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1.
研究了温度、时间、浓度等对 A3钢片上 Ni-P-Zn3(PO4)2、 Ni-P-ZnSnO3和 Ni-P-ZnSiO3纳米复合化学镀层外貌的影响。用扫描电子显微镜( SEM)观察外貌;称重法测定厚度;通过 10% NaCl溶液、 1% H2S气体加速腐蚀试验、 10% CuSO4溶液点滴试验等多种手段测定其耐腐蚀性能;用 X-射线光电子谱 (XPS)及俄歇电子能谱 (AES)测定其价态及组成。结果表明:在最佳施镀条件下,可得光亮、致密、耐腐蚀性强于 A3钢、磷化膜及 Ni-P镀层的纳米复合化学镀层。镀层的原子百分组成约为 (% ): Ni-P-Zn3(PO4)2: Ni 70.00,P 12.47,Zn3(PO4)2 13.93,C 3.6; Ni-P-ZnSnO3: Ni 77.56,P 10.00,ZnSnO3 9.84,C 2.6; Ni-P-ZnSiO3: Ni 83.00,P 10.96,ZnSiO3 5.15,C 0.89。  相似文献   

2.
ELECTRON TRANSFER BETWEEN Eu~(3+) AND Ce~(3+) IN SrMgF_4 MATRIXELECTRONTRANSFERBETWEENEu~(3+)ANDCe~(3+)INSrMgF_4MATRIX¥YingWU;Ch...  相似文献   

3.
对Q235碳钢片和D310硅钢片表面表面镍-磷-硅酸锌纳米复合化学镀层,用SEM观察外貌,称重法测定厚度;10%NaCl、1%H2S加速腐蚀试验,10%CuSO4溶液点滴试验循环伏安(CV)、抗粘性及抗高温氧化试验等测定其性能。用X-射线电子谱(XPS)及俄歇电子能谱(AES)测定其价态及组成。结果表明其性能优镍-磷镀层和其它微米复合化学镀层,表面的镀层Q235碳钢片优于D310硅钢片表面的镀层,镀层的原子百分组成为:D235碳钢片:Ni79.00,P10.06,Zn2.01,Si1.88,O5.87,C1.18;D310硅钢片:Ni80.50,P10.67,Zn1.70,Si1.52,O4.83,C0.78.  相似文献   

4.
THE SYNTHESIS AND CRYSTAL STRUCTURE OF NdBr_3(i-C_3H_7OH)_2(THF)_2¥HongYeSUN;ChunHuiHUANGandGuangXianXU(ResearchCenterofRareE...  相似文献   

5.
SYNTHESIS,CHARACTERIZATIONOF2-[2-(3-NITRO-4-METHOXYLPHENYL)VINYLI-1-METHYLPYRIDINIUMPENTAANDHEXANITRATORAREEARTH(Ⅲ)COMPLEXESH...  相似文献   

6.
SYNTHESISOF3-PER(POLY)FLUOROALKYLPYRAZOLESSYNTHESISOF3-PER(POLY)FLUOROALKYLPYRAZOLES¥XiaoQingTANGandChangMingHU(ShanghaiInsti...  相似文献   

7.
STUDIES ON THE SYNTHESIS OF TRACHYLOBAGIBBERELLINANALOGUE(Ⅱ)SYNTHESIS OF DIMETHYLESTER OF 3-HYDROXY-△1_10-12,16-CYCLOGIBBEREL?..  相似文献   

8.
NEWMETHODOFSYNTHESISOF1-OXO-3-ACETONYL-DIHYDROBENZO(C)FURANLiYaZHU;QiDongZHANG;XianYuZENGandZiYunLIN(InstituteofMateriaMedica...  相似文献   

9.
ISSANDAESSTUDIESOFCHANGESINDUCEDONNi_3Ti(0001)BYOXYGENEXPOSURE¥LiJunYAO;GuoXingXIONG;DeZhengWANG;ShiShanSHENG;HengRongCHENand?..  相似文献   

10.
A FACILE TOTAL SYNTHESIS OF (±)-SELINA-3, 11-DIEN-9-OLAFACILETOTALSYNTHESISOF(±)-SELINA-3,11-DIEN-9-OLLiJunLIU;ZhaoMingXIONG;...  相似文献   

11.
以V2O5、NH4H2PO4、LiOH、柠檬酸、三嵌段聚合物表面活性剂P123为原料, 用流变相(RPR)法制备了Li3V2(PO4)3/C正极材料. 用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)等方法表征, 结果表明: 材料为单一纯相的单斜晶体结构, 颗粒均匀并呈现珊瑚结构; 恒流充放电, 循环伏安(CV)及电化学交流阻抗(EIS)等电化学性能测试表明, 采用P123 辅助合成材料电化学性能明显优于未采用P123 辅助合成材料. 3.0-4.3 V放电区间, 0.1C充放电下P123 辅助合成Li3V2(PO4)3/C材料首次放电比容量为129.8 mAh·g-1, 经过50 次循环后容量只衰减0.9%; 倍率性能及循环性能优异, 1C、10C、25C的首次放电比容量分别为128.2、121.3、109.1 mAh·g-1, 50次循环后容量保持率分别为99.1%, 96.9%, 90.7%. 这归因于三嵌段聚合物P123 作为分散剂的同时也作为有机碳源在颗粒表面及间隙形成碳网络, 有利于材料导电率的改善, 降低了其电荷转移阻抗, 减小了电极充放电过程的极化现象.  相似文献   

12.
采用优化的高温固相方法制备了稀土离子Eu3+和Tb3+掺杂的La7O6(BO3)(PO42系荧光材料,并对其物相行为、晶体结构、光致发光性能和热稳定性进行了详细研究。结果表明,La7O6(BO3)(PO42:Eu3+材料在紫外光激发下能够发射出红光,发射光谱中最强发射峰位于616 nm处,为5D07F2特征能级跃迁,Eu3+的最优掺杂浓度为0.08,对应的CIE坐标为(0.610 2,0.382 3);La7O6(BO3)(PO42:Tb3+材料在紫外光激发下能够发射出绿光,发射光谱中最强发射峰位于544 nm处,对应Tb3+5D47F5能级跃迁,Tb3+离子的最优掺杂浓度为0.15,对应的CIE坐标为(0.317 7,0.535 2)。此外,对2种材料的变温光谱分析发现Eu3+和Tb3+掺杂的La7O6(BO3)(PO42荧光材料均具有良好的热稳定性。  相似文献   

13.
New complex phosphates of the general formula K2M0.5Ti1.5(PO4)3 (M=Mn, Co) have been obtained from the melting mixture of KPO3, K4P2O7, TiO2 and CoCO3·mCo(OH)2 or Mn(H2PO4)2 by means of a flux technique. The synthesized phosphates have been characterized by the single-crystal X-ray diffraction and the FTIR-spectroscopy. The compounds crystallize in the cubic system with the space group P213 and cell parameters a=9.9030(14) Å for K2Mn0.5Ti1.5(PO4)3 and a=9.8445(12) Å for K2Co0.5Ti1.5(PO4)3. Both phosphates are isostructural with the langbeinite mineral and contain four formula unit K2M0.5Ti1.5(PO4)3 per unit cell. The structure can be described using [M2(PO4)3] framework composed of two [MO6] octahedra interlinked via three [PO4] tetrahedra. The Curie-Weiss-type behavior is observed in the magnetic susceptibility.  相似文献   

14.
A new complete solid solution of NASICON-type compounds between LiZr2(PO4)3 and La1/3Zr2(PO4)3 was evidenced with the general formula Li1−xLax/3Zr2(PO4)3 (0?x?1). These phases were synthesized by a complex polymerizable method and structurally characterized from Rietveld treatment of their X-ray and neutron powder diffraction data. This solid solution results from the substitution mechanism Li+→1/3La3++2/3□ leading to an increase of the vacancies number correlated to an increase of the La content. According to this substitution mechanism, the general formula can then be written Li1−xLax/32x/3Zr2(PO4)3 (0?x?1) in order to underline the correlation between the La content and the vacancies rate. For all the compounds, the structure is clearly related to that of the NASICON family with three crystallographic domains evidenced. For 0?x?0.5, all the members adopt at high temperature the typical NASICON-type structure (s.g. Rc), while at lower temperature, their structure distorts to a triclinic form (s.g. C 1¯), as observed for LiZr2(PO4)3 prepared above 1100 °C. Moreover, in this domain, the reversible transition is clearly soft and the transition temperature strongly depends of the x value. For 0.6?x?0.9, the compounds crystallize in a rhombohedral cell (s.g. R3¯), while for x=1, the phase La1/3Zr2(PO4)3 is obtained (s.g. P3¯, Z=6, a=8.7378(2) Å, c=23.2156(7) Å).This paper is devoted to the structure analysis of the series Li1−xLax/3Zr2(PO4)3 (0?x?1), from X-ray and neutron powder thermo diffraction and transmission electron microscopy (TEM) studies.  相似文献   

15.
Li3V2(PO4)3的溶胶-凝胶法合成及其性能研究   总被引:11,自引:0,他引:11  
以LiOH·H2O、NH4VO3、H3PO4和柠檬酸等为原料采用溶胶-凝胶法合成了锂离子二次电池正极材料磷酸钒锂(Li3V2(PO4)3)。考察了煅烧温度和配位剂种类等条件对产物组成及电化学性能的影响。研究了优化条件下制得样品的循环伏安、充放电性能和循环性能。0.1 C条件下,样品首次放电比容量达129.81 mAh·g-1,经过100次循环后容量几乎没有衰减,仍保持在128 mAh·g-1。X射线衍射研究表明合成单一Li3V2(PO4)3晶体所需温度比固相法低;并考察了循环20次后材料充电到各个单相的晶体结构,通过X射线衍射和最小二乘法计算给出了其晶胞参数变化过程,证实了循环嵌Li过程中晶体结构能够得到重现。  相似文献   

16.
The FT IR and FT Raman spectra of Co(en)3Al3P4O16 · 3H2O (compound I) and [NH4]3[Co(NH3)6]3[Al2(PO4)4]2 · 2H2O (compound II) are recorded and analysed based on the vibrations of Co(en)33+, Co(NH3)63+, NH4+, Al---O---P, PO3, PO2 and H2O. The observed splitting of bands indicate that the site symmetry and correlation field effects are appreciable in both the compounds. In compound I, the overtone of CH2 deformation Fermi resonates with its symmetric stretching vibration. The NH4 ion in compound II is not free to rotate in the crystalline lattice. Hydrogen bonding of different groups is also discussed.  相似文献   

17.
采用简单的化学偏聚法合成出Ag3PO4纳米颗粒、磷酸钴(Co3(PO42,CoP)纳米片以及它们两者的纳米复合结构(CoP/Ag3PO4),同时还比较了它们的可见光催化活性. 采用场发射扫描电镜(FESEM)、X 射线衍射(XRD)、紫外-可见(UV-Vis)吸收光谱以及光致发光谱等手段对其形貌、结构、光学以及可见光催化性能等进行表征. 结果表明,CoP/Ag3PO4复合纳米结构的可见光降解甲基橙(MO)的速率和循环稳定性均明显优于其它两种物质. 这表明CoP应该起着共催化剂的作用,它能够抑制光生电子与空穴之间的复合,并且提供大量高活性的光生空穴. 此外,我们还发现CoP/Ag3PO4降解另一种阳离子型染料——罗丹明B(RhB)的能力则远不如纯Ag3PO4,这可能是与光催化剂的表面性质发生改变有关,造成更低的RhB吸附能力. 本文提供了一种廉价制备高效可见光催化剂的新方法.  相似文献   

18.
采用优化的高温固相方法制备了稀土离子Eu~(3+)和Tb~(3+)掺杂的La_7O_6(BO_3)(PO_4)_2系荧光材料,并对其物相行为、晶体结构、光致发光性能和热稳定性进行了详细研究。结果表明,La_7O_6(BO_3)(PO_4)_2∶Eu~(3+)材料在紫外光激发下能够发射出红光,发射光谱中最强发射峰位于616 nm处,为5D0→7F2特征能级跃迁,Eu~(3+)的最优掺杂浓度为0.08,对应的CIE坐标为(0.610 2,0.382 3);La_7O_6(BO_3)(PO_4)_2∶Tb~(3+)材料在紫外光激发下能够发射出绿光,发射光谱中最强发射峰位于544 nm处,对应Tb~(3+)的5D4→7F5能级跃迁,Tb~(3+)离子的最优掺杂浓度为0.15,对应的CIE坐标为(0.317 7,0.535 2)。此外,对2种材料的变温光谱分析发现Eu~(3+)和Tb~(3+)掺杂的La_7O_6(BO_3)(PO_4)_2荧光材料均具有良好的热稳定性。  相似文献   

19.
用液相反应-前驱物烧结法制备了Cr2(WO4)3和Cr2(MoO4)3粉体。298~1 073 K的原位粉末X射线衍射数据表明Cr2(WO4)3和Cr2(MoO4)3的晶胞体积随温度的升高而增大, 本征线热膨胀系数分别为(1.274±0.003)×10-6 K-1和(1.612±0.003)×10-6 K-1。用热膨胀仪研究了Cr2(WO4)3和Cr2(MoO4)3在静态空气中298~1 073 K范围内热膨胀行为,即开始表现为正热膨胀,随后在相转变点达到最大值,最后表现为负热膨胀,其负热膨胀系数分别为(-7.033±0.014)×10-6 K-1和(-9.282±0.019)×10-6 K-1。  相似文献   

20.
溶胶-凝胶法制备Li3V2(PO4)3及其性能研究   总被引:6,自引:0,他引:6       下载免费PDF全文
0引言具有类NASICON结构的Li3V2(PO4)3是继过渡金属氧化物LMO后的一种新型的锂离子二次电池正极材料。与目前市场上应用最为广泛的正极材料LiCoO2相比,Li3V2(PO4)3具有超常的稳定性,即使在脱出的Li 与过渡金属原子的物质的量之比大于1的时候仍然具有超乎寻常的稳定性,而通常情况下1mol LiCoO2在脱出0.5mol Li 就会变得不稳定。并且Co是一种战略物资,全球储量十分有限;Co也是一种有毒金属,对于环境污染较为严重。LiNiO2因其合成较为困难而使应用受限,尖晶石LiMn2O4虽然属于环境友好型化合物,但其理论比容量仅为148mAh·g-1,且…  相似文献   

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