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排序方式: 共有271条查询结果,搜索用时 15 毫秒
1.
L. Ya. Karachinsky T. Kettler N. Yu. Gordeev I. I. Novikov M. V. Maximov Yu. M. Shernyakov N. V. Kryzhanovskaya A. E. Zhukov E. S. Semenova A. P. Vasil’ev V. M. Ustinov N. N. Ledentsov A. R. Kovsh V. A. Shchukin S. S. Mikhrin A. Lochmann O. Schulz L. Reissmann D. Bimberg 《Semiconductors》2005,39(12):1415-1419
Lasers based on InAs/InGaAs quantum dots grown on metamorphic (In,Ga,Al)As layers deposited by MBE on GaAs substrates exhibited emission near 1.5 μm with a differential quantum efficiency of about 50%. The narrow-stripe lasers operate in a single transverse mode and withstand continuous current density above 20 kA cm?2 without significant degradation. A maximum continuous-wave output power of 220 mW is obtained. Neither current nor beam filamentation was observed up to the highest pumping levels. 相似文献
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N. A. Cherkashin M. V. Maksimov A. G. Makarov V. A. Shchukin V. M. Ustinov N. V. Lukovskaya Yu. G. Musikhin G. E. Cirlin N. A. Bert Zh. I. Alferov N. N. Ledentsov D. Bimberg 《Semiconductors》2003,37(7):861-865
The effect of the growth temperature on the density, lateral size, and height of InAs-GaAs quantum dots (QD) has been studied by transmission electron microscopy. With the growth temperature increasing from 450 to 520°C, the density and height of QDs decrease, whereas their lateral size increases; i.e., the QDs are flattened. The blue shift of the photoluminescence line indicates decreasing QD volume. The observed behavior is in agreement with the thermodynamic model of QD formation. The effect of lowering the substrate temperature immediately after the formation of QDs on the QD parameters has been studied. On lowering the temperature, the lateral size of QDs decreases and their density increases; i.e., the parameters of QD arrays tend to acquire the equilibrium parameters corresponding at the temperature to which the cooling is done. The QD height rapidly increases with cooling and may exceed the equilibrium value for a finite time of cooling, which enables fabrication of QD arrays with a prescribed ratio between height and lateral size by choosing the time of cooling. 相似文献
5.
A. I. Grigor’ev D. F. Belonozhko S. O. Shiryaeva S. I. Shchukin 《Technical Physics Letters》1997,23(11):831-832
This paper shows that, in an electrostatic field normal to the flat interface of two viscous electrically conductive liquids,
an oscillatory instability of the interface with periodically increasing amplitude can be produced when the electrical conductivity
of the upper liquid is substantially greater than that of the lower one. Results are obtained by numerical analysis of the
dispersion equation.
Pis’ma Zh. Tekh. Fiz. 23, 32–36 (November 12, 1997) 相似文献
6.
Scientific-Research and Design Institute of Electrical Engineering, Special Office of Machine Design. Translated from Atomnaya
énergiya, Vol. 79, No. 4, pp. 304–306, October, 1995. 相似文献
7.
V. Yu. Shchukin 《Problems of Information Transmission》2016,52(4):329-343
We obtain bounds on the rate of (optimal) list-decoding codes with a fixed list size L ≥ 1 for a q-ary multiple access hyperchannel (MAHC) with s ≥ 2 inputs and one output. By definition, an output signal of this channel is the set of symbols of a q-ary alphabet that occur in at least one of the s input signals. For example, in the case of a binary MAHC, where q = 2, an output signal takes values in the ternary alphabet {0, 1, {0, 1}}; namely, it equals 0 (1) if all the s input signals are 0 (1) and equals {0, 1} otherwise. Previously, upper and lower bounds on the code rate for a q-ary MAHC were studied for L ≥ 1 and q = 2, and also for the nonbinary case q ≥ 3 for L = 1 only, i.e., for so-called frameproof codes. Constructing upper and lower bounds on the rate for the general case of L ≥ 1 and q ≥ 2 in the present paper is based on a substantial development of methods that we designed earlier for the classical binary disjunctive multiple access channel. 相似文献
8.
A. M. Nadtochiy W. Hofmann T. D. Germann S. A. Blokhin L. Ya. Karachinskiy M. V. Maximov V. A. Shchukin A. E. Zhukov D. Bimberg 《Semiconductors》2013,47(5):695-700
The high-frequency electrical properties of a vertical-cavity surface-emitting laser with a monolithically integrated electro-optical modulator are studied using small-signal modulation analysis of the electroreflectance. The experimental data obtained are approximated using the suggested equivalent electrical circuit, which accounts for the formation of a nonequilibrium space charge in the carrier-depletion region of the modulator. The bandwidth of the high-frequency electrical-signal transfer to the electro-optical region, determined for the suggested equivalent electrical circuit of the modulator, is shown to be 3GHz. 相似文献
9.
Sytschev A. E. Vadchenko S. G. Shchukin A. S. Boyarchenko O. D. 《Inorganic Materials》2021,57(7):683-686
Inorganic Materials - We have studied the structuring of combustion products in the Ti–Al system upon interaction with carbon fibers during self-propagating high-temperature synthesis. The... 相似文献
10.
M. Strassburg R. Heitz V. Türck S. Rodt U. W. Pohl A. Hoffmann D. Bimberg I. L. Krestnikov V. A. Shchukin N. N. Ledentsov Zh. I. Alferov D. Litvinov A. Rosenauer D. Gerthsen 《Journal of Electronic Materials》1999,28(5):506-514
We report on structural and optical investigations of submonolayer-CdSe/ZnSe superlattices with varying thicknesses of the ZnSe spacer layers. High-resolution electron microscopy images demonstrate the formation of two-dimensional nanoscale CdSe islands for submonolayer-CdSe depositions. The vertical island arrangement is anti-correlated for spacer layer thicknesses exceeding 30Å, while predominantly vertically correlated growth occurs for thinner spacers. The different vertical ordering of the CdSe islands results in two clearly distinguishable lines in photoluminescence and optical reflectance spectra, which are attributed to excitons localized in quantum dots (QDs) formed by vertically coupled and uncoupled (Cd,Zn)Se islands, respectively. δ-like emission of single QDs is demonstrated and the different carrier localization in uncoupled and coupled QDs is reflected in the polarization of the edge emission. Stimulated emission and resonant waveguiding effects are observed for both states. At the highest excitation densities, we observe saturation of the stimulated emission in edge geometry attributed to saturation of localized states. 相似文献