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21.
22.
It has been found that carbon dioxide gas is an efficient acid-catalyst to promote hydrolysis of a solution of sucrose. The conditions for this reaction to proceed have been found to be dependent on the partial pressure of the gas. 相似文献
23.
Raquel Rodríguez‐Solana Jorge Dias Carlier Maria Clara Costa Anabela Romano 《Journal of the Institute of Brewing》2018,124(3):300-309
Carob pod, fig and almond liqueurs are produced in various Mediterranean regions. This work reports the mineral content of these traditional beverages and evaluates the influence of the raw material. Twenty‐five fruit liqueurs from 16 producers were analysed. A simple open‐vessel sample mineralization by wet digestion using nitric acid–hydrogen peroxide (1:1) was used before spectrometric analysis. Nine essential elements (Cu, Ca, Mg, Na, K, Fe, Zn, Mn and P) and two non‐essentials (Cd and Pb) were quantified by microwave plasma–atomic emission spectrometry (MP‐AES). Carob liqueur presented the broader profile of minerals and was the only fruit liqueur containing iron (72.7% of samples), phosphorous, manganese and low levels of lead (in two of the 11 samples). Conversely, almond liqueurs contained the lowest mineral content with only five elements detected. Fruit liqueurs showed variability in mineral content even within the same liqueur, presumably as a consequence of the different manufacturing processes. Despite this variability, application of principal component analysis to essential mineral concentrations (K, Na, Ca, Mg, Mn, Fe and Zn) resulted in satisfactory classification (PC1 and PC2 accounting for 78.5% of the total variance) of the Portuguese liqueurs evaluated. Copyright © 2018 The Institute of Brewing & Distilling 相似文献
24.
Ângela Fernandes João C. M. Barreira Amilcar L. Antonio M. Beatriz P. P. Oliveira Anabela Martins Isabel C. F. R. Ferreira 《Food and Bioprocess Technology》2014,7(6):1606-1617
Mushrooms are very perishable foods due to their high susceptibility to moisture loss, changes in color and texture, or microbiological spoilage. Drying is considered as the most appropriate method to prevent these alterations, but it has some limitations, such as shrinkage, enzymatic and non-enzymatic browning reactions, and oxidation of lipids and vitamins. According to previous studies, irradiation might effectively attenuate the undesirable changes caused by drying process, ensuring also higher shelf-life of mushrooms and their decontamination. Electron-beam irradiation presents some technological advantages, since it allows higher dose rates and the possibility to be used in most foods/or thin products in a short period. Herein, the combined effects of electron-beam irradiation (0, 0.5, 1 and 6 kGy) and storage time (0, 6 and 12 months) were evaluated by measuring changes in nutritional parameters, namely, free sugars, tocopherols, fatty acids and antioxidant activity. As indicated by linear discriminant analysis, storage time had a higher effect on all the evaluated parameters, except fatty acids, which suffer significant changes with both factors. Overall, the obtained results indicate that electron-beam irradiation might be considered as a suitable technique, allowing long-lasting conservation periods while reducing changes induced by drying treatment. 相似文献
25.
Joana Tavares Dr. Ali Ouaissi Dr. Paul Kong Thoo Lin Prof. Dr. Inês Loureiro Simranjeet Kaur Nilanjan Roy Dr. Anabela Cordeiro‐da‐Silva Prof. Dr. 《ChemMedChem》2010,5(1):140-147
The NAD+‐dependent deacetylases, namely sirtuins, are involved in the regulation of a variety of biological processes such as gene silencing, DNA repair, longevity, metabolism, apoptosis, and development. An enzyme from the parasite Leishmania infantum that belongs to this family, LiSIR2RP1, is a NAD+‐dependent tubulin deacetylase and an ADP‐ribosyltransferase. This enzyme's involvement in L. infantum virulence and survival underscores its potential as a drug target. Our search for selective inhibitors of LiSIR2RP1 has led, for the first time, to the identification of the antiparasitic and anticancer bisnaphthalimidopropyl (BNIP) alkyl di‐ and triamines (IC50 values in the single‐digit micromolar range for the most potent compounds). Structure–activity studies were conducted with 12 BNIP derivatives that differ in the length of the central alkyl chain, which links the two naphthalimidopropyl moieties. The most active and selective compound is the BNIP diaminononane (BNIPDanon), with IC50 values of 5.7 and 97.4 μM against the parasite and human forms (SIRT1) of the enzyme, respectively. Furthermore, this compound is an NAD+‐competitive inhibitor that interacts differently with the parasite and human enzymes, as determined by docking analysis, which might explain its selectivity toward the parasitic enzyme. 相似文献
26.
Luciano Senff Pedro A. Barbetta Wellington L. Repette Dachamir Hotza Helena Paiva Victor M. Ferreira João A. Labrincha 《Construction and Building Materials》2009,23(10):3107-3111
This paper reports the effects of distinct contents of silica fume (SF), superplasticizer (SP) and water/binder ratio (W/B) in mortars. Samples with SF (0–10 wt%), SP (1.0–1.2 wt%) and W/B ratio (0.30–0.35) were produced. Flow table test and rheometry were used as parameters to formulate mortars by means of a factorial design experiment. Setting time, water absorption, apparent porosity and compressive strength of mortars at 28 days were also determined. Mortar formulations with lower fluidity are restricting when a rheometer was used. For higher torques, adjustments with the regressive equation of the Bingham model are less accurate, since the flow behavior is less constant. On the other hand, mortars with higher fluidity it is limited by spread test. The spread value on flow table test is more related to yield stress than to plastic viscosity. The design experiments identified the main factors (SF, SP and W/B) and their interactions for all properties on the fresh and hardened state, showing that experimental design with multiple regression equations is an appropriate tool to be applied in this case. Water content was the controlling parameter for practically all properties studied. 相似文献
27.
Results of copper–gold rougher-flash flotation in a three-product column (3PC) are presented, and separation parameters are compared with results of an existing industrial small mill (rougher–scavenger–cleaner treating 100–120 t/day). This 3PC cell yielded 2%–5% richer Cu and Au concentrate grades at higher recoveries (5% RCu and 15% RAu, respectively) while consuming only 5% of the circuit energy and occupying 10% of the actual footprint. The flotation of the fresh tailings from the same industrial circuit was also successful in recovering more than 40% of the copper losses and 25% of the gold losses with concentrate grades that were high enough to permit recycling of the recovered copper and gold. The cleaning action of the cell is due to the selective separation of the third product (froth drop-back), which corresponded to a low-grade material amenable for discard. This third product is primarily composed of misplaced (entrained) gangue particles, and the mass recoveries were found to be a function of froth height with an optimal value varying from 40 to 60 cm. Results are discussed in terms of the high potential of this 3PC cell and the positive impact on the design of a more simplified and efficient flotation flowsheet. 相似文献
28.
Christiane Reis Fonseca José Luiz Paiva Eva Maria Rodriguez Fernando Juan Beltrán Antonio Carlos Silva Costa Teixeira 《臭氧:科学与工程》2017,39(4):255-263
The sugar industry is concerned with color formation due to the oxidation of phenolic compounds in the presence of carbohydrates. In this study, we investigated the ozonation of a mixture of five phenolic compounds in water and aqueous sucrose solution: p-coumaric (p-COU), caffeic (CAF), syringic (SYR), and chlorogenic (CHO) acids, as well as the flavonoid quercetin (QUE). The experiments were carried out in a 3-L glass reactor with magnetic stirring and a diffuser plate at the bottom to feed the ozone-oxygen gas mixture. Initial solution concentrations of 5 mg L?1 of each acid, 15 mg L?1 of quercetin, and 40 g L?1 of sucrose were used. The degradation of phenolic compounds followed apparent first-order kinetics, with rate constants and percent removals decreasing in the presence of sucrose. In water, average consumed ozone dosages of 10.4 and 18.7 mg L?1 were necessary for 50% and 90% removals, respectively, for CHO, CAF, and p-COU; for QUE they were slightly higher (13.9 and 20.5 mg L?1, respectively). At a consumed dosage of 20.8 mg O3 L?1, more than 99% removal was obtained for CHO, CAF, and p-COU, while 96.2% was achieved for SYR. In contrast, QUE revealed to be more recalcitrant during ozonation in the absence of sucrose, with only 70% removal at the highest consumed O3 dosage. The consumed ozone dosages for 50% and 90% removals were higher for CHO, CAF, and p-COU in aqueous sucrose solution, which may impact ozone consumption during real sugarcane juice treatment. Sucrose and t-butanol were the main influential parameters that significantly affected the total amount of phenolic compounds degraded. 相似文献
29.
Fabricio J. Pontes João R. Ferreira Messias B. Silva Anderson P. Paiva Pedro Paulo Balestrassi 《The International Journal of Advanced Manufacturing Technology》2010,49(9-12):879-902
In recent years, several papers on machining processes have focused on the use of artificial neural networks for modeling surface roughness. Even in such a specific niche of engineering literature, the papers differ considerably in terms of how they define network architectures and validate results, as well as in their training algorithms, error measures, and the like. Furthermore, a perusal of the individual papers leaves a researcher without a clear, sweeping view of what the field’s cutting edge is. Hence, this work reviews a number of these papers, providing a summary and analysis of the findings. Based on recommendations made by scholars of neurocomputing and statistics, the review includes a set of comparison criteria as well as assesses how the research findings were validated. This work also identifies trends in the literature and highlights their main differences. Ultimately, this work points to underexplored issues for future research and shows ways to improve how the results are validated. 相似文献
30.
Ana Paiva Gerd Andersson Kristina Höök Dário Moura˜o Marco Costa Carlos Martinho 《Personal and Ubiquitous Computing》2002,6(5-6):378-389
We describe the design process of an affective control toy, named SenToy, used to control a synthetic character in a computer game. SenToy allows players to influence the emotions of a synthetic
character placed in FantasyA, a 3D virtual game. By expressing gestures associated with anger, fear, surprise, sadness and
joy through SenToy, players influence the emotions of the character they control in the game. When designing SenToy we hypothesized
that players would manipulate the toy to express emotions using a particular set of gestures. Those gestures were drawn from
literature on how we express emotions through bodily movements and from emotion theories. To evaluate our idea we performed
a Wizard Of Oz study [1]. The results of the study show that there are behaviours that players easily pick up for expressing
emotions through the gestures with the toy, though not necessarily the ones extracted from literature. The study also provided
some indication on what type of toy we should build, in particular, its ‘look and feel’.
Correspondence to: Ms A. Paiva, IST & Instituto de Engenharia de Sistemas e Computadores, Rua Alves Redol 9, 1000 Lisboa, Portugal. Email: Ana.Paiva@inesc.pt 相似文献