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71.
踢球阶梯式程序教学法是指在踢球教学中按照踢球技术动作难度设定一定的程序,指导学生逐步提高踢球技术水平的教学方法。实践证明,踢球阶梯式程序教学法比传统踢球教学法有明显的成效。 相似文献
72.
Kaiwen Xiang Qian Yang Mengqun Liu Xiaodong Yang Jifang Li Zhishuai Hou Haishen Wen 《International journal of molecular sciences》2022,23(15)
Smolting is an important development stage of salmonid, and an energy trade-off occurs between osmotic regulation and growth during smolting in rainbow trout (Oncorhynchus mykiss). Growth hormone releasing hormone, somatostatin, growth hormone and insulin-like growth factor (GHRH-SST-GH-IGF) axis exhibit pleiotropic effects in regulating growth and osmotic adaptation. Due to salmonid specific genome duplication, increased paralogs are identified in the ghrh-sst-gh-igf axis, however, their physiology in modulating osmoregulation has yet to be investigated. In this study, seven sst genes (sst1a, sst1b, sst2, sst3a, sst3b, sst5, sst6) were identified in trout. We further investigated the ghrh-sst-gh-igf axis of diploid and triploid trout in response to seawater challenge. Kidney sst (sst1b, sst2, sst5) and sstr (sstr1b1, sstr5a, sstr5b) expressions were changed (more than 2-fold increase (except for sstr5a with 1.99-fold increase) or less than 0.5-fold decrease) due to osmoregulation, suggesting a pleiotropic physiology of SSTs in modulating growth and smoltification. Triploid trout showed significantly down-regulated brain sstr1b1 and igfbp2a1 (p < 0.05), while diploid trout showed up-regulated brain igfbp1a1 (~2.61-fold, p = 0.057) and igfbp2a subtypes (~1.38-fold, p < 0.05), suggesting triploid trout exhibited a better acclimation to the seawater environment. The triploid trout showed up-regulated kidney igfbp5a subtypes (~6.62 and 7.25-fold, p = 0.099 and 0.078) and significantly down-regulated igfbp5b2 (~0.37-fold, p < 0.05), showing a conserved physiology of teleost IGFBP5a in regulating osmoregulation. The IGFBP6 subtypes are involved in energy and nutritional regulation. Distinctive igfbp6 subtypes patterns (p < 0.05) potentially indicated trout triggered energy redistribution in brain and kidney during osmoregulatory regulation. In conclusion, we showed that the GHRH-SST-GH-IGF axis exhibited pleiotropic effects in regulating growth and osmoregulatory regulation during trout smolting, which might provide new insights into seawater aquaculture of salmonid species. 相似文献
73.
74.
构件库模糊查询技术研究 总被引:2,自引:0,他引:2
本文研究了在构件库管理系统中模糊查询理论,引入新概念,在此基础上给出了一种领域字典库 D D D 的定义、构造算法及构件库模糊查询算法。 相似文献
75.
Feiping Nie Author Vitae Shiming Xiang Author VitaeAuthor Vitae Changshui Zhang Author Vitae 《Pattern recognition》2009,42(1):105-114
Supervised dimensionality reduction with tensor representation has attracted great interest in recent years. It has been successfully applied to problems with tensor data, such as image and video recognition tasks. However, in the tensor-based methods, how to select the suitable dimensions is a very important problem. Since the number of possible dimension combinations exponentially increases with respect to the order of tensor, manually selecting the suitable dimensions becomes an impossible task in the case of high-order tensor. In this paper, we aim at solving this important problem and propose an algorithm to extract the optimal dimensionality for local tensor discriminant analysis. Experimental results on a toy example and real-world data validate the effectiveness of the proposed method. 相似文献
76.
77.
本文首先介绍了windows映像劫持的原理,对映像劫持进行了分析.同时根据笔者的日常工作经验总结除了一套比较完善的映像劫持防护方法,具有较强的针对性和实际意义. 相似文献
78.
79.
The study of the phase equilibrium characteristics of CO2-ionic liquids(ILs)as new absorption-compression type refrigeration working pairs is of great importance.Three kinds of ILs,i.e.,[emim][FAP],[bmim][FAP]and[hmim][FAP],were chosen as potential absorbents.The solubility of CO2in these ILs was measured experimentally within 0 to 5.0 MPa at temperatures of 293.15 K to 333.15 K,and the effects of temperature,pressure,IL anion and cation structure and stirring action on CO2solubility were also discussed and analyzed.The results showed that the longer alkyl chains in an identical IL family,the alkyl fluoride group in IL anions and the stirring action by a magnetic stirrer had positive effects on the solubility of CO2.In the three ILs,[hmim][FAP]possessed the best performance for CO2absorption;the solubility of CO2reached 0.7641 at a pressure of 5 MPa and temperature of 293.15 K,the maximum solubility measured in this work.The CO2-[hmim][FAP]binary mixture is recommended as a potentially applicable working pair for CO2absorption-compression refrigeration systems. 相似文献
80.
十二烷基多季铵盐Gemini型阳离子表面活性剂的合成 总被引:1,自引:0,他引:1
控制反应物乙二胺与环氧氯丙烷的配比,得到乙二胺与环氧氯丙烷的摩尔比分别为1∶5、1∶4、1∶1的产物。然后与自制十二烷基二甲胺进一步反应制备十二烷基多季铵盐Gemini型阳离子表面活性剂,反应条件是:反应温度60℃;反应时间1h;反应溶剂、水和乙醇的混合溶剂。通过测定不同浓度下溶液的表面张力,得到其产物Ⅰ、Ⅱ的临界胶束浓度为0.05%(质量百分比)左右。说明产品具有很低的临界胶束浓度和较好的表面活性。进一步的实验证明:合成产物具有较好的发泡力、稳泡力和金属腐蚀的抑制性能,并考察了其与阴离子表面活性剂的复配性能。 相似文献