全文获取类型
收费全文 | 1453篇 |
免费 | 29篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 8篇 |
综合类 | 4篇 |
化学工业 | 157篇 |
金属工艺 | 12篇 |
机械仪表 | 10篇 |
建筑科学 | 36篇 |
矿业工程 | 2篇 |
能源动力 | 34篇 |
轻工业 | 116篇 |
水利工程 | 5篇 |
石油天然气 | 4篇 |
无线电 | 64篇 |
一般工业技术 | 107篇 |
冶金工业 | 824篇 |
原子能技术 | 8篇 |
自动化技术 | 97篇 |
出版年
2022年 | 13篇 |
2021年 | 18篇 |
2020年 | 13篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 17篇 |
2016年 | 13篇 |
2015年 | 9篇 |
2014年 | 18篇 |
2013年 | 46篇 |
2012年 | 37篇 |
2011年 | 20篇 |
2010年 | 22篇 |
2009年 | 19篇 |
2008年 | 29篇 |
2007年 | 26篇 |
2006年 | 34篇 |
2005年 | 30篇 |
2004年 | 23篇 |
2003年 | 22篇 |
2002年 | 25篇 |
2001年 | 17篇 |
2000年 | 25篇 |
1999年 | 25篇 |
1998年 | 196篇 |
1997年 | 123篇 |
1996年 | 93篇 |
1995年 | 49篇 |
1994年 | 40篇 |
1993年 | 48篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 13篇 |
1989年 | 6篇 |
1988年 | 20篇 |
1987年 | 15篇 |
1986年 | 14篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 8篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1980年 | 18篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 43篇 |
1976年 | 86篇 |
1975年 | 11篇 |
1968年 | 5篇 |
1960年 | 5篇 |
排序方式: 共有1488条查询结果,搜索用时 0 毫秒
51.
Solomon Sundar Manoharan Swati Sigamani John Prasanna Manju Lata Rao Ranjan Kumar Sahu 《Journal of the American Ceramic Society》2002,85(10):2469-2471
Interaction of electromagnetic radiation with a physical mixture of metal nitrates and amides/hydrazides is observed to initiate high-temperature reactions, useful for realizing several high-temperature ceramic materials. A judicious choice of such redox mixtures undergoes exothermic reactions when they couple with microwave radiation. The coupling of electromagnetic radiation with metal salts and amides/hydrazides depends on the dielectric properties of the individual components in the reaction mixture. The approach has been used to prepare γ-Fe2 O3 , Fe3 O4 , MgCr2 O4 , α-CaCr2 O4 , and La0.7 Ba0.3 MnO3 . 相似文献
52.
Graeme Moad Ezio Rizzardo David H. Solomon Athelstan L. J. Beckwith 《Polymer Bulletin》1992,29(6):647-652
Summary A method is described for determining the absolute rate constants for the first few propagation steps in radical polymerization. The procedure involves a product analysis of the oligomeric alkoxyamines formed when an initiator is decomposed in monomer containing a very low concentration of a nitroxide radical scavenger. The method is illustrated with analysis of data for methyl acrylate. The rate constants for the first two propagation steps for polymerization of this monomer,k
p(1) andk
p(2), are at least an order of magnitude greater thank
p(average). Values of the absolute rate constants for reactions of phenyl and primary alkyl radicals with methyl acrylate are also estimated. 相似文献
53.
Alex L. Riley Sarah E. Pepper Adam J. Canner Solomon F. Brown Mark D. Ogden 《分离科学与技术》2018,53(1):22-35
Work has been carried out screening hydrometallurgical resins for application in the valorization of industrially produced jarosite. Of the seven resins tested, anion exchange resins performed poorly for valuable metal recovery. Purolite S950+ and S957, along with a strong acid resin, show good extraction properties, but are selective for Fe3+ over the other (divalent) metals. Purolite S930+ (iminodiacetic acid-functionalized resin) demonstrates selectivity for Cu2+ over Fe3+, but poor selectivity for Ni2+, Zn2+, and Co2+. Dowex M4195 (bispicolylamine-functionalized resin) demonstrates promise for extracting metals of value away from a mixed metal pregnant liquor solution (PLS). A three-stage column-based recovery process is proposed for jarosite leachate treatment. 相似文献
54.
Moses M. Solomon 《Journal of Adhesion Science and Technology》2013,27(11):1060-1080
The inhibition performance of poly (methacrylic acid) (PMAA) and the effect of addition of iodide ions on the inhibition efficiency for mild steel corrosion in 0.5 M H2SO4 solution were investigated in the temperature range of 303–333 K using electrochemical, weight loss, scanning electron microscopy (SEM), and water contact angles measurements. The results show that PMAA is a moderate inhibitor for mild steel in 0.5 M H2SO4 solution. Addition of small amount of KI to PMAA significantly upgraded the inhibition efficiency up to 96.7%. The adsorption properties of PMAA and PMAA + KI are estimated by considering thermodynamic and kinetic parameters. The results reveal that PMAA alone was physically adsorbed onto the mild steel surface, while comprehensive adsorption mode characterized the adsorption of PMAA + KI. Adsorption of PMAA and PMAA + KI followed Temkin adsorption isotherm. The SEM and water contact angle images confirmed the enhanced PMAA film formation on mild steel surface by iodide ions. 相似文献
55.
B. M. Jenkins J. J. Mehlschau R. B. Williams C. Solomon J. Balmes M. Kleinman 《Aerosol science and technology》2013,47(5):437-454
A unique burner system was designed for the purposes of exposing human subjects to rice straw smoke under highly controlled conditions. The system burns individual straws and has produced particle concentrations up to 900 w g m m 3 in a temperature- and humidity-controlled exposure chamber. Burner operation is fully automatic and programmable. Ignition is by radiant heating in a manner similar to the field. Particle concentration is controlled by the firing interval between straws and by the ratio of burner outlet flow mixing with the main purified air supplied to the exposure chamber. Steady-state particle concentrations are achieved within 5 min from start. Repeatability of particle concentration is excellent at the two exposure levels used, 200 and 500 w g m m 3 . Measurements of particle size distributions suggest that approximately 80% of mass is in the size fraction below 1 w m. Although particle concentrations are controlled at target levels with good precision, emission factors are higher than achieved with similar material in wind tunnel and field experiments. Further characterization of particulate matter is needed to determine if higher emission factors are associated with changes in particle composition and morphology that may influence exposure results. 相似文献
56.
57.
Chemical methods were used to assess the inhibitive and adsorption behaviour of carboxymethyl cellulose (CMC) for mild steel in H2SO4 solution at 30-60 °C. Results obtained show that CMC act as inhibitor for mild steel in H2SO4. The inhibition efficiency was found to increase with increase in CMC concentration but decreased with rise in temperature, which is suggestive of physical adsorption mechanism. The adsorption of the CMC onto the mild steel surface was found to follow Langmuir and Dubinin-Radushkevich adsorption isotherm models. The inhibition mechanism was further corroborated by the values of activation parameters obtained from the experimental data. 相似文献
58.
Prof. Alessia Carocci Dr. Mariagrazia Roselli Prof. Roberta Budriesi Dr. Matteo Micucci Prof. Jean-François Desaphy Dr. Concetta Altamura Dr. Maria Maddalena Cavalluzzi Dr. Maddalena Toma Dr. Giovanna Ilaria Passeri Dr. Gualtiero Milani Dr. Angelo Lovece Prof. Alessia Catalano Dr. Claudio Bruno Dr. Annalisa De Palma Prof. Filomena Corbo Prof. Carlo Franchini Prof. Solomon Habtemariam Prof. Giovanni Lentini 《ChemMedChem》2021,16(3):578-588
Under the hypothesis that cardioprotective agents might benefit from synergism between antiarrhythmic activity and antioxidant properties, a small series of mexiletine analogues were coupled with the 2,2,5,5-tetramethylpyrroline moiety, known for its antioxidant effect, in order to obtain dual-acting drugs potentially useful in the protection of the heart against post-ischemic reperfusion injury. The pyrroline derivatives reported herein were found to be more potent as antiarrhythmic agents than mexiletine and displayed antioxidant activity. The most interesting tetramethylpyrroline congener, a tert-butyl-substituted analogue, was at least 100 times more active as an antiarrhythmic than mexiletine. 相似文献
59.
Solomon Hanson Duntu Francis Tetteh Iftikhar Ahmad Mohammad Islam Solomon Boakye-Yiadom 《Ceramics International》2021,47(1):367-380
The onset of hybrid alumina-based composites, which combines two or more nano-particles within the alumina matrix has already shown promising improvements in the matrix material. However, variations in mechanical properties including the optimum compositions that give improved properties faced with the development of alumina-based composites require further studies to understand the underlying mechanisms and synergistic effects of the nano-particle additions on the alumina matrix. In the current study, the structure and properties of Al?O?-graphene (0.5 wt%) and Al?O?–ZrO? (4 wt% and 10 wt%) composites fabricated via hot-pressing was studied as a baseline for multiple combinations. Even though the addition of 10 wt%ZrO? resulted in a 23% reduction in the grain size of the alumina matrix, the 4 wt%ZrO? addition resulted in a 14% increase in grain size as compared to the parent alumina matrix. X-ray diffraction analysis revealed that there was approximately 85% monoclinic (m-ZrO2) vs. 15% tetragonal (t-ZrO2) crystal structures in the A4ZrO? sample whilst the A10ZrO? had approximately 93% m-ZrO2 vs. 7% t-ZrO2. The high-volume fraction of the monoclinic crystal structures in the A10ZrO? accounts for the induced microcracks in the sample since the transition from the ductile-tetragonal to brittle-monoclinic is associated with the exertion of compressive stresses on the alumina matrix by the associated elastic volume expansion of m-ZrO2. Also, the addition of 0.5 wt%graphene resulted in about 37% reduction in the grain size of the alumina matrix, and approximately 10% increase in hardness as a result of the distribution of graphene along the grain boundaries of the parent alumina matrix, which restricts grain coalescence and growth during processing. Furthermore, an increase up to 115% and 164% were observed in the fracture toughness (KIC) with the inclusion of 0.5 wt%graphene and 10 wt%ZrO? respectively, which was primarily ascribed to the fine-grained microstructures and toughening mechanisms of the intergranular graphene and ZrO? particles. 相似文献
60.