bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine-learning-assisted space-transformation accelerates discovery of high thermal conductivity alloys
Authors: Visaria Dhvaneel , Jain Ankit
Published: November 2020

We study the thermal conductivity distribution of hypothetical graphene-like materials composed of carbon and heavy carbon atoms. These materials are representative of alloys and disordered materials, which are relatively unexplored for thermal properties owing to their large configuration spaces. Since the full thermal conductivity calculations using the Boltzmann transport equation based solutions are computationally prohibitive for each of the 232 considered configurations, we employ regularized autoencoders, a class of generative machine learning models that transform the configuration space to the latent space in which materials are clustered according to the target property. Such conditioning allows selective sampling of high thermal conductivity materials from the latent space. We find that the model is able to learn the underlying thermal transport physics of the system under study and is able to predict superlattice-like configurations with high thermal conductivity despite their higher mass.
The relationship between the doping concentration and d ferromagnetism in n-type 4H-SiC
Authors: Peng Bo , Chen Jiajie , Hu Jichao , Cao Xingzhong , Yuan Lei , Wang Yutian , Zhang Yuming , Jia Renxu
Published: November 2020

To date, research on defect-induced magnetism in SiC has been conducted to clarify the relationship between the ferromagnetic signal and the carrier concentration. It has been experimentally proven that there is an interaction between the d0 magnetic moment and the hole carrier in p-type 4H-SiC. However, for n-type SiC, the existing theoretical predictions are insufficient to explain the variation in magnetization with the doping concentration. To solve this problem, we prepared 4H-SiC epitaxial layers with different nitrogen doping concentrations and introduced defects by ion implantation. By measuring and analyzing the magnetic properties, we found that the ferromagnetic composition depends on both the implantation dose and the doping concentration. By performing first-principles calculations, we studied the magnetic moments and interactions of defects with different charge states, which is related to defect-induced ferromagnetism. These defects include not only the paramagnetic centers reported in previous studies, such as silicon vacancies and divacancies, but also the NCVSi complex defect of recent interest, which are indicated by positron annihilation experiments. Combining experimental observations with theoretical calculations, we explained the relationship between magnetic properties and the nitrogen doping concentration in the epitaxial samples. Our research will help us to better understand the physical mechanism of defect-induced magnetism in doped semiconductors and provide a potential platform for the control of defect-induced magnetism by carrier density modulation and the fabrication of SiC spintronic devices without transition metals.
Dual-mode thin film bulk acoustic wave resonator and filter
Authors: Zou Yang , Nian Laixia , Cai Yao , Liu Yan , Tovstopyat Alexander , Liu Wenjuan , Sun Chengliang
Published: November 2020

Bulk acoustic wave (BAW) filters have been extensively used in consumer products for mobile communication systems due to their high performance and a standard CMOS compatible integration process. However, a traditional BAW filter generally presents only one frequency transmission band; hence, it cannot meet the demands of multi-mode wireless communication systems. In this work, we propose a radio frequency dual-band filter based on a dual-mode film bulk acoustic resonator (FBAR). The dual-mode FBAR consists of molybdenum electrodes and an aluminum nitride film with a c axis tilt angle, which leads to the coexistence of the longitudinal mode and the shear mode in the resonator. The influence of the tilt angle on the resonant frequency and electromechanical coupling coefficient of the dual-mode FBAR is investigated. Subsequently, the behaviors of the dual-mode FBAR have been emulated by a modified Butterworth–Van Dyke model with two motional branches, which is further used to design and optimize the dual-band filter. The dual-mode FBAR-based filters connected in a ladder configuration present two dual passbands of 43 MHz and 105 MHz, respectively. The developed filters with dual passbands can give an inspiration to the design of BAW devices in modern wireless communications.
Dynamics of spheroids in an unbound quadratic flow of a general second-order fluid
Authors: Wang Shiyan , Tai Cheng-Wei , Narsimhan Vivek
Published: November 2020

This work employs the second-order fluid model to investigate the effect of first and second normal stresses on the motion of spheroidal particles in unbound parabolic flows, where particles migrate toward the flow center. We specifically examine the effects of fluid Weissenberg number Wi and the ratio of normal stress coefficients α = ψ2/ψ1. Previous works have considered the motion of spheroidal particles in the co-rotational limit (α = −0.5), where the effect of fluid viscoelasticity is to modify the fluid pressure but not the shear stresses. Here, we examine all ranges of α that are found for functional complex fluids such as dilute polymer solutions, emulsions, and particulate suspensions and determine how viscoelastic shear stresses alter particle migration. We use perturbation theory and the Lorentz reciprocal theorem to derive the O(Wi) corrections to the translational and rotational velocities of a freely suspended spheroid in an unbound tube or slit flow. Our results show that for both prolate and oblate particles, the viscoelasticity characterized by α significantly affects the particle cross-stream migration, but does not qualitatively change the trends seen in the co-rotational limit (α = −0.5). For a range of α (−0.9 ≤ α ≤ 0) investigated in this work, particles possess the largest mobility when α = −0.9 and smallest mobility when α = 0. Although α does not alter particle rotation at a given shear rate, we observe significant changes in particle orientation during migration toward the flow center because changes in migration speed give rise to particles experiencing different shear histories.
A partially linearized spin-mapping approach for nonadiabatic dynamics. I. Derivation of the theory
Authors: Mannouch Jonathan R. , Richardson Jeremy O.
Published: November 2020

We present a new partially linearized mapping-based approach for approximating real-time quantum correlation functions in condensed-phase nonadiabatic systems, called the spin partially linearized density matrix (spin-PLDM) approach. Within a classical trajectory picture, partially linearized methods treat the electronic dynamics along forward and backward paths separately by explicitly evolving two sets of mapping variables. Unlike previously derived partially linearized methods based on the Meyer–Miller–Stock–Thoss mapping, spin-PLDM uses the Stratonovich–Weyl transform to describe the electronic dynamics for each path within the spin-mapping space; this automatically restricts the Cartesian mapping variables to lie on a hypersphere and means that the classical equations of motion can no longer propagate the mapping variables out of the physical subspace. The presence of a rigorously derived zero-point energy parameter also distinguishes spin-PLDM from other partially linearized approaches. These new features appear to give the method superior accuracy for computing dynamical observables of interest when compared with other methods within the same class. The superior accuracy of spin-PLDM is demonstrated in this paper through application of the method to a wide range of spin-boson models as well as to the Fenna–Matthews–Olsen complex.
Ferroic orders in two-dimensional transition/rare-earth metal halides
Authors: An Ming , Dong Shuai
Published: November 2020

Since the discovery of graphene, two-dimensional materials with atomic level thickness have rapidly grown to be a prosperous field of physical science with interdisciplinary interest for their fascinating properties and broad applications. Very recently, the experimental observation of ferromagnetism in a Cr2Ge2Te6 bilayer and a CrI3 monolayer opened a door to pursue long-absent intrinsic magnetic orders in two-dimensional materials. Meanwhile, the ferroelectricity was also experimentally found in a SnTe monolayer and CuInP2S6 few layers. The emergence of these ferroic orders in the two-dimensional limit not only brings new challenges to our physical knowledge but also provides more functionalities for potential applications. Among various two-dimensional ferroic ordered materials, transition/rare-earth metal halides and their derivants are very common. In this Research Update, based on transition/rare-earth metal halides, the physics of various ferroic orders in two-dimensional materials will be illustrated. The potential applications based on their magnetic and polar properties will also be discussed.
Multiscale structural complexity of natural patterns
Authors: Bagrov Andrey A. , Iakovlev Ilia A. , Iliasov Askar A. , Katsnelson Mikhail I. , Mazurenko Vladimir V.
Published: November 2020

Significance

Structural complexity of patterns, systems, and processes is a very basic and intuitively clear concept in human’s perception of reality that is very difficult to describe quantitatively. A demand in a mathematical notion that properly reflects complexity of hierarchical nonrandom structures exists in many areas of science, from geology to social sciences. Here, we propose an easy to compute, robust, and universal definition of complexity based on interscale dissimilarity of patterns. Using classical magnetic patterns as an example, we demonstrate that our approach leads to maximization of complexity for the most visually nontrivial patterns and can be used to detect phase transitions with high accuracy, making it a promising tool for studying pattern formation in a variety of systems.
Topological Weaire–Thorpe models of amorphous matter
Authors: Marsal Quentin , Varjas Dániel , Grushin Adolfo G.
Published: November 2020

Significance

Topological insulators respond to external fields in fundamentally different ways compared to trivial insulators. Combining topologically robust responses with the long history of large-scale growth and broad applications of amorphous materials, a door for technological progress opens. The absence of realistic models that exploit the accumulated knowledge of both fields, and the lack of criteria to establish when topological phases emerge in amorphous solids, stalls progress. Here we propose models that are realistic and topological and display useful symmetry properties despite their lack of periodicity. They allow us to predict when amorphous topological phases occur and their physical responses, opening up a path to identify, classify, and discover amorphous topological insulators.
Dirac cones and chiral selection of elastic waves in a soft strip
Authors: Lanoy Maxime , Lemoult Fabrice , Eddi Antonin , Prada Claire
Published: November 2020

Significance

We monitor the propagation of in-plane elastic waves in an incompressible thin strip and observe a Dirac cone in a soft material. Additional remarkable wave features such as negative phase velocities, pseudo-zero group velocity, and one-way chiral selection are highlighted. These results are universal: Any thin strip made of any soft elastomer will display the same behavior. Dirac cones have inspired many developments in the condensed-matter field over the last decade. Our findings enable the search for analogs in the realm of soft matter, leading to a wide range of potential applications. Additionally, they are of practical interest for biologists since soft strips are ubiquitous among human tissues and organs.
Korean Bibimbap mothers’ family language policies (FLPs) for their children’s bilingualism in
Australia
Authors: Park Eun Kyong , Vass Gregory , Davison Chris
Published: November 2020

The influential role of parents has long been acknowledged as a key contributor to children’s bilingual development.
Parents’ home-based informal efforts to foster children’s bilingual abilities are described as family language policies (FLPs). The
important connection between bilingualism and FLP has been established, but to date there are few studies concerning Korean immigrant
families in Australia, highlighting their unique cultural values. According to traditional Korean cultural values, mothers play a central
role as An-hae (the sun inside) to facilitate their children’s language development (Kim, 2006).
This study aimed to create a clearer picture of Korean mothers’ beliefs about bilingualism and their FLPs. The participants were six Korean
mothers with their children attending a community language program in Sydney. There are two data sets for this study: a six-weeks’ FLP daily
log of each family and a focus group interview. A thematic analysis of these data revealed the richness and specificity of FLPs for
bilingual development. This paper concludes with implications for a future research agenda.
Desiderata for metaphor theory, the Motivation &
Sedimentation Model and motion-emotion metaphoremes
Authors: Zlatev Jordan , Jacobsson Göran , Paju Liina
Published: November 2020

Metaphor research has increasingly diversified,
leading to extensive disagreements. A set of desiderata for any
contemporary theory of metaphor are (i) to account for both
communication and cognition, (ii) to explain both universal and
culture-specific aspects, (iii) to achieve a balance between stable
structures and contextual processes, (iv) to apply not only to
different languages, but to other semiotic systems such as gesture,
(v) to provide clear theoretical and operational definitions. We
argue that a recent cognitive-semiotic theory, the Motivation &
Sedimentation Model (MSM) is capable of fulfilling these
desiderata. To evaluate predictions from the theoretical model we
compare motion-emotion metaphoremes, such as my heart
jumped, in six differentially related European
languages – English, Swedish, Spanish, Bulgarian, Finnish and
Estonian.
Evaluating metaphor accounts via their pragmatic effects
Authors: Colston Herbert L.
Published: November 2020

A prominent pragmatic effect of metaphor is
meaning enhancement (Colston,
2015). Relative to comparable non-metaphorical language,
metaphors can provide stronger, richer, or more poignant delivery of
a proposition, idea, attitude, emotion, schema, or other meaningful
construct. Metaphor constructions also alter their component
parts (e.g., source and target domains). The paper measures
pragmatic effect performance when metaphors are assembled in
different ways, as a means of evaluating metaphor accounts. In four
experiments metaphors were altered by using; (1) weak versus strong
SDs, (2) mixed versus unmixed SDs, (3) single versus double
instantiations of SDs, and (4) using standard metaphor versus simile
constructions. Observed differences (e.g., in meaning enhancement)
support the idea that metaphor understandings arise in part due to
embodied simulations.
Metaphor, metonymy and polysemy
Authors: Allan Kathryn
Published: November 2020

Polysemy is a basic principle of the lexis of
English, but the full range of senses of a lexeme and the ways in
which these interact are not often considered in accounts of
metaphor and metonymy. This paper presents a case study of the
lexeme dull, which develops multiple meanings that
do not appear to represent the kind of straightforward concrete >
abstract metaphorical mapping that might be assumed. Rather, the
complex semantic history of the word reveals gradual shifts in
meaning involving metonymy, and change motivated by analogy. I argue
that ignoring word histories risks synchronic ‘misreading’ of the
relationship between their senses (Geeraerts, 2015), and that polysemy should
be acknowledged more prominently in standard accounts.
Sources of verbal humor in the lexicon
Authors: Winter-Froemel Esme
Published: November 2020

Lexical items with a ludic potential have not
been systematically studied up to now. The aim of this paper is thus
to explore sources of humor in the French and Italian lexicon and to
investigate to what extent the notion of incongruity can explain the
humorous effects and ludic usage of lexical items. Incongruity will
be reinterpreted from a usage-based perspective, stressing the
interactional dimension of communication (see also Kotthoff, 1998; Onysko, 2016), which
defines the relative inappropriateness and pragmatic markedness of
the items. In addition, the semantic distance and (in)compatibility
of the meanings as well as the semiotic nature of the relevant
reference entities will be taken into account, and a typology of
relevant subtypes of incongruity will be proposed.
Gauging expansion in synchrony
Authors: Fløgstad Guro Nore , Rodríguez Louro Celeste
Published: November 2020

One of the hallmarks of present-day Rioplatense
Spanish is the highly specialised use of the periphrastic perfect or
Pretérito Perfecto Compuesto (PPC). Most
perfect nuances are instead encoded in this dialect through the
synthetic past or Pretérito Perfecto Simple (PPS).
Exploration of a novel corpus of historical media and theatre plays
shows that, in nineteenth century Rioplatense, the PPC was
productively used to encode hot news, hodiernality and hesternality.
These nineteenth century uses are in line with a cross-linguistic
perfect-to-perfective grammaticalization pathway but the path is
halted in present-day Rioplatense. We draw on cognitive
grammaticalization theory to argue that there is no determinacy in
grammaticalizing constructions: a source meaning does not uniquely
determine the path a grammaticalizing construction may take.
Auxiliary reduction in secondary grammaticalization
Authors: Howe Chad
Published: November 2020

At the center of grammaticalization studies has
been an effort to understand the interplay between form and function
throughout the development of a construction. A recent analysis by
Dehé & Stathi
(2016) has made the case that desemanticization (semantic
reduction) and erosion (phonetic reduction) occur in parallel and
that different phonetic patterns can be associated with different
degrees of grammaticalization. This paper approaches Dehé and
Stathi’s proposal by means of the periphrastic past (PP) in Spanish,
a form that shows considerable variation across dialects and has
been shown to display various degrees of grammaticalization (Howe 2013). Focusing
specifically on the PP’s use in sequenced past narratives in
Peninsular Spanish, this analysis observes the behavior of the haber
auxiliary and finds evidence for increased reduction/omission in
these innovative narrative contexts. The patterns of reduction shown
in this analysis are consistent with the claim made by Dehé and
Stathi regarding the association of specific reductive processes
with more advanced stages of grammaticalization. These data reveal a
coevolution of form and meaning with the PP not yet discussed in the
literature, one that has broader implications for the study of
periphrastic past forms in Romance.
Synthesis, Modification and Study on the Electrochemical Properties of LiNi0.8Co0.1Mn0.1O2@ Li2ZrO3
Authors: Yang Jiahui
Published: November 2020

LiNi0.8Co0.1Mn0.1O2 (NCM811) is considered as a promising cathode material for lithium-ion batteries (LIBs) due to its advantages of high lithium storage capacity, low cost and excellent safety. However, lithium element of NCM series is easily lost in the preparation process, which leads to the rapid decline of cathode material capacity. Previous researches show that coating is an effective way to reduce the loss of elements, improve the electrochemical properties and thermal stability of the material. In this paper, the author focuses on different synthesis methods and different molar (or weight) ratios of Li2ZrO3, finding out that different synthesis methods can affect the electrochemical performances of target materials and right now research result is that 1wt.% NCM811@ Li2ZrO3 has the best property among other molar (or weight) ratios of NCM811@ Li2ZrO3.
Study on the enhancement of optical and electrical properties of GaN by doping
Authors: Liu Weili
Published: November 2020

GaN is a hot material of semiconductor devices, and it is extensive researched because of its outstanding performance. At the same time, doping can change the performance of GaN in the expected direction. This paper mainly introduces the main properties of GaN material. Meanwhile, according to the current application of GaN, it focuses on the effects of some common doping-types on the optical and electrical properties of GaN material. Through the doping of different elements, the optical and electrical properties of GaN will be improved in different aspects. For example, c-doping improves the breakdown voltage of AlGaN/GaN devices. Finally, the development prospect of GaN doped materials and devices is described.
Correlation Characteristic Research on Orthogonal Cutting the Plastic Metal Material-C10100 with Negative Rake Angle Tool
Authors: Ding Yanchun , Shi Guangfeng
Published: November 2020

With the high-speed development of the delicateness grinding, mechanical scratching and micro-cutting technology, scholars have become more and more interested in the forming mechanism and related characteristics of the negative rake angle tool. Based on DEFORM-2D forming software, this paper investigates the forming mechanism and related characteristics of the negative rake angle tool. Through the simulation comparison analysis, it is clear that as the negative rake angle decreased form 0° to 60° (the negative rake angle does not attain to the critical value), the shear angle becomes smaller, the ability of the chip formation in the front of the tool surface becomes weaker, the chip shape becomes blunter, the action state of the tool effect on the material is cutting and ploughing, and the tangential force and normal force increase, significantly. When the negative rake angle reaches the critical value (no chip formation, negative rake angle is approximately equal to -80°), the shear angle is approximately equal to 0°, no chip formed in front of the tool surface, the tool pure ploughing the material, and the tangential force and normal force both show a significant downward trend. Meanly, a triangular stagnant region appears in front of the tool surface when the negative rake angle decreased form -20° to -80°.
Corrosion Degradation Behavior of Forged Mg-Zn-Zr/-Y Alloy in Simulated Body Fluid
Authors: Ma Chunhua , Xu Dongguang , Yang Hao , Zhong Zhiguo , Lu Zhiwen
Published: November 2020

The corrosion degradation rate of pure magnesium and forged Mg-Zn-Zr/-Y magnesium alloy was compared by static immersion corrosion weight loss experiment and electrochemical corrosion experiment at constant temperature (37±0.5°C) and room temperature (25±1°C) SBF to simulate the corrosion degradation rate in body fluids. The results show that the corrosion resistance of magnesium alloy can be improved by adding Zn, Zr, Y compared with pure magnesium. The results of static immersion corrosion test and electrochemical corrosion test of forged Mg-Zn-Zr-Y show that the corrosion resistance of magnesium alloy can be improved by adding Zn, Zr, Y element. The average corrosion rate of the forged Mg-Zn-Zr-Y alloy was 0.62mm/a by weight loss method after 240 h immersion corrosion in SBF at 37 ± 0.5 °C, and the corrosion resistance of forged Mg-Zn-Zr-Y alloy was better than Mg-Zn-Zr alloy.
Preparation and Research on Expanded Perlite Composite Phase Change Material
Authors: Li-guang XIAO , Jing-wei WANG
Published: November 2020

To improve the application of phase change energy storage materials in residential geothermal heating, a composite phase change material with a phase change temperature range of 40°C to 65°C is designed. In this paper, two inorganic hydrated salt phase change materials Na2HPO4⋅12H2O and CH3COONa3H2O are mixed in different proportions and make eutectic mixture of binary phase change materials, composite phase change material prepared using expanded perlite as carrier. The samples were analyzed by step cooling curve, DSC, SEM, XRD, the results show: the best ratio of Na2HPO4⋅12H2O to CH3COONa⋅3H2O is 60:40, it has no phase separation and the subcooling is 3.6°C, its phase transition temperature range is 31.48 °C ~ 72.36 °C, and its phase transition enthalpy is 115.21 J/g. Expanded perlite composite phase change material has no leakage phenomenon, its phase change enthalpy is 109.34 J/g, and the phase change temperature range is 40.84°C ~ 60.52 °C, it meets the application standards of geothermal heating.
Research on Flow Characteristics of Throttle Valve Based on Fluent
Authors: Dongpo Wei , Hongxia Zhao
Published: November 2020

In order to improve the design of the throttle, a certain throttle is taken as the research object, and its flow coefficient is studied. Investigate the flow line characteristics of the throttle valve flow channel and the value of the flow coefficient of the throttle valve, use Fluent fluid software to perform numerical simulation analysis on the throttle valve flow channel, study the relationship between the throttle opening and the switching stroke, and simulate Calculation results The chamfer design of the throttle valve has a great influence on the initial section of the flow coefficient curve, and the opening range of the valve that can accurately control the flow rate is obtained.
Effect of sintering atmosphere on the microstructure and properties of nano-WC modified copper-iron-based oil-containing bearing
Authors: Li Dongyu , Li Xiaoqiang , Li Jingmao , Qu Shengguan
Published: November 2020

Nano-WC modified copper-iron-based oil bearing was prepared by powder metallurgy. The effect of sintering atmosphere on the microstructure, crushing strength, hardness and oil content of the oil bearing were studied. The results show that under the sintering condition of 865 °C×30min, when the sintering atmosphere is 100%N2, the sintering process stays in the early stage of sintering neck growth, there are a large number of irregular pores in the microstructure. The sintering densification is insufficient, and the sample is in the state of undersintering. When the sintering atmosphere is 100%H2, the dezincification of matrix phase α(Cu) is serious, and there are many long strip microcracks between metal particles. The effective connection between α(Cu) and Fe phase is cut off, so the density of sample is very low. When the sintering atmosphere is 75%H2+25%N2, α(Cu) forms a united whole through sufficient sintering diffusion bonding, and encapsulates the Fe-rich phase. The sintering densification is very sufficient, the pores in the microstructure tend to be circular. The sintered samples have good comprehensive properties, the density and oil content are 6.60 g/cm3 and 18.21vol.%, the crushing strength and hardness are 235.81 MPa and 42.41 HB, respectively, showing the best sintering state.
Effect of Total Nitrogen on the Physical and Mechanical Properties and Deformation Characteristics of Soil
Authors: Wu Yan , Ren Haiping , Yang Zhongfang
Published: November 2020

To determine the effect of total nitrogen on the physical and mechanical properties and deformation characteristics of soil, samples were tested in the laboratory after being soaked in deionized water and different concentrations of nitrogen solution. The results indicate that the total nitrogen content has a significant influence on soil characteristics. Specifically, the plasticity index, specific gravity and effective cohesive strength of the samples decrease and the effective friction angle increases with increases in the total nitrogen concentration of the solution. The strain hardening phenomenon is observed in the stress-strain relationship, and the variation of the stress-strain curve of samples soaked in deionized water and nitrogen solution are highly similar. The peak shear strength of the samples initially decreased and then increased with increases in the total nitrogen concentration of the solution. The mineral composition, particularly the composition of clay minerals, is affected by the interaction with total nitrogen in the soil, leading to changes in the soil macro-characteristics.
Springback compensation of high strength 21-6-9 tube after NC bending
Authors: Fang Jun , Ouyang Fang , Lu Shiqiang
Published: November 2020

In order to achieve high strength 21-6-9 (HS-21-6-9) tube numerical control (NC) bending precision forming, the springback law and compensation should be studied for the HS-21-6-9 tube NC bending. By using a finite element (FE) simulation method, the effects of bending angle θ on springback angle Δθ and springback radius ΔR of the HS-21-6-9 tube NC bending were investigated. The results show that the Δθ increases linearly with the increase of the θ, and the relationship between the Δθ and the θ can be described as Δθ=2.47179+0.02208θ. The ΔR decreases along the curve with the increase of the θ, and the relationship between the ΔR and the θ can be described as ΔR=33.86587θ
−0.64431. The compensation methodology is proposed considering the Δθ and the ΔR simultaneously, and the viability of the methodology is validated by an example.
Studies on the Synthesis and Photocatalytic Properties of Zinc Ferrite Materials
Authors: Wang Xinxin , Wang Nan
Published: November 2020

Zinc ferrite precursors are prepared by coprecipitation method using zinc nitrate and ferric nitrate as reactants, monohydrate ammonia and citric acid as precipitants and dispersants respectively. And zinc ferrite precursors are calcined at high temperature to obtain zinc ferrite photocatalysts at different temperatures(350°C, 450°C, 550°C). Methylene blue is used as substrates. The quality of the catalyst, the type of catalyst and the temperature of calcining are measured to study the photocatalytic performance. The results show that the preparation of zinc ferrite under 450°C has an optimal effect on the degradation of methylene blue dye. Compared with iron oxide and zinc oxide, the photocatalytic properties of zinc ferrite are superior to that of single oxide.
Synthesis of Graphene Oxide/Corn Cob Composites and investigation of their adsorption performance of Dye
Authors: Qu Yanping , Kang Song , Sun Jingjing , Zhang Ling , Sun Junqing , Yang Shaoliang , Yang Jinghui
Published: November 2020

Corncob and Graphene oxide were used to prepare and characterize corncob/graphene oxide (GO/CC) composites. The adsorption performance of GO/CC on dye wastewater was studied, and the factors affecting the adsorption effect were investigated. The results showed that GO/CC had rich functional groups which could provide sufficient binding sites for Congo red. It could remove Congo red solution strongly, and the removal rate was as high as 80%. GO/SP was endothermic in the process of Congo red adsorption. The reaction was mainly based on chemical adsorption.
Experiment on Recycled Construction Waste Mixture Used in Subbase
Authors: Liu Haitao
Published: November 2020

In order to improve the recycling efficiency of construction waste and make rational use of the concrete and brick demolished in the process of urban construction, the application of construction waste recycling mixture in road engineering was studied in this paper. Test results showed that the reasonable combination of recycled concrete and brick slag could achieve the purpose of reasonable utilization of construction waste and meet the strength of municipal road base mixture.
Grain Size Distribution Law of Cold-rolled Low-carbon Steel with Various Holding Temperatures
Authors: Wu Lei
Published: November 2020

With the cold-rolled low-carbon steel sheet produced by CSP process as the object of study, uniformity of microstructure and grain size distribution law of “pancake” (elongated) grains were investigated. The samples were annealed under laboratory condition to simulate batch annealing processes with holding temperatures from 660 °C to 700 °C. Conclusions are drawn that the grain size distribution of annealed test steel along both the rolling direction and the thickness direction of the sheet samples accords well with the law described by the Log-normal function.
Effects of Alloying Additions on the Glass Forming Ability and Corrosion Resistance of Bulk Zr-Based Amorphous Alloys
Authors: Shuang Yang
Published: November 2020

By using the real-place Recursion method,the effects of alloying additions (Nb, Ta, Y, La) on glass forming ability(GFA) and corrosion resistance of bulk Zr-based amorphous alloys are studied. An atomic group model in the Zr2Ni primary crystalline phase centered to Ni atom are constructed by computer programming. We have calculated the total bond order integral (£BOI) between Ni atom and its neighbor elements (Nb, Ta, Y, La), also calculated the Fermi energy level of alloying elements. The calculation results show that the XBOI and the glass forming ability are greatly enhanced after Y substitution. Nb, Ta, La decrease the GFA and La has little influence on the GFA of the alloys.Nb, Y, La enable Zr-based amorphous easy to passive and increase corrosion resistance. Therefore, Y and La are most effective on glass forming ability and corrosion resistance of Zr-based amorphous alloys. By addition of minor Y and La can produce the new bulk amorphous alloys with good corrosion resistance.
Design and experimental study of a new type of 45° overflow falling film distributor
Authors: Ciji Gong , Xuesheng Wang , Qinzhu Chen
Published: November 2020

A petrochemical acrylic fiber factory introduced a set of acrylic fiber device in the 1980s. Among them, the evaporation device used for solvent recovery of acrylic fiber appeared to be difficult to heat exchange in the tube. In order to solve the problem, we designed a new 45° overflow falling film distributor device and an experimental system for single tube. The effects of flow rate, liquid level and orifice flow coefficient were investigated experimentally. The results show that the correlation between the orifice flow coefficient and the structure size of the fabric determines the film formation effect. When the flow rate of the single tube is constant, the absolute error of the orifice flow coefficient does not exceed 9%. Therefore, the orifice flow coefficient proposed in this experiment is a good guide to the optimal design of the fabric size.
Research Progress of Biochar Materials for Remediation of Heavy Metal Contaminated Soil
Authors: Wang Han , Tang Yuheng
Published: November 2020

In recent years, with the acceleration of urbanization and the high-speed development of industry, heavy metal pollution of soil has become increasingly serious, posing a huge threat to economic development and human health. The use of biochar to control soil pollution has become a research hotspot. Biochar has unique physical and chemical properties. It can lessen the transfer and transformation of heavy metals when being used to adsorb and fix heavy metals, and has great application potential in repairing heavy metal pollution. This article reviews the factors affecting biochar remediation of soil heavy metal pollution, the preparation and application of functional biochar, and the adsorption mechanism and remediation effect of biochar on heavy metals. Finally, the article summarizes the current problems of biochar repair technology and makes prospects for future development, hoping to provide reference for future research by science and technology workers.
Structural Analysis for Tensile Behavior of Silicon-Carbon Core-Shell Nanotube
Authors: Li Min , Tian Zean , Xie Quan , Dong Kejun
Published: November 2020

This paper presents a molecular dynamics study on the tensile behavior of carbon nanotubes (CNT) with or without nanowire of Si (SiNW) encapsulated. Compared to the CNT without SiNW, the CNT with the SiNW (denoted as SiNW@CNT) shows a decreased tensile strength but an increased maximum tensile deformation rate. The micromechanisms of the different tensile behaviors were explored through the structural analysis including the radial distribution function, the bond angle distribution function, and the statistics of the polygon defects. The results showed that the C-C bond in the CNT under the maximum tensile deformation becomes longer and more uniform due to the van der Waals force between the SiNW and the CNT, which accounts for the change in the macroscopical tensile behavior. Moreover, it has been found that after tensile fracture, the CNT mainly form long chains consisting of triangle, pentagon, and heptagonal defects, while SiNW@CNT cannot form long chains due to the lack of triangular defects. These differences in the microstructures are probably because the C-C bonds in the SiNW@CNT can be strengthened by the SiNW. The results provide a better understanding of the fracture of the CNT and its nano composites, and have certain reference value for the application of the SiNW@CNT.
A Design of combined pipe cleaning and spraying robot based on new cutting tool material
Authors: Yangli  , Wei Tianlu , Chen Xingqiang , Li Dasheng
Published: November 2020

The combined pipeline cleaning and spraying robot based on new cutting tool material includes four components, namely milling mechanism, walking mechanism, spraying mechanism and external coating supply device. The robot’s milling cutter is a special coating cutter. The coating material of the cutter can be used to meet the peeling strength of the pipe surface after spraying. From the view of environmental protection, the robot can reduce the impact of passive process on the environment. According to the actual situation the combination robot can be combined freely, which has a strong practicability.
The partial isothermal section of the Mg-Er-Si Ternary System at 500°C
Authors: Ma Chunhua , Zhang Dingfei , Pan Fusheng , Lu Zhiwen , Zhao Yazhong
Published: November 2020

The partial isothermal section of the Mg-Er-Si ternary system in the Mg-Corner at 500°C has been studied through the equilibrated alloy method by using X-ray diffraction analyses and scanning electron microscopy assisted with energy dispersive spectroscopy of X-ray (SEM-EDS). There is convincing evidence for three compounds which have been clarified to be existing in equilibrium with the a-Mg solid solution at 500°C, i.e. Mg2Si, Er2MgSi2 and Er5Mg24. The results show that the partial isothermal section in the Mg-Corner consists of four single phase regions, five two-phase regions: α-Mg+Er5Mg24, α-Mg+Mg2Si, Mg2Si+Er2MgSi2, α-Mg+Er2MgSi2 and Er5Mg24+Er2MgSi2 and two three-phase regions: α-Mg+Er5Mg24+Er2MgSi2 and α-Mg+Mg2Si+Er2MgSi2. The homogeneity ranges of Mg solid solution as well as the solid solubilities of the intermediate phases at 500°C are reported. The phase of Er5Mg24 (cI58-Mn-type), Mg2Si (cF12-CaF2-type) and Er2MgSi2 have been mainly studied.
Multi-color modulation of phase-changing optical coatings
Authors: Chen Qing Yuan , Liu Fu Rong , Huang Yin , Li Yu
Published: November 2020

Now, various display screens transmit massive information to people all the time and become an important window of human-computer interaction. Solid state optical coating utilizes optical interference effect and inherent optical properties of materials to achieve multiple colors. In this paper, between Fabry-Perot (F-P) cavity coating with dielectric layer and strong interference effect (SIE) coating without dielectric layer were compared. Effect of film thickness on F-P cavity optical phase change coating was studied. The results show that the F-P cavity coating with a dielectric layer has more reflective states than the coating without a strong interference effect, that is, potential for optical coating display. In addition, in the F-P cavity coating, by controlling the thickness of SiO2 and Ge2Sb2Te5 (GST) film, the optical coating shows rich color due to the change of F-P optical cavity length and strong interference effect of materials. We also carried out a study of the flexible substrate compatibility and substrate color of the two structures, and found that they are well compatible with flexible materials, and F-P is more sensitive to substrate color than SIE structures in terms of substrate color. Due to the far subwavelength layer thickness, most phase shift is accumulated on reflection at the interfaces, which makes the reflectance profile robust under tilted incidence.
Investigation of the evolution of free carriers during femtosecond laser-induced ultrafast amorphization in nitrogen doped Ge2Sb2Te5 films
Authors: Wang Y.H. , Liu F.R.
Published: November 2020

The femtosecond laser-driven ultrafast evolution of free carriers during the phase-change process of N-doped Ge2Sb2Te5 (N-GST) film was studied in this paper. And mechanism of initial absorption peak was calculated by two-temperature model. We found that the formation of Ge-N weaken the initial optical absorbance and decreased the concentration of free carriers, then improved the temperature of crystallization in N-GST. The doping(N) can reduce the grain size because of the easing of optical energy absorbance. At last, we inferred that, if the incident laser fluence is enough for phase transformation point, the transformation velocity of N-doped GST is faster than GST.
Hamiltonian System and Viscoelastic Boundary Conditions
Authors: Zhang WX , Zhang XC
Published: November 2020

By using Laplace integral transformation, the viscoelastic stress-strain relationship in the time domain is described as an algebraic equation in Laplace space, which makes the Hamiltonian system method smoothly implemented. Thus, the basic control equations with displacement and stress as basic variables are established, and the viscoelastic problem is transformed into the eigenvalue and eigensolutions. The eigensolutions include a series of independent functions, in which the zero eigenvalue eigensolutions cover all the basic deformations such as tension and bending, and do not decay with the space coordinates.
Electronic and transport properties of armchair graphene nanoribbons with defects
Authors: Zhang Yu , Xu Wenjing , Liu Guangjie , Zhu Jinlong
Published: November 2020

Density-functional theory (DFT) in combination with the nonequilibrium Green’s function formalism is performed to study the electronic and transport properties of armchair graphene nanoribbons with defects. The results show that the electronic and transport properties vary with different type of defects. The binding energy indicate that single-defect AGNRs are the most stable structure and line-defect AGNRs are the most unstable structure. The transmission spectra show that the defective AGNRs become disorder and the value decreases. The energy gap at the Fermi level become wider. These results would guide the experiments in real applications.
Performance Analysis of Absolute Acceleration Shock Response Spectrum
Authors: Sun Wenjuan , Su Qiaoping , Yuan Hongli , Chen Song
Published: November 2020

The Absolute Acceleration Shock Response Spectrum (AASRS), which is most commonly used in engineering is analyzed in detail, and the effects of shock duration, shock amplitude and shock waveform on AASRS are discussed respectively. Shock duration has the greatest influence on the shape and change trend of AASRS, followed by shock amplitude. However, shock amplitude only affects the amplitude of AASRS and does not change the overall change trend. Shock waveform has the smallest influence on AASRS and mainly affects the frequency point of peak acceleration.
Failure Analysis on Galvanized Steel-tube Pole Used for Supporting Electrical Equipment in 500 kV Substation
Authors: Chen Hao , Tian Feng , Zhao Xiaochun , Gong Weiwei
Published: November 2020

Electrical equipment in substation plays a key role in power transmission and distribution, which is usually supported by the steel-tube pole. In recent years, more and more crack defects were found in steel-tube pole used for supporting electrical equipment in substations, thus the safety and stability of power grids is severely affected. In this paper, the cracked steel-tube support of electrical equipment in a 500kV substation was investigated by means of macro-morphology inspection, chemical composition analysis, mechanical properties test, microstructure analysis, water sample analysis and fireworks experiment. The result showed that there was a grouting hole with poor sealing in the top of the steel-tube pole, so the rainwater and snowmelt could flow into the tube through the gaps. Once the temperature dropped abruptly, the water inside the tube would freeze and expand, led to the bursting of the steel-tube pole. Finally, effective suggestions were put forward, which could ensure the electrical equipment operating safely and stably.
A Safety Risk Evaluation Index System of Subway Projects Based on the Analytic Hierarchy Process
Authors: Wu Han , Qian Zhixin , Wang Junwu
Published: November 2020

The construction process of the subway project, which is a hidden underground project, is facing many unknown factors, and construction technology is difficult and the quality requirement is high. In order to ensure the safety of subway construction personnel, property and smooth completion of the project, this paper selects and constructs the influencing factors of subway project construction safety risk evaluation according to the 4E1M method, calculates the weight of each index by the analytic hierarchy process, selects 60% of the indexes before the weight ranking, and establishes an index system including 5 criteria indexes and 16 secondary indexes.This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.
Dynamics Performance Analysis of a 400 km/h EMU
Authors: Liu Jun , Wang Qi , Yu Yunhai
Published: November 2020

In order to study the dynamics performance of a 400 km/h high-speed train, a nonlinear dynamics model of a 400 km/h EMU (Electric Multiple Units) composed of three vehicles is built. The dynamics performance of those vehicles under new and worn wheel/rail interactions are examined and compared through numerical analysis. It shows that the lateral acceleration on the middle vehicle is 23% smaller than that of the head vehicle and the tail vehicle under a new tread condition; in case of wheel wear, the lateral acceleration on the middle vehicle is 31% smaller than that of the head vehicle and the tail vehicle; the vertical wheel/rail force of the middle vehicle is 10.5% larger than that of the head vehicle and the tail vehicle; the lateral wheelset force under the worn wheel case is 52% greater than that under the new wheel condition. In all numerical cases, the vehicle dynamics indexes all meet the required limits which proves that the 400 km/h high-speed train is properly designed.
Finite element error analysis on transmission shaft parts and application of local mesh refinement
Authors: Xiaoying Wang , Xiaowei An
Published: November 2020

In view of the strength problem of the transmission shaft parts in the swinging and punching structure of the forging press, based on the finite element analysis theory and the mesh refinement method, the accuracy of the finite element calculation in the whole mesh refinement process is analyzed by comparing the element strain energy error and the energy percentage error of different node numbers. The results show that the edge length of the discretized element is reduced and the calculation accuracy is improved correspondingly, but the calculation amount of the whole mesh refinement is large.Therefore, local mesh refinement is applied to improve the calculation accuracy. The results show that the error of energy percentage tends to be 10%, and the calculation accuracy is high. The accuracy analysis method and the application of local grid refinement provide the theoretical basis for the structural optimization of mechanical products.