Southwest University

About: Southwest University is a education organization based out in Chongqing, China. It is known for research contribution in the topics: Gene & Population. The organization has 29772 authors who have published 27755 publications receiving 409441 citations. The organization is also known as: Southwest University in Chongqing & SWU.

Drought Induced Changes in Growth, Osmolyte Accumulation and Antioxidant Metabolism of Three Maize Hybrids.

Abstract: Consequences of drought stress in crop production systems are perhaps more deleterious than other abiotic stresses under changing climatic scenarios. Regulations of physio-biochemical responses of plants under drought stress can be used as markers for drought stress tolerance in selection and breeding. The present study was conducted to appraise the performance of three different maize hybrids (Dong Dan 80, Wan Dan 13, and Run Nong 35) under well-watered, low, moderate and SD conditions maintained at 100, 80, 60, and 40% of field capacity, respectively. Compared with well-watered conditions, drought stress caused oxidative stress by excessive production of reactive oxygen species (ROS) which led to reduced growth and yield formation in all maize hybrids; nevertheless, negative effects of drought stress were more prominent in Run Nong 35. Drought-induced osmolyte accumulation and strong enzymatic and non-enzymatic defense systems prevented the severe damage in Dong Dan 80. Overall performance of all maize hybrids under drought stress was recorded as: Dong Dan 80 > Wan Dan 13 > Run Nong 35 with 6.39, 7.35, and 16.55% yield reductions. Consequently, these biochemical traits and differential physiological responses might be helpful to develop drought tolerance genotypes that can withstand water-deficit conditions with minimum yield losses.

Basic Reproduction Numbers for Reaction-Diffusion Epidemic Models

Abstract: The theory of the principal eigenvalue is developed for an elliptic eigenvalue problem associated with a linear parabolic cooperative system with some zero diffusion coefficients. Then the basic reproduction number and its computation formulae are established for reaction-diffusion epidemic models with compartmental structure. These theoretical results are applied to a spatial model of rabies to study the influence of spatial heterogeneity and population mobility on disease transmission.

Chemically Exfoliating Biomass into a Graphene‐like Porous Active Carbon with Rational Pore Structure, Good Conductivity, and Large Surface Area for High‐Performance Supercapacitors

Abstract: DOI: 10.1002/aenm.201702545 various important applications, especially in energy conversion/storage due to their large surface area, good electrical conductivity, great physicochemical stability, and high surface reactivity.[1–9] In these carbons, 2D materials, such as graphene, have drawn much more attention because their low-dimension structure could shorten ion-diffusion length and realize fast electron transfer in an electrochemical reaction process. Extensive efforts have been devoted to controllably exfoliate graphite into 2D carbon materials.[10–13] ACs have been broadly used for various application over the past years due to their low cost, high specific surface area, and rich porous structure, but their conductivity and ratio of surface to weight are still not comparable with graphene.[14–16] ACs are normally derived from various carbon-rich organic precursors by carbonization at high temperatures following by different activation process such as treatments with KOH, ZnCl2, and H3PO4. ACs can have high porosity, large specific surface area (≈2000 m2 g−1) and excellent adsorption capacity through different activation processes; however, the currently used carbonrich organic precursors are easily to result in large aggregates and end-died pores at high temperature carbonization for poor accessibility of reactants and/or ions, low conductivity, and low utilization in energy storage devices.[22,23] Post-treatment of carbon materials can punch pores only on the surface of bulk carbon and is hard to destroy chemical forces between aggregated layers for separation. Graphene-like lamellar nanomaterials can have inherent advantages of high ratio of surface area to weight, high exposure surface atoms, and fast charge transport behavior. The space and channels between the lamellar layers can greatly boost ions or/and reactants accessibility and significantly shorten the diffusion length to an electrode. It is also very meaningful to convert biomass into valuable carbons,[24–26] in particular for “waste-to-wealth” purpose. Chemical modification for biomass is much easier than that for carbon materials. Moreover, chemical modification and biomass carbonization will induce heteroatoms into carbon materials to tailor the carbon electron-donor properties, the electrical and chemical behaviors of carbons. Active carbons have unique physicochemical properties, but their conductivities and surface to weight ratios are much poorer than graphene. A unique and facile method is innovated to chemically process biomass by “drilling” holes with H2O2 and exfoliating into graphene-like nanosheets with HAc, followed by carbonization at a high temperature for highly graphitized activated carbon with greatly enhanced porosity, unique pore structure, high conductivity, and large surface area. This graphene-like carbon exhibits extremely high specific capacitance (340 F g−1 at 0.5 A g−1) and high specific energy density (23.33 to 16.67 W h kg−1) with excellent rate capability and long cycling stability (remains 98% after 10 000 cycles), which is much superior to all reported carbons including graphene. Synthesis mechanism for deriving biomass into porous graphene-like carbons is discussed in detail. The enhancement mechanism for the porous graphene-like carbon electrode reveals that rationally designed mesoand macropores are very critical in porous electrode performance, which can network micropores for diffusion freeways, high conductivity, and high utilization. This work has universal significance in producing highly porous and conductive carbons from biomass including biowastes for various energy storage/conversion applications.