A novel approach of jet polishing for interior surface of small-grooved components using three developed setups

It is a challenge to polish the interior surface of an additively manufactured component with complex structures and groove sizes less than 1 mm.Traditional polishing methods are disabled to polish the component,meanwhile keeping the structure intact.To overcome this challenge,small-grooved components made of aluminum alloy with sizes less than 1 mm were fabricated by a custom-made printer.A novel approach to multi-phase jet(MPJ)polishing is proposed,utilizing a self-developed polisher that incorporates solid,liquid,and gas phases.In contrast,abrasive air jet(AAJ)polishing is recommended,employing a customized polisher that combines solid and gas phases.After jet polishing,surface roughness(Sa)on the interior surface of grooves decreases from pristine 8.596μm to 0.701μm and 0.336μm via AAJ polishing and MPJ polishing,respectively,and Sa reduces 92%and 96%,correspondingly.Furthermore,a formula defining the relationship between linear energy density and unit defect volume has been developed.The optimized parameters in additive manufacturing are that linear energy density varies from 0.135 J mm^(-1)to 0.22 J mm^(-1).The unit area defect volume achieved via the optimized parameters decreases to 1/12 of that achieved via non-optimized ones.Computational fluid dynamics simulation results reveal that material is removed by shear stress,and the alumina abrasives experience multiple collisions with the defects on the heat pipe groove,resulting in uniform material removal.This is in good agreement with the experimental results.The novel proposed setups,approach,and findings provide new insights into manufacturing complex-structured components,polishing the small-grooved structure,and keeping it unbroken.

THE INTERIOR TRANSMISSION EIGENVALUE PROBLEM FOR AN ANISOTROPIC MEDIUM BY A PARTIALLY COATED BOUNDARY

We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method.

The Non-Singular Fast Terminal Sliding Mode Control of Interior Permanent Magnet Synchronous Motor Based on Deep Flux Weakening Switching Point Tracking

This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.

Mapping the Child’s Grey Interior:Authenticity of Plague Narrative in The Great Plague

The Great Plague:The Diary of Alice Paynton,London 1665-1666 adopts the realistic painting style and direct writing to the painful experience,describes the situation of the Great Plague in London truly from the perspective of children,and breaks people’s cognitive expectation of children’s literature,the construction of children’s Gray inner world is completed behind the true description of the Great Plague in London with the true brushwork,which presents a different world of childlike innocence.Despite the importance of epidemics writing in literature,the child’s diary perspective of them is one of the least developed of Plague Narrative.Only when authenticity and the child’s grey interior are integrated will we reveal a true picture of society as it was.

Ideological and Political Integration Strategies in Interior Design Professional Courses Under the Background of Innovation and Entrepreneurship

Based on the ideological and political requirements of interior design professional courses,exploring the integrated education path of professional plus innovation and entrepreneurship requires first expanding the ideological and political content of professional introductory courses,core courses,and expanded courses.Then,we will reshape the curriculum system based on the principle of connecting professional teaching and ideological and political courses,focusing on the realistic principle of talent needs,striving for student growth,adjusting the course content,optimizing the teaching model,and transforming teaching through in-and out-of-class practice and counterpoint guidance.

Reform and Practice of Talent Training of Architectural Interior Design Professionals in Higher Vocational Skills Competition: Taking Chongqing Energy Vocational College as an Example

For higher vocational colleges,skills competition is an important indicator of professional personnel training quality.In this paper,the architectural interior design professional skills competition in Chongqing Energy Vocational College is taken as an example,the many years of teaching and competition experience are taken into account,the problems existing in the cultivation of architectural interior design professionals in higher vocational colleges are analyzed,and corresponding solutions are proposed.

Research on the Interior Decoration Characteristics of Peking Union Medical College Phase I Project

Peking Union Medical College was founded in the late Qing Dynasty and the early Republic of China.Since then,society and politics have been rapidly changing,and its architectural aesthetics reflect the idea of advocating the West and inheriting tradition.Through research and actual investigation,this paper summarizes the current status of its building from two aspects,interior decoration art and interior decoration technology,analyzes the interior decoration characteristics of Peking Union Medical College Phase I Project,and records the archives of Peking Union Medical College’s decoration technology.

Teaching Strategy of Higher Vocational Interior Design Based on “Internet Plus” Thinking

“Internet Plus”thinking has been widely adopted in the teaching of interior design in colleges and universities,and its application has significant implications that cannot be disregarded.“Internet Plus”thinking not only realizes the innovation of interior design teaching but also significantly improves the level and quality of teaching.Through an analysis of the advantages of“Internet Plus”education platform and the current situation of higher vocational interior design teaching,effective strategies for higher vocational interior design teaching based on“Internet Plus”thinking are proposed in this paper in hope that this study will contribute to the efficient development of interior design teaching activities.

The Hiding Characteristic of F-interior Hiding Image and Its Applications

By using function one direction S-rough sets,the concept of F-interior hiding image is presented; the theorem of F-interior hiding and the recognition criteria of interior hiding are proposed; and the applications of F-interior hiding image are given. F-interior hiding image is a new application area of function S-rough sets,and function S-rough sets is a new theory and new tools for iconology research.

Cluster Warhead Dispersing Technique and Its Interior Ballistic Calculation

Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. The interior ballistic performances of this system are calculated with numerical calculation method. The performances such as the pressure in the pressure chambers and the velocity of the sub missiles are obtained in curve form.

An Improved Affine-Scaling Interior Point Algorithm for Linear Programming

In this paper, an Improved Affine-Scaling Interior Point Algorithm for Linear Programming has been proposed. Computational results of selected practical problems affirming the proposed algorithm have been provided. The proposed algorithm is accurate, faster and therefore reduces the number of iterations required to obtain an optimal solution of a given Linear Programming problem as compared to the already existing Affine-Scaling Interior Point Algorithm. The algorithm can be very useful for development of faster software packages for solving linear programming problems using the interior-point methods.

Primary Study on the Artistic Value of Interior Decoration of Ancient Huizhou Folk Houses

From the creation,materials,colors and technical artistic characteristics of exterior and exterior spatial decoration,the artistic value of ancient Huizhou folk houses were analyzed.

Enlightenment of Modern Interior Design from the Interior Decoration of Ancient Huizhou Vernacular Dwellings

Through analyzing the basic structure of ancient Huizhou vernacular dwellings and the spatial order of interior decoration,this study rethought profoundly about modern interior design and put forward the inheritance of traditional methods in interior decoration.

The Application of Landscape Plants in Humanized Interior Environmental Design

Landscape plants play a role of decorating and beautifying the indoor environment.From the perspective of humanization,the functions and application patterns of landscape plants in the interior environmental design are analyzed in this study,and finally the application rules of landscape plants in the humanized interior environmental design are summarized.

Signature of helium rain and dilute cores in Jupiter’s interior from empirical equations of state

Measurements of Jupiter’s gravity field by Juno have been acquired with unprecedented precision, but uncertainties in the planet’s hydrogen–helium equation of state(EOS) and the hydrogen–helium phase separation have meant that differences remain in the interior model predictions. We deduce an empirical EOS from Juno gravity field observations in terms of the hydrostatic equation and then investigate the structure and composition of Jupiter by comparison of the empirical EOS with Jupiter’s adiabats obtained from the physical EOS. The deduced helium mass fraction suggests depletion of helium in the outermost atmosphere and helium concentration in the inner molecular hydrogen region, which is a signature of helium rain in Jupiter’s interior. The deduced envelope metallicity(the heavy-element mass fraction) is as high in the innermost envelope as 11–13 times the solar value. Such a high metallicity provides sharp support to the dilute core model with the heavy elements dissolved in hydrogen and expanded outward. No matter how the core mass is varied, the empirical EOS derived from the two-layer interior model generally suggests higher densities in the innermost envelope than does the best-fit Jupiter’s adiabat;this result is, again, a signature of dilute cores in Jupiter’s interior. Moreover, no matter the core mass,the empirical EOS is found to exhibit an inflexion point in the deep interior, around 10 Mbar, which can be explained as the combined effect of helium concentration in the upper part and dilute cores in the lower part.

Effects of interior ballistic factors on dispersion of central blast tube cluster munitions

This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube duster munitions dispersion was simulated. The state of submunitions dispersion was obtained as interior ballistic conditions changed. The effect of shell stress groove on shell opening was discussed. The shell with stree groove is helpful for submunitions dispensing effectively and uniformly. The effect of liner material on submunitions dispersing was discussed. It can be found that foam liner can reduce the interior ballistic pressure, increase the pressure action time, reduce the acceleration of the submunitions and increase the sub- munitions dispersing velocity. These results provide some reference for the theory and experiment research of the central blast tube cluster munitions dispersion.

Sound Source Localisation for a High-Speed Train and Its Transfer Path to Interior Noise

Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound source distribution of a high-speed train and presents a method for performing the contribution analysis of airborne sound with regard to the interior noise. First, both exterior and interior sound source locations of the high-speed train are identified through in-situ measurements. Second, the sound source contribution for di erent regions of the train and the relationships between the exterior and interior noises are analysed. Third, a method for conducting the contribution analysis of airborne sound with regard to the interior noise of the high-speed train is described. Lastly, a case study on the sidewall area is carried out, and the contribution of airborne sound to the interior noise of this area is obtained. The results show that, when the high-speed train runs at 310 km/h, dominant exterior sound sources are located in the bogie and pantograph regions, while main interior sound sources are located at the sidewall and roof. The interior noise, the bogie area noise and the sound source at the middle of the coach exhibit very similar rates of increase with increasing train speed. For the selected sidewall area, structure-borne sound dominates in most of the 1/3 octave bands.

Numerical simulation and optimized design of cased telescoped ammunition interior ballistic

In order to achieve the optimized design of a cased telescoped ammunition(CTA) interior ballistic design,a genetic algorithm was introduced into the optimal design of CTA interior ballistics with coupling the CTA interior ballistic model. Aiming at the interior ballistic characteristics of a CTA gun, the goal of CTA interior ballistic design is to obtain a projectile velocity as large as possible. The optimal design of CTA interior ballistic is carried out using a genetic algorithm by setting peak pressure, changing the chamber volume and gun powder charge density. A numerical simulation of interior ballistics based on a 35 mm CTA firing experimental scheme was conducted and then the genetic algorithm was used for numerical optimization. The projectile muzzle velocity of the optimized scheme is increased from 1168 m/s for the initial experimental scheme to 1182 m/s. Then four optimization schemes were obtained with several independent optimization processes. The schemes were compared with each other and the difference between these schemes is small. The peak pressure and muzzle velocity of these schemes are almost the same. The result shows that the genetic algorithm is effective in the optimal design of the CTA interior ballistics. This work will be lay the foundation for further CTA interior ballistic design.

Comparison of basic features and origins of oolitic shoal reservoirs between carbonate platform interior and platform margin locations in the Lower Triassic Feixianguan Formation of the Sichuan Basin,southwest China

The oolitic shoal reservoirs of the Lower Triassic Feixianguan Formation carbonates in the Sichuan Basin of southwest China are an important target for gas exploration in the basin.Their occurrence,like other cases worldwide,can be divided into two locations in general,i.e.,platform interior and platform margin locations.Their differences of reservoir features and origins,however,have not been investigated comprehensively due to different exploration degrees.This issue is addressed in this paper,to provide basic data and information for the basin＇s hydrocarbon exploration and for the study of carbonate platform sedimentology and reservoir geology worldwide.We compared the features of these two types of reservoirs in detail,including the depositional and diagenetic features,pore types and petrophysical features.Based on the comparison,the origin of the reservoirs was further discussed.It is shown that the reservoirs in platform interior and platform margin locations differ significantly.The interior carbonates were deposited in moderate to high energy settings and the dominant lithologic type was limestone,which was weakly compacted and intensely cemented and has undergone meteoric dissolution.Pore types include intragranular dissolution and moldic pores,with low porosities（6%） and low permeabilities（0.1 mD）.By contrast,the platform margin carbonates were deposited in relatively high energy settings and mainly consisted of dolostones with some limestones.The rocks were strongly compacted but incompletely cemented.As a result,some primary intergranular pores were preserved.Both meteoric solution and burial solution have taken place.There are various types of pore spaces including intergranular and intercrystalline solution pores and residual intergranular pores.This type of reservoir generally has better petrophysical properties（9% porosity and 0.1 mD permeability） and pore-throat structures than the interior reservoirs.These differences were influenced by both primary depositional features and secondary diagenesis.For the interior carbonate reservoirs,early meteoric dissolution,weak compaction and strong cementation are important controlling factors.By contrast,the factors controlling the formation of the margin carbonate reservoirs mainly include dolomitization,preservation of primary pores and burial dissolution.

Simulation of two-dimensional interior ballistics model of solid propellant electrothermal-chem ical launch with discharge rod plasma generator

Instead of the capillary plasma generator(CPG),a discharge rod plasma generator(DRPG)is used in the30 mm electrothermal-chemical(ETC)gun to improve the ignition uniformity of the solid propellant.An axisymmetric two-dimensional interior ballistics model of the solid propellant ETC gun(2D-IB-SPETCG)is presented to describe the process of the ETC launch.Both calculated pressure and projectile muzzle velocity accord well with the experimental results.The feasibility of the 2D-IB-SPETCG model is proved.Depending on the experimental data and initial parameters,detailed distribution of the ballistics parameters can be simulated.With the distribution of pressure and temperature of the gas phase and the propellant,the influence of plasma during the ignition process can be analyzed.Because of the radial flowing plasma,the propellant in the area of the DRPG is ignited within 0.01 ms,while all propellant in the chamber is ignited within 0.09 ms.The radial ignition delay time is much less than the axial delay time.During the ignition process,the radial pressure difference is less than 5 MPa at the place 0.025 m away from the breech.The radial ignition uniformity is proved.The temperature of the gas increases from several thousand K(conventional ignition)to several ten thousand K(plasma ignition).Compare the distribution of the density and temperature of the gas,we know that low density and high temperature gas appears near the exits of the DRPG,while high density and low temperature gas appears at the wall near the breech.The simulation of the 2D-IB-SPETCG model is an effective way to investigate the interior ballistics process of the ETC launch.The 2D-IB-SPETC model can be used for prediction and improvement of experiments.