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271.
Pesticides have become more necessary in modern agricultural production. However, these pesticides have an unforeseeable long-term impact on people's wellbeing as well as the ecosystem. Due to a shortage of basic pesticide exposure awareness, farmers typically utilize pesticides extremely close to harvesting. Pesticide residues within foods, particularly fruits as well as veggies, are a significant issue among farmers, merchants, and particularly consumers. The residual concentrations were far lower than these maximal allowable limits, with only a few surpassing the restrictions for such pesticides in food. There is an obligation to provide a warning about this amount of pesticide use in farming. Previous technologies failed to forecast the large number of pesticides that were dangerous to people, necessitating the development of improved detection and early warning systems. A novel methodology for verifying the status and evaluating the level of pesticides in regularly consumed veggies as well as fruits has been identified, named as the Hybrid Chronic Multi-Residual Framework (HCMF), in which the harmful level of used pesticide residues has been predicted for contamination in agro products using Q-Learning based Recurrent Neural Network and the predicted contamination levels have been analyzed using Complex Event Processing (CEP) by processing given spatial and sequential data. The analysis results are used to minimize and effectively use pesticides in the agricultural field and also ensure the safety of farmers and consumers. Overall, the technique is carried out in a Python environment, with the results showing that the proposed model has a 98.57% accuracy and a training loss of 0.30.  相似文献   
272.
A new approach for the synthesis of homoallylic alcohols and amines directly from alcohols via one‐pot sequential oxidation–Barbier reaction and oxidation–condensation–Barbier reactions, respectively, is reported. The protocol involves the one‐pot ferric chloride‐catalyzed oxidation of alcohols to the corresponding aldehydes with chloramine‐T followed by indium‐mediated Barbier allylation with allyl bromide to afford homoallylic alcohols in 70–90% overall yields. The ferric chloride‐catalyzed condensation of aldehydes and oxidation by‐product p‐toluenesulfonamide followed by indium‐mediated Barbier‐type allylation of the resulting aldimines with allyl bromide affords homoallylic amines in 60–80% overall yields in the same reaction vessel. The present work demonstrates a new one‐pot approach toward homoallylic alcohol and amine synthesis directly from alcohols.  相似文献   
273.
Two‐ and three‐dimensional numerical simulations have been performed on a laboratory scale bubble column reactor using a volume‐of‐fluid approach. The effect of hole‐size and superficial gas velocity on the bubble size distribution and their trajectories has been investigated on a 20 cm diameter and 1 m high cylindrical reactor. All simulations were performed in a transient manner using a FLUENT solver. Surface tension between two phases has been modelled as a body force with a constant value. Turbulence was modelled using the k‐? turbulence approach. A comparison between simulation predictions and the reported experimental studies has shown a good agreement.  相似文献   
274.
Increasing water scarcity and stringent environmental regulation have necessitated effective water conservation policies. Pinch analysis has been proved as one of the powerful tools to locate targets of waste water minimization. Two earlier water pinch targeting methods known as Water Cascade Analysis and Material Recovery Pinch Diagram have focused on the “threshold problems”. However, these methodologies have not systematically analyzed the introduction of external utility. In this work, three scenarios are proposed for this reason. The “Infeasible Threshold Problem” is addressed prior to employing external utility through the proposed scenarios. By systematically analyzing this specific problem, it is revealed that existing Water Cascade Analysis method cannot locate correct infeasible targets. Some adjustments are proposed to deal with this drawback. Moreover, to illustrate the applicability of proposed scenarios, Water Cascade Analysis and Material Recovery Pinch Diagram approaches are utilized for addressing a literature problem as a case study. It is shown that harvesting the impure fresh water source with a higher quality, in the “threshold problem with zero discharge”, leads to more pure fresh water saving.  相似文献   
275.
BACKGROUND: Sorghum (Sorghum bicolor (L.) Moench) is an important coarse cereal crop grown for grain and fodder in the semi‐arid Tropics, mainly in Asian and African countries. In India sorghum is consumed as human food and poultry feed. Sorghum grain grown in the rainy season (kharif) is becoming severely affected by grain moulds, the major fungi involved being Aspergillus, Fusarium and Curvularia. If the extent of mould is severe, the grain is unsafe for consumption owing to contamination by mycotoxins. RESULTS: This paper presents a multi‐centre study conducted in sorghum to evaluate natural contamination of aflatoxin B1 in India. A total of 1606 grain sorghum samples were collected during the rainy (kharif) season across 4 years from seven states of India, representing different geographical regions of the country. Aflatoxin B1 contamination during 2007–08 was the highest (13.1%), followed by samples from the year 2004–05 (2.85%). The samples collected in years 2005–06 and 2006–07 showed contamination below 1%. The number of samples (35) showing aflatoxin B1 contamination above the safety limit was also highest during 2007–08 as compared to samples from the other years. CONCLUSION: This study, conducted for 4 years, showed that natural contamination of aflatoxin B1 in sorghum grown in India is within safety limits (20 µg kg?1) recommended by the Codex Alimentarius Committee and 73% of samples were positive for toxin. However, 0.75% (12) of total samples contained aflatoxin above the safety limit. The overall occurrence of toxin from Madhya Pradesh and Rajasthan was below 5 µg kg?1. Copyright © 2012 Society of Chemical Industry  相似文献   
276.
Various mono and bicyclic pyrimidine analogs ( 3–15 ) were prepared as leishmanicides from 6-aryl-4-chloro-2-methylthiopyrimidine-5-carbonitrile ( 2 ), obtained from the halogenation of 6-aryl-3,4-dihydro-2-methylthio-4-oxopyrimidine-6-carbonitrile ( 1 ).  相似文献   
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