全文获取类型
收费全文 | 520篇 |
免费 | 45篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 222篇 |
金属工艺 | 12篇 |
机械仪表 | 6篇 |
建筑科学 | 12篇 |
矿业工程 | 1篇 |
能源动力 | 12篇 |
轻工业 | 152篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
无线电 | 11篇 |
一般工业技术 | 74篇 |
冶金工业 | 12篇 |
自动化技术 | 45篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 50篇 |
2021年 | 52篇 |
2020年 | 25篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 21篇 |
2016年 | 26篇 |
2015年 | 16篇 |
2014年 | 22篇 |
2013年 | 43篇 |
2012年 | 48篇 |
2011年 | 44篇 |
2010年 | 30篇 |
2009年 | 28篇 |
2008年 | 20篇 |
2007年 | 13篇 |
2006年 | 17篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 13篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有565条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
Ivana Barravecchia Chiara De Cesari Olga V. Pyankova Francesca Scebba Marco Carlo Mascherpa Alessandra Vecchione Arianna Tavanti Lorena Tedeschi Debora Angeloni 《Microgravity science and technology》2018,30(3):309-319
Performing cell biology experiments in space imposes the use of hardware that essentially allows fluid exchange in a contained environment. Given the technical and logistical peculiarities, the limited opportunities and the high cost of access to space, a great effort during mission preparation of scientific studies is devoted to preventing loss of the experiment. The European Space Agency (ESA) requires, at the end of the preparation phase, the execution of an Experiment Sequence Test (EST), a dry-run version of the space experiment to check all procedures. At conclusion of the EST of our experiment ‘ENDO’ (ESA ILSRA-2009-1026), we found pitting corrosion of metal parts and biofilm formation within the cell-culture devices. The subsequent chemical (spectral assays), instrumental (OGP SmartScope) and microbiological (MALDI-TOF, 16S rRNA gene sequencing) investigations allowed the identification in contaminated material of Paenibacillus glucanolyticus, a ubiquitous, aerobic, facultative anaerobic, endospore forming, acid-producing, Gram-positive microorganism. A concurrence of P. glucanolyticus contamination and galvanic corrosion determined massive fouling, rust precipitation and damage to cells and cell-culture devices being, to our knowledge, the association between this microbe and corrosion never reported before in literature. As a consequence of the episode a critical procedure of experiment set up, i.e. hardware sterilization, was modified. The ENDO experiment was successfully launched to the International Space Station on September 2nd 2015 and returned to the PI laboratory on September 13th, with all cell culture samples in optimal condition. 相似文献
105.
Ivana I. Mladenović-Ranisavljević Lj. Takić Đ. Nikolić 《Water Resources Management》2018,32(7):2261-2276
This work presents combined approach to water quality assessment based on both Water Quality Indices (WQI) and Multi-Criteria Decision-Making (MCDM) methods. Using weights from the official WQI calculation algorithm, the model for MCDM was formed and presented on the case of the Danube River water quality in Serbia. By applying PROMETHEE method, locations of potential environmental risk were determined and ranked according to the quality of water. Using its visual modeling option GAIA, the most dominant variables that affect the quality of water at certain locations were identified as polluting parameters (suspended matter, BOD-5, total N, NH4-N and PO4-P). Concentrations of identified pollutants were compared with limits of both EU and national recommendations so the actual water quality of the river was determined. The results showed that although WQI analysis indicated good and very good water quality, extension with MCDM methods revealed that there is a significant excess in values of PO4-P and E.coli at almost every location on the course of the river, as well as in values of total N and NH4-N. Proposed combined approach could serve to engineers and decision makers involved in water quality management in creating more detailed reports on water quality while facilitating the process of decision-making in the choice of selection of particular locations with critical water quality, where appropriate measures for remediation of pollution should be taken. 相似文献
106.
Samuela Cataldi Maria Rachele Ceccarini Federica Patria Tommaso Beccari Martina Mandarano Ivana Ferri Andrea Lazzarini Francesco Curcio Elisabetta Albi 《International journal of molecular sciences》2022,23(3)
Vitamin D3, known to regulate bone homeostasis, has recently been shown to have many pleiotropic effects in different tissues and organs due to the presence of its receptor in a wide range of cells. Our previous study demonstrated that vitamin D3 was able to increase the wound healing respect to the control sample, 24 h after cutting, without however leading to a complete repair. The aim of the study was to combine vitamin D3 with silver nanoparticles to possibly enable a faster reparative effect. The results showed that this association was capable of inducing a complete wound healing only after 18 h. Moreover, a treatment of vitamin D3 + silver nanoparticles yielded a small percentage of keratinocytes vimentin-positive, suggesting the possibility that the treatment was responsible for epithelial to mesenchymal transition of the cells, facilitating wound healing repair. Since vitamin D3 acts via sphingolipid metabolism, we studied the expression of gene encoding for the metabolic enzymes and protein level. We found an increase in neutral sphingomyelinase without involvement of neutral ceramidase or sphingosine kinase2. In support, an increase in ceramide level was identified by Ultrafast Liquid Chromatography–Tandem Mass Spectrometry, suggesting a possible involvement of ceramides in wound healing process. 相似文献
107.
Ivana Perná Tomáš Hanzliček Patrik Boura Adam Lučaník 《Materials and Manufacturing Processes》2016,31(5):667-672
This article describes the successful manufacture of new grinding wheels based on a binding agent from a clay substance and blast-furnace slag (the Ca–K geopolymer matrix) on industrial presses. Trained factory staff of the company Best – Business, a.s. tested the pressing process for the manufacture of geopolymer-bonded wheels and verified their quality by factory control equipment (Grindo Sonic and Zeiss-Mackensen methods, test of the safe peripheral speed). The results have shown that the Ca–K geopolymer matrix is suitable for grinding-tool preparation and the grinding-wheel properties are comparable with similar products based on the fired ceramic binding agent. 相似文献
108.
Dana Nir Ivana Ribarski-Chorev Chen Shimoni Carmit Strauss Jan Frank Sharon Schlesinger 《International journal of molecular sciences》2022,23(10)
Mesenchymal stem cells (MSC) have many roles that are important for the body’s proper functioning. When the MSC pool is damaged, it is often correlated with impaired development or health of the organism. MSC are known for their anti-inflammatory, immunomodulatory and trophic characteristics that play an important role in the physiological homeostasis of many tissues. Heat shock impairs MSC capacity by inducing the generation of reactive oxygen species and mitochondrial dysfunction, which, in turn, send the cells into a state of premature senescence. Here, we pre-exposed MSC to melatonin, resveratrol, or curcumin, which are natural antioxidative compounds, and tested the protective effects of these substances from oxidative stress and aging. Our data showed that pre-exposure of MSC to antioxidants decreased reactive oxygen species while mitochondrial damage remained high. Additionally, although the proliferation of the cells was slow, antioxidants protected the cells from premature senescence, and subsequent cytokine release was prevented. We conclude that while elevated temperatures directly cause mitochondrial damage, senescence is induced by elevated ROS levels. We suggest that heat shock alters cell and tissue homeostasis by several independent mechanisms; however, reducing tissue senescence will reduce damage and provide a pathway to overcome physiological challenges in animals. 相似文献
109.
Caterina Anania Giulia Brindisi Ivana Martinelli Edoardo Bonucci Miriam DOrsi Sara Ialongo Anna Nyffenegger Tonia Raso Mattia Spatuzzo Giovanna De Castro Anna Maria Zicari Carlo Carraro Maria Grazia Piccioni Francesca Olivero 《International journal of molecular sciences》2022,23(10)
Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by relapsing eczematous injuries and severe pruritus. In the last few years, the AD prevalence has been increasing, reaching 20% in children and 10% in adults in high-income countries. Recently, the potential role of probiotics in AD prevention has generated considerable interest. As many clinical studies show, the gut microbiota is able to modulate systemic inflammatory and immune responses influencing the development of sensitization and allergy. Probiotics are used increasingly against AD. However, the molecular mechanisms underlying the probiotics mediated anti-allergic effect remain unclear and there is controversy about their efficacy. In this narrative review, we examine the actual evidence on the effect of probiotic supplementation for AD prevention in the pediatric population, discussing also the potential biological mechanisms of action in this regard. 相似文献
110.
Jelena Markovi Filipovi Jelena Karan Ivana Ivelja Milica Matavulj Milena Stoi 《International journal of molecular sciences》2022,23(11)
Diabetes mellitus is a frequent endocrine disorder characterized by hyperglycemia. Acrylamide (AA) is food contaminant formed during the high-temperature processing of food rich in carbohydrates and low in proteins. Recent human epidemiological studies have shown a potential association between AA exposure and the prevalence of diabetes in the general population. In male rats, AA treatment promoted pancreatic islet remodeling, which was determined by alpha-cell expansion and beta-cell reduction, while in female rats AA caused hyperglycemia and histopathological changes in pancreatic islets. In vitro and in vivo rodent model systems have revealed that AA induces oxidative stress in beta cells and that AA impairs glucose metabolism and the insulin signaling pathway. Animal studies have shown that diabetic rodents are more sensitive to acrylamide and that AA aggravates the diabetic state. In this review, we provide an overview of human epidemiological studies that examined the relation between AA exposure and glucose disorders. In addition, the effects of AA treatment on pancreatic islet structure, beta-cell function and glucose metabolism in animal models are comprehensively analyzed with an emphasis on sex-related responses. Furthermore, oxidative stress as a putative mechanism of AA-induced toxicity in beta cells is explored. Finally, we discuss the effects of AA on diabetics in a rodent model system. 相似文献