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Erbium-doped glasses with composition x GeO 2 –(80 − x )TeO 2 –10ZnO–10BaO were prepared by melt-quenching technique. The phonon sideband spectra and the optical absorption band edges for the host matrix were confirmed by means of the spectral measurements. Standard Judd–Ofelt calculations have been completed to these glasses. The dependence of up-conversion and infrared emission under 980 nm excitation on the glass composition was studied. The quantum efficiencies for the 4 I 13/2 → 4 I 15/2 transition of trivalent erbium in the glasses were estimated.

A novel red emitting phosphor Gd2(MoO4)3:Eu3+ was prepared by solid reaction, using Gd2O3, Eu2O3 and WO3 as starting materials and NH4F as flux. The effects of flux content and Eu3+ concentration on the crystal structure, morphology and luminescent properties were investigated using XRD, SEM and fluorescent spectrum measurement. The XRD patterns showed that the resultants had the monoclinic structure. With the increase in flux amount, their crystallization significantly improved. The SEM images indicated that the mean size of the phosphor particles was around 2 μm, and agglomeration of the phosphor particles appeared while introducing higher flux amount. The excitation spectra exhibited more intense f-f transitions originating from ground state 7F0 to upper states 5L6 and 5D2 than the charge transfer band. The concentration quenching of Eu3+ emission indicated that energy transfer from Eu3+ to molybdate host existed even at lower Eu3+ concentration.

In this work, we used the solution precipitation route to synthesize Eu{sup 3+}-doped YPO{sub 4}.nH{sub 2}O nanowires. The structure, morphology, composition, thermal behavior, and photoluminescence of as-synthesized product were characterized by X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopic (FE-SEM) and photoluminescence (PL) spectra. The dependence of the structure, morphology, composition and luminescent properties on the thermal treatment was investigated. The results indicate that the aqueous synthesis has a better control on the structure, morphology, composition of the products, and that the heat treatment induces the transitions of the structure, composition, and luminescent properties. - Graphical abstract: The emission efficiency of the sample annealed at 250 deg. C is about six times as high as that of as-synthesized sample. This is attributed primarily to the coordinated water as the nonradiative relaxation pathways in the as-synthesized sample.

Predation is a strong selective force acting on both morphology and behaviour of prey animals. While morphological defences (e.g. crypsis, presence of armours or spines or specific body morphologies) and antipredator behaviours (e.g. change in foraging or reproductive effort, or hiding and fleeing behaviours) have been widely studied separately, few studies have considered the interplay between the two. The question raised in our study is whether antipredator behaviours of a prey fish to predator odours could be influenced by the morphology of prey conspecifics in the diet of the predator. We used goldfish (Carassius auratus) as our test species; goldfish exposed to predation risk significantly increase their body depth to length ratio, which gives them a survival advantage against gape-limited predators. We exposed shallow-bodied and deep-bodied goldfish to the odour of pike (Esox lucius) fed either form of goldfish. Deep-bodied goldfish displayed lower intensity antipredator responses than shallow-bodied ones, consistent with the hypothesis that individuals with morphological defences should exhibit less behavioural modification than those lacking such defences. Moreover, both shallow- and deep-bodied goldfish displayed their strongest antipredator responses when exposed to the odour of pike fed conspecifics of their own morphology, indicating that goldfish are able to differentiate the morphology of conspecifics through predator diet cues. For a given individual, predator threat increases as the prey become more like the individual eaten, revealing a surprising level of sophistication of chemosensory assessment by prey fish.

A novel red emitting phosphor α-Gd2(MoO4)3:Eu3+ was developed for white light emitting diodes (LEDs). The phosphor was prepared by solid-state reaction. The effects of the flux content and the activator concentration on the crystal structure, morphology and luminescent properties were investigated by using XRD, SEM, and fluorescent spectra. These results showed that this phosphor can be effectively excited by ultraviolet (UV) (395 nm) and blue (465 nm) light, matching the output wavelengths of ultraviolet or blue LED chips. The α-Gd2 (MoO4)3 phosphor may be a better candidate for solid state lighting application.

In a series of experiments, we investigated the effects of food availability and risk frequency on the dynamics of predator-induced changes in growth and morphology of prey fish using goldfish (Carassius auratus) as our test species. In experiment 1, we fed goldfish high or low food rations and exposed them to either alarm cues from conspecifics, cues from swordtails or a water control. After 60 days, goldfish in the alarm cue treatment significantly increased their body depth and body weight but had smaller body length than goldfish exposed to swordtails cues or water, likely reducing their vulnerability to gape-limited predators. Importantly, food level had an impact on the amplitude of the morphological changes. In experiment 2, goldfish were exposed to two different frequencies of predation cues or a water control for 50 days. The cues were either continued or discontinued from day 51 to 100, and all cues were resumed from day 101 to 150. We found that goldfish exposed to predation cues increased their depth and weight at a faster rate than did the goldfish exposed to water, and of particular significance was the fact that frequency of risk had an effect on the amplitude of the change. When the cues were interrupted, the increase in growth rate parameters was reduced to the level of the goldfish exposed to water. However, when the cues were resumed, the rate increased to match the growth rate of the goldfish that were continuously exposed to the cues. Finally, we staged encounters between goldfish of differing morphologies and yellow perch (Perca flavescens) and found that deep-bodied goldfish had better survival than the shallow-bodied ones. These experiments illustrate the dynamic nature of inducible morphological defences.

The abundance and size composition of stream isopods Lirceus fontinalis were investigated from April 2001 to August 2002 in 3 streams in southern Ontario, Canada. Effects of current speed was released from the analysis by choosing slow flowing water. The effects of substrate, season and water depth on the abundance, distribution and size composition of the isopods were analyzed. It was found that substrate and season influence isopods the most. The rocky substrate with attached filamentous macro-algae contains an isopod abundance 7.05 times that of bare rock substrate and 14.6 times that of fine-sand and mud substrate. There was a large variation with respect to seasonality in both abundance and size composition of the isopods, with the highest abundance occurring in summer and the lowest in winter and spring; individual isopods also tend to be larger in the winter and spring. In all substrates, shallow areas tend to support higher densities of isopods than deeper areas.

The gene coding for transglutaminase 2 (TGM2) has been reported to be associated with schizophrenia in a White population. The present study was then designed to replicate this initial finding in a Chinese population. A total of 428 individuals with schizophrenia and 555 control participants were recruited for genetic analysis. Four single nucleotide polymorphisms present in the TGM2 gene were selected for genotyping, including rs2076380, rs7270785, rs4811528, and rs6023526, by PCR-based restriction fragment length polymorphism analysis. None of these four single nucleotide polymorphisms genotyped showed an association with schizophrenia, although these 428 cases and 555 controls had 97% power to detect a disease association in small effect size (odds ratio=1.5). The present results did not support the TGM2 association with schizophrenia. It is thus possible that the TGM2 finding may have resulted from a random error of sampling.

A long cavity passively mode locked fiber laser in the anomalous dispersion regime is reported. Nonlinear polarization rotation technique is employed to achieve the mode locking in our experiments. The output pulse from the fiber laser has the Gaussian profile spectrum and right angle trapezoid shape. Stable mode locking is achieved without using any dispersion-compensation components. The single pulse with an energy of 652 nJ and a repetition rate of 836 kHz at the pump power of approximately 500 mW is obtained and the duration of the output pulse increases linearly with the pump power. Different from the conventional low-energy soliton pulse, experimental results demonstrate that the passively mode locked fiber laser operating in the anomalous regime can also realize high energy pulse.

Jungerius et al. (2008) have reported that the myosin IXB (MYO9B) gene is strongly associated with susceptibility to schizophrenia in a Dutch population. However, this initial work failed to be replicated in a British population (Law et al., 2011). The present study was then undertaken to examine whether the association of MYO9B with schizophrenia could be replicated in a Chinese population.

With the help of statistical software Eview6.0, qualitative analysis is carried out of China's civil aviation passenger traffic since reform and opening up. It is found that China’s civil aviation passenger traffic development experienced three stages: slow development stage from 1978 to1990, relatively rapid development stage from 1991 to 2003 and rapid development stage from 2004 until now. By carrying on the empirical analysis and forecasting through constructing the ARIMA model of passenger traffic, it shows that ARIMA (2, 2, 1) has a better fitting effect on the original data sequence and can undertake short-term forecast of passenger traffic, which provide data support for civil aviation passenger traffic regulation.

This paper proposes a new Distributed Bayesian Algorithm (DBA) for data fault detection in order to address problems of data fault in wireless sensor networks. Although many methods for data fault detection have been proposed, the diagnosis accuracy is still very low especially in the situation of the densely deployed WSN with a large number of faulty nodes. In DBA, the Bayesian network is introduced to calculate the fault probability of sensor nodes, and the fault probability will be adjusted by exploiting the border nodes to improve the accuracy of fault probability and avoid the negative impact of the large number of faulty nodes. A comprehensive simulation has been made to compare the performance of DBA and Distributed Fault Detection (DFD). The simulation results show DBA can improve the fault detection accuracy significantly even in the situation with a large number of faulty nodes.

To examine the interactive effects of prey density, prey mobility and habitat structure on prey selection by benthic feeding fish, feeding experiments were conducted with 95-105 mm (total length) pumpkinseed (Lepomis gibbosus), given four sizes ( 9 mm) of active or immobilized amphipods (Gammarus pseudolimnaeus) as prey. The experiments involved the assessment of prey size selectivity, total number of prey consumed and size-specific indicators of foraging efficiency such as capture success and handling time. Pumpkinseeds were size selective only at medium and high prey densities, preferring large Gammarus when selectivity occurred. The proportion of mobile and immobile prey consumed increased with prey size in unstructured habitat, whereas no selectivity occurred with mobile prey in structured habitat. Both habitat and prey density significantly affected prey consumption, with more prey eaten at higher densities and in unstructured habitat. Prey mobility did not affect the number of prey consumed when mobile or immobile prey were offered in separate trials, but the consumption rate of immobile prey increased in structured habitat when they were offered with mobile prey in the same trial. We conclude that prey density and habitat structure affect pumpkinseed size selectivity and consumption rates in a similar manner, whereas the effect of prey mobility on these factors is more dependent on the combination of density and habitat and on whether mobile and immobile prey are present at the same time.

[Many prey animals have a remarkable ability to match the intensity of their behavioural responses to the degree of threat posed by specific predators. However, little is known about how such threat-sensitive predator avoidance develops. In a series of laboratory experiments we tested whether goldfish (Carassius auratus) could learn to recognize predator odours in a threat-sensitive manner. We exposed predator-naive goldfish to various concentrations of chemical cues of pike (Esox lucius) fed goldfish and pike fed another fish diet (swordtails,Xiphophorus helleri). During the conditioning trials goldfish showed behavioural responses to pike fed goldfish but not to pike fed swordtails. Moreover, the intensity of the responses to pike cues increased as the concentration of pike cues increased. Subsequent test trials showed that goldfish that had originally been exposed to pike fed goldfish showed responses to pike fed swordtails, indicating learned recognition of the pike as a predator. Of particular importance, the intensity of the learned responses by the goldfish matched the intensity of the responses observed in the original conditioning trials, thereby demonstrating threat-sensitive learning. Prey should have a selective advantage if they are able to adjust the intensity of their anti-predator response to match the threat posed by their predators. Our preliminary investigations revealed that this threat-sensitive learning has important survival implications during encounters with pike., Many prey animals have a remarkable ability to match the intensity of their behavioural responses to the degree of threat posed by specific predators. However, little is known about how such threat-sensitive predator avoidance develops. In a series of laboratory experiments we tested whether goldfish (Carassius auratus) could learn to recognize predator odours in a threat-sensitive manner. We exposed predator-naive goldfish to various concentrations of chemical cues of pike (Esox lucius) fed goldfish and pike fed another fish diet (swordtails,Xiphophorus helleri). During the conditioning trials goldfish showed behavioural responses to pike fed goldfish but not to pike fed swordtails. Moreover, the intensity of the responses to pike cues increased as the concentration of pike cues increased. Subsequent test trials showed that goldfish that had originally been exposed to pike fed goldfish showed responses to pike fed swordtails, indicating learned recognition of the pike as a predator. Of particular importance, the intensity of the learned responses by the goldfish matched the intensity of the responses observed in the original conditioning trials, thereby demonstrating threat-sensitive learning. Prey should have a selective advantage if they are able to adjust the intensity of their anti-predator response to match the threat posed by their predators. Our preliminary investigations revealed that this threat-sensitive learning has important survival implications during encounters with pike.]

In this paper, we compute the complete Einstein-Kahler metric with explicit formula for the Cartan-Hartogs domain of the fourth type in some cases. Under this metric the holomorphic sectional curvature is given, which intervenes between -2k and -1. This is the sharp estimate.

Green-emitting phosphor YPO 4 :Tb used in a PDP was prepared by two different methods, i.e., conventional solid-state reaction route and solution-based co-precipitation route. Results indicated that in solution-based co-precipitation route, a lower temperature was required, no grinding and milling processes were introduced, and the starting materials were mixed at molecular level, compared with conventional solid-state reaction route. Therefore, the phosphor particles obtained from solution-based co-precipitation route had several advantages in the morphology, such as excellent surface quality, almost spherical shape, narrow size distribution, and homogeneous composition. The excitation spectrum measurement showed that YPO 4 hosts had high energy absorption in VUV range, which makes it possible that YPO 4 :Tb phosphors are used in a PDP. The emission spectrum of YPO 4 :Tb under 147 nm excitation indicated that the phosphor powders obtained from solution-based co-precipitation route had high luminance since they have excellent morphologies and homogeneous composition, compared with those obtained from conventional solid-state reaction route.

The Einstein-Kahler metric for the Cartan-Hartogs domain of the second type is described. Firstly, the Monge-Amp`ere equation for the metric to an ordinary differential equation in the auxiliary function X = X(z, ω) is reduced, by which an implicit function in X is obtained. Secondly, for some cases, the explicit forms of the complete Einstein-Kahler metrics on Cartan-Hartogs domains which are the non-homogeneous domains are obtained. Thirdly, the estimate of holomorphic sectional curvature under the Einstein-Kahler metric is given, and in some cases the comparison theorem for Kobayashi metric and Einstein-Kahler metric on Cartan-Hartogs domain of the second type is established.

In this paper, the holomorphic sectional curvature under invariant metric on a Cartan-Hartogs domain of the second type YII(N, p,K) is presented and an invariant Kalher metric which is complete and not less than the Bergman metric is constructed, such that its holomorphic sectional curvature is bounded above by a negative constant. Hencea comparison theorem for the Bergman and Kobayashi metrics on YII(N, p, K) is obtained.

The X-ray crystal structure of Cowpea chlorotic mottle bromovirus (CCMV) revealed a unique tubular structure formed by the interaction of the N-termini from six coat protein subunits at each three-fold axis of the assembled virion. This structure, termed the β-hexamer, consists of six short β-strands. The β-hexamer was postulated to play a critical role in the assembly and stability of the virion by stabilizing hexameric capsomers (Speir et al., 1995). Mutational analyses of the β-hexamer structure, utilizing both in vitro and in vivo assembly assays, demonstrate that this structure is not required for virion formation devoid of nucleic acids in vitro or for RNA-containing virions in vivo. However, the β-hexamer structure does contribute to virion stability in vitro and modulates disease expression in vivo. These results support a model for CCMV assembly through pentamer intermediates.

Deletion and substitution mutations affecting the oligomerization of alfalfa mosaic virus (AMV) coat protein (CP) were studied in protoplasts to determine their effect on genome activation, an early step in AMV replication. The CP mutants that formed dimers, CPDeltaC9 and CPC-A(R)F, were highly active in initiating replication with 63-84% of wild-type (wt) CP activity. However, all mutants that did not form dimers, CPDeltaC18, CPDeltaC19, CPC-WFP, and CPC-W, were much less active with 19-33% of wt CP activity. The accumulation and solubility of mutant CPs expressed from a virus-based vector in Nicotiana benthamiana were similar to that of wt CP. Analysis of CP-RNA interactions indicated that CP dimers and CP monomers interacted very differently with AMV RNA 3' ends. These results suggest that CP dimers are more efficient for replication than CP monomers because of differences in RNA binding rather than differences in expression and accumulation of the mutant CPs in infected cells.

Light trapping induced by plasmonic metal nanoparticles is of extensive interest for photovoltaics. In this paper, plasmonic effect of silver nanoparticles embedded in dielectric layers hybrid structures on c-Si photoactive absorbing material is presented. Dielectric SiN x and SiO 2 layers were considered and deposited by plasma enhanced chemical vapor deposition (PECVD) and electron beam evaporation (EBE) respectively. Silver nanoparticles were prepared by annealing of thermally evaporated silver thin films ranging from 5 to 25 nm in N 2 gas atmosphere at 260 °C for an hour. For comparative study, thicknesses of each layer including silver thin flim, SiN x spacer layer and c-Si wafer were varied to attempt preliminary judgement of the appropriate structure. It is shown that reflection near bandgap of Si can be reduced while silver nanoparticles are fabricated on SiN x layer and covered by SiO 2 layer. By comparing the morphologies of nanoparticle arrays resulted from different thicknesses of silver thin film, it is indicated that nanoparticle arrays with large average sizes and high surface coverage on the front surface can greatly increase undesirable reflection in visible wavelength region in spite of their advantage in reflection reducing at longer wavelength. In addition, light trapping of the hybrid structures for varying thicknesses of SiN x spacer layer and c-Si wafer were also investigated respectively. Results suggest that hybrid plasmonic structures (HPS) can play an even greater part as c-Si wafers become thinner.

A compressive fusion of remote sensing images is presented based on the block compressed sensing (BCS) and non-subsampled contourlet transform (NSCT). Since the BCS requires small memory space and enables fast computation, firstly, the images with large amounts of data can be compressively sampled into block images with structured random matrix. Further, the compressive measurements are decomposed with NSCT and their coefficients are fused by a rule of linear weighting. And finally, the fused image is reconstructed by the gradient projection sparse reconstruction algorithm, together with consideration of blocking artifacts. The field test of remote sensing images fusion shows the validity of the proposed method.

A new strategy for images fusion is developed on the basis of block compressed sensing (BCS) and multiwavelet transform (MWT). Since the BCS with structured random matrix requires small memory space and enables fast computation, firstly, the images with large amounts of data can be compressively sampled into block images for fusion. Secondly, taking full advantages of multiwavelet such as symmetry, orthogonality, short support, and a higher number of vanishing moments, the compressive sampling of block images can be better described by MWT transform. Then the compressive measurements are fused with a linear weighting strategy based on MWT decomposition. And finally, the fused compressive samplings are reconstructed by the smoothed projection Landweber algorithm, with consideration of blocking artifacts. Experiment result shows that the validity of proposed method. Simultaneously, field test indicates that the compressive fusion can give similar resolution with traditional MWT fusion.

FePt and FePt/Ag multilayered nanowires were fabricated by a pulse ‐ plating technique in nanoporous anodic alumina templates. The effect of Ag layers on the chemical ordering of FePt was investigated. It is found that the ordering rate of FePt is enhanced by introducing Ag layers in the FePt nanowire during post-deposition annealing. Measurements of the structure and magnetic properties of FePt 5 nm/Ag 1 nm multilayered nanowires reveal that the disorder–order transformation temperature of FePt is lowered to 350 °C. The possible reason for the enhancement in the ordering of FePt by introducing the Ag layers in the FePt nanowire is discussed.

This paper firstly sums up the main security threats to data confidentiality in cloud computing environment, then classifies and introduces the existing access control models according to the core strategy they have adopted. Lastly this paper points out the main challenges facing access control in cloud computing environment and the subsequent research directions.

We have designed and demonstrated a simple, wide field-of-view (FOV=60\circ) foveated imaging system utilizing a deformable mirror. The deformable mirror is used to dynamically correct the off-axis aberrations that limit the useful FOV of the system. The system mimics the operation of human eye through creating an image with variable spatial resolution and can be made significantly smaller and more compact than a conventional wide FOV system. Experiments show that this system can be used in many areas where size, weight, and data transmission bandwidth are critical.

We derive and calculate numerically laser linewidth by means of the laser rate equation in an extending diode laser cavity provided by an end reflector. We found that narrow linewidth is closely connected with phase modulation and frequency modulation. The numerical simulation shows the dominance of effect over another depends on inherent factors such as the α coefficient, bandwidth of laser, length of external cavity, reflective coefficient etc.

An understanding of virion assembly and disassembly requires a detailed understanding of the protein–protein and protein–nucleic acid interactions which stabilize the virion. We have characterized a mutant of cowpea chlorotic mottle virus (CCMV) that is altered in virion stability. The mutant virions resist disassembly in 1.0 M NaCl, pH 7.5, whereas the wild-type virions completely disassociate into RNA and capsid protein components. Sequence analysis of the mutant coat protein gene identified a single A to G nucleotide change at position 1484 of RNA 3 (position 134 of RNA 4), which results in a lysine to arginine change at position 42 of the coat protein. Introduction of the K42R mutation into wild-type CCMV coat protein results in a salt stable virion phenotype. Likewise, expression of the K42R mutant coat protein in Escherichia coli followed by in vitro assembly produces virions that exhibit the salt stable phenotype. Analysis of this mutation demonstrates how a single amino acid change in the primary structure of the coat protein leads to tertiary interactions which stabilize the virion.

Accumulating evidences indicate that the functional FAS− 1377G > A, − 670A > G and FASL− 844T > C polymorphisms affect the risk of several kinds of cancers. However, their roles in the development of larynx and hypopharynx squamous cell carcinoma (SCC) were still unknown in the Chinese. In the current study, we examined whether these functional genetic variants were associated with the risk of larynx and hypopharynx squamous SCC in a Han Chinese population. The FAS and FASL polymorphisms were genotyped in 300 patients with laryngeal and hypopharyngeal SCC and 300 control subjects by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Logistic regression analysis revealed that subjects carrying the FASL–844CT or TT genotype had a significantly decreased risk of developing laryngeal and hypopharyngeal SCC [odds ratio (OR) = 0.69; 95% confidence interval (CI) = 0.51–0.93; P = 0.016; or, OR = 0.41; 95% CI = 0.20–0.86; P = 0.009] compared with those carrying the CC genotype. Joint gene-smoking and gene-drinking effects were also observed, with the OR of CC genotype for smokers or drinkers were 5.15 (95%CI = 3.24–8.97) or 12.52 (95%CI = 7.31–22.47), respectively. Therefore, the FASL− 844T > C polymorphism is associated with genetic susceptibility of developing laryngeal and hypopharyngeal SCC in a Han Chinese population.

Pearl oyster Pinctada martensii is cultured for production of pearl in China. It needs to implant a mantle graft cut from a donor oyster and a seed nucleus into the gonad of the host oyster to produce a pearl. Pearl sac surrounding the nucleus is formed by the proliferation of the implanted mantle graft from the outer mantle epithelial cells in the host oyster. The pearl sac is responsible for production of a cultured pearl. A comprehensive transcriptome analysis on pearl sac will help to understand the mechanism on pearl formation and immune response of host oyster after nucleus implantation. In the present study, 39,400,004 reads were produced from the pearl sac using RNA-sequence technology and then assembled into 102,762 unigenes. More than 22.4% of these unigenes were possibly involved in approximately 219 known signaling pathways. A total of 37,188 unigenes were annotated based on sequences similarities with known proteins. Fifty-one biomineralization-related unigenes and 268 immune-related unigenes were not previously detected in P. martensii. The un-annotated unigenes may be some genes specifically existed in P. martensii. These annotated or un-annotated unigenes in the present studies were valuable for the future investigation on molecular mechanism of pearl formation and immune response of the species.

It is summarized the research hotspots of flue gas desulfurization (FGD) and analyzed the advantages and disadvantages of Limestone-Gypsum wet flue gas desulfurization (WFGD) and microbic desulfurization methods. Put forward a new idea of combining the Limestone-Gypsum WFGD, microbial method with catalytic oxidation of transition metal (Fe3+/Fe2+ galvanic couple) reasonably. Then established the model of the new type method and analyzed the mechanism and feasibility deeply, promoted the development of FGD technic.

Fast and accurate estimation of background model in video sequences is a basic task in many computer vision and video analysis applications. Underwater vision is a new area and the background of underwater has special quality such as unstable light spot, water ripple. To this end, this paper proposes an algorithm based on Kalman Filter, which is applied to the estimation of dynamic underwater background with a static monitoring camera of swimming pool's bottom. Experimental on several underwater video sequences performing the model can efficiently adapt to the environmental of underwater.

The effect of the tilted substrate on the lithography patterns in maskless Laser Interference Lithography (MLIL) was numerically and experimentally studied. The experiments showed that the period of interference patterns becomes larger with increasing tilt angles of the substrate, as is in good agreement with theoretical analysis. It was also shown that there is no evident change when the rotational angle was less than 3 degree in our experiment. The significance of our analytical results for MLIL and the fabrication of integrated circuit was discussed.

Images are often significantly degraded by fog and their values are greatly reduced. According to retinex theory and the properties of fogged images, fog degradation can be eliminated by modifying illumination variation. The multi-scale retinex (MSR) algorithm was analyzed and an enhancement method directing to fogged images was proposed. Firstly, a preliminary global luminance was adjusted by linear stretching and screen algorithm to increase the luminance of darker pixels and compress the dynamic range as well. Then the local contrast was increased by an improved algorithm based on MSR. Finally, the output of local contrast enhancement was processed by the normal clipping stretching to realize color correction. Experiments show that the algorithm can effectively remove fog degradation from color images.

Anti-poverty is a common subject that all countries are facing with today. Amartya Sen defined it as a lack of capability instead of just a low income. According to his theory, combined with great changes in rural management structure since China implemented reform and opening-up policy, the thesis proposes a new concept of anti-poverty to develop communities’ capability on the basis of rural communities. The break-ground activities of anti-poverty can begin with the rural communities on the principle of adhering to capability construction rather than material input with the fundamental purpose of developing community capability in rural areas. It is suitable to construct a multi-dimensional anti-poverty system taking governments as the leading part, villagers as the self-managers, and social institutions as the supporting parts and market as the adjustment mean. Thus, capability-oriented anti-poverty mechanism and the development road on inner resources can take shape in china’s rural areas.

Y2O3:Ln3+ (Ln = Eu or Tb) nanocrystals with different Ln3+ doping concentrations and average sizes were prepared by chemical self-combustion. The corresponding bulk materials with various doping concentrations were obtained by annealing the nanomaterials at high temperature. The emission spectra, excitation spectra, and X-ray diffraction spectra were used in this study. It was found that the charge transfer band of Y2O3:Eu3+ red-shifted as particle size decreased, and the charge transfer band in the 5-nm particles obviously broadened toward the long wavelength. It was also found that the profile of excitation spectra corresponding to the 4f5d (4f8 --4f(7)5d1) transition changed a lot with the variation of the particle size. The dependence of the excitation spectra of Y2O3:Ln3+ on particle size was investigated.

The notion of a rough set was originally proposed by Pawlak (1982). Later on, there is a fast growing interest in this theory. In this paper we present a more general approach to the generalization of rough sets. Specifically, generalized formulation has been studied by using a binary relation on two universes without any restriction on the cardinality. The algebraic properties of generalized rough sets are given, and the extension principle for crisp sets is explained as the upper approximations of rough sets. The relationship between the extension principle for fuzzy sets and the upper approximations of fuzzy rough sets is investigated.

In this work, we use the solution precipitation method to synthesize Tb3+-doped yttrium orthophosphate, which is a green-emission luminescent material. The evolution of hydrated yttrium orthophosphate (YPO4.2H2O) to dehydrated yttrium orthophosphate (YPO4) is observed in the heat-treatment process, simultaneously, accompanying the structural transformation from monoclinic churchite-type to tetragonal xenotime-type structure. Furthermore, the luminescent efficiency of Tb3+-doped YPO4 presents a sharp jump at a critical temperature in this heat-treatment process. Interestingly, this critical temperature is close to the structural transformation temperature. The remarkable change of luminescent efficiency seems to be related to the structural transformation. However, the FTIR and fluorescent decay measurements at 10 and 300 K indicate that the OH group is the origin of luminescent efficiency change. OH- ions with high vibration frequency provide an efficient means to quench the luminescence. The comparison of the luminescent efficiency, OH- content, and lifetime of 5D4 of Tb3+ between two samples with the same crystal structure proves that the structural transformation has no significant effect on the luminescent efficiency and lifetime. On the basis of these results, it is proposed that correctly preventing OH- ions inside the host matrix or effectively eliminating them may improve the luminescent efficiency greatly. This idea also may be applied to other optical systems.

In this article, we have investigated energy upconversion process in erbium doped oxyfuoride tellurite glasses exciated with 980 nm diode laser. The glasses used in measurements are with a mol% composition of 70TeO2-9PbF2-190AlF3-10BaF2-1Er2O3. The Ωs intensity parameters, the radiative rates, the branching ratios and the fluorescence lifetimes were calculated based upon the Judd-Ofelt theory and the experimental absorption spectrum. Under 980 nm excitation, efficient 530, 544, and 665 nm upconversion emission are due to two-photon absorption processes.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The solution precipitation is used to synthesize the Tb doped yttrium phosphates. The as-synthesized is the monoclinic phased YPO4×2H2O with churchite-type structure, which is transformed to the tetragonal phased YPO4 with xenotime-type structure as the temperature approaches 200°C during the thermal treatment process. This phase transformation process can not be observed in some routes that need a higher synthetic temperature, in which, only a high-temperature phase is obtained. The luminescent efficiency dependence on the heat-treatment temperature is investigated. The luminescent efficiency presents a two-step increase respectively around 300 and 700°C. Results indicate that the significant increase of luminescent efficiency at 300°C is not related to the phase structure transformation, but to the decrease of OH- ions content, and that the significant increase of luminescent efficiency at 700°C is related to the increase of crystallinity, which may increase the absorption to VUV light.

Ce-, Tb-doped and co-doped YBO 3 were prepared by solid-state reaction. The structure of the powder is identified as vaterite-type structure. The photoluminescence of the samples under UV/ VUV excitation were investigated. The results indicate that the energy is transferred between Ce 3+ and Tb 3+ under UV excitation while Ce 3+ is not beneficial to the emission of Tb 3+ under VUV excitation due to the different luminescence mechanism. The blue emission of Tb 3+ was observed at low Tb 3+ concentration and disappeared at high activator concentration due to the relaxation.

Bulk Y 2 O 3 : Eu (1% in molar ratio) powders and nanocrystals with different particle size were prepared by chemical self-combustion, all of them exhibits cubic structure. Fluorescent decay curves at room temperature and 10k, excitation and emission spectra were measured. The dependence of fluorescence lifetime on the particle size and temperature were discussed. Meanwhile, the quantum efficiency of 5 D 0 level of europium ion occupying C 2 site was estimated.