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51.
文耀智 《邵阳学院学报(社会科学版)》2001,23(2):42-48
上世纪初发现自由基反应,其特点有三引发、传递和终止;分为单分子和双分子反应.共振杂化体越多的自由基越稳定,对自由基稳定有利的空间构型其反应易进行,溶剂化作用、氢键的形成、过渡态活化能等对自由基反应都有影响. 相似文献
52.
本文根据热力学原理分析了由化学反应的△H判断化学反应方向的条件.找出了由化学反应式估计△S的符号的一般规律.从热力学和动力学的角度分析了△H与化学反应速度率的关系,以及△H与温度对化学反应限度的影响. 相似文献
53.
比较近几届世界杯足球赛与我国足球甲A联赛的角球及前场任意球的进球率,说明角球和前场任意球进攻得分的重要性,并设计了战术和手势配合图,为以后教学和训练提供理论上的依据。 相似文献
54.
Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid 总被引:1,自引:0,他引:1
Cai W Xu Y Chen JZ Huang SR Lu ZY Wang ZK 《Journal of Zhejiang University. Science. B》2005,6(9):892-896
Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA)content of the VSMC were assayed. Results: 1×10-9, 1×10-8, 1×10-7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%,and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01)respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10-7mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion. 相似文献
55.
Whether someone has ever had free school meal (FSM) eligibility over a six‐year period is the measure of socio‐economic disadvantage currently used in the English school system. It is used to monitor the socio‐economic gap in achievement in the education system, to identify particular children at risk of low achievement and to direct funding to particular children and schools. In this paper we assess how well this measure predicts pupil attainment in secondary school in comparison to other measures of socio‐economic background known to influence pupil attainment, such as parental education or income. We ask whether the FSM measure is an adequate proxy for a pupil's socio‐economic disadvantage in an educational context. To do this we draw on the Longitudinal Study of Young People in England and matched administrative data. We find that the FSM eligibility measure correlates highly with other measures of socio‐economic disadvantage, however it does not identify all children living in what would be deemed deprived households. We then compare the extent to which the FSM eligibility measure predicts educational achievement relative to other measures of deprivation and find that its predictive power is only marginally lower than many richer survey measures. This provides some reassurance on its use in policy. 相似文献
56.
王咏梅 《廊坊师范学院学报》2002,18(2):24-25
豪放与婉约,是学风格审美表现形态中最基本的两种。章着重从语言美学的视角,对二由于语言表达方式、常规修辞与艺术修辞等话语方式的不同而呈现出的不同的审美特征进行比较性分析。 相似文献
57.
文双春 《衡阳师范学院学报》1996,(3)
根据电子在长直载流导线磁场中的运动和相对论性电子产生辐射的一般规律,计算并分析了电子在这种磁场中运动所产生的自发辐射强度分布,最后的结果中包含一个重要因子sin2η,正是它把自由电子的自发辐射与受激辐射联系起来了。 相似文献
58.
范文婷 《株洲师范高等专科学校学报》2007,12(4):35-38
鲁迅《野草》中包含了三种话语模式,即独白模式、对话模式和自由间接引语模式。这些具有不同表达效果的话语模式的运用,生动地展现了鲁迅对精神世界的探索和自我灵魂的剖析,表达了他复杂的情感体验和思想矛盾。 相似文献
59.
The whole Marxist theory centers on the emancipation and freedom of human beings, the naming of his highest ideal as ‘association
of free individuals’ being the clear proof. However, it would be superficial to announce Marxism as humanism of individualism
according to Marx’s pursuit of ‘free development of each’. The ‘free development of each’ put forward by Marx when describing
the ‘association of free individuals’ refers to individuals’ re-subjecting their social relations that have been changed into
material powers owing to private ownership and alienation. In this sense, the free development of each is the condition for
the free development of all. In this very sense, too, the foundation of the real community is required as the presupposition
so as to relate his theory of freedom to the theory on the elimination of private ownership and the alienation and elimination
of class and state finally.
Project supported by National Social Science Foundation of China(No. 00BZZ001) and the Excellent Young Teachers Program of
Ministry of Education, China. 相似文献
60.
本文根据费米气体模型理论,研究金属中自由电子气的能量,讨论电子的最高能量、平均能量和电子气的能级密度. 相似文献