Preparation and characterizat ion of polypropylene/silica composite particl e with interpenetrating network via hot emulsion sol–gel approach

A novel interpenetrating structural ultrafine polypropylene-silica nanocomposite particles were synthesized by a modified sol–gel approach in the presence of the melt polypropylene emulsion. A series of samples with different polypropylene content was prepared to investigate the unique characteristics of this original nanocomposite. The thermal gravimetric analysis and differential scanning calorimetry results showed that the nanocomposites had the interpenetrating structure and good thermal stability,and the crystallization behavior of polypropylene was confined by the silica matrix. The interpenetrating structure of nanocomposites was also suggested by the nitrogen adsorption–desorption measurement results. The scanning electronic microscope and transmission electron microscopy images indicated that the nanocomposites had irregular particle morphology. The nanoparticle tracking analysis results show that the mean size of the nanocomposites was around 160 nm. According to the results obtained from different measurements,a reasonable formation mechanism was proposed.     

Effect of Sr on microstructure and aging behavior of Mg–14Li alloys

The as-cast and as-extruded Mg–14 wt%Li–x Sr ( x=0.14, 0.19, 0.39 wt%) alloys were,respectively, prepared through a simple alloying process and hot extrusion. The effects of Sr addition on microstructure and aging behavior of the Mg–14 wt%Li–xSr alloys were studied. The results indicated that β(Li) and Mg2Sr were the two primary phases in the microstructures of both as-cast and as-extruded Mg–14 wt%Li–xSr alloys. Interestingly, with the increase of Sr content from 0.14 wt% to 0.39 wt%, the grain sizes of the as-cast and as-extruded Mg–14 wt%Li–xSr alloys markedly decreased from 5000mm and 38mm to 330 mm and 22mm respectively, while no obvious changes of the micro-hardness and microstructure of the as-extruded alloys were observed during the aging treatment.     

Effect of MgO content in sinter on the softening–melting behavior of mixed burden made from chromium-bearing vanadium–titanium magnetite

The effect of sinter with different MgO contents on the softening–melting behavior of mixed burden made from chromium- bearing vanadium–titanium magnetite was investigated. The results show that with increasing MgO content in the sinter, the softening interval and melting interval increased and the location of the cohesive zone shifted downward slightly and became moderately thicker. The softening–melting characteristic value was less pronounced when the MgO content in the sinter was 2.98wt%–3.40wt%. Increasing MgO content in the sinter reduced the content and recovery of V and Cr in the dripped iron. In addition, greater MgO contents in the sinter resulted in the generation of greater amounts of high-melting-point components, which adversely affected the permeability of the mixed burden. When the softening–melting behavior of the mixed burden and the recovery of valuable elements were taken into account, proper MgO contents in the sinter and slag ranged from 2.98wt% to 3.40wt% and from 11.46wt% to 12.72wt%, respectively, for the smelting of burden made from chromium-bearing vanadium–titanium magnetite in a blast furnace.     

Influence of catalyst on structural and morphological properties of TiO2 nanostructured films prepared by sol–gel on glass

Transparent TiO2 thin films have been prepared by the sol-gel method using titanium alkoxides as precursors.Thin films were deposited on glass supports by the dip-coating technique.The TiO2 layer acts as a self-cleaning coating generated from its photocatalysis and photoinduced superhydrophilicity.The crystalline structure of TiO2 films was dominantly identified as the anatase phase,consisted of uniform spherical particles of about 14-50 nm in size,which strongly depends upon catalyst-type and heat treatment temperature.Increasing heat treating temperature can lead to an increase in crystalline size.The results indicated that the sample S.S(sample derived from sol containing sulfuric acid as catalyst) exhibits superhydrophilic nature and better photocatalytic activity,which can be attributed to its higher anatase content and lower crystalline size.Morphological studies,carried out using Atomic Force Microscopy(AFM),confirm the presence of crystalline phase with such a grain size and low surface roughness.Thus,the applied films exhibiting high photocatalytic activity,superhydrophilic behavior,and low surface roughness can be used as an efficient self-cleaning coating on glass and other optical applications.     

Effect of Ni content on the wear behavior of Al–Si–Cu–Mg–Ni/SiC particles composites

In recent years, the addition of Ni has been widely acknowledged to be capable of enhancing the mechanical properties of Al–Si alloys. However, the effect of Ni on the wear behaviors of Al–Si alloys and Al matrix composites, particularly at elevated temperatures, remains an understudied area. In this study, Al–Si–Cu–Mg–Ni/20wt% SiC particles(SiCp) composites with varying Ni contents were prepared by using a semisolid stir casting method. The effect of Ni content on the dry sliding wear behavior ...     

Influence of clusters in melt on the subsequent glass-formation and crystallization of Fe–Si–B metallic glasses

The liquid structure of seven representative Fe–Si–B alloys has been investigated by ab initio molecular dynamics simulation focusing on the role of clusters in terms of glass-forming ability(GFA) and crystallization. It is demonstrated that the type of primary phase precipitated from amorphous state under heat treatment is determined by the relative fraction and role of various clusters in melt. The alloy melt shows higher stability and resultantly larger GFA when there is no dominant cluster or several clusters coexist, which explains the different GFAs and crystallization processes at various ratios of Si and B in the Fe–Si–B system. The close correlation among clusters, crystalline phase and GFA is also studied.     

Effect of benzaldehyde on the electrodeposition and corrosion properties of Ni–W alloys

The effect of different concentrations of benzaldehyde on the electrodeposition of Ni–W alloy coatings on a mild steel substrate from a citrate electrolyte was investigated in this study. The electrolytic alkaline bath (pH 8.0) contained stoichiometric amounts of nickel sulfate, sodium tungstate, and trisodium citrate as precursors. The corrosion resistance of the Ni–W-alloy-coated specimens in 0.2 mol/L H₂SO₄ was studied using various electrochemical techniques. Tafel polarization studies reveal that the alloy coatings obtained from the bath containing 50 ppm benzaldehyde exhibit a protection efficiency of 95.33%. The corrosion rate also decreases by 21.5 times compared with that of the blank. A higher charge-transfer resistance of 1159.40 Ω·cm2 and a lower double-layer capacitance of 29.4 μF·cm-2 further confirm the better corrosion resistance of the alloy coating. X-ray diffraction studies reveal that the deposits on the mild steel surface are consisted of nanocrystals. A lower surface roughness value (R_max) of the deposits is confirmed by atomic force microscopy.     

Microstructure and electric characteristics of AETiO_3(AE=Mg,Ca, Sr)doped CaCu_3Ti_4O_(12) thin films prepared by the sol–gel method

This paper focuses on the effects of alkline-earth metal titante AETiO_3(AE = Mg,Ca,Sr) doping on the microstructure and electric characteristics of CaCu_3Ti_4O_(12) thin films prepared by the sol-gel method.The results showed that the grain size of CCTO thin films could be increased by MgTiO_3 doping.The movement of the grain boundaries was impeded by the second phases of CaTiO_3 and SrTiO_3 concentrating at grain boundaries in CaTiO_3 and SrTiO_3 doped CCTO thin films.Rapid ascent of dielectric constant could be observed in 0.1Mg TiO_3 doped CCTO thin films,which was almost as three times high as pure CCTO thin film and the descent of the dielectric loss at low frequency could also be observed.In addition,the nonlinear coefficient(α),threshold voltage(V_T) and leakage current(I_L) of AETiO_3 doped CCTO thin films(AE = Mg,Ca,Sr) showed different variation with the increasing content of the MgTiO_3,CaTiO_3 and SrTiO_3.     

Effect of cold rolling and first precipitates on the coarsening behavior of γ″-phases in Inconel 718 alloy

The coarsening behaviors of γ″-phase particles in Inconel 718 alloy aged at 750, 800, and 850°C were investigated by scanning electron microscopy (SEM). Detailed observations and quantitative measurements were conducted to characterize the coarsening behavior of the γ″-phase under various aging conditions. The experimental results indicate that the existence of the δ-phase retards the formation and coarsening of the γ″-phase, without influencing its final particle size or amount. Moreover, when cold rolled with a reduction of 50%, the dimensions of the γ″ particles in Inconel 718 alloy decrease with increasing aging time. Furthermore, the coarsening behavior of the γ″-phase in the Inconel 718 alloy after a normal aging treatment (sample A) and that of the primary δ-phase (sample B) follow the Lifshitz–Slyozov–Wagner (LSW) diffusion-controlled growth theory; the thus-obtained activation energies for the γ″-phase are 292 kJ·mol-1 and 302 kJ·mol-1, respectively.     

Effect of pickling processes on the microstructure and properties of electroless Ni–P coating on Mg–7.5Li–2Zn–1Y alloy

The electroless plating Ni–P is prepared on the surface of Mg–7.5Li–2Zn–1Y alloys with different pickling processes.The microstructure and properties of Ni–P coating are investigated.The results show that the Ni–P coatings deposited using the different pickling processes have a different high phosphorus content amorphous Ni–P solid solution structure,and the Ni–P coatings exhibit higher hardness.There is higher phosphorus content of Ni–P amorphous coating using 125 g/L Cr O3and 110 ml/L HNO3(w68%)than using 180 g/L Cr O3and 1 g/L KF during pre-treatment,and the coating structure is more compact,and the Ni–P coatings exhibit more excellent adhesion with substrate(Fcup to22 N).The corrosion potential of Ni–P coating is improved and exhibits good corrosion resistance.As a result,Mg-7.5Li-2Zn-1Y alloy is remarkably protected by the Ni–P coating.     

pH值和煅烧温度对莫来石生成的影响

以溶胶凝胶法为基础,采用正硅酸乙酯(C8H20O4Si)、硝酸铝(Al(NO3)3·9H2O)为主要原料,借助X射线衍射仪进行检测,系统研究了pH值、煅烧温度对生成3∶2型莫来石以及生成过程的影响。结果表明：莫来石凝胶介于单相凝胶和双相凝胶的混合尺度,pH值在4~10范围内均可生成莫来石,煅烧温度为1175 ℃时出现明显的莫来石化;pH=4时,不利于无定形硅的转化;在pH值为5~9范围、煅烧温度1200 ℃时完全莫来石化,且生成的莫来石结晶度总体变小,晶胞参数上下波动。莫来石的生成经历了无定形硅和铝的氧化物到铝硅尖晶石再到莫来石的过程。     

Effects of AlN on the densification and mechanical properties of pressureless-sintered SiC ceramics

In the present work, Si C ceramics was fabricated with Al N using B_4 C and C as sintering aids by a solid-state pressureless-sintered method. The effects of Al N contents on the densification, mechanical properties, phase compositions, and microstructure evolutions of as-obtained Si C ceramics were thoroughly investigated. Al N was found to promote further densification of the Si C ceramics due to its evaporation over 1800 °C,transportation, and solidification in the pores resulted from Si C grain coarsening. The highest relative density of 99.65% was achieved for Si C sample with 15.0 wt% Al N by the pressureless-sintered method at 2130 °C for 1 h in Ar atmosphere. Furthermore, the fracture mechanism for Si C ceramics containing Al N tended to transfer from single transgranular fracture mode to both transgranular fracture and intergranular fracture modes when the sample with 30.0 wt% Al N sintered at 1900 °C for 1 h in Ar. Also, Si C ceramics with 30.0 wt% Al N exhibited the highest fracture toughness of 5.23 MPa m~(1/2) when sintered at 1900 °C.     

硬脂酰胺对热塑性聚氨酯氢键及等温结晶行为的影响

利用傅里叶变换红外光谱仪（FT-IR）研究了硬脂酰胺对热塑性聚氨酯（TPU）氢键化程度的影响。利用差示扫描量热仪（DSC）研究了硬脂酰胺对TPU等温结晶行为的影响,采用Avrami方程分析了TPU等温结晶过程,并计算出其结晶动力学参数。结果表明：加入硬脂酰胺后的TPU氢键化程度显著增大,结晶时间缩短,结晶速率提高。     

成核剂对小本体聚丙烯结晶行为和性能的影响

研究了不同的成核剂对聚丙烯结晶行为的影响，探讨了不同结晶形态对聚丙烯的力学性能、熔体流动速率的影响，结果表明，不同的成核聚丙烯其性能有很大差别。     

Effect of Fe_2O_3 on the crystallization behavior of glass-ceramics produced from naturally cooled yellow phosphorus furnace slag

CaO–Al_2O_3–SiO_2(CAS) glass-ceramics were prepared via a melting method using naturally cooled yellow phosphorus furnace slag as the main raw material.The effects of the addition of Fe_2O_3 on the crystallization behavior and properties of the prepared glass-ceramics were studied by differential thermal analysis,X-ray diffraction,and scanning electron microscopy.The crystallization activation energy was calculated using the modified Johnson–Mehl–Avrami equation.The results show that the intrinsic nucleating agent in the yellow phosphorus furnace slag could effectively promote the crystallization of CAS.The crystallization activation energy first increased and then decreased with increasing amount of added Fe_2O_3.At 4wt% of added Fe_2O_3,the crystallization activation energy reached a maximum of 676.374 k J×mol-1.The type of the main crystalline phase did not change with the amount of added Fe_2O_3.The primary and secondary crystalline phases were identified as wollastonite(CaSiO_3) and hedenbergite(Ca Fe(Si_2O_6)),respectively.     

添加剂对废水中COD,N和P去除的影响

实验室规模的ＡＮＡＮＯＸ工艺（ＡＮａｅｒｏｂｉｃ－ＡＮｏｘｉｃ－ＯＸｉｃ）用来处理豆制品废水，阐明添加剂对此工艺去除ＣＯＤ、Ｎ和Ｐ能力．研究结果表明：ＴＣＯＤ去除９５．７％，ＳＣＯＤ去除９５．８％，去除９４．２％，去除８９．１％，ＴＫＮ去除８２．４％，ＴＰ去除８７．４％，ＳＰ去除７７．２％，ＳＳ去除９８．０％．比加添加剂之前去除率提高了ＴＣＯＤ９．９％，ＳＣＯＤ１０．３％，ＴＰ４１．４％，ＳＰ３０．８％，ＳＳ８．１％     

溶解气体和纳米气泡对固—液溶胶电导率的影响

为了研究溶剂中溶解气体和憎水颗粒表面纳米气泡对固-液溶胶性质的影响,采用深度脱气的方法对溶剂和分散质粒子进行处理,从而制备获得溶胶样品.对制备的溶胶样品进行了丁达尔效应和电导率的测定.丁达尔效应的测定结果表明:同一种胶体,经深度脱气的样品和未经深度脱气的样品相比较,前者具有更好的光散射现象.电导率的测试结果显示:经过深度脱气的溶胶样品的电导率,比未深度脱气的样品的电导率平均增加30%～80%.     

烧结助剂和工艺对RBSN性能的影响

本文介绍了新型非金属材料Si3N4利用反应烧结方法（简称RBSN）的制取过程,并以MgO、AlO3、Y2O3和ZrO2为助剂,探讨烧结助剂和成型工艺对制品性能的影响;温度和助剂对氨化率的影响;ZrO2含量、烧结时间和气氛对制品烧结性能的影响。为提高制品的致密度和机械强度等方面做了一定的工作。     

Effect of the extract of intestine from stressed rat on lymphocyte proliferationin vitro

Immuno-suppressive protein, with a molecular weight of 155 and 370 ku, was generated in spleen and lymph node in stressed rats. It strongly inhibited lymphocyte proliferation. The results of activity assay, molecular weight determination and histological localization all demonstrated that under stress the immuno-suppressive protein was also generated in intestinal rnucosa of rats.     

玻璃组成对CaO-Al2O3-SiO2系玻璃烧结、晶化和性能的影响

采用烧结法制备以钙长石为主晶相的微晶玻璃.采用差热分析(DTA)、X射线衍射(XRD)、扫描电镜(SEM)和性能测试研究玻璃组成对玻璃的烧结、晶化特性和性能的影响.结果表明:随着CaO含量的增加,玻璃转变温度和析晶放热峰温度逐渐降低,而且析晶放热峰变得尖锐;增加氧化钙降低玻璃的析晶活化能,有利于玻璃的析晶;随着SiO2量的增加,玻璃转变温度和析晶放热峰温度移向高温,使玻璃的析晶困难;玻璃样品的烧结温度随CaO含量的增加而降低, 但过多的CaO促进硅酸钙的析出,增加样品的介电常数和热膨胀系数;增加SiO2能够降低微晶玻璃样品的热膨胀系数,改善其介电性能;所制备的微晶玻璃具有相对密度高(≥98.3%),介电常数适中(6.9～7.5),介电损耗低(≤0.1%),热膨胀系数低(3.8×10-6～4.5×10-6 /℃),烧结温度(900～1 000 ℃)低,及介电常数温度稳定性低(66×10-6～113×10-6 /℃).