共查询到20条相似文献,搜索用时 281 毫秒
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构图亦称章法、布局,是山水画创作中的重要环节。构图的成功与否关系到山水画的好与坏。构图必须与画面立意相结合,也就是要与画面的内容相协调。构图要运用对立统一规律,要体现宾与主、远与近、虚与实、疏与密、聚与散、开与合、藏与露、黑与白、大与小等关系。对立是变化的,统一是均衡的。只有把这些对立关系统一在画面中,才可称得上是好的构图。好的构图是要我们在万象纷纭、变化万千的复杂事物中 相似文献
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轮胎的绿色特性与发展 总被引:5,自引:0,他引:5
概述了绿色轮胎起源与发展历程、轮胎安全认证与节能环保法规以及轮胎"三化"与技术创新;阐述了欧盟、美国等国家对节能与环保轮胎滚动阻力限制,以及低噪声与静音轮胎、冬用与全天候轮胎、仿生与高速安全轮胎、高性能与超高性能轮胎、保用与智能轮胎、高里程与长寿命轮胎及其他功能轮胎的性能特点;指出了绿色轮胎将要步入一个安全保用、智能以及全天候、高里程、长寿命的新时期。 相似文献
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该书系编译自由日本橡胶协会模具分会编写、日本工业调查会于2004年11月出版的《ゴム.エラストマ用金型技术》一书。全书共分10章:模具工业动向、橡胶与弹性体、橡胶与弹性体的硫化方法及其进步、模具内胶料流动和硫化行为与模具设计的关系、配炼与配方设计、模具设计、橡胶制品模具、模具制作、脱模与防止污染、硫化事故与对策。 相似文献
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以腐植酸为原料合成了阳离子生物质水处理剂,并对其杀菌灭藻、阻垢、缓蚀性能进行了评价。结果表明,阳离子生物质的杀菌灭藻性能得到很大提高,在药剂质量浓度为20~30mg/L时,可与癸甲氯铵的杀菌灭藻性能相媲美,同时阻垢、缓蚀性能也得到较大幅度的改善。 相似文献
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新型高效复合肥料硝酸铵钙生产及市场概况 总被引:1,自引:0,他引:1
介绍硝酸铵钙的物化性能,采用硝铵熔融液与石灰石混合法生产硝酸铵钙的工艺技术,简述硝酸铵钙在农作物种植上的施用效果及市场前景. 相似文献
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介绍模糊控制的概念,给出模糊控制的特点,总结模糊控制在生产生活中的应用现状,最后提出模糊控制未来的发展趋势。 相似文献
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综述了聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)及其衍生物作为非病毒基因载体的研究进展,包括PDMAEMA及其衍生物相对分子质量及结构与转染效率之间的关系、亲水性聚合物修饰的PDMAEMA和低相对分子质量的PDMAEMA接枝共聚物,并展望了PDMAEMA及其衍生物作为非病毒基因载体的发展方向。 相似文献
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镁及镁合金电镀与化学镀 总被引:20,自引:0,他引:20
介绍了镁及镁合金电镀与化学镀工艺流程、浸锌及直接化学镀镍等前处理工艺,以及已应用于镁及镁合金上的各种镀层.同时,对电镀及化学镀在镁及镁合金上的应用和发展状况作了简要评述. 相似文献
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Graphene and its derivatives show great potential for biosensing due to their extraordinary optical, electrical and physical properties. In particular, graphene and its derivatives have excellent optical properties such as broadband and tunable absorption, fluorescence bursts, and strong polarization-related effects. Optical biosensors based on graphene and its derivatives make nondestructive detection of biomolecules possible. The focus of this paper is to review the preparation of graphene and its derivatives, as well as recent advances in optical biosensors based on graphene and its derivatives. The working principle of face plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence resonance energy transfer (FRET) and colorimetric sensors are summarized, and the advantages and disadvantages of graphene and its derivatives applicable to various types of sensors are analyzed, and the methods of surface functionalization of graphene and its derivatives are introduced; these optical biosensors can be used for the detection of a range of biomolecules such as single cells, cellular secretions, proteins, nucleic acids, and antigen-antibodies; these new high-performance optical sensors are capable of detecting changes in surface structure and biomolecular interactions with the advantages of ultra-fast detection, high sensitivity, label-free, specific recognition, and the ability to respond in real-time. Problems in the current stage of application are discussed, as well as future prospects for graphene and its biosensors. Achieving the applicability, reusability and low cost of novel optical biosensors for a variety of complex environments and achieving scale-up production, which still faces serious challenges. 相似文献