.The faster the viscosity increases,the less evident is the effect.
基金financially supported by 1226 major project [Grant no.AWS16J018]
文摘Hypoxia is a common pathological process in various clinical diseases and is characterized by abnormal changes in metabolism, function, and morphological structure of tissues resulting from insufficient oxygen supply or oxygen barriers in tissues. In particular, hypoxia in vital organs such as the brain and heart is an important cause of death;. The prevention of tissue hypoxia and the
基金Supported by the National Natural Science Foundation of China under Grant Nos 11390363 and 11325209
文摘The propagation mechanism of steady cellular detonations in curved channels is investigated numerically with a detailed chemical reaction mechanism, The numerical results demonstrate that as the radius of the curvature decreases, detonation fails near the inner wall due to the strong expansion effect. As the radius of the curvature increases, the detonation front near the inner wall can sustain an underdriven detonation. In the case where deto- nation fails, a transverse detonation downstream forms and re-initiates the quenched detonation as it propagates toward the inner wall. Two kinds of propagation modes exist as the detonation is propagating in the curved channel. One is that the detonation fails first, and then a following transverse detonation initiates the quenched detonation and this process repeats itself. The other one is that without detonation failure and re-initiation, a steady detonation exists which consists of an underdriven detonation front near the inner wall subject to the diffraction and an overdriven detonation near the outer wall subject to the compression.
文摘A robust iterative method suitable for the numerical simulation of high angle-of-attack vortex flows is established based upon the multiple line-vortex model(MLVM).With symmetric or asymmetric positions of sep- aration lines given,the first converged solution at an angle of attack as high as 60 degree is obtained by means of the present method.Numerical experiments for a tangent-ogive forebody indicate the viscous onset mechanism of asymmetric vortex flows over a body of revolution at high angles of attack and zero sideslip.
文摘ESR measurements using spin trapping technique were carried out for β-carotene-halobenzene system under UV light irradiation.The ESR spectra observed in the presence and in the absence of β-carotene are markedly different.The possible scheme of β-carotene interacting with halogen atom was proposed.
文摘The question of possible teleconnections between the middle latitude general circulation and the Indian south-west monsoon was investigated in this paper. Within the framework of a simple model it was shown that there can exist such an interaction via the ultra-long Rossby waves.
基金Supported by the Education Department of Ministry of Metatturgical Industry of PRC.
文摘In the presence of alkali nitrite and carbonate,some nitrobenzenes subs- tituted by strongly electron withdrawing group undergo a self condensation in an aprotic polar sotvent to give symmetrical disubstituted diphenyl ethers in good yields.A possible mechanism is discussed,the nucteophilic aromatic substitution S_NAr and S_(Ru)Ar may occur simultaneously.
文摘For the superconductors(Rb_xK_(1-x))_3C_(60)(x=0.1),according to BCS theory and assuming that the virtual phonon acting on electron-pair is corresponding to the intrasolecular vibration in the bnckminnterfullerene C_(60),a linear relationship of the superconducting transition temperature T_c with x has been derived,which is in agreement with the experimentals,
文摘When criminal suspects are being investigated for criminal responsibil- ity, they are the most vulnerable to infringement by public power. Thus, they need more special attention and protection. It is the in- evitable requirement of the modern democratic rule of law, and also the inevitable historic choice of respecting and protecting human rights.
基金support for this work,provided by the National Natural Science Foundation of China (No.50834005)
文摘Based on the particularities of gas outbursts,i.e.,low gas bearing capacity and low gas pressure in the "Three Soft" coal seam in western Henan,we applied the theories of plate tectonics and regional structural evolution to investigate the mechanism of this seam and its impact on the coal seam gas formation.Our investigation revealed that coal and gas outbursts are distributed in a strip in a NW direction,with a number of high-penetration mines scattered towards the south side and low-gas mines largely located on the north side.We analyzed the statistics of 38 gas explosions and the rock-coal sturdiness number coefficient f of 167 sampling sites in the region and found the gas outburst mechanism that features a "low indicator outburst phenomenon".The mechanism is characterized by structural coal as its core,a low gas bearing capacity,low gas pressure and sturdiness coefficient f mostly less than 0.3.Our research results provide a theoretical foundation for effective control of gas disasters.
文摘[Mg(H2O)6](NTO)2·2H2O Was prepared by adding magnesium carbonate hydroxide to the aqueous solution of 3-nitro-1,2,4-triazol-5-one(NTO).Its thermal decomposition mechanism was studied by DSC,TG/DTGand IR.The quantum chemical calculation on the title complex as a structure unit with the experimental geometry as atartmg values was carried out at B3LYP level with 6-31G basis set.The results show that the bonds between the coordinate waters and the Mgatom have certain extent covalent character.The net charges on nitrogen atoms of the NTO ring appear to be negative while the nitrogen atom on the nitro group(—NO2)appears to be positive which indicates—NO2 will lost first when the complex is heated to some uniform temperature and this result is in agreement with that of the thermal decomposition experiment.
文摘Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted based on the research site conditions. The geological conditions, dumping operation, and waste particle size distribution were investigated in the Heidaigou open pit mine. Particle size distribution, dumping height, dumping volume, and floor inclination were varied to examine their effects on a single pile formation. The design of blasting can be modified to make the particle size of waste smaller. The volume of the bucket does not have a pronounced effect on dumping pile repose angle, capacity of dumping pile, and dumping area stability. The smaller the floor inclination, the better it is. Two measures are proposed to increase the kinetic force of friction between waste material and floor surface. The interval distance, dumping volume and dumping height were also varied to examine the interaction between the formations of multiple piles. The dumping width should be decided through optimization efficiency of bulldozer and dumping device in bucket wheel excavator-belt-stacker dumping operation and dragline dumping operation. Moreover, the volume of the bucket does not have a pronounced interaction effect. In the dumping operation, the work amount of bulldozer decreases as dumping pile increases. The design of the dumping operation must consider the total efficiency of ground leveling operation and forming dumping the area.
基金Supported by the Youth Science Foundation of Shanxi Province under Grant No 2013021010-3the National Natural Science Foundation of China under Grant Nos 61434002 and 11404202
文摘Effect of mechanical stress on magnetic properties of an exchange-biased ferromagnetic/antiferromagnetic bilayer deposited on a flexible substrate is investigated. The hysteresis loops with different magnitudes and orientations of the stress can be classified into three types. The corresponding physical conditions for each type of the loop are deduced based on the principle of minimal energy. The equation of the critical stress is derived, which can judge whether the loops show hysteresis or not. Numerical calculations suggest that except for the magnitude of the mechanical stress, the relative orientation of the stress is also an important factor to tune the exchange bias effect.
基金sponsored by the China Postdoctoral Science Foundation (Grant No. 2020M673156)Shanghai Pujiang Program (Grant No. 20PJ1404900)。
文摘In this study,the texture evolutions of two Mg materials during tension are explored.In-situ X-ray synchrotron and Visco-Plastic SelfConsistent(VPSC) modeling are employed to investigate the different deformation modes between pure Mg and Mg-15Gd(wt.%) alloy.These two materials with a strong extrusion texture show large different slip/twinning activity behaviors during tensile deformation.The basal(a) slip has the highest contribution to the initial stage of plastic deformation for pure Mg.During the subsequent plastic deformation,the prismatic slip is dominant due to the strong ED//(100) fiber texture.In contrast,the deformation behavior of Mg-15Gd alloy is more complex.Twinning and basal slip are dominant at the early stage of plastic deformation,but further deformation results in the increased activation of prismatic and pyramidal slips.In comparison to pure Mg,the ratios of the critical resolved shear stress(CRSS) between non-basal slip and basal slip of the Mg-15Gd alloy are much lower.
文摘In recent years, many countries implement the TBT in the export trade practice of agricultural products, which has greatly positive influence on the Chinese agricultural products export enterprise. On the basis of green technical innovation concept, the paper had determined the enterprise green technical innovation motivation mechanism, analyzed the influence of TBT on green technical innovation of the enterprise, and integrated Chinese reality to analyze the influence of TBT on green technical innovation of Chinese agricultural enterprise. Finally, based on the above analysis, the paper proposed corresponding suggestions to the Chinese government.
文摘The understanding of the geotechnical problems and failure mechanisms of stone structures of Sakakini palace (1897 after century) entails a comprehensive study on the mechanical behaviour of the stones and other construction materials. In addition to micro analysis, geological and geomorphologic interests, several investigations on stone deterioration and engineering geology were performed, First phase included more sophisticated techniques, which provided additional information on particular aspects of site deterioration and it included laser induced breakdown spectroscopy (LIBs), electron probe micro analysis, micro XRD and XRF analyses, scanning electron microscope analysis coupled with EDX probing, transmission electron microscopy and grain size distribution analysis, permeability and pore size distribution of stone, mortars, core binders and other construction materials. Second phase included the determination of mechanical properties of building stones, such as compressive strength, modulus of elasticity, tensile strength, and shear strength. To arrive at reliable values for these properties, a suitable number of samples should be extracted, prepared for testing, and properly tested. The test results are then analyzed to establish the investigated stone properties. The testing program includes extracting seven cylindrical cores from the basement stone walls of Sakakini’s mansion in down townCairo. The cores are extracted using rotary cylindrical diamond blade coring machine. The top and bottom surfaces of every core were prepared to be flat circular surfaces perpendicular to the vertical axis of the core. Because the palace is museum and attractive places for the tourists, core sampling could be carried out only at a limited number of locations under official permission. For the purpose, cylindrical specimens with a diameter of 42 - 44 mm and height of 90 - 100 mm, prepared by the use of a core drilling machine and some collected blocks from the archaeological site under investtigation were taken to determine the bulk structure, physical, short and long-term mechanical properties of the stone and other construction materials in the laboratory. A number of specimens prepared from these blocks were employed for testing. Furthermore, limitation due to the number of blocks was overcome by the determination of the in situ characteristics of the stones by Schmidt hammer tests, geo-tomographic investigations and rock mass classification on some stone rock structures where testing has been permitted. The objectives of the study are to provide a characterization of micro structures and the mechanical properties of the stones of Sakakini’s Mansion;describe the required testing plan;describe the test results and conclude the values of the basic mechanical properties of the building stones. The following sections provide detailed descriptions of the steps taken to achieve the objectives of the study. The purpose of the present research is to provide recommendations regarding the strengthening and the safety of architectural heritage under long and short-term loading. For this purpose, a set of experimental tests and of advanced numerical analyses are to be carried out.
文摘Objective:To investigate the influencing mechanism of Jin-Shui-Liu-Jun-Jian and Acupoint Application combined therapy on hemorheology, inflammatory factors and pulmonary functions in patients with chronic bronchitis, thus to offer relevant help for clinical therapies on patients with chronic bronchitis. Methods:120 cases of patients with chronic bronchitis treated in our hospital were selected and randomly divided to be the therapeutic group and the control group, 60 cases each. Patients in control group were provided some basic treatments, such as spasmolysis, anti-inflammation, asthma relieving, oxygen inhalation and dissolve phlegm. For therapeutic group on this basis, Jin-Shui-Liu-Jun-Jian and Acupoint Application combined therapy was provided. Hemorheology, inflammatory factors and pulmonary functions in the two groups of patients were detected before and after treatment. Results:Differences of hemorheology indexes, inflammatory factors and pulmonary function relevant indexes between the two groups of patients with chronic bronchitis before treatment showed no statistical significance (P>0.05). Compared with prior treatment, hemorheology relevant indexes [whole blood high shear viscosity (WHV), whole blood low shear viscosity (WLV), packed cell volume (PCV), plasma viscosity (PV) and red cell assembling index (RCAI)], inflammatory factors [IL-8 (interleukin-8) and TNF-α(tumor necrosis factor-α)] were significantly decreased and pulmonary function relevant indexes [forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), peak expiratory flow (PEF), maximal voluntary ventilation (MVV) and expiratory flow rate when exhale vital capacity was 0.50], inflammatory factors (IL-4, IL-2) were significantly increased in the two groups of patients with chronic bronchitis after relevant treatments;The differences between the groups showed statistical significance (P<0.05). After combined therapy provided, pulmonary function relevant indexes (FVC, FEV1.0, PEF, MVV and V0.50) and inflammatory factors (IL-4, IL-2) in therapeutic group were significantly higher than control group after basic therapy. Hemorheology relevant indexes (WHV, WLV, PV, PCV and RCAI) and inflammatory factors (IL-8 and TNF-α) in therapeutic group were significantly lower than control group;Differences between the two groups showed statistical significance (P<0.05). Conclusions: Combination of Jin-Shui-Liu-Jun-Jian and Acupoint Application significantly improved the levels of hemorheology, inflammatory factors and pulmonary functions in patients with chronic bronchitis. It has a great important clinical significance on therapies for patients with chronic bronchitis.