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Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a mathematical analysis method, fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties. Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions. Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces. However, fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials. From the perspective of two-dimensional planes and three-dimensional curved surfaces, this paper reviews the current research status of the fractal analysis of metal precipitate interfaces, metal grain boundary interfaces, metal-deposited film surfaces, metal fracture surfaces, metal machined surfaces, and metal wear surfaces. The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized. Starting from three perspectives of fractal analysis, namely, research scope, image acquisition methods, and calculation methods, this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed. It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future. [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

LiFe0.97Ni0.03PO4 composited with different contents of GO were prepared as lithium-ion batteries by carbothermal reduction methods, named as LFNP/G-x (x stands for GO contents). The study investigates the impact of varying composite ratios on electrochemical performance and crystal structure. The results showed that appropriate compounding with GO had a positive effect on cycling and rate properties. This is attributed to the fact that GO composite can increase LiFe0.97Ni0.03PO4 surface activity and make them more uniformly dispersed, which enhances the material's specific surface and improves its electrical conductivity. In particular, the charge–discharge capacity of LFNP/G-0.05 is 161 mAh g−1 at 0.1 C. After 100 turns, the capacity retention of materials is 93.9%. Hence, incorporating an optimal quantity of GO offers a novel approach to enhance the capability of LiFe0.97Ni0.03PO4 materials. [ABSTRACT FROM AUTHOR]

Compared to traditional methods, artificial neural networks can achieve low-cycle fatigue life more accurately when considering the effects of processes and environments on metal materials. However, extensive sample data are essential for training artificial neural networks. To address the sample shortage, this paper presents a deep neural network method. First, the small samples are divided into training and test samples. Second, the training samples are divided according to the processes. Then, the new samples are generated equally based on the division using beta-variational autoencoders. Finally, the ensemble learning model is used to predict the low-cycle fatigue life of metal materials using new samples. Min–Max normalization and log10 are used to standardize and destandardize samples in the deep neural network method. The deep neural network method is evaluated using the experimental data of Ti-685, Ti-6242S, Alloy D9, and AISI 4140 steel. Furthermore, the results reveal that the deep neural network method has good predictive performance. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Mechanics is the property of Chinese Journal of Applied Mechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

When shield TBM tunnelling in abrasive sandy ground, the rational design of cutter parameters is critical to reduce tool wear and improve tunnelling efficiency. However, the influence mechanism of cutter parameters on scraper wear remains unclear due to the lack of a reliable test method. Geometry and material optimisation are often based on subjective experience, which is unfavourable for improving scraper geological adaptability. In the present study, the newly developed WHU-SAT soil abrasion test was used to evaluate the variation in scraper wear with cutter geometry, material and hardness. The influence mechanism of cutter parameters on scraper wear has been revealed according to the scratch characteristics of the scraper surface. Cutter geometry and material parameters have been optimised to reduce scraper wear. The results indicate that the variation in scraper wear with cutter geometry is related to the cutting resistance, frictional resistance and stress distribution. An appropriate increase in the front angle (or back angle) reduces the cutting resistance (or frictional resistance), while an excessive increase in the front angle (or back angle) reduces the edge angle and causes stress concentration. The optimal front angle, back angle and edge angle for quartz sand samples are α = 25°, β = 10° and γ = 55°, respectively. The wear resistance of the modelled scrapers made of different metal materials is related to the chemical elements and microstructure. The wear resistances of the modelled scrapers made of 45#, 06Cr19Ni10, 42CrMo4 and 40CrNiMoA are 0.569, 0.661, 0.691 and 0.728 times those made of WC-Co, respectively. When the alloy hardness is less than 47 HRC (or greater than 58 HRC), scraper wear decreases slowly with increasing alloy hardness as the scratch depth of the particle asperity on the metal surface stabilizes at a high (or low) level. However, when the alloy hardness is between 47 HRC and 58 HRC, scraper wear decreases rapidly with increasing alloy hardness as the scratch depth transitions from high to low levels. The sensitive hardness interval and recommended hardness interval for quartz sand are [47, 58] and [58, 62], respectively. The present study provides a reference for optimising scraper parameters and improving cutterhead adaptability in abrasive sandy ground tunnelling.

The static and dynamic corrosion experimental platforms of supercritical fluid reactor were used for the static and dynamic corrosion test of Q235, 304, 316L, P91, N80 and 3Cr13 in the supercritical water pseudo-critical region (22.5 MPa, 375.6 ℃) and gas-like region (22.5 MPa, 407.6 ℃) for 72 h. The results show that the dynamic corrosion rate of materials in supercritical water environment is significantly higher than the static corrosion rate, and the flow accelerates the corrosion process, in which 304 is increased by more than 4 times; the strengthening effect of dynamic conditions on corrosion mass gain is weakened with the decrease of corrosion resistance. The factors that exacerbate corrosion under dynamic conditions are: flow shear force accelerates the movement of the corrosive medium in the supercritical fluid to the substrate surface, promoting the corrosion chemical reaction; the flow shear force scours the material surface, promotes the dissolution of Fe on the material surface, and accelerates the corrosion chemical reaction; the erosion effect of shear force promotes the detachment of corrosion product crystals during the formation process of the wall, accelerating the corrosion process.

Metal materials are widely used in the degradation of pollutants, especially for the degradation of some refractory organics in sewage. A large and growing body of researchers has investigated the relationship between the fate of antibiotics and antibiotic resistance genes (ARGs) and the addition of iron-based materials during anaerobic digestion (AD) of sludge. In this article, firstly, the mechanisms by which iron-based materials affect the biodegradation of antibiotics in the process of AD are discussed. The biodegradation of antibiotics is promoted through physical and chemical reactions such as adsorption, redox, and chelation, and the improvement of microbial activity after iron-based materials is added. Secondly, the effect of iron-based materials on ARGs in AD is discussed in this article. The addition of iron-based materials can reduce the generation and spread of ARGs by altering the microbial community, affecting the proliferation of mobile genetic elements (MGEs), the synergistic effect of metal resistance genes (MRGs) and ARGs, and other pathways. Finally, the application and development prospects of iron-based materials in the biodegradation of antibiotics during AD are prospected. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soft tissue integration is one major difficulty in the wide applications of metal materials in soft tissue-related areas. The inevitable inflammatory response and subsequent fibrous reaction toward the metal implant is one key response for metal implant-soft tissue integration. It is of great importance to modulate this inflammatory-fibrous response, which is mainly mediated by the multidirectional interaction between fibroblasts and macrophages. In this study, macrophages are induced to generate M1 and M2 macrophage immune microenvironments. Their cytokine profiles have been proven to have potentially multi-regulatory effects on fibroblasts. The multi-reparative effects of soft tissue cells (human gingival fibroblasts) cultured on metal material (titanium alloy disks) in M1 and M2 immune microenvironments are then dissected. Fibroblasts in the M1 immune microenvironment tend to aggravate the inflammatory response in a pro-inflammatory positive feedback loop, while M2 immune microenvironment enhances multiple functions of fibroblasts in soft tissue integration, including soft tissue regeneration, cell adhesion on materials, and contraction to immobilize soft tissue. Enlighted by the close interaction between macrophages and fibroblasts, we propose the concept of an “inflammatory-fibrous complex” to disclose possible methods of precisely and effectively modulating inflammatory and fibrous responses, thus advancing the development of metal soft tissue materials.

In recent decades, the background level of electromagnetic fields (EMFs) has increased extremely. One of the decisive factors influencing this increase is the increase in the quality, volume, and speed of voice and data services of mobile operators. This paper deals with the protection of the internal environment from the negative effects of EMFs through elements made of metal materials that absorb this radiation. For the purposes of this research, a series of measurements were carried out on individual days of the week and hours during the day. The results of the measurements were evaluated by the ANOVA method. The aim was to obtain a summary overview of the effects of electromagnetic fields and propose measures for their elimination in the interior. Therefore, measurements of electromagnetic fields were also carried out using shielding elements made of various metal materials, and a comparison of their shielding efficiency was subsequently made. Applications of shading blinds with the highest shading efficiency were recommended to increase safety, protect people's health from its effects, and prevent electromagnetic fields. [ABSTRACT FROM AUTHOR]

Improving the corrosion protection level of metal materials for ocean engineering equipment is of great significance for the improvement of the abilities to explore ocean resources. The macro corrosion mechanism of such metal materials have been investigated extensively, but the micro corrosion mechanism is still unclear. In this paper, the research progress of molecular dynamics simulation of metal materials for ocean engineering equipment was summarized. Besides, the potential function and model describing the reaction between metal and solution/gas, and the influence of different factors on metal corrosion were introduced respectively. Finally, in order to provide a reference for the study of more efficient and inexpensive corrosion protection methods, the problems existing in the current calculation and simulation of metal material corrosion were also analyzed and the prospects were put forward.

In recent years, microwave-based processing of metallic material has emerged as a novel technique that offers cost, time, and energy-saving solutions compared to conventional processing. Microwave processing of metals has been represented with past, present, and future research development. This article provides a brief overview of microwave interaction with metals, beginning with the fundamentals and progressing to applications in many fields such as sintering, joining, cladding, drilling, and casting with special tooling requirements. A special emphasis has been made on microwave casting applications with the necessary tooling design specifications of microwave applicator, susceptor, casket, crucibles, mold, and temperature measurement. The effect of different tooling design parameters on microstructure characteristics and mechanical properties of the processed material has been analyzed. In the end, the challenges in tooling design parameters, various processing strategies by critical analysis, and future research opportunities in microwave processing of metals have been outlined. [ABSTRACT FROM AUTHOR]

The design of metal material curved surface die is a common problem in engineering. From the perspective of intelligent manufacturing, this paper analyzes the mechanism and design key points of metal material curved surface die, establishes the mathematical model of die design by using the matrix equation method, and puts forward a general engineering mathematical calculation method of segmented die design. Based on the look-up table calculation, this scheme can simplify the calculation method and reduce the calculation error, which is suitable for general engineering die processing calculation. [ABSTRACT FROM AUTHOR]

With the development of electronic information technology and people's pursuit of convenient life, smart flexible wearable devices have attracted the attention of many scholars. In the development of smart wearable devices, flexible conductive materials play a vital role. As the most basic flexible conductive textile material, conductive yarn is widely used in smart wearable products. However, most traditional textile materials are insulating materials and cannot directly form conductive yarns and smart wearable products. The preparation methods and application research progress of metal-based conductive yarns, carbon-based conductive yarns, and conductive polymer-based conductive yarns, as well as the application research progress in wearable strain sensors, wearable supercapacitors, wearable electric heating devices and other aspects were introduced. The problems that need to be solved in the research of conductive yarns in recent years were analyzed, mainly including improving the conductivity, flexibility and environmental stability of conductive yarns. In addition, in view of the convenience, comfort, washing durability, and sensitivity required by smart wearable devices, it was proposed that the sensitivity, durability of flexible conductive yarn and the combination of textile materials and conductive materials have become the main development of wearable flexibles smart product.

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Taking the commonly used metal material aluminum 3003 as an example, and based on the simulated lightning current metal damage test results in the four typical compositions of actual lightning current, the damage characterization parameters such as damage area and damage depth of aluminum 3003 alloy and lightning current parameters were analyzed. Taking the building as an example, and based on the parameter analysis of the combined probability distribution of lightning strike density, lightning interception area, lightning current amplitude and transferred charge amount, the annual average number of lightning strikes and the distribution characteristics of lightning current parameters of metal materials were calculated. A damage estimation method considering the probability distribution of lightning current parameters when a metal material with aluminum 3003 alloy and building carrier as an example was subjected to lightning strikes was established. The results show that the damage depth of the aluminum 3003 alloy material under the action of short-term first return current component and short-duration subsequent return current component is less than 0.1 mm, which can be ignored. The damage area of the aluminum 3003 alloy material is proportional to the magnitude of the lightning current suffered, and the damage depth of the alloy is proportional to the amount of charge transferred by the lightning current.

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Machine operating conditions can be obtained through lubrication oil detection; solid metal particles are the primary factor causing mechanical wear. The surface of the friction pair is usually specially treated with the nonferrous metal protective coating. Therefore, there are many kinds of nonferrous particles in the lubricating oil. In this paper, a method for measurement of nonferrous particles sizes independent of materials using the impedance signal of the inductive sensor is presented. Both the imaginary part and real part of the coil impedance signal are studied in this paper, which is different from traditional inductive sensor research only the imaginary part of impedance signal output is considered. Through theoretical analysis, it is found that the real and imaginary parts of coil impedance changes with different materials at the same size are corresponding to an elliptic function. Combining with the coil impedance measured in the experiment, the particle size can be obtained, which is independent of particle material. [ABSTRACT FROM AUTHOR]

Design an implant similar to the human bone is one of the critical problems in bone tissue engineering. Metal porous scaffolds have good prospects in bone tissue replacement due to their matching elastic modulus, better strength, and biocompatibility. However, traditional processing methods are challenging to fabricate scaffolds with a porous structure, limiting the development of porous scaffolds. With the advancement of additive manufacturing (AM) and computer-aided technologies, the development of porous metal scaffolds also ushers in unprecedented opportunities. In recent years, many new metal materials and innovative design methods are used to fabricate porous scaffolds with excellent mechanical properties and biocompatibility. This article reviews the research progress of porous metal scaffolds, and introduces the AM technologies used in porous metal scaffolds. Then the applications of different metal materials in bone scaffolds are summarized, and the advantages and limitations of various scaffold design methods are discussed. Finally, we look forward to the development prospects of AM in porous metal scaffolds.

This research article presents metal material cleaner by applied high frequency ultrasonics is one choice to utilize the sound energy. This method is to transfer ultrasonics energy to the cleaning unit.In this research, the IC# SG3525A is used to generate frequency at 28 kHz. The IC#TLP250 is a optocoupler which is used to interface between the output of the IC#SG3525A and the input of the isolated drive circuit. The high frequency circuit is used to drive the gate of Power MOSFETs#IRFP450 in half-bridge Inverter circuit. Then, the output signal is transferred to high frequency transformer to step up the voltage. After that, the receiving A/C 350 watt drives the seven ultrasonic transducers in order to transfer electric energy to mechanical vibrating energy by the frequency of ultrasonics. In addition, there is a timekeeper to control the work duration. This metal material cleaner by ultrasonic can increase the ability of cleaning for the huge material parts and it can be used in another cleaning industry.

Copyright of Journal of Shenzhen University Science & Engineering is the property of Editorial Department of Journal of Shenzhen University Science & Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pitting corrosion directly affects the usability and service life of metal material, so the effective nondestructive testing and evaluation on pitting corrosion is of great significance for fatigue life prediction because of data supporting. The features of pitting corrosion are elaborated, and the relation between the pitting corrosion parameters and fatigue performance is pointed out. Through introducing the fundamental principles of pitting corrosion including mainly magnetic flux leakage inspection, pulsed eddy current and guided waves, the research status of nondestructive testing technology for pitting corrosion is summarized, and the key steps of nondestructive testing technologies are compared and analyzed from the theoretical model, signal processing to industrial applications. Based on the analysis of the signal processing specificity of different nondestructive testing technologies in detecting pitting corrosion, the visualization combined with image processing and signal analysis are indicated as the critical problems of accurate extraction of pitting defect information and quantitative characterization for pitting corrosion. The study on non-contact nondestructive testing technologies is important for improving the detection precision and its application in industries.

• Temperature distribution during metal fatigue is a function of applied plastic work. • Integration of area under temperature-fatigue cycle curve isn't necessarily constant. • Plastic work can be modeled by two-terms exp. function in typical metal fatigue tests. • Entropy generation due to heat conduction to the test apparatus is neglectable. In the present study, a general model was developed for temperature evolution prediction during metal's uniaxial fatigue loading. The prediction model leads to a reasonably accurate determination of specimen temperature distribution. It also identifies the effective parameters of fatigue temperature variation. It was observed that plastic strain energy is an important contributor to the temperature evolution trend. The proposed model is also employed to evaluate empirical relations, proposed for fatigue life prediction. At the last stage, based on the proposed model for temperature and Morrow model as plastic work density, the proposed model was utilized for the entropy generation prediction. [ABSTRACT FROM AUTHOR]

This study investigated the influence of the main metal materials of transformers on the oil-paper insulation performance. Ten types of insulating specimens were subjected to accelerated thermal aging at 120°C. Some aging parameters, including oil acid number, furfural content and degree of polymerization (DP) of insulating paper, were measured and compared. At the same time, we conducted frequency domain spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry on the insulating paper. The following conclusions were drawn: silicon lamination slightly deteriorates the insulating oil, copper increases the acidity and accelerates the production of furfural, metal materials can decrease DP of insulating paper and the effect of copper is greater than that of silicon lamination. During thermal aging, the dielectric dissipation factor of insulating paper increases and the carbon content of insulating paper increases. Metal materials can significantly increase the dielectric dissipation factor and carbon content of insulating paper and the effect of copper is greater than that of silicon lamination. [ABSTRACT FROM AUTHOR]

As the microporous structure has been widely used in the field of precision machining, at the same time, the requirements for the quality of microporous machining are continuously increasing. Water jet-guide laser processing technology (WJGL) has been gradually applied for its high machining precision. However, there are a few researches on the heat conduction process of WJGL processing metal materials. Therefore, it is of great significance to study the transient thermal effect of metal materials and the mechanism of material removal to improve the processing quality. In order to explore the heat conduction model of WJGL processing metal materials, this paper is based on the “element birth and death” technique in the finite element method, and the three-dimensional transient temperature field of four typical metal materials (titanium alloy, stainless steel, aluminum alloy, copper) and material removal model are established. Under this model, the removal mechanism of different metal materials and the influence of different process parameters on the temperature field distribution of the material are studied, and the influence of fixed-position drilling and helix drilling on the microporous morphology is compared. The results show that copper and aluminum alloys can obtain a larger depth-to-diameter ratio and a smaller hole taper. Titanium alloy and stainless steel have better hole roundness, lower hole edge temperature, and smaller thermal deformation. Hole roundness error and hole taper decrease with the increase of laser power. The roundness error of each material is reduced to within 10 μm when the laser power is 10 W, and the average hole taper is 8.73°.

The 6061 alloy cooling curve is determined by analysis software, and the 6061 semi-solid alloy is prepared by manual paddling process. The primary solid fraction is tested through prepared water quenched samples under different temperature. With H1F100 type servo press and cup type test mold, the forming of the 6061 semi-solid alloy rheological casting-forging is made. The influence of alloy temperature, forming pressure, upper mould temperature and holding time on the formability of 6061 alloy is researched. The results show that within the same set of mold completing casting and forging of the alloy is feasible. Along with the increase of the alloy temperature and the upper mould temperature, the formability of finished products becomes better. Under this experimentation, when the temperature of the semi-solid alloy is amongst 642 ℃ to 645 ℃ and the upper mould preheating temperature is amongst 200 ℃ to 300 ℃, casting defects such as cold insulation will form in the casting-forging sample of semi-solid 6061 alloy with the prolongation of holding time.

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study devised a measurement system to estimate the thermal conductivity of electronic product materials, especially in HILEDs lighting materials, exhibiting distinct thermal characteristics by conducting thermal performance experiments and theoretical analyses. First, steady-state conduction analysis with thermal resistance method was investigated on three composite material substrates of unknown heat conduction coefficients through a substrate material named Bakelite of low thermal conductivity revealing stable quality. Second, one-dimension semi-infinite transient conduction analysis was utilized to investigate metal materials with high thermal conductivities. Results showed that the Bakelite experimental module was verified for 62.5 % of the original wattages, which closest to the thermal conductivity 0.233 W/m-K of the Bakelite. And these composite materials M1, M2 and M3 composed of polymer and epoxy were 1.311, 0.844 and 2.403 W/m-K, respectively. The thermal performance experiments were investigated and the results have proved the correctness of the theoretical model. According to the experimental results, calculating the temperature value of the metal materials comprising cotton insulation and the transient analysis, this study determined the temperature error to be less 20 %. Consequently, a transient measurement system and method for metal materials with high heat conduction coefficients was established. Finally, the results of this work are the useful thermal conductivity method to facilitate rapid analysis in the future. [ABSTRACT FROM AUTHOR]

Poly-D-L lactide (PDLLA) biodegradable implants to heal fractures are widely applied in orthopedic surgeries. However, whether the process of fracture healing is regulated differently when PDLLA is used compared with traditional metal materials remains unclear. Runt-related transcription factor 2 (Runx2) and canonical Wnt signaling are essential and may interact reciprocally in the regulation of osteogenesis during bone repair. In the present study, a rat femoral open osteotomy model was used to compare the curative efficacy of a PDLLA rod and Kirschner wire under intramedullary fixation for fracture treatment. The dynamic expression of Runx2 and key components of the canonical Wnt signaling in callus tissue during fracture healing was also investigated. The results of the current study indicate that at weeks 4 and 6 following fixation, the callus bone structural parameters of microCT were significantly improved by PDLLA rod compared to that of Kirschner wire. In addition, at weeks 4 and 6 after fixation, the protein and mRNA expression of Runx2 and the positive regulators of canonical Wnt signaling, such as Wnts and ß-catenin, were significantly increased. However, the protein and mRNA expression levels of the negative regulators of canonical Wnt signaling, such as glycogen synthase kinase-3ß, were significantly decreased in callus tissue when treated with PDLLA rod compared with Kirschner wire. Collectively, these data indicate that compared to the traditional metal material, using PDLLA internal fixation for fracture treatment may further improve bone formation, which is associated with the increased expression of Runx2 and the enhancement of canonical Wnt signaling. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulation was performed in order to investigate mechanisms of crack propagation in nanoscale single crystal, bicrystal and tricrystal nickels, respectively. The grain boundary plays a significant role in the initiation and propagation of crack. As for tricrystal, in particular, a void occurs at the triple junction of grain boundaries and contributes to accelerating the crack propagation. The existence of the grain boundary contributes to the increase of Shockley partial dislocations along with stacking faults. The orientation difference among the grains causes the dislocations to move along different directions in the different slip systems, which lays the foundation for the formation of the crossed or closed Lomer-Cottrell locks. The Lomer-Cottrell locks are able to impede the movement of dislocations and cause the pile-up of dislocations. Amorphous atoms are induced in the region near the Lomer-Cottrell lock. The deformation energy is relaxed when the amorphous atoms are separated one another, which consequently leads to the initiation and propagation of crack. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of different factors on the electrical properties of a well-bonded metal/PET composite during tensile deformation were systematically analyzed, including metal materials, metal coating film thickness and environmental temperature. It was found that, before a crack appearance in the coated metal film, the critical elongation of a well-bonded metal/PET composite depended on the differences of modulus and Poisson's ratio between the coated metal material and PET substrate. After cracking, the metal/PET composites with different metal films showed different elongations when there was a sudden increase in the resistance of the metal/PET composite; the thicker the metal film deposited on PET substrate was, the lower resistance the metal/PET composite had. The thickness of metal film had no obvious effect on the critical elongation of the metal/PET composites. In addition, the resistance of the metal/PET composite increased with the increasing environmental temperature. [ABSTRACT FROM AUTHOR]

Quite often in order to improve the performance of a product it is necessary to form a strengthened structure that will be extremely hard and have good plasticity at the same time. One way to meet this challenge is to apply shock wave mechanical hardening to produce micro- or nanocrystalline heterogeneous structures in homogeneous metals or alloys. A peculiar feature of such structure is its layer by layer formation with smooth transition between hard and plastic areas, which improves the performance of the strengthened item significantly. [ABSTRACT FROM AUTHOR]

Abstract: A two-step anodization method was adopted to prepare the porous anode alumina (PAA) template through the oxalic acid solution. By adjusting the parameters (such as current density, oxidation time, electrolyte concentration and other factors), the PAA template was obtained, which has the evenly distributed pores with similar diameters and hexagonal-shaped mouth. Meanwhile, by removing the barrier layer without peeling off the film, the residual aluminum becomes the base and acts as electrode. In the non-aqueous system, the nanowire of RE simple-substance (SS) Nd has been prepared with the template DC electrodeposition. The aperture diameter of PAA template is approximately 60 nm, and there is little change before and after the barrier layer is removed. The Nd nanowire given is orderly and in similar size. EDS shows that the nanowires contain simple-substance (SS) Nd and a tiny of Nd2O3, while the content of SS Nd is 92.73 wt%. Both the SS Nd and Nd2O3 nanowire are possessed of hexagonal structure. [Copyright &y& Elsevier]

The corrosion of materials in combustion chamber of yellow phosphor tall gas was investrgated. The results reveal that the corrosion behavior is different for different materials under actual work conditions. [ABSTRACT FROM AUTHOR]

The effects of heat treatment on the microstructure and mechanical properties of laser solid forming (LSF) Ti-6Al-4V alloy were investigated. The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstätten α laths and a little acicular in columnar prior β grains with an average grain width of 300 µm, which grow epitaxially from the substrate along the deposition direction ( Z). Solution treatment had an important effect on the width, aspect ratio, and volume fraction of primary and secondary α laths, and aging treatment mainly affects the aspect ratio and volume fraction of primary α laths and the width and volume fraction of secondary α laths. Globular α phase was first observed in LSFed samples when the samples were heat treated with solution treatment (950°C, 8 h/air cooling (AC)) or with solution treatment (950°C, 1 h/AC) and aging treatment (550°C, above 8 h/AC), respectively. The coarsening and globularization mechanisms of α phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested. [ABSTRACT FROM AUTHOR]