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Aiming to realize the wastewater treatment of various pollutants simultaneously, a dual-functional poly(ether amine)-polydopamine (PEA-PDA)-modified filter material was fabricated in this work for in situ separation of stable oil-in-water emulsion and adsorption of anionic azo dyes. PEA and PDA could be copolymerized via the Michael addition reaction on a polyurethane sponge substrate firmly. The as-prepared filter shows superhydrophilic and underwater superoleophobic wettability. After being squeezed in a glass tube, the material could separate different kinds of stabilized oil-in-water emulsions with high flux and efficiency. Besides, the PEA-PDA copolymer endows the material with the ability to adsorb large amounts of anionic azo dyes during the separation of emulsions with good adsorption capacity. Moreover, adsorbed dyes in the filter material could be easily desorbed in base aqueous solution and the whole process is conducted under gravity without external aid. This dual-functional material shows great potential for the application in industrial field because of its ability for the complex wastewater treatment.

Current emphasis on automotive engine has evoked the desire to improve tribological performance by both reducing friction and making starting easier in the automotive industry. The present study was conducted to determine the effects of viscosity of fully-formulated oil on tribological properties of the typical coatings for automotive engine components, e.g. ta-C, CrN and Cr-diamond coatings, under simulated lubrication conditions. Results showed that compared to Cr-diamond and CrN coating, the ta-C coating exhibited superior tribological properties with the lowest friction coefficients and wear rates under various testing conditions. Low-viscosity oil 0W-20 could significantly improve the tribological properties of ta-C coatings at different testing temperatures. Furthermore, in cyclic start/stop tests, ta-C coatings have been proven to possess excellent low temperature cycle starting performance when lubricated by low-viscosity oil. A synergistic effect of the low-viscosity oil and a nanoscale adaptive tribofilm was speculated for ta-C coatings to be responsible for achieving lower friction and wear simultaneously. The lubrication adaptability of low-viscosity oil to ta-C coating is technologically important and provides a high potential of industrial application for lubrication and wear prevention under actual conditions.

Extrusion limit diagram can be used to locate available deformation conditions for materials. The developed extrusion limit diagram of IN 690 (Inconel 690) tube was constructed through a new method by integrating analytic method, FE simulation and hot processing map. Extrusion force limit curve determined by the maximum extrusion pressure of the extruder, and temperature limit curve defined by the melting temperature of the material, which are two conventional curves for extrusion limit diagram, were obtained through FE simulations. Based on the hot processing map, high power dissipation efficiency limit curve calculated through analytical equations was firstly employed to construct the developed extrusion limit diagram. The overlap of reasonable regions bounded by these curves not only ensures smooth extrusion process, but also guarantees qualified products. Given that some special conditions were verified through FE simulations and one condition was validated through the on-site testing, the optimum region on the extrusion limit diagram is thus authentic and practical for the extrusion process of the IN 690 tube.

Purpose – The purpose of this paper is to propose a hybridization numerical method to solve the plastic deformation of metal working based on the flow function method and meshless method. Design/methodology/approach – The proposed method is named as flow function-element free Galerkin (F-EFG) method. It uses the flow function as the basic unknown quantity to get the basic control equation, the compactly supported approximate function to establish a local approximate flow function by means of moving least square approximation, and the element free Galerkin (EFG) method to solve variational equation. The F-EFG method takes the upper limit method essence of flow function method, and the convergence, stability, and error characteristics of EFG method. Findings – The steady extrusion process of the axisymmetric extrusion problems as well as the extrusion deformation law and main field variables are subjects in the modeling and simulation analysis using F-EFG method. The results show that the F-EFG method has good computational efficiency and accuracy. Originality/value – The F-EFG method proposed in this paper has the advantages of high-solution precision of flow function method and large deformation solution of element free method. It overcomes the difficulties in global flow function establishment in flow function method and low-solution efficiency in element free method. The method is beneficial to the development of flow function method and element free method.

Hydrodynamics of core shooting process is simulated using a computational fluid dynamics model. The model is established based on the Eulerian–Eulerian formulation of a two-fluid model in which a frictional-kinetic constitutive model is incorporated. Both the kinetic stress and the frictional stress are considered in this model. A hyperbolic tangent function is chosen to provide a smooth transition between the kinetic regime and the frictional regime. Experiments are carried out to validate the model and the comparison of the predicted flow behaviour and the pressure curves shows good agreement with the experimental observations. The simulation results indicate that the frictional stress has a significant influence on the flow behaviour of sand and that the frictional-kinetic constitutive model can be well applied to model the core shooting process.

Fluorescent PEGylation agents have been facilely synthesized through the Hantzsch reaction. Different from other methods, a protein reactive group has been linked at the PEG chain ends through a Hantzsch ester, which is inherently fluorescent, to in situ generate fluorescent protein-reactive PEGs. Therefore, after conjugation with a protein, the multifunctional polymers can not only act as a protective umbrella to the protein like normal PEGylation agents, but also introduce new functions to the protein conjugates to achieve multifunctional protein conjugates. The multifunctional protein conjugates are directly visible under UV and retain nearly intact bioactivity, preliminarily suggesting the new application of the ‘old’ Hantzsch reaction in other areas (polymer chemistry, chemical biology) outside organic chemistry.

Biochar, a carbon-rich material formed by a biomass pyrolyzed at relatively low temperatures (≤700 °C), showed attractive sorption capacity on both organic pollutants and heavy metals and wildly used in various areas of environmental engineering. However, polycyclic aromatic hydrocarbons (PAHs) may also be assumed to be produced for the oxygen-limited pyrolysis condition in biochar production process. It is not well known about the affect of particle size in concentration and distributing characteristic of PAHs of biochar. In the current study, twenty-seven PAHs concentration in maize straw biochar produced with different powder particle size (9.31, 20.26, 60.77, 71.07, 101.9 μm) were quantified, and the ∑ 27 PAHs, total LMW PAHs, total MMW PAHs and total HMW PAHs concentration were analyzed. As the particle size increase, the ∑ 27 PAHs concentrations show a trend of firstly increase and then decrease, and the maximum appears at 60.77 μm (166.52 ng/g) and the minimum appears at 101.90 μm (14.63 ng/g). LMW total PAHs and total MMW PAHs concentrations firstly increase and then decrease, with the particle size increasing from 9.31 μm to 101.9 μm. Meanwhile, the total HMW PAH concentrations decrease gradually when biochar particle size increasing. Compared to US, UK background soil concentrations and Canada standards, it is appropriate to conclude that PAHs in straw biochar have minimal effects after application to soil especially at 101.9 μm.

In this study, we prepared a highly efficient PE coated mesh by simply using recycled PE gloves as raw materials. This mesh showed high separation efficiency and large flux when separating water from different types of oil/water mixtures. It also exhibited excellent stability and maintained high hydrophobicity and super-oleophilicity properties after being reused at least thirty times. In view of the advantages of this as-prepared mesh, it will contribute to reduce white pollution from used PE materials and will have wide applications in wastewater treatment utilizing oil/water separation.

Core shooting process plays a decisive role in the quality of sand cores, and core box vents distribution is one of the most important factor determining the effectiveness of core shooting process. In this paper, the influence of core box vents distribution on the flow dynamics of core shooting process was investigated based on in situ experimental observations with transparent core box, high-speed camera and pressure measuring system. Attention was focused on the variation of both the flow behavior of sand and pressure curves due to different vents distribution. Taking both kinetic and frictional stress into account, a kinetic-frictional constitutive model was established to describe the internal momentum transfer in the solid phase. Two-fluid model (TFM) simulation was then performed and good agreement was achieved between the experimental and simulated results on both the flow behavior of sand and the pressure curves. It was found that vents distribution has direct effect on the pressure difference of different locations in the core box, which determines the buoyancy force exerting on the sand particles and significantly influences the filling process of core sand.

Continuous rolling technology of seamless steel pipe is the leading technology in the production of steel pipes in recent years. However, due to the complicated pipe rolling process, the rolling parameters must be adjusted according to the rolling conditions after many trials of rolling. This paper focuses on a Φ180mm retained mandrel pipe mill, and the continuous rolling process finite element analysis model of seamless steel pipe is established by using ABAQUS software. The finite element model is validated by the measured wall thickness and pipe diameter data of industrial production, and the model is designed to reveal the evolution of rolling pressure distribution, metal flow, strain, wall thickness and pipe diameter during the continuous rolling process. The simulation results support key structural design of the rolling mill, the determination of rolling process parameters and the optimization of process parameters in engineering commissioning.

The elastic constants, ideal strength, band structure and electronic density state of Fe and B2 under tension and compression were studied by using the first principle. The structural parameters calculated at 0 pressure are consistent with the experimental results. The dependence of elastic constant and stress can be obtained by using static finite strain technique. The ideal tensile and compressive strength of Fe and B2 were studied by calculating the stress-strain relationship. At last, the micro mechanism which affects the stability of the structure was analyzed by using the results of electronic structure calculation. The results show that the compressive strength of Fe and B2 structure is higher than the tensile strength. When the stress of cell structure exceeds a limit, it will be destroyed, resulting in the sudden decrease of Poisson’s ratio, B and G, the asymmetry of energy band structure and the decrease of electron density of state energy.

Al3BC has been proved to be a promising candidate as the reinforcement for Al alloys. However the deformation behavior and strengthening mechanisms remain unclear hitherto. In this work, the deformation behavior and strengthening mechanisms of Al3BC/Al composites were investigated via in-situ micropillar compression. Wrinkled slip bands and slip homogenization were observed in the composites instead of large parallel slip bands in pure Al. The interaction between Al3BC and dislocations was investigated in this work. Microstructural characterization reveals that the high density dislocations and Al3BC-induced ultrafine sub-grains determine its excellent strengthening effects on Al matrix.

The effect of substrate on metallographic corrosion of cladding in stainless/carbon steel bimetal plate is investigated in this paper. The metallographic observation results show that the presence of substrate (carbon steel) would lead to the over-corrosion of stainless steel grain boundary, interfering with the metallographic observation results of stainless steel. The over-corrosion of stainless steel grain boundary could be attributed to the iron ion released from carbon steel. The excessive iron ion would enlarge the difference of iron ion concentration between etchant and stainless steel grain boundary, forming the concentration cell. The concentration cell would promote the localized corrosion of stainless steel, aggravating the corrosion degree of stainless steel.

Al3BC has been proved to be a promising candidate as reinforcement of Al alloy. In this work, Al3BC reinforced 6061 Al composites were in-situ fabricated through a liquid-solid reaction method followed by hot extrusion, and the micromechanical properties as well as deformation behavior of the composites were investigated via micropillar compression. The Al3BC/6061 composites show a significant improvement of compression strength than the matrix alloy, indicating an outstanding strengthening effect of Al3BC. Compared with the large parallel local slip bands on the post-compressed pillars of unreinforced matrix materials, the wrinkled slip bands were observed and homogenously distribute on the post-compressed pillars of the composites, indicating an impeding effect on the propagation of slip bands and a better slip homogenization caused by Al3BC particles. The strengthening mechanisms were also discussed and microstructural characterizations reveal that the high strength of the composites is mainly attributed to its high dislocation density, grains refinement and load transfer effects caused by Al3BC.

Drastic flatness changes in high-strength steel strips during water quenching cause problems for both their subsequent manufacture and final products. In this work, a temperature–microstructure–stress coupled finite element model is established to simulate the quenching process of cold-rolled high-strength steel strips using a UMAT subroutine in ABAQUS. The evolution mechanisms of two main forms of flatness defects, including C warping defect and edge wave defect, are investigated. Our simulations reveal that the temperature gradients of the strips induce their extension differences along transversal/thickness direction and the sequential phase transformation, both of which finally cause the flatness changes. Furthermore, flatness control strategies are proposed according to the integrated effects of the tension and initial temperature differences during quenching. In addition, quenching experiments are implemented to validate the numerical results.

The rotation-traction (RT) manipulation is an effective therapeutic technique for cervical spondylosis in traditional china medicine (TCM). However, the physicians have little opportunities to practice. In order to solving this problem, the concept of RT manipulation training robot is proposed. The robot can be a replacement for patient and assist physicians to practice the manipulation. The neck part of the robot is simulated by a two degree of freedom (DOF) platform and the impedance control is applied to simulate the behaviors of human neck. The spine part is simulated by a variable stiffness structure. In this paper, the structure of the robot is presented, and the control strategy and the detailed design principle are given. The prototype of the robot is manufactured, and experiment results show that the robot can effectively assist the physician to practice the RT manipulation, which can provide a feasible scheme for the RT manipulation training robot.

Food waste water is one of the most urgent environmental problems for the close connection between food and our daily life. Herein, we use a simple hydrothermal method to prepare a highly efficient catalyst-CeO

A highly reactive thiourea-contained polycondensate, poly(dihydropyrimidin-2(1H)-thione) (poly(DHPMT)) has been facilely synthesized via the Biginelli polycondensation using thiourea and a difunctional compound containing benzaldehyde and β-keto ester groups as monomers. The thiourea moiety in the polymer structure has similar reactivity as the thiourea, thus the poly(DHPMT) is an excellent polymer precusor for preparing new functional polymers through the postpolymerization modification (PPM) strategy. After simple reaction with functional haloalkanes, the parent poly(DHPMT) could be almost completely converted (>99%) to daughter polymers containing alkene or alkyne side groups. Then, the daughter polymers have been further transferred to granddaughter polymers through another PPM via thiol–ene or Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reactions. Besides, when 3-phenylpropargyl chloride was used as the reactant, a bright yellow fluorescent polymer could be simply achieved due to the in situ f...

How to control surface roughness of steel strip in a narrow range for a long time has become an important question because surface roughness would significantly influence the appearance of the products. However, there are few effective solutions to solve the problem currently. In this paper, considering both asperities of work roll pressing in and squeezing the steel strip, two asperity contact models including squeezing model and pressing in model in a two-stand temper mill rolling are established by using finite element method (FEM). The simulation investigates the influences of multiple process parameters, such as work roll surface roughness, roll radius and roll force on the surface roughness of steel strip. The simulation results indicate that work rolls surface roughness and roll force play important roles in the products; furthermore, the effect of roll force in the first stand is opposite to the second. According to the analysis, a control method for steel strip surface roughness in a narrow range for a long time is proposed, which applies higher work roll roughness in the first stand and lower roll roughness in the second to make the steel strip roughness in a required narrow range. In the later stage of the production, decreasing the roll force in the first stand and increasing the roll force in the second stand guarantee the steel strip roughness relatively stable in a long time. The following experimental measurements on the surface topography and roughness of the steel strips during the whole process are also conducted. The results validate the simulation conclusions and prove the effect of the control method. The application of the proposed method in the steel strip production shows excellent performance including long service life of work roll and high finished product rate.

A novel multicomponent system has been constructed through the combination of Hantzsch reaction and reversible addition-fragmentation chain transfer (RAFT) polymerization in a one-pot manner. Compared to traditional stepwise methods, this one-pot system exhibits much more advantages to facilely and efficiently prepare well-defined poly(1,4-dihydropyridine)s (poly(1,4-DHP)s). A series of poly(1,4-DHP) derivatives have also been successfully prepared through this Hantzsch-RAFT system using different aldehydes as reactants, suggesting this system is a general and versatile approach to prepare well-defined functional polymers with 1,4-DHPs as side groups. Since 1,4-DHP derivatives are an important class of bioactive molecules in the pharmaceutical field, this simple method to prepare poly(1,4-DHP)s might have potential to prepare related functional polymers for biological and pharmaceutical applications.

The reactions for polymer synthesis should be simple and efficient using easily available raw materials. A new difunctional monomer containing benzaldehyde and beta-keto ester groups (monomer AB) has been successfully prepared on a medium scale, and the corresponding poly(dihydropyrimidin-2(1H)-one)s (DP ∼84) can be synthesized via the Biginelli polycondensation in a short time (∼1 h). The in situ generated polycondensates could glue two metal sheets, demonstrating an interesting metal bonding property which cannot be observed in small molecules. The optimized multifunctional monomers (AB2, A2B2 monomers) were subsequently used for the in situ polycondensation between metal sheets, and metal bonding strength could be improved to the similar level of commercial cyanoacrylate glue. Since the monomers could be easily prepared on a large scale and the polymerization could be simply performed, the Biginelli polycondensation might have potential as a new strategy to synthesize new functional polymers.

The decontamination of various pollutants including oils, organic dyes, and surfactants from water is an unprecedented issue throughout the world. A facile filtration process for in situ multifunctional water purification by employing a low-cost and easy-made catechol-polyethylenimine (PEI) nanocomposite deposited membrane has been designed. In combination with the intrinsic hydrophilicity of amino-rich groups, the resultant membrane possesses superhydrophilicity and underwater superoleophobicity, which is simultaneously advantageous for capturing anionic pollutants due to the electrostatic interaction. Such membrane can be successfully used for sundry surfactant-stabilized oil-in-water emulsions separation and pH-controllable removal of water-soluble dyes and the remaining surfactants at the same time. The excellent characteristics, i.e., fabrication protocol that is easy to scale up, better alkaline resistance, selectively controllable removal ability of anionic dyes, and surfactants with unaltered adsorption performance over 30 consecutive adsorption-desorption-washing cycles, will facilitate its versatility and practicability in environmental remediation and wastewater purification.

The deformation behavior of IN 028 alloy in the temperature range of 950–1150 °C and strain rate range of 0.01–30 s−1 has been studied using processing maps by isothermal hot compression tests. The power dissipation efficiency and instability parameter were evaluated with temperature and stain rate. The power dissipation map reveals that two domains of fine dynamic recrystallization (DRX) exist at the (i) temperature 950–1050 °C and strain rate 0.01 s−1 with its peak efficiency of 50%; (ii) temperature 1150 °C and strain rate 1 s−1 with its peak efficiency of 36%, with activation energy of 150 kJ/mol. The instability domain of flow behavior can also be recognized at the strain rate more than 1 s−1 at lower temperature and strain rate more than 10 s−1 at high temperature. The optimum hot working conditions for the superalloy IN 028 are suggested based on the processing map. The characteristic microstructures predicted from the processing map agreed well with the results of microstructural observations.

The interfacial fracture behavior of a stainless/carbon steel bimetal plate in a uniaxial tensile test was investigated in this paper. The ultrasonic C-scan results showed that the internal fracture had already appeared in the necking area before the tensile sample snapped, and the internal fracture occurred in the middle of the necking area and propagated with the tensile strain increase. The fractography showed that the internal fracture occurred at the interface between the diffusion layer and carburization stainless steel. The contribution of the internal stress to the interface fracture was analyzed by finite element method. The FEM results showed that, due to the different material mechanical properties, the large stress difference between the diffusion layer and the carburized stainless steel induced the interface shear stress. The shear stress value was related to the location and tensile strain, and when the stress difference was larger than 500 MPa, the interface would crack. Keywords: Bimetal plate, Ultrasonic C-scan, Fracture analysis, Stress difference, Interface shear stress

The interfacial fracture morphologies of stainless steel clad plates, dividing into stainless steel layer, diffusion layer and carbon steel layer, after uniaxial tension loading are investigated. It is found that the fractures occur randomly along the interface line between the stainless steel and diffusion layers, which could be induced by the stress concentration effect. The relatively high ductility of the carbon steel reduces the stress concentration to avoid the possible generation of the interfacial fracture in its layer. Furthermore, the bonding forces between the stainless steel and diffusion layers determine the distribution of the fractures. High bonding force could retain the interface without fracture, while the fractures would occur in the domains with low bonding force. This work deepens the failure mechanism of the stainless steel clad plates and is useful in the safety evaluation in their applications.

The purpose of this paper is to present orientation estimation for small unmanned aerial vehicle (SUAV). An extended Kalman filter with adaptive PR (P denotes the estimation error covariance matrix, and R denotes the measurement noise covariance matrix) is designed to estimate orientation by sensors of gyroscope, accelerometer, and magnetometer integrated in Micro Electronic Mechanic System-based heading reference systems. Since ferromagnetic materials or other magnetic fields near the magnetometer disturb the measurement of local earth magnetic field and the external forces which produce maneuvering acceleration effect the measurement of gravity by the accelerometer, the orientation estimation is disturbed. Accordingly, the error equations of sensors are established using a current statistical model, and then the extended Kalman filter with adaptive PR with 12 state variables is designed. In the filter, the orientation error, gyroscope offset error, magnetic disturbance error, and maneuvering acceleration error are estimated. The swing experiment in hand with the magnetic disturbance and small maneuvering acceleration, and flight experiment for SUAV with the magnetic disturbance and large maneuvering acceleration, are developed. The compensation results show that the orientation is accurately calculated with disturbances. A new methodology for the orientation estimation is proposed, which could also be considered for other special application such as the robot on the ground and the autonomous underwater vehicles. This paper provides a novel realization method for accurate orientation estimation for SUAV. The method can be applied in many applications with a simple hardware.

Commercially pure titanium (CP Ti) sheets show typical planar anisotropy due to the inherently crystallographic texture and manufacturing process. To characterize the planar anisotropic behaviors of CP Ti sheets in the forming process, uniaxial tensile tests of TA0 sheets were performed along rolling, transverse, and diagonal directions at room temperature; corresponding stress–strain curves and Lankford coefficients were obtained. Based on Hill’48 and Barlat’89 yield functions, the planar anisotropy of TA0 sheets was investigated. In order to verify the accuracy of two models, we compared the experimental and predicted values of yield stress and Lankford coefficients. It reveals that Barlat’89 criterion with M = 10 is good agreement with experimental data, and the obtained function can be used in simulation of forming process. The planar anisotropy of TA0 sheets was investigated by Hill’48 and Barlat’89 yield functions. The comparison of experimental and predicted normalized yield stress (σ θ/σ 0) distribution shows that Barlat’89 criterion with M = 10 is good agreement with experimental data. The obtained Barlat’89 yield criterion can be used in the simulation of forming process.

For the deficiencies of traditional stress detection methods for steel strips in industrial production, this paper proposes a non-contact stress detection scheme based on the magnetoelastic effect. The theoretical model of the transmission-type stress detection is established, in which the output voltage and the tested stress obey a linear relation. Then, a stress detection device is built for the experiment, and Q235 steel under uniaxial tension is tested as an example. The result shows that the output voltage rises linearly with the increase of the tensile stress, consistent with the theoretical prediction. To ensure the accuracy of the stress detection method in actual application, the temperature compensation, magnetic shielding and some other key technologies are investigated to reduce the interference of the external factors, such as environment temperature and surrounding magnetic field. The present research develops the theoretical and experimental foundations for the magnetic stress detection system, which can be used for online non-contact monitoring of strip flatness-related stress (tension distribution or longitudinal residual stress) in the steel strip rolling process, the quality evaluation of strip flatness after rolling, the life and safety assessment of metal construction and other industrial production links.

Aiming to solve the worldwide challenge of stabilized oil-in-water emulsion separation, a PAM-PDVB decorated nylon membrane is fabricated via a facile solvothermal route in our group. The main composition is PAM, while the PDVB plays a role as cross-linker in order to improve the interaction between the polymer and the substrate. By the combination of the superhydrophilic and underwater superoleophobic wettability of the PAM polymer with the micropore size of the substrate, the as-prepared material is able to achieve the separation of various stabilized oil-in-water emulsions including cationic type, nonionic type, and anionic type. Compared with previous works, the emulsions used in this case are more stable and can stay for several days. Besides, the solvothermal method is facile, cost saving, and relatively environmentally friendly in this experiment. Moreover, the PAM-PDVB modified membrane exhibits excellent pH stability, recyclability, and high separation efficiency (above 99%), which can be scaled up and used in the practical industrial field.

T3-induced Xenopus metamorphosis is an ideal model for detecting thyroid hormone (TH) signaling disruption of chemicals. To optimize the T3-induced Xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for T3 induction. Xenopus laevis at stage 52 were exposed to series of concentrations of T3 (0.31–2.5 nmol/L) for 6 days. By comparing morphological changes induced by T3, we propose head area, mouth width, unilateral brain width/brain length, and hindlimb length/snout-vent length as quantitative parameters for characterizing T3-induced morphological changes, with body weight as a parameter for indicating integrated changes. By analyzing time-response curves, we found that following 4-day exposure, T3-induced grossly morphological changes displayed linear concentration–response curves, with moderate morphological changes resulting from 1.25 nmol/L T3 exposure. When using grossly morphological endpoints to detect TH signaling disruption, we propose 4 days as exposure duration of T3, with concentrations close to 1.25 nmol/L as induction concentrations. However, it is appropriate to examine morphological and molecular changes of the intestine on day 2 due to their early response to T3. The quantitative endpoints and T3 induction concentrations and durations we determined would improve the sensitivity and the reproducibility of the T3-induced Xenopus metamorphosis assay.

Chiral structures have many technologically significant applications in engineering. In this paper, we investigate, both theoretically and experimentally, the structural transformation from a symmetric X-shaped tensegrity to a chiral structure under uniaxial tension. When the applied tensile force exceeds a critical value, the initially achiral structure would exhibit snap-through buckling. At the critical state, the in-plane deformation mode of the tensegrity switches into an off-plane one. The critical condition of the structural transformation is provided in terms of structural parameters. An experiment was performed to validate the theoretical model. This work may not only deepen our understanding of the stability of tensegrities but also help design chiral structures for engineering applications.

The hot deformation behavior of IN690 superalloy was characterized in a temperature range of 1273–1473 K and a strain rate range of 0.01–10 s−1 using uniaxial compression tests on process annealed material. The constitutive relations between flow stress and effective strain, effective strain rate as well as deformation temperature were studied. It can be concluded that the flow stress significantly reduces with the deformation temperature of IN690 superalloy increasing. Whereas, there is a significant increase of flow stress when the strain rate increases from 0.1 s−1 to 10 s−1. Based on the hyperbolic-sine Arrhenius-type equation, a constitutive equation considering compensation of strain was developed. The activation energy and the material constants (Q, n and ln A) decrease as the deformation strain increases. The strain dependent term is successfully incorporated in the constitutive equation through a quartic equation. A good agreement between the experimental data and the predicted results has been achieved, indicating that the proposed constitutive equation and the methods of determing the material constants are suitable to model the high temperature deformation behavior of IN690 superalloy.

The interfacial bonding process and mechanical properties of AISI (American Iron and Steel Institute) stainless steel/Q235A carbon steel were investigated by deformation bonding, heat preservation, and tensile tests. The results reveal that the deformation temperature has a beneficial effect on the bonding rate, and that the critical temperature for the large-area bonding of stainless steel and carbon steel is approximately 700 °C. However, owing to the short contact time, only a shallow diffusion of approximately 2–3 µm can be achieved. A slight decrease in the interfacial bonding rate after heat preservation is correlated to the difference between the thermal expansion coefficients of the two materials, but the thickness of the diffusion layer shows a significant increase. It was found that the strength of the composites is mostly related to the bonding rate and the strength of the relatively soft material, which can be determined using an explicit equation. Moreover, with the increase in the interfacial bonding rate, the crack source changes from the junction of the unbonded and bonded areas of the interface to the interior of the carbon steel. The failure mode evolves from cleavage brittle fracture to ductile–brittle mixed-mode fracture, and then to ductile fracture.

A novel morphology-induced TiO2 nanowire-based mesh with visible light catalytic ability and super wetting behavior is successfully fabricated by a simple hydrothermal reaction. Combined the special wettability and the excellent photoelectric property of TiO2 nanowires, such material can realize reusable oil removal and soluble dye molecules degradation under visible light within 30 s. It is believed that the special nanowire morphology reduces the bandgap of TiO2 from 3.18 to 2.07 eV, and the composite of Cu(OH)2 substrate provides the material with higher light absorption efficiency, changing the catalytic degradation condition of dye from original UV light to visible light. Such material expands the application of traditional semiconductor oxide, owns outstanding prospect to be used in industrial wastewater treatment and drinking water purification, and provides a brand new method for combining catalytic and environmental chemistry.

No matter what the flatness of a strip is, flat or defective, at an annealing furnace entrance, the strip can not keep its original shape and a remarkable change of its shape can be seen at the annealing furnace exit. By inves tigating this phenomenon at the 2030 mm continuous annealing line which belonged to Baosteel, a finite element model of thermo-mechanical buckling deformation of strips in a continuous annealing furnace were established, and the mechanism of flatness changing and the contributing factors were researched by the finite element software ANSYS.

Research into plate elongation distribution between the tension leveler and temper mill for pickling line 2030 at Baosteel is conducted. The study, which involved performance testing of mechanics, is designed at different elongation distributions and analyzed from many aspects. Finally, the optimal elongation of the tension leveler and temper mill is given.

This paper reported the utilization of water spray for controlling H2S release in a confined space, which is especially important in industry. A typical spray tower was modified to simulate the confined space for people's enterable routine operation (e.g., pump room), in which the dilution capacity of water sprays can also be evaluated. This work consists of two parts: the first part focuses on the influences of different operating conditions on chemical dilution capacities of water sprays in mechanisms; the second one is comparison between two nozzle configurations for evaluating their feasibilities of practical application. Water sprays express eligible performance for H2S release control even though their dilution capacity was weakened at high gaseous concentrations and rates of releases. The presence of Na2CO3can significantly improve absorption effectiveness of H2S in water and the optimal Na2CO3additive was found to be 1.0 g·L−1in this test. Compared with Na2CO3, adjusting water flow rate may be an effective strategy in enhancing dilution capacity of water sprays due to the fact that larger flow rate led to both less dilution time (TD) and dilution concentration (CD). Furthermore, multinozzle configuration is more efficient than single-nozzle configuration under the same water consumption.

Reforming local government organizations is of decisive significance. Reform at the local level is not only affected by the exemplary role of the central government organization reform, but also has its own special background and contents. Reforming local governments is a greater challenge than reforming the central government as there usually are few posts offered by local govemments at lower levels or few private companies in the small cities and lawns of China with the capacity to absorb the downsized government employees. Beijing. Zhejiang, Liaoning, Sichuan, Guangdong, and others have made valuable explorations into the formidable task of reform, and each city has accumulated a wealth of experiences.

To investigate the impact of occupational stress on serum monoamine neurotransmitters in nurses.A total of 131 nurses were included as study subjects by stratified cluster sampling. The occupational health information collection system (based on the Internet of things) was used to measure occupational stress. Serum levels of monoamine neurotransmitters were also measured.Epinephrine (E) was negatively correlated with superior support (P0.05) and colleague support (P0.05). Negative correlation was also found between dopamine (DA) and job prospect (P0.05). Level of 5-hydroxytryptamine was negatively correlated with promotion opportunities (P0.05). Norepinephrine (NE), E, and DA were all negatively correlated with work satisfaction (P0.05) and positively correlated with daily stress (P0.01). NE and E were negatively correlated with sufficient confidence (P0.05) and positively correlated with physical complaints (P0.01). There was a negative correlation between NE and psychological satisfaction (P0.05).Occupational stress in nurses is correlated with serum monoamine neurotransmitters, and it may affect serum levels of monoamine neurotransmitters to a certain extent.

To investigate the effect of occupational stress on the oxidation/antioxidant capacity in nurses.A total of 131 nurses were included as study subjects. The occupational health information collection system (based on the Internet of things) was used for measurement of occupational stress. Levels of hydroxyl free radicals and antioxidant enzymes were determined.The serum level of superoxide dismutase (SOD) was the highest in nurses under the age of 30 and the lowest in those over 45 (P0.05). The serum levels of glutathione peroxidase (GSH-Px) and peroxidase (POD) were the highest in nurses of working age less than 5 years, followed by those of 5-15 years, and nurses with more than 25 years' working experience showed the lowest GSH-Px and POD levels (P0.05). Furthermore, nurses with a university (college) degree had a higher GSH-Px level and a lower POD level compared with those with junior and senior high school degrees (P0.05). Job prospects and job control were positive occupational stress factors for SOD. Job hazards were negative occupational stress factors for POD. Psychological satisfaction was negative occupational stress reaction for hydroxyl free radicals. Calmness was positive occupational stress reaction for SOD, and daily stress was a negative one. The positive occupational stress reactions for GSH-Px were psychological satisfaction and job satisfaction, and daily stress was negative reaction.Nurses with higher occupational stress have stronger oxidation and weaker antioxidant capacity, which intensifies oxidant-antioxidant imbalance and leads to oxidative stress damage.

A mixed H 2 /H ∞ guaranteed cost control approach is presented in this paper to improve the head and tail strip thickness accuracy in the first stand of a tandem cold rolling mill during steel rolling process, it is very difficult to maintain a good thickness accuracy and tension stability in an unsteady state for various disturbances and uncertainties. The mixed H 2 /H ∞ guaranteed cost controller can guarantee both the stability of tension control and the high degree of accuracy in gauge control. The simulation results show that the accuracy of strip thickness and the stability of strip tension can be improved compared to the conventional industrial control.