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991.
992.
K.L. Parker Gaddis S. Dikmen D.J. Null J.B. Cole P.J. Hansen 《Journal of dairy science》2017,100(4):2877-2891
The objectives of this study were to estimate variance components and identify regions of the genome associated with traits related to embryo transfer in Holsteins. Reproductive technologies are used in the dairy industry to increase the reproductive rate of superior females. A drawback of these methods remains the variability of animal responses to the procedures. If some variability can be explained genetically, selection can be used to improve animal response. Data collected from a Holstein dairy farm in Florida from 2008 to 2015 included 926 superovulation records (number of structures recovered and number of good embryos), 628 in vitro fertilization records (number of oocytes collected, number of cleaved embryos, number of high- and low-quality embryos, and number of transferrable embryos), and 12,089 embryo transfer records (pregnancy success). Two methods of transformation (logarithmic and Anscombe) were applied to count variables and results were compared. Univariate animal models were fitted for each trait with the exception of pregnancy success after embryo transfer. Due to the binary nature of the latter trait, a threshold liability model was fitted that accounted for the genetic effect of both the recipient and the embryo. Both transformation methods produced similar results. Single-step genomic BLUP analyses were performed and SNP effects estimated for traits with a significant genetic component. Heritability of number of structures recovered and number of good embryos when log-transformed were 0.27 ± 0.08 and 0.15 ± 0.07, respectively. Heritability estimates from the in vitro fertilization data ranged from 0.01 ± 0.08 to 0.21 ± 0.15, but were not significantly different from zero. Recipient and embryo heritability (standard deviation) of pregnancy success after embryo transfer was 0.03 (0.01) and 0.02 (0.01), respectively. The 10-SNP window explaining the largest proportion of variance (0.37%) for total structures collected was located on chromosome 8 beginning at 55,663,248 bp. Similar regions were identified for number of good embryos, with the largest proportion of variance (0.43%) explained by a 10-SNP window on chromosome 14 beginning at 26,713,734 bp. Results indicate that there is a genetic component for some traits related to superovulation and that selection should be possible. Moreover, the genetic component for superovulation traits involves some genomic regions that are similar to those for other fertility traits currently evaluated. 相似文献
993.
994.
Helle Hvid Hansen 《Information and Computation》2010,208(12):1368-1397
Subsequential transducers combine (input) language recognition with transduction and thereby generalise classic deterministic automata as well as Mealy and Moore type state machines. These well known subclasses all have a natural coalgebraic characterisation, and the question arises whether their coalgebraic modelling can be extended to subsequential transducers and their underlying structures. In this paper, we show that although subsequential structures cannot generally be regarded as coalgebras, the subclass of normalised structures do form a subcategory of coalgebras. Moreover, normalised structures are reflective in the category of all subsequential structures, and a final normalised structure exists. The existence and properties of the minimal subsequential transducer can be derived from this result. We also show that for the class of subsequential structures in which all states are accepting, an alternative coalgebraic representation is obtained by taking differentials. This differential representation gives rise to a new method of deciding equivalence and computing minimal representations which does not involve normalisation. Both normalisation and taking differentials can be formalised as functors into reflective subcategories of coalgebras, and we can therefore see these constructions as coalgebraisation. 相似文献
995.
M Schwarz OO Versolato A Windberger FR Brunner T Ballance SN Eberle J Ullrich PO Schmidt AK Hansen AD Gingell M Drewsen JR López-Urrutia 《The Review of scientific instruments》2012,83(8):083115
Storage and cooling of highly charged ions require ultra-high vacuum levels obtainable by means of cryogenic methods. We have developed a linear Paul trap operating at 4 K capable of very long ion storage times of about 30 h. A conservative upper bound of the H(2) partial pressure of about 10(-15) mbar (at 4 K) is obtained from this. External ion injection is possible and optimized optical access for lasers is provided, while exposure to black body radiation is minimized. First results of its operation with atomic and molecular ions are presented. An all-solid state laser system at 313 nm has been set up to provide cold Be(+) ions for sympathetic cooling of highly charged ions. 相似文献
996.
Global land cover classification at 1 km spatial resolution using a classification tree approach 总被引:4,自引:0,他引:4
M. C. Hansen R. S. Defries J. R. G. Townshend R. Sohlberg 《International journal of remote sensing》2013,34(6-7):1331-1364
This paper on reports the production of a 1 km spatial resolution land cover classification using data for 1992-1993 from the Advanced Very High Resolution Radiometer (AVHRR). This map will be included as an at-launch product of the Moderate Resolution Imaging Spectroradiometer (MODIS) to serve as an input for several algorithms requiring knowledge of land cover type. The methodology was derived from a similar effort to create a product at 8 km spatial resolution, where high resolution data sets were interpreted in order to derive a coarse-resolution training data set. A set of 37 294 x 1 km pixels was used within a hierarchical tree structure to classify the AVHRR data into 12 classes. The approach taken involved a hierarchy of pair-wise class trees where a logic based on vegetation form was applied until all classes were depicted. Multitemporal AVHRR metrics were used to predict class memberships. Minimum annual red reflectance, peak annual Normalized Difference Vegetation Index (NDVI), and minimum channel three brightness temperature were among the most used metrics. Depictions of forests and woodlands, and areas of mechanized agriculture are in general agreement with other sources of information, while classes such as low biomass agriculture and high-latitude broadleaf forest are not. Comparisons of the final product with regional digital land cover maps derived from high-resolution remotely sensed data reveal general agreement, except for apparently poor depictions of temperate pastures within areas of agriculture. Distinguishing between forest and non-forest was achieved with agreements ranging from 81 to 92% for these regional subsets. The agreements for all classes varied from an average of 65% when viewing all pixels to an average of 82% when viewing only those 1 km pixels consisting of greater than 90% one class within the high-resolution data sets. 相似文献
997.
Fotios Spyridonis Jarle Hansen Tor-Morten Grønli Gheorghita Ghinea 《Multimedia Tools and Applications》2014,72(1):191-206
Earlier studies in the field of pain research suggest that little efficient intervention currently exists in response to the exponential increase in the prevalence of pain. In this paper, we present an Android application (PainDroid) with multimodal functionality that could be enhanced with Virtual Reality (VR) technology, which has been designed for the purpose of improving the assessment of this notoriously difficult medical concern. PainDroid has been evaluated for its usability and acceptability with a pilot group of potential users and clinicians, with initial results suggesting that it can be an effective and usable tool for improving the assessment of pain. Participant experiences indicated that the application was easy to use and the potential of the application was similarly appreciated by the clinicians involved in the evaluation. Our findings may be of considerable interest to healthcare providers, policy makers, and other parties that might be actively involved in the area of pain and VR research. 相似文献
998.
Plants recognize biotic challengers and respond with the appropriate defense by utilizing phytohormone signaling and crosstalk. Despite this, microbes and insects have evolved mechanisms that compromise the plant surveillance system and specific defenses, thus ensuring successful colonization. In nature, plants do not experience insect herbivores and microbes in isolation, but in combination. Over time, relationships have developed between insects and microbes, varying on a continuum from no-relationship to obligate relationships that are required for both organisms to survive. While many reviews have examined plant-insect and plant-microbe interactions and the mechanisms of plant defense, few have considered the interface where microbes and insects may overlap, and synergies may develop. In this review, we critically evaluate the requirements for insect-associated microbes to develop synergistic relationships with their hosts, and we mechanistically discuss how some of these insect-associated microbes can target or modify host plant defenses. Finally, by using bioinformatics and the recent literature, we review evidence for synergies in insect-microbe relationships at the interface of plant-insect defenses. Insect-associated microbes can influence host-plant detection and/or signaling through phytohormone synthesis, conserved microbial patterns, and effectors, however, microbes associated with insects must be maintained in the environment and located in opportunistic positions. 相似文献
999.
X. J. Jiang B. Noble V. Hansen J. Tafto 《Metallurgical and Materials Transactions A》2001,32(5):1063-1073
The effects of zirconium and copper on the early stages of the precipitation processes in an Al-5.5 wt pct Zn-1.2 wt pct Mg
alloy have been studied by differential scanning calorimetry (DSC) thermal analysis. Electron diffraction has been used as
a complementary technique to aid in the interpretation of the thermal effects observed in the DSC thermograms. The results
show that the initial stages of Guinier-Preston zone I (GP(I)) formation at room temperature are not affected by the presence
of zirconium, but the rate of Guinier-Preston zone II (GP(II)) precipitation is slowed down significantly. For aging at 100
°C, the stability of GP zones is reduced by the addition of zirconium, and this leads to a reduction in the amount of η′ produced during aging. The addition of copper to an Al-5.4 wt pct Zn-1.2 wt pct Mg-0.2 wt pct Zr alloy intensifies the electron
diffraction spots from GP(I), suggesting that the strong electron-scatterer copper may be incorporated into GP zones. The
rate of growth of GP(I) at room temperature is unaffected by the presence of copper, but the rate of formation of GP(II) at
room temperature is retarded. For artificial aging at 100 °C, the development of GP(I) and GP(II) is not affected significantly
by the presence of copper, but the formation of η′ is stimulated, producing a high number density of very fine η′ precipitates. Preaging at room temperature results in accelerated η′ formation during subsequent aging at 100 °C in the zirconium-containing alloy. However, this acceleration of η′ formation is absent when copper is present in the alloy. 相似文献
1000.
Nielsen T.N. Eggleton B.J. Rogers J.A. Westbrook P.S. Hansen P.B. Strasser T.A. 《Photonics Technology Letters, IEEE》2000,12(2):173-175
A compact tunable fiber Bragg grating that uses distributed thin-film heaters on the surface of the fiber is used to dynamically optimize the post dispersion compensation of a multi-span 40-Gb/s nonreturn-to-zero (NRZ) transmission system. Dynamic post dispersion compensation with this device enables the system to operate over a much wider range of launch power than is otherwise possible with simple, fixed compensation using dispersion compensating fiber 相似文献