4,658 research outputs found
Testing for Asymmetric Employer Learning and Statistical Discrimination
No full textWe test the implications of a statistical discrimination model with asymmetric learning. Firms receive signals of productivity over time and may use race to infer worker's productivity. Incumbent employers have more information about workers productivity than outside employers. Using data from the NLSY79, we find evidence of asymmetric learning. In addition, employers statistically discriminate against non-college educated black workers at time of hiring. We also find that employers directly observe most of the productivity of college graduates at hiring, and learn very little over time about these workers
Rhizosphere bacteria show a stronger response to antibiotic-based biopesticide than to conventional pesticides
No full textThe plant microbiota can substantially contribute to various functions related to host health, fitness, and productivity. Therefore, maintaining the integrity of the microbiota is beginning to be seen as a crucial factor in modern agriculture. Here, we evaluated the effects of two chemical pesticides (azoxystrobin and carbendazim) and an antibiotic-based biopesticide (wuyiencin) on the rhizosphere microbiome of tomato plants. It was found that all treatments resulted in changes in the bacterial community structure to varying degrees. The most pronounced changes were observed with the biopesticide, which resulted in an enrichment of Streptomyces in the microbiome. In contrast, the relative abundance of Actinobacteria decreased in samples that were treated with low and high dosages of carbendazim. Clostridia were enriched after the applications of azoxystrobin and wuyiencin. When functioning of the microbiome was assessed, it was shown that genes encoding multidrug efflux pumps and ABC transporters related to nutrient uptake were enriched. This enrichment is likely to overcome potentially negative effects linked to the exposure to the employed substances. The study provides new insights into the potential of different pesticides to modulate native plant microbiomes, and thus highlights the importance to include such evaluations when new active agents are developed
sj-docx-1-dhj-10.1177_20552076241239182 - Supplemental material for Comparative effectiveness of interventions on promoting physical activity in older adults: A systematic review and network meta-analysis
No full textSupplemental material, sj-docx-1-dhj-10.1177_20552076241239182 for Comparative effectiveness of interventions on promoting physical activity in older adults: A systematic review and network meta-analysis by Shuang Wu, Guangkai Li, Beibei Shi, Hongli Ge, Si Chen, Xianliang Zhang and Qiang He in DIGITAL HEALTH</p
sj-tif-1-ear-10.1177_0145561320963627 – Supplemental Material for Predictive Significance of Enhanced Level of Angiogenesis and Tissue Neutrophils for Antrochoanal Polyps Recurrence in Children
No full textSupplemental Material, sj-tif-1-ear-10.1177_0145561320963627 for Predictive Significance of Enhanced Level of Angiogenesis and Tissue Neutrophils for Antrochoanal Polyps Recurrence in Children by Yeran Yang, Beibei Song, Xiaojian Yang, Chunju Zhou, Lixing Tang, Jie Lu, Pengpeng Wang, Ping Chu, Shujing Han, Yongli Guo and Wentong Ge in Ear, Nose & Throat Journal</p
Ge1-ySny (y=0.01-0.10) alloys on Ge-buffered Si: Synthesis, microstructure, and optical properties
No full textabstract: Novel hydride chemistries are employed to deposit light-emitting Ge [subscript 1- y] Sn [subscript y] alloys with y ≤ 0.1 by Ultra-High Vacuum Chemical Vapor Deposition (UHV-CVD) on Ge-buffered Si wafers. The properties of the resultant materials are systematically compared with similar alloys grown directly on Si wafers. The fundamental difference between the two systems is a fivefold (and higher) decrease in lattice mismatch between film and virtual substrate, allowing direct integration of bulk-like crystals with planar surfaces and relatively low dislocation densities. For y ≤ 0.06, the CVD precursors used were digermane Ge [subscript 2]H[subscript 6] and deuterated stannane SnD[subscript 4]. For y ≥ 0.06, the Ge precursor was changed to trigermane Ge [subscript 3]H[subscript 8], whose higher reactivity enabled the fabrication of supersaturated samples with the target film parameters. In all cases, the Ge wafers were produced using tetragermane Ge [subscript 4]H[subscript 10] as the Ge source. The photoluminescence intensity from Ge [subscript 1− y] Sn [subscript y] /Ge films is expected to increase relative to Ge [subscript 1− y] Sn [subscript y] /Si due to the less defected interface with the virtual substrate. However, while Ge [subscript 1− y] Sn [subscript y] /Si films are largely relaxed, a significant amount of compressive strain may be present in the Ge [subscript 1− y] Sn [subscript y] /Ge case. This compressive strain can reduce the emission intensity by increasing the separation between the direct and indirect edges. In this context, it is shown here that the proposed CVD approach to Ge [subscript 1− y] Sn [subscript y] /Ge makes it possible to approach film thicknesses of about 1 μm, for which the strain is mostly relaxed and the photoluminescence intensity increases by one order of magnitude relative to Ge [subscript 1− y] Sn [subscript y] /Si films. The observed strain relaxation is shown to be consistent with predictions from strain-relaxation models first developed for the Si[subscript 1− x] Ge [subscript x] /Si system. The defect structure and atomic distributions in the films are studied in detail using advanced electron-microscopy techniques, including aberration corrected STEM imaging and EELS mapping of the average diamond–cubic lattice.Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. along with the following message: The following article appeared in 116, 13 (2014) and may be found at http://dx.doi.org/10.1063/1.489678
Constructing an expeditious and durable composite as an air electrode of solid oxide cells through synergistic phase transformation and phase segregation engineering
No full textThe sluggish catalytic activity of iron-rich perovskite-based air electrodes at low temperatures (<650 degrees C) is a common problem faced by solid oxide cells (SOCs). Herein, an expeditious and durable iron-rich, multifunctional, composite material is reported as an outstanding air electrode for SOCs. Such a composite consists of a dominant cubic single perovskite (SP) phase, SrFe1-x(Ta,Nb)(x)O3-delta, and a minor oxygen vacancy-rich double perovskite (DP) phase, Sr2FeNbO6-delta. The incorporation of pentavalent Ta and Nb effectively inhibits the formation of tetragonal SP and induces phase transformation to a cubic SP with high symmetry, while the in-situ separated DP phase synergistically boosts the performance of oxygen activation. Such multiple benefits result in the generation of an oxygen-ion conductor-based solid oxide fuel cell (O-SOFC) with the developed composite electrode that yields a superb maximum power density (P-max) of 1259 mW cm(-2) at 600 degrees C, similar to 2.1 times that of an O-SOFC with SrFeO3-delta parent electrode (595 mW cm(-2)). A reversible protonic ceramic cell (R-PCC) with such composite air electrode delivers a remarkable electrochemical performance, e.g., a P-max of 844 mW cm(-2) and an electrolysis current density of -957 mA cm(-2) @ 1.3 V at 650 degrees C. More attractively, the resulting cell exhibits an outstanding operating endurance of 500 h in fuel cell mode and 210 h in cycle mode (i.e., alternating between fuel cell and electrolysis cell modes).
Atomic layer deposition of crystalline SrHfO3 directly on Ge (001) for high-k dielectric applications
No full textabstract: The current work explores the crystalline perovskite oxide, strontium hafnate, as a potential high-k gate dielectric for Ge-based transistors. SrHfO3 (SHO) is grown directly on Ge by atomic layer deposition and becomes crystalline with epitaxial registry after post-deposition vacuum annealing at ∼700 °C for 5 min. The 2 × 1 reconstructed, clean Ge (001) surface is a necessary template to achieve crystalline films upon annealing. The SHO films exhibit excellent crystallinity, as shown by x-ray diffraction and transmission electron microscopy. The SHO films have favorable electronic properties for consideration as a high-k gate dielectric on Ge, with satisfactory band offsets (>2 eV), low leakage current (<10[superscript −5] A/cm[superscript 2] at an applied field of 1 MV/cm) at an equivalent oxide thickness of 1 nm, and a reasonable dielectric constant (k ∼ 18). The interface trap density (Dit ) is estimated to be as low as ∼2 × 10[superscript 12] cm[superscript −2] eV[superscript −1] under the current growth and anneal conditions. Some interfacial reaction is observed between SHO and Ge at temperatures above ∼650 °C, which may contribute to increased Dit value. This study confirms the potential for crystalline oxides grown directly on Ge by atomic layer deposition for advanced electronic applications.Copyright 2015 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. along with the following message: The following article appeared in JOURNAL OF APPLIED PHYSICS 117, 5 (2015) and may be found at http://dx.doi.org/10.1063/1.490695
OB00040 - Damodarpur Copper Plate 1 (GE 163) of Budhagupta
No full textDamodarpur Copper Plate 1 (GE 163) of Budhagupt
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