The madelung constant of the sodium chloride crystal lattice

An analysis of the Madelung constant of the sodium chloride crystal lattice has been made, in an effort to supplement information available in undergraduate textbooks. A method of approximation of the constant using the personal computer is presented. An erratum to this article is available at .     

Synthesis of arbutin by two-step reaction from glucose

Arbutin was synthesized from glucose by two-step reaction below: (a) 2,3,4,6-tetra-O-acetyl-α-D-glucosyl chloride or bromide was prepared by glucose and acetyl halide (chloride or bromide), (b) 2,3,4,6-tetra-O-ace-tyl-α-D-glucosyl halide (Cl, Br) reacted with hydroquinone, methanol as solvent at pH=9.5-10.0.     

Preparation and Tribological Performance of Novel Organotin Compound as Lubricant Additive

Oil-soluble stannous naphthenate (SN) is synthesized by using naphthenatic acid and SnO. And its molecular structure is confirmed by IR and multielement oil analyzer (MOA). The tribological performances of the organotin as lubricant additive are evaluated with a four-ball friction and wear tester. These experiments indicate that the wear scar diameter (WSD) and friction coefficient are diminished while the load-carrying capability increased by comparison with that of base oil. The elemental composition of the boundary lubricating film is examined by means of Auger electron spectroscopy (AES). Synergistic effect is found in the load-carrying capability of the complex of SN and sulfured olefin. The analytical results of AES indicate that the good performance of stannous naphthenate is attributed to the formation of a boundary lubricating film containing Sn on the rubbed surface.     

Development of an evaporation crystallizer for desalination of alkaline organic wastewater before incineration

A wastewater evaporation-desalination pretreatment method was introduced to remove the Na^＋ and K^＋ salts in volatile organic compounds （VOCs） wastewater before it was fed into the incinerator. VOCs in the wastewater were volatilized in the evaporation system and then the vapor was combusted in an incinerator. Simulated phenol wastewater containing sodium chloride was evaporated and concentrated and sodium chloride was crystallized in different parameters. The experimental results showed that the higher initial concentration of sodium chloride increases the ratio of volatilization of VOCs, which was due to the effect of “salting out” （a decrease in the solubility of the nonelectrolyte in the solution, or more rigorously, an increase in its activity coefficient, caused by the salt addition （Furter and Cook, 1967））. When evaporation speed was increased from 1.67 ml/min to 2.73 ml/min, the total removal coefficient of sodium chloride was about 99.88%-99.99%. This pretreatment procedure eliminates the slag phenomenon caused by Na^＋ and K^＋ salts during wastewater incineration, so the incinerator could operate continuously, and the wastewater evaporation could increase the heat value of wastewater, and the operation cost would be reduced.     

C3H6/C3H8在AgCl、CuCl上吸附作用的量子化学计算研究

用ZINDO/ 1和abinitio/STO -6G 方法 ,对C3H6 、C3H8与AgCl、CuCl间的吸附态优化构型、原子净电荷、吸附能、前沿轨道能量作了计算。计算结果表明 ,C3H6 /C3H8在AgCl、CuCl上吸附作用机理为 :C3H6 在AgCl、CuCl上发生了强相互作用 ,为化学吸附 ;而C3H8与AgCl、CuCl仅发生了较弱的物理吸附 ,因此C3H6 /C3H8在AgCl、CuCl上具有较大的吸附选择性 ,比较而言 ,CuCl较AgCl更适合于作为C3H6 /C3H8分离吸附剂的活性组分     

载铁改性沸石吸附剂去除含氟水中氟离子的研究

研究了用三氯化铁改性的沸石在水中的除氟性能．对使用条件及除氟机理进行了研究．并对洗脱、再生后的吸附荆进行吸附柱实验．结果表明，该吸附剂对含氟水中的氟具有吸附容量高、速度快、选择性高、易洗脱再生的特性．多次洗脱再生后的吸附剂可重复使用，吸附剂性能稳定，吸附剂机械强度高．该吸附剂的静态饱和吸附容量可达26．57mg(F^-)／g(吸附剂)．     

卤化亚汞声光器件换能器电输入阻抗

利用压电换能器等效电路网络分析法,计算了以环氧树脂为缓冲层(粘接层)的x-cutLN/卤化亚汞声光器件中换能器三层结构规一化电输入阻抗|Zj|随规一化频率f/f0的变化值,绘出了|Zj|-f/f0关系立体图。得出器件的输入阻抗是射频频率复杂的复数函数及在不同频率段分别呈现感抗和容抗特性且随电极层厚度变化而变化的结论。     

总铝浓度对聚合氯化铝中Al形态分布的影响

通过微量加碱法制备了具有不同总铝浓度、相同碱化度的聚合氯化铝（PAC）溶液.然后通过Al-Ferron逐时络合比色法以及废水混凝实验,分析了不同条件下制备的PAC样品中各种铝形态的含量及混凝效果.结果表明：高的总铝浓度有利于聚合度较高的铝形态的形成,但过高会导致不溶性氢氧化铝沉淀的含量过高,从而影响其混凝效果.常温条件下,碱化度为2.5时,总铝浓度为0.5 mol/L条件下制备的的PAC溶液混凝效果最好.     

四氯化锡催化合成橙花素

四氯化锡能够代替硫酸作为醚化催化剂.在五水四氯化锡存在下,由β 萘酚和乙醇合成了橙花素(β 萘乙醚).当β 萘酚、乙醇和四氯化锡的物质的量比为1:4:0.114,回流反应12h,醚收率达74.4%.     

灌浆料加速腐蚀仪的研制与应用

参照钢筋阳极极化作用原理和加速腐蚀实验方法，研制了具有6套能同时独立工作的腐蚀装置的灌浆料加速腐蚀仪。试验方法是在恒电位条件下测定腐蚀电流急剧变化时所经历的时间，并由此反映灌浆料在极端苛刻的腐蚀条件下抵御氯离子侵蚀的能力。应用该仪器对预应力混凝土灌浆料的优选进行了系统试验，取得了良好的效果。结果表明该加速腐蚀仪具有良好的可靠性和精度，可用于灌浆料的抗氯离子侵蚀性能的试验研究。