Quantifying reasonable crop yield gaps and determining potential regions for yield improvement can facilitate regional plant structure adjustment and promote crop production. The current study attempted to evaluate the yield gap in a region at multi-scales through model simulation and farmer investigation. Taking the winter wheat yield gap in the Huang-Huai-Hai farming region (HFR) for the case study, 241 farmers’ fields in four typical high-yield demonstration areas were surveyed to determine the yield limitation index and attainable yield. In addition, the theoretical and realizable yield gap of winter wheat in 386 counties of the HFR was assessed. Results showed that the average field yield of the demonstration plots was 8282 kg/ha, accounting for 0.72 of the potential yield, which represented the highest production in the region. The HFR consists of seven sub-regions designated 2.1–2.7: the largest attainable yield gap existed in the 2.6 sub-region, in the southwest of the HFR, while the smallest was in the 2.2 sub-region, in the northwest of the HFR. With a high irrigated area rate, the yield gap in the 2.2 sub-region could hardly be reduced by increasing irrigation, while a lack of irrigation remained an important limiting factor for narrowing the yield gap in 2.3 sub-region, in the middle of the HFR. Therefore, a multi-scale yield gap evaluation framework integrated with typical field survey and crop model analysis could provide valuable information for narrowing the yield gap.

Intensive poultry production is heavily reliant on electricity for maintaining shed environments as well as in the supply of feed, lighting, the shed environment and water. During the last three decades, the demand and supply gap for electricity has plagued Pakistan. The energy crisis became even worse from 2006-07, with 18 hours rotational load shedding being implemented. During the last decade, there has been a major increase in environmentally controlled poultry farms in Pakistan which require continuous electricity supply to operate their automatic feeding, drinking and environmental control systems. Broiler farmers have opted for diesel generators to meet their electricity needs, which has subsequently increased total cost of production. Therefore, sustainable and economical energy solutions are required for Pakistani broiler farmers to be competitive in local and international markets. In this paper, the potential for solar energy is analysed, the poultry industry's energy needs are quantified and the use of PV-diesel hybrid power systems in environmentally controlled broiler houses is examined.

We examined the spatial distribution pattern and meteorological drivers of dengue fever (DF) in Guangdong Province, China. Annual incidence of DF was calculated for each county between 2005 and 2011 and the geographical distribution pattern of DF was examined using Moran's I statistic and excess risk maps. A time-stratified case-crossover study was used to investigate the short-term relationship between DF and meteorological factors and the Southern Oscillation Index (SOI). High-epidemic DF areas were restricted to the Pearl River Delta region and the Han River Delta region, Moran's I of DF distribution was significant from 2005 to 2006 and from 2009 to 2011. Daily vapour pressure, mean and minimum temperatures were associated with increased DF risk. Maximum temperature and SOI were negatively associated with DF transmission. The risk of DF was non-randomly distributed in the counties in Guangdong Province. Meteorological factors could be important predictors of DF transmission.

We are presently using the Chandra X-ray Observatory to conduct the first systematic X-ray survey of planetary nebulae (PNe) in the solar neighborhood. The Chandra Planetary Nebula Survey (ChanPlaNS) is a 570 ks Chandra Cycle 12 Large Program targeting 21 high-excitation PNe within ~1.5 kpc of Earth. When complete, this survey will provide a suite of new X-ray diagnostics that will inform the study of late stellar evolution, binary star astrophysics, and wind interactions. Among the early results of ChanPlaNS (when combined with archival Chandra data) is a surprisingly high detection rate of relatively hard X-ray emission from CSPNe. Specifically, X-ray point sources are clearly detected in roughly half of the ~30 high-excitation PNe observed thus far by Chandra, and all but one of these X-ray-emitting CSPNe display evidence for a hard (few MK) component in their Chandra spectra. Only the central star of the Dumbbell appears to display “pure” hot blackbody emission from a ~200 kK hot white dwarf photosphere in the X-ray band. Potential explanations for the“excess” hard X-ray emission detected from the other CSPNe include late-type companions (heretofore undetected, in most cases) whose coronae have been rejuvenated by recent interactions with the mass-losing WD progenitor, non-LTE effects in hot white dwarf photospheres, self-shocking variable winds from the central star, and slow (re-)accretion of previously ejected red giant envelope mass.

An amorphous silicon (a-Si:H) photoconductor array with two distinct integrated amorphous silicon carbon alloy (a-SiC:H) high pass filters is used to detect two of the cell intrinsic fluorophores. The cutoff wavelength of the filters is tuned by the carbon content in the film. The fluorophores of interest – reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are indicative of the redox state of the cells. Concentrations down to 1 μM for NADH and 50 μM for FAD were detected.

The factors which influence the ductility of cast samples of TiAl-based alloys are briefly reviewed with emphasis on alloys where microstructural refinement has been used in an attempt to improve ductility. The grain size in cast samples of different TiAl-based alloys can be refined either by high additions of about 1at% boron, or by lower additions of about 0.2at%. In addition it is possible to refine the microstructure by massively transforming samples and heat treating the transformed samples in the (alpha + gamma) phase field to precipitate alpha. Significantly different ductilities are found in different alloys with similar grain sizes or with similar microstructures and the origins of the improvements in ductility and of these differences are discussed in this paper. The role of alloying elements in influencing the degree of order in alpha 2 and in turn influencing slip in alpha 2 is discussed.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Saunders's Gull Larus saundersi is a breeding endemic of Common Seepweed Suaeda glauca habitats on the east coast of China and south-west coast of South Korea. Much of this habitat has been lost and degraded due to human land use and expansion of the introduced Smooth Cordgrass Spartina alterniflora. Yancheng National Nature Reserve (NNR) is one of three breeding and wintering areas in China. We used satellite images from 1992 to 2007 and visual interpretation combined with ground truthing to classify the land cover and quantify changes in land use and land cover (LULC) in areas of Yancheng NNR used by Saunders's Gull. The Common Seepweed habitat, in which this species nests, decreased in area by 79.1% (27,358 ha) over 15 years, predominantly as a result of conversion to aquaculture ponds (18,929 ha), and is now centred in the south-east of Yancheng NNR. The total population size of Saunders's Gull was maintained at over 900 individuals from 1999 to 2006 in Yancheng NNR, but was only 575 in 2007, and the number of breeding sites decreased from eight in 1992 and 1994 to a single site in 2000–2006 and two sites in 2007. From 1999 to 2007, the breeding population in the core area of Yancheng NNR accounted for 94.93% of the total population, and its nest-site spatial turnover rate was 0.84 ± 0.08 (n = 7 years), but it tended to decrease by about 40% in 2007 because of degradation of the Common Seepweed community. The conversion of Common Seepweed habitats to other habitat types and expansion of introduced Smooth Cordgrass were the major and direct reasons for the loss and degradation of breeding habitats of Saunders's Gull. Smooth Cordgrass habitats increased in area by 321.9% (11,057 ha) during this period and centred on the east, gradually occupying the mudflats, except the beach from Liangduo River to the south of Yancheng NNR, where potential breeding sites for the Saunders's Gull could be located. We discuss the implications of our results for the conservation this species and management of its habitats.

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

A microfabricated amorphous silicon photodiode is used to detect chemiluminescent and colorimetric horseradish peroxidase (HRP) enzymatic reactions. Detections limits of 1 nM and 1 pM of HRP are obtained for chemiluminescent and colorimetric measurements, respectively, with the reactions carried out in solution volume of 50 μL in polystyrene microwells. Surface-adsorbed HRP can be detected with a limit of 1 fmol.cm-2 by both detection methods. Immunoassays were performed using HRP-labeled antibodies and the detection of specific antibody-antigen molecular recognition is demonstrated both in the plastic well and inside a microfluidic channel. The application of the a-Si:H/HRP system is extended by coupling HRP with oxidase enzyme systems for glucose detection and a sensitivity of 0.1 mmol/L was achieved.

The main pathological characteristics of hepatic fibrosis in schistosomiasis are the proliferation of hepatic stellate cells (HSCs) and the deposition of collagen type I (Col I) and collagen type III (Col III). Transforming growth factor beta-1 (TGF-β1) plays an important role in hepatic fibrosis. Paeoniflorin (PAE) has been reported to have immunoregulatory effects; however, the mechanism of its anti-hepatic fibrosis in S. japonicum has not been elucidated. In the present study, we found that mouse peritoneal macrophages (PMφs) stimulated by soluble egg antigen (SEA) of S. japonicum could secrete TGF-β1, and the TGF-β1 in the peritoneal macrophage-conditioned medium (PMCM) could induce proliferation of HSCs and secretion of Col I and III. We selected PMCM at 1:2 dilution as the optimum PMCM (OPMCM). Then we treated HSCs pre-incubated with OPMCM with PAE, and found that the inhibition of HSC proliferation or Col I and III production were closely correlated with the concentration of PAE. Further investigation found that PAE significantly decreased the Smad3 transcription and phosphorylation in HSCs stimulated by OPMCM. In conclusion, SEA plays a key role in hepatic fibrosis by inducing TGF-β1 from PMφs. PAE can exert anti-fibrogenic effects by inhibiting HSCs proliferation and down-regulating Smad3 expression and phosphorylation through TGF-β1 signalling.

Silicon on insulator (SOI) substrate is a key materials for nano-scaling IC device and the requirement for its crystal structure and quality is really high. Nanothick silicon thin film can be transferred onto a handle wafer from a donation wafer to form a SOI wafer after this process including hydrogen implantation of donation wafer, wafer bonding, and thermal treatment at moderately high temperatures of 400 to 600 degree centigrade. The expansion of the hydrogen molecular evolving from the implanted hydrogen ions interacting with silicon dangling bonds and trapped inside the microcavities located near the ion projected range resulted in exfoliation of the silicon thin film in the final heating step. The hydrogen molecules inside the microcavities tend to expand along the bonded interface rather than radially to form individual blisters. Finally, the fracture failure of ion implanted area parallel to the bonded interface near the projected ion range is formed by the sideway expansion of the cavities due to the diffusion supply of implanted hydrogen excited by thermal energy. Microwave processing can lower the activity energy to speed the chemical reaction so that it leads the format of microcavities occurring at low temperature by directly exciting the implanted hydrogen ions by microwave energy and also results in decreasing the critical dosage for layer splitting. However, microwave irradiation alone at room temperature causes the formation of lots of nucleus sites of micro-voids filled by hydrogen molecule which is immobility in silicon resulting in the issue of uniformity of transferred layer. In this study, the hydrogen implanted silicon substrate was irradiated by microwave at low temperature (200 degree centigrade) rather than microwave alone to co-activate the implanted hydrogen ions in silicon to increase not only kinetic energy but also mobility to successfully achieve a completely transferred layer in a short time.

Recently, PVDF-TrFE-CFE terpolymer was developed in Penn State University. The polymer exhibits relaxor ferroelectric behavior. At room temperature, the low-field dielectric constant can be as high as 50-60, more than ten times larger than other dielectric polymer materials, such as Polypropylene, the most widely-used polymer materials for capacitor applications. Due to the large change of electric field induced polarization and high breakdown field, energy density of the terpolymer can reach ∼10 J/cm3, much larger than other polymer materials. In this paper, experimental results on energy density and non-linear dielectric behavior of the terpolymer will be reported.

An overview of SiGe modulation-doped field-effect transistor (MODFET) technology is provided. The layer structures and mobility enhancements for both p- and n-channel modulation-doped quantum wells are described and compared to mobilities in Si/SiO2 inversion layers. Next, previous results on high-performance n- and p-MODFETs fabricated at IBM and elsewhere are reviewed, followed by recent results on laterally-scaled Si/SiGe n-MODFETs with gate lengths as small as 70 nm. We conclude with a discussion of the materials issues for the future vertical and lateral scaling of SiGe MODFETs.

Novel nanocrystals and polymer composite thin films for the applications of electro-optical devices were prepared. We used PbTiO3 nanocrystals as a nonlinear chromophore (guest) in the NLO polymer system. The transparent polymer polyetherketone (PEK-c) was chosen as the polymer host due to its high glass transition temperature. The PbTiO3 nanocrystals were synthesized successfully by the chemical solution decomposition method. The size of the PbTiO3 nanocrystals was estimated to be 30–40 nm. The weight ratio of PbTiO3 nanocrystals to polymer polyetherketone was 15 %. The composite thin films of PbTiO3 / PEK-c were prepared by spin-coating technique. The films were then electrically poled to induce asymmetry in the material by heating the films to a temperature close to their glass transition and applying an electric field. The refractive indices of the un-poled composite PbTiO3 / PEK-c film were found to be 1.55165 for 633 nm and 1.65352 for 414 nm by using the Metricon prism coupling system. In the poled composite PbTiO3 / PEK-c film sample, the TE- and TM-indices differences were found to be 0.02945 for 633 nm and 0.03915 for 414 nm, showing very good optical anisotropy properties. Dielectric constant ε of the film was determined to be 7.32 at room temperature at 100 KHz using an Impedance Analyzer. The electro-optic coefficient, γ33, of poled PbTiO3 / PEK-c composite film was measured to be 18.34 pm/Vat 633 nm under room temperature by the simple transmission technique. The factor F 2 = n 7 γ2 /ε, figures of merit, was estimated to be 1546. The relaxation time constant was calculated to be 5836 min.

GeB− Cluster ions have been used to effectively produce 0.65-2keV boron for low energy ion implantation. We have generated the GeB− cluster ions using the SNICS ion source (source of negative ion by cesium sputtering). Shallow junctions have been made by the GeB− cluster ions implanting into Si substrates at 15keV, 1×1015/cm2 and 5keV, 5×1014/cm2. The junction depth as small as 37nm has been achieved by rapid thermal annealing of the 5 keV sample at 1000°C for 1 second. A two-step annealing was also performed to study the diffusion of B in the GeB− ion cluster implanted Si by annealing the 15 keV implanted sample at 550°C/300sec+1000°C/10sec. We found that the junction depth of the two-step annealed sample was only half of the one-step annealed sample. TEM (transmission electron microscopy) showed clear recrystallization of the amorphized layer with no observable residual defects. We briefly discussed the role of Ge in regards to reduction of the junction depth.

Transmission electron microscopy and high-resolution electron microscopy have been used to study microstructural properties of conductive SrRuO3 films grown by pulsed laser deposition on (001) LaAlO3 and (001) SrTiO3 substrates. It was found that the SrRuO3 films deposited on both substrates consist of mixed domains of [001] and [110] orientations, with orientation relationships that can be described as (i) (001)f ‖ (001)s and [110]f ‖ [100]s and (ii) (110)f ‖ (001)s and [001]f ‖ [100]s, respectively. The SrRuO3 films deposited on SrTiO3, in particular, were found to have a layered domain structure, with the [110] domain grown initially on the substate, followed by growth of the [001] oriented domain with increasing thickness. The films on SrTiO3 are strained and have a coherent interface with the substrate. The SrRuO3 films deposited on LaAlO3, on the other hand, contain a high density of structural defects such as stacking faults and microtwins on the (022) planes. Microtwins as large as 50 nm in thickness are observed in the films deposited on LaAlO3. Possible causes for the observed structural defects in the films are discussed.

There are several activities in the development of low dielectric constant materials, including fluorlnation of SiO2, low-k organic polymers, and porous materials. No one material satisfies all the requirements for multilevel interconnections, which include low dielectric constant, high mechanical strength, good dimensional stability, good high temperature stability, easy processing, and low H2O absorption and outgassing. In this research, a new material system has been studied. This process-controlled low-k material can have dielectric constant as low as 2.0 with good thermal stability. It can provide low viscosity for reflow processing to achieve excellent planarization and gap filling. Low moisture uptake and high mechanical strength can be achieved. Most interesting is, it can be made to be photosensitive at deep-UV range, which provides the possibility of eliminating many chemicals and complicated processes in photolithography. Process cost can be expected to drop significantly. Damascene and dual damascene processes were proposed using this new low-k material, which can be much simpler compared to the traditional process.

We have made a comparative invetigation of the surface microstructures of epitaxially grown ferroelectric SrBi2Ta2O9, BaTiO3 films, and metallic SrRuO3 films, using scanning probe microscopy. Though their lattices (or pseudotetrogonal lattices) match closely with SrTiO3 (001) substrates, SPM results show very different surface microstructures. The surfaces of SrRuO3 films display atomically flat terraces of 90° oriented step edges. The size of steps is about 6 Å. The surface of BaTiO3 films deposited at various temperatures displays uniform rectangular islands. Different stages of SrBi2Ta2O9 epitaxial growth have been studied on thickness gradient films, which show clearly 2D nucleation and layer-by-layer growth, following a transition from 2D to 3D island growth. It finally develops into a surface exhibiting round hills consisting of curved terraces with size of steps ranging from 6 Å to 12.5 Å.