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Background Forage production is the fundamental ecosystem service of grasslands. Although forage consumption occurs at community level, most studies focused on species-level changes of forage quality. The quantitative and qualitative changes of forage production are driven by species-specific trait, intra-specific plasticity, and species turnover. We examined the changes in forage production and digestibility after 5-year factorial treatments of nitrogen (N) addition and mowing in a temperate steppe and linked such changes to community assembly under the Price equation framework. Results Nitrogen addition significantly reduced species richness, increased forage production, but did not change forage digestibility (indicated by the total Ca+Mg concentrations). Mowing did not affect forage production and digestibility. The positive effects of N addition on forage production were driven by the enhancement of abundance of the remaining species following N enrichment, rather than by species loss or species gain. The species identity effects could offset the effects of species richness loss or gain on forage production and digestibility. Conclusions Our results highlight the importance of a community perspective in addressing the quantitative and qualitative changes of forage production under global change pressure of N enrichment. Species identity is important in determining the contribution of different processes of community assembly to ecosystem services.

Anthropogenic nitrogen (N) deposition has affected plant community composition and nutrient cycling in terrestrial ecosystems worldwide. This includes changes to the way plants use and recycle nutrients, including effects on nutrient resorption, which is a key process through which plants recover nutrients from tissue during senescence. Nutrient resorption has considerable adaptive and functional significance for plants and helps regulate core ecosystem processes such as decomposition. However, our understanding of how N deposition affects nutrient resorption and, in particular, of how N inputs alter ecosystem resorption via changes to existing species’ resorption compared with changes to community composition remains poor. To disentangle the role of species versus community composition controls driving variation in nutrient resorption responses to N inputs, we carried out an experiment with six different N addition rates in a temperate steppe. We found that species-scale nutrient resorption responses to N enrichment were variable; for example, only half of the measured species reduced both N and P resorption efficiency in response to increased N inputs. In contrast, community-scale responses consistently resulted in reduced N and P resorption. Still, N-induced changes in community composition were a weaker control on overall resorption responses than were the effects on individual species; however, it was the synergistic interaction between the two that resulted in the large total reductions of nutrient resorption in the face of increased N. Taken together, our results highlight that understanding and predicting nutrient resorption responses will be most accurately scaled by accounting not only for species’ reductions in resorption but also for changes in community composition.

The stoichiometric traits of litter play an important role in driving litter decomposition and ecosystem nutrient cycling. While the impacts of nitrogen (N) deposition on the species-level litter stoichiometric traits have been well addressed, we know little about that at community-level, which is supposed to be driven by both intra-specific variation and changes in community composition. We examined the effects of N deposition on litter phosphorus (P) concentration and N:P ratio at both species- and community-level in a semi-arid grassland of northern China. We further decomposed the community-level variations of litter nutritional traits into intra- and inter-specific variation. Nitrogen addition, especially at high rates, substantially changed community composition. Litter P concentrations and N:P ratios significantly varied among different species. Litter P concentrations and N:P ratios at both species- and community-level were positively correlated with N addition rates. Biomass-weighted community-level N:P ratios were more sensitive to N addition than the non-weighted ones, indicating that community composition strengthened the positive impacts of N addition on litter N:P ratios. There was positive co-variation between intra- and inter-specific variation for litter N:P ratio, indicating the consistency of community composition and intra-specific variation in their effects on litter N:P ratio. Our results indicated that the imbalance of N and P following N enrichment would be much larger than the expectation based on the findings from species-level, and thus highlight the importance of changes in community composition in driving the responses of community-level litter N:P stoichiometry to N deposition in the semi-arid grassland.

A 2D/3D compatible display is proposed. The proposed 2D/3D compatible display can make viewers freely choose to view 2D or 3D images, and do not interact with each other. The proposed 2D/3D compatible display consists of a 2D display panel, a polarization modulator, and a pair of polarizing glasses. The 2D display panel is used to display a 2D synthetic image. The 2D synthetic image can be used to show the first parallax image. The polarization modulator can change the polarization directions of 2D synthetic image. Therefore, the component of the 2D synthetic image on specific polarization direction can be used to show the second parallax image. The polarizing glasses have only one lens covered with polarizer. This lens is used to view the second parallax image. And another lens without polarizer is used to view the first parallax image included in the original 2D synthetic image. Therefore, 3D image is displayed. A prototype of the proposed display is developed. Experimental results agree well with the theory. We believe it will be a potential application in 2D/3D compatible display.

We propose a crosstalk-free integral imaging three-dimensional (3D) display using a pinhole array. It consists of a back light unit, a pinhole array and a liquid crystal panel. The pinhole array, which is attached to the back light unit, is located between the back light unit and the liquid crystal panel. Three imaging models of the integral imaging 3D display with different pinhole arrays are analyzed to reveal the relationship between the aperture width of the pinhole array and the crosstalk. The optimal value of the aperture width of the pinhole array is also obtained to eliminate the crosstalk. A prototype using the optimal pinhole array is developed, and the experiment results agree well with the theory.

Aims The stoichiometric characteristics of plant communities are important controller for several fundamental ecological processes. The effects of environmental changes on community stoichiometric characteristics are driven by intra- and inter-specific variation. However, the relative importance of both pathways has seldom been empirically examined. Methods We quantified the relative contribution of intra- and inter-specific variation to the changes of community nitrogen (N) and phosphorus (P) concentrations after seven-year factorial N addition and mowing treatments in a semi-arid grassland of northern China. Results Nitrogen addition significantly increased community N and P concentrations and N:P ratio. Mowing significantly increased community N concentration and N:P. Intra-specific variation contributed more than inter-specific variation to the total variability of all the nutritional and stoichiometric characteristics, with intra-specific variation accounting for 68%, 70%, and 75% of the total variation in community-level N, P, and N:P, respectively. Negative covariations between the contribution of intra- and inter-specific variation occurred for community N and P concentrations. Further, N addition and mowing interacted to affect the impacts of intra- and inter-specific variation on community N concentration and N:P stoichiometry. Conclusions Our results highlight different ways of trait selection for N addition and mowing treatments. Interactions between those two factors make it more difficult to accurately predict the responses of plant-mediated biogeochemical cycles under co-occurrence of environmental changes.

Increasing availability of reactive nitrogen (N) threatens plant diversity in diverse ecosystems. While there is mounting evidence for the negative impacts of N deposition on one component of diversity, species richness, we know little about its effects on another one, species evenness. It is suspected that ecosystem management practice that removes nitrogen from the ecosystem, such as hay-harvesting by mowing in grasslands, would mitigate the negative impacts of N deposition on plant diversity. However, empirical evidence is scarce. Here, we reported the main and interactive effects of N deposition and mowing on plant diversity in a temperate meadow steppe with 4-year data from a field experiment within which multi-level N addition rates and multiple N compounds are considered. Across all the types of N compounds, species richness and evenness significantly decreased with the increases of N addition rate, which was mainly caused by the growth of a tall rhizomatous grass, Leymus chinensis. Such negative impacts of N addition were accumulating with time. Mowing significantly reduced the dominance of L. chinensis, and mitigated the negative impacts of N deposition on species evenness. We present robust evidence that N deposition threatened biodiversity by reducing both species richness and evenness, a process which could be alleviated by mowing. Our results highlight the changes of species evenness in driving the negative impacts of N deposition on plant diversity and the role of mowing in mediating such negative impacts of N deposition.

Forage yield is the fundamental ecosystem service of grasslands. While the quantitative responses of forage yield to nitrogen (N) enrichment are well known, its qualitative responses remain unclear. Even less known is the relative contribution of changes in community composition to the quality of the yield at the community level. We examined the quantitative and qualitative responses of forage yield at both plant functional group and community levels with factorial treatments of N addition and mowing in a temperate steppe. Nitrogen addition significantly enhanced the community-level yield by favoring the growth of rhizomatous grass. Mowing tended to mediate the impacts of N addition on the yield. Nitrogen addition increased the concentrations of crude protein and crude fat in forage at the community level. Neither the main effects of mowing nor its interactive effects with N addition affected forage quality. The N-induced shifts in plant species composition significantly contributed to the effects of N addition on forage quality at the community level. Our results suggest that mowing wound weaken the positive effects of N deposition on the quantity but not the quality of forage yield. Changes in plant community composition are important in driving the qualitative responses of yield to N deposition.

A real-time viewpoint generation-based 3D display with low crosstalk and high resolution is proposed. The proposed 3D display consists of a pattern image display (PID), a lenticular lens, and a transparent liquid crystal display (LCD) panel. For each eye of the observer, the PID can provide a pattern image with stripes that have a calculated pitch and displacement according to the eye position. The light from the stripes can be concentrated 3D display eye tracking by the lenticular lens and generate a viewpoint at the eye position. The transparent LCD panel is used to provide parallax images. This transparent LCD panel will not change the direction of light propagation and the location of the generated viewpoints. Then the whole parallax image on the transparent LCD panel can be projected by the PID and the lenticular lens to the viewpoint, so the resolution will not suffer like that in the convention 3D displays. Because the viewpoints are real-time generated according to the position of the observer’s eyes, the observer’s eyes will completely coincide with the position of the generated viewpoint. So crosstalk can be limited at a low level, and the viewing range is almost unlimited.

Nitrogen (N) enrichment has great consequences on several fundamental ecological processes through its impacts on plant nutrition traits (i.e. nutrient concentration and stoichiometric ratios); however, the extent to which the effects of N enrichment depend on phosphorus (P) availability are less well understood. While there is mounting evidence for the species-specific responses of plant nutrition traits to nutrient enrichment, we know little about the changes at the community-level. Here, we measured community-level biomass weighted (CWM) and non-weighted (CM) plant N and P concentrations and N:P ratio in a temperate meadow steppe after four years factorial N and P addition, with biomass and nutrition traits of each species in each plot being recorded. Nitrogen addition significantly increased community-level N concentration, decreased P concentration, and enhanced community N:P ratio. Phosphorus addition had no impacts on community-level N concentration, significantly increased P concentration, and reduced community N:P ratio. The impacts of N addition on community nutrition traits were not dependent on P addition and the community-level nutrition trait responses to N and P additions were primarily driven by intraspecific trait variation (ITV) rather than by species turnover. Community-level nutrition traits in the temperate meadow steppe were sensitive to the projected N and P enrichment. While nutrient enrichment had substantially changed community composition, its impacts on community nutrition traits were driven by ITV. Nitrogen deposition would result in imbalance of N and P in plant community, as indicated by the substantial increase in community-level N:P, which was not affected by increased P availability.

Hawk tea, prepared from the young leaves of Litsea coreana Levl. var. lanuginosa, is consumed as a tonic in China. Essential oils (EOs) from Hawk tea collected from six habitats in China were obtained by hydro distillation. Extraction yields ranged from 0.42% (g/g) in samples from Ningguo to 0.11% (g/g) in samples from Qingchuan. A total of 50 compounds in the six EO samples were identified by Gas Chromatography-Mass Spectrometer. The dominant compounds were citral (4.67–21.12%), caryophyllene (2.31–15.74%), dodecanal (2.10–15.38%), α-humulene (1.45–13.56%) and decanal (1.91–13.17%). Altitude may contribute the greatest effect on the chemical variation of the six EO samples. All the EO samples showed bioactivities. Among them, the EOs from the Pingshan sample showed the best ABTS radical scavenging activity (78.67 mg TEs /g) and better antimicrobial activities (MIC = 156.25–625 μg/mL) and had stronger DPPH radical scavenging activity (IC50 = 0.71 mg/mL) than BHT (IC50 = 0.76 mg/mL). The EOs from the Ningguo sample showed the highest reducing power (26.06 mg Fe2+/g) in a FRAP assay, the best inhibitory effect on α-glucosidase (1.71 mg/mL) and was the most cytotoxic (66.03–77.03 μg/mL) in an MTS assay. Therefore, the EOs from Hawk tea could be suitable for commercialization in the food, cosmetic or medical industries. Due to the activities of their EOs, plants growing in Pingshan and Ningguo are the optimal candidates.

Crop-type classification is one of the most significant applications in polarimetric synthetic aperture radar (PolSAR) imagery. As a remote sensing technique, PolSAR has been proved to have the ability to provide high-resolution information of illustrated objects. However, single-temporal PolSAR data are restricted to provide sufficient information for crop identification due to the complicated condition of varying morphology within various growing stages. With an increasing number of spaceborne PolSAR systems launched, a large amount of real PolSAR data are being generated and used to provide great opportunities for multitemporal analysis. The main contribution of this paper is to improve crop classification accuracy with various features of classical $H$ / $\alpha$ parameters. First, in order to deal with dual-PolSAR data, $H$ / $\alpha$ decomposition algorithm for quad-PolSAR is modified to suit to the case of dual polarization. Second, according to the differential scattering characteristics of main crops, a new parameter is innovatively defined to measure the differential characteristics in the $H$ / $\alpha$ classification plane. Third, crop types are discriminated by applying a supervised classification method with the newly defined parameter. Furthermore, the correctness of the parameter is verified with simulated and real Sentinel-1 data as well as AirSAR data. Finally, the performances of the classification method are investigated by the comparison with complex Wishart, Freeman–Wishart, and support vector machine (SVM) classifiers. Hence, the experimental results show that the proposed method and SVM classifier with the newly defined parameter have the ability to improve crop classification accuracy.

Organic–inorganic halide perovskites are quite promising in applications of large scale photovoltaic technology. However, toxicity is one of the crucial issues in these materials, and searching for environmentally friendly perovskite materials for green energy applications is in high demand. Here we present a systematic ab initio study on the replacement of toxic Pb in the perovskite CH3NH3PbI3 (MAPbI3) with possible mono- and a few binary replacements. In the mono-replacements study, Ge and Sn are the best alternatives to Pb. In the binary replacements, we replace Pb by mixing Ca/Si and Zn/Si. In case of Ca/Si, a monotonic decrease in band gaps with a monotonic increase in the optical absorption was observed with increasing the Ca concentration. It is observed for the first time that the substitution of Ca/Si (or Zn/Si) at the B-site with various ratios would lead to remarkably high device absorption efficiencies. The band gaps of the studied mixed replacements are in the ideal ranges for single-junction...

In just a few years the efficiency of organic–inorganic perovskites has reached 22.1%. Long term stability and lead toxicity are their two main hurdles to overcome for commercialization as solar cells. Keeping these significant challenges in mind, we use ab initio density functional theory (DFT) and incorporate mixed Ca/(Ge, Sn) and Sr/(Ge, Sn) at the B-site of CH3NH3PbI3 (MAPbI3) to get Pb-free perovskites with excellent properties. Tunability of the band gaps is observed while decreasing the ratios of Sn and Ge. The predicted band gaps (

The responses of functional structures in plant communities to global change drivers is predicted to be driven by both species turnover and intraspecific trait variability (ITV). However, the relative importance of those two drivers is not well-known, which retards our ability to predict the functional changes of plant community under global change scenarios. We hypothesized that ITV rather than species turnover would drive the nutritional responses of plant community at the initial stage after nitrogen and water enrichment. We measured community weighted means (CWM) and non-weighted means (CM) of foliar N and P concentrations and N:P ratio in a temperate steppe after two years factorial N and water addition. Species composition and nutrition traits of each species were recorded in each plot. The impacts of N addition on community level nutrition traits were highly dependent on water conditions, as indicated by significant interactive effects between N and water addition. Nitrogen addition significantly increased CWM of foliar N, but only under ambient water condition. Water addition decreased CWM of foliar P and increased that of N:P. Consistent with our hypothesis, communities responded to both N and water addition after two years treatments mainly through ITV. Our results highlight the importance of ITV in driving short-term responses of community functional composition to the increases of nitrogen and water availability in the temperate steppe. The existence of interactive effects of N and water addition would make it more difficult to predict the impacts of N deposition on plant-mediated biogeochemical cycling under the scenarios of precipitation regime changes than previously assumed.

Autotoxicity is among the major reasons that are causing continuous cropping obstacle. It is a toxic influence of chemicals released from one plant species on the germination and growth of individuals of the same species. Here, in order to analyze the autotoxicity of tobacco root exudates, root exudates were collected from tobacco plants cultivated in both cultural solution and natural soil. Through ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry main autotoxic chemical substances in the root exudates were identified. Further, the autotoxic effects of the suspected autotoxins on seed germination (including germination rate, germination potential, germination index and vigor index) and seedling growth were also analyzed. As a result, dibutyl phthalate (or diisobutyl phthalate), dioctyl phthalate and diisooctyl phthalate were identified in tobacco root exudates. It was observed high concentration (greater than 0.5 mmol L −1 ) of each produced phthalate esters caused the significant ( P

A 30 m long × 20 m wide capillary barrier cover (CBC) test site was constructed at the Jiangcungou landfill in Xi’an, China. The cover consisted of a compacted loess layer with a thickness of 0.9 m underlain by a gravel layer. After the cover surface was kept bare and exposed to natural climate conditions for nearly 5 months, one artificial rainfall event was implemented at the site. Vegetation was established at the test site after the first rainfall event. Four months later, a second artificial rainfall event was applied to the surface of the vegetated site. The pore-water pressures (PWPs) and volumetric water contents (VWCs) of the cover were monitored using jet-filled tensiometers and time-domain reflectometry moisture probes, respectively. Surface runoff and percolation were measured using field collection devices. The field measurements demonstrated a more rapid response of PWPs to the rainfall compared to the response of the VWCs. Percolation was observed when the PWPs near the interface reached the water-entry value of the gravel at local points. At that moment, the measured VWC near the interface was less than the VWC according to the water-entry value. The observation indicated that preferential flows took place in the compacted loess during the rainfall. As a result, the maximum water storage capacity was not reached at the onset of percolation. When percolation ceased, the average PWP near the interface decreased below the water-entry value, while the VWC near the interface was higher than that at the onset of percolation. Water storage at the completion of percolation was approximately 5% greater than that at the onset of percolation. Compared with the monolithic loess cover, the loess–gravel CBC increased the available water storage capacity by 41% at the completion of percolation. Vegetation had an insignificant influence on water storage capacity.

Changes in litter chemistry and stoichiometry following N enrichment have important consequences on litter decomposition and plant-mediated nutrient cycling. Our knowledge about the responses of litter stoichiometry at different biological organization levels to N enrichment remains poorly understood. Moreover, whether the impacts of N enrichment on stoichiometric ratios in litter would depend on ecosystem management strategies remains unknown. We examined the effects of N addition and mowing on C:N:P stoichiometry in standing litter at plant organ, species, functional group, and community levels in a semi-arid grassland of northern China, taking advantage of a field experiment that has been running for seven years. Nitrogen addition altered biomass allocation between different organs and among different plant functional groups, with consequences on litter stoichiometry at community level. N addition had no impacts on litter C concentration, increased litter N, and N:P ratio, and decreased litter C:N ratio from plant organ to community. The impacts of N addition on litter P and C:P depended on the identity of plant species and functional group. Mowing did not affect litter nutrient characters across all organization levels. Furthermore, no interactive effects between N addition and mowing on litter nutrient characters were observed from plant organ to community levels. We conclude that N deposition will enhance litter quality even in the heavily-used grasslands with shifts in biomass allocation and species composition, which may contribute to the enhancement of plant-mediating nutrient cycling.

Loess is widely distributed in Northwest China where the rainy season coincides with the warm and vegetation growth period. The use of loess as a capillary barrier cover (CBC) material is promising. However, how the loess/gravel CBC perform as a capillary barrier and landfill gas emissions controller remains elusive. In this study, the performance of a designed CBC comprised 1.3 m-thick compacted loess underlain by 0.3 m-thick gravel in extremely wet and dry years of Xi'an city from 1950 to 2000 was analyzed using numerical modeling. An instrumented CBC test section comprised 0.9 m-thick compacted loess underlain by 0.3 m-thick gravel was constructed to show the hydraulic responses in real conditions from January 2015 to January 2017. The numerical results indicated that the designed CBC performed well as a capillary barrier as no percolation occurred during the extremely wet periods. Despite adopting a CBC of 0.4 m thinner than the designed one, the test section produced only 16.16 mm percolation during the two-year monitoring period, and that can meet the recommended limit of 30 mm/yr. The effect of the capillary break on increasing the water storage within the CBC was observed at the test section in fall. The increased water storage can significantly decrease the gas permeability, and thus improve the performance of the CBC as a LFG emissions controller. Furthermore, the LFG emissions can be controlled to meet the limit set by the Australian guideline by decreasing the bottom gas pressure and artificial watering. Finally, a procedure was proposed to enhance the performance of CBCs.

Globally, chronic nitrogen (N) deposition into terrestrial ecosystems has resulted in changes in community composition, depending on the responses of co-existing species to increasing soil N availability. The levels of plant non-structural carbohydrates (NSCs) produced by photosynthesis are associated with leaf N content, and together they represent the capital of a plant for its life including competitive ability. However, the specific ways that concentrations of plant NSCs, and also N, influence the growth of plants, and thus their productivity, are still abscue. Here, we explored the effect of variations in plant leaf NSCs (starch and soluble sugars) and N concentrations on the growth of plants with different soil N uptake capacities, i.e. two grasses (Leymus chinensis and Stipa baicalensis), two forbs (Potentilla tanacetifolia and Galium verum), and one legume (Thermopsis lanceolate) in Inner Mongolian grasslands subjected to three N addition rates (i.e., 0, 10, or 20 g N m−2 yr−1) and three N forms [i.e., NH4NO3, (NH4)2SO4, or CO(NH2)2] for four years. Irrespective of N addition rate and N form, N addition significantly increased aboveground biomass of the grasses, but not that of the forbs or the legume. The grasses had higher increase in N concentrations than the forbs and the legume. N addition increased the starch concentrations of grasses, but decreased that of forbs and the legume. Changes in the aboveground biomass of all tested plant species were significantly positively correlated with changes in concentrations of both NSCs and N. Our results indicate that, irrespective of the N addition rates and N forms, greater increase in NSCs and N concentrations contributed to higher aboveground productivity in grasses, but not in forbs and legumes. These results imply that future nitrogen deposition will benefit grasses over other plant forms, and thus the former may become more dominant in grasslands in northern China.

A dual-view one-dimensional integral imaging (DV1DII) display with large viewing angle is proposed. It is composed of a display panel, a polarizer, a lenticular lens array and two pairs of polarized glasses. The elemental images 1 and 2, which are captured from the 3D scenes 1 and 2, are respectively displayed on the left and right half of the display panel. The lights emitted from the elemental images 1 are sequentially polarized and modulated by the sub-polarizer 1 and the corresponding lenticular lenses. The orthoscopic 3D image 1 is observed in the right viewing direction by wearing the polarized glasses 1. In a similar way, the orthoscopic 3D image 2 is seen in the left viewing direction by wearing the polarized glasses 2. A prototype of the proposed DV1DII display is developed, and good experimental results agree well with the theory.

Retro-reflection based projection 3D display with low crosstalk is proposed. The 3D display consists of a retro-reflective sheet, an image projector array, a vertical scattering layer, and two optical noise sources projectors. The image projector array is used to provide parallax images. The retro-reflective sheet is used to reflect parallax images to different horizontal viewpoints to form 3D images. The vertical scattering layer is used to scatter the reflected light in the vertical directions, and form viewing areas in the vertical projection area of each corresponding projector. The optical noise source projector provides salt and pepper noise to reduce crosstalk. A prototype of the proposed 3D display is developed, and the experiment results agree well with the theory.

The gridded sea level anomaly (SLA) data-set provided by AVISO is used to track the propagation of intraseasonal Kelvin waves in the Indonesian Throughflow (ITF) region. The large root mean square of intraseasonal SLA along the Sumatra and Java coast is closely related to the propagation of intraseasonal Kelvin waves that derive from the equatorial Indian Ocean. These Kelvin waves are further found to propagate following different pathways at the Lombok Strait. Pathway A propagates eastward throughout the Sumba Strait and Savu Sea to reach the Ombai Strait. Pathway B penetrates into Lombok and propagates northward to reach the Makassar Strait. Pathway C propagates southeastward along the southwest coast of the Sumba Island. The equatorial Kelvin waves take around 15 days to travel from the equatorial Indian Ocean to Lombok Strait, and around 5 days to penetrate into the Makassar and Ombai straits. The Kelvin wave-induced SLA persists in the ITF region for an additional 5 days and then diminishes s...

Wheat yellow mosaic disease (WYM) became more serious in China in the recent years. Cultivation of resistant varieties is the major strategy for disease control. To identify WYM resistant genes in Chinese wheat cultivar ‘Yining Xiaomai’, a population of 106 recombinant inbred lines (RIL) from a cross between Yining Xiaomai and Zhen 9523 (WYM-susceptible) was generated. Phenotypic data of WYM resistance of the RILs were collected over three successive years in a naturally infected field nursery. A linkage map consisting of 29 genetic linkage groups involving 144 SSR or EST markers was constructed, using the JoinMap 4.0 software. By composite interval mapping using IciMapping 4.0, a stable major QTL associated with WYM resistance, designated QYm.nau-2D, was mapped to chromosome 2D which explained up to 93.2 % of the phenotypic variance. More linkage markers including 11 SNP and 11 STS markers were developed to saturate the QYm.nau-2D region. The presence of WYM resistance was further validated using a resistant RIL derived F2 population consisting 318 lines. A high resolution map at QYm.nau-2D region was re-constructed which established a basis for map-based cloning of the resistant gene. Four markers were validated to be diagnostic markers to discriminate 195 breeding lines with known pedigree. These markers could be used in marker-assisted selection to breeding WYM resistance.

The electroreduction behavior of bromostyrenes 1 in DMF has been detected by cyclic voltammetry (CV) on GC and Ag electrodes. Under the atmospheric pressure of CO2, selective electrocarboxylation of 1 was carried out in an undivided cell at Ag cathode under potentiostatic conditions, with the corresponding vinyl-benzoic acid methyl ester 3 as the principal product, accompanied by styrene 2. Moderate to good electrocarboxylation yields were obtained by preparative electrolysis. Synthetic parameters such as supporting electrolyte, applied potential, electric charge, and temperature, were found to influence the carboxylation efficiencies. Both CV and electrolysis confirm that the positions of C–Br and C C groups strongly affect the electrocarboxylation. Higher yields were obtained by changing from ortho to meta to para isomers.

An Ag-ZSM-5/SS zeolite modified electrode has been prepared by a facile one-step method, during which Ag nanoparticles were formed in situ with a ZSM-5 film grown on a stainless steel substrate. The morphology and composition were characterized by XRD, SEM, TEM, EDX, H2-TPR, XPS, etc. Ag-ZSM-5/SS possessed much higher catalytic activity towards the electroreduction and electrocarboxylation of PhCH2Cl compared with an Ag bulk electrode.

We propose a dual-view integral imaging display using a polarizer. It consists of a display panel, a polarizer, a microlens array, and two pairs of polarizer glasses. The polarizer comprises the left and right subpolarizers whose polarization directions are orthogonal. Two kinds of elemental images are captured from different three-dimensional scenes and located on the left and right half of the display panel. The lights emitting from two kinds of elemental images are polarized by the left and right subpolarizers. The polarization directions of the two pairs of polarizer glasses used in the left and right viewing zones are the same as those of the right and left subpolarizers, respectively. Two different three-dimensional images are simultaneously viewed in the left and right viewing directions by wearing two pairs of polarizer glasses. A prototype of the proposed dual-view integral imaging display is developed, and the experimental results verify the hypothesis.

Traditional traveltime inversion for anisotropic medium is, in general, based on a “weak” assumption in the anisotropic property, which simplifies both the forward part (ray tracing is performed once only) and the inversion part (a linear inversion solver is possible). But for some real applications, a general (both “weak” and “strong”) anisotropic medium should be considered. In such cases, one has to develop a ray tracing algorithm to handle with the general (including “strong”) anisotropic medium and also to design a non-linear inversion solver for later tomography. Meanwhile, it is constructive to investigate how much the tomographic resolution can be improved by introducing the later arrivals. For this motivation, we incorporated our newly developed ray tracing algorithm (multistage irregular shortest-path method) for general anisotropic media with a non-linear inversion solver (a damped minimum norm, constrained least squares problem with a conjugate gradient approach) to formulate a non-linear inversion solver for anisotropic medium. This anisotropic traveltime inversion procedure is able to combine the later (reflected) arrival times. Both 2-D/3-D synthetic inversion experiments and comparison tests show that (1) the proposed anisotropic traveltime inversion scheme is able to recover the high contrast anomalies and (2) it is possible to improve the tomographic resolution by introducing the later (reflected) arrivals, but not as expected in the isotropic medium, because the different velocity (qP, qSV and qSH) sensitivities (or derivatives) respective to the different elastic parameters are not the same but are also dependent on the inclination angle.

Geophysical Journal International, 195 (2), ISSN:0956-540X, ISSN:1365-246X

An autostereoscopic 3D display with high brightness and low crosstalk is proposed. This display consists of a liquid crystal display (LCD) panel, a reflective light source (RLS), and a parallax barrier or lenticular lens. The RLS behind the LCD panel consists of a light source, a light guide plate, and a reflection cavity. The RLS can make light reflect continuously in the reflection cavity and exit from the slits on the cavity surface. The widths of these slits are narrower than those of the subpixels, so they can provide a low aperture ratio, which is helpful in obtaining low crosstalk. Because of the reflection cavity, the optical efficiency is higher than that using a single barrier. The parallax barrier or lenticular lens can project parallax images on the LCD panel into different directions. Then 3D images are formed. A prototype of the proposed 3D display having high brightness 3D images and low crosstalk is developed. The experimental results agree well with the theory.

A wireless sensor network is a network consisting of wireless sensor nodes. There are usually requirements that need to be met when deploying a wireless sensor network, one being the placement of nodes. Due to placement requirements and limited node transmission range, a network might be partitioned initially. Therefore, additional relay nodes are added to the network to form an interconnected network. In this article, the minimum relay nodes placement problem in wireless sensor networks is addressed. This problem addresses the placement of relay nodes: the minimum number needed and where the nodes should be placed. The problem is formulated as a Steiner tree problem with minimum Steiner points and a bounded edge length problem, which is NP-hard. In this article, we present a variable-dimension meta-heuristic based on particle swarm optimization called multi-space particle swarm optimization to address the problem. We tested multi-space particle swarm optimization using randomly generated instances of the Steiner tree problem with minimum Steiner points and a bounded edge length problem of varying sizes and found that multi-space particle swarm optimization is effective in addressing the Steiner tree problem with minimum Steiner points and a bounded edge length problem.

Perovskite (CH3NH3PbI3) solar cells have made significant advances recently. In this paper, we propose a bilayer heterojunction solar cell comprised of a perovskite layer combining with a IV-VI group semiconductor layer, which can give a conversion efficiency even higher than the conventional perovskite solar cell. Such a scheme uses a property that the semiconductor layer with a direct band gap can be better in absorption of long wavelength light and is complementary to the perovskite layer. We studied the semiconducting layers such as GeSe, SnSe, GeS, and SnS, respectively, and found that GeSe is the best, where the optical absorption efficiency in the perovskite/GeSe solar cell is dramatically increased. It turns out that the short circuit current density is enhanced 100% and the power conversion efficiency is promoted 42.7% (to a high value of 23.77%) larger than that in a solar cell with only single perovskite layer. The power conversion efficiency can be further promoted so long as the fill factor and open-circuit voltage are improved. This strategy opens a new way on developing the solar cells with high performance and practical applications., Comment: 8 pages, 8 figures, 3 tables, accepted by Solar Energy

A three-dimensional (3-D) display with optimized view distribution is proposed. The proposed 3-D display consists of a two-dimensional (2-D) display panel, a pixel mask, and a lenticular lens. The 2-D display panel is used to provide parallax images. The pixel mask has a designed pinhole array and is located close to the 2-D display panel. This pinhole array can modulate the location and size of the pixels on the 2-D display panel to provide an optimized view distribution. Finally, the lenticular lens projects the pixels in different spatial directions to form 3-D images. Different from conventional 3-D displays, the proposed 3-D display can concentrate views into the center area and form a better parallax continuity. A prototype of the proposed 3-D display is developed. Experiment results agree well with the theory.

This paper presents a new Phase Measuring Deflectometry (PMD) method to measure specular object having\ud discontinuous surfaces. A mathematical model is established to directly relate absolute phase and depth, instead of phase\ud and gradient. Based on the model, a hardware measuring system has been set up, which consists of a beam splitter to\ud change the optical path, and two LCD screens to display the same sinusoidal fringe patterns. By using model-based and\ud machine vision method, system calibration is accomplished to provide the required parameters and conditions. The\ud verification tests are given to evaluate the effectiveness of the developed system. The 3D shape of an artificial step\ud having multiple specular surfaces and a concave mirror has been measured. Initial experimental results show that the\ud proposed measurement method can obtain 3D shape of specular objects with discontinuous surface effectively.

We propose an autostereoscopic three-dimensional (3-D) display using a time-multiplexed method. This display consists of a two-dimensional (2-D) display panel, a time-multiplexed liquid crystal parallax barrier (LCPB), and a lenticular sheet. The 2-D display provides four-view synthetic images. The time-multiplexed LCPB located in front of the 2-D display panel is used to project parallax images in different spatial directions. With the time-multiplexed method, 3-D pixels with different locations can be provided for a time sequence, allowing a high 3-D resolution to be achieved. The lenticular lens is located between the 2-D display panel and the LCPB. Because of congregating ray functions of the lenticular sheet, cross talk can be effectively reduced. We describe the principle and parameter calculations for the prototype of the proposed display. Compared with the conventional autostereoscopic 3-D display, the proposed display has a higher resolution and minimal cross talk.

We propose a dual-view integral imaging (DVII) three-dimensional (3D) display using polarized glasses. The DVII 3D display consists of a display panel, a polarized parallax barrier, a microlens array, and two pairs of polarized glasses. Two kinds of elemental images, which are captured from two different 3D scenes, are alternately arranged on the display panel. The polarized parallax barrier is attached to the display panel and composed of two kinds of units that are also alternately arranged. The polarization directions between adjacent units are perpendicular. The polarization directions of the two pairs of polarized glasses are the same as those of the two kinds of units of the polarized parallax barrier, respectively. The lights emitted from the two kinds of elemental images are modulated by the corresponding polarizer units and microlenses, respectively. Two different 3D images are reconstructed in the viewing zone and separated by using two pairs of polarized glasses. A prototype of the DVII 3D display is developed and two 3D images can be presented simultaneously, verifying the hypothesis.

Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

A one-dimensional integral imaging (1DII) display with large viewing angle is proposed in this paper. The proposed 1DII display is composed of a display panel, a barrier array and a parallax barrier. The barriers, which are located at the junction of adjacent elemental images on the display panel, are perpendicular to the display panel and the parallax barrier. It is different from the previous 1DII display using the barrier array that the aperture centers of the slits aren’t aligned with the centers of the corresponding element images. Moreover, the most important difference is that the pitch of the slit is small than that of the elemental image. The widths of all viewing zones reconstructed by elemental images are identical at the optimal viewing distance. Thus, the viewing angle of the proposed 1DII display isn’t affected by the number of the slits and the elemental images. A prototype of the proposed 1DII display is developed, and good experimental results are obtained.

A reflected-light-source (RLS)-based 3D display is proposed. This display consists of an RLS and a 2D display panel. The 2D display panel is located in front of the RLS. The RLS consists of a light source, a light guide plate (LGP), and a reflection cavity. The light source and the LGP are located in the reflection cavity. Light from the light source can enter into the LGP and reflect continuously in the reflection cavity. The reflection cavity has a series of slits, and light can exit only from these slits. These slits can work as a postpositional parallax barrier, so when they modulate the parallax images on the 2D display, 3D images are formed. Different from the conventional 3D display based on a parallax barrier, this RLS has less optical loss, so it can provide higher brightness. A prototype of this display is developed. Experimental results show that this RLS-based 3D display can provide higher brightness than the conventional one.