21世纪纺织品湿加工设备的发展趋势

1 引言 现在,纺织机械在制造和应用方面的任何发展都受到环境保护方面的影响,这是一个普遍被接受的事实。在合成纤维如再生纤维素纤维的制造过程中由于使用了有机溶剂,致使现在这一工艺受到了严厉的批评,从这一点也可看出以上的变化趋势。除此之外,目前相当大一部分织物是非织造物制成的,而且非织造物的应用还有日益增加的趋势。本文举例介绍了几种特种纤维和非织造布的制造工艺。     

涤纶织物有机氟整理的水洗牢度

1 引言 织物拒水和防沾污性质可通过以下整理获得:用聚四氟乙烯或聚酯共聚物薄膜涂层,用含有亲水性和疏水性链段的聚氨酯在织物上形成多孔薄膜或所有纤维用有机氟化物整理剂覆盖。 三氟甲基的表面张力为6 mN/m,比二氟甲基端基(15 mN/m)和二氟亚甲基(18 mN/m)低得多。理想的全氟化碳化合物含有8个碳氟链并以—CF_3,为端基。增加碳氟链的长度对表面张力的影响不大。 有机氟整理剂主要用于服装用织物,少量也用于产业用纺织品(例如医用、防化或防有害气体防     

浅谈摩擦学的发展与现状

简要叙述了摩擦学的历史、现状和发展方向.     

塔机综合数显监控装置设计

介绍一种对塔机作业工况实施测量、数显及越限报警的控制装置。详细描述系统软硬件设计原理。     

利用选择性絮凝从含高氧化镁磷酸盐中分选磷灰石

将来美国佛罗里达州磷酸盐资源氧化镁的含量比现在开采的矿床要高。氧化镁含量高归因子白云石、富镁粘土和坡缕石。选择性絮凝试图被用来减少磷灰石与白云石及坡继石人工混合物中磷灰石的ＭｇＯ含量，混合矿物的选择性在磷灰石－白云石及磷灰石－坡缕石体系中用聚合物絮凝剂进行预测，在混合矿物体系中选择性的丧失，主要归因于杂絮凝，这种杂絮凝可以通过添加质点遮盖剂来减小，即一种在絮凝剂之前添加的ＰＥＯ的较低分子量部分。８     

大型工程中塔机基础型式的合理选用

以一个大型综合体建筑工程为例,介绍了塔机合理布置及基础型式的选择,工程中应用了组合式、独立式、底板一体式等多种大型塔机基础型式,介绍了其各自特点及基础施工方法.     

The National Cohort of Dairy Farms--a data collection platform for mastitis research in Canada

Costs and feasibility of extensive sample collection and processing are major obstacles to mastitis epidemiology research. Studies are often consequentially limited, and fundamental mastitis researchers rarely have the opportunity to conduct their work in epidemiologically valid populations. To mitigate these limitations, the Canadian Bovine Mastitis Research Network has optimized research funds by creating a data collection platform to provide epidemiologically meaningful data for several simultaneous research endeavors. This platform consists of a National Cohort of Dairy Farms (NCDF), Mastitis Laboratory Network, and Mastitis Pathogen Culture Collection. This paper describes the implementation and operation of the NCDF, explains its sampling protocols and data collection, and documents characteristics, strengths and limitations of these data for current and potential users. The NCDF comprises 91 commercial dairy farms in 6 provinces sampled over a 2-yr period. Primarily Holstein-Friesian herds participating in Dairy Herd Improvement milk recording were selected in order to achieve a uniform distribution among 3 strata of bulk tank somatic cell counts and to reflect regional proportions of freestall housing systems. Standardized protocols were implemented for repeated milk samplings on clinical mastitis cases, fresh and randomly selected lactating cows, and cows at dry-off and after calving. Just fewer than 133,000 milk samples were collected. Demographic and production data were recorded at individual cow and farm levels. Health management data are documented and extensive questionnaire data detailing farm management and cleanliness information are also captured. The Laboratory Network represents coordinated regional mastitis bacteriology laboratories using standardized procedures. The Culture Collection archives isolates recovered from intramammary infections of cows in the NCDF and contains over 16,500 isolates, all epidemiologically cross-referenced between linked databases. The NCDF is similar to Canadian dairies in relation to mean herd size, average production, and freestall percentages. Pathogen recovery was greater than anticipated, particularly for coagulase-negative staphylococci and Corynebacterium spp. International scientists are encouraged to use this extensive archive of data and material to enhance their own mastitis research.     

First evidence of the presence of genomic islands in Escherichia coli P4, a mammary pathogen frequently used to induce experimental mastitis

Mastitis pathogens belonging to Escherichia coli species are often considered as environmental opportunistic pathogens that invade the udder and are rapidly killed by the immune system of cows. However, several studies have reported that some of these strains are able to persist in the udder for prolonged periods or to adhere and invade mammary epithelial cells, suggesting that they might possess some specific properties or genes that could be involved in their capacity to provoke mastitis. The aim of this work was to search for such specific genes in the E. coli strain P4, which was isolated from a case of severe mastitis and is often used to induce experimental mastitis. We established that this strain belongs to phylogenetic group A of the E. coli species, and that its core genome is very similar to that of the commensal nonpathogenic strain E. coli K-12 MG1655. Seventeen transfer RNA loci, known to be frequently associated with genomic islands, were screened and an altered structure was detected for 7 of them. The partial characterization of 5 of these loci (asnT, leuX, pheV, serU, and thrW) and the complete characterization of 1 (argW) revealed the presence of genomic islands that differ from those already described in pathogenic or nonpathogenic E. coli strains.