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61.
Tokuda T. Sakano Y. Mori D. Ohta J. Nunoshita M. Vaccaro P.O. Vorob'ev A. Kubota K. Saito N. 《Electronics letters》2004,40(21):1333-1334
A micromirror structure with SiGe/Si heteroepitaxial layer on a silicon-on-insulator (SOI) substrate using a 'Micro-origami' technique has been successfully fabricated. The micromirror is supported by two curved hinge structures. The device is driven by application of a current, and net angular displacements larger than 10/spl deg/ (static) and 30/spl deg/ (in resonance) were obtained. These values are comparable with or even larger than the reported values for other MEMS optical switches or beam scanning devices. The experimental results suggest that the movement is evoked by a thermal effect. The Micro-origami device has advantages of low operation voltage smaller than 2 V, and structural compatibility with the Si or SiGe LSIs. 相似文献
62.
Annealing effects of a high-quality ZnTe substrate 总被引:1,自引:0,他引:1
Kenji Yoshino Minoru Yoneta Kenzo Ohmori Hiroshi Saito Masakazu Ohishi Takayuki Yabe 《Journal of Electronic Materials》2004,33(6):579-582
The sharp photoluminescence (PL) and optical-reflection spectra in the bandedge region of the high-quality nondoped ZnTe substrate
(100) were observed at 4.2 K. Free exciton, associated with lower and upper polaritons (EXL and EXU) at 2.382 eV and 2.381 eV, respectively, were clearly observed. This meant that this substrate was high quality. The intensity
of a bound exciton peak (2.375 eV), which is caused by a Zn vacancy, of a neutral acceptor decreased with an increase of the
Zn vapor pressures. 相似文献
63.
Hirose T. Saito K. Kojima S. Yao B. Ohsono K. Sato S. Takada K. Ikushima A.J. 《Electronics letters》2007,43(8):443-445
Long-period fibre grating (LPFG) writing by a CO2 laser-annealing using a fibre-drawing process is demonstrated. The fibre in the drawing process was irradiated periodically by a CO2 laser to modify the refractive index. An LPFG with transmission loss of -10 dB and full width at half-maximum of 13 nm has been fabricated. Results show that the refractive index change was induced by stress at the moment of laser annealing 相似文献
64.
分别对日本三代移动通信系统的发展进行了描述。第一代系统致力于实现随时、随地的通话,第二代系统的特征是基于语音的附加服务、低速的移动计算、移动因特网和位置服务,第三代系统将以基于视频的全球范围内高速多媒体服务和移动IT为特征。在未来的后3G系统中,这些服务都将以虚拟永远在线的方式无缝、高速地普遍提供。 相似文献
65.
Zhi Jiang Kenjiro Fukuda Wenchao Huang Sungjun Park Roda Nur Md. Osman Goni Nayeem Kilho Yu Daishi Inoue Masahiko Saito Hiroki Kimura Tomoyuki Yokota Shinjiro Umezu Daisuke Hashizume Itaru Osaka Kazuo Takimiya Takao Someya 《Advanced functional materials》2019,29(6)
Flexible and stretchable organic photovoltaics (OPVs) are promising as a power source for wearable devices with multifunctions ranging from sensing to locomotion. Achieving mechanical robustness and high power conversion efficiency for ultraflexible OPVs is essential for their successful application. However, it is challenging to simultaneously achieve these features by the difficulty to maintain stable performance under a microscale bending radius. Ultraflexible OPVs are proposed by employing a novel metal‐oxide‐free cathode that consists of a printed ultrathin metallic transparent electrode and an organic electron transport layer to achieve high electron‐collecting capabilities and mechanical robustness. In fact, the proposed ultraflexible OPV achieves a power conversion efficiency of 9.7% and durability with 74% efficiency retention after 500 cycles of deformation at 37% compression through buckling. The proposed approach can be applied to active layers with different morphologies, thus suggesting its universality and potential for high‐performance ultraflexible OPV devices. 相似文献
66.
Numerical analysis of IM signal propagation in an optical fibre is carried out taking selfphase modulation and group-velocity dispersion into account. The transmission distance yielding a prescribed eye opening penalty, in the normal dispersion region, is shown to be inversely proportional to the square root of the signal power.<> 相似文献
67.
We examined the fine structure of the upper and lower surfaces of stratified squamous epithelial cells in the skin of frogs (Hyla japonica). SEM revealed the upper surface of superficial cells covered with ramified microridges (type 3). The width of the microridges was 0.20-0.24 microns. Microridges found at the cell boundary were about 0.30 microns in width and a narrow furrow was seen between the two cells. The numerous oval disk-like structures (0.23 x 0.32 microns in diameter) covered the lower surface of these superficial cells. The upper surface of cells in the 2nd layer was covered with baculiform or ramified microridges (type 2 or 3). On the cell boundary, two linear microridges (0.23-0.27 microns in width) were parallelly arranged. The width of the microridges covering the upper cell surface was 0.09-0.10 microns. Microvilli-like processes with a height of 0.32-0.37 microns were interspersed among the microridges. Their tip formed an oval plane (0.23 x 0.31 microns), which corresponded to the size of the disk-like structures on the lower surface of the superficial cells. Desmosomes were observed on the tip by TEM. These findings show that the disk-like structures on the lower surface of the superficial cells are the sites of binding with the microvilli-like processes on the upper surface of the 2nd layer cells. The disk-like structures observed in the present study seem to be equivalent to the binding site on the upper surface of the surface cell layer of mammalian stratified squamous epithelium. 相似文献
68.
Wladimir Bocquet Kazunori Hayashi Hideaki Sakai 《Wireless Communications and Mobile Computing》2009,9(12):1618-1628
In this paper, we propose several power allocation schemes for multi‐input multi‐output (MIMO) orthogonal frequency division multiplexing (OFDM) transmission based on the minimization of an approximated bit error rate (BER) expression, and we evaluate the different solutions via field trial experimentations. The methods illustrated in this paper, serve to allocate power among the different transmit antennas and the different subcarriers which compose the MIMO OFDM transmitted signal. Several solutions are available to perform power allocation. Frequency domain power allocation, spatial domain power allocation and combined spatial and frequency power allocation are evaluated. We first review and describe the analytical solution for each power allocation scheme and then evaluate the complexity in terms of both computational operations and BER performances. Simulation results show the performance in term of BER and link the advantage of each possibility of power distribution with the associated complexity. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
69.
Saito M. Yoshitomi T. Hara H. Ono M. Akasaka Y. Nii H. Matsuda S. Momose H.S. Katsumata Y. Ushiku Y. Iwai H. 《Electron Devices, IEEE Transactions on》1993,40(12):2264-2272
A p-MOSFET structure with solid-phase diffused drain (SPDD) is proposed for future 0.1-μm and sub-0.1-μm devices. Highly doped ultrashallow p+ source and drain junctions have been obtained by solid-phase diffusion from a highly doped borosilicate glass (BSG) sidewall. The resulting shallow, high-concentration drain profile significantly improves short channel effects without increasing parasitic resistance. At the same time, an in situ highly-boron-doped LPCVD polysilicon gate is introduced to prevent the transconductance degradation which arises in ultrasmall p-MOSFETs with lower process temperature as a result of depletion formation in the p+-polysilicon gate. Excellent electrical characteristics and good hot-carrier reliability are achieved 相似文献
70.