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1.
环锭纺纱过程中的纱线断头主要取决于纱线张力与纱线强力之间的矛盾,而纺纱张力是气圈底端纱线张力经由气圈、导纱钩向上传递而产生的.以往关于气圈底端张力的推算大都是在忽略空气阻力和哥氏惯性力的情况下进行的.针对考虑空气阻力和哥氏惯性力影响的情况,对钢丝圈受力及气圈底端张力进行分析计算,并指出随着纺纱的高速化及对纱线质量要求的提高,在研究纱线张力时,应考虑空气阻力及哥氏惯性力.  相似文献   

2.
本文包含了下面三部分的内容: 1.对环锭细纱机纺纱动力的基本概念进行了讨论。纺纱动力是由七部分的动力消耗所组成,其中钢丝圈的摩擦功率占有最大的比重。 2.提出了瞬时纺纱功率的测试方法,并利用该法在高速、纺中支纱的情况下,对纺纱动力进行了测定,得到了一些重要的结论:①在钢领板升降动程中,大直径纺纱功率大于小直径纺纱功率;②在一落纱中,纺纱功率的大小具有一定的分布。最大功率发生在成形结束大直径时,而最小功率发生在大纱小直径时;③在实际纺纱中,纺纱功率是气圈高度的指数函数,其指数的变化范围为:2.1—2.6。此外,对锭速与纺纱功率的关系,钢丝圈重量与纺纱功率的关系也作了测定与讨论。 3.讨论了减少纺纱动力消耗的途径:①通过设计新型钢领钢丝圈来减小一落纱的平均张力;②通过改变导纱钩的升降型式来降低一落纱的平均气圈高度。  相似文献   

3.
本文介绍一种新型棉纺钢领与钢丝圈,它的设计思想是利用钢丝圈在一落纱期间子午面上的偏转运动,气圈较大时增加钢丝圈与外跑道的接触点,防止气圈膨胀,阻止钢丝圈继续外倾,减轻钢领掣口磨损。而在气圈小时,脱离接触。因而起调节张力,降低平均张力,节约动力消耗的作用。同时,内跑道又能良好支持钢丝圈稳定运转,经常维持较大的接触面。经纺涤棉29 tex 及13 tex 两种纱支的实测结果证实了钢领、钢丝圈的接触情况及其磨损大为减轻,使用寿命均延长一倍以上,动力消耗降低约2%,断头率较采用 ZM-6型钢领及与之配套的钢丝圈时可降低30%左右。此外,有白粉少、拎头轻等优点,由中试厂估算,包括增产6.1%在内经济效益每万绽每年约为13万元。  相似文献   

4.
本试验工作是在棉纺环锭细纱机运转情况下,用高速闪光摄影的方法,对纱段(纺纱段、气圈段、卷绕段)捻度及其分布进行了比较系统细仔的实验研究。实验结果得出了各纱段在一落纱中捻度变化及其分布的规律、捻度传递的关系等作了分析,并通过锭速与钢丝圈对捻度影响的实验,予以论证。实验进一步证实:气圈段捻度大于卷绕段捻度,纺纱段捻度最小;在一落纱中,满纱时捻度最大,管底完成时大直径位置最小;在改变各工艺参数使捻度分布发生变化时,气圈形态对捻度的影响较张力的影响为大,因而应注意控制气圈形态偏小掌握。  相似文献   

5.
采用下向渗透试验方法测定了在氯化钙和水玻璃溶液中添加十二烷基苯磺酸钠后溶液在粉尘介质中的渗透规律.测定结果表明,十二烷基苯磺酸钠能在不同程度上提高溶液的渗透能力和降低溶液的表面张力,对于质量分数为5%,15%,25%的CaCl2溶液,十二烷基苯磺酸钠的适宜添加量分别为0.5%~0.6%,0.2%~0.5%,0.2%~0.4%,此时溶液的渗透能力比不加添加剂时可提高约15%,14%,28%.对于质量分数为5%,15%,25%的Na2SiO3·9H2O溶液,十二烷基苯磺酸钠的适宜添加量分别为0.2%~0.4%,0.3%~0.5%,0.3%~0.5%,此时溶液的渗透能力可提高19%,23%,11%.该研究结果对有效利用氯化钙和水玻璃进行固土抑尘具有重要的意义.  相似文献   

6.
由于氯化钙会与土壤络合产生胶结和硅化,作者选择了表面活性剂丁二酸钠作为助渗剂,采用试验方法测定了在氯化钙溶液中添加该助渗剂后在粉尘中的渗透行为.试验结果表明,合适的丁二酸钠添加量可在一定程度上提高氯化钙溶液的渗透能力和降低溶液的表面张力;对于浓度为5%,15%,25%(质量分数)的CaCl2溶液,丁二酸钠的适宜添加量分别为0.2%~0.5%,0.2%~0.3%,0.2%~0.3%(质量分数),此时溶液的渗透能力可分别提高约18%,14%,13%.这一研究结果对用氯化钙固土抑尘具有积极作用.  相似文献   

7.
本文包含以下四部分内容: 1、介绍棉纺锥面钢领的两种主要形式——ZM-6型和SH型,钢领和钢丝圈的几何配合及工艺效果。目前钢丝圈最高线速度达45米/秒。 2.测量了钢丝圈的磨损位置,从简单的力矩分析,讨论了锥面钢领、钢丝圈的抗楔性能,结果表明了锥面钢领比平面抗楔钢领具备较好的抗楔性能。 3.测量了锭速在15000—19000转/分的纺纱张力,测量结果表明,锥面钢领、钢丝圈的纱条张力变异比平面抗楔钢领低,特别是大纱阶段,张力峰值低。所以降低了细纱断头率。 4.讨论了钢丝圈的发热和磨损。由于锥面钢领和钢丝圈较大地增加了接触面积和良好的散热性能,使得它们特别适用合成纤维纺纱和棉与合成纤维混纺。对于纺制细号纱,钢领和钢丝圈的寿命延长。最后指出了目前使用锥面钢领的优点和缺陷。  相似文献   

8.
喷气纺纱是利用旋转气流作用推动纱条形成气圈运动,使头端自由纤维加捻成纱。本文采用本组研制的纱条气圈转速仪对喷气纺纱纱条动态气圈的转速进行了测试,并就改变加捻成纱过程中的第一喷嘴和第二喷嘴的气圈转速,探讨其与成纱强力的关系。  相似文献   

9.
试验目的在于以偏心圆锯有效偏心量。供试圆锯是直径335mm、齿数50、锯厚2.0mm、锯路2.4mm的硬质合金锯片,每次锯下厚5mm的竹材胶合板,测定进给阴力、切削功率。实验因子是偏心量为0.0、0.25、0.50、0.70、1.00、1.25mm;锯片转速3000r/min;进料速度为8、14m/min。  相似文献   

10.
本文通过理论分析与实验结果均证明纺纱张力大小对细纱毛羽的影响,只产生于采用传统类型钢丝圈的条件下,如果采用改进型钢丝圈,则尽管纺纱张力降低,细纱毛羽仍可保持不变。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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