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Abstract:通過對(duì)鈦酸鉛陶瓷氣相擴(kuò)滲稀土元素,制備了導(dǎo)電陶瓷材料。通過X射線衍射、電子探針X射線能譜和掃描電鏡測(cè)試分析,表明稀土元素La,Ce,Gd,Sm等均已滲入到PbTiO3陶瓷體相中,并生成了新的化合物L(fēng)a5O7NO3,La2C2O2,Gd2O3,La2Ti6O15,SmO和CeTi21O38,并使擴(kuò)滲后的PbTiO3基陶瓷的導(dǎo)電性能發(fā)生了十分顯著的變化,其室溫電阻率從純PbTiO3陶瓷的2.0×1010?·m下降為0.2?·m,而且隨著溫度的變化,晶粒電阻呈現(xiàn)明顯的PTCR效應(yīng),而晶界電阻隨著溫度的升高,呈急劇連續(xù)降低狀態(tài),總電阻的變化規(guī)律與晶界電阻的變化相類似,試樣總電阻的PTCR效應(yīng)已不存在,已表現(xiàn)出導(dǎo)電體特征。

Abstract:Luminescence fibers of Eu3+ doped ZnO-MgO-La2O3-B2O3 were prepared by solid state reaction at high temperatures. Their diameters were in the range of 0.01 mm~0.30 mm and their lengths were more than 10 m. Their curves of stress-strain were measured by the axial extension test. The change of the yield surface and the constitutive relations of the stress-strain were investigated based on the theory of elastic-brittle-plastic. Their elastic modulus, intensity, stress peak load, strain of stress intensity, elongation ratio to rupture of the axial extension, and brittleness index of the material were calculated. It is found that their strong emission band of Eu3+ with a maximum at 614 nm belongs to the electric dipole transition of 5D0-7F2 and the emission at 581 nm with 40% relative intensity to 614 nm belongs to magnetic dipole transition of 5D0-7F1. The host emission peak presenting to 438 nm overlaps its excitation band. The result shows that their elastic modulus are higher than those of common glass and marble, close to hard aluminum alloy and rolled aluminum. Their stress intensity and peak load are relatively big.

Abstract:The microstructure, optical absorption properties and luminescence function of GaN thin films grown on the sapphire substrate with the buffer layer of GaN by MOCVD have been studied by means of XRD, TEM, infrared transmission spectrum, and photoluminescence. The XRD results show that the crystal of GaN is hexagonal wurtzite structure. The thin films have perferred orientation in c axis with very high quality. The TEM images of cross-sectional specimen show that the thicknesses of every layer in the superlattices are uniform with the average period of 13.3 nm, but there are high-density dislocations in the superlattices region. With the related optical experimental data, it had been found that the optical absorption edge was at about 370 nm. The theory calculation indicates that the five samples are direct transition semiconductor with band-gaps of about 3.4 eV. The refractive indexes of the samples increase with the photon energy enhance and decrease with the wavelength increasing. The results show that the extinction coefficients have the minimum at 370 nm. Photoluminescence test results show that the superlattice has preferable luminescence property and a yellow luminescence is found.

Abstract:運(yùn)用鹽-金屬反應(yīng)法制備了亞微米TiB_2 顆粒增強(qiáng)鋁基復(fù)合材料(TiB_2/AC8A)。TiB_2 顆粒通過鈦鹽和硼鹽與鋁合金反應(yīng)原位生成。對(duì)復(fù)合材料進(jìn)行了顯微組織觀察和高溫蠕變性能實(shí)驗(yàn)。原位TiB2顆粒的尺寸約為0.5 μm,近似呈球形。TiB_2/AC8A 復(fù)合材料具有優(yōu)異的高溫蠕變性能。10 ω/% TiB2原位顆粒(~0.5 μm)增強(qiáng)AC8A 復(fù)合材料的蠕變抗力比10 φ/% SiCp(1.7 μm)外加顆粒增強(qiáng)Al 復(fù)合材料至少要高兩個(gè)數(shù)量級(jí)。10 ω/% TiB_2/AC8A 復(fù)合材料表現(xiàn)出高的名義應(yīng)力指數(shù)(11.7~12.5)和名義激活能(265 kJ/mol),其穩(wěn)態(tài)蠕變數(shù)據(jù)能夠用應(yīng)力指數(shù)為8 的亞結(jié)構(gòu)不變模型和門檻應(yīng)力來解釋。TiB_2/AC8A 復(fù)合材料的蠕變斷裂行為符合Monkman-Grant 關(guān)系式。

Abstract:This paper reports that nano- La0.7Pb0.3FeO3 powders can be used as a new type of gas-sensing material for detecting CO. The La0.7Pb0.3FeO3 powders were prepared by a citric method. The powders are characterized by X-ray diffraction, showing that the La0.7Pb0.3FeO3 is still perovskite phase with orthorhombic structure and its crystallite size is about 17 nm, smaller than that of LaFeO3. The La0.7Pb0.3FeO3 is a kind of p-type semiconductive material, and its conductivity is higher than that of LaFeO3. The CO sensitivity of La0.7Pb0.3FeO3-based sensor is investigated. We found that La3+ partly substituted by Pb2+ in LaFeO3 can enhance its sensitivity for CO gas.

Abstract:通過液態(tài)原位反應(yīng)合成制備MgO/Mg2Si增強(qiáng)Mg-Li基復(fù)合材料,利用TEM對(duì)增強(qiáng)相形態(tài)及界面結(jié)構(gòu)進(jìn)行了觀察。實(shí)驗(yàn)結(jié)果表明,復(fù)合材料中增強(qiáng)粒子與基體界面結(jié)合良好,無反應(yīng)物生成。確定了增強(qiáng)粒子與基體的界面取向關(guān)系,MgO與基體α相的晶體學(xué)關(guān)系為[100]MgO‖[4043]α,(011)MgO‖(1210)α;Mg2Si與基體β相的晶體學(xué)關(guān)系為[310]Mg2Si‖[411]β,(131)Mg2Si‖(001)β。

Abstract:The intermetallic-compounds-strengthened composite was reaction synthesized by hot pressing sintering the mixture of ball-milled Ti-Al powder and TiC+Al2O3 powder. According to the X-ray analysis and thermal analysis (DSC) of the powder and its components analysis of the sintering product, it shows that there are no other compounds but Ti3Al.Through thermodynamic calculation, the author analysized the reaction synthesized process, and found the gradual synthesis process from TiAl3 to TiAl, then to Ti3Al controlled by the diffusion under lower temperature and the formation mechanism of intermetallics compounds at high temperature, and it is in stable state at the interface between matrix and strengthening phases.

Abstract:TiO2 films were prepared by dc reactive magnetron sputtering. The UV-Vis spectra and PL spectra of samples before and after heat treatment were studied in detail. An absorption peak (496 nm) in UV-Vis spectra and an emission shoulder (496.5 nm) in PL spectra are observed clearly. The analysis of X-ray photoelectron spectroscopy (XPS) indicates that the lattice oxygen can be removed by heat treatment to form the Ti3+ and oxygen vacancies. Taking the XPS analysis and theory calculation into consideration together, it can be concluded that the absorption peak (496 nm) in UV-Vis spectra and the emission shoulder (496.5 nm) in PL spectra are attributed to the d-electron transition of Ti3+ in TiO2 films.

Abstract:The micro-arc oxidization is an efficient and pollution-free technique of surface processing and can form in situ a ceramic layer on the surface of nonferrous metal. In this paper, the micro-arc oxidization ceramic layer was formed on the surface of TiAl alloy by using a self-designing pulse power supply equipment of micro-arc oxidization. The oxidation dynamics of the ceramic layer on the surface of TiAl alloy was studied in the cycle high temperature condition and the experimental results show that the oxidation dynamics curve of TiAl alloy micro-arc oxidization ceramic layer submitted a parabolic function, which indicates that the ceramic layer can protect the TiAl alloy. Moreover, the effect of SiO32- on the characteristics of the ceramic layer was also studied, the results show that the working temperature with a micro-arc oxidization ceramic layer can be increased to 1273 K after adding SiO32- in the solution of the micro-arc oxidization. Analyzing by SEM and XRD test, the TiAl alloy ceramic layer contained 80 percent Al2TiO5, 11 percent TiO2 and 9 percent SiO2, which indicates that the addition of SiO2 can effectively restrain the decomposition of Al2TiO5 at high temperature and thus significantly increase the anti-oxidation of the TiAl alloy.

Abstract:采用SiC/Si3N4陶瓷先驅(qū)體聚硅氮烷連接反應(yīng)燒結(jié)碳化硅陶瓷,研究了連接溫度、連接壓力、浸漬/裂解增強(qiáng)處理對(duì)連接強(qiáng)度的影響。結(jié)果表明:在1100℃~1400℃溫度范圍內(nèi),連接強(qiáng)度先升高后降低;連接過程中施加適當(dāng)?shù)妮S向壓力可提高連接層致密度;浸漬/裂解增強(qiáng)處理可大幅度提高接頭強(qiáng)度。當(dāng)連接溫度為1300℃,連接壓力為15kPa,經(jīng)3次增強(qiáng)處理的連接件抗彎強(qiáng)度達(dá)最大值169.1MPa。這種連接件的斷口表面粘有大量SiC母材。由XRD研究表明,隨著溫度的逐步升高,聚硅氮烷的裂解產(chǎn)物發(fā)生了由非晶態(tài)向晶態(tài)的轉(zhuǎn)變。微觀結(jié)構(gòu)及成分分析顯示:連接層為厚度2μm~3μm的SiCN無定形陶瓷,其結(jié)構(gòu)較為均勻致密;連接層與基體間界面接合良好。

Abstract:Performance of Ni-MH batteries for the Mm(NiCoMnAl)5 alloy prepared by casting and melt-spinning techniques as negativeelectrode was studied. Different preparation methods show little influence on the capacity and internal resistance of the batteries, whiletheir discharge voltage plateau decreases after annealing the as-cast alloy and also decreases with increasing solidification rate of the alloysprepared by melt-spinning technique. The internal resistance, the alloys particle size of negative electrodes and the aluminum content inpositive electrodes were examined for the batteries during cycling. The results show that the cycling stability of the battery with the as-castalloy as negative electrode deteriorates due to the rapid pulverization and poor corrosion resistance of the alloy but could be improved afterannealing. Melt-spinning suppresses the pulverization and corrosion of the alloy and results in the prolonged cycle life of the batteries.

Abstract:系統(tǒng)研究了TiV2.1Nix(x=0.2,0.3,0.4,0.5,0.6)貯氫合金的相結(jié)構(gòu)及電化學(xué)性能。XRD及SEM分析表明:合金均由體心立方(bcc)結(jié)構(gòu)的V基固溶體主相和TiNi基第二相組成;隨著Ni含量x的增加,合金中V基固溶體主相的相含量和晶胞參數(shù)逐漸減小,TiNi基第二相含量逐漸增多,且當(dāng)x≥0.4時(shí),TiNi基第二相組織沿主相晶界形成明顯的三維網(wǎng)絡(luò)狀結(jié)構(gòu)。電化學(xué)測(cè)試表明:隨著x的增加,合金的高倍率放電性能及循環(huán)穩(wěn)定性均得到顯著改善;但當(dāng)x從0.4增加到0.6時(shí),合金的活化性能變差,最大放電容量降低。在研究的合金中,TiV2.1Ni0.4表現(xiàn)出較好的綜合性能。

Abstract:采用低溫燃燒合成工藝在甘氨酸-硝酸鹽體系中制備出Ce0.8Nd0.2O1.9固溶體納米粉末,重點(diǎn)考察了甘氨酸與硝酸鹽的配比(G/N)以及焙燒溫度對(duì)粉末特性的影響。通過熱重-差示掃描量熱分析(TG-DSC)得知,燃燒反應(yīng)的點(diǎn)火溫度為257℃。利用X射線衍射(XRD)、透射電鏡(TEM)、比表面積儀(BET)及傅里葉紅外光譜(FTIR)等手段對(duì)粉末的結(jié)構(gòu)、形貌、成分、尺寸及比表面積進(jìn)行了分析。結(jié)果表明:燃燒反應(yīng)后直接得到螢石型結(jié)構(gòu)的單相固溶體,晶粒尺寸為8nm~12nm之間,比表面積為38m2/g~47m2/g;晶粒尺寸隨焙燒溫度升高而增加,在800℃下焙燒1h后,可以去除反應(yīng)殘留物質(zhì),并使獲得的晶形更加完整。

Abstract:采用直流磁控濺射法制備了Co1_(-x)Pt_x合金薄膜,并詳細(xì)研究了其結(jié)構(gòu)和磁學(xué)性能隨x變化的規(guī)律。通過XRD結(jié)構(gòu)分析可知:濺射態(tài)的薄膜當(dāng)x≤28%時(shí),為hcp結(jié)構(gòu);x=35%和40%時(shí),為hcp和fcc的混合結(jié)構(gòu);x≥46%以后,為fcc結(jié)構(gòu)。VSM測(cè)試結(jié)果表明:隨x的增大,濺射態(tài)薄膜的矯頑力先增大后減小,當(dāng)x=23%時(shí),矯頑力達(dá)到最大值2147×79.6A/m,在x=46%處矯頑力急劇下降至100×79.6A/m左右,x>46%以后,矯頑力隨x的增大不再明顯變化。退火后,hcp結(jié)構(gòu)的薄膜矯頑力基本不變,而接近等原子比的fcc結(jié)構(gòu)的CoPt薄膜,由于部分轉(zhuǎn)變?yōu)閒ct結(jié)構(gòu),矯頑力有很大提高;fcc結(jié)構(gòu)的CoPt3薄膜矯頑力有所增大,但是增大不多。

Abstract:Anodizing process is an effective method to improve the surface properties of magnesium alloys. By now, much progress, including the optimization of electrolyte compositions, the selection of electric parameters, the film formation mechanism, the film structure and the post treatment, have been obtained based the traditional process, such as Dow 17 and HAE. In this paper, the details are reviewed and the trend of development is indicated.

Abstract:The investigations on the thermal physical properties of refractory metals (V, Nb, Ta, Mo, W et al) were reviewed in this paper. The interrelation between the thermal properties of the refractory metals and their microstructures were discussed from theoretical and experimental aspects. The study of the nanostructured refractory metals was mentioned. Finally the prospect for the research and application of the refractory metals was present.

Abstract:Technologic parameters of preparing nanocrystalline ITO(Indium Tin Oxide) powders by a hydroxide coprecipitation method were studied in this paper. The pH values of deposition beginning and its complete ending in the alkalescent solutions, and the pH values of dissolving beginning and its complete dissolving in the acidic solutions were computed, respectively, by using the equilibrium theory of thermodynamics. It is found that the pH values are functions of temperature. Thereout, the optimized designs of technologic parameters for manufacturing ITO powder have been made. HTEM, SEM, XRD have been used for measuring the nanosized ITO powders and found that the mean size is about 28 nm and grows along the crystal face (400).

Abstract:The mechanisms of the creep damage and the failure of the short fiber reinforced metal matrix composites (MMCs) have been investigated. The unit cell models are applied for the plane randomly-distributed-fiber MMCs by means of the finite element method (FEM) of ABAQUS. The creep damage and failure of the matrix is simulated by the K-R damage model, which has been implemented as the user subroutine CREEP of ABAQUS. The breakage of the fibers is simulated by the stress criterion, it means that the breakage will occur when the axial stress of the fibers reaches the critical value. This stress criterion has also been implemented into the ABAQUS. The influence of the fiber breakage on the stress distribution has been obtained. The FEM results show that the creep damage is localized near the corners of the fibers and the fractured surfaces of the fibers after the breakages of the fibers occur. And the fiber breakage has very limited influence on the creep damage of the matrix, but it reduces a high stress concentration in the matrix near the fractured surface. This high stress concentration will help the crack enlargement in the matrix by the stress criterions.

Abstract:通過對(duì)鈦酸鉛陶瓷氣相擴(kuò)滲稀土元素,制備了導(dǎo)電陶瓷材料. 通過X射線衍射、電子探針X射線能譜和掃描電鏡測(cè)試分析,表明稀土元素La,Ce,Gd,Sm等均已滲入到PbTiO3陶瓷體相中,并生成了新的化合物L(fēng)a5O7NO3,La2C2O2,Gd2O3,La2Ti6O15,SmO和CeTi21O38,并使擴(kuò)滲后的PbTiO3基陶瓷的導(dǎo)電性能發(fā)生了十分顯著的變化,其室溫電阻率從純PbTiO3陶瓷的2.0×1010 (·m下降為0.2 (·m,而且隨著溫度的變化,晶粒電阻呈現(xiàn)明顯的PTCR效應(yīng),而晶界電阻隨著溫度的升高,呈急劇連續(xù)降低狀態(tài),總電阻的變化規(guī)律與晶界電阻的變化相類似,試樣總電阻的PTCR效應(yīng)已不存在,已表現(xiàn)出導(dǎo)電體特征.

Abstract:采用直流磁控濺射法制備了Co1-xPtx合金薄膜,并詳細(xì)研究了其結(jié)構(gòu)和磁學(xué)性能隨x變化的規(guī)律.通過XRD結(jié)構(gòu)分析可知濺射態(tài)的薄膜當(dāng)x≤28%時(shí),為hcp結(jié)構(gòu);x=35%和40%時(shí),為hcp和fcc的混合結(jié)構(gòu);x≥46%以后,為fcc結(jié)構(gòu).VSM測(cè)試結(jié)果表明隨x的增大,濺射態(tài)薄膜的矯頑力先增大后減小,當(dāng)x=23%時(shí),矯頑力達(dá)到最大值2147×79.6 A/m,在x=46%處矯頑力急劇下降至100×79.6 A/m左右,x＞46%以后,矯頑力隨x的增大不再明顯變化.退火后,hcp結(jié)構(gòu)的薄膜矯頑力基本不變,而接近等原子比的fcc結(jié)構(gòu)的CoPt薄膜,由于部分轉(zhuǎn)變?yōu)閒ct結(jié)構(gòu),矯頑力有很大提高;fcc結(jié)構(gòu)的CoPt3薄膜矯頑力有所增大,但是增大不多.

Abstract:The isothermal section of Ni-Cr-Mo ternary system at 1358 K was determined by means of diffusion triple and electron microprobe analysis. The results indicate that one binary intermetallic of NiMo is formed in Ni-Cr-Mo ternary system at 1358 K. In this diffusion triple, Cr and Mo formed into a continuous solid solution, and Ni and (Cr,Mo) formed into a finite solid solution. No ternary compound was observed. One three-phase region of Ni+NiMo+(Cr, Mo) exixts in the isothermal section of Ni-Cr-Mo ternary system at 1358 K.

Abstract:采用高溫固相反應(yīng)法制備了Eu^3＋摻雜ZnO-MgO-La203-B203基質(zhì)的光致發(fā)光光纖，通過軸向拉伸試驗(yàn)測(cè)量了該光纖的應(yīng)力-應(yīng)變曲線。應(yīng)用彈脆塑性理論研究了屈服面的變化和應(yīng)力-應(yīng)變的本構(gòu)關(guān)系，計(jì)算了拉伸彈性模量、拉伸強(qiáng)度、拉伸最大負(fù)荷、拉伸強(qiáng)度的應(yīng)變、斷裂伸長(zhǎng)率和材料的脆性指數(shù)。結(jié)果表明，該光纖彈性模量高于普通玻璃和大理石，接近于硬鋁合金和軋制鋁，其拉伸強(qiáng)度和所能承載的負(fù)荷都較大。

Abstract:采用分子動(dòng)力學(xué)法建立了熔體ZA27合金模型,并通過計(jì)算機(jī)模擬獲得α相-熔體ZA27界面、α相- TiAl3化合物界面原子集團(tuán).用遞歸法計(jì)算了α相、TiAl3化合物的結(jié)構(gòu)能,α相與熔體金屬,α相與TiAl3化合物的界面能.計(jì)算結(jié)果表明：TiAl3化合物的結(jié)構(gòu)能高于α相的結(jié)構(gòu)能,合金凝固時(shí)TiAl3化合物先于α相從熔體中析出;α相與TiAl3化合物間的界面能低于α相與熔體金屬間的界面能,α相以TiAl3化合物為基體形核比之從熔體金屬直接形核增加的界面能少,可減少形核功,因此,TiAl3可成為α相的異質(zhì)核心,增加α相形核率,細(xì)化合金組織.

Abstract:對(duì)用無壓浸滲法制備的高含量Si/Al復(fù)合材料的浸滲及凝固組織進(jìn)行了研究,對(duì)Si骨架間的凝固組織和浸滲過程中的水淬組織進(jìn)行了詳細(xì)的分析,并對(duì)2種組織進(jìn)行了比較.結(jié)果表明,Si骨架間的過共晶Al-Si合金液的水淬組織為偽共晶組織,高速率的凝固阻礙了Si的析出和擴(kuò)散.而在緩慢冷卻凝固時(shí),隨著初晶Si的析出,形成呈網(wǎng)絡(luò)狀連續(xù)的Si相骨架,Si骨架間隙進(jìn)一步減小,剩余的過共晶成分的液相被分隔局限其間,液相比例減少.在被Si相骨架分隔的微區(qū)內(nèi)產(chǎn)生了類似于離異共晶的析出現(xiàn)象――初晶Si和共晶Si只能沿原預(yù)制體Si多孔體骨架上附著析出,凝固后的Al基體為α相,而不是典型的Al-Si共晶組織.另外,Si相的體積分?jǐn)?shù)決定于浸滲溫度.

Abstract:The microstructure, optical absorption properties and luminescence function of GaN thin films grown on the sapphire substrate with the buffer layer of GaN by MOCVD have been studied by means of XRD, TEM, infrared transmission spectrum, and photoluminescence. The XRD results show that the crystal of GaN is hexagonal wurtzite structure, The thin films have perferred orientation in c axis with very high quality. The TEM images of cross-sectional specimen show that the thicknesses of every layer in the superlattices are uniform with the average period of 13.3 nm, but there are high-density dislocations in the superlattices region. With the related optical experimental data, it had been found that the optical absorption edge was at about 370 nm. The theory calculation indicates that the five samples are direct transition semiconductor with band-gaps of about 3.4 eV. The refractive indexes of the samples increase with the photon energy enhance and decrease with the wavelength increasing. The results show that the extinction coefficients have the minimum at 370 nm. Photoluminescence test results show that the superlattice has preferable luminescence property and a yellow luminescence is found.

Abstract:采用熔滲/氮化復(fù)合處理技術(shù)對(duì)TiC-TiN基、WC基金屬陶瓷進(jìn)行了高溫高壓熔滲/氮化處理,通過掃描電鏡、能譜儀、X射線衍射等分析技術(shù)對(duì)其顯微組織、成分及結(jié)構(gòu)進(jìn)行了分析.結(jié)果表明：經(jīng)過高溫高壓熔滲/氮化處理,WC-Co金屬陶瓷未形成梯度結(jié)構(gòu);WC-TiC-Co金屬陶瓷表面形成了TiN,但是從材料表面向內(nèi)部的成分過渡存在明顯的界面;TiC-TiN基金屬陶瓷由表面到心部形成了梯度結(jié)構(gòu),其硬度自表面向心部呈現(xiàn)高-低-高的變化趨勢(shì), 該金屬陶瓷表面主要形成了Ti（C0.3N0.7）.

Abstract:運(yùn)用鹽-金屬反應(yīng)法制備了亞微米TiB2顆粒增強(qiáng)鋁基復(fù)合材料（TiB2/AC8A）.TiB2顆粒通過鈦鹽和硼鹽與鋁合金反應(yīng)原位生成.對(duì)復(fù)合材料進(jìn)行了顯微組織觀察和高溫蠕變性能實(shí)驗(yàn).原位TiB2顆粒的尺寸約為0.5μm,近似呈球形。TiB2／AC8A復(fù)合材料具有優(yōu)異的高溫蠕變性能。10ω／％TiB2原位顆粒（～0．5μm）增強(qiáng)AC8A復(fù)合材料的蠕變抗力比10φ／％SiCp（1．7μm）外加顆粒增強(qiáng)AI復(fù)合材料至少要高兩個(gè)數(shù)最級(jí)。10ω／％TiB2／AC8A復(fù)合材料表現(xiàn)出高的名義應(yīng)力指數(shù)（11．7～12．5）和名義激活能（265kJ／mol），其穩(wěn)態(tài)蠕變數(shù)據(jù)能夠用廊力指數(shù)為8的亞結(jié)構(gòu)不變模型和門檻應(yīng)力來解釋。TiB2／AC8A復(fù)合材料的蠕變斷裂行為符合Monkman-Grant關(guān)系式。

Abstract:采用高溫熔煉方法后機(jī)械球磨和機(jī)械合金化方法分別制備了CoFe_3Sb_(12)和FeSb_2合金粉末,并對(duì)其電化學(xué)嵌鋰性能進(jìn)行了研究。研究發(fā)現(xiàn),FeSb_2 的首次可逆容量為394 mAh·g-1,比CoFe_3Sb_(12) 的首次可逆容量(485 mAh·g-1)低。但是FeSb_2 容量衰減的速度要遠(yuǎn)遠(yuǎn)小于CoFe3Sb12。FeSb2 的容量保持率在第10 個(gè)循環(huán)時(shí)仍保持在70%以上,而CoFe_3Sb_(12 )卻只有50%左右。通過二者嵌鋰性能對(duì)比研究表明,減少嵌鋰活性中心能有效地緩解合金類負(fù)極材料在循環(huán)中的容量衰減現(xiàn)象。

Abstract:利用溶膠-凝膠法制備了納米晶La0.7Pb0.3FeO3氣敏材料,并對(duì)其相組成、電導(dǎo)及其對(duì)CO氣敏性能進(jìn)行了研究.XRD結(jié)果表明：摻鉛固溶體La0.7Pb0.3FeO3仍為正交晶系鈣鈦礦結(jié)構(gòu),粒徑約為17nm,低于純相LaFeO3的粒徑31nm。電導(dǎo)測(cè)鼉顯示：該材料足P型半導(dǎo)體導(dǎo)電行為，電導(dǎo)大于同溫度下純相LaFeO3的電導(dǎo)，且電導(dǎo)突變溫度有所降低。氣敏性能研究表明：Pb摻雜對(duì)其CO氣敏性能有了明顯改善。

Abstract:為計(jì)及強(qiáng)散射偶極子間的相互作用,引入?yún)⒘喀舎和μh,利用廣義多重散射理論及MATLAB計(jì)算機(jī)軟件對(duì)在2 GHz～18 GHz頻率下的體積占空比為8%的鐵纖維隨機(jī)混合媒質(zhì)等效磁導(dǎo)率的實(shí)驗(yàn)值進(jìn)行曲線的擬合,導(dǎo)出了耦合系數(shù)εh和μh,并在此基礎(chǔ)上,對(duì)體積占空比分別為30%和20%的鐵纖維隨機(jī)混合媒質(zhì)等效磁導(dǎo)率進(jìn)行了計(jì)算,計(jì)算結(jié)果與實(shí)驗(yàn)吻合良好.

Abstract:在950℃的氮化溫度下,通過單氫氧化鎵（GaO2H）粉末與流動(dòng)的NH3反應(yīng)35 min制備出粒狀GaN微晶.通過X射線衍射（XRD）和掃描電鏡（SEM）研究發(fā)現(xiàn),GaN粉末是六角纖鋅礦結(jié)構(gòu)的粒狀微晶,其晶格常數(shù)a和c分別為0.3191 nm和0.5192 nm.X射線光電子能譜（XPS）揭示試樣中有Ga-N鍵形成,Ga與N兩元素比為1∶1.

Abstract:Pure Ni nanopowders were successfully prepared by the anodic arc discharged plasma method with homemade experimental apparatus. The nanoparticles by this process were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and BET adsorption to determine the chemical composition, morphology, crystal structure, specific surface area, particle size and particle size distribution. Element analyze instrument is also used to determine the C, H, N contents. The main constituent elements were examined by energy dispersive X-ray spectroscopy (EDS) equipped in SEM and the structure compose was qualitatively analyzed by FT-IR spectrum. The experimental results showed that the crystal structure of samples was fcc structure same as the bulk material with an average grain size of about 47 nm, ranging from 20 nm to 70 nm. The sample has high purity and strong adsorption, whose particles distributed uniformly in spherical chain shape with a specific surface area of 14.23 m2/g.

Abstract:It is important by in-situ synthesis method to fabricate magnesium matrix composites. In-situ synthesis of magnesium matrix composites reinforced with TiC ceramics by remelting and diluting method was studied in the paper. It was found through microstructure observation and XDR analysis that the fine reinforcements dispersed uniformly in magnesium matrix composites. It was indicated that the damping capacity of magnesium matrix composites was less than that of pure magnesium due to the addition of TiC, but the damping capacity of magnesium matrix composites can be enhanced by heat treatment.

Abstract:采用液相壓力浸漬工藝制備出碳化硅顆粒(SiCp)和硅酸鋁短纖維(Al2O3·SiO2f)混雜增強(qiáng)的鎂基復(fù)合材料,研究了其機(jī)械與阻尼性能。發(fā)現(xiàn)鎂基復(fù)合材料的強(qiáng)度與純鎂相比得到了顯著的改善,而阻尼性能有所降低。并且2個(gè)弛豫內(nèi)耗峰存在于復(fù)合材料試樣中,出現(xiàn)在約150℃的峰Ⅰ不僅存在于純鎂試樣中而且還存在于其復(fù)合材料試樣中,認(rèn)為其與位錯(cuò)的運(yùn)動(dòng)有關(guān);出現(xiàn)在約250℃的峰Ⅱ僅存在于復(fù)合材料的試樣中,分析認(rèn)為是由于碳化硅顆粒與鎂基體的界面滑移所致。

Abstract:通過液態(tài)原位反應(yīng)合成制備MgO/Mg2Si增強(qiáng)Mg-Li基復(fù)合材料,利用TEM對(duì)增強(qiáng)相形態(tài)及界面結(jié)構(gòu)進(jìn)行了觀察.實(shí)驗(yàn)結(jié)果表明,復(fù)合材料中增強(qiáng)粒子與基體界面結(jié)合良好,無反應(yīng)物生成.確定了增強(qiáng)粒子與基體的界面取向關(guān)系,MgO與基體α相的晶體學(xué)關(guān)系為[100]MgO//[40（￣4）3]α,（011）MgO//（（￣1）2（￣1）0）α;Mg2Si與基體β相的晶體學(xué)關(guān)系為[310]Mg2Si//[411]β,（1（￣3）（￣1））Mg2Si//（001）β.

Abstract:Morphological evolutions and kinetics process controlled by transformation-induced elastic strain (include external strain field) during isostructure phase separation are systematically investigated using prototype binary alloy by diffuse-interface field model. The results show that various types of morphologies, such as basket-weave structures, sandwich-like multi-domain structures, precipitate macro lattices and plate-like structures, are predicted in different stages of phase separation. It is demonstrated that the precipitates are preferentially oriented with an external stress for an inhomogeneous elastic modulus system. Moreover, the simulation results also indicate that the small particles will be connected along elastic soft directions to formation bigger particles in the stage of growth and those small isolated particles will be consumed by bigger particles in the stage of ripening.

Abstract:通過調(diào)整合金的組成,優(yōu)化其熔煉和熱處理過程,制備出一種新組成的富La貯氫合金La0.62Ce0.25Pr0.03Nd0.10Ni3.69Co0.71Mn0.34Al0.29Zr0.005,用掃描電鏡、壓力-恒溫實(shí)驗(yàn)、X射線衍射、恒電流充放電和循環(huán)伏安掃描方法對(duì)合金進(jìn)行了表征.結(jié)果表明：該合金為六方晶系的CaCu5型結(jié)構(gòu);高溫下氫的吸脫附平臺(tái)低,65℃時(shí)壓力平臺(tái)為0.1MPa：初始容量高達(dá)335mAh／g，2C經(jīng)500次循環(huán)后，容降僅為18．6％．

Abstract:Nanocrystalline CuCr alloys with a relative density of above 98% can be prepared by high energy ball milling and hot pressing technique. The grain size of nanocrystalline CuCr alloy is less than 50 nm. The vacuum arc instability and chopping current of nanocrystalline CuCr materials were studied in an artificial circuit. The results show that the vacuum arc of nanocrystalline CuCr is more stable than that of conventional materials, the chopping current is 17%-35 % of that of conventional alloys.

Abstract:將高能球磨后的Ti-Al粉末和TiC,Al2O3粉末混合進(jìn)行熱壓燒結(jié),在燒結(jié)的過程中反應(yīng)生成金屬間化合物為增強(qiáng)相的復(fù)合材料.通過對(duì)粉料的X射線衍射分析、熱分析（DSC）和燒結(jié)體的成分分析表明,最終的金屬間化合物只有Ti3Al而沒有其它金屬間化合物相.通過熱力學(xué)計(jì)算,分析了反應(yīng)燒結(jié)過程并發(fā)現(xiàn)在低溫由固相間原子擴(kuò)散控制生成TiAl3,TiAl,Ti3Al的漸進(jìn)過程,和在高溫下金屬間化合物的合成機(jī)理,而且增強(qiáng)相和基體界面間處于穩(wěn)定狀態(tài).

Abstract:研究了化學(xué)計(jì)量比對(duì)AB4.8~AB5.2貯氫合金電化學(xué)性能的影響。結(jié)果表明:在本實(shí)驗(yàn)研究范圍內(nèi),當(dāng)x=0.1時(shí),貯氫合金電極的0.2C,1C和5C放電容量、高倍率放電特性及3C循環(huán)壽命分別達(dá)到324mAh·g-1,301mAh·g-1,263mAh·g-1,0.81和530次。此外,化學(xué)計(jì)量比對(duì)貯氫合金的活化性能和溫度特性均有較大的影響,當(dāng)x分別為–0.2,–0.1,0.0,0.1和0.2時(shí),貯氫合金電極在0.2C充放電的條件下活化次數(shù)分別為3次、4次、7次、5次和6次,且隨著x的增大,貯氫電極的高溫(45℃,1C)和常溫(25℃,1C)放電效率下降,低溫(–18℃,1C)放電效率則有增大的趨勢(shì)。從合金活化性能、大電流充放電特性和循環(huán)穩(wěn)定性來看,x=0.1時(shí)(AB5.1),能得到具有較佳的電化學(xué)性能的貯氫材料。

Abstract:用直流反應(yīng)磁控濺射法制備了TiO2薄膜,并對(duì)熱處理前后試樣的紫外可見光譜（UV-Vis spectrum）和熒光發(fā)射光譜（PL Spectrunm）做了研究。發(fā)現(xiàn)熱處理后試樣的紫外可見光譜在496nm處出現(xiàn)了一個(gè)較為明顯的吸收峰，熒光發(fā)射光譜496．5nm處出現(xiàn)一個(gè)熒光發(fā)射帶肩。X射線光電予能譜（XPS）的分析結(jié)果表明，熱處理可使薄膜中晶格氧擴(kuò)散出去，生成Ti^3＋離子和氧空位。結(jié)合XPS的分析結(jié)果和理論計(jì)算，可推斷熱處理后出現(xiàn)的位于496nm處的吸收峰和496．5nm處的熒光帶肩可被指認(rèn)為薄膜中Ti^3＋離子的d電子躍遷產(chǎn)生。

Abstract:The micro-arc oxidization is an efficient and pollution-free technique of surface processing and can form in situ a ceramic layer on the surface of nonferrous metal. In this paper, the micro-arc oxidization ceramic layer was formed on the surface of TiAl alloy by using a self-designing pulse power supply equipment of micro-arc oxidization. The oxidation dynamics of the ceramic layer on the surface of TiAl alloy was studied in the cycle high temperature condition and the experimental results show that the oxidation dynamics curve of TiAl alloy micro-arc oxidization ceramic layer submitted a parabolic function, which indicates that the ceramic layer can protect the TiAl alloy. Moreover, the effect of SiO3^2- on the characteristics of the ceramic layer was also studied, the results show that the working temperature with a micro-arc oxidization ceramic layer can be increased to 1273 K after adding SiO3^2- in the solution of the micro-arc oxidization. Analyzing by SEM and XRD test, the TiAl alloy ceramic layer contained 80 percent Al2TiO5, 11 percent TiO2 and 9 percent SiO2, which indicates that the addition of SiO2 can effectively restrain the decomposition of Al2TiO5 at high temperature and thus significantly increase the anti-oxidation of the TiAl alloy.

Abstract:通過冷變形拉拔并結(jié)合中間熱處理制備了纖維相增強(qiáng)的Cu-12%Ag合金線材.通過不同溫度下退火不同時(shí)間,研究了等溫過程對(duì)Cu-12%Ag合金組織性能的影響.200℃等溫退火時(shí)強(qiáng)化相仍能基本保持纖維形態(tài),強(qiáng)度略有下降,電導(dǎo)率略有上升.300℃等溫退火時(shí)纖維相界面局部遷移,退火初期合金電導(dǎo)率較快上升而強(qiáng)度較快下降,隨后電導(dǎo)率上升或強(qiáng)度下降速率變緩.400℃等溫退火時(shí)組織發(fā)生明顯再結(jié)晶和晶粒粗化,退火初期合金電導(dǎo)率劇烈上升而強(qiáng)度劇烈下降,隨時(shí)間延長(zhǎng),強(qiáng)度下降趨勢(shì)變緩而電導(dǎo)率達(dá)到最高值后略有下降.可以用纖維組織的回復(fù)、再結(jié)晶、次生相析出及溶質(zhì)原子溶解等因素在等溫退火過程中的變化來分析材料組織、性能的變化.

Abstract:Tow kinds of Mo-N alloyed Iayers were fabricated on the surface of Ti6Al4V alloy by Xu-Tec process. One process was Mo-diffusing with nitriding simultaneously,and the other is nitriding after Mo-diffusing. This paper investigated their friction and wear behaviors against a polished 2100 steel counterbody ball under ball-on-disc test condition.It has been found that both the two Mo-N diffusion layers have excellent wear-resistant hehavior in sliding hut their friction coefficient increases slightly.The war rate for Mo-diffusing with simullaneous nitriding 400 times less than Ti6Al4V and 1080 times less for nitriding after Mo-diffusing.

Abstract:采用SiC/Si3N4陶瓷先驅(qū)體聚硅氮烷連接反應(yīng)燒結(jié)碳化硅陶瓷,研究了連接溫度、連接壓力、浸漬/裂解增強(qiáng)處理對(duì)連接強(qiáng)度的影響.結(jié)果表明：在1100℃～1400℃溫度范圍內(nèi),連接強(qiáng)度先升高后降低;連接過程中施加適當(dāng)?shù)妮S向壓力可提高連接層致密度;浸漬/裂解增強(qiáng)處理可大幅度提高接頭強(qiáng)度.當(dāng)連接溫度為1300℃,連接壓力為15kPa，經(jīng)3次增強(qiáng)處理的連接件抗彎強(qiáng)度達(dá)最大值169．1MPa。這種連接件的斷口表面粘有大量SiC母材。由XRD研究表明，隨著溫度的逐步升高，聚硅氮烷的裂解產(chǎn)物發(fā)生了由非晶態(tài)向晶態(tài)的轉(zhuǎn)變。微觀結(jié)構(gòu)及成分分析顯示：連接層為厚度2μm-3μm的SiCN無定形陶瓷，其結(jié)構(gòu)較為均勻致密；連接層與基體間界面接合良好。

Abstract:研究了采用懸浮熔煉（常規(guī)鑄態(tài)）和不同冷卻速度的單輥快淬方法制備的Mm（NiCoMnAl）5型稀土系貯氫合金負(fù)極活性材料對(duì)金屬氫化物鎳（MH/Ni）電池性能的影響.結(jié)果表明,采用不同方法制備的合金對(duì)整個(gè)電池活化后的容量和內(nèi)阻影響很小,但是常規(guī)鑄態(tài)合金在退火后降低了電池的放電電壓平臺(tái),快淬合金隨著冷凝速率的提高,放電平臺(tái)呈降低趨勢(shì).對(duì)循環(huán)充放電過程中電池內(nèi)阻、循環(huán)到一定次數(shù)時(shí)負(fù)極貯氫合金的粒度和正極內(nèi)鋁含量的測(cè)試結(jié)果表明,鑄態(tài)不退火合金較差的抗粉化性和較差的耐腐蝕性使電池的循環(huán)性能較差,經(jīng)退火后其性能均有所提高,快淬合金使電池的循環(huán)性能優(yōu)于常規(guī)鑄態(tài)合金.

Abstract:利用超臨界CO2流體、溶劑和熱處理3種方法對(duì)ZrO2陶瓷注射成型坯體進(jìn)行脫脂,并對(duì)試樣進(jìn)行了一系列的性能測(cè)試.實(shí)驗(yàn)結(jié)果顯示,脫脂方法對(duì)陶瓷性能有較大的影響.超臨界流體脫脂克服了熱脫脂的開裂、變形等各種缺陷,使燒結(jié)件獲得較好的力學(xué)性能,平均抗彎強(qiáng)度σ為1074MPa，Weibull模數(shù)m達(dá)到18．93，高于利用溶劑脫脂的燒結(jié)件（σ=1038．4MPa，m=13．28）和熱脫脂燒結(jié)件（σ=983．5MPa，m=7．59）。此外，超臨界CO2流體脫脂、溶劑脫脂可使陶瓷注射成型脫脂時(shí)間大大減少，脫脂過程約縮短到熱脫脂的1／20。

Abstract:采用純度分別為99.94%和99.2%的稀土金屬Gd,配制了Gd5Si1.9Ge2.1和Gd5Si1.72Ge2.28兩組合金,研究雜質(zhì)對(duì)Gd5（SixGe1-x）4合金磁熵變的影響原因。粉末衍射結(jié)構(gòu)分析表明，所研究的合金中都有Gd5Si2Ge2相，而采用低純Gd配制的Gd5（SixGe1-x）4合金中還出現(xiàn)了明顯的Gd5（Si，Ge）3相。磁性測(cè)量表明，雜質(zhì)不改變合金中主相的居里溫度，即沒有改變合金中主相磁性原了的相互作用，但由于低溫反鐵磁性Gd5（Si，Ge）3相對(duì)室溫Gd5Si2Ge2相的磁熵變沒有貢獻(xiàn)，導(dǎo)致Gd5（Si，Ge1-x）4合金在室溫附近的磁熵變下降。

Abstract:采用中性鹽霧、周期浸潤(rùn)等人工加速腐蝕試驗(yàn)和電化學(xué)測(cè)試方法,研究了Al-6Mg-Zr和Al-6Mg-Zr-Sc 2種鋁合金在模擬海水環(huán)境中的腐蝕行為.結(jié)果發(fā)現(xiàn)：在試驗(yàn)環(huán)境中2種鋁合金都發(fā)生了點(diǎn)蝕;添加了Sc元素的Al-6Mg-Zr-Sc合金比Al-6Mg-Zr合金表現(xiàn)出更好的耐蝕性.自腐蝕電位和動(dòng)電位陽極極化曲線研究也發(fā)現(xiàn),添加Sc元素后鋁合金的耐蝕性能增強(qiáng).SEM/EDX分析表明,Al-6Mg-Zr-Sc合金中存在的Al3（Sc, Zr）復(fù)合相能細(xì)化晶粒、有效地抑制Al-6Mg-Zr合金中β相（Mg5Al8）的析出,使β相在合金基體中呈不連續(xù)分布,從而降低了合金的腐蝕敏感性.

Abstract:To obtain a better bioactive apatite coating, a brushite coating on the carbon/carbon composite prepared by sonoelectrodeposition technique was treated for 1 hour in an alkaline solution. The morphologies, structures and compositions of the calcium phosphate coatings were analyzed with SEM, XRD, FTIR and EDAX, and the bonding strength of coatings was also measured. The results show that the difference in the morphologies of the calcium phosphate coatings is no significant before and after the alkaline-heat treatment, however, a more compact coating can be obtained after the alkaline-heat treatment. The vertical distributions of different elements such as P, O, Ca and C were found between the coating and substrate. The bonding strength is more than 3 MPa, maximum to 4.2 MPa. Failure of the coating mainly occurred inside the coating due to the cohesive breakage of apatite coating.

Abstract:In the present work, the principles and processing modes of equal channel angular pressing (ECAP) for as-cast magnesium alloys were investigated. With structural design of ECAP die, the accumulated effect of shear strains under ECAP was calculated. By observation of optical microstructure of single-passed ECAP deformed cast ingot of AM60 magnesium, the effective relationship of die geometric structure (angle and subtending one at corner between entry and exit channels) to the evolution of deformed microstructure was discussed. Based on the curves of displacement versus extrusion force during multi-passed ECAP, a mode of evolution of deformed microstructure was analyzed under different pressing conditions (e.g. number of passes, back-forces, and deforming rate). Routine of experiment and modeling for ECAP of magnesium alloys was schemed. It can be concluded from the study that the ECAP deformed microstructure of AM60 casting ingot fits the one estimated by theory of plastic mechanics well. Multi-passed ECAP can perfect the microstructure of alloy tremendously. For as-cast magnesium alloys characterized by coarse-grained structure, ECAP is an effective thermo-mechanical processing to make their ultra-fine grains.

Abstract:研究了包套鍛造對(duì)大尺寸高鈮TiAl合金室溫塑性的影響.結(jié)果表明,經(jīng)過多步包套鍛造后,合金室溫塑性大大改善,延伸率可達(dá)2.29%.這主要?dú)w于：多步包套鍛造有效地破碎了粗大的鑄態(tài)組織以及在鍛造過程發(fā)生了動(dòng)態(tài)再結(jié)晶,這樣不僅使合金平均晶粒尺寸降低,而且使合金晶粒分布均勻化,得到均勻細(xì)小的雙態(tài)組織.此外,高鈮TiAl合金經(jīng)多步鍛造后,有效消除了晶界偏析的脆性β相,從而使合金的室溫塑性得到改善.

Abstract:系統(tǒng)研究了TiV2.1Nix（x=0．2，0．3，0．4，0．5，0．6）貯氫合金的相結(jié)構(gòu)及電化學(xué)性能。XRD及SEM分析表明：合金均由體心立方（bcc）結(jié)構(gòu)的V基固溶體主相和TiNi基第二相組成；隨著Ni含量x的增加，合金中V基固溶體主相的相含量和品胞參數(shù)逐漸減小，TiNi基第二相含量逐漸增多，且當(dāng)x≥0．4時(shí)，TiNi基第二相組織沿主相晶界形成明顯的三維網(wǎng)絡(luò)狀結(jié)構(gòu)。電化學(xué)測(cè)試表明：隨著x的增加，合金的高倍率放電性能及循環(huán)穩(wěn)定性均得到顯著改善；但當(dāng)x從0．4增加到0．6時(shí)，合金的活化性能變差，最大放電容量降低。在研究的合金中，TiV2.1Ni0.4表現(xiàn)出較好的綜合性能。

Abstract:采用低溫燃燒合成工藝在甘氨酸-硝酸鹽體系中制備出Ce0.8Nd0.2O1.9固溶體納米粉末,重點(diǎn)考察了甘氨酸與硝酸鹽的配比（G/N）以及焙燒溫度對(duì)粉末特性的影響.通過熱重-差示掃描量熱分析（TG-DSC）得知,燃燒反應(yīng)的點(diǎn)火溫度為257℃.利用X射線衍射（XRD）、透射電鏡（TEM）、比表面積儀（BET）及傅里葉紅外光譜（FTIR）等手段對(duì)粉末的結(jié)構(gòu)、形貌、成分、尺寸及比表面積進(jìn)行了分析.結(jié)果表明：燃燒反應(yīng)后直接得到螢石型結(jié)構(gòu)的單相固溶體,晶粒尺寸為8nm-12nm之間，比表向積為38m^2/g～47m^2／g；晶粒尺寸隨焙燒溫度升高而增加，在800℃下焙燒1h后，可以去除反應(yīng)殘留物質(zhì)，并使獲得的品形更加完整。

Abstract:采用磁控濺射方法制備FePt（50nm）和[FePt（2nm，3nm，5nm）／C（1nm）]。膜，并在550℃退火30min，研究了周期數(shù)（n）對(duì)FePt／C系列多層膜結(jié)構(gòu)及磁學(xué)性能的影響。結(jié)果表明：退火后多層膜的矯頑力在總膜層厚度約為30nm時(shí)出現(xiàn)最大值；隨著n的增大，多層膜的飽和磁化強(qiáng)度和晶粒尺寸均不斷增大；C的加入可以有效降低晶粒間交換耦合作用。剛此可以通過控制周期數(shù)得到縣仃合適的微觀結(jié)構(gòu)和高的磁學(xué)性能的FePt／C多層膜，從而滿足超高密度磁記錄介質(zhì)的要求。