The finite segment method is used to model the line throwing rocket system.A dynamic model of line throwing rocket with flight motion based on Kane's method is presented by the kinematics description of the system...The finite segment method is used to model the line throwing rocket system.A dynamic model of line throwing rocket with flight motion based on Kane's method is presented by the kinematics description of the system and the consideration of the forces acting on the system.The experiment designed according to the parameters of the dynamic model is made.The simulation and experiment results,such as range,velocity and flight time,are compared and analyzed.The simulation results are basically agreed with the test data,which shows that the flight motion of the line throwing rocket can be predicted by the dynamic model.A theoretical model and guide for the further research on the disturbance of rope and the guidance,flight control of line throwing rocket are provided by the dynamic modeling.展开更多
Disabled shoulders of throwing athletes typically present with extended undersurface partial tears of the rotator cuff, which include the posterior supraspinatus and the anterior infraspinatus tendon to a variable ext...Disabled shoulders of throwing athletes typically present with extended undersurface partial tears of the rotator cuff, which include the posterior supraspinatus and the anterior infraspinatus tendon to a variable extent. We propose a modified transtendon repair technique to adequately treat this subset of patients. The repair includes two double-loaded anchors, at the anterior and the posterior end of the tear, respectively. With the help of an angulated penetrator we create a medial and a lateral band of sutures on top of the cuff, producing a broad contact in the tendon-to-bone interface. All the 9 so far operated patients were young men, 7 of them base-ball pitchers, and 5 active in competitive sports. The Constant Score rose from 72 points preoperatively to 99 points at 12 months follow-up. Three of the still active pitchers were able to return to their previous level in sports after one year. The improved footprint contact of our novel repair construct should allow for better healing and, therefore, a higher chance of return to competition.展开更多
In this paper, the characteristics of Jiangzao 361, as well as its appear- ance in throwing transplanting are introduced, and the high-yielding throwing tech- nique for Jiangzao 361 is summed up. On the basis of the e...In this paper, the characteristics of Jiangzao 361, as well as its appear- ance in throwing transplanting are introduced, and the high-yielding throwing tech- nique for Jiangzao 361 is summed up. On the basis of the experimental demon- stration, the corresponding matching throwing technique is put forward.展开更多
Variable crank length cam⁃linkage mechanism has attracted much attention due to its compact overall structure when realizing complex motion laws.According to the special trajectory requirements,the kinematic character...Variable crank length cam⁃linkage mechanism has attracted much attention due to its compact overall structure when realizing complex motion laws.According to the special trajectory requirements,the kinematic characteristics and parameters of the mechanism have been analyzed and solved,which lays foundation for the implementation of the variable crank length snow melting agent throwing mechanism designed in this paper.Based on the trajectory equation of the point,the mathematical model of the throwing mechanism was established,and the theoretical trajectory of the end point of the throwing mechanism was obtained by programming.The parametric modeling and trajectory drawing were carried out by computer aided three⁃dimensional interactive application(CATIA),and the correctness of the mathematical model was verified by comparison.The regional trajectory distribution characteristics of the end points of the throwing mechanism were studied by using the trajectory region location method,and the influence of various parameters on the trajectory was investigated by using the numerical cycle comparison method.The human⁃computer interaction system of snow melting agent throwing mechanism with variable crank length was constructed by using Microsoft Visual Basic(VB)software.Based on the restriction conditions,the optimum combination of structural adjustment parameters and operational parameters suitable for Harbin first⁃class roads was obtained by using orthogonal test table,which provides an effective method to solve the parameters of the variable crank length cam mechanism with smooth impulse trajectory.展开更多
Understanding the scaling relation of damage zone width with displacement of faults is important for predicting subsurface faulting mechanisms and fluid flow processes. The understanding of this scaling relationship i...Understanding the scaling relation of damage zone width with displacement of faults is important for predicting subsurface faulting mechanisms and fluid flow processes. The understanding of this scaling relationship is influenced by the accuracy of the methods and types of data utilized to investigate faults. In this study, seismic reflection data are used to investigate the throw and damage zone width of five strike-slip faults a ecting Ordovician carbonates of the Tarim intracraton basin,NW China. The results indicate that fault slips with a throw less than 200 m had formed wide damage zones up to 3000 m in width. Also, damage zone width is found to have both a positive correlation and a power-law relation with throw of two orders of magnitude, with a ratio of these values varying in a range of 2–15. The relationship between throw and damage zone width is not a simple power-law and changes its slope from small to larger size faults. The results indicate that throw scales well with damage zone width for the studied faults, and hence these can be used to predict fault geometries in the Tarim Basin. The study of the wide carbonate damage zones presented here provides new insights into scaling of large-size faults, which involve multiple faulting stages.展开更多
Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography.In particular,the security of widely used public-key cryptosystems merits dee...Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography.In particular,the security of widely used public-key cryptosystems merits deep research to protect against new types of attacks.It is therefore highly meaningful to research cryptanalysis in the quantum computing environment.Shor proposed a wellknown factoring algorithm by finding the prime factors of a number n=pq,which is exponentially faster than the best known classical algorithm.The idea behind Shor's quantum factoring algorithm is a straightforward programming consequence of the following proposition:to factor n,it suffices to find the order r;once such an r is found,one can compute gcd(a^(r/2)±1,n)=p or q.For odd values of r it is assumed that the factors of n cannot be found(since a^(r/2)is not generally an integer).That is,the order r must be even.This restriction can be removed,however,by working from another angle.Based on the quantum inverse Fourier transform and phase estimation,this paper presents a new polynomial-time quantum algorithm for breaking RSA,without explicitly factoring the modulus n.The probability of success of the new algorithm is greater than 4φ(r)/π~2 r,exceeding that of the existing quantum algorithm forattacking RSA based on factorization.In constrast to the existing quantum algorithm for attacking RSA,the order r of the fixed point C for RSA does not need to be even.It changed the practices that cryptanalysts try to recover the private-key,directly from recovering the plaintext M to start,a ciphertext-only attack attacking RSA is proposed.展开更多
Shor in 1994 proposed a quantum polynomial-time algorithm for finding the order r of an element a in the multiplicative group Z_(n)^(*),which can be used to factor the integer n by computing gcd(a^(r/2)±1,n),and ...Shor in 1994 proposed a quantum polynomial-time algorithm for finding the order r of an element a in the multiplicative group Z_(n)^(*),which can be used to factor the integer n by computing gcd(a^(r/2)±1,n),and hence break the famous RSA cryptosystem.However,the order r must be even.This restriction can be removed.So in this paper,we propose a quantum polynomial-time fixed-point attack for directly recovering the RSA plaintext M from the ciphertext C,without explicitly factoring the modulus n.Compared to Shor’s algorithm,the order r of the fixed-point C for RSA(e,n)satisfying C^(er)≡C(mod n)does not need to be even.Moreover,the success probability of the new algorithm is at least 4φ(r)/π^(2)r and higher than that of Shor’s algorithm,though the time complexity for both algorithms is about the same.展开更多
The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas turbine.First,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fract...The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas turbine.First,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fractal theory and the finite element method are utilized.For contact analysis,a novel contact force model is introduced in this paper.Meanwhile,the Coulomb model is adopted to expound the friction characteristics.Second,the governing equations of motion of the rotor system are numerically solved,and the nonlinear dynamic characteristics are analyzed in terms of the bifurcation diagram,Poincarémap,and time history.Third,the potential effects provided by contact degree of joint interface,distribution position,and amount of contact layer are discussed in detail.Finally,the contrast analysis between the integral rotor and the rod fastening rotor is conducted under the condition of fixed-point rubbing.展开更多
文摘The finite segment method is used to model the line throwing rocket system.A dynamic model of line throwing rocket with flight motion based on Kane's method is presented by the kinematics description of the system and the consideration of the forces acting on the system.The experiment designed according to the parameters of the dynamic model is made.The simulation and experiment results,such as range,velocity and flight time,are compared and analyzed.The simulation results are basically agreed with the test data,which shows that the flight motion of the line throwing rocket can be predicted by the dynamic model.A theoretical model and guide for the further research on the disturbance of rope and the guidance,flight control of line throwing rocket are provided by the dynamic modeling.
文摘Disabled shoulders of throwing athletes typically present with extended undersurface partial tears of the rotator cuff, which include the posterior supraspinatus and the anterior infraspinatus tendon to a variable extent. We propose a modified transtendon repair technique to adequately treat this subset of patients. The repair includes two double-loaded anchors, at the anterior and the posterior end of the tear, respectively. With the help of an angulated penetrator we create a medial and a lateral band of sutures on top of the cuff, producing a broad contact in the tendon-to-bone interface. All the 9 so far operated patients were young men, 7 of them base-ball pitchers, and 5 active in competitive sports. The Constant Score rose from 72 points preoperatively to 99 points at 12 months follow-up. Three of the still active pitchers were able to return to their previous level in sports after one year. The improved footprint contact of our novel repair construct should allow for better healing and, therefore, a higher chance of return to competition.
文摘In this paper, the characteristics of Jiangzao 361, as well as its appear- ance in throwing transplanting are introduced, and the high-yielding throwing tech- nique for Jiangzao 361 is summed up. On the basis of the experimental demon- stration, the corresponding matching throwing technique is put forward.
基金Sponsored by the Young Talents Project of Northeast Agriculture Scholars Program(Grant No.54971412)the National Key R&D Program of China(Grant No.2017YFD0700105-2).
文摘Variable crank length cam⁃linkage mechanism has attracted much attention due to its compact overall structure when realizing complex motion laws.According to the special trajectory requirements,the kinematic characteristics and parameters of the mechanism have been analyzed and solved,which lays foundation for the implementation of the variable crank length snow melting agent throwing mechanism designed in this paper.Based on the trajectory equation of the point,the mathematical model of the throwing mechanism was established,and the theoretical trajectory of the end point of the throwing mechanism was obtained by programming.The parametric modeling and trajectory drawing were carried out by computer aided three⁃dimensional interactive application(CATIA),and the correctness of the mathematical model was verified by comparison.The regional trajectory distribution characteristics of the end points of the throwing mechanism were studied by using the trajectory region location method,and the influence of various parameters on the trajectory was investigated by using the numerical cycle comparison method.The human⁃computer interaction system of snow melting agent throwing mechanism with variable crank length was constructed by using Microsoft Visual Basic(VB)software.Based on the restriction conditions,the optimum combination of structural adjustment parameters and operational parameters suitable for Harbin first⁃class roads was obtained by using orthogonal test table,which provides an effective method to solve the parameters of the variable crank length cam mechanism with smooth impulse trajectory.
基金partly supported by National Natural Science Foundation of China(Grant No.41472103)Technology Major Project(2016ZX05004001)
文摘Understanding the scaling relation of damage zone width with displacement of faults is important for predicting subsurface faulting mechanisms and fluid flow processes. The understanding of this scaling relationship is influenced by the accuracy of the methods and types of data utilized to investigate faults. In this study, seismic reflection data are used to investigate the throw and damage zone width of five strike-slip faults a ecting Ordovician carbonates of the Tarim intracraton basin,NW China. The results indicate that fault slips with a throw less than 200 m had formed wide damage zones up to 3000 m in width. Also, damage zone width is found to have both a positive correlation and a power-law relation with throw of two orders of magnitude, with a ratio of these values varying in a range of 2–15. The relationship between throw and damage zone width is not a simple power-law and changes its slope from small to larger size faults. The results indicate that throw scales well with damage zone width for the studied faults, and hence these can be used to predict fault geometries in the Tarim Basin. The study of the wide carbonate damage zones presented here provides new insights into scaling of large-size faults, which involve multiple faulting stages.
基金partially supported by he State Key Program of National Natural Science of China No.61332019Major State Basic Research Development Program of China(973 Program)No.2014CB340601+1 种基金the National Science Foundation of China No.61202386,61402339the National Cryptography Development Fund No.MMJJ201701304
文摘Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography.In particular,the security of widely used public-key cryptosystems merits deep research to protect against new types of attacks.It is therefore highly meaningful to research cryptanalysis in the quantum computing environment.Shor proposed a wellknown factoring algorithm by finding the prime factors of a number n=pq,which is exponentially faster than the best known classical algorithm.The idea behind Shor's quantum factoring algorithm is a straightforward programming consequence of the following proposition:to factor n,it suffices to find the order r;once such an r is found,one can compute gcd(a^(r/2)±1,n)=p or q.For odd values of r it is assumed that the factors of n cannot be found(since a^(r/2)is not generally an integer).That is,the order r must be even.This restriction can be removed,however,by working from another angle.Based on the quantum inverse Fourier transform and phase estimation,this paper presents a new polynomial-time quantum algorithm for breaking RSA,without explicitly factoring the modulus n.The probability of success of the new algorithm is greater than 4φ(r)/π~2 r,exceeding that of the existing quantum algorithm forattacking RSA based on factorization.In constrast to the existing quantum algorithm for attacking RSA,the order r of the fixed point C for RSA does not need to be even.It changed the practices that cryptanalysts try to recover the private-key,directly from recovering the plaintext M to start,a ciphertext-only attack attacking RSA is proposed.
基金Supported by Nanhu Scholars Program for Young Scholars of Xinyang Normal University。
文摘Shor in 1994 proposed a quantum polynomial-time algorithm for finding the order r of an element a in the multiplicative group Z_(n)^(*),which can be used to factor the integer n by computing gcd(a^(r/2)±1,n),and hence break the famous RSA cryptosystem.However,the order r must be even.This restriction can be removed.So in this paper,we propose a quantum polynomial-time fixed-point attack for directly recovering the RSA plaintext M from the ciphertext C,without explicitly factoring the modulus n.Compared to Shor’s algorithm,the order r of the fixed-point C for RSA(e,n)satisfying C^(er)≡C(mod n)does not need to be even.Moreover,the success probability of the new algorithm is at least 4φ(r)/π^(2)r and higher than that of Shor’s algorithm,though the time complexity for both algorithms is about the same.
基金the National Natural Science Foundation of China(No.12172307)the Key Laboratory of Vibration and Control of Aero-Propulsion System,Ministry of Education,Northeastern University of China(No.VCAME202103)the Fundamental Research Funds for the Central Universities in Southwest Jiaotong University of China(No.2682021ZTPY036)。
文摘The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas turbine.First,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fractal theory and the finite element method are utilized.For contact analysis,a novel contact force model is introduced in this paper.Meanwhile,the Coulomb model is adopted to expound the friction characteristics.Second,the governing equations of motion of the rotor system are numerically solved,and the nonlinear dynamic characteristics are analyzed in terms of the bifurcation diagram,Poincarémap,and time history.Third,the potential effects provided by contact degree of joint interface,distribution position,and amount of contact layer are discussed in detail.Finally,the contrast analysis between the integral rotor and the rod fastening rotor is conducted under the condition of fixed-point rubbing.
