区域水资源优化配置多目标模型求解的Matlab与Excel集成实现

区域水资源优化配置模型是决策变量多、结构复杂的非线性多目标模型,简洁快速的求解方法是模型用于实践的关键。利用excel和matlab的特点,通过excellink工具建立excel和matlab的数据通道,实现两者之间的通信,把excel作为数据输入端,调用matlab的函数求解多目标规划问题,实现了对区域水资源配置多目标模型的求解.以郑州市水资源优化配置为例进行了实践应用,应用结果表明,求解方法具有操作简便、易于实现、通用性强的特点。     

Integrating knowledge to assess coastal vulnerability to sea-level rise: The development of the DIVA tool

This paper describes the development of the DIVA tool, a user-friendly tool for assessing coastal vulnerability from subnational to global levels. The development involved the two major challenges of integrating knowledge in the form of data, scenarios and models from various natural, social and engineering science disciplines and making this integrated knowledge accessible to a broad community of end-users. These challenges were addressed by (i) creating and applying the DIVA method, an iterative, modular method for developing integrating models amongst distributed partners and (ii) making the data, scenarios and integrated model, equipped with a powerful graphical user interface, directly and freely available to end-users.     

Retrieval of aerosol optical properties over the Beijing area using POLDER/PARASOL satellite polarization measurements

Aerosol optical properties over Beijing and Xianghe under several typical weather conditions (clear sky, light haze, heavy pollution and dust storm) are derived from POLDER (POLarization and Directionality of the Earths Reflectances)/PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar) multi-directional, multi-spectral polarized signals using a more reliable retrieval algorithm as proposed in this paper. The results are compared with those of the operational retrieval algorithm of POLDER/PARASOL group and the ground-based AERONET (AErosol RObotic NETwork)/PHOTONS (PHOtometrie pour le Traitement Operational de Normalisation Satellitaire) measurements. It is shown that the aerosol optical parameters derived from the improved algorithm agree well with AERONET/PHOTONS measurement. The retrieval accuracies of aerosol optical thickness (AOT) and effective radius are 0.06 and 0.05 mu m respectively, which are close to or better than the required accuracies (0.04 for AOT and 0.1 mu m for effective radius) for estimating aerosol direct forcing.     

Micromechanical parameters in bonded particle method for modelling of brittle material failure

Bonded particle modelling (BPM) is nowadays being extensively used for simulating brittle material failure. In BPM, material is modelled as a dense assemblage of particles (grains) connected together by contacts (cement). This sort of modelling seriously depends on the mechanical properties of particle and contact, which are named here as micro‐parameters. However, a definite calibration methodology to obtain micro‐parameters has not been so far established; and many have reported some serious problems. In this research, a calibration procedure to find a unique set of micro‐parameters is established. To attain this purpose, discrete element code of UDEC is used to perform BPM. This code can be conveniently developed by the user. The proposed BPM is composed of rigid polygonal particles interacting at their contact points. These contacts can undergo a certain amount of tension, and their shear resistance is provided by cohesion and friction angle. The results demonstrate that each material macro‐property (i.e. Young's modulus, Poisson's ratio, internal friction angel, internal cohesion, and tensile strength) is directly originated from and distinctly related to the contact properties (i.e. normal and shear stiffness, friction angel, cohesion, and tensile strength). Copyright © 2010 John Wiley & Sons, Ltd.     

浅谈黄土物理力学特性与湿陷性关系研究

通过对盐镇至潼关间隧道区的黄土进行物理力学试验研究,得出其物理力学指标并分析其物理指标与力学特性的关系及影响,重点指出各物理力学指标对黄土湿陷性的影响,进而指出其对黄土区工程建设可能带来的危害和影响,提出相应的工程处理措施,对黄土区的工程建设等具有一定的指导和借鉴意义。     

土石混合料的结构分类

探讨了振动三参数：离心力、激振频率和名义振幅对土石混合料振动压实效果的影响,提出了两种对比工艺。并根据土石混合料在同一振动工艺下的压实特性,指出土石混合料具有三种结构类型,以最大干密度为判据,含石量为指标进行了结构分类,给出了分类区间。     

Stress integration approach to evaluate damping ratio in torsional tests

The complexity of determining strain associated with shear modulus and damping ratio in torsional tests has been resolved by means of several approaches. The stress integration approach is adequate when generating the plots of equivalent radius ratio versus strain more effectively over any range of strains in resonant column and torsional shear (RC/TS) tests. The stress integration approach was applied for hyperbolic, modified hyperbolic, and Ramberg–Osgood models in evaluating damping ratio. This study showed that using a single value of equivalent radius ratio in evaluating damping ratio is not appropriate. The combined hysteretic‐nonviscous damping model was developed and employed to consider the increased damping behavior at small strains using the stress integration approach. The results suggest that adding viscous behavior has no significant effect strain calculations in RC/TS testing. Copyright © 2010 John Wiley & Sons, Ltd.     

Response of multilayered transversely isotropic medium due to axisymmetric loads

A novel procedure associated with the precise integration method (PIM) and the technique of dual vector is proposed to effectively calculate the magnitude and distribution of deformations in a homogeneous multilayered transversely isotropic medium. The planes of transverse isotropy are assumed to be parallel to the horizontal surface of the soil system. The linearly elastic medium is subjected to four types of vertically acting axisymmetric loads prescribed either at the external surface or in the interior of the soil medium. There are no limits for the thicknesses and number of soil layers to be considered. By virtue of the governing equations of motion and the constitutive equations of the transversely isotropic elastic body, and based on the Hankel integral transform and a dual vector formulation in a cylindrical coordinate system, the partial differential motion equations can be converted into first‐order ordinary differential matrix equations. Applying the approach of PIM, it is convenient to obtain the solutions of ordinary differential matrix equations for the continuously homogeneous multilayered transversely isotropic elastic soil in the transformed domain. The PIM is a highly accurate algorithm to solve the sets of first‐order ordinary differential equations, which can ensure to achieve any desired accuracy of the solutions. What is more, all calculations are based on the standard method with the corresponding algebraic operations. Computational efforts can be reduced to a great extent. Finally, numerical examples are provided to illustrate the accuracy and effectiveness of the proposed approach. Some more cases are analyzed to evaluate the influences of the elastic parameters of the transversely isotropic media on the load‐displacement responses. Copyright © 2015 John Wiley & Sons, Ltd.     

A method of symplectic integrations with adaptive time-steps for individual Hamiltonians in the planetary <Emphasis Type="Italic">N</Emphasis>-body problem

A new algorithm is developed for long-term integrations of the N-body problem. The method uses symplectic integrations of the Hamiltonian equations of motion for each body. This allows one to employ individual adaptive time-steps in computations. The efficiency of this technique is demonstrated by several tests performed for typical problems of Solar System dynamics.     

遥感、GIS结合与区域天然滑坡调查

以香港大屿山岛中部为试验研究区，探讨了遥感与GIS结合在区域滑坡调查中应用的可能性。在详细分析滑坡与环境因子关系后，将岩土类型、地貌、侵蚀、坡度等环境因子引入到影像中，与影像组成多源复合图像，可使地物的空间属性信息得到补充。同时采用适合高维复合数据的BP神经元网络对研究区天然滑坡进行识别，结果表明，区域滑坡的识别能力有较大提高。该方法的应用，将为大区域滑坡调查与监测奠定基础。