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Background: Ferroptosis is associated with cancer initiation and progression. However, the molecular mechanism and prognostic value of ferroptosis-related genes in lung squamous cell carcinoma (LUSC) are poorly understood. Methods: The mRNA expression profiles, methylation data, and clinical information of patients with LUSC were downloaded from TCGA and GEO database. Ferroptosis-related differentially expressed genes (DEGs) were identified between cancerous and non-cancerous tissues, and their prognostic value was systemically investigated by bioinformatic analyses. Results: A ferroptosis-related gene signature (ALOX5, TFRC, PHKG2, FADS2, NOX1) was constructed using multivariate Cox regression analysis and represented as a risk score. Overall survival (OS) probability was significantly lower in the high-risk group than in the low-risk group (P Conclusions: A ferroptosis-related gene signature was constructed to predict OS probability in LUSC. This could facilitate novel therapeutic methods and guide individualized therapy.

Structural design of composite shells are more challenging than conventional metals due to the complex mechanical behavior and damage mechanisms which composite materials exhibit. Postbuckling analysis for a moderately thick anisotropic laminated cylindrical shell subjected to combined loadings of external pressure and axial compression is presented which extends the boundary layer theory of shell buckling. The governing equations are based on Reddy’s higher order shear deformation shell theory with von Karman-Donnell-type of kinematic nonlinearity. Both nonlinear prebuckling deformations and initial geometric imperfections of the shell are taken into account. A two-step singular perturbation method is used to determine interactive buckling loads and postbuckling equilibrium paths. A verification study is conducted, and the validity of the formulation is established through comparison with results of nonlinear finite element software such as ABAQUS®. The internal physical mechanism of the shell geometric parameters on the buckling load and the postbuckling equilibrium path is obtained. The numerical illustrations concern the postbuckling response of perfect and imperfect, moderately thick, anisotropic laminated cylindrical shells with different load-proportional parameters. The analytical model can provide an effective tool to investigate postbuckling of composite shell structures .

This paper investigates the small- and large-amplitude vibrations of thermally postbuckled carbon nanotube-reinforced composite (CNTRC) beams resting on elastic foundations. For the CNTRC beams, uniformly distributed (UD) and functionally graded (FG) reinforcements are considered where the temperature-dependent material properties of CNRTC beams are assumed to be graded in the thickness direction and estimated through a micromechanical model. The motion equations are derived based on a higher order shear deformation beam theory with including the beam-foundation interaction. The initial deflection caused by thermal postbuckling is also included. The numerical illustrations concern small- and large-amplitude vibration characteristics of thermally postbuckled CNTRC beams under uniform temperature field. The effects of carbon nanotube (CNT) volume fraction and distribution patterns as well as foundation stiffness on the vibration characteristics of CNTRC beams are examined in detail.

A design of semi-submersible platform is mainly based on the extreme response analysis due to the forces experienced by the components during lifetime. The external loads can induce the extreme air gap response and potential deck impact to the semi-submersible platform. It is important to predict air gap response of platforms accurately in order to check the strength of local structures which withstand the wave slamming due to negative air gap. The wind load cannot be simulated easily by model test in towing tank whereas it can be simulated accurately in wind tunnel test. Furthermore, full scale simulation of the mooring system in model test is still a tuff work especially the stiffness of the mooring system. Owing to the above mentioned problem, the model test results are not accurate enough for air gap evaluation. The aim of this paper is to present sensitivity analysis results of air gap motion with respect to the mooring system and wind load for the design of semi-submersible platform. Though the model test results are not suitable for the direct evaluation of air gap, they can be used as a good basis for tuning the radiation damping and viscous drag in numerical simulation. In the presented design example, a numerical model is tuned and validated by ANSYS AQWA based on the model test results with a simple 4 line symmetrical horizontal soft mooring system. According to the tuned numerical model, sensitivity analysis studies of air gap motion with respect to the mooring system and wind load are performed in time domain. Three mooring systems and five simulation cases about the presented platform are simulated based on the results of wind tunnel tests and sea-keeping tests. The sensitivity analysis results are valuable for the floating platform design.

Buckling of composite riser assumed beam structure is one of numerous engineering challenges in deep water pipeline design. Thermal postbuckling analysis of shear deformable anisotropic laminated composite beams with tubular cross-section subjected to uniform, linear and non-linear temperature distribution through the thickness resting on a two-parameter elastic foundation is presented. The material of each layer for the composite beam with tubular section is assumed to be linearly elastic and fiber-reinforced. The governing equations are introduced by using high-order shear deformation beam model with a von Karman-type of kinematic nonlinearity. Composite beams with clamped–clamped, clamped–hinged, and hinged–hinged boundary conditions are considered. A numerical solution for nonlinear partial-integral differential form in terms of the transverse deflection by using Galerkin׳s method is employed to determine the buckling temperatures and postbuckling equilibrium paths of anisotropic laminated beams with different types of temperature distribution through the thickness. The numerical illustration concern the thermal postbuckling response of laminated beams with different types of boundary conditions, ply arrangements (lay-ups), geometric and physical properties. The results reveal that the geometric and physical properties, temperature dependent properties, initial geometry imperfection, boundary conditions and elastic foundation have a significant effect on thermal postbuckling behavior of anisotropic laminated composite tubular beams.

This paper presents a novel type of cylindrical cellular shell with bidirectional negative stiffness (NS) metamaterial cores. The unit cell is composed of a trapezoidal frame and four cosine-shaped curved walls, therefore showing NS effect in both the circumferential and radial directions. Numerical analyses are conducted to investigate the mechanical properties, including the quasi-static behavior under radial compression and the sound transmission loss (STL) performance under an outward radiation wave within a wide frequency range. The acoustic performance is compared with those of cylindrical shells with annular hexagonal and re-entrant honeycomb cores. The NS-core and honeycomb-core cylindrical cellular shells are with the same outline dimensions and overall weight. Parametric studies of the STL on the thicknesses of the curved cell walls and the weight of mass inclusions are performed, followed by optimizations with the purpose of maximal averaged STL in two specified frequency ranges. It was found that the NS-core cylindrical shell yielded much higher STL than those honeycomb-core cylindrical shells for frequencies larger than about 200 Hz. Furthermore, the averaged STLs of the optimized designs increased by 123.7% and 39.5% for the two ranges, respectively. The results indicate that the proposed shell is not only able to endure large strain due to elastic instability, but also isolates sound waves under the very small sound-induced deformation. This design provides an alternative to the conventional core types in cellular structures by showing abundant designability and desirable structural and vibro-acoustic characteristics.

A design of offshore floating structure is mainly based on the extreme response analysis due to the forces experienced. The extreme response can induce the negative air gap response and potential impact to the deck bottom of floating structure. It is important to predict the slamming load in order to check the strength of local structures which withstand the wave slamming. In recent years, studies of the effects of wind load on air gap response and slamming load are ignored. When the platform suffers the extreme wave, the wind is also harsh. Moreover, the wind load can affect the motion response of the platform. The wind load cannot be simulated easily by model test in towing tank whereas it can be simulated accurately in wind tunnel test. Though the model test results are not accurate enough for air gap and slamming load evaluation due to the loss of wind effect, they can be used as a good basis for tuning the radiation damping and viscous drag in numerical simulation. This paper aims at presenting the sensitivity analysis results of wave slamming load with respect to the wind load for the design of semi-submersible platform. As an example of semi-submersible drilling platform design, the wind tunnel test has been carried out, and the sea-keeping model test is also performed in towing tank, while the wind load effect is ignored. According to the model test results, a numerical model is tuned and validated by ANSYS AQWA. Sensitivity analysis studies of the relative velocity between water particle and platform surface and the wave slamming load with respect to the wind load are performed in time domain by the tuned numerical model. Five simulation cases about the presented platform are simulated based on the results of wind tunnel tests and sea-keeping tests. The sensitivity analysis results are valuable for the floating platform design.

A large amplitude flexural vibration of a hybrid laminated beam resting on an elastic foundation in thermal environments is investigated. The hybrid laminated beam is consists of fiber reinforced composite (FRC) layers and piezoelectric fiber reinforced composite (PFRC) actuators. The fiber reinforcements are assumed to be distributed either uniformly (UD) or functionally graded (FG) of piece-wise type along the thickness of the beam. The motion equations are based on a higher order shear deformation theory and von Karman strain displacement relationships. The beam-foundation interaction and thermo-piezoelectric effects are also included. The material properties of both FRCs and PFRCs are estimated through a micromechanical model and are assumed to be temperature dependent. A two-step perturbation approach is employed to determine the nonlinear to linear frequency ratios of hybrid laminated beams. Detailed parametric studies are carried out to investigate effects of material property gradient, temperature variation, applied voltage, stacking sequence as well as the foundation stiffness on the linear and nonlinear vibration characteristics of the hybrid laminated beams.

The effect of hygrothermal conditions on the linear and nonlinear free flexural vibration of anisotropic shear deformable laminated cylindrical shells is investigated. The cylindrical shell is made of fiber-reinforced composites (FRCs) with the reinforcement being distributed either uniformly (UD) or functionally graded (FG) of piece-wise type along the thickness of the shells. The motion equations are based on a higher order shear deformation shell theory with a von Karman-type of kinematic nonlinearity. The hygrothermal effects are also included, and the material properties of FRCs are estimated through a micromechanical model and are assumed to be temperature-dependent and moisture-dependent. The equations of motion are solved by a singular perturbation technique along with a two-step perturbation approach to determine the linear and nonlinear frequencies of the FRC laminated cylindrical shells. Detailed parametric studies are carried out to investigate effects of material property gradient, the temperature change, the degree of moisture concentration, shell geometric parameter, stacking sequence, as well as the end conditions on the vibration characteristics of FRC shells with polymer matrix. The results show that the temperature/moisture variation has a moderately effect on the natural frequencies of the FRC cylindrical shells, but only has a small effect on the nonlinear to linear frequency ratios of the same shell.

This paper deals with the small and large amplitude flexural vibrations of anisotropic shear deformable laminated cylindrical shells with piezoelectric fiber reinforced composite (PFRC) actuators in thermal environments. Two kinds of fiber reinforced composite (FRC) laminated shells, namely, uniformly distributed and functionally graded reinforcements, are considered. The motion equations are based on a higher order shear deformation shell theory with a von Karman-type of kinematic nonlinearity and including the extension-twist, extension-flexural and flexural-twist couplings. The thermo-piezoelectric effects are also included, and the material properties of both FRCs and PFRCs are estimated through a micromechanical model and are assumed to be temperature dependent. A boundary layer theory and associated singular perturbation technique are employed to determine the linear and nonlinear frequencies of hybrid laminated cylindrical shells. The numerical illustrations concern the cross-ply and angle-ply laminated cylindrical shells with fully covered or embedded PFRC actuators under different sets of thermal and electric loading conditions. Detailed parametric studies are carried out to investigate effects of material property gradient, temperature variation, applied voltage, shell geometric parameter, stacking sequence, as well as the shell end conditions on the linear and nonlinear vibration characteristics of the hybrid laminated cylindrical shells.

According to the example of using a common grinding and composition of parts processing movement and achievement elements, the design of construction of special NC technologies in ordinary grinding machine was formulated. . The grinding and polish-grinding were performed by using two NC systems in series to achieve multi-axis movement. The function and application scope of NC technology were expanded because the instantaneous compensation of the grinding wheel and the polish-grinding wheel were performed under a rectangular coordinate system and a polar coordinate system by using an open loop NC system. The application of surface recovery of grinding wheel by NC reconstruction and extension applications of processing the track of involute curve were referred.

numerical control system is used to control the gear hob and gear blank in autorotation and linkage generative movement, to realize the machining of teeth shape and teeth dividing; and at the same time it controls the vertical displacement of the gear hob and the horizontal displacement of gear blank, to make a circular arc track whose radius is the sum of gear blank’s radius and gear hob’s radius, thus realizing the NC machining of circular-arc aligned gear. Before and after the machining of teeth form, transition arc is used to finish the trimming and thinning of the teeth thickness at the teeth end; on the prerequisite of machining the circular-arc aligned gear, this method successfully solves the puzzle of gear chamfering, and discharges all gear burr into the lower end of the teeth. The advantage of this machining method lies in that when the hob cuts deeper, as the both side-blades are cutting the work-piece at the same time, the thinning on both sides are quite symmetrical, and the fine symmetry remains during the uniform change of the teeth thickness. So, the machining precision of the parts is prior to the requirements in the drawing, and this method yields good effect, which broadens the application of NC technology.

A postbuckling analysis is presented for a shear deformable anisotropic laminated cylindrical shell with stiffener of finite length subjected to axial compression. The material of each layer of the shell is assumed to be linearly elastic, anisotropic and fiber-reinforced. The governing equations are based on a higher order shear deformation shell theory with von Karman-Donnell-type of kinematic nonlinearity and including the extension/twist, extension/flexural and flexural/twist couplings. The ‘smeared stiffener’ approach is adopted for the beam stiffeners. This arrangement allows the beam stiffeners to be assembled directly into the global stiffness matrix. The nonlinear prebuckling deformations and initial geometric imperfections of the shell are both taken into account. A singular perturbation technique is employed to determine the buckling loads and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling response of perfect and imperfect, grid, axial, ring stiffened, and unstiffened shells. The results confirm that there exists a compressive stress along with an associate shear stress and twisting when the anisotropic shell is subjected to axial compression. The postbuckling equilibrium path is unstable for the moderately thick cylindrical shell under axial compression and the stiffened shell structure is imperfection-sensitive.

Numerical control milling machine with a special transformation can be achieved the involute path processing functions. By using Fan method to process a way to synthesize involute track requirements and involute contour processing. This method is particularly suitable for gear modulus m ≥ 12 ~ 40 of the big modulus gear machining, and omit the big modulus gear-specific complex tool manufacturing. Another advantage is that as the basic parameters of the coordinates programming trajectory calculation as a way to carry out involute trajectories run control, gears accuracy can be effective control and assurance. Furthermore, it can be revised and the edge of the involute tooth surface in the tangential connection.

Machining of the variable pitch screw is difficult in mechanical manufacturing and that of variable pitch and depth screw is more difficult.This paper argues about applying macro program to machine profiled screw in NC milling machine tool and the result is of satisfaction.This provides another method for the machining of profiled screws.

The uniformly accelerated motion in NC systems is analysed based on the constitution and realization of a uniformly accelerated motion, in order to implementing the uniformly accelerated motion, the corresponding means is explained, the conversion of program parameters is calculated, the rule of uniformly accelerated motion is analyzed and some factors, and the effect on the uniformly accelerated motion is illuminated.

The paper discusses the NC polishing and NC repairing of the arc surface with an ultra-large radius of the paper machine’s press roll. It is very difficult to polish and repair press rolls whose radius is up to several thousands of meters because it is quite beyond the range which a NC system permits. The special NC reconstruction of a machine tool and its principle and method were elaborated. In an example the accuracy of parameters conversion was calculated and related formulas were derived, and also the methods of eliminating errors and the measures to compensate errors were discussed. In view of the abrasion of the grinding (or polishing) wheel, the measure for instantaneous automatic compensation was discussed.

Radar cross section (RCS) reduction technologies are very important in survivability of the military naval vessels. Ship appearance shaping as an effective countermeasure of RCS reduction redirects the scattered energy from one angular region of interest in space to another region of little interest. To decrease the scattering electromagnetic signals from ship scientifically, optimization methods should be introduced in shaping design. Based on the assumption of the characteristic section design method, mathematical formulations for optimal shaping design were established. Because of the computation-intensive analysis and singularity in shaping optimization, the response surface method (RSM) combined genetic algorithm (GA) was proposed. The polynomial response surface method was adopted in model approximation. Then genetic algorithms were employed to solve the surrogate optimization problem. By comparison RCS of the conventional and the optimal design, the superiority and effectiveness of proposed design methodology were verified.