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81.
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de León AG Dirix Y Staedler Y Feldman K Hähner G Caseri WR Smith P 《Applied optics》2000,39(26):4847-4851
Pixelated, multicolor polarizing filters-of potential use in full-color displays-were produced by what we believe to be a novel method, i.e., masked evaporation of silver and gold onto glass substrates partially covered with separated sub-micrometer-wide strips of oriented poly(tetrafluoroethylene) (PTFE), prepared by friction deposition. The evaporated metal films preferentially nucleated at the glass surface and, consequently, formed parallel arrays in between the PTFE strips. The structures thus produced feature a strong angle-dependent absorption of polarized visible light, allowing for optical switching between red and blue and between green and yellow. 相似文献
83.
Lee D. Johnson A.M. Zucker J.E. Burrus C.A. Feldman R.D. Austin R.F. 《Photonics Technology Letters, IEEE》1992,4(9):949-951
Low-lasing-threshold quasi-continuous optically pumped II-VI quantum-well lasers were operated well above room temperature at 620 nm. This result shows promise for high-repetition-rate, short-pulse generation by direct modulation of the injection current and also CW operation of future wide-gap II-VI diode lasers above room temperature 相似文献
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The monoamines, serotonin, dopamine, norepinephrine, epinephrine and histamine, play a critical role in the function of the hypothalamic-pituitary-adrenal axis and in the integration of information in sensory, limbic, and motor systems. The primary mechanism for termination of monoaminergic neurotransmission is through reuptake of released neurotransmitter by Na+, CI-dependent plasma membrane transporters. A second family of transporters packages monoamines into synaptic and secretory vesicles by exchange of protons. Identification of those cells which express these two families of neurotransmitter transporters is an initial step in understanding what adaptive strategies cells expressing monoamine transporters use to establish the appropriate level of transport activity and thus attain the appropriate efficiency of monoamine storage and clearance. The most recent advances in this field have yielded several surprises about their function, cellular and subcellular localization, and regulation, suggesting that these molecules are not static and most likely are the most important determinants of extracellular levels of monoamines. Here, information on the localization of mRNAs for these transporters in rodent and human brain is summarized along with immunohistochemical information at the light and electron microscopic levels. Regulation of transporters at the mRNA level by manipulation in rodents and differences in transporter site densities by tomographic techniques as an index of regulation in human disease and addictive states are also reviewed. These studies have highlighted the presence of monoamine neurotransmitter transporters in neurons but not in glia in situ. The norepinephrine transporter is present in all cells which are both tyrosine hydroxylase (TH)- and dopamine beta-hydroxylase-positive but not in those cells which are TH- and phenyl-N-methyltransferase-positive, suggesting that epinephrine cells may have their own, unique transporter. In most dopaminergic cells, dopamine transporter mRNA completely overlaps with TH mRNA-positive neurons. However, there are areas in which there is a lack of one to one correspondence. The serotonin transporter (5-HTT) mRNA is found in all raphe nuclei and in the hypothalamic dorsomedial nucleus where the 5-HTT mRNA is dramatically reduced following immobilization stress. The vesicular monoamine transporter 2 (VMAT2) is present in all monoaminergic neurons including epinephrine- and histamine-synthesizing cells. Immunohistochemistry demonstrates that the plasma membrane transporters are present along axons, soma, and dendrites. Subcellular localization of DAT by electron microscopy suggests that these transporters are not at the synaptic density but are confined to perisynaptic areas, implying that dopamine diffuses away from the synapse and that contribution of diffusion to dopamine signalling may vary between brain regions. Interestingly, the presence of VMAT2 in vesicles underlying dendrites, axons, and soma suggests that monoamines may be released at these cellular domains. An understanding of the regulation of transporter function may have important therapeutic consequences for neuroendocrine function in stress and psychiatric disorders. 相似文献
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Our aim was to investigate the relationships between defensiveness and repression, on the one hand, and self-reported stressor exposure and resting blood pressure, on the other hand. In addition, different operationalizations of defensiveness and repression were compared. Participants were 310 male and 90 female employees representing a wide range of occupations. Before a medical examination, all subjects completed questionnaires measuring defensiveness, anxiety, repression, daily hassles, and life events. After controlling for potentially confounding variables, multiple regression analyses revealed an inverse association between defensiveness and self-reported number of daily hassles and a positive link between defensiveness and resting systolic blood pressure. In general, the interaction between defensiveness and anxiety (representing repression) did not add to the predictive power of defensiveness and anxiety alone. The results support the notion that defensive individuals tend to underreport problems, while exhibiting elevated resting blood pressures. 相似文献
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