不同运动干预方法对青少年反应能力的影响研究

目的:研究青少年学生反应能力的影响因素,为运动选材提供可靠的参考依据,探寻青少年提高反应能力的体质健康运动方法和模式。方法:通过对西南地区(重庆市)10所学校的青少年进行为期10周的干预实验。结果表明:青少年反应时特点与其生长发育的生理规律相一致,年龄越小的简单反应时越快,选择反应时越慢;不同性别的反应时在9岁以下差异不显著,到9岁以后女生简单反应时比男生快很多且差异非常显著,而选择反应时则相反。结论:参与运动锻炼对反应能力的提高有显著作用;有三种不同的运动干预实验模式在不同年龄段中对反应时缩短有积极影响。     

论罗宾逊的“翻译身体学”理论

道格拉斯·罗宾逊是活跃在译界的一位重要翻译理论研究者,他在其著作《译者登场》中提出了＂翻译身体学＂这一理论,揭示在翻译过程中普遍存在的身体反应,并将其进一步划分为＂个人身体学＂和＂意识形态身体学＂两个方面。罗宾逊的＂翻译身体学＂理论使翻译成为了一个由身体主宰的动态过程,有力地说明了翻译是译者从事的一种创造性活动。     

酸变性微孔淀粉的制备工艺研究

微孔淀粉是具有重大应用价值的新型变性淀粉,根据淀粉酸变性的反应机理,采用一次回归正交试验,研究了硫酸用量、反应温度、反应时间、尿素用量等因素对酸变性微孔淀粉性能的影响,并用红外光谱对产品的结构进行了表征。以产品对酶变性微孔淀粉样品的流度偏差为指标,得到了酸法制备微孔淀粉的最优化工艺条件：5％的稀硫酸用量为2mL/g淀粉,反应温度为40℃,反应时间为4h,尿素用量为0．75g／g淀粉。     

实验研究设计中变量的分析与控制

任何一个科学的实验结论都是从实验中变量所表现出来的数量、质量或状态的事实中推导或分析出来的。变量是实验研究的基本单位也是资料分析和收集的依据。文章在对生物学实验中常见的变量进行详尽分析的基础上,以新教材中典型的生物学实验案例阐释实验中变量的调控方法主要有单因子变量法、对照实验法、平行重复法,以期对生物学的实验研究设计具有很好的促进作用。     

Synthesis of Ca2 ZnSi2O7:Eu phosphor by a modified solid-state reaction and its luminescent properties

This paper reports the detailed preparation and phosphorescence properties of Eu2+-activated Ca2 ZnSi2O7 phosphors by a modified solid-state reaction. Phase-pure crystalline Ca2ZnSi2O7 is obtained at 600℃, a much lower temperature than by conventional solid-state reaction and the preparation process of Ca2ZnSi2O7 is simple. The obtained phosphors showed three emission peaks at 480,580 and 620 nm,respectively. Auxiliary activator R3+(R=Dy, Nd, Tm) would enhance their luminescent properties.     

生物模板法制备纳米羟基磷灰石及其结构研究

利用田螺厣片作为生物模板制备纳米羟基磷灰石,并与纯水体系下制备的纳米羟基磷灰石进行对照研究,利用傅里叶变换红外光谱仪、透射电子显微镜和X射线衍射仪对产物进行表征,结果表明:纯水体系所得为刺球状的羟基磷灰石,其直径平均为50nm,而田螺厣片的诱导作用可形成棒状纳米羟基磷灰石,且其结晶度更好,并对其形成机理作初步探讨。     

硒-高分子复合微球的微凝胶模板法制备研究

采用反相悬浮聚合法合成了聚丙烯酰胺（PAM）高分子微凝胶,以其为模板,在室温条件下,以硒代硫酸钠（Na2SeSO3）作为硒源,制备得到了Se—PAM无机-有机复合微球材料,利用扫描电子显微镜（SEM）、X射线衍射（XRD）等手段对复合微球的形貌、无机物硒晶形结构等进行了表征。     

异戊二烯和OH反应机理的理论研究

利用多体微扰理论方法计算了羟基和异戊二烯反应通道,在MP2／6-31G（d,P）的水平上优化了反应物,中间体,过渡态,产物的几何构型和谐振频率。并在QCISD／6-31G（d,p）的理论水平下进行了单点能计算,计算表明：异戊二烯与OH反应时,碳碳双键的末端碳原子与羟基加成反应是主要的反应通道,而其它的是次要通道。     

Reaction thrust characteristics of high-pressure submerged water jet of cylinder nozzles

The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. The simulation of the flow field characteristics was conducted via the FLUENT computational fluid dynamics package. Effects of the inlet conditions and the nozzle dimensions on the reaction thrust of a water jet were addressed particularly. The reaction thrust experiments were performed on a custom-designed test apparatus. The experimental results reveal that a） the nozzle diameter and the inlet conditions exert great influence on the water jet reaction thrust; and b） for L≤4d0, where the nozzle is treated as a thin plate-orifice, the reaction thrust is independent of nozzle length; for L〉4d0, where the nozzle is treated as a long orifice, the reaction thrust can reach maximum under the condition of a certain flow rate. These findings lay a theoretical foundation for the design of nozzles and have significant value, especially for the future development of high-oressure water-let orooulsion technology.     

Reaction thrust of water jet for conical nozzles

Clear knowledge on the reaction thrust of water jet is valuable for better design of water jet propulsion system. In
this paper, theoretical, numerical and experimental studies were carried out to investigate the effects of the nozzle geometry
as well as the inlet conditions on the reaction thrust of water jet. Comparison analyses reveal that the reaction thrust has a
direct proportional relationship with the product of the inlet pressure, the square of flow rate and two-thirds power exponent
of the input power. The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence
on the reaction thrust characteristics. In addition, the best values of the half cone angle and the cylinder column length exist
to make the reaction thrust reach its maximum under the same inlet conditions．