ABSTRACT
To quantitatively characterize the pyramidal texture of monocrystalline silicon cells and to optimize the parameters of the texturing process, the relative standard deviation Sh was proposed to quantitatively characterize the uniformity of the pyramidal texture. Referring to the definition and calculation of the standard deviation in mathematical statistics, Sh was defined as the standard deviation of the pyramid relative height hi after normalization of the pyramid height Hi of monocrystalline silicon wafer surfaces. Six different silicon cells, with different pyramidal textures, were obtained by applying different texturing times. The relationships between Sh and the photoelectric characteristics were analyzed. The feasibility of quantitatively characterizing the uniformity of the pyramidal texture using Sh was verified. By fitting the Sh curve, the feasibility of optimizing the texturing process parameters and predicting the photoelectric characteristics using Sh was verified. The experimental and analytical results indicate that, when the relative standard deviation Sh was smaller, the uniformity of the pyramidal texture obtained by texturing was better. The photoelectric conversion efficiency (PCE) of the silicon cells monotonically increased with decreasing Sh. The silicon cell obtained by texturing with 2% tetramethylammonium hydroxide (TMAH) solution for 18.1 min had a textured surface with a minimum of Sh, the reflectivity of the silicon cell reached its minimum value of 2.28%, and the PCE reached its maximum value of 19.76%.
ABSTRACT
OBJECTIVE: To study the expressions of survivin, PTEN and their relationships with tissue grade and pathology stage in prostatic carcinoma (PCa). METHODS: The immunohistological staining was used to evaluated the expressions of survivin protein and PTEN in 43 case of prostatic carcinoma (PCa) and 5 cases of benign prostatic hyperplasia (BPH). RESULTS: The positive rate of survivin protein was 81.40%. Expression of survivin protein in 5 case of BPH was negative. The positive rate of PTEN was 30.23%, and the higher the grade and the clinical stage of tumors were, the lower the expression of PTEN was, PTEN of 5 case of BPH was positive. CONCLUSION: The positively correlation was found between the abnormal expressions of survivin protein, PTEN and the biological behavior of prostatic carcinoma (PCa). Detection of survivin combined with PTEN is valuable for diagnosing PCa, and evaluating malignancy extent and prognosis.
