Electronic structures and optical properties of two anthracene derivatives

People have paid extensive attention to the investi- gation of the organic π-conjugated materials with elec- troluminescent (EL) properties during the last two dec- ades. Up to date, the organic luminescent electronicdevice is heading for the promising applications of flat panel displays[1―5]. As well known, the full-color dis- plays require the particular combination of red, green, and blue (named RGB) light emitters. Therefore, it is the principal task for the experimental researchers to…     

Design of unknown input observer with H_∞ performance for linear time-delay systems

1 .INTRODUCTIONThe dynamic behavior of many physical processes ,such as chemical process , long transmission lineand rolling mill systems , contain ti me-delay anduncertainties . Ti me-delay usually results in unsat-isfactory performance andis frequently a source ofinstability , so control of ti me-delay systems ispractically i mportant , especially state feedbackcontrol . A unknown input observer has i mportantapplications in realization of state feedback con-trol . An UIO is an esti ma…     

Synthesis and magnetic properties of one-dimensional Mn(II) complexes linked by dithiooxalato

Three dithiooxalato (Dto) bridging one-dimensional Mn(II) complexes [Mn(L)Dto](L = Phen (1), Bpy (2) and en (3)) were synthesized. All of the complexes have the similar one-dimensional structure through Dto bridge. The measurement of the variable temperature magnetic susceptibility of complex 1 showed that there are weak antiferromag-netic interactions between the Mn(II) ions.     

Porous α-Al2O3 thermal barrier coatings with dispersed Pt particles prepared by cathode plasma electrolytic deposition

Porous α-Al₂O₃ thermal barrier coatings (TBCs) containing dispersed Pt particles were prepared by cathode plasma electrolytic deposition (CPED). The influence of the Pt particles on the microstructure of the coatings and the CPED process were studied. The prepared coatings were mainly composed of α-Al₂O₃. The average thickness of the coatings was approximately 100 μm. Such single-layer TBCs exhibited not only excellent high-temperature cyclic oxidation and spallation resistance, but also good thermal insulation properties. Porous α-Al₂O₃ TBCs inhibit further oxidation of alloy substrates because of their extremely low oxygen diffusion rate, provide good thermal insulation because of their porous structure, and exhibit excellent mechanical properties because of the toughening effect of the Pt particles and because of stress relaxation induced by deformation of the porous structure.     

A new section of Kaili Formation （Cambrian） and a biostratigraphic study of the boundary interval across the undefined Cambrian Series 2 and Series 3 at Jianshan,Jianhe County,China with a discussion of global correlation based on the first appearance datum of Oryctocephalus indicus （Reed, 1910）

A trilobite biostratigraphic study of a new section of the Kaili Formation at Jianshan, Chuandong Village, Jianhe County, Guizhou is reported. Additional occurrences of key species associated with the Ovatoryctocara granulata-Bathynotus holopygus Zone and the overlying Oryctocephalus indicus Zone that were originally defined from the trilobite assemblages at the WuliuZengjiayan section of the Kaili are reported from this new section. The first appearance datum （FAD） of Oryctocephalus indicus occurs at the 44.52 m above the base of the unit. Based on study of abundant specimens （n = 800） from the Kaili Formation, we argue that Oryctocephalus indicus is a widespread taxon with a global distribution. O. reticulatus （Lermontova, 1940） from the middle part of the Kounamkites Zone of the Amganian Stage in the Molodo River region of Siberia and O. americanus （Sundberg and McCollum, 2003） from Nevada, North America are similar to representatives of O. indicus which occur in the O. indicus Zone of the Kaili Formation. O. reticulatus and O. americanus are here synonymized with O. indicus （Reed, 1910）. This study strengthens the Wuliu-Zengjiayan section of the Kaili Formation as a candidate section for a Global Stratotype for the base of the unnamed Cambrian Series 3.     

高压脉冲放电预处理强化卡林金浸出效果分析

A high-voltage pulsed discharge (HVPD) pretreatment was used to strengthen the leaching effect of Carlin-type gold ore containing arsenic. Optimal results of the pretreatment experiments were obtained at the following operating conditions: a spherical gap spacing of 20 mm, pulse number of 100, and voltage of 30 kV. The leaching rate of gold was increased by 15.65% via the HVPD pretreatment. The mass fraction of –0.5+0.35 mm and –0.35+0.1 mm was increased by 10.97% and 6.83% compared to the untreated samples, respectively, and the Au grade of –0.1 mm was increased by 22.84%. However, the superiority of the HVPD pretreatment would be weakened by prolonged grinding time. Scanning electron microscopy results indicated that the pretreated products presented as a melting state and then condensation, accompanying by some pore formation. More micro-cracks were generated at the interface of the ore and the original crack were expended via pulsed discharge pretreatment, with the contact area between the leaching reagent and ore increased, the leaching reaction rate enhanced and the leaching effect strengthened.     

Implementation of a new chaotic encryption system and synchronization

1.INTRODUCTIONChaos phenomenonis a kind of deterministic andran-domlike process in nonlinear dynamics.Chaos signalis very sensitive to initial conditions and chaotic se-quences are unpredictable,which makeits applicationin secure communication become a research hotspot innowadays,at the same ti me,it shows the potentialvitality of chaos,but some problems such as the de-sign of secret keys and the li mited models of the gen-eration of chaotic signals,have not resolved yet.It isknown to all …     

Lead-bismuth-free piezoceramics （Na0.5K0.44Li0.06）Nb0.95Sb0.05O3-Na5.6Cu1.2Sb10O29

Newly developed sintering aid Na5.6Cu1.2Sb10O29 (NCS) and lead-bismuth-free piezoceramics (Na0.5K0.44Li0.06) Nb0.95Sb0.05O3 (NKLNS) were prepared by the conventional solid state reaction. The effects of sintering aid NCS on the electrical properties of NKLNS were investigated. It was found that the addition of a proper amount of sintering aid NCS to NKLNS is effective not only on improving the density and the piezoelectric activity, but also on reducing the dielectric loss of NKLNS. The NKLNS doped with 0.4 mol% NCS has a piezoelectric constant d33 as high as 261pC/N and an electromechanical coupling factor k33 above 60%. These results show that NCS-doped NKLNS is a promising and practicable candidate for lead-bismuth-free piezoceramics.     

Cyclic oxidation behavior of b-NiAlDy alloys containing varying aluminum content at 1200 1C

b-NiAlDy cast alloys containing varying aluminum content were prepared by arcmelting. The microstructures and cyclic oxidation behavior of the alloys at 1200 1C were investigated. Grain refinement was achieved by increasing aluminum content in the alloy, which is beneficial to selective oxidation. The Ni–55Al–0.1Dy alloy showed excellent cyclic oxidation resistance due to the formation of a continuous, dense and slow-growing oxide scale. In contrast to this, severe internal oxidation as well as large void formation at the scale/alloy interface occurred in the Ni–45Al–0.1Dy alloy. The aluminum content dependence of the reactive element effects in b- NiAlDy was established that Dy doping strengthened the scale/alloy interface by pegging mechanism in high-aluminum alloys but accelerated internal oxidation in low-aluminum alloys during high-temperature exposure.     

PREPARATION OF VARIOUS TYPES OF PULP FROM OIL PALM LIGNOCELLULOSIC RESIDUES

Oil palm, ElaeisGuineensis, (Figure 1) is one of the most important plants in Malaysia. It produces palm oil and palm kernel oil, which is widely being used in food and other industries such as detergents and cosmetics. Malaysia is the world's largest producer and exporter of the oil, so that the country's economy is very much dependent on these oil products. Although oil from the palm tree is an excellent product for the country, residues from oil palm have not been used sufficiently. In th…