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271.
Gilles Nalbone Jeannie Leonardi Elise Termine Henri Portugal Paulette Lechene Anne-Marie Pauli Huguette Lafonf 《Lipids》1989,24(3):179-186
In this study, we investigated the effect of various types of fats on heart lipid peroxidation status and on blood lipid parameters.
Rats were fed either a low-fat diet (2.2% lard plus 2.2% corn oil), a corn oil diet (17%), a salmon oil diet (12.5%) supplemented
with 4.5% corn oil, or a lard diet (15%) supplemented with 2% corn oil. All diets were supplemented with 1% cholesterol. Rats
were fed for eight weeks. When compared with the low-fat diet, the salmon oil-diet intake resulted in a lower blood cholesterol,
triglyceride and phospholipid concentrations (−50, −56 and −30%, respectively). Corn oil only tended to lower blood lipids;
this decrease was significant for triglycerides only (−40%). The hypocholesterolemic effect of salmon oil diet is even more
pronounced, if blood cholesterol values are compared with those of rats fed the lard diet. Heart lipid composition was not
affected by dietary manipulations. Fatty acid composition of cardiac phosphatidylcholines and phosphatidylethanolamines, however,
were altered by high-fat diets. In phosphatidylcholine, salmon oil induced a twelvefold decrease in the n−6/n−3 ratio and
a 26% increase in the unsaturation index. For phosphatidylethanolamine, the n−6/n−3 ratio decreased 7.7-fold and the unsaturation
index increased by 13%. A 50% decrease of the n−6/n−3 ratio was observed in animals fed the lard diet. Ultramicroscopic examination
of ventricles revealed that those of the salmon oil group significantly accumulated lipofuscin-like or ceroid material, whereas
this accumulation was barely detectable in hearts of the other groups. Seleniumdependent glutathione peroxidase activity tended
to be the highest in hearts of rats fed the salmon oil diet; this increase is significant (+36% and +54% for total and specific
activities, respectively), if values are compared with those of the rats fed the lard diet. Liver glutathione peroxidase and
heart glutathione S-transferases activities remained unchanged. These results indicate that fish oil did not lower the selenium
involved in glutathione peroxidase activity. This rules out that a deficiency in this enzyme was at the origin of heart lipofuscinosis.
Also, it is concluded that the n−6/n−3 ratio of the diet is likely more determinant in the alteration of heart lipid peroxidation
status than is the polyunsaturated/saturated ratio.
Part of this work was presented at the International Congress: “Selenium in Medicine and Biology,” Avoriaz, France, March,
15–18, 1988. 相似文献
272.
Collision analysis indicates that many car accidents occur when negotiating a bend. Excessive speed and steering wheel errors are often given by way of explanation. Nevertheless, the underlying origin of these dramatic errors could be, at least in part, a poor estimation of bend curvature. The aim of this study was to investigate both the assessment of bend curvature by drivers and the impact of symbolic road signs that indicate a hazardous bend on this assessment. Thus, participants first viewed a video recording showing approaching bends of different curvature before being asked to assess the curvature of these bends. This assessment could either be a verbal (symbolic control) estimation of the bend's curvature and risk, or a sensorimotor (subsymbolic control) estimation of the bend's curvature (participants were asked to turn a steering wheel to mimic the position that would be necessary to accurately negotiate the bend). Results show that very severe bends (with a radius of less than 80 m) were actually underestimated. This was associated with an underestimation of risk corresponding to these bends and a poor sensorimotor anticipation of bend curvature. Road signs, which indicate risk significantly improve bend assessment, but this was of no use for sensorimotor anticipation. Thus, other indicators need to be envisaged in order to also improve this level of control. 相似文献
273.
The possibility of performing FT-IR spectromicroscopy experiments on individual living cells is the focus of considerable attention. Among the applications of interest, the obtainment of structural information in rapid measurements, with a time resolution of the minute or better, is a prized goal. In this work, we show that the use of synchrotron FT-IR spectromicroscopy allows one to extract weak spectral changes, of less than 10(-3) au per minute, in the absorption spectrum of single rod cells following photostimulation. We also show that absorption changes are accompanied by other optical effects due to changes in the real part of the refractive index of the cell. The use of two-dimensional correlation spectroscopy allows us to assign bands to specific molecular chromophores and to extract weak spectral variations in the presence of a noisy background. 相似文献
274.
275.
Local Energy Approach to Steel Fatigue 总被引:1,自引:0,他引:1
Abstract: This paper presents an experimental protocol developed to locally estimate different terms of the energy balance associated with the fatigue of DP600 steel. The method involves two quantitative imaging techniques. First, digital image correlation provides displacement fields and, after derivation, strain and strain-rate fields. A variational method, associated with an energy functional, is used to simultaneously identify elastic parameter and stress fields. The deformation energy rate distribution can then be determined on the basis of the stress and strain data. Secondly, infrared thermography provides thermal images which are used to separately estimate the thermoelastic source amplitude and mean dissipation per cycle distributions. The image processing uses a local form of the heat diffusion equation and a special set of approximation functions that take the frequency spectra of the sought sources into account. 相似文献
276.
A field study was performed in a building complex to investigate the extent and sources of lead (Pb) release in tap water and brass material was found to be the main contributor in the very first draw (250 mL). Based on these results, a pilot installation was built to study Pb leaching from old and new faucets in the presence and absence of a connection to Cu piping. Four water quality conditions were tested: i) no treatment; ii) addition of 0.8 mg P/L of orthophosphate; iii) pH adjustment to 8.4; and iv) adjustment to a higher chloride to sulfate mass ratio (CSMR; ratio from 0.3 to 2.9). Pb concentrations in samples taken from the faucets without treatment ranged from 1 to 52 μg/L, with a mean of 11 μg/L. The addition of orthophosphate @ 0.8 mg P/L (OrthoP) was the most effective treatment for all types of faucets tested. On average, OrthoP reduced mean Pb leaching by 41%, and was especially effective for new double faucets (70%). In the presence of orthophosphates, the relative proportion of particulate Pb (Pbpart) (>0.45 μm) increased from 31% to 54%. However, OrthoP was not efficient to reduce Zn release. The higher CSMR condition was associated with greater dezincification of yellow brass but not of red brass. Corrosion control treatment influenced Pb concentration equilibrium, directly impacting maximal exposure. Significantly higher Pb release (3 fold) was observed for 1 of the 8 faucets connected to Cu exposed to high CSMR water, suggesting the presence of galvanic corrosion. 相似文献
277.
Targeted Analysis of HSP70 Isoforms in Human Spermatozoa in the Context of Capacitation and Motility
Sarah Grassi Marie Bisconti Baptiste Martinet Vanessa Arcolia Jean-Franois Simon Ruddy Wattiez Baptiste Leroy Elise Hennebert 《International journal of molecular sciences》2022,23(12)
HSP70s constitute a family of chaperones, some isoforms of which appear to play a role in sperm function. Notably, global proteomic studies analyzing proteins deregulated in asthenozoospermia, a main cause of male infertility characterized by low sperm motility, showed the dysregulation of some HSP70 isoforms. However, to date, no clear trend has been established since the variations in the abundance of HSP70 isoforms differed between studies. The HSPA2 isoform has been reported to play a key role in fertilization, but its dysregulation and possible relocation during capacitation, a maturation process making the spermatozoon capable of fertilizing an oocyte, is debated in the literature. The aim of the present study was to investigate the fate of all sperm HSP70 isoforms during capacitation and in relation to sperm motility. Using Multiple-Reaction Monitoring (MRM) mass spectrometry, we showed that the relative abundance of all detected isoforms was stable between non-capacitated and capacitated spermatozoa. Immunofluorescence using two different antibodies also demonstrated the stability of HSP70 isoform localization during capacitation. We also investigated spermatozoa purified from 20 sperm samples displaying various levels of total and progressive sperm motility. We showed that the abundance of HSP70 isoforms is not correlated to sperm total or progressive motility. 相似文献
278.
Litt Mark D.; Kadden Ronald M.; Kabela-Cormier Elise; Petry Nancy 《Canadian Metallurgical Quarterly》2007,75(4):542
The aim of this study was to determine whether a socially focused treatment can effect change in the patient's social network from one that reinforces drinking to one that reinforces sobriety. Alcohol dependent men and women (N = 210) recruited from the community were randomly assigned to 1 of 3 outpatient treatment conditions: network support (NS), network support + contingency management (NS + CM), or case management (CaseM; a control condition). Analysis of drinking rates for 186 participants at 15 months indicated a significant interaction effect of Treatment × Time, with both NS conditions yielding better outcomes than the CaseM condition. Analyses of social network variables at posttreatment indicated that the NS conditions did not reduce social support for drinking relative to the CaseM condition but did increase behavioral and attitudinal support for abstinence as well as Alcoholics Anonymous (AA) involvement. Both the NS variables and AA involvement variables were significantly correlated with drinking outcomes. These findings indicate that drinkers' social networks can be changed by a treatment that is specifically designed to do so, and that these changes contribute to improved drinking outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
279.
Engineered living materials (ELMs) composed entirely of fungal cells offer significant potential due to their functional properties such as self-assembly, sensing, and self-healing. Alongside rapid developments in the ELM field, there is significant and growing interest in mycelium materials, which are made from the vegetative part of filamentous fungi, as a potential source of advanced functional materials. In order to advance the development of fungal ELMs that utilize the organism's ability to regenerate as self-repair, new methods for controlling and optimizing mycelium materials are needed, as well as a better understanding of the biological mechanisms behind regeneration. In this study, pure mycelium materials are fabricated for use as leather substitutes, and it is found that chlamydospores, thick-walled vegetative cells formed at the hyphal tip, may be the key to the material's self-healing properties. The results suggest that mycelium materials can survive in dry and oligotrophic environments, and self-healing is possible with minimal intervention after a two-day recovery period. Finally, the study characterizes the mechanical recovery and physical properties of damaged and healed samples, allowing for the first characterization of fungal ELMs. 相似文献