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41.
To determine the relative sensitivities of tomato, cucumber, and bean to exogenously applied concentrations of ferulic acid (FA) and to determine whether FA-induced stress responses increase endogenous levels of abscisic acid (ABA), wild-type andFlacca (ABA-deficient mutant) tomato (Lycopersicon esculentum Mill. cv. Ailsa Craig), cucumber, (Cucumis sativus L. cv. Early Green Cluster), and bean (Phaseolus vulgaris L. cv. Oregon 91) were treated with FA (0.0, 0.2, 0.4, 0.8 mM) in nutrient solution every other day for a total of two or three treatments. FA inhibited leaf growth and water utilization of wild-type tomato,Flacca tomato, and cucumber, but not of bean. Acclimation to FA was observed following the first FA treatment and increased endogenous ABA levels were found in wild-type tomato,Flacca tomato, and cucumber following multiple FA treatments. Induction of ABA biosynthesis occurred in wild-type tomato within 8 hr of FA treatment and maximum ABA levels were observed 24 hr after treatment. At that time, ABA levels of tomato treated with 0.4 and 0.8 mM FA were 13.7 times and 2.6 times higher than control levels, respectively. A second FA (0.4 or 0.8 mM) treatment, 48 hr after the first, did not appear to affect ABA levels. Ninety-six hours after the first treatment, ABA levels of tomato treated with 0.4 mM FA approached control levels; ABA levels of plants treated with 0.8 mM FA were 1.9 times higher than control levels. Control ABA levels increased gradually with time. The data showed that plant sensitivity and ability of subsequent acclimation to phenolic acids, such as FA, were taxa dependent.The use of trade names in this publication does not imply endorsement by North Carolina Agricultural Research Service of the products named, nor criticism of similar ones not mentioned.  相似文献   
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43.
Manufacture of fatty alcohols based on natural fats and oils   总被引:1,自引:0,他引:1  
The present worldwide capacity of fatty alcohols is ca. 1.0 million metric tons per year. About 60% of this capacity is based on petrochemical feedstocks, 40% on natural fats and oils. Three basic dominating commercial-scale processes are used to manufacture fatty alcohols: the Ziegler process and the Oxo synthesis starting from petrochemical feedstocks, and the high-pressure hydrogenation of natural fatty acids and esters. Basically, the high-pressure hydrogenation can be used with triglycerides, fatty acids or fatty acid esters as feedstock. The direct hydrogenation of fats and oils has not been developed to a commercial-scale process, mainly because it was not possible to prevent decomposition of the valuable byproduct glycerol. Conversion of fatty acids into fatty alcohols by catalytic hydrogenation without preesterification requires corrosion-resistant materials of construction and acid-resistant catalysts. Required reaction temperatures are higher, resulting in a higher hydrocarbon content. The majority of fatty alcohol plants based on natural fats and oils use methyl esters as feedstock. These can be made either by esterification of fatty acids or by-transesterification of triglycerides. For catalytic high-pressure hydrogenation of methyl esters to fatty alcohols, several process options have been developed. The bawic distinguishing feature is the catalyst application either in a fixed bed arrangement or suspended in the methyl ester feed.  相似文献   
44.
Kinetics of aerobic waste water treatment by degrading organic compounds and by nitrification . Both aerobic degradation of organic substances and nitrification can be described by the double substrate kinetics of Monod; dissolved organic material and ammonium or nitrite are the first substrate and oxygen the second one. The determination of the different kinetic coefficients by evaluation of measurements on a laboratory scale is explained first, and known results are then presented and discussed. Finally, it is demonstrated by two examples, viz. the simultaneous oxidation of carbon and nitrogen compounds and oxygen-limited substrate removal, how reaction kinetic models can be used to obtain important information about the characteristics of the bioreactions.  相似文献   
45.
During the last years changes in aging indicators have been observed, supposedly resulting from modern brewing technology. The Research Brewery Weihenstephan (Forschungsbrauerei Weihenstephan) offers excellent opportunities for comparing different modern wort boiling systems under semi‐industrial conditions. Employing three different boiling systems, nine brews were produced. The resulting worts were compared regarding the most common wort parameters. Furthermore the influence of the different boiling systems on aging indicators in the resulting beers was analyzed using a newly developed mass spectrometry‐based method. The decrease in the total amount of aging indicators in industrial beers over the last years is very likely the result of lower thermal intake in modern brewhouse equipment. The total amount of aging indicators is sufficient to describe the differences in modern boiling systems. In summary, 2‐furfural dominates all other indicators in terms of thermal influence. 2‐Furfuryl ethyl ether can be suggested as good indicator of aging as postulated by Eichhorn, whereas β‐damascenone is questionable as an aging indicator. Supplementary experiments were carried out to investigate the role of the aging indicators as stale flavour components. Because of synergistic effects, many stale flavour compounds act as aroma compounds and not only as indicators.  相似文献   
46.
Competitive advantage in the information age is based, in large part, on a firm's capability to acquire and use quality information as well as effective and efficient services, with its information technology resources at the least possible cost. One possible strategy for improving the cost-performance ratio of information technology resources is known as downsizing. The downsizing effort is a strategic move that is believed by many organizations to be capable of yielding significant benefits. It can also be a costly endeavour which may leave a firm worse off. Therefore, careful planning and control must be exercised if information systems downsizing is to succeed. This paper reports the results of a study whose purpose is to identify and explain the critical success factors for a downsizing effort. Results of the study show that information systems downsizing may produce benefits such as improved information systems, improved organizational structure, higher productivity, and lower cost. The results also indicate that downsizing success is dependent upon complex linkages of communications, action plans, needs for downsizing as perceived by employees, and the specific method of downsizing used.  相似文献   
47.
Epigenetics play a vital role in early embryo development. Offspring conceived via assisted reproductive technologies (ARTs) have a three times higher risk of epigenetic diseases than naturally conceived children. However, investigations into ART-associated placental histone modifications or sex-stratified analyses of ART-associated histone modifications remain limited. In the current study, we carried out immunohistochemistry, chip-sequence analysis, and a series of in vitro experiments. Our results demonstrated that placentas from intra-cytoplasmic sperm injection (ICSI), but not in vitro fertilization (IVF), showed global tri-methylated-histone-H3-lysine-4 (H3K4me3) alteration compared to those from natural conception. However, for acetylated-histone-H3-lysine-9 (H3K9ac) and acetylated-histone-H3-lysine-27 (H3K27ac), no significant differences between groups could be found. Further, sex -stratified analysis found that, compared with the same-gender newborn cord blood mononuclear cell (CBMC) from natural conceptions, CBMC from ICSI-boys presented more genes with differentially enriched H3K4me3 (n = 198) than those from ICSI-girls (n = 79), IVF-girls (n = 5), and IVF-boys (n = 2). We also found that varying oxygen conditions, RNA polymerase II subunit A (Polr2A), and lysine demethylase 5A (KDM5A) regulated H3K4me3. These findings revealed a difference between IVF and ICSI and a difference between boys and girls in H3K4me3 modification, providing greater insight into ART-associated epigenetic alteration.  相似文献   
48.
49.
The aim of this study was to analyze the expression of peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RxRα), a binding heterodimer playing a pivotal role in the successful trophoblast invasion, in the placental tissue of preeclamptic patients. Furthermore, we aimed to characterize a possible interaction between PPARγ and H3K4me3 (trimethylated lysine 4 of the histone H3), respectively H3K9ac (acetylated lysine 9 of the histone H3), to illuminate the role of histone modifications in a defective trophoblast invasion in preeclampsia (PE). Therefore, the expression of PPARγ and RxRα was analyzed in 26 PE and 25 control placentas by immunohistochemical peroxidase staining, as well as the co-expression with H3K4me3 and H3K9ac by double immunofluorescence staining. Further, the effect of a specific PPARγ-agonist (Ciglitazone) and PPARγ-antagonist (T0070907) on the histone modifications H3K9ac and H3K4me3 was analyzed in vitro. In PE placentas, we found a reduced expression of PPARγ and RxRα and a reduced co-expression with H3K4me3 and H3K9ac in the extravillous trophoblast (EVT). Furthermore, with the PPARγ-antagonist treated human villous trophoblast (HVT) cells and primary isolated EVT cells showed higher levels of the histone modification proteins whereas treatment with the PPARγ-agonist reduced respective histone modifications. Our results show that the stimulation of PPARγ-activity leads to a reduction of H3K4me3 and H3K9ac in trophoblast cells, but paradoxically decreases the nuclear PPARγ expression. As the importance of PPARγ, being involved in a successful trophoblast invasion has already been investigated, our results reveal a pathophysiologic connection between PPARγ and the epigenetic modulation via H3K4me3 and H3K9ac in PE.  相似文献   
50.
In flame spray pyrolysis (FSP), the evolution of metal oxide nanoparticles relies on quite a number of droplet (liquid) and vapor phase related physical mechanism as for instance precursor evaporation, oxidation, nucleation via gas-to-particle conversion mechanism, and subsequent particle (solid) growth mechanisms based on coagulation, sintering/coalescence, and agglomeration. The liquid precursor and dispersion oxygen feed rates are relevant control parameters of the FSP process for tailoring the nanoparticle size (diameter) and structure as well as the atomizer nozzle configuration. Sophisticated nonintrusive, laser-based in situ and ex situ diagnostics with multiscale spatial resolution (micrometer to meter range) are applied for analyzing droplet formation and size, gas velocity, temperature, species concentration, as well as primary and agglomerate diameters along the flow direction. Computational fluid dynamics (CFD) are coupled with population balance modeling (PBM) to elucidate the nanoparticle dynamics within the reactive spray. It is found that the CFD-PBM approach allows estimations of primary and agglomerate nanoparticle diameters within 80 and 75% accuracy compared to experimental data, suggesting that the methods presented could pave the way for designing next-generations of flame reactors.  相似文献   
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