As the scale of residual oil treatment increases and cleaner production improves in China,slurry bubble column reactors face many challenges and opportunities for residual oil hydrogenation technology.The internals de...As the scale of residual oil treatment increases and cleaner production improves in China,slurry bubble column reactors face many challenges and opportunities for residual oil hydrogenation technology.The internals development is critical to adapt the long-term stable operation.In this paper,the volumetric mass transfer coefficient,gas holdup and bubble size in a gas-liquid up-flow column are studied with two kinds of internals.The gas holdup and volumetric mass transfer coefficient increase by 120% and 42% when the fractal dimension of bubbles increases from 0.56 to 2.56,respectively.The enhanced mass transfer processing may improve the coke suppression ability in the slurry reactor for residual oil treatment.The results can be useful for the exploration of reacting conditions,scale-up strategies,and oil adaptability.This work is valuable for the design of reactor systems and technological processes.展开更多
Deep rock mass has the unique "self-stressed" block-hierarchical structure,anomalous low friction(ALF) was one of the typical nonlinear geo-mechanical and dynamic responses in deep block rock mass,which occu...Deep rock mass has the unique "self-stressed" block-hierarchical structure,anomalous low friction(ALF) was one of the typical nonlinear geo-mechanical and dynamic responses in deep block rock mass,which occurred as the result of movements of large-scale geo-blocks under the impact of external pulses(such as a deep confined explosion,earthquakes,rock bursts and etc.).ALF phenomenon obtained its name to describe the curious phenomenon that the friction between interacting geo-blocks quasi-periodically disappears at some discrete points in time along the direction orthogonal to the direction of the external pulse.With the objective to confirm the existence of the ALF phenomenon and study the geo-mechanical conditions for its occurrence experimentally and theoretically,laboratory tests on granite and cement mortar block models were carried out on a multipurpose testing system developed independently.The ALF phenomenon was realized under two loading schemes,i.e.,blocks model and a working block were acted upon jointly by the action of a vertical impact and a horizontal static force,as well as the joint action of both vertical and horizontal impacts with differently delayed time intervals.We obtained the rules on variation of horizontal displacements of working blocks when the ALF phenomenon was realized in two tests.The discrete time delay intervals,corresponding to local maxima and minima of the horizontal displacement amplitudes and residual horizontal displacements of the working block,satisfied canonical sequences multiplied by(2～(1/2))i.Some of these time intervals satisfied the quantitative expression(2～(1/2))i Δ /Vp.At last,1D dynamic theoretical model was established,the analytical results agreed better with the test data,while the quantitative expression drawn from test data was not validated well in theoretical analyses.展开更多
In this work we consider a mechanism for mass creation based on the periodicity condition dictated from the compactification of extradimensions. It is shown that the existence and the compactification of extradimensio...In this work we consider a mechanism for mass creation based on the periodicity condition dictated from the compactification of extradimensions. It is shown that the existence and the compactification of extradimensions are the origin for creating particle mass in ordinary 4-dimensional space-time. Mass of Higgs particles themselves would be also originated from the geometric topology of extradimensions.展开更多
Based on the mechanism for mass creation in the space-time with extradimensions proposed in our previous work, (arXiv: 1301.1405 [hep-th] 2013) we consider now the mass spectrum of vector bosons in extradimensions. It...Based on the mechanism for mass creation in the space-time with extradimensions proposed in our previous work, (arXiv: 1301.1405 [hep-th] 2013) we consider now the mass spectrum of vector bosons in extradimensions. It is shown that this spectrum is completely determined by some function of compactification length and closely related to the metric of extradimensions.展开更多
Space is a common entity in any static or dynamic system of objects whether the system is a bound system or an open system. Space is described by either measured or abstract dimensions. All motions, momentum and energ...Space is a common entity in any static or dynamic system of objects whether the system is a bound system or an open system. Space is described by either measured or abstract dimensions. All motions, momentum and energy transfers take place in space in any given system of objects. By understanding space we understand many physical phenomena happening in space. One method is to observe similarities among phenomena, deduce possible relations and validate the relations through known results. De Broglie wavelength for matter waves is a typical theorized abstract dimension existence of which is established through experiments later. In this paper, the author studies two bound spaces in two bound systems, namely, atomic bound systems and gravitationally bound systems. Both these bound systems have similar characteristics;they have inertial masses in motion with constant kinetic energies for a given orbital distance around the respective central object. In atomic bound space, the central object is the central positive charge which plays the role of creating the bound space around it. In gravitationally bound space, it is the central mass that plays the same role. Thus for these two bound systems a common constitutive relation between the energies of inertial masses in kinetic state, their distance from central object could be present. By noticing the similarities of the two systems, the author proposes such a relation through introduction of an additional space dimension. The existence of the proposed additional dimension is proved in this paper by considering hydrogen atom for atomic bound space and by considering any gravitational system for gravitationally bound space. Though the magnitude of the additional space dimension is different in both the situations, the additional space dimension exists. It is observed that in hydrogen atom the additional space dimension is a constant for the given positive charge of hydrogen atom when electron is in any energy state having principal quantum number of any value from 1 to 5 and with the orbital quantum number zero. For other quantum numbers additional space dimension exists. In the case of gravitational bound space, the additional space dimension is constant for a given mass of the central object for any energy of orbiting inertial mass. The author concludes that total mass energy of an inertial mass having a constant kinetic energy in any bound space is related to an additional space dimension defined by the constitutional property of the central object creating that bound space. As the relation is generic, it throws opportunity to examine other known similar macro, micro or quantum bound spaces created by central objects with different constitutive properties.展开更多
The geological strength index(GSI) system,widely used for the design and practice of mining process,is a unique rock mass classification system related to the rock mass strength and deformation parameters based on the...The geological strength index(GSI) system,widely used for the design and practice of mining process,is a unique rock mass classification system related to the rock mass strength and deformation parameters based on the generalized Hoek-Brown and Mohr-Coulomb failure criteria.The GSI can be estimated using standard chart and field observations of rock mass blockiness and discontinuity surface conditions.The GSI value gives a numerical representation of the overall geotechnical quality of the rock mass.In this study,we propose a method to determine the GSI quantitatively using photographic images of in situ jointed rock mass with image processing technology,fractal theory and artificial neural network(ANN).We employ the GSI system to characterize the jointed rock mass around the working in a coal mine.The relative error between the proposed value and the given value in the GSI chart is less than 3.6%.展开更多
Background Anomalous origin of the left coronary artery cardiac lesion resulting in myocardial ischemia even infarction, from the pulmonary artery is a rare congenital morphological impairment and dysfunction of left ...Background Anomalous origin of the left coronary artery cardiac lesion resulting in myocardial ischemia even infarction, from the pulmonary artery is a rare congenital morphological impairment and dysfunction of left ventricle, together with mitral regurgitation. Here we will introduce our experience in the surgical repair of this kind of congenital lesion and the retrospective analysis about the improvement of left ventricular dimension and mitral regurgitation in early postoperative term. Method From May 1998 to July 2012, 38 consecutive patients with anomalous coronary artery from the pulmonary artery underwent surgical correction （33 received left coronary artery re-implantation, 4 left coronary artery ligation or primary closure, 1 Takeuchi procedure, and 10 simultaneous mitral valve plasty）. Left ventricular dimension, mitral regurgitation, and ejection fraction, were measured by color Doppler echocardiography preoperatively, and 1 month after discharge. Results Hospital survival was 94.7% （2 in-hospital deaths）. Ten paptients with more than moderate mitral regurgitation received simultaneous mitral plasty, one of whom was converted to mechanical prosthetic valve replacement. Mitral valve annuloplasty was applied in 9 cases of coronary re-implantation correction, 3 of whom also received additional mitral leaflet cleft repair. Meanwhile 8 patients underwent other different concomitant operations. Echocardiographic results for the survivals 1 month after discharge showed that left ventricular end-diastolic, endsystolic dimension decreased from 40.05 ± 5.56 mm and 28.94 ± 6.21 mm to 33.07 ± 6.82 mr, （P 〈 0.01） and 23.04 ±5.87 mm （P 〈 0.01） respectively. The average mitral regurgitation grade was also reduced from 2.36 ± 1.08 to 1.64 ± 93 （P 〈 0.05） in the group. All survival patients improved clinically and NYHA functional class decreased significantly from 2.37 ± 1.08 to 2.10 ±0.54 （P 〈 0.05）. Conclusions The surgical repair of anomalous origin of the left coronary artery from the pulmonary artery is safe and effective, and can get satisfactory dimensional and functional improvement of the left ventricle in early term. Although controversial, concomitant mitral valve plasty can be helpful for critical patients with severe mitral regurgitation.展开更多
In the present work, we develop a method to derive the anomalous velocity of a spinning electron. From Dirac equation, the relationships among the expectation values of the Pryce's mass-center operator, the positi...In the present work, we develop a method to derive the anomalous velocity of a spinning electron. From Dirac equation, the relationships among the expectation values of the Pryce's mass-center operator, the position operator, the spin operator and the canonical momentum operator are investigated. By requiring that the center of mass for a classical spinning electron is related to the expectation value of Pryce's mass-center operator, one can obtain a classical expression for the position of the electron.With the classical equations of motion, the anomalous velocity of a spinning electron can be easily obtained. It is shown that two factors contribute to the anomalous velocity: one is dependent on the selection of Pryce's mass-center operators and the other is a type-independent velocity expressed by the rotational velocity and the Lorentz force.展开更多
基金the National Natural Science Foundation of China(51678238,51722806,51608325,21908057)National Key R&D Program of China(2018YFC1802704,2018YFC1801904)+1 种基金China Postdoctoral Science Foundation funded project(2018M641942)Shanghai Sailing Program(19YF1411800)for financial support.
文摘As the scale of residual oil treatment increases and cleaner production improves in China,slurry bubble column reactors face many challenges and opportunities for residual oil hydrogenation technology.The internals development is critical to adapt the long-term stable operation.In this paper,the volumetric mass transfer coefficient,gas holdup and bubble size in a gas-liquid up-flow column are studied with two kinds of internals.The gas holdup and volumetric mass transfer coefficient increase by 120% and 42% when the fractal dimension of bubbles increases from 0.56 to 2.56,respectively.The enhanced mass transfer processing may improve the coke suppression ability in the slurry reactor for residual oil treatment.The results can be useful for the exploration of reacting conditions,scale-up strategies,and oil adaptability.This work is valuable for the design of reactor systems and technological processes.
基金Projects 50525825 and 90815010 supported by the National Natural Science Foundation of China2009CB724608 by the National Basic Research Program of ChinaBK2008002 by the Natural Science Foundation of Jiangsu Province
文摘Deep rock mass has the unique "self-stressed" block-hierarchical structure,anomalous low friction(ALF) was one of the typical nonlinear geo-mechanical and dynamic responses in deep block rock mass,which occurred as the result of movements of large-scale geo-blocks under the impact of external pulses(such as a deep confined explosion,earthquakes,rock bursts and etc.).ALF phenomenon obtained its name to describe the curious phenomenon that the friction between interacting geo-blocks quasi-periodically disappears at some discrete points in time along the direction orthogonal to the direction of the external pulse.With the objective to confirm the existence of the ALF phenomenon and study the geo-mechanical conditions for its occurrence experimentally and theoretically,laboratory tests on granite and cement mortar block models were carried out on a multipurpose testing system developed independently.The ALF phenomenon was realized under two loading schemes,i.e.,blocks model and a working block were acted upon jointly by the action of a vertical impact and a horizontal static force,as well as the joint action of both vertical and horizontal impacts with differently delayed time intervals.We obtained the rules on variation of horizontal displacements of working blocks when the ALF phenomenon was realized in two tests.The discrete time delay intervals,corresponding to local maxima and minima of the horizontal displacement amplitudes and residual horizontal displacements of the working block,satisfied canonical sequences multiplied by(2～(1/2))i.Some of these time intervals satisfied the quantitative expression(2～(1/2))i Δ /Vp.At last,1D dynamic theoretical model was established,the analytical results agreed better with the test data,while the quantitative expression drawn from test data was not validated well in theoretical analyses.
文摘In this work we consider a mechanism for mass creation based on the periodicity condition dictated from the compactification of extradimensions. It is shown that the existence and the compactification of extradimensions are the origin for creating particle mass in ordinary 4-dimensional space-time. Mass of Higgs particles themselves would be also originated from the geometric topology of extradimensions.
文摘Based on the mechanism for mass creation in the space-time with extradimensions proposed in our previous work, (arXiv: 1301.1405 [hep-th] 2013) we consider now the mass spectrum of vector bosons in extradimensions. It is shown that this spectrum is completely determined by some function of compactification length and closely related to the metric of extradimensions.
文摘Space is a common entity in any static or dynamic system of objects whether the system is a bound system or an open system. Space is described by either measured or abstract dimensions. All motions, momentum and energy transfers take place in space in any given system of objects. By understanding space we understand many physical phenomena happening in space. One method is to observe similarities among phenomena, deduce possible relations and validate the relations through known results. De Broglie wavelength for matter waves is a typical theorized abstract dimension existence of which is established through experiments later. In this paper, the author studies two bound spaces in two bound systems, namely, atomic bound systems and gravitationally bound systems. Both these bound systems have similar characteristics;they have inertial masses in motion with constant kinetic energies for a given orbital distance around the respective central object. In atomic bound space, the central object is the central positive charge which plays the role of creating the bound space around it. In gravitationally bound space, it is the central mass that plays the same role. Thus for these two bound systems a common constitutive relation between the energies of inertial masses in kinetic state, their distance from central object could be present. By noticing the similarities of the two systems, the author proposes such a relation through introduction of an additional space dimension. The existence of the proposed additional dimension is proved in this paper by considering hydrogen atom for atomic bound space and by considering any gravitational system for gravitationally bound space. Though the magnitude of the additional space dimension is different in both the situations, the additional space dimension exists. It is observed that in hydrogen atom the additional space dimension is a constant for the given positive charge of hydrogen atom when electron is in any energy state having principal quantum number of any value from 1 to 5 and with the orbital quantum number zero. For other quantum numbers additional space dimension exists. In the case of gravitational bound space, the additional space dimension is constant for a given mass of the central object for any energy of orbiting inertial mass. The author concludes that total mass energy of an inertial mass having a constant kinetic energy in any bound space is related to an additional space dimension defined by the constitutional property of the central object creating that bound space. As the relation is generic, it throws opportunity to examine other known similar macro, micro or quantum bound spaces created by central objects with different constitutive properties.
文摘The geological strength index(GSI) system,widely used for the design and practice of mining process,is a unique rock mass classification system related to the rock mass strength and deformation parameters based on the generalized Hoek-Brown and Mohr-Coulomb failure criteria.The GSI can be estimated using standard chart and field observations of rock mass blockiness and discontinuity surface conditions.The GSI value gives a numerical representation of the overall geotechnical quality of the rock mass.In this study,we propose a method to determine the GSI quantitatively using photographic images of in situ jointed rock mass with image processing technology,fractal theory and artificial neural network(ANN).We employ the GSI system to characterize the jointed rock mass around the working in a coal mine.The relative error between the proposed value and the given value in the GSI chart is less than 3.6%.
基金supported by The Twelfth National Five-Year Plan (Grant No. 2011BAI11B22)
文摘Background Anomalous origin of the left coronary artery cardiac lesion resulting in myocardial ischemia even infarction, from the pulmonary artery is a rare congenital morphological impairment and dysfunction of left ventricle, together with mitral regurgitation. Here we will introduce our experience in the surgical repair of this kind of congenital lesion and the retrospective analysis about the improvement of left ventricular dimension and mitral regurgitation in early postoperative term. Method From May 1998 to July 2012, 38 consecutive patients with anomalous coronary artery from the pulmonary artery underwent surgical correction （33 received left coronary artery re-implantation, 4 left coronary artery ligation or primary closure, 1 Takeuchi procedure, and 10 simultaneous mitral valve plasty）. Left ventricular dimension, mitral regurgitation, and ejection fraction, were measured by color Doppler echocardiography preoperatively, and 1 month after discharge. Results Hospital survival was 94.7% （2 in-hospital deaths）. Ten paptients with more than moderate mitral regurgitation received simultaneous mitral plasty, one of whom was converted to mechanical prosthetic valve replacement. Mitral valve annuloplasty was applied in 9 cases of coronary re-implantation correction, 3 of whom also received additional mitral leaflet cleft repair. Meanwhile 8 patients underwent other different concomitant operations. Echocardiographic results for the survivals 1 month after discharge showed that left ventricular end-diastolic, endsystolic dimension decreased from 40.05 ± 5.56 mm and 28.94 ± 6.21 mm to 33.07 ± 6.82 mr, （P 〈 0.01） and 23.04 ±5.87 mm （P 〈 0.01） respectively. The average mitral regurgitation grade was also reduced from 2.36 ± 1.08 to 1.64 ± 93 （P 〈 0.05） in the group. All survival patients improved clinically and NYHA functional class decreased significantly from 2.37 ± 1.08 to 2.10 ±0.54 （P 〈 0.05）. Conclusions The surgical repair of anomalous origin of the left coronary artery from the pulmonary artery is safe and effective, and can get satisfactory dimensional and functional improvement of the left ventricle in early term. Although controversial, concomitant mitral valve plasty can be helpful for critical patients with severe mitral regurgitation.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11405136, and 11747311)the Fundamental Research Funds for the Central Universities (Grant No. 2682016CX059)
文摘In the present work, we develop a method to derive the anomalous velocity of a spinning electron. From Dirac equation, the relationships among the expectation values of the Pryce's mass-center operator, the position operator, the spin operator and the canonical momentum operator are investigated. By requiring that the center of mass for a classical spinning electron is related to the expectation value of Pryce's mass-center operator, one can obtain a classical expression for the position of the electron.With the classical equations of motion, the anomalous velocity of a spinning electron can be easily obtained. It is shown that two factors contribute to the anomalous velocity: one is dependent on the selection of Pryce's mass-center operators and the other is a type-independent velocity expressed by the rotational velocity and the Lorentz force.
