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11.
DP Callan 《Canadian Metallurgical Quarterly》1993,13(2):172-179
In the two cases described, the problems of insufficient bone and insufficient soft tissue in the edentulous ridge were addressed concurrently. Freeze-dried demineralized bone was used to fill the osseous defect. Freeze-dried fascia lata was used to prevent epithelial migration into the defect, act as a barrier, and eliminate a second surgery for membrane removal. This regeneration procedure can provide increased alveolar bone for better implant placement and esthetics. 相似文献
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Considerable variation remains in the reported effects of disease, age and gender on high frequency electroencephalographic activity. We examined the topographic differences in relative and absolute beta power in the 14-54 Hz range in 49 subjects with dementia of the Alzheimer's type (DAT), 25 subjects with multi-infarct dementia (MID), and 62 normal control subjects (CON). Associations of these spectral parameters with age, gender and cognitive status were assessed. Normal control subjects showed modest positive correlations in frontal, central and parietal regions across the age range of 24-90 years but not across a narrower 60-90 year range. Women, particularly women over 60 years of age, showed increased relative and absolute beta power compared to men. Subjects with dementia showed global decreases particularly in relative power. Decreases were most prominent in central and parietal regions for DAT subjects, with MID subjects additionally showing prominent frontal decreases. DAT and MID subjects differed in their correlations of power with age, Folstein Mini Mental State Exam (MMSE) and gender across frontal, central, parietal and temporal regions. Differences in the regional attenuation of absolute and relative beta power within specific high frequency bands may reflect the disparate neuropathologic processes of DAT and MID, as well as the extent of brain dysfunction and the effects of gender. 相似文献
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TM Drabkina DP Matyushkin VK Radzjukevich Romanovsky DYu 《Canadian Metallurgical Quarterly》1995,14(2):153-170
The effect of frog skeletal muscle incubate on fatigue was studied in frog sciatic nerve, sartorius muscle preparation. Fatigue was produced by prolonged repetitive (1 s-1) stimulation of motor nerve or of curarized muscle. The incubate partially restored isometric contraction amplitudes of muscle fatigued by nerve stimulation. This effect of partial recovery from fatigue (PRF effect) was exerted mainly by a relatively low-molecular fraction (LMF; < 10 kDa) of the incubate. The incubate and its fractions failed to produce the PRF effect in experiments with directly stimulated muscle. The action of LMF on synaptic transmission in unfatigued cutaneous-pectoris muscle was examined using binomial analysis of quantal transmitter release. LMF produced an increase in the end-plate potential quantal content (m) at synapses with low initial m values. In contrast, it produced a decrease i n m at synapses with higher m values. Both effects were due to respective changes in binomial parameter n. It is assumed that the stimulatory presynaptic action of the incubate on synapses the effectiveness of which was lowered during fatigue, could account for the PRF effect. A possible contribution of low- and high-molecular components of the incubate is discussed. 相似文献
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The prevalence of preferential nasal breathing was studied in an awake adult population. One hundred and ninety-four people consented to gentle manual compression of the nostrils. They were advised to 'breathe in and out', but no further information regarding breathing was given to avoid influencing the patient. One hundred and eighty patients (92.8%) commenced immediate regular relaxed breathing. Fourteen patients (7.2%) had difficulty with oral breathing which ranged from irregular mouth breathing associated with distress to no spontaneous respiration. The prevalence of preferential nasal breathing was strongly associated with increasing age (chi 2 for trend, P = 0.007). In addition, a weakly significant association was demonstrated between a history of asthma and this phenomenon (P = 0.047). These findings suggest a tendency for the elderly person to revert to the infant pattern of obligate nasal breathing. Physicians should be aware of this possibility in the elderly patient, especially prior to any procedure which may induce nasal obstruction. 相似文献
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