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51.
Jian Yin Shiqiong ZhouYoujun Xie Yu ChenQinlian Yan 《Cement and Concrete Research》2002,32(2):173-177
This paper presents the compounding technology and application of C80-C100 high-performance concrete (HPC) containing ultra-pulverized fly ash composite (PFAC) and superplasticizer. The properties of C80-C100 HPC are also studied systematically. The experimental results indicate that this concrete has excellent workability, high strength, lower drying shrinkage, outstanding volume stability, durability, etc. 相似文献
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We studied 722 reexcision scars of benign and malignant lesions (except melanocytic lesions) excised over a 24-month period. The formalin-fixed, paraffin-embedded tissue sections were examined histologically and immunohistochemically. The histological features of melanocytic hyperplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most common sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). Basal cell carcinoma was the most frequent original lesion in both sexes (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen this reaction pattern following reexcision of melanocytic lesions as well. Thus, interpreting reexcision margins when lentigo maligna or similar lesions are reexcised may be fraught with difficulty. It is important for pathologists and dermatopathologists to recognize this phenomenon because histologically the presence of increased numbers of large melanocytes could be misinterpreted as melanoma in situ. 相似文献
54.
Weitang Li Zhenghui Li Shifu Zhu Shujun Yin Beijun Zhao Guanxiong Chen 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1996,370(2-3):435-437
Instead of the temperature oscillation method (TOM), a modified vapor growth method was applied in this paper to grow large HgI2 crystals with fewer lattice defects by providing a relatively stable temperature field during growth. And a new processing technique of HgI2 crystals was developed for detector fabrication by merging solution string-sawing and hand-cleaving. The lattice deformations caused during cleaving were reduced greatly by eliminating passivated layers on the sawed crystal platelets before cleaving. 相似文献
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A theoretical model is presented to describe the effect of ion beam bombardment rate on the formation of tetrahedral amorphous carbon (ta-C) films. The critical ion energy, Ec, corresponding to a 50% sp3 content in the films, is found to be dependent on both the effective thermal resistance and the ion beam bombardment rate. In the model, the ‘window’ width in the ion energy scale for the formation of ta-C material increases with decreasing deposition rate and with a reduction in the effective thermal resistance, until limited by lower and upper boundary thresholds. Experimental data are reproduced by the model. The plasmon energy, which correlates with sp3 fraction, is found experimentally of be higher for lower deposition rate and smaller effective thermal resistance. Data points for high sp3 content ta-C films deposited on silicon substrates at room temperature occupy a region in the ion energy-deposition rate (E-r) diagram similar to that predicated from the theory. 相似文献
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本文研究了经济分析基本方法之一最优等效替代法的实质,系统地导出了被评价方案的绝对经济指标与相对经济指标的关系,并结合典型案例分析指出了该方法的应用条件,对正确进行建设项目的经济评价具有现实意义。 相似文献
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