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轴箱对轨道不平顺的响应及其可测性分析 被引量:3
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作者 方格 吴天行 +1 位作者 彭志科 王誉蓉 《噪声与振动控制》 CSCD 2017年第2期13-17,100,共6页
轨道不平顺会加剧轮轨的动态作用,引起轮轨部件损坏、噪声等问题,一直是铁路维护工作的重点。考虑到维护的成本,对轨道不平顺程度的实时监测显得尤为重要,其中轴箱加速度信号的二次积分是使用较多的方法。然而轴箱加速度包含的成分复杂... 轨道不平顺会加剧轮轨的动态作用,引起轮轨部件损坏、噪声等问题,一直是铁路维护工作的重点。考虑到维护的成本,对轨道不平顺程度的实时监测显得尤为重要,其中轴箱加速度信号的二次积分是使用较多的方法。然而轴箱加速度包含的成分复杂,为了更深入地认识轴箱加速度的测量结果,建立多车轮与轨道相互作用模型,详细分析轨道不平顺激励下的轴箱与转向架的动态位移响应,重点关注轴箱响应对轨道不平顺的可测性,并给出了扩大测量频率范围的建议。结果显示:低频(长波长)情况下轴箱对轨道不平顺的响应接近理想,但是高频的位移响应受到多车轮耦合作用的影响,呈现很大的不确定性。 展开更多
关键词 振动与波 轨道不平顺 轴箱加速度 多车轮作用 驻波
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Science Letters:Effects of dietary supplementation with Clostridium butyricum on the growth performance and humoral immune response in Miichthys miiuy 被引量:24
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作者 SONG Zeng-fu wu tian-xing +1 位作者 CAI Li-sheng ZHENG Xiao-dong 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第7期596-602,共7页
关键词 梭菌 生长性能 体液免疫响应 营养
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Effects of α-tocopheryl acetate supplementation in preslaughter diet on antioxidant enzyme activities and fillet quality of commercial-size Sparus macrocephalus 被引量:3
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作者 ZHANG Xiao-dong wu tian-xing +1 位作者 CAI Li-sheng ZHU Yong-fei 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第9期680-685,共6页
This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (35... This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (350±12) g] were divided into three groups (E250, E500 and E1000) and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary α-tocopheryl acetate (289, 553, 1 069 mg/kg). Over the experimental period, fish were fed to satiation and reached a final mean weight of (465±28) g without significant body weight difference and proximate composition difference. Fillet α-tocopherol was significantly (P<0.05) different between groups, reaching levels of 14.2, 22.1, 30.9 μg/mg fillet for groups E250, E500 and E1000, respectively. Total serum superoxide dismutase (SOD) activity increased significantly (P<0.05) in fish fed the diets high in α-tocopheryl acetate, but serum glutathione peroxidase (GPX) activity was unaffected. In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower (P<0.05) levels of oxidation. These results suggested that increased dietary α-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxi-dation of Sparus macrocephalus fillets in retail storage on ice. 展开更多
关键词 黑鲷 鱼肉品质 日粮 抗氧化剂 酶活力 醋酸盐 α-维生素E
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Influence of fasting on muscle composition and antioxidant defenses of market-size Sparus macrocephalus 被引量:1
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作者 ZHANG Xiao-dong wu tian-xing +1 位作者 CAI Li-sheng ZHU Yong-fei 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第12期906-911,共6页
The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (cont... The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (control and fasted) and reared in 6 cages. After two weeks of adaptation, group I fasted for 28 d; group II was fed normally as a control. In 3, 7, 14, 21 and 28 d, 6 fish per group were sampled for proximate flesh composition, liver antioxidant enzyme activities and malondialdehyde flesh content analyses. In fasted fish, the reduction of lipid content in muscle occurred after day 3, and, compared to controls, the content of protein decreased from day 14, the activities of liver antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) increased from day 3, and flesh malondialdehyde levels increased from day 21. Flesh fat reduction shows that fasting may be used as a technique to reduce flesh lipid content in Sparus macrocephalus. However, considering flesh protein loss and the subsequent oxidative stress, the fasting technique should be used with precautions. 展开更多
关键词 抗氧化剂 禁食 肉质 黑鲷
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