全文获取类型
收费全文 | 805篇 |
免费 | 75篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 463篇 |
金属工艺 | 9篇 |
机械仪表 | 5篇 |
建筑科学 | 23篇 |
矿业工程 | 1篇 |
能源动力 | 19篇 |
轻工业 | 146篇 |
水利工程 | 2篇 |
无线电 | 46篇 |
一般工业技术 | 75篇 |
冶金工业 | 28篇 |
自动化技术 | 55篇 |
出版年
2024年 | 2篇 |
2023年 | 19篇 |
2022年 | 137篇 |
2021年 | 135篇 |
2020年 | 45篇 |
2019年 | 36篇 |
2018年 | 32篇 |
2017年 | 32篇 |
2016年 | 43篇 |
2015年 | 29篇 |
2014年 | 32篇 |
2013年 | 54篇 |
2012年 | 49篇 |
2011年 | 56篇 |
2010年 | 30篇 |
2009年 | 23篇 |
2008年 | 22篇 |
2007年 | 24篇 |
2006年 | 18篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1931年 | 1篇 |
1928年 | 1篇 |
1927年 | 2篇 |
排序方式: 共有881条查询结果,搜索用时 15 毫秒
31.
32.
Aleksandra A. Kuznetsova Olga S. Fedorova Nikita A. Kuznetsov 《International journal of molecular sciences》2022,23(12)
DNA polymerases catalyze DNA synthesis during the replication, repair, and recombination of DNA. Based on phylogenetic analysis and primary protein sequences, DNA polymerases have been categorized into seven families: A, B, C, D, X, Y, and RT. This review presents generalized data on the catalytic mechanism of action of DNA polymerases. The structural features of different DNA polymerase families are described in detail. The discussion highlights the kinetics and conformational dynamics of DNA polymerases from all known polymerase families during DNA synthesis. 相似文献
33.
Pia Fahlbusch Aleksandra Nikolic Sonja Hartwig Sylvia Jacob Ulrike Kettel Cornelia Kllmer Hadi Al-Hasani Stefan Lehr Dirk Müller-Wieland Birgit Knebel Jrg Kotzka 《International journal of molecular sciences》2022,23(12)
Alterations in mitochondrial function are an important control variable in the progression of metabolic dysfunction-associated fatty liver disease (MAFLD), while also noted by increased de novo lipogenesis (DNL) and hepatic insulin resistance. We hypothesized that the organization and function of a mitochondrial electron transport chain (ETC) in this pathologic condition is a consequence of shifted substrate availability. We addressed this question using a transgenic mouse model with increased hepatic insulin resistance and DNL due to constitutively active human SREBP-1c. The abundance of ETC complex subunits and components of key metabolic pathways are regulated in the liver of these animals. Further omics approaches combined with functional assays in isolated liver mitochondria and primary hepatocytes revealed that the SREBP-1c-forced fatty liver induced a substrate limitation for oxidative phosphorylation, inducing enhanced complex II activity. The observed increased expression of mitochondrial genes may have indicated a counteraction. In conclusion, a shift of available substrates directed toward activated DNL results in increased electron flows, mainly through complex II, to compensate for the increased energy demand of the cell. The reorganization of key compounds in energy metabolism observed in the SREBP-1c animal model might explain the initial increase in mitochondrial function observed in the early stages of human MAFLD. 相似文献
34.
Organic whey as a source of Lactobacillus strains with selected technological and antimicrobial properties
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Anna Rzepkowska Dorota Zielińska Aleksandra Ołdak Danuta Kołożyn‐Krajewska 《International Journal of Food Science & Technology》2017,52(9):1983-1994
Twenty‐five strains, isolated from raw, non‐pasteurised, organic whey samples, were identified phenotypically and genotypically. Biochemical tests were performed, and enzyme profiles, antibiotic resistance and antimicrobial properties were investigated. Sixteen strains were identified as genus Lactobacillus. Based on 16S rDNA gene sequence, the strains were identified as Lb. plantarum and Lb. fermentum. All of the strains had β‐galactosidase activity, and some of them reduced nitrate content. All strains utilised carbohydrates. The tested strains were characterised by low or average lipolytic and esterolytic activity. Moreover, the strains showed low proteolytic activity which is advantageous for their use as starter cultures for foods with low protein content. Strains Lb. fermentum S20, SM1, SM3, S2R and Lb. plantarum SM5 produced harmful N‐acetyl‐β‐glucosaminidase; moreover, the strain S20 produced also β‐glucuronidase. None of the strains produced α‐chymotrypsin. In phenotypic studies, most of the test strains were susceptible to gentamicin, ampicillin, tetracycline, chloramphenicol, penicillin and erythromycin. Strains Lb. plantarum S1 and Lb. fermentum S4, S7, S8, S10, SM1 and SM3 did not possess any transfer resistance genes. Antagonistic activity of the culture LAB strains was assessed as high or moderate in relation to the indicator strains, with the greatest zones of inhibition for E.coli and the smallest for L. monocytogenes ATCC 15313. This study reveals that the LAB strains isolated from organic whey have high potential for food application. Some strains of species Lb. fermentum (S4, S7, S8, S10) have been identified as the best candidates. 相似文献
35.
Adam Pietras Aleksandra Węglowska Beata Rams Marek Węglowski 《Welding International》2016,30(2):112-118
The article presents the results of research on the use of the new technology of friction welding with a non-wearing tool for welding pipe ends with lids. The pipes and lids were made of aluminium alloy EN AW 2017A, non-weldable by conventional methods. The aim of the study was to verify the possibility of welding the lid to the pipe using the FSW method as well as a new method with a tool with specially profiled friction surface. The article presents the results of structural tests and strength tests of the weld joints obtained using the new technique. 相似文献
36.
37.
Dr. Travis Coyle Dr. Liang Wu Dr. Aleksandra W. Debowski Prof. Gideon J. Davies Dr. Keith A. Stubbs 《Chembiochem : a European journal of chemical biology》2019,20(11):1365-1368
The sugar fucose plays a myriad of roles in biological recognition. Enzymes hydrolyzing fucose from glycoconjugates, α-l -fucosidases, are important targets for inhibitor and probe development. Here we describe the synthesis and evaluation of novel α-l -fucosidase inhibitors, with X-ray crystallographic analysis using an α-l -fucosidase from Bacteroides thetaiotamicron helping to lay a foundation for future development of inhibitors for this important enzyme class. 相似文献
38.
39.
Aleksandra Marciniak Weronika Witak Giuseppina Sabatino Anna Maria Papini Justyna Brasu 《International journal of molecular sciences》2020,21(22)
Somatostatin analogues are useful pharmaceuticals in peptide receptor radionuclide therapy. In previous studies, we analyzed a new bicyclic somatostatin analogue (BCS) in connection with Cu(II) ions. Two characteristic sites were present in the peptide chain: the receptor- and the metal-binding site. We have already shown that this ligand can form very stable imidazole complexes with the metal ion. In this work, our aim was to characterize the intramolecular interaction that occurs in the peptide molecule. Therefore, we analyzed the coordination abilities of two cyclic ligands, i.e., P1 only with the metal binding site and P2 with both sites, but without the disulfide bond. Furthermore, we used magnetic circular dichroism (MCD) spectroscopy to better understand the coordination process. We applied this method to analyze spectra of P1, P2, and BCS, which we have described previously. Additionally, we analyzed the MCD spectra of P3 ligand, which has only the receptor binding site in its structure. We have unequivocally shown that the presence of the Phe-Trp-Lys-Thr motif and the disulfide bond significantly increases the metal binding efficiency. 相似文献
40.