全文获取类型
收费全文 | 3121篇 |
免费 | 181篇 |
国内免费 | 30篇 |
专业分类
电工技术 | 30篇 |
综合类 | 16篇 |
化学工业 | 653篇 |
金属工艺 | 72篇 |
机械仪表 | 79篇 |
建筑科学 | 123篇 |
矿业工程 | 8篇 |
能源动力 | 90篇 |
轻工业 | 337篇 |
水利工程 | 22篇 |
石油天然气 | 8篇 |
无线电 | 332篇 |
一般工业技术 | 662篇 |
冶金工业 | 170篇 |
原子能技术 | 16篇 |
自动化技术 | 714篇 |
出版年
2023年 | 36篇 |
2022年 | 34篇 |
2021年 | 83篇 |
2020年 | 70篇 |
2019年 | 46篇 |
2018年 | 123篇 |
2017年 | 136篇 |
2016年 | 166篇 |
2015年 | 116篇 |
2014年 | 156篇 |
2013年 | 253篇 |
2012年 | 227篇 |
2011年 | 186篇 |
2010年 | 191篇 |
2009年 | 175篇 |
2008年 | 193篇 |
2007年 | 160篇 |
2006年 | 148篇 |
2005年 | 99篇 |
2004年 | 95篇 |
2003年 | 86篇 |
2002年 | 82篇 |
2001年 | 39篇 |
2000年 | 27篇 |
1999年 | 37篇 |
1998年 | 49篇 |
1997年 | 38篇 |
1996年 | 25篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 15篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 11篇 |
1985年 | 6篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 18篇 |
1980年 | 14篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1973年 | 6篇 |
排序方式: 共有3332条查询结果,搜索用时 276 毫秒
1.
2.
Thea Lyseid Authen Andreas Wilden Jenny Halleröd Dimitri Schneider Fabian Kreft Giuseppe Modolo 《溶剂提取与离子交换》2021,39(1):1-17
ABSTRACT Studies have been performed with the purpose of determining the optimal solvent composition of a Chalmers grouped actinide extraction (CHALMEX) solvent for the selective co-extraction of transuranic elements in a novel Grouped ActiNide EXtraction (GANEX) process. The solvent is composed of 6,6’-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo-[1,2,4]-triazin-3-yl)-[2,2’]-bipyridine (CyMe4-BTBP) and tri-n-butyl phosphate (TBP) in phenyl trifluoromethyl sulfone (FS-13). The performance of the system has been shown to significantly depend on the ratios of the two extracting agents and the diluent to one another. Furthermore, the performance of the determined optimal solvent (10 mM CyMe4-BTBP in 30% v/v TBP and 70% v/v FS-13) on various simulated PUREX raffinate solutions was tested. It was found that the solvent extracts all transuranic elements with high efficiency and good selectivity with regard to most other elements (fission products/activation products) present in the simulated PUREX raffinate solutions. Moreover, the solvent was found to extract a significant amount of acid. Palladium, silver, and cadmium were co-extracted along with the TRU-radionuclides, which has also been observed in other similar CHALMEX systems. The extraction of plutonium and uranium was preserved for all tested simulated PUREX raffinate solutions compared to experiments using trace amounts. 相似文献
3.
Shiming Xie Chen Song Zexin Yu Shaowu Liu Frédéric Lapostolle Didier Klein Chunming Deng Min Liu Hanlin Liao 《Journal of the European Ceramic Society》2021,41(1):535-543
Suspension plasma spraying (SPS) as a potential technique to prepare thermal barrier coatings (TBCs) has been attracting more and more attention. However, most reports on SPS were carried out in the atmosphere. Given the unique features of in-flight particles and plasma jets under low pressure, the resulting coatings are expected to be different from those under atmospheric pressure. In this article, yttria-stabilized zirconia (YSZ) thermal barrier coatings were prepared using suspension plasma spraying under different environmental pressures. The results show that as the environmental pressure decreased, the column-like structural coating turned into a vertical crack segmented structure, as well as a dramatic decrease in surface roughness. More nanoparticle agglomerates were formed in the coating under lower environmental pressures. The real porosity of the coating increased with a decrease in environmental pressure. 相似文献
4.
Lun Feng William G. Fahrenholtz Gregory E. Hilmas Frédéric Monteverde 《Journal of the European Ceramic Society》2021,41(1):92-100
Dense high-entropy (Hf,Zr,Ti,Ta,Nb)B2 ceramics with Nb contents ranging from 0 to 20 at% were produced by a two-step spark plasma sintering process. X-ray diffraction indicated that a single-phase with hexagonal structure was detected in the composition without Nb. In contrast, two phases with the same hexagonal structure, but slightly different lattice parameters were present in compositions containing Nb. The addition of Nb resulted in the presence of a Nb-rich second phase and the amount of the second phase increased as the Nb content increased. The relative densities were all >99.5 %, but decreased from ~100 % to ~99.5 % as the Nb content increased from 0 to 20 at%. The average grain size decreased from 13.9 ± 5.5 μm for the composition without Nb additions to 5.2 ± 2.0 μm for the composition containing 20 at% Nb. The reduction of grain size with increasing Nb content was due to the suppression of grain growth by the Nb-rich second phase. The addition of Nb increased Young’s modulus and Vickers hardness, but decreased shear modulus. While some Nb dissolved into the main phase, a Nb-rich second phase was formed in all Nb-containing compositions. 相似文献
5.
Chanh Constance Gourment Anaïs Petit Betrand Gourgues-Lorenzon Anne-Françoise 《International Journal of Fracture》2022,235(2):215-230
International Journal of Fracture - The development of high-performance automotive steels involves increasingly complex chemistries and heat treating sequences, to produce stronger and lighter... 相似文献
6.
Virginija Sacevičienė Milda Jucienė Vaida Dobilaitė Valentina Krylova Skirma Žalenkienė Nijolė Dukštienė Raimondas Bliūdžius 《应用聚合物科学杂志》2019,136(21):47523
The aim of this work was to investigate the physical and mechanical performance of architectural polyester (PES)–poly(vinyl chloride) (PVC) membranes exposed to different artificial aging conditions. Two commercially available architectural membranes were chosen as research objects. The durability of the PES/PVC fabrics was evaluated by the loss in mechanical performance, scanning electron microscopy, and X-ray diffraction analysis in order to understand the effect of the degradation agents on the surface of the membranes. The mechanical performance of the PES/PVC membranes was unchanged. Scanning electron microscopy images of the tested materials showed initial cracks after aging. The X-ray fluorescence analysis showed that at the time of aging, the amount of Cl and Si decreased slightly, while Ti decreased by half, and Ca by volume increased twice. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47523. 相似文献
7.
Saint Martin Marie-Judith Orlhac Fanny Akl Pia Khalid Fahad Nioche Christophe Buvat Irène Malhaire Caroline Frouin Frédérique 《Magma (New York, N.Y.)》2021,34(3):355-366
Magnetic Resonance Materials in Physics, Biology and Medicine - Quantitative analysis in MRI is challenging due to variabilities in intensity distributions across patients, acquisitions and... 相似文献
8.
Océane Florès Dr. Denis Velic Nesrine Mabrouk Prof. Ali Bettaïeb Christophe Tomasoni Prof. Jean-Michel Robert Dr. Catherine Paul Dr. Christine Goze Christos Roussakis Dr. Ewen Bodio 《Chembiochem : a European journal of chemical biology》2019,20(17):2255-2261
A family of bi- and tetrametallic gold(I) phosphine dithiocarbamate complexes were synthesized, starting from cyclam and dimethylcyclam polyazamacrocycles, respectively, along with their monometallic gold(I) chloridophosphine precursors. Their antiproliferative properties were evaluated on two cancer cell lines (A549 and NSCLC-N6-L16). Most of the mono- and bimetallic complexes displayed strong activities and, in particular, one bimetallic derivative showed antiproliferative properties in the low micromolar range. Insights into the structure–activity relationships are given, along with determination of the thioredoxin reductase inhibition potential, two-photon imaging of the fluorescent derivatives, and evaluation of gold uptake. 相似文献
9.
Pierre Santucci Christina Dedaki Alexandros Athanasoulis Laura Gallorini Anaïs Munoz Dr. Stéphane Canaan Dr. Jean-François Cavalier Dr. Victoria Magrioti 《ChemMedChem》2019,14(3):349-358
In the quest for new antibacterial agents, a series of novel long- and medium-chain mono- and disubstituted β-lactones was developed. Their activity against three pathogenic mycobacteria—M. abscessus, M. marinum, and M. tuberculosis—was assessed by the resazurin microtiter assay (REMA). Among the 16 β-lactones synthesized, only 3-hexadecyloxetan-2-one (VM005) exhibited promising activity against M. abscessus, whereas most of the β-lactones showed interesting activities against M. marinum, similar to that of the classical antibiotic, isoniazid. Regarding M. tuberculosis, six compounds were found to be active against this mycobacterium, with β-lactone VM008 [trans-(Z)-3-(hexadec-7-en-1-yl)-4-propyloxetan-2-one] being the best growth inhibitor. The promising antibacterial activities of the best compounds in this series suggest that these molecules may serve as leads for the development of much more efficient antimycobacterial agents. 相似文献
10.
Dr. Hannes M. Beyer Dr. Hideo Iwaï 《Chembiochem : a European journal of chemical biology》2019,20(15):1933-1938
Protein-splicing domains are frequently used engineering tools that find application in the in vivo and in vitro ligation of protein domains. Directed evolution is among the most promising technologies used to advance this technology. However, the available screening systems for protein-splicing activity are associated with bottlenecks such as the selection of pseudo-positive clones arising from off-pathway reaction products or fragment complementation. Herein, we report a stringent screening method for protein-splicing activity in cis and trans, that exclusively selects productively splicing domains. By fusing splicing domains to an intrinsically disordered region of the antidote from the Escherichia coli CcdA/CcdB type II toxin/antitoxin system, we linked protein splicing to cell survival. The screen allows selecting novel cis- and trans-splicing inteins catalyzing productive highly efficient protein splicing, for example, from directed-evolution approaches or the natural intein sequence space. 相似文献