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101.
Reproductive isolation among four sympatric small ermine moths (Yponomeuta) is analyzed in terms of niches in the sexual communication channel. Potential pheromone components were identified from pheromone gland secretions ofY. evonymellus,Y. cagnagellus,Y. padelius, andY. vigintipunctatus by gas chromatography with flame ionization and electroantennographic detection and tested for behavioral activity in the field. The species were found to share (Z)-11-tetradecenyl acetate (Z11-14: OAc) in combination with varying proportions of theE isomer as primary sex pheromone components.Y. cagnagellus differs from the rest of the species by having only a small amount (1.5%) ofE isomer relative toZ isomer in its pheromone. The closely relatedY. padelius has a three-component pheromone including large amounts (ca. 400%) of (Z)-11-hexadecenyl acetate (Z11–16:OAc) in addition toZ11–14: OAc (100%) andE11–14: OAc (34%).Z11–16: OAc appears to reduce trap catches ofY. evonymellus andY. vigintipunctatus when added to the pheromone. Although these species are the two most distantly related European small ermine moths, they seem to share the same sex pheromone, i.e.,Z11–14OAc (+20%E) and (Z)-11-tetradecenol. Our interpretation is that this might have been the sex pheromone of the ancestor of today'sYponomeuta species.1 Lepidoptera: Yponomeutidae Latr.  相似文献   
102.
The dynamic mechanical properties of paper during restrained drying are reported in this article. The apparatus used was a servohydraulic material testing system (MTS), connected to a computer unit. It has been found that the ratio of drying stress to elastic modulus at a given dry solids content corresponds to the instantaneous linear contraction of the sheet when the drying stress is relieved. It is therefore deduced that paper behaves as a linear viscoelastic body during restrained drying. The finding of a maximum loss coefficient and the drastic change in elastic modulus during drying of paper are interpreted in terms of a transitional change in the amorphous regions of wood polymers plasticized by water.  相似文献   
103.
The drop size distribution of vinyl chloride in water emulsions has been studied using a photographic technique. A large difference in coalescence stability was observed between emulsions stabilized by a poly(vinyl alcohol), Rhodoviol 5/270, and those stabilized by a cellulose ether, Methocel MF50. Experiments simulating the transport of a monomer soluble initiator to the monomer phase of a coalescence stable vinyl chloride in water emulsion showed that the manner of introducing the initiator may have large consequences on the polymerization process.  相似文献   
104.
A comparison of catabolic capacity was made between S. cerevisiae cells subjected to 24 h carbon or nitrogen starvation. The cells were shifted to starvation conditions at the onset of respiratory growth on ethanol in aerobic batch cultures, using glucose as the carbon and energy source. The results showed that the catabolic capacity was preserved to a much larger extent during carbon compared to nitrogen starvation. Nitrogen starvation experiments were made in the presence of ethanol (not glucose) to exclude the effect of glucose transport inactivation (Busturia and Lagunas, 1986). Hence, the difference in catabolic capacity could not be attributed to differences in glucose transport capacity during these conditions. In order to understand the reason for this difference in starvation response, measurement of protein composition, adenine nucleotides, inorganic phosphate, polyphosphate and storage carbohydrates were performed. No clear correlation between any of these variables and catabolic capacity after starvation could be obtained. However, there was a positive correlation between total catabolic activity and intracellular ATP concentration when glucose was added to starved cells. The possible mechanism for this correlation, as well as what determines the ATP level, is discussed.  相似文献   
105.
In this article, we explore how the key concepts of lean manufacturing, value, value adding and waste are conceived and operationally used by Lean trainers in operational work processes. A comparative case study with a mixed method approach, using an explanatory sequential design, was conducted. This means that a set of quantitative data were collected, which was followed by the collection of qualitative data with the purpose of explaining and understanding the quantitative measures. An interpretivist approach is used as a framework, which implies a perspective on contemporary operations management paradigms, such as lean manufacturing, as a continuous construction of inter-subjective experiences. What becomes evident in the empirical findings is that there are both similarities and differences in the Lean trainers conceptions and use of value adding and waste. The similarities and differences can be explained by variations in two dimensions: (a) the character of the work process, which ranges between mechanical and craftsmanship, and (b) Lean trainers approach to key concepts, which ranges between being rule-based and reflective. By using a research design where the concepts of value adding and waste were used simultaneously, and adopting an interpretivist approach on lean manufacturing, we were able to reveal conditions that in other cases remain hidden.  相似文献   
106.
The dynamic use of voice qualities in spoken language can reveal useful information on a speakers attitude, mood and affective states. This information may be very desirable for a range of, both input and output, speech technology applications. However, voice quality annotation of speech signals may frequently produce far from consistent labeling. Groups of annotators may disagree on the perceived voice quality, but whom should one trust or is the truth somewhere in between? The current study looks first to describe a voice quality feature set that is suitable for differentiating voice qualities on a tense to breathy dimension. Further, the study looks to include these features as inputs to a fuzzy-input fuzzy-output support vector machine (F2SVM) algorithm, which is in turn capable of softly categorizing voice quality recordings. The F2SVM is compared in a thorough analysis to standard crisp approaches and shows promising results, while outperforming for example standard support vector machines with the sole difference being that the F2SVM approach receives fuzzy label information during training. Overall, it is possible to achieve accuracies of around 90% for both speaker dependent (cross validation) and speaker independent (leave one speaker out validation) experiments. Additionally, the approach using F2SVM performs at an accuracy of 82% for a cross corpus experiment (i.e. training and testing on entirely different recording conditions) in a frame-wise analysis and of around 97% after temporally integrating over full sentences. Furthermore, the output of fuzzy measures gave performances close to that of human annotators.  相似文献   
107.
金属切削加工车间总是致力于获得更好的质量、更高的一致性及更快的产出,同时也非常关注控制或降低成本。为满足更高的性能标准或更低的单位成本,加工中心与多任务机床正不断更新换代。可转位刀片能够显著降低成本,不过随着切削速度的提高,要获得高质量的加工、  相似文献   
108.
刀具的一致性 (1)一致性是确保螺纹车削最佳质量和生产效率的关键如果螺纹质量在生产过程中不能保证前后的一致性,那么加工将毫无戍本效益可言。在任何生产状况下,出现停机和废品都会降低生产效率和经济效益。  相似文献   
109.
加工航空零件时所用冷却液的角色正在经历一定程度的演变。加工车间多年来的做法是:直接将冷却液冲向加工区域,特别是对于需要使用冷却液加工的材料。现在,高压冷却技术可将冷却液精准地导向加工区域,能够获得一些新的益处。随着与之配套的全新刀具概念的推出,高压冷却技术已经在很多现代化的数控机床上广泛地使用。  相似文献   
110.
This longitudinal study investigated whether smoking bans influence passive smoking at work and/or at home in the same subjects. Passive smoking at work and/or at home was investigated in random population samples (European Community Respiratory Health Survey) in 1990‐1995, with follow‐up interviews in 1998‐2003 and 2010‐2014. National smoking bans were classified as partial (restricted to public workplaces) or global (extended to private workplaces). Multivariable analysis was accomplished by three‐level logistic regression models, where level‐1, level‐2, and level‐3 units were, respectively, questionnaire responses, subjects, and centers. Passive smoking at work was reported by 31.9% in 1990‐1995, 17.5% in 1998‐2003, and 2.5% in 2010‐2014. Concurrently, passive smoking at home decreased from 28.9% to 18.2% and 8.8%. When controlling for sex, age, education, smoking status, and ECHRS wave, the odds of passive smoking at work was markedly reduced after global smoking bans (OR = 0.45, 95% CI 0.25‐0.81), particularly among non‐smokers, while the protective effect of global smoking bans on passive smoking at home was only detected in non‐smokers. Smoking bans both in public and private workplaces were effective in reducing passive smoking at work in Europe. However, given the inefficacy of smoking bans in current smokers’ dwellings, better strategies are needed to avoid smoking indoors.  相似文献   
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