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《Food Control》2015
There is a growing interest in donkey's milk as food for sensitive consumers, such as infants with cow's milk protein allergy and elderly people. The aim of this study was to carry out a survey on the dairy donkeys farming in Piedmont, Italy. The research was conducted in order to analyze the farm characteristics as well as the chemical and microbiological quality of milk. All the farms were small-sized, family-run, and, in most cases, animals were farmed semi-extensively. The donkey milk from Piedmont farms was characterized by a protein content around 1.5 g/100 mL and a fat content lower than 0.1 g/100 mL. Lysozyme activity was considerably higher than that reported in raw cow milk. The milk microbiological profile greatly differed among the farms. Milk sampled in the farm that performed hand milking showed total viable counts significantly lower than milk collected in the farms equipped with automatic milking. Samples were tested for several pathogens and negative results were observed, except for the detection of Bacillus cereus in one sample. The survey provided useful data for the laying down of recent regional regulation for the production and commercialization of donkey's milk. The results of the survey indicate that further research is needed in order to define the best management and nutritional strategies for the improvement of the quali-quantitative production of dairy donkeys. 相似文献
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对通信设备抗震试验方法进行了讨论,重点研究了NEBS GR-63-CORE抗震试验方法。针对抗震试验中地震模拟振动台频宽不够及存在非线性因素影响的问题,设计了地震模拟振动台三参量伺服控制算法,有效拓展了试验系统的频宽,提高试验系统的动态响应范围;并提出一种基于频域的驱动信号修正迭代算法,通过在线迭代修正驱动信号,补偿试验系统中非线性因素对系统的影响。NEBS GR-63-CORE抗震试验表明,基于三参量控制算法及驱动信号修正迭代算法的地震模拟振动台控制策略,能够实现高精度的地震波形复现试验。 相似文献
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相比于传统的串联连接方式,提出了一种基于二进制电抗分流器实现热电转换器共地比较测量的方法,通过串联连接的方式实现交流电流量程扩展。二进制电抗分流器产生两路共地可自校的电流输出,为热电转换器之间进行相互比较提供已知关系的1:1电流比例;该方法可以减少电流泄漏和三通连接器串联连接的影响。基于这种共地测量方法,热电变换器结合100 mA和1 A分流器进行了实验分析,测量频率范围1~200 kHz,同时在串联模式下进行换臂测量。实验结果表明基于二进制电抗分流器和换臂法可以很好地消除泄露电流所引起的测量误差,且两种不同方法在200 kHz频率下一致性优于3 μA/A。3种不同热电变换器和分流器组合在10 mA~1 A测量电流下交流转换误差一致性优于6 μA/A。 相似文献
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对地震模拟振动台三参量控制算法进行了深入的研究,详细研究了三参量反馈及前馈环节对振动台系统特性的校正作用,并通过仿真和试验的方法进一步验证三参量控制算法对地震模拟振动台系统频响特性的改善效果:通过引入三参量速度反馈可以有效扩展系统的频宽,引入三参量加速度反馈可以有效提高系统的阻尼,三参量前馈控制能够对消系统闭环传递函数中距离虚轴较近的极点,实现系统频宽的进一步扩展。最后,通过对三参量伺服控制的地震模拟振动台进行地震波形再现试验,证明三参量控制算法能够实现较高精度的地震波形再现试验。 相似文献
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The storage time at 4 ± 1 °C of liquid smoked fillets of trout (Salmo gairdnerii) produced with a new smoking technique, using a combination of liquid smoke and steaming at 2 bar pressure for 30, 45 and 60 min, was studied. Maximum total viable counts (TVC) were reached after 25 days in the samples processed for 30 min and after 48 days in those processed for 45 and 60 min. However, panellists rejected the samples long after maximum TVC was observed. The increase of TVC was also confirmed using a particle size analyser, indicating a possible direct detection of microbial growth. A reduction of about 50% in the C22:6n − 3/C16:0 ratio was found across the whole period of storage, indicating lipid oxidation. The hypoxanthine/inosine (Hx/Ino) ratio showed a good relationship with both TVC and sensory results. Thus, when the Hx/Ino ratio was higher than 1.3, the products had reached their maximum acceptable TVC and were approaching their rejection time by the panellists, indicating that the Hx/Ino ratio is a good indicator of the shelf-life of smoked products of trout (S. gairdnerii). 相似文献
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The effect of modified atmosphere packaging (MAP 1: 40%CO2+60%N2 and MAP 2: 100%CO2) on the shelf-life of carp steaks was studied. Carp steaks were stored at +3±0.5˚C and on days 1, 3, 6, 9, 13 and 15, microbiological, chemical and sensory testing was performed. Based primarily on odour scores it was observed that carp steaks packaged in MAP1 remained acceptable up to 13 days of storage, while carp steaks packaged in MAP2 remained unchanged until the end of the study. By using MAP, especially 100% CO2, products shelf-life can be significantly prolonged. 相似文献
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《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,656(1):11-38
The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given. 相似文献
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《International Journal of Hydrogen Energy》2022,47(2):1292-1305
The detonation wave in a rotating detonation engine is highly adaptable to the incoming flow, making the wave easier to control. In this study, a numerical simulation method is used to analyze the working process and flow field structure of a rotating detonation model engine with dual cavity injection of an H2/air mixture by controlling the injection pressure ratio of the dual cavity and the number of detonation wave heads. It is found that the rotating detonation engine offers the possibility to control the thrust vector with two different modes. The first is a one-cycle alternate control mode with a small injection pressure ratio. Here two deflections occur in different directions occur across one detonation wave propagation cycle, but the overall deflection direction is in the low-pressure region. The second is a one-way control mode, with a large injection pressure ratio, and the deflection direction towards the low-pressure region. For the multi wave-mode, it belongs to one-way control mode because of constant deflection direction in the low-pressure area. From the perspective of thrust distribution along the circumference, the one-way control strategy satisfies the ability of a rotating detonation thrust vector control. 相似文献