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G. T. Harrison M. C. Spadaro C. L. Pang D. C. Grinter C. M. Yim P. Luches 《Materials Science & Technology》2016,32(3):203-208
Ultrathin films of TiO2 were grown on a W(100)–O(2?×?1) substrate and characterised with a combination of scanning tunneling microscopy (STM) and low energy electron diffraction. In addition to islands of rutile TiO2(110) with (1?×?1) termination that were reported previously, we also observed rutile TiO2(110) islands with a (1?×?2) film termination. A lepidocrocite-like TiO2 nanosheet was also observed on the W(100) surface. High resolution STM images show that the nanosheet grows in the principal orthogonal directions of the W(100) substrate and forms a commensurate (1?×?7) coincident cell. 相似文献
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介绍大块的、致密的、用作介电材料的非化学计量比化合物(“掺杂材料“)的合成及其应用。介质阻挡放电(DBD)是指在两金属电极之间插入一层绝缘材料的等离子放电装置。从放电物理学角度来讲,这层材料的介电常数越高,所产生的等离子能量就越高,这样,如果应用到等离子化学领域,就会提高化学反应能力。目前商业化生产的高介电常数材料的强度都较低,如BaTiO_3,在等离子发生的瞬间就会被击穿。所以要在DBD中使用高介电常数的材料,就必须进行新型介电材料的研发。介绍了高强度、高密度、高介电常数的非化学计量比化合物[(Ca_(1-x)Sr_x)_(2-2y)](Ti_(2-2y)Li_(2y))Si_(2y)O_(6-y)的合成理论、工艺方法及其在CO_2减排、资源化利用方面的应用。 相似文献
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半导体级,纯度妇8.7%物理I性质分子量蒸汽压(ZoOC)沸点(1大气压)冰点(1大气压)无色1 01。OO。63巴(表压)8。2“C一122“C液态密度(20OC)1.261克/毫升气态密度(沸点,1大气压)4.94克/升在空气中燃烧界限4.1一98.8体积%气态比重(空气=1)3.93有刺激性和窒息性气味安全 警告:易燃、有毒和腐蚀物质。 危害性 八小时工作时间内空气中最大允许含量值未定气但毒性类似于四氯化硅。在空气中易燃,可燃范围极宽。在钢瓶中蒸汽压力约为0.6巴(表压)时呈液态。蒸汽比空气重得多。即使与少量卤素和其它氧化剂接触也会发生激烈反应,与水能发生激烈反应。… 相似文献
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The crystal structure of (NpO2)2(OOC)2C6H4·4H2O [rhombic cell: a = 15.937(3), b = 26.922(5), c = 8.020(2) Å, space group Pbcn, Z = 8, V = 3441.0(12) Å3, d
calc = 2.988 g cm-
3, CAD4, MoK
, graphite monochromator, 2934 independent reflections; R
1 = 0.0352, wR
2 = 0.0951] was studied. The structure consists of NpO2
+ cations, H4C6(COO)2
2
- anions, and molecules of coordinated and crystallization water. The crystal lattice involves neutral layers [(NpO2)2(OOC)2C6H4(H2O)3]
n
parallel to the {101} plane. The dioxocations in these layers are bonded to each other to form cationic networks [the Np···Np distance is 3.911(1)-4.202(1) Å]. The coordination polyhedra of Np(1) and Np(2) are pentagonal bipyramids (CN 7). The point group of the neptunyl(V) groups is close to D
h. These groups are bidentate ligands in the cation-cation interaction. The Np = O bond lengths are 1.852(6) [Np(1)-O(1)], 1.849(7) [Np(1)-O(2)], 1.845(7) [Np(2)-O(3)], and 1.841(7) Å [Np(2)-O(4)]; the O = Np = O bond angles are 178.6(3)° [O(2)-Np(1)-O(1)] and 177.4(3)° [O(3)-Np(2)-O(4)]. The equatorial plane of the Np(1) bipyramid consists of two oxygen atoms of adjacent Np(2)O2
+ dioxocations, two water molecules, and a single oxygen atom of the phthalate anion. The equatorial plane of the Np(2) bipyramid consists of two oxygen atoms of adjacent Np(1)O2
+ dioxocations, two oxygen atom of the phthalate anion, and a single water molecule. The bond lengths in the equatorial plane of the bipyramid lie in the following ranges: Np-Oyl 2.373(7)-2.437(7) Å (average 2.397 Å) , Np-Ophth 2.360(7)-2.474(7) Å (average 2.431 Å), and Np-Owater 2.534(8)-2.558(9) Å (average 2.544 Å). The phthalate anions are tridentate bridging ligands binding neptunium atoms only within a single cationic network. 相似文献
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成色剂的类别和应用特点现代彩色多层感光材料应用减色法原理形成彩色影象。在每一个乳剂层中成色剂与显影剂氧化物分别生成黄、品红和青等三补色。根据成色剂所能形成的颜色不同,在化学结构上把它分为三种类型,即黄、品红和青成色剂(实例见表2、表3和表4) 。人们对彩色感光材料在清晰度、颗粒性、彩色还原、影象色牢度等质量特性方面不断提出的改进要求,促进了成色剂的研制工作。在 相似文献
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Complexation of An(VI) (An = U, Np, Pu), and Np(V) with 2,3-pyridinedicarboxylic (quinolinic, H2Quin) acid in aqueous solutions was studied. Np(V) can form 1: 1 and 1: 2 complexes, and An(VI), also 1: 3 complexes (at pH ? 6 and [H2Quin] ? 0.1 M). Quinolinate ion can coordinate to actinide(VI) and (V) ions in solutions in different modes. The apparent stability constants of the complexes in a wide pH range and the concentration stability constants of the An(VI) complexes were measured. In the series from Pu(VI) to U(VI), the stability of the complexes slightly increases. Crystalline complexes [UO2(HQuin)2], [(NpO2)2(HQuin)2(HL)2]·2H2O (HL is N-protonated 2-hydroxypyridine-3-carboxylic acid anion), and [PuO2Quin(H2O)] were synthesized, and their structures were determined by single crystal X-ray diffraction. Different types of coordination of quinolinate ions to actinide ions are also observed in the crystalline complexes. 相似文献
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工业膜分离法(2) 总被引:1,自引:0,他引:1
(续第 5期 )3 毫微滤孔径介于反渗透膜和超滤膜 (平均 2nm )的膜称为毫微滤膜。与水分离的溶质的粒径和操作压力的范围也介于反渗透和超滤之间。毫微滤有时亦称为“松散反渗透” ,特别适用于因粒径排拒作用截留无电荷的分子或因静电相互作用截留荷电成分的用途。毫微滤膜极适用于截留分子量 >2 0 0的有机物(例如乳糖、蔗糖和葡萄糖 )和多价离子。这类膜比反渗膜通量更高 ,操作压力低得多。例如前者在70 psig压力下的通量为 2 5gal/ft2 day ,后者在2 2 5psig压力下通量亦为 2 5gal/ft2 day。3 1 毫微滤膜目前… 相似文献
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样本)品洲化学纯级典垫分析,二氧化碳二硫化碳二氧化硫’甲硫醇氧硫化碳甲烷平衡气规格(查阅现行产 纯度”二,重量%(液相)COZCS:50:CH:SHCOSCH40 .13%0。09%0。05%0。02%0。01%量气痕空物理性质分子量34.08蒸汽压(20OC)17.38巴(表压)比容(20OC,l大气压)701毫升/克沸点(i大气压)一6o.33oC气态密度(ooC,1大气压)1。539克/升液态密度(沸点)。.993克/毫升临界温度ioo.4oC在空气中的燃烧界限4.3~45%(体积)气态比重(空气=1)’1.189无色,含量超过Ivpm时,有令人不快的臭鸡蛋味。安全 替告:有毒、腐蚀、可燃。 危害性 有毒,空气中允许最大浓… 相似文献
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研究了Ti(acac)2Cl2/AlEt2Cl催化丙烯腈聚合反应,分析了加入第三组分ZnCl2对聚合反应的影响,用^13C—NMR对聚合产物进行了表征,并探讨了聚合反应机理。结果表明,随着聚合温度的提高和聚合反应时间的增加,单体转化率增大,聚丙烯腈的分子量提高。当体系中n(AN)/n(Cat)超过一定量时,则得不到高聚物。体系中加入ZnCl2能明显提高单体转化率和产物分子量,并且产物的三单元规整结构含量明显增加。 相似文献
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采用并流化学共沉淀法合成了Dy_(2)O_(3)掺杂ZrO_(2)(DySZ)纳米粉体材料,系统研究稳定剂掺杂量、阳离子浓度、反应系统pH值和煅烧温度对粉体材料物相组成、晶体结构和微观形貌的影响。结果表明:不同合成工艺条件下,DySZ粉体材料均具有纳米尺度特征,球形颗粒尺寸为10~30 nm,Dy_(2)O_(3)的掺杂可以起到稳定晶型的作用;稳定剂掺杂量对DySZ粉体的物相组成具有明显影响,掺杂量为10%(质量分数)时可合成单一四方相结构的DySZ粉体;DySZ粉体材料的四方度和微观形貌对稳定剂掺杂量、阳离子浓度、反应体系pH值和煅烧温度均不敏感,但其平均晶粒尺寸随稳定剂掺杂量、阳离子浓度和反应体系pH值的升高略有降低,随煅烧温度的提高而显著增加。 相似文献