Effects of soil flooding on photosynthesis and growth of Zea mays L. seedlings under different light intensities

Soil flooding is one of the major abiotic stresses that repress maize (Zea mays L.) growth and yield, and other environmental factors often influence soil flooding stress. This paper reports an experimental test of the hypothesis that light intensity can influence the responses of maize seedlings to soil flooding. In this experiment, maize seedlings were subjected to soil flooding at the two-leaf stage under control light (600 μmol m-2 s-1) or low light (150 μmol m-2 s-1) conditions. Under control light growth conditions, the average photosynthetic rate (PN), transpiration rate (E) and water use efficiency (WUE) were 70, 26 and 59%, respectively, higher in non-flooded than in flooded seedlings; and the average chlorophyll a (Chl a), chlorophyll b (Chl b) and Chl a+b were 31, 42 and 34%, respectively, higher in non-flooded than in flooded seedlings; and the average belowground biomass and total biomass were 52 and 34%, respectively, higher in non-flooded than in flooded seedlings. There was a slight decrease of seedling biomass in six days flooded seedlings under low light growth conditions. The effects of flooding on photosynthetic, seedling growth and shoot/root ratio were more pronounced under control light growth conditions than under low light growth conditions, which indicate that even for maize which is a C4 plant, relatively high light intensity still aggravated soil flooding stress, while low light growth condition mitigated soil flooding stress, and suggests that light effects should be considered when we study maize responses to soil flooding.Keywords: Biomass accumulation, gas exchange, light limitation, maize, stres

QTL Analysis of Shading Sensitive Related Traits in Maize under Two Shading Treatments

During maize development and reproduction, shading stress is an important abiotic factor influencing grain yield. To elucidate the genetic basis of shading stress in maize, an F2:3 population derived from two inbred lines, Zhong72 and 502, was used to evaluate the performance of six traits under shading treatment and full-light treatment at two locations. The results showed that shading treatment significantly decreased plant height and ear height, reduced stem diameter, delayed day-to-tassel (DTT) and day-to-silk (DTS), and increased anthesis-silking interval (ASI). Forty-three different QTLs were identified for the six measured traits under shading and full light treatment at two locations, including seven QTL for plant height, nine QTL for ear height, six QTL for stem diameter, seven QTL for day-to-tassel, six QTL for day-to-silk, and eight QTL for ASI. Interestingly, three QTLs, qPH4, qEH4a, and qDTT1b were detected under full sunlight and shading treatment at two locations simultaneously, these QTL could be used for selecting elite hybrids with high tolerance to shading and high plant density. And the two QTL, qPH10 and qDTS1a, were only detected under shading treatment at two locations, should be quit for selecting insensitive inbred line in maize breeding procedure by using MAS method

Structural Performance Characteristics of Nanomaterials and Its Application in Traditional Architectural Cultural Design and Landscape Planning

In recent years, with the rapid development of industrial technology, industrial materials have also begun to develop in more and more refined directions. Nanotechnology is one of the most developed core technologies in industrial technology, and these characteristics of nanomaterials make them shine in many fields, especially in the field of construction. Nowadays, conventional materials still have the problems of heavy weight and high thermal conductivity as thermal insulation materials for external walls. At the same time, it has outstanding performance that conventional materials do not have. Nanomaterials are widely used in various fields with rapid growth due to their many excellent properties and have produced huge economic benefits and social significance. This article describes the basic characteristics of nanomaterials, including surface effects, quantum size effects, small size effects, and macroscopic quantum tunneling effects. As nanomaterials and nanotechnology become more and more mature, the research on architectural coatings in our country has been slightly strengthened. Nanomaterials have a huge impact on future economic development and have become the most promising objects in the current material field. The experimental results prove that the foaming ability of nanomaterials is much better than that of ordinary materials, and the fault tolerance rate of the cement paste is also the highest. This can also positively show that the relationship between nanotechnology and construction engineering is getting closer and closer, and the combination of nanomaterials and construction materials shows people the broad prospects of construction materials for the development of ecological construction materials that improve the living environment and improve the quality of life

Evolution of Virtual Water Transfers in China’s Provincial Grids and Its Driving Analysis

In China, electricity transmission has increased rapidly over the past decades, and a large amount of virtual water is delivered from power generation provinces to load hubs. Understanding the evolution of the virtual water network embodied in electricity transmission is vital for mitigating water scarcity. However, previous studies mainly calculated the virtual water transferred in short periods in low-spatial resolution and failed to reveal driving forces of the evolution of virtual water. To solve this problem, we investigated the historical evolution of the virtual water network and virtual scarce water network embodied in interprovincial electricity transmission between 2005 and 2014. The driving forces of the evolution of virtual (scarce) water networks were analyzed at both national level and provincial level. The results show that the overall virtual water transmission and virtual scarce water transmission increased by five times, and the direction was mainly from southwest and northwest provinces to eastern provinces. Sichuan, Yunnan, and Guizhou played an increasingly important role in virtual water exporting, and northwestern provinces had dominated the virtual scarce water exporting in the decade. At the national level, the increase of virtual water is mainly driven by the change of power generation mix and power transmission. At the provincial level, the increase of virtual water transmission in the largest virtual water exporter (Sichuan) is driven by the power generation mix and the power transmission, between 2005 and 2010, and 2010 and 2014, respectively. Considering the expanding of electricity transmission, the development of hydropower in the southwestern provinces and other renewable energies (solar and wind) in the northeastern provinces would overall mitigate the water scarcity in China

Large-Scale Synthesis of MOF-Derived Superporous Carbon Aerogels with Extraordinary Adsorption Capacity for Organic Solvents

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high-performance CAs on a large scale in a simple and sustainable manner. We report an eco-friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework-8 (ZIF-8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF-8/AG-derived nitrogen-doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm−3, a high specific surface area of 516 m2 g−1, and a large pore volume of 0.58 cm−3 g−1. The resulting CAs exhibit significant potential for application in the adsorption of organic pollutants

MOF-derived single-atom catalysts: The next frontier in advanced oxidation for water treatment

Over the last decade, single-atom catalysts (SACs) have emerged as a new frontier in the field of advanced oxidation processes (AOPs), since they allow combining the advantages of homogeneous and heterogeneous catalysts, eventually maximizing the atomic efficiency. Metal-organic frameworks (MOFs), periodic porous structures formed through self-assembly of transition metal cations and organic ligands, are regarded as an ideal precursor for the synthesis of SACs. In this review, the synthetic strategies and characterization methods for MOF-derived SACs are described, with special focus on experimental techniques and theoretical simulations employed to verify the existence of single atoms and metal-binding sites. In addition, applications of these catalysts in water treatment by AOPs and electrochemical AOPs based on the activation of persulfate and H2O2 are discussed, paying attention to reaction mechanisms investigated via DFT calculations. Finally, perspectives and research challenges for future development of MOF-derived SACs as catalysts in AOPs are commented

Improving the Error of Time Differences of Arrival on Partial Discharges Measurement in Gas-Insulated Switchgear

Partial Discharge (PD) detection based on Ultra-High-Frequency (UHF) measurements in Gas-Insulated Switchgear (GIS) is often used for fault location based on extraction of Time Differences of Arrival (TDoA), and the core technique is to obtain the precise time difference of each UHF signal. Usually, TDoA extraction algorithms can be categorized as cross-correlation function method (CCF), minimum energy method (ME), and threshold value method (TV) are not qualified to analyze the time difference with high accuracy and efficiency, especially the complicated UHF PD signals in the field. In this paper, multiple tests were carried out based on the real GIS UHF signals. Three typical algorithms (CCF, ME, and TV) were used to extract and calculate the TDoA of UHF signals. Afterwards, depending on the disassembly of equipment, the accuracy and effective range of the algorithms are analyzed by means of error and variance. To minimize the error and the variance, an average method with the combination (CA) and portfolio of traditional algorithms is proposed and verified in different situations. The results demonstrate that the improved algorithm could increase the accuracy of time difference extraction, less than 4.0%

Nitrified coke wastewater sludge flocs: an attractive precursor for N,S dual-doped graphene-like carbon with ultrahigh capacitance and oxygen reduction performance

The handling of a huge amount of sludge produced from industrial wastewater treatment plants is a critical issue. We report a facile and cost-effective pyrolysis approach to transform coke wastewater sludge flocs into valuable carbon materials that show the potential of being used in energy-storage devices and fuel cells. The nitrified sludge flocs are naturally rich in carbon, nitrogen, sulfur, and other inorganic particles and thus are attractive precursors for producing N,S dual-doped carbon with a hierarchical mesoporous graphene-like structure via the simple one-step pyrolysis method without the addition of external N- and/or S-containing organic compounds, chemical activation agents, or graphitization catalyst precursors. Owing to its unique features, the resulting nitrified sludge floc derived carbon (NSFC) exhibits outstanding capacitive performance. The specific capacitance determined in 1 M H2SO4 at a current density of 1 A g−1 is 889 F g−1, the highest among reported values for carbon-based materials in inorganic electrolytes, as far as we are aware. The NSFC also shows an excellent cycling stability with only 1.2% loss in capacitance after 10 000 cycles at a current density of 20 A g−1. The NSFC also achieves superior activity towards the oxygen reduction reaction (ORR) and proves to be a promising metal-free ORR electrocatalyst showing comparable electrocatalytic performance, higher selectivity, and longer durability as compared to the commercial Pt/C benchmark.MOE (Min. of Education, S’pore)Accepted versio