全文获取类型
收费全文 | 820篇 |
免费 | 37篇 |
专业分类
电工技术 | 8篇 |
综合类 | 1篇 |
化学工业 | 335篇 |
金属工艺 | 18篇 |
机械仪表 | 17篇 |
建筑科学 | 8篇 |
矿业工程 | 1篇 |
能源动力 | 11篇 |
轻工业 | 63篇 |
水利工程 | 3篇 |
石油天然气 | 2篇 |
无线电 | 44篇 |
一般工业技术 | 125篇 |
冶金工业 | 77篇 |
原子能技术 | 2篇 |
自动化技术 | 142篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 68篇 |
2021年 | 107篇 |
2020年 | 31篇 |
2019年 | 19篇 |
2018年 | 28篇 |
2017年 | 26篇 |
2016年 | 36篇 |
2015年 | 24篇 |
2014年 | 43篇 |
2013年 | 73篇 |
2012年 | 35篇 |
2011年 | 48篇 |
2010年 | 33篇 |
2009年 | 34篇 |
2008年 | 23篇 |
2007年 | 29篇 |
2006年 | 20篇 |
2005年 | 18篇 |
2004年 | 16篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1967年 | 3篇 |
1964年 | 1篇 |
排序方式: 共有857条查询结果,搜索用时 15 毫秒
661.
Magorzata Dawidowska Natalia Makowska-Malak Monika Drobna-
ledziska Maria Kosmalska Roman Jaksik Donata Szymczak Magorzata Jarmu-Szymczak Alicja Sadowska-Klasa Marzena Wojtaszewska ukasz Sdek Tomasz Wrbel Jan Maciej Zaucha Tomasz Szczepaski Krzysztof Lewandowski Sebastian Giebel Micha Witt 《International journal of molecular sciences》2022,23(17)
662.
Kamila Kasprzak-Drozd Tomasz Oniszczuk Iwona Kowalska Jarosaw Modoch Maciej Combrzyski Marek Gancarz Bohdan Dobrzaski Jr. Adrianna Kondracka Anna Oniszczuk 《International journal of molecular sciences》2022,23(22)
A new type of corn snack has been created containing additions of wild garlic (Allium ursinum L.). This medicinal and dietary plant has a long tradition of use in folk medicine. However, studies on wild garlic composition and activity are fairly recent and scarce. This research aimed to investigate the influence of the screw speed and A. ursinum amounts on the antiradical properties as well as the content of polyphenolic compounds and individual phenolic acids of innovative snacks enriched with wild garlic leaves. The highest radical scavenging activity and content of polyphenols and phenolic acids were found in the snacks enriched with 4% wild garlic produced using screw speed 120 rpm. The obtained findings demonstrated that snacks enriched with wild garlic are a rich source of polyphenolic compounds. Since the concentration of such compounds is affected by many factors, e.g., plant material, presence of other compounds, and digestion, the second aim of this study was to determine radical scavenging activity, the content of polyphenols, and individual phenolic acids of snacks after in vitro simulated gastrointestinal digestion. Using an in vitro two-stage model, authors noted a significant difference between the concentration of polyphenolic compounds and the polyphenol content of the plant material before digestion. 相似文献
663.
Dorota Maszczak-Seneczko Maciej Wiktor Edyta Skurska Wojciech Wiertelak Mariusz Olczak 《International journal of molecular sciences》2022,23(15)
Nucleotide sugars (NSs) serve as substrates for glycosylation reactions. The majority of these compounds are synthesized in the cytoplasm, whereas glycosylation occurs in the endoplasmic reticulum (ER) and Golgi lumens, where catalytic domains of glycosyltransferases (GTs) are located. Therefore, translocation of NS across the organelle membranes is a prerequisite. This process is thought to be mediated by a group of multi-transmembrane proteins from the SLC35 family, i.e., nucleotide sugar transporters (NSTs). Despite many years of research, some uncertainties/inconsistencies related with the mechanisms of NS transport and the substrate specificities of NSTs remain. Here we present a comprehensive review of the NS import into the mammalian Golgi, which consists of three major parts. In the first part, we provide a historical view of the experimental approaches used to study NS transport and evaluate the most important achievements. The second part summarizes various aspects of knowledge concerning NSTs, ranging from subcellular localization up to the pathologies related with their defective function. In the third part, we present the outcomes of our research performed using mammalian cell-based models and discuss its relevance in relation to the general context. 相似文献
664.
R. Krieg B. Dolensky B. Gller G. Hailfinger O. Jonatzke T. Malmberg G. Messemer E. Stratmanns G. Vorberg H. Benz W. Ratajczak 《Nuclear Engineering and Design》2000,202(2-3)
The load carrying capacity of the pressure vessel head to withstand an in-vessel steam explosion is investigated. Firstly, as a key problem, the impact of molten core material against the vessel head is studied by model experiments scaled down 1:10. Structural details are considered carefully. The results are converted to reactor dimensions using similarity theory. This approach was checked by simplified liquid-structure impact experiments in different scale. Secondly, the upward acceleration of molten core material is studied by computational models. As results the mechanical energies which the vessel head can withstand are presented. 相似文献
665.
Marcin Pajak Marcin Mozdzierz Maciej Chalusiak Shinji Kimijima Janusz S. Szmyd Grzegorz Brus 《International Journal of Hydrogen Energy》2018,43(45):20474-20487
The presented paper focuses on a numerical analysis of a heat and mass transfer process in a novel type of methane/steam reforming reactor. The novelty of the macro-patterned reactor design lies in dividing a reformer into segments of various lengths and reactivity. Precisely, splitting the catalyst and filling the created empty volume with porous, non-reactive, thermal conducting material such as metallic foam. This approach allows for moderating a sharp temperature drop at the inlet of the reactor typical for the endothermic methane/steam reforming process. To analyze the considered system, the mathematical and numerical models of transport phenomena and the reaction kinetics were developed and implemented into an in-house solver. The kinetics of methane/steam reforming was taken from the literature. The outlet composition obtained from the kinetic model was compared with the experimental measurements and good agreement was found. The conducted numerical analysis includes cases that differ from a number and lengths of catalytic and non-catalytic segments. The obtained results indicate that the macro-patterned design is a promising strategy that allows for a significant improvement of temperature distribution in a reforming reactor. It was shown that the proposed approach could help to cut the cost of the catalyst material by allowing for the conversion of methane with a smaller amount of the catalyst close to the reference case. 相似文献
666.
Marta Szandruk-Bender Benita Wiatrak ukasz Szczukowski Piotr
witek Maria Rutkowska Stanisaw Dzimira Anna Merwid-Ld Maciej Danielewski Adam Szelg 《International journal of molecular sciences》2020,21(24)
Despite the availability of the current drug arsenal for pain management, there is still a clinical need to identify new, more effective, and safer analgesics. Based on our earlier study, newly synthesized 1,3,4-oxadiazole derivatives of pyrrolo[3,4-d]pyridazinone, especially 10b and 13b, seem to be promising as potential analgesics. The current study was designed to investigate whether novel derivatives attenuate nociceptive response in animals subjected to thermal or chemical noxious stimulus, and to compare this effect to reference drugs. The antinociceptive effect of novel compounds was studied using the tail-flick and formalin test. Pretreatment with novel compounds at all studied doses increased the latency time in the tail-flick test and decreased the licking time during the early phase of the formalin test. New derivatives given at the medium and high doses also reduced the late phase of the formalin test. The achieved results indicate that new derivatives dose-dependently attenuate nociceptive response in both models of pain and exert a lack of gastrotoxicity. Both studied compounds act more efficiently than indomethacin, but not morphine. Compound 13b at the high dose exerts the greatest antinociceptive effect. It may be due to the reduction of nociceptor sensitization via prostaglandin E2 and myeloperoxidase levels decrease. 相似文献
667.
Magorzata Szczuko Justyna Kikut Dominika Maciejewska Danuta Kulpa Zbigniew Celewicz Maciej Zitek 《International journal of molecular sciences》2020,21(23)
Short-chain fatty acids (SCFAs) mediate the transmission of signals between the microbiome and the immune system and are responsible for maintaining balance in the anti-inflammatory reaction. Pregnancy stages alter the gut microbiota community structure, which also synthesizes SCFAs. The study involved 90 pregnant women, divided into two groups: 48 overweight/obese pregnant women (OW) and 42 pregnant women with normal BMI (CG). The blood samples for glucose, insulin, and HBA1c were analyzed as well as stool samples for SCFA isolation (C2:0; C3:0; C4:0i; C4:0n; C5:0i; C5:0n; C6:0i; C6:0n) using gas chromatography. The SCFA profile in the analyzed groups differed significantly. A significant positive correlation between C2:0, C3:0, C4:0n and anthropometric measurements, and between C2:0, C3:0, C4:0n, and C5:0n and parameters of carbohydrate metabolism was found. SCFA levels fluctuate during pregnancy and the course of pregnancy and participate in the change in carbohydrate metabolism as well. The influence of C2:0 during pregnancy on anthropometric parameters was visible in both groups (normal weight and obese). Butyrate and propionate regulate glucose metabolism by stimulating the process of intestinal gluconeogenesis. The level of propionic acid decreases with the course of pregnancy, while its increase is characteristic of obese women, which is associated with many metabolic adaptations. Propionic and linear caproic acid levels can be an important critical point in maintaining lower anthropometric parameters during pregnancy. 相似文献
668.
Benita Wiatrak Paulina Sobierajska Marta Szandruk-Bender Paulina Jawien Maciej Janeczek Maciej Dobrzynski Patrycja Pistor Adam Szelag Rafal J. Wiglusz 《International journal of molecular sciences》2021,22(9)
Hydroxyapatite has been used in medicine for many years as a biomaterial or a cover for other biomaterials in orthopedics and dentistry. This study characterized the physicochemical properties (structure, particle size and morphology, surface properties) of Li+- and Li+/Eu3+-doped nanohydroxyapatite obtained using the wet chemistry method. The potential regenerative properties against neurite damage in cultures of neuron-like cells (SH-SY5Y and PC12 after differentiation) were also studied. The effect of nanohydroxyapatite (nHAp) on the induction of repair processes in cell cultures was assessed in tests of metabolic activity, the level of free oxygen radicals and nitric oxide, and the average length of neurites. The study showed that nanohydroxyapatite influences the increase in mitochondrial activity, which is correlated with the increase in the length of neurites. It has been shown that the doping of nanohydroxyapatite with Eu3+ ions enhances the antioxidant properties of the tested nanohydroxyapatite. These basic studies indicate its potential application in the treatment of neurite damage. These studies should be continued in primary neuronal cultures and then with in vivo models. 相似文献
669.
Marta Andres-Mach Aleksandra Szewczyk Mirosaw Zagaja Joanna Szala-Rycaj Marta Kinga Lemieszek Maciej Maj Micha Abram Krzysztof Kaminski 《International journal of molecular sciences》2021,22(6)
Status epilepticus (SE) is a frequent medical emergency that can lead to a variety of neurological disorders, including cognitive impairment and abnormal neurogenesis. The aim of the presented study was the in vitro evaluation of potential neuroprotective properties of a new pyrrolidine-2,5-dione derivatives compound C11, as well as the in vivo assessment of the impact on the neurogenesis and cognitive functions of C11 and levetiracetam (LEV) after pilocarpine (PILO)-induced SE in mice. The in vitro results indicated a protective effect of C11 (500, 1000, and 2500 ng/mL) on astrocytes under trophic stress conditions in the MTT (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide) test. The results obtained from the in vivo studies, where mice 72 h after PILO SE were treated with C11 (20 mg/kg) and LEV (10 mg/kg), indicated markedly beneficial effects of C11 on the improvement of the neurogenesis compared to the PILO control and PILO LEV mice. Moreover, this beneficial effect was reflected in the Morris Water Maze test evaluating the cognitive functions in mice. The in vitro confirmed protective effect of C11 on astrocytes, as well as the in vivo demonstrated beneficial impact on neurogenesis and cognitive functions, strongly indicate the need for further advanced molecular research on this compound to determine the exact neuroprotective mechanism of action of C11. 相似文献
670.
Maciej Nastaj Konrad Terpiłowski Bartosz G. Sołowiej 《International Journal of Food Science & Technology》2020,55(5):2179-2187
The aim of this paper was to investigate the effect of whey protein isolate (WPI) and polymerised whey protein isolate (WPP) addition on physicochemical properties of processed cheese with partial fat replacement. Surface properties were determined by advancing (θa) and receding (θr) contact angles, apparent free surface energy (γs). Roughness measurements, cheese meltability and Turbiscan Stability Index (TSI) were evaluated by Turbiscan. Higher WPP concentrations produced the more hydrophobic surfaces of the samples. Conversely, increase in WPI addition promoted the hydrophilic cheese surfaces. The effect of roughness was much larger for samples containing WPI. The increase in protein addition caused a decrease in meltability and an increase in stability of cheeses. The optical and confocal images have proved that cheeses with WPP demonstrated more packed and denser structure in comparison to samples with WPI. 相似文献