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排序方式: 共有420条查询结果,搜索用时 10 毫秒
1.
Abbas Shockravi Samad Bavili T Esmael Rostami Ali Yousefi Ali Dehjurian Rahim Tohidi 《Journal of inclusion phenomena and macrocyclic chemistry》2004,49(1-2):163-166
Some new dibenzosulfo, dibenzosulfoxo macrocyclic diamides are synthesized. 相似文献
2.
Tee Lee Theng Zaharuddin Ahmad Che Abd Rahim Mohamed 《Journal of Radioanalytical and Nuclear Chemistry》2004,262(2):485-488
Polonium-210 has been measured in the soft parts of Anadara granosa purchased at Kuala Selangor, West Coast of Malaysia in August 2001, April 2002 and September 2002. It is shown that 210Po is non-uniformly distributed within cockles of various sizes (i.e., 2.5, 3.0, 3.5 and 4.0 cm of shell length) and the concentration
of 210Po in the soft parts of cockle was significantly different (p<0.05) due to sampling date. The highest value was observed in the smallest cockle with a shell length of 2.5 cm (411.6±26.16
Bq/g dry wt.). It is clear that there is an allometric relationship between 210Po activity concentration and individual cockle weight. This may reflect on the differences of metabolic rate and growth age
of cockles. The mean activity concentration of 210Po measured in Kuala Selangor filtered water were 1.75±0.17, 0.79±0.08 and 1.13±0.20 Bq/kg for August 2001, April 2002 and
September 2002, respectively. The yield concentration factors for 210Po in the soft parts of cockles varies from 27.3. 103 to 106.9. 103.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Shariff?E.?KabirEmail author M.?Arzu?Miah M.?Abdur?Rahim Sonia?Sultana G.?M.?Golzar?Hossain Ebbe?Nordlander Edward?Rosenberg 《Journal of Cluster Science》2005,16(1):93-110
Treatment of Ru3(CO)12 with dpphSe2 (dpph = 1,6-bis(diphenylphosphino)hexane) in refluxing toluene in the presence of Me3NO afforded two new compounds, Ru3(CO)7(-CO)(3-Se)(-dpph) (1) and Ru3(CO)7(3-Se)2(-dpph) (2). A similar reaction of Ru3(CO)12 with dpppeSe2 (dpppe = 1,5-bis(diphenylphosphino)pentane) gave exclusively Ru3(CO)7(3-Se)2(-dpppe) (3). Treatment of Ru3(CO)12 with dpphS2 and dpppeS2 at 110°C in the presence of Me3NO afforded Ru3(CO)7(3-S)2(-dpph) (4) and Ru3(CO)7(3-S)2(-dpppe) (5), respectively. Reactions of Fe3(CO)12 with dpphSe2 and dpppeSe2, under identical conditions, afforded Fe3(CO)7(3-Se)2(-dpph) (6) and Fe3(CO)7(3-Se)2(-dpppe) (7), respectively. Compounds 1–7 were characterized spectroscopically and the molecular structures of compounds 1–4 were determined by single crystal X-ray crystallography. The core of 1 contains an equilateral triangle of ruthenium atoms with one capping selenium, one bridging dpph, one doubly bridging carbonyl and seven terminal carbonyl ligands. Complexes 2–4 have a square-pyramidal structure with two metal and two chalcogenide atoms alternating in the basal plane and the third metal atom at the apex of the pyramid, and belong to the family of well-known nido clusters with seven skeletal electron pairs. 相似文献
4.
5.
6.
Osman Ayop Mohamad Kamal A. Rahim Noor Asniza Murad Huda A. Majid 《Applied Physics A: Materials Science & Processing》2014,117(2):651-656
This paper presents the analysis of circular ring metamaterial absorber with the existing of copper lines. The structure is designed using lossy FR4 substrate with thin copper layers. The circular ring shape with copper lines is printed on the top surface of FR4 substrate, while at the bottom surface is printed with full copper ground plane. Parametric study is done to investigate the effect of copper lines on the resonance frequency. From the simulation, the circular ring metamaterial absorber with vertical copper lines can resonates at lower frequency, but this structure is polarized sensitive. This drawback can be improved by adding horizontal copper lines together with the vertical copper lines. The circular ring structure with vertical and horizontal copper lines is not only polarization insensitive, but it can works at wide operating angle of incident waves. 相似文献
7.
Thermodynamic simulation of performance of a dual cycle with stroke length and volumetric efficiency
This article presents finite-time thermodynamics analysis of an irreversible air standard dual cycle. An irreversible dual cycle model which is more close to practice is established. In this model, the effects of stroke length and volume efficiency by considering the nonlinear relation between the specific heats of working fluid and its temperature, the frictional loss, the internal irreversibility, and heat transfer loss are analyzed. The results show that if compression ratio is less than certain value, the power output increases with increasing stroke length, while if compression ratio exceeds certain value, the power output first increases and then starts to decrease with increasing stroke length. With further increase in compression ratio, the increase of stroke length results in decreasing the power output. The results also show that, throughout the compression ratio range, the power output increases with the increasing volumetric efficiency. The results obtained in this study are of importance to provide good guidance for performance evaluation and improvement of practical internal combustion engines. 相似文献
8.
This paper proposes to obtain homogeneous and stable blends of oligo(9,9-dioctylfluorene)-co-phenylene (OF), a conjugated oligomer with strong tendency of formation of excimers in the solid state, and nitrile rubber (NBR). This rubber protection reduces the formation of polymer excimers in the films. The fluorene oligomer was synthesized via Suzuki reaction and incorporated in the nitrile rubber. The films were formed by spin coating and casting techniques on the proportions of 1, 5, 10, 20 and 50 % (w/w) of OF in the nitrile rubber (NBR). The structural, optical and thermal properties of the films were evaluated with infrared, UV–Vis, fluorescence and thermogravimetry, respectively. The nitrile rubber proved to be essential for the preparation of homogeneous and stable films, since it was not possible to obtain films with only fluorene using the above-mentioned techniques. Furthermore, luminescent properties of OF are unchanged and the excimers formation in the solid state decrease suggesting the efficiency of nitrile rubber as the matrix for making films. 相似文献
9.
Majid M. Heravi Navabeh Nami Hossien A. Oskooie Rahim Hekmatshoar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1873-1878
The addition of dialkyl acetylenedicarboxylate to o-phenylenediamine, o-aminophenol, and o-aminothiophenol under microwave irradiation in solventless system rapidly afforded quinoxaline, benzoxazine, and benzothiazine derivatives, respectively. 相似文献
10.
Rahim Hekmat Shoar Majid M. Heravi Leila Pedram Shadi Hasan Raeiat Zeinab Jaddi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2563-2567
A facile and rapid synthesis of thio compounds, analogues to ciprofloxacin, and norfloxacin is described. 相似文献