全文获取类型
收费全文 | 400篇 |
免费 | 23篇 |
专业分类
电工技术 | 5篇 |
综合类 | 1篇 |
化学工业 | 96篇 |
金属工艺 | 12篇 |
机械仪表 | 13篇 |
建筑科学 | 23篇 |
矿业工程 | 5篇 |
能源动力 | 15篇 |
轻工业 | 22篇 |
水利工程 | 2篇 |
无线电 | 45篇 |
一般工业技术 | 81篇 |
冶金工业 | 26篇 |
自动化技术 | 77篇 |
出版年
2023年 | 10篇 |
2022年 | 6篇 |
2021年 | 21篇 |
2020年 | 13篇 |
2019年 | 19篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 19篇 |
2014年 | 20篇 |
2013年 | 22篇 |
2012年 | 15篇 |
2011年 | 33篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 22篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1963年 | 2篇 |
排序方式: 共有423条查询结果,搜索用时 15 毫秒
61.
K Sannes-Lowery RH Griffey GH Kruppa JP Speir SA Hofstadler 《Canadian Metallurgical Quarterly》1998,12(23):1957-1961
In this work we present a novel in-source dissociation scheme referred to as multipole storage assisted dissociation (MSAD) for electrospray ionization (ESI) generated ions in which dissociation is effected by employing extended ion accumulation intervals in a high pressure rf-only hexapole assembly prior to mass analysis. Following an extended ion accumulation interval in which ions are confined in the rf-only hexapole, ions are gated out of the hexapole, trapped, and mass analyzed in the trapped ion cell of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. The accumulation region is comprised of an rf-only hexapole ion guide which separates two electrodes, a biased skimmer cone, and an auxiliary 'gate' electrode at the low pressure end of the hexapole. This technique should be applicable to other mass spectrometry platforms compatible with pulsed ionization sources including quadrupole ion traps, and time-of-flight mass analyzers. This concept is demonstrated with the dissociation of a small protein in which selective fragmentation is observed at labile amino acid linkages producing primarily y-type fragment ions. 相似文献
62.
Process control of lightly salted wild and farmed Atlantic cod (Gadus morhua) by brine injection, brining, and freezing--a low field NMR study 总被引:1,自引:0,他引:1
Gudjonsdottir M Gunnlaugsson VN Finnbogadottir GA Sveinsdottir K Magnusson H Arason S Rustad T 《Journal of food science》2010,75(8):E527-E536
The aim of this study was to use low-field nuclear magnetic resonance (NMR) and traditional chemical methods to investigate the physical and chemical differences in wild and farmed cod processed pre- and postrigor, and how these properties were affected by brine injection, brining, and freezing. In prerigor processed farmed or wild cod, brine injections followed by brining for 2 d, with brine concentrations up to 5.5% and 4%, respectively, were not sufficient to reach a muscle salt concentration of 2% as aimed for, while wild cod processed postrigor had sufficient salt uptake after the same processing. Low-field NMR gave valuable information about the differences in the muscle structure between wild and farmed cod as well as the state of the water in the muscle during brine injection, brining, and during rigor tension. Low-field NMR is, therefore, a valuable tool that can be used to optimize the salting and storing processes of lightly salted cod products from both wild and farmed cod. For farmed cod to be used in the production of lightly salted products further research is needed. Practical Application: Optimal processing of lightly salted cod products is important to the fish industry, due to an increasing market for this product in southern Europe. Farmed cod, which is seen as a potential steady raw material source for this production, differs considerably from its wild counterparts by having other chemical and physical muscle properties, such as lower water content and lower pH. With the processing procedures used today the farmed cod can, therefore, only be used in some of the products, where wild cod is currently used as raw material. It is, therefore, important that the processing of these products is optimized with regard to these differences in the raw material. This study gives a valuable contribution to further studies about optimal combinations of brine injections, brining, and freezing of pre- and postrigor processed farmed compared to wild cod. 相似文献
63.
Oswald Devisch Els Hannes T Anh Trinh Maria Leus Jo Berben &Dstrok ặng Thế Hiến 《建筑学研究前沿(英文版)》2019,8(3):406-414
Intercultural student exchange can positively impact education, research, and society. Research-by-design has been put forward in design education as an approach to explicitly address the integration of education and research. The problem is that design schools develop their own interpretation of this approach, which brings difficulty in virtually comparing and learning from the generated design proposals. This case is evident in intercultural parallel design studios that deal with diverging socio-cultural and institutional traditions. In addressing this problem and maximizing the benefits of intercultural exchange, this study proposes to adopt a meta perspective and use the design as co-evolution model as a framework for analyzing and comparing design data generated by different research-by-design approaches. The study applies this meta perspective on an intercultural architectural design studio jointly organized by Ton Duc Thang University (Vietnam) and Hasselt University (Belgium). 相似文献
64.
Volker Kahlenberg Richard Albrecht Daniela Schmidmair Hannes Krüger Biljana Krüger Martina Tribus Anuschka Pauluhn 《Journal of the American Ceramic Society》2019,102(4):2084-2093
In a sequence of temperature-dependent solid-state reactions in the system CaO–Al2O3–MgO the formation of the ternary phase Ca3Al4MgO10 or C3A2M has been studied. Whereas the compound could not be prepared at 1200°C, a yield of 85 wt.-% of Ca3Al4MgO10 was obtained at 1320°C (incongruent melting point: 1330°C). Powder diffraction data compare well with results of previous investigations from the 1960s. Single crystals of Ca3Al4MgO10 could be retrieved from the sinter-pellets. Basic crystallographic data are as follows: orthorhombic symmetry, space group Pbcm, a = 5.14073(8), b = 16.7576(2), c = 10.70977(16) Å, V = 922.61(2) Å3, Z = 4. Using synchrotron diffraction data it was possible to solve the crystal structure. Least-squares refinements resulted in a residual of R(|F|) = 0.021 for 1000 independent observed reflections with I > 2σ(I) and 97 parameters. The structure contains [TO4]-tetrahedra (T=Al,Mg) forming a three-dimensional (3-D) framework whose topological characteristics have been determined. Al-Mg distributions on the different T-sites have been studied. The calcium cations are located in voids of the network. More than 50 years after its first observation our investigation clarifies the crystal structure of a compound belonging to a system that is of relevance for several fields of materials science. 相似文献
65.
Marcus Weyd Christian Pflieger Andy Vogel Hannes Richter Volker Prehn Christiane Günther Frank Splittgerber Alessa Gäbler Daniel Kaulbars Patrick Bräutigam Marcus Franke Samira Lambertz Julian Schlechtweg Ingolf Voigt 《化学,工程师,技术》2021,93(9):1432-1439
Reducing micropollutant pollution of water bodies is an important objective of water management and an integral part of environmental policy. Ceramic nanofiltration membranes were developed as multichannel membranes of increased membrane area and rotating disk filters. The membranes developed show retention of over 80 % for PEG 400. The membranes are currently being tested for the separation of micropollutants from wastewater contaminated with pharmaceuticals. With the help of a downstream oxidative process, the trace substances remaining in the permeate are degraded. 相似文献
66.
Mylena M.M. Carrijo Hannes Lorenz Carlos R. Rambo Peter Greil Nahum Travitzky 《Ceramics International》2018,44(7):8116-8124
This paper describes the development and fabrication of pastes suitable for screen printing process using Ti3SiC2 as the ceramic filler and ethyl cellulose as the binder. With the aim of obtaining high quality screen printed films, the influence of different amounts of Ti3SiC2 filler (20–40?vol%) and binder (0–5?vol%) on the rheological properties of the pastes was investigated. Samples with higher viscosity, such as pastes containing 30?vol% and 40?vol% Ti3SiC2 filler, regardless of the amount of ethyl cellulose, showed a higher printing quality compared to the samples with other compositions. The different paste compositions were screen printed onto paper-derived Al2O3 substrates containing 28.6 ± 4.8% open porosity and sintered for 1?h under an argon atmosphere at 1600?°C. X-ray diffraction (XRD) measurements and scanning electron microscopy (SEM) analysis showed that the sintered films contained TiC as a primary phase and Ti3SiC2 as a secondary phase. The partial decomposition of Ti3SiC2 after sintering can be attributed to residual carbon from the organic additives, which decreases the thermal stability of this material. 相似文献
67.
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
68.
69.
UNStudio Ben van Berkel Hannes Pfau Astrid Piber Jin Xing Hufton+Crow Seth Powers 《中国建筑装饰装修》2018,(4)
正UNStudio由Ben van Berkel和Caroline Bos创立,是一个国际性的建筑设计网络。拥有三个全方位服务的国际事务所,分别位于阿姆斯特丹、香港和上海。专于建筑、室内建筑、产品设计、城市发展和基础设施项目。地址:浙江省杭州市钱江新城富春路业主方:凯德集团建筑面积:392526m~2项目年份:2017醒目的裙楼之上坐落着两座流线型的高楼,从中可以饱览钱塘江和西湖的迷人风光。 相似文献
70.
Low‐Temperature Chemical Synthesis of High‐Purity Diacylglycerols (DAG) from Monoacylglycerols (MAG)
下载免费PDF全文
![点击此处可从《Lipids》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A chemical method was developed for low‐temperature synthesis of DAG from MAG followed by an easy purification procedure in order to obtain high‐purity DAG. Solvent‐assisted and solvent‐free reaction conditions were used, combined with different catalysts (sodium methoxide, p‐toluenesulfonic acid, methanesulfonic acid, and sulfuric acid). All reactions were performed at 35 and 70 °C. By increasing both acidity and polarity of the catalyst the equilibrium shifts towards the formation of DAG. When using sulfuric acid in solvent‐assisted condition at 70 °C, 88 % conversion was obtained after 20 min of reaction (77 % w/w DAG in the reaction mixture after evaporation of the solvent). After purifying by means of column chromatography, 96 % pure DAG were obtained. The overall yield of DAG was 81 %. 相似文献