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山区高等级公路平曲线计算与敷设的实用方法
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作者 梁忠恒 《交通科技》 2002年第6期27-30,共4页
针对山区地形、地物较复杂的特点 ,介绍一种适合于山区高等级公路平曲线测设新方法 ,该方法综合性及灵活性较强 。
关键词 高等级公路 山区公路 平曲线计算 敷设方法
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特殊车辆平曲线路面加宽的计算 被引量:4
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作者 陈桂军 林杰 罗珂 《广西城镇建设》 2006年第8期71-73,共3页
按照公路设计规范的要求,当圆曲线半径小于等于250m时,应设置加宽,规范提供了相应条件下的加宽值。规范针对的是设计车型(可代表当前绝大多数车辆),但在一些有较多的超长、超宽车辆行驶的公路上,宜对曲线加宽值进行特殊设计,本文结合盘... 按照公路设计规范的要求,当圆曲线半径小于等于250m时,应设置加宽,规范提供了相应条件下的加宽值。规范针对的是设计车型(可代表当前绝大多数车辆),但在一些有较多的超长、超宽车辆行驶的公路上,宜对曲线加宽值进行特殊设计,本文结合盘县~百色二级公路改建工程实例,对特殊车辆的平曲线路面加宽计算进行了研究,提出了一种简单、安全、实用的计算方法。 展开更多
关键词 公路 特殊车辆 曲线加宽计算
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平曲线半径对计算斜交涵长的影响
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作者 何攀光 廖琳 《山西建筑》 2005年第10期252-253,共2页
针对当前平曲线上斜交涵洞长度计算平曲线半径的影响因素,介绍了考虑R影响的斜交涵长计算方法,并通过工程算例将两种计算结果加以比较和分析,指出考虑平曲线半径影响的必要性和可行性。
关键词 斜交 涵长计算 曲线半径
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CASIOFX-4800P在线路平曲线坐标计算中的应用
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作者 欧星明 《江西测绘》 2008年第1期61-62,共2页
本文应用CASIOFX-4800P的特点和功能,利用线路中的已知坐标、桩号和曲线元素推导出直线、曲线中心线上的坐标以及法线上点坐标。
关键词 计算器编程 曲线坐标计算 应用
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The Neglected Significance of Glomerular Density as a 5-year Progression Indicator for IgA Nephropathy 被引量:4
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作者 陈振杰 李航 +8 位作者 蔡建芳 张鑫 李超 邹佩美 李明喜 陈丽萌 李雪梅 李学旺 文煜冰 《Chinese Medical Sciences Journal》 CAS CSCD 2017年第3期145-151,共7页
Objective To investigate whether glomerular density (GD) could be an independent prognostic factor for patients of IgA nephropathy with estimated glomerular filtration rate (eGFR) of 30 to 60 ml/min per 1.73 m2, ... Objective To investigate whether glomerular density (GD) could be an independent prognostic factor for patients of IgA nephropathy with estimated glomerular filtration rate (eGFR) of 30 to 60 ml/min per 1.73 m2, or for patients with time-average proteinuria 〈 0.5 g/d. Methods A total of 173 patients with biopsy-confirmed IgA nephropathy diagnosed from January 2000 to December 2010 were included. All of these patients were followed up for more than 5 years. The endpoint was a 〉 30% of decline in eGFR from baseline after 5-year follow-up. The optimal cut-off value of GD was calculated by ROC curve. Kaplan-Meier method and Cox regression analysis was used for survival analysis. Results A 30% of decline in eGFR occurred in 14.5% of all patients. The optimal diagnostic cut-off value of GD was 1.99/mm2 (AUC = 0.90, sensitivity = 84.0%, specificity = 81.8%) determined by ROC curve. The low GD group (GD 〈 1.99 per mm2) experienced a significant increase in renal endpoint for patients with eGFR of 30 to 60 ml/min per 1.73 m2 (six patients in lower GD group, while one patient in the other group). For patients with time-average proteinuria 〈 0.5 g/d, the lower GD group showed a higher eGFR decline from baseline (4.5±16.7 ml/min per 1.73 m2 vs. –8.1±21.4 ml/min per 1.73 m2, P = 0.038); two patients in this group reached the endpoint, while no patients in the higher GD group did. Conclusion GD could be an independent prognostic factor for patients of IgA nephropathy with eGFR at 30 to 60 ml/min per 1.73 m2 of body surface, particularly for those with time-averaged amount of urine protein less than 0.5 g per day. 展开更多
关键词 glomerular density IgA nephropathy renal progression
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Computing the topology of an arrangement of implicitly defined real algebraic plane curves~§
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作者 Jorge CARAVANTES Laureano GONZALEZ-VEGA 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第12期1685-1693,共9页
We introduce a new algebraic approach dealing with the problem of computing the topology of an arrangement of a finite set of real algebraic plane curves presented implicitly. The main achievement of the presented met... We introduce a new algebraic approach dealing with the problem of computing the topology of an arrangement of a finite set of real algebraic plane curves presented implicitly. The main achievement of the presented method is a complete avoidance of irrational numbers that appear when using the sweeping method in the classical way for solving the problem at hand. Therefore, it is worth mentioning that the efficiency of the proposed method is only assured for low-degree curves. 展开更多
关键词 Topology computation Real plane curves Sweeping method
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Phase Diagram of Transverse Spin-2 Ising Model with Longitudinal Crystal Field
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作者 ZHAO Jie XU Xing-Guang WEI Guo-Zhu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第7期163-167,共5页
The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal field is studied within themean-field theory.The phase diagrams and magnetization curves are obtained by diagonalizing the Hamiltonian H_i of... The transverse spin-2 Ising ferromagnetic model with a longitudinal crystal field is studied within themean-field theory.The phase diagrams and magnetization curves are obtained by diagonalizing the Hamiltonian H_i ofthe Ising system numerically,and the first order-order phase transitions,the first order-disorder phase transitions,andthe second-order phase transitions are discussed in details.Reentrant phenomena occur when the value of the transversefield is not zero and the reentrant diagram is given. 展开更多
关键词 transverse spin-2 Ising model phase diagram first order-order phase transition reentrant phenomenon
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Fast adaptive flat-histogram ensemble to enhance the sampling in large systems
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作者 XU Shun ZHOU Xin +1 位作者 JIANG Yi WANG YanTing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第9期5-10,共6页
An efficient novel algorithm was developed to estimate the Density of States(DOS) for large systems by calculating the ensemble means of an extensive physical variable, such as the potential energy, U, in generalized ... An efficient novel algorithm was developed to estimate the Density of States(DOS) for large systems by calculating the ensemble means of an extensive physical variable, such as the potential energy, U, in generalized canonical ensembles to interpolate the interior reverse temperature curve β_s(U)=SU/U, where S(U) is the logarithm of the DOS. This curve is computed with different accuracies in different energy regions to capture the dependence of the reverse temperature on U without setting prior grid in the U space. By combining with a U-compression transformation, we decrease the computational complexity from O(N3/2) in the normal Wang Landau type method to O(N1/2) in the current algorithm, as the degrees of freedom of system N. The efficiency of the algorithm is demonstrated by applying to Lennard Jones fluids with various N, along with its ability to find different macroscopic states, including metastable states. 展开更多
关键词 molecular dynamics simulations enhanced sampling density of states generalized canonical ensemble flat-histogram ensemble
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