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1.
改变CHF3 CH4 流量比R =[CHF3] ([CHF3]+[CH4 ]) ,采用微波电子回旋共振等离子体化学气相沉积 (MWECR CVD)方法沉积a C :F :H薄膜。a C :F :H薄膜的结构和光学带隙使用傅立叶变换红外光谱和紫外 可见光谱来表征。红外结果表明 ,在低流量比R(R <6 4 % )下 ,薄膜的红外特征结构主要以 CF(10 6 0cm- 1 ) , CF2(112 0cm- 1 )以及 CHx(2 80 0~ 30 0 0cm- 1 )的伸缩振动为主 ;在高流量比R(R >6 4 % )下 ,薄膜表现为类聚四氟乙烯(PTFE)的结构特征 ,典型的红外特征峰是位于 12 2 0cm- 1 处的 -CF2 反对称伸缩振动。薄膜的光学带隙Eg 随流量比R的变化表现为先降后升。进一步研究表明 ,薄膜中的H和F浓度调制着薄膜的CC共轭双键结构 ,使光学带隙Eg 从 2 37到 3 3之间变化  相似文献   

2.
用强电流直流伸展电弧化学气相沉积金刚石薄膜装置,在CH4-Ar和CH4-H2-Ar气氛中沉积了纳米金刚石薄膜,研究了沉积气氛中H2加入量和沉积压力对金刚石薄膜显微组织和生长机制的影响.沉积气氛中H2含量对金刚石薄膜的表面形貌、晶粒尺寸和生长速度有显著影响,随着H2含量增加,金刚石晶粒尺寸增大,薄膜生长速度提高.在1%CH4-Ar气氛中沉积的纳米金刚石薄膜,晶粒尺寸细小,薄膜表面形貌光滑平整.在1%CH4-少量H2-Ar气氛中沉积的金刚石薄膜,晶粒尺寸小于100nm,薄膜表面形貌较平整.随着沉积压力提高,金刚石薄膜的生长速度增大.用激光Ram an对金刚石薄膜进行了表征.  相似文献   

3.
报道了以SiCl4和H2为气源,用等离子体增强化学气相沉积技术,在小于300℃的低温下快速生长多晶硅薄膜.实验发现, 生长速率强烈依赖于放电功率、H2/SiCl4流量比和衬底温度, 而薄膜的晶化度只依赖于放电功率和H2/SiCl4流量比,与衬底温度的关系不大.通过控制和选择工艺条件,我们获得了生长速率高达0.35nm/s,晶化度高于75%的多晶硅薄膜.薄膜的暗电导率和光电导率分别达到10-4S-1·cm-1和10-3S-1·cm-1.  相似文献   

4.
在 8 5 0℃的低温下 ,在Si( 10 0 )衬底上生长了 3C SiC薄膜 ,气源为SiH4和C2 H4混合气体。用X射线衍射、X射线光电子能谱和傅立叶红外吸收谱分析了薄膜的晶体结构、组分以及键能随深度的变化。研究表明薄膜为富硅的 3C SiC结晶层 ,其中的Si/C比约为 1 2。  相似文献   

5.
按In:Sn(物质的量比)=9:1,InCl3·4H2O和SnCl4·5H2O为前驱物,采用自制甩胶喷雾热分解制备薄膜装置在普通玻璃衬底上沉积了ITO薄膜,结果表明,采用自制甩胶喷雾热分解制备薄膜新装置成功制备出ITO薄膜。该装置结构简单、操作方便。制备ITO薄膜优化条件为:甩胶转速800r/min、衬底温度250℃、退火温度450℃、载气为空气、流量为7L/min、液体雾化速度0.2ml/min、雾粒速度3.5m/s。薄膜的沉积时间为5min,薄膜厚度约1000nm,最低电阻率为0.75*10-4Ω·cm,薄膜在可见光范围(波长在400-700nm)内平均透光率为87.2%。衬底温度在200℃以上时呈现立方相结构。  相似文献   

6.
阴离子交换膜渗析法回收含硫酸钠的高浓度硫酸废水   总被引:1,自引:0,他引:1  
根据Fick扩散定律 ,提出了测定H2 SO4和Na2 SO4在阴离子交换膜中扩散速度的方法 .静态法测定结果显示 ,对含 2 5 0~ 3 5 0g/LH2 SO4、1 0 0~ 1 2 0g/LNa2 SO4的废水 ,常温下 ,A2 0 和 3 3 62BW膜中H 平均扩散速度分别为 8.0× 1 0 -4m/h和 7.8× 1 0 -4m/h,Na 平均扩散速度分别为 5 .9× 1 0 -5m/h和 6.6× 1 0 -5m/h,这预示两膜都能实现废酸中H2 SO4和Na2 SO4的有效分离 .动态法分离废酸结果表明 ,H2 SO4回收率达 83 .4% ,回收酸中Na2 SO4含量下降至 5 .2 g/L  相似文献   

7.
用可溶性无机盐制备BaPbO3薄膜   总被引:5,自引:0,他引:5  
以Ba(OH)2·8H2O和Pb(NO3)2为原料,以EDTA和柠檬酸为复合鳌合剂,采用溶胶-凝胶工艺制得BaPbO3薄膜研究了pH值、螯合剂用量对薄膜制备的影响以及薄膜的表面形态和成分发现薄膜的成分、致密度和错的价态都受热处理的影响膜厚0.1~0.4μm;薄膜的表面电阻率为150~500Ω/.  相似文献   

8.
本文研究了应用新型的超高真空等离子增强化学气相沉积 (VHV- PECVD)复合腔系统沉积a- Si1-XCX∶ HK薄膜及其特性。系统的真空度可达 10 -7Pa(10 -9Torr)以上。通过控制 H2 对常规用混合气体(Si H4 CH4 )的稀释程度以及相应的 CH4 比例 ,优化沉积工艺参数 ,制备出能带宽度范围变化较大的高质量非晶氢化硅碳 (a- Si1-XCX∶ HK)薄膜。通过 RBS、ERDA、IR和 Ramam光谱等方法分析和确定这种薄膜材料的基本特性。对 H2 氢稀释作用及其效应进行了分析。  相似文献   

9.
杨洋  于宗元 《材料保护》2019,52(2):55-57
为了进一步提高人体植入材料Ti6Al4V钛合金的生物功能,采用多弧离子在其表面沉积纯Mg薄膜。采用现代表面分析技术研究了不同气压下沉积的纯Mg薄膜的组织结构和降解特性。结果表明:当气压为10-3Pa时,Ti6Al4V钛合金表面覆盖有粒径为1~3μm的Mg颗粒且具备优异的结晶性能,纯Mg薄膜在Hank’s人体模拟液中浸泡1 d时,浸泡液的p H值从7.5快速升高至10.0,略小于纯Mg块体之p H值,之后p H值有一定程度的减小;在100Pa压力下沉积纯Mg薄膜时浸泡液的pH值降低速度比10-3Pa下时的慢,10-3Pa沉积的纯Mg薄膜浸泡液的p H值降低速度最快,具备更优的耐蚀性能; Mg2+的释放速率属于先快速后缓慢的变化过程。  相似文献   

10.
以SeO2,CdCl2.5/2H2O,H2SO4为原料,采用三电极体系,分别在ITO玻璃和TiO2纳米管阵列基底上沉积CdSe薄膜。研究了不同沉积电压(-0.6,-0.7,-0.8,-0.9V,均相对于SCE)下制备的复合薄膜的晶体结构和微观形貌,并测试了其光电性能。结果表明:制备出的纳米粒子呈不均匀团聚状态;随沉积电压的增大,光吸收增强,光响应电流增大,在沉积电压为-0.8V时复合薄膜的光响应电流达到最大值,但此沉积电压下的薄膜容易剥落。综合考虑薄膜质量和光响应电流,沉积电压为-0.7V时制备的复合薄膜最佳。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
13.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

14.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

15.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

16.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

17.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

18.
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...  相似文献   

19.
Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.  相似文献   

20.
Cubic boron nitride(c-BN) film was deposited on a Si (100) substrate by the RF-magnetron sputtering.The mainly problems for fabrication of c-BN films are the low purity and high intrinsic compressive stress. In order to solve the two problems, the c-BN film with the buffer interlayer was deposited on the substrate which had been implanted with nitrogen and/or boron ions. The results show: the implantation of nitrogen ions can obviously increase c-BN content and reduce the internal stress slightly; while the implantation of boron shows no obvious improvement to the content of c-BN, which can reduce the internal stress in the film obviously. In addition, it is suggested that the implantation of nitrogen and boron shows the best result, which not only can increase the content of c-BN, but also reduce the internal stress in the c-BN film obviously.  相似文献   

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