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1.
用自制的LaF3多晶粉末作固体电解质,分别以Pt黑,Au,Ag,Ni粉作敏感电极,以Sn/SnF2为参比电极制备半电池,研究其室温下对空气中少量氢的传感性。实验发现,20℃时以Pt黑为敏感电极的电池对空气中少量氢的响应很灵敏,最快响应时间为15s,且电动热与lnpH2服从能斯特定律,而以Au,Ag,Ni粉为敏感电极的同种电池室温下对空气中少量氢表现为惰性。  相似文献   

2.
选用Ni/Al2O3和PtSnK/Al2O3作为催化剂,分别研究了甲苯在低温(90~150℃)下的贮氢反应和甲基环己烷的释氢反应(考虑随车脱氢的反应条件)。结果表明,甲苯的低温贮氢容易实现,贮氢量主要由甲基环己烷的释氢量决定。在常压、温度为300~400℃、重时空速(WHSV)为6h-1等条件下,纯甲基环己烷进料时,其贮氢量为2.8%~6.1%.当甲基环己烷随车脱氢为汽车提供氢燃料时,应特别强调催化剂的低温活性和高温稳定性。改性的PtSnK/Al2O3比PtSn/Al2O3(3861)的催化剂稳定性可提高8倍以上,但低温活性无明显改善。  相似文献   

3.
治岭头金矿矿体主要赋存在中元古界陈蔡群变质岩系和上侏罗统磨石山组火山岩中。成矿元素组合为Au,Ag,Sr,Ti,Co,Sn,Mn,Li,V,Cr,W,Ga,Mn,Ni,Cu,Pb,Zn,Ba,Nb,Fe,S,Si,O等。蚀变带元素地球化学异常显示Au与Ag,Cu,Pb,Zn,Sn,Mn异常有较好的相关性。矿床成矿元素侧向综合分带系列为:Au,Ag,Zn,Cu,Pb,Mo,Sn,Cr,Co,Ni,Mn;成矿元素的地球化学演化为Si,Fe ̄(2+)→Fe ̄(2+),Pb,Zn,Cu,Au,Ag,Mn,Sn→Ca,Si,Cr,Co,Ni,Mn,Au是在约200~300℃时,由大量的黄铁矿和金属硫化物沉淀后络合物解离而停积成矿的。  相似文献   

4.
将Pt「111」电极分别浸在SnSO4、Sn(SO4)2、SnCL4溶液中,形成的Sn/Pt「111」修饰电极对甲醇氧化的催化效果不一样,当浸渍溶液为Sn(SO4)2a或SnCl4时,在较高电势(0.8V以上),Sn有提高Pt「111」电极的电催化活性,当浸渍溶液为SnSO4时,Sn却表现出阻碍作用,研究中还发现,吸附了Sn的Pt「111」电极灼烧后表现出的催化活性超过浸渍形成的Sn/Pt「111  相似文献   

5.
镍钨合金电沉积及其析氢电催化性能的研究   总被引:4,自引:0,他引:4  
本文研究以钛或铁为基体的Ni-W合金电镀,阴极极化曲线表明,以Ti为基体的Ni-W合金镀层为阴极,电解300g/LNaCl(25℃),3.0A/dm^2能降低析氢过电势420mV,电解1mol/L MnSO4+0.5mol/LH2SO4能降低810mV,说明Ni-W镀层是析氢的优良电催化阴极。  相似文献   

6.
基于甲苯与甲基环己烷可逆反应的贮氢技术   总被引:1,自引:0,他引:1  
选用Ni/Al2O3和Pt-Sn-K/Al2O3作为催化剂,分别研究了甲苯在低温下的贮氢反应和甲基环己烷的释氢反应。结果表明,甲苯的低温贮氢容易实现,贮氢量主要收甲基环己烷的释氢量决定。  相似文献   

7.
对电解工艺与Ni粉粒度和粒度组成的关系作了研究。结果表明:ρNi2+为3g/L时,粒度小于10.8μm的粉末可高达99.3%;电流密度为1500A/m2时,粒度为2.7~8.1μm的粉末占全部粉末的80%;随着(NH4)2SO4含量增大,Ni粉粒度变粗;电解液温度以40~50℃为佳;每次刷粉时间以20~30min为宜.  相似文献   

8.
为了改善气敏元件的性能,人们通常采用掺杂的方式以提高其灵敏度和选择性,该文将SnO2粉和Ag粉混合研磨,制成烧结型气敏元件,实验表明其对氢、乙醇的灵敏度有显著提高.  相似文献   

9.
研究了乙醇水溶液光催化脱氢中Ag对Pt/CdS的助催效应,最佳匹配量和制备顺序为Pt(3%)/Ag(1%)/CdS.应用脱附法,XPS和XRD等实验方法研究了助催机理。结果表明:Ag的助催作用包括化学效应-Ag的s,d电子向Pt对H2的脱附能,有利于产氢,及Ag的中介传递光生电子促进光生电子空穴对的分离;物理效应-Ag对Pt的集团分散作用减小了热处理时Pt的烧结降活,前者化学效应可能是主要的。  相似文献   

10.
本文论述循环伏安法(CV)中铂(Pt)对乙醇(EtOH)的定量吸附特性,及其对葡萄酒中EtOH测定的应用问题。用自制的Pt梳状工作电极。在0.1M的NaOH溶液中,EtOH的氧化峰电位为-240mV(相对Ag/AgCl参比电极)。以3σ背景值计,检出限为0.023%(V/V)。样品分析结果准确度为95.2-104.7%重现性范围2.8-3.1%RSD(n=8)。校准曲线的线性动态范围0.1-8%(  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.
<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   

20.
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