Due to the increasing demand for aerospace structural components, the need for strength-plasticity matching materials has become more urgent. The development of titanium matrix composites (TMCs) has ...provided new ideas to address the issue. In this work, we prepared TMCs by spark plasma sintering (SPS) with Ti-6Al-4 V (TC4) and TiB2 as the matrix and reinforcement, respectively. The TiB whisker (TiBw) generated by the in-suit reaction between the matrix and TiB2 results in grain size refinement of α-Ti, local strains, and additional dislocations in the composites, which enhance the mechanical properties. To further optimize the tensile properties, the sintered composites underwent hot rolling, inducing grain fragmentation and ordered arrangement of reinforcement, thus preventing dislocation movement and improving the bearing effect. In addition, we investigated the effect of rolling reduction on the arrangement direction of TiBw and quantified the strength increase attributed to its directional arrangement. We have achieved TMCs with the ultimate strength of 1440 MPa while maintaining good elongation up to 7.3%. This work may promote the design and applications of TMCs.
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1.The directional arrangement of reinforcements in titanium matrix composites is realized by hot-rolled treatment.2.The composite exhibits excellent tensile strength and plasticity, reaching 1440 MPa and 7.3%, respectively.3.The outstanding mechanical properties are related to α-Ti grain refinement, ordered arrangement of reinforcements, local strain, and additional dislocations.
Fusarium head blight (FHB), mainly caused by
, has become one of the most serious diseases that damage wheat. The
(pore-forming toxin-like) and
(histidine-rich calcium-binding protein) genes at the ...quantitative trait locus
were identified to confer resistance to FHB in the wheat cultivar Sumai 3. In this study, a wheat ricin B-like lectin gene (designated
) that interacted with TaPFT was isolated by a yeast two-hybrid screen of a wheat cDNA library. A yeast two-hybrid and bimolecular fluorescence complementation study further verified that TaRBL interacted with TaPFT but not with TaHRC. Gene expression studies showed that upon
infection,
expression was upregulated in resistant cultivars but downregulated in susceptible cultivars. Furthermore, knockdown of
expression by barley stripe mosaic virus-induced gene silencing significantly reduced the resistance of wheat to FHB in both the resistant cultivar Sumai 3 and the susceptible cultivar Jimai 22. Thus, we conclude that
encodes a ricin B-like lectin protein that interacts with TaPFT and is involved in resistance to FHB in wheat.
To learn the relationship between sunlight intensity and cyanobacterial proliferations for the further control of the heavy blooms, enclosure experiment were conducted in Meiliang Bay, Lake Taihu by ...regulating the natural light intensities with different shading ratio （0% （full sunlight）, 10%, 25%, 50% and 75% of original natural sunlight intensities） from September to November in 2010. The results indicated that phytoplankton biomass （mean） decreased significantly when the shading ratios reached 50% or more. Higher shading ratios （e.g. 75%） were very efficient in controlling the average and total cyanobacterialbloom biomass, while 50% shading ratio was proven very effective either in controlling the peak value of phytoplankton biomass or postponing the occurrence of cyanobacterial blooms in Lake Talhu. In addition, phytoplankton composition and photosynthesis efficiency were also affected by altering the shading ratios, and in turn, they might also act on phytoplankton growth. Based on the results from the present study, intermediate shading strategies such as regulation of water level or turbidity through the hydrology regulations would probably be an effective and efficient method in controlling cyanobacterial blooms in large and shallow lakes.
In this study,the distribution,transfer and fate of both polychlorinated biphenyls（PCBs）and cyanotoxins via phytoplankton routes were systematically investigated in two Chinese lakes.Results ...indicated that PCB adsorption/bioaccumulation dynamics has significantly positive correlations with the biomass of green alga and diatoms.Total lipid content of phytoplankton is the major factor that influences PCB adsorption/bioaccumulation.Cyanobacterial blooms with relatively lower lipid content could also absorb high amount of PCBs due to their high cell density in the water columns,and this process was proposed as major route for the transfer of PCBs in Chinese eutrophic freshwater.According to these findings,a novel route on fates of PCBs via phytoplankton and a green bioadsorption concept were proposed and confirmed.In the practice of mechanical collections of bloom biomass from Lake Taihu,cyanotoxin/cyanobacteria and PCBs were found to be removed simultaneously very efficiently followed this theory.
The hot working behavior of Mg-Gd-Y-Nb-Zr alloy was investigated using constitutive model and hot processing maps in this work. Isothermal compression tests were conducted with temperature and strain ...rate range of 703-773 K and 0.01-5 s~（-1）, respectively. Improved Arrhenius-type equation incorporated with strain compensations was used to predict flow behavior of the alloy, and the predictability was evaluated using correlation coefficient, root mean square error and absolute relative error. Processing maps were constructed at different strains for Mg-Gd-Y-Nb-Zr alloy based on dynamic materials model.The processing maps are divided into three domains and the corresponding microstructure evolutions are referred to the forming of straight grain boundaries, twinning, dynamic recrystallization and grain growth. Instability occurred mainly at the strain rate range of 0.3s~（-1）-0.5s~（-1）. The optimum processing domain is mainly at the temperature range of 703-765 K with the strain rate range of 0.01-0.1 s~（-1）.
Dear Editor, In this study, we re-identified the hosts of cyanophage PP. Twenty-three candidate algal strains were tested, and the results indicated that seven strains belonging to Plectonema and ...Phormidium are the hosts of cyanophage PP, including two previously reported filamentous cyanobacteria, Plectonema boryanum and Phormidium foveolarum （Zhao et al. 2002）. However, several species or strains within the two genera were found not to be hosts of cyanophage PP, implying that the host range is relatively specific.
The objective of this study was to investigate the effect of atractyloside, a promoter of the mitochondrial membrane permeability transition pore (MPTP), on mitochondrial membrane permeability, ...cristae structure, cytochrome c release and tenderness of postmortem beef and to explore the effect of injury on meat tenderness by releasing cytochrome c and activating caspases. The postmortem longissimus dorsi muscle of adult crossbred cattle was treated or not treated (control) with atractyloside, stored at 4 ℃ and evaluated for mitochondrial ultrastructure, membrane potential, the amount of cytochrome c released to the cytoplasm, cell apoptotic rate, caspase-3 and myofibrillary fragmentation index (MFI) after 0, 12, 24, 72, and 120 h. With postmortem aging time, the number of mitochondrial cristae decreased significantly, and swelling and rupture were observed. The mitochondrial membrane potential decreased significantly, and cytochrome c was released gradually. Starting from 72 h postmortem, the activity of caspase-3 and the apoptosis rate of myocytes increased, and so did MFI. Compared with the control group, atractyloside treatment induced mitochondrial damage by destroying mitochondrial cristae structure, reducing the membrane potential and causing cytochrome c release. In addition, the apoptosis of muscle cells and the fragmentation of myofibrils were accelerated by atractyloside. The opening of the MPTP significantly affected mitochondrial injury in beef after slaughter. Apart from increasing cell membrane permeability, atractyloside also significantly altered the structure of mitochondrial cristae. The internal and external mitochondrial membranes could synergistically regulate the release of cytochrome c, which in turn could affect postmortem tenderization of beef.
Recently, the graph convolutional network (GCN) has drawn increasing attention in the hyperspectral image (HSI) classification. Compared with the convolutional neural network (CNN) with fixed square ...kernels, GCN can explicitly utilize the correlation between adjacent land covers and conduct flexible convolution on arbitrarily irregular image regions; hence, the HSI spatial contextual structure can be better modeled. However, to reduce the computational complexity and promote the semantic structure learning of land covers, GCN usually works on superpixel-based nodes rather than pixel-based nodes; thus, the pixel-level spectral-spatial features cannot be captured. To fully leverage the advantages of the CNN and GCN, we propose a heterogeneous deep network called CNN-enhanced GCN (CEGCN), in which CNN and GCN branches perform feature learning on small-scale regular regions and large-scale irregular regions, and generate complementary spectral-spatial features at pixel and superpixel levels, respectively. To alleviate the structural incompatibility of the data representation between the Euclidean data-oriented CNN and non-Euclidean data-oriented GCN, we propose the graph encoder and decoder to propagate features between image pixels and graph nodes, thus enabling the CNN and GCN to collaborate in a single network. In contrast to other GCN-based methods that encode HSI into a graph during preprocessing, we integrate the graph encoding process into the network and learn edge weights from training data, which can promote the node feature learning and make the graph more adaptive to HSI content. Extensive experiments on three data sets demonstrate that the proposed CEGCN is both qualitatively and quantitatively competitive compared with other state-of-the-art methods.
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