全文获取类型
收费全文 | 243篇 |
免费 | 19篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 63篇 |
金属工艺 | 4篇 |
机械仪表 | 6篇 |
建筑科学 | 11篇 |
能源动力 | 1篇 |
轻工业 | 65篇 |
石油天然气 | 1篇 |
无线电 | 30篇 |
一般工业技术 | 28篇 |
冶金工业 | 23篇 |
自动化技术 | 29篇 |
出版年
2023年 | 1篇 |
2022年 | 12篇 |
2021年 | 22篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 13篇 |
2016年 | 3篇 |
2015年 | 9篇 |
2014年 | 4篇 |
2013年 | 19篇 |
2012年 | 14篇 |
2011年 | 19篇 |
2010年 | 15篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有262条查询结果,搜索用时 15 毫秒
101.
This work is focused on the role of intermetallics in pitting corrosion of Al2219 alloy. Second phase particles were characterized by AES, SAM and EDX. Their behaviour in a solution of NaCl was investigated as a function of exposure time. The results confirmed the cathodic nature of the intermetallics with respect to the aluminium matrix. Corrosion products rich in aluminium and oxygen were found to progressively accumulate around the particles and iron was dissolved from the intermetallic, followed by back-deposition. Copper and manganese did not show any major activity. After 32 h of exposure the larger intermetallics were completely covered. 相似文献
102.
Giovanna Loredana La Torre Lara La Pera Rossana Rando Vincenzo Lo Turco Giuseppa Di Bella Marcello Saitta Giacomo Dugo 《Food chemistry》2008,110(3):729-734
Marsala is a popular Sicilian fortified aged wine with ancient tradition. Nowadays Marsala is exported all over the world and is considered one of the most important dessert wines. The aim of this study was to determine the concentration of carbohydrates, polyphenols and heavy metals in different types of Marsala wines and to achieve statistical classifications by stepwise forward canonical discriminant analysis (CDA). The obtained results provided evidence that different types of Marsala were correctly classified according to their phenolic and carbohydrate compositions. In particular, the residual sugars allowed a good discrimination among Marsalas having similar total sugar contents. CDA, performed using heavy metals as independent variables, showed that Superiore Ambra Secco and Vergine Marsalas were not discriminated, whereas a good separation among Fine Oro Dolce, Superiore Riserva and Fine Ambra Secco wines was obtained. Finally, an overall statistical model showed that the variables with the highest discriminant power were: tyrosol, caffeic acid, procyanidin B1, catechin, quercetin, kaempferol, lactose, rhamnose, zinc, copper and lead. 相似文献
103.
Controlling the Functional Properties of Oligothiophene Crystalline Nano/Microfibers via Tailoring of the Self‐Assembling Molecular Precursors
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Francesca Di Maria Mattia Zangoli Massimo Gazzano Eduardo Fabiano Denis Gentili Alberto Zanelli Andrea Fermi Giacomo Bergamini Davide Bonifazi Andrea Perinot Mario Caironi Vittorio Morandi Giuseppe Gigli Andrea Liscio Giovanna Barbarella 《Advanced functional materials》2018,28(32)
Oligothiophenes are π‐conjugated semiconducting and fluorescent molecules whose self‐assembly properties are widely investigated for application in organic electronics, optoelectronics, biophotonics, and sensing. Here an approach to the preparation of crystalline oligothiophene nano/microfibers is reported based on the use of a “sulfur overrich” quaterthiophene building block, ? T4S4 ? , containing in its covalent network all the information needed to promote the directional, π–π stacking‐driven, self‐assembly of Y‐T4S4‐Y oligomers into fibers with hierarchical supramolecular arrangement from nano‐ to microscale. It is shown that when Y varies from unsubstituted thiophene to thiophene substituted with electron‐withdrawing groups, a wide redistribution of the molecular electronic charge takes place without substantially affecting the aggregation modalities of the oligomer. In this way, a structurally comparable series of fibers is obtained having progressively varying optical properties, redox potentials, photoconductivity, and type of prevailing charge carriers (from p‐ to n‐type). With the aid of density functional theory (DFT) calculations, combined with powder X‐ray diffraction data, a model accounting for the growth of the fibers from molecular to nano‐ and microscale is proposed. 相似文献
104.
Roberta Papagni Carmen Pellegrino Francesco Di Gennaro Giulia Patti Aurelia Ricciardi Roberta Novara Sergio Cotugno Maria Musso Giacomo Guido Luigi Ronga Stefania Stolfa Davide Fiore Bavaro Federica Romanelli Valentina Totaro Rossana Lattanzio Giuseppina De Iaco Fabrizio Palmieri Annalisa Saracino Gina Gualano 《International journal of molecular sciences》2022,23(7)
Vitamin D plays a crucial role in many infectious diseases, such as tuberculosis (TB), that remains one of the world’s top infectious killers with 1.5 million deaths from TB in 2021. Vitamin D suppresses the replication of Mycobacterium tuberculosis in vitro and showed a promising role in TB management as a result of its connection with oxidative balance. Our review encourages the possible in vivo benefit of a joint administration with other vitamins, such as vitamin A, which share a known antimycobacterial action with vitamin D. However, considering the low incidence of side effects even at high dosages and its low cost, it would be advisable to assess vitamin D level both in patients with active TB and high-risk groups and administer it, at least to reach sufficiency levels. 相似文献
105.
Use of sourdough fermented wheat germ for enhancing the nutritional, texture and sensory characteristics of the white bread 总被引:3,自引:1,他引:3
Carlo Giuseppe Rizzello Luana Nionelli Rossana Coda Raffaella Di Cagno Marco Gobbetti 《European Food Research and Technology》2010,230(4):645-654
Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5, isolated from wheat germ and selected based on the kinetics of acidification, were used as starters for the manufacture
of sourdough fermented wheat germ. A bread containing sourdough fermented wheat germ as an ingredient (SFWGB) was compared
to breads made with (raw wheat germ bread, RWGB) or without (wheat flour bread, WFB) raw wheat germ. The higher concentration
of free amino acids mainly differentiated SFWGB from WFB and RWGB. The in vitro protein digestibility of WFB was the highest,
even if sourdough fermentation of wheat germ attenuated the difference. Phytase and antioxidant activities of SFWGB were highest.
The specific volume and cell-total areas were also the highest for SFWGB. As determined by texture profile analysis, the values
of hardness, resilience and fracturability of breads containing wheat germ were lower than those found in WFB. The crust lightness
showed a decrease from WFB to SFWGB. As determined by sensory analysis, SFWGB had mainly acid taste and flavour and resulted
more salty. Sourdough fermented wheat germ is an ingredient able to enhance nutritional, texture and sensory properties of
bread. 相似文献
106.
107.
Chiara Orsi Ottavia E. Ferraro Cristina Montomoli Dietmar Otte Anna Morandi 《Accident; analysis and prevention》2014
Cycling, being easy, inexpensive and healthy, is becoming one of the most popular means of transport. Cyclists, however, are among the most vulnerable road users in traffic collisions. 相似文献
108.
Flavio Della Pelle Maria Chiara Di Crescenzo Manuel Sergi Camilla Montesano Francesca Di Ottavio Rossana Scarpone 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(2):291-299
A rapid, selective and effective method of extraction, clean-up and concentration of organophosphorous pesticides from wheat followed by electrospray (ESI) LC-MS/MS analysis was developed. The μ-SPE (micro-solid-phase extraction) procedure resulted in good analytical performance and reduced at the same time matrix effects, analysis time and solvent consumption. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.3–10 and 1–30 μg kg?1, respectively, with good reproducibility (RSD ≤ 13.8) and recoveries between 75% and 109%. Coefficients of determination (r2) were greater than 0.996 for the studied pesticides. Despite the reduced sorbent bed mass of μ-SPE tips (4.2 mg), the analytical data showed that no saturation phenomena occurs in the tested range of concentration both for single compounds and mixtures. Several real samples were analysed and the concentrations of the selected pesticides were found to be below the respective maximum residue limit (MRLs). 相似文献
109.
110.
Research on totally blind subjects performing tasks that involve visual imagery has often shown that they do not behave differently from matched sighted subjects, even when their blindness is congenital. If visual imagery is based on visual perception, such tasks may not require visual imagery. In the present article visual images are considered as representations maintaining some properties of visible objects and constructed on the basis of information from various sources. Owing to the absence of visual experience, the limitations of such representations are explored in a series of experiments requiring memorization of single nouns, pairs of nouns, or triplets of nouns associated with a cue noun. Recall by blind subjects was impaired when multiple interactive images (with noun pairs and triplets) are formed. The poorer recall of blind subjects reflected also loss of order information. Recall was better for both groups with locative noun cues and high-imagery targets. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献