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41.
US Bilsbak PJ Bolstad S Fretland O Hauso J Leversund 《Canadian Metallurgical Quarterly》1997,117(12):1746-1750
The increasing frequency of suicide in Norway from 1970 to 1990 has called attention. This paper raises the question of whether any controlled studies have been conducted on prevention of suicide. A search was made in Medline; the criteria for including articles were: controlled studies concerning the effects of suicide-preventive intervention by measuring the number of suicides, parasuicides or suicidal thoughts/ideation. The result of our search was 13 randomised controlled trials and two case-control studies. Most of the studies were unable to confirm any effect of suicide-preventive intervention. In most studies the experiment and control groups were far too small to arrive at significant conclusions. Prior to starting prevention programmes, it is necessary for the health service to know the potential effects. This systematic review revealed that few good controlled studies have been conducted on suicide prevention. For the time being we have to accept the suggestive evidence for certain types of intervention, and use these as a basis for action. 相似文献
42.
Treatment of HeLa cells with retinoic acid (RA) gives rise to a marked stimulation in the incorporation of [alpha-32P]GTP into an approximately 87-kDa cytosolic protein that cross-reacts with a monoclonal antibody raised against tissue transglutaminases. In the absence of RA treatment, the transglutaminase immunoreactivity elutes from a gel filtration column with an apparent size of approximately 600 kDa (designated TGa), whereas following RA treatment, a second peak of transglutaminase immunoreactivity (designated TGb) is detected with an apparent size of approximately 150 kDa. The TGa fractions show little or no GTP-binding or GTP hydrolytic activity and very little transglutaminase activity. However, the TGb fractions show all three activities. Retinoic acid treatment also promotes the association of the GTP-binding protein/transglutaminase with membrane fractions, as detected by Western blotting and photoaffinity cross-linking with [alpha-32P]GTP. In addition, the TGb fraction shows a markedly enhanced ability (relative to TGa) to associate with membranes from control (non-RA-treated) cells. The ability of the GTP-binding protein/transglutaminase to bind to membranes is correlated with the stimulation of a membrane-associated phospholipase C activity. Thus, these findings indicate that RA treatment results in a number of changes in the biochemical properties of a GTP-binding protein/transglutaminase which strongly enhance its ability to bind GTP, associate with plasma membranes, and stimulate phosphoinositide lipid turnover. 相似文献
43.
Abstract In this paper, the authors continue developing a Linguistic Theory of the Complex Structural Models, but in terms of the Semantics. Each symbol (transformed function) is syntactically a lexeme, carrying associate a sememe or atomic semantic unit. Each sememe can be decomposed in semes or quantic semantic unities. They are studied the semantic systems, associated with the syntactic, and that serve them as suprastruc-ture, in terms of two levels: the quantic and the atomic. Also, it is demonstrated that for all model of the complex reality, will exist always a most complex model from the syntactic and semantic point of view. 相似文献
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Thoroughbred (TB) and draft horses (DH) have long been selected for tasks of very different intensities and force-speed relationships. To study their adaptations, we measured O2 consumption and related variables in three TB and four DH during progressive exercise tests on a level treadmill. The horses exerted a draft force of 0, 5, 10, 15, or 20% of their body weight at speeds that increased by 2 m/s every 3 min until they could not maintain that speed. We found that TB could exert the same draft forces as DH and, at each force, TB achieved about twice the speed, twice the external power, and twice the O2 consumption as DH; thus the two breeds had the same gross efficiencies. We also found maximal O2 consumption of TB to be about twice that of DH (134 vs. 72 ml . kg-1 . min-1, respectively), suggesting adaptations to high-intensity exercise. Peak efficiency was reached at lower speeds in DH than in TB, suggesting adaptations to high-force, low-speed exercise. These differences between TB and DH in force-speed and aerobic capacities and in speed for peak efficiency likely reflect different contraction velocities in locomotor muscles. 相似文献
48.
US Barzel 《Canadian Metallurgical Quarterly》1997,337(9):637; author reply 637-637; author reply 638
49.
D Candinas BA Lesnikoski SC Robson T Miyatake SM Scesney HC Marsh US Ryan AP Dalmasso WW Hancock FH Bach 《Canadian Metallurgical Quarterly》1996,62(3):336-342
Mice that are deficient in either the Pms2 or Msh2 DNA mismatch repair genes have microsatellite instability and a predisposition to tumours. Interestingly, Pms2-deficient males display sterility associated with abnormal chromosome pairing in meiosis. Here mice deficient in another mismatch repair gene, Mlh1, possess not only microsatellite instability but are also infertile (both males and females). Mlh1-deficient spermatocytes exhibit high levels of prematurely separated chromosomes and arrest in first division meiosis. We also show that Mlh1 appears to localize to sites of crossing over on meiotic chromosomes. Together these findings suggest that Mlh1 is involved in DNA mismatch repair and meiotic crossing over. 相似文献
50.
Bacteriology of spirometer tubing and evaluation of methodology to prevent transmission of infection
Transmission of respiratory infection by a spirometer is a definite risk in countries like India where a majority of respiratory diseases are infective in nature. To assess this problem, scrapings and washing from a spirometer tube in regular use were taken for microbiological studies. Significant bacterial growth on culture included Aspergillus and acid fast bacilli. In order to check contamination, a segregation chamber was attached to the spirometer. Twenty-three patients used the spirometer with or without segregation chamber and a good correlation was shown between the two methods in forced expiratory volume in one second (r = 0.94), forced vital capacity (r = 0.92) and mid maximum expiratory flow rate (r = 0.90). It can be concluded that a spirometer may have significant growth of pathogenic bacteria and a segregation chamber may be used routinely with the spirometer in order to prevent its contamination. 相似文献