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•Single PI/rGO composite nanofiber by in-situ polymerization and in-situ thermal conversion.•Tensile strength of single nanofiber up to 4.2 GPa (PI/rGO-1.0% single nanofiber).•Modulus ...of single nanofiber up to 121 GPa (PI/rGO-1.2% single nanofiber).•Homogeneous dispersion of rGO by in-situ strategies.•In-situ strategies enhance the interfacial interaction between rGO and PI fibrous matrix.
High mechanical performance electrospun polymeric nanofibers are highly desired for practical applications, especially as reinforcements for composites. However, most of the electrospun polymeric nanofibers present tensile strength < 3 GPa. To overcome such limitation, this work successfully prepared single rGO reinforced polyimide composite nanofiber with tensile strength up to 4.2 GPa (PI/rGO-1.0%) and modulus up to 121 GPa (PI/rGO-1.2%) by applying in-situ polymerization, electrospinning, and in-situ thermal conversion. These mechanical properties are higher than other polymer-based electrospun nanofibers, and 45% and 236% higher than those of neat PI single nanofiber, respectively. The in-situ strategies provide the homogeneous dispersion of rGO in single electrospun nanofibers and enhance the interfacial interaction between rGO and PI. In addition, the PI/rGO composite nanofibers also present excellent thermal stability with glass transition temperature (Tg) > 295 °C, and the 5% thermal decomposition temperature (T5%) > 539 °C. This work would open a new route for the preparation of high performance electrospun nanofibers for composites.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The stress at the support structure of the clarification tank is large, which will have a certain impact on the whole clarification tank structure. The typical stress concentration phenomenon will ...cause structural damage and serious harm to the steel clarification tank itself. In order to study the influence of the bearing plate on the seismic response of steel clarification tank, this paper analyzes the dynamic response of the clarification tank by setting different thickness bearing plates at the connection between the steel column and the structure body of the steel clarification tank. Based on the displacement, stress, and liquid sloshing height of the steel clarification tank, the thickness of the bearing plate is obtained. The results show that the maximum stress of the steel clarification tank under different seismic waves decreases with the increase of the thickness of the bearing plate. The thickness of the bearing plate has a certain influence on the maximum displacement of the clarification tank structure, but the increase in the thickness of the bearing plate does not necessarily reduce the maximum displacement. Different bearing plate thicknesses have no effect on the position of displacement, and the maximum displacement occurs at the top of the outer wall.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
As a physical analysis method, susceptibility not only predicts the probability of failure of a structure under different hazard levels but also prevents disasters induced by structural damage due to ...vulnerable members. To study the susceptibility of steel clarification tank under earthquake action, this study analyzes the dynamic response of steel clarification tank under near-field impulse, near-field no impulse, and far-field ground shaking, derives IDA curve clusters by incremental dynamic analysis method, and conducts related studies to analyze the susceptibility of clarification tank structures through susceptibility curves. The results of the study show that the probability of failure of the clarification tank under different ground shaking intensities is different. The probability of liquid wave height transcendence of the clarification tank under seismic action is the largest, the probability of liquid wave height transcendence of the clarification tank under near-field pulsed seismic action is the second, the probability of liquid wave height transcendence of the clarification tank under near-field nonpulsed seismic action is the smallest, and the probability of transcendence occurs similarly in near-field pulsed and far-field seismic actions.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
High-strength and high-toughness nanofibers were made from polyimide 6F-PI through electrospinning. The 6F-PI had a backbone made up with 3,3′,4, 4′-biphenyl-tetracarboxylic dianhydride and ...2,2-bis4-(4-aminophenoxy)phenyl-hexafluoro-propane residues. Electrospun 6F-PI precursor nanofibers were collected in the form of aligned fiber sheet on the rim of a rotating disc. Heating process converted the precursor fiber sheets to 6F-PI nanofiber sheets. Gel permeation chromatography and Ostwald Viscometer were used to determine the molecular weight and the molecular weight distribution of the 6F-PI precursor, i.e., the 6F-polyamic acid. Scanning electron microscopy, infrared spectroscopy, X-ray scattering, tensile testing, dynamic mechanical analysis, thermogravimetric analysis, and differential scanning calorimetry were employed to characterize the surface morphology, thermal stability, and mechanical properties of the 6F-PI nanofiber sheets. Experimental results show that the nanofibers were well aligned in the sheets with fiber diameters ranging from 50 to 300 nm. The nanofiber sheets were stable to over 450°C, with a glass transition at 265.2°C. The uniaxial tension test showed that the 6F-PI nanofiber sheets had superior mechanical properties. The ultimate tensile strength, modulus, toughness, and elongation to break of the 6F-PI nanofiber sheets are respectively, 308 ± 14 MPa, 2.08 ± 0.25 GPa, 365 ± 20 MPa, and 202 ± 7%. It is expected that electrospun PI nanofibers with such high toughness and high ultimate tensile strength can find applications in high-performance textiles and composites, for example.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract Developing strong and simultaneously tough polymeric materials with excellent thermal stability and mechanical performance even under extreme temperatures is truly a challenge. In a ...disruptive progress, continuous polymeric yarns are developed with a combination of high tensile strength of (1145 ± 44) MPa and ultrahigh toughness of (350 ± 24) J g −1 and high thermomechanical properties from −196 to 200 °C. The comprehensive thermomechanical performance of this yarn surpasses that of previously developed polymeric materials and dragline spider silks. The results demonstrate that the molecular structure of polyimide (PI) with the incorporation of flexible‐rigid macromolecular, hierarchically spiral‐oriented fibers, and high glass transition temperature (248 °C) are keys for the yarn's notable comprehensive performance in thermomechanical properties. The materials are ideal for technical components exposed to high thermomechanical loadings, such as those encountered in spacecraft or automotive engineering for safety‐critical applications.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background
Thalassemia is a common inherited hematological disease in tropical and subtropical regions. This study aimed to investigate the mutation spectrum of thalassemia in the Dongguan region of ...southern China and comprehensively analyze hematologic features of thalassemia carriers with various types of globin mutations.
Methods
A hematological screening including hematological indices such as mean corpuscular volume (MCV), mean corpuscular hemoglobin content (MCH), and mean corpuscular hemoglobin concentration (MCHC) was conducted in 19 442 people from Dongguan region, Guangdong province of China. Then, 4891 suspected thalassemia carriers were further investigated by genetic analysis of combined NGS and gap‐PCR.
Results
Totally, 2319 (11.9%) cases were diagnosed as carriers of thalassemia, of which 1483 cases (7.6%) were α‐thalassemia, 741 cases (3.8%) were β‐thalassemia, and 95 cases (0.5%) were co‐inheritance of α‐ and β‐thalassemia. In α‐thalassemia carriers, the phenotypic severity increases with the number of nonfunctional α‐globin genes. The patients with –SEA/αWSα genotype have less severe clinical phenotypes than those with other Hb H diseases. As for β‐thalassemia, the MCV and MCH in both β0 and β+ carriers are markedly reduced.
Conclusions
This is the first comprehensive molecular epidemiological survey and hematological profiling of thalassemia in Dongguan area. This study will be benefit for genetic counseling in the clinic and may help pediatricians to make a correct diagnosis of different types of thalassemia.
This study is the first large‐scale epidemiological investigation and full‐spectrum analysis of mutations and hematological profile in thalassemia in Dongguan, southern China. The results of this study will provide reference for genetic counseling and preventive measures to reduce cases of the severe thalassemia. In addition, the genotype‐phenotype correlation in this study might help the clinicians to have rapid and accurate referrals in genetic counseling.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PUC separator filled with ceramic (Al2O3) materials were prepared by electrostatic spinning technique in polyurethane (PU) with three-dimensional nanofiber structure, which has a smaller average pore ...size (1.088 μm), higher porosity (63.7%), higher liquid absorption (371%) and higher ionic conductivity (6.5 × 10-4 S cm-1) compared with commercial polypropylene (Celgard, PP) separators. The electrode composed of a separator and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material has a low interfacial resistance and good rate performance (139.5 mAh g-1) at 5C, furthermore, it keeps 82.7% discharge capacity after 200 cycles at 1C, which is slightly higher than that of Celgard as separator (78.8%), it shows that PUC separator is conducive to the infiltration of electrolyte, and has no obvious effect on circulation performance.
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•PUC separator filled with ceramic (Al2O3) materials were prepared by electrostatic spinning technique in polyurethane (PU).•The PUC separator exhibits superior thermal stability, higher porosity, higher liquid absorption and higher ionic conductivity.•The PUC separator manifests better battery performances than the PP separator, especially at rate performance and cycling performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The distinguishing ability of typical overall indicators is becoming increasingly insufficient in the evaluation tasks of landslide displacement prediction models while the predicting ability of the ...models in the highrisk deformation periods has unexpectedly not been paid enough attention. Therefore, two supplemental evaluation indicators for landslide displacement prediction models, combined error of rapid displacement period (CERDP) and peak prediction error (PPE), along with their application process, are accordingly designed. To verify the feasibility and performance of the proposed supplemental evaluation indicators, a case study based on actual landslide monitoring data has been carried out. It can be concluded that the proposed supplemental evaluation indicators and application process are reasonable, feasible, and practical for effectively addressing the evaluation issues caused by insignificant differences in indicators, such as root mean squared error (RMSE), and are able to finally select an overal
The aim of this study was to test the impact of variants rs900400 (located near LEKR1 and CCNL1) and rs9883204 (located in ADCY5) on birth weight in a Chinese population. We conducted a case control ...study including 156 low-birth- weight infants as the case group and 100 normal-birth-weight infants as the control group. The rs900400 and rs9883204 variants were analyzed by gene sequencing in all the participants. Our results revealed a significant difference in the genotype distribution (v2 = 10.449, p = 0.005) and allele distribution (v2 = 9.277, p = 0.002) of rs900400 between the case group and the control group. The C allele of rs900400 was associated with lower birth weight (OR 1.771 95 % CI 1.237'2.535) in the Chinese population. However, the rs9883204 polymorphism was not informative in the Chinese population. Our study shows that the birth weightlowering variant rs900400 located near LEKR1 and CCNL1, which is strongly associated with birth weight in European cohorts, appears to have a similar association in Chinese cohorts. However, the rs9883204 variant located in ADCY5 does not appear to be correlated with low birth weight in the same population. Moreover, we found that the variant rs900400 may also be associated with premature birth, thereby supporting the need for further research in this area.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A Transformer-based short-term landslide displacement prediction model is proposed by combining temporal convolutional network (TCN) with a Transformer decoder. This model takes the preprocessed ...displacement and rainfall sequences as input and outputs the displacement predictions for the next three days in a time-series autoregressive manner. The experimental results show that the model achieves higher prediction accuracy than support vector machine (SVM) and long short-term memory (LSTM), and performs particularly well during predicting rapid deformation periods. At the same time, through the analysis of the attention mechanism of the model, it is found that the model focuses on the peak of displacements and heavy rainfalls, indicating that the model is reasonably reliable.
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