共查询到20条相似文献,搜索用时 15 毫秒
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V. F. Vazhov V. M. Muratov S. Yu. Datskevich M. Yu. Zhurkov R. R. Gafarov 《Physics of the Solid State》2013,55(4):725-729
The electric strength of rocks (granite, limestone, and sandstone) for the first time has been measured under the simultaneous effect of the pressure up to 35 MPa and temperature up to 120°C in the system of rod-rod electrodes arranged on one sample surface and point-plane electrodes in the liquid medium of a drilling agent. With the simultaneous increase in pressure and temperature, the electric strength of rocks for point-plane electrodes continuously increases (especially rapidly in the pressure range of 10–24 MPa and temperature range of 35–85°C), while for rod-rod electrodes arranged on the same sample surface, the electric strength varies with a maximum at pressures of 5–12 MPa and temperatures 20–35°C. 相似文献
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Molecular dynamics simulations are used to investigate the shape and structure evolution of single platinum clusters of cubic and spherical shape containing 256 and 260 atoms, respectively, deposited on a static graphite substrate. The evolution is monitored at variable temperature, and as a function of metal-substrate interactions at constant temperature. The Pt-Pt interactions are modelled with the many-body Sutton-Chen potential, whereas a Lennard-Jones potential is used to describe the Pt-C interactions. Heating and cooling curves calculated between 200 K and 1800 K are used to determine solid-solid and solid-liquid transitions. Structural changes are detected through analyses of density profiles and diffusion coefficients. A clear analogy is observed between temperature-induced wetting phenomena and those resulting from enhancement of the metal-substrate interactions. 相似文献
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基于半导体光放大器四波混频效应的多种调制格式的波长转换实验 总被引:1,自引:2,他引:1
实验报道了利用半导体光放大器(SOA)的四波混频(FWM)效应实现多种码型的波长转换.其中对于非归零(NRZ)信号实现了从单信道到三信道的多波长转换.调制速率从10 Gb/s到40 Gb/s均实现多波长转换.对于归零(RZ)信号分别实现了20 Gb/s和40 Gb/s的RZ格式的波长转换和40 Gb/s的载波抑制归零(CSRZ)格式的波长转换,利用光纤布拉格光栅(FBG)作为带陷滤波器消除共轭光和抽运光之间的串扰.对于非归零差分相移键控(NRZ_DPSK)信号分别实现了20 Gb/s和40 Gb/s的波长转换,利用实验室自制的光纤延时干涉仪进行NRZ-DPSK信号的解调.基于FWM效应的转换光的输出消光比大于7 dB,转换后消光比退化约为3 dB. 相似文献
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运用电化学循环伏安(CV)、原位FTIR反射光谱和电化学石英晶体微天平(EQCM)等方法研究了碱性介质中正丁醇在Pt电极表面吸附和氧化行为。结果表明:正丁醇电氧化过程与溶液酸碱性有着密切的关系。酸性介质中正丁醇在Pt电极上的CV曲线有2个正向氧化峰,而碱性介质中只有1个正向氧化峰, 第2个氧化峰的消失可能是由于碱性介质中Pt电极表面钝化引起的。原位FTIR反射光谱检测到,在实验条件下,碱性介质中正丁醇电氧化过程的最终产物只有丁酸根。EQCM研究还从电极表面质量定量变化的角度提供了正丁醇反应机理的新数据。 相似文献
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We report fabrication of low-dimensional structures in air by a pulsed laser on SiGe alloy samples in which different oxide structures are formed by laser irradiation and annealing treatment. The micro-structures on SiGe are more complex than those on Si. A series of photolumineseence (PL) emission is observed due to various trap states at the SiGe-SiO2 interface formed under different preparing conditions. The peak centre of PL emission exhibits red=shift from Si to SiGe because of narrower gap. A model for explaining the PL emission is proposed in which the trap states of the interface between some oxide and SiGe play an important role. 相似文献
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M. Manolova V. Ivanova D.M. Kolb H.-G. Boyen P. Ziemann M. Büttner A. Romanyuk P. Oelhafen 《Surface science》2005,590(2-3):146-153
In this study we describe details of a new technique that allows to deposit metal on top of a self-assembled monolayer (SAM). Monoatomic high platinum islands were formed on a 4-mercaptopyridine SAM on Au(1 1 1) by first immersing the SAM-covered gold electrode in an aqueous solution of K2PtCl4 without potential control to allow Pt(II) ions to form a complex with the pyridine nitrogen. The complexed Pt(II) ions were then reduced electrochemically to Pt(0) after transferring the electrode to a Pt(II) ion-free solution. Upon reduction, monoatomic high Pt islands were observed in STM, the total coverage depending on the time for complexation. Ex situ angle-resolved XPS studies reveal that the Pt islands indeed reside on top of the SAM. 相似文献
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常温常压下吡咯及其衍生物的镍催化加氢反应考察 总被引:1,自引:0,他引:1
为进一步研究常温常压下及其衍生物的镍催化加氢反应,我们对试剂吡咯、吡咯烷和吡咯烷酮做了相应的催化加氢实验。并采用电镜(TEM-HREM)、X射线衍射(XRD)对Ni基催化剂的形貌、结构、加氢活性和超声波对其影响进行了检测,同时不用紫外吸收光谱、气相色谱等对加氢产物进行了分析考察。结果表明超声波能促进镍催化剂活性,使镍微晶(111)晶面间距增大1.5%,并保持高分状态。常温常压下纳米镍基催化剂对吡咯、吡咯烷和吡咯烷酮的加氢反应显示一定的催化活性;吡咯加氢首先生成吡咯烷,进而使环打开生成低碳烃、氨等产物,总反应为零级,符合表面接触反应特征。 相似文献
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Conditions for the electric breakdown of the accelerating gap of a plasma electron source are determined. It is shown that, depending on the gas pressure and the size of openings in the emission electrode, two types of breakdown can occur. One of them is due to the ignition of a low-voltage discharge between the electrodes of the accelerating system, and the other one is caused by switching of the main discharge from the anode to the accelerating electrode. 相似文献
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利用循环伏安法研究了酸性介质中甲醛在粗糙铂电极上电氧化行为 ,考察了支持电解质浓度 ,电极表面结构等因素对甲醛氧化行为的影响 ,发现了甲醛在粗糙铂电极上的自发解离现象。采用共焦显微拉曼技术研究了甲醛在粗糙铂电极上解离吸附行为 ,获得了甲醛在该电极表面解离吸附的分子水平信息 ,并且从分子水平验证了甲醛在粗糙铂电极上的自发解离现象。 相似文献
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Journal of Experimental and Theoretical Physics - In honor of Igor Dzyaloshinskii on his 90th birthday, we revisit his pioneering work on the linear magnetoelectric effect in light of the modern... 相似文献
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A solution is found for the electric field in the boundary layer of a spherically symmetric two-component (solid-liquid) system. The establishment of polarization is taken into account.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 34–37, November, 1970. 相似文献