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金属离子在煤界面吸附对煤成浆性的影响 总被引:7,自引:1,他引:7
本文研究了六种金属离子在三种煤表面的吸附规律,研究结果表明:铜离子能够改善煤的制浆效果,即铜离子加入煤浆中,分散剂的用量降低50%,煤浆浓度提高;钙、镁、钴、锌离子对煤的成浆性不利的原因是它们不能有效地被吸附到煤表面,游离的金属离子和分散剂发生反应,使得吸附到煤表面的分散剂相对减少,煤的成浆性变差。 相似文献
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《Journal of Coordination Chemistry》2012,65(1-2):127-130
Abstract Complexation of some heavy metal cations in aqueous solution by diaza crown ethers and cryptands has been studied using pH-metric titrations. In most cases, macrobicyclic cryptands form more stable complexes than diaza crown ethers. The size of the cavity aiso influences the stability of the complexes formed. 相似文献
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THE STIMULATORY EFFECT OF HEAVY METAL CATIONS ON PROLIFERATION OF AORTIC SMOOTH MUSCLE CELLS 总被引:1,自引:0,他引:1
Heavy metal cations Cd~(2+), Pb~(2+), and Hg~(2+)were added to substitute for Ca~(2+)in culture media to study their effect on the relationship between CaM and the proliferation of cultured rabbit aortic smooth muscle cells (ASMC). It was found that all the heavy metal cations studied stimulated the proliferation of ASMC in varying degrees, increased the CaM content in cells at late G_1 stage and decreased the activity of cAMP PDE. These results suggest that the adverse effect of heavy metals may be related to the pathogenesis of atherosclerosis and hypertensive disease. 相似文献
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13X分子筛去除水中重金属离子的研究 总被引:3,自引:0,他引:3
以人工合成的13X型分子筛为吸附剂,研究了水中Pb2 、Cd2 和Cu2 在分子筛上的吸附行为,讨论了Pb2 、Cd2 和Cu2 共存条件下的竞争吸附,并考察了水中存在的Na 、Mg2 、Ca2 等离子对分子筛吸附去除重金属的影响.实验结果表明,13X分子筛对Pb2 、Cd2 和Cu2 3种离子的吸附符合Langmuir模型,最大吸附量分别为2.47mmol/L、2.0mmol/L和1.78mmol/L.在竞争吸附条件下,13X分子筛对3种重金属离子的选择性依次为pb2 >Cd2 >Cu2 .水中存在的Na 、Mg2 、Ca2 等对分子筛吸附重金属效率有一定的影响,其中Ca2 对Cu2 在分子筛上的去除影响最为显著. 相似文献
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酪氨酸电化学行为研究及其动力学参数的测定 总被引:1,自引:0,他引:1
本文以玻碳为工作电极用循环伏安法研究了在0.50mol/L NaClO_4—B.R.缓冲溶液中酪氨酸的氧化行为及吸附;用计时电流法测定了扩散系数;用线性扫描伏安法测定了电子传递系数;分别用线性扫描伏安法和旋转园盘电极法测定了异相反应速度常数. 相似文献
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An irreducible tensor method based on M. O. theory for solving many-body Schrodinger equation of valence-electron system of metal complexes has been proposed. Electronic structures of several typical octahedral transition metal complexes have been studied by means of this method. Calculated excitation energies agree with observed ones within several kcm-1. 相似文献
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Xiao-pingYan Bao-linHe JieZhang Han-fanLiua 《高分子科学》2005,(4):393-399
Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate. Compared to the enantiomeric excess (e.e.) value (71.4%) obtained without the presence of metal cations, obvious e.e. enhancement (up to 82.5%) was resulted from the addition of Zn^2 but with a certain decrease in activity. The reaction parameters in the presence of Zn^2 were also studied. It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations. 相似文献
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本文研究了竹红菌素HA,HB以及13-SO3Na-DDHA在DMF-H2O(体积分数φ=1)混合体系中的电化学氧化还原性质。结果表明,它们都为两步单电子还原过程,反应机理为:HA,HB:HA(HB)+e+H+⇔HAH·(HBH·)+e⇔HAH·油溶性。水溶性13-SO3Na-DDHA:(第一步)13-SO3Na-DDHA+e⇔13-SO3Na-DDHA-·(质子化)13-SO3Na-DDHA-·+H+⇔13-SO3Na-DDHAH·;(第二步)13-SO3Na-DDHAH·+e⇔13-SO3Na-DDHAH-·.并且,HA,HB的单电子还原半醒自由基非常稳定,而13-SO3Na-DDHA单电子还原半醌自由基存在歧化反应,其速率常数kf=0.408. 相似文献
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铟—4—(2—噻唑偶氮)—间苯二酚络合物电化学性质研究 总被引:1,自引:0,他引:1
在0.06mol·L~(-1)NH_4OAc底液中,铟与4-(2-噻唑偶氮)-间苯二酚(TAR)形成的络合物产生一灵敏还原吸附峰,可用于单扫描示波极谱法测定痕量铟。铟浓度在1×10~(-8)~1×10~(-6)mol·L~(-1)范围内与峰电流呈线性关系。加入少量十二烷基磺酸钠,灵敏度提高,检出下限为5×10~(-9)mol·L~(-1)。该法应用于测定矿石中痕量铟,结果令人满意,用多种电化学手段对络合物的电化学性质进行了研究。 相似文献
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应用Y分子筛吸附Fe(CO)5、Co(CO)3NO和Mo(CO)6的温和热分解制备分子筛负载金属催化剂,从分子筛交换阳离子和吸附金属络合物之间的相互作用说明其CO加氢产物的分布特点。实验结果表明,分子筛内阳离子和吸附金属络合物间的相互作用显著影响制得催化剂的结构和反应的产物分布。由于金属络合物和分子筛内阳离子间的电子转移,使NiY附载金属催化剂显示出高的CO转化率和甲烷选择性。在CuY中,这种电子 相似文献
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Abstract— Photo-induced electron transfer from cuprous ion to electronically excited 10-methyiacridinium tetrafluoroborate in acetonitrile-water solutions is described. The final photoproducts are Cu2+ (aq) and 10,10'-dimethyl-9,9'-biacridane. The proposed mechanism, based on microsecond flash excitation and fluorimetry experiments, is one-electron transfer from Cu+ to the 10-methylacridinium ion triplet state (and possibly the singlet state), followed by dimerization of the neutral acridinyl radical. Because the high energy photoproducts revert slowly to reactants, the system may have potential for storage and controlled recovery of light energy. 相似文献
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Solid-state cyclic voltammetry was used to study electrochemical behavior of ferroin,which indicates that ferroin performs a reversible redox process in the improved PEO-LiClO_4complex.An activation energy of ca.6.0 Kcal/mol for ferroin diffusion was evaluated fromtemperature dependence of diffusion coefficient. 相似文献
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Nano-sized polyacrylonitrile (PAN) particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70℃. The overall activation energy (Ea, 49.79 kJ/mol), energy of dissociation of initiator (Ed,82.68 kJ/mol), number of micelles (0.163×1018) and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy (TEM). It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50-150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature. 相似文献
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Nano-sized polyacrylonitrile (PAN) particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70oC. The overall activation energy (Ea, 49.79 kJ/mol), energy of dissociation of initiator (Ed, 82.68 kJ/mol), number of micelles (0.163 x 1018) and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy (TEM). It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50–150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature. 相似文献