Three-dimension electronic chart display information system (ECDIS) is one of the new developing directions of electronic navigation chart, and its real-time quality is one of the important requirements. In this paper...Three-dimension electronic chart display information system (ECDIS) is one of the new developing directions of electronic navigation chart, and its real-time quality is one of the important requirements. In this paper the algorithm of simplifying triangle surface using edge contraction, which can ensure the real-time display of objects in seabed enviromnent, was put forward. The optimum contraction point was determined by the Lagrange matrix, so that the algorithm ensures that the contraction point locates on the original model, meanwhile meets the demands of least deviation. This algorithm can improve the plotting speed, and preserve the boundary character by using the fewer triangles to simulate objects.展开更多
By properly selecting the time-dependent unitary transformation for the linear combination of the number operators, we construct a time-dependent invariant and derive the corresponding auxiliary equations for the dege...By properly selecting the time-dependent unitary transformation for the linear combination of the number operators, we construct a time-dependent invariant and derive the corresponding auxiliary equations for the degenerate and non-degenerate coupled parametric down-conversion system with driving term. By means of this invariant and the Lewis-Riesenfeld quantum invariant theory, we obtain closed formulae of the quantum state and the evolution operator of the system. We show that the time evolution of the quantum system directly leads to production of various generalized one- and two-mode combination squeezed states, and the squeezed effect is independent of the driving term of the Hamiltonian. In some special cases, the current solution can reduce to the results of the previous works.展开更多
It is known that the slabs on soil constitute one of the most difficult types of structures despite their apparent simplicity. The objective of this paper is to give a general survey of the design of ground supported ...It is known that the slabs on soil constitute one of the most difficult types of structures despite their apparent simplicity. The objective of this paper is to give a general survey of the design of ground supported slabs with the interposition of a suitable subbase. A solution is proposed with the following characteristics： （1） complete suppression of joints; （2） conventional reinforcement with meshes in the upper and lower fiber of the slab in order to confront and distribute cracking that is caused by hindrance of free contractions and expansions; （3） effective confrontation of problems of bulging. The proposal is in effect on one hand for industrial floorings and on the other hand for concrete pavings with large durability requirement.展开更多
A reduced chemical kinetic model （44 species and 72 reactions） for the homogeneous charge compression ignition （HCCI） combustion of n-heptane was optimized to improve its autoignition predictions under different e...A reduced chemical kinetic model （44 species and 72 reactions） for the homogeneous charge compression ignition （HCCI） combustion of n-heptane was optimized to improve its autoignition predictions under different engine operating conditions. The seven kinetic parameters of the optimized model were determined by using the combination of a micro-genetic algorithm optimization methodology and the SENKIN program of CHEMKIN chemical kinetics software package. The optimization was performed within the range of equivalence ratios 0.2-1.2, initial temperature 310- 375 K and initial pressure 0, 1-0.3 MPa, The engine simulations show that the optimized model agrees better with the detailed chemical kinetic model （544 species and 2 446 reactions） than the original model does.展开更多
AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma(SESCC) on Narrow Band Imaging combined with magnifying endoscopy(NBI-ME).METHODS This study was based on the post-hoc analysis...AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma(SESCC) on Narrow Band Imaging combined with magnifying endoscopy(NBI-ME).METHODS This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopistsdetected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: "intervascular background coloration"; "proliferation of intrapapillary capillary loops(IPCL)"; and "dilation", "tortuosity", "change in caliber", and "various shapes(VS)" of IPCLs(i.e., Inoue's tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue's criteria.RESULTS Fifty-four lesions(65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC(P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue's tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue's tetrad criteria, respectively.CONCLUSION The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBIME.展开更多
The calculating method of flow field diagnosis in multistage axial compressors is presented in this paper.The distributions of loss and deviation angle of every blade row, and blockage factors are evaluated using test...The calculating method of flow field diagnosis in multistage axial compressors is presented in this paper.The distributions of loss and deviation angle of every blade row, and blockage factors are evaluated using tested total temperature and total pressure at inlet and outlet of compressor, as well as the endwall static pressures. One operating mode of a two-stage fan is presented comparing results from the diagnostic method with measurements, and the results have demonstrated the important effects of diagnostic method.展开更多
文摘Three-dimension electronic chart display information system (ECDIS) is one of the new developing directions of electronic navigation chart, and its real-time quality is one of the important requirements. In this paper the algorithm of simplifying triangle surface using edge contraction, which can ensure the real-time display of objects in seabed enviromnent, was put forward. The optimum contraction point was determined by the Lagrange matrix, so that the algorithm ensures that the contraction point locates on the original model, meanwhile meets the demands of least deviation. This algorithm can improve the plotting speed, and preserve the boundary character by using the fewer triangles to simulate objects.
基金supported by the National Natural Science Foundation of China under Grant Nos.40674076 and 40474064the Hunan Natural Science Foundation of China under Grant No.07JJ3123the Scientific Research Fund of Hunan Provincial Education Department under Grant Nos.06C163,05B023,and 06B004
文摘By properly selecting the time-dependent unitary transformation for the linear combination of the number operators, we construct a time-dependent invariant and derive the corresponding auxiliary equations for the degenerate and non-degenerate coupled parametric down-conversion system with driving term. By means of this invariant and the Lewis-Riesenfeld quantum invariant theory, we obtain closed formulae of the quantum state and the evolution operator of the system. We show that the time evolution of the quantum system directly leads to production of various generalized one- and two-mode combination squeezed states, and the squeezed effect is independent of the driving term of the Hamiltonian. In some special cases, the current solution can reduce to the results of the previous works.
文摘It is known that the slabs on soil constitute one of the most difficult types of structures despite their apparent simplicity. The objective of this paper is to give a general survey of the design of ground supported slabs with the interposition of a suitable subbase. A solution is proposed with the following characteristics： （1） complete suppression of joints; （2） conventional reinforcement with meshes in the upper and lower fiber of the slab in order to confront and distribute cracking that is caused by hindrance of free contractions and expansions; （3） effective confrontation of problems of bulging. The proposal is in effect on one hand for industrial floorings and on the other hand for concrete pavings with large durability requirement.
基金SUPPORTED BY NATIONAL KEY BASIC RESEARCH PLAN ("973" PLAN, NO. 2001CB209202).
文摘A reduced chemical kinetic model （44 species and 72 reactions） for the homogeneous charge compression ignition （HCCI） combustion of n-heptane was optimized to improve its autoignition predictions under different engine operating conditions. The seven kinetic parameters of the optimized model were determined by using the combination of a micro-genetic algorithm optimization methodology and the SENKIN program of CHEMKIN chemical kinetics software package. The optimization was performed within the range of equivalence ratios 0.2-1.2, initial temperature 310- 375 K and initial pressure 0, 1-0.3 MPa, The engine simulations show that the optimized model agrees better with the detailed chemical kinetic model （544 species and 2 446 reactions） than the original model does.
文摘AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma(SESCC) on Narrow Band Imaging combined with magnifying endoscopy(NBI-ME).METHODS This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopistsdetected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: "intervascular background coloration"; "proliferation of intrapapillary capillary loops(IPCL)"; and "dilation", "tortuosity", "change in caliber", and "various shapes(VS)" of IPCLs(i.e., Inoue's tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue's criteria.RESULTS Fifty-four lesions(65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC(P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue's tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue's tetrad criteria, respectively.CONCLUSION The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBIME.
文摘The calculating method of flow field diagnosis in multistage axial compressors is presented in this paper.The distributions of loss and deviation angle of every blade row, and blockage factors are evaluated using tested total temperature and total pressure at inlet and outlet of compressor, as well as the endwall static pressures. One operating mode of a two-stage fan is presented comparing results from the diagnostic method with measurements, and the results have demonstrated the important effects of diagnostic method.
