P2O5—PbO—Bi2O3系统玻璃和微晶玻璃的结构

通过传统熔体冷却方法制成了Ｐ２Ｏ５ＰｂＯＢｉ２Ｏ３系统玻璃、微晶玻璃及晶体，利用Ｘ射线衍射谱、红外光谱和喇曼光谱考察了该系统中晶体、微晶玻璃及玻璃结构上的差异。结果表明，晶体中含不带Ｐ＝Ｏ双键的［ＰＯ４］四面体；微晶玻璃中含少量带Ｐ＝Ｏ双键的［ＰＯ４］四面体及较多量不带Ｐ＝Ｏ双键的［ＰＯ４］四面体；玻璃结构中Ｐ５＋主要以带Ｐ＝Ｏ双键的［ＰＯ４］四面体形式存在，这些［ＰＯ４］四面体间共顶而形成链式结构，链与链之间通过Ｐｂ２＋或Ｂｉ３＋离子联接而形成层状无定形玻璃结构     

Effect of TiO2 on thermal,structural and third-order nonlinear optical properties of Ca–La–B–O glass system

A series of calcium lanthanum metaborate glasses in the composition (wt%) of 23.88CaO–28.33La₂O₃–47.79B₂O₃ modified with TiO₂ up to 20 wt% are prepared by a melt quenching technique to study the influence of TiO₂ on their thermal, structural, linear and nonlinear optical properties. The differential thermal analysis (DTA) studies have demonstrated significant effects due to the presence of TiO₂ on the glass forming ability and crystallization situations. The glass with 15 wt% TiO₂ has achieved a eutectic composition and also exhibited a better glass forming ability among the glasses studied. The FT-IR spectra of these glasses show mainly vibration modes corresponding to stretching of BO₃ trigonal, BO₄ tetrahedral units and of B–O–B bending bonds. At higher concentrations of TiO₂, development of vibration band around 400 cm^?1 has indicated the formation of TiO₆ structural units in the glass network. The red shift of optical absorption edge (UV cutoff) shows a monotonous decrease in direct and indirect optical band gap energies (E_opt) with an increase of TiO₂ content in the glasses based on their absorption spectra. The optical transparency of these glasses is found to be varied from 64 to 87% within the wavelength range 450–1100 nm depending on the TiO₂ content. Besides these studies, linear refractive indices, the nonlinear optical properties of these glasses have also been evaluated.     

BRIGHT LONG AFTERGLOW PHOSPHORESCENCE GLASS MADE OF SrAl2O4 ： Eu^2＋, Dy^3＋ AND GLASS FRITS

Bright long afterglow phosphorescence glasses were prepared by using SrAl2O4： Eu^2＋, Dy^3＋ phosphors and suitable glass frits together. The SrAl2O4： Eu^2＋, Dy^3＋ phosphors were initially prepared by the solid reaction method. Three kinds of glass frits were prepared to match the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. Effects of the compositions of the glass frits, the ratios of the phosphors to the frits us well us the firing temperature and firing times on the properties of the samples were discussed. XRD analysis indicated the samples exhibited the typical diffraction peaks of SrAlwO4： Eu^2＋, Dy^3＋. The emission spectra of the samples showed broad bands peaking at 510nm.The excitation spectra of the samples showed broad bands ranging from 300 to 480hm. These are believed due to the 5d4f-4f transitions of Eu^2＋ in the SrAl2O4： Eu^2＋, Dy^3＋ phosphors. The afterglow luminescence of the samples excited by a 40W fluorescence lamp for 30min can be observed in the dark for more lOh with the naked eyes. It can find wide applications in many fields.     

Spectroscopic and dielectric studies on MnO doped PbO–Nb2O5–P2O5 glass system

PbO–Nb₂O₅–P₂O₅ glasses containing different concentrations of MnO ranging from 0 to 2.5 mol% were prepared. A number of studies viz., differential thermal analysis, infrared, optical absorption, luminescence, Raman and ESR spectra, magnetic susceptibility and dielectric properties (constant ′, loss tan δ, ac conductivity σ_ac over a range of frequency and temperature) of these glasses have been carried out. The results have been analyzed in the light of different oxidation states of manganese ions. The analysis indicates that when the concentration of MnO is around 1.0 mol%, manganese ions mostly exist in Mn²⁺ state, occupy network forming positions with MnO₄ structural units and increase the rigidity of the glass network. When MnO is present in higher concentrations, these ions seem to exist mostly in Mn³⁺ state and occupy modifying positions.     

FERROELECTRIC CHARACTERISTICS OF SrBi2Ta2O9 THIN FILMS ANNEALED IN FORMING GAS

1. IlltroductionRecently, SrBi2Ta2O9 (SBT) thin films had been attracting considerable attention forapplication to nonvolatile ferroelectric random access memory (FeRAM). It had been re-ported that SBT thin films had superior properties of free--fatigue and Iow leakage currentllJ.However, it was a serious problem that fOrming gas (5%H2+95%N2) annealing could causethe severe degradation of SBT thin films in ferroelectric polarization. It had been suggestedthat the origin of H2 damage …     

FORMATION OF MANGANESE SILICIDE THIN FILMS BY SOLID PHASE REACTION

1. IntroductionThe transition metal silicides have attraeted much attention because of their potentialapplicatiOIl in very large scale integration (VLSI) de.ice[1]. Near-noble metal silicides canbe used as Schottky al1d ohn1ic col1tacts in silicon-based d…     

316不锈钢和825镍基合金在超临界水氧化毒死蜱介质中的腐蚀

在连续式超临界水氧化试验装置中，测量了316不锈 钢和825镍基合金在150℃～450℃分解杀虫剂毒死蜱过程中的腐蚀速度.两种合金的均匀腐蚀 速度随温度升高而增加，825镍基合金的腐蚀速度比316不锈钢的腐蚀速度小，450℃下316不 锈钢和825镍基合金的均匀腐蚀速度分别达143 μm/h和125 μm/h；200℃以上发生孔蚀 ，在较高分解温度下，由于孔蚀和均匀腐蚀的同时进行，形成相互贯穿的敞口蚀坑腐蚀形貌 .热力学分析表明，Fe-Cr-Ni合金在高温氧化性介质中是不稳定的，并且低熔点金属氯化物 的产生也可能是合金在超临界条件下出现高腐蚀速度的原因之一.     

钼合金Si-Cr-Ti-SiC-MnO2涂层的制备与组织性能

目的提高钼合金表面红外辐射性能与高温抗氧化性能。方法将40%Si、20%Cr、5%Ti、5%SiC、30%Mn O_2五种粉末与酒精、粘结剂按比例混合,经高能球磨6 h后制得均匀悬浮的料浆。采用浸涂工艺对预处理的钼合金试样进行料浆涂覆,在1450℃真空烧结0.5 h后制得黑色涂层试样。通过1550℃高温静态氧化试验和高温粒子薄片红外光谱综合实验系统,分别评价涂层抗氧化性能和红外辐射性能,并通过扫描电镜(SEM)、能谱分析(EDS)、X射线衍射仪(XRD)对涂层氧化前后的形貌与组织结构进行分析。结果钼合金Si-Cr-Ti-SiC-Mn O_2涂层在700、900℃的法向发射率分别达0.85、0.88,在1550℃高温有氧环境下的静态抗氧化寿命达7 h。原始涂层呈四层复合梯度结构,由外到内分别为SiO_2+Mn3O_4+M5Si3(M指Mo、Cr、Ti)、M5Si3+Mo Si2+SiC+Mn3O_4、Mo Si2、Mo5Si3。高温氧化后,涂层四层复合结构由外到内转变为SiO_2+(Cr,Ti)5Si3+Mn Cr2O_4+Mn3O_4、M5Si3+SiC+Mn Cr2O_4+Mn3O_4、Mo Si2、M5Si3。高温氧化过程中,MSi2高硅化物层逐渐转变为M5Si3低硅化物层,涂层表面形成含Mn Cr2O_4尖晶石相和复合硅化物的致密SiO_2玻璃膜。结论 Si-Cr-Ti-SiC-Mn O_2涂层可有效提高钼合金基体的红外辐射性能和高温抗氧化性能,复合硅化物与硅锰复杂氧化物具有良好的抗氧化性能、高辐射性能和自愈合性能。     

FeS2对AZ91D镁合金熔炼保护机理研究

在空气气氛的镁合金密封熔炼炉中加入固态硫铁矿(FeS2),研究了FeS2对AZ91D镁合金熔炼的保护效果,并采用SEM、EDS和XRD等检测分析技术对保护膜形貌、成分和相组成进行了研究.研究结果表明,在空气气氛中,硫铁矿对镁合金熔炼有良好的保护效果.在730℃中保温30 min时保护膜由MgS、MgO和MgF2混合物组成,保护膜致密;保护膜的厚度随保温时间的延长而增加,其厚度在1.0～2.0 μm之间.FeS2在空气中分解和氧化生成S和SO2,产物与空气中的O2以及镁液反应生成MgS和MgO,使镁熔体表面氧化膜变致密,从而起到熔炼保护作用.通过热力学分析可知,受热时硫铁矿消耗密封熔炼炉内的氧,并且在表面膜中MgS形成趋势大,形成的MgS的稳定性比MgO好.     

Shielding behavior of V2O5 doped lead borate glasses towards gamma irradiation

Undoped lead borate glass of the composition PbO 70%-B₂O₃ 30% together with samples of the same composition and doped with varying V₂O₅ contents were prepared. UV-visible absorption spectra were measured out in the range 200-1500 nm before and after successive gamma irradiation. Infrared absorption measurements within the range 4000-400 cm⁻¹ were carried out for the undoped and V₂O₅ doped samples before gamma irradiation and after being irradiated with a dose of 6 Mrad. All the glass samples are observed to absorb strongly in the UV region due to the combined contributions of absorption due to trace iron impurities and that from the divalent lead Pb²⁺ ions. The V₂O₅-doped glasses reveal extra visible absorption bands which are attributed to the existence of V³⁺ ions in measurable content but not neglecting the other valence states of vanadium ions (V⁴⁺, V⁵⁺). Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites.     

Optical and thermal properties of P2O5-Na2O-CaO-Al2O3:CoO glasses doped with transition metals

The aim of this paper is to report the optical and thermal properties of V₂O₅ and CuO doped P₂O₅-Na₂O-CaO-Al₂O₃:CoO glasses so as to investigate their possible use in solar collection applications. The optical absorption spectra of the glasses at room temperature were in the spectral range of 200-1100 nm. The optical band gaps of the glass samples were determined for direct and indirect transitions. When transition metal ions doped to the base glass, the optical band gap decreased. Changes in the refractive indices vs. wavelength for all the specimens were also examined by spectroscopic ellipsometry. By measuring the heat capacities and thermal diffusion coefficients of the specimens at varying temperatures, their thermal conductivities were calculated to be in the 320-620 K temperature range. The obtained glasses seem to be promising materials and can be used in solar collector applications.     

THE STABILITY INVESTIGATION OF FERROELECTRIC SrBi_2Ta_2O_9 THIN FILMS ANNEALED IN FORMING GAS

The hysteresis loop changes of ferroelecric SrBi2Ti2O9 (SBT) thin films (330nm) vs the temperature of forming gas (5% hydrogen 95% nitrogen) annealing were measured when the annealing time was 1min and 10min. The selected annealing temperature was at 100℃, 200℃, 250℃, 300℃, 350℃, 400℃ and 450℃, respectively. Our results showed that the ferroelectric properties were easily destroyed and the leakage current changed abruptly when the SBT thin films were in their ferroelectric phase (<270℃). The space charges at the grain boundary may take an important role in absorption polarity molecular hydrogen when the SBT thin films were in the ferroelectric phase. The oxygen recovery experiments were also performed and investigated in this work.     

XPS和AES研究铜表面PMTA防变色膜

本工作对比了各种防铜变色剂的防变色效果,结果表明,1-苯基-5-巯基四氮唑(PMTA)的防变色效果优于化学钝化、电解钝化、苯骈三氮唑(BTA)、羟基苯骈三氮唑(HBT)、2-巯基苯骈噻唑(MBT)。用PMTA处理铜的最佳条件为:PMTA1～1.2g/L,pH=5,20～40℃,4min。XPS和AES分析表明,PMTA在Cu_2O上形成配合物膜,膜中铜为+1价。PMTA分子中的N、S均参与配位。从膜的AES元素深度分布曲线的恒组成区求得的配合物膜组成(A.C.％)为:Cu 40.9,C 32.3,N 16.2,O 7.9,S 2.9。     

Fe_(78)Si_9B_(13)非晶合金的高温变形性能

通过高温拉伸及胀形实验,研究了Fe78Si9B13非晶合金的塑性变形性能。高温拉伸的温度范围为430℃~530℃,初始应变速率为1.67×10-4s-1~1.67×10-3s-1。利用X射线衍射(XRD)和扫描电镜(SEM)对高温变形后的微观组织进行了分析。高温拉伸的延伸率随温度的升高先增大后减小,450℃时达到最大;在450℃,初始应变速率为8.33×10-4s-1时延伸率为40%。在450℃胀形得到半径为5mm、高4mm的近半球试件,显示了Fe78Si9B13非晶合金具有良好的高温变形性能。高温塑性变形过程中伴随着非晶的晶化,使塑性流动应力增大,影响了Fe78Si9B13非晶合金的高温变形性能。     

Structural impact of tungsten ions on ZnO-Sb2O3-As2O3 glass system

Five glasses in the quaternary system 5 ZnO-(50 − x) As₂O₃-45 Sb₂O₃: x WO₃ with the values of x ranging from 0 to 20 mol% (in steps of 5 mol%) are prepared. The samples are characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and differential thermal analysis (DTA) techniques. The DTA studies have indicated that the glass forming ability decreases with the increasing content of WO₃. A number of studies, like, spectroscopic (optical absorption, IR, Raman, ESR spectra) and dielectric studies (dielectric constant ?, loss tan δ, a.c. conductivity σ_a.c.) over a wide range of frequency and temperature and dielectric break down strength at room temperature, have been carried out and are analysed in the light of different oxidation states and environment of tungsten ions in these glasses. These glasses have potential photonic applications.     

EFFECT OF COPPER ON THE HOT PLASTICITY OF 304HC STAINLESS STEEL

The plasticity map of 304HC stainless steel was determined by using tensile and compressive test. The effect of Cu on the hot plasticity of 304HC stainless steel was analyzed. The microstructure, inclusion and fracture surface were studied by using the method of optical microscopy, SEM, EDS and EPMA. The results showed that Cu has effect on the hot plasticity and the hot plasticity of 304HC stainless steel decrease with the increase of Cu content. The deformation temperature also has much effect on the hot plasticity, the suitable deformation temperature are 1100-1200℃. The reason is that the brittle compounds were precipitated from austenite during cooling. These brittle compounds are Cu2S, Cu2O and PbCI etc.     

Zr基块体金属玻璃的形成和性能

研究了一系列具有很强非晶形成能力（ＧＦＡ）和优异性能的块体金属玻璃（ＢＭＧ）及含有纳米晶的ＢＭＧ的制备过程,结果表明,对掺碳的Ｚｒ／Ｔｉ基ＢＭＧ,当碳含量（原子分数,％,下同）,在１－２时,合金具有很宽的过冷液相区（ＳＬＲ,晶化开始温度Ｔｘ和玻璃转变温度Ｔｇ之间的温区）和较高的约化玻璃转变温度Ｔｒｇ（Ｔｒｇ＝Ｔｇ／Ｔｍ）;当碳含量增至３－８时,合金为含有纳米晶ＺｒＣ的ＢＭＧ基复合材料。加Ｆｅ的Ｚｒ     

无压烧结制备Al_2O_3-TiC复合陶瓷

本文采用无压烧结方法制备Al_2O_3－TiC复合陶瓷，较详细地研究了助烧剂含量、采用的埋粉种类及烧结温度对烧结体致密度的影响，结果表明，当采用助烧剂CaO含量为Al_2O_3量的0．5wt％采用Al_2O_3＋TiC作埋粉时具有较好的促进体系烧结的作用，在1860℃的烧结温度下，烧结体相对密度为98％。     

INVESTIGATION OF SURFACE MORPHOLOGY, STRUCTURE AND ELECTROCATALYTIC PROPERTIES FOR O_2 EVOLUTION OF TITANIUM BASED IrO_2+Ta_2O_5 COATINGS

1.IntroductionTitaniumbasednoblemetalokidecoatingshavebeenwidelyinvestigatedsincethepast3oyears[l':].Inthisperiod,variousmirtures,compositiollswerepreparedanddifferentmulti-coatingprocessesweredevelopedaselectrodematerialsinelectrochemicalfieId.Inbinaxysystems,thecoatingsof7Omol%IrO2 3Omol%Ta2O5wereverifiedtopossessthemaximumactivityanddurabilityforoxygenevolutio.[3'4],Iroz Taosdepositshavebeenstudiedentensively;ThehighstabilityofthisbinarymixturecouldbeattributedtotheformationofIro2baseds…     

Preparation and properties of Ba3ZnzCo2-zFe24O41／SiO2 microcrystalline glass ceramics

Ba3ZnzCo2-zFe24O41/SiO2(Z varies from 0.0 to 1.2 in step of 0.4) microcrystalline glass ceramics were prepared by citrate sol-gel process at 1200℃ in the system of BaO-Fe2O3-CoO-ZnO-SiO2. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The complex dielectric constant and complex permeability of Ba3ZnzCo2-zFe24O41/SiO2 microcrystalline glass ceramics were measured in the range of 0.1-6.0 GHz by transmission/reflection coaxial line method. The natural resonance phenomenon was observed in μ”spectra for all the Ba3ZnzCo2-zFe24O41/SiO2 microcrystalline glass ceramics, which was closely affected by the substitution of Zn^2 ion.