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Prognostics, in other words, remaining useful life (RUL) estimation is a core task of prognostics and health management (PHM). Reliable RUL predictions can reduce maintenance costs, improve production efficiency, and avoid unexpected downtime. Lots of models for RUL predictions have been proposed; however, noise and the nonlinear nature of degradation phenomena often leads to poor prognostics results, and the acquired engineered system data are usually subject to a high level of uncertainty. This makes the RUL estimation models less than satisfactory. Accurate RUL estimation and prediction not only rely on an accurate model but also depend on the adjustments of model parameters to track the variation. In this paper, an ensemble model combining the health index synthesis (HIS) approach and improved particle filtering (PF) is introduced. HIS approach was used to obtain the synthesized health index (SHI) for an engineered system with multiple sensors, which indicated the system's degradation model, while the improved PF approach was used to adjust the parameters of the degradation model obtained from the HIS approach and optimized the RUL estimation results. The performance of the prognostics approach introduced in this paper was demonstrated by using turbofan engine degradation data sets, which was supplied by NASA Ames, and results were compared with several usually used methods. [ABSTRACT FROM AUTHOR]

To measure the contributions of parental inbreds per se and heterosis to the genetic gain of single- cross maize (Zea mays L.) hybrids, yield trials of 29 historically important hybrids used in China during 1964 through 2001 and their parental inbreds were conducted. Mean rate of genetic gain for single-cross hybrids when measured across all locations was 55 kg ha-1 yr-1; heterosis contributed 37 kg ha-1 yr-1 (67%) of yield gain. Inbred yields at stressed locations were exceptionally poor and may have inflated measurements of heterosis. At unstressed locations, heterosis contributed 5 kg ha-1 yr-1 (8%) and 16 kg ha-1 yr-1 (39%) or 10 kg ha-1 yr-1 (19%) when locations were combined. For individual characteristics, the highest percent heterosis was for kernel weight per ear (58.6%), corresponding to and emphasizing the historic goal in China of increasing yield on an individual plant rather than on a unit area basis. There are opportunities to further improve the productivity of Chinese maize by increasing inbred parent yields, increasing tolerances to stresses associated with higher planting densities, and also increasing the contribution of heterosis through optimal assignation of inbreds into complementary heterotic groups. [ABSTRACT FROM AUTHOR]

The aim of the maintenance allocation is to allocate the maintenance time to the subsystems reasonably and accurately. Traditional mean time to repair (MTTR) allocation methods are widely used in the industry. However, there are many deficiencies in practical application, which is inconsistent with the purpose of the maintenance allocation. To allocate the MTTR more precisely and reasonably, a better model is needed. The aim of this paper is to develop a maintenance allocation model, which can improve the applicability and operability, and solve the residue problem that exists in maintenance allocation. A case study is used to demonstrate how the model can be applied in practice. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sodium bismuth titanates Na1/2Bi1/2TiO3 (NBT) doped with 0–3 wt% Er2O3 were prepared by the conventional solid-state reaction method. The X-ray diffraction results revealed that the sintered Er-doped NBT ceramics exhibited a pure perovskite structure with Er3+ concentrations ranging from 0 to 1 wt%. At a low Er2O3 concentration, the Er-doped NBT ceramics showed enhanced electrical properties with dielectric constant ℇ33T/ℇ0=636, a low dielectric dissipation factor (tan δ=3.3%), a low coercive field ( Ec=4.56 kV/mm), and a high piezoelectric constant ( d33=75 pC/N). The relationship between the composition and properties of Er-doped NBT ceramics has been discussed. [ABSTRACT FROM AUTHOR]

The properties of an aqueous Bi[sub 4]Ti[sub 3]O[sub 12] suspension stabilized b x an acrylic acid/acrylic ester copolymer have been investigated. The adsorption of a copolymer on Bi[sub 4]Ti[sub 3]O[sub 12] surface resulted in a dramatic increase in the absolute zeta potential at pH 3-11. Coincidentally, the rheological property of the suspension was significantly improved. The adsorption quantity increased with increasing copolymer concentration at first, then decreased as the copolymer concentration was beyond 1.5 wt%. The viscosity varied in a complicated manner with copolymer concentration, due to the variations in the adsorption quantity and adsorption configuration of the copolymer molecules on Bi[sub 4]Ti[sub 3]O[sub 12] particle surface. High-quality tapes were prepared through tape casting. [ABSTRACT FROM AUTHOR]

The article presents a study which discusses lithofacies Paleogeography and Paleoenvironmental evolution of the Cenozoic in the Weihe Basin in China. Topics discussed include research on the sedimentation and environmental evolution, division of lithostratigraphic units of the Cenozoic, and reconstruction of lithofacies paleogeography and environment evolution processes.

Increasing seed yield and quality of key cool-season perennial grasses is an important component of meeting China's environmental, food security, and urban beautification goals. Determining a suitable seed producing region and developing best management practices for this region with specific, high priority grasses will contribute to the availability of seed for reducing desertification, increasing livestock production, and improving urban living conditions. Previous research in other areas has addressed various agronomic practices on some grasses, but none has evaluated optimal row spacings for producing high yields of high quality seed in conditions similar to the Hexi Corridor, currently a major seed producing area in China for other seed crops. We compared our field trials in this area with those of other regions in China and the world to determine if this area would be suitable as a grass seed production center. Five important perennial, cool-season grasses {[Elymus kamoji (ohwi) S.L. Chen, slender wheatgrass [Elymus trachycaulus (Link) Gould ex Shinners ssp. Trachycaulus], smooth bromegrass (Bromus inermis Leyss), Siberian wildrye (Elymus sibiricus L.), and Chinese sheepgrass [Leymus chinensis (Trin) Tzvel]} were evaluated from 2010 to 2012 under four row spacing treatments (30, 50, 70, and 90 cm). Results showed all five grasses have potential for high seed production in this region, with yields equivalent to or significantly higher than other areas. Optimal row spacing for Elymus kamoji and smooth bromegrass was 30 cm while a 50 cm row spacing was better for seed production and weed control for slender wheatgrass, Siberian wildrye, and Chinese sheepgrass. This work will allow multinational seed companies, development agencies, and government program directors to better evaluate the potential economic sustainability of grass seed production in this region compared to importing seed from other regions of the world. [ABSTRACT FROM AUTHOR]

The effect of B2O3–SiO2 liquid-phase additives on the sintering, microstructure, and microwave dielectric properties of LiNb0.63Ti0.4625O3 ceramics was investigated. It was found that the sintering temperature could be lowered easily, and the densification and dielectric properties of LiNb0.63Ti0.4625O3 ceramics could be greatly improved by adding a small amount of B2O3–SiO2 solution additives. No secondary phase was observed for the ceramics with B2O3–SiO2 additives. With the addition of 0.10 wt% B2O3–SiO2, the ceramics sintered at 900°C showed favorable microwave dielectric properties with ℇr=71.7, Q× f=4950 GHz, and τf=−2.1 ppm/°C. The energy dispersive spectra analysis showed an excellent co-firing interfacial behavior between the LiNb0.63Ti0.4625O3 ceramic and the Ag electrode. It indicated that LiNb0.63Ti0.4625O3 ceramics with B2O3–SiO2 solution additives have a number of potential applications on passive integrated devices based on the low-temperature co-fired ceramics technology. [ABSTRACT FROM AUTHOR]

Upconversion emission properties of Na1/2Bi1/2TiO3:Er3+ ceramics prepared by the solid-state reaction method were analyzed as a function of Er3+ concentration and incident pump power. Strong green (550 nm) and red (670 nm) emission bands were observed with 980 nm excitation at room temperature. Experimental results showed that the emission bands can be tuned by changing Er3+ concentration. Upconversion processes in these samples result from not only a two-photon excited-state absorption process but also a nonradiative energy transfer and cross-relaxation process. [ABSTRACT FROM AUTHOR]