•FPU without hydrophilic CH2OH groups were prepared by introducing fluorine with the method of TEOH-10 for modification of MDI and regulating the dosage and time of the MDI added.•There was organic ...fluorine membrane which was equivalent to the hydrophobic effect of the lotus leaf on the surface of FPU.•Comprehensive consideration of water conservancy and hydropower engineering application requirements of underwater protective coating, when the molar ratio of TEOH-10 versus MDI was about 0.5, the cavitation erosion amount of FPU reduced from 2.3756×10−3kg to 0.9334×10−3kg, and the cohesive pressure of FPU stayed over 10MPa, which can be used as protective coating of flow components under water.
Hydrophobic fluorinated polyurethanes (FPU) without hydrophilic CH2OH groups were prepared by introducing fluorine with the method of perfluoroalkyl ethanols (TEOH-10) for modification of diphenyl-methane-diisocyanates (MDI) and regulating the dosage and time of the MDI added. The experiment of water resistance indicates that the hydrophobicity of the FPU are very strong, owing to the low surface energy of fluorocarbon chains (-CF2CF3) migrating to the surface of material and forming the organic fluorine membrane which was equivalent to the hydrophobic effect of the lotus leaf. Especially when the molar dosage of TEOH-10 was 0.3–0.5 theoretical quantity of MDI, the water absorption of FPU is only between 0.0146% and 0.0182%, and the high cohesive pressure of FPU maintained at 10.31MPa–10.79MPa after 3200h’ water soaking. The erosion wear experiment showes that the anti-erosion performance of FPU continuously improved with the increasing of fluorine content, however, the cohesive pressure of FPU continuously reduced with the increasing of fluorine content. Comprehensive consideration of water conservancy and hydropower engineering application requirements of underwater protective coating, when the molar ratio of TEOH-10 versus MDI was about 0.5, the cavitation erosion amount of FPU reduced from 2.3756×10−3kg to 0.9334×10−3kg, and the cohesive pressure of FPU stayed over 10MPa, which can be used as protective coating of flow components under water.
Rice direct seeding has the significant potential to save labor and water, conserve environmental resources, and reduce greenhouse gas emissions tremendously. Therefore, rice direct seeding is ...becoming the major cultivation technology applied to rice production in many countries. Identifying and utilizing genes controlling mesocotyl elongation is an effective approach to accelerate breeding procedures and meet the requirements for direct-seeded rice (DSR) production. This study used a permanent mapping population with 144 recombinant inbred lines (RILs) and 2 828 bin-markers to detect quantitative trait loci (QTLs) associated with mesocotyl length in 2019 and 2020. The mesocotyl lengths of the rice RILs and their parents, Lijiangxintuanheigu (LTH) and Shennong 265 (SN265), were measured in a growth chamber at 30°C in a dark environment. A total of 16 QTLs for mesocotyl length were identified on chromosomes 1(2), 2(4), 3(2), 4, 5, 6, 7, 9, 11(2), and 12. Seven of these QTLs, including qML1a, qML1b, qML2d, qML3a, qML3b, qML5, and qML11b, were reproducibly detected in both years via the interval mapping method. The major QTL, qML3a, was reidentified in two years via the composite interval mapping method. A total of 10 to 413 annotated genes for each QTL were identified in their smallest genetic intervals of 37.69 kb to 2.78 Mb, respectively. Thirteen predicted genes within a relatively small genetic interval (88.18 kb) of the major mesocotyl elongation QTL, qML3a, were more thoroughly analyzed. Finally, the coding DNA sequence variations among SN265, LTH, and Nipponbare indicated that the LOC_Os03g50550 gene was the strongest candidate gene for the qML3a QTL controlling the mesocotyl elongation. This LOC_Os03g50550 gene encodes a mitogen-activated protein kinase. Relative gene expression analysis using qRT-RCR further revealed that the expression levels of the LOC_Os03g50550 gene in the mesocotyl of LTH were significantly lower than in the mesocotyl of SN265. In conclusion, these results further strengthen our knowledge about rice's genetic mechanisms of mesocotyl elongation. This investigation's discoveries will help to accelerate breeding programs for new DSR variety development.
Sn is a well-known grain boundary segregation element that improves the machinability of steel. Sn has been considered as a replacement for Pb in super-free-machining steels. The effect of Sn on the ...microstructure of the Fe-0.05C-0.03Si-1.28Mn-0.36S-0.05P base composition containing 0.0002 (without addition), 0.062, 0.12, and 0.18 Sn (wt.%) low-carbon free-machining steels was investigated though thermodynamic calculations, optical microscopy, scanning electron microscopy, transmission electron microscopy, electron probe microanalysis, and high-temperature laser scanning confocal microscopy. The microstructure of the free-machining steels was composed of α-ferrite, pearlite, and manganese sulfide. Sn significantly decreased the pearlite content of the steels. Most of the Sn was dissolved in the matrix, and the remainder was dissolved in manganese sulfide. No FeSn intermetallic compound precipitation was observed through transmission electron microscopy, but a significant strengthening effect was observed in α-ferrite. Sn had little effect on the solidification behavior or sulfide precipitation behavior of the steels when its content was lower than 0.2 wt.%. Similar to Al and Si, Sn is a ferrite-stabilizing element that expands both the δ-ferrite and α-ferrite phase regions, promotes α-ferrite formation, and inhibits carbide precipitation. Sn segregates at the interface, decreasing the interfacial energy and promoting the Widmanstätten ferrite phase transformation. A much lower cooling rate than that of Sn-free free-machining steels should be adopted to restrain the formation of Widmanstätten ferrite after hot rolling. Sn addition greatly improved the machinability of the experimental steels.
To successfully deploy an intelligent transportation system, it is essential to construct an effective method of traffic speed prediction. Recently, due to the advancements in sensor technology, ...traffic data have experienced explosive growth. It is therefore a challenge to construct an efficient model with highly accurate predictions. To improve the accuracy and the efficiency of short-term traffic predictions, we propose a prediction model based on deep learning approaches. We use a long short-term memory (LSTM) network to analyze sequential sensor data to predict the car speed of the next time interval on the freeway. Unlike the traditional model that only considers the changes in traffic speed which is used to derive the temporal and spatial features from the prediction road section, we mainly consider the features of the number of the most representative car types and the traffic speed variation of the front road segment that is ahead of the prediction road segment in addition to the number of cars, the road occupancy, and the traffic speed latency to successfully learn and capture the hidden patterns from the sensor data so as to improve the prediction accuracy. To the best of our knowledge, very few investigations have been conducted to consider the correlation between car speed and car type for a prediction model. Moreover, our extensive experiments demonstrate that the proposed method for traffic speed prediction has achieved high accuracy.
With austenite under 50% compression using a dilatometer, ferrite transformation in a low-carbon Ti-V-bearing steel was sequenced through the isothermal transformation at 650°C for various holding ...times (10s, 20s, 30s). Bimodal grain size distribution was observed in the prolonged holding conditions. Corresponding measurements of Vickers and nano-indentation hardness were carried out; the tiny ferrite grains possessed lower hardness (303HV and 4.8GPa) as compared to larger ferrite grains (336HV and 5.6GPa). Transmission electron microscopy provided strong evidence attributing this discrepancy to interphase precipitation taking place in the larger-grained ferrite, instead of in the tiny-grained ferrite.
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Gerstmann-Sträussler-Scheinker syndrome (GSS) is a rare genetic prion disease caused by a mutation in the prion protein (
PRNP
) gene. It is typically characterized by progressive cerebellar ataxia ...and slowly progressive dementia. We present a case study of the GSS from China in which a 45-year-old male with a progressive gait and balance disorder developed cerebellar ataxia onset but was misdiagnosed as spinocerebellar ataxia (SCA) for 2 years. The patient's clinical, electrophysiological, and radiological data were retrospectively analyzed. Examination revealed ataxia, dysarthria, muscle weakness, areflexia in lower limbs, including a pyramidal sign, whereas cognitive decline was insignificant. His late mother had a similar unsteady gait. An electroencephalogram (EEG) showed normal findings, and 14-3-3 protein was negative. A brain MRI was performed for global brain atrophy and ventricular enlargement. Positron emission tomography–computed tomography (PET–CT) (18F-fluoro-2-deoxy-d-glucose, FDG) images showed mild to moderate decreased glucose metabolism in the left superior parietal lobe and left middle temporal lobe. According to genetic testing, his younger brother also had the P102L variant in the
PRNP
gene. This single case adds to the clinical and genetic phenotypes of GSS.
Zinc metal has a hexagonal close packing hcp structure with an unusual axial ratio c/a. This work presents the local atomic structure analysis of elemental zinc using the x-ray atomic pair ...distribution function (PDF) method and total synchrotron x-ray scattering in the temperature range of 100–300 K. In this PDF study, we determined the evolution of local bonding in zinc structure in the temperature range of 100–300 K by fitting the first two peaks in the radial distribution function (RDF), R(r), with two Gaussian peaks. Our local structure results reveal a piece of evidence for unusual bond length behavior at low temperatures. The PDF analysis revealed that the a-axis varies linearly from 300 to 160 K and remains constant below 160 K. This local structural result indicates that at temperatures below 160 K, the Zn–Zn bonds are no longer thermally contractible in the ab plane, in agreement with standard crystallographic analysis J. Nuss et al., Z. Anorg. Allg. Chem. 636, 309 (2010). Another significant observation is that the local thermal expansion for the a-axis was found to be three times larger than the one obtained using conventional crystallographic methods U. Wedig et al., Z. Anorg. Allg. Chem. 639, 2036 (2013). This PDF result shows the advantage of total scattering PDF methods in studying the local structural features in elemental zinc, which cannot be captured by the crystallographic model. In addition, this PDF study demonstrates that multiple RDF-peak fitting is a useful approach for interpreting the local structural features of such a non-ideal hcp structure.
In capacitive deionization (CDI) process, the electrosorption capacity of the electrode is related to the electrochemical characteristics of electrode material and the electrolyte solution ...concentration. In this study, two electrochemical techniques, including the cyclic voltammetry (CV) and the electrochemical impedance spectrometry (EIS) are used to characterize the electrochemical properties of four activated carbon (AC) electrodes at different NaCl concentrations. The results indicate that the EIS analysis can provide clearer and whole electrochemical pictures of the AC electrodes. From the EIS analysis, the detailed electrochemical information of the ions in solution and their transport behavior can be well clarified. In practical application, EIS analysis can provide a valuable direction to select the appropriate type of AC as electrode material for CDI application. At lower NaCl concentration, the ions are highly hydrated and the solution conductivity is low. The EIS results indicate that the diffusion accessibility of the hydrated ions into the micropores of AC is impeded. It is beneficial to select the AC with high content of external mesopore ratio. At higher NaCl concentration, the hydration degree of ion is less and the ion size is relatively small. The AC with high total surface area becomes more favorable.
Synchrotron based in situ x-ray diffraction measurements and an analysis of the dehydrogenation of MgH2 and MgH2 with Ti-based additives, including TiH2 and TiMn2, are presented. γ-MgH2 to β-MgH2 ...phase transformation in ball milled MgH2 samples was observed prior to the dehydrogenation reaction. During the dehydrogenation of MgH2 there were no significant phase transformations observed of the additives. These Ti-based additives functioned as catalysts during the dehydrogenation process resulting in lower temperature of dehydrogenation.
•Dehydrogenation of MgH2 with Ti-based additives was studied in situ using XRD.•γ-MgH2 to β-MgH2 phase transformation was found to proceed the dehydrogenation.•No phase transformations of the Ti-additives were observed during dehydrogenation.
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