全文获取类型
收费全文 | 295篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 48篇 |
金属工艺 | 3篇 |
机械仪表 | 4篇 |
建筑科学 | 10篇 |
能源动力 | 3篇 |
轻工业 | 52篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
无线电 | 16篇 |
一般工业技术 | 24篇 |
冶金工业 | 113篇 |
自动化技术 | 24篇 |
出版年
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 9篇 |
2012年 | 11篇 |
2011年 | 16篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 3篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 13篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 53篇 |
1997年 | 26篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 5篇 |
排序方式: 共有306条查询结果,搜索用时 15 毫秒
31.
R Arumugam HE Soriano AO Scheimann BS Reid GS Gopalakrishna O Barakat CF Ozaki PR Wood 《Canadian Metallurgical Quarterly》1998,12(6):588-592
Lipopolysaccharide (LPS) from S. typhimurium on exposure to gamma-radiation resulted in decrease in toxicity and was less mitogenic, Silver stained profiles of irradiated LPS on polyacrylamide gels revealed complete loss of its heteropolysaccharides which was confirmed further by analysing lipid A and LPS from Salmonella minnesota Re mutants on SDS-PAGE. Glucosamine and 2-keto 3-deoxy-octonate(Kdo) contents were significantly decreased on treatment. Lipid A obtained by removal of heteropolysaccharides from LPS was less toxic on exposure to gamma radiations. 相似文献
32.
33.
H Uyttendaele JV Soriano R Montesano J Kitajewski 《Canadian Metallurgical Quarterly》1998,196(2):204-217
The ab initio folding problem can be divided into two sequential tasks of approximately equal computational complexity: the generation of native-like backbone folds and the positioning of side chains upon these backbones. The prediction of side-chain conformation in this context is challenging, because at best only the near-native global fold of the protein is known. To test the effect of displacements in the protein backbones on side-chain prediction for folds generated ab initio, sets of near-native backbones (< or = 4 A C alpha RMS error) for four small proteins were generated by two methods. The steric environment surrounding each residue was probed by placing the side chains in the native conformation on each of these decoys, followed by torsion-space optimization to remove steric clashes on a rigid backbone. We observe that on average 40% of the chi1 angles were displaced by 40 degrees or more, effectively setting the limits in accuracy for side-chain modeling under these conditions. Three different algorithms were subsequently used for prediction of side-chain conformation. The average prediction accuracy for the three methods was remarkably similar: 49% to 51% of the chi1 angles were predicted correctly overall (33% to 36% of the chi1+2 angles). Interestingly, when the inter-side-chain interactions were disregarded, the mean accuracy increased. A consensus approach is described, in which side-chain conformations are defined based on the most frequently predicted chi angles for a given method upon each set of near-native backbones. We find that consensus modeling, which de facto includes backbone flexibility, improves side-chain prediction: chi1 accuracy improved to 51-54% (36-42% of chi1+2). Implications of a consensus method for ab initio protein structure prediction are discussed. 相似文献
34.
M. Soriano M. Snchez‐Maran M. Melgosa E. Gmiz R. Delgado 《Color research and application》2002,27(6):430-440
Commercial talcs are pulverized mineral products with a variable chemical and mineralogic composition, widely used in industry. Although generally white, they have color variations. The aim of this study was to establish relationships between color parameters and the chemical and mineralogic composition of commercial talc samples, in order to investigate the causes of color. Chlorite, dolomite, magnesite, and calcite were the most abundant accessory minerals. Fe, Mn, Ti, and Ni were the most abundant chromophore chemical elements. Factor statistical analysis (89.8% of total variance explained) revealed that the influence of each mineral species on the different color parameters a*, b*, and L* is well defined (the highest loading factors). Chlorite associated with Fe, Mn, Ti, Zr, Cu, Zn, and V, and calcite associated with Zn, Cu, Sr (and, to a lesser degree, Fe, Mn, Ni, and Co) affect the color parameters a* and b* by inducing chromatic variations (greening and yellowing). Dolomite and magnesite associated with Fe, Sr, Ni, Co, V (and, to a lesser extent, Mn and Cu) affect L* by inducing darkening. 相似文献
35.
C Villanueva J Balanzó MT Novella G Soriano S Sáinz X Torras X Cussó C Guarner F Vilardell 《Canadian Metallurgical Quarterly》1996,334(25):1624-1629
BACKGROUND: Patients who have bleeding from esophageal varices are at high risk for rebleeding and death. We compared the efficacy and safety of endoscopic sclerotherapy with the efficacy and safety of nadolol plus isosorbide mononitrate for the prevention of variceal rebleeding. METHODS: Eighty-six hospitalized patients with cirrhosis and bleeding from esophageal varices diagnosed by endoscopy were randomly assigned to treatment with repeated sclerotherapy (43 patients) or nadolol plus isosorbide-5-mononitrate (43 patients). The primary outcomes were rebleeding, death, and complications. The hepatic venous pressure gradient was measured at base line and after three months. RESULTS: Base-line data were similar in the two groups, and the median follow-up was 18 months in both. Eleven patients in the medication group and 23 in the sclerotherapy group had rebleeding. The actuarial probability of remaining free of rebleeding was higher in the medication group for all episodes related to portal hypertension (P = 0.001) and variceal rebleeding (P = 0.002). Four patients in the medication group and nine in the sclerotherapy group died (P = 0.07 for the difference in the actuarial probability of survival). Seven patients in the medication group and 16 in the sclerotherapy group had treatment-related complications (P = 0.03). Thirty-one patients in the medication group underwent two hemodynamic studies; 1 of the 13 patients with more than a 20 percent decrease in the hepatic venous pressure gradient had rebleeding, as compared with 8 of the 18 with smaller decreases in the pressure gradient (P = 0.04) for the actuarial probability of rebleeding at two years). CONCLUSIONS: As compared with sclerotherapy, nadolol plus isosorbide mononitrate significantly decreased the risk of rebleeding from esophageal varices. 相似文献
36.
I Irminger-Finger JV Soriano G Vaudan R Montesano AP Sappino 《Canadian Metallurgical Quarterly》1998,143(5):1329-1339
BRCA1-associated RING domain (BARD1) was identified as a protein interacting with the breast cancer gene product BRCA1. The identification of tumorigenic missense mutations within BRCA1 that impair the formation of BARD1-BRCA1 complexes, and of BARD1 mutations in breast carcinomas, sustain the view that BARD1 is involved in BRCA1-mediated tumor suppression. We have cloned the murine Bard1 gene and determined that its expression in different tissues correlates with the expression profile of Brca1. To investigate the function of Bard1, we have reduced Bard1 gene expression in TAC-2 cells, a murine mammary epithelial cell line that retains morphogenetic properties characteristic of normal breast epithelium. Partial repression of Bard1, achieved by the transfection of TAC-2 cells with plasmids constitutively expressing ribozymes or antisense RNAs, resulted in marked phenotypic changes, consisting of altered cell shape, increased cell size, high frequency of multinucleated cells, and aberrant cell cycle progression. Furthermore, Bard1-repressed cell clones overcame contact inhibition of cell proliferation when grown in monolayer cultures and lost the capacity to form luminal structures in three-dimensional collagen gels. These results demonstrate that Bard1 repression induces complex changes in mammary epithelial cell properties which are suggestive of a premalignant phenotype. 相似文献
37.
Physico-chemical changes in ‘Saba’ bananas, a variety widely used as a raw material for several products in the Philippine food industry, were analysed under conditions of normal and acetylene-induced ripening.Starch degradation, the formation of reducing and non-reducing sugars and an increase in the moisture content, pectins and acidity of the pulp, occurred during ripening. Acetylene accelerated the rate of chemical change, without significantly affecting the final levels at which chemical constituents were present in the ripe pulp.Peel colour and pulp texture were both found to be useful indices of the stage of ripeness of the pulp after harvest. Changes in these physical parameters correlated well with the starch and sugar content of the pulp, irrespective of the rate of ripening. 相似文献
38.
A Milián Masanet JV Bagán Sebastián J Riera Grimalt E Lloria de Miguel Y Jiménez Soriano 《Canadian Metallurgical Quarterly》1998,49(5):408-410
Aspergillosis is an opportunistic deep mycosis that occurs in immunocompromised patients, often in the paranasal sinuses. However, it sometimes occurs in healthy subjects, producing symptoms similar to those of a chronic sinusitis that is unresponsive to conventional treatment. A possible entry point for Aspergillus is the oroantral communication originated by perforation of the dental root cavity during root canal of a molar with penetration of material. We report the clinical case of a patient with symptoms of chronic sinusitis who was diagnosed as sinus aspergillosis after radiological and histological study. The origin may have been a third upper molar in which a root canal was performed. 相似文献
39.
Alkali metal-doped MoVSbO catalysts have been prepared by impregnation of a MoVSbO-mixed oxide (prepared previously by a hydrothermal synthesis) and finally activated at 500 or 600 °C in N2. The catalysts have been characterized and tested for the selective oxidation of propane and propylene. Alkali-doped catalysts improved in general the catalytic performance of MoVSbO, resulting more selective to acrylic acid and less selective to acetic acid than the corresponding alkali-free MoVSbO catalysts. However, the specific behaviour strongly depends on both the alkali metal added and/or the final activation temperature. At isoconversion conditions, catalysts activated at 600 °C present selectivity to acrylic acid higher than that achieved on those activated at 500 °C, both K-doped catalysts presenting the highest yield to acrylic acid. The changes in the number of acid sites as well as the nature of crystalline phases can explain the catalytic behaviour of alkali-doped MoVSbO catalysts. 相似文献
40.
M.D. Soriano J. Jimnez-Jimnez P. Concepcin A. Jimnez-Lpez E. Rodríguez-Castelln J.M. Lpez Nieto 《Applied catalysis. B, Environmental》2009,92(3-4):271-279
Vanadium oxide supported on mesoporous zirconium phosphate catalysts has been synthesized, characterized and tested in the selective oxidation of H2S to sulfur. The nature of the vanadium species depends on the V-loading of catalyst. Catalysts with a V-content lower than 4wt% present both isolated vanadium species and V2O5 crystallites. However, V2O5 crystallites have been mainly observed in catalysts with higher V-content, although the presence of isolated V-species on the surface of the metal oxide support cannot be completely ruled out. The catalytic behaviour also depends on V-loading of catalysts. Thus, while the catalytic activity of catalysts can be related to the number of V-sites, the catalyst decay is clearly observed in samples with low V-loading. The characterization of catalysts after the catalytic tests indicates the presence of sulfur on the catalyst, which is favoured on catalysts with low V-loading. However, a clear transformation of V2O5 to V4O9 can be proposed according to XRD and Raman results of used catalysts with high V-loading. The importance of V5+–O–V4+ pairs in activity and selectivity is also discussed. 相似文献