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Abstract:采用三元微觀離散格點(diǎn)形式的相場(chǎng)模型,對(duì)Ni75Al25-xFex合金γ'相的原子占位、濃度和長(zhǎng)程序參數(shù)等進(jìn)行了模擬計(jì)算.結(jié)果表明:γ'相沉淀析出為等成分有序化兼失穩(wěn)分解機(jī)制;在γ'相內(nèi),隨Fe含量的增加,Fe原子在β位的占位呈明顯的上升趨勢(shì),Al原子反之,且發(fā)現(xiàn)有少量Ni原子占據(jù)β位.另一方面,在α格點(diǎn),Fe原子的占位只呈現(xiàn)略微的增長(zhǎng),Al原子幾乎不變,而Ni原子則略微下降:β位主要由Al,Fe原子共同占據(jù),形成的γ'相是Ni3(AlFe)單相.

Abstract:采用PⅢ對(duì)Ti6A14V合金進(jìn)行表面處理,溫度控制在300～400℃之間,利用小掠射角X射線衍射技術(shù)(GXRD)、掃描電鏡(SEM)研究不同工藝條件下的相結(jié)構(gòu)和表面形貌,并且測(cè)量處理后試樣的顯微硬度、摩擦磨損性能.結(jié)果表明:試樣表面形成了金紅石相,且試樣表面變得粗糙;在390℃處理后的試樣硬度提高27%,抗磨損性能提高.

Abstract:In this paper, the types and development of long persistence luminescent materials including sulphide long persistence materials, alkali-earth aluminate long persistence materials and silicate long persistence materials etc. are introduced. The recent progress and luminescent mechanism are summarized, and the preparation methods are reviewed. Finally, the future development directions and latent application fields of the long persistence luminescent materials are discussed.

Abstract:The recent progress on study of composite hydrogen storage alloy as negative electrode of Ni/MH battery is reviewed, focusing on the major component, main methods of preparation, analysis and characteristic methods, micro-structural characteristics, electrochemical performance, and mechanism of hydriding and dehydriding. The composites are classified into five kinds based on the major component, e.g. AB5 type rare-earth hydride material, AB2 type hydride material with laves phase, A2B, AB type Mg-based hydride material, solid solution hydrogen storage alloy with BCC structure and new type La-Mg-Ni-based hydride material with stacked structure, respectively. The existing problems on research of the composite hydride materials are pointed out and the prospect of the composite development has been viewed.

Abstract:An increasing interest in PZT ferroelectric memories is presented for their commercial applications in recent years, but fatigue behavior of PZT capacitors has been a critical problem in commercial applications for FRAM devices. Changing of electrode materials of PZT capacitors is an effective method to overcome the fatigue behavior of PZT capacitors. In this paper the structure, properties and characteristics of electrode materials for PZT thin films are introduced systematically. The effect of different electrode materials on structure and ferroelectric properties of PZT thin films are compared. The mechanism how to improve the ferroelectric properties of PZT capacitors via conducting metal oxide electrodes are discussed. The main problems and directions of development of electrodes are presented.

Abstract:基于三元體系的微觀相場(chǎng)動(dòng)力學(xué)模型,從原子層次上模擬了Ni-11at%Al-7at%Cr合金在873 K預(yù)時(shí)效,1023 K再時(shí)效的組織演化過(guò)程,結(jié)合原子圖像,計(jì)算了有序相內(nèi)序參數(shù)分布和體積分?jǐn)?shù)隨時(shí)間的變化,并與1023 K下的單級(jí)時(shí)效工藝進(jìn)行了對(duì)比.研究結(jié)果表明:兩種工藝條件下. 均析出單一的LI2結(jié)構(gòu)有序相,分級(jí)時(shí)效的沉淀機(jī)制為非經(jīng)典形核長(zhǎng)大與失穩(wěn)分解的混合機(jī)制;單級(jí)時(shí)效的沉淀機(jī)制為失穩(wěn)分解機(jī)制:分級(jí)時(shí)效獲得的沉淀相呈45°方向傾斜排列的彌散顆粒狀,單級(jí)時(shí)效獲得的沉淀相呈45°方向傾斜的條紋狀;分級(jí)時(shí)效工藝下孕育期縮短,達(dá)到平衡時(shí),二者的體積分?jǐn)?shù)相等.

Abstract:用電子密度泛函方法(DFT)對(duì)YBa2Cu3O7晶胞39個(gè)原子模型系統(tǒng)計(jì)算了其能隙隨溫度的變化規(guī)律,并在能隙計(jì)算基礎(chǔ)上,應(yīng)用電子比熱的雙極化和熱激發(fā)的極化子模型計(jì)算了電子比熱及其系數(shù)隨溫度的變化關(guān)系.計(jì)算結(jié)果表明:超導(dǎo)能隙在超導(dǎo)臨界溫度點(diǎn)93 K附近有不為零的極小值;能隙曲線中的幾個(gè)轉(zhuǎn)折溫度點(diǎn)依次分別與Tc,T*和T0相對(duì)應(yīng);在Tc～T*溫度范圍,超導(dǎo)態(tài)消失,但有反鐵磁自旋相干引起的自旋能隙的存在;在T*～T0溫度范圍,有周期性條紋相產(chǎn)生的電子密度波引起的能隙的存在;在T=T0,電子比熱系數(shù)發(fā)生了從增大到減小的轉(zhuǎn)折變化.

Abstract:從第一原理角度,用基于密度泛函理論(DFT)的全電勢(shì)線性綴加平面波法(FLAPW)和廣義梯度近似(GGA),計(jì)算了摻Sn銳鈦礦相 TiO2的晶格優(yōu)化結(jié)構(gòu)和電子結(jié)構(gòu).結(jié)果表明:摻Sn以后晶胞體積明顯增大,在z方向有伸長(zhǎng)的趨勢(shì);摻Sn銳鈦礦相TiO2典型晶面的電子密度分布與純的銳鈦礦相TiO2的比較表明,摻雜后的Sn-O鍵比原來(lái)的Ti-O鍵強(qiáng);摻Sn銳鈦礦相TiO2的能帶結(jié)構(gòu)圖表明,摻雜后仍為間接帶隙的半導(dǎo)體,與未摻雜時(shí)比較,能隙減小了0.24 eV,與實(shí)驗(yàn)趨勢(shì)相符.

Abstract:The finite element simulation was adopted for severe plastic deformation of reactive synthesis AgMeO composites. The homogenization degree of microstructure was researched by simulation and experiment in same true strain condition for AgSnO2 and AgCuO composites. The results showed that the model of finite element, according to the sinter microstructure of AgMeO composites, can effectively simulate the program of severe plastic deformation. The results of simulation and experiment were consistent. From the result of simulation and experiment, the phenomena of microstructure delaminating was inevitable due to the clustering of reinforce phase in the deformation. The homogenization of microstructure can be obtained through the bigger deformation strength.

Abstract:通過(guò)拉伸試驗(yàn)研究了不同組織結(jié)構(gòu)不銹鋼纖維織物的電阻與應(yīng)變之間的關(guān)系,觀察到不銹鋼織物的電阻變化依賴于不同的組織結(jié)構(gòu),線圈轉(zhuǎn)移少、接觸電阻變化大的織物有利于提高電阻響應(yīng)的靈敏度和重現(xiàn)性.另外不銹鋼纖維織物的相對(duì)電阻變化還與加載條件如最大循環(huán)應(yīng)變、加載速率等相關(guān).

Abstract:Two alloys of Ti-25V-15Cr-0.2Si and Ti-25V-10Cr-0.2Si with different content of alloying element Cr after different thermal exposure were studied. The results show that Cr could refine the grain of Ti-V-Cr bum resistant alloy, and strengthen its mechanical property at room temperature. With the decrease of Cr, the amount of the second precipitation phase is reduced and the thermal stability of alloy becomes better, which can be interpreted by the eutectoid feature of alloying element Cr in titanium alloy.

Abstract:采用低溫高能球磨法制備了兩種Ti/Al復(fù)合粉末,粉末組成為Ti-47Al(at%),Ti-45Al-2Cr_2Nb-1B-0.5Ta(at%).研究?jī)煞N粉末在球磨過(guò)程中顯微組織結(jié)構(gòu)演化、形貌變化.結(jié)果表明,降低球磨溫度能夠有效控制球磨顆粒尺寸,低溫條件及合金元素共同作用可以獲得高質(zhì)量的細(xì)晶均勻化復(fù)合結(jié)構(gòu)粉末.在低溫(-140-5)℃不加過(guò)程控制劑條件下球磨12 h,Ti-45Al-2Cr-2Nb-1B-0.5Ta(at%)粉末粒度得到有效細(xì)化,表現(xiàn)出精細(xì)均勻化復(fù)合結(jié)構(gòu)粉末,Ti與Al晶粒尺寸分別約為16 nm,9 nm.在相同條件成分為Ti-47Al(at%)球磨5.2 h,Ti與Al元素沒(méi)有很好復(fù)合及成分均勻化,兩種成分球磨條件下均未有新相生成.在不加過(guò)程控制劑條件下,低溫環(huán)境球磨和合金元素添加對(duì)機(jī)械合金化過(guò)程具有十分重要影響.

Abstract:Coercivity is improved, while remanence is decreased for the annealed ribbons with the increase of rare earth content, the coercivity for ribbons reaches 955 kA/m upon 10at% in rare earth content and 12 m/s in wheel speed. Wheel speed almost has no effect on magnetic properties of ribbons with 9,5at% in rare earth. The amorphous formation ability and thermal stability are improved for as-spun ribbons upon Dy or Pr substitution for Nd element. Coercivity and Curie temperature are improved and remanence is decreased slightly for ribbons upon Dy substitution for Nd element. But for ribbons with Pr substitution for Nd element, both of coercivity and remanence are increased slightly .

Abstract:在不同的球磨時(shí)間下,應(yīng)用機(jī)械合金化法制備出Mg2-xZrxNi(x=0,0.15,0.3,0.45,0.6)電極合金.系統(tǒng)地測(cè)試了合金的微觀結(jié)構(gòu)及電化學(xué)性能,研究了球磨時(shí)間對(duì)合金微觀結(jié)構(gòu)及電化學(xué)性能的影響.XRD及 TEM的分析結(jié)果表明,合金中的非晶相隨球磨時(shí)間的延長(zhǎng)而增加.電化學(xué)測(cè)試的結(jié)果顯示,隨球磨時(shí)間的增加,合金的循環(huán)穩(wěn)定性及放電電壓特性得到顯著改善.球磨時(shí)間對(duì)合金容量的影響與合金的成分相關(guān),對(duì)于x≤0.3的合金,其放電容量隨球磨時(shí)間的延長(zhǎng)而單調(diào)增加;而對(duì)于x>0.3的合金,放電容量隨球磨時(shí)間的增加有一個(gè)極大值.

Abstract:利用定向凝固技術(shù)制備了取向良好的YBCO棒材,其a-b晶面與提拉方向的夾角小于5°.為研究YBCO生長(zhǎng)的各向異性及其定向凝固機(jī)制,分別通過(guò)空淬及爐冷的方式獲取了熔體生長(zhǎng)的YBCO晶粒形貌及固液界面形貌.YBCO晶粒呈現(xiàn)片層狀結(jié)構(gòu),其長(zhǎng)厚比約為2～5.晶體生長(zhǎng)的固液界面清晰反映出了外延生長(zhǎng)的特征.基于上述結(jié)果,討論了YBCO的定向凝固機(jī)制,認(rèn)為YBCO的定向凝固是由擇優(yōu)生長(zhǎng)及外延生長(zhǎng)兩階段構(gòu)成,這很好地解釋了本文的試驗(yàn)結(jié)果.

Abstract:Ni-Co高溫合金廣泛用于生產(chǎn)燃?xì)鉁u輪機(jī)葉片和熱交換器等工作于高溫和腐蝕環(huán)境的零部件,采用改良靜滴法測(cè)定了1773～1873K溫度范圍內(nèi)熔融Ni,Ni-(5～10)%Co合金在Al2O3基板上Ar 3%H2氣氛下的表面張力.熔融Ni,Ni-(5～10)%Co合金的表面張力隨著溫度的升高而降低.在此基礎(chǔ)上采用Butler模型推導(dǎo)了表面張力隨溫度與濃度的變化,計(jì)算了合金體系中元素的偏聚.結(jié)果表明,Co在合金表面的濃度低于在體相的濃度.

Abstract:研究了 IN718高溫合金在650℃下的熔鹽(75%Na2SO4 25%NaCl)熱腐蝕行為及其對(duì)合金力學(xué)性能的影響.研究表明,IN718合金熱腐蝕層分為兩層,外層由Fe3O4,FeCr2O4和Cr2O3等氧化物組成,內(nèi)層由Ni和Ni的硫化物組成.熱腐蝕過(guò)程中S沿晶界快速擴(kuò)散并在晶界形成硫化物.IN718合金在650℃,100 h浸鹽熱腐蝕預(yù)處理后,室溫拉伸性能和650℃拉伸強(qiáng)度變化不大,合金在650℃拉伸塑性略微降低,但650℃,700 MPa持久性能顯著降低,其主要原因是S降低晶界強(qiáng)度,同時(shí)外加應(yīng)力提高腐蝕速率.

Abstract:采用電子探針(EPMA)、X射線衍射(XRD)和電化學(xué)測(cè)試研究了在6 mol/L KOH電解液中添加Cu(OH)2對(duì)La2MgNi7.5Co1.5貯氫合金電極電化學(xué)性能的影響.結(jié)果表明,合金電極外表面上被鍍上Cu膜,Cu膜的厚度和致密性隨充放電循環(huán)次數(shù)的增加而增加,合金電極表面形成致密性Cu膜,可以有效地抑制電極內(nèi)部貯氫合金的氧化,但對(duì)貯氫合金顆粒粉化的抑制作用不明顯.在電解液中添加Cu(OH)2,增加了La2MgNi7.5Co1.5合金電極的活化次數(shù),降低了該合金電極的高倍率放電性能,但對(duì)合金電極的最大電化學(xué)放電容量沒(méi)有負(fù)面影響.此外,利用電沉積方法在電極表面鍍Cu膜能夠明顯改善該合金電極的電化學(xué)循環(huán)穩(wěn)定性.

Abstract:為了改善鉑基催化劑氧化甲醇的催化活性,采用循環(huán)伏安法制備了聚苯胺修飾分散鉑電極(Pt-Pan/Pt)、聚苯胺和磷鉬酸共同修飾分散鉑電極(PMo12-Pt-Pan/Pt).并用循環(huán)伏安法研究了制備電極在0.5 mol·L-1H2SO4溶液中的電化學(xué)行為以及對(duì)甲醇氧化的催化效果.結(jié)果表明:PMo12-Pt-Pan/Pt電極對(duì)甲醇氧化具有很高的催化活性.PMo12-Pt-Pan/Pt電極對(duì)甲醇氧化的最大電流是33.43 mA,是Pt/Pt電極的1.37倍.催化活性的提高來(lái)源于聚苯胺和磷鉬酸與鉑的協(xié)同作用.

Abstract:建立了納米結(jié)構(gòu)組織鋯-4合金腐蝕速率.晶粒尺寸關(guān)系模型,計(jì)算了高溫下納米組織鋯-4合金和腐蝕速率曲線,并與納米組織鋯-4合金在400℃水蒸氣中的腐蝕試驗(yàn)數(shù)據(jù)進(jìn)行了對(duì)比.結(jié)果表明:與普通晶粒相比,納米晶粒尺寸下鋯合金的速率低于普通晶粒鋯-4合金的腐蝕速率,隨著納米晶粒尺寸的減小,鋯-4合金的腐蝕速率也降低;同時(shí),納米化組織處理推遲了鋯-4合金氧化轉(zhuǎn)折時(shí)間,使其抗氧化性能得到了提高.

Abstract:用粉末燒結(jié)法制備了相對(duì)密度為0.2的開(kāi)孔泡沫純鈦材料,并在室溫20～600℃溫度范圍內(nèi),對(duì)其壓縮性能進(jìn)行了測(cè)試,并從理論上分析了其楊氏模量、彈性極限和屈服強(qiáng)度對(duì)溫度的相依性.結(jié)果表明:該開(kāi)孔泡沫材料在室溫下表現(xiàn)出脆性泡沫材料變形斷裂特征;在200℃以及更高溫度下,該材料表現(xiàn)出塑性開(kāi)孔泡沫材料變形特征,其應(yīng)力-應(yīng)變曲線分為3個(gè)階段,即彈性階段,平臺(tái)階段和壓實(shí)階段.開(kāi)孔泡沫鈦的楊氏模量、彈性極限和屈服強(qiáng)度隨著溫度的升高而減小,其對(duì)溫度的相依性可分別表示為:E*=1.5217×109-5.988×105T,σ*ys=85.7-0.095T,σ*ys=99.1-0.16T 7.02×10-5T2.

Abstract:用相圖計(jì)算軟件Pandat計(jì)算了Mg-Gd-Y合金的液相面投影圖、室溫(25℃)的等溫截面圖、Mg-xGd-2Y和Mg-xGd-7Y合金系的垂直截面圖,并選取了Mg-5Gd-2Y和Mg-1Gd-7Y兩種合金,通過(guò)相圖計(jì)算與實(shí)驗(yàn)驗(yàn)證相結(jié)合的方法對(duì)合金的相平衡及凝固過(guò)程進(jìn)行了研究.用光學(xué)顯微鏡、掃描電鏡、能譜儀及示差掃描量熱儀對(duì)該合金的室溫平衡相組成及凝固過(guò)程的相變溫度點(diǎn)進(jìn)行了驗(yàn)證.結(jié)果表明,相平衡熱力學(xué)計(jì)算結(jié)果與實(shí)驗(yàn)結(jié)果吻合,Mg-5Gd-2Y合金的凝固順序?yàn)長(zhǎng)-L α-Mg-α-Mg Mg5Gd-α-Mg Mg24Y5 Mg5Gd;Mg-1Gd-7Y合金的凝固順序?yàn)長(zhǎng)--L α-Mg-α-Mg Mg24Y5--α-Mg Mg24Y5 Mg5Gd,兩合金的室溫平衡組織均為α-Mg Mg24Y5 MgM5Gd.

Abstract:采用點(diǎn)壓方式研究非晶FeCuNbSiB帶材的壓磁性能,利用X-Ray測(cè)試帶材結(jié)構(gòu),用DSC確定相轉(zhuǎn)變,用4294A阻抗分析儀測(cè)試阻抗.結(jié)果表明:非晶FeCuNbSiB帶材具有優(yōu)越的壓磁性能和壓磁穩(wěn)定性,壓磁敏感性可以通過(guò)調(diào)整退火工藝來(lái)實(shí)現(xiàn).當(dāng)退火溫度為300℃,保溫時(shí)間為1 h時(shí)非晶FeCuNbSiB帶材的壓磁性能最佳,在壓力為1.42 MPa,頻率為100MHz時(shí),|△Z|可達(dá)2.88Ω.

Abstract:利用電化學(xué)測(cè)試技術(shù)、掃描電鏡(SEM)及X射線能譜(EDS)對(duì)磁控濺射離子鍍鈮貧鈾的電化學(xué)腐蝕行為進(jìn)行了研究.實(shí)驗(yàn)結(jié)果表明:在50μg/g Cl-的KCl溶液中,鈮的腐蝕電位遠(yuǎn)高于貧鈾的腐蝕電位,鈮鍍層對(duì)貧鈾是陰極性鍍層,對(duì)貧鈾的保護(hù)是基于其對(duì)腐蝕介質(zhì)的物理屏障作用;鍍鈮貧鈾的極化電阻和電化學(xué)阻抗幅值遠(yuǎn)大于貧鈾,腐蝕電流遠(yuǎn)小于貧鈾,鈮鍍層對(duì)貧鈾具有良好的防腐蝕性能;鍍鈮貧鈾的腐蝕特征為局部腐蝕,并由孔蝕向電偶腐蝕轉(zhuǎn)變.

Abstract:應(yīng)用光學(xué)顯微鏡、掃描電鏡(SEM)、X射線衍射(XRD)、透射電鏡(TEM)以及磨粒磨損試驗(yàn),研究了質(zhì)量分?jǐn)?shù)為0.8%的Y2O3對(duì)等離子熔覆鈷基合金組織結(jié)構(gòu)和耐磨性能的影響.結(jié)果表明:沒(méi)有添加Y2O3的鈷基合金熔覆層主要是由面心立方的γ(Co)和六方結(jié)構(gòu)的M2C3構(gòu)成,并且在鈷基固溶體中存在著許多堆垛層錯(cuò):0.8%Y2O3的加入,并未改變?nèi)鄹矊拥南嘟M成,未熔的Y2O3存在,提高了位于鈷基固溶體中堆垛層錯(cuò)的密度和寬度;此外,由于Y2O3的加入,熔覆層的凝固組織發(fā)生了變化,由柱狀晶轉(zhuǎn)變?yōu)榈容S晶;稀土氧化物Y2O3作為異質(zhì)形核核心,細(xì)化了組織,改善了熔覆層組織的擇優(yōu)分布,從而提高了熔覆層的耐磨性能.

Abstract:利用膠體鈀活化后的銅電極在化學(xué)鍍鎳溶液中的混合電位-時(shí)間曲線來(lái)判斷膠體鈀活化液的活性,經(jīng)催化活性好的膠體鈀活化后的銅電極化學(xué)鍍誘導(dǎo)時(shí)間短,而催化活性不好的誘導(dǎo)時(shí)間長(zhǎng).采用100 ml·L-1HCl解膠可將誘導(dǎo)時(shí)間縮短10 s.活化后銅電極在HClO4溶液中循環(huán)伏-安曲線也用來(lái)表征活化液的活性,活性好的活化液在HClO4溶液中析氫電位較正,析氫峰較明顯,而活性差的反之.

Abstract:用電弧放電法在H2 Ar混合氣氛下同時(shí)制備了氣相穩(wěn)定和液相穩(wěn)定的Cu納米粉,并用Cu納米粉配制了導(dǎo)電漿料.用XRD,TEM,DSC-TG,化學(xué)分析等手段研究了粉體的相結(jié)構(gòu)、表面組成、形貌、粒度和氧化特性.結(jié)果表明:氣相穩(wěn)定和液相穩(wěn)定的Cu納米顆粒具有殼核結(jié)構(gòu),核為納米Cu,殼分別為氧化層和松油醇(C10H18O)分子層;粉體的平均粒度分別為80 nm和70 nm;在空氣中,包覆在Cu納米粒子表面的松油醇分子在190℃左右基本脫附和分解;Cu納米粉導(dǎo)電漿料在燒結(jié)溫度180～200℃、保溫時(shí)間60～70 min、真空度1.33 Pa條件下可獲得電阻率為(2.12～5.82)×10-4Ω·cm的導(dǎo)電膜.

Abstract:采用溫壓工藝制備了釹鐵硼粘結(jié)磁體,研究了溫壓壓力、溫壓溫度、粘結(jié)劑種類及含量對(duì)磁體磁性能的影響,以及溫壓工藝對(duì)釹鐵硼粘結(jié)磁體氧含量的影響.利用Nd2Fe14B/a-Fe系雙相納米晶磁粉為原料,在200℃下,采用12MPa的壓力,獲得性能最佳的磁體,其密度為6.43 g/cm3,磁性能為:Br=0.808 T,Hcb=461 kA/m,Hci=623 kA/m,(BH)max=101 kJ/m3.

Abstract:LaNiAl hydrogen storage alloys were prepared by arc melting method. The effects of annealing-treatment, Cu plating and SiO2 coating on the surfaces of annealing-treatment alloys were investigated. The results show the intensities of diffraction peaks increase after the alloy was annealed, revealing that the alloy was recrystalllzed and dendritic segregation was eliminated during the annealing process. the result that the surface compositions changed from the enrichment of La, Ni and Al to that of Si and O indicates that Si was coated on the powder surfaces in the form of SiO2. Electrochemical study indicates that the alloys treated show excellent performance. The discharge voltage increases and discharge curves become smooth. It is found that the annealed alloy coated with Cu shows the best performance with high discharge voltage and long discharge platform. The annealed alloy coated with SiO2 shows low discharge voltage, and longest discharge platform. The capacity losses of the alloys annealed, plating with Cu, and coated with SiO2 over 25 cycles are 7%, 4% and 5.5%, respectively. However, capacity loss of the alloys without modification is 21.8%.

Abstract:采用PⅢ對(duì)Ti6Al4V合金進(jìn)行表面處理，溫度控制在300～400℃之間，利用小掠射角X射線衍射技術(shù)（GXRD）、掃描電鏡（SEM）研究不同工藝條件下的相結(jié)構(gòu)和表面形貌，并且測(cè)量處理后試樣的顯微硬度、摩擦磨損性能。結(jié)果表明：試樣表面形成了金紅石相，且試樣表面變得粗糙；在390℃處理后的試樣硬度提高27％，抗磨損性能提高。

Abstract:利用銅模鑄造的方法制備了(Zr41.2Ti13.8Ni10Be22.5)1-x/87.5Cu12.5 x(x=1.6,6,11.2)塊體非晶合金及其復(fù)相組織,分析了合金的相組成,熱穩(wěn)定性、力學(xué)性能及斷口形貌.結(jié)果表明:隨著銅含量的不斷增多,盡管過(guò)冷液相區(qū)(ΔTx)逐漸增大,但非晶形成能力卻不斷下降.當(dāng)合金的銅含量提高到18.5%時(shí),非晶合金的壓縮斷裂強(qiáng)度達(dá)到2.2 Gpa,進(jìn)一步增加銅含量到23.7%,壓縮強(qiáng)度出現(xiàn)下降趨勢(shì).

Abstract:采用大功率電子束物理氣相沉積(EB-PVD)技術(shù)制備了層厚比為1:1的Ti/Ti-Al微疊層復(fù)合材料薄板,用XRD和SEM對(duì)材料的微觀結(jié)構(gòu)進(jìn)行了表征,對(duì)其室溫及高溫拉伸性能進(jìn)行了測(cè)試.結(jié)果表明:材料由Ti,α2-Ti3Al和γ-TiAl相組成,層狀結(jié)構(gòu)對(duì)提高材料的室溫塑性有利;盡管未經(jīng)致密化處理的材料存在著較多微孔,但在金屬間化合物層的反常強(qiáng)化及層間界面對(duì)裂紋的鈍化作用下,材料仍具有較高的抗高溫拉伸強(qiáng)度和良好的高溫延遲斷裂特性.

Abstract:利用直流電弧等離子體法成功制備了分散性較好的納米鏈狀A(yù)g-Cu-In-Sn合金粉末.用X射線衍射(XRD)、透射電鏡(TEM)和差示掃描量熱分析(DSC)等手段對(duì)粉末的結(jié)構(gòu)、粒度和熱性能進(jìn)行了表征.研究結(jié)果表明:通過(guò)優(yōu)化工藝可制備粒度分布均勻,產(chǎn)率較高,平均粒度在45.03 nm的Ag-Cu-In-Sn合金粉末.該粉末具有獨(dú)特的熱性能,與微米合金粉末的熔點(diǎn)相比,其熔點(diǎn)下降了近160℃.

Abstract:采用放電等離子燒結(jié)(SPS)方法制備Ag摻雜四元Ag-Bi-Se-Te合金,并分析研究其熱電性能.結(jié)果表明:摻雜Ag后,合金AgxBi(2-x)Se0.3Te2.7(x=0.005～0.04)的Seebeck系數(shù)均為負(fù)值,說(shuō)明材料屬于n-型半導(dǎo)體;當(dāng)溫度大約在428.0K時(shí),x=0.04合金的Seebeck系數(shù)絕對(duì)值(|a|)出現(xiàn)最大值,其值為1.80×10-4V·K-1,比三元合金B(yǎng)i2Se0.3Te2.7的最大值增大約16%;材料電導(dǎo)率隨Ag含量的增加而下降.如果采用相同方法制備且成分按(Bi2Te3)0.9-(Bi2-xAgxSe3)0.1(x=0～0.4)設(shè)計(jì)的材料熱擴(kuò)散系數(shù)進(jìn)行估算,當(dāng)溫度在477.0 K時(shí),合金AgxBi(2-x)Se0.3Te2.7(x=0.04)的ZT值出現(xiàn)最大值,其值為0.75,比典型三元合金B(yǎng)i2Se0.3Te2.7的最大值增大約0.09.

Abstract:The Ag/SnO2 composites were prepared by reactive synthesis and the microstructure uniformity and performance variation of Ag/SnO2 composites in the severe plastic deformation were investigated. The SEM analysis shows that with increasing of true strain, the fiber like microstructure vanishes gradually, and the distribution of SnO2 particles changes from cluster like to uniform. The test results of electrical and mechanical performances as well as grain sizes indicate that the performances of the Ag/SnO2 composites by severe plastic deformation are improved greatly, their mass loss of the contacts via larger true strain extrusion decreases obviously.

Abstract:采用復(fù)合鍍技術(shù)在銅箔基體上沉積了K2Ti6O13晶須增強(qiáng)鎳磷基化學(xué)復(fù)合鍍層(Ni-P-PTWS).通過(guò)拉伸試驗(yàn)數(shù)據(jù)擬合得到了Ni-P-PTWs復(fù)合鍍層的彈性模量與K2Ti6O13晶須體積分?jǐn)?shù)的計(jì)算公式.用X射線衍射法分析了不同pH值和不同熱處理溫度下所得Ni-P-PTWs復(fù)合鍍層的殘余應(yīng)力.結(jié)果表明,當(dāng)鍍液pH值為3.8時(shí),鍍層的本征應(yīng)力為壓應(yīng)力,而當(dāng)鍍液pH值為4.4或5.2時(shí),鍍層的本征應(yīng)力為拉應(yīng)力.經(jīng)過(guò)200℃,1 h熱處理,鍍層的本征應(yīng)力減小;經(jīng)過(guò)400℃,1 h或600℃,1h熱處理,鍍層的本征應(yīng)力增大.

Abstract:分別采用直流和脈沖電沉積工藝制各了兩種納米晶銅DC-Cu和PE-Cu,平均晶粒尺寸分別為65nm和33nm.室溫單向拉伸試驗(yàn)表明,DC-Cu和PE-Cu的屈服強(qiáng)度分別為332 MPa和545 MPa,基本符合Hall-Petch經(jīng)驗(yàn)公式;其斷裂應(yīng)變分別為18.2%和3.4%,與粗晶銅相比韌性大幅下降.隨著應(yīng)變速率的升高,兩種納米晶銅均表現(xiàn)出強(qiáng)度增大、韌性降低的規(guī)律.DC-Cu和PE-Cu的應(yīng)變速率敏感系數(shù)分別為0.020和0.029,激活體積分別為90b3和36b3.分析認(rèn)為,兩種納米晶銅的變形機(jī)制仍以位錯(cuò)模式為主.

Abstract:采用Zn置換HAuCl4溶液的方法制備了具有不同形貌的納米金,并研究了HAuCl4溶液的濃度對(duì)納米金形貌的影響.實(shí)驗(yàn)結(jié)果表明,納米金的形貌主要取決于HAuCl4溶液的濃度.當(dāng)HAuCl4溶液的濃度為0.01 mmol/L時(shí),置換反應(yīng)進(jìn)行5 min后的產(chǎn)物是金納米顆粒,其粒徑為10～50 nm,24 h后金顆粒的粒徑超過(guò)100 nm,金顆粒團(tuán)聚成金花狀.當(dāng)HAuCl4溶液的濃度為1 mmol/L時(shí),金顆粒的粒徑為數(shù)百納米,部分金顆粒團(tuán)聚成金花狀.當(dāng)HAuCl4溶液的濃度為10 mmol/L時(shí),在金顆粒中出現(xiàn)由納米金片組成的多晶枝晶,多晶枝晶隨后通過(guò)OA和OR機(jī)制轉(zhuǎn)變成單晶枝晶.當(dāng)HAuCl4溶液的濃度為30 mmol/L時(shí),反應(yīng)時(shí)直接生成金枝晶.因此,通過(guò)控制HAuCl4溶液的濃度,可制備具有不同形貌的納米金.

Abstract:采用DSC技術(shù)研究了SIMA法制備半固態(tài)AZ91D鎂合金坯料過(guò)程中形變率與共晶熔化激活能的關(guān)系.結(jié)果表明:形變AZ91D鎂合金內(nèi)部存在位錯(cuò)、孿晶缺陷,合金的共晶熔化激活能隨變形率的增大而變小,當(dāng)形變率達(dá)到40%時(shí),共晶熔化激活能下降很少;共晶熔化開(kāi)始溫度隨變形率的增大略有下降.

Abstract:利用酸堿刻蝕兩步化學(xué)法對(duì)Ti進(jìn)行活化處理,經(jīng)水熱電沉積制備Ti/羥基磷灰石涂層(HA),用SEM,XRD,FTIR和EDS對(duì)涂層進(jìn)行分析和表征,用微控電子萬(wàn)能試驗(yàn)機(jī)對(duì)基體和涂層的界面結(jié)合強(qiáng)度進(jìn)行測(cè)試,將涂層在牛血清白蛋白溶液(BSA)中浸泡2 h～3 d后,分析涂層與BSA溶液的FTIR和XSP光譜.結(jié)果表明:活化處理后的Ti表面形成了活性TiO2過(guò)渡層,活化過(guò)渡層使涂層與基體的結(jié)合強(qiáng)度顯著提高;涂層形貌、元素比例與骨組織纖維相一致.涂層與BSA作用后的FTIR光譜表明,在涂層中引入了BSA酰胺帶基團(tuán),在BSA溶液中又出現(xiàn)HA中PO43-基團(tuán),蛋白質(zhì)酰胺Ⅰ帶、酰胺Ⅱ帶和HA中PO43-的紅外光譜的位置和譜峰均發(fā)生變化,由此推測(cè)了Ti/HA涂層與BSA間的作用機(jī)制,指出:正是由于Ti/HA涂層與BSA間的相互作用使涂層得以在蛋白質(zhì)結(jié)構(gòu)中交互有序地排列生長(zhǎng),這是Ti/HA涂層具有生物相容性的基礎(chǔ).

Abstract:The microstructure and corrosion resistant property of AZ91 magnesium alloy with different additions of Sc were investigated The microstructures were observed by OM and SEM, and the corrosion properties were studied by electrochemical technique. The results show that with the increase of Sc content in the range from 0.18%-0.57%, the alloy microstructures are fined continuously, and the corrosion resistance of the alloy is improved. Although the change of the corrosion voltage is not big, the corrosion current density increases obviously. When Sc content is 0.39%, the minimum current density appears.

Abstract:采用直流電沉積方法,通過(guò)改變特殊添加劑C7H4NO3SNa·2H2O濃度、沉積液溫度、電流密度,制備出不同厚度的納米晶鎳覆層材料,利用高分辨透射電子顯微鏡(HRTEM)對(duì)沉積覆層材料的組織結(jié)構(gòu)進(jìn)行分析,從理論上推導(dǎo)了電流效率的計(jì)算公式,對(duì)不同工藝條件下電流效率的變化規(guī)律進(jìn)行了研究.結(jié)果表明:電沉積納米晶鎳的電流效率可按ηMk=2.4403×105v/ik計(jì)算得出;電沉積納米晶鎳的電流效率隨著添加劑C7H4NO3SNa·2H2O濃度的增加而下降;隨著電流密度和溫度的增加先增加后下降,在溫度60℃左右時(shí)最大.

Abstract:用固相反應(yīng)法制備ZnO:Eu3 納米粉末,研究其發(fā)光特性.觀察到從基質(zhì)ZnO到Eu3 的能量傳遞現(xiàn)象.研究表明,不論是ZnO基質(zhì)的激子激發(fā)還是Eu3 的高能態(tài)激發(fā),隨著Eu3 濃度從0.1 mol%增加到1 mol%,Eu3 的發(fā)射增強(qiáng).在基質(zhì)激子的激發(fā)下,ZnO:Eu3 納米粉末產(chǎn)生了很強(qiáng)的Eu3 紅色特征發(fā)射而沒(méi)有ZnO的寬帶發(fā)光.結(jié)果表明,ZnO:Eu3 納米粉末的XRD譜中不存在可觀測(cè)到的Eu2O3雜相,激發(fā)光譜中出現(xiàn)ZnO的帶間激發(fā)與純Eu2O3的激發(fā)光譜不同,這幾方面說(shuō)明了Eu3 進(jìn)入了ZnO的晶格中.

Abstract:Fe的添加,提高了金屬釩的活化性能和放氫平臺(tái)壓力,降低吸放氫容量.Fe含量<1%(原子分?jǐn)?shù),下同),對(duì)二氫化物并無(wú)明顯影響,Fe含量>1%,二氫化物平臺(tái)壓明顯升高,容量明顯下降,氫化物的生成焓明顯降低;Fe的添加對(duì)一氫化物并無(wú)明顯的影響.隨著Fe含量的增加,合金的晶格常數(shù)和晶胞體積呈線性趨勢(shì)降低.