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991.
以目前广泛使用的全板簧结晶振动器机构作为研究对象,建立了一种将板簧简化成等效弹簧、考虑振动机构自重和载荷影响、将结晶器载荷看作悬挂重物的动力学模型。以上海重矿连铸技术有限公司生产的结晶器机构为研究对象,运用Matlab编程、Newton法以及四阶Runge-Kutta法对所建立的动力学模型进行数值求解,分别研究了偏心轴的偏心量、偏心轴转速、载荷大小等参数变化对偏心安装的滚动轴承载荷的影响规律。当偏心距减小时,轴承上载荷的平均值没有变化,但是幅值减小;当偏心轮转速减小时,轴承上载荷的平均值下降,而其幅值有少量的减少;当载荷变小时,轴承上载荷的平均值变小,而幅值不变。 相似文献
992.
MicroRNAs (miRNAs or miRs) are endogenous non-coding RNAs that negatively regulate gene expres- sion by binding to the 3' non-coding regions of target mRNAs, resulting in their cleavage or blocking their translation. miRNAs may have an impact on cell differentiation, proliferation, and survival, and their deregulation can be inclined to diseases and cancers, including thyroid tumors. The purpose of this review is to summarize the existing findings of deregulated miRNAs in different types of thyroid tumors and to exhibit their potential target genes, especially to demonstrate those involved in tumor invasion and metastasis. In addition, new findings of circulating miRNA expres- sion profiles, single nucleotide polymorphism (SNP) in thyroid tumors, and the correlation of somatic mutations with deregulated miRNA expression in thyroid tumors were all included in this review. 相似文献
993.
Establishing a reasonable evaluation index system is the basis and premise for the scientific evaluation of geographic national conditions. By analyzing the DPSIR model and its correlation and relation with the evaluation index system, the indexes for geographic national conditions were selected from the aspects of resources, ecology, environment, economy, society, etc to build an evaluation index system for geographic national conditions that consists of three hierarchies: index, criterion, and target levels. Furthermore, the index system was analyzed in terms of index integrity, low overlapping of elements, non-existence of isolated indexes, hierarchy of index system, etc., for the purpose of demonstrating that the DPSIR model-based evaluation index system for geographic national conditions meets the principles of index system establishment. 相似文献
994.
995.
实验室水槽装置液位模糊控制系统的设计 总被引:4,自引:0,他引:4
介绍一种带修正因子和寻优参数的水位模糊控制系统。实验表明 ,该系统具有较强的抗干扰能力及适应内部参数变化的能力。阐述了控制方案及软、硬件的设计。 相似文献
996.
To compare two microspheres of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin loaded theophylline as pulmonary sustained drug delivery carriers, the characteristics and ciliotoxicity were
studied. The drug loadings of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres were 21.09% and 21.42%, and the encapsulation efficiencies were 91.40% and 92.80%. The distributions
of 50% (d
0.5) of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres were 4.89 and 5.83 μm, respectively. Both microspheres showed spherical shape with smooth or wrinkled
surfaces. FT-IR of chitosan/β-cyclodextrin microspheres demonstrated that theophylline had formed hydrogen bonds with chitosan and β-cyclodextrin, while for the carboxymethyl chitosan/β-cyclodextrin microspheres theophylline had interaction with carboxymethyl chitosan. The moisture absorption showed that an
equilibrium was reached within 24 h. The two microspheres possessed better adaptability. In vitro release of theophylline from chitosan/β-cyclodextrin microspheres was slower than that from carboxymethyl chitosan/β-cyclodextrin microspheres at pH 6.8.
Biography: LI Ruobao(1968–), male, Associate professor, research direction: foundation research of respiratory system. 相似文献
997.
活性炭负载纳米零价铁去除溴酸盐的研究 总被引:1,自引:0,他引:1
实验采用液相还原法制备活性炭负载纳米零价铁材料(nZVI/AC),并利用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)等对其结构进行表征.考察了不同反应条件下nZVI/AC对BrO3-的去除效率,并研究其去除机理.结果表明nZVI/AC具有很高的表面反应活性,且nZVI和活性炭(AC)之间存在协同作用. BrO3-的去除效率随 pH 值的减小而增大, 共存离子NO3-和SO42-对其去除率影响不大但降低了去除速率.机理分析表明BrO3-被nZVI/AC吸附而使局部BrO3-浓度升高,并被nZVI迅速还原为无毒的Br-. 相似文献
998.
LIU Rui QI ShuYuan ZHANG TongLai ZHOU ZunNing YANG Li ZHANG JianGuo 《科学通报(英文版)》2013,58(16):1892-1896
The theoretical crystal-morphology of zinc tricarbohydrazide perchlorate (ZnCP) was studied using the morphology simulation software. The growth trends and surface characteristics were calculated using the Bravais-Friedel-Donnay- Harker (BFDH), Growth Morphology, and Equilibrium Morphology methods; these provide theoretical guidance for the choice of crystal-control reagents. On the basis of the simulations, experiments were carried out to study the effects of five different crystal-control reagents, including carboxymethylcellulose (A), polyacrylamide (B), dextrin (C), Tween 40 (D), and Tween 60 (E), in the control of the crystal-morphology of ZnCP. Mixtures of two reagents and higher temperatures were used to further optimize the ZnCP crystals. The results show that ZnCP crystals are well dispersed, and have a large apparent density and regular crystal-morphology under the control of a mixture of reagents A and E in a mass ratio of 1:4 at 80°C. 相似文献
999.
万师 《武汉科技学院学报》2013,26(4):42-45
《三字经》高度浓缩着中国传统文化的和谐价值思想,通过辩证逻辑的方法,具体分析了其中蕴含的生态伦理因素,独创性的探索《三字经》中人与自然的和谐环境、和谐的社会环境、"诚信"的人际环境的内涵,其目的在于突破传统启蒙读物的伦理水平,更好地促进社会主义和谐社会的建设,对文化的支撑、道德的修养、学习的提升起到了有益的借鉴。 相似文献
1000.
本文介绍了微悬浮体预处理工艺在活性染料冷轧堆染色中的应用.将经过预处理的纯棉织物与传统前处理的纯棉织物在相同染色条件下染色,与采用传统工艺所得染品相比,采用新工艺所得染品有明显的色泽增深效果,经济效益明显.采用新工艺染色可降低生产废水中的废弃染料量,可减轻环境污染,社会效益可观. 相似文献