Chemical mass balance model (CMB model) is one of several receptor models applied to air pollution source management. CMB model was first proposed by Miller, Friedlander and hidy in 1972, and formally named as chemical mass balance method by Cooper and Watson in 1980. It is an important method recommended by EPA to study the sources and contributions of PM10, PM2.5 and VOC.. The CMB model established by this method is the most studied and widely used receptor model in the practical work of source apportionment of atmospheric particulates. Chemical mass balance (CMB) model epa-cmbv8.2 is one of several receptor models applied to air quality problems in the past 20 years. Based on the least squares method of effective variance (EVLS), EPA supports CMB as a regulatory planning tool by approving a large number of state implementation plans (SIPS). CMB needs potential sources of analytical samples collected at a single receptor site and corresponding environmental data. CMB is an ideal tool for ideal local non reaching problems and has been proved to be a useful tool.

Soil crop simulation model has become an effective tool to provide scientific basis for agricultural production and management decision-making. APSIM model was developed by Australian scientists to simulate various biological processes in agricultural system. In particular, the mechanism model of ecological and economic output of each component of the system under climate risk. APSIM has been verified and applied in soils with temperate continental climate, temperate marine climate, subtropical arid climate and Mediterranean climate zone, including clay, expansive soil, deformable soil, silty sandy soil, silty loam and silty clay loam, which can be used to simulate more than 20 crops such as wheat. APSIM model has good ability to describe crop structure and crop rotation sequence adjustment, crop yield, quality prediction and control, and soil water flow imbalance control under different planting patterns.

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.

Epic is a continuous simulation model used to study the long-term effects of various soil erosion factors on crop production. Epic is a public domain model for studying the impact of soil erosion on crop production in more than 60 countries in Asia, South America and Europe. The model is used to study soil erosion, economic factors, hydrological models, weather effects, nutrition, plant growth dynamics and crop management. The main components of the epic are weather simulation, hydrology, erosion deposition, nutrient cycling, pesticide fate, plant growth, soil temperature, farming, economy and plant environmental control. Epic assessed the impact of soil erosion on productivity and predicted the impact of management decisions on soil, water, nutrient and pesticide movement, as well as their combined effects on soil fertility and managed soil loss, water quality and crop yield.

The SPAW (soil plant air water) model simulates the daily hydrological and water budget of agricultural landscapes. There are two connected modules, one for farmland and the other for reservoirs such as wetland ponds, lagoons or reservoirs. The model was established to understand and predict agrohydrology and its interaction with soil and crop production. It can be applied to a variety of hydrological analyses, including: estimation of farmland runoff and leakage of agricultural farms, as well as the design and performance evaluation of water supply, waste management and water management of agricultural ponds, lagoons and reservoirs. The simulation results estimate daily vertical water budget depths for all major hydrological processes, including runoff, infiltration, evapotranspiration, soil moisture profile and seepage.

The common land surface model was developed by scientists interested in land model for public use and further development. The main characteristics of the model include sufficient non-uniform interlayer to fully represent soil temperature and soil moisture, and multi-layer parameterization of snow process; clear treatment of liquid water and ice water quality in snow soil system; runoff parameterization under the concept of topmeod; a canopy photosynthetic conductivity model, which describes the simultaneous transfer of carbon dioxide and water vapor in plants; and a model of canopy photosynthesis conductivity; The sub grid fraction of energy and water balance is tiled. CLM has been widely evaluated in offline mode and coupled with the NCAR community climate model (CCM3).