An urban traffic environment model

１　ＩｎｔｒｏｄｕｃｔｉｏｎＵｒｂａｎｓｕｓｔａｉｎａｂｌｅｄｅｖｅｌｏｐｍｅｎｔ，ｐｏｐｕｌａｔｉｏｎａｎｄＧＤＰｐｒｏｄｕｃｔｉｏｎ，ｔｒａｆｆｉｃ，ａｎｄｅｎｖｉｒｏｎｍｅｎｔａｒｅｉｎｔｅｒａｃｔｉｎｇｗｉｔｈｅａｃｈｏｔｈｅｒ．Ｐｒｏｄｕｃｔｉｏｎｏｆｐｏｐｕｌａｔｉｏｎａｎｄｇｏｏｄｓｒａｉｓｅｔｈｅｎｅｅｄｆｏｒｅｘｃｈａｎｇｅｉｎｓｐａｃｅ，ｌｅａｄｉｎｇｔｏｔｒａｆｆｉｃｆｌｏｗ．Ｔｈｅｔｒａｆｆｉｃｆｌｏｗ，ｉｎｒｅｖｅｒｓｅ，ｆｕｒｔｈｅｒｅｎｈａｎｃｅｔｈｅｐｒｏｄｕｃｔ…     

Plug-flow/dispersion model of longitudinal dispersion

A modified Fickian plug-flow/dispersion model (P/D model) is developed in this study. In P/D model, the flow process is divided into two belts, plug flow belt and dispersion belt. P/D model is very similar to Fickian model and rather perfect. The prediction by P/D model can be always consistent with experimental data in river, flume, and pond, even though the data are much skew. Therefore, P/D model is better than Fickian model and other dispersion models.     

Quantitative model for species distribution of hydroxy polyaluminum chloride

ＱｕａｎｔｉｔａｔｉｖｅｍｏｄｅｌｆｏｒｓｐｅｃｉｅｓｄｉｓｔｒｉｂｕｔｉｏｎｏｆｈｙｄｒｏｘｙｐｏｌｙａｌｕｍｉｎｕｍｃｈｌｏｒｉｄｅＦｅｎｇＬｉ，ＬｕａｎＺｈａｏｋｕｎ，ＴａｎｇＨｏｎｇｘｉａｏＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏＥｎｖｉｒ...     

Prediction model of mercury accumulation in fish of reservoirs

ＩｎｔｒｏｄｕｃｔｉｏｎＨｅａｌｔｈｈａｚａｒｄｓｆｒｏｍｍｅｒｃｕｒｙｉｎｔｈｅｅｎｖｉｒｏｎｍｅｎｔｈａｖｅｃａｕｓｅｄｒｅｓｔｒｉｃｔｉｏｎｓｉｎｔｈｅｕｓｅｏｆｍｅｒｃｕｒｙａｎｄａｓｔｒｉｃｔｅｒｃｏｎｔｒｏｌｏｆｔｈｅｒｅｌｅａｓｅｏｆｍｅｒｃｕｒｙｆｒｏｍｉｎｄｕｓｔｒｉａｌａｎｄｏｔｈｅｒｕｓｅｓ.Ｂｕｔａｔｔｈｅｓａｍｅｔｉｍｅｔｈｅｓｅｓｏｕｒｃｅｓｏｆｍｅｒｃｕｒｙｈａｖｅｂｅｅｎｓｕｂｊｅｃｔｅｄｔｏｒｅｇｕｌａｔｉｏｎ ,ｔｗｏｎｅｗｓｏｕｒｃｅｓｈａｖｅａｐｐｅａｒｅｄ …     

Effect of domestic sewage on growth of phytoplankton-mathematical model

A mathematical model relating to the change in phytoplankton biomass in the period of growth and nutrient concentration in the media was proposed on the basis of the Monod equation and was testified by simulation experiments. Analysis of the experiment data showed that: the half-saturation constants for growth Kp (μmol/L) for Skeletonema, Chaetoceros and Prorocentrum were 5.52, 1.90 and 0.46, respectively; the balance between stimulation of nutrients and the inhibition of some other materials was found in the effect of domestic sewage on algal growth and the stimulation played a leading role; domestic sewage was more stimulative on dinoflag-ellate than on diatom and chlorophyte when the assemblage of the algae was cultured. The experiment suggested that mathematical model reasonably explained the characteristics of phytoplankton growth in different nutrient conditions and was worthy to be further improved for eutrophication prediction in off-shore water.     

A variable-resolution transport model applied for NHχ in Europe

The statistical atmospheric transport model TREND has been applied for the calculation of concentrations and depositions of ammonia (NH₃) and ammonium (NH₄⁺). The model is capable of describing dispersion, conversion and deposition from both local sources (necessary to obtain good results for NH₃) and from more distant sources (necessary to obtain good results for NH₄⁺). Model results show that in western Europe 44% of the emitted NH₃ from a 1 m high score is dry deposited as NH₃, 6% is wet deposited as the contribution of NH₃ to the wet deposition of NH_x, 14% is dry deposited as NH₄⁺ and 36% is wet deposited as the contribution of NH₄⁺ to the wet deposition of NH_x. The model results agree well with measured NH₃ and NH₄⁺ concentrations—the latter in both aerosol form and precipitation—in The Netherlands, Belgium, Denmark, the U.K., the F.R.G., Sweden and other parts of Europe. Vertical concentration profiles of NH₃ and NH₄⁺ at Cabauw, The Netherlands are also reproduced well, as well as the diurnal variation of the NH₃ concentration at Elspeetsche Veld, The Netherlands.     

A preliminary study on simplified simulation model of spring wheat growth

In the model developed in this paper, taking the characters and requirements of meteorological services into account, some conventional meteorological observations which are easy to be obtained have been ch.osen, and mathematical equations describing micro-growth processes of crops have been established on the basis of the field experiments, laboratorial analysis and computer's modelling tests with time interval of ten-days for several years (1987-1989), in accordance with the known biological and physical rules and corresponding reference literatures. It is a preliminary simplified simulation model of spring wheat growth in optimal water and nutrient conditions. The field experiments show that simulation results of this simplified model are satisfactory. The potential operational application and theoretical sense are significant in the meteorological forecast of yield and in the assessment of influences of climatic change on agriculture.     

A computer simulation model for room sound field considering diffuse reflection

１ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｆｉｒｓｔｐａｐｅｒｐｕｂｌｉｓｈｅｄｉｎ１９５８，ｃｏｍｐｕｔｅｒｓｉｍｕｌａｔｉｏｎｔｅｃｈｎｉｑｕｅｆｏｒｒｏｏｍａｃｏｕｓｔｉｃｓｈａｓｄｅｖｅｌｏｐｅｄａｌｏｔ．Ｉｔｐｌａｙｓａｖｅｒｙｉｍｐｏｒｔａｎｔ...     

Multimedia model of atrazine in plant-soil-groundwater system with a fugacity approach

ＩｎｔｒｏｄｕｃｔｉｏｎＣｏｎｔａｍｉｎａｔｉｏｎｏｆｅｄｉｂｌｅｖｅｇｅｔａｔｉｏｎｂｙｐｅｒｓｉｓｔｅｎｔ,ｕｂｉｑｕｉｔｏｕｓｃｈｅｍｉｃａｌｓｓｕｃｈａｓＰＣＢｓ,ｄｉｏｘｉｎｓ,ｐｅｓｔｉｃｉｄｅｓ,ａｎｄｈｅｒｂｉｃｉｄｅｓｐｒｏｖｉｄｅｓａｍａｊｏｒｅｘｐｏｓｕｒｅｒｏｕｔｅｔｏｈｕｍａｎｓ ,ｄｏｍｅｓｔｉｃａｎｉｍａｌｓａｎｄｗｉｌｄｌｉｆｅ .Ｕｐｔａｋｅｏｆｔｈｅｓｅｏｒｇａｎｉｃｃｈｅｍｉｃａｌｓｂｙｐｌａｎｔ,ａｎｄｓｕｂｓｅｑｕｅｎｔｄｉｓｔｒｉｂｕｔｉｏｎｉｎｔｈｅｐｌａｎ…     

The CALGRID mesoscale photochemical grid model—I. Model formulation

A new photochemical oxidant model, CALGRID, has been developed for regulatory assessments of ozone control strategies. The model features: low numerical diffusion transport schemes that explicitly conserve mass on a terrain following mesh; modern boundary-layer representations converted to K-theory and applied to a variety of both fixed level and space-time variable vertical meshes; the ability to switch chemical schemes easily among the SAPRC hierarchy; a comprehensive resistance-based, dry deposition algorithm; and a highly-modular, streamlined FORTRAN 77 code that is highly vectorized and easily adapted to emerging parallel processor technology. The model is controlled by an easy to modify, self-documenting “control file” which also enables many consistency checks and serves to protect against a number of simple, yet common, simulation errors. The paper describes each of the model's principal technical modules in detail.     

Multiphase chemistry in a microphysical radiation fog model—A numerical study

A microphysical radiation fog model is coupled with a detailed chemistry module to simulate chemical reactions in the gas phase and in fog water during a radiation fog event. In the chemical part of the model the microphysical particle spectrum is subdivided into three size classes corresponding to non-activated aerosol particles, small and large fog droplets. Chemical reactions in the liquid phase are separately calculated in the small and in the large droplet size class. The impact of the chemical constitution of activated aerosols on fogwater chemistry is considered in the model simulations. The mass transfer of chemical species between the gas phase and the two liquid phases is treated in detail by solving the corresponding coupled differential equation system. The model also accounts for concentration changes of gas-phase and aqueous-phase chemical species which are induced by turbulence, gravitational settling and by evaporation/condensation processes.Numerical results demonstrate that fogwater chemistry is strongly controlled by dynamic processes, i.e. the vertical growth of the fog, turbulent mixing processes and the gravitational settling of the particles. The concentrations of aqueous-phase chemical species are different in the two droplet size classes. Reactands with lower water solubility are mainly found in the large droplet size class because the characteristic time for their mass transfer from the gas phase into the liquid phase is essentially longer than the characteristic time for the formation of large fog droplets. Species with high water solubility are rapidly transferred into the small fog droplets and are then washed out by wet deposition before these particles grow further to form large droplets. Thus, the concentrations of the major ions (NO₃⁻, NH₄⁺) are much higher in small than in large droplets, yielding distinctly lower pH values of the small particles. In the present study the reaction of sulfur with H₂O₂ and the Fe(III)-catalysed autoxidation of S(IV) are the major S(VI) producing mechanisms in fog water. Most of the time the sulfur oxidation rates are higher in the large than in the small droplets. Fogwater deposition by gravitational settling occurs mainly in the large droplet size class. However, since in the small droplets the concentrations of chemical species with very good water solubility are relatively high, in both droplet size classes the total wet deposition of these reactands is of the same order of magnitude.     

Ecological niche suitability model with an application in Taojiang land use planning

ＥｃｏｌｏｇｉｃａｌｎｉｃｈｅｓｕｉｔａｂｉｌｉｔｙｍｏｄｅｌｗｉｔｈａｎａｐｐｌｉｃａｔｉｏｎｉｎＴａｏｊｉａｎｇｌａｎｄｕｓｅｐｌａｎｎｉｎｇＯｕｙａｎｇＺｈｉｙｕｎ；ＷｅｉｓｍａｎＪａｓｏｎ；ＷａｎｇＲｕｓｏｎｇ（ＲｅｓｅａｒｃｈＣｅｎｔｅｒｆ...     

A dynamic food-chain model and program for predicting the consequences of nuclear accident

ＡｄｙｎａｍｉｃｆｏｏｄｃｈａｉｎｍｏｄｅｌａｎｄｐｒｏｇｒａｍｆｏｒｐｒｅｄｉｃｔｉｎｇｔｈｅｃｏｎｓｅｑｕｅｎｃｅｓｏｆｎｕｃｌｅａｒａｃｉｄｅｎｔＨｕＥｒｂａｎｇ，ＧａｏＺｈａｎｒｏｎｇ，ＺｈａｎｇＨｅｙｕａｎ，ＷｅｉＷｅｉｑｉａｎｇ...     

A three-dimensional model for the transportation of Fe and Mn in Arha Reservoir

ＩｎｔｒｏｄｕｃｔｉｏｎＡｒｈａＲｅｓｅｒｖｏｉｒｉｓｌｏｃａｔｅｄｉｎｔｈｅｐｌａｔｅａｕｒｅｇｉｏｎｏｆＳｏｕｔｈｗｅｓｔＣｈｉｎａ.Ｔｈｉｓｒｅｓｅｒｖｏｉｒ,ｗｉｔｈａｖｏｌｕｍｅｏｆ445ｍｉｌｌｉｏｎｍ3,ｗａｓｂｕｉｌｔｉｎ1960ａｎｄｉｓｔｈ?..     

Heavy metal adsorption on the Le An River sediment —The adsorption model

In this study,the surface properties and adsorption properties of the Le An River sediment were modelled via surface complexation approach.The model parameters were determined based on the data of our potentiometric titration experiments and the metal adsorption experiments with the Le An River sediment samples.Consequently,the surface complexation models for the natural sediment,in our case the Le An River sediments,which can interpret the experimental data very well were successfully established.Three typical surface complexation models that is the constant capacitance model,the diffuse layer model and the triple layer model,were considered in this research.This work indicated that the consistency and the interdependency among model parameters together with the selection of the surface adsorbed species should be emphasized.     

Dynamic pursuing ecological model concerning the nitrogen cycle in the environment of Chinese mainland

The paper gives a special dynamic pursuing ecological model on the bio-geochemical cycle of nitrogen in the whole range 9.6 million square kilometers of Chinese mainland, basing on the reservoir-content and flux-rate of nitrogen and among the four spheres: atmosphere, pedosphere, biosphere, and hydrosphere, and the law of bio-geochemical cycle of nitrogen, the model predicted the size of reservoir capacities and fluxes of nitrogen in each sphere. Through tested and verified, the model was proven reasonable and reliable.     

Prediction of the amount of urban waste solids by applying a gray theoretical model

ＩｎｔｒｏｄｕｃｔｉｏｎＵｒｂａｎｗａｓｔｅｓｏｌｉｄｓａｒｅｍｏｓｔｌｙｐｒｏｄｕｃｅｄｆｒｏｍｒｅｓｉｄｅｎｔｉａｌａｒｅａｓ ,ｆａｃｔｏｒｉｅｓｏｒｍａｎｕｆａｃｔｕｒｅｓ,ｍａｒｋｅｔｐｌａｃｅｓ,ｈｏｔｅｌｓ,ｒｅｓｔａｕｒａｎｔｓ,ｓｔｒｅｅｔｓａｎｄｏｔｈｅｒｆｕｎｃｔｉｏｎａｌａｒｅａｓ.ＷｉｔｈｔｈｅｐｏｐｕｌａｔｉｏｎｉｎｃｒｅａｓｉｎｇａｌｌｏｖｅｒＣｈｉｎａ ,ｕｒｂａｎｗａｓｔｅｓｏｌｉｄｓａｒｅｎｏｗｂｅｃｏｍｉｎｇｏｎｅｏｆｔｈｅｍｏｓｔｃｒｕｃｉａｌｅｎｖｉｒｏｎｍｅｎ…     

Prediction for emission of trace gases by GM(1，1)model

This paper recommend the grey control system model(GM 1,1 )to approach the problem of prediction for emission of trace gases．When the number of data in the system is not enough for mathermatics statistics analysis，the application of GM(1，1)model can get available results．This model can be used for prediction of emission trace gases and trend of global concentration of C0₂．The atmospheric concentration of CO₂ will be 365.9 ppmv by the year 2000 The prediction for emission of CO₂ from buming coal will be 1123．3 TgC in China．The emissions of CO in China are estimated．     

Water and matter dynamic balance in the rite field and its overflow estimate model

The rice field is the main Iand use type in the watershed of Chaohu Lake．Because of the water dryness alternative farming applied there，the paddy soil has a unique quality regarding soil profile as well as special water and nutrient dynamms．Through the analysis of water and matter dynamics in rice fields．the field water level(H)and the concentrations of total nitrogen(TN)and total phosphorus(TP)in flood water layers of the fields were chosen to estimate the nonpoint pollution from rice fields．A simple model was built and used to calculate the quantRy of N and P pollutants from rice field overflow．it shows the po．tential effects of rice fields on Chaohu Lake eutrophication．     

Numerical simulation of a combined oxidation ditch flow using 3D k-ε turbulence model

The standard three dimensional(3D) k-ε turbulence model was applied to simulate the flow field of a small scale combined oxidation ditch. The moving mesh approach was used to model the rotor of the ditch. Comparison of the computed and the measured data is acceptable. A vertical reverse flow zone in the ditch was found, and it played a very important role in the ditch flow behavior. The flow pattern in the ditch is discussed in detail, and approaches are suggested to improve the hydrodynamic performance in the ditch.