Application of the Physical Quantity Field Evolution under Numerical Model in Precipitation Forecast of Yantai

[Objective] The research aimed to understand role of the forecast data about physical quantity field in precipitation forecast.[Method] By contrasting forecast and actual situation of the precipitation in Yantai during 2-3 July and 12-15 September,2011,advantages and disadvantages of the different numerical forecast models (Japan fax chart,European center,MM5,Grapes and T639) were analyzed.[Result] MICAPS system could provide live situation of the physical quantity field,but couldn't provide the future evolution situation.Japan fax chart,European center,MM5,Grapes and T639 could provide future evolution situation of the physical quantity field.[Conclusion] The contrasts and analyses on forecast situations of the physical quantity fields in many precipitation processes showed that evolutions of the vertical velocity,temperature dew point difference,relative humidity and wind field at the different heights could improve forecast accuracy of the precipitation in Yantai.

The Physical Nature of H_2CO Clouds in Dark Clouds, B5 and L1535

By fitting the data of the H 2CO 2 mm (140 GHz and 150 GHz), 2cm (1 45GHz) and, 6 cm (4 3GHz) lines we observed in the dark clouds, B5 and L1535, to the values calculated by the hydrostatic equitlibrium polytropic model developed by B.E. Turner, we derived the total density, the fractional abundance of H 2CO, the column densities of H 2 and CO, the line temperature arising from various transitions, the line temperature ratio between different transitions, and visual extinction at the cores of the clouds. We also examined the effect of external UV field intensity on the line temperatures and their ratios.

The Physical and Clinical Aspects of Radiation Therapy in Skin Cancer and Subcutaneous Tissue Neoplasm

Cancers, malignant melanoma and sarcomas of the skin represent the most common group of malignancies in humans. The main treatment method of almost all skin cancers and subcutaneous tissue tumours is surgery, which consists of complete removal of a neoplastic lesion, with an adequate margin of healthy tissue. Radiotherapy plays an adjuvant role in this process, meaning complementing of the surgical procedure. This study compared four methods of irradiation treatment of cancer located in the skin or in subcutaneous tissues: contact brachytherapy, conventional orthovoltage therapy, electron beam conformal teleradiotherapy and IMRT dynamically shaped photonic beams conformal teleradiotherapy. In order to compare the methods and techniques of surface radiotherapy, following specific objectives were formulated. At the beginning in order to compare the scopes of the absorbed doses at different tissue depths, an analysis of parameters describing particular beams or radiation source has been performed—the curves for the absorbed-dose depth drop-offs. Doses distribution in tissue-like phantoms stimulating homogeneous cuboidal tissue block has been determined. A quality comparison of dose distribution in 2D and 3D treatment planning system for contact brachytherapy application has been made. The dose distribution for electron beam in the system has been determined. Conformal plannings for electron beam treatment, contact brachytherapy applicator treatment and 4 photon beams treatment optimized in IMRT technology have been performed. Dose distribution has been performed for the irradiated female patient within the well chest—the target included the recurrence area in the post-operative scar. The radiation therapy with X-rays has actually been completely eliminated from skin cancer and subcutaneous tissue radiotherapy by the electrons generated in linear accelerators, contact brachytherapy HDR and by high-energy photons used in conformal techniques, ex. IMRT. It is because the residual dose beyond the target is the highest for single X-ray beam. Although in brachytherapy HDR a rapid dose drop-off is observed, 5 cm from its normalization level for the target the residual radiation remains at the level of several percent. So, both X-rays beam radiation and brachytherapy in skin cancer treatment is connected with the administration of the dose with a high gradient in the health tissues. The dose distribution for photon conformal techniques IMRT or for electron radiation looks different. There with the dose normalization at the level of 90% or 85% we deal with the dose layer, the division does not exceed 15% of heterogeneity.

MY CONTRIBUTIONS TO THE PHYSICAL PROCESS OF SOLIDIFICATION

In 1950, I graduated from Tsinghua University,majoring in machine building. Three years later, Ientered the Iron & Steel College in Moscow to start studying metallurgy as a postgraduate. After obtaining my associate professorship, I came back home. I devoted the succeeding 40 years to the theory and technology of solidification, because I had realized the importance of the physical process of solidification in materials science and engineering technologies as a means of upgrading the properties of traditional materials and developing new materials. My contributions in this field might be listed as follows:

Theoretical relationship between sound velocity and the physical properties of submarine sediment

Density and elastic modulus change ratios are introduced to describe the sound velocity of submarine sediment. The density change ratio is a composite parameter describing the sound velocity. It is expressed by three physical parameters： porosity, solid phase density and seawater density. The elastic modulus change ratio is also a composite parameter of sound velocity. It is expressed by three physical parameters, including porosity, solid phase modulus and seawater bulk modulus. The sound velocity formula can be developed into a Taylor polyno- mial formula of these two composite parameters. The change in the two composite parameters constitutes the sound velocity surface, which contains the complete information regarding ve- locity properties and sediment characteristics. The one-parameter velocity formula is a curve on the velocity surface. Each porosity-velocity empirical formula, which represents various sea locations and conditions, is transformed to a standard form. This result is the product of a reference velocity and a modulation function. Comparisons of the numerical calculation and measurements show that the derived modulation functions yield similar results. The difference between the velocity formula derived in this paper and the Wood velocity formula is due to the elastic modulus models.

Study on the physical basis of pressure and particle velocity combine processing

Some basic studies of pressure and particle velocity combine processing such as correlation between them, average acoustic intensity processing, rotating and sharpening of directivity are described. Preliminary results based on theoretical analysis and lake trail will lay a foundation for further research.

Energy Balance-Based SWAT Model to Simulate the Mountain Snowmelt and Runoff——Taking the Application in Juntanghu Watershed(China) as an Example

In order to predict long-term flooding under extreme weather conditions in central Asia, an energy balance-based distributed snowmelt runoff model was developed and coupled with the Soil and Water Assessment Tool(SWAT) model. The model was tested at the Juntanghu watershed on the northern slope of the Tian Shan Mountains, Xinjiang,China. We compared the performances of temperature-index method and energy balanced method in SWAT model by taking Juntanghu river basin as an application example(as the simulation experiment was conducted in Juntanghu River, we call the energy balanced method as SWAT-JTH). The results suggest that the SWAT snowmelt model had overall Nash-Sutcliffe efficiency(NSE) coefficients ranging from 0.61 to 0.85 while the physical based approach had NSE coefficients ranging from 0.58 to0.69. Overall, on monthly scale, the SWAT model provides better results than that from the SWAT-JTH model. However, results generated from both methods seem to be fairly close at a daily scale. Thestructure of the temperature-index method is simple and produces reasonable simulation results if the parameters are well within empirical ranges. Although the data requirement for the energy balance method in current observation is difficult to meet and the existence of uncertainty is associated with the experimental approaches of physical processes, the SWAT-JTH model still produced a reasonably high NSE. We conclude that using temperature-index methods to simulate the snowmelt process is sufficient, but the energy balance-based model is still a good choice to simulate extreme weather conditions especially when the required data input for the model is acquired.

Concrete Physics Method for Solving NP hard Problem

With a NP hard problem given, we may find a equivalent physical world. The rule of the changing of the physical states is simply the algorithm for solving the original NP hard problem .It is the most natural algorithm for solving NP hard problems. In this paper we deal with a famous example , the well known NP hard problem——Circles Packing. It shows that our algorithm is dramatically very efficient. We are inspired that, the concrete physics algorithm will always be very efficient for NP hard problem.