Gas-solid two-phase turbulent flows,mass transfer,heat transfer and catalytic cracking reactions areknown to exert interrelated influences in commercial fluid catalytic cracking(FCC)riser reactors.In the presentpaper,...Gas-solid two-phase turbulent flows,mass transfer,heat transfer and catalytic cracking reactions areknown to exert interrelated influences in commercial fluid catalytic cracking(FCC)riser reactors.In the presentpaper,a three-dimensional turbulent gas-solid two-phase flow-reaction model for FCC riser reactors was devel-oped.The model took into account the gas-solid two-phase turbulent flows,inter-phase heat transfer,masstransfer,catalytic cracking reactions and their interrelated influence.The k-V-k_P two-phase turbulence modelwas employed and modified for the two-phase turbulent flow patterns with relatively high particle concentration.Boundary conditions for the flow-reaction model were given.Related numerical algorithm was formed and a nu-merical code was drawn up.Numerical modeling for commercial FCC riser reactors could be carried out with thepresented model.展开更多
In this study, we present a Pareto-based chemicalreaction optimization(PCRO) algorithm for solving the multiarea environmental/economic dispatch optimization problems.Two objectives are minimized simultaneously, i.e.,...In this study, we present a Pareto-based chemicalreaction optimization(PCRO) algorithm for solving the multiarea environmental/economic dispatch optimization problems.Two objectives are minimized simultaneously, i.e., total fuel cost and emission. In the proposed algorithm, each solution is represented by a chemical molecule. A novel encoding mechanism for solving the multi-area environmental/economic dispatch optimization problems is designed to dynamically enhance the performance of the proposed algorithm. Then, an ensemble of effective neighborhood approaches is developed, and a selfadaptive neighborhood structure selection mechanism is also embedded in PCRO to increase the search ability while maintaining population diversity. In addition, a grid-based crowding distance strategy is introduced, which can obviously enable the algorithm to easily converge near the Pareto front. Furthermore,a kinetic-energy-based search procedure is developed to enhance the global search ability. Finally, the proposed algorithm is tested on sets of the instances that are generated based on realistic production. Through the analysis of experimental results, the highly effective performance of the proposed PCRO algorithm is favorably compared with several algorithms, with regards to both solution quality and diversity.展开更多
In this paper,finite element method(FEM)is used to solve two-dimensional diffu-sion-reaction equations of boundary layer type.This kind of equations are usually too complicatedand diffcult to be solved by applying the...In this paper,finite element method(FEM)is used to solve two-dimensional diffu-sion-reaction equations of boundary layer type.This kind of equations are usually too complicatedand diffcult to be solved by applying the traditional methods used in chemical engineering becauseof the steep gradients of concentration and temperature.But,these difficulties are easy to be over-comed when the FEM is used.The integraded steps of solving this kind of problems by the FEMare presented in this paper.By applying the FEM to the two actual examples,the conclusion can bereached that the FEM has the advantages of simplicity and good accuracy.展开更多
A mathematical model for heap bioleaching is developed to analyze heat transfer, oxygen flow, target ion distribution and oxidation leaching rate in the heap. The model equations are solved with Comsol Multiphysics so...A mathematical model for heap bioleaching is developed to analyze heat transfer, oxygen flow, target ion distribution and oxidation leaching rate in the heap. The model equations are solved with Comsol Multiphysics software. Numerical simulation results show the following facts： Concentration of oxygen is relatively high along the boundary of the slope, and low in the center part where leaching rate is slow. Temper- ature is relatively low along the slope and reaches the highest along the bottom region near the slope, with difference being more than 6℃. Concentration of target mental ions is the highest in the bottom region near the slope. Oxidation leaching rate is relatively large in the bottom and slope part with a fast reaction rate, and small in the other part with low oxygen concentration.展开更多
A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-contain...A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-containing foods or cross-reactivity between α-gliadin and non-gluten foods consumed on a GFD. We measured the reactivity of affinity-purified polyclonal and monoclonal α-gliadin 33-mer peptide antibodies against gliadin and additional food antigens commonly consumed by patients on a GFD using ELISA and dot-blot. We also examined the immune reactivity of these antibodies with various tissue antigens. We observed significant immune reactivity when these antibodies were applied to cow’s milk, milk chocolate, milk butyrophilin, whey protein, casein, yeast, oats, corn, millet, instant coffee and rice. To investigate whether there was cross-reactivity between α-gliadin antibody and different tissue antigens, we measured the degree to which this antibody bound to these antigens. The most significant binding occurred with asialoganglioside, hepatocyte, glutamic acid decarboxylase 65, adrenal 21-hydroxylase, and various neural antigens. The specificity of anti-α-gliadin binding to different food and tissue antigens was demonstrated by absorption and inhibition studies. We also observed significant cross-reactivity between α-gliadin 33-mer and various food antigens, but some of these reactions were associated with the contamination of non-gluten foods with traces of gluten. The consumption of cross-reactive foods as well as gluten-contaminated foods may be responsible for the continuing symptoms presented by a subgroup of patients with coeliac disease. The lack of response of some CD patients may also be due to antibody cross-reactivity with non-gliadin foods. These should then be treated as gluten-like peptides and should also be excluded from the diet when the GFD seems to fail.展开更多
In this paper, we use the Adomian decomposition method (ADM), the finite differences method and the Alternating Direction Implicit method to estimate the advantages and the weakness of the above methods. For it, we ma...In this paper, we use the Adomian decomposition method (ADM), the finite differences method and the Alternating Direction Implicit method to estimate the advantages and the weakness of the above methods. For it, we make a numerical simulation of the different solutions constructed with these methods and compare the error investigated case.展开更多
A practical synthesis of symmetrical vicinal diamines with broad chemistry scope is described. The key step is the ultrasonicwave promoted tandem-reaction, two-step reaction sequence combining Mannich double condensat...A practical synthesis of symmetrical vicinal diamines with broad chemistry scope is described. The key step is the ultrasonicwave promoted tandem-reaction, two-step reaction sequence combining Mannich double condensations with benzo- triazole, glyoxal and primary or secondary amines and reduction of the bis（benzotriazole）-adducts with sodium borohydride proceeded smoothly in tetrahydrofuran in high yield at room temperature.展开更多
Insertion of species A into species B forms a product P through two kinetic processes, namely, （1） the chemical reaction between A and B that occurs at the B-P interface, and （2） the diffusion of species A in prod...Insertion of species A into species B forms a product P through two kinetic processes, namely, （1） the chemical reaction between A and B that occurs at the B-P interface, and （2） the diffusion of species A in product P. These two processes are symbiotic in that the chemical reaction provides the driving force for the diffusion, while the diffusion sustains the chemical reaction by providing sufficient reactant to the reactive interface. In this paper, a math- ematical framework is developed for the coupled reaction- diffusion processes. The resulting system of boundary and initial value problem is solved analytically for the case of interface-reaction controlled diffusion, i.e., the rate of diffu- sion is much faster than the rate of chemical reaction at the interface so that the final kinetics are limited by the interface chemical reaction. Asymptotic expressions are given for the velocity of the reactive interface and the concentration of diffusing species under two different boundary conditions.展开更多
According to probability theory and atomic activation on bonding interface of metals, a mathematical model was developed for the atomic interfacial reaction during diffusion bonding.The effect of parameters of bonding...According to probability theory and atomic activation on bonding interface of metals, a mathematical model was developed for the atomic interfacial reaction during diffusion bonding.The effect of parameters of bonding processing and material on the bonding strength was then gained.It was suggested that the activation centre of atomic interfacial reaction of bonding may be,in situ,the boundary dislocation and its elastic stress field. A substantial agreement about the quantitative prediction of the model was made with the results of diffusion bonding experiments for 7075Al alloy展开更多
Objective: To study the bidirectional adjustment effe ct of ele ctroacupuncture (E A) on the electrical activities of neurons in caudate nucleus (CN) and parafasci cular nucleus (PFN) in rats with acute cerebral hemor...Objective: To study the bidirectional adjustment effe ct of ele ctroacupuncture (E A) on the electrical activities of neurons in caudate nucleus (CN) and parafasci cular nucleus (PFN) in rats with acute cerebral hemorrhage (ACH). Methods: ① 32 male Wistar rats were evenly randomize d into normal, EA+normal, model and model +EA groups for observing the effect of EA on pain reaction; ② another 40 male Wi star rats were equally randomized into control, saline, model and EA groups for comparing the effects of EA on discharges of pain-reaction neurons in CN and P FN . ACH model was established by intracerebral injection of the rat’s own arteria l blood sample (30μL) into CN and PFN. Pain reaction was tested by using tail -flicking (TF) reflex induced by radiation-heat irradiation. Extra-cellular d ischarges of neurons of CN and PFN were recorded by using glass micropipettes. E A (1 V, 15 Hz and duration of 10 min) was applied to "Baihui"(百会 GV 20) and "Taiyang" (太阳 EX-HN 5). Frequency of discharges of CN and PFN neurons was calculated be fore and after intracerebral injection of blood sample, heat nociceptive stimula tion and EA respectively. Results: Compared with con trol group and pre-EA in the same group, TF latency (TFL) values of normal rats increased significantly; compared w ith pre-injection of blood, TFL of model group also increased pronouncedly ( P<0.0 1). In comparison with model group, TFL values of EA group decreased significant ly (P<0.01), indicating that EA of GV 20 and EX-HN 5 could suppress ACH induced increase of TFL. In ACH rats, the latency of pain-excitement response of disch ar ges of CN and PFN neurons increased significantly, while the net increase values of pain-excitement response decreased significantly in model group (P< 0.05～0.01 ), the duration of pain-inhibitory response and the net decrease values of dis ch arges of CN and PFN neurons increased clearly. Comparison between model and EA groups showed that the latency values of the pain-excitement reaction of disch ar ges of CN and PFN neurons in EA group were significantly lower than those in mod el group (P<0.01), while the net increase values of discharges of CN and PFN neu rons in EA group were considerable higher than those in model group (P< 0.01); th e latency and net decrease values of pain-inhibitory CN and PFN neurons in EA gr oup were clearly lower than those in model group. It indicated that EA could pro l ong the latency of pain-excitatory reaction and shorten the duration of pain-i nhi bitory reactions of the neurons induced by cerebral hemorrhage and raise the exc itement degree of CN and PFN neurons. Conclusion: EA can reduce the excitability of pain-excitement neurons (PEN) and lower the inhibitory degree of pain -inhibitory neurons (PIN) in both CN and PFN, an d thus possesses a bidirectional regulation effect on cerebral hemorrhage-induced c hanges of the electrical activities of neurons in both CN and PFN.展开更多
To describe properties of the high frequency gravitational wave (HFGW) propagating through the vacuum gravitational field in Robertson-Walker background space-time,we calculated its energy momentum pseudo-tensor (EMPT...To describe properties of the high frequency gravitational wave (HFGW) propagating through the vacuum gravitational field in Robertson-Walker background space-time,we calculated its energy momentum pseudo-tensor (EMPT) in the limit of short wavelengths by taking the Brill-Hartle average on the second order perturbation of the Einstein tensor over several wavelengths. By rewriting the EMPT as a form of perfect fluid,the dynamical back-reaction of HFGW on the background space-time was discussed. The result shows that the energy density of HFGW,which is in the gauge we chose,is positive definite. The HFGW serves as a source for curving the background space-time and affects the dynamical evolution and time evolution of the scale factor of the Robertson-Walker metric.展开更多
文摘Gas-solid two-phase turbulent flows,mass transfer,heat transfer and catalytic cracking reactions areknown to exert interrelated influences in commercial fluid catalytic cracking(FCC)riser reactors.In the presentpaper,a three-dimensional turbulent gas-solid two-phase flow-reaction model for FCC riser reactors was devel-oped.The model took into account the gas-solid two-phase turbulent flows,inter-phase heat transfer,masstransfer,catalytic cracking reactions and their interrelated influence.The k-V-k_P two-phase turbulence modelwas employed and modified for the two-phase turbulent flow patterns with relatively high particle concentration.Boundary conditions for the flow-reaction model were given.Related numerical algorithm was formed and a nu-merical code was drawn up.Numerical modeling for commercial FCC riser reactors could be carried out with thepresented model.
基金partially supported by the National Natural Science Foundation of China(61773192,61773246,61603169,61803192)Shandong Province Higher Educational Science and Technology Program(J17KZ005)+1 种基金Special Fund Plan for Local Science and Technology Development Lead by Central AuthorityMajor Basic Research Projects in Shandong(ZR2018ZB0419)
文摘In this study, we present a Pareto-based chemicalreaction optimization(PCRO) algorithm for solving the multiarea environmental/economic dispatch optimization problems.Two objectives are minimized simultaneously, i.e., total fuel cost and emission. In the proposed algorithm, each solution is represented by a chemical molecule. A novel encoding mechanism for solving the multi-area environmental/economic dispatch optimization problems is designed to dynamically enhance the performance of the proposed algorithm. Then, an ensemble of effective neighborhood approaches is developed, and a selfadaptive neighborhood structure selection mechanism is also embedded in PCRO to increase the search ability while maintaining population diversity. In addition, a grid-based crowding distance strategy is introduced, which can obviously enable the algorithm to easily converge near the Pareto front. Furthermore,a kinetic-energy-based search procedure is developed to enhance the global search ability. Finally, the proposed algorithm is tested on sets of the instances that are generated based on realistic production. Through the analysis of experimental results, the highly effective performance of the proposed PCRO algorithm is favorably compared with several algorithms, with regards to both solution quality and diversity.
基金Project financially supported by scientific research foundation coferring to Ph.D.
文摘In this paper,finite element method(FEM)is used to solve two-dimensional diffu-sion-reaction equations of boundary layer type.This kind of equations are usually too complicatedand diffcult to be solved by applying the traditional methods used in chemical engineering becauseof the steep gradients of concentration and temperature.But,these difficulties are easy to be over-comed when the FEM is used.The integraded steps of solving this kind of problems by the FEMare presented in this paper.By applying the FEM to the two actual examples,the conclusion can bereached that the FEM has the advantages of simplicity and good accuracy.
基金Supported by the National Natural Science Foundation of China (20233040) and the "973 Projet"of department of Science and Technology of P. R. China (1999022408)
基金Project supported by the National Natural Science Foundation of China (Nos. 50934002 and 50774011)the Postdoctoral Science Foundation of China (No. 20090450014)the DoctoralNatural Science Foundation of China (No. 20070008038)
文摘A mathematical model for heap bioleaching is developed to analyze heat transfer, oxygen flow, target ion distribution and oxidation leaching rate in the heap. The model equations are solved with Comsol Multiphysics software. Numerical simulation results show the following facts： Concentration of oxygen is relatively high along the boundary of the slope, and low in the center part where leaching rate is slow. Temper- ature is relatively low along the slope and reaches the highest along the bottom region near the slope, with difference being more than 6℃. Concentration of target mental ions is the highest in the bottom region near the slope. Oxidation leaching rate is relatively large in the bottom and slope part with a fast reaction rate, and small in the other part with low oxygen concentration.
文摘A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-containing foods or cross-reactivity between α-gliadin and non-gluten foods consumed on a GFD. We measured the reactivity of affinity-purified polyclonal and monoclonal α-gliadin 33-mer peptide antibodies against gliadin and additional food antigens commonly consumed by patients on a GFD using ELISA and dot-blot. We also examined the immune reactivity of these antibodies with various tissue antigens. We observed significant immune reactivity when these antibodies were applied to cow’s milk, milk chocolate, milk butyrophilin, whey protein, casein, yeast, oats, corn, millet, instant coffee and rice. To investigate whether there was cross-reactivity between α-gliadin antibody and different tissue antigens, we measured the degree to which this antibody bound to these antigens. The most significant binding occurred with asialoganglioside, hepatocyte, glutamic acid decarboxylase 65, adrenal 21-hydroxylase, and various neural antigens. The specificity of anti-α-gliadin binding to different food and tissue antigens was demonstrated by absorption and inhibition studies. We also observed significant cross-reactivity between α-gliadin 33-mer and various food antigens, but some of these reactions were associated with the contamination of non-gluten foods with traces of gluten. The consumption of cross-reactive foods as well as gluten-contaminated foods may be responsible for the continuing symptoms presented by a subgroup of patients with coeliac disease. The lack of response of some CD patients may also be due to antibody cross-reactivity with non-gliadin foods. These should then be treated as gluten-like peptides and should also be excluded from the diet when the GFD seems to fail.
文摘In this paper, we use the Adomian decomposition method (ADM), the finite differences method and the Alternating Direction Implicit method to estimate the advantages and the weakness of the above methods. For it, we make a numerical simulation of the different solutions constructed with these methods and compare the error investigated case.
文摘A practical synthesis of symmetrical vicinal diamines with broad chemistry scope is described. The key step is the ultrasonicwave promoted tandem-reaction, two-step reaction sequence combining Mannich double condensations with benzo- triazole, glyoxal and primary or secondary amines and reduction of the bis（benzotriazole）-adducts with sodium borohydride proceeded smoothly in tetrahydrofuran in high yield at room temperature.
基金supported in part by an ISEN Booster Award at Northwestern Universityin part by NSF(CMMI-1200075)
文摘Insertion of species A into species B forms a product P through two kinetic processes, namely, （1） the chemical reaction between A and B that occurs at the B-P interface, and （2） the diffusion of species A in product P. These two processes are symbiotic in that the chemical reaction provides the driving force for the diffusion, while the diffusion sustains the chemical reaction by providing sufficient reactant to the reactive interface. In this paper, a math- ematical framework is developed for the coupled reaction- diffusion processes. The resulting system of boundary and initial value problem is solved analytically for the case of interface-reaction controlled diffusion, i.e., the rate of diffu- sion is much faster than the rate of chemical reaction at the interface so that the final kinetics are limited by the interface chemical reaction. Asymptotic expressions are given for the velocity of the reactive interface and the concentration of diffusing species under two different boundary conditions.
基金supported by the National Natural Science Foundation of China under Grant No. 10671156the Program for New Century Excellent Talents in Universities under Grant No. NCET-04-0968
文摘According to probability theory and atomic activation on bonding interface of metals, a mathematical model was developed for the atomic interfacial reaction during diffusion bonding.The effect of parameters of bonding processing and material on the bonding strength was then gained.It was suggested that the activation centre of atomic interfacial reaction of bonding may be,in situ,the boundary dislocation and its elastic stress field. A substantial agreement about the quantitative prediction of the model was made with the results of diffusion bonding experiments for 7075Al alloy
基金This work was subsidized by National Natural Science Foundation of China (No .39670902)
文摘Objective: To study the bidirectional adjustment effe ct of ele ctroacupuncture (E A) on the electrical activities of neurons in caudate nucleus (CN) and parafasci cular nucleus (PFN) in rats with acute cerebral hemorrhage (ACH). Methods: ① 32 male Wistar rats were evenly randomize d into normal, EA+normal, model and model +EA groups for observing the effect of EA on pain reaction; ② another 40 male Wi star rats were equally randomized into control, saline, model and EA groups for comparing the effects of EA on discharges of pain-reaction neurons in CN and P FN . ACH model was established by intracerebral injection of the rat’s own arteria l blood sample (30μL) into CN and PFN. Pain reaction was tested by using tail -flicking (TF) reflex induced by radiation-heat irradiation. Extra-cellular d ischarges of neurons of CN and PFN were recorded by using glass micropipettes. E A (1 V, 15 Hz and duration of 10 min) was applied to "Baihui"(百会 GV 20) and "Taiyang" (太阳 EX-HN 5). Frequency of discharges of CN and PFN neurons was calculated be fore and after intracerebral injection of blood sample, heat nociceptive stimula tion and EA respectively. Results: Compared with con trol group and pre-EA in the same group, TF latency (TFL) values of normal rats increased significantly; compared w ith pre-injection of blood, TFL of model group also increased pronouncedly ( P<0.0 1). In comparison with model group, TFL values of EA group decreased significant ly (P<0.01), indicating that EA of GV 20 and EX-HN 5 could suppress ACH induced increase of TFL. In ACH rats, the latency of pain-excitement response of disch ar ges of CN and PFN neurons increased significantly, while the net increase values of pain-excitement response decreased significantly in model group (P< 0.05～0.01 ), the duration of pain-inhibitory response and the net decrease values of dis ch arges of CN and PFN neurons increased clearly. Comparison between model and EA groups showed that the latency values of the pain-excitement reaction of disch ar ges of CN and PFN neurons in EA group were significantly lower than those in mod el group (P<0.01), while the net increase values of discharges of CN and PFN neu rons in EA group were considerable higher than those in model group (P< 0.01); th e latency and net decrease values of pain-inhibitory CN and PFN neurons in EA gr oup were clearly lower than those in model group. It indicated that EA could pro l ong the latency of pain-excitatory reaction and shorten the duration of pain-i nhi bitory reactions of the neurons induced by cerebral hemorrhage and raise the exc itement degree of CN and PFN neurons. Conclusion: EA can reduce the excitability of pain-excitement neurons (PEN) and lower the inhibitory degree of pain -inhibitory neurons (PIN) in both CN and PFN, an d thus possesses a bidirectional regulation effect on cerebral hemorrhage-induced c hanges of the electrical activities of neurons in both CN and PFN.
基金the National Basic Research Program of China (No.2003 CB 716300)the National Natural Science Foundation of China (No.10575140)+1 种基金the Nature Science Foundation of Chongqing (No. 8562)the Foundation of China Academy of Engineering Physics.
文摘To describe properties of the high frequency gravitational wave (HFGW) propagating through the vacuum gravitational field in Robertson-Walker background space-time,we calculated its energy momentum pseudo-tensor (EMPT) in the limit of short wavelengths by taking the Brill-Hartle average on the second order perturbation of the Einstein tensor over several wavelengths. By rewriting the EMPT as a form of perfect fluid,the dynamical back-reaction of HFGW on the background space-time was discussed. The result shows that the energy density of HFGW,which is in the gauge we chose,is positive definite. The HFGW serves as a source for curving the background space-time and affects the dynamical evolution and time evolution of the scale factor of the Robertson-Walker metric.
