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991.
VA Spencer AS Coutts SK Samuel LC Murphy JR Davie 《Canadian Metallurgical Quarterly》1998,273(44):29093-29097
In a previous study we showed that the levels of the intermediate filament proteins, cytokeratins 8, 18, and 19, in the nuclear matrix-intermediate filament (NM-IF) fraction from the hormone-dependent and estrogen receptor (ER)-positive human breast cancer cell line T-47D5 were regulated by estrogens. In contrast, estrogens did not regulate the cytokeratins in the NM-IF fraction of the hormone-independent and ER-positive cell line, T5-PRF. In this study, human breast cancer cells were treated with cis-diamminedichloroplatinum to cross-link protein to nuclear DNA in situ, and proteins bound to DNA were isolated. We show that cytokeratins 8, 18, and 19 of T-47D5 and T5-PRF were associated with nuclear DNA in situ. The levels of the cytokeratins 8, 18, and 19 bound to nuclear DNA or associated with the cytoskeleton of T-47D5 human breast cancer cells decreased when estrogens were depleted or the pure antiestrogen ICI 164,384 was added. In contrast, the cytokeratin levels associated with nuclear DNA or cytoskeleton were not significantly affected by estrogen withdrawal or antiestrogen administration in T5-PRF cells. These observations suggest that estrogen regulates the organization of nuclear DNA by rearrangement of the cytokeratin filament network in hormone-dependent, ER-positive human breast cancer cells and that this regulation is lost in hormone-independent, ER-positive breast cancer cells. 相似文献
992.
Arvind S. Soni Chang Sheng-Huei Lin Michael E. P. Murphy Dr. Martin E. Tanner 《Chembiochem : a European journal of chemical biology》2019,20(12):1591-1598
The enzymes Csd6 and Pgp2 are peptidoglycan (PG) proteases found in the pathogenic bacteria Helicobacter pylori and Campylobacter jejuni, respectively. These enzymes are involved in the trimming of non-crosslinked PG sidechains and catalyze the cleavage of the bond between meso-diaminopimelic acid (meso-Dap) and d -alanine, thus converting a PG tetrapeptide into a PG tripeptide. They are known to be cell-shape-determining enzymes, because deletion of the corresponding genes results in mutant strains that have lost the normal helical phenotype and instead possess a straight-rod morphology. In this work, we report two approaches directed towards the synthesis of the tripeptide substrate Ac-iso-d -Glu-meso-oxa-Dap-d -Ala, which serves as a mimic of the terminus of an non-crosslinked PG tetrapeptide substrate. The isosteric analogue meso-oxa-Dap was utilized in place of meso-Dap to simplify the synthetic procedure. The more efficient synthesis involved ring opening of a peptide-embedded aziridine by a serine-based nucleophile. A branched tetrapeptide was also prepared as a mimic of the terminus of a crosslinked PG tetrapeptide. We used MS analysis to demonstrate that the tripeptide serves as a substrate for both Csd6 and Pgp2 and that the branched tetrapeptide serves as a substrate for Pgp2, albeit at a significantly slower rate. 相似文献
993.
Quantitative analysis of seizure frequency 1 week and 6, 12, and 24 months after surgery of epilepsy
H Lüders D Murphy I Awad E Wyllie DS Dinner HH Morris AD Rothner 《Canadian Metallurgical Quarterly》1994,35(6):1174-1178
We made quantitative analysis of seizure frequency 1 week and 6, 12, and 24 months after seizure surgery. Seizure recurrence was significantly higher when seizures occurred in the first postoperative week. Seizure recurrence increased progressively with longer follow-ups, but the 6 month postoperative follow-up period was an excellent index of long-term outcome. In operative follow-up studies, seizure frequency should be reported at fixed follow-up periods, e.g., at 6 months and 1, 2, 5, and 10 years. Meaningful comparison of outcomes between different studies is possible only when reports include outcome at fixed postoperative follow-up periods (as opposed to ranges of follow-up periods). 相似文献
994.
Targeted Fluorination of a Nonsteroidal Anti‐inflammatory Drug to Prolong Metabolic Half‐Life 下载免费PDF全文
Maxwell J. Shaughnessy Antal Harsanyi Jingji Li Tara Bright Dr. Cormac D. Murphy Prof. Graham Sandford 《ChemMedChem》2014,9(4):733-736
In drug design, one way of improving metabolic stability is to introduce fluorine at a metabolically labile site. In the early stages of drug design, identification of such sites is challenging, and a rapid method of assessing the effect of fluorination on a putative drug’s metabolic stability would be of clear benefit. One approach to this is to employ micro‐organisms that are established as models of drug metabolism in parallel with the synthesis of fluorinated drug analogues. In this study, we have used the filamentous fungus Cunninghamella elegans to identify the metabolically labile site of the nonsteroidal anti‐inflammatory drug flurbiprofen, to aid in the design of fluorinated derivatives that were subsequently synthesised. The effect of the additional fluorine substitution on cytochrome P450‐catalysed oxidation was then determined via incubation with the fungus, and demonstrated that fluorine substitution at the 4′‐position rendered the drug inactive to oxidative transformation, whereas substitution of fluorine at either 2′ or 3′ resulted in slower oxidation compared to the original drug. This approach to modulating the metabolic stability of a drug‐like compound is widely applicable and can be used to address metabolic issues of otherwise good lead compounds in drug development. 相似文献
995.
Dmytro Voskoboinyk Niusha Mahmoodi Chang Sheng-Huei Lin Michael E. P. Murphy Martin E. Tanner 《Chembiochem : a European journal of chemical biology》2023,24(11):e202300205
The O-acetylation of the muramic acid residues in peptidoglycan (PG) is a modification that protects the bacteria from lysis due to the action of lysozyme. In Gram-negative bacteria, deacetylation is required to allow lytic transglycosylases to promote PG cleavage during cell growth and division. This deacetylation is catalyzed by O-acetylpeptidoglycan esterase (Ape) which is a serine esterase and employs covalent catalysis via a serine-linked acyl enzyme intermediate. Loss of Ape activity affects the size and shape of bacteria and dramatically reduces virulence. In this work, we report the first rationally designed aldehyde-based inhibitors of Ape from Campylobacter jejuni. The most potent of these acts as a competitive inhibitor with a Ki value of 13 μM. We suspect that the inhibitors are forming adducts with the active site serine that closely mimic the tetrahedral intermediate of the normal catalytic cycle. Support for this notion is found in the observation that reduction of the aldehyde to an alcohol effectively abolishes the inhibition. 相似文献
996.
Kate Cochrane Flora Cornish Annette Murphy Neil Denton Louise Bracken 《突发事故与危机管理杂志》2023,31(2):185-197
Crises do not affect populations equally but expose and exacerbate long-standing vulnerabilities and inequalities. Recovery language such as ‘build back better’, or ‘bounce forward’ has been criticised for neglecting underlying inequalities. This paper reports on the process and early outcomes of an inclusive Community Recovery Planning process for the Falkland Islands, in response to Covid-19. The Falkland Islands is home to a complex community, with close ties and short power distances (due to its small size and remoteness), with differences institutionalised in citizenship statuses and entitlements, and shaped by geopolitical tensions. We aimed to use the ‘pandemic as a portal’, seeking out previously ‘less heard’ voices, to make visible previously hidden impacts, and initiate incremental systemic change to tackle them. Community Impact Assessments evidenced specific areas of vulnerability (e.g., housing and income insecurity) and inequalities, largely shaped by differing citizenship status. In tandem with other government currents, the Community Recovery Planning process has contributed to progressive policy changes in Equalities legislation and Income Support. We offer this paper as a demonstration of our methodology for inclusive recovery planning that could be adapted elsewhere. We argue that the inclusion of previously unheard voices contributed to incremental systemic change to reduce inequalities. 相似文献
997.
Mingtao Chen Brendan B. Murphy Yuchen Wang Flavia Vitale Shu Yang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(6):2205854
Cell engineering, soft robotics, and wearable electronics often desire soft materials that are easy to deform, self-heal readily, and can relax stress rapidly. Hydrogels, a type of hydrophilic networks, are such kind of materials that can be made responsive to environmental stimuli. However, conventional hydrogels often suffer from poor stretchability and repairability. Here, hydrogels consisting of boronic ester dynamic covalent bonds in a double network of poly(vinyl alcohol)/boric acid and chitosan are synthesized, which demonstrate extreme stretchability (up to 310 times the original length), instant self-healing (within 5 s), and reusability and inherent adhesion. Their instant stress relaxation stems from a low activation energy of the boronic ester bond exchange (≤20 kJ mol−1) and contributes to the extreme stretchability and self-healing behaviors. Various water-dispersible additives can be readily incorporated in the hydrogels via hand kneading for potential applications such as soft electronics, bio-signal sensing, and soft artificial joints. 相似文献
998.
Pseudomonas spp. are important spoilage bacteria that negatively affect the quality of refrigerated fluid milk and uncultured cheese by generating unwanted odors, flavors, and pigments. They are frequently found in dairy plant environments and enter dairy products predominantly as postpasteurization contaminants. Current subtyping and characterization methods for dairy-associated Pseudomonas are often labor-intensive and expensive or provide limited and possibly unreliable classification information (e.g., to the species level). Our goal was to identify a single-copy gene that could be analyzed in dairy spoilage-associated Pseudomonas for preliminary species-level identification, subtyping, and phenotype prediction. We tested 7 genes previously targeted in a Pseudomonas fluorescens multilocus sequence typing scheme for their individual suitability in this application using a set of 113 Pseudomonas spp. isolates representing the diversity of typical pasteurized milk contamination. For each of the 7 candidate genes, we determined the success rate of PCR and sequencing for these 113 isolates as well as the level of discrimination for species identification and subtyping that the sequence data provided. Using these metrics, we selected a single gene, isoleucyl tRNA synthetase (ileS), which had the most suitable traits for simple and affordable single-gene Pseudomonas characterization. This was based on the number of isolates successfully sequenced for ileS (113/113), the number of unique allelic types assigned (83, compared with 50 for 16S rDNA), nucleotide and sequence diversity measures (e.g., number of unique SNP and Simpson index), and tests for genetic recombination. The discriminatory ability of ileS sequencing was confirmed by separation of 99 additional dairy Pseudomonas spp. isolates, which were indistinguishable by 16S rDNA sequencing, into 28 different ileS allelic types. Further, we used whole-genome sequencing data to demonstrate the similarities in ileS-based phylogenetic clustering to whole-genome-based clustering for 27 closely related dairy-associated Pseudomonas spp. isolates and for 178 Pseudomonas type strains. We also found that dairy-associated Pseudomonas within an ileS cluster typically shared the same proteolytic and lipolytic activities. Use of ileS sequencing provides a promising strategy for affordable initial characterization of Pseudomonas isolates, which will help the dairy industry identify, characterize, and track Pseudomonas in their facilities and products. 相似文献
999.
Machine Learning - In mobile health (mHealth) smart devices deliver behavioral treatments repeatedly over time to a user with the goal of helping the user adopt and maintain healthy behaviors.... 相似文献
1000.
The authors present a polarisation-insensitive, 3*3 fused biconical tapered coupler with a variable screw gauge that can change the coupling ratios from a splitting percentage of 11%-44%-45% to a uniformity of 33%-33%-34%, with excess loss maintained below 1.1 dB. The fabrication and packaging methods are described and wavelength tunability of the coupler is demonstrated.<> 相似文献