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71.
72.
利用扫描电子显微镜(SEM)、压汞法(MIP)、快速氯离子迁移系数法(RCM)等手段,研究了偏高岭土(MK)掺量对高强机制砂混凝土抗压强度以及抗氯离子渗透性能的影响.研究发现: 掺入MK能够有效改善高强机制砂混凝土的力学性能和抗氯离子渗透性能:随MK掺量增加,抗压强度与抗氯离子渗透性能均呈先增大后减小的趋势,最佳MK掺量为8%,此时28 d抗压强度为98.5 MPa,较基准组增加13%,氯离子迁移系数为1.89×10-12 m2/s,较基准组减小60%.微观结构试验表明适宜的偏高岭土掺量能够有效促进水泥水化;偏高岭土颗粒的晶核效应和微集料填充效应协同作用,使得机制砂混凝土的微观结构更加均匀密实,机制砂混凝土的多害孔、有害孔减少,少害孔增加,从而提高了机制砂混凝土抗压强度和抗氯离子渗透性能. 相似文献
73.
The effects of setting time, whey protein concentrate (WPC), and calcium chloride (CaCl2) on textural properties of silver carp surimi were investigated. Response surface methodology was used to evaluate and compare the effects of setting time (30–90 min), WPC (1–9% of protein ratio), and CaCl2 (1–59 mmol/kg) on the gel strength. Models for breaking force, breaking distance, and gel strength of surimi gel were established. The maximum gel strength was achieved at the setting time of 60 min, WPC and CaCl2 at 5% protein ratio, and 15–18 mmol/kg. CaCl2 was the most significant factor affecting the gel strength. 相似文献
74.
Use of treated mine water for rainbow trout (Oncorhynchus mykiss) culture: a production scale assessment 总被引:1,自引:0,他引:1
Roger C. Viadero Jr. Aislinn E. Tierney Kenneth J. Semmens 《Aquacultural Engineering》2004,31(3-4):319-336
In previous proof-of-concept work, it was shown that the use of treated coal mine water for rainbow trout (Oncorhynchus mykiss) culture in a cage was technically feasible, though only a 50-fish bioassay was grown and no work on production-related issues was conducted. To further advance the use of treated mine water, an under-utilized water resource throughout Mid Appalachia, work was conducted to assess the effects of using treated coal mine water for the intensive production of rainbow trout in a flow-through system. During this study, comprehensive water quality data were collected to supplement fish weight and length data taken during routine monthly sampling events. The 8000 fish grew well in the raceway system over the 9 months of production, where a feed conversion ratio of 1.4 and a condition factor of 5.1 × 10−4 were measured with stocking and harvest densities of 26.4 and 50.2 kg/m3, respectively. Further, total net production was 3275 kg (7220 lb) with 98.6% survival. Throughout the study, dissolved ion concentrations (Fe, Al, Mg, Ca, and SO4) often exceeded recommended tolerance limits. Further, elevated ammonia nitrogen concentrations generated from a component of the mine water-treatment process were identified as a potential limiting factor for aquaculture development. However, when the non-ideal effects of high ionic strength and the speciation of dissolved metal–ligand complexes were taken into account, the concentrations of free metal ions were within recommended tolerance limits. 相似文献
75.
狭鳕(Theragra chalcogramma Palas)目标强度的现场测定 总被引:2,自引:2,他引:2
1993年夏季“北斗”号调查船白令海狭鳕(TheragrachalcogrammaPalas)资源声学调查期间,利用计数—积分法对狭鳕的目标强度进行了现场测定。结果表明,平均叉长516cm的狭鳕的平均目标强度为-343dB;以常规的20Logl形式表示,其目标强度与叉长的关系式为TS=20Logl-68.6dB。该测定结果较目前采用的关系式:TS=20Logl-66.0dB低26dB;应用于资源量计算,其估算值将比现估算值高82%。 相似文献
76.
高强度聚乙烯拖网网具性能的研究 总被引:5,自引:2,他引:5
对4顶单船中层拖网和双船底拖网的前部以高强度聚乙烯网线替代常规聚乙烯网线,依田内渔具模型试验准则制成模型网,进行水池对比试验。结果表明,在其它条件不变的前提下,应用高强度聚乙烯网线的拖网与原生产网相比,在2.5~4.5kn拖速下,网具阻力可平均下降6.5%~16.2%,网口垂直扩张可提高0.9%~25.7%,能耗系数下降14.5%~33.5%。 相似文献
77.
Teruo Nakayama Keiko Hatae Midori Kasai Atsushi Ooi 《Journal Of Aquatic Food Product Technology》2017,26(5):578-592
The season for finding the firmest sashimi made from wild Japanese sea bass was investigated. Flesh rigor tension and contraction were measured by a “new” device with isometric (muscle length kept constant) and isotonic (balance beam moves freely) transducers. Both flesh rigor tension and contraction peaks appeared at the same postmortem times, with attainment of ultimate pH and adenosine triphosphate/inosine monophosphate ratio in four seasons. Seasonal seawater temperature correlated negatively to seasonal maximum rigor contraction and positively to seasonal flesh breaking strength at 72 h postmortem. After rigor peak tension attainment, the tension relaxation was much lower than that of other wild fish species, especially in summer. The sea bass muscle resisted structure disruption in rigor isometric tension generation. Wild sea bass sashimi was firmest in breaking strength in summer. 相似文献
78.
汽油机曲轴圆角和下沉量的研究 总被引:1,自引:0,他引:1
以某汽油机曲轴为载体,计算分析了曲轴的静态性能,并改变圆角半径和圆角下沉量的大小,分析对曲轴强度的影响,从而为圆角滚压工艺选取曲轴圆角参数奠定理论基础。 相似文献
79.
2种离子固化剂改善黄土抗剪强度和抗渗性的研究 总被引:2,自引:0,他引:2
为了探讨CONAID和LUKANG 2种离子固化剂的固土性能及其影响因素,对不同固化剂掺量、养护龄期、压实度和含水率的固化黄土进行了直剪试验和渗透试验.研究结果表明:随着固化荆掺量、养护龄期和压实度增大,2种固化土的内摩擦角和黏聚力呈上升趋势,渗透系数呈下降趋势,且规律比较接近.其中LUKANG固化剂对黄土抗剪强度和抗渗性的改善效果优于CONAID固化荆.建议在施工过程中选用LUKANG固化剂,掺量宜取0.01%.为了达到更好的抗剪和抗渗效果,应尽量延长固化土的养护龄期,增加压实度. 相似文献
80.
转向纵拉杆是汽车转向传动机构中重要的零部件,通过转向纵拉杆受力分析,对转向纵拉杆的强度、稳定性进行了校核,提供了纵拉杆设计分析的参考. 相似文献