钙长石对刚玉-莫来石质陶粒支撑剂结构及性能的影响

以二级铝矾土为主要原料,通过添加不同含量的长石在1350 ℃烧结温度下制备了高强度的刚玉-莫来石质陶粒支撑剂.通过X射线衍射(XRD)和扫描电子显微分析(SEM)对陶粒的物相组成及显微形貌进行表征.结果表明,所制备陶粒支撑剂的物相成组为刚玉和莫来石,而且发现随着长石添加量的逐步增加,可以明显促进莫来石的形核过程,并抑制其进一步长大.当长石添加量为8wt;时,所制备的陶粒支撑剂体积密度为1.72 g/cm3,在52 MPa闭合压力下的破碎率为3.2;,酸溶度为5.0;,满足油气开采行业的要求.     

烧结温度对添加复合助剂制备莫来石-刚玉基陶粒支撑剂性能的影响

为了降低陶粒支撑剂的烧结温度,本文以低品位铝矾土和粘土为主要原料,通过添加复合助剂锰矿粉及白云石制备陶粒支撑剂,并研究烧结温度对陶粒支撑剂结构、性能的影响.在烧结过程中发现,引入一定量的锰矿粉和白云石后,在陶粒内部会形成适量液相,可以填充孔隙,包覆于莫来石和刚玉晶粒间促进晶体的生长发育,从而形成致密结构.当烧成温度为1310℃时,制备得到的支撑剂体积密度与视密度分别为1.65 g/cm3和2.99 g/cm3,52 MPa闭合压力下破碎率为8.97;,符合石油天然气行业标准对低密、高强陶粒支撑剂的要求,说明复合助剂在降低烧结温度的前提下还能够提高支撑剂抗破碎能力.     

锰矿粉掺量对莫来石-刚玉质陶粒支撑剂结构及性能的影响

以阳泉产三级铝矾土与粘土为原料,锰矿粉为烧结助剂,于1420℃下制备了莫来石-刚玉质陶粒支撑剂,讨论了锰矿粉含量对支撑剂样品结构及性能的影响.结果表明:随锰矿粉掺量的增加,支撑剂样品的主晶相莫来石颗粒形状由针状变为柱状,晶粒尺寸逐渐变大,并且刚玉相衍射峰强度增加;当锰矿粉掺量为4wt;时,试样的性能最佳:视密度2.998 g/cm3,体积密度1.62 g/cm3以及52 MPa闭合压力下的破碎率8.13;.     

保温时间对添加废陶粒砂制备支撑剂结构和性能的影响

为了缓解高品位铝矾土资源日益匮乏的现状,同时降低支撑剂的生产成本,本研究以二级铝矾土和固废陶粒砂为主要原料,通过添加锰矿粉和白云石作为烧结助剂,最终经1260℃烧结制备得到刚玉-莫来石基陶粒支撑剂.在烧结过程中,讨论了保温时间对支撑剂物相结构和性能的影响.结果表明:随着保温时间的延长,支撑剂物相开始析出针状莫来石,而且晶粒尺寸逐渐变大,随之转变为棒状莫来石并与颗粒状的刚玉相互交叉分布于支撑剂内部,从而形成致密的交联结构.当保温时间为2 h时,支撑剂的性能最佳:体积密度为1.65 g/cm3,52 MPa闭合压力下的破碎率达到8.5;,符合石油天然气行业标准要求,说明固废陶粒砂可以被循环利用制备支撑剂.     

铝矾土空心陶粒支撑剂的制备及性能研究

以尿素为成孔模板,MnO2为烧结助剂,铝矾土粉为球壳包覆材料,采用模板法制备了空心内半径可控的铝矾土空心陶粒支撑剂.运用X射线荧光分析,热分析、XRD和SEM等技术对铝矾土原料粉预处理前后矿物相组成和化学成分及支撑剂产品微观形貌的变化进行了比较分析,探究了原料预处理对支撑剂结构和性能的影响,并对其影响机理进行了分析.结果表明:原料粉体经预处理后可提高支撑剂的强度.在1440 ℃烧结后的主要物相为莫来石相和刚玉相.利用预处理后的铝矾土粉体制备出的空心支撑剂的体积密度为1.35 g·cm-3,视密度2.47 g·cm-3,25 MPa闭合压力破碎率为5.21;,单粒抗压平均值为58 N,试样质量稳定,制备过程较易控制.     

氧化钙对陶粒支撑剂结构和破碎率的影响

以铝矾土和煤矸石为主要原料,添加不同含量的碳酸钙,在1350℃制备了低成本的陶粒支撑剂,通过X射线衍射(XRD)和扫描电子显微镜(SEM)对陶粒支撑剂的物相组成和微观形貌进行表征.结果表明,添加了碳酸钙的陶粒支撑剂形成新的物相钙长石,随着氧化钙含量的增加,莫来石的晶粒逐渐细化,细化的晶粒提高了陶粒的强度和抗破碎能力.添加量为5wt;碳酸钙的陶粒支撑剂在35 MPa、52 MPa闭合压力下的破碎率均最低,符合石油天然气行业标准SY/T5108-2014.     

透辉石改性粉煤灰基莫来石的性能和微观结构

为提高粉煤灰基莫来石的力学性能,以透辉石为烧结助剂,低温条件下采用无压烧结法制得了致密高强的莫来石.通过对莫来石线收缩率、体积密度、抗折强度、孔结构的测试,并借助X射线衍射、显微镜观察、扫描电镜微观分析等方法,研究了不同烧结温度时透辉石掺量对莫来石性能和结构的影响.结果表明:烧结温度为1400℃、透辉石掺量为8;时制得的莫来石性能最佳.此时,莫来石试样的线收缩率、体积密度和抗折强度最大,分别为13.3; 、2.88 g/cm3和160.6 MPa;试样的显气孔率仅为2.5;,莫来石试样致密程度高.透辉石在高温(≥1250℃)下熔融成液相,不但可填补莫来石烧结形成的孔洞,提高了试样结构的致密性,且有利于莫来石液相烧结,促进莫来石晶相的形成,莫来石晶相由细针状发育成短柱状,晶粒交叉生长,形成致密高强的粉煤灰基莫来石.     

莫来石轻质球形料结构与性能

对以铝矾土为主要原料制备获得的莫来石轻质球形料进行了系统的结构与性能研究,研究结果表明:轻质莫来石球形料的主要化学成分为Al2O3和SiO2,物相为莫来石相,球形颗粒表面莫来石柱状结晶交织排布,内部含有大量气孔,堆积密度为1.60 g/cm3,颗粒体积密度为1.75 g/cm3,显气孔率为38;,耐火度大于1790℃,800℃下导热系数为0.245 W/(m· K),热震5次后球形保持率大于95;.     

透辉石微晶玻璃的低温烧结制备及性能表征

以废弃建筑玻璃为主体原料,将废玻璃粉、高岭土和氧化镁进行球磨混和,压制成型后直接烧结,在低温下成功制备出具有单一透辉石晶相结构的微晶玻璃.采用X射线衍射、场发射扫描电子显微镜等测试手段,研究了MgO加入量和烧结温度对微晶玻璃样品的晶相组成、显微结构及性能等的影响.结果表明:随着MgO加入量的增多以及烧结温度的升高,微晶玻璃的体积密度和抗弯强度均呈现先增大后减小的趋势.MgO加入量和烧结温度的提高可以有效促进透辉石晶相的析出.当MgO加入量为4;、975℃烧结2 h时所制备得到的透辉石微晶玻璃性能最好,其体积密度为2.395 g·cm-3,抗折强度102.1 MPa.     

熔融法制备金尾矿微晶玻璃及性能研究

以金尾矿为主要原料,采用熔融法制备CaO-Al2O3-SiO2系微晶玻璃.利用差热分析(DSC)、X射线衍射分析(XRD)、扫描电镜(SEM)等分析手段对所制备的微晶玻璃进行了分析测试与表征,并研究了不同晶化温度对制得微晶玻璃的物相组成、微观结构及性能的影响.结果表明:在850～ 950℃下,随着晶化温度的提高,所制备微晶玻璃的性能均提高.确定较佳的晶化制度为950℃保温3h,所制备微晶玻璃的热膨胀系数、抗折强度及密度分别为68.7×10-7/℃,122 MPa和2.836 g/cm3.     

Syntheses and structures of N-phenylmaleimidetriazoles and by-products

The syntheses, properties, and structures of N-phenylmaleimidetriazole derivatives are described. Intermediates and by-products are also discussed. 1b. a = 43.997(7) Å, 5.7610(9) Å, 8.245(1) Å, = 99.339(4), C₂/c; 2a. a = 13.646(4) Å, b = 7.744(2) Å, c = 10.612(3) Å, = 91.979(6), P2₁/c. 3a. a = 22.245(1) Å, b = 22.245(1) Å, 10.010(1) Å, P42/n. 3a. a = 11.727(2) Å, b = 14.075(3) Å, c = 16.080(3) Å, = 105.859(3), = 105.331(3), = 98.187(3), P-1. 3b. a = 8.561(3) Å, b = 14.755(5) Å, c = 22.771(7) Å, = 97.006(5), P2₁/c. 3c. a = 10.500(2) Å, b = 12.189(2) Å, c = 13.040(2) Å, = 109.091(3), = 106.089(3), = 101.022(3), P-1. 8a. a = 16.389(8) Å, b = 5.749(3) Å, c = 19.316(3) Å, = 97.467(9), P2₁/n. 8b. a = 5.822(2) Å, b = 10.114(3) Å, c = 16.705(4) Å, = 84.681(5), = 82.840(5), = 75.769(4), P-1. 9b. a = 11.251(1) Å, 13.335(3) Å, 13.376(3) Å, = 102.456(4), P2₁/n. 9c. a = 15.836(3) Å, b = 8.236(2) Å, c = 5.447(3) Å, = 92.551(3), P2₁/c. 10a. a = 13.177(2) Å, b = 14.597(2) Å, c = 5.5505(8) Å, = 110.979(2), Cc. 11a. a = 14.720(2) Å, b = 13.995(2) Å, c = 38.245(6) Å, = 94.430(3), P2₁/n. 12b. a = 15.067(5) Å, b = 20.378(6) Å, c = 8.669(5) Å, = 99.16(4), = 99.32(3), = 105.23(3), P-1. 13b. a = 8.2824(6) Å, b = 10.5245(7) Å, c = 15.518(1) Å, = 92.305(1), = 100.473(1), = 100.124(1), P-1. 15a. a = 15.357(3) Å, b = 7.778(2) Å, c = 22.957(2) Å, Pbca. 16b. a = 18.0384(4) Å, b = 12.474(3) Å, c = 20.078(5) Å, Pbca.     

Sol-gel synthesis and characterization of adsorbent and photoluminescent nanocomposites of starch and silica

Using sol-gel method, mesoporous and photoluminescent silica nanocomposites of soluble starch have been synthesized and characterized. Different ratios of H₂O, TEOS and EtOH were used at fixed template (soluble starch) and catalyst (NH₄OH) concentrations to obtain materials of different performances in terms of heavy metal binding from a solution which has been monitored using Cd(II) as representative divalent heavy metal ion. Optimum material was obtained when H₂O, TEOS and EtOH were used in 14:1:2 ratio. This sample was not only an efficient metal ion adsorbent but also had an intense luminescence in ultra-violet region and potentially may be used in silicon-based UV-emitting devices. Metal binding by the material was further enhanced after calcination (at 800 °C in air) while its luminescence had a multipeak profile in UV-visible region. In a batch adsorption study, calcined hybrid composite (0.25 g/L) could remove 98.5% Cd(II) from 100 mg/L Cd(II) solution in 2 h. The chemical, structural and textural characteristics of the synthesized materials have been investigated using Fourier Transform Infrared Spectroscopy (FTIR), X-rays Diffraction (XRD), Thermal Analysis (TGA/DTA), Photoluminescence (PL), Brunauer-Emmett-Teller Analysis (BET) and Scanning Electron Microscopy (SEM).     

Chemistry and Electrocrystallization of Organic Metals and Superconductors

Abstract

Considerable variation in the conditions of electrochemical crystal growth of TMTSF₂X (i.e., constant current versus constant potential, ambient versus inert atmosphere, etc.) and in the purity of the constituents (donor, electrolyte, solvent) does not significantly affect the unusual low-temperature properties of this class of materials. Our results suggest that the electrocrystallization procedure may be self-purifying by selecting for conducting crystal phases with constituents having specific oxidation potentials and solubility properties. However, doping solutions with structurally and chemically similar constituents (i.e., TMTTF, and IO^? ₄ in CIO^? ₄) leads to their incorporation in the crystal structure where they have a profound effect. Several mole percent of these dopants suppress superconductivity in the PF^? ₆ and CIO^? ₄ salts, and increase and broaden the metal-insulator phase transition.     

晶体中负离子配位多面体结晶方位、形变与晶体压电、铁电性

本文研究了压电、铁电晶体中负离子配位多面体的结晶方位与形变,提出了压电晶体中同一种负离子配位多面体的结晶方位是一致的.在铁电晶体中,负离子配位多面体发生形变,伴随着晶体发生顺电-铁电相变,并从这一基本过程出发,对铁电体相变的形成机理进行了讨论.     

Structural and spectral studies of N-trans-cinnamylidene-m-toluidine and N-trans-cinnamylidene-m-chloroaniline

N-trans-cinnamylidene-m-toluidine (1) C₁₆H₁₅N, and N-trans-cinnamylidene-m-chloroaniline (2) C₁₅H₁₂NCl form isomorphous crystals which are monoclinic, space group P2_l/c, with unit cell dimensionsa=5.967(2),b=13.793(3),c=15.048(5) Å, =91.97(3)° anda=5.868(2),b=13.788(4),c=15.191(4) Å, =91.87(3)°, respectively. The single-crystal X-ray structure determinations of the title compounds revealtrans structures. Ring (A) C_10–15 and ring (B) C_1–6, are practically planar in both structures with dihedral angels of 61.3(3) and 63.6(2)°, respectively.¹H nmr, u.v. and i.r. spectra are also reported.     

Di- and triindolylmethanes: molecular structures and spectroscopic characterization of potentially bidentate and tridentate ligands

4-Bromophenyldi(3-methylindol-2-yl)methane (2) and 2-methoxyphenyldi(3-methylindol-2-yl)methane (3) were prepared by sulfuric-acid-catalyzed reactions of 3-methylindole with 4-bromobenzaldehyde and o-anisaldehyde, respectively. Di(3-methylindol-2-yl)phenylmethane (1) and tri(3-methylindol-2-yl)methane (4) were similarly prepared as described previously. Spectroscopic data (¹H, ¹³C NMR) and the X-ray crystal structures for 1 C₂H₅OH and 2–4 are reported. The molecular structure of 1 C₂H₅OH shows hydrogen bonding of both indolyl NH protons to the oxygen of an ethanol molecule. Crystal data for 1 C₂H₅OH: Orthorhombic, Pca2₁, a = 23.9782(17) Å, b = 8.4437(7) Å, c = 11.3029(9) Å, V = 2288.4(3) ų, R ₁ = 0.0597. Crystal data for 2: Orthorhombic, P2₁2₁2₁, a = 8.911(3) Å, b = 9.584(4) Å, c = 24.040(11) Å, V = 2053.0(14) ų, R ₁ = 0.0454. Crystal data for 3: Monoclinic, P2₁/c, a = 9.737(2) Å, b = 25.035(6) Å, c = 9.359(2) Å, = 114.853(4), V = 2070.2(8) ų, R ₁ = 0.0511. Crystal data for 4: Trigonal, R3, a = 14.2214(10) Å, c = 9.6190(10) Å, V = 1684.8(2) ų, R ₁ = 0.0425.     

Synthesis and crystal structure of indium arsenate and phosphate dihydrates with variscite and metavariscite structure types

The hydrothermal synthesis, crystal structure analysis, and spectroscopic studies of InPO₄·2H₂O (1) and InAsO₄·2H₂O (2) are reported. Compound 1 is isomorphic with metavariscite: monoclinic P2₁/n (No. 14), a = 5.4551(3) Å, b = 10.2293(4) Å, c = 8.8861(3) Å, = 91.489(4)°, Z = 4, and compound 2 is isomorphic with variscite: orthorhombic Pbca (No. 61), a = 10.478(1) Å, b = 9.0998(8) Å, c = 10.345(1) Å, Z = 8. Their three-dimensional frameworks are built of corner sharing InO₄(H₂O)₂ octahedra and MO₄ (M = P⁵⁺ or As⁵⁺) tetrahedra. The water molecules in both compounds have different environments and are involved in different types of hydrogen bonding. Infrared spectroscopy indicates that water molecules are true H₂O species.     

Structures and properties of 1,4-dithiins and related molecules

A series of organosulfur compounds was characterized by NMR, IR, mass spectroscopy, cyclic voltammetry, and chemical analyses. The crystal structures of six compounds were determined: 1,3-dithioleno[4,5-e]naphtho[2,3-b]1,4-dithiin-2,5, 10-trione (1b), P , a = 7.665(4), b = 7.997(4), c = 11.443(5) Å, = 91.311(8), = 92.516(8), = 117.53(7)° 6,7-dimethylbenzo[1,2-b]1,3-dithioleno[4,5-e]1,4-dithiin-2,5,8-trione (2b), P2₁/m, a = 3.933(1), b = 12.864(2), c = 11.943(3) Å, = 99.161(4)° 6-phenyl-2-thioxo-6-hydrocyclopenta[2,1-b]1,3-dithioleno[4,5-e]1,4-dithiin-5,7-dione (3a), C2/c, a = 32.408(6), b = 3.8743(8), c = 27.123(5) Å, = 125.171(7)° 6-phenyl-1,3-dithioleno[4,5-e]3-pyrrolino[3,4-b]1,4-dithiin-5,7-trione (3b), P2₁/n, a = 7.9712(9), b = 6.1976(7), c = 55.978(6) Å, = 91.096(1)° 2,3,7,8-tetramethylthianthrene-1,4,6,9-tetraone (4), P2₁/c, a = 4.195(1), b = 17.924(5), c = 9.682(3) Å, = 98.509(5)° 3H,6H-1,4-oxathiino[6,5-2,1]naphtho[3,4-e]1,4-oxathiin-2,7-dione (5), P2₁/n, a = 9.3522(7), b = 7.8782(6), c = 17.118(1) Å, = 93.171(1)°. Several structures exhibited significant S—S intermolecular interactions, suggesting that the molecules might be precursors for preparing nonmetallic conductors.     

石墨烯及其纳米复合材料的制备与应用研究

石墨烯作为一种新兴二维碳纳米材料,具有完美的晶体结构和诸多优异的物理化学性能.石墨烯独特的电学、热学、光学和力学性能,使其在电子器件、导热材料、气体传感器、感光元件以及环境科学等领域具有广阔的应用前景.其潜在的实际应用价值,使石墨烯材料的开发成为当前最受关注的研究热点之一.本文从石墨烯的来源、结构、分类和基本性质出发,概述了石墨烯及其衍生物的制备方法及属性特征,进而介绍了石墨烯及其衍生物纳米复合材料在电子、材料、储能和环境等领域中的最新研究进展,并对石墨烯及其纳米复合材料的发展前景进行了展望.     

Structures of nitroso- and nitroguanidine X-ray crystallography and computational analysis

The X-ray structures of solid nitroguanidine (ngoH):orthorhombic, Fdd2, a = 17.6181(14), b = 24.848(2), c = 3.5901(4) Å, V = 1571.7(3) ų, Z = 16 and nitrosoguanidine (ngH); monoclinic, P 2₁/n, a = 3.64510(10), b = 11.746(2), c = 8.6483(14) Å, = 99.167(2), V = 365.55(9) ų, Z = 4 have been determined utilizing single crystal X-ray diffraction methods. The results are compared with the most stable gaseous configurations derived from ab inito calculations. The lowest energy calculated configuration for the ligands and experimentally observed crystal structures are in excellent agreement. In the solid state, both the ngoH and ngH contain discrete molecules in their unit cells which are planar (within experimental error), in the diamine configurations and are structurally identical except for an oxygen atom. In solid ngH, two ligand molecules have four nitrogen atoms arranged in a plane such that they are suitable for coordination to a nickel ion (1.945, 2.064 Å), when it is at the 1/2, 1/2, 1/2 unit-cell position giving the observed complex. As far as we are aware, this is the first instance in which a ligand crystal structure is essentially the same, with minor distance, angle and torsion angle changes, as the complex it forms and suggests some potentially unique properties and applications for this material.