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981.
982.
Aranzazu García Manuel Brenes Mª Carmen Dobarganes Concepción Romero Ma Victoria Ruiz‐Méndez 《European Journal of Lipid Science and Technology》2008,110(12):1136-1141
Triterpenic acids are natural compounds present in plants and foods with beneficial properties for human health and thus they are desirable in the food, cosmetics and pharmaceutical industries. Pomace olive is considered a good source of these substances. In this study, oleanolic and maslinic acids were found to be the main triterpenic acids identified in pomace olive oil obtained from stored “Alpeorujo”. Determination of the two acids was achieved by a new procedure that consists of extracting the acids from the oil with a mixture of methanol/ethanol, and then separating and quantifying them by HPLC. Results showed that their concentration increased up to 16 g/kg of oil during storage of the pomace in large ponds for 7 months. The concentration of both triterpenic acids was similar in the pomace olive oil obtained by using the centrifugation system. By contrast, a much lower concentration of maslinic than oleanolic acid was detected in pomace olive oils obtained by solvent extraction from the previously centrifugated “Alpeorujo” paste. These triterpenic acids also contributed to the acidity of the crude oil. Likewise, the oil of the pomace paste was enriched in other substances such as 4‐ethylphenol and aliphatic alcohols during the storage of the paste in large ponds. Consequently, crude pomace olive oil can be considered a good source of triterpenic acids when obtained from a stored olive paste. 相似文献
983.
A detailed knowledge of dependence of mechanical properties on orientation in materials prepared by directional processes
may present an important factor influencing the design of construction parts. Toward this end, the compressive creep testing
of short specimens may be useful. Three different magnesium-based materials were subjected to this testing: (i) pure magnesium,
(ii) magnesium matrix composite reinforced with 10 vol.% of titanium, and (iii) magnesium alloy WE54. All three materials
were prepared through a powder metallurgical route with final hot extrusion. The specimens for creep tests were cut in such
a way that their longitudinal axis (i.e., the direction of compressive creep stress) and the axis of extruded bar contained
a predestined angle. Two extreme cases can be observed: In pure Mg and in Mg-Ti composites, the dependence of the creep rate
is very sensitive to the orientation especially at small inclinations from extrusion axis. The greatest creep resistance is
observed in specimens with stress axis parallel to the extrusion axis, the lowest at declinations from 45 to 90°. On the other
hand, in WE54 no orientation dependence was observed. Possible explanations of the behavior based on microstructural observations
are discussed.
__________
Translated from Problemy Prochnosti, No. 1, pp. 125–128, January–February, 2008. 相似文献
984.
Perán M García MA López-Ruiz E Bustamante M Jiménez G Madeddu R Marchal JA 《International journal of molecular sciences》2012,13(3):3847-3886
In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application. 相似文献
985.
Astobiza I Ruiz-Fons F Piñero A Barandika JF Hurtado A García-Pérez AL 《Journal of dairy science》2012,95(4):1632-1638
A large-scale investigation on Coxiella burnetii was carried out in dairy cattle herds from a Q fever-endemic region to evaluate the degree of exposure to C. burnetii and to estimate prevalences. This study included all of the dairy cattle herds from the province of Bizkaia, Northern Spain (n=178). Herds were visited between September 2009 and February 2010, and 100mL of bulk-tank milk (BTM) per farm was collected to be analyzed by ELISA and PCR. Blood samples were also taken from about 15 animals randomly selected from each herd. One hundred nineteen of the 178 studied herds (66.9±6.9%) were positive for the presence of anti-C. burnetii antibodies in BTM. Serum samples from 1,306 cows, 654 heifers, and 502 calves were analyzed by ELISA, and cows showed a statistically significantly higher seroprevalence (12.3±1.8%) than heifers (1.1±0.8%) and calves (0.0±0.0%). Eighty-nine herds (50.0±7.3%) had at least 1 seropositive animal, but within-herd prevalences higher than 20% were only observed in 24 herds (13.5±5.0%). A significant correlation was observed between BTM ELISA sample-to-positive control ratios and within-herd seroprevalence, being higher when considering only cows (R(2)=0.21). Animals from herds with negative BTM by ELISA showed a mean seroprevalence of 2.5%, whereas animals from herds with positive BTM samples had a statistically significantly higher seroprevalence (8.9%, F=19.7, degrees of freedom=1). The proportion of herds C. burnetii positive by BTM PCR was 51.7±7.3% (92/178). The widespread distribution of C. burnetii in cattle advocates for the implementation of Q fever control strategies. 相似文献
986.
X Valldecabres-Torres E García-Roselló A García-Muñoz J Cuervo-Arango 《Journal of dairy science》2012,95(8):4389-4395
Luteolysis is a key event in cattle reproduction. A standard dose of exogenous PGF(2α) will induce full luteolysis in the majority of cows with a matured corpus luteum (CL). However, this will not occur in cows with a CL <5d old. To date, it is not known whether a larger dose will have a more potent luteolytic effect in cows during early diestrus. The objective of this study was to characterize the effect of 2 doses of d-cloprostenol (150 and 300 μg) on the progesterone concentration, luteal diameter, and ovulation rate in nonlactating dairy cattle 96 to 132 h postovulation. Twenty nonlactating dairy cows were included in the study. Each cow received 2 treatments of d-cloprostenol in 2 consecutive cycles: a standard dose of 150 μg and a double dose of 300 μg. The cows were allocated randomly to 1 of 4 groups (5 cows in each group) according to the age of the CL at the time of treatment: 96, 108, 120, and 132 h. The exact time of ovulation was known within 12h, because of twice per day ultrasound examination. The CL diameter and progesterone concentration were measured before treatment (d 0) and 2 and 4d after treatment. Within each CL age group, the effect of d-cloprostenol dose on luteolysis was determined. More cows treated with double dose tended to have full luteolysis compared with the standard dose (8/10 vs. 4/10, respectively). This effect was only apparent in cows with CL of 120 and 132 h but not in earlier CL. The interval from treatment to ovulation was shorter (3.3 ± 0.1d) in cows treated with a double dose than in cows treated with the standard dose (4.5 ± 0.4d). 相似文献
987.
Kharla A. Segovia‐Bravo Pedro García‐García Antonio López‐López Antonio Garrido‐Fernández 《Journal of food science》2012,77(5):S194-S201
Abstract: Subjecting bruised olives to a nitrogen atmosphere during the postharvest period prevented the oxidation of phenols and subsequent browning. However, a rapid phenol oxidation and browning occurred when fruits were re‐exposed to air. Based on models deduced from the effects of aqueous antioxidant solutions on changes in different color parameters in the fermented product, the treatments to prevent browning were optimized. The recommended procedure consists of placing the harvested olives in a cold (4 to 8 °C) solution of 3% sodium metabisulfite with the pH adjusted to 3.0 (by adding food grade HCl) and applying the lye treatment before 8 h from picking. The use of these conditions led to mechanically harvested Spanish style olives with hardly any visible browning. Practical Application: The procedure developed may be applicable to prevent browning on the bruised areas of manually or mechanically harvested olives. The system is simple, requires low investment, and may lead, in fermented olives, to undetectable differences between undamaged and bruised areas and better ratings in the visual observation of healthy fruits. 相似文献
988.
María del Carmen Rodríguez‐Hernández Diego A. Moreno Micaela Carvajal Cristina García‐Viguera María del Carmen Martínez‐Ballesta 《Journal of food science》2012,77(10):C1058-C1063
Abstract: Broccoli, (Brassica oleracea var. Italica), is generally recognized as a nutritive food rich in natural antioxidants, including vitamins and phenolics compounds. Phytochemical composition of 3 different purple sprouting broccoli varieties according with their production cycle: EEP (Extra Early), EP (Early), and LP (Late) were determined. The 3 cultivars tested were grown under the same conditions in an experimental field (SE Spain) where they were not previously cultivated since these cultivars are typical of cold, Northern‐European areas. EP variety showed greater growth according to the photosynthetic rate and C assimilation. However, it was not possible to obtain inflorescences for variety LP. The health‐promoting compounds (vitamin C, phenolic compounds, and glucosinolates) were higher in purple broccolis than in traditionally grown green broccolis and showed differences according to the variety. With respect to the use of broccoli byproducts as source of antioxidants, any variety would be suitable although the leaves of EP variety seems the richest in total phenolic acids, whereas the amount of anthocyanins was higher in LP variety, followed by EP and EEP varieties. Under our experimental conditions, the levels of glucosinolates were higher in purple broccoli than in green cultivars and also higher than other purple broccolis grown under different climate conditions. Therefore, the results reported data for production of the EEP and EP varieties in the Mediterranean climate with potential to obtain vegetables with improved nutritional quality. Practical Application: The results of this study reported data of the health‐promoting nutrients and natural antioxidants of EEP, EP, and LP purple sprouting broccoli varieties grown under the Mediterranean climate. The vitamin C, phenolic compounds, and glucosinolates in these purple varieties were higher than in traditionally grown green broccolis and other purple broccolis grown under different climate conditions. 相似文献
989.
García-Martínez S Gálvez-Sola LN Alonso A Agulló E Rubio F Ruiz JJ Moral R 《Journal of the science of food and agriculture》2012,92(6):1178-1185
BACKGROUND: Several tomato landraces are very popular in south‐eastern Spain for their organoleptic fruit quality, but these cultivars are highly susceptible to several viruses. A breeding programme is being carried out for the introduction of virus resistances into these landraces. In the last steps of our breeding programme a high number of breeding lines must be evaluated for agronomic and organoleptic quality parameters. Near infrared reflectance spectroscopy (NIRS) technology shows considerable promise and is ideally suited to the requirements of breeders. RESULTS: Significant differences between a set of 35 tomato breeding lines, seven landraces and one commercial hybrid were observed for quality and mineral content parameters, suggesting that there are considerable levels of genetic diversity between the cultivar groups studied. Using NIRS on dry samples of tomato constitutes a feasible technique to estimate the content of several minerals (C, N, P, K, Ca, Na, Mn, Mg and Cu) according to the coefficient of determination for calibration (R2 > 0.90). NIRS estimations of soluble solids content and titratable acidity obtained were considered useful only for general screening purposes. CONCLUSIONS: NIRS technology may be a useful tool in the selection of lines coming out of tomato breeding programs, allowing a quick estimation of mineral content. However, the estimation of soluble solids content and titratable acidity by NIRS must be improved. Copyright © 2011 Society of Chemical Industry 相似文献
990.
Pavón MÁ González I de la Cruz S Martín R Lacarra TG 《Journal of the science of food and agriculture》2012,92(1):74-77
BACKGROUND: Detection and quantification of ochratoxin A (OTA) in dried fig samples purchased in Spain has been carried out using high‐performance liquid chromatography with fluorescence detection after extraction with methanol and sodium bicarbonate, and clean‐up by using an immunoaffinity column. RESULTS: The detection limit of the method was 0.06 ng g?1, and the limit of quantification 0.18 ng g?1. OTA was detected in 31 (88.6%) out of 35 samples of dried figs analysed, with concentrations that ranged from < 0.1 to 277 ng g?1. However, only three samples contained OTA concentrations above the tolerable level set by European Commission regulations for dried vine fruits (10 ng g?1). CONCLUSION: The results of this survey show the value of monitoring OTA in dried figs especially if they are home grown. Copyright © 2011 Society of Chemical Industry 相似文献