基于BIM的杭黄高铁建德东站现浇梁支架方案研究

针对杭黄高铁建德东站站场地形地貌复杂,桥墩高度变化大,18种现浇非标准箱梁型式各异,支架搭设、拆除、周转施工组织难度大,提出采用Revit建立支架贝雷梁BIM模型进行三维审查细化支架布置方案,三维技术交底,工程材料数量提取,虚拟推演施工过程,4D施工进度动态控制,材料周转方案优化,采用Midas.civil进行力学分析计算,优化支架设计方案,确保支架布置形式合理,支架结构安全稳定,为实现支架施工过程的安全控制、质量控制、进度控制、成本控制提供了一种基于BIM技术的解决方案。     

一种基于改进的减缩模型修正方法

提出一种改进的模型修正方法,该方法采用多目标优化技术使得结构的减缩模型与实测结果相吻合。即首先建立一个多目标优化模型,其中包括一个关于单元修正系数的隐式非线性特征方程组,然后通过遗传算法来求解该多目标优化问题,来同时实现模型修正和损伤检测。文中通过对一个悬臂梁的数值仿真,表明本文所提出的方法的有效性,即在较大的测量噪声的情况下,同时具有模型修正和损伤检测两种功能,且较改进前的基于迭代的方法具有更好的噪声鲁棒性。     

发射内弹道计算模型研究

对以燃气-蒸汽式发射动力装置为动力源的导弹冷弹射过程进行了分析，对冷却水汽化机理进行了研究，针对不同状态的冷却水，提出了不同汽化方式组合的冷却水汽化模型，在此基础上将弹射过程划分为4个阶段，并推导出各个阶段的汽化方程和能量平衡方程，建立了发射内弹道基本方程组。计算模型改进后，发射内弹道的计算精度有很大提高。     

三维设计在船体结构中的应用

在三维空间里设计水面舰艇的船体结构是军船结构设计的发展趋势。介绍船体结构三维设计的构思;三维设计方法与传统二维设计方法的比较;目前三维设计可达到的设计深度。详细论述结构三维设计的研究内容和具体实施方法,揭示三维设计中的关键技术,最后提出舰艇船体结构三维设计的发展构想。     

一种新的基于云模型映射关系的威胁评估方法

结合现代舰艇编队防空作战的特点,对影响目标威胁评估的各种因素进行了分析。在讨论了常用威胁评估算法优缺点的基础上,提出了一种新的基于云模型映射关系的威胁评估方法。设计了一个仿真实例,结果表明所研究的威胁评估方法具有可行性。     

基于改进型Boussinesq方程的二维波浪数值模型

基于改进型Boussinesq方程，在非交错网格下，建立了二维波浪数值模型。模型计算采用了有限差分法，时间格式上采用混合四阶Adams—Bashforth—Mouhon，空间格式上采用了Wei等（1995）给出的格式。数值计算中。采用了内部造渡技术。数值模拟针对3纽经典浅滩地形上波浪传播变形的实验进行，数值计算结果与实验结果吻合较好。验证了数值模型，该模型可期望用于实际港口渡浪预报。     

汉江石泉枢纽下游非恒定流数学模型研究

汉江石泉枢纽运用后,其下游河道受日调节影响,水位陡涨陡落,碍航情况严重。文中建立了一维数学模型,利用汉江石泉水文站至汉王城68 km河段非恒定流资料对模型进行了验证,计算结果表明该模型稳定性好、准确可靠。选择石泉水文站若干个下泄过程组合概化了一种新的下泄过程,该下泄过程满足河道最低通航保证率的要求。     

A generalized model of pelagic biogeochemistry for the global ocean ecosystem. Part II: Numerical simulations

This paper presents a global ocean implementation of a multi-component model of marine pelagic biogeochemistry coupled on-line with an ocean general circulation model forced with climatological surface fields (PELAgic biogeochemistry for Global Ocean Simulations, PELAGOS). The final objective is the inclusion of this model as a component in an Earth System model for climate studies. The pelagic model is based on a functional stoichiometric representation of marine biogeochemical cycles and allows simulating the dynamics of C, N, P, Si, O and Fe taking into account the variation of their elemental ratios in the functional groups. The model also includes a parameterization of variable chlorophyll/carbon ratio in phytoplankton, carrying chl as a prognostic variable. The first part of the paper analyzes the contribution of non-local advective–diffusive terms and local vertical processes to the simulated chl distributions. The comparison of the three experiments shows that the mean chl distribution at higher latitudes is largely determined by mixing processes, while vertical advection controls the distribution in the equatorial upwelling regions. Horizontal advective and diffusive processes are necessary mechanisms for the shape of chl distribution in the sub-tropical Pacific. In the second part, the results have been compared with existing datasets of satellite-derived chlorophyll, surface nutrients, estimates of phytoplankton community composition and primary production data. The agreement is reasonable both in terms of the spatial distribution of annual means and of the seasonal variability in different dynamical oceanographic regions. Results indicate that some of the model biases in chl and surface nutrients distributions can be related to deficiencies in the simulation of physical processes such as advection and mixing. Other discrepancies are attributed to inadequate parameterizations of phytoplankton functional groups. The model has skill in reproducing the overall distribution of large and small phytoplankton but tends to underestimate diatoms in the northern higher latitudes and overestimate nanophytoplankton with respect to picoautotrophs in oligotrophic regions. The performance of the model is discussed in the context of its use in climate studies and an approach for improving the parameterization of functional groups in deterministic models is outlined.     

最优设计及分配理论在舰船维修中的应用研究

通过基于多服务台有限源排队系统的理论,分析舰船维修工作中在满足一定的可靠性要求下的最优设计与最优分配问题,同时结合计算机技术,提出了求解的方法,最终通过举例确定其最优设计理论的准确性。     

A macroscopic theory of two-lane rural roads

A macroscopic theory for predicting the operation on two-lane, two-way roads is proposed. In this theory, the interaction between fast and slow vehicles obeys Newell’s kinematic wave theory of moving bottlenecks. Calibration is not required as all parameters are fully observable. Closed-form expressions for the capacity, average speed, percent time spent following and overtaking rates are proposed and the biases of current practice are identified. Comparisons between the proposed theory and empirical data are also included.