全文获取类型
收费全文 | 2361篇 |
免费 | 114篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 31篇 |
综合类 | 8篇 |
化学工业 | 701篇 |
金属工艺 | 44篇 |
机械仪表 | 49篇 |
建筑科学 | 131篇 |
矿业工程 | 6篇 |
能源动力 | 73篇 |
轻工业 | 205篇 |
水利工程 | 21篇 |
石油天然气 | 7篇 |
无线电 | 190篇 |
一般工业技术 | 404篇 |
冶金工业 | 204篇 |
原子能技术 | 22篇 |
自动化技术 | 384篇 |
出版年
2023年 | 33篇 |
2022年 | 38篇 |
2021年 | 52篇 |
2020年 | 38篇 |
2019年 | 47篇 |
2018年 | 54篇 |
2017年 | 55篇 |
2016年 | 74篇 |
2015年 | 68篇 |
2014年 | 87篇 |
2013年 | 128篇 |
2012年 | 109篇 |
2011年 | 154篇 |
2010年 | 112篇 |
2009年 | 101篇 |
2008年 | 120篇 |
2007年 | 110篇 |
2006年 | 85篇 |
2005年 | 82篇 |
2004年 | 63篇 |
2003年 | 77篇 |
2002年 | 55篇 |
2001年 | 39篇 |
2000年 | 35篇 |
1999年 | 44篇 |
1998年 | 76篇 |
1997年 | 42篇 |
1996年 | 40篇 |
1995年 | 34篇 |
1994年 | 33篇 |
1993年 | 34篇 |
1992年 | 18篇 |
1991年 | 22篇 |
1990年 | 24篇 |
1989年 | 20篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 20篇 |
1985年 | 22篇 |
1984年 | 21篇 |
1983年 | 11篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 11篇 |
1978年 | 17篇 |
1977年 | 11篇 |
1976年 | 19篇 |
1974年 | 12篇 |
1973年 | 8篇 |
排序方式: 共有2480条查询结果,搜索用时 0 毫秒
101.
A Conjugate of an Anti‐Epidermal Growth Factor Receptor (EGFR) VHH and a Cell‐Penetrating Peptide Drives Receptor Internalization and Blocks EGFR Activation 下载免费PDF全文
Sanne A. M. van Lith Dr. Dirk van den Brand Dr. Rike Wallbrecher Dr. Sander M. J. van Duijnhoven Dr. Roland Brock Dr. William P. J. Leenders 《Chembiochem : a European journal of chemical biology》2017,18(24):2390-2394
Overexpression of (mutated) receptor tyrosine kinases is a characteristic of many aggressive tumors, and induction of receptor uptake has long been recognized as a therapeutic modality. A conjugate of a synthetically produced cell‐penetrating peptide (CPP), corresponding to amino acids 38–59 of human lactoferrin, and the recombinant llama single‐domain antibody (VHH) 7D12, which binds the human epidermal growth factor receptor (EGFR), was generated by sortase A mediated transpeptidation. The conjugate blocks EGF‐mediated EGFR activation with higher efficacy than that of both modalities alone; a phenomenon that is caused by both effective receptor blockade and internalization. Thus, the VHH–CPP conjugate shows a combination of activities that implement a highly powerful new design principle to block receptor activation by its clearance from the cell surface. 相似文献
102.
The purpose of this study was to investigate the effect of solvent type on the solidification rate of ethyl cellulose (EC) microparticles and particle size/distribution of emulsion droplets/hardened microparticles during the solvent evaporation process using focused beam reflectance measurement (FBRM). EC microparticles were prepared with a water‐in‐oil‐in‐water solvent evaporation method using various solvents, including dichloromethane, dichloromethane–methanol (1:1), ethyl acetate and chloroform. The particle size/distribution of the emulsion droplets/hardened microparticles was monitored using FBRM. The morphology of EC microparticles was characterized using scanning electron microscopy (SEM). The transformation of the emulsion droplets into solid microparticles for all solvents occurred within the first 10–90 min. The square weighted mean chord length of EC microparticles prepared using chloroform was smallest, but the chord count was not the highest. The chord length distribution (CLD) measured by FBRM showed that a larger mean particle size gave longer CLD and a lower peak of particle number. SEM data revealed that the morphology of microparticles was influenced by the type of solvent. FBRM can be employed for online monitoring of the shift in the microparticle CLD and detect transformation of emulsion droplets into solid microparticles during the solvent evaporation process. The microparticle CLD and transformation process were strongly influenced by solvent type. © 2017 Society of Chemical Industry 相似文献
103.
ABSTRACT The concept of steam drying originates from the mid of the last century. However, a broad industrial acceptance of the technique has so far not taken place. The paper deals with modelling the steam drying process and applications of steam drying with in certain industrial sectors where the technique has been deemed to hove special opponunities. In the modelling scction the mass and heat transfer proceases are described along with equilibrium, capillarity and sorption phenomena occurring in porous materials during the steam drying process. In addition existing models in the literslure are presented. The applications discussed involve drying of fuels with high moisture contcna, cattle feed exemplified by sugar beet pulp. lumber. paper pulp. paper and sludges. Steam drying is compared to flue gas drying of biofuels prior to combustion in a boiler. With reference to a current insrallation in Sweden. the exergy losses. as manifested by loss of co-generation cupacity. are discussed. The energy saving potentid when using steam drying of sugar beet pulp as compared to other possible plant configurations is demonstrated. Mechanical vapour recompression applied to steam drying is analysed with reference to reponed dau from industriul plsnts. Finally. environmcntul advantages when using steam drying are presented. 相似文献
104.
Ulrich Müller Martine Philipp Jan Christoph Gaukler Wulff Possart Roland Sanctuary Jan Kristian Krüger 《The Journal of Adhesion》2013,89(3):253-276
The curing of an epoxy consisting of the solid hardener dicyandiamide (DICY) and the resin diglycidyl ether of bisphenol A (DGEBA) is studied in a system consisting of a tablet of DICY embedded in liquid DGEBA. Dissolution of DICY within the liquid DGEBA in combination with the transport of dissolved DICY from the tablet border into DGEBA and the chemical reaction of both reactants is studied by scanning Brillouin microscopy and infrared spectroscopy. Scanning Brillouin microscopy demonstrates the spatial and temporal evolution of the static and dynamic hypersonic properties in the course of curing in the vicinity of the DICY tablet. Infrared spectroscopy performed on epoxy pieces extracted from the final sample at different distances from the tablet surface give information about the spatial evolution of the curing process. The results achieved by both techniques are finally combined to yield a better understanding of the curing of DICY-based epoxies, which transform upon curing from strongly heterogeneous systems towards increasingly homogeneous systems. 相似文献
105.
Klicia A. Sampaio Jose V. Ayala Simone M. Silva Roberta Ceriani Roland Verhé Antonio J. A. Meirelles 《Journal of the American Oil Chemists' Society》2013,90(2):191-198
In the present work, a detailed study is performed for carotene thermal degradation in palm oil at four temperatures ranging from 170 to 230 °C. The heating process was carried out with injection of nitrogen, and the samples were collected every 20 min during a total heating period of 140 min. HPLC analysis was conducted to monitor the carotenoids and tocols variations over the heating time at each temperature. The experimental data were then compared to literature data concerning carotenoids thermal degradation. The thermal degradation kinetics of carotenoids in palm oil followed an order superior to 1. The dependence of constant rates with temperature obeyed the Arrhenius relationship. The activation energy for the carotenoids thermal degradation in palm oil was found to be 109.4 kJ/mol. 相似文献
106.
Katrin Greimel Annemarie Marold Christian Sohar Roland Feola Armin Temel Thomas Schoenbacher Enrique Herrero Acero Georg M. Guebitz 《Reactive and Functional Polymers》2013,73(10):1335-1339
The potential of two hydrolytic enzymes, namely a lipase from Thermomyces lanuginosus (TlL) and a cutinase from Humicola insolens (HiC) for hydrolysis of the phthalic acid backbone based polyester coatings was assessed. Two phthalic acid/trimethylolpropane based model substrates resembling the structure of the polyester backbone of coatings were synthesized. Out of both enzymes, only the cutinase was able to hydrolyze both model substrates while the larger substrate was hydrolyzed at a lower rate. The cutinase was also able to hydrolyze a coating (alkyd resin) both in suspension and as dried film. LC–MS analysis of the hydrolysis products released from the coating revealed the presence of oleic acid, its monoglyceride, phthalic acid and 2-((3-((2-((2,3-dihydroxypropoxy)carbonyl)benzoyl)oxy)-2-hydroxypropoxy)carbonyl)benzoic acid. These results indicate that the enzyme was able to hydrolyze the polyester backbone as well as to release fatty acid side chains. Consequently, enzymatic hydrolysis has a potential for the removal of coatings, their recycling or their functionalization. 相似文献
107.
Analysis of Transcriptional Regulation of the Human miR-17-92 Cluster; Evidence for Involvement of Pim-1 总被引:1,自引:0,他引:1
108.
Dendrimers or Nanoparticles as Supports for the Design of Efficient and Recoverable Organocatalysts?
Michel Keller Arnaud Perrier Roland Linhardt Laurie Travers Sebastian Wittmann Anne‐Marie Caminade Jean‐Pierre Majoral Oliver Reiser Armelle Ouali 《Advanced Synthesis \u0026amp; Catalysis》2013,355(9):1748-1754
The Jørgensen–Hayashi catalyst [(S)‐α,α‐diphenylprolinol trimethylsilyl ether] was grafted onto the surface of two different supports: phosphorus dendrimers (generations 1 to 3) and magnetic, polymer‐coated cobalt/carbon (Co/C) nanobeads. These new supported catalysts displayed high activities and selectivities in the Michael additions of a wide range of aldehydes to different nitroolefins. Moreover, the dendrimer of the third generation displayed excellent recycling abilities since it could be recovered and reused in 7 consecutive runs without loss of activity. 相似文献
109.
C.A. Fustin M. Sclavons N. Pantoustier S. Bebelman D. Truffier‐Blanc C. Bailly P. Merlin 《Polymer Engineering and Science》2005,45(8):1067-1072
Based on a previous model compound study, we investigated the melt reactivity of Si‐H and Si‐vinyl end‐functionalized siloxane oligomers towards polybutylene terephthalate (PBT) in the presence of platinum(0)‐catalyst. We clearly observed grafting of the Si‐H functional oligomer onto PBT and have also indications for grafting of the Si‐vinyl oligomer. The grafting efficiencies and kinetics of both siloxane model compounds are compared and roughly quantified by infrared spectroscopy. This result indicates that the same reactive groups that are used to vulcanize silicone gums at high temperature can also be used to favor compatibility with a polyester matrix, opening perspectives toward polyester‐siloxane thermoplastic elastomers. POLYM. ENG. SCI. 45:1067–1072, 2005. © 2005 Society of Plastics Engineers 相似文献
110.
Controlling micro‐ and nanofibrillar morphology of polymer blends in low‐speed melt spinning process. Part II: Influences of extrusion rate on morphological changes of a PLA/PVA blend through a capillary die 下载免费PDF全文
Nguyen Hoai An Tran Harald Brünig Maria Auf der Landwehr Roland Vogel Jürgen Pionteck Gert Heinrich 《应用聚合物科学杂志》2016,133(47)
The effects of the extrusion rate on the morphological changes of poly(lactic acid) (PLA)/poly(vinyl alcohol) (PVA) blend through a capillary die were investigated. In this study, the extrusion rate or mass flow rate is altered from 0.5 g min?1 to 2 g min?1 with an increment of 0.5 g min?1. The PLA/PVA blend with a composition of 30/70 (wt %) exhibits a particle matrix morphology with dispersed PLA droplets within the PVA matrix. It is found that, the spherical or ellipsoidal dispersed PLA droplets are elongated and coalesced into rod‐like or longer ellipsoidal droplets when they pass through the capillary die. When the extrusion rate increases, the coalescence between the large PLA droplets occurs more intense. However, the changes of the extrusion rate have no strong effect on the coalescence of small droplets having diameter less than about 150 nm. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44257. 相似文献