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排序方式: 共有381条查询结果,搜索用时 15 毫秒
61.
Maniyan CG Mohan G Pillai PM Sujata R Haridasan PP Khan AH 《Radiation protection dosimetry》2003,104(1):71-76
Potassium (K) content in 408 male workers of a rare earths processing plant was estimated using a shadow shield whole body counter. The average K content in the non-vegetarian and vegetarian group was found to be 1.5 g kg(-1) and 2.1 g kg(-1) respectively. The absorbed dose due to 40K is determined as 0.18 +/- 0.02 mGy. While the K content was found to be proportional to body build index, it is inversely proportional to slenderness. Body K was maximum in the middle aged group (35-45 y) and a minimum in younger and older persons. The correlation of potassium content with some disease patterns was also studied. Diabetes mellitus patients were observed to have low K content of 0.9 +/- 0.2 g kg(-1) and those who suffer from cardiovascular disorders were found to have high K content 2.7 +/- 0.3 g kg(-1). The studies showed that the depletion of body K content takes place a few years prior to the clinical detection of diabetes and it builds up a few years before the clinical detection of cardiovascular disorders. It is stressed that the medical information is preliminary as the number of subjects studied was not very large. Wider and in depth study by various groups can hopefully strengthen the observation. 相似文献
62.
63.
Sudipta BISWAS Satadru PRAMANIK Suman MANDAL Sudeshna SARKAR Sujata CHAUDHURI Swati DE 《材料科学前沿(英文版)》2020,14(1):24
Asymmetric patchy Ag/Cu Janus nanoparticles (NPs) were synthesized via a “seed-mediated” approach. This is the first report of synthesis of nanometer sized metal-based Janus NPs without using complicated methods. Selective adsorption of the surfactant onto the seed NPs leads to the formation of Janus type structure. Subsequently the reduction potential of Ag+/Ag0 and Cu2+/Cu0 systems directs the formation of the “patch”. The patchy Janus NPs show significant antifungal activity towards a potent rice pathogen thus offering the prospect of future application in crop protection. 相似文献
64.
Bikas C. Maji Madangopal Krishnan M. Sujata Gouthama Ranjit K. Ray 《Metallurgical and Materials Transactions A》2013,44(1):172-185
The effect of Co addition has been studied in Fe-30Mn-6Si-xCo (x = 0 to 9 wt pct) shape memory alloys in terms of their microstructure, martensitic transformation and shape recovery. Microstructural investigations reveal that in Fe-Mn-Si-Co alloys, the microstructure remains single-phase austenite (??) up to 5 pct Co and beyond that becomes two-phase comprising ?? and off-stoichiometric (Fe,Co)5Mn3Si2 intermetallic ??-phases. The forward ??-?? martensite transformation start temperature (M S) decreases with the addition of Co up to 5 pct, and alloys containing more than 5 pct Co, show slightly higher M S possibly on account of two-phase microstructure. Unlike M S, the ??-?? reverse transformation start temperature (A S) has been found to remain almost unaltered by Co addition. In general, addition of Co to Fe-Mn-Si alloys deteriorates shape recovery due to decreasing resistance to plastic yielding concomitant with the formation of stress induced ?? martensite. However, there is an improvement in shape recovery beyond 5 pct Co addition, possibly due to the strengthening effect arising from the presence of (Fe,Co)5Mn3Si2 precipitates within the two-phase microstructure and due to higher amount of stress induced ?? martensite. 相似文献
65.
A. K. Bhattacharya A. Hartridge K. K. Mallick J. L. Woodhead 《Journal of Materials Science》1994,29(23):6076-6078
Free-flowing Ln2Zr2O7 microspheres (Ln=lanthanide) were prepared by an aqueous inorganic sol-gel route without any intermediate phase formation. The gel spheres obtained at room temperature were shown by X-ray diffraction to be amorphous but calcination to 750 °C produced fully crystalline fluorite phases. On calcination to 850 °C, pyrochlore phases were formed with suitable lanthanides. The microspheres were characterized by X-ray diffraction and scanning electron microscopy with energy dispersive analysis of X-rays to give accurate determination of structure, composition and crystallite size. 相似文献
66.
Bijayani Panda R. Balasubramaniam Gopal Dwivedi Sujata Mahapatra 《Transactions of the Indian Institute of Metals》2008,61(2-3):177-181
Eutectoid steels, which are traditionally used as rails in railway systems, are prone to corrosion, especially in coastal environments. In order to minimize this problem, four new rail steel compositions, with different combinations of microalloying elements Cu, Cr, Ni and Si, were designed and processed as per the thermomechanical schedule for normal rail steel processing in industry. Corrosion behavior of the rail steels were studied by weight loss measurement after immersion test and Tafel polarization in freely aerated 3.5 % NaCl. The rust obtained after immersion test were characterized by Fourier transform infrared spectroscopy (FTIR). Corrosion rate obtained weight loss measurement was similar for all the rail steels. γ-FeOOH (lepidocrocite) and δ-FeOOH were identified as the major rust phases from the FTIR spectra of the rail steels. The relative absorption intensities of these rust phases were similar for all the rail steels. Corrosion rates calculated from Tafel polarization tests were similar for all the rail steels. The corresponding free corrosion potentials were also similar for all the rail steels. The zero corrosion potential obtained from Tafel polarization of Cu-Mo, Cr-Mn, Cu-Ni, Cr-Cu-Ni and Cr-Cu-Ni-Si rail steels was more noble compared to C-Mn and Cu-Si rail steels indicating better corrosion resistance of these alloys. The importance of conducting alternate wetting and drying test has been emphasized. 相似文献
67.
68.
In this paper, yield and fatigue behavior of a polypropylene nanocomposite and a polyamide-6 nanocomposite has been studied. The Eyring equation was used to model the temperature and strain rate sensitivity of the yield strengths of these two nanocomposites. Both activation volume and activation energy of the polypropylene nanocomposite were higher than those of the polyamide-6 nanocomposite. The fatigue strength of the polyamide-6 nanocomposite was higher than that of the polypropylene nanocomposite. However, the ratio of maximum fatigue stress to yield strength of the polypropylene nanocomposite was higher than that of the polyamide nanocomposite. The fatigue failure in both composites was initiated at agglomerated nanoparticles. 相似文献
69.
Ray Arpita Chowdhury Chandreyee Mallick Sakil Mondal Sukanta Paul Soumik Roy Sarbani 《Mobile Networks and Applications》2020,25(3):932-942
Mobile Networks and Applications - In mobile crowd-sensing, smartphone users take part in sensing and then share the data to the server (cloud) and get an incentive. These data can be utilized for... 相似文献
70.
J. A. Saggio K. Sujata J. Hahn S. J. Hwu K. R. Poeppelmeier T. O. Mason 《Journal of the American Ceramic Society》1989,72(5):849-853
Solid-phase relationships have been determined for the Bi2 O3 –SrO–CuO system at 800°C in air with and without Li2 CO3 mineralizer. Two ternary compounds were detected with Bi:Sr:Cu ratios of approximately 2:2:1 and a solid-solution phase 11−;x:9+x:5 with 0x0.4. The solid-solution phase is a 9 K super-conductor at x=0.4. Two additional compounds with Bi:Sr:Cu ratios of approximately 4:9:1 and 2:7:2 are apparently stabilized by the presence of Li2 CO3 , but do not form without it. X-ray crystallographic data are provided for each compound. Ramifications for quaternary Bi:Sr:Ca:Cu-O superconductors are discussed. 相似文献