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I plan to begin my Ph. D. Degree study in your Biophysics program in the fall term of 1995 and wish to obtain the degree within five years or so. Biophysics develops fast with the fruits of modern physics and chemistry. There is a wide range of fascinating questions in understanding life systems. During these years' study at Tsinghua University, I constantly tried to improve myself through independent reading. This kept me well informed of the latest development in Biophysics which attracts me a lot.
E. Schrodinger's famous work "What is Life" let me think a lot of questions in Biophysics. Up to now, physicist have made great success in studying simple periodic crystals, but for the complex biological structures possess both a periodicity and order such as DNA, there still exist many challenges. Why these a periodic matter can control the life strictly and precisely? Why a small amount of nature catalyst-enzyme can be far more efficient than plenty of man-made catalysts? Is the growth of life determined by genetic materials or by self-assembly or by both of them? From the book "Liquid Crystals and Biological Structures" written by Glenn H.Brown and Jerome J.Wolken, I got deeper understanding of biological structures which possess both mobility and long-range structure order, respond to a variety of external stimuli just like the properties of liquid crystals. The striking architecture at the molecular level shows there is a common physical-chemical origin for all life systems. The oriented molecules in liquid crystals furnish an ideal medium for catalytic action, particularly of the complex type needed to account for growth and reproduction. Water, especially the weak hydrogen bond plays critical role in all organism. It determines the protein folding, stabilizes the double helix structure of DNA. If we substitute deuterium for hydrogen, the biological system may be destroyed.
Many physical and mathematical approaches can be applied to biology such as the quantum mechanics, non-equilibrium thermodynamics, information theory. But a basic difficult by using the non-equilibrium thermodynamics in biology is the spatial heterogeneity in biological systems and the feedback existing in all kinds of reactions and processes. Condensed Matter Physics also concerns closely with Biophysics. The theory of phase transitions and critical phenomena can be used to explain problems such as how the temperature of the phase transition of lipids from the solid state to the liquid crystalline depends on the fatty acid composition.
On the other hand, researches in biophysics also push forward the development of physics, lead to more applications in bionics such as AI and neural net work.
Now I am doing my Diploma Thesis at the Institute of Physics, Chinese Academy of Science. My Topic is about investigating coherent backscattering in a random scattering medium by the He-New laser. Light in certain dielectric microstructures exhibits localized modes, similar to the localized wave function of electrons in disordered solids-Anderson Localization. The propagation of light in a scattering medium can be described as random walk of photons with the direction of each succeeding step determined by the laws of probability. The Topic spans the disciplines of Condensed Matter Physics and Quantum Optics. I have absorbed a lot of relative knowledge such as random walk, peroration models stochastic process to prepare for my project .I think the method I dynamics of chemical reactions.
Since my background focused on physics, mathematics, electronics, lasers and optics, I have taught myself some beginning biology and chemistry courses this year, discussed them with teachers in the Dept of Biological Science and Technology at Tsinghua University. I would also like to take more basic courses in this field under your guidance to make up my deficiency. From college guides I learned with pleasure that you had strong faculty with a variety of background in physics, chemistry, mathematics and electrical engineering. It is often in the multi-disciplinary research that came the most exciting discovery. Your group also provides outstanding opportunities for close interaction between graduate students and faculty. That is why I deem your program as my best choice. Besides, I want to link modern biophysics with Chinese Medicine to get comprehensive understanding of life.
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