全文获取类型
收费全文 | 1143篇 |
免费 | 127篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 20篇 |
综合类 | 3篇 |
化学工业 | 357篇 |
金属工艺 | 22篇 |
机械仪表 | 11篇 |
建筑科学 | 55篇 |
矿业工程 | 5篇 |
能源动力 | 38篇 |
轻工业 | 77篇 |
水利工程 | 6篇 |
石油天然气 | 2篇 |
无线电 | 116篇 |
一般工业技术 | 222篇 |
冶金工业 | 95篇 |
原子能技术 | 6篇 |
自动化技术 | 236篇 |
出版年
2024年 | 3篇 |
2023年 | 32篇 |
2022年 | 60篇 |
2021年 | 76篇 |
2020年 | 50篇 |
2019年 | 67篇 |
2018年 | 68篇 |
2017年 | 67篇 |
2016年 | 70篇 |
2015年 | 53篇 |
2014年 | 68篇 |
2013年 | 69篇 |
2012年 | 62篇 |
2011年 | 94篇 |
2010年 | 38篇 |
2009年 | 40篇 |
2008年 | 46篇 |
2007年 | 50篇 |
2006年 | 35篇 |
2005年 | 16篇 |
2004年 | 15篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 30篇 |
1997年 | 17篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1942年 | 2篇 |
1908年 | 2篇 |
1904年 | 2篇 |
排序方式: 共有1271条查询结果,搜索用时 15 毫秒
111.
A. Andres Leal Mohammadreza Naeimirad Laura Gottardo Philipp Schuetz Ali Zadhoush Rudolf Hufenus 《国际聚合物材料杂志》2016,65(9):451-456
The development of thermoplastic fibers containing a liquid core is described. Internal morphology analysis confirms that the liquid-containing core is composed of a continuous cylindrical microchannel of constant diameter. Microfluidic experiments on both liquid core and reference hollow fibers were conducted by pumping distilled water through several filaments simultaneously. The observed fluid motions are satisfactorily described by the Hagen-Poiseuille law, indicating that the hollow and liquid core fibers have internal diameters of 31.6 and 14.8 µm, respectively. Flushing the liquid core fibers with a surfactant solution efficiently removes the saturated ester initially used during the melt spinning of the fiber. 相似文献
112.
113.
Judit Molnár Gábor J. Szebeni Boglárka Csupor-L?ffler Zsuzsanna Hajdú Thomas Szekeres Philipp Saiko Imre Ocsovszki László G. Puskás Judit Hohmann István Zupkó 《International journal of molecular sciences》2016,17(2)
Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC50 values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents. 相似文献
114.
Current Trends in Pretreatment and Fractionation of Lignocellulose as Reflected in Industrial Patent Activities 下载免费PDF全文
The pretreatment process to disintegrate lignocellulose and to fractionate its three main components hemicellulose, cellulose, and lignin, is a crucial step to enable sustainable and economic value chains based on biomass feedstock. This review provides an overview of the recent patenting activities on pretreatment. Most of these activities focus on optimization of different known processes to improve economics, such as increased catalyst efficiency, effluents recirculation, or lignin valorization. However, also a number of patents and demonstration activities based on emerging concepts for pretreatments are observed. 相似文献
115.
116.
Ive Hermans Joaquim Henrique Teles Richard Dehn Till-Christian Brüggemann Robert Send Philipp Nikolaus Plessow 《Topics in Catalysis》2014,57(14-16):1256-1264
In this contribution we use computational tools to investigate the reaction of alcohol substrates with reactive nitrogen oxide species such as N2O3 and N2O4, leading to the formation of alkyl nitrites. These nitrites are interesting intermediates which can be processed to various valuable chemicals such as ketones/aldehydes and dimethyl oxalate while regenerating NO x . As such, NO x is used as an oxidation mediator, converting alcohol substrates to more reactive nitrites which can be selectively converted to more desired compounds, closing a catalytic cycle in NO x species. 相似文献
117.
Stefan Alexander Tennigkeit Raziye Karapinar Till Rudack Max-Aylmer Dreier Philipp Althoff Dennis Eickelbeck Tatjana Surdin Michelle Grömmke Melanie D. Mark Katharina Spoida Mathias Lübben Udo Höweler Prof. Dr. Stefan Herlitze Prof. Dr. Klaus Gerwert 《Chembiochem : a European journal of chemical biology》2019,20(14):1766-1771
The primary goal of optogenetics is the light-controlled noninvasive and specific manipulation of various cellular processes. Herein, we present a hybrid strategy for targeted protein engineering combining computational techniques with electrophysiological and UV/visible spectroscopic experiments. We validated our concept for channelrhodopsin-2 and applied it to modify the less-well-studied vertebrate opsin melanopsin. Melanopsin is a promising optogenetic tool that functions as a selective molecular light switch for G protein-coupled receptor pathways. Thus, we constructed a model of the melanopsin Gq protein complex and predicted an absorption maximum shift of the Y211F variant. This variant displays a narrow blue-shifted action spectrum and twofold faster deactivation kinetics compared to wild-type melanopsin on G protein-coupled inward rectifying K+ (GIRK) channels in HEK293 cells. Furthermore, we verified the in vivo activity and optogenetic potential for the variant in mice. Thus, we propose that our developed concept will be generally applicable to designing optogenetic tools. 相似文献
118.
Katja-Emilia Lillsunde Dr. Tihomir Tomašič Dr. Philipp Schult Dr. Volker Lohmann Prof. Danijel Kikelj Dr. Päivi Tammela 《ChemMedChem》2019,14(3):334-342
Cellular chaperones that belong to the heat-shock protein 90 (Hsp90) family are a prerequisite for successful viral propagation for most viruses. The hepatitis C virus (HCV) uses Hsp90 for maturation, folding, and modification of viral proteins. Based on our previous discovery that marine alkaloid analogues with a 4,5,6,7-tetrahydrobenzo[1,2-d]thiazole-2-amine structure show inhibition of HCV replication and binding to Hsp90, a series of twelve novel compounds based on this scaffold was designed and synthesized. The aim was improved Hsp90 affinity and anti-HCV activity. Through structural optimization, improved binding to Hsp90 and specific HCV inhibition in genotype 1b and 2a replicon models was achieved for three compounds belonging to the newly synthesized series. Furthermore, these compounds efficiently inhibited replication of full-length HCV genotype 2a in a reporter virus RNA assay with IC50 values ranging from 0.03 to 0.6 μm . 相似文献
119.
Philipp Marx Angelo Romano Ignazio Roppolo Angela Chemelli Inge Mühlbacher Wolfgang Kern Sunny Chaudhary Thomas Andritsch Marco Sangermano Frank Wiesbrock 《大分子材料与工程》2019,304(12)
Tri(ethylene glycol) divinyl ether and the spiro‐orthoester 2‐((allyloxy)methy)‐1,4,6‐trioxospiro[4.4]nonane can be formulated in different ratios and crosslinked by thiol‐ene reactions. The spiro‐orthoester is used as anti‐shrinkage additive, enabling shrinkage reduction of up to 39%. Addition of a radical photoinitiator for the thiol‐ene reaction and a cationic photoinitiator for the double ring‐opening of the spiro‐orthoester enables dual‐curing for application in 3D‐printing. The formulation free of the spiro‐orthoester shows gelation during the printing process and, correspondingly, low resolution. The formulations containing the spiro‐orthoester exhibit higher resolutions in the range of 50 µm. The resins containing mixtures of tri(ethylene glycol) divinyl ether and the spiro‐orthoester show permittivities as high as 104. The dielectric loss factor of the resins is in the range of 0.5–7.6, and the conductivity in the range of 1.3?10?11 to 2.0?10?11 S cm?1. These high‐κ materials can be 3D‐printed by digital light processing for the next generation of electronic materials. 相似文献
120.
Jan Kuneš Ryotaro Arita Philipp Wissgott Hiroaki Ikeda 《Computer Physics Communications》2010,181(11):1888-1895
We present an implementation of an interface between the full-potential linearized augmented plane wave package Wien2k and the wannier90 code for the construction of maximally localized Wannier functions. The FORTRAN code and a documentation is made available and results are discussed for SrVO3, Sr2IrO4 (including spin-orbit coupling), LaFeAsO, and FeSb2. 相似文献