首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 218 毫秒
1.
无梭织机制织真丝绸   总被引:1,自引:0,他引:1  
裘愉发 《纺织学报》1989,10(2):40-41,35
中国纺织工程学会丝绸专业委员会主持召开的全国无梭织机制织真丝绸学术讨论会,于1988年6月14~16日在江苏省盛泽召开。本文根据大会论文及交流资料综述如下。  相似文献   

2.
织可穿技术     
从花型准备系统和织可穿电脑横机两方面介绍德国Stoll公司的织可穿技术。以平针组织和1 1罗纹组织为例详细阐述织可穿编织原理与过程,并总结设计织可穿服装时应注意的问题。应用该织可穿技术编织的服装不需要进行任何的衣片缝合,减少了服装的加工工序,大大提高了生产效率。  相似文献   

3.
为对比经面织物正织与反织的优缺点,在相同工艺条件下织造同一品种,通过耗电量、织口位移和经纱张力的测定,分析织物外观风格、生产效率和物理性能。认为棉纺织厂织造组织循环不大的经面织物以正织为宜,而毛纺织、丝织厂情况特殊,适当调节工艺参数可采用反织。  相似文献   

4.
本文首先简要介绍了织编机的织编过程,然后通过对织编物的结构分析和物理性能试验,讨论了织编物的性能特征,包括透气性、延伸性与断裂伸长、强度、厚度、顶裂强力和耐磨性等。这些性能说明织编物透气性好,纬向伸长率较高,强度不低于一般机织物,并且有良好的耐磨性,比较适宜用于春、夏、秋季服装。文章也指出目前织编物生产中还存在一些疵点,同时提出为了减少布面疵点,在织造工艺中应注意的一些问题。  相似文献   

5.
本文就喷水织机制织高密尼丝纺的工艺进行了探讨,并指出了其中的技术关键,为同类产品的生产提供了参考资料。  相似文献   

6.
无梭织机制织细号,高密织物生产线织前工程配套的研讨   总被引:1,自引:1,他引:0  
本文通过对全国引进无梭织机制织细号、高密织物生产状况的分析,提出无梭织机织前设备配套、工艺路线和对原纱和半制品质量要求的要点。  相似文献   

7.
以适应高效能棉毛机配套织针的需要,我厂从一九七五年开始,设计试制了一寸五路高效能织针。这种织针要求: ①针舌短; ②舌坐小,小曲档尺寸小。我厂在党支部领导下,发动群众攻难关,于一九七六年试制成功了这种织针。主要技术参数:  相似文献   

8.
设计一种不需织针帮助即可完成成圈动作的编织装置的想法困扰着发明家们已经有相当长的时间了。对于任何熟悉针织机械设备的人来说,省去织针的优点是显而易见的。织针昂贵,损坏频繁,造成许多的织物疵点,并且需要复杂的机构来推动它们并控制其运动,织针也是提高编织速度的一个主要的制约因素。无织针的针织机优点是制造成本低廉,  相似文献   

9.
简述了织样机的发展现状,结合剑杆织机的工艺要求,重点探讨了一种新型织样机——剑杆织样机的设计构思及其机构原理。  相似文献   

10.
为研究横机织针混合磁悬浮驱动的空间磁场分布规律,通过构建圆柱形和长方体形2种永磁织针结构,根据安培环路定理,将永磁体等效为纵向的多圈电流环结构,并据此推导出织针垂直向上运动至空间任意位置的磁感应强度。在此基础上利用有限元电磁仿真软件对永磁织针模型进行仿真,同时搭建织针空间磁场强度实验测量平台进行数值测量。通过对比计算、仿真和实验测量发现:在圆柱型永磁织针中,厚径比越大,磁感应强度越大;在长方形永磁织针中,厚度不变磁感应强度随着长宽比增大而减小。  相似文献   

11.
Vascular changes play an important role in the pathogenesis of claw horn disruption lesions in cattle. The aim of the study was to measure arterial blood flow in the hind limbs of German Holstein cows with claw horn disruption lesions. A 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the dorsal pastern region in the hind limbs of 11 non-lame and 33 lame German Holstein cows in which lameness was scored clinically. Qualitative and quantitative blood flow parameters were compared in affected limbs and unaffected contralateral hind limbs in lame cows and in the hind limbs of lame cows and non-lame cows. A pulsed-wave Doppler signal suitable for analysis was obtained in 78 of 88 limbs (33 affected and contralateral limbs, 22 limbs of control cows). Blood flow curve types 1 and 2 were predominant in the hind limbs of lame cows. Vessel diameter, end-diastolic velocity, and blood flow rate were significantly greater in lame cows than in non-lame cows and were numerically greater in moderately lame cows than in mildly lame cows. The differences in the qualitative and quantitative parameters between lame and non-lame cows were most likely caused by inflammation of the pododerm. The role of weight distribution between the paired hind limbs and the existence of claw horn disruption appeared to have an effect on the differences in local circulation in the affected and unaffected contralateral hind limbs in lame cows.  相似文献   

12.
This is the first account of PCDDs, PCDFs, and non-ortho PCBs in Canadian Arctic seabirds. Livers and eggs of thick-billed murres, northern fulmars, and black-legged kittiwakes were collected in 1975 and 1993 from Prince Leopold Island in Lancaster Sound, Canada. Detectable concentrations of PCDDs, PCDFs, and non-ortho PCBs were found in all the Arctic seabird samples analyzed. Of the PCDD congeners assayed, only 2,3,7,8-substituted PCDDs were detected in the samples, whereas non-2,3,7,8-substituted PCDFs were found in addition to 2,3,7,8-substituted PCDFs in some of the samples. The predominant PCDD/F congener found in the livers of all three species was 2,3,4,7,8-PnCDF, both in 1975 and 1993. Concentrations of most dioxins and furans decreased in the fulmars and kittiwakes between 1975 and 1993 but increased in the murres. Of the non-ortho PCBs measured, PCB-126 occurred in the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in all three species in both years. The highest concentrations of dioxins and furans as well as the highest TEQ values were found in the northern fulmar livers in both 1975 and 1993. Concentrations of some of the PCDDs and PCDFs are among the highest reported for Canadian Arctic biota.  相似文献   

13.
The aim of this study was to determine the ultrastructure of cross-sectioned zonae pellucidae of in vitro-matured and ovulated pig oocytes before or after sperm penetration in vitro and in vivo, respectively. The in vitro and in vivo (ovulated) oocytes and zygotes (fertilized in vitro and in vivo) were fixed with glutaraldehyde either directly or after pretreatment with ruthenium red and saponin, processed and then examined using transmission electron microscopy. The thickness of the zona pellucida, as measured on the section of the specimens with largest diameter fixed with glutaraldehyde, differed between the in vivo (9.19 +/- 0.47 microm) and in vitro (5.95 +/- 0.51 microm) oocytes. The in vivo oocytes had a rather thick external mesh-like structure, whereas it was much thinner in the in vitro oocytes. This mesh-like external rim was less apparent in both in vivo and in vitro zygotes. Obvious differences in the density of the lattice formed by the fixed zonae pellucidae were visible between the outer and inner (ad-oolemmal) zonae. The outer area always formed a concentrically arrayed fibrillar network, whereas the inner area showed a much more compact, trabecule-like mesh. However, both areas, but particularly the outer network, were much more compacted after the zona reaction. Clear differences in the degree of fibrillar aggregation of the inner zona area were also observed between in vitro and in vivo zygotes, being much higher in the latter. This fibrillar network was more clearly visible in the zygotes pretreated with ruthenium red and saponin; the in vitro zygotes had a fibrillar, radially oriented set of parallel fibrils, whereas it was much more aggregated and trabecule-like in the in vivo zygotes. These results demonstrate that the fine structure of the zona pellucida and the zona reaction at sperm penetration differ between pig oocytes fertilized in vivo and in vitro. Moreover, the ultrastructure of the outer and inner pig zonae pellucidae has a different network organization.  相似文献   

14.
Effects of duration of grain feeding on the concentration of endotoxic lipopolysaccharide (LPS) in digesta throughout the digestive tract and on acute phase proteins and LPS in peripheral blood were determined in Holstein yearling calves. Twenty-five Holstein yearling steer calves received either a forage-based diet containing 92% hay and 8% of a mineral and vitamin pellet on a dry matter basis (CON) or a moderate-grain diet, obtained by replacing 41.5% of the hay in the forage-based diet with barley grain, for 3 (MG3), 7 (MG7), 14 (MG14), or 21 d (MG21) before slaughter. Immediately before slaughter, blood samples were collected from the jugular vein. Immediately after slaughter, digesta samples were collected from the rumen, jejunum, ileum, cecum, colon, and rectum. Rumen liquid digesta, digesta from the intestines, and peripheral blood plasma were analyzed for LPS. Peripheral blood plasma and serum were analyzed for the acute phase proteins amyloid A, haptoglobin, and LPS-binding protein. Feeding the grain diet increased the LPS concentration in rumen fluid linearly from 15,488 endotoxin units (EU)/mL for CON to 70,146 EU/mL for MG7. Concentrations of LPS in rumen fluid in MG14 and MG21 were 61,944 and 56,234 EU/mL, respectively, and did not differ. The LPS concentrations in jejunal digesta were much lower than that in digesta elsewhere in the digestive tract, which suggests that ruminal LPS is broken down in the abomasum or proximal jejunum. The concentration of digesta LPS in the ileum was higher than that of digesta elsewhere in the intestines and similar to that in rumen fluid. The duration of grain feeding increased the LPS concentration in digesta in the ileum and cecum and tended to increase that in the colon cubically. Concentrations of LPS in this part of the digestive tract were highest in the MG3 and MG21 groups. The highest concentrations of LPS in digesta in the cecum, colon, and rectum were 3.7, 3.8, and 5.6 times higher than that in CON, respectively. Grain feeding and the increase in LPS in digesta were not accompanied by an acute phase response or a detectable concentration of LPS in peripheral blood. The absence of LPS in peripheral blood and the lack of increase in acute phase proteins indicated that the grain feeding protocol used in the current study and the accompanying changes in LPS concentrations of the digesta did not result in systemic inflammation.  相似文献   

15.
国产烤烟挥发碱含量对比分析   总被引:4,自引:0,他引:4  
测定了全国6个省2002和2003年的170个烤烟烟叶样品的挥发碱含量。结果表明:①各产区各等级烟叶挥发碱含量集中在0.10%~0.45%范围内;②相同等级不同产区烟叶挥发碱含量以云南弥勒的最高,贵州毕节和四川会理的较高,福建和山东临沂的较低,河南宜阳的最低,各产区烟叶的挥发碱含量差异显著;③不同部位烟叶挥发碱含量是下部叶最低,中部叶次之,上部叶最高,而且上部叶比下部叶高2倍左右,挥发碱含量差异极显著;④各产区相同部位桔黄颜色烟叶的挥发碱含量均高于柠檬黄,烟叶挥发碱含量差异极显著;⑤烟叶挥发碱含量随其身份由薄到厚、油份由少到多和色度由淡到浓均逐渐增加,差异都极显著。  相似文献   

16.
Follicle dynamics and oocyte viability in Holstein primiparous and multiparous cows and the relationships between fertility and the biochemical and physical properties of oocyte membranes with season were examined. The conception rates of primiparous (n = 70 885) and multiparous (n = 143 490) cows differed, peaking in the winter and decreasing in the summer. The number of follicles 3-8 mm in diameter per ovary was higher in winter (19.6) compared with summer (12.0). However, in winter the percentage of ovaries with fewer than ten follicles per ovary was 16%, in contrast to 50% in summer. After aspiration of follicles, 7.5 oocytes per ovary were found in winter and 5.0 oocytes per ovary in summer. Cleavage to the two- to four-cell stage after chemical activation was greater in winter than in summer; this was enhanced at the morula stage and embryo development to the blastocyst stage was significantly higher in winter than in summer. Determination of the lipid phase transition in oocyte membranes revealed a shift of 6 degrees C between summer and winter. Fatty acid composition of phospholipids from follicular fluid, granulosa cells and oocytes indicated that there was a higher percentage of saturated fatty acids during the summer and that the percentages of mono-unsaturated and polyunsaturated fatty acids were higher in oocytes and granulosa cells during the winter. Oocytes and granulosa cells had similar fatty acid compositions, in contrast to follicular fluid. These results may explain the differences in the ability of oocytes to develop to the blastocyst stage at different seasons. Thus, temperature changes may lead to changes in membrane properties, which, in turn, can influence oocyte function and fertility.  相似文献   

17.
The authors studied several groups of children in terms of the height in endemic goiter regions and in the regions with no goiter incidence. Subject to study were also processes of osteogenesis and phosphocalcium metabolism in animals with iodine deficiency in the diet. It was established that in goiter endemic regions, the number of children under medium and of low height was increased while that of medium and over medium height, and the number of tall children were reduced. It was also found that iodine deficiency in the diet of animals entailed abnormalities in the growth patterns, destructive alterations in the bones and bone marrow, a decrease in the content of hydroxyproline, hexosamines, and in the activity of phosphomonoesterase-I in animal bones, as well as disorders of phosphocalcium metabolism.  相似文献   

18.
This study determined the distribution of drugs to different milk fractions according to their physicochemical properties. Hydrophilic drugs tend to concentrate in skim milk, whereas lipophilic drugs tend to concentrate in cream. The concentration of a drug in casein is related to its degree of binding to milk proteins. Thus, we aimed to determine whether withdrawal time in whole milk differs from that in cream, casein, and skim milk. Amoxicillin and tylosin were selected as prototype hydrophilic and lipophilic drugs, respectively. The study was conducted in vitro and in vivo to determine whether in vitro conditions reflect the distribution of drugs in the different milk fractions in vivo. The in vivo study was conducted using a crossover design on 6 healthy Holstein dairy cattle. First, amoxicillin (i.m., single dose, 14 mg/kg) was administered to cows. Following a 1-wk washout period, tylosin (i.m., single dose, 15 mg/kg) was administered. Concentrations of amoxicillin and tylosin in milk and milk fractions were measured using HPLC-UV. In the in vitro study, 0.04 to 400 μg/g of amoxicillin and 0.05 to 50 μg/g of tylosin were spiked to drug-free milk and the concentrations in milk and milk fractions were measured. In addition, the percentage of total protein in milk and milk fractions was determined. Amoxicillin accumulated more in skim milk than in cream and casein, both in vitro (92%) and in vivo (73%, skim milk-to-whole milk ratio). The distribution of tylosin in whole and skim milk was similar to that of amoxicillin in the in vitro study, in contrast to the accumulation of tylosin in cream seen in vivo. However, the accumulation ratio of tylosin in cream was lower than expected. By either method, tylosin was less concentrated in casein than in skim milk and cream. The percentage of total protein was similar in skim milk and whole milk and higher than in cream. Thus, amoxicillin accumulates less in cream and casein, suggesting that these fractions would pose a lower risk to the consumer. Tylosin was still present at the maximum residue limit (50 μg/kg) 24 h after injection in the casein fraction and 48 h after injection in the cream fraction.  相似文献   

19.
采用顶空固相微萃取-气相色谱-质谱(HS-SPME-GC-MS)联用技术对两酱香酒厂(H、G厂)酒曲、第四轮次窖内酒醅的挥发 性成分进行检测,并进行主成分分析(PCA),探讨酒厂间酒曲、窖内酒醅风味物质的差异及酒曲与窖内酒醅挥发性成分的关系。 结果 表明,在酒曲、窖内酒醅中共检测到105种挥发性成分,共性成分为4种。 H酒曲以烷烃类为主,G酒曲则以醇、吡嗪类为主,共性成分为 8种。 H、G窖内酒醅均以醇、酯类为主要风味物质,共性成分为23种,但上层酒醅的主要酯类物质不同,下层酒醅的醇酯比相差较大。 两酒厂的酒曲挥发性成分相近;窖内酒醅上层挥发性风味成分相似度高,窖内酒醅下层具有差异性;酒曲和酒醅样的挥发性成分具 有较大差异。  相似文献   

20.
The orientation of fibers is known to play a very important role in determining the quality of the carded and drawn slivers as well as the quality of the ultimate yarns produced from those slivers. Also, the orientation of fibers is considered to be a very useful parameter for evaluating the effectiveness of the carding and drawing processes in aligning the fibers. In addition, the orientation of fibers is known to determine the length utilization of the fibers in the slivers. This article reports on the influence of carding and drawing processes on the orientation of fibers in the carded and drawn slivers. A series of carded and drawn slivers were prepared by using polyester staple fibers and making various changes in the carding and drawing processes and the orientation of fibers in the slivers was evaluated based on Lindsley’s methodology in conjunction with a mathematical model of fiber orientation in slivers. It was observed that the increase in cylinder speed and the decrease in doffer speed resulted in more anisotropic fiber orientation distribution in the carded slivers and the degree of anisotropy was found to be more in the forward direction as compared to the backward direction of the carded slivers. The higher draft and doubling in the drawframe resulted in higher anisotropy in the orientation of fibers in the drawn slivers and the drawn slivers displayed more anisotropy in the backward direction as compared to the forward direction. The higher delivery speed of the drawframe resulted in higher anisotropy in fiber orientation in the drawn slivers and the drawn slivers exhibited more anisotropy in the backward direction as compared to the forward direction. The results of fiber orientation in the carded and drawn slivers obtained by using the mathematical model were compared to the fiber orientation parameters suggested by earlier researchers and a satisfactory correlation between them was observed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号