正交试验在减阻高聚物合成研究中的应用

通过L_(18)(6~1×3~6)混合水平正交试验确定减阻高聚物的最优配方和生产工艺条件,虽然实验次数较少,但被考察的因素及每个因素的水平都很充分。通过正交试验结果的极差分析,迅速发现了试验的规律性,即α-烯烃的种类、助催化剂的种类、主催化剂的用量、主催化剂和助催化剂的摩尔比、反应温度等因素对聚合产物减阻率的影响程度,以及每一因素各个水平对聚合产物的影响趋势,从而制定出可能更优的试验方案。     

南输成品油管道应用国产减阻剂试验

减阻剂是一种高分子聚合物,能有效地减少油品流动阻力,增加输量.介绍了PIPEWAY-S304国产成品油减阻剂在南输管道柴油输送的试验情况,分析了减阻剂的减阻原理,并根据试验数据给出了不同浓度下的摩阻计算公式.     

高分子减阻剂对非牛顿型流体流动特性的影响

以普兰德动量传递理论为基础,按照卡门的三层模型,通过室内模拟环道用0号柴油及加入减阻剂在圆管内的流动参数的测定,计算了非牛顿型流体管内湍流边界层的层流内层、过渡层、湍流中心的涡流粘度,涡流粘度与运动粘度比、总应力随相对位置的变化等定量参数,探讨了高分子减阻剂对非牛顿流体流动特性的影响,对湍流减阻现象的机理与增大减阻率的条件进行了定量分析.     

含沙水流在植被斑块中的输沙规律及阻力机制试验

为深入探究自然状态下含植被水沙运动过程及植被阻水拦沙机理,利用室内开闸式平坡水槽试验研究了泥沙粒径级配、植被冠层形态特征、植被密度对含沙水流输沙规律及阻力机制的影响。提出植物叶片长宽比作为衡量单株植物的冠层形态特征指标,用无量纲沉积通量和不同尺度下的无量纲冠层阻力划分含沙水流运动状态,掲示冠层形态特征及泥沙粒径级配对含沙水流运动过程的影响。研究结果表明,含沙水流中泥沙沉积通量受植物冠层形态和粗粒径悬移质（10～100 μm的弱黏性颗粒）含量影响,且植被冠层形态及泥沙粒径级配与无量纲沉积通量之间在阻力主导阶段存在强烈的反馈机制。植被冠层形态较大或粗粒径悬移质含量高的含沙水流中,沿水流运动方向床沙细化趋势更显著。相较于受叶片长宽比影响的冠层形态特征及植被密度,悬移质泥沙粒径级配因素对植被阻水拦沙效果的影响程度较为微弱。研究成果可为流域侵蚀输沙过程和河流水沙资源管理提供一定的科学依据。     

Development of rice introgression lines with brown planthopper resistance and KDML105 grain quality characteristics through marker-assisted selection

‘Khao Dawk Mali 105’ (KDML105), a Thai aromatic rice cultivar, has been accepted in markets as a prime jasmine rice with premium prices. It has been extensively used as a parental line to develop new cultivars for rainfed lowland areas in Thailand because of its favorable quality and fragrance. However, this cultivar is highly susceptible to brown planthopper (BPH), a phloem sap-feeding insect pest of rice. The main objective of this study was to combine KDML105 essential grain quality traits with BPH resistance from the donor cultivar, ‘Rathu Heenati’. The linkage drag between Bph3 and Wx^a alleles was successfully broken by phenotypic and marker-assisted selections. All introgression lines (ILs) developed in this study showed a broad spectrum resistance against BPH populations in Thailand and had KDML105 grain quality standards. Finally this study was revealed that the ILs can be directly developed into BPH resistant varieties or can be used as genetic resources of BPH resistance to improve rice varieties with the Wx^b allele in rice breeding programs.     

Microbial diversity in the saline-alkali soil of a coastal Tamarix chinensis woodland at Bohai Bay,China

Soil salinization or alkalization is a form of soil desertification. Coastal saline-alkali soil represents a type of desert and a key system in the network of ecosystems at the continent-ocean interface. Tamarix chinensis is a drought-tolerant plant that is widely distributed in the coastal saline-alkali soil of Bohai Bay, China. In this study, we used 454 pyrosequencing techniques to investigate the characteristics and distribution of the microbial diversity in coastal saline-alkali soil of the T. chinensis woodland at Bohai Bay. A total of 20,315 sequences were obtained, representing 19 known bacterial phyla and a large proportion of unclassified bacteria at the phylum level. Proteobacteria, Acidobacteria and Actinobacteria were the predominant phyla. The coverage of T. chinensis affected the microbial composition. At the phylum level, the relative abundance of γ-Proteobacteria and Bacteroidetes decreased whereas Actinobacteria increased with the increasing coverage of T. chinensis. At the genus level, the proportions of Steroidobacter, Lechevalieria, Gp3 and Gp4 decreased with the increase of the vegetation coverage whereas the proportion of Nocardioides increased. A cluster analysis showed that the existing T. chinensis changed the niches for the microorganisms in the coastal saline-alkali soil, which caused changes in the microbial community. The analysis also distinguished the microbial community structure of the marginal area from those of the dense area and sparse area. Furthermore, the results also indicated that the distance to the seashore line could also affect certain groups of soil bacteria in this coastal saline-alkali soil, such as the family Cryomorphaceae and class Flavobacteria, whose population decreased as the distance increased. In addition, the seawater and temperature could be the driving factors that affected the changes.     

马铃薯仿生挖掘铲片的设计与仿真

据蝼蛄前足胫节爪趾第1趾的体视显微镜照片设计了马铃薯挖掘机挖掘铲铲片,为马铃薯挖掘机提供了一种减阻效率较高的挖掘铲。应用AutoCAD软件获取爪趾外侧曲线和内侧曲线的轮廓点,并将点坐标值数据使用LIST命令导出,并借助EXCEL软件多项式拟合法对爪趾的侧面轮廓线进行拟合,在拟合多项式的基础上在Solidworks软件中进行仿生铲片的建模,最后应用LS-DYNA软件仿真模拟普通铲片与仿生铲片挖削土壤的过程,并测定两种铲片的土壤阻力。仿真结果表明,仿生铲片较普通铲片土壤阻力减小近61%。所设计的仿生挖掘铲片为马铃薯挖掘机挖掘铲减阻技术要求提供了一种解决思路,且结构新颖。     

中洛线添加减阻剂运行现场试验

介绍了HG减阻剂的使用特点和作用机理,简述了中洛线添加减阻剂运行现场试验的情况,讨论了分散时间对减阻剂的减阻增输效果的影响。结果表明,添加不同量的减阻剂均可获得较好的减阻增输效果,并能提高管道运行的安全性。     

气压劈裂式深松铲的土壤劈裂减阻机理及有限元分析

针对我国现有土壤深松机械存在深松阻力大、深松幅度小等问题,研制了一种工作阻力小、深松效率高的气压劈裂式深松铲。首先建立了土壤与铲面在有无气压劈裂的工况下的力学模型,并进行对比分析,研究气压劈裂减阻机理,推导出在气压劈裂下的牵引阻力计算公式;然后,为验证设计的可靠性,对深松铲整体结构进行静力学分析与动力学分析。结果表明:气压劈裂式深松铲能够有效减小深松阻力,深松铲的最大应力远小于所选材料的屈服应力,且固有频率可明显避开与机身结构的共振频率。     

Numerical simulation and on-site test of anincreasing pipe gas delivery capacity device

The theoretical analysis and experiment show that the wall oscillation can reduce the friction drag of the pipe. The operation mechanism, on-site test and numerical simulation of the Increasing Gas Delivery Capacity Device for the Pipe (IGDCDP) invented by the author are introduced in the paper. The on-site test shows that the IGDCDP can not only reduce the friction drag, but also enhance the gas delivery capacity obviously in the natural gas network. The numerical simulation results show that at the time of inducing some new vortex disturbance waves, the pressure pulse wave generated from the impinging edge has an effect on the oscillation cavity wall to cause oscillation with the large structured vortex rings, so the oscillation cavity is the main component that generating the pulsed jet.