全文获取类型
收费全文 | 87篇 |
免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 17篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 5篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 23篇 |
一般工业技术 | 19篇 |
冶金工业 | 12篇 |
自动化技术 | 5篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有89条查询结果,搜索用时 15 毫秒
1.
R. Oedegard S. Roenning S. Rolseth J. Thonstad 《JOM Journal of the Minerals, Metals and Materials Society》1985,37(11):25-28
This paper examines the catalytic effects offlourides on the ?→α-Al2O3 phase transformation by heat treating commercial alumina samples with 2wt% additions of different flouride compounds. The various additives were ranked according to their effect on transformation temperature. Experiments were conducted to explain the high temperature coherence of crusts. The findings indicate that an alumina network is formed during ?→α phase transformation, which reinforces the crust on top of the cryolite bath. 相似文献
2.
Sørland Kaia Ingerdatter Sunoqrot Mohammed R. S. Sandsmark Elise Langørgen Sverre Bertilsson Helena Trimble Christopher G. Lin Gigin Selnæs Kirsten M. Goa Pål E. Bathen Tone F. Elschot Mattijs 《Magma (New York, N.Y.)》2022,35(4):573-585
Magnetic Resonance Materials in Physics, Biology and Medicine - Signal intensity normalization is necessary to reduce heterogeneity in T2-weighted (T2W) magnetic resonance imaging (MRI) for... 相似文献
3.
Asbjørn Solheim Sverre Rolseth Egil Skybakmoen Lisbet Støen Åsmund Sterten Trond Støre 《Metallurgical and Materials Transactions B》1996,27(5):739-744
Temperatures for primary crystallization of Na3AlF6 in multicomponent electrolyte systems of interest for the aluminum electrolysis process were determined by thermal analysis. The results are presented as binary and quasibinary diagrams and discussed in view of the literature data. An empirical equation describing liquidus temperatures for primary crystallization of Na3AlF6 was derived: $$\begin{gathered} t/(^\circ C) = 1011 + 0.50[AlF_3 ] - 0.13[AIF_3 ] - \frac{{3.45[CaF_2 ]}}{{1 + 0.0173[CaF_2 ]}} \hfill \\ + 0.124[CaF_2 ] \cdot [AlF_3 ] - 0.00542([CaF_2 ] \cdot [AlF_3 ])^{1.5} \hfill \\ - \frac{{7.93[Al_2 O_3 ]}}{{1 + 0.0936[Al_2 O_3 ] - 0.0017[Al_2 O_3 ]^2 - 0.0023[AlF_3 ] \cdot [Al_2 O_3 ]}} \hfill \\ - \frac{{8.90[LiF]}}{{1 + 0.0047[LiF] + 0.0010[AlF3]^2 }} - 3.95[MgF_2 ] - 3.95 \hfill \\ \end{gathered} $$ wheret is the temperature in degree Celsius and the square brackets denote the weight percent of components in the system Na3AlF6-AlF3-CaF2-Al2O3-LiF-MgF2-KF. The composition limitations are [AlF3] ≈ [CaF2] ≈ [LiF] < 20 wt pct, [MgF2] ≈ [KF] < 5 wt pct, and [A12O3] up to saturation. 相似文献
4.
In this paper we present two simple, reliable and readily applicable methods for calibrating cantilevers and measuring the thickness of thin gold films. The spring constant calibration requires knowledge of the Young's modulus, density of the cantilever and resonant frequency. The thickness of thin gold layers was determined by measuring changes in the resonant frequency and Q-factor of beam shaped AFM cantilevers before and after coating.The techniques for measuring the spring constant and thin film thickness provide accuracy on the order of 10-15%. 相似文献
5.
Annika K. E. Andersson Sverre M. Selbach Christopher S. Knee Tor Grande 《Journal of the American Ceramic Society》2014,97(8):2654-2661
The crystal structures of proton‐conducting BaZr1?xYxO3?x/2 (BZY05–BZY20) and BaCe0.8Y0.2O2.9 (BCY20) during hydration/dehydration has been studied by in situ high‐temperature X‐ray diffraction and thermal analysis. A contraction/expansion of the crystal lattice associated with dehydration/hydration was observed for all materials at elevated temperatures and the polymorphic phase transition temperatures of BaCe0.8Y0.2O2.9 were depressed by lowering the vapor pressure of water. A thermodynamic formalism is introduced to describe the chemical expansion associated with the hydration of oxygen vacancies in acceptor‐doped oxides. A conventional point defect model was applied to describe the lattice strain associated with the hydration. The chemical expansion is discussed with respect to the available volumetric data on the hydration of proton‐conducting oxide materials and its likely impact on ceramic fuel cells/hydrogen separation membranes utilizing a proton‐conducting electrolyte. 相似文献
6.
Maria Teresa Calejo Anna‐Lena Kjøniksen Atoosa Maleki Bo Nyström Sverre Arne Sande 《应用聚合物科学杂志》2014,131(7)
In this work, a hydrophobically modified (HM) chitosan derivative was prepared by covalent linkage of C12 groups to the chitosan backbone. HM‐chitosan microparticles were prepared according to an emulsification‐solvent evaporation method and naltrexone (NTX) was used as a model drug. For comparison, unmodified chitosan and poly lactic‐co‐glycolic acid (PLGA) microparticles were also tested as carriers for NTX. HM‐chitosan formed viscous semi‐dilute solutions, suggesting a high level of chain entanglements and hydrophobic associations. HM‐chitosan microparticles generally showed higher production yield and encapsulation efficiency, as compared with chitosan and PLGA. The burst release shown by chitosan microparticles was significantly reduced when using the HM‐chitosan derivative. An enhanced control of drug release was observed over at least 50 days. PLGA particles demonstrated inferior controlled release properties as compared to HM‐chitosan subsequent to the initial release stage. These results revealed the potential of hydrophobic modification of chitosan as a means to improve the stability and sustained delivery properties of the polymer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40055. 相似文献
7.
Anna‐Lena Kjøniksen Maria Teresa Calejo Kaizheng Zhu Bo Nyström Sverre Arne Sande 《应用聚合物科学杂志》2014,131(13)
Several different polysaccharides have been added to pluronic F127 (poloxamer 407) gels to test their ability to stabilize the gels against dissolution in aqueous media over time. The studied polysaccharides include κ‐carrageenan, chitosan, hyaluronic acid, pectin, alginate, hydroxyethylcellulose, and ethyl(hydroxyethyl)cellulose. Although all the considered polysaccharides slowed down the dissolution time of the pluronic gels, unmodified polysaccharides only had a modest stabilization effect. However, hydrophobic modification of polysaccharides with a sufficiently long hydrocarbon chain (C16) was found to partly prevent the gels from dissolving for more than 6 months. Shorter hydrocarbon chains did not have the same effect, even at high degrees of hydrophobicity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40465. 相似文献
8.
A historical overview highlights the evolutionary nature of developments in accident investigations in the transport industry. Based on a series of major events outside transportation, the concept of accident investigations has broadened to other domains and to a widening of the scope of the investigation. Consequently, existing investigation boards are forced to adapt their mandates, missions and methods. With the introduction of social risk perception and application of the concept of safety investigation in the public sector, a change of focus towards the aftermath and non-technical issues of a more generic nature emerges. This expansion has also gained the interest of social sciences and public governance, generating new underlying models and theories on risk and responsibility. The evolutionary development of safety investigations is demonstrated by the various organisational forms which shaped accident investigations in different countries. Underneath these organisational differences, a need for a common methodology and a reflection on fundamental notions is discussed. In particular differences among human operator models, the allocation of responsibilities in design concepts and methodological issue are elaborated. The needs and opportunities for a transition from accident prevention towards systems change are indicated. At present, the situation is ambiguous. An encompassing inventory can only provide a general oversight over emerging trends and lacks analytic rigor on specific topics. The societal dimensions, institutional changes at the level of governance and control and the powers that advocate or challenge investigations are not yet fully described.Therefore, in the conclusions a small number of critical challenges and threats are identified that should be open to scrutiny in order to facilitate a new, evolutionary step in safety enhancement. 相似文献
9.
Electrocatalytic Formation and Inactivation of Intermetallic Compounds in Electrorefining of Silicon 总被引:1,自引:0,他引:1
Espen Olsen Sverre Rolseth Jomar Thonstad 《Metallurgical and Materials Transactions B》2010,41(4):752-757
Silicon for solar cell purposes is today produced by an energy intensive process exhibiting high irreversible thermodynamic
energy losses. The purity of the product; 99,9999999 pct (9N), far exceeds what is generally accepted to be the requirements
for photovoltaic purposes (4-6N). According to thermodynamics, all elements except boron may be removed from silicon by three
layer electrochemical refining above the melting point of Si. Boron, on the other hand, shows higher affinity to specific
transition metals compared to silicon. This may be exploited by applying two principles in parallel; electrochemical refining
and electrocatalyzed reaction-precipitation of transition metal borides as heavy, stable particles. In this study we report
on the formation of such compounds at the cathode-electrolyte interface during electrochemical refining. The trends and mechanisms
observed in the laboratory scale investigation indicate that high purity silicon may be produced in industrial scale reactors
at low cost- and energy intensity. 相似文献
10.
The complex heterogeneous equilibria associated with the production of manganese ferroalloys have been simulated using recently
developed thermochemical databases. Over 600 measured equilibrium data have been used to verify and calibrate the model calculations.
Good agreement is obtained for many important technical relations such as carbon solubility, equilibrium diagrams and phase
relations, and element distribution as a function of temperature and composition. Experimental slag/metal and slag/metal/gas
equilibria in MnO-SiO2 binary, MnO-SiO2-CaO and MnO-SiO2-Al2O3 ternary, MnO-SiO2-CaO-Al2O3 quaternary, and MnO-SiO2-CaO-Al2O3-MgO quinary systems can be reproduced within experimental uncertainties. The influence of temperature, CO partial pressure,
and slag chemistry on the Mn- and Si-distribution equilibria has been quantitatively evaluated. This leads to a sound basis
for optimizing the manganese ferroalloy production processes. 相似文献