检索结果-南通市图书馆

马里兰州salisbury地区远视老年同胞人群的家族聚集现象

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

世界核心医学期刊文摘（眼科学分册） 2005年第5期1卷 53-53页

作者： Wojciechowski R. Congdon N. Bowie H. 张少娟

To determine whether hyperopia aggregates in families in an older mixed-race population. Cross-sectional familial aggregation study using sibships. We recru ited 759 subjects (mean age, 73.4 years) in 241 families through the population -based salisbury Eye Evaluation study. Subjects underwent noncycloplegic refrac tion if best-corrected visual acuity (BCVA) was ≤20/40, had lensometry to meas ure their currently worn spectacles if BCVA was > 20/40 with spectacles, or were considered to be plano (refraction of zero) if the BCVA was > 20/40 without spe ctacles. Preoperative refraction from medical records was used for bilaterally p seudophakic subjects. Utilizing hyperopia cutoffs from 1.00 to 2.50 diopters, ag e-, race-, and gender-ad-justed odds ratios for hyperopia with an affected s ibling ranged from 2.72 (95%confidence interval [CI], 1.84-4.01) to 4.87 (95 % CI, 2.54-9.30). The odds of hyperopia increased with age until 75 years, after which they remained relatively constant. Black men were significantly less likel y to be hyperopic than white men, white women, or black women. Hyperopia appears to be under strong genetic control in this older population.

关键词：家族聚集现象 salisbury 马里兰州人工晶体眼睫状肌麻痹家族聚集性矫正视力病例记录截断值横断面研究

维普期刊数据库

在线全文

学校读者我要写书评

暂无评论

Kosa更新salisbury工厂的设备

聚酯工业 2002年第2期15卷 24-24页

作者：王德诚

Design and Measurement of Microwave Absorbers Comprising Resistive Frequency Selective Surfaces

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Electromagnetic Analysis and Applications 2014年第8期6卷 203-208页

作者： Meng Zhang Tian Jiang Yijun Feng School of Electronic Science and Engineering Nanjing University Nanjing China

Frequency selective surfaces (FSSs) have been successfully used in constructing microwave absorbers which demonstrate the ability of modifying and improving its absorbing performances. In this paper, microwave absorber based on ferromagnetic nano-films has been proposed and investigated with a structure similar to that of the salisbury screen except that the resistive sheet is replaced by FSS of square patch array of the nano-film. We have explored the FSS absorber from three aspects: equivalent circuit model, electromagnetic full-wave simulation and the actual sample measurement. By carefully tuning the patch size, the thickness of the dielectric spacer and the specification of the ferromagnetic nano-film, we obtain the optimized performance of broadband microwave absorbing. Due to the light weight of the nano-films, the proposed absorbers can achieve an ultra-low surface density less than 0.25 kg/m2.

关键词： salisbury Screen Frequency Selective Surface Equivalent Circuit Model Electron Beam Evaporation

短切碳纤维树脂膜/聚乙烯泡棉材料的制备与吸波性能研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

化工新型材料 2020年第12期48卷 81-83页

作者：吴赛杨东方张旭王彦北京航空材料研究院北京100095

分别以短切碳纤维(添加环氧树脂)膜和轻质闭孔聚乙烯泡棉作为电阻层和无损间隔层,通过将短切纤维树脂膜粘接在聚乙烯泡棉上,制备具有salisbury Screen结构的雷达吸波材料。通过测试材料的反射率,研究吸收剂含量和泡棉厚度对材料吸波性... 详细信息

分别以短切碳纤维(添加环氧树脂)膜和轻质闭孔聚乙烯泡棉作为电阻层和无损间隔层,通过将短切纤维树脂膜粘接在聚乙烯泡棉上,制备具有salisbury Screen结构的雷达吸波材料。通过测试材料的反射率,研究吸收剂含量和泡棉厚度对材料吸波性能的影响规律。结果表明,当短切碳纤维含量为0.3%(wt,质量分数),聚乙烯泡棉厚度为3mm时,材料在8G^18GHz的吸波性能最优,其最大反射率可达-26.9dB。

关键词：短切碳纤维聚乙烯泡棉雷达吸波材料 salisbury Screen结构

维普期刊数据库