As a global 3D atmospheric chemical transport model (CTM), geoschem mainly aims at the source and sink of atmospheric components and the physical and chemical effects in the transport process, so as to simulate the actual concentration distribution and evolution process of each component. GEOS Chem uses the meteorological plants from GEOS assimilation provided by NASA's global modeling and data assimilation Office (gmao) as the initial field to drive the model. The geoschem model includes a detailed tropospheric ozone NOx VOC aerosol Hox chemical process. It fully considers the joint effect of emission sources and natural sources. It considers that the emission of CO, NOx and SO2 is taken as the default in geoschem, using Edgar 3.2's monthly global inventory in 2000, while the anthropogenic non methane VOC is used as the default, using retro 2000 as the default Geoschem uses the advection algorithm of tpcore to simulate the horizontal transport process, which is consistent with the GEOS GCM meteorological simulation, while the convective mass flux calculation includes wet deposition, dry deposition and sea salt deposition. The geoschem mixing in the boundary layer uses a non local scheme, and the simulation of mercury is extended from the original geoschem air sea coupling simulation to a coupled atmosphere ocean land model.

Topoflow is a powerful and spatially distributed hydrological model with a user-friendly click interface. Its main purpose is to simulate many different physical processes in a watershed, and its goal is to accurately predict how various hydrological variables will evolve in response to climate forces.

IBIS model is used to describe the input, output and I / obuffer behavior characteristics of IC devices, and to simulate the interaction between buffer and on-board circuit system. The core content of IBIS model is the buffer model, because these buffers produce some simulated waveforms, so the simulator uses these waveforms to simulate the influence of transmission line and some high-speed phenomena. Specifically, Ibis describes the input and output impedances (in the form of I / V curves), rise and fall times, as well as pull-up and pull-down in different situations. Engineers can use this model to analyze Si, crosstalk, EMC and timing in the circuit system on PCB.

Exams is an interactive software application for developing aquatic ecosystem models and rapidly assessing the processes, transport and exposure concentrations of synthetic organic chemicals, including pesticides, industrial materials and waste disposal sites. Exams contains an integrated database management system (DBMS), which is specially used to store and manage the project database required by the software. User interaction is provided by a fully functional command line interface (CLI), the use of flexible help menus, an online data dictionary, and a cli user guide, and maps the ability to check output data.

Delft3D is a powerful software package developed by WL Delft hydraulics of Delft University in the Netherlands, which is mainly used in free surface water environment. The software has a flexible framework, which can simulate two-dimensional and three-dimensional flow, wave, water quality, ecology, sediment transport and bed topography, as well as the interaction among various processes. It is one of the most advanced hydrodynamic water quality models in the world. Delft3D system is widely used in the world, such as the Netherlands, Poland, Germany, Australia, the United States and so on, especially the United States has a long history of application. The Delft3D system has been used in Hong Kong since the mid-1970s and has become a standard product of the Hong Kong Environment Agency. Delft3D has been applied more and more in mainland China since the mid 80s, such as Changjiang Estuary, Hangzhou Bay, Bohai Bay, Taihu and Dianchi. Delft3D is the most advanced and complete 3D hydrodynamic water quality model system in the world, especially the unique support surface format.

LSPC is a watershed modeling system, including streamline hydrological simulation program FORTRAN (HSPF) algorithm, which is used to simulate hydrology, sediment and general water quality on land, as well as simplified river transport model. LSPC is derived from the mining data analysis system (MDAS) developed by the U.S. Environmental Protection Agency's zone 3, and is widely used in mining applications and TMDLs. A key data management feature of the system is that it uses Microsoft Access database to manage model data and weather text files to drive simulation. The system also includes a module to assist TMDL calculation and source allocation. For each model run, it will automatically generate a comprehensive text file output of the sub watershed for all layers, arrival and simulation modules, which can be represented at hourly or daily intervals. The output of the LSPC is associated with other model applications, such as EFDC, wasp, and - qual-w2. LSPC has no inherent limitations in modeling scale or model operation. The Microsoft Visual C + + programming architecture allows seamless integration with modern, widely used software such as Microsoft Access and excel.

MODFLOW is a three-dimensional finite difference groundwater model. It uses modular structure, which makes it easy to modify to adapt to specific application code. Modflow-2000 simulates stable and unsteady flow in irregular flow systems. Aquifers can be closed or unclosed, or a combination of the two, flowing under external pressure, such as flowing to wells, surface recharge, evaporation, flowing to drainage channels, and flowing through riverbed. In addition to simulating groundwater flow, some related functions are extended, such as sediment transport.