石油沥青碳纤维摩擦复合材料

石油化工科学研究院采用石油沥青碳纤维和改性酚醛树脂制成摩擦材料，这种材料在100～300℃范围摩擦系数变化幅度为0．40～0．44，磨损率在250℃下仅为0．057×10－7cm3／（N·m），这种摩擦材料的原材料来源容易，价格便宜，成型工艺简单，成本大大低于碳纤维增强碳基体材料（碳／碳材料）和粉末冶金材料，并且不会污染环境，可用来取代石棉制作汽车及一些设备的制动器衬片。     

一种基于BF模型的基音检测改进算法

该文提出一种改进的在基于Bloomfield模型语音检测算法，该方法引入数值滤波器克服了BF模型固有的缺陷。通过实验分析表明，该方法与传统方法相比，提高了基音周期提取的准确性和分辨率，增强了清浊音判决的可靠性。     

Acoustic analysis of lexical tone in Mandarin infant-directed speech.

Using Mandarin Chinese, a "tone language" in which the pitch contours of syllables differentiate words, the authors examined the acoustic modifications of infant-directed speech (IDS) at the syllable level to test 2 hypotheses: (a) the overall increase in pitch and intonation contour that occurs in IDS at the phrase level would not distort lexical pitch at the syllable level and (b) IDS provides exaggerates cues to lexical tones. Sixteen Mandarin-speaking mothers were recorded while addressing their infants and addressing an adult. The results indicate that IDS does not distort the acoustic cues that are essential to word meaning at the syllable level; evidence of exaggeration of the acoustic differences in IDS was observed, extending previous findings of phonetic exaggeration to the lexical level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

高密度球键合质量的影响因素和解决方法

随着焊盘间距的减小和引线数目的增多,键合失效的发生也越来越频繁。系统分析了影响高密度球键合质量的各种主要因素得出在诸多因素中金属熔球(FAB free air ball)直径,引线摆动幅度和劈刀顶端形状等三个因素对键合质量的影响最大。文中介绍了线弧固定技术,紫外线金属熔球控制工艺和新型劈刀等三种能有效减少键合失效的新工艺和新方法。     

Research on the Speech Coding Algorithm at 1200bit/s

ＲｅｓｅａｒｃｈｏｎｔｈｅＳｐｅｃｈＣｏｄｉｎｇＡｌｇｏｒｉｔｈｍａｔ１２００ｂｉｔ／ｓＣｈｅｎＸｉｎｆｕＷｕＪｉａ’ａｎ（ＡｉｒＦｏｒｃｅＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓＥｎｇｉｎｅｒｉｎｇＩｎｓｔｉｔｕｔｅ，Ｘｉ’ａｎ７１００７７）Ａｂｓｔｒ...     

自制螺旋叶片下料的实用计算新方法

采用螺旋叶片下料经验公式解决了传统的螺旋叶片下料计算方法复杂的难题。经验公式计算叶片下料圆环外径时,仅需已知螺旋外径和螺距;对同一规格的螺旋,无论螺旋轴直径如何取值,下料圆环外径值唯一。经验公式突破了传统理论,计算简便,实用性强。     

马格磨齿机液性胀胎心轴的精度分析

本文从应力变形的角度分析了液性胀胎心轴受力后外径不能复原的原因和所采取的修复措施,以阻止变形的延续,保证进口机床正常运转.     

Visualization of wound periderm and hyphal profiles in pine stems inoculated with the pitch canker fungus Fusarium circinatum

Postpenetration behavior of Fusarium circinatum in stems of pine species was investigated with light and transmission electron microscopy. Two‐year‐old stems of Pinus rigida and P. densiflora were wound‐inoculated with the fungal conidial suspension and subjected to 25°C for up to 30 days. It was common to observe the formation of wound periderm on each pine species, recovering wounded sites with newly formed tissues. The outermost thick layer of wound periderm was pink to red colored with the phloroglucinol‐EtOH staining, indicating heavy deposition of lignin in wound periderm. The cork layers in the wound periderm of the two pine species consisted of cells that were mostly devoid of cellular contents in cytoplasm. The cork cells showed convoluted cell walls with different electron density (lamellations), which was seemingly more prevalent in P. densiflora than P. rigida. Hyphae of F. circinatum appeared normal with typical eucaryotic cytoplasm in P. rigida on ultrathin sections. Meanwhile, hyphae in P. densiflora were found to possess highly vacuolated cytoplasm, implying hyphal weakening and disintegration. Hyphal cytoplasm appeared to be a thin layer between the vacuole and the plasma membrane surrounded by cell wall. In addition, intrahyphal hyphae and concentric bodies were observed in hyphal cytoplasm. These results suggest that the architecture of wound periderm may be responsible for different responses of pine species to the invasion of F. circinatum. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

Fe/C复合纳米材料的制备研究

以强酸为絮凝剂，将碱性溶液中的水性中间相沥青絮凝，从而使水性中间相沥青在酸性介质中形成炭基溶胶和凝胶。将此炭基溶胶和硝酸铁溶液混合形成复合溶胶、凝胶，进而采用醇水交换和超临界干燥制备出粒度为5nm-20nm的Fe/C复合纳米材料。考察了硝酸铁和水性中间相沥青的比例，以及热处理条件对Fe/C复合纳米材料织构和结构的影响。利用透射电镜、物理吸附、ICP－AES、X－射线衍射、热重等表征手段对Fe/C复合纳米材料特性和热处理的变化规律进行了研究。结果表明：通过改变炭基溶胶中硝酸铁的加入量可以制备不同铁含量的Fe/C复合纳米材料；在惰性气氛下，于较低温度热处理时，Fe/C复合纳米粉中铁是以Fe2O3的形式存在，热处理温度升高（900℃）后Fe2O3被还原为单质铁，且金属颗粒团聚长大，在高温（1300℃）时，铁以Fe3C的形式存在，颗粒进一步长大且有部分炭石墨化。在还原性气氛下，在300℃－500℃热处理范围内，随温度的升高铁被还原为单质铁。     

沥青环氧树脂重防腐涂料的研制

利用环氧树脂改性煤焦沥青涂料,以达到它的重防腐性及使沥青涂料的软化温度提高到80℃以上,能在常温下很快干燥,从而扩大沥青涂料的应用范围。