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排序方式: 共有1508条查询结果,搜索用时 46 毫秒
21.
针对QY、PRI、NDVI、水势分别从不同的方面反映玉米的生理状况,以甜糯二号玉米作为材料,通过田间试验测量玉米昼夜4个参数值,研究了QY、PRI、NDVI、水势4个参数的昼夜变化,并且分析它们之间的相关性。结果表明,QY、水势、PRI三者具有很强的相关性,并且能建立回归模型表示它们之间的联系。  相似文献   
22.
黑龙江省国有林场管理体制机制改革立法研究   总被引:1,自引:0,他引:1  
在对黑龙江省国有林场管理体制机制的立法现状和立法中存在的问题进行分析后,从立法角度探讨黑龙江省国有林场改革的新思路与措施,进而提出改革的建议,为国有林场的改革提供理论和法律支撑.  相似文献   
23.
绩效预算是我国部门预算管理改革的重要内容。国家重点实验室专项经费绩效预算安排机制,是财政科研经费绩效预算的典型示例。文章通过剖析国家重点实验室专项经费绩效考评管理机制,对国家重点实验室绩效预算机制推广应用于其他财政专项的范围、考评指标、考评工作方法、考评结果应用等方面提出了意见建议。  相似文献   
24.
The aim of this study was to evaluate the effects of dietary betaine (BET) on growth performance, redox state, and related gene expression in broilers under heat stress (HS). A total of 144 21-day-old male broiler chickens with similar body weights were assigned randomly to three treatments with six replicates (eight chickens per replicate cage). Broilers in the control (CON) group were kept at thermoneutral (TN, 22±1°C) conditions and fed a basal diet until they were 42 days of age. Broilers in the other two groups (defined as HS and HS + BET) were exposed to HS (34±1°C, 8 h/day) and fed the basal diet without or with 1000 mg/kg BET, respectively. Rectal and cockscomb temperature of broilers was increased (P<0.05) in HS and HS + BET groups compared with the CON group, whereas there was no difference between HS and HS + BET groups. Dietary BET supplementation restored (P<0.05) average daily gain (ADG) and average daily feed intake (ADFI) of broilers and reversed (P<0.05) the increase in serum alanine transaminase (ALT) activity and malondialdehyde (MDA) content in the liver tissue of broilers under HS. The HS + BET group had higher (P<0.05) activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the liver tissue and mitochondria than the HS group, and the same pattern was observed for glutathione (GSH) and GSH/glutathione disulphide (GSSG) in the liver tissue. The decreased mRNA levels of GPX1 and uncoupling protein (UCP) in the liver induced by HS were restored by BET supplementation. In conclusion, dietary BET supplementation can alleviate HS-induced hepatic and mitochondrial oxidative damage of broilers by regulating mRNA expressions of GPX1 and UCP.  相似文献   
25.
陆地棉品种间杂种苏杂16棉铃发育动态研究   总被引:5,自引:6,他引:5  
棉铃发育过程中,苏杂16单铃子棉主的提高表现为二个方面:一是纤维干重的增加,1991~1992两年平均增加10.0%;二是种子重量的提高,两年平均单铃种仁重增加9.4%。单铃纤维干重的增长与棉铃对位叶大小呈正相关关系,与棉铃对位叶中全N含量呈负相关关系.该杂文组合在棉铃发育过程中表现了较强的“源”“库”生理优势,光合产物积累多,营养物质运转快是该组合获得高产的重要生理基础。  相似文献   
26.
The paper discuss the concept of fiberoptic smart civil structure,and analysis the principle of non destructive evaluation of civil structure with the help of embeded fiberoptic sensor in sensing the inner state and integrity of the structure.The typical experiment and development of fiberoptic sensing system in the health monitoring of dam,highway,bridge and buildings are overriewed.  相似文献   
27.
The authors analyze the influence in vector controlled induction machine caused by parameter variation and main flux saturation affects speed estimation of adaptive state observer. According to simulation of the modified scheme with saturated induction motor model, it is proved that when the vector control scheme operates in field weakening region, the main flux saturation will obviously influence precision of speed observer and bring great error of speed estimation. Thereby, the main flux saturation should be compensated to improve performance of the vector control system.  相似文献   
28.
Several aspects of the conditional equation derived from the accumulative equation are discussed in detail. The results indicate that the conditional equation not only is well consistent with the principles of electronegativity and absolute hardness equalization, but also satisfies the bonding of a full -prerequisite condition, e. g. two like electronic charge species repel and unlike attract each other'. In addition these principles are in the accumulative state. Mathematically, some other aspects of the conditional equation are worth studying based on the generalization of this equation.  相似文献   
29.
In accordance with the special characteristics of state medium-sized construction enterprises and their reform objects of "having a free hand and enlivening", the suitable objective model, the stock cooperative system for state medium-sized construction enterprises has been put forward in this paper by analyzing the system mechanism of stock cooperative system enterprises. Then the causes for it were expounded.  相似文献   
30.
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