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排序方式: 共有634条查询结果,搜索用时 671 毫秒
71.
This study investigates the effectiveness of ozonated water and flake ice (combined Petfrost system) to increase the quality and stability of fresh megrim on fishing boats. The captured fish were washed, placed in plastic boxes, covered with flake ice and refrigerated at 2 °C for up to 2-weeks onboard and, thereafter, for 11 days onshore. The experiments employed sterile, filtered and ozonated water at a concentration of 2 ppm for washing the fish and making the flake ice. The results are compared with samples from a traditional treatment consisting of water and flake ice of marine origin. Fish were caught in four different hauls, which took 14, 12, 8 and 3 days in being landed. Subsequently, fish were stored for 1, 5, 7 and 11 days at 3 °C. The different treatments were evaluated using sensory, microbiological and chemical techniques. Fish treated with ozone always showed the best quality. Megrim treated with ozone was still suitable for consumption after 14 days on board, and megrim stored for 12, 8 and 3 days on board could be stored for a further five days in the ice state once landed with an acceptable quality. In contrast, control fish were not suitable for consumption if stored for longer than three days on board.The results indicate that treatment with water and ice flakes made from sterile and ozonated water maintains the quality of fresh megrim onboard fishing boats and upon arrival onshore. 相似文献
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73.
What can we learn from the spatial logic of collections of trees in the rainforest? Evan Greenberg of the EmTech programme at the Architectural Association (AA) School of Architecture in London and George Jeronimidis of the Centre for Biomimetics at the University of Reading combine forces to analyse the rainforest's morphology and its potential as an urban model. They suggest how the sectional height differentiation of trees could present a new way of thinking about urban organisation, accommodating varied microclimates, programmes and the city's infrastructural flows. 相似文献
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75.
齿轮磨损状态的在线铁谱监测试验研究 总被引:2,自引:1,他引:2
对OLF1在线铁谱仪用于齿轮磨损状态的监测进行了研究。试验数据分析表明,OLF-1在线铁谱仪对大磨粒有很强的敏感性,其采样值的大小和变化反映了齿面状态的变化。在正常磨损情况下,采样值曲线比较平稳;而一旦采样值出现无规律波动,则意味着不正常磨损的开始。与分析铁谱仪数据对比,也显示出非常近似的变化趋势。因而,OLF-1在线铁谱仪用于齿轮磨损状态的实时和连续监测具有良好的性能。本文同时指出,OLF-1在线铁谱与其它油液分析技术相结合,可以更准确地进行齿轮磨损状态的监测和诊断 相似文献
76.
MOA在线监测中的几个问题 总被引:12,自引:0,他引:12
研究了MOA在线监测中存在的几个主要问题,提出了有效解决信号取样、相间去耦,数值分析、诊断评估的技术和方法。从试验研究和在线监测来看,收到了良好的效果。可供有关人员参考。 相似文献
77.
变压器油中溶解氢气在线监测仪的研制 总被引:6,自引:1,他引:5
用气相色谱法检测中溶解的可燃气体可以预报变压器内部存在的潜伏性故障。用本文研制的在线监侧仪检测油中的氢气比气相色谱法更能及进地做到这一点。本文介绍了该仪器的原理和结构特点。该仪器具有结构简单,安装方便性能稳定,寿命长,不需要经常维护等特点。 相似文献
78.
In this study, we developed and tested a high-precision motion trajectory tracking controller of a pneumatic cylinder driven by four costless on/off solenoid valves rather than by a proportional directional control valve. The relationship between the pulse width modulation (PWM) of a signal's duty cycle and control law was determined experimentally, and a mathematical model of the whole system established. Owing to unknown disturbances and unmodeled dynamics, there are considerable uncertain nonlinearities and parametric uncertainties in this pneumatic system. A modified direct adaptive robust controller (DARC) was constructed to cope with these issues. The controller employs a gradient type adaptation law based on discontinuous projection mapping to guarantee that estimated unknown model parameters stay within a known bounded region, and uses a deterministic robust control strategy to weaken the effects of unmodeled dynamics, disturbances, and parameter estimation errors. By using discontinuous projection mapping, the parameter adaptation law and the robust control law can be synthesized separately. A recursive backstepping technology is applied to account for unmatched model uncertainties. Kalman filters were designed sepa- rately to estimate the motion states and the derivative of the intermediate control law in synthesizing the deterministic robust control law. Experimental results illustrate the effectiveness of the proposed controller. 相似文献
79.
介绍了恢复Mandelli加工中心在线检测功能所做的工作.分析了影响壳体零件加工质量的因素,并探索出实现加工过程在线检测功能与作用的有效途径. 相似文献
80.
李文正 《工业仪表与自动化装置》2002,(3):42-43,45
本文通过丙烯腈反应工段氧浓度在线分析仪表应用中出现的问题,着重介绍了改造后的氧分析仪预处理系统。 相似文献