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Jackknifing refers to the serious situation where a vehicle-trailer system enters a jackknife state and the vehicle and trailer eventually collide if trailer operation is not corrected. This paper considers low speed trailer maneuvering typical of trailer backing. Jackknife state limits can vary due to sideslip caused by physical interaction between the vehicle, trailer, and environment. Analysis of a kinematic model considers sideslip at the vehicle and trailer wheels. Results indicate that vehicle-trailer systems should be divided into three categories based on the ratio of hitch length and trailer tongue length, each with distinct behaviors. The Long Trailer category may have no jackknifing state while the other two categories always have states leading to jackknifing. It is found that jackknife limits, which are the boundaries between the jackknifing state and the recoverable regions, can be divided into safe and unsafe limits. The latter of which must be avoided. Simulations and physical experiments support these results and provide insight about the implications of vehicle and trailer states with slip that lead to jackknifing. Simulations also demonstrate the benefit of considering these new slip-based jackknife limits in trailer backing control. [ABSTRACT FROM AUTHOR]

In recent studies, phase junctions constructed as photocatalysts have been found to possess great prospects for organic degradation with visible light. In this study, we designed an elaborate rhombohedral corundum/cubic In2O3 phase junction (named MIO) combined with polymeric carbon nitride (PCN) via an in situ calcination method. The performance of the MIO/PCN composites was measured by photodegradation of Rhodamine B under LED light (λ = 420 nm) irradiation. The excellent performance of MIO/PCN could be attributed to the intimate interface contact between MIO and PCN, which provides a reliable charge transmission channel, thereby improving the separation efficiency of charge carriers. Photocatalytic degradation experiments with different quenchers were also executed. The results suggest that the superoxide anion radicals (O2−) and hydroxyl radicals (·OH) played the main roles in the reaction, as opposed to the other scavengers. Moreover, the stability of the MIO/PCN composites was particularly good in the four cycling photocatalytic reactions. This work illustrates that MOF-modified materials have great potential for solving environmental pollution without creating secondary pollution. [ABSTRACT FROM AUTHOR]

Miscarriage can cause significant physical and psychological harm to women. The stromal cell-derived factor 1 (SDF-1, also known as CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) and C-X-C motif chemokine receptor 7 (CXCR7) axis can promote the proliferation and invasion of trophoblast cells in early pregnancy, and maintain immune tolerance at the maternal-fetal interface to aid with pregnancy success. From our findings, the serum CXCL12 level of women who have miscarried (n = 25) was significantly lower than that of healthy early pregnancy women (n = 20) by ELISA (P <.001). Additionally, CXCL12 levels in normal non-pregnant women (n = 20) were significantly lower than those in early pregnancy women (P <.001) and women who have miscarried (P <.001). Quantitative real-time PCR detected no significant difference in the mRNA transcription levels of CXCR4 and CXCR7 in the decidua tissues of women with early pregnancy (n = 20) and miscarriage (n = 20) (P =.724, P =.281, respectively). However, Western blot and immunohistochemistry of CXCR4 and CXCR7 in decidual tissue of women who have miscarried (n = 20) were significantly lower than those in early pregnancy women (n = 20) (P <.05 for both). Therefore, we believe that the increased serum CXCL12 levels in pregnant offspring may benefit normal pregnancy maintenance. The low level of CXCL12 in peripheral blood and the low expression of CXCR4 and CXCR7 proteins in decidua may be associated with the occurrence of early spontaneous abortion, and the clinical application value of serum CXCL12 in predicting adverse pregnancy outcomes is worth further exploring. [ABSTRACT FROM AUTHOR]

Chrysin (CHR) is a flavonoid with extensive pharmacological activity. The molecular formula of CHR is C15H10O4. CHR is reported to have antioxidative, antitumour and antiviral functions. To evaluate its potential function as a vaccine adjuvant, we prepared a melanoma vaccine using a soluble protein extract of B16F10 melanoma cells as antigen and CHR as an adjuvant. The melanoma model was developed after two immunizations, and it was discovered that combining B16F10 soluble protein antigen‐mixed CHR vaccine could inhibit tumour growth in the mouse model, and the overall survival rate was higher than that of the B16F10 antigen vaccine alone. In vivo and in vitro experiments were conducted to determine whether CHR functioned as an adjuvant by activating antigen‐presenting cells (APCs). We discovered that CHR activated APCs both in vivo and in vitro and may enhance Th1 cell function by activating the IL12‐STAT4 signal pathway, thereby enhancing the antitumour response of cytotoxic T lymphocytes (CTLs) in vivo. Next, to verify the critical role of CD8+ T cells in suppressing melanoma development, we transplanted CD8+ T cells from immunized mice to B16F10 tumour‐bearing mice and discovered that the survival rate of tumour‐bearing mice was significantly prolonged. In summary, our experimental results indicate that CHR can be used as a potential adjuvant to enhance antigen immunogenicity, inhibit B16F10 tumour growth in mice and improve tumour immune response. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting is one of the promising approaches to solving environmental problems and energy crises. However, the sluggish 4e− transfer kinetics in water oxidation half-reaction restricts the 2e− reduction efficiency in photocatalytic water splitting. Herein, cobalt vanadate-decorated polymeric carbon nitride (named CoVO/PCN) was constructed to mediate the carrier kinetic process in a photocatalytic water oxidation reaction (WOR). The photocatalysts were well-characterized by various physicochemical techniques such as XRD, FT-IR, TEM, and XPS. Under UV and visible light irradiation, the O2 evolution rate of optimized 3 wt% CoVO/PCN reached 467 and 200 μmol h−1 g−1, which were about 6.5 and 5.9 times higher than that of PCN, respectively. Electrochemical tests and PL results reveal that the recombination of photogenerated carriers on PCN is effectively suppressed and the kinetics of WOR is significantly enhanced after CoVO introduction. This work highlights key features of the tuning carrier kinetics of PCN using charge-conducting materials, which should be the basis for the further development of photocatalytic O2 reactions. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIONs), γ-Fe2O3, with hydrophilic surfaces are fabricated in ethylene glycol solutions, without surfactant or additive, by solvothermal process from α-Fe2O3 nanoparticle as precursors. With the addition of a trace of hydrazine hydrate, the cubic phase Fe3O4 nanoparticles are obtained instead of γ-Fe2O3. The saturation magnetization value of γ-Fe2O3 nanoparticles is up to 74.3 emu/g. This study provides a low cost, safe, and universal route to serve as excellent biocompatibility magnetic core for future applications in biomedical, agriculture, and horticulture applications. [ABSTRACT FROM AUTHOR]

In this paper, a curvature-based control method capable of both forward and backward path following is developed for off-axle hitching trailers. Compared with earlier methods, this controller handles varying path curvature better while also being easy to implement and tune. The controller also addresses two major issues that deteriorate tracking accuracy: limited steering actuation and sideslip. An active speed limiter brakes the vehicle when the steering angle error is too high and therefore allows the same set of control gains to work across a relatively large range of reference speeds without significantly increasing lateral error or losing stability, which further simplifies controller tuning. An extended Kalman filter (EKF) sideslip estimator is designed to allow sideslip compensation, which considers the varying noise magnitude in GPS measurements caused by varying vehicle speeds so that the braking maneuver will not significantly deteriorate the estimations. To our knowledge, this paper presents the first publication of these two algorithms with trailer control. This method is compared with results from two earlier hitch-angle-based control methods in simulation and experiment. The active speed limiter and the EKF are also implemented on these control methods for fair comparison, during which it is found that the two algorithms can directly work with other control methods and benefit their performance. The results show the curvature-based controller provides better maneuverability and reduced tracking error. [ABSTRACT FROM PUBLISHER]

Recently, much attention has been given to the synthesis and application of 3D hierarchical nanomaterials, which can have superior performance for supercapacitors compared with other nanostructured materials. Herein, unique hierarchical nanoribbon-based 3D fan-like nanostructures of α-MnMoO4 were controllably synthesized for the first time by using a simple method. We have assembled supercapacitors based on the hierarchical nanoribbon-based α-MnMoO4 3D fan-like nanostructures, which display a specific capacitance of 562 F g−1 at a current density of 1 A g−1, and good cycling stability with 99.8% specific capacitance retention after 1000 cycles. These results further implied that constructing unique 3D hierarchical structures can improve electrochemical properties. [ABSTRACT FROM AUTHOR]

The tensile and compressive behaviors of an extruded Mg- 8 Y- 1 Er-2Zn alloy containing a long period stacking ordered (LPSO) phase were investigated. Compared with the tensile results, the alloy exhibits higher values of the yield stress, strain to failure and work hardening rate in compressive tests, which indicates that the alloy exhibits an asymmetry of tensile-compressive mechanical behaviors. The LPSO phase cracks during tensile deformation while it exhibits a kinking characteristic in the process of compression. It can be concluded that the two different deforming modes of the LPSO phase are the cause of the asymmetry of tensile-compressive mechanical behaviors. [ABSTRACT FROM AUTHOR]

Abstract: The microstructure and mechanical properties of Mg–9RY–4Zn (wt.%) alloy were investigated. In the as-extruded condition, the typical microstructure is plenty of fine DRX grains and 14H long period stacking ordered (LPSO) structure with two forms: the secondary phase with bending long strip morphology distributed along the extruded direction and the fine lamellar phase in the interior of DRX gains. The latter form of LPSO structure suggests that the effect of external force is one of the mechanisms of forming LPSO structure. The as-extruded Mg–9RY–4Zn alloy exhibits high strength and ductility whether at room or elevated temperatures. The yield strength, ultimate tensile strength and elongation are 265MPa, 353MPa and 9.7% at room temperature, 204MPa, 247MPa and 29.2% at 300°C, respectively. The fine DRX gains containing LPSO lamellae and the bending LPSO strips along the direction of extrusion with good characteristics such as high microhardness, plasticity and thermal stability as well as good combination with the Mg matrix are mainly responsible for the excellent mechanical properties of this alloy. [Copyright &y& Elsevier]

Abstract: Mg–4Al–xCe–0.3Mn (x =0, 1, 2, 4 and 6wt.%) alloys were prepared by high-pressure die-casting. The microstructures, mechanical properties and corrosion behavior were investigated. The cross-section of test bar is divided into the fine skin region and the relatively coarse interior region by a narrow band. The dendritic arm spacing is greatly reduced and the secondary phases Al11Ce3 and (Al, Mg)2Ce with the former being the dominant one substitute the Mg17Al12 phase with addition of Ce. When Ce content reaches 4wt.%, the alloy exhibits an optimal cost performance ratio. The improved mechanical properties maintained up to 200°C are mainly related to the fine grain size and the main strengthening phase Al11Ce3, which is present in a high volume fraction, and possesses fine acicular morphology and relatively good thermal stability. The improved corrosion resistance is attributed to the microstructure modification of the alloys and the corrosion product films. [ABSTRACT FROM AUTHOR]

Flexible and stretchable conductive materials have received significant attention due to their numerous potential applications in flexible printed electronics. In this paper, we describe a new type of conductive filler for flexible electrodes—silver nanonets prepared through the "dissolution–recrystallization" solvothermal route from porous silver nanoflakes. These new silver fillers show characteristics of both nanoflakes and nanoparticles with propensity to form interpenetrating polymer–silver networks. This effectively minimizes trade-off between composite electrode conductivity and stretchability and enables fabrication of the flexible electrodes simultaneously exhibiting high conductivity and mechanical durability. For example, an electrode with uniform, networked silver structure from the flakiest silver particles showed the lowest increase of resistivity upon extension (3500%), compared to that of the electrode filled with less flaky (3D) particles (>50,000%). [ABSTRACT FROM AUTHOR]

Polymeric nanoparticle suspension is a newly developed oil-displacing agent for enhanced oil recovery (EOR) in low-permeability reservoirs. In this work, SiO2/P(MBAAm-co-AM) polymeric nanoparticles were successfully synthesized by a simple distillation–precipitation polymerization method. Due to the introduction of polymer, the SiO2/P(MBAAm-co-AM) nanoparticles show a favorable swelling performance in aqueous solution, and their particle sizes increase from 631 to 1258 nm as the swelling times increase from 24 to 120 h. The apparent viscosity of SiO2/P(MBAAm-co-AM) suspension increases with an increase of mass concentration and swelling time, whereas it decreases as the salinity and temperature increase. The SiO2/P(MBAAm-co-AM) suspension behaves like a non-Newtonian fluid at lower shear rates, yet like a Newtonian fluid at shear rates greater than 300 s−1. The EOR tests of the SiO2/P(MBAAm-co-AM) suspension in heterogeneous, low-permeability cores show that SiO2/P(MBAAm-co-AM) nanoparticles can effectively improve the sweep efficiency and recover more residual oils. A high permeability ratio can result in a high incremental oil recovery in parallel cores. With an increase of the permeability ratio of parallel cores from 1.40 to 15.49, the ratios of incremental oil recoveries (low permeability/high permeability) change from 7.69/4.61 to 23.61/8.46. This work demonstrates that this SiO2/P(MBAAm-co-AM) suspension is an excellent conformance control agent for EOR in heterogeneous, low-permeability reservoirs. The findings of this study can help to further the understanding of the mechanisms of EOR using SiO2/P(MBAAm-co-AM) suspension in heterogeneous, low-permeability reservoirs. [ABSTRACT FROM AUTHOR]

In this work, the role of long period stacking ordered (LPSO) phase in the crack propagation behavior of an as-cast Mg95.5Y3Zn1.5 alloy was investigated by dynamic four-point bent tests. The as-cast Mg95.5Y3Zn1.5 alloy is mainly composed of Mg matrix, 18R LPSO phase located at the grain boundaries and 14H LPSO phase located within the Mg matrix. The alloy exhibits excellent dynamic mechanical properties; the yield stress, maximum stress and strain to failure are 190.51 ± 3.52 MPa, 378.32 ± 4.26 MPa and 0.168 ± 0.006, respectively, at the strain rate of ~3000 s−1. The LPSO phase effectively hinders dynamic crack propagation in four typical ways, including crack tip blunting, crack opening inhibition, crack deflection and crack bridging, which are beneficial to the mechanical properties of the alloy under dynamic loadings. [ABSTRACT FROM AUTHOR]

Abstract: Mg–3.4wt.% Al-based alloy modified with 2.4wt.% Ce-rich and 0.3wt.% Y-rich misch metals was prepared by high-pressure die-casting. The microstructure, thermal stability of intermetallic phases and mechanical properties were investigated. The cross-section of test bar is divided into the fine skin region and the wide core region by a narrow band. Two intermetallic phases Al11RE3 and Al2RE, with the former being the dominant one, are mainly distributed at the interdendritic regions. The Al11RE3 intermetallics possess high volume fraction, fine acicular/lamellar morphology and layered arrangement. It is suggests that each rare earth element has the individual preference for the above two Al–RE intermetallics. The thermal stability of Al11RE3 is conditioned. It is basically stable at temperature up to 200°C within 800h, while almost all Al11RE3 intermetallics transform to Al2RE at higher temperature of 450°C for 800h. The alloy exhibits remarkably improved tensile and compressive yield strengths at room temperature and 200°C and they are the results of the reinforcement of dendrite boundaries with Al11RE3 intermetallics, the fine dendritic arm spacing effect as well as the solid solution strengthening with various rare earth elements. [Copyright &y& Elsevier]

18R long-period stacking ordered (LPSO) structure was introduced into Mg–Li alloys. For the investigated Mg–8Li–6Y–2Zn alloy, LPSO phase cannot be formed in the as-cast state as Mg–Y–Zn alloys, but it can be transformed from (Mg,Zn)24Y5 phase via heat treatment at 500°C. Tensile test results indicate that the formation of 18R LPSO phase can effectively improve both the strength and plasticity of extruded Mg–8Li–6Y–2Zn alloy. [Copyright &y& Elsevier]

Abstract: Mg–3.0Al–2.2La–0.3Y–0.2Mn (wt.%) alloy was prepared by high-pressure die-casting. The microstructure, thermal stability of intermetallic phases and mechanical properties were investigated. The dominant strengthening phase is Al11La3, mainly distributed in the interdendritic regions. The Al11La3 phase exhibits good thermal stability with no significant decomposition at temperatures up to 200°C within 800h, while almost all Al11La3 intermetallics decompose to Al2La at higher temperature of 450°C for 800h. The alloy exhibits significantly improved tensile and compressive yield strengths at room temperature and 200°C. The outstanding mechanical properties are mainly attributed to the formation of Al11La3 intermetallics, which is present in a high volume fraction, and possesses fine morphology and relatively good thermal stability. [Copyright &y& Elsevier]

Constructing novel and efficient p-n heterojunction photocatalysts has stimulated great interest. Herein, we report the design and synthesis of fiber-shaped Ag 2 O/Ta 3 N 5 p-n heterojunctions as a kind of efficient photocatalysts. Ta 3 N 5 nanofibers were prepared by an electrospinning-calcination-nitridation method, and then the in-situ anchoring of Ag 2 O on their surfaces was realized by a facile deposition method. The resulting Ag 2 O/Ta 3 N 5 heterojunctions were comprised of porous Ta 3 N 5 nanofibers (diameter: ∼150 nm) and Ag 2 O nanoparticles (size: ∼12 nm). The photocatalytic activity of these heterojunctions were studied by decomposing rhodamine B (RhB) dye and tetracycline (TC) antibiotic under visible light (λ > 400 nm). In all the samples, the heterojunction with Ag 2 O/Ta 3 N 5 molar ratio of 0.2/1 displays the best activity. It is found that a synergistic effect contributes to the effective suppression of charges recombination between Ta 3 N 5 and Ag 2 O, leading to an enhanced photocatalytic activity with good stability. The photogenerated holes (h + ) and superoxide radicals ( O 2 - ) play dominant roles in the photocatalytic process. These p-n heterojunctions will have great potential for environmental remediation because of the facile preparation process and exceptional photocatalytic activity. [ABSTRACT FROM AUTHOR]

The present work investigated the evolution of (Ti, Mo)C particles in austenite of a Ti-Mo-bearing steel during isothermal holding after hot deformation at 925 °C. Results show that the (Ti, Mo)C particles sequentially undergo dislocation-assisted diffusion controlled growth stage, interface-reaction controlled slow coarsening stage, and bulk diffusion controlled fast coarsening stage. The Mo-enriched region near the outer layer of the (Ti, Mo)C particles results in the slow coarsening stage. To reduce the total interface and strain energy correlated with austenite matrix, the particle morphology evolution follows spherical → polyhedral → irregular route. Compared to TiC, dispersive refined (Ti, Mo)C particles suppress austenite recovery and recrystallization more effectively, which favors maintaining the deformed microstructures at high temperatures. [ABSTRACT FROM AUTHOR]

In this work, continuous Mo fiber as a reinforcement was introduced into Ti/Al 3 Ti metal-intermetallic-laminated (MIL) composite via vacuum hot pressing (VHP). In order to avoid excessive consumption of Mo fibers reacting with Al, and also obtain an appropriate amount of Al 3 Ti, a Ti foil with the thickness of 0.1 mm as an expendable was inserted between the Al foil and Mo fibers. The microstructure characterization of the MIL composite was performed via X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the tensile mechanical properties were measured by employing an Instron-5500R load frame. Results indicated that after VHP, the inserted thin Ti foils were completely depleted and converted into the dominant phase Al 3 Ti, which existed in the intermetallic layer. Four Al–Mo intermetallic, Al 8 Mo 3 , Al 4 Mo, Al 5 Mo and Al 12 Mo were successively formed around Mo fiber. The sequence of these Al–Mo intermetallic can be well explained by the thermodynamics calculation combined with the kinetic factor. Tensile tests show that when the arrangement of the fibers is parallel to the tensile direction, the introduction of Mo fibers significantly improves the tensile strength and strain to failure of the composite fibers, which is obviously related to the excellent mechanical properties of the Mo fibers themselves and their good bonding with the matrix. • A novel Mo fiber reinforced Ti/Al 3 Ti metal intermetallic laminated (MIL) composite was prepared. • The Al 3 Ti was the dominant phase in the intermetallic layer. • Four Al–Mo intermetallic, Al 8 Mo 3 , Al 4 Mo, Al 5 Mo and Al 12 Mo were successively formed around Mo fiber. • The effect of the fiber was evaluated by calculating the energy consumption of material during the tensile process. [ABSTRACT FROM AUTHOR]