全文获取类型
收费全文 | 102篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 35篇 |
金属工艺 | 4篇 |
能源动力 | 1篇 |
一般工业技术 | 44篇 |
冶金工业 | 16篇 |
自动化技术 | 1篇 |
出版年
2022年 | 2篇 |
2009年 | 1篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 9篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有102条查询结果,搜索用时 0 毫秒
31.
Microwave Effects in Lead Zirconium Titanate Synthesis: Enhanced Kinetics and Changed Mechanisms 总被引:5,自引:0,他引:5
Balasubramaniam Vaidhyanathan Anirudh P. Singh Dinesh K. Agrawal Thomas R. Shrout Rustum Roy Suman Ganguly 《Journal of the American Ceramic Society》2001,84(6):1197-1202
A novel, simple, and fast solid-state procedure has been demonstrated for the synthesis of Pb(Zr,Ti)O3 (PZT), using microwave radiation. The process consists of starting with the respective oxides mixed in the required proportions and exposing the charge to the microwaves. By making one or more of the constituent oxides slightly nonstoichiometric, enormous enhancement in reaction rates has been achieved, and single-phase PZT can be synthesized at temperatures as low as 600°C. Moreover, it has been shown that the combined use of nonstoichiometric precursors and microwave irradiation leads to different reaction pathways for the formation of PZT. Further, the microwave method diminishes PbO loss. 相似文献
32.
Ramesh Peelamedu rzej Badzian Rustum Roy Richard P. Martukanitz 《Journal of the American Ceramic Society》2004,87(9):1806-1809
A new hybrid sintering process has been developed by replacing all but one laser by microwaves in the existing simultaneous multiple laser process (SIMPLE). Microwave energy has been used to preheat the material before laser radiation, and the synergism between microwave and laser energies could effectively heat the material to temperatures of 1700°C and beyond in just a few minutes. Using this process, rapid sintering of 3Y–ZrO2 (3Y–TZP) pellets has been achieved in a few minutes. Microstructural investigations reveal that the microwave–laser hybrid sintered pellets of 3Y–ZrO2 have nanograins averaging about 20 nm. The microwave–laser hybrid sintering process can clearly be a new approach for fabrication of nanoceramics and nanocomposites. 相似文献
33.
34.
Socially responsible materials research 总被引:1,自引:0,他引:1
35.
The relation of the structures of metamict mineral phases and non-crystalline solids is discussed; the question of radiation effects in solidified nuclear waste forms is considered in this regard. In ceramics, if the actinides can be concentrated in radiation-resistant phases such as uraninite or monazite, the overall radiation effects on the ceramics should be quite small. 相似文献
36.
Palaniappan Ravindranathan Sridhar Komarneni Amar S. Bhalla Rustum Roy 《Journal of the American Ceramic Society》1991,74(12):2996-2999
A solution sol-gel method has been developed to prepare 0.9Pb(Mg1/3 Nb2/3 )O3 -0.1PbTiO3 (0.9PMN-0.1PT) ceramics. During the processing the gel first converted to cubic pyrochlore phase at a calcination temperature of 600°C followed by the formation of pure perovskite phase at 775°C. The ceramics sintered at 1250°C for 4 h showed ≈98% of the theoretical density. The room-temperature dielectric constant of the pellets sintered at 1250°C showed a maximum value of 25035 at 1 kHz. Sintering studies at different temperatures revealed that the dielectric constant increased with increasing grain size in these ceramics. 相似文献
37.
38.
HM Faessel HK Slocum RC Jackson TJ Boritzki YM Rustum MG Nair WR Greco 《Canadian Metallurgical Quarterly》1998,58(14):3036-3050
The combined action among polyglutamylatable and nonpolyglutamylatable antifolates, directed against dihydrofolate reductase (DHFR), glycinamide ribonucleotide formyltransferase (GARFT), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase (AICARFT), and thymidylate synthase (TS), in human ileocecal HCT-8 cells was examined in a 96-well plate growth inhibition assay (96-h continuous drug exposure). An interaction parameter, alpha, was estimated for each of 95 experiments by fitting a seven-parameter model to data with weighted nonlinear regression. In a representative experiment, raising the folic acid concentration in the medium dramatically increased the Loewe synergy for the combination of trimetrexate (TMTX) and the GARFT inhibitor AG2034 (from a mean alpha +/- SE of 1.50 +/- 0.25 at 2.3 microM folic acid to 146 +/- 20 at 78 microM folic acid). Enhancements were also found for combinations of TMTX with the GARFT inhibitors AG2032, Lometrexol, and LY309887, the AICARFT inhibitor AG2009, and the TS inhibitors LY231514 and Tomudex but not with the GARFT inhibitor LL95509 or with the TS inhibitors AG337, ZD9331, and BW1843U89. Replacing TMTX with methotrexate in two-drug mixtures decreased the intensity of Loewe synergy. Examination of isobolograms at different effect levels revealed informative reproducible changes in isobol patterns. No two-drug combinations among inhibitors of GARFT, AICARFT, and TS exhibited Loewe synergy at either 2.3 or 78 microM folic acid. Thus, the ideal requirement for the folic acid-enhanced synergy is that a nonpolyglutamylatable DHFR inhibitor be combined with a polyglutamylatable inhibitor of another folate-requiring enzyme. A hypothesis to explain this general phenomenon involves the critical role of folylpoly-gamma-glutamate synthetase and the effect of the DHFR inhibitor in decreasing the protection by folic acid of cells to the other antifolates. 相似文献
39.
A study has been made of the growth of tellurium films sputtered onto four substrate materials (cover glass, spinel, quartz and alumina), unheated as well as heated to 100°, 150°, 200° and 250°C. It was found that the structure of the substrate exerted no measurable influence on the structure of the films. However, sputtering conditions do influence the preferred orientation. Tellurium films sputtered onto unheated substrates have a preferred orientation of the (100) type (i.e. with the (100) planes parallel to the substrate). Those on heated substrates show a preferred orientation of the (101) type. Furthermore, thickness is an important factor. Tellurium films with thickness less than 6000 Å have a (100)-type preferred orientation, but thicker films have a (101) orientation. All the observations can be explained in terms of recrystallization taking place during deposition due to heating of the film. 相似文献
40.
A Harstrick A Gonzales N Schleucher U Vanhoefer K Lu JL Formento G Milano H Wilke S Seeber Y Rustum 《Canadian Metallurgical Quarterly》1998,9(7):625-634
Recent preclinical and clinical data indicate that the main mechanisms of 5-fluorouracil (5-FU) cytotoxicity depend on the mode of administration. To gather further insight into the major causes of acquired 5-FU resistance, drug-sensitive human gastric (M2), colon (HT29) and breast (MCF7) cancer cell lines were repeatedly exposed to a fixed concentration of 5-FU given either for 1 or 24 h. Although equieffective doses (IC50) of 5-FU were used, resistance to a 1 h exposure of 5-FU developed faster in all models than to a 24 h exposure. Cell lines with acquired resistance to a 1 h application of 5-FU were only partly cross-resistant to a 24 h exposure, whereas lines with resistance to protracted application of 5-FU displayed significant cross-resistance to the 1 h schedule. Resistance to methotrexate was only seen in cell lines with acquired resistance to 24 h of 5-FU. All 5-FU-resistant cell lines showed reduced incorporation of 5-FU into cellular RNA. Furthermore, elevations of thymidylate synthase were seen in all cell lines with resistance to 24 h of 5-FU but also in one cell line with resistance to a bolus schedule. No alterations in folylpolyglutamate synthase developed in the resistant cell lines. These data support the concept that the main mechanisms of 5-FU cytotoxicity depend on the mode of application. Incorporation of fluorouridine triphosphate into RNA appears to be the most important mechanism of action for 5-FU bolus schedules, whereas inhibition of thymidylate synthase becomes more important as the infusion time is prolonged. These data could have implications on the interaction of 5-FU given at different schedules with various other cytostatic agents. 相似文献