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131.
针对传统水质化学需氧量(COD)在线检测方法检测稳定性差、易受环境影响等缺陷,为提高水质COD在线检测效率和稳定性,本文基于超声化学原理和氧化还原电位法(ORP),提出一种在超声波辅助消解(UASD)作用下基于ORP法的COD检测方法:UASD-ORP法。通过超声波辐照下空化气泡微射流的加强传质、表面自由基活化等特效作用消解待测水样,结合ORP监测溶液的宏观氧化-还原性,保证COD检测中后续滴定过程的准确性、稳定性。实验表明,经该方法检测标准邻苯二甲酸氢钾(KHP)溶液的COD值同国标法测得的COD值非常接近,相对误差在-6.0%~-3.0%之间;对污水样品实地测试中,该方法测得的COD值与标准方法测得的COD值的准确度在-10%~-1.5%之间。应用UASD-ORP法完成COD检测周期在15min~20min,且测量值重复性≤3%。实验验证了该方法具有可行性,可以用于开发在线检测技术。 相似文献
132.
One new organic adduct,isonicotinamide·3,5-dinitrosalicylic acid with isonico-tin-amide(ina) and 3,5-dinitrosalicylic acid(3,5-dnsa) in 1:1 molar ratio,has been synthesized.Its struc-ture(C13H10N4O8,Mr = 350.25) was characterized by elemental analysis,IR and single-crystal X-ray diffraction analysis.The crystal belongs to the triclinic system,space group P1,with a = 8.812(4),b = 9.487(5),c = 9.604(6) ,α = 116.54(2),β = 97.29(5),γ = 98.35(4)°,V = 693.8(7) 3,Z = 2,Dc = 1.677 g/cm3,λ(MoKα) = 0.71073 ,μ = 0.142 mm-1,F(000) = 360,the final R = 0.0539 and wR = 0.1402 for 2417 unique reflections(Rint = 0.0288) with 1819 observed ones(Ⅰ 2σ(Ⅰ)).Proton transfer reaction occurs between 3,5-dnsa and ina molecules,and the hydrogen bonds(N-H…O and C-H…O) with other interactions(π…π stacking and weak interactions of O…O and C…O) cooperatively construct a three-dimensional(3D) supramolecular structure. 相似文献
133.
The fractional Landau-Lifshitz-Maxwell equation is considered in this paper. We show the global existence of suitable weak solutions by Galerkin method and the vanishing viscosity method. The main difficulties in this study are due to the loss of compactness of this system and the fact that the nonlinear term is nonlocal and of the same order of the equation. To overcome these difficulties, we introduce the commutator estimates and some cancellation properties to this equation, which prove to be proper tools in the study of Landau-Lifshitz type equations. 相似文献
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一维链状配位聚合物{[Pb(PTCP)(2,5-pydc)]_2·H_2O}_n的水热合成、晶体结构和发光性质研究(英文) 总被引:1,自引:1,他引:0
A new metal-organic coordination compound framework formulated {[Pb(PTCP)(2,5-pydc)]2·H2O}n (1) (PTCP=2-phenyl-1H-1,3,7,8-tetraazacyclopenta[l]-phenanthrene, H2pydc=pyridine-2,5-dicarboxylic acid) has been prepared in the hydrothermal condition and characterized by single-crystal X-ray diffraction, elemental analysis, IR and TG. It crystallizes in monoclinic, space group C2/c with a=2.129 2(4) nm, b=1.111 2(2) nm, c=2.049 4(4) nm, β=105.02(3)°, V=4.683 2(16) nm3, Z=4, Pb2C52H32N10O9, Mr=1 355.26, Dc=1.922 g·cm-3, F(000)=2 600, S= 0.825, R1=0.056 2 and wR2=0.168 9. In the crystal, the Pb atom is five-coordinated by three N and two O atoms. The complex forms a one-dimensional zigzag polymeric chain along the b axis which is stacked to furnish a two- dimensional supramolecular layer structure via aromatic π-π interactions in the ab plane. In addition, hydrogen bonds are observed in the compound which play an important role in forming the final structure. Solid-state fluorescence spectrum of 1 exhibits the maximum emission peak at 621 nm. 相似文献
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A novel crown ether,2,3-naphtho-10-aza-15-crown-5(NAC) was synthesized.This compound does not show strong fluorescence and phosphorescence due to photoinduced intramolecular electron transfer from the nitrogen lone pair of electrons to the singlet excited state of the naphthalene chromophore.Complexation with heavy-metal ions results in the quenching of the fluorescence and enhancement of the phosphorescence significantly.These observations were interpreted in terms of the binding interactions,between the nitrogen lone pair electrons and the metal cation,which prevent photoinduced intramolecular electron transfer,and the heavy-atom effects which induce quenching of the fluorescence and enhancement of the phosphorescence.These azacrown and heavy-metalbased systems could be useful as potential chemical sensors and molecular photonic devices. 相似文献
140.
煤灰及各种矿物质对SO2排放特性的影响 总被引:4,自引:0,他引:4
利用TG-DTG采用低加热速率实验研究了煤阶、脱灰及煤中主要矿物质成分对煤燃烧过程中SO2排放特性的影响,并对矿物质成分的影响机理进行了讨论。结果表明,煤中硫质量分数的高低对烟气中SO2的排放有明显影响,排放水平与硫质量分数不成比例;煤中硫向SO2转化率与煤阶之间没有明显的关联;脱灰能较小程度地促进SO2的生成,抚顺煤主要矿物质成分中Na、K、Mg以及Ca等碱金属与碱土金属明显抑制SO2的排放,同时纳米级的TiO2也减少烟气中SO2体积分数,这些成分对SO2抑制作用的顺序为MgNa≈K>Ca>Mg>Ti的次序加速焦炭的氧化;Si和Al属于惰性成分,对煤中硫的迁徙以及煤的燃烧特性没有显著影响。 相似文献