改善火炕炕面温度分布技术模拟

为了使火炕的表面温度分布均匀,提高室内环境的热舒适性,提出了倾斜布置炕板来改善炕面温度分布的不均匀性．通过对炕板倾斜程度不同的落地炕和吊炕进行数值模拟,结果表明:当落地炕的炕头粘土层厚度为80 mm、炕梢粘土厚度为20 mm时具有相对最佳的取暖效果;当吊炕的炕头粘土层厚度为80 mm、炕梢粘土厚度为20 mm时具有相对最佳的取暖效果．     

Artificial neural network to evaluate proton conductivity of sulfonated fluorinated membranes: Effect of sulfonation degree,fluorine content,and cost for membranes of synthesized copolymers,blends, and nanofibrous electrospun composite case studies

Proton conductivity is determining parameter of performance for proton exchange membrane cells in energy systems. The presence of sulfonated and fluorinated groups in polymer and using theoretical techniques make it possible to design a high-performance membrane with optimized conductivity. Thus, proton conductivity of 19 membranes of sulfonated/fluorinated polysulfone case studies are evaluated using artificial neural network (ANN). Fluorinated regions are incorporated into sulfonated polymer via synthesis of sulfonated/partially fluorinated polymers, blending sulfonated and fluorinated polymers, and electrospun fluorinated mat impregnated with a sulfonated matrix. Sulfonation degree (WR_S), content of fluorinated groups (WR_F), and membrane cost are studied as influential factors on conductivity. According to ANN, there is a direct relationship between WR_S and proton conductivity. Regarding WR_F, the optimal value should be allocated. Membrane cost including the effect of diol structure, WR_S, and WR_F has the highest impact. Additionally, at high WR_S, proton conductivity is determined by WR_S and WR_F.     

WDX-Analysis of the New Superconductors RO1−x F x FeAs and Its Consequences on the Electronic Phase Diagram

Polycrystalline samples of RO_1−x F _x FeAs (0≤x≤0.25) (R=La, Sm, Gd) were investigated by wavelength-dispersive X-ray spectroscopy (WDX) in the electron microscope to determine the composition of the samples, in particular the fluorine content. It was found that the measured fluorine content can deviate considerably from the initial weight. In the lanthanum compound LaO_1−x F _x FeAs, we found good agreement mainly for x≥0.05, but for x<0.05 the fluorine hardly goes into the sample. For the samarium compound we measured less than half the fluorine in the sample as initially weighed at all fluorine concentrations. These measured values are taken into account when drawing the electronic phase diagrams of LaO_1−x F _x FeAs and SmO_1−x F _x FeAs. This leads to a more consistent picture of both of the diagrams in comparison to the plot of the initial weight.     

Synthesis and Characterization of Some Nonionic Bolaamphiphiles

A series of nonionic bolaamphiphiles were synthesized from the reaction of fluoroalkylene (dimercaptoacetates) with maleate crown ethers. Surface activity of the new surfactants was evaluated on the basis of surface tension measurements. The new fluorinated bolamphiphiles exhibit a remarkable lowering of surface tension in comparison with nonfluorinated analogues.     

降低包钢选矿厂铁精矿氟含量的选矿试验研究

针对包钢选厂铁精矿中氟含量高的问题,采用新型JF-3反浮选捕收剂、FA抑制剂对包头氧化矿系列中的铁精矿中的氟矿物的选别进行了研究。试验结果表明,JF-3反浮选捕收剂和FA抑制剂较好地降低了铁精矿中氟含量,可以将铁精矿的氟含量降低到0．39％,氟去除率达81．28％。     

磷石膏氟化物的浸取动力学特性

应用旋转圆盘法研究了三蛱库区堆放的磷石膏中氟化物的浸取动力学特性。在288．308K的温度区间,pH=5．0—5．5的酸度区间和258—900r／min的圆盘转速区间下,使用氟离子选择性电极连续在线检测水相氟离子的瞬时浓度,得到了磷石膏中浸取氟化物的微分速率常数,计算了浸取过程的表观活化能为19．6kJ／mol。根据微分速率常数特点判断,从磷石膏浸取氟化物的微观控制过程为外部扩散步骤,提高过程温度及旋转圆盘转速据可提高磷石膏中氟化物的浸取速率。     

Effects of fluorine doping on the structural properties of the CdO films deposited by ultrasonic spray pyrolysis

The fluorine doped cadmium oxide samples have been deposited at 250 °C by ultrasonic spray pyrolysis method. X-ray diffraction patterns of the CdO:F samples have revealed that the samples are polycrystalline with cubic sodium chloride structure. The texture coefficients calculated for various planes at different fluorine concentrations indicate that the samples have exhibited (1 1 1) and (2 0 0) preferential orientations. The lattice parameters for cubic structure of each diffraction plane have been calculated. The crystallite size of the samples being nearly constant until 4% of fluorine doping showed reasonable decrease above this concentration value. The macro strain and dislocation density vary with fluorine concentrations.     

F2, H2O, and O2 etching rates of diamond and the effects of F2, HF and H2O on the molecular O2 etching of (110) diamond

Oxidation kinetics of natural (110) diamond by oxygen and water were investigated using in situ Fizeau interferometry. Apparent activation energies of 53 and 26 kcal mol⁻¹ were obtained for the etching of (110) type Ia diamond by O₂ and H₂O respectively. The etch rate was found to follow second-order kinetics with respect to O₂ pressure in the pressure range 0.04–10 Torr. For water over the vapour pressure range 0.1–2 Torr, the reaction has a reaction order near unity. The diamond (110) surface was impervious to etching by molecular fluorine at all temperatures up to 1300 °C. Fluorine, hydrogen fluoride and water were found to inhibit the molecular oxygen etching of diamond. Below 900 °C, oxidation is inhibited by the addition of F₂ and HF presumably by blocking reactive sites on the diamond surface through formation of C---F bonds. Above 900 °C, the fluorine is thought to desorb from the diamond (110) surface, rendering the surface susceptible to further oxidation. Addition of water below 800 °C was found to retard etching by molecular oxygen. This is attributed to the formation of C---OH bonds, analogous to C---F.     

Modification of Hβ zeolite by fluorine and its influence on olefin alkylation thiophenic sulfur in gasoline

By modifying the Hβ zeolite with proper amount HF, the catalytic performance of fluorinated Hβ was obviously improved for the olefin alkylation thiophenic sulfur process. Particularly, the acid sites of the fluorinated Hβ catalysts were increased, especially its distribution of medium and stronger Lewis and Brönsted acid sites was optimized, and its thiophene alkylation activity and stability are thus promoted as well as its coking behavior is suppressed during OATS process.     

含氟表面活性剂的研究与应用

综述了含氟表面活性剂的国内外研究进展,以及其在造纸、石油、涂料和消防领域的应用情况.