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991.
Quantum-mechanical modeling of electron tunneling current from the quantized inversion layer of ultra-thin-oxide (<40 Å) nMOSFET's is presented, together with experimental verification. An accurate determination of the physical oxide thickness is achieved by fitting experimentally measured capacitance-versus-voltage curves to quantum-mechanically simulated capacitance-versus-voltage results. The lifetimes of quasibound states and the direct tunneling current are calculated using a transverse-resonant method. These results are used to project an oxide scaling limit of 20 Å before the chip standby power becomes excessive due to tunneling currents, 相似文献
992.
PR Carlier MM Lo PC Lo E Richelson M Tatsumi IJ Reynolds TA Sharma 《Canadian Metallurgical Quarterly》1998,8(5):487-492
Mortality data for B6CF1 mice exposed to 60Co gamma rays for the duration of life were used to make quantitative predictions of age-specific mortality observed in comparably exposed beagles. Simple Kaplan-Meier survival curves for the beagles and their 95% confidence intervals were computed for each dose-rate group observed. A dose-response equation was estimated from the mortality data for mice using a proportional hazard model. The dose-response model for mice was then used to generate predicted survivorship curves at dose rates that would recreate the dose burdens observed in the beagle at comparable points within the life span of the two organisms. When these predicted survivorship curves were scaled to adjust for species differences in the life span of control animals, the predictions for the mouse fell within the confidence intervals observed for the beagle. The successful interspecies extrapolation of age-specific mortality risks for species as different as the mouse and dog enhances both the value of studies involving laboratory animals and the potential relevance of the animal studies to the prediction of health effects in humans. 相似文献
993.
In this work, a new order-8 dyadic transform (DT) is developed for image compression. Implementation of DT is very simple that it can be computed using a fast algorithm with operations of addition and binary shift only. Various evaluations show that the performance of the new transform is very close to DCT and there is a certain degree of compatibility between DCT and DT. 相似文献
994.
C Lo Cunsolo I Casciano B Banelli GP Tonini M Romani 《Canadian Metallurgical Quarterly》1998,82(3-4):199-201
We report the identification of a mouse cDNA Tpd52l1 (tumor protein D52-like 1), which represents the first demonstrated orthologue of the human TPD52L1 (alias D53) gene, a member of the breast carcinoma-associated TPD52 (alias D52) gene family. In situ hybridization mapping located the Tpd52l1 gene to chromosome 10A4-10B2. Since the TPD52L1 gene is found at human chromosome 6q22-->q23, the mouse and human TPD52L1 loci are syntenically conserved. 相似文献
995.
Fractal modeling and segmentation for the enhancement of microcalcifications in digital mammograms 总被引:3,自引:0,他引:3
The objective of this research is to model the mammographic parenchymal and ductal patterns and enhance the microcalcifications using a deterministic fractal approach. According to the theory of deterministic fractal geometry, images can be modeled by deterministic fractal objects which are attractors of sets of two-dimensional (2-D) affine transformations. The iterated functions systems and the collage theorem are the mathematical foundations of fractal image modeling. Here, a methodology based on fractal image modeling is developed to analyze and model breast background structures. The authors show that general mammographic parenchymal and ductal patterns can be well modeled by a set of parameters of affine transformations. Therefore, microcalcifications can be enhanced by taking the difference between the original image and the modeled image. The authors' results are compared with those of the partial wavelet reconstruction and morphological operation approaches. The results demonstrate that the fractal modeling method is an effective way to enhance microcalcifications. It may also be able to improve the detection and classification of microcalcifications in a computer-aided diagnosis system. 相似文献
996.
Random sampling is one of the methods that can overcome the Nyquist limit when evaluating a frequency spectrum of a signal. However, the computational complexity becomesN
2 as the FFT cannot be used. A new approach, called hybrid additive random sampling, is proposed. This new scheme is devised by concatenating random sampling sequences in such a way that symmetry is created in the transform kernel for reducing the computational effort while the anti-alias property is maintained. A savings of the least 75% in computation is achieved. The sampling scheme is also found to be suitable for parallel implementation. In this paper, the algorithms for generating the sampling sequence and evaluating the spectrum are described in detail. The performances of the scheme in terms of noise, accuracy, etc., are compared with genuine random sampling and another approach proposed previously. The advantages and limitations are included. 相似文献
997.
998.
Interference detection and mitigation in global navigation satellite systems (GNSSs) are important issues for both military and civilian applications. In this paper, a novel time-frequency algorithm for GNSS application is proposed. The use of infinite impulse-response notch filters for the interference excision is introduced and analytical formulas for the detection of the disturbing signals are derived. The proposed method is tested by simulations and compared with time-frequency excision algorithms reported in literature, proving its effectiveness for interference removal. 相似文献
999.
R Simantov JM LaSala SK Lo AE Gharavi LR Sammaritano JE Salmon RL Silverstein 《Canadian Metallurgical Quarterly》1995,96(5):2211-2219
Circulating antiphospholipid antibodies (aPL) are associated with a syndrome of thrombosis, recurrent fetal loss, and thrombocytopenia. We have demonstrated the activation of cultured human umbilical vein endothelial cells (HUVEC) by IgG from patients with anticardiolipin antibodies (aCL). Incubation of HUVEC for 4 h with purified IgG (100 micrograms/ml) from patients with high-titer aCL induced a 2.3-fold increase in monocyte adhesion over that seen in HUVEC incubated with IgG's from normal subjects. The effect of aCL was not attributable to LPS contamination, Fc receptors, or immune complexes. Monocyte adhesion was not induced when the aCL were added in serum-free media but was restored by the addition of purified beta 2GP1, previously described as a necessary cofactor for aCL reactivity. Purified rabbit polyclonal IgG raised against beta 2GP1 also induced monocyte adhesion when incubated with HUVEC. Preadsorption of patient serum with cardiolipin reduced monocyte adhesion by 60%. Immunofluorescent microscopy demonstrated that endothelial cells incubated with patient IgG expressed cell adhesion molecules, including E-selectin, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1. These data support the hypothesis that aPL activate vascular endothelial cells, thereby leading to a pro-thrombotic state. 相似文献
1000.
Tien-Yu Lo Chung-Chih Hung 《IEEE transactions on circuits and systems. I, Regular papers》2008,55(1):246-253
A configuration of a linearized operational transconductance amplifier (OTA) for low-voltage and high-frequency applications is proposed. By using double pseudodifferential pairs and the source-degeneration structure under nano-scale CMOS technology, the nonlinearity caused by short channel effect from a small feature size can be minimized. A robust common-mode control system is designed for input and output common-mode stability and thus reduces distortion caused b y common-mode voltage variation. Tuning ability can be achieved by using MOS transistors in the linear region. The linearity of the OTA is about -60-dB third-order inter-modulation (IM3) distortion for up to 0.9 Vpp at 40 MHz. This OTA was fabricated by the TSMC 180-nm deep n-well CMOS process. It occupies a small area of 15.1times10-3 mm2 and the power consumption is 9.5 mW under a 1.5-V supply voltage. 相似文献