替代紫木节复合原料研究

通过优选复合方案、选择原料预处理工艺、调整泥浆性能,实现了复合粘土原料化学组成、颗粒组成与紫木节一致,保证了复合粘土可塑性及泥浆性能均达到或超过紫木节各项性能指标。试验结果表明:以长白山高岭土81.3wt%,苏州土4.1wt%,东北黑泥12.2wt%,龙岩土2.4wt%复合使用最佳,复合粘土原料注浆泥的比重、细度、流动性、稳定性基本与紫木节一致,厚化度略有减小,有利于泥浆的输送和注浆成型操作;坯体的收缩率减小,大大降低坯体变形、开裂的可能性;生坯干燥强度提高,有利于提高成品率;复合原料杂质含量低,烧后坯体白度提高。     

悬浮法VCM—VAc共聚树脂生产工艺研究

研究了氯乙烯-醋酸乙烯（简称VCM—VAc）共聚树脂（氯醋树脂）合成技术在30m,聚合釜中的工业化生产情况。该工艺采用复合引发剂体系、复合分散剂体系、VCM滴加工艺、微正压汽提技术和3#塔冷风干燥技术。应用结果表明,该工艺运行平稳、安全,装置利用率高,产品中醋酸乙烯酯分布均匀。     

改进的非参数核估计预测上证指数

改进了单纯利用非参数核估计预测上证指数的方法。首先利用隐马尔科夫模型将数据分成两种状态,即正常状态和非正常状态。然后对正常状态的数据仍然使用非参数核估计进行预测,而对非正常状态的数据则结合支持向量机(SVM)进行预测。由于在较少数据预测问题中支持向量机模型预测具有较大的优势,从而使新的预测方法较以前的方法具有更好的预测效果。     

家纺企业员工跳槽现象调查研究

员工的高跳槽率一直是困扰家纺企业管理者的难题,对家纺企业普通员工跳槽现状与影响因素进行分析,旨在为控制跳槽率、防范员工流失提供政策建议。采用企业调查、实证研究、模型分析等方法,得出员工工作压力、与领导关系、企业升迁制度、学习培训机会、与同事关系、工作回报公平性、工作机会等是影响员工跳槽的主要因素。因此,企业管理者应重视员工的职业生涯规划、完善企业的薪酬与绩效考评机制、建立畅通的正式沟通渠道,从而创造和谐的工作环境,降低员工跳槽的倾向。     

人文学科实验室建设与复合型人才培养探析

人文学科实验室的构建,既有利于激发学生对于学习的兴趣和渴望,也为复合型人才的培养营造了良好的学习环境。该文从文科实验室的建设、复合型人才的培养和文科实验室建设对复合型人才培养的效用三方面来探析文科实验室建设与复合型人才培养之间的内部联系,提出优化校园学习环境、坚持以学生为本、强化锻炼学生的实践能力、推动校外人文学科教学基地合作等具体措施。     

Application of digital image correlation to full-field measurement of shrinkage strain of dental composites

Objectives: Polymerization shrinkage of dental composites remains a major concern in restorative dentistry because it can lead to micro-cracking of the tooth and debonding at the tooth-restoration interface. The aim of this study was to measure the full-field polymerization shrinkage of dental composites using the optical digital image correlation (DIC) method and to evaluate how the measurement is influenced by the factors in experiment setup and image analysis. Methods: Four commercial dental composites, Premise Dentine, Z100, Z250 and Tetric EvoCeram, were tested. Composite was first placed into a slot mould to form a bar specimen with rectangular-section of 4 mm mm, followed by the surface painting to create irregular speckles. Curing was then applied at one end of the specimen while the other part were covered against curing light for simulating the clinical curing condition of composite in dental cavity. The painted surface was recorded by a charge-coupled device (CCD) camera before and after curing. Subsequently, the volumetric shrinkage of the specimen was calculated with specialist DIC software based on image cross correlation. In addition, a few factors that may influence the measuring accuracy, including the subset window size, speckle size, illumination light and specimen length, were also evaluated. Results: The volumetric shrinkage of the specimen generally decreases with increasing distance from the irradiated surface with a conspicuous exception being the composite Premise Dentine as its maximum shrinkage occurred at a subsurface distance of about 1 mm instead of the irradiated surface. Z100 had the greatest maximum shrinkage strain, followed by Z250, Tetric EvoCeram and then Premise Dentine. Larger subset window size made the shrinkage strain contour smoother. But the cost was that some details in the heterogeneity of the material were lost. Very small subset window size resulted in a lot of noise in the data, making it difficult to discern the general pattern in the strain distribution. Speckle size did not seem to have obvious effect on the volumetric shrinkage strain along specimen length; however, larger speckles resulted in higher level of noise or heterogeneity in the shrinkage distribution. Compared with bright illumination, dimmer lighting produced larger standard deviations in the measured shrinkage, indicating a higher level of noise. The longer the specimen, the greater was the rate of reduction with distance from the irradiated surface, especially for the longitudinal strain. Significance: The image correlation method is capable of producing full-field polymerization shrinkage of dental composites. The accuracy of the measurements relies on selection of optimal parameters in experimental setup and DIC analysis.     

Solvent Vapour Use – The Unintended Consequences in Textile Conservation

ABSTRACT

The impact of solvent vapour from two solvents, acetone and industrial denatured alcohol (IDA), commonly used in adhesive reactivation in textile conservation, when applied to artificially soiled silk fabric through either Gore-Tex^® or Reemay^® membranes for exposure times of either 1 or 3 min, was measured using microscopy and ImageJ to monitor the movement of the solid particulates of the soiling, and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) to monitor the movement of the oily components. Analysis using these techniques successfully showed the movement of large particulates through the textile and a decrease in the presence of oil. Analysis with FTIR-ATR showed that the application of solvent vapour by a poultice method produces more than just a surface change and the vapour can penetrate far enough into the fibres to cause a change in the level of oil through the entire textile. The results showed that the solvents and barrier membranes have characteristic differences which impact on the changes on the soiling. The application of acetone produced a greater change in the movement of oil on the front and back of the samples than the application of IDA, while a comparison between the barrier membranes showed a greater change occurring in the level of oil with the use of Gore-Tex^® rather than Reemay^®. The time of exposure to solvent vapour made little difference to the changes to the textile soiling. Quantitatively significant results were gathered from analysis of the changes in the oil measured with FTIR-ATR, and qualitative changes in the large particulate soiling, demonstrating the potential usefulness of ImageJ open access software in future historic textile soiling monitoring studies.     

Speech and the learning process

The semiotic assumption that language is a system of symbols, signals, or signs minimally entails a commitment to the position that there are two worlds, one linguistic and the ether non‐linguistic, and that they are related by some sort of representation. This essay challenges this view insofar as it purports to account for all language functions. It offers a complementary idea that emerges from the writings of Heidegger, Gadamer, and Buber: that language in spoken conversation is often constitutive, not merely instrumental and representional.     

高校体育专业排球普修课运用"组合"模式教学的实验研究

通过教学实验和问卷调查,对"组合"教学模式在高校排球教学中的教学效果进行了研究,证明该模式能够明显提高教学质量,并从理论分析的角度论证了该模式的显著优势。     

产业集聚水平测度方法及实证研究——以中国纺织产业为例

利用区位商指数对中国纺织产业2003~2005年的集聚水平进行了测定。计算结果表明:我国纺织产业在东部地区如上海、江苏、天津、浙江、广东、山东等省的产业集群程度比较高;中西部地区纺织产业集聚程度相对较低;纺织产业集聚程度与工业经济增长呈现高度的正相关性;我国纺织产业集聚弹性是0.8823,该行业的规模经济效益非常明显,存在较强的规模经济效应。