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61.
Chandra Sekhar Pedamallu Linet Özdamar Tibor Csendes Tamás Vinkó 《Journal of Global Optimization》2008,42(3):369-384
A new efficient interval partitioning approach to solve constrained global optimization problems is proposed. This involves
a new parallel subdivision direction selection method as well as an adaptive tree search. The latter explores nodes (intervals
in variable domains) using a restricted hybrid depth-first and best-first branching strategy. This hybrid approach is also
used for activating local search to identify feasible stationary points. The new tree search management technique results
in improved performance across standard solution and computational indicators when compared to previously proposed techniques.
On the other hand, the new parallel subdivision direction selection rule detects infeasible and suboptimal boxes earlier than
existing rules, and this contributes to performance by enabling earlier reliable deletion of such subintervals from the search
space. 相似文献
62.
Bone provides an important source of forensic evidence. The storage conditions of bone have been recognised as a factor in
maintaining the integrity of such evidence. Thermogravimetric analysis (TG) has been employed to examine the effects of storage
environments and preparation methods on the structural properties of pig bones. A comparison of oven and freeze drying has
been made to study the effect of storage conditions. A comparison has also been made of ground bone specimens with cut specimens.
Freeze-dried hand ground specimens provided the most consistent results and, thus, this is the recommended method of preparation
of bone specimens for TG analysis. 相似文献
63.
Natarajan Raman Ramaraj Jeyamurugan Mariyyappan Subbulakshmi Raja Boominathan Chithu Ramakrishnan Yuvarajan 《Chemical Papers》2010,64(3):318-328
A novel series of Co(II), Ni(II), Cu(II), Zn(II), and VO(IV) complexes has been synthesized from the Schiff base derived from
4-[(3,4-dimethoxybenzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one and 1,2-diaminobenzene. Structural features
were determined by analytical and spectral techniques. Binding of synthesized complexes with calf thymus DNA (CT DNA) was
studied by spectroscopic methods and viscosity measurements. Experimental results indicate that the complexes are able to
form adducts with DNA and to distort the double helix by changing the base stacking. Lower DNA affinity of the VO(IV) complex
is caused by the change of coordination geometry by the vanadyl ion resulting in a somewhat unfavorable configuration for
the DNA binding. Oxidative DNA cleavage activities of the complexes were studied with supercoiled (SC) pUC19 DNA using gel
electrophoresis; the mechanism studies revealed that the hydroxyl radical is likely to be the reactive species responsible
for the cleavage of pUC19 DNA by the synthesized complexes. The in vitro antimicrobial screening effects of the investigated
compounds were monitored by the disc diffusion method. The synthesized Schiff base complexes exhibit higher antimicrobial
activity than the respective free Schiff base. 相似文献
64.
Nabil Smichi Ahmed Fendri Raja Chaabouni Faouzi Ben Rebah Youssef Gargouri Nabil Miled 《Applied biochemistry and biotechnology》2010,162(5):1483-1496
A lipolytic activity was located in the sardine digestive glands (pyloric caeca), from which a sardine digestive lipase (SaDL)
was purified. Pure SaDL has a molecular mass of 43 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis
analysis. The enzyme was found to be more active on short-chain triacylglycerols than on long-chain ones. SaDL does not present
the interfacial activation phenomenon. Control experiments were performed under the same experimental conditions, with dromedary
and turkey pancreatic lipases and showed a positive interfacial activation phenomenon. Sodium deoxycholate (NaDC) has an inhibitory
effect on the lipase activity. The pure enzyme lost 40% of its activity in presence of 8 mM NaDC. SaDL was found to be mostly
stable at low pH values. Interestingly, no colipase was detected in the sardine pyloric caeca. Analogous results were reported
for the scorpion and the crab digestive systems. This is in line with the idea that colipase might has evolved in mammal animals
simultaneously with the appearance of an exocrine pancreas. No similarity was found between the NH2-terminal amino acid residues of SaDL and those of lipases from the digestive tract of other species. Altogether, these results
suggest that SaDL is a member of a new group of lipases belonging to aquatic species. 相似文献
65.
66.
67.
Rohini S. Bhalerao-Panajkar Mandar M. Shirolkar Raja Das Pankaj Poddar 《Solid State Communications》2011,151(1):55-60
Cupric oxide nanoparticles of ∼8-10 nm width and 40-45 nm length self assembled as large particles ∼1-1.5 μm have been investigated, in the 10-325 K temperature range, using magnetic and dielectric measurements. In magnetic measurements a single broad peak at ∼230 K in a zero field cooled sample has been observed. Coercivity, in magnetization measurements at 10 K, suggests that the nanoparticles are core-shell type particles with an antiferromagnetic core and a ferromagnetic shell. Dielectric measurements, at various frequencies from 3.7 Hz to 949 kHz, exhibit a sharp peak at 284 K followed by weak anomalies around 213 and 230 K. 相似文献
68.
69.
D.M. Raj KumarM. Manivel Raja K. PrabaharV. Chandrasekaran Asok PoddarR. Ranganathan K.G. Suresh 《Journal of magnetism and magnetic materials》2011,323(13):1750-1754
The effect of Si/Ge ratio on resistivity and thermopower behavior has been investigated in the magnetocaloric ferromagnetic Gd5SixGe4−x compounds with x=1.7-2.3. Microstructural studies reveal the presence of Gd5(Si,Ge)4-matrix phase (5:4-type) along with traces of secondary phases (5:5 or 5:3-type). The x=1.7 and 2.0 samples display the presence of a first order structural transition from orthorhombic to monoclinic phase followed by a magnetic transition of the monoclinic phase. The alloys with x=2.2 and 2.3 display only magnetic transitions of the orthorhombic phase. A low temperature feature apparent in the AC susceptibility and resistivity data below 100 K reflects an antiferromagnetic transition of secondary phase(s) present in these compounds. The resistivity behavior study correlates with microstructural studies. A large change in thermopower of −8 μV/K was obtained at the magneto-structural transition for the x=2 compound. 相似文献
70.
Calcined Mg-Al hydrotalcites (Mg/Al=3) can be used as an efficient catalyst in the selective O-methylation of phenol and catechol and N-monomethylation of aniline employing dimethylcarbonate (DMC) as a methylating agent in vapor phase at 275°C. 相似文献