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本文采用微波吸收介电谱检测技术,系统研究了甲酸根离子掺杂的立方体卤化银乳剂在35ps脉冲激光作用下所产生的光电子衰减行为,分析了甲酸根离子的空穴陷阱效应以及光电子衰减特性与掺杂条件的关系.通过分析不同位置和浓度甲酸根离子掺杂的立方体AgBr乳剂中光电子衰减时间特性,讨论了AgBr乳剂中甲酸根离子掺杂条件的变化对光电子衰减的影响,揭示了其空穴陷阱效应的作用机理.实验结果表明:不同浓度的甲酸根离子对立方体AgBr乳剂都有增感作用,最佳掺杂浓度为10-3mol/molAg;最佳掺杂位置是90;,说明了在接近微晶表面掺杂的空穴陷阱对提高乳剂感光度有较好的作用. 相似文献
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研究了硼酸钙掺量对电瓷的相结构、显微结构、电气性能和机械性能的影响.通过不同硼酸钙添加量的电瓷在不同烧结温度条件下的断裂强度、气孔率、电阻率,结合电瓷的晶相结构和显微结构的变化,探讨其构效关系.结果表明:硼酸钙含量的增加或烧结温度升高,电瓷的电阻率和气孔率降低.但当硼酸钙掺量超过10;,烧结温度超过1120℃之后,电阻率和气孔率的变化不明显.电瓷的断裂强度随着硼酸钙的添加而提高,当硼酸钙含量超过10;后开始降低,添加量为10;时电瓷的断裂强度随着烧结温度而提高,1120℃后无显著变化.硼酸钙促进莫来石相的析出,但硼酸钙含量过高时,会促进CaAl2Si2O8形成,降低莫来石相的析出量,并使其形貌从细针状向短柱状和粒状发生转变.硼酸钙掺量恒定时,提高烧结温度可促进细针状莫来石相的生成. 相似文献
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以七水硫酸亚铁(FeSO4·7H2O)与六水三氯化铁(FeCl3·6H2O)为原料,离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim] BF4)为添加剂,70℃下反应2h制备了Fe3O4纳米粒子.通过X射线衍射仪(XRD)、傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)以及热重分析(TG)等方法对样品的结构和形貌进行表征,并测试了所合成样品的磁性能.实验结果表明:离子液体辅助制备的Fe3O4纳米粒子形貌较为均一,呈近似球状,平均直径约为14 nm,产品在室温下表现出超顺磁性,饱和磁化强度为60.66 emu/g.利用密度泛函理论(DFT)计算模拟了Fe3O4分别与离子液体和水相互作用的电子结构,发现离子液体通过阴离子的桥联,更易吸附在Fe3O4晶粒表面. 相似文献
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首次以乙酸锌、三(2-氨基乙基)胺及四氟硼酸钠为原料在甲醇介质中反应,合成得到了新颖桥联配合物{[( tren)Zn(CH3COO)Zn(tren)](BF4)3},用元素分析、红外光谱、核磁共振氢谱和热重分析对其进行了表征,用X-射线单晶衍射仪测定了其晶体结构,其晶体属于四方晶系,空间群为P-42(1)m,晶体参数分别为a=1.16106(19) nm,b=1.16106(19) nm,c=1.0851(3) nm,α=β=γ=90 °,V= 1.4627(6) nm3 ;Dc=1.686 g/cm3;Z = 3;F(000)=756;μ=1.745 mm-1. 相似文献
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采用离子液体(1-丁基3-甲基咪唑四氟硼酸盐)作为反应体系和氟源合成稀土镧的氟化物,研究了原料配比对合成产物及形貌的影响,分析了反应的机理.通过XRD、SEM等测试方法对得到的NaLaF4∶Er/Yb,及LaF3∶Er进行了表征和分析.使用980 nm激光激发,测试了样品的上转换发光性能,分析了Er3+浓度及yb3+的双掺对上转换性能的影响.在303 ~583 K温度范围内,测试了NaLaF4∶Er和LaF3∶Er变温上转换发光性能,讨论了524 nm与542 nm处的荧光强度比与温度的依赖关系. 相似文献
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本研究以硼酸和碱式碳酸镁为原料,采用原位合成法制备了硼酸镁晶须,通过热分析(TG)、X射线衍射(XRD)和扫描电子显微镜(SEM)对样品进行表征,考察不同烧结助剂对硼酸镁晶须晶体结构、表面形貌、孔隙率及抗压强度的影响.实验结果表明,当未添加烧结助剂时,孔隙率为62.57;,抗压强度为10.32 MPa,晶须直径为0.2~0.6 μm,长度为3~5 μm.添加烧结助剂会降低硼酸镁晶须的孔隙率并提高其抗压强度.当烧结助剂为MgF2时,孔隙率为51.77;,抗压强度为14.51 MPa;当烧结助剂为Na4P2O7时,孔隙率为43.79;,抗压强度为21.09 MPa. 相似文献
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以氧化锌、甲酸为原料合成甲酸锌,再与三(2-氨基乙基)胺及四氟硼酸钠在甲醇介质中反应,合成得到了新颖双核锌配合物{[Zn2(tren)2(HCO2)](BF4)3},用IR和1H-NMR等手段对该化合物的结构进行了表征,测得其晶体结构为单斜晶系,空间点群为Cc,晶体学参数为:a=0.85382(17)nm,b=1.4503(2)nm,c=2.3785(3)nm,α=90.00°,β=94.441(5)°,γ=90.00°,V=2.9364(8)nm3;Dc=1.646g/cm3;Z=4;F(000)=1476;μ=1.737mm-1。 相似文献
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Stephanie D. Warner Anne-Marie Lebuis Jean-Pierre Farant Ian S. Butler 《Journal of chemical crystallography》2003,33(3):213-217
In 6-nitrobenzo(a)pyrene, an environmental pollutant, the nitro substituent lies at 69.5(1) to the mean plane of the aromatic moiety. The C–C bond distances range from 1.341(3) to 1.443(3) Å. The crystal is in the monoclinic space group, P21/c, with a = 8.3239(3) Å, b = 8.9530(3) Å, c = 18.0678(5) Å, = 99.264(2) and Z = 4. Molecules are assembled in sheets in the unit cell through stacking and alternating C–H O interactions. 相似文献
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James I. Paul Marc J J. Schmidt Timothy J. Abram 《Crystal Research and Technology》2016,51(7):441-445
Silicon Carbide (SiC) has been deposited onto an alumina substrate by the thermal decomposition of the gaseous precursor tetramethylsilane (TMS). A 500 W ytterbium fibre laser was used to heat the surface of an alumina substrate locally, resulting in deposition of SiC at the sample surface. The SiC deposit was analysed using energy dispersive X‐ray spectroscopy and X‐ray diffraction (XRD). The deposit was confirmed to be silicon carbide and found to be face centre cubic (FCC) crystal structure. Raman spectroscopy was used to measure the stoichiometry of the deposit which initially was found to be carbon rich. Further analysis by Raman spectroscopy suggests the deposit may be more stoichiometric following a two hour thermal treatment of the sample at 600 degrees celcius in an atmosphere of air. 相似文献
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以碳酸盐和氧化物为原料,通过凝胶浇注法制得了Sm_(0.5)Sr_(0.5)Co_(1-x)Fe_xO_(3-δ)(SSCF, x=0~1.0)粉体,对不同温度煅烧所得粉体的相组成和微观形貌进行了测定.制备的Sm_(0.5)Sr_(0.5)Co_(1-x)Fe_xO_(3-δ)粉体模压成形后烧结得到SSCF烧结体.测定了烧结体的密度和孔隙率并对烧结体的微观结构进行了观测,用直流四端子法测定了烧结样品的电导率并对其热膨胀系数及电化学性能等进行了测定.结果表明:干凝胶在1000 ℃煅烧可以得到粒度均匀细小的SSCF粉体,其晶体结构随Fe含量发生变化;一定温度烧结的Sm_(0.5)Sr_(0.5)Co_(1-x)Fe_xO_(3-δ)材料具有多孔结构,随烧结温度的增加,烧结体的密度增大,孔隙率减小;Fe的掺杂降低了Sm_(0.5)Sr_(0.5)CoO_(3-δ)材料的热膨胀系数,Sm_(0.5)Sr_(0.5)Co_(0.2)Fe_(0.8)O_(3-δ)材料在800 ℃时的热膨胀系数为16.4×10~(-6) K~(-1);SSCF材料的电导率随Fe含量的增加而减小,但在500~800 ℃,其电导率均大于100 S·cm~(-1).此外,Sm_(0.5)Sr_(0.5)Co_(1-x)Fe_xO_(3-δ)材料均表现出良好的催化活性. 相似文献
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Ren Xiaoming Xu Yan Meng Qingjin Hu Chuanjiang Lu Changsheng Wang Huaqing 《Journal of chemical crystallography》2000,30(2):91-94
The structure of [NO2Py]2[Ni(mnt)2], as determined by x-ray single crystal analysis, consists of two 1-(4-nitrobenzyl)pyridinium cations and one [Ni(mnt)2]2– anion. The crystallographic data for the complex:monoclinic P21/n, a = 9.913(2) Å, b = 11.968(2) Å, c = 14.566(3) Å, = 100.36(3)°, V = 1699.9(6) Å3, Z = 2. The [Ni(mnt)2]2– anion has a crystallographically imposed center of symmetry and exhibits a relatively planar structure. The cation, [NO2Py]+, adopts a conformation where both the aromatic rings are twisted to the C11-C10-N3 reference plane. The anions (A) and the cations (C) consist of alternating layers (i.e., of type ···C1A1C2A2C1A1C2···) along the c axis of the crystallographic unit cell. 相似文献
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合成了铜-钠混合金属配位聚合物 [(CuL)2(CH3OO)Na(H2O)4]2 (简写为1)并进行了元素分析和单晶X射线衍射分析,L为{2-(2′-酚基)- Δ 2-噻唑-4-羧酸}.晶体结构分析表明配合物形成Cu4Na2的六核混合金属大环.相邻的Cu4Na2环之间通过进一步的配位作用连结成包含更大的Cu8Na4大环的二维网状结构.该晶体属于三斜晶系Pī空间群,晶胞参数分别为:a = 1.0777(4) nm, b = 1.5221(6) nm, c = 1.6994(6) nm, α = 84.58(1)°, β = 76.31(1)°, γ = 89.97(1) °, V = 2.696 (2) nm3, Z = 2, Mr= 1447.26, dc = 1.783 g·cm-3, T = 293(2) K, μ = 1.816 mm-1, F(000) = 1472, R1 = 0.0794, wR2 = 0.1819 [I>2σ(I)]. 相似文献
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Song Gao Ou Bai Bao-Qing Ma Tao Yi Chun-Hua Yan Guang-Xian Xu 《Journal of chemical crystallography》2000,30(3):163-166
A novel two-dimensional 4f-3d heterometallic coordination polymer Ce2Co3(EDTA)3(H2O)11·12H2O (EDTA = ethylenediamine-N,N,N,N-tetraacetate) has been synthesized using complex Na[Ce(EDTA)] as ligand. The complex crystallines in the space group C2, with lattice parameters a = 15.974(3) Å, b = 14.676(3) Å, c = 14.773(3) Å, = 116.39(3)°,V = 3102.4(11) Å3, Dx = 1.858 g/m3, Z = 2. It consists of a two-dimensional sheet in which the Ce(III) is ten-coordinated by six carboxylic O atoms from three EDTA molecules and four O atoms of water molecules, forming a distorted bicapped square antiprism, and the Co(II) atom is seven-coordinated by two N, four O atoms from one EDTA molecule and one O atom from the water molecule, giving rise to a monocapped trigonal prism. Each chelated Co(II) atom is connected to two hydrated Ce(III) atoms through tridendate bridging carboxylate groups, while each Ce(III) atom has three Co(II) atoms as neighbors. These sheets are linked into a three-dimensional network by the water molecules between layers through rich hydrogen bonds. 相似文献