高性能混凝土配合比设计思考

通过分析高性能混凝土配合比和拌和材料的改变,说明了提高混凝土性能的具体方法和措施,从而使高性能混凝土具有良好的体积稳定性、高耐久性、高强度和高工作性能。     

生物科学课程体系的优化与教学改革探索

为实现新形势下人才培养的要求与目标,高等学校必须优化课程体系,改革教学模式.一个优化的课程体系主要包括教学模式的优化和课程内容的优化.因此,要构成优化的课程体系,必须进行教学模式的改革和教学内容的有机整合.     

离子径迹模板法制备纳米线

重离子辐照的高分子有机膜,经过适当的处理,可以作为模板制备金属和可溶性盐纳米线,此方法称为离子径迹模板法。介绍了用电化学沉积方法和过饱和溶液法制备金属纳米线和可溶性盐纳米线的基本原理和制各实例,同时还展望了离子径迹模板法制备纳米线的一些可能的应用。The polymer foils irradiated by heavy ions can be used as temptates to prepai nanowires and some inorganic salt nanowires. It is called ＂ion-track template method＂. Compared to other templates, such as AAO template and porous silicon, etched ion-track template is more convenient and flexible. The density of the pores can be easily controlled by changing the ion fluences and the diameter of the pores can be altered through changing the etching condition. The pores of the etched ion-track template are well aligned. We present some examples of preparing metallic nanowires and inorganic salt wires by electrochemical deposition and by supersaturation solution method, respectively. We also introduce some applications of nanowires prepared with ion-track template method.     

Synthesis and characterization of captopril derivatives

To develop more potential angiotensin converting enzyme (ACE) inhibitors, a series of captopril (Cap) derivatives were synthesized, including Cap-glycine methyl ester, Cap-l-alanine methyl ester, Cap-l-aspartic acid dimethyl ester, Cap-l-lysine methyl ester, Cap-O-acylisourea, acetyl captopril, and benzoyl captopril. The resulting products were characterized by IR and UV–visible spectroscopy and MS, which showed the desired products were successfully synthesized. This could serve as a guide for rational design of highly potent ACE inhibitors.     

退火对电弧离子镀制备的ZnO薄膜的影响

采用阴极电弧离子镀在Si、Al2O3以及玻璃衬底上制备出具有择优取向的ZnO薄膜,并对其进行退火处理.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、光致发光光谱(PL)、紫外-可见光光谱仪对ZnO薄膜的结构、表面形貌和光学性能进行分析.XRD结果表明,所制备的ZnO薄膜具有很好的ZnO(002)择优取向,退火使ZnO(002)衍射峰向高角度方向偏移.SEM结果表明,随着退火温度升高,表面晶粒由隆起的山脉或塔状变为平面状,晶粒002面呈六边状.PL谱结果表明,随着退火温度的升高,紫外发光峰强度逐渐增强,可见光发光峰强度逐渐相对减弱.紫外可见光透过谱结果表明,退火使可见光透过率增高,光学带隙发生红移.     

数据通信及其应用发展前景

数据通信是依照通信协议,利用数据传输技术在两个功能单元之间传递数据信息,它可实现计算机与计算机、计算机与终端以及终端之间的数据信息传递。本文介绍了数据通信的基本原理、交换方式及其优点、缺点、适用范围和分类,并展望了数据通信未来的应用前景。     

击实参数对砂土EPS颗粒混合轻质土的影响

为了明确击实参数对砂土EPS颗粒混合轻质土(LSES)物理力学性质的影响,利用室内试验研究了击实能量(击实一次的击实功)和击实次数对LSES物理力学性质的影响.结果表明:LSES的干密度、无侧限抗压强度、黏聚力、内摩擦角均随击实次数的增加而增加,增加速度由快逐渐减慢并逐渐趋于稳定;随着击实能量的增加也会增加,但增加速度不趋于稳定.根据室内试验结果总结了干密度和无侧限抗压强度的计算式.     

Fluorinated <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">n</Emphasis> type copolyfluorene as polymer electret for stable nonvolatile organic transistor memory device

In this study, a kind of fluorinated copolyfluorene, named poly[(4-(octyloxy)-9,9-diphenylfluorene-2,7-diyl)-alt-(2,3,5,6-tetrafluoro-1,4-phenylene)] (PODPF-TFP), is synthesized by facile palladium-based direct aromatization. Compared to the non-fluorinated counterpart, poly[(4-(octyloxy)-9,9-diphenylfluorene-2,7-diyl)-alt-(p-phenylene)] (PODPF-P), deeper HOMO/LUMO energy level combined with steric hindrance effect endow PODPF-TFP with excellent spectra and morphology stability. Finally, organic field-effect transistor (OFET) memory devices are fabricated with PODPF-P/PODPFTFP as the dielectric layers, and they both exhibit flash type storage characteristic. Owing to the electronegativity of fluorine atom, the device based on PODPF-TFP exhibits larger memory window and more stable I _on/I _off ratio during a retention time of 10⁴ s as well as a better aging stability. The present study suggests that fluorinated p-n copolyfluorene electrets could enhance the capabilities of charge trapping and storage, which are promising for OFET memory devices.     

利用ISM法分析网络协作探究学习的要素关系

文章利用系统论的基本观点,深入分析了网络协作探究学习的要素,并利用ISM结构解释模型法详细分析了网络协作探究学习的一般模型,从而给网络协作探究学习的开展和设计提供了理论依 .据.     

辐射板强化喷管换热与红外抑制效果试验研究

试验研究了在发动机喷管中加装金属辐射板前后,喷管壁面温度、热喷流温度与喷管红外辐射特征的变化。结果表明,加装金属辐射板后,热喷流与喷管壁面之间的热量传递显著增强,热喷流中心温度降低,壁面温度明显升高,在90°方向上,热喷流3～5μm波段的红外辐射强度降低了38.5%。文中从热喷流、喷管壁面以及金属辐射板等相关部件的温度变化情况对红外辐射强度的变化原因进行了解释。 