bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Thermal Conductivity of Fluorinated Graphene
Authors: Yan Yunrui
Published: July 2023

With the rapid development of technology and the advent of the 5G era in recent years, the heat dissipation of electronic devices has received great attention. However, the high intrinsic conductivity of ordinary graphene materials limits their potential applications in electronic packaging materials because of their poor thermal management. The results show that fluorinated graphene has excellent heat resistance, corrosion resistance, and strong wear resistance. It can also play a role in lubrication and is commonly used in high-temperature coatings, wear-resistant lubrication coatings and corrosion-resistant coatings because it does not react easily with other substances. Due to the strong electronegativity of fluorine, fluorinated graphene has strong stability and oxidation resistance at high temperatures. Therefore, in this paper, a fluorinated graphene with high compressibility, high thermal conductivity, and high electrical insulation was developed by hydrothermal method assisted by hydrofluoric acid, and the effect on the thermal conductivity of fluorinated graphene was investigated by changing the fluorine-to-carbon ratio (F/C) by adjusting the hydrofluoric acid content. The structure of fluorinated graphene was characterized by SEM and XRD, which proved to be porous and a customized interconnected graphene network with adjustable fluorine coverage. The prepared fluorinated graphene has good insulating properties with a minimum conductivity of 4×10-7 S cm-1 and a thermal conductivity of 1.254 W m-1 K-1, which has been confirmed by the electrical conductivity test results. Meanwhile, because of the porous structure of graphene fluoride, we prepared epoxy resin/fluorinated graphene nanocomposites by vacuum-assisted infiltration process using epoxy resin as the filler material. This material and fluorinated graphene showed outstanding thermal performance during the typical cooling process. The conclusion shows that graphene fluoride and epoxy resin/fluorinated graphene nanocomposites are promising for electronic packaging.
An aging study of PLA-PBAT blends in commercial beverages
Authors: Han Guocheng
Published: July 2023

To evaluate the potential of biodegradable materials in beverage packaging applications, five aquatic simulants and eight different commercial beverages were set up to study the aging effects of PLA-PBAT blends. The experimental data for 6 months consistently indicate that aquatic conditions have a small impact on the weight change and surface characters. PLA-PBAT blends show slow oxidation and decomposition process, which were less than ±1%, like the samples exposed to air. Among different beverages, non-alcoholic and alcoholic drinks showed little difference, while acidic beverages had a relatively remarkable surface erosion effect on the biodegradable materials.
The Study and Application of Nanosilica Biosensor for Sweat Detection
Authors: Chen Chen , Chen Yanxia , Chen Zhiwei , Qin Lei
Published: July 2023

Sweat analysis is a non-invasive, simple, and convenient means of disease detection, which is extremely useful in human daily supervision. This work demonstrates the design of the nanosilica biosensor for simple, sensitive, and low-cost colorimetric sensing of glucose and pH in sweat. The nanosilica biosensing interface was prepared by chemical vapor deposition, surface modification, superwettable patterning, and sensing regions functionalization. The nanosilica substrate has high mechanical robustness and is stable enough as a biosensing platform. Colorimetric tests enable direct naked-eye observation monitoring of sweat indicators like pH and glucose without the need for electrical or optical apparatus. This will greatly enhance the convenience and reduce costs. The design of a biosensing platform will be made possible by the nanosilica biosensor, which also has significant promise for applications in clinical detection and multicomponent biosensing.
Study on Bonded Dispersant for Ultrafine CL-20
Authors: Zhao Yuanyu , Jiang Xiabing , Ba Shuhong , Ma Li , Guo Xiaowei , Wang Fei , Xia Ping , Qiang Zhiduo
Published: July 2023

To improve the problem that ultrafine hexanitrohexaazaisowurtzite (CL-20) is prepared by the solvent nonsolvent method, which tends to coalesce and automatically affects its thermal properties, the bonding agent @CL-20 core-shell composite energetic materials (ammonium dodecylbenzene sulfonate@CL-20, trimethylsilyl monooleate@CL-20 and boron nitride@CL-20) were prepared by water suspension method. The coated ultrafine CL-20 was characterized by an optical microscope, scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC), and its sensitivity was tested according to GJB 772-1997. The results showed that the three bonded dispersants completely coated CL-20, and the crystal form of CL-20 was still ε-. Compared with the raw material CL-20, the characteristic drop increased by 27.5cm at most and the thermal decomposition temperature increased by 4 °C.
Research on the application of new functional materials in concrete
Authors: Li Geli
Published: July 2023

The self-made polycarboxylic acid water reducer was used as a dispersant to investigate its influence on the dispersion property of new functional material graphene slurry. The dispersion technology in the preparation process of new functional material and the influence of the dosage of new functional material on the performance of concrete were studied. The results showed that the self-made polycarboxylic acid water reducer as a dispersant can improve the dispersibility of the new functional material graphene in water. When the ultrasonic dispersion time is 40min, it can be used to discharge bubbles in the graphene dispersion solution and improve the strength of concrete. By means of manual mixing, the concrete containing the dispersible liquid of the new functional material has less slump and less expansion loss at 1h, and higher compressive strength at 3 d, 7 d, and 28 d. The 7 d and 28 d compressive strength of concrete can be significantly improved when the content of new functional material graphene dispersion is 0 ∼ 0.23 %, and the optimal content of graphene dispersion is 0.05 %.
An Attempt to Evaluate and Optimize the Hydroforming of Fiber Metal Laminates with the Comprehensive Forming Limit Curve
Authors: Zhang Meng , Mirza Hasnain Ali , Li Yong
Published: July 2023

Although some papers have studied the formability of fiber metal laminates (FMLs), there is still a lack of a standard criterion for the engineering field. To give a standard for predicting the failure and provide the optimized method of the hydroforming process for FMLs, a comprehensive forming limit curve (FLC) was established by a hydro-bulging test method. The influence of pressure rate (PR), blank holder pressure (BHP), and temperature (T) was studied in this paper. Both theoretical and experimental results showed that the higher BHP and PR have a significant negative effect on limit height, while increased T has a positive effect. Moreover, the semi-cured forming of a real part was evaluated by this FLC for the very first time and the improvement suggestions of process parameters were given based on the comprehensive research. Finally, the real part that met the quality requirements was obtained by numerical simulation and trial production, which verifies the effectiveness of this comprehensive FLC.
The Study of the Material Principle and Physical Characteristic Analysis of eGaN FETs
Authors: Jiang Jie , Liu Zhe , Wang Ti , Chen Qinglai , Wang Lin
Published: July 2023

As for the typical representatives of wide bandgap semiconductors, eGaN FETs (Enhancement Mode High Electron Mobility Transistors) are most commonly used for envelope tracking, wireless power supply, automatic pilot, the defence industry, etc. This paper compares the characteristics of different semiconductor materials and analyzes the performance advantages of GaN-based materials. On the basis of device structure analysis, this paper illustrates the Miller Effect during the device conduction process and discusses working modes under different working conditions. With respect to the drive circuit, it calculates the optimum gate driving resistor and theoretically computes the various losses of eGaN FETs.
Application of waterborne epoxy acrylic photosensitive resin in coating and wet-end addition during pulping and papermaking
Authors: Zhou Yan , Yang Zhiyong , Xing Renwei
Published: July 2023

Light curing coating has many advantages and it has the potential prospect in chemical engineering. It could be popularized as a new paper-reinforcing agent. In this paper, the waterborne epoxy acrylic photosensitive resin was prepared with the raw materials of epoxy resin, acrylic acid, and maleic anhydride. Its applications were studied in coating and wet-end addition during pulping and papermaking. At the same time, the effects of feed ratio (Solid content), pH value, and UV (Ultraviolet) curing sequence on the strength of the resin were discussed. The results showed that the physical strength of papers was significantly improved when the resin was used in coating and wet-end addition. In addition, the photosensitive resin had the characteristics of being fast and environmental-friendly. It indicated that the waterborne epoxy acrylic photosensitive resin met the requirements of being a paper-wet strength agent.
Adsorption properties of the composite of cross-linked starch and magnesium hydroxide
Authors: Li Haihua , Gao Yuhua , Zhang Lihui
Published: July 2023

Magnesium hydroxide has good adsorption performance for Cu2+ in wastewater as an adsorbent, while magnesium hydroxide particles carry a lot of electric charges, which makes it difficult for the particles to settle. To solve this problem, the composite of cross-linked starch and magnesium hydroxide IStMg was synthesized. IStMg was prepared by using cross-linked starch and MgSO4·7H2O as raw materials and NaOH as an alkalizing agent, and the adsorption performance of this composite for Cu2+ was tested. In the adsorption experimentials, when ρ

0cu2+=20 mg/L and the dosage of IStMg was 300 mg/L, the removal rate of Cu2+ was 91.7%. The absorption mechanism contains the complexation of the hydroxyl group in magnesium hydroxide to Cu2+ and the ion exchange between Mg2+ and Cu2+.
Study on the Aging Mechanism of Aerospace Plexiglass by Ultraviolet
Authors: Yao Zhipeng , Gai Di , An Tingrui , Shao Yongxuan , Yu Shengjie , Lan Shuowen , Jiang Zihao , Gao Jianan
Published: July 2023

As the main material of aircraft windshield glass, the safety and reliability of aviation plexiglass are very important. YB-3 aviation Plexiglass was used as aircraft windshield material for a four-seater electric aircraft developed in China to explore the mechanism of ultraviolet aging. The artificially accelerated aging test of YB-3 aviation plexiglass was carried out, and the mechanical and thermodynamic system of YB-3 aviation Plexiglass after aging was studied. Through the thermogravimetric dynamic analysis, it is to explore the internal aging mechanism of PMMA photolysis materials, and combined with the mechanical test data to quantitatively and qualitatively reveal the aging law of YB-3 aviation plexiglass under ultraviolet radiation. The results show that the tensile ultimate stress decreases from 72.74 MPa to 45.63 MPa when the aging time reaches 1440 h. During the aging process, the elastic modulus decreased from 4.45 GPa to 3.68 GPa and then increased to 4.12 GPa. The results show that the photolysis of YB-3 aero-plexiglass under ultraviolet radiation first results in the fracture of the polymer and then the production of small molecules, which leads to the decrease of tensile resistance and the improvement of thermal stability of the material.
Study on Synthesis of 9,9-Bis (4-hydroxyphenyl) Fluorene by Heteropoly Acid Catalysis
Authors: Liu Bin , E Yongsheng
Published: July 2023

9,9-Bis (4-hydroxyphenyl) fluorene is synthesized with heteropoly acid instead of inorganic acid as the catalyst, which has great significance for environmental protection. In this experiment, the synthesis of 9,9-bis (4-hydroxyphenyl) fluorene is studied by using fluorenone and phenol as raw materials, using homemade heteropoly acid 11-tungsten-titanium titanium (molecular formula H4Ti(H2O)TiW11O39) as the catalyst and 3-mercaptopropionic acid as the cocatalyst. The structure of the catalyst was characterized. The effect of the molar ratio of raw material, reaction temperature, reaction time, and the dosage of catalyst and cocatalyst on the purity and yield of 9,9-bis(4-hydroxyphenyl) fluorene are investigated, and the best reaction conditions are obtained. The results show that the new catalyst has a good catalytic effect, and the product has good quality and a high yield.
Study on the Synthesis and Rheological Properties of Polycarboxylate Superplasticizer with Different Main Link Density
Authors: Wang Zhaopeng
Published: July 2023

Rheological properties of concrete are considered to be the most ideal method to characterize the working performance of concrete. Rheological models are used to quantitatively characterize the working performance of concrete based on the yield stress and viscosity of fresh cement paste. In this paper, Rheology QC was used to study the influence of different main link densities (acid-ether ratios) on the rheological properties of fresh paste. The Bingham model was used to fit the rheological curve of the slurry, and the influence of different main link densities on the yield stress, plastic viscosity, and thixotropic ring area of the slurry was analyzed. And the structural characterization and concrete performance characterization were carried out. The results show that the plastic viscosity and yield stress decrease with the increase of the main link density, and the thixotropic area also increases first and then decreases. When the acid-ether ratio is 3.5, the dispersion, rheology, and thixotropy properties of the sample are better.
Study on Preparation of Homogenized Highly Dispersible AlON Powder
Authors: Xue Zhongyuan , Liu Yuyang , Wang Xingming
Published: July 2023

The quality of Aluminum oxynitride (AlON) powder is the main factor affecting the properties of ceramics. To accurately control the nitrogen AlON content and improve the dispersion degree of powder, AlON powder was prepared from γ-Al2O3 and activated carbon powder by carbothermic reduction and nitridation. The uniformity of distribution of raw materials and the dimension and microstructure of AlON powder was controlled by changing the time and rotation rate of the ball milling process. The influences of ball milling process parameters on the microstructure and distribution uniformity of Al2O3/C mixed powder, microstructure, and particle size of AlON powder were studied. The results show that powder agglomeration was effectively reduced, and the uniformity of raw material distribution was increased by controlling the time and rotation rate of the ball milling process. The Al2O3/C mixed powder has good particle size and uniform distribution with roller ball milling for 24 h. After holding the powder at 1700 °C for 60 min, the homogenized AlON powder was obtained, and the residual carbon content was about 0.04 wt%. When the time of planetary ball milling at 250 rpm was 16 h, highly dispersible AlON powder was obtained.
Achieving Long Cycle Life and Single-Crystal of Li-rich Mn-based Cathodes by Reheating with Sintering Additives
Authors: He Haocheng , Li Hao , Mou Lisha , Ou Mei , Wang Hua , Ren Zhimin , Zhang Xiangjun
Published: July 2023

Lithium-rich layered oxides, as one of the most potential cathode materials for lithium-ion batteries, still need crucial improvements in mechanical strength and cycle life. Herein, we present an effective strategy to improve the compacted density and cycle stability of Li-rich materials by adding the sintering additive (H3BO3, Li2WO4) for reheating. After reheating with a complex additive of Li2WO4 and H3BO3, the compacted density increased from 3.07 to 3.29, and micromorphology changed from spherical secondary agglomerate to dispersive single crystals with micrometer size. It was found that after reheating with Li2WO4, the sample exhibited a discharge capacity of 241.9 mAh g-1 with an improved ICE of 80.9 %, and cycle life extended to 658 cycles, increased by nearly 250 cycles. This work guides the industrialization of Li-rich cathodes.
Study on Preparation of Slow-release Polycarboxylate Superplasticizer by Macromonomer EPEG at Room Temperature
Authors: Chen Hao
Published: July 2023

Slow-release polycarboxylate superplasticizer was synthetic under room-temperature conditions, a free radical copolymerization reaction occurred under the action of a redox initiator, and the optimal preparation process and temperature effect were discussed in detail. The results show that the best preparation process (EP-15) is: acid-to-ether ratio is 1.89, the amount of NaH2PO2 is 2.27%, the appropriate reaction temperature is 15-25°C, and the suitable macromonomer is EPEG-3000 of OXIRANCHEM. Tests have verified that compared to a commercially available slow-release polycarboxylate superplasticizer (PCE-1), EP-15’s dispersion retention performance and the strength growth of concrete in 3 d, 7 d, and 28 d are significantly better.
Preparation and Characterization of fluorinated copolymer emulsion for concrete protection
Authors: Qiu Xi-Rong , Xu An-Hou
Published: July 2023

Emulsifier-free copolymerizations of 2,2,2-trifluoroethyl 2-methylpropanoate (TFMPA) and methyl acrylate in the presence of surface-active commoner, undecylenic acid (UA), were carried out using potassium persulfate (KPS) as initiator. The prepared copolymer emulsions were characterized and analyzed by FT-IR, 1H and 19F NMR spectra, TEM, dynamic light scattering (DLS), and contact angle testing. The results showed that the average particle size of copolymer latex particles was 200-300 nm with a relatively uniform particle size distribution. The glass transition temperature was controlled with the monomer feed ratios. After copolymer emulsions coating on the concrete surface, the contact angle was significantly increased, and the water absorption of the concrete was significantly reduced.
Study on sustained-release polycarboxylate superplasticizer prepared by EPEG macromonomer
Authors: Chen Zhanhua
Published: July 2023

Ethylene glycol monomer polyoxyethylene ether (EPEG) is a new macromonomer that has been introduced in recent years. Its special molecular structure enables it to form copolymers with acrylic acid (AA) that are closer to the ideal copolymerization structure. However, the current production capacity is relatively small, so there are not many related studies. Therefore, this paper uses EPEG as the main raw material to prepare a slow-release polycarboxylate superplasticizer SP-YH. By studying the effects of different reaction conditions on the properties of SP-YH, the optimum synthesis conditions were determined. The structure of the polymer was characterized by gel permeation chromatography (GPC) and infrared spectroscopy (FTIR). In addition, the concrete test and hydration heat test results show that it has better slump protection performance and compression resistance than the commercial slump protection polycarboxylic acid water reducer.
The study on performances of environment-friendly colorless chemical conversion coatings on aluminum alloy
Authors: Hou Bin , Zhu Lizhi
Published: July 2023

With the increasingly high requirements on the appearance of electronic equipment and environmental protection, conventional chromate chemical conversion coatings on aluminum alloys gradually showed some shortcomings, such as the color difference in appearance and harm to human health and the environment in the process. In this paper, three kinds of environment-friendly colorless chemical conversion coatings (LANTH-613, ALTRCHR-250, YMT-631) were prepared by using 5056 and 6061 aluminum alloy samples and visually observing the appearance of the coatings. Then, the performances of the coatings, such as the morphology, corrosion resistance, electrical contact resistance, and paint adhesion, were characterized by scanning electron microscope, salt spray test, electrical contact resistance test, and cross-cut test, respectively. As a result, we proposed YMT-631 colorless chemical conversion coating could be used alone as a long-term protective coating for aluminum alloy parts that require the natural appearance of aluminum in electronic equipment, by which corrosion resistance and adaptability in the harsh environment could be significantly improved.
Study of Fe-Doped Ordered Mesoporous Titanium Dioxide Synthesis
Authors: Yan Zhiyuan , Ren Han , Geng Yuan , Yuan Yuehui , Meng Sicong , Cheng Rongchao , Qu Yuanzhi , Wang Ren , Yang Hong , Gao Shifeng , Zhang Yan , Zhang Zhilei
Published: July 2023

Titanium dioxide is often designed as an excellent catalyst carrier and photocatalyst due to its tunable structure. In this paper, iron-doped ordered mesoporous titanium dioxide was prepared. These powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen physisorption (BET). It was found that mesoporous titanium dioxide powders containing 1% Fe doping were roasted at 350 °C to favor the formation of ordered mesoporous titanium dioxide. This is due to the fact that Fe doping can enhance the pore structure and improve the orderliness of pores, while the increase in temperature can accelerate the growth of grains.
Determination of Several Free Radicals in Electrochemical Disinfection
Authors: Tie Zihan , Qi Lihong , Zhang Jidong , Yang Jinxing , Wang Xuefeng , Zhang Jianhong
Published: July 2023

Electrochemical disinfection is a broad spectrum, efficient, clean, and environment-friendly, and is widely used in water treatment technology. In addition to the active chlorine generated by electrolysis, the oxidation of active oxygen free radicals cannot be ignored. In this paper, the electron spin resonance (ESR) technique is used to measure the ESR spectra of ·OH. 1O2, and O2
- that may exist during the electrolysis process and after the electrification by using two methods of mixed electrolysis of capture agent and electrolyte and adding capture agent after electrolysis. The catalytic activity of four DSA titanium base plates is compared, the existence of several active oxygen free radicals in the electrolysis process is confirmed, and the generated path is inferred. The experiment shows that these reactive oxygen radicals can be produced during the electrification process, and they accumulate continuously with the extension of electrolysis time. After the electrification, the process will continue for a period of time due to the Fenton reaction of metal catalytic ions.
Study on preparation and properties of nanocrystalline TiO2/graphite photocatalytic composite by mechanochemistry
Authors: Pan Xiaoyan
Published: July 2023

Graphite-modified TiO2 composite is a promising photocatalyst in environmental purification. In this study, TiO2/graphite photocatalytic composites were prepared by mechanochemistry using natural flake graphite and nanocrystalline TiO2 as raw materials. The composites were examined by X-ray diffractometer, Raman spectrometer, X-ray photoelectron spectrometer, scanning electron microscope and UV-vis spectrophotometer. The photoelectrochemical properties of the composites were investigated via electrochemical impedance spectroscopy and photocurrent response. The influences of the content and premilling time of graphite on the photocatalytic properties of the composites were studied through the photocatalytic decomposition of methylene blue. The results showed that graphite was exfoliated and broken during ball milling, and defects of graphite increased with the extension of milling time. In the composite, there is no solid solution of carbon atoms in TiO2 lattice. The photocatalytic results indicated that a proper amount of graphite could improve the photocatalytic behavior of TiO2. The TiO2/graphite composite containing 1wt% graphite exhibited the best photocatalytic behavior. The pretreatment of graphite by ball milling could enhance the photocatalytic behavior of the TiO2/graphite composite and the optimal premilling time of graphite was 4 hours.
A Research of Selective Catalytic Reduction of NOx with NH3 by Using Novel Catalysts
Authors: Bai Shuiquan
Published: July 2023

Nitrogen oxides are one of the most important industrial pollutants, which have many harmful effects on the human body and the environment. In this paper, the formation mechanism of nitrogen oxides was studied, and the selective catalytic reduction of nitrogen oxides was carried out by selective catalytic reduction technology. This paper also reviews the low-temperature denitration performance of molecular sieve catalysts, manganese oxide and ceria-based catalysts, and expounds on the influence of catalysts on denitration activity under different active components. It is found that ceria-based catalytic materials have better structural properties and catalytic performance, the methods to improve the performance of ceria-based catalysts are discussed, and the future development of ceria-based catalysts has been prospected.
Finite element analysis on first deep drawing process of combustion calotte made of high temperature alloy GH536
Authors: Wu Shibao , Gao Jing , Li Wenbo , Ma Jia , Wang Heng
Published: July 2023

In order to investigate the characteristics of the deep drawing process of a combustion’s calotte which was made of the high temperature alloy GH536, a finite element model which could simulate the first deep drawing process of this calotte was presented and change features of some key parameters in this deep drawing process were solved by ABAQUS software. Finite element analysis results revealed that ruptures were easy to occur and a press machine with larger tonnage was needed during this deep drawing process.
Study on the influence law and mechanism of industrial atmospheric environment on the corrosion behavior of Q235 carbon steel
Authors: Liu Sen , Wen Xiaohan , Hu Jiayuan , Zhu Liwei , Li Yanwei
Published: July 2023

This paper combines the traditional hanging test and corrosion sensor technology to study and explore the corrosion law and its mechanism of Q235 carbon steel in industrial atmospheric environment. The results show that Hangzhou’s industrial atmospheric corrosion is a constantly changing and highly variable corrosion intensity process with the corrosive strength shows a seasonal trend. Through the analysis of weight loss, macroscopic corrosion morphology, microscopic corrosion morphology and elemental distribution, it showed that the traditional hanging test results and sensor test results had a good correspondence, indicating that the sensor values can be used to study the corrosion of the outdoor samples.
Contributions of Different Functional Groups to Particles in Electrophoretic Display
Authors: Xu Shuteng , Zhang Yue , Zeng Debo
Published: July 2023

Electrophoretic display (EPD) has excellent research potential because of its ultra-low power consumption and friendliness to the eyes. To obtain efficient electrophoretic inks, researchers need to understand the charging mechanism of electrophoretic particles. In this work, several silane coupling agents with similar main chains but different functional groups on the side chains were used to investigate the effects of different functional groups on the charging properties of the electrophoresis particles. The results showed that silane coupling agents containing amino groups resulted in the most positively charged particles, and those containing carboxyl groups resulted in the most negatively charged particles. More importantly, after introducing many additional amino groups by grafting, it was found that the charge on the particle surface was only slightly elevated, indicating that the polymer layer grafted on the particle surface would cover the functional groups inside and hinder the acid-base interactions between the functional groups in the inner layer and the charge control agent. The findings of these results may contribute to the precise design of materials for electrophoretic display.
Influence of Guest Molecular Mass on Gas Hydrate Nucleation via Molecular Simulation
Authors: Li Liwen , Zhong Jie , Zhang Jun
Published: July 2023

Hydrates are ice-like crystals. Its nucleation event has important significance for many industrial fields, such as seawater desalination, gas separation, and gas storage. Therefore, researchers are looking for a kind of highly effective promoters to accelerate hydrate nucleation and stabilize hydrate crystals so that hydrate-based technology can be sustainable and economical. Herein, we use the molecular simulation method and construct ideal guest molecules to study the influence of guest molecular mass on the hydrate nucleation process. Our results show that lighter guest molecules nucleate more easily. However, when the light and heavy guest molecules coexist, the light guest molecules can only enhance the formation of the nucleation precursor but cannot effectively reduce the free energy barrier of hydrate nucleation because of the competition between the light and heavy guest molecules around the critical nuclear state. Overall, our work provides a theoretical basis for the development of hydrate promoters, which is expected to be helpful for their efficient design.
A mathematical study of the influences of dynamic parameters on the memory effect of glasses
Authors: Li Yan Zhuo , Bian Xiao Min , Fu Hao
Published: July 2023

Retaining an imprint of their thermal history is a hallmark of glassy materials. Although its microscopic origin is still in debate, this memory effect is the potential to be utilized in engineering applications as a way to rejuvenate the glasses. For a better understanding of it, we investigated how the memory effect is affected by non-exponentiality and non-linearity, which are two basic features of glass dynamics. A mathematical model with a linear superposition of relaxation functions at a series of experienced temperatures was employed to reproduce the memory effect. The results demonstrate that non-exponentiality has a leading role in determining memory behaviors while non-linearity influences it weakly. An enhanced memory effect found in a recent multistep temperature training experiment is understood with the decreasing non-exponentiality caused by the increasing dynamical heterogeneities of the system. This work provides a guide to regulating the memory effect in practical applications.
Preparation and Properties of Nitrogen-doped Graphene Composite Carbon Materials Prepared from Different Nitrogen Sources
Authors: Zhu Yangyang , Zhu Yu , Ni Hongjun , Gu Ruobo
Published: July 2023

To get materials with better electrochemical properties, the physicochemical properties of nitrogen-doped graphene composite carbon materials prepared from different nitrogen sources are investigated in this paper. Nitrogen-doped graphene composite carbon materials with pyridine, urea, and melamine as nitrogen sources (NGpyridine, NGurea, and NGmelamine) were prepared by electrospinning and post-heat treatment. The results show that graphene exists in all three kinds of composite carbon fibers in the form of multi-layers. The NGmelamine fibers have more defects, the distribution of NGpyridine fibers is more uniform and the diameter of NGpyridine fibers is mostly concentrated in 270-330 nm. The maximum current density of NGpyridine is 27.51 mA/cm2, that of NG urea is 8.99 mA/cm2, and that of NGmelamine is 2.24 mA/cm2. In comparison, NGpyridine shows better electrochemical performance.
Study on Modification Technology of Superfine Dry Powder Fire Extinguishing Agent
Authors: Wang Xuancheng
Published: July 2023

The superfine dry powder fire extinguishing agent has the characteristics of high fire extinguishing efficiency and low cost and has been widely used in the field of fire extinguishing. This paper briefly describes the classification and current problems of dry powder and analyzes the current technology of micronization and surface modification. The superfine dry powder fire extinguishing agent is greatly improved in water resistance by surface grafting modification, the water repellency meets the standard requirements, and the D90 particle size of the dry powder extinguishing agent after modification is ≤15μm.
Effect of oxygen-containing functional groups and pore structure characteristics of coal on the slurryability of coal wastewater slurry
Authors: Li Dedi , Feng Biao , Zong Yue , Lai Xinjie , Luo Yuanlin , Wu Yuechao , Huang Huimin
Published: July 2023

The physical and chemical characteristic of coal have an important influence on the slurryability of coal wastewater slurry. In this paper, eight different coals are used to make coal wastewater slurry, and the effects of oxygen containing functional groups and pore structure characteristics of different coal samples on the slurryability are analyzed. Results show that (a) Coal with more oxygen-containing functional groups on surface have stronger hydrophilicity, higher surface activity and have stronger adsorption capacity for water molecules, this will lead to the reduction of free water and the increase of viscosity of the slurry. (b) Coal with larger BET specific surface area and pore volume and smaller average pore diameter have the stronger ability to adsorb and store water in coal wastewater slurry, thus the concentration of coal wastewater slurry prepared from these coal is low. The conclusion of this paper can provide reference for coal selection in the preparation of coal wastewater slurry.
Research and synthesis of polyolefins materials
Authors: Qi Yuanxia , Li Xiaofang
Published: July 2023

Polyolefins are widely used in our lives, such as food packaging materials, agricultural films, and lubricants, but the lack of polar groups that can make polyolefins compatible with other types of materials has limited the use of polyolefins. This has been a challenging and highly concerned issue in academia and industry. Therefore, it is great significance that we introduce polar groups into polyolefins to improve the use of performance to synthesize functional polyolefins. In this paper, we introduce the direct catalytic polymerization of polar α olefin monomers using rare earth catalysts, and the experimental data shows that we have obtained a higher molecular weight and better selectivity polar α olefin monomer of homopolymer. Subsequently, we determined the optimal reaction conditions for the synthetic polymer through screening of different reaction conditions.
Analysis of damping characteristics in carbon fiber sheet embedded with an Acoustic Black Hole structure
Authors: Zheng Feng , Tang Zhiwen
Published: July 2023

Acoustic Black Hole (ABH) is a newly developed passive control method. It commonly uses the gradual change of the vertical thickness of the structure to control the propagation and aggregation of bending waves, which has excellent performance in structural vibration suppression and other aspects. Carbon fiber is the most famous composite material, the structure of low density, high strength and stiffness. The dynamic characteristics of carbon fiber sheet with ABH structure were analyzed by finite element method, and the vibration suppression performance was further verified by experiments. The results show that in the frequency range of 180~3000 Hz, the vibration level of the CFRP-ABH structure is reduced by 6~20 dB compared with the uniform thickness plate, showing excellent broadband vibration reduction performance.
Study on the technology of controlling nitrogen content in molten steel
Authors: Li Huicheng , Xie Changsheng , Yu Fei , Zhang Jianbin , Zhang Zhenglin
Published: July 2023

Nitrogen content has an prominent effect on the properties of rolling material and demands should be paid more attention. Even then the residuary nitrogen in steel is quite small, it has an impotent effect on the mechanical properties of materials. The present nitrogen content control process is relatively briefness and it needs to be farther studied. In this paper, through the analysis of possible nitrogen increase and nitrogen control-related production processes in the whole metallurgical process of steel, nitrogen control, and nitrogen reduction are carried out in stages by using an optimized smelting process. After adopting the new process, the final nitrogen in EAF can be reduced by 50%, the vacuum nitrogen removal efficiency can be increased by 20%, the nitrogen increase in continuous casting can be controlled below 5 ppm, and the final nitrogen content in rolled steel can be reduced to below 50 ppm.
Implementation of ACTS for STCF track reconstruction
Authors: Ai Xiaocong , Huang Xingtao , Liu Yi
Published: July 2023

With an electron-positron collider operating at
center-of-mass-energy 2–7 GeV and a peak luminosity above
0.5 × 1035 cm-2 s-1, the STCF physics program
will provide an unique platform for in-depth studies of hadron
structure and non-perturbative strong interaction as well as probing
new physics beyond the Standard Model in the τ-Charm sector,
succeeding the present Beijing Electron-Positron Collider. To
fulfill the physics targets and further maximize the physics
potential at STCF, the STCF tracking software should have capability
to reconstruct charged particles with high efficiency and excellent
momentum resolution, especially for the charged particles with low
transverse momentum down to 50 MeV. A Common Tracking Software
(ACTS) providing a set of detector-independent tracking algorithms
is adopted for reconstructing charged tracks with the information of
two sub-detectors, a μRWELL-based inner tracker and a drift
chamber, at STCF. This is the first demonstration of ACTS for a
drift chamber. The implementation details and performance of track
reconstruction are presented.
Attributing the driving mechanisms of the 2015–2017 drought in the Western Cape (South Africa) using self-organising maps
Authors: Odoulami Romaric C , Wolski Piotr , New Mark
Published: July 2023

The Southwestern Cape (SWC) region in South Africa experienced a severe rainfall deficit between 2015–2017. The resulting drought caused the City of Cape Town to almost run out of water during the summer of 2017–2018. Using the self-organising maps approach, we identify and classify the synoptic circulation states over Southern Africa known to influence the local climate in the SWC into three groups (dry, intermediate, and wet circulation types) using large ensembles of climate model simulations with anthropogenic forcing and natural forcing. We then assessed the influence of anthropogenic climate change on the likelihood of these circulation types and associated rainfall amounts over the SWC during the drought. Our findings suggest that during the drought, the frequency of dry (wet) circulation types increases (decreases) across all models under anthropogenic forcing relative to the natural forcing. While there was no clear direction in the associated rainfall change in the dry circulation types, rainfall decreased across most models in wet nodes. All models agree that anthropogenic climate change has increased the likelihood of dry circulation types (median probability ratio (PR): 0.93–0.96) and decreased that of wet circulation types (median PR: 1.01 and 1.12), indicating a shift towards lesser (more) wet (dry) synoptic circulation states and associated rainfall during the drought. The long-term climatology also depicts similar patterns indicating the drought may result from long-term changes in the frequency of wet circulations and their associated rainfall. This study further explains the anthropogenic influence on the dynamic (synoptic circulation states) and thermodynamic (rainfall) factors that influenced the SWC 2015–2017 drought.
Spatially detailed agricultural and food trade between China and the United States
Authors: Pandit Akshay , Karakoc Deniz Berfin , Konar Megan
Published: July 2023

The United States and China are key nations in global agricultural and food trade. They share a complex bilateral agri-food trade network in which disruptions could have a global ripple effect. Yet, we do not understand the spatially resolved connections in the bilateral US–China agri-food trade. In this study, we estimate the bilateral agri-food trade between Chinese provinces and U.S. states and counties. First, we estimate bilateral imports and exports of agri-food commodities for provinces and states. Second, we model link-level connections between provinces and states/counties. To do this, we develop a novel algorithm that integrates a variety of national and international databases for the year 2017, including trade data from the US Census Bureau, the US Freight Analysis Framework database, and Multi-Regional Input-Output tables for China. We then adapt the food flow model for inter-county agri-food movements within the US to estimate bilateral trade through port counties. We estimate 2,954 and 162,922 link-level connections at the state-province and county-province resolution, respectively, and identify core nodes in the bilateral agri-food trade network. Our results provide a spatially detailed mapping of the US–China bilateral agri-food trade, which may enable future research and inform decision-makers.
Generalized Hamiltonian drift-fluid and gyrofluid reductions
Authors: Tassi E
Published: July 2023

We provide a procedure for deriving Hamiltonian reduced fluid models for plasmas, starting from a Hamiltonian gyrokinetic system in the

δ
f

approximation. The procedure generalizes, to a considerable extent, previous results. In particular, the evolution of moments with respect to the magnetic moment coordinate is also taken into account, together with background density and magnetic inhomogeneities. In the limit of vanishing Finite Larmor Radius (FLR) effects, an infinite family of reduced electron drift-fluid equations is derived, evolving all the electron moments

g

i

j
e

, with

i
=
0
,
…
,
N

and

j
=
0
,
…
,
M

, where N and M are arbitrary non-negative integers counting the maximum order of the moments taken with respect to the parallel velocity and to the magnetic moment coordinates, respectively. An analogous result is found in the gyrofluid case and applied to the ion species. The gyrofluid result holds for

M
⩽
1

, finite FLR effects and a low ratio β

e
between electron internal pressure and magnetic guide field pressure. In both the drift and gyrofluid case, the key for the identification of the Hamiltonian structure resides in changes of variables based on orthogonal matrices that diagonalize the Jacobi matrices associated with Hermite and Laguerre polynomials. In terms of the transformed variables, the drift and gyrofluid equations are cast in a simple form, which reduces to advection equations for Lagrangian invariants in the two-dimensional case with homogeneous background. Because the procedure requires to evolve, for a particle species s, all and only the moments

g

i

j
s

, with

i
=
0
,
…
,
N

and

j
=
0
,
…
,
M

, not every choice for the set of moments is admissible, for fixed N and M. This might also explain the scarcity of Hamiltonian reduced fluid models obtained so far which account for anisotropic temperature fluctuations.
University of Genoa best practices in managing Energy and Climate Change
Authors: Massucco S , Del Borghi A , Delfino F , Laiolo P , Marin V , Moreschi L , Vinci A
Published: July 2023

Since 2011, the University of Genoa (UniGe), Italy, focused on sustainable management of its campuses. In one of them, the Savona Campus, research and projects are specifically focused on Sustainable Energy and Smart City topics. Great efforts were made to reduce the carbon footprint by the creation of two large Research Infrastructures (a Smart Microgrid and an energy self-sufficient building) integrating different renewable energy sources and system automation. These infrastructures allowed to improve the energy performance of the Campus. Several actions have been then carried out also in the Genova Campus, including the implementation of a system for the real-time monitoring of the consumption of electricity for the most energy-intensive buildings. Results permitted to reduce energy consumption and provided significative and practical guidelines for energy saving. In 2015, the UniGe Commission on Environmental Sustainability was created and since then UniGe joined several international sustainability networks, such as ISCN (International Sustainable Campus Network) and UNICA GREEN (Network of Universities from the Capitals of Europe), sharing its best practices with other universities. UniGe is also active member of the Italian Universities’ Network for Sustainable Development (RUS). In 2022 UniGe made a strong and explicit pledge against climate change, defining its Climate Neutrality Strategy 2022-2030. The strategy, starting from its latest UniGe greenhouse gases (GHG) inventory, outlines a path that the university must follow to reduce both direct and indirect emissions and defines the actions to do for the offsetting of residual emissions. This is the last step of the strong and continuous commitment towards the spreading of the sustainability culture in all the Campus activities.
Adopting Smart Integrated AgriAquaculture IAA Techniques: A Sustainable Approach by Al-Furat Al-Awsat Technical University
Authors: Al-Zaini Essam O.
Published: July 2023

In light of recent developments in urban agriculture and the ongoing effects of climate change, there is a growing need for innovative irrigation practices that do not require potable water. On the other hand, significant environmental hazards are associated with the effective usage, treatment, and disposal of ever-increasing quantities of wastewater and sewage sludge in our modern times. Therefore, wastewater usage in irrigation might provide a potential alternative approach. In this regard, the water drained from fish farms is one type of wastewater capable of being employed in irrigation operations in a way that is both effective and helpful.

This article highlights the efforts made by Al-Furat Al-Awsat Technical University to establish intelligent integrated AgriAquaculture (IAA) systems on its campuses as part of its strategies to achieve sustainable goals. These efforts are part of Al-Furat Al-Awsat Technical University’s more enormous efforts to achieve its goals.
Green Metrics Questionnaire as the basis of Green University strategy
Authors: Rakhmetullina S , Shaimardanov Zh , Petrova O , Idrisheva Zh , Kolpakova V , Apseitova A
Published: July 2023

Today we are facing environmental challenges that include climate change and energy security, environmental degradation, water and food security, overexploitation of all natural resources and other pressing environmental issues. The participation of D.Serikbayev EKTU in the Green Metric world ranking has become the basis for the strategic development of the university to maintain the sustainability and environmental of the campus. Systematic work to improve the indicators of the Green Metric questionnaire provided not only a worthy position of EKTU (123 place) among almost 1000 universities in the world, but also allowed to increase the share of buildings where “green” and “smart” campus technologies are implemented, thereby reducing energy and resource consumption. The results achieved in the field of energy and climate change show that purposeful work to improve the indicators in the ratings can lead to the desired results in terms of sustainability and environmental friendliness.