全文获取类型
收费全文 | 418篇 |
免费 | 18篇 |
专业分类
化学工业 | 123篇 |
金属工艺 | 1篇 |
机械仪表 | 7篇 |
建筑科学 | 30篇 |
能源动力 | 3篇 |
轻工业 | 113篇 |
水利工程 | 3篇 |
石油天然气 | 3篇 |
无线电 | 16篇 |
一般工业技术 | 45篇 |
冶金工业 | 55篇 |
原子能技术 | 1篇 |
自动化技术 | 36篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 25篇 |
2021年 | 20篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 29篇 |
2012年 | 32篇 |
2011年 | 29篇 |
2010年 | 23篇 |
2009年 | 29篇 |
2008年 | 25篇 |
2007年 | 20篇 |
2006年 | 26篇 |
2005年 | 15篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有436条查询结果,搜索用时 0 毫秒
421.
Aline?M.?C.?Racanicci Bente?Danielsen José?Fernando?M.?Menten Marisa?A.?B.?Regitano-d’Arce Leif?H.?SkibstedEmail author 《European Food Research and Technology》2004,218(6):521-524
Dittany (Origanus dictamnus L.) has been compared with rosemary (Rosmarinus officinalis L.) as an antioxidant in pre-cooked meat balls made from chicken breast and added 0.50% salt during chill storage for up to ten days packed in atmospheric air. For an addition of 0.10% of dried leaves, dittany yielded protection of the product against oxidation a little less efficiently but comparable to dried rosemary added at the same concentration. For addition of 0.050%, dittany was less efficient than rosemary, while dittany at this concentration protected vitamin E against degradation in the product during storage even better than rosemary. 相似文献
422.
Giuseppina Adiletta Paola Russo Alessio Crescitelli Marisa Di Matteo 《Food and Bioprocess Technology》2016,9(11):1912-1923
A combined pretreatment of trehalose (0.5 %) and NaCl (0.5 %) solution was applied prior to drying eggplant to reduce shrinkage, browning and loss of polyphenols. Drying behaviour of eggplant slabs was experimentally examined in a convective dryer at temperatures of 50, 60 and 70 °C and at 2.3 m/s air velocity. Then the effects of pretreatment and drying temperature on the quality of the eggplant slabs in terms of microstructure, porosity, colour, total phenolic content, rehydration ratio and texture were investigated. It was noted that the pretreated eggplants (TR) dried more rapidly than the untreated ones (UTR) with a reduction of up to 1/4 of drying time. After drying at 50 and 60 °C, they showed no significant differences (p < 0.05) in terms of White index compared with fresh eggplant (78.59 ± 0.63). They had higher total phenolic content (19.86 and 18.24 mg/g (db), respectively) than the UTR ones (11.91 and 12.89 mg/g (db)), but only for the TR samples at 50 °C the value is not statistically different (p < 0.05) from the fresh ones (20.00 mg/g (db)). The pretreatment can hold also a higher porosity (85, 86 % at 50 and 60 °C, respectively) than the UTR ones (78, 82 %), but scanning electron microscopy (SEM) images indicated a total damage structure of the UTR samples. On the contrary, after the pretreatment, the porous structure was more uniform with more not lacerated cellular walls. Hence, the main effect of pretreatment was of protecting the microstructure of the eggplants by reinforcing the cell walls and to reduce the resistance of the water evaporation by avoiding the structural changes. After rehydration, the pretreated samples absorbed more water (rehydration ratio had almost doubled) than the untreated ones and showed lower firmness (95,500 Nm?1) compared with the untreated ones (132,000 Nm?1). 相似文献
423.
Thirty Large White×Great York gilts were fed six experimental diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20 mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200 mg α-tocopheryl acetate/kg diet). Concentration of α-tocopherol was significantly higher in hams from pigs fed supplemented dietary levels of vitamin E (P<0.0001), but no significant effect of dietary fat was observed. Dietary vitamin E supplementation reduced the concentration of thiobarbituric acid reactive substances after 9 days storage of sliced samples (P<0.0001), while dietary fat source showed no significant effect. Significantly lower oxidation was observed in ham homogenates from pigs fed higher concentrations of monounsaturated fatty acids after 120 min of incubation under pro-oxidant conditions (P=0.013). No effect of dietary treatment was observed in ham volatile aldehyde profile. No significant effect of dietary vitamin E was observed on surface redness during storage, but a significant effect was observed for luminosity after 7 days of storage (P=0.033). Hams from pigs fed diets enriched in monounsaturated fatty acid showed higher ‘a’ values (P=0.040) in stored sliced samples. Sensory evaluation revealed a significant effect of dietary vitamin E on redness of ham slices (P<0.001). Dietary supplementation with vitamin E also produced a significantly higher odour and flavour intensity (P=0.006 and P=0.01 respectively). Dry cured ham samples from pigs fed higher amounts of monounsaturated fatty acids showed a significantly higher consistency fat than those from pigs fed polyunsaturated fatty acids. 相似文献
424.
Gianluigi?Scolari Marisa?VescovoEmail author Carla?Zacconi Alfredo?Bonadé 《European Food Research and Technology》2004,218(3):274-277
The influence of a Lactobacillus plantarum (B4) on the growth of Staphylococcus aureus (Sa4) was verified by impedometric methods in a suitable model reproducing the characteristics of fresh vegetables. The inoculum size of the single strains and their growth temperature were varied according to a Central Composite Design. The results obtained via statistical analysis showed that the temperature affected the growth of both S. aureus and L. plantarum strains. The pathogenic strain, independently of its inoculum size, was inhibited by L. plantarum at all the tested temperatures. A proper combination of specific lactic acid bacteria and storage temperature should improve the safety of the vegetable products. 相似文献
425.
Kich JD Coldebella A Morés N Nogueira MG Cardoso M Fratamico PM Call JE Fedorka-Cray P Luchansky JB 《International journal of food microbiology》2011,151(3):307-313
Swine can carry Salmonella strains that may be transmitted to humans by pork products. This investigation determined the distribution and types of Salmonella in 12 swine finishing herds and a slaughter facility in Santa Catarina, Brazil. A total of 1258 samples, consisting of environmental, feed, carcass, lymph node, and fecal material were collected and submitted to bacteriological isolation of Salmonella. From 487 positive samples, 1255 isolates were recovered and confirmed to be Salmonella. The distribution of positive samples was as follows: finishing pen floors 26% (16/61); feed 29% (42/143); feces 44% (52/119); pooled feces 59% (35/59); slaughter holding pens 90% (36/40); lymph nodes 46% (220/478); pre-chilled carcass surfaces 24% (24/98); and post-chilled carcass surfaces 24% (62/260). The most prevalent serovars were Typhimurium, Panama, Senftenberg, Derby, and Mbandaka. By pulsed-field gel electrophoresis, 1071 isolates were subtyped using XbaI, and duplicate isolates were removed. From the remaining 747 isolates, 163 macrorestriction profiles (pulsotypes) were identified. Six pulsotypes were considered very frequent, occurring in 33 isolates or more. The multiple correspondence analyses showed correlations between pulsotypes from shedding pigs (feces), herd environment (pen floors), and subiliac and prescapular lymph nodes and between lairage and carcass surface samples before and after chilling. All sources of Salmonella investigated contributed to the carrier state; however, pre-slaughter contamination at lairage was the variable most strongly associated with carcass contamination. A total of 59 different antimicrobial resistance profiles were observed in 572 Salmonella isolates. From these isolates, 17% (97/572) were susceptible to all 15 antibiotics tested, 83% (475/572) were resistant to at least one, and 43% (246/572) were resistant to four or more antibiotics (multi-resistant). The AmpGenKanTet profile was the most prevalent in carcass isolates and was associated with farm origin. 相似文献
426.
Biocomposite membranes from biodegradable and biocompatible natural polymers were prepared from sodium alginate solution reinforced with silk fibroin fibers in several fiber content by casting and solvent evaporation. The properties of these biocomposites were investigated by scanning electron microscopy, swelling test, water vapor transmission, mechanical and thermal analyses, and cytotoxicity test. A biocomposite with uniform fiber dispersion and good fiber–matrix interaction was obtained through the incorporation of fibroin fibers in the alginate membrane, even though the fibers were used without any surface treatment to enhance the interfacial adhesion. The incorporation of fibroin fibers improved the tensile strength and also provided a new property to the alginate, that is, the resistance to tear. Moreover, the use of silk fibroin fibers in polymeric composites can result in a material with adequate characteristics for application in the biomaterial field, especially as wound dressings, because of its nontoxic effect to cells, flexibility, and resistance to tear. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3451–3457, 2013 相似文献
427.
J Kjeldsen-Kragh M Haugen O F?rre H Laache UF Malt 《Canadian Metallurgical Quarterly》1994,33(6):569-575
In a controlled, single blind clinical trial we have demonstrated recently a beneficial effect of fasting and vegetarian diet in RA. In the present study we compared 53 patients who participated in this clinical trial with 71 other RA patients with regard to some psychological parameters. The patients who participated in the clinical trial differed significantly from other RA patients. Firstly, they had a higher internal score and a lower chance score on the Multi-dimensional Health Locus of Control Scale (MHLCS). Secondly, their belief in the effect of ordinary medical treatment, evaluated by a 10-cm visual analogue scale, was lower, and their belief in the effect of 'alternative', unconventional forms of treatment was higher. Of the patients who were randomized to a vegetarian diet, there was no significant difference between diet responders and diet non-responders with regard to the MHLCS scores. But, diet responders had a significantly lower belief in the effect of ordinary medical treatment compared with diet non-responders. The psychological distress imposed on the patients by changing from an omnivorous diet to a vegetarian diet was monitored during the clinical trial by means of the General Health Questionnaire. Throughout the clinical trial, this variable favoured the vegetarians compared with the omnivorous and the diet responders vs the diet non-responders. We conclude, firstly, that patients with certain psychological characteristics were selected to the clinical trial; secondly, that the MHLCS scores could not explain the clinical improvement, but it may have been influenced by the patients' beliefs in ordinary and 'alternative' forms of treatment; and thirdly, that dietary treatment decreased psychological distress. 相似文献
428.
Giuseppina Adiletta Marisa Di Matteo Milena Petriccione 《International journal of molecular sciences》2021,22(5)
Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years. 相似文献
429.
Marisa Rodriguez‐Carmona Benjamin E. W. Evans John L. Barbur 《Color research and application》2021,46(1):21-32
The main purpose of this study was to produce reliable, color assessment outcomes to examine the extent to which single and multi‐test protocols in use meet current clinical and occupational needs. The latter include the detection of small changes in chromatic sensitivity as the earliest signs of retinal and/or systemic disease, and the need to assess the class of color vision in congenital deficiency and to quantify severity of loss. Color vision was assessed using Ishihara (IH), Farnsworth Munsell D‐15, City University (CU, 2nd ed.) and Holmes‐Wright type A (HW‐A) lantern tests. All subjects also carried out Colour Assessment and Diagnosis and Nagel anomaloscope tests. The sample included 350 normal trichromats, 1012 deutans and 465 protans (age 31.1 ± 12.4, range 10‐65 years). The results reveal the trade‐off between sensitivity and specificity, depending on the number of errors accepted as a pass on the IH test. The D‐15 and CU tests pass all normals and almost 50% of subjects with color vision deficiency. The HW‐A lantern passes all normals, 22% of deutans and 1% of protans. The multi‐test protocols designed to identify protans and to pass only subjects with mild color loss, pass over 50% of protans and deutans. Many of the subjects who fail exhibit less severe loss of color vision than others who pass. When high sensitivity for detection of congenital deficiency is achieved, single‐test protocols fail many normal trichromats. Multi‐test protocols produce large variability and fail to achieve desired aims. 相似文献
430.
Benjamin E. W. Evans Marisa Rodriguez‐Carmona John L. Barbur 《Color research and application》2021,46(1):7-20
The Farnsworth D‐15 test (D‐15) is commonly used to screen for moderate to severe congenital color vision deficiency. The aim of this study was to establish reliable D‐15 statistics for normal, deutan and protan subjects, and to investigate the different visual signals one can use to carry out the test, even in dichromats and rod monochromats. Six hundred and seventy‐four subjects were examined using the D‐15, the Colour Assessment and Diagnosis test and the Nagel anomaloscope. A rod monochromat and five dichromats were tested using the standard D‐15 protocol before the caps were separated into two groups and subjects were asked to repeat the task. D‐15 spectral radiance data, measured under D65 illumination, were used to estimate differences in photoreceptor excitations for each of the caps. When no crossings and up to two adjacent transpositions on the D‐15 results diagram are accepted as a pass, 100% of normal trichromats, 54% of deutans and 43% of protans pass the D‐15. A rod monochromat and two protanopes and deuteranopes were able to complete the D‐15 when the caps were separated into two groups, despite severe loss or even complete absence of color vision. When up to two adjacent transpositions are accepted 50% of color deficient subjects, some with severe red/green loss, pass the D‐15. While the D‐15 is normally used to screen for moderate to severe color deficiency, subjects with severe loss can still use combined, residual red/green, yellow/blue and luminance signals to pass. 相似文献