Phosphorus Inputs to Lake Simcoe from 1990 to 2003: Declines in Tributary Loads and Observations on Lake Water Quality

Total phosphorus (TP) inputs to Lake Simcoe have led to hypolimnetic dissolved oxygen (DO) depletion and loss of cold water fish habitat. Since 1990, efforts have been made to reduce the total TP input to the lake below a defined target of 75 t/year, which was predicted to lead to reductions in spring TP concentration and improvements in end-of-summer hypolimnetic DO concentrations. The total TP load to the lake during the most recent period of record (1998/99-2003/04) ranged from 53 to 76 t/yr and averaged 67 t/yr, compared to an average of 114 t/yr estimated between 1990/91 and 1997/98 (range 85-157 t/yr). Reductions in TP loads from the catchment via tributary discharge (∼26 t) accounted for the majority of the decrease in total load between the two time periods. Total P concentrations decreased significantly in four out of six long-term monitored tributaries; however, concentrations in all six tributaries remain above the level recommended to avoid nuisance plant growth (30 μg/L). Although TP loads to the lake are currently below the target 75 t/yr, excessive growths of filamentous algae and macrophytes continue to be a problem in the nearshore zone. End-of-summer minimum hypolimnetic DO concentrations (average 4.3 mg/L, 1998/99-2003/04) remain substantially below the level (7 mg/L) that is considered protective of lake trout. Efforts to reduce TP loads to the lake therefore need to continue.     

The influence of various reaction parameters on the performance of (α‐diimine)nickel(II) catalysts in ethylene oligomerization reactions

Modified (α‐diimine)nickel(II) catalysts are suitable for ethylene oligomerization reactions. Due to the mechanism (“chain running”), the formation of double‐bond isomers and branched olefins can be observed. The obtained oligomer mixtures show a Schulz–Flory distribution. Increasing ethylene pressure favors the selectivity of α‐olefin formation. The same effect can be observed when Lewis bases like thiophene or furane are added to the oligomerization reaction mixture. These results can be related to an interaction of the additives with the catalytic active species during the oligomerization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1356–1361, 2003     

Ni的添加对TiB2-CU基复合材料微观组织的影响

利用燃烧合成工艺原位合成了TiB2-Cu基复合材料，为了改善TiB2陶瓷和Cu基体的润湿性，将金属Ni作为合金化元素加入到TiB2-Cu复合材料。通过XRD，SEM，EPMA和TEM等检测手段对金属Ni的添加对TiB2-Cu基复合材料微观组织的影响进行了研究。结果表明，含Ni复合材料的金属粘结相的面间距比不含Ni时Cu的面间距均有不同程度的减小；Ni加入后，TiB2-Cu-Ni复合材料的组织较TiB2-Cu复合材料更加致密，但陶瓷颗粒尺寸却大于TiB2-Cu复合材料的颗粒尺寸；Ni的加入降低了复合材料的导热率和冷却速度，使得部分TiB2陶瓷颗粒有足够的时间长成棒状，同时造成TiB2陶瓷颗粒间形成更多的烧结颈；Ni的加入也改善了陶瓷与金属粘结相之间的润湿性，使陶瓷相与金属粘结相的界面结合牢固，看不到TiB2-Cu复合材料中界面脱开的现象。金属Ni的添加有利于改善TiB2-Cu基复合材料的微观组织，进而利于复合材料的致密化。     

The electropolymerization of pyrrole at a CuNi electrode: corrosion protection properties

Pyrrole was successfully electropolymerized at a copper–nickel electrode in a near-neutral sodium oxalate solution containing Cu²⁺ cations to generate a homogenous and adherent polypyrrole film. The presence of the Cu²⁺ ions increased both the rate of the electropolymerization reaction and the adherence of the polymer at the CuNi interface. In the absence of these cations, oxidation of the electrode occurred generating a nickel-rich layer that was not sufficiently conducting, under the electropolymerization conditions employed, to facilitate the electron-transfer reaction and the electropolymerization of pyrrole.These films remained stable and exhibited significant corrosion protection properties in acidified and neutral 0.1 mol dm⁻³ NaCl solutions even on polarization of the electrodes to high anodic potentials.     

化学镀SiCp／Ni－P复合镀层与基体结合强度及其影响因素

论述了ＳｉＣｐ／Ｎｉ－Ｐ复合镀层与钢基体的结合强度及其影响因素。复合镀层中离界面５μｍ厚度以内区域的组成及应力状态对镀层／基体的界面结合有决定性作用，在该区域以外ＳｉＣ粒径变化不影响镀层的结合强度。适当的热处理可提高界面结合力。     

Electrochemical intercalation in NiOx thin films

In this work we investigated the mechanism of the electrochemical intercalation reactions in rf sputtered nickel oxide thin films electrodes by two techniques: mechanical stress change measurements by means of an optical technique and mass changes using an electrochemical quartz microbalance (EQCM). The experiments were performed in alkaline electrolytes containing cations of the first column of the periodic table. Reversible mass and volume changes were observed. In order to explain these experimental results, an exchange reaction is proposed, in which the oxidation process is accompanied by the deinteractional of a relative large number of “light” cations, simultaneously with the intercalation of a smaller number of heaviest cations.     

Magnetic properties of nickel filament polymer-matrix composites

The magnetic properties of polyethersulfone-matrix composites with 3-19 vol.% polycrystalline nickel filaments (0.4 (im diam) were investigated. These filaments were found to exhibit hysteresis energy loss 10800 J/m³ of nickel and coercive force 16.9 kA/m, compared to corresponding values of 4930 J/m³ and 4.7 kA/m for 2 μ.m diam polycrystalline nickel fibers, 1020 J/m³ and 0.5 kA/m for 20 μm diam polycrystalline nickel fibers, and 1280 J/m³ and 2.3 kA/m for solid polycrystalline nickel.     

The current and residual value of superphosphate for lupins grown in rotation with oats and wheat on a deep sandy soil

In a field experiment on a deep pale-yellow sand in a 600 mm per annum rainfall Mediterranean environment of south-western Australia, six levels of phosphorus (P) as superphosphate (O up to 546 kg P ha^–1) were applied once only, to the soil surface, before sowing lupins (Lupinus angustifolius). The lupins were grown in a continuous arable cropping rotation with, in successive years, oats (Avena sativa), wheat (Triticum aestivum), lupins. Five such rotations were started in the experiment from 1985 to 1989. The experiment continued until the end of 1990.The relationship between lupin seed (grain) yields and the level of P applied was measured in the year of P application for five successive years (1985 to 1989). The relationship had the same general form but it varied between years, largely due to different maximum yields (yield plateaux) in each year.The residual value of superphosphate applied three years previously was measured for lupins on two occasions (1988 and 1989) relative to superphosphate applied in the current year. The residual values was different in the two years. The superphosphate applied three years previously was about 30% as effective as freshly applied superphosphate in 1988, and 12% as effective in 1989.At each harvest, the relationship between grain yield and the P concentration in the grain differed for different species. However, for each species at each harvest, the relationship was similar regardless of when the P was applied in the previous years. Thus each species had the same internal efficiency of P use curve, and yields varied only with P concentration in tissue.Bicarbonate-extractable soil P was determined on soil samples taken in mid-July of 1989 and 1990. These soil test values were related to grain yields at harvest. The relationship between yield and soil test values had the same general form but varied for different species within years and for each species between years. It also varied for each species within years depending on the year the P was applied.     

磷系水质稳定剂的合成和应用

介绍了国内外磷系水质稳定剂的现状和发展，重点讨论了作为水质稳定剂的聚磷酸钠、有机多元膦酸、膦羧酸以及磷酸酯的合成和应用。