本文界定环境哲学的基本范畴框架，以“天人合一”和“主客恶性二分”分别概括中国和西方的传统环境形上学特征，分析环境哲学的源流及其在当代可持续发展要求下的学科建构。

The time evolution of a line puff, a turbulent non-buoyant element with significant momentum, is studied using the renormalization group (RNG) K-∈ model. The numerical results show that the puff motion is characterized by a vortex pair flow; the computed flow details and scalar mixing characteristies can be described by self-similar relations beyond a dimensionless time of around 30. The added mass coefficient of the puff motion is found to be approximately unity, The predicted puff flow and mixing rate are substantially similar to those obtained from the standard K-∈ model and are well supported by experimental data. The computed scalar field reveals significant significant secondary concentration peaks trailing behind in the wake fo the puff. The present results suggestthat the overall mixing rate of a puff is primarily detenmined by the large-scale motion and that stremline curvature probably plays a minor role.

A perturbational h4 compact exponential finite difference scheme with diagonally dominant coefficient matrix and upwind effect is developed for the convective diffusion equation. Perturbations of second order arerted on the convective coefficients and source term of an h2 exponential finite difference scheme proposed in this paper based on a transtormation to eliminate the upwind effect of the convective diffusion equation. Four numerical examples including one to three-dimensional model equations of fluid flow and a problem of natural convective heat transfer are given to illustrate the excellent behavior of the present exponential schemes. Besides, the h4 accuracy of the perturbational scheme is vernfied using double precision arithmetic.

Thepresent work discusses coupled heat and mass transfer during freeze-drying of a rigid product, as well as accelerated freeze-drying where sublimation and desorption occur concurrently. A desorption mushy zone model was developed to describe the desorption drying. An exaxt solution was obtained for coupled heat and mass transfer with one discrete sublimation moving interface and one desorption mushy zone where mass transfer is controlled by both Fick and Darcy laws. The effects of several parameters on the sublimation and desorption are analyzed and discussed.

As an emerging approach for unified resource accounting and energy-utilization assessment for the transportation sector, the exergy method to embody the second law fo thermodynamics is investigated and applied to the energy-utilization assessment of the Chinese transport sector from 1978 to 2002. The exergy consumed by the sector in 2000 was 3.3 times that in 1978. The exergy of the oil consumed by transportation accounted for 30.5% of the total oil consumption in the whole country up to 2000, almost equal to the exergy of the net oil import. In terms of the exergy consumption intersity, taken as the exergy consumption per Converted Tumover, proposed to assess the overall effectiveness of the system, and conventional exergy efficiency to reflect the technical performance of involved transport vehicles, both the energy-utilization effectiveness and efficiency of the sector have been declining generally. Waterways transport was proved the most effective one, and railways, highways and clvil aviation were the second, third and fourth, respectively.The historical evolution and structural variation of energy use in terms of the total exergy consumption, exergy effciency and exergy consumption intensity are revealed and explored against drastic backgrud transitions in related policies and socioeconomies.

Prsented in this paper are a systematic study on the global exergy consumption in the earth and a budget and a budget of the exergy consumption with respect to main terrestrial processes. Based on Szargut's definition of exergy for thermal radiation, a global exergy balamce of the thermodynamic system of the earth, driven by cosmic exeryflow originated from the temperature difference between the sun and the cosmic background, is carried out to give the global cosmic exergy consumption as the multiplication of the cosmic background microwave (CBM) radiation temperature and the global entropy generation due to irreversibility in the earth system. Concrete formulae are derived for cosmic exergy, with emphasis on generalization of a simple blackbody relationship between entropy and energy flux densities to the cases of gray body radiation with moderate or large emissivity associated with the earth system. Global entropy generation is evaluated with a result compared very with a widely accepted datum based on satellite observations in earth science. A budget of the global entropy generation is made with respect to the terrestrial radiation processes associated with the atmosphere and the earth's surface and to the molecular transport phenomena in the material earth. A mechanism of multiplication goveming transformation between cosmic exergy and terrestrial exergy is developed. An overall exergy budget of the earth system, based on the entropy budget by means of the Gouy-Stodola law, are presented with essential implication to the problem of global sustainability.

This study deals with the formulation, mathematical property and phydival meaning of the simplified Navier-Stokes (SNS) eguations. The tensorial SNS equations proposed is the simplest in, form and is applicable to flow tields with arbitrary body boundaries. The zones of influence and dependence of the SNS equations, which are of primary importance to numerical solutions, are expounded for the first rime from the viewpoint of subcharacteristics. Besides, a detailed snalysis of the diffusion process in flow fields shows that the diffnsion effect has an influence zone globalty windward and an upwind propagation greatly depressed by, convection. The maximum upwind influential distance of the viscous effect and the relative importance of the viscous effect in the flow direction to that in the direction normal to the flow are represented by the Reynolds number, which illustrates the conversion of the complete Navier-Stokes (MS) equarions to the SNS equations for flows with large Reynolds numher.

The time evolution of a turbulent lock release gravity current, formed by a finite volume of homogeneous fluid released instantaneously into another fluid of slightly lower density, was studied by experimental measurements of the density structure via elaborate digital image processing and by a numerical simulation of the flow and mixing using a two-equation turbulence model. The essential fact that the gravity current passes through an initial slumping phase in which the current head advances steadily and a second self-similar phase in which the front velocity decreases like the negative third power of the time after release is satisfactorily presented by the laboratory observation. An overall entrainment ratio proportional to the distance from the release point is found by the numerical simulation. The renormalization group (RNG) K-E model for Reynolds-stress closure is validated to characterize the gravity current with transitional and localized turbulence.

A compact fourth-order upwind finite difference scheme, which takes classieal first-order upwind scheme as basic representation and thus has no grid Reynoldsaumber limitarion, is developed for the convection including model equations of fluid flow and a problem of high Rayleigh-number natural convection with boundary-layer effect are given to illustrate the excellent behavior of the present scheme.

本文提出所谓迎风变换，将对流扩散方程分解为对流迎风函数和扩散方程，并构造相应的有限差分格式。对流迎风函数以简明的指数解析形式反映对流扩散现象的迎风效应，原则上消除了源于不对称对流算子的困难，能够便利对流扩散方程的数值求解，有限差分格式具有二阶精度和无条件稳定性，算例表明其准确性、收敛速度及对边界层效应的适应能力均明显优于中心差分格式和迎风差分格式。