Effect of sex and rearing system on the quality and mineral content of fiber from raeini cashmere goats

The aim of this study was to compare the quality characteristics and mineral content of the fiber from male and female cashmere goats raised under different management systems. Male and female Raeini cashmere goats （〈1.5 years of age, n=48） were selected from flocks raised at a government breeding station or raised commercially under either rural or nomadic conditions. The staple length, cashmere fiber diameter, coefficient of variation for fiber diameter, percentage of cashmere in a fleece, percentage of guard hair in a fleece and cashmere tenacity averaged 4.6 ±0.1 cm, 18.0 ±0.1 um, 20.9±0.4%, 66.1 ± 1.5%, 33.8± 1.5% and 1.8±0.2 gf/tex, respectively. The sulfur, copper and zinc content of the cashmere averaged 2.8 ± 0.1%, 0.00065 ± 0.00002% and 0.01276 ± 0.00025%, respectively. Rearing method significantly affected staple length, coefficient of variation of fiber diameter, cashmere tenacity and copper content. Males had a higher coefficient of variation of fiber diameter and cashmere tenacity than females （P 〈 0.05）.

Mechanical Properties of Mo Fiber-reinforced Resin Mineral Composites with Different Mass Ratio of Resin and Hardener

Mo fibers were added to RMC with different mass ratios of resin and hardener to improve its mechanical properties. The influences of fiber surface state and hardener content on interface bonding strength and mechanical properties of RMC were studied, respectively. Furthermore, strain values of typical measuring points on samples of Mo fiber reinforced RMC(MFRRMC) under different loads were obtained by experiments and finite element analysis. The experimental results prove that scrap Mo fibers can improve interface bonding strength and mechanical properties of RMC better than new smooth Mo fibers because of the discharge pits randomly distributed on the surface of scrap fibers. With the decrease of hardener content, not only interface bonding strength between fiber and matrix, but also compression and flexural strength of MFRRMC increase firstly and then decrease. The properties are best while the mass ratio of resin and hardener reaches 4:1. It is indicated that finite element calculation data basically agree with experimental data by comparison of strain values on typical measuring points, which can provide an important intuitive reference for successive study on other mechanical properties of MFRRMC, validating the correctness of simulation method as well.

Status and development of mineral wool made from molten blast furnace slag

This study describes the characteristics of mineral wool and its applications,and also introduces the traditional process of mineral wool made from molten blast furnace （BF） slag. Compared with high energy consumption of the traditional process,the production of mineral wool by using molten BF slag will be able to take full advantage of the sensible heat of molten slag, and also reduce production costs. However, there are also further issues to resolve such as how to obtain the required amount of molten BF slag and how to make it homogeneous. Based on the physical and chemical properties of the molten BF slag,the investigation into the relationship between temperature and viscosity under different acidity coefficients of the slag and silicon mixture was conducted. Combined with the crystallization and phase diagram of slag wool, its heat resistance, water resistance, durability and corrosion resistance were analyzed. Finally, trends of the technology development are proposed.

沙漠砂混凝土力学性能试验研究

研究了不同沙漠砂单掺、沙漠砂-矿渣粉复掺以及沙漠砂-矿渣粉-钢纤维三掺量对沙漠砂混凝土(Desert Sand Concrete, DSC)抗压强度、劈裂抗拉强度的影响,结果表明,随着沙漠砂掺量的增加,混凝土的抗压强度先增加后减小,当掺量为20%时达到最佳状态;矿渣粉掺量20%时显著提高了混凝土的强度;钢纤维掺量在0.8%时对抗压强度和劈裂抗拉强度的提升效果最为显著。沙漠砂、矿渣粉钢纤维的加入能够改善混凝土的孔隙结构,钢纤维的桥接作用有效阻止裂缝扩展,对增强材料韧性最为显著。

基于T-N曲线和Miner理论的绷紧式深海系泊缆疲劳损伤研究

采用基于T-N曲线和Miner线性累积损伤准则的疲劳累积损伤法对绷紧式系泊系统中聚酯纤维缆的疲劳损伤进行研究。简单阐述了系泊系统疲劳分析的相关理论,并给出了疲劳损伤的具体计算步骤。借助于Ansys/Aqwa以及Matlab软件,以'海洋石油981'为半潜式平台模型,计算了1 500 m水深的绷紧式系泊系统中聚酯纤维缆顶端的疲劳损伤。研究结果表明:低频海况以及高幅值海况对系缆的损伤较大。

Interaction between PCC Filler and Cellulosic Fiber in Fiber/Filler Co-refining System

Mineral fillers are important for conserving raw fiber materials and reducing production costs in the paper industry.However,the increase in filler content will inevitably result in strength reduction,which limits the adding amount of filler in paper production.In this study,we designed a cellulose fiber/filler co-refining approach to improve the strength and optical properties of paper;moreover,the synergistic interaction between fibers and precipitated calcium carbonate(PCC)fillers in the co-refining process was investigated.Results of fiber separation and PCC particle size analysis showed that,compared with conventional refining,the content of fines increased,whereas the PCC particle size decreased.More importantly,composites were formed between the PCC and fines,which promoted strength improvement of paper.Physical tests show that the tensile index of paper with 15%PCC content increased by 22%compared with that of the paper filled by conventional method,whereas the brightness and opacity of paper improved by fiber/filler co-refining for a specified filler content.These findings provide a basis for the further development of co-refining filling technology.

Effect of Silane Coupling Agent Concentration on Interfacial Properties of Basalt Fiber Reinforced Composites

The purpose of this study is to investigate the effect of the concentration of silane coupling solution on the tensile strength of basalt fiber and the interfacial properties of basalt fiber reinforced polymer composites.The surface treatment of basalt fibers was carried out using an aqueous alcohol solution method.Basalt fibers were subjected to surface treatment with 3-Methacryloxypropyl trimethoxy silane at 0.5 wt.%,1 wt.%,2 wt.%,4 wt.%and 10 wt.%.The basalt monofilament tensile tests were carried out to investigate the variation in strength with the concentration of the silane coupling agent.The microdroplet test was performed to examine the effect of the concentration of the silane coupling agent on interfacial strength of basalt reinforced polymer composites.The film was formed on the surface of the basalt fiber treated silane coupling agent solution.The tensile strength of basalt fiber increased because the damaged fiber surface was repaired by the firm of silane coupling agent.The firm was effective in not only the surface protection of basalt fiber but also the improvement on the interfacial strength of fiber-matrix interface.However,the surface treatment using the high concentration silane coupling agent solution has an adverse effect on the mechanical properties of the composite materials,because of causing the degradation of the interfacial strength of the composite materials.

纤维增强微生物混凝土抗裂性能及自修复试验

为了探究纤维对微生物混凝土抗裂性能和裂缝自修复效果的改善作用,试验优选出聚丙烯腈纤维并掺入微生物混凝土中,测试掺入纤维后微生物混凝土的力学性能、自修复养护期的裂缝透水性和裂缝残余宽度。试验结果表明,当纤维掺量为1.5 kg/m^(3)时,混凝土试件的劈裂抗拉强度恢复至未加载体试件的95.1%;修复养护28 d后,平均裂缝宽度为0.43 mm的试件透水性系数由3.35×10^(-5)m/s降至3.40×10^(-6)m/s,降幅达89.9%;能够愈合的最大裂缝宽度为0.82 mm。在微生物自修复混凝土中掺入纤维可有效提高其抗裂性能,增强裂缝自修复效果。

PERFORMANCE OF STEEL MICRO FIBER REINFORCED MORTAR MIXTURES CONTAINING PLAIN,BINARY AND TERNARY CEMENTITIOUS SYSTEMS

Steel micro fibers provide strengthening,toughening and durability improve-ment mechanisms in cementitious composites.However,there is not much data in the literature regarding how the extent of their effectiveness changes depend-ing on the type of matrix being reinforced.For clarifying this point,the influ-ence of a constant volumetric ratio(1%)of 6 mm long steel micro fibers on the performance of 5 mortar mixtures was investigated and were prepared using plain,binary and ternary cementitious systems.A total of 10 mixtures were cast.The mineral admixtures used in the study include silica fume(SF),metakaolin(MK)and a Class C fly ash(FA).While the replacement levels of SF and MK were 10%by weight of the total mass of the binder,this ratio was chosen as 30%for FA.In addition to the behavior of the mixtures under compressive,flexural and impact loads,abrasion,water absorption,chloride ion penetration,freez-ing-thawing resistance and drying shrinkage characteristics of the mixtures were determined.Test results indicate that generally the refinement in the pore struc-ture of the matrix provided by mineral admixtures and the increase in resistance against growth and coalescence of micro-cracks provided by fibers produce a syn-ergistic effect and improve the investigated performances of the mixtures.

纤维对复合矿物掺合料混凝土强度影响的研究

采用单掺与正交的方法,研究了玄武岩纤维与聚丙烯纤维对混凝土7 d和28 d抗压强度的影响,分析了两种纤维分别提升混凝土强度的机理。结果表明,玄武岩纤维与聚丙烯纤维限制早期混凝土内部微裂缝的产生,二者最佳掺量分别为0.1%和0.15%,此时抗压强度相较于对照组,分别提升了13%和9.5%。正交实验得出三因素对混凝土抗压强度影响顺序依次是玄武岩纤维>矿物掺合料>聚丙烯纤维,此时正交实验最佳配合比为:粉煤灰∶矿渣=1∶1.25(球磨15 min),玄武岩纤维掺量0.125%,聚丙烯纤维掺量0.175%,28 d混凝土的抗压强度为68.6 MPa。

钢渣基CO_(2)矿化板材的制备与性能研究

采用铺浆注模、压制脱水成型、CO_(2)养护等工艺措施制备钢渣板材,考察了原材料掺量、脱水压力、养护方式等对钢渣板材力学性能的影响。试验结果表明:水胶比0.35抗折强度最高;随着水泥、熟石灰以及木质纤维掺量的增加,板材的抗折强度均提高;随脱水压力的增加,板材的抗折强度先提高后降低;养护时间延长,板材的抗折强度提高;耐碱玻璃纤维长度减小,板材的抗折强度提高,耐碱玻璃纤维掺量为1.5%时,板材抗折强度最高。

纤维增强树脂矿物复合材料的细观力学特性及损伤机理

纤维增强树脂矿物复合材料因优异的力学性能得到广泛应用,但有关材料损伤机理的研究仅停留在宏观层面,较少关注损伤过程中材料的细观力学特性和微裂纹演化规律。针对这一问题,基于颗粒流离散元技术建立了纤维树脂矿物复合材料的细观模型,分析了材料应力-应变曲线的变化规律,揭示了材料的微裂纹萌生扩展机制和其破坏失效形式。结果表明,相比于树脂矿物复合材料,纤维增强树脂矿物复合材料的抗压强度更高,起裂应力和损伤应力更大;骨料颗粒形状对纤维的增强增韧作用影响较小;纤维对树脂矿物复合材料具有增韧阻裂的作用。研究从细观角度揭示了纤维增强树脂矿物复合材料的损伤性能,能够为该材料的推广应用提供指导。

仿生矿化改性废弃PAN纤维对SBS沥青低温抗裂性能的影响

为了研究废弃聚丙烯腈纤维(PAN)作为SBS复合改性沥青增强剂的可行性,提高SBS复合改性沥青的低温抗裂性能,促进“双碳”战略的实施和可持续发展,采用仿生矿化方法对废弃聚丙烯腈纤维进行改性处理,并将其与SBS复合于沥青中,制备新型复合改性沥青。扫描电子显微镜和X射线荧光分析仪分析表明,纤维表面成功构建了仿生结构,并确认了仿生矿化改性纤维(HP-PAN)的粗糙表面。纤维表面的仿生矿化结构作为沥青中的缓冲器,增强了纤维和沥青之间的相互作用。动态流变剪切和拉伸试验表明,HP-PAN/SBS改性沥青比PAN/SBS改性沥青表现出更好的黏弹性、抗车辙性和拉伸性能,并且在废弃聚丙烯腈纤维的添加量质量分数为2%时,复合改性沥青的性能最好,其低温抗裂性能相较于普通沥青提高了146.94%。

一种高强度混凝土材料配比优化及应用效果

为提高公路隧道加固等施工中混凝土材料的强度,主要使用矿粉、钠激发剂、碳纤维等材料,制备了一种高强度混凝土材料,并对钠激发剂模数和掺量、碳纤维掺量进行优化,分析材料应用效果。结果表明,随着钠激发剂模数从0.7增加到2.2,材料力学性能先升后降。当钠激发剂掺量从10%增多至20%时,材料力学性能也先升后降。而适量碳纤维的添加,可以进一步提高材料强度。试验中高强度混凝土材料配比优化为:钠激发剂模数1.3、钠激发剂掺量16%、碳纤维掺量1%。在最佳配比下,该材料在施工中28 d抗压、抗折强度分别为67.79 MPa、16.95 MPa,且抗渗水性能良好。

桥梁转体球铰支座用活性粉末混凝土试验研究

为提高活性粉末混凝土(RPC)的流动性,开展桥梁转体球铰支座用RPC材料试验。通过控制变量法,研究RPC性能的基础配合比,探讨矿物掺合料、钢纤维及减水剂掺量对RPC性能的影响。结果表明:矿粉、硅灰适量替代水泥掺加到RPC体系,能充分发挥微集料填充效应及火山灰活性,提高体系抗压强度,矿粉与硅灰最佳掺量分别为45,20kg/m^(3);钢纤维的掺加能大幅度提高RPC抗压强度,钢纤维最佳掺量为75kg/m^(3);减水剂在RPC中作用机理主要表现为静电斥力与空间位阻,减水剂最佳掺量为18kg/m^(3);通过最优试验配合比测试,RPC材料综合性能满足桥梁转体球铰支座应用要求。

羊毛、涤纶纤维同浴染色原位矿化工艺

针对毛/涤混纺织物染色流程长、用水量大的问题,采用Lanasol染料和分散染料对羊毛和涤纶纤维进行原位矿化工艺同浴染色,分析了矿化工艺参数对染色效果的影响,并与传统染色进行比较。优化的工艺为环保载体2.0%(omf),矿化助剂XBD 1.00%(omf)、XYS 5.0%(omf),85℃矿化处理20 min。结果表明,原位矿化染色产品的颜色、色牢度与传统工艺基本一致,且具有显著的节水减排和提高生产效率的作用。

4种颜色藜麦的营养价值比较

为比较不同颜色藜麦的营养价值,选取我国藜麦主产省的白、黑、红、灰藜麦主要品种样品各4份,比较其营养成分含量,用层次聚类分析对样品和营养指标分类。结果表明,同小麦粉、大米等主粮及燕麦、荞麦、小米、青稞等杂粮相比,藜麦具有更高的粗蛋白、粗脂肪、灰分、不溶性膳食纤维(IDF)、P、K、Zn和更低的总淀粉含量;藜麦维生素B_(1)、B_(2)高于小麦粉和大米,但低于荞麦、小米和青稞。不同颜色藜麦相比,灰藜麦同其它3种颜色藜麦的区分度最大,红藜麦和黑藜麦的相似度最高。总膳食纤维(TDF)、IDF、Cu、Zn、总淀粉、Mn和K这7种组分在黑色和红色等深色藜麦中含量较高;维生素B1、可溶性膳食纤维(SDF)和Se在灰色和白色等浅色藜麦中含量较高;总黄酮、Fe、粗脂肪在灰色和红色藜麦中含量较高;维生素B2、粗蛋白在白色和红色藜麦中的含量较高;Ca、Mg和P在灰色和黑色藜麦中含量较高。综上,不同颜色藜麦的营养特性有一定的互补性,混合颜色的藜麦可提供更全面的营养。

矿物掺合料对FHPC性能影响及其尺寸效应研究

为提高纤维高强混凝土(FHPC)的性能,探究了硅灰、I级粉煤灰和S95矿渣粉在不同掺量和掺加方式下对FHPC力学性能及尺寸效应的影响。结果表明单掺矿物掺料中,S95矿渣粉对提高FHPC抗压强度和抗折强度效果最好,硅灰次之,I级粉煤灰效果最弱。当I级粉煤灰与S95矿渣粉以1:2复掺时,FHPC的抗压强度显著提高;硅灰与S95矿渣粉以1:1复掺时,FHPC的抗折强度提升效果最好。同时加入3种掺合料,保持硅灰掺量不变的情况下,I级粉煤灰与S95矿渣粉以1:1复掺,可以显著提高FHPC的力学性能。此外,低水胶比下FHPC的抗压抗折强度尺寸效应更为显著,但随着水胶比的增加,FHPC的抗压抗折强度尺寸效应逐渐减弱。

Type ⅡB human skeletal muscle fibers positively correlate with bone mineral density irrespective to age

Background Age-associated decrease in type ⅡA/B human skeletal muscle fibers was detected in human biopsies in our previous study. The relationship between change in muscle fiber typing and bone mineral density （BMD） is, however,unknown either cross-sectionally or longitudinally. We therefore conducted a cross-sectional study to investigate their correlation using human muscle biopsies.Methods Forty human subjects aged （53.4±20.2） years were recruited. Histomorphometric parameters of their muscle biopsies were measured by ATPase staining and image analysis, including average area percentage, fiber number percentage, mean fiber area, and area percentage of connective tissues. Hip and spine BMD was measured by dual-energy X-ray absorptiometry. Partial correlation with adjusting age was performed.Results Type ⅡB muscle fiber was found positively correlated with hip BMD irrespective to age and demonstrated significantly stronger relationship with BMD among all fiber types, in terms of its cross-sectional area （r=0.380, P=0.029）and size （r=0.389, P=0.025）. Type ⅡA muscle fibers associated with hip BMD in mean fiber area only （r=0.420, P=0.015）.Conclusions Type ⅡB muscle fiber may play an important role in maintaining bone quality. This may also be a relatively more sensitive fiber type of sarcopenia and osteoporosis. These findings further consolidate the muscle-bone relationship.

连续矿物纤维增强3D打印砂浆的力学性能

为验证连续矿物纤维增强3D打印混凝土的力学性能,分别采用浇筑成型和3D打印成型的方式测试了砂浆抗拉、抗折、抗压强度。结果表明,不同连续矿物纤维复合使砂浆的抗拉强度较素砂浆提高了2%~19%;但由于连续矿物纤维耐磨性较差,抗折强度有所降低,但是对抗压强度有一定提升作用;连续矿物纤维增强砂浆的抗拉强度随连续玄武岩纤维数量的增加而提高,但不呈线性关系;连续纤维与短切纤维复合使用,对砂浆抗拉、抗折强度具有协同作用,也有助于降低短切纤维对抗压强度的不良影响,但其抗压强度仍低于素砂浆。