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991.
Changes in biochemical properties of myofibrillar proteins of rabbit muscle, which had been subjected to electrical stimulation soon after slaughter, during postmortem storage at 0°C were investigated. Myofibrillar ATPase activity and the ATPase activity of acto-heavy meromyosin (HMM) complex, reconstituted from actin and HMM which had been prepared from at-death and postmortem muscles, decreased at first and then increased slightly during 7 days storage. In addition, the change of the dissociation constant of acto-HMM complex of electrically stimulated muscle during postmortem storage was quite small, i.e., 1.59 ± 10?4M for at-death muscle, 1.70 ± 10?4M for muscle stored for 1 day and 1.49 ± 10?4M for muscle stored for 7 days. This indicates that electrical stimulation treatment minimized the postmortem change of actin-myosin interaction. 相似文献
992.
The effect of frozen storage on the biochemical properties of myofibrils, and of their major constituents, actin and myosin, was investigated. Extractability of myofibrillar proteins increased slightly for 3 weeks during frozen storage of muscle, decreasing thereafter. The change in myofibrillar ATPase activity during frozen storage was consistent with that of a reconstituted acto-heavy meromyosin (HMM) complex prepared from frozen stored muscle at the same weight ratio of actin to myosin as in situ. However, myosin ATPase activity showed a different pattern of change when compared with myofibrillar ATPase activity. The maximum velocity of acto-HMM ATPase activity and the apparent dissociation constant of the acto-HMM complex decreased for 1 week during frozen storage, increasing thereafter, indicating that the affinity of actin for myosin was greatest in muscle which had been frozen for 1 week. 相似文献
993.
Cameron K. Lyon Paul F. Knowles George O. Kohler 《Journal of the science of food and agriculture》1983,34(8):849-854
Leaf protein concentrates (LPC) were prepared in large pilot plant equipment from seven Brassica varieties grown on plots of up to 0.06 ha. Plants were harvested about a month before and after the lucerne processing season. Best yields of LPC, from leafier or forage-type species, were up to 0.9 t ha?1. Properties were as good as or better than those of LPC from lucerne. Lucerne processing procedures were modified to maximize yields from the more succulent Brassica plants. 相似文献
994.
We design and implement an efficient on-line approach, FlowMate, for clustering flows (connections) emanating from a busy server, according to shared bottlenecks. Clusters can be periodically input to load balancing, congestion coordination, aggregation, admission control, or pricing modules. FlowMate uses in-band (passive) end-to-end delay measurements to infer shared bottlenecks. Delay information is piggybacked on feedback from the receivers, or, if impossible, TCP or application round-trip time estimates are used. We simulate FlowMate and examine the effects of network load, traffic burstiness, network buffer sizes, and packet drop policies on clustering correctness, evaluated via a novel accuracy metric. We find that coordinated congestion management techniques are more fair when integrated with FlowMate. We also implement FlowMate in the Linux kernel v2.4.17 and evaluate its performance on the Emulab testbed, using both synthetic and tcplib-generated traffic. Our results demonstrate that clustering of medium to long-lived flows is accurate, even with bursty background traffic. Finally, we validate our results on the Internet Planetlab testbed. 相似文献
995.
In the context of the thermodynamics of irreversible processes, general expressions for the temperature dependence of the thermoelectric power in the region of hopping conductivity in disordered materials at low temperatures are derived. The effect of degeneracy of impurity levels on the thermoelectric power is taken into account. On the basis of the results, the experimental data on the thermoelectric power in amorphous and impurity-containing semiconductors are discussed. 相似文献
996.
Scaling Laws for One- and Two-Dimensional Random Wireless Networks in the Low-Attenuation Regime 总被引:1,自引:0,他引:1
Ozgur A.. Leveque O.. Preissmann E.. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(10):3573-3585
The capacity scaling of extended two-dimensional wireless networks is known in the high-attenuation regime, i.e., when the power path loss exponent alpha is greater than 4. This has been accomplished by deriving information-theoretic upper bounds for this regime that match the corresponding lower bounds. On the contrary, not much is known in the so-called low-attenuation regime when 2lesalphales4. (For one-dimensional networks, the uncharacterized regime is 1lesalphales2.5.) The dichotomy is due to the fact that while communication is highly power-limited in the first case and power-based arguments suffice to get tight upper bounds, the study of the low-attenuation regime requires a more precise analysis of the degrees of freedom involved. In this paper, we study the capacity scaling of extended wireless networks with an emphasis on the low-attenuation regime and show that in the absence of small scale fading, the low attenuation regime does not behave significantly different from the high attenuation regime. 相似文献
997.
O‐P. Kwon S.‐J. Kwon M. Jazbinsek A. Choubey V. Gramlich P. Günter 《Advanced functional materials》2007,17(11):1750-1756
A series of new nonlinear optical chromophores based on configurationally locked polyenes (CLPs) with chiral pyrrolidine donors are synthesized. All CLP derivatives exhibit high thermal stability with decomposition temperatures Td at least > 270 °C. Acentric single crystals of enantiopure D ‐ and L ‐prolinol‐based chromophores with a monoclinic space group P21 exhibit a macroscopic second‐order nonlinearity that is twice as large than that of analogous dimethylamino‐based crystal. This is attributed to a strong hydrogen‐bonded polar polymer‐like chain built by these molecules, which is aligned along the polar crystallographic b‐axis. Five α‐phase CLP crystals with different donors grown from solution exhibit a reversible or irreversible thermally induced structural phase transition to a β‐phase. These phase transitions are unusual, changing the crystal symmetry from higher to lower at increasing temperatures, for example, from centrosymmetric to non‐centrosymmetric, enhancing their macroscopic second‐order nonlinear optical properties. 相似文献
998.
S. J. C. Irvine J. Bajaj L. O. Bubulac W. P. Lin R. W. Gedridge K. T. Higa 《Journal of Electronic Materials》1993,22(8):859-864
A new indium precursor, triisopropyl indium (TIPIn), has been used for doping MCT at low carrier concentrations. Previous
attempts using indium organometallics resulted in a strong memory effect where residual doping would persist for many growth
runs. Introducing TIPIn on the tellurium inject line resulted in a similarly strong memory doping but this was not observed
when feeding the dopant in on the cadmium injection line. The TIPIn is believed to have been forming a low volatility adduct
with diisopropyl tellurium (DIPTe) in the feed line and to have continued to evaporate at a low but significant rate. By keeping
the TIPIn and DIPTe precursors separate until they entered the reactor, the desired low 1015 cm−3 carrier concentration and flat indium profiles could be achieved with good reproducibility. Good electrical characteristics
were measured for these layers with Auger limited lifetime >1 μs at 77K. 相似文献
999.
The paper presents convolutional linear data models for the processing of one-dimensional (1D) and two-dimensional (2D) spatial data. The models assume that the measured data is the superposition of a stochastic innovation process and a deterministic system function. The innovation process is described by a fractal scaling noise, which has a power spectral density proportional to some power (-β) of the frequency. The system function is assumed to be symmetric and is constructed using autoregressive (AR) filtering procedures. Iterative deconvolution procedures are developed to recover the fractal innovation from the data. For computational convenience, these procedures assume a spectrally white (β=0) innovation, but modify the data prior to inversion by prewhitening the a priori assumed fractal innovation. The filter coefficients recovered by inverting the modified data are then applied to the original data to recover the fractal innovation. The ability of the deconvolution procedures to recover the fractal innovation is demonstrated using 1D and 2D synthetic data sets. As a practical example, the 2D deconvolution technique is applied to an aeromagnetic map from northeastern Ontario, Canada, and is shown to be effective in enhancing magnetic field anomalies 相似文献
1000.
D.Janiaud O.LeTraon S.Muller A.Bernard P.Bouniol 《战术导弹控制技术》2004,(2):68-72
当考虑到标度因数精度要求的时候,振梁加速度计是一种很有吸引力的概念。这种概念基于当梁受到因加速度引起的拉力或压力时,振梁谐振频率发生变化。 相似文献