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1.
本文用 H_2水冷毛细管真空紫外辐射源对 CsI/Ni/LiF 半透明真空紫外光阴极进行了测试研究,得出该光阴极的伏安特性曲线,光阴极厚度与光电发射关系;测出真空紫外辐射源的工作特性.通过测试与计算得出 CsI/Ni/LiF 半透明光阴极的量子产额,利用对照测试法指出该阴极具有良好的“日盲”效应.  相似文献   

2.
在不同的温度下烧结制备 Ni O靶 ,用射频磁控溅射法淀积 Ni O/ Ni81 Fe1 9双层膜 ,研究了不同的温度烧结 Ni O靶对 Ni O/ Ni Fe双层膜特性的影响 ,结果表明 ,使用不同的烧结温度制备的 Ni O靶溅射所得的 Ni O膜中 Ni的化学价态及其含量不同 ,进而影响 Ni O/ Ni81 Fe1 9双层膜的磁滞回线的矩形度及层间交换耦合作用  相似文献   

3.
长波红外宽光谱长波通滤光片是光谱成像技术中重要的光学元件。论述了设计长波红外宽光谱长波通滤光片的设计原则和方法,并对这种长波红外宽光谱长波通滤光片优化设计进行了研究。根据等效折射率理论,以周期性对称膜系为基础,使用压缩透射区内波纹幅度的部分膜层优化方法,设计了满足性能指标要求的长波红外长波通滤光片。经过优化,所设计的长波红外宽光谱长波通滤光片,高透射波段内平均透射率大于90%,最低透射率高于85%;截止波段内平均透射率小于1%,最高透射率低于5%。研究表明,用部分膜层优化方法设计的膜系,膜层结构简单,有利于膜层厚度的监控,既能克服全自动优化方法给工艺上带来的困难,又弥补了解析法设计膜系时不能调整光谱特性的不足。  相似文献   

4.
研究Ni/ZrO2催化剂对水蒸气重整甲烷制合成气的催化性能.研究表明,当Ni负载量低于10%(质量分数)时,催化剂活性随Ni负载量增加而增大,Ni负载量大于10%后,反应温度为1 073 K时,CH4转化率逐渐接近其热力学平衡值.用Ni或NiO的纳米粉体机械混合法制得的Ni ZrO2催化剂,因Ni纳米微晶发生部分团聚,催化剂活性相对于浸渍法制备的Ni/ZrO2低.  相似文献   

5.
采用钙钛矿型管式致密透氧膜反应器,在Ni/Al2O3催化剂上进行了甲烷部分氧化制合成气的实验研究,考察了进料气中甲烷的摩尔分数和反应温度对反应结果的影响,并对膜在反应条件下的稳定性作了分析.  相似文献   

6.
目的 研究成膜电位、温度和氯离子等对X80管线钢在1 mol/L NaHCO3/0.5 mol/L Na2CO3缓冲溶液中所形成的钝化膜的电化学性能的影响.方法 利用电化学阻抗谱技术研究了X80管线钢在1 mol/L NaHCO3/0.5 mol/L Na2CO3缓冲溶液中所形成的钝化膜的电化学性能.结果 随着成膜电位的增加,传递电阻R1减小,而膜电阻R2和扩散阻抗YW增加,表明膜的致密性增加;成膜温度升高,传递电阻R1、膜电容Q2和膜电阻.尺2减小,说明膜的致密性减小;同一温度下增加溶液中的氯离子浓度,传递电阻R1、膜电容Q2和膜电阻R2:均减小;在同一氯离子浓度下升高温度,传递电阻R1、膜电容Q2:和膜电阻R2:均减小.结论 成膜电位、成膜温度和氯离子会对钝化膜的电化学性能产生显著的影响.  相似文献   

7.
把4个直径5cm的复合晶体探测器(NaI/BaF_2,NaI/BGO,NaI/CsI和NaI/NaI)用气球载至36km高空,观测了它们的本底水平。无论是在符合或反符合状态工作,4个复合晶体探测器主晶体的积分计数率基本一致。NaI/BGO探测器的计数率微分谱低于NaI/CsI和NaI/NaI探测器的相应值;NaI/BaF_2探测器的符合计数率微分谱低于NaI/CsI和NaI/NaI,而反符合计数率微分谱不高于NaI/CsI和NaI/NaI的相应值。  相似文献   

8.
为了提高钛-钢复合板界面结合强度,本文提出在钛-钢之间加入Ni箔作为过渡层,采用真空轧制方法制备TA1-Ni-Q235复合板,研究了Ni中间层厚度及轧制温度对复合板组织及结合强度的影响。实验结果表明,Ni中间层可有效阻止Ti-Fe和TiC化合物生成,随着Ni中间层厚度增加,阻止C元素扩散作用加强,界面结合强度提高;随着轧制压下率的增加,界面结合强度提高;随着轧制温度的提高,界面化合物层厚度增加,界面结合强度下降,其中,Ti-Ni界面处形成Ti2Ni和TiNi化合物。  相似文献   

9.
为研究Cu/Ni多层膜的调制波长与力学性能的关系,采用计算机控制的单槽双脉冲控电位沉积系统,在Cu基体上沉积Cu/Ni多层膜,分别采用扫描电镜和纳米压痕技术对Cu/Ni多层膜的截面和硬度进行了测试.结果表明:电沉积方法制备的Cu/Ni多层膜具有良好的周期结构;在调制波长为37 nm时硬度达到极值;在调制波长小于37 nm时其硬度值明显下降.实验结果符合理论分析中多层膜的硬度随调制波长的变化规律,但临界调制波长大于理论计算结果.  相似文献   

10.
用静电自组装的方法在长周期光栅的表面制备了聚二甲基二烯丙基氯化铵/聚苯乙烯磺酸钠(PDDA/PSS)膜,并研究了它们对空气中湿度的响应。实验结果表明,随着空气绝对湿度的增加,长周期光栅传输谱的谐振峰波长逐渐向长波方向移动,在25~45℃范围内,饱和蒸气压与谐振峰波长呈现了很好的线性关系,相关系数为0.9727。涂覆PDDA/PSS膜的长周期光栅能感受空气中水蒸气的含量,有望用于制作湿度传感器。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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