全文获取类型
收费全文 | 1042篇 |
免费 | 39篇 |
专业分类
电工技术 | 13篇 |
综合类 | 3篇 |
化学工业 | 397篇 |
金属工艺 | 20篇 |
机械仪表 | 17篇 |
建筑科学 | 17篇 |
矿业工程 | 1篇 |
能源动力 | 20篇 |
轻工业 | 96篇 |
水利工程 | 7篇 |
石油天然气 | 2篇 |
无线电 | 56篇 |
一般工业技术 | 136篇 |
冶金工业 | 126篇 |
自动化技术 | 170篇 |
出版年
2023年 | 10篇 |
2022年 | 75篇 |
2021年 | 114篇 |
2020年 | 36篇 |
2019年 | 21篇 |
2018年 | 31篇 |
2017年 | 31篇 |
2016年 | 38篇 |
2015年 | 24篇 |
2014年 | 51篇 |
2013年 | 84篇 |
2012年 | 46篇 |
2011年 | 56篇 |
2010年 | 41篇 |
2009年 | 36篇 |
2008年 | 30篇 |
2007年 | 31篇 |
2006年 | 24篇 |
2005年 | 23篇 |
2004年 | 21篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1973年 | 3篇 |
1970年 | 6篇 |
1969年 | 3篇 |
1967年 | 8篇 |
1966年 | 3篇 |
1923年 | 3篇 |
排序方式: 共有1081条查询结果,搜索用时 0 毫秒
41.
Garrett BC Dixon DA Camaioni DM Chipman DM Johnson MA Jonah CD Kimmel GA Miller JH Rescigno TN Rossky PJ Xantheas SS Colson SD Laufer AH Ray D Barbara PF Bartels DM Becker KH Bowen KH Bradforth SE Carmichael I Coe JV Corrales LR Cowin JP Dupuis M Eisenthal KB Franz JA Gutowski MS Jordan KD Kay BD Laverne JA Lymar SV Madey TE McCurdy CW Meisel D Mukamel S Nilsson AR Orlando TM Petrik NG Pimblott SM Rustad JR Schenter GK Singer SJ Tokmakoff A Wang LS Wettig C Zwier TS 《Chemical reviews》2005,105(1):355-390
42.
ZhiBo Yang XueFeng Chen Maciej Radzienski Pawel Kudela Wieslaw Ostachowicz Yong Xie 《中国科学:技术科学(英文版)》2017,60(10):1505-1517
The continuous wavelet transform (CWT) is one of the crucial damage identification tools in the vibration-based damage assessment. Because of the vanishing moment property, the CWT method is capable of featuring damage singularity in the higher scales, and separating the global trends and noise progressively. In the classical investigations about this issue, the localization property of the CWT is usually deemed as the most critical point. The abundant information provided by the scale-domain information and the corresponding effectiveness are, however, neglected to some extent. Ultimately, this neglect restricts the sufficient application of the CWT method in damage localization, especially in noisy conditions. In order to address this problem, the wavelet correlation operator is introduced into the CWT damage detection method as a post-processing. By means of the correlations among different scales, the proposed operator suppresses noise, cancels global trends, and intensifies the damage features for various mode shapes. The proposed method is demonstrated numerically with emphasis on characterizing damage in noisy environments, where the wavelet scale Teager-Kaiser energy operator is taken as the benchmark method for comparison. Experimental validations are conducted based on the benchmark data from composite beam specimens measured by a scanning laser vibrometer. Numerical and experimental validations/comparisons present that the introduction of wavelet correlation operator is effective for damage localization in noisy conditions. 相似文献
43.
Ammonium-based ionic liquid monomers and their corresponding polymers [poly(ionic liquid)s] are synthesized and characterized for CO2 sorption. The polymers have much higher CO2 sorption capacities than the room-temperature ionic liquids and imidazolium-based poly(ionic liquid)s. For example, P[VBTMA][PF6] with polystyrene backbone has a CO2 sorption capacity of 10.67 mol%. The CO2 sorption is selective over N2 and O2. The effects of cation, backbone, substituent, anion and crosslinking on CO2 sorption are discussed. The sorption mechanism study indicates that CO2 sorption by the poly(ionic liquid)s is a bulk and surface phenomenon. 相似文献
44.
We developed and elaborated manufacturing conditions for the production of alginic acid fibers with high sorption properties. The fibers' tenacity obtained at a level of 16 cN/tex is suitable for textile processing these fibers, and will make it possible to produce a new generation of highly absorptive dressing materials. The presence of acid groups in the fiber‐forming material allows us to use them for the addition of new generation antibiotics, which makes it possible to extend the antibacterial effects of these fibers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
45.
Karolina Bukowska-Strakova Joanna Wodek Ewelina Pitera Magdalena Kozakowska Anna Konturek-Ciela Maciej Ciela Monika Goka Witold Nowak Aleksandra Wieczorek Katarzyna Pawiska-Wsikowska Alicja Jzkowicz Maciej Siedlar 《International journal of molecular sciences》2021,22(3)
Whilst the survival rates of childhood acute lymphoblastic leukemia (ALL) have increased remarkably over the last decades, the therapy resistance and toxicity are still the major causes of treatment failure. It was shown that overexpression of heme oxygenase-1 (HO-1) promotes proliferation and chemoresistance of cancer cells. In humans, the HO-1 gene (HMOX1) expression is modulated by two polymorphisms in the promoter region: (GT)n-length polymorphism and single-nucleotide polymorphism (SNP) A(−413)T, with short GT repeat sequences and 413-A variants linked to an increased HO-1 inducibility. We found that the short alleles are significantly more frequent in ALL patients in comparison to the control group, and that their presence may be associated with a higher risk of treatment failure, reflecting the role of HO-1 in chemoresistance. We also observed that the presence of short alleles may predispose to develop chemotherapy-induced neutropenia. In case of SNP, the 413-T variant co-segregated with short or long alleles, while 413-A almost selectively co-segregated with long alleles, hence it is not possible to determine if SNPs are actually of phenotypic significance. Our results suggest that HO-1 can be a potential target to overcome the treatment failure in ALL patients. 相似文献
46.
Katarzyna Szkudelska Marzanna Deniziak Maciej Sassek Ignacy Szkudelski Wojciech Noskowiak Tomasz Szkudelski 《International journal of molecular sciences》2021,22(5)
Resveratrol is a biologically active diphenolic compound exerting multiple beneficial effects in the organism, including anti-diabetic properties. This action is, however, not fully elucidated. In the present study, we examined effects of resveratrol on some parameters related to insulin signaling, and also on diabetes-associated dysregulation in Goto-Kakizaki (GK) rats with congenital type 2 diabetes. Resveratrol was given at the dose of 20 mg/kg b.w. for 10 weeks. It was shown that the expression and phosphorylation levels of insulin receptor in the skeletal muscle of GK rats were significantly decreased, compared with control animals. However, these changes were totally prevented by resveratrol. Liver expression of the insulin receptor was also reduced, but in this case, resveratrol was ineffective. Resveratrol was also demonstrated to significantly influence parameters of insulin binding (dissociation constant and binding capacity) in the skeletal muscle and liver. Moreover, it was shown that the expression levels of proteins related to intracellular glucose transport (GLUT4 and TUG) in adipose tissue of GK rats were significantly decreased. However, treatment with resveratrol completely abolished these changes. Resveratrol was found to induce normalization of TUG expression in the skeletal muscle. Blood levels of insulin and GIP were elevated, whereas proinsulin and GLP-1 diminished in GK rats. However, concentrations of these hormones were not affected by resveratrol. These results indicate that resveratrol partially ameliorates diabetes-associated dysregulation in GK rats. The most relevant finding covers the normalization of the insulin receptor expression in the skeletal muscle and also GLUT4 and TUG in adipose tissue. 相似文献
47.
Daniela M. Ushizima Hrishikesh A. Bale E. Wes Bethel Peter Ercius Brett A. Helms Harinarayan Krishnan Lea T. Grinberg Maciej Haranczyk Alastair A. Macdowell Katarzyna Odziomek Dilworth Y. Parkinson Talita Perciano Robert O. Ritchie Chao Yang 《JOM Journal of the Minerals, Metals and Materials Society》2016,68(11):2963-2972
48.
Robert Nawrot Alicja Warowicka Piotr Jzef Rudzki Oskar Musidlak Katarzyna Magdalena Dolata Jacek Musijowski Elbieta Urszula Stolarczyk Anna Go
dzicka-Jzefiak 《International journal of molecular sciences》2021,22(21)
Chelidonium majus L. is a latex-bearing plant used in traditional folk medicine to treat human papillomavirus (HPV)-caused warts, papillae, and condylomas. Its latex and extracts are rich in many low-molecular compounds and proteins, but there is little or no information on their potential interaction. We describe the isolation and identification of a novel major latex protein (CmMLP1) composed of 147 amino acids and present a model of its structure containing a conserved hydrophobic cavity with high affinity to berberine, 8-hydroxycheleritrine, and dihydroberberine. CmMLP1 and the accompanying three alkaloids were present in the eluted chromatographic fractions of latex. They decreased in vitro viability of human cervical cancer cells (HPV-negative and HPV-positive). We combined, for the first time, research on macromolecular and low-molecular-weight compounds of latex-bearing plants in contrast to other studies that investigated proteins and alkaloids separately. The observed interaction between latex protein and alkaloids may influence our knowledge on plant defense. The proposed toolbox may help in further understanding of plant disease resistance and in pharmacological research. 相似文献
49.
Anna Stasiowicz Natalia Rosiak Ewa Tykarska Maciej Kozak Jacek Jenczyk Piotr Szulc Joanna Kobus-Cisowska Kornelia Lewandowska Anita Paziska Wojciech Paziski Judyta Cielecka-Piontek 《International journal of molecular sciences》2021,22(8)
Piperine is an alkaloid that has extensive pharmacological activity and impacts other active substances bioavailability due to inhibition of CYP450 enzymes, stimulation of amino acid transporters and P-glycoprotein inhibition. Low solubility and the associated low bioavailability of piperine limit its potential. The combination of piperine with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) causes a significant increase in its solubility and, consequently, an increase in permeability through gastrointestinal tract membranes and the blood–brain barrier. X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) were used to characterize interactions between piperine and HP-β-CD. The observed physicochemical changes should be combined with the process of piperine and CD system formation. Importantly, with an increase in solubility and permeability of piperine as a result of interaction with CD, it was proven to maintain its biological activity concerning the antioxidant potential (2,2-diphenyl-1-picryl-hydrazyl-hydrate assay), inhibition of enzymes essential for the inflammatory process and for neurodegenerative changes (hyaluronidase, acetylcholinesterase, butyrylcholinesterase). 相似文献
50.
Fernanda Monedeiro Viorica Railean-Plugaru Maciej Monedeiro-Milanowski Pawe Pomastowski Bogusaw Buszewski 《International journal of molecular sciences》2021,22(9)
Considering the advent of antibiotic resistance, the study of bacterial metabolic behavior stimulated by novel antimicrobial agents becomes a relevant tool to elucidate involved adaptive pathways. Profiling of volatile metabolites was performed to monitor alterations of bacterial metabolism induced by biosynthesized silver nanoparticles (bio-AgNPs). Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae and Proteus mirabilis were isolated from pressure ulcers, and their cultures were prepared in the presence/absence of bio-AgNPs at 12.5, 25 and 50 µg mL−1. Headspace solid phase microextraction associated to gas chromatography–mass spectrometry was the employed analytical platform. At the lower concentration level, the agent promoted positive modulation of products of fermentation routes and bioactive volatiles, indicating an attempt of bacteria to adapt to an ongoing suppression of cellular respiration. Augmented response of aldehydes and other possible products of lipid oxidative cleavage was noticed for increasing levels of bio-AgNPs. The greatest concentration of agent caused a reduction of 44 to 80% in the variety of compounds found in the control samples. Pathway analysis indicated overall inhibition of amino acids and fatty acids routes. The present assessment may provide a deeper understanding of molecular mechanisms of bio-AgNPs and how the metabolic response of bacteria is untangled. 相似文献