Novel wood-plastic composite fabricated via modified steel slag:Preparation,mechanical and flammability properties

A novel method was developed to enhance the utilization rate of steel slag(SS).Through treatment of SS with phosphoric acid and aminopropyl triethoxysilane(KH550),we obtained modified SS(MSS),which was used to prepare MSS/wood-plastic composites(MSS/WPCs)by replacing talcum powder(TP).The composites were fabricated through melting blending and hot pressing.Their mechanical and combustion properties,which comprise heat release,smoke release,and thermal stability,were systematically investigated.MSS can improve the mechanical strength of the composites through grafting reactions between wood powder and thermoplastics.Notably,MSS/WPC#50(16wt%MSS)with an MSS-to-TP mass ratio of 1:1 exhibited optimal comprehensive performance.Compared with those of WPC#0 without MSS,the tensile,flexural,and impact strengths of MSS/WPC#50 were increased by 18.5%,12.8%,and 18.0%,respectively.Moreover,the MSS/WPC#50 sample achieved the highest limited oxygen index of 22.5%,the highest vertical burning rating at the V-1 level,and the lowest horizontal burning rate at 44.2 mm/min.The formation of a dense and stable char layer led to improved thermal stability and a considerable reduction in heat and smoke releases of MSS/WPC#50.However,the partial replacement of TP with MSS slightly compromised the mechanical and flame-retardant properties,possibly due to the weak grafting caused by SS powder agglomeration.These findings suggest the suitability of MSS/WPCs for high-value-added applications as decorative panels indoors or outdoors.

Damage-ignition mechanism studies on modified propellant with different crosslinking density under dynamic loading

The study of high-energy and low-vulnerability propellants is important for the power performance and safety of solid propellant rocket motors.The modified split Hopkinson pressure bar(SHPB)tests are performed on two kinds of propellant with different crosslinking density to study the dynamic mechanical responses and damage-ignition mechanism.SHPB apparatus is equipped with a highperformance infrared camera and high-speed camera to capture the deformation,damage-ignition feature and temperature evolution images in the impact process.The results suggested that the mechanical responses and damage-ignition mechanism of the propellants were affected by the strain rates and crosslinking density.The damage-ignition degree is more intense and the reaction occurs earlier with the increase of strain rates.For propellant 1 with higher crosslinking density,the critical ignition strain rate is 4500 s^(-1).Two kinds of propellants show different ignition mechanism,i.e.crack generation,propagation and final fracture for propellant 1 while viscous shear flow for propellant 2.Meanwhile,the SEM images also reveal the difference of damage-ignition mechanism of the two kinds of propellants.Finally,the ignition mechanism under different strain rates and critical ignition strain rate of propellants are further explained by the theoretical calculation of temperature variations.

Effect of ZrC Modified Graphite on Structure and Properties of Low-carbon Al_(2)O_(3)-C Refractories

To address the issues of reduced performance and shortened lifespan during the low-carbonizating process of Al_(2)O_(3)-C refractories,nano-crystalline ZrC modified graphite was prepared using Zr powder and flake graphite as raw materials,with NaCl and NaF mixed salt serving as the medium.The flake graphite was gradually replaced by ZrC modified graphite in the preparation of Al_(2)O_(3)-C refractories,and its impact on the material’s structure and properties was investigated.The results indicate that,compared to samples with only flake graphite,the introduction of 1 mass%to 5 mass%nano-crystalline ZrC modified graphite can significantly enhance the mechanical performance of low-carbon Al_(2)O_(3)-C refractories.When 5 mass%ZrC modified graphite is added,the mechanical properties of the samples are optimal,with the cold modulus of rupture and elastic modulus reaching 22.5 MPa and 65.0 GPa,respectively.

An aqueous BiI_(3)-Zn battery with dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox

The development of aqueous battery with dual mechanisms is now arousing more and more interest.The dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox bring unexpected effects.Herein,differing from previous studies using Zn I_(2)additive,this work designs an aqueous Bi I_(3)-Zn battery with selfsupplied I^(-).Ex situ tests reveal the conversion of Bi I_(3)into Bi(discharge)and Bi OI(charge)at the 1st cycle and the dissolved I^(-)in electrolyte.The active I^(-)species enhances the specific capacity and discharge medium voltage of electrode as well as improves the generation of Zn dendrite and by-product.Furthermore,the porous hard carbon is introduced to enhance the electronic/ionic conductivity and adsorb iodine species,proven by experimental and theoretical studies.Accordingly,the well-designed Bi I_(3)-Zn battery delivers a high reversible capacity of 182 m A h g^(-1)at 0.2 A g^(-1),an excellent rate capability with 88 m A h g^(-1)at 10 A g^(-1),and an impressive cyclability with 63%capacity retention over 20 K cycles at 10 A g^(-1).An excellent electrochemical performance is obtained even at a high mass loading of 6 mg cm^(-2).Moreover,a flexible quasi-solid-state Bi I_(3)-Zn battery exhibits satisfactory battery performances.This work provides a new idea for designing high-performance aqueous battery with dual mechanisms.

Inhibitory Effect of Flavonoid Glycosides from Chlorophytum comosum on Nasopharyngeal Carcinoma 5-8F Cells and Its Mechanism

[Objectives]To study the inhibitory activity of two flavonoid glycosides isolated from Chlorophytum comosum Laxum R.Br on human nasopharyngeal carcinoma(NPC)cell line 5-8F in vitro and its mechanism.[Methods]The flavonoid glycosides were isolated and purified from the ethanol alcoholic extract of the roots of Liliaceae plant Chlorophytum comosum by silica gel column chromatography,macroporous resin column chromatography,Sephadex LH-20,and reverse column chromatography(ODS).The inhibitory activity of flavonoid glycosides on human nasopharyngeal carcinoma cells was analyzed by CCK-8 method,and the potential mechanism was preliminarily analyzed by molecular docking.[Results]Two flavonoid glycosides were identified as isovitexin 2″-0-rhamnoside and 7-2″-di-O-β-glucopyranosylisovitexin.Two flavonoid glycosides showed promising inhibitory effect on human nasopharyngeal carcinoma cell line 5-8F,with IC_(50) values of 24.8 and 27.5μmol/L,respectively.Molecular docking results showed that the potential targets of two flavonoid glycosides include CyclinD1,Bcl-2β-Catenin,ILK,TGF-β,in addition,two glycosides showed higher predicted binding affinity towards CyclinD1,which verifies the cytotoxicity of the two compounds on human nasopharyngeal carcinoma cell line 5-8F in vitro.[Conclusions]Two flavonoid glycosides are the active molecules in Chlorophytum comosum that can inhibit the proliferation of human nasopharyngeal carcinoma cells,and have the potential to be used in the research and development of anti nasopharyngeal carcinoma drugs.

A comprehensive review on polyurethane modified asphalt: Mechanism, characterization and prospect

Polyurethane(PU),with excellent physical and chemical properties and high designability,is one of the ideal materials for asphalt modification in the future.In this paper,based on the limitations of traditional asphalt modifiers,the preparation process,relative advantages and development prospects of PU as asphalt modifiers are described.Subsequently,the spatial structure,physical and chemical properties of PU synthetic raw materials were combined with the modification properties of PU to analyze the effect and influence of PU on asphalt modification.Specifically,polyurethane modified asphalt(PUMA)is divided into thermoplastic polyurethane modified asphalt(TP-PUMA)and thermosetting polyurethane modified asphalt(TS-PUMA).The gain effect of TPPUMA in high-temperature performance,low-temperature performance,aging resistance,fatigue resistance,weathering performance and bonding performance is obvious.In addition,it has good storage stability.With excellent road performance,TS-PUMA makes up for the shortcomings of epoxy asphalt in terms of lowtemperature performance and compatibility.Finally,due to the development trend of functional diversification of modified asphalt,the research basis and status of several new modified asphalts based on PU properties are described.Because the systematic study of PUMA is insufficient,this paper proposes corresponding research.To provide guidance and ideas for the research of PU modified asphalt.

Materials,preparation,performances and mechanism of polyurethane modified asphalt and its mixture:A systematic review

With the rapid development of asphalt pavement technology,it has attracted considerable attention to improving the durability of asphalt pavement.An effective action is to use modified asphalt with high performance and durability.Polyurethane(PU)has been used in asphalt pavement engineering to enhance the durability and service life of asphalt pavement because of its excellent high-temperature performance,toughness,wear resistance,aging resistance and oil resistance.However,PU modified asphalt technology is still in the exploratory stage.The preparation,modification mechanism and working performances of PU modified asphalt need to be further clarified.Therefore,this paper summarized the research progress of PU modified asphalt and its mixture.The composition of PU modified asphalt was introduced.The addition methods of PU materials and preparation process parameters of the PU modified asphalt were determined.The modification mechanism of PU on asphalt was discussed.The effects of polyurethane on asphalt were analyzed and the road performances of its mixture were evaluated.Finally,the development tendency towards PU modified asphalt and its mixture were forecasted.

Mechanism of Action and Therapeutic Effect of Modified Qiwei Baishu Powder in Diabetes

Objective:To study the mechanism of action and therapeutic effect of modified Qiwei Baishu powder in diabetic patients.Methods:From January 2021 to January 2022,80 diabetic patients were recruited in our study and divided into two groups by the random number table method.Group A was treated with modified Qiwei Baishu powder,whereas group B was treated with western medicine.The therapeutic effect,traditional Chinese medicine(TCM)syndrome score,blood sugar level,and incidence of adverse reaction were compared between the two groups.Result:The therapeutic effect in group A was significantly higher than that in group B(P<0.05);the TCM syndrome scores of group A were significantly lower than those of group B(P<0.05);the fasting blood glucose(FBG),2 hour-postprandial blood glucose(PBG),and glycosylated hemoglobin(HbA1c)levels of group A were significantly lower than those of group B(P<0.05);the incidence of adverse reaction in group A was significantly lower than that in group B(P<0.05).Conclusion:On the basis of western medicine,the addition of modified Qiwei Baishu powder can maintain stable blood sugar levels in patients and alleviate diabetic symptoms;thus,it is not only effective,but also safe for clinical use in diabetes.

Characterization of Metal Oxide-modified Walnut-shell Activated Carbon and Its Application for Phosphine Adsorption: Equilibrium, Regeneration, and Mechanism Studies

We prepared a kind of metal oxide-modified walnut-shell activated carbon(MWAC) by KOH chemical activation method and used for PH_3 adsorption removal. Meanwhile, the PH_3 adsorption equilibrium was investigated experimentally and fitted by the Toth equation, and the isosteric heat of PH_3 adsorption was calculated by the Clausius-Clapeyron Equation. The exhausted MWAC was regenerated by water washing and air drying. Moreover, the properties of five different samples were characterized by N_2 adsorption isotherm, SEM/EDS, XPS, and FTIR. The results showed that the maximum PH_3 equilibrium adsorption capacity was 595.56 mg/g. The MWAC had an energetically heterogeneous surface due to values of isosteric heat of adsorption ranging from 43 to 90 kJ/mol. The regeneration method provided an effective way for both adsorption species recycling and exhausted carbon regeneration. The high removal efficiency and big equilibrium adsorption capacity for PH_3 adsorption on the MWAC were related to its large surface area and high oxidation activity in PH_3 adsorption-oxidation to H_3 PO_4 and P_2 O_5. Furthermore, a possible PH_3 adsorption mechanism was proposed.

Healthy Functions and Mechanisms of Bamboo-Charcoal Modified Polyesters

In this paper, healthy functions and mechanisms of bamboo-charcoal modified polyesters are studied. The results show that there are five healthy functions incorporated effectively in bamboo-charcoal modified polyesters, such as good far-infrared radiation, good UV protection, certain negative ion emission, certain antibacteria and good absorption functions. The metal elements and carburets are mainly responsible for far-infrared, negative ion emission functions. UV prevent/on function results mainly from the carbon elements. The absorbability and bacteriostasis functions lie in the porous structures.

Review of emulsified asphalt modification mechanisms and performance influencing factors

In recent years,with the improvement of the requirements of road performance,modified emulsified asphalts with better performance has gradually replaced the emulsified asphalt and become the primary material for road maintenance.This paper introduces the modified emulsified asphalt materials commonly used in pavement maintenance projects,definitions and modified mechanisms of polymerized styrene butadiene rubber(SBR)modified emulsified asphalt,styrene butadiene styrene block polymer(SBS)modified emulsified asphalt and waterborne epoxy resin(WER)modified emulsified asphalt are summarized.The analysis focused on comparing the effects of modifiers,preparation process,auxiliary additives,and other factors on the performance of modified emulsified asphalt.In this paper,it is considered that the greatest impact on the performance of emulsified asphalt is the modifier,emulsifier mainly affects the speed of breaking the emulsion,stabilizers on the basic performance of emulsified asphalt evaporative residue is small;and when the modifier is distributed in the asphalt in a network,the dosage at this time is the recommended optimum dosage.Finally,this study recommends that in the future,the polymer-asphalt compatibility can be improved through composite modification,chemical grafting and other methods to continue to develop broader applicability and better performance of modified emulsified asphalt.

Preparation, morphology and mechanical properties of acrylate-modified polyurethane/unsaturated polyester resin graft-IPNs

Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.

Performance and mechanism of solid waste coking sulfur paste modified asphalt mixture before and after curing

For the resource utilization of the solid waste coking sulfur paste and the improvement of performance of the asphalt mixture,a method for preparing modified asphalt mixture with coking sulfur paste modifier(CSPM)is herein proposed.Compared with the matrix asphalt mixture,the Marshall stability of the 30%CSPM modified asphalt mixture increased by 38.3%,the dynamic stability increased by nearly one time(reaching 1847.5 times/mm),the splitting strength ratio increased by 39.3%while the splitting tensile strength decreased by 11.7%.After curing,the performance of the CSPM modified asphalt mixture was further improved.The results show that CSPM improved the high temperature stability and water damage resistance of the asphalt mixture,and the low-temperature anti-cracking performance of that was slightly reduced.Chemical analysis of asphalt binders shows that a little sulfur reacted with asphalt to produce polysulfide compounds(R-Sx-R′),and a part of sulfur existed in the form of crystalline sulfur which was further increased after curing.The presence of crystalline sulfur as an inorganic filler is the key point for improving the high temperature stability and water resistance performance of modified asphalt mixture.

Pseudospin symmetric solutions of the Dirac equation with the modified Rosen-Morse potential using Nikiforov-Uvarov method and supersymmetric quantum mechanics approach

Employing the Pekeris-type approximation to deal with the pseudo-centrifugal term,we analytically study the pseudospin symmetry of a Dirac nucleon subjected to equal scalar and vector modified Rosen-Morse potential including the spin-orbit coupling term by using the Nikiforov-Uvarov method and supersymmetric quantum mechanics approach.The complex eigenvalue equation and the total normalized wave functions expressed in terms of Jacobi polynomial with arbitrary spin-orbit coupling quantum number k are presented under the condition of pseudospin symmetry.The eigenvalue equations for both methods reproduce the same result to affirm the mathematical accuracy of analytical calculations.The numerical solutions obtained for different adjustable parameters produce degeneracies for some quantum number.

Characteristics and Mechanism of Modified Triethanolamine as Cement Grinding Aids

Effects of modified triethanolamine as cement grinding aids on particles characteristics and mechanical property of cement were studied, and its reaction mechanism was analyzed by IR, Zeta potential, SEM, XRD and TG-DTA. The results show that the content of 3-32 μm particles for cement with 0.015% modified triethanolamine（M-TEA） is increased by 12.4%, and the compressive strengths of cement with 0.03% M-TEA are increased by 5.5 and 8.2 MPa at 3 and 28 days, respectively. And both the grinding and enhancement effects of M-TEA on cement are better than triethanolamine. The mechanism analysis shows that M-TEA not only has the amino and hydroxyl groups of TEA, but also has the ester, carbonyl, carboxyl groups which easily combine with metal ions of cement minerals, resulting in that M-TEA can promote surface adsorption and shield the unsaturated charges in the surface and crack section of particles, thus particles reunion is prevented and grinding efficiency is improved. Enhancement of M-TEA on cement mainly lies in that it can promote or induce hydration reaction of cement mineral with gypsum and water, which accelerates formation of hydration products, and then improves the structure and morphology of cement hydration products, thus the uniformity and compactness of product structure is increased.

Friction and wear behaviors of Nb-Ti-Si-Cr based ultrahigh temperature alloy and its Zr-Y jointly modified silicide coatings

Zr-Y jointly modified silicide coatings were prepared on an Nb-Ti-Si-Cr based ultrahigh temperature alloy by pack cementation process. The wear behaviors of both the base alloy and coatings were comparatively studied at room temperature and 800 ℃ using SiC balls as the counterpart. The Zr-Y jointly modified silicide coating is mainly composed of a thick （Nb,X）Si2 outer layer and a thin （Ti,Nb）5Si4 inner layer. The coatings possess much higher microhardness than the base alloy. The wear rates of both the base alloy and coatings increase with increasing the sliding loads. However, the coatings have much lower wear rates than the base alloy under the same sliding conditions. The coatings have superior anti-friction property, and can provide effective protection for the base alloy at both room temperature and 800 ℃ in air.

Kinematics and dynamics analysis of a 3-7R parallel decoupling mechanism

One kind of movable-pair analysis method is adopted to analyze the configuration of a 3-7R （revolute-pair） parallel decoupling mechanism, and the mechanism＇s characteristics are summarized. The mechanism has three orthogonal distributional branch-chains, and all movable pairs are rotational joints. The movable platform of the mechanism has x, y, z translational decoupling directions. Furthermore, in order to verify the mechanism＇s decoupling characteristics, the mechanism＇s kinematics analysis is solved, and the mechanism＇s direct/inverse kinematics model, input/output velocities and accelerations are deduced, which confirm its decoupling movement characteristics. Finally, one kind of mechanism link decomposed-integrated approach is adopted, and the mechanism＇s dynamics model is completed with the Lagrange method, which also proves its decoupling force characteristics. All of these works provide significant theory for the further study of the mechanism＇s control strategy, design, path planning etc.

改性钢渣-沥青混合料的性能及机理

采用甲基硅酸钠溶液、二氧化硅胶体溶液、聚丙烯酸酯乳液对钢渣进行浸泡改性处理,通过性能测试、扫描电子显微镜(SEM)、声发射等测试方法研究了改性钢渣的物理、力学性能,改性钢渣-沥青混合料的性能,钢渣的改性机理和改性钢渣-沥青混合料的抗裂机理。结果表明,4.75~19 mm钢渣经1%~4%浓度溶剂改性后,物理性能得到明显改善;经3%浓度溶剂改性后的钢渣制备的改性钢渣-沥青混合料的体积稳定性较未改性钢渣-沥青混合料(RSAM)提高了27.92%~39.09%;改性钢渣表面包裹着不同状态的不溶于水的改性保护层,经二氧化硅改性后的钢渣(SMS)表面呈现出致密的层状结构且保持表面粗糙,改性效果最优;二氧化硅改性钢渣-沥青混合料(SMSAM)的裂纹宽度减小,主裂纹出现的时间较晚,SMS对SMSAM的断裂破坏起到了一定的减缓作用,提高了混合料的抗开裂性能。

改性生物炭作为聚α-烯烃添加剂的摩擦学性能研究

将在不同温度下热解的棉花秆粉末进行球磨处理与碱化改性后得到纳米生物炭材料,并采用拉曼光谱、傅里叶红外光谱、X射线光电子能谱(XPS)对其进行表征。将纳米生物炭粉末加入聚α-烯烃-6(PAO6)中制备纳米生物炭润滑油,通过粒度分析和自然沉降观测表征其分散稳定性,并考察其润湿性能和摩擦学性能。结果表明:改性处理能提高生物炭含氧官能团的数量从而提升纳米润滑油的润湿性;加入700℃处理的生物炭制成的质量分数0.2%的纳米润滑油性能最佳,与PAO6相比,摩擦因数下降21.2%,磨损量下降43.0%。基于生物炭纳米润滑油理化特性,结合磨损表面XPS分析与形貌分析,将NBC能够改善PAO6摩擦学特性归因于:NBC作为一种薄片状的类二维材料,其中还包括部分极小的颗粒状物质,使其同时发挥层间材料的剪切效应与颗粒材料的填补修复效应;此外,纳米生物炭的添加也可以通过提升润湿性改善局部细缝的摩擦特性,并促进含Fe_(3)O_(4)摩擦膜的形成。

TPU/Nano-ZnO复合改性沥青的性能研究及微观机制

为促进聚合物/纳米改性沥青在耐久性路面中的应用,在实验室将不同掺量的聚氨酯及纳米氧化锌添加到A-70#基质沥青中制备了复合改性沥青。采用传统物理性能试验、动态剪切流变试验(DSR)、弯曲梁流变试验(BBR)研究了其物理性能与流变特性,基于响应面法的优化设计来明确两种改性剂的最佳掺量。借助傅里叶红外光谱试验(FTIR)对其微观改性机理进行探讨。采用高压紫外汞灯环境箱对改性沥青进行不同时间的紫外老化,分析其抗紫外老化能力,并基于主成分分析法评价了老化性能测试指标的显著性。结果表明:聚氨酯与纳米氧化锌的共同作用提高了基质沥青的高温稳定性及低温抗裂性,两种改性剂的最佳掺量分别为5%、3%。根据FTIR结果,复合改性沥青的改性过程既存在物理共混,又有化学加成反应。聚氨酯及纳米氧化锌的加入在基质沥青紫外老化过程中能够抑制羰基、亚砜基等极性基团的生成,复数剪切模量、羰基指数、劲度模量及亚砜基指数对沥青紫外老化性能的影响最为显著。