跳管纱的成因及预防措施

细纱出现跳管纱,对下道工序会形成不利影响,造成浪费.究其原因:一是纱管与锭子配合不良.锭子弯曲、锭盘偏心、缺油、锭子轴承损坏、锭盘内有杂物、纱管芯子磨损或缺少、纱管弯曲变形、纱管振幅大等因素,都会形成纱管和锭子配合不良,造成跳管纱;二是锭子速度过高,由于纱管材质或内在结构不均匀引起的跳管;三是操作不良.落纱插管时出现高管,落纱工责任心不强,不及时处理,锭子缠回丝,清理不及时,出现跳管纱.针对以上跳管原因,我们制定了以下几条措施.     

塑料细纱管锭孔结构的研究

分析了细纱管跳管的诸多因素，用闪光测速仪和红外测速仪测试了管速与锭速，从纱管锭孔结构上作了改进。５年多使用改进后的纱管计纬纱管２０万只，经纱管３０万只，效果良好，纱管振幅合格率提高１０％。     

纱管的握持力和刚度

跳管问题是纱管生产和使用中永恒的话题,多年来人们对此进行了大量研究,对产生跳管的原因也提出了许多见解,诸如离心力说,纱线张力说、临界转速共振说等等;为解决跳管问题,也提出了许多改进措施,如研究塑料"合金"、改进工艺和管体结构等等。但人们关注的焦点最终归结为纱管的握持力和刚度及其与纱管运转状态之间的内在联系。本文以塑料经纱管为例,对此进行分析和讨论.     

纱管的握持力的刚度

跳管问题是纱管生产和使用中永恒的话题，多年来人们对此进行了大量研究，对产生跳管的原因也提出了许多见解，诸如离心力说，纱线张力说，临界围速共振说等等。为解决跳管问题，也提出了许多改进措施，如研究塑料“合金”，改进工艺和管体结构等等。但人们关注的焦点最终归结为纱管的握持力和刚度及其与纱管运转状态之间的内在联系，本文以塑料经纱管为例，对此进行分析和讨论。     

光电式纱管振幅检验机

一、概述纱管振动幅度的大小,是衡量纱管质量的重要指标之一。由于纱管的振动,使细纱机锭子尖端的磨损和动力消耗增大。振幅过大还会引起跳管,增加断头,造成坏纱,直接影响纺纱的质量和产量。纱管振幅大小的检验,长期以来全靠工人老师傅凭经验手感目测,这样不仅劳动强度大,而且由于各人感觉上的差异和技术熟练程度的不同,造成纱管振幅的测定既不准确又不科学。     

205塑料经纱管动态变形问题

一、概述 1979年下半年,我厂用西德拜耳公司的ABS塑料生产205经纱管。经纺织厂使用,普遍反映当锭速超过15000转/分时,断头增加,跳管严重,尤其是中纱以上产生跳管,一落纱占4～8％。     

塑料经纱管改用PC芯眼

塑料经纱管的芯眼通常用热固性树脂(如酚醛树脂)制作。存在问题是:1.在高速运转情况下,纱管摆幅明显增大;2.如果芯眼和锭子配合较松,容易造成跳管;反之,若芯眼和锭子配合很紧,虽然防止了跳管,但拔管就很     

木纱管变形规律的初步探讨

木纱管,特别是纬纱管,因为要与梭子配合使用,所以对纱管规格要求是严格的,例如项颈外径、管箍外径的公差只有0.2mm。我厂地处大陆性气候的华北地区,四季空气含水变化大,有时木纱管项径、底孔、管箍外径变形量高达0.3～0.4mm。因此,过去经常出现产品规格不稳,定位底孔忽高忽低、忽大忽小,也常出现箍裂及松动等现象,严重影响梭管配合。因此,我们从1973年开始摸索木纱管变形的规律,逐渐掌握了从成形到成品这一过程中不同季节变化的情况,从而找到合适的加工留量,保证了成品木纱管规格要求,使木纱管质量趋于稳定。     

影响塑料经纱管弯曲变形的探讨

塑料经纱管弯曲变形是纱管变形中的主要和常见的一种(还有下口变小、锭孔变形、管子扁等变形),它在纱管下注射机后和纱管长期存放、长期使用中都会发生。弯曲变形影响塑料经纱管的同心度,因而也就直接影响塑料经纱管的生产效率、使用寿命。     

浅谈纱管对成纱质量的影响

为了引起纺织企业对纱管使用及管理的重视,阐述了58纺纱对纱管的材质及制作精度的技术要求,总结纱管的日常管理经验,分析不合格纱管对细纱成纱质量的影响;指出纱管是重要的纺织器材,其与锭子是否匹配,直接影响锭、管的同轴度;应用优质纱管可提高成纱质量,减少消耗,增加效益。     

纺纱牵伸胶辊胶圈应用技术概要

阐述棉纺牵伸胶辊、胶圈的应用技术和牵伸原理,重点探讨了胶辊、胶圈的牵伸工艺特性及其合理配置、胶辊制作、周期管理、质量管理、使用管理、产品缺陷与其机械波分析、纺纱环境和挡车工操作水平对纺纱性能的影响,提出胶辊、胶圈有关机件的质量要求等。     

Original semiologic standardized evaluation of stratum corneum hydration by Diagnoskin stripping sample

In a normal and healthy skin, the regular elimination of the superficial corneocytes, called desquamation, is a fundamental physiologic process intended to protect the barrier function of the skin. This invisible loss of corneocytes, individually or in small groups, is incessantly compensated by the divisions of the proliferative layer and the upward cellular maturation in order to maintain the harmonious renewal of the epidermis and the integrity of the stratum corneum. The harmony of this desquamation process is intimately conditioned by a sufficient hydration of the stratum corneum: (i) an abnormal desquamation leads to a disruption of the water barrier function and consequently to a dehydration tendency of the stratum corneum, and (ii) a cutaneous dryness (whatever the cause) is able to disturb the desquamation process. Protecting the water content of the stratum corneum has always been a major preoccupation of the cosmetic industry scientists. Consequently, the moisturizing properties of a cosmetic product are objectively measured by various explorations directly targeted on the hydration (corneometry) and on the level of the water barrier function (transepidermal water loss (TEWL) measurements), which depends directly on the skin hydration state. This intimate linkage of the desquamation process and the water content of the stratum corneum enable us to suggest an indirect assessment of the hydration from a direct study of the desquamation by examining a skin-stripping sample (D-Squames) by an optical microscope (linked to a computer). We will describe this already known technique and mainly its new and unpublished semiologic exploitation, named Diagnoskin, whose advantages are its simplicity and its reproducibility particularly interesting in the case of sequential appraisal of dermatologic or cosmetic treatments.     

Non-destructive analysis of anthocyanins in cherries by means of Lambert-Beer and multivariate regression based on spectroscopy and scatter correction using time-resolved analysis

In high-value sweet cherry (Prunus avium), the red coloration - determined by the anthocyanins content - is correlated with the fruit ripeness stage and market value. Non-destructive spectroscopy has been introduced in practice and may be utilized as a tool to assess the fruit pigments in the supply chain processes. From the fruit spectrum in the visible (Vis) wavelength range, the pigment contents are analyzed separately at their specific absorbance wavelengths.A drawback of the method is the need for re-calibration due to varying optical properties of the fruit tissue. In order to correct for the scattering differences, most often the spectral intensity in the visible spectrum is normalized by wavelengths in the near infrared (NIR) range, or pre-processing methods are applied in multivariate calibrations.In the present study, the influence of the fruit scattering properties on the Vis/NIR fruit spectrum were corrected by the effective pathlength in the fruit tissue obtained from time-resolved readings of the distribution of time-of-flight (DTOF). Pigment analysis was carried out according to Lambert-Beer law, considering fruit spectral intensities, effective pathlength, and refractive index. Results were compared to commonly applied linear color and multivariate partial least squares (PLS) regression analysis. The approaches were validated on fruits at different ripeness stages, providing variation in the scattering coefficient and refractive index exceeding the calibration sample set.In the validation, the measuring uncertainty of non-destructively analyzing fruits with Vis/NIR spectra by means of PLS or Lambert-Beer in comparison with combined application of Vis/NIR spectroscopy and DTOF measurements showed a dramatic bias reduction as well as enhanced coefficients of determination when using both, the spectral intensities and apparent information on the scattering influence by means of DTOF readings. Corrections for the refractive index did not render improved results.     

高校宝石及材料工艺学专业的构建研究

通过回顾高校宝石及材料工艺学专业的创建历程,深入探讨了该专业未来发展所面临的、深层次的理论问题,即学科属性与文化背景,学科构成与知识内涵,学科方向与实践定位,学科任务与社会功能。在此基础上,建立了多层次技术教育的社会功能模型,由此推断：高校中的宝石及材料工艺学专业属于多层次技术教育中的高等职业技术教育。同时,还构建了该专业的技术教育的社会功能模型和学科构成模型,进一步确立了该专业的社会实践定位。     

Chlorophylls,carotenoids and anthocyanin concentrations in the skin of ‘Gala’ apples during maturation and the influence of foliar applications of nitrogen and magnesium

‘Gala’ apple fruit were sampled over two growing seasons, to determine the effects of maturation, and of foliar applications of nitrogen and magnesium on pigment concentrations and colour development in maturing fruit. Treatments of urea and/or magnesium sulphate sprays were applied to the trees in a commercial orchard. The chlorophyll, carotenoid and anthocyanin concentrations in the fruit skin were determined for both the blush and back sides over 15 harvests in 1991–1992. In 1990–1991, the skin chlorophyll concentrations were determined only for the back side of the fruit. The fruit nitrogen, magnesium and sulphur concentrations were determined near maturity. The concentrations of chlorophyll and carotenoids in apple skin decreased from the first harvest in 1991–1992 as the fresh weight increased from 12 g, 40 days from flowering to 140 g, 138 days from flowering. Chlorophyll continued to decrease whereas carotenoid concentrations increased after 138 days and until at least 153 days. The average skin chlorophyll and carotenoid concentrations were higher on the blush side of the fruit than on the back. The total chlorophyll per fruit increased from the first harvest to a peak about 70 days after flowering in 1990–1991 and then decreased over the remainder of the period studied. The time of this peak was about 40 days later in the 1991–1992 season compared with the 1990–1991 season. The total carotenoid increased up to about 50 days after flowering in 1991–1992, fluctuated and then decreased up to 138 days when the amount increased again. The ratio of carotenoids to chlorophylls was highest for the first three harvests, fluctuated somewhat up to c 138 days after flowering after which the ratio increased rapidly. The anthocyanin concentrations were low and fluctuated up to 130 days from flowering and then increased markedly only on the blush side at 130 days, about 14 days before the carotenoids started to increase. The treatment of the tree canopy with urea increased the chlorophyll and carotenoid concentrations in the fruit skin, 14–20 days after the first application until after maturity, more so on the blush side than on the back side. These increased concentrations were maintained up to the harvest after which carotenoid concentrations increased. The urea treatment lessened the increase of anthocyanin concentrations in the blush side skin of the fruit, at maturity. At maturity, the nitrogen concentration of fruit from urea treated trees was higher than those from untreated trees. The magnesium sulphate treatment of the canopy increased the chlorophyll and carotenoid concentration on the back of the fruit within 20–30 days from commencing spraying. The ‘ground colour’ scores for the back sides of the fruit (used for fruit picking and grading) were greener for the urea treated fruit and reached an acceptable score about two weeks later than the untreated fruit. ©1998 SCI     

赛络纺纱钢领、钢丝圈的选配实践

为了提高赛络纺纱成纱质量,减少细纱断头,从钢领、钢丝圈的种类,卷绕过程中对纺纱的影响及其运动配合等诸多因素出发,论述了钢领、钢丝圈的选配原则,重点阐述了赛络纺纱钢丝圈运动形态的变化及钢领、钢丝圈的选配要求,通过纯棉、非棉纤维纺纱的选配实践,指出赛络纺纱线毛羽少,结构紧密,应根据纺纱纤维性能和纺纱特点,以纱线通道通畅降毛羽、运行平稳少断头、散热良好延长使用寿命为原则对钢领、钢丝圈进行选配。     

Measurement of paralytic shellfish toxins in molluscan extracts: comparison of the microtitre plate saxiphilin and sodium channel radioreceptor assays with mouse bioassay, HPLC analysis and a commercially available cell culture assay

This study compared five methods of measuring paralytic shellfish toxins (PSTs) including the long-used mouse lethality bioassay, a commercially available cell culture test (MIST ® Quantification kit), HPLC analysis, and two newly developed radioreceptor assays utilizing mammalian sodium channels and saxiphilin. Methods were challenged with toxic shellfish extracts prepared according to the AOAC official method. The best correlations between predicted toxicity values being 0.9 or better, were those between HPLC analysis when compared with both radioreceptor assays and the mouse lethality bioassay, as well as that between the saxiphilin and the sodium channel radioreceptor assays. In all cases, statistically significant correlations existed between the toxicity measurements of the same extracts. The ratios between some methods were not unitary as measured by the slopes of the regression lines used for correlation analyses. HPLC analysis predicted more toxicity than all of the bioassays. The saxiphilin assay underestimated toxicity relative to the mouse bioassay, the MIST ® kit determinations and the sodium channel assay. The sodium channel assay predicted there to be less toxicity than the mouse bioassay and the MIST ® kit. Of all of the techniques used, the MIST ® kit correlation with the mouse bioassay was nearest to one. Each method possesses different virtues and it may be that a multi-method approach would harness the benefits of each method for various aspects of a shellfish testing regime.     

Prediction of worst case migration: presentation of a rigorous methodology

An improvement of the Piringer model, allowing the prediction of a worst case migration from packaging to food is presented here. The authors are proposing other constants for the calculation of the upperbound value of the diffusion coefficient, using experimental data determined by a film to film method. Considering the plasticizing effects of food simulants, a model involving the variation of the diffusion coefficient versus space and time must be used. Future fields of investigation are discussed: the relationship between diffusion coefficients and the volume of the migrant (instead of molar mass), and the variation of diffusion coefficient activation energy with temperature.     

合理优化并条工艺 减少针织纱细节

为了减少并条工序对成纱细节的影响,分析了并条机的工艺参数设置和工艺配置原则以及运转管理对棉纱细节的影响,针对影响棉纱细节的因素提出优化工艺配置、完善生产管理时应注意合理选择罗拉隔距及前后区牵伸分配、喇叭口直径,压力棒调节环直径以及胶辊直径,同时在生产管理中应减少意外牵伸、加强巡回检查和操作管理工作,从而保证棉条更加均匀、棉纱细节大幅降低。