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991.
The voltage ΔV and electric current ΔI of the p- and n-type Cu/Bi–Te/Cu composite thermoelectric devices were measured as a function of ΔT for four regions of the intrinsic Bi–Te compound, Cu/Bi–Te and Bi–Te/Cu interfaces and Cu/Bi–Te/Cu composite using thermocouples
set at intervals of s = 2 and 6 mm, where the lengths of Bi–Te compound and copper are 4 and 5 mm, respectively. ΔV and ΔI of all regions tended to increase linearly with an increase of ΔT. The resultant α was obtained from the relation ΔV/ΔT. The resultant α values of regions including the interface are much higher in absolute value than those of the intrinsic
Bi–Te compounds, so that the barrier thermo-emf is found to occur in the forward-bias direction. It indicates that the barrier
thermo-emf appears even in the semiconductor-metal junction, as in the case of the p–n junctions. The resultant α of Cu(T
H)/Bi–Te interface rich in the heat flow increases with an increase of ΔT, while that of Bi–Te/Cu(T
C
) interface poor in the heat flow decreases with an increase of ΔT. The ΔT-dependence of α of the interfaces is entirely opposite at the hot and cold sides. As a result, the resultant α of the p-
and n-type Cu/Bi–Te/Cu composites remained little varied with changes of ΔT, so that the present composites have a thermal stability superior to the intrinsic Bi–Te compounds.The generating powers
ΔW
Bi-Te and ΔW
Cu/Bi-Te/Cu for the p- and n-type intrinsic Bi–Te compounds and Cu/Bi–Te/Cu composites increased parabolalically with an increase of
ΔT, and the ratios of ΔW
Cu/Bi–Te/Cu to ΔW
Bi–Te reached great values of 1.41 and 1.45 for the p- and n-type composites, respectively. It was thus found that the enhancement
in the resultant α of the composite materials results in a significant improvement in the conversion efficiency for generators. 相似文献
992.
Osamu Kawanami Teruo Nishida Itsuro Honda Yousuke Kawashima Haruhiko Ohta 《Microgravity science and technology》2007,19(3-4):137-138
The gravity effects on quenching of tube by cryogenic fluids for the development of cryogenic fluid management on orbit are studied. In this paper, the effects of the tube diameter, the flow directions, and the mass velocity on the tube quenching using liquid nitrogen are investigated systematically in the terrestrial conditions. The experiments are performed by the mass velocity between 100–600 kg/m2s in downward and upward flow directions by using three difference inner diameters of the transparent heated tube (7, 10, 13.6 mm) for measuring fluid behavior observations and heat transfer measurements simultaneously. The results indicate that the difference between the minimum heat fluxes under downward and upward flow conditions increased as the mass velocity increased. These characteristics of heat transfer were caused by filamentary flow pattern that was found in only downward flow and high mass velocity conditions. 相似文献
993.
Sato O 《Accounts of chemical research》2003,36(9):692-700
A possible route to finding new optically switchable molecular solids is to investigate the photoeffects of compounds that exhibit an abrupt phase transition or hysteresis loop. Such compounds must possess at least bistable states that are separated by a potential barrier in free energy. In fact, on the basis of this idea, we have recently succeeded in identifying three kinds of optically switchable molecular compounds. These include an Fe(III) spin-crossover complex exhibiting light induced excited spin state trapping effects and a Cu(II) photochromic complex and an FeCo Prussian blue exhibiting photoinduced magnetization. It should be noted that abrupt phase transitions or phase transitions with a hysteresis loop are observed when cooperativity due to an intermolecular interaction operates within the crystals. This suggests that the introduction of intermolecular interactions such as pi-pi interactions, hydrogen bonding, or an ion-dipole interaction might serve to achieve optical switching effects in molecular compounds. 相似文献
994.
Aga H Nishimoto T Kuniyoshi M Maruta K Yamashita H Higashiyama T Nakada T Kubota M Fukuda S Kurimoto M Tsujisaka Y 《Journal of Bioscience and Bioengineering》2003,95(3):215-224
A bacterial strain, Bacillus globisporus N75, produced two glycosyltransferases, 6-alpha-glucosyltransferase (6GT) and 3-alpha-isomaltosyltransferase (IMT), jointly catalyzing formation of cyclo-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1--> (CTS) from alpha-1,4-glucan. The N75 enzymes produced CTS from dextrin in a 43.8% yield at the reaction temperature of 50 degrees C, which was 10 degrees C higher than a critical temperature of CTS-forming by the enzymes from B. globisporus C11. The optimum temperatures for 6GT and IMT reactions were 55 degrees C and 50 degrees C, respectively. The thermal stability of both enzymes was 45 degrees C under the condition at pH 6.0 for 60 min. The genes for 6GT and IMT were cloned from the genomic DNA of N75. The amino acid sequences deduced from the 6GT and IMT genes showed 82% and 85% identities, respectively, to the sequences of the enzymes from C11. CTS yield was decreased by high concentrations of the substrate. It was found that the reaction yield was improved by adding cyclomaltodextrin glucanotransferase (CGTase). We demonstrated mass-production of CTS from starch by using the N75 enzymes and CGTase. 相似文献
995.
In visual information processing, feedforward projection from primary to secondary visual cortex (V1-to-V2) is essential for integrating combinations of oriented bars in order to extract angular information embedded within contours that represent the shape of objects. For feedback (V2-to-V1) projection, two distinct types of pathways have been observed: clustered projection and diffused projection. The former innervates V1 domains with a preferred orientation similar to that of V2 cells of origin. In contrast, the latter innervates without such orientation specificity. V2 cells send their axons to V1 domains with both similar and dissimilar orientation preferences. It is speculated that the clustered feedback projection has a role in contour integration. The role of the diffused feedback projection, however, remains to be seen. We simulated a minimal, functional V1-V2 neural network model. The diffused feedback projection contributed to achieving ongoing-spontaneous subthreshold membrane oscillations in V1 cells, thereby reducing the reaction time of V1 cells to a pair of bars that represents specific angular information. Interestingly, the feedback influence took place even before V2 responses, which might stem largely from ongoing-spontaneous signaling from V2. We suggest that the diffusive feedback influence from V2 could act early in V1 responses and accelerate their reaction speed to sensory stimulation in order to rapidly extract angular information. 相似文献
996.
997.
Osamu Fukuda Jonghwan Kim Isao Nakai Yasunori Ichikawa 《Artificial Life and Robotics》2011,16(1):90-93
This article presents the control method for a 5-fingered artificial hand using electromyography (EMG) signals. Our targeted
artificial hand is driven by pneumatic actuators to reduce its weight, and we use ON/OFF solenoid valves instead of electro
pneumatic regulators to simplify the control system. The pneumatic hand has 15 degrees of freedom, and it seems difficult
to reproduce all the finger motions from the EMG signals only. Therefore, we describe typical hand motions using a Petri net,
and control the finger motions efficiently based on this model. Each state of the Petri net indicates one step in the hand
posture to complete the intended motion. Simultaneously, this state corresponds to the ON/OFF pattern of the 15 solenoid valves.
This enables the operator to control the 5-fingered dexterous hand smoothly, transiting the state in the Petri net according
to the EMG motion signals. We conducted an experiment to verify the validity of the proposed method. In the experiment, five
typical motions (spherical grasp, power grip, hook grip, key grip, precision grip) were successfully performed using the 6-channel
EMG signals measured from the operator’s forearm. 相似文献
998.
We propose a multimodal “scene understanding” framework using sensory and text information. Scene understanding is defined by extracting information such as What, When, Where, Who, Why, and How on the surrounding environment. Although scene understanding has been studied, information on why and how was not considered. We constructed a framework for extracting how information, in addition to the conventional information based on multimodality and background knowledge. This framework was applied to a cooking scene, in which how information was defined as a cooking procedure. This framework was evaluated by constructing an audio-visual multimodal cooking recognition system, utilizing recipes as background knowledge. A Convolutional Neural Network (CNN) and a Hierarchical Hidden Markov Model (HHMM) were adopted in this system. Our experiments showed the robustness of the proposed framework in noisy and/or occluded situations. An interactive cooking support system based on the proposed framework might suggest the next step for cooking procedures via human–robot communications. 相似文献
999.
In this paper, we propose a novel medium for interactions based on an interpersonal psychological approach referred to as ‘naïve psychology’. We adopt the visual assessment of clustering tendency (VAT) to naïve psychology for the visual understanding of other people. The VAT algorithm produces a visual display that can be used to assess clustering tendencies in a set of persons (notions) by reconstructing a digital image representation of a square relational dissimilarity matrix for its set. This algorithm clearly represents two types of imbalanced situations in naïve psychology: crisp and fuzzy. The visual image of a balanced or imbalance situation is useful for a deeper human understanding. 相似文献
1000.
We study the closure properties of the function classes GapP and GapP+. We characterize the property of GapP+ being closed under decrement and of GapP being closed under maximum, minimum, median, or division by seemingly implausible collapses among complexity classes, thereby giving evidence that these function classes don't have the stated closure properties.We show a similar result concerning operations we callbit cancellation andbit insertion: Given a functionf GapP and a polynomialtime computable function , we ask whether the functionsf
*
(x) andf
+
(x) are in GapP or not, wheref
*
(x) is obtained fromf(x) by cancelling the (x)-th bit in the binary representation off(x), andf
+
(x) is obtained fromf(x) by inserting a bit at position (x) in the binary representation off(x). We give necessary and sufficient conditions for GapP being closed under bit cancellation and bit insertion, respectively. 相似文献