Fault diagnosis in multiprocessor systems is critical for ensuring system reliability.The exchanged crossed cube(ECQ(s,t)),which combines the advantages of the exchanged cube and the crossed cube,offers a high perform...Fault diagnosis in multiprocessor systems is critical for ensuring system reliability.The exchanged crossed cube(ECQ(s,t)),which combines the advantages of the exchanged cube and the crossed cube,offers a high performance-to-cost ratio but lacks comprehensive analysis in terms of fault tolerance.This paper investigates the 1-good-neighbor diagnosability of the ECQ(s,t),assuming that each fault-free node has at least one fault-free neighbor.We rigorously prove that the 1-good-neighbor diagnosability of The ECQ(s,t)under the Preparata,Metze,and Chien(PMC)model and Maeng and Malek(MM)model is t_(1)=2s+1(for t≥s≥4)and t_(1)=2s+1(for t≥s≥5),respectively.Furthermore,we design an efficient diagnostic algorithm based on the 1-good-neighbor criterion.Simulation results demonstrate the algorithm’s effectiveness,exhibiting lower time complexity and improved performance in faulty node identification.These results offer theoretical insights and practical tools for enhancing the fault diagnosis capabilities of ECQ(s,t).展开更多
The pioneering works have demonstrated that the method of single collisions in crossed molecular beams is an important technique for achieving kinetic cooling of atoms or molecules in specific rotational states.In thi...The pioneering works have demonstrated that the method of single collisions in crossed molecular beams is an important technique for achieving kinetic cooling of atoms or molecules in specific rotational states.In this study,we investigated the elastic and inelastic collisions between Al(^(2)P_(1/2))metal atoms and O_(2)molecules at high collision energies in the range of 6.4-14.8 kcal/mol,utilizing the laser-ablation crossed beams in conjunction with time-sliced ion velocity map imaging technique.We observed kinetic cooling of Al(^(2)P_(1/2))atoms with an upper-limit laboratory-frame root-mean-square velocity of 24±3 m/s,corresponding to a translational temperature of 0.9±0.2 K in the laboratory frame,facilitated by the vibrational excitation of O_(2)(v′=1)in inelastic collisions.The translational cooling of Al atoms in the lab frame enhanced detection probability in the transformation of density-to-flux,as evidenced by the scattering images obtained during the experiments.展开更多
The linear operations of the equivalent classes of crossed modules of Lie color algebras are studied. The set of the equivalent classes of crossed modules is proved to be a vector space, which is isomorphic with the h...The linear operations of the equivalent classes of crossed modules of Lie color algebras are studied. The set of the equivalent classes of crossed modules is proved to be a vector space, which is isomorphic with the homogeneous components of degree zero of the third cohomology group of Lie color algebras. As an application of this theory, the crossed modules of Witt type Lie color algebras is described, and the result is proved that there is only one equivalent class of the crossed modules of Witt type Lie color algebras when the abelian group Г is equal to Г＋. Finally, for a Witt type Lie color algebra, the classification of its crossed modules is obtained by the isomorphism between the third cohomology group and the crossed modules.展开更多
The reaction of crossed diperoxidation between the cyclic ketones and the alkyl ketones was investigated. The reaction is a competing in different ketones. It is slightly favorable to resulting in crossed ketone diper...The reaction of crossed diperoxidation between the cyclic ketones and the alkyl ketones was investigated. The reaction is a competing in different ketones. It is slightly favorable to resulting in crossed ketone diperoxide and to resulting in crossed cycloketone diperoxide when the cycloketone reacts with the aliphatic ketone.展开更多
In this paper we generalize the notions of crossed products and L-R smash products in the context of multiplier Hopf algebras. We use comodule algebras to define generalized diagonal crossed products, L-R smash produc...In this paper we generalize the notions of crossed products and L-R smash products in the context of multiplier Hopf algebras. We use comodule algebras to define generalized diagonal crossed products, L-R smash products, two-sided smash products and two-sided crossed products and prove that they are all associative algebras. Then we show the isomorphic relations of them.展开更多
The crossed beams scattering dynamics of the F＋HD→HF＋D reaction have been studied at collision energies ranging from 8.19 k J/tool to 18.98 k J/tool using the high resolution H-atom Rydberg tagging time-of-flight m...The crossed beams scattering dynamics of the F＋HD→HF＋D reaction have been studied at collision energies ranging from 8.19 k J/tool to 18.98 k J/tool using the high resolution H-atom Rydberg tagging time-of-flight method. Product rotational state-resolved differential cross sections have been measured. Most of the DF products are backward scattered at low collision energies and then gradually shift to the sideway as the collision energy increases. In addition to the backward and sideway scatterings, we have also observed the DF（v＇=4） product in the forward direction for the first time for this reaction. The forward scattering DF（v=4） product also increases with the collision energy. Angular and collision energy dependence of the product energy disposals in different degrees of freedom have been determined. Collision energy dependence of the vibrational branching ratios has also been examined. Possible dynamical origins of the forward scattering DF（v＇=4） products were discussed.展开更多
keep one s fingers crossed 的字面意思是将手指交叉起来,通常是用中指压住食指,也有人习惯于食指压住中指。这个短语的比喻意义是 to hope that nothing will happento upset one s plans,即“希望一切如愿”“但愿别出差错”。如:He ...keep one s fingers crossed 的字面意思是将手指交叉起来,通常是用中指压住食指,也有人习惯于食指压住中指。这个短语的比喻意义是 to hope that nothing will happento upset one s plans,即“希望一切如愿”“但愿别出差错”。如:He is keeping his fingers crossed that itwon t rain on Sunday when he wants to playfootball.他想星期天去踢球。展开更多
Some sufficient and necessary conditions are given for the equivalence between two crossed product actions of Hopf algebra H on the same linear category, and the Maschke theorem is generalized. Based on the result of ...Some sufficient and necessary conditions are given for the equivalence between two crossed product actions of Hopf algebra H on the same linear category, and the Maschke theorem is generalized. Based on the result of the crossed product in the classic Hopf algebra theory, first, let A be a k-linear category and H be a Hopf algebra, and the two crossed products A#_σH and A#＇_σH are isomorphic under some conditions. Then, let A#_σH be a crossed product category for a finite dimensional and semisimple Hopf algebra H. If V is a left A#σH-module and WC V is a submodule such that W has a complement as a left A-module, then W has a complement as a A#_σH-module.展开更多
We have investigated the dynamics of the F＋C4H6 reaction using the universal crossed molecular beam method. The C4H5F＋H reaction channel was observed in this experiment. Angular resolved time-of-flight spectra have ...We have investigated the dynamics of the F＋C4H6 reaction using the universal crossed molecular beam method. The C4H5F＋H reaction channel was observed in this experiment. Angular resolved time-of-flight spectra have been measured for the C4H5F product. Prod- uct angular distributions as well as kinetic energy distributions were determined for this product channel. Experimental results show that the C4H5F product is largely backward scattered with considerable forward scattering signal, relative to the F atom beam direction. This suggests that the reaction channel mainly proceeds via a long-lived complex formation mechanism, with possible contribution from a direct SN2 type mechanism.展开更多
The dynamics of F＋HD→HF＋D reaction has been studied at ten collision energies ranging from 5.43 kJ/mol to 18.73 kJ/mol using high-resolution H/D atom Rydberg tagging time-of-flight method. Product vibrational and r...The dynamics of F＋HD→HF＋D reaction has been studied at ten collision energies ranging from 5.43 kJ/mol to 18.73 kJ/mol using high-resolution H/D atom Rydberg tagging time-of-flight method. Product vibrational and rotational state-resolved differential cross sections have been determined. The intensity of the HF（v1=2） forward products decreases as the collision energy increases, suggesting that the resonance contribution is reduced as the collision energy increases. The forward peak of HF（vl=3） product has also been observed above the threshold of this product channel. Product energy disposals in different degrees of freedom have been analyzed. The collision energy dependence of the HF vibrational product branching was also determined. This work presents a comprehensive dynamic picture of this resonance mediated reaction in a wide collision energy regime, providing a good test ground for theoretical understandings of this interesting reaction at higher collision energies.展开更多
Beveloid gears,also known as conical gears,gain more and more importance in industry practice due to their abilities for power transmission between parallel,intersected and crossed axis.However,this type of gearing wi...Beveloid gears,also known as conical gears,gain more and more importance in industry practice due to their abilities for power transmission between parallel,intersected and crossed axis.However,this type of gearing with crossed axes has no common plane of action which results in a point contact and low tooth durability.Therefore,a geometry design approach assuming line contact is developed to analyze the tooth engagement process of crossed beveloid gears with small shaft angle for marine transmission applications.The loaded gear tooth contact behavior is simulated by applying a quasi-static analysis to study the effects of gearing parameters on mesh characteristics.Using the proposed method,a series of sensitivity analyses to examine the effects of critical gearing parameters such as shaft angle,cone angle,helix angle and profile-shift coefficient on the theoretical gear mesh is performed.The parametric analysis of pitch cone design shows that the dominant design parameters represented by the angle between the first principle directions（FPD） and normal angular factor are more sensitive to the shaft and cone angles than they are to the helix angle.The theoretical contact path is highly sensitive to the profile-shift coefficient,which is determined from the theoretical tooth contact analysis.The FPD angle is found to change the distribution of contact pattern,contact pressure and root stress as well as the translational transmission error and the variation of the mesh stiffness significantly.The contact pattern is clearly different between the drive and coast sides due to different designed FPD angles.Finally,a practical experimental setup for marine transmission is performed and tooth bearing test is conducted to demonstrate the proposed design procedure.The experimental result compared well with the simulation.Results of this study yield a better understanding of the geometry design and loaded gear mesh characteristics for crossed beveloid gears used in marine transmission.展开更多
The dynamics of the Cl＋SiH4 reaction has been studied using the universal crossed molecular beam method. Angular resolved time-of-flight spectra have been measured for the channel SiH3Cl＋H. Product angular distribut...The dynamics of the Cl＋SiH4 reaction has been studied using the universal crossed molecular beam method. Angular resolved time-of-flight spectra have been measured for the channel SiH3Cl＋H. Product angular distributions as well as energy distributions in the center-ofmass frame were determined for the channel. Experimental results show that the SiH3Cl product is mainly backward scattered relative to the Cl atom beam direction, suggesting that the channel takes place via a typical SN2 type reaction mechanism.展开更多
We study the H＋CH4/CD4-＋H2/HD＋CH3/CD3 reactions using the time sliced velocity map ion imaging technique. Ion images of the CH3/CD3 products were measured by the （2＋1） resonance enhanced multi-photon ionization ...We study the H＋CH4/CD4-＋H2/HD＋CH3/CD3 reactions using the time sliced velocity map ion imaging technique. Ion images of the CH3/CD3 products were measured by the （2＋1） resonance enhanced multi-photon ionization （REMPI） detection method. Besides the CH3/CD3 products in the ground state, ion images of the vibrationally excited CH3/CD3 products were also observed at two collision energies of 0.72 and 1.06 eV. It is shown that the angular distribution of the products CH3/CD3 in vibrationally excited states gradually vary from backward scattering to sideways scattering as the collision energy increases. Compared to the CH3/CD3 products in the ground state, the CH3/CD3 products in vibrationally excited states tend to be more sideways scattered, indicating that larger impact parameters play a more important role in the vibrationally excited product channels.展开更多
We introduce a special tracial Rokhlin property for unital C~＊-algebras. Let A be a unital tracial rank zero C~＊-algebra（or tracial rank no more than one C~＊-algebra）. Suppose that α ： G → Aut（A） is an actio...We introduce a special tracial Rokhlin property for unital C~＊-algebras. Let A be a unital tracial rank zero C~＊-algebra（or tracial rank no more than one C~＊-algebra）. Suppose that α ： G → Aut（A） is an action of a finite group G on A, which has this special tracial Rokhlin property, and suppose that A is a α-simple C~＊-algebra. Then, the crossed product C~＊-algebra C~＊（G, A, α） has tracia rank zero（or has tracial rank no more than one）. In fact,we get a more general results.展开更多
TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,t...TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,the presence of alcohol and the temperature were carefully investigated on the crystallization process.The high alkalinity was proved to be highly important for the preservation of the microsphere morphology initially formed,due to the unique intergrown stacking style.An alkali treatment with the aqueous solution of structure-directing agent,organic amine and ammonium salt and subsequent Na+ion-exchange were performed to enhance the catalytic activity of TS-2 microsphere in the cyclohexanone ammoximation reactions,with both the conversion and selectivity higher than 99%.In the continuous reaction,the TS-2 microspheres exhibited to be durable catalyst with potential application in industrial ammoximation processes.展开更多
The tunneling between double wells of atom in crossed electromagnetic fields is investigated by a one-dimensional Hamiltonian model. The crossed fields induced outer well is apart from the nuclear origin and it is ver...The tunneling between double wells of atom in crossed electromagnetic fields is investigated by a one-dimensional Hamiltonian model. The crossed fields induced outer well is apart from the nuclear origin and it is very difficult to access by means of spectroscopy but it will be possible if there exists the tunneling of the electron between the outer well and the Coulomb potential predominated well at the nuclear origin. A one-dimensional quantum calculation with B-spline basis has been performed for hydrogen atom in crossed fields accessible in our laboratory, at B = 0.8 T and F = -220 V.cm^-1. The calculation shows that the wavefunctions of some excited states close to the Stark saddle point in the outer well extend over to the Coulomb potential well, making it possible to penetrate the quantum information of the outer well. However, the tunneling rate is very small and the spectral measurement of the transitions from the ground state should be of a high resolution and high sensitivity.展开更多
The H+H2 reaction is the simplest chemical reaction system and has long been the prototype model in the study of reaction dynamics. Here we report a high resolution experimental investigation of the state-to-state rea...The H+H2 reaction is the simplest chemical reaction system and has long been the prototype model in the study of reaction dynamics. Here we report a high resolution experimental investigation of the state-to-state reaction dynamics in the H+HD→H2+D reaction by using the crossed molecular beams method and velocity map ion imaging technique at the collision energy of 1.17 eV. D atom products in this reaction were probed by the near threshold 1+1'(vacuum ultraviolet+ultraviolet) laser ionization scheme. The ion image with both high angular and energy resolution were acquired. State-to-state differential cross sections was accurately derived. Fast forward scattering oscillations, relating with interference effects in the scattering process, were clearly observed for H2 products at H2(v'=0,j'=1) and H2(v'=0,j'=3) rovibrational levels. This study further demonstrates the importance of measuring high-resolution differential cross sections in the study of state-to-state reaction dynamics in the gas phase.展开更多
By using first-principles calculations and nonequilibrium Green＇s function technique, we study elastic transport properties of crossed graphene nanoribbons. The results show that the electronic transport properties o...By using first-principles calculations and nonequilibrium Green＇s function technique, we study elastic transport properties of crossed graphene nanoribbons. The results show that the electronic transport properties of molecular junctions can be modulated by doped atoms. Negative differential resistance （NDR） behaviour can be observed in a certain bias region, when crossed graphene nanoribbons are doped with nitrogen atoms at the shoulder, but it cannot be observed for pristine crossed graphene nanoribbons at low biases. A mechanism for the negative differential resistance behaviour is suggested.展开更多
基金Supported by Guangxi Natural Science Foundation(No.2025GXNSFAA069414)Guangxi Key R&D Project(No.Gui Ke AB24010049).
文摘Fault diagnosis in multiprocessor systems is critical for ensuring system reliability.The exchanged crossed cube(ECQ(s,t)),which combines the advantages of the exchanged cube and the crossed cube,offers a high performance-to-cost ratio but lacks comprehensive analysis in terms of fault tolerance.This paper investigates the 1-good-neighbor diagnosability of the ECQ(s,t),assuming that each fault-free node has at least one fault-free neighbor.We rigorously prove that the 1-good-neighbor diagnosability of The ECQ(s,t)under the Preparata,Metze,and Chien(PMC)model and Maeng and Malek(MM)model is t_(1)=2s+1(for t≥s≥4)and t_(1)=2s+1(for t≥s≥5),respectively.Furthermore,we design an efficient diagnostic algorithm based on the 1-good-neighbor criterion.Simulation results demonstrate the algorithm’s effectiveness,exhibiting lower time complexity and improved performance in faulty node identification.These results offer theoretical insights and practical tools for enhancing the fault diagnosis capabilities of ECQ(s,t).
基金supported by the National Natural Science Foundation of China(Nos.22473029,21327901,and 22073019)the Science and Technology Commission of Shanghai Municipality(No.2024ZDSYS02)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning.
文摘The pioneering works have demonstrated that the method of single collisions in crossed molecular beams is an important technique for achieving kinetic cooling of atoms or molecules in specific rotational states.In this study,we investigated the elastic and inelastic collisions between Al(^(2)P_(1/2))metal atoms and O_(2)molecules at high collision energies in the range of 6.4-14.8 kcal/mol,utilizing the laser-ablation crossed beams in conjunction with time-sliced ion velocity map imaging technique.We observed kinetic cooling of Al(^(2)P_(1/2))atoms with an upper-limit laboratory-frame root-mean-square velocity of 24±3 m/s,corresponding to a translational temperature of 0.9±0.2 K in the laboratory frame,facilitated by the vibrational excitation of O_(2)(v′=1)in inelastic collisions.The translational cooling of Al atoms in the lab frame enhanced detection probability in the transformation of density-to-flux,as evidenced by the scattering images obtained during the experiments.
基金The Natural Science Foundation of Jiangsu Province(No.BK2012736)the Natural Science Foundation of Chuzhou University(No.2010kj006Z)
文摘The linear operations of the equivalent classes of crossed modules of Lie color algebras are studied. The set of the equivalent classes of crossed modules is proved to be a vector space, which is isomorphic with the homogeneous components of degree zero of the third cohomology group of Lie color algebras. As an application of this theory, the crossed modules of Witt type Lie color algebras is described, and the result is proved that there is only one equivalent class of the crossed modules of Witt type Lie color algebras when the abelian group Г is equal to Г＋. Finally, for a Witt type Lie color algebra, the classification of its crossed modules is obtained by the isomorphism between the third cohomology group and the crossed modules.
基金Supported by the Fundamental Research Fund for the Central Uuiversities(KYZ201125)Grant for Young Teachers of College of Science,Nanjing Agricultural University(LXY20090101)
文摘The reaction of crossed diperoxidation between the cyclic ketones and the alkyl ketones was investigated. The reaction is a competing in different ketones. It is slightly favorable to resulting in crossed ketone diperoxide and to resulting in crossed cycloketone diperoxide when the cycloketone reacts with the aliphatic ketone.
基金Foundation item： Supported by the Scientific Research Foundation for Doctoral Scientists of Henan University of Science and Technology（09001303） Supported by the National Natural Science Foundation of China（11101128）
文摘In this paper we generalize the notions of crossed products and L-R smash products in the context of multiplier Hopf algebras. We use comodule algebras to define generalized diagonal crossed products, L-R smash products, two-sided smash products and two-sided crossed products and prove that they are all associative algebras. Then we show the isomorphic relations of them.
基金This work was supported by the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Ministry of Science and Technology of China.
文摘The crossed beams scattering dynamics of the F＋HD→HF＋D reaction have been studied at collision energies ranging from 8.19 k J/tool to 18.98 k J/tool using the high resolution H-atom Rydberg tagging time-of-flight method. Product rotational state-resolved differential cross sections have been measured. Most of the DF products are backward scattered at low collision energies and then gradually shift to the sideway as the collision energy increases. In addition to the backward and sideway scatterings, we have also observed the DF（v＇=4） product in the forward direction for the first time for this reaction. The forward scattering DF（v=4） product also increases with the collision energy. Angular and collision energy dependence of the product energy disposals in different degrees of freedom have been determined. Collision energy dependence of the vibrational branching ratios has also been examined. Possible dynamical origins of the forward scattering DF（v＇=4） products were discussed.
文摘keep one s fingers crossed 的字面意思是将手指交叉起来,通常是用中指压住食指,也有人习惯于食指压住中指。这个短语的比喻意义是 to hope that nothing will happento upset one s plans,即“希望一切如愿”“但愿别出差错”。如:He is keeping his fingers crossed that itwon t rain on Sunday when he wants to playfootball.他想星期天去踢球。
基金The National Natural Science Foundation of China(No.11371088)the Natural Science Foundation of Jiangsu Province(No.BK2012736)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Research Innovation Program for College Graduates of Jiangsu Province(No.KYLX15_0109)
文摘Some sufficient and necessary conditions are given for the equivalence between two crossed product actions of Hopf algebra H on the same linear category, and the Maschke theorem is generalized. Based on the result of the crossed product in the classic Hopf algebra theory, first, let A be a k-linear category and H be a Hopf algebra, and the two crossed products A#_σH and A#＇_σH are isomorphic under some conditions. Then, let A#_σH be a crossed product category for a finite dimensional and semisimple Hopf algebra H. If V is a left A#σH-module and WC V is a submodule such that W has a complement as a left A-module, then W has a complement as a A#_σH-module.
文摘We have investigated the dynamics of the F＋C4H6 reaction using the universal crossed molecular beam method. The C4H5F＋H reaction channel was observed in this experiment. Angular resolved time-of-flight spectra have been measured for the C4H5F product. Prod- uct angular distributions as well as kinetic energy distributions were determined for this product channel. Experimental results show that the C4H5F product is largely backward scattered with considerable forward scattering signal, relative to the F atom beam direction. This suggests that the reaction channel mainly proceeds via a long-lived complex formation mechanism, with possible contribution from a direct SN2 type mechanism.
基金This work was supported by the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Ministry of Science and Technology of China.
文摘The dynamics of F＋HD→HF＋D reaction has been studied at ten collision energies ranging from 5.43 kJ/mol to 18.73 kJ/mol using high-resolution H/D atom Rydberg tagging time-of-flight method. Product vibrational and rotational state-resolved differential cross sections have been determined. The intensity of the HF（v1=2） forward products decreases as the collision energy increases, suggesting that the resonance contribution is reduced as the collision energy increases. The forward peak of HF（vl=3） product has also been observed above the threshold of this product channel. Product energy disposals in different degrees of freedom have been analyzed. The collision energy dependence of the HF vibrational product branching was also determined. This work presents a comprehensive dynamic picture of this resonance mediated reaction in a wide collision energy regime, providing a good test ground for theoretical understandings of this interesting reaction at higher collision energies.
基金supported by Fundamental Research Funds for Central Universities of China (Grant No. CDJXS11111138,Key Projects in the National Science & Technology Pillar Program during the 11th Five-Year Plan Period of China(Grant No. 2011BAF09B07)National Natural Science Foundatlon of China(Grant No. 51175523)
文摘Beveloid gears,also known as conical gears,gain more and more importance in industry practice due to their abilities for power transmission between parallel,intersected and crossed axis.However,this type of gearing with crossed axes has no common plane of action which results in a point contact and low tooth durability.Therefore,a geometry design approach assuming line contact is developed to analyze the tooth engagement process of crossed beveloid gears with small shaft angle for marine transmission applications.The loaded gear tooth contact behavior is simulated by applying a quasi-static analysis to study the effects of gearing parameters on mesh characteristics.Using the proposed method,a series of sensitivity analyses to examine the effects of critical gearing parameters such as shaft angle,cone angle,helix angle and profile-shift coefficient on the theoretical gear mesh is performed.The parametric analysis of pitch cone design shows that the dominant design parameters represented by the angle between the first principle directions（FPD） and normal angular factor are more sensitive to the shaft and cone angles than they are to the helix angle.The theoretical contact path is highly sensitive to the profile-shift coefficient,which is determined from the theoretical tooth contact analysis.The FPD angle is found to change the distribution of contact pattern,contact pressure and root stress as well as the translational transmission error and the variation of the mesh stiffness significantly.The contact pattern is clearly different between the drive and coast sides due to different designed FPD angles.Finally,a practical experimental setup for marine transmission is performed and tooth bearing test is conducted to demonstrate the proposed design procedure.The experimental result compared well with the simulation.Results of this study yield a better understanding of the geometry design and loaded gear mesh characteristics for crossed beveloid gears used in marine transmission.
基金This work is supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China and the Ministry of Science and Technology.
文摘The dynamics of the Cl＋SiH4 reaction has been studied using the universal crossed molecular beam method. Angular resolved time-of-flight spectra have been measured for the channel SiH3Cl＋H. Product angular distributions as well as energy distributions in the center-ofmass frame were determined for the channel. Experimental results show that the SiH3Cl product is mainly backward scattered relative to the Cl atom beam direction, suggesting that the channel takes place via a typical SN2 type reaction mechanism.
文摘We study the H＋CH4/CD4-＋H2/HD＋CH3/CD3 reactions using the time sliced velocity map ion imaging technique. Ion images of the CH3/CD3 products were measured by the （2＋1） resonance enhanced multi-photon ionization （REMPI） detection method. Besides the CH3/CD3 products in the ground state, ion images of the vibrationally excited CH3/CD3 products were also observed at two collision energies of 0.72 and 1.06 eV. It is shown that the angular distribution of the products CH3/CD3 in vibrationally excited states gradually vary from backward scattering to sideways scattering as the collision energy increases. Compared to the CH3/CD3 products in the ground state, the CH3/CD3 products in vibrationally excited states tend to be more sideways scattered, indicating that larger impact parameters play a more important role in the vibrationally excited product channels.
文摘We introduce a special tracial Rokhlin property for unital C~＊-algebras. Let A be a unital tracial rank zero C~＊-algebra（or tracial rank no more than one C~＊-algebra）. Suppose that α ： G → Aut（A） is an action of a finite group G on A, which has this special tracial Rokhlin property, and suppose that A is a α-simple C~＊-algebra. Then, the crossed product C~＊-algebra C~＊（G, A, α） has tracia rank zero（or has tracial rank no more than one）. In fact,we get a more general results.
文摘TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,the presence of alcohol and the temperature were carefully investigated on the crystallization process.The high alkalinity was proved to be highly important for the preservation of the microsphere morphology initially formed,due to the unique intergrown stacking style.An alkali treatment with the aqueous solution of structure-directing agent,organic amine and ammonium salt and subsequent Na+ion-exchange were performed to enhance the catalytic activity of TS-2 microsphere in the cyclohexanone ammoximation reactions,with both the conversion and selectivity higher than 99%.In the continuous reaction,the TS-2 microspheres exhibited to be durable catalyst with potential application in industrial ammoximation processes.
基金Project supported by the National Natural Science Foundation of China (Grant No 10774162)National 973 Project (GrantNo 2005CB724501)
文摘The tunneling between double wells of atom in crossed electromagnetic fields is investigated by a one-dimensional Hamiltonian model. The crossed fields induced outer well is apart from the nuclear origin and it is very difficult to access by means of spectroscopy but it will be possible if there exists the tunneling of the electron between the outer well and the Coulomb potential predominated well at the nuclear origin. A one-dimensional quantum calculation with B-spline basis has been performed for hydrogen atom in crossed fields accessible in our laboratory, at B = 0.8 T and F = -220 V.cm^-1. The calculation shows that the wavefunctions of some excited states close to the Stark saddle point in the outer well extend over to the Coulomb potential well, making it possible to penetrate the quantum information of the outer well. However, the tunneling rate is very small and the spectral measurement of the transitions from the ground state should be of a high resolution and high sensitivity.
基金supported by the National Key R&D Program of China (No.2016YFF0200500)the National Natural Science Foundation of China (No.21473173, No.21590802, No.21403207, No.21503206)the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDB17000000)
文摘The H+H2 reaction is the simplest chemical reaction system and has long been the prototype model in the study of reaction dynamics. Here we report a high resolution experimental investigation of the state-to-state reaction dynamics in the H+HD→H2+D reaction by using the crossed molecular beams method and velocity map ion imaging technique at the collision energy of 1.17 eV. D atom products in this reaction were probed by the near threshold 1+1'(vacuum ultraviolet+ultraviolet) laser ionization scheme. The ion image with both high angular and energy resolution were acquired. State-to-state differential cross sections was accurately derived. Fast forward scattering oscillations, relating with interference effects in the scattering process, were clearly observed for H2 products at H2(v'=0,j'=1) and H2(v'=0,j'=3) rovibrational levels. This study further demonstrates the importance of measuring high-resolution differential cross sections in the study of state-to-state reaction dynamics in the gas phase.
基金supported by the National Natural Science Foundation of China (Grant Nos.10325415 and 50504017)the Natural Science Foundation of Hunan Province,China (Grant No.07JJ3102)the Science Develop Foundation of Central South University,China (Grant Nos.08SDF02 and 09SDF09)
文摘By using first-principles calculations and nonequilibrium Green＇s function technique, we study elastic transport properties of crossed graphene nanoribbons. The results show that the electronic transport properties of molecular junctions can be modulated by doped atoms. Negative differential resistance （NDR） behaviour can be observed in a certain bias region, when crossed graphene nanoribbons are doped with nitrogen atoms at the shoulder, but it cannot be observed for pristine crossed graphene nanoribbons at low biases. A mechanism for the negative differential resistance behaviour is suggested.
