李白、崔颢《黄鹤楼》诗案考辨

分析了李白、崔颢《黄鹤楼》诗案本末,认为肯定诗案的观点缺乏有力的依据,质疑诗案的观点值得重视。提出否定诗案的5个视点及澄清诗案的4点意义。     

陶瓷转化工艺在空调镀锌钢板涂装中的应用

介绍一种新型陶瓷转化工艺在空调镀锌钢板的粉末喷涂中的应用.通过转化膜的晶相、附着力及盐雾试验表征,对预转化板的现有工艺进行控制.盐雾试验结果表明,预转化镀锌钢板经过弱碱性脱脂剂清洗,经陶瓷转化后与粉末涂料结合,可以得到良好耐蚀性和附着力强的膜层.     

Neutral and polar lipid phase transition of soybeans with various saturated fatty acid contents

Soybeans with modified saturated fatty acid compositions sometimes have lower seed germination rate or other undesirable agronomic traits. To determine if seed germination could be related to the melting transitions of their lipids, triacylglycerols (TAG) and phospholipids (PL) from soybeans with a wide range of saturated fatty acid compositions were examined by differential scanning calorimetry. The melting transition temperatures of both TAG and PL increased with increasing palmitate and stearate percentages. The mean melting points of the various lipids calculated on the basis of the melting points of their fatty acids correlated with the observed transition temperatures. Increased lipid saturation and elevated phase transition temperatures may have contributed to the reduced germination and seedling growth rates of these modified seeds.     

一种简易实用的开口剪切腹板有限元建模方法

研究含开口剪切腹板结构简易的有限元建模技术,提出当量厚度的有限元建模方法,给出内含椭圆形开口以及长方形和弧形组合开口腹板的当量厚度计算式.该计算式考虑腹板形心与开口中心不重合及开口边缘有加强件.为了验证文中提出的当量厚度有限元建模方法的正确性,采用MSC.Nastran分别对含两种开口墙腹板的盒段进行有限元建模分析,并分别与常规的网格细化的有限元建模分析结果进行比较.结果表明,所给出的当量厚度建模方法与常规网格细化的建模方法吻合很好,相对误差不大于2.0％,验证了所提出建模方法的正确性和有效性.     

第7次普通高等学校图学教育现状的调查与研究

2008年初对全国高等院校图学教育的现状进行了问卷调查.这是继1997、1998、2000、2002、2004、2006年6次调查之后的第7次大规模调查.此次调查的内容是在总结了前6次调查的基础上,根据形势的发展,由中国工程图学学会图学教育专业委员会开会讨论确定的.在对本次调查结果汇总和分析的基础上,介绍了我国普通高等学校图学教育的现状与发展趋势,供广大图学工作者参考.     

Synthesis and formation mechanism of hematite hollow microspheres by a one-pot templateless surfactant-free hydrothermal process

Hollow microspheres of hematite (α-Fe₂O₃) were prepared by a simple hydrothermal treatment of ferrous ammonium sulphate hexahydrate ((NH₄)₂Fe(SO₄)₂·6H₂O) aqueous solution without any surfactants and additives at 180–200 °C. The products were characterized by XRD, FE-SEM and TEM. The results show that α-Fe₂O₃ hollow microspheres are about 1 μm in diameters and are composed of α-Fe₂O₃ nanoparticles with a diameter range from 50 nm to 150 nm. The effects of reaction parameters such as reaction time, temperature and [(NH₄)₂Fe(SO₄)₂·6H₂O] on the morphology of the final product were investigated. A potential formation mechanism of α-Fe₂O₃ hollow microspheres was also proposed, where the intermediate, urchin-like goethite, served as a sacrificial template for the formation of hollow structure. The reaction parameters-depended morphologies of the final products consisted well with the proposed formation mechanism.     

从软硬件发展看影视后期制作核心任务的变迁

随着计算机技术的发展，数字技术被广泛地应用到影视制作当中，增强并完善了影视后期制作的功能，尤其满足了大规模制作的需求。数字技术已经开始对影视制作的流程本身进行改造，如媒体资产管理系统。本文重点分析了不同时期影视后期制作的自身特征，并根据目前影视制作的需求趋势讨论了影视后期制作系统的发展趋势。     

Novel full range vacuum pressure sensing technique using free decay of trapezoid micro-cantilever beam deflected by electrostatic force

This paper reports a novel full-range vacuum pressure sensing device, capable of exceeding the sensing range of most gauges and reducing the volume by a factor of 10. The proposed device gauges the free decay rate of a micro-cantilever beam deflected using electrostatic force and measurements of capacitance are used to determine the free decay rate of the sensing beam with respect to deflection force and vacuum pressure. This novel design enables the full-range measurement of vacuum pressure from 0.2 to 1?×?10^?8?torr. The trapezoidal micro-cantilever beam provides uniform in-plane stress across the surface of the beam, while a thick square plate connected to the trapezoid beam serves as a proof mass and receiver of electrostatic force. Results demonstrate that the free decay rate of the deflected beam is linearly proportional to vacuum pressure. The decay time constant was 0.69?s under low vacuum and 42.56?s under high vacuum. In addition, a change in vacuum pressure of one torr resulted in a change of 47.6 (1/s) in the decay rate. This rapid response to changes in pressure demonstrates the high degree of sensitivity demonstrated by the device. The proposed device represents a considerable advancement in the development of miniature full-range pressure gauges as well as the applicability of micro-electromechanical systems.