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1.
利用核反应堆产生的裂变重离子碎片辐照固体薄膜,是生产核孔膜的主要方式之一。为优化反应堆核孔膜生产工艺参数,应用Geant4模拟计算了热中子辐照铀靶的出射裂变碎片数据,并基于ROOT搭建了核孔膜生产可视化分析平台。平台基于裂变碎片数据开展核孔膜生产过程模拟及分析,并将分析结果可视化展示。平台可分析计算膜厚度、孔隙率、连孔率等关键产品参数,从理论上指导准直角度、入射粒子密度等生产工艺参数。该平台可作为反应堆核孔膜生产中优化工艺参数的辅助工具。  相似文献   

2.
本文报道了聚乙烯对苯二酸酯固体核径迹探测器对裂变碎片记录性能的实验过程,并在改变温度,腐蚀时间和腐蚀液浓度等条件下测量了裂变碎片径迹的平均直径的变化,实验结果表明,腐蚀液温度的变化对裂变碎片径迹的影响最灵敏;而浓度和时间的变化对裂变碎片径迹的影响不大,同时用低能^16O重离子辐照PETP探测器。  相似文献   

3.
北京HI-13串列静电型加速器提供的32S离子辐照聚对苯二甲酸乙二醇酯(PET)膜,采用主峰波长为365 nm的紫外光灯对辐照过的PET膜的正反面敏化3 h,用电导法制备不同孔型的核孔膜。分别在室温(15℃)、干冰冷却(-78℃)、液氮冷冻(-196℃)条件下,制得核孔膜剖面的扫描电子显微镜样品。结果表明,温度越低,膜的塑性大幅降低且脆化程度增加。液氮冷冻条件下,薄膜不与液氮发生反应且断裂时伸长率大幅度降低。扫描电子显微镜观察结果表明,液氮冷冻后制得的截面残余形变最小,从而很好地反应了核孔膜孔道内部的形状、尺寸等特征。  相似文献   

4.
为了得到优质的亚微米孔径PET微孔膜的生产方法,为它投入实际应用奠定基础,采用被中国原子能科学研究院HI-13串列加速器产生的32S轰击过的聚对苯二甲酸乙二醇酯薄膜,薄膜放置在空气中陈化三个月,在模拟生产条件下利用自主设计加工具有高精度温控的小型生产蚀刻装置,使用NaOH溶液对薄膜进行蚀刻处理,制备出孔径0.2至0.93μm的重离子微孔膜。研究添加表面活性剂和紫外线敏化以及蚀刻时间对孔型的影响。结果表明,紫外线敏化可以减小微孔锥角,紫外线敏化后再添加表面活性剂蚀刻可以消除孔锥角。在蚀刻出平均孔径为0.2至0.93μm核孔膜的前提下,得到了孔锥角与随着时间增加的变化趋势。  相似文献   

5.
利用磁控溅射法在玻璃基片上进行了太阳能电池预镀层Mo薄膜的制备,研究了氩气分压、溅射功率、溅射时间等工艺条件对Mo膜性能及厚度的影响,并对Mo膜的物理性能及电学性能进行了研究.结果表明,Mo薄膜的厚度与溅射时间近似的成正比关系,Mo膜的电阻率先降低,并在膜厚为0.3 μm处达到最低,而后电阻率逐渐增加.  相似文献   

6.
在室温条件下,用直流磁控溅射Cu靶制备出了不同厚度的Cu膜,测量了Cu膜的光学透过率和面电阻,分析了光电性质薄膜厚度的变化情况.实验结果表明,随着Cu膜厚度的增加,其光学透过率逐渐减小,透过率在波长为580nm处出现峰值.Cu膜的面电阻随薄膜厚度的增加先急剧减小,然后减小变得缓慢,最后趋于定值.理论模拟了Cu膜的光学透过率随薄膜厚度的变化和光学透过率随入射光波长的变化,理论模拟结果与实验结果吻合.  相似文献   

7.
用PECVD法制备氮化硅介质薄膜 ,分析了沉积温度、本底真空度及气体流量比等工艺参数对氮化硅薄膜绝缘耐压性能的影响 ,制备出 0 .4 μm的性能良好的氮化硅介质绝缘膜  相似文献   

8.
为探究斑马鱼胚胎接受α粒子辐照剂量的计算方法,以模式生物斑马鱼为研究对象,使用能量为5.41 MeV的241Am为α粒子辐照源对受精后5 h脱绒毛膜的胚胎进行辐照处理,以12 μm厚的聚酯迈拉膜为固体核径迹探测器,利用正交实验筛选迈拉膜化学蚀刻的最优蚀刻条件,用显微镜观测迈拉膜上的粒子径迹数量,并通过计算胚胎相关参数,计算得到5hpf斑马鱼胚胎受到的最大辐照剂量值。结果分析表明,12 μm厚的聚酯迈拉膜化学蚀刻的最佳条件是蚀刻液KOH浓度6 mol/L,温度60 ℃,蚀刻时间3 h,此时粒子径迹轮廓清晰,大小适中。辐照5 min后,斑马鱼胚胎受到的最大剂量为约8.59 mGy,剂量率为约1.7 mGy/min。  相似文献   

9.
采用非平衡分子动力学方法,基于优化的集成势函数COMPASS力场,预测了室温下(300K)硅纳米薄膜的热导率.模拟结果表明:厚度约4~10nm的硅薄膜的热导率在3.06~7.28 W/(m·K)范围,并且随着膜厚的增加而增大,表现出明显的尺度效应.在所计算的薄膜厚度范围内,硅纳米薄膜的热导率与薄膜厚度呈现近似线性变化的关系.应用气动理论对产生的尺度效应进行了初步的理论分析,当薄膜厚度在几纳米到十几纳米时,有效声子平均自由程与膜厚有关,不再等于体材料的平均自由程.同时也将本文的预测结果与其他研究者采用Stillinger-Weber势所进行的模拟结果进行了比较.为分子动力学方法在低维材料热物性方面的研究提供了有益的参考.  相似文献   

10.
对光催化沉积法(PCD)制备Pd膜进行了改进,使含有TiO2与Pd2 的悬浮液膜层在多孔陶瓷膜表面形成液体薄膜,该薄膜在紫外光直接照射下发生光催化还原反应,烧结后得到含TiO2及Pd晶种的超薄膜层,用化学镀修饰得致密Pd膜.采用SEM、EDAX方法对所制的Pd膜表征结果表明,Pd膜厚度为5~6 μm.在350~500 ℃和0.05~0.15 MPa下进行气体渗透实验,当温度为450℃时,H2渗透系数为4.07×10-6 mol/(m2·s·Pa),N2的渗透量检测不出,高温热循环测试表明该Pd膜致密且具有良好的热稳性.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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