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Introduction: 7.5F digital fURS and 9.5/11.5F ureteral access sheaths (UAS), both conventional (cUAS) and vacuum-assisted (vaUAS), are commercially available. Irrigation increases intrarenal pressure (IRP). This study analyzes the IRP with various irrigation rates using 7.5F fURS without UAS or with either cUAS or vaUAS in an ex-vivo porcine model. Pyelo-tubular backflow was also studied during these experiments. Materials and methods: 11 porcine kidneys were used. 7.5F digital fURS was tested without UAS and with 9.5/11.5F cUAS and vaUAS. 6F pressure monitor catheters were placed into the upper and lower calyces. IRPs were recorded under different irrigation rates. When vaUAS was used, the air vent was either open or closed. 300 mmHg aspiration pressure was chosen. Lastly, contrasted irrigation fluid was delivered until IRP reached above 30 mmHg. Fluoroscopy images were obtained at 5 mmHg intervals over this threshold to study the pyelo-tubular backflow. Results: Using cUAS, IRP reached 30 mmHg with irrigation rates between 60 and 70 cc/min. Using vaUAS with vent closed, IRP never exceeded 10 mmHg with irrigation up to 120 cc/min. vaUAS with vent open performed marginally better than cUAS. fURS without UAS performed better than cUAS. Pyelo-tubular backflow became prominent at 40 mmHg. Conclusion: In an ex-vivo porcine model, 7.5F fURS could be used safely without UAS with irrigation rates up to 120 cc/min. The safety margin dropped to 60–70 cc/min with cUAS. vaUAS with vent closed maintained IRP < 10 mmHg with irrigation rates up to 120 cc/min. Pyelo-tubular backflow was observed with IRP > 35 mmHg. [ABSTRACT FROM AUTHOR]

Based on Newton's second law and the thermal network method, a mechanical thermal coupling model of the bearing rotor system of high-speed trains is established to study the interaction between the bearing vibration and temperature. The influence of lubrication on the vibration and temperature characteristics of the system is considered in the model, and the real-time relationship between them is built up by using the transient temperature field model. After considering the lubrication, the bearing outer ring vibration acceleration and node temperature considering grease are lower, which shows the necessity of adding the lubrication model. The corresponding experiments for characteristics of vibration and temperature of the model are respectively conducted. In the envelope spectrum obtained from the simulation signal and the experimental signal, the frequency values corresponding to the peaks are close to the theoretical calculation results, and the error is very small. In the three stages of the temperature characteristic experiment, the node temperature change of the simulation model is consistent with the experiment. The good agreement between simulation and experiments proves the effectiveness of the model. By studying the influence of the bearing angular and fault size on the system node temperature, as well as the change law of bearing lubrication characteristics and temperature, it is found that the worse the working condition is, the higher the temperature is. When the ambient temperature is low, the viscosity of grease increases, and the oil film becomes thicker, which increases the sliding probability of the rolling element, thus affecting the normal operation of the bearing, which explains the phenomenon of frequent bearing faults of high-speed trains in the low-temperature area of Northeast China. Further analysis shows that faults often occur in the early stage of train operation in the low-temperature environment. [ABSTRACT FROM AUTHOR]

This paper reports the complete mitochondrial genome (mitogenome) sequence of Channa maculate (Taiwan snakehead). The mitogenome of Taiwan snakehead was determined to be 16,558 bp in length. It contains 13 typical vertebrate protein-coding genes, 22 tRNA genes, 2 rRNA genes, 1 OL (putative light-strand origin of replication), and 1 putative control region (D-loop). This is the first report on the complete mitogenome sequence of Channa maculata. [ABSTRACT FROM AUTHOR]

The next generation genome sequencing technology and traditional polymerase chain reaction method were employed to obtain the complete mitochondrial genome of Amur ide ( Leuciscus waleckii) from Dalinor Lake in Inner Mongolia, China. The mitogenome of Amur ide was determined to be 16,605 bp in length. It contains 13 protein-coding genes, 2 rRNA and 22 tRNA genes. This is the first report on the complete mitogenome sequence of Amur ide ( L. waleckii). [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Oujiang color carp was determined to be 16,581 bp in length accurately using the next generation sequencing technology and bioinformatics tools. The complete mitochondrial genome of Oujiang color carp shows typical circular molecule structure of vertebrate's mitochondrial genome, which consists of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region. The whole genome base composition was estimated to be 31.89% A, 27.53% C, 15.76% G, and 24.82% T with A/T bias of 56.71%. The complete mitochondrial genome of Oujiang color carp provides the basis for genetic breeding and conservation studies. [ABSTRACT FROM AUTHOR]

To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings, a dynamic model of the high-speed train including axle box bearings is developed. Subsequently, the dynamic response characteristics of the axle box bearing are examined. The investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel flats. In addition, experiments on both normal and faulty bearings are conducted separately, and the correctness of the model and some conclusions are verified. According to the research, track irregularity is unfavorable for bearing fault detection based on resonance demodulation. Under the same speed conditions, the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its depth. The paper will contribute to a deeper understanding of the dynamic performance of axle box bearings. [ABSTRACT FROM AUTHOR]

As a green travel mode, bike sharing is developing rapidly across China. At present, charging deposits from users is the common operation mode adopted by shared bicycle enterprises. The large number of shared bicycle enterprises generates fierce market competition, and the eliminated enterprises always refuse to return user deposits. Even regular running enterprises still have trouble with the immediate return of deposits. This situation severely affects the reputation of shared bicycle enterprises, and concerns have been shared widely across the society. Meanwhile, there is a general expectation among users that their deposits could be refunded timely and a broad appeal for technical management to resolve this problem. This article uses blockchain technology to reform the current management mode for shared bicycle deposits and constructs a decentralized, user information and deposit visualized, and multidimensional supervised management system. The proposed management system makes the real-time flow direction supervision of user deposits to be realized. Furthermore, a smart contract of shared bicycle deposits with punishment mechanism is also designed. Finally, the differences between the proposed deposit management mode and the current deposit management mode are analyzed, and a simulation experiment is conducted. In the simulation experiment, the deposit theft rate of our deposit management system is 0%, which is far better than the two existing bike deposit management systems. The results show that the outstanding advantages of the proposed deposit management mode, which include improving deposit supervision and guaranteeing user deposit security, are also conducted. This article has made effective technical management exploration to reduce deposit management risks and improve deposit management institutions for shared bicycles. It has important practical reference value for accelerating the sustainable development of shared bicycle enterprises. [ABSTRACT FROM AUTHOR]

TiAl alloy becomes a promising high-temperature structural material due to excellent mechanical properties at elevated temperature. However, the inherent brittleness makes it difficult to be processed by traditional technologies. Therefore, an innovative twin-wire plasma arc additive manufacturing (TW-PAAM) process is developed to fabricate TiAl alloy. Substrate heating is indispensable during additively manufactured TiAl alloy, which can alleviate its crack tendency. In this paper, crack-free TiAl alloy samples are fabricated using TW-PAAM, and the effect of substrate temperature (560, 620 and 680 °C) on as-deposited TiAl alloy is investigated in detail. With the increase in substrate temperature, microstructural lamellar spacing and colony size exhibit the tendency of increase. Also, α2 phase content, recrystallization degree and high Schmid factor frequency present the decrease tendency. These variations of microstructure characteristics further lead to the decrease in both microhardness and tensile properties of the deposit. These findings provide a valuable reference for optimizing microstructures and mechanical properties of additively manufactured TiAl alloys. [ABSTRACT FROM AUTHOR]

Modified medium manganese steel (MMMS) samples were joined using gas metal arc welding (GMAW) and pulse-GMAW (P-GMAW) techniques. The joints were examined using optical microscope, scanning electron microscope, hardness tests, tensile tests and side bend tests. The use of P-GMAW was found to be superior to the GMAW process, resulting in a noteworthy enhancement of the plastic deformation capacity of the weld joint while maintaining comparable tensile properties. Microstructural study and measurement of primary and secondary dendrite arm spacing were also performed to better understand the important aspects of weld metal solidification, i.e., pulse current. The treatment with pulse current restrained the dendrite growth in the welds, resulting in finer dendritic grains, which improved the ductility of the weld joint. The refinement of the microstructure can be attributed to the application of the pulse current, which intensified the effective vibration of the molten pool, facilitated the diffusion of the alloy and reduced the microsegregation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Post-weld heat treatment effects on microstructure of deposited metal are studied. [•] Coarsening of γ′ phase at different post-weld heat treatment temperature is revealed. [•] Formation of δ phase in deposited metal is a bainite-like transformation process. [ABSTRACT FROM AUTHOR]

Background: Amur ide (Leuciscus waleckii) is an economically and ecologically important species in Northern Asia. The Dali Nor population inhabiting Dali Nor Lake, a typical saline-alkaline lake in Inner Mongolia, is well-known for its adaptation to extremely high alkalinity. Genome information is needed for conservation and aquaculture purposes, as well as to gain further understanding into the genetics of stress tolerance. The objective of the study is to sequence the transcriptome and obtain a well-assembled transcriptome of Amur ide. Results: The transcriptome of Amur ide was sequenced using the Illumina platform and assembled into 53,632 cDNA contigs, with an average length of 647 bp and a N50 length of 1,094 bp. A total of 19,338 unique proteins were identified, and gene ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses classified all contigs into functional categories. Open Reading Frames (ORFs) were detected from 34,888 (65.1%) of contigs with an average length of 577 bp, while 9,638 full-length cDNAs were identified. Comparative analyses revealed that 31,790 (59.3%) contigs have a significant similarity to zebrafish proteins, and 27,096 (50.5%), 27,524 (51.3%) and 27,996 (52.2%) to teraodon, medaka and three-spined stickleback proteins, respectively. A total of 10,395 microsatellites and 34,299 SNPs were identified and classified. A dN/dS analysis on unigenes was performed, which identified that 61 of the genes were under strong positive selection. Most of the genes are associated with stress adaptation and immunity, suggesting that the extreme alkaline-saline environment resulted in fast evolution of certain genes. Conclusions: The transcriptome of Amur ide had been deeply sequenced, assembled and characterized, providing a valuable resource for a better understanding of the Amur ide genome. The transcriptome data will facilitate future functional studies on the Amur ide genome, as well as provide insight into potential mechanisms for adaptation to an extreme alkaline-saline environment. [ABSTRACT FROM AUTHOR]

Stainless steel clad plates have been gradually applied in the areas required for both good mechanical properties and corrosion resistance effects, but welding technology is still playing a limiting role in its further large-scale application. The aim of this paper is to review the welding status and future prospective of stainless steel clad plates so as to offer a basis for following research. The paper carefully discussed the welding issues of stainless steel clad plates from three aspects of conventional multi-layer and multi-pass welding, high efficiency welding, and welding finite element simulation, respectively. And simultaneously, the relevant future works were planned too. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bonding mechanism of AA5083/FH36 steel dissimilar welded joint was analyzed. • Lattice misfits of Fe 3 Zn 10 /Fe 2 Al 5 Zn 0.4 and FeZn 10 /Fe 2 Al 5 Zn 0.4 were calculated. • The fracture behavior of welded joint was analyzed by a finite element model. • A novel interface structure to improve the strength of dissimilar joint was obtained. Replacing steel with aluminum alloy is appealing to realize the lightweight of ship structure, so it is inevitable to weld these two materials in products. When joining AA5083 aluminum alloy to FH36 steel with the thickness of 6 mm by tungsten inert gas (TIG) arc welding process, the liquid Zn-based filler metal reacted with steel matrix to form Fe-Zn intermetallic compounds (IMCs) and Fe-Al IMCs. A novel interface structure composed of spinous Г-Fe 3 Zn 10 , thinner η-Fe 2 Al 5 Zn 0.4 and a small number of dispersed δ-FeZn 10 with a relatively high bonding strength can be obtained at the weld seam/steel interface by optimizing the backing welding current. When the backing welding current was 120 A, the maximum tensile strength of joint could reach 98 MPa. Simulation indicated that a large stress concentration developed at the weld seam/steel interface, within crack active temperature range of Fe-Zn and Fe-Al IMCs, during the backing welding process. The lattice misfit of δ-FeZn 10 /η-Fe 2 Al 5 Zn 0.4 and Г-Fe 3 Zn 10 /η-Fe 2 Al 5 Zn 0.4 interfaces were 19.9% and 9.4%, which revealed that dislocations were more likely to accumulate around δ-FeZn 10 , providing the location of crack initiation in aluminum alloy/steel welded joints. [ABSTRACT FROM AUTHOR]

Zr-doped LiNi 0.5 Mn 1.49 Z r0.01 O 4 and pristine LiNi 0.5 Mn 1.5 O 4 with ordered and disordered structures were prepared by a low-temperature solution combustion synthesis method. The phase compositions, structural ordering and micro-morphologies of the products were characterized by X-ray diffraction, energy-dispersive spectroscopy, inductive coupled plasma, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy measurements. The electrochemical performances of the products were investigated by charge/discharge testing, cyclic voltammetry, and electrochemical impedance spectroscopy. The results indicate that the effects of Zr doping on ordered or disordered LiNi 0.5 Mn 1.5 O 4 are different. Ordered LiNi 0.5 Mn 1.49 Z r0.01 O 4 shows much better cycling stability and rate capability than that of ordered LiNi 0.5 Mn 1.5 O 4 . In contrast, the cycling stability of disordered LiNi 0.5 Mn 1.5 O 4 changes little, and the rate capability decreases after Zr doping. After 200 cycles at 1 C, the capacity retentions of ordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 and LiNi 0.5 Mn 1.5 O 4 are 95.0% and 78.0%, respectively, while the capacity retentions of disordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 and LiNi 0.5 Mn 1.5 O 4 are 98.6% and 95.1%, respectively. In particular, the specific capacity of ordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 is as high as 129.4 mA h/g and retains 94.5% after 100 cycles at 10 C, whereas the specific capacity of ordered LiNi 0.5 Mn 1.5 O 4 is only 103.0 mA h/g and retains 84.0% at the same conditions. The excellent electrochemical performance of ordered LiNi 0.5 Mn 1.49 Zr 0.01 O 4 could be attributed to its better crystallinity, higher lithium diffusion coefficient ( D Li ), and lower polarization. [ABSTRACT FROM AUTHOR]

SmBaCo 2−x−y Mn x Mg y O 5+δ (x = 0.5, 1, 1.5 and y = 0.05, 0.1) samples are synthesized by sol-gel method. The influence of different substitution of Mn and Mg for Co on crystal structures, thermal expansion coefficient (TEC), electrical conductivities and electrochemical performances have been investigated. The generation of the secondary phase BaMnO 3 is suppressed with Mg 2+ increasing. Demonstrated by temperature-dependent X-ray diffraction from 25 °C to 700 °C, the structure of SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ in high temperature is stable. The TEC of SmBaCo 1.45 Mn 0.5 Mg 0.05 O 5+δ , SmBaCo 0.95 MnMg 0.05 O 5+δ , SmBaCo 0.45 Mn 1.5 Mg 0.05 O 5+δ and SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ are 15.77 × 10 −6 K −1 , 16.20 × 10 −6 K −1 , 12.19 × 10 −6 K −1 and 12.58 × 10 −6 K −1 , respectively, which are much lower than those of cobalt-based layered perovskites and more compatible with the thermal expansion of SDC electrolyte. Although the electrochemical performances of SmBaCo 2−x−y Mn x Mg y O 5+δ (x = 0.5, 1, 1.5 and y = 0.05, 0.1) decrease slightly with Mn increasing, the polarization resistances of the SmBaCo 1.45 Mn 0.5 Mg 0.05 O 5+δ and SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ are 0.17 Ω cm 2 and 0.30 Ω cm 2 at 800 °C, respectively, which can meet the electrochemical performance requirements of cathode materials. Among the samples, the SmBaCo 1.45 Mn 0.5 Mg 0.05 O 5+δ and SmBaCo 0.4 Mn 1.5 Mg 0.1 O 5+δ show better tradeoff properties between TEC and electrochemical performance as cathode materials for IT-SOFCs. [ABSTRACT FROM AUTHOR]

The high HCO 3 − concentrations in the Yellow River (China) are generally believed to originate primarily from the carbonate-rich Loess Plateau as a result of carbonate weathering reactions that consume atmospheric CO 2 . We studied chemical weathering across the entire Yellow River basin in 2007 and 2009 and found that the amounts of CO 2 consumption by carbonate and silicate weathering were 87.61 × 10 9 mol/a and 10.70 × 10 9 mol/a, respectively. As the source of water for the Yellow River, although the Qinghai–Tibet Plateau accounts for only 30% of the area of the basin, it has a strong leaching effect and contributes a majority (61%) of the atmospheric CO 2 consumption of the entire basin and a majority of the riverine DIC flux (66%) to the ocean. As a result, the dissolved inorganic carbon (DIC) concentrations in this river are among the highest of the world's major rivers. In contrast, despite the abundant carbonate mineral content in the Loess Plateau, the high ratio of evaporation to precipitation (4.2) limits the weathering processes, and the low amount of runoff restricts the transport of weathering products, which results in a relatively low contribution (38%) to the basin-wide atmospheric CO 2 consumption, which is much lower than was previously thought. The Qinghai–Tibet Plateau is the origin of the high levels of HCO 3 − in and acts as the main DIC contributor to the Yellow River. [ABSTRACT FROM AUTHOR]

Additively manufactured TiAl alloy presents heterogeneous and anisotropic microstructure and mechanical properties, resulting from the characteristic of layer by layer deposition, which is detrimental to its further application. In this work, TiAl alloy is built using an innovative twin-wire directed energy deposition-arc (TW-DED-arc). In order to eliminate the heterogeneity and anisotropy of additively manufactured TiAl alloy, the effect of heat treatment on the TiAl alloy fabricated by TW-DED-arc process is investigated. The experimental results indicate that the suitable heat treatment process (1420 °C, 2 min, furnace cooling) can effectively eliminate the heterogeneity and anisotropy of TiAl alloy fabricated using TW-DED-arc process. After the heat treatment, the layer-band like microstructure transforms into homogeneous fully lamellar colony with relatively smaller size, microstructure homogeneity is significantly improved, and the microstructure is also closer to equilibrium state. Also, the microhardness distribution of sample becomes more homogeneous, whose anisotropy is also effectively weakened. • The TiAl alloy is fabricated successfully by twin-wire directed energy deposition-arc • The additively manufactured TiAl alloy presents heterogeneous and anisotropic microstructure and mechanical properties • The heat treatment method to eliminate the heterogeneity and anisotropy of additively manufactured TiAl alloy is obtained successfully • The layer-band like microstructure transforms into homogeneous fully lamellar colony after the heat treatment • The heterogeneity and anisotropy of mechanical properties are significantly improved after the heat treatment. [ABSTRACT FROM AUTHOR]

The microstructural evolution, coarsening behavior of vanadium carbide (VC) and the mechanical properties of the simulated heat-affected zone (HAZ) of modified medium manganese steel (MMMS) were investigated as a function of peak temperature ( T p ). Cementite precipitated at the grain boundary at 650 °C–850 °C, and the formation of a carbide network was not observed even at a higher T p . The nucleation of VC precipitates occurred at a T p of 650 °C, and with increasing T p , they grew at a rate that is greater than the theoretical value calculated according to the volume diffusion-controlled mechanism. However, coarse VC particles disappeared when the T p reached 1250 °C, and VC particles less than 2.0 nm precipitated during cooling. The lattice parameter of austenite in the simulated HAZ first decreased with VC precipitation, then increased with VC dissolution and finally decreased again at 1250 °C due to VC regeneration. Meanwhile, the formation of the VC nanoparticles increased the microhardness and tensile strength of the simulated HAZ. [ABSTRACT FROM AUTHOR]

The common carp, Cyprinus carpio, is one of the most important cyprinid species and globally accounts for 10% of freshwater aquaculture production. Here we present a draft genome of domesticated C. carpio (strain Songpu), whose current assembly contains 52,610 protein-coding genes and approximately 92.3% coverage of its paleotetraploidized genome (2n = 100). The latest round of whole-genome duplication has been estimated to have occurred approximately 8.2 million years ago. Genome resequencing of 33 representative individuals from worldwide populations demonstrates a single origin for C. carpio in 2 subspecies (C. carpio Haematopterus and C. carpio carpio). Integrative genomic and transcriptomic analyses were used to identify loci potentially associated with traits including scaling patterns and skin color. In combination with the high-resolution genetic map, the draft genome paves the way for better molecular studies and improved genome-assisted breeding of C. carpio and other closely related species. [ABSTRACT FROM AUTHOR]

In order to simplify the template method for the synthesis of cathode materials for lithium ion batteries, a facile template method using plant stalks as bio-templates has been introduced. Based on this method, LiNi 0.5 Mn 1.5 O 4 spinel with a significantly improved electrochemical performance has been synthesized using corn stalk as a template. X-ray diffraction (XRD), Fourier transform infrared pectroscopy (FTIR) and scanning electron microscope (SEM) have been used to investigate the phase composition and micro-morphologies of the products. Charge-discharge measurements in lithium cells, cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) have been used to study the electrochemical performance of the products. The results indicate that the templated product exhibits higher crystallinity than that of non-templated product. Both of the templated product and the non-templated product are combination of the ordered space group P4 3 32 and the disordered Fd-3 m. The specific BET surface area of the templated product is about twice larger than that of the non-templated product. Moreover, the electrochemical performances of the templated product including specific capacity, cycling stability and rate capability are significantly improved as compared with the non-templated product, due to its higher crystallinity, larger Li + diffusion coefficient and lower charge transfer resistance. [ABSTRACT FROM AUTHOR]

The LiNi0.5Mn1.5O4 (LNM) spinel lithium-ion battery cathodes were prepared by a modified low temperature solution combustion synthesis method at 600 °C for 3 h. Structural analyses reveal that the modified method is an effective process to eliminate an impurity phase. In comparison with the LNM prepared by a conventional method, the modified sample has higher purity, better crystallinity, smaller amount of Mn3+ ions and higher structural ordering. It exhibits remarkably superior initial discharge specific capacity of 117.0 mAh/g, and delivers a reversible capacity of ~116.0, 116.6, 113.8, 108.9 and 85.9 mAh/g at 0.2 C, 0.5 C, 1 C, 2 C and 5 C, respectively. While the LNM prepared by the conventional method offers a lower reversible capacity of ~96.3, 95.4, 89.1, 77.0 and 40.6 mAh/g at the same rate. After 50 cycles, about 95.5% of reversible capacity is retained for the LNM prepared by modified method vs. 90.7% for the LNM prepared by the conventional method. It suggests that the modified method is a simple and effective method to prepare LiNi0.5Mn1.5O4 with high performance at low temperature and in short time. [ABSTRACT FROM AUTHOR]

High-voltage LiNi0.5Mn1.5O4 spinels were synthesized by a low temperature solution combustion method at 400°C, 600°C and 800°C for 3h. The phase composition, structural disordering, micro-morphologies and electrochemical properties of the products were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and constant current charge–discharge test. XRD analysis indicated that single phase LiNi0.5Mn1.5O4 powders with disordered Fd-3m structures were obtained by the method at 400°C, 600°C and 800°C. The crystallinity increased with increasing preparation temperatures. XRD and FTIR data indicated that the degree of structural disordering in the product prepared at 800°C was the largest and in the product prepared at 600°C was the least. SEM investigation demonstrated that the particle size and the crystal perfection of the products were increased with increasing temperatures. The particles of the product prepared at 600°C with ~200nm in size are well developed and homogeneously distributed. Charge/discharge curves and cycling performance tests at different current density indicated that the product prepared at 600°C had the largest specific capacity and the best cycling performance, due to its high purity, high crystallinity, small particle size as well as moderate amount of Mn3+ ions. [ABSTRACT FROM AUTHOR]

Spinel LiMnO has been synthesized by a glycerol-assisted combustion synthesis method. The phase composition and morphologies of the compound were ascertained by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical characterization was performed by using CR2032 coin-type cell. XRD analysis indicates that single phase spinel LiMnO with good crystallinity has been obtained as a result of 5 h treatment at 600 °C. SEM investigation indicates that the average particle size of the sample is 200 nm. The initial discharge specific capacity of the LiMnO is 123 mAh/g at a current density of 30 mA/g. When the current density increased to 300 mA/g, the LiMnO offered a discharge specific capacity of 86 mAh/g. Compared with the LiMnO prepared by a conventional solution combustion synthesis method at the same temperature, the prepared LiMnO possesses higher purity, better crystallinity and more uniformly dispersed particles. Moreover, the initial discharge specific capacity, rate capability and cycling performance of the prepared LiMnO are significantly improved. [ABSTRACT FROM AUTHOR]

Abstract: Coarsening, embrittlement and corrosion sensitization in high temperature heat-affected zone (HTHAZ) are the major problems when low carbon 12% chromium stainless steel is being welded, which induce deterioration of the impact toughness at low temperature and intergranular corrosion resistance. This study investigated the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests. There are several primary conclusions: (1) When ferrite factor (FF) is above 9.0, the microstructure in HTHAZ is fully ferrite or a small amount of martensite net likely distributing along delta ferrite grain boundaries. On the other hand, if FF is below 9.0, the martensite content increases with the decreasing of FF. (2) Heat input influences the microstructure of high FF steel in HTHAZ. The martensite content and its distribution of low FF steel are not sensitive to heat inputs, but the grain size grows up with the increase of heat inputs. (3) The coarse Ti-rich particles in low FF steels containing Ti can promote intragranular austenite formation inside delta ferrite resulting in packet morphology of martensite. On the other hand, martensite of low FF steels only stabilized with Nb is characterized by grain boundary allotriomorphs, Widmanstätten structures and secondary sawteeth. This martensite reticularly distributes along ferrite grain boundaries. [Copyright &y& Elsevier]

Thick Fe–23Mn-1.5Al-0.45C high-Mn steel plates were multi-pass metal inert gas (MIG) welded with 307Si stainless steel wire. The microstructure, grain orientation and grain boundary evolution of the joint were investigated. The toughness impact at ambient and cryogenic temperatures, the microhardness and tensile strength were also measured. The weld metal (WM) is mainly composed of columnar dendrites, and the growth of grains in WM has obvious preferred orientation and significant stress concentration exists in the heat-affected zone (HAZ) and WM. In comparison to base material (BM), lower cryogenic impact toughness was obtained in WM, which was attributed to the precipitation of rod-shaped M 7 C 3 carbide and the high proportion of low angle grain boundaries in WM. The microhardness is higher in HAZ than in BM, and the average microhardness of each pass weld is very different. The joint strength and efficiency are 669 MPa and 91.5%, respectively. With the decrease of impact test temperature (25 °C, 0 °C, −40 °C, −196 °C), the impact toughness of BM and WM both decreased and the fracture mode of WM diverted from ductile to intergranular brittle. [ABSTRACT FROM AUTHOR]