采用磷灰石新型常温捕收剂DJX-6优化某铁尾矿中磷的回收工艺

河北柏泉铁矿磁选尾矿粒度较粗,-0.074 mm粒级产率为30.76%,有用矿物磷灰石主要富集在细粒级中,且解离度较低,现场在矿浆温度为37 ℃情况下,以氧化石蜡皂+脂肪酸+MES为捕收剂,采用1粗3精1扫、中矿顺序返回闭路流程选磷,获得了P₂O₅品位和回收率分别约为33%和85%的磷精矿。为了解决现场浮磷需要加温且精矿指标不理想的问题,采用东北大学相关课题组研制的新型常温浮磷捕收剂DJX-6进行了选磷试验,结果表明,试样在磨矿细度为-0.074 mm占60%,浮选矿浆温度为20 ℃、pH=10（Na₂CO₃用量为400 g/t）,水玻璃用量为200 g/t,DJX-6用量为400 g/t的情况下,采用1粗3精1扫闭路流程处理,最终获得P₂O₅品位为33.30%、P2O5回收率为93.36%的磷精矿。与现场相比,不仅药剂用量大幅度降低、浮选矿浆无需加温,而且磷精矿P₂O₅回收率从85%左右提高至93.36%,因此,现场浮磷改用DJX-6为捕收剂将取消配套加温系统,大幅度降低能源成本,增加精矿产量,为企业创造显著的经济效益。     

钢铁表面处理“四合一”磷化液的研究

通过单因素试验和正交法试验,确定了钢铁表面除油、除锈、磷化、钝化“四合一”磷化液的最佳配方和最佳工艺条件。最佳配方为：硝酸锌26g／L,氧化锌14g／L,氯酸钾4g／L,氟化钠8g／L,磷酸310mL／L,硝酸镍6g／L,硝酸铜0．03g／L,乙醇7．5g／L,表面活性剂A5g／L,表面活性剂B5g／L。经过交流阻抗测试、塔菲尔极化试验、SEM表征和硫酸铜点滴试验表明,磷化膜具有可靠的耐腐蚀性,完全满足钢铁制品加工工序间的防腐要求。     

数据中心的环境设计与供电系统选型（1）

本文介绍了数据中心机房建设需要考虑的几个问题：可靠性分配,高可用性机房建设的要点,UPS的选型要点以及UPS系统容量选择的考虑,并以实例介绍了选择的计算方法。     

Room temperature nanoindentation creep of nanoscale Ag/Fe multilayers

This paper deals with room temperature indentation creep behavior of nanoscale Ag/Fe multilayers. The constant-load nanoindentation test results reveal that all the multilayers exhibit steady-state creep after transient creep occurring at first 150 s and decreasing periodicity leads to a decrease in the stress exponent and an increase in creep rate. The dependence of the stress exponent and creep rate on the periodicity indicates that the creep process is dominated by dislocation glide-climb mechanism and the increasing fraction of grain boundaries and interfaces provide effective diffusion paths for the creep climb that determines the whole creep rate.     

New glyme-cyclic imide lithium salt complexes as thermally stable electrolytes for lithium batteries

New glyme-Li salt complexes were prepared by mixing equimolar amounts of a novel cyclic imide lithium salt LiN(C₂F₄S₂O₄) (LiCTFSI) and a glyme (triglyme (G3) or tetraglyme (G4)). The glyme-Li salt complexes, [Li(G3)][CTFSI] and [Li(G4)][CTFSI], are solid and liquid, respectively, at room temperature. The thermal stability of [Li(G4)][CTFSI] is much higher than that of pure G4, and the vapor pressure of [Li(G4)][CTFSI] is negligible at temperatures lower than 100 °C. Although the viscosity of [Li(G4)][CTFSI] is high (132.0 mPa s at 30 °C), because of its high molar concentration (ca. 3 mol dm⁻³), its ionic conductivity at 30 °C is relatively high, i.e., 0.8 mS cm⁻¹, which is slightly lower than that of a conventional organic electrolyte solution (1 mol dm⁻³ LiTFSI dissolved in propylene carbonate). The self-diffusion coefficients of a Li⁺ cation, a CTFSI⁻ anion, and a glyme molecule were measured by the pulsed gradient spin-echo NMR method (PGSE-NMR). The ionicity (dissociativity) of [Li(G4)][CTFSI] at 30 °C is ca. 0.5, as estimated from the PGSE-NMR diffusivity measurements and the ionic conductivity measurements. Results of linear sweep voltammetry revealed that [Li(G4)][CTFSI] is electrochemically stable in an electrode potential range of 0-4.5 V vs. Li/Li⁺. The reversible deposition-stripping behavior of lithium was observed by cyclic voltammetry. The [LiCoO₂|[Li(G4)][CTFSI]|Li metal] cell showed a stable charge-discharge cycling behavior during 50 cycles, indicating that the [Li(G4)][CTFSI] complex is applicable to a 4 V class lithium secondary battery.     

ROOM FOR THE WAAL IN NIJMEGEN,THE NETHERLANDS

The Room for the River project around Nijmegen, The Netherlands is one of the most integrated and most complex cases in the national flood safety strategy. Along the Waal River in Nijmegen, a bypass channel and a new urban river park were created that not only reduce flood risks, but also offer recreational, ecological and aesthetic values.     

Room temperature hydrogen gas sensing properties of mono dispersed platinum nanoparticles on graphene-like carbon-wrapped carbon nanotubes

We present platinum nanoparticles dispersed wrinkled graphene-like carbon-wrapped carbon nanotubes (Pt/GCNTs) as a room temperature chemiresistive hydrogen gas sensor. Pt nanoparticles are decorated over GCNTs surface using poly (sodium 4-styrene sulfonate) (PSS) functionalization, followed by ethylene glycol reduction method. The highly defective wrinkled graphene-like surface of GCNTs provides large surface area and PSS functionalization provides stable immobilization of mono dispersed Pt nanoparticles on the carbon surface. A simple and inexpensive drop cast technique is used to fabricate the thick film sensor of the material. Hydrogen resistive gas sensing properties of Pt/GCNTs are studied at different gas concentrations, temperatures and Pt wt. % loadings. Pt/GCNTs sensor shows optimal sensitivity at room temperature with stable and reproducible response towards hydrogen. The sensor with 2 wt. % of Pt showed maximum sensitivity that is three fold higher than Pt decorated carbon nanotubes (Pt/CNTs) with the same Pt wt. % loading. The present study shows potential to explore novel H2 sensors^.     

通信机房节能技术

简要介绍通信机房的节能背景以及节能降耗的基本原则,着重阐述UPS电源节能、新风节能和专业空调节能等技术的应用,分析造成能源浪费的原因,提出当前机房环境下的节能措施。     

The electrodeposition of polypyrrole on Al alloy from room temperature ionic liquids

The direct electrodeposition of conjugated polymers onto active metals such as aluminum and its alloys is complicated by the concomitant oxidation of the metal that occurs at the positive potential required for polymer formation/deposition. We previously described an approach that uses electron transfer mediation to reduce the deposition potential of polypyrrole (PPy) on aluminum and aluminum alloy by nearly 500 mV, permitting film deposition from aqueous solution with nearly 100% current efficiency. In this report, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIM⁺TFSI⁻) has been successfully employed both as the growth medium and the supporting electrolyte for directly depositing uniform and conductive PPy coatings onto Al alloy 2024-T3 surface via a potentiodynamic technique. The depositions of PPy were carried out under cyclic voltammetric conditions from 0.3 M pyrrole in ionic liquid solutions. Film morphology was characterized by atomic force microscopy, optical microscopy, and scanning electron microscopy (SEM). Energy dispersive X-ray analysis and X-ray photoelectron spectroscopy verified that the TFSI⁻ anion was incorporated into the polymer as the dopant ion. Thickness of the film was measured by SEM and film conductivity was determined by both a four-point probe technique and by conducting atomic force microscopy. Electrochemical activity of the film was assessed by cyclic voltammetry. Results from these preliminary studies will be reported. Presented at the 2007 FutureCoat! conference, sponsored by the Federation of Societies for Coatings Technology, in Toronto, Ont., Canada, on October 3–5, 2007.     

Synthesis of phosphinic acid resin using acidic 1-butyl-3-methylimidazolium chloroaluminate ionic liquid as catalyst

The resin is functionalized by the introduction of phosphinic acid moieties by Friedel–Crafts phosphination reaction using acidic 1-butyl-3-methylimidazolium chloroaluminate ionic liquid as catalyst. The phosphorous and hydroxyl capacities of the resin are compared with those obtained by using conventional aluminium chloride catalysis. Extraction of uranium(VI) from nitric acid medium by the resins has been studied, and it was found that the distribution coefficient (K_d, mL/g) of uranium(VI) initially decreases with the increase in the concentration of nitric acid, and reaches a minimum value at 1.5 M in nitric acid followed by the increase in K_d values. A maximum distribution coefficient has been obtained when the concentration of nitric acid was 4.0–5.0 M. The extraction data have been fitted in to a Langmuir adsorption model for obtaining the apparent experimental capacity.