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排序方式: 共有710条查询结果,搜索用时 15 毫秒
1.
A technique is proposed for introducing microdoses (10?5–10?10 g) of germanium and indium metals into semiconductor compounds by coulometric titration in a solid electrolyte cell. The solid electrolytes that are reversible with respect to germanium cations (the GeSe-GeI2 system containing 5 mol % GeI2) and indium cations (the InCl3-MgCl2 system containing 15 mol % MgCl2, the InCl3-CdCl2 system containing 1.5 mol % CdCl2, and the In2S3-InCl3 system containing 5 mol % InCl3) are chosen, and their electric transport properties are characterized. The optimum conditions for electrochemical doping (temperature, current density), under which the current efficiency reaches 90–100%, are determined. The doping with germanium and indium is performed for nonstoichiometric compounds, such as lead monotelluride, indium sulfide, and ternary chalcogenide spinel Cd1 ± δCr2Se4. The doping efficiency is controlled by measuring the electromotive force of the corresponding electrochemical cells and the Hall effect, as well as using the electrical conductivity method. The solid electrolytes that are reversible with respect to indium are used to determine the standard Gibbs energies of formation of a number of indium-containing semiconductors. 相似文献
2.
Porous carbon nanofibers are synthesized by CVD method from acetylene with use of iron-containing catalysts. Activation of the nanofibers in melted potassium hydroxide results in increasing surface area from initial 300–400 m2 g−1 to 1700 m2 g−1. As follows from XRD data, activated nanofibers do not contain regular packages of graphene layers, but retain high electric conductivity. Deposition of copper improves electrochemical hydrogen storing characteristics of carbon nanofibers. Carbon nanomaterials obtained can be used as hydrogen storing materials in batteries instead of hydride forming metals. 相似文献
3.
The paper compares experimental and calculated pulse shapes and spectra of signals for bidirectional right transducers with radically different protectors, namely, those from epoxy glue with a filler and ceramic. The new data support the previously made conclusion (from calculated parameters of emitted pulses) that in protectors from composite materials (with low propagation velocities of longitudinal elastic waves) signal spectra can have several pronounced peaks, and their waveforms can exhibit beats (oscillating amplitude modulation). 相似文献
4.
A theoretical study is reported of the magnetic-field-controlled optical transmission through a stack of identical bilayers in which one layer is bigyrotropic and the other is nonmagnetic and isotropic. An analytical expression for the complex transmittance is derived. The transmittance–wavelength characteristic is examined for different magnetizations and for fixed materials parameters and total number of bilayers. The magnetization dependence of the position, height, and width of the center peak is investigated. The effect is calculated of magnetization on the ellipticity of transmitted light and the angle of optical rotation. 相似文献
5.
G. D. Zakumbaeva A. D. Gazizova A. V. Danilov R. I. Egizbaeva D. V. Sokol’skii 《Chemistry and Technology of Fuels and Oils》2007,43(5):408-410
A polyfunctional catalyst for hydrorefining of the catalytic naphtha cut with a high olefin content is proposed. This catalyst
induces isomerization and hydrogenation of olefins on contact with the feedstock with formation of isoparaffins, isomerization
of n-paraffins, hydrotreating to remove sulfur, and other processes. The naphtha obtained satisfies the Euro-4 standard (2005)
with respect to quality.
__________
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 5, pp. 35–3 6, September–October, 2007. 相似文献
6.
S. A. Panasenko V. I. Grishchuk N. N. Makarchenko F. I. Danilov 《Materials Science》1995,30(5):607-614
We analyze various possibilities for improving the anticorrosive properties of metallic coatings, including alloying, modification of the base (prior to coating), the choice of the optimum (for producing anticorrosive structures) conditions of electrolysis, the use of multilayer coatings (sandwich-type structures), and modification of coatings by depositing passive layers by high-energy treatment (laser, electron-beam, plasmachemical, etc.).Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 5, pp. 81–87, September – October, 1994. 相似文献
7.
V. N. Danilov 《Russian Journal of Nondestructive Testing》2005,41(6):340-344
The directivity characteristic of a normal probe with a circular piezoelectric plate has been calculated with allowance for pressure (elastic stress) oscillations within both the excitation region (the surface of the electrodes applied to the piezoelectric plate) and the plate itself, whose dimensions exceed those of the excitation region. It is established that, in the first and second cases, the directivity characteristics are somewhat wider and narrower, respectively, than those used in the conventional stepwise approximation of the pressure applied from a transmitting probe to the surface of a tested article. The effective piezoelectric-plate size is estimated. 相似文献
8.
The Monte Carlo method is used to simulate video signals from a scanning electron microscope in backscattered electrons from slit-like structures with a rectangular profile and widths of 0.1, 0.5, and 4.0 m.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 22–23, August, 1995. 相似文献
9.
Amir Yair Danilov Claudiu Dolev Danny Kirsch Jonathan Lane John Nita-Rotaru Cristina Olsen Josh Zage David 《Dependable and Secure Computing, IEEE Transactions on》2010,7(1):80-93
This paper presents the first hierarchical Byzantine fault-tolerant replication architecture suitable to systems that span multiple wide-area sites. The architecture confines the effects of any malicious replica to its local site, reduces message complexity of wide-area communication, and allows read-only queries to be performed locally within a site for the price of additional standard hardware. We present proofs that our algorithm provides safety and liveness properties. A prototype implementation is evaluated over several network topologies and is compared with a flat Byzantine fault-tolerant approach. The experimental results show considerable improvement over flat Byzantine replication algorithms, bringing the performance of Byzantine replication closer to existing benign fault-tolerant replication techniques over wide area networks. 相似文献