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Abstract: The cast pipe joint of the Fe‐15Mn‐5Si‐8Cr‐5Ni‐0.25C alloy was manufactured (the numbers in the composition denote the weight percentage of the elements while the weight percentage of Fe is the balance). The corresponding microstructure and shape memory effect are compared with those of a forged alloy. The results show that the cast joint has a good shape memory effect and may be industrially applied while the cast joint keeps jointing under a tensile force of 20 kN and a sealing pressure of 5 MPa. Moreover, it is found that the addition of nitrogen in the alloy doesn’t evidently improve the shape memory effect of the alloy. 相似文献
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Peng Wang Benjamin Barnes Xiaojian Wu Haoran Qu Chiyu Zhang Yang Shi Robert J. Headrick Matteo Pasquali YuHuang Wang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(33)
Single‐walled carbon nanotubes (SWCNTs) are a class of 1D nanomaterials that exhibit extraordinary electrical and optical properties. However, many of their fundamental studies and practical applications are stymied by sample polydispersity. SWCNTs are synthesized in bulk with broad structural (chirality) and geometrical (length and diameter) distributions; problematically, all known post‐synthetic sorting methods rely on ultrasonication, which cuts SWCNTs into short segments (typically <1 µm). It is demonstrated that ultralong (>10 µm) SWCNTs can be efficiently separated from shorter ones through a solution‐phase “self‐sorting”. It is shown that thin‐film transistors fabricated from long semiconducting SWCNTs exhibit a carrier mobility as high as ≈90 cm2 V?1 s?1, which is ≈10 times higher than those which use shorter counterparts and well exceeds other known materials such as organic semiconducting polymers (<1 cm2 V?1 s?1), amorphous silicon (≈1 cm2 V?1 s?1), and nanocrystalline silicon (≈50 cm2 V?1 s?1). Mechanistic studies suggest that this self‐sorting is driven by the length‐dependent solution phase behavior of rigid rods. This length sorting technique shows a path to attain long‐sought ultralong, electronically pure carbon nanotube materials through scalable solution processing. 相似文献
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Moutusi Banerjee Abhisek Gupta Shyamal K. Saha Dipankar Chakravorty 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(28):3451-3457
Attachment of Li+ ion on graphene surface to realize Li+‐ion conductor is a real challenge because of the weak interaction between the ions and the functional groups of graphene oxide; although, a large number of theoretical results are already available in the literature. To overcome this problem, graphene oxide is functionalized by 1‐aza‐15‐crown‐5, the cage‐like structure containing four oxygens that can bind Li+ ion through electrostatic interaction. Li+ migration on graphene surface has been investigated using ac relaxation mechanism. Perfect Debye‐type relaxation behavior with β (relaxation exponent) value ≈1 resulting from single ion is observed. The activation energy of Li+ migration arising due to cation‐π interaction is found to be 0.37 eV, which agrees well with recently reported theoretical value. It is believed that this study will help to design isolated ion conductors for Li+‐ion battery. 相似文献
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Directed Self‐Assembly of Liquid‐Crystalline Molecular Building Blocks for Sub‐5 nm Nanopatterning
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The thin‐film directed self‐assembly of molecular building blocks into oriented nanostructure arrays enables next‐generation lithography at the sub‐5 nm scale. Currently, the fabrication of inorganic arrays from molecular building blocks is restricted by the limited long‐range order and orientation of the materials, as well as suitable methodologies for creating lithographic templates at sub‐5 nm dimensions. In recent years, higher‐order liquid crystals have emerged as functional thin films for organic electronics, nanoporous membranes, and templated synthesis, which provide opportunities for their use as lithographic templates. By choosing examples from these fields, recent progress toward the design of molecular building blocks is highlighted, with an emphasis on liquid crystals, to access sub‐5 nm features, their directed self‐assembly into oriented thin films, and, importantly, the fabrication of inorganic arrays. Finally, future challenges regarding sub‐5 nm patterning with liquid crystals are discussed. 相似文献
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Hemodialysis decreases carotid‐brachial and carotid‐femoral pulse wave velocities: A 5‐year follow‐up study
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Edmundo I. Cabrera Fischer Daniel Bia Cintia Galli Rodolfo Valtuille Yanina Zócalo Sandra Wray Ricardo L. Armentano 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(3):419-428
Aortic stiffness is a prognostic parameter associated with patient mortality. Vascular access creation has been shown to have effects on arterial stiffness both in the aorta and in the upper limb arteries in chronically hemodialyzed patients (CHPs). However, no longitudinal studies have been conducted in order to characterize the evolution of arterial stiffness in CHPs. The aims of this work were (a) to measure baseline pulse wave velocity (PWV) in the carotid‐femoral and in right and left carotid‐brachial pathways in a cohort of CHP and (b) to conduct a 5‐year prospective study on the same cohort to determine possible time‐related differences. Pulse wave velocity was measured both in the carotid‐femoral and in the carotid‐brachial pathways, and clinical and biochemical parameters were collected in 25 CHPs, which were followed up after a 5‐year lapse. Right and left carotid‐brachial pathway PWV values showed significant decreases after the 5‐year follow‐up, independently of the presence of the vascular access (P < 0.001). Additionally, baseline carotid‐brachial PWV was significantly higher (P < 0.001) than values measured 5 years later for upper limbs with vascular access (11.97 ± 2.97 m/sec vs. 6.76 ± 1.48 m/sec, respectively) and without vascular access (12.25 ± 2.38 m/sec vs. 7.18 ± 1.88 m/sec, respectively). Similarly, PWV values in the carotid‐femoral pathway decreased significantly (P < 0.001) over the same period (13.27 ± 2.96 m/sec vs. 9.75 ± 2.99 m/sec, respectively). The 5‐year follow‐up of PWV showed significant decreases in both carotid‐brachial and carotid‐femoral pathways. The general changes in arterial stiffness could be related to the vascular access creation, hemodialysis therapy, and to the improvement of arterial pressure management. 相似文献
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Yihua Mao Xuwen Yang Wenbin Gong Jing Zhang Ting Pan Hongzhao Sun Zhigang Chen Zhen Wang Junfa Zhu Jun Hu Shan Cong Fengxia Geng Zhigang Zhao 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(23)
The high‐temperature molten‐salt method is an important inorganic synthetic route to a wide variety of morphological phenotypes. However, its utility is limited by the fact that it is typically incapable of producing ultrathin (<5 nm diameter) nanowires, which have a crucial role in novel nanotechnology applications. Herein, a rapid molten salt‐based synthesis of sub‐5‐nm‐sized nanowires of hexagonal tungsten oxide (h‐WO3) that is critically dependent on a substantial proportion of molybdenum (Mo) dopant is described. This dopant‐driven morphological transition in tungsten oxide (WO3) may be attributable to the collapse of layered structure, followed by nanocluster aggregation, coalescence, and recrystallization to form ultrathin nanowires. Interestingly, due to the structural properties of h‐WO3, the thus‐formed ultrathin nanowires are demonstrated to be excellent photocatalysts for the production of ammonia (NH3) from nitrogen (N2) and water. The ultrathin nanowires exhibit a high photocatalytic NH3‐production activity with a rate of 370 µmol g?1 h?1 and an apparent quantum efficiency of 0.84% at 420 nm, which is more than twice that obtained from the best‐performing Mo‐doped W18O49 nanowire catalysts. It is envisaged that the dopant replacement‐driven synthetic protocol will allow for rapid access to a series of ultrathin nanostructures with intriguing properties and increase potential applications. 相似文献
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The binary titanium‐ 5wt% aluminum alloy (VT‐5) is a commonly used Russian grade of titanium. It has much higher strength compared to the well known commercially pure titanium grades; at the same time it exhibits reasonable toughness values. Hot rolled bars of this grade were to be manufactured and supplied conforming to OST I 90173‐75 specification. Material was hot rolled to final size; as the hydrogen level was higher than the specified maximum, the bars were subjected to vacuum annealing. The vacuum annealed material did not meet the specification with reference to Charpy impact toughness. Repeat vacuum heat treatment was therefore carried out at a higher temperature; material was then found to be meeting all specification requirements. The paper brings out the details of failure, analysis carried out to identify the factors responsible for the failure and the rejuvenation steps taken to render the product acceptable. 相似文献
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Pengfei Zhang Luzi Zhao Qinyou An Qiulong Wei Liang Zhou Xiujuan Wei Jinzhi Sheng Liqiang Mai 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(8):1082-1090
V2O5 hollow microclews (V2O5‐HMs) have been fabricated through a facile solvothermal method with subsequent calcination. The synthesized V2O5‐HMs exhibit a 3D hierarchical structure constructed by intertangled nanowires, which could realize superior ion transport, good structural stability, and significantly improved tap density. When used as the cathodes for lithium‐ion batteries (LIBs), the V2O5‐HMs deliver a high capacity (145.3 mAh g‐1) and a superior rate capability (94.8 mAh g‐1 at 65 C). When coupled with a lithiated Li3VO4 anode, the all‐vanadium‐based lithium‐ion full cell exhibits remarkable cycling stability with a capacity retention of 71.7% over 1500 cycles at 6.7 C. The excellent electrochemical performance demonstrates that the V2O5‐HM is a promising candidate for LIBs. The insight obtained from this work also provides a novel strategy for assembling 1D materials into hierarchical microarchitectures with anti‐pulverization ability, excellent electrochemical kinetics, and enhanced tap density. 相似文献
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Uncovering the Rab5‐Independent Autophagic Trafficking of Influenza A Virus by Quantum‐Dot‐Based Single‐Virus Tracking
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Qiu‐Mei Wu Shu‐Lin Liu Gang Chen Wei Zhang En‐Ze Sun Geng‐Fu Xiao Zhi‐Ling Zhang Dai‐Wen Pang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(12)
Autophagy is closely related to virus‐induced disease and a comprehensive understanding of the autophagy‐associated infection process of virus will be significant for developing more effective antiviral strategies. However, many critical issues and the underlying mechanism of autophagy in virus entry still need further investigation. Here, this study unveils the involvement of autophagy in influenza A virus entry. The quantum‐dot‐based single‐virus tracking technique assists in real‐time, prolonged, and multicolor visualization of the transport process of individual viruses and provides unambiguous dissection of the autophagic trafficking of viruses. These results reveal that roughly one‐fifth of viruses are ferried into cells for infection by autophagic machineries, while the remaining are not. A comprehensive overview of the endocytic‐ and autophagic‐trafficking process indicates two distinct trafficking pathway of viruses, either dependent on Rab5‐positive endosomes or autophagosomes, with striking similarities. Expressing dominant‐negative mutant of Rab5 suggests that the autophagic trafficking of viruses is independent on Rab5. The present study provides dynamic, precise, and mechanistic insights into the involvement of autophagy in virus entry, which contributes to a better understanding of the relationship between autophagy and virus entry. The quantum‐dot‐based single‐virus tracking is proven to hold promise for autophagy‐related fundamental research. 相似文献
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Bioceramic materials based on CaTiZr3(PO4)6 were synthesised by a ceramic route, characterised by XRD and EMPA analyses, and used as a precursor material to coat Ti6Al4V substrates by atmospheric plasma spraying. This led to multiphase bioactive layers with sufficient porosity for medical applications. In‐vitro biocompatibility tests conducted with primary cultures of rat bone marrow cells incubated for two weeks showed that the CaTiZr3(PO4)6 substrates supported a distinctly higher cell growth rate compared with Thermanox™ cell cover slips used as a control. 相似文献