R12TAB/正丁醇/正癸烷/水体系相态的研究

绘制了阳离子表面活性剂R12TAB／正丁醇／正癸烷／水体系的拟三元相图，确定了微乳液区、微乳液／液晶共存区及不同液晶区域的范围。用^2HNMR和差示扫描量热法(DSC)与液晶纹理相互对照，研究了该体系的液晶结构特点。结果表明：含质量分数为25％～75％正癸烷的各相图内，除了存在着层状、六角状单相液晶区和层状／六角状／立方状共存的混合液晶区域外，还存在着液晶／微乳液共存的区域，且随着正癸烷质量分数的增加，微乳液及液晶区域逐渐缩小。     

The effect of increasing application rate of granular calcium ammonium nitrate on net nitrification in a laboratory study of grassland soils

Soil incubation studies were undertaken in controlled environment cabinets at 15°C to investigate the effect of increasing application rates of calcium ammonium nitrate (CAN) on net nitrification in two grassland soils. Granular CAN was applied to the surface of freshly collected, moist soil, at a rate equivalent to 0, 100, 200, 400, 800 and 1600µg NH ₄ ⁺ -N and NO ₃ ^- -N per gram of oven dry soil. In half the treatments finely ground CaCO₃ was incorporated into the moist soil to raise the starting pH. Changes in soil mineral N and pH were measured at weekly intervals up to six-weeks. The most probable number (MPN) technique was used to enumerate the NH ₄ ⁺ -N and NO ₂ ^- -N oxidizers at the beginning and end of the incubation.At low rates of CAN application there was considerable NH ₄ ⁺ -N oxidation to NO ₃ ^- -N during the incubation of both soils. Lime stimulated this N transformation. At high application rates (i.e. 800 and 1600 ppm) there was little change in NH ₄ ⁺ -N or NO ₃ ^- -N on either soil during the 6 week incubation, in the presence or absence of lime. The rate of NO ₃ ^- -N produced peaked at 5.6 and 3.8 mg NO ₃ ^- -N kg^–1 d^–1 on soil 1 and 2 respectively, in the presence of lime. Above a level of 400 ppm CAN (equivalent to 38 kg N ha^–1) the rate of NO ₃ ^- -N produced decreased. The higher rate of net nitrification in soil 1 compared with soil 2 was probably due to a higher number of nitrifying bacteria. Although high rates of CAN decreased the nitrifying activity of both soils there was little difference between treatments in the actual numbers of NH ₄ ⁺ -N and NO ₂ ^- -N oxidizers determined by the MPN technique.The results showed that the rate of granular CAN applied to the soil surface can influence the local activity of nitrifying bacteria and subsequent N transformations. At application rates of CAN generally used agriculturally for grass production, it is likely that net nitrification of the NH ₄ ⁺ -N in the fertilizer granule will be inhibited.     

由二氧化碳出发合成有机碳酸酯

对以二氧化碳为原料合成有机碳酸酯的环氧路线、酯交换和直接合成方法作了综合评述 ,认为直接合成是最佳的合成路线。碳酸酯的直接合成可在均相及多相催化体系中进行 ,负载金属、金属甲氧基化合物及碱均可作为催化剂。直接法研究的关键在于高性能催化剂的开发、由二氧化碳对金属 -氧键插入反应导致的催化循环的构筑及耦合反应的应用。     

纳米碳酸钙/炭黑并用对丁苯橡胶性能的影响

研究了纳米碳酸钙／N330炭黑并用比对丁苯橡胶性能的影响。结果表明，随着CaCO3／N330并用比的改变，材料的强度有了显著的提高，特别是CaCOa／N330并用比为20／30(质量份)时复合材料的拉伸强度达到了20MPa以上，同时材料具有较好的弹性和较低的硬度；两种处理剂相比，树脂酸处理的碳酸钙具有较好的性能；表面处理的纳米炭酸钙与炭黑并用，可以降低炭黑填充橡胶的动态滞后，表面处理的纳米碳酸钙的加工性能比纳米炭黑好，可以通过并用纳米碳酸钙来改善炭黑胶料的加工性能。     

稀土复合热稳定剂对聚氯乙烯性能影响研究

主要以有机锡热稳定剂为对比物，研究了稀土热稳定剂对聚氯乙烯(PVC)的热稳定性及其他性能的影响。稀土热稳定剂对PVC的力学性能、加工性能都有不同程度的提高，稀土热稳定剂的热稳定性能符合PVC的加工条件要求，并研究了抗冲改性剂ACR(丙烯酸酯共聚物)对体系的影响。     

Nucleation and crystallization of polypropylene by mineral fillers: relationship to impact strength

The mechanical properties of mineral-filled polypropylene (PP) are determined not only by the size, shape and modulus of the filler particles, but also by microstructure. For example, poor impact strength is correlated with a high capacity for nucleation of crystallization. In the present study, optical microscopy has been used to measure the growth rate of spherulites in PP. In tandem with this, isothermal d.s.c. measurements have been made of the crystallization of the PP filled with talc, calcium carbonate and stearate-coated carbonate at different loading levels. Computer simulation of spherulite growth has been used to derive the number of nucleating sites per unit volume of polymer and, using surface area measurements, the number of sites per unit area of mineral surface was obtained. Values for talc were, as expected, considerably higher than those for carbonate (and especially coated carbonate) fillers. The presence of filler affects not only the nucleation and kinetics of the crystallization process but also the crystallinity and orientation indices and the proportion of β-phase crystallites present. The connection between these factors and impact strength is discussed. It is concluded that impact properties are determined by inter alia crack pinning and blocking by filler particles, stress concentrations at the edges of the filler particles, and the nucleating ability of the filler.     

Guayule seedling response to nitrogen fertilizers

Slow growth and high seedling mortality limit direct seeding establishment of guayule (Parthenium argentatum G.). This study was conducted to assess seedling growth enhancement by the addition of different rates and forms of N fertilizers and Ca salts. Experiments were conducted in a greenhouse with cultivar 593 under both surface and subirrigated conditions using water low in salts (salinity of 0.8 dSm^–1, SAR of 5.0 and 10 mg Ca L^–1). Under surface-irrigated conditions, seedling height and fresh plant weight increased with N application to the irrigation water to 70 mg L^–1. The best seedling growth was observed when (NH₄)₂SO₄ was added in combination with CaCl₂ or CaSO₄. Progressively less growth was observed by addition of (NH₄)₂SO₄ alone, CO(NH₂)₂ plus CaSO₄, CO(NH₂)₂ alone and Ca(NO₃)₂. When seedlings were subirrigated, however, the best growth was observed with Ca(NO₃)₂. Intermediate growth was obtained with (NH₄)₂SO₄ plus CaSO₄ and lowest growth rates with (NH₄)₂SO₄ alone. These differential responses may be explained by the differences in leaching and volatile characteristics of the N forms. Growth enhancement from N and Ca additions increased with time with significant increases 45 days after seeding. Nitrogen application with Ca may be effective amendment in promoting subsequent growth of direct seeded guayule.     

料浆法磷铵工艺的历史和近期技术进展

简单回顾“中和料浆浓缩法磷铵工艺”在我国的发展历史和现状 ,着重介绍该工艺与采用传统“磷酸浓缩工艺”的大型进口磷铵装置实现“联产”,促进、优化后者的生产和经营的科技创意和实践 ,展望该工艺最新技术进展的推广应用前景     

碱式碳酸铅的生产工艺研究

介绍了由氧化铅与冰醋酸在一定温度下反应生成碱式醋酸铅，碱式醋酸铅在一定条件下与二氧化碳反应生成碱式碳酸铅，再经沉淀、抽滤，制得结晶产品。探讨了溶液pH、反应温度、二氧化碳流量、水中的杂质、总铅质量分数等对碱式碳酸铅结晶的影响，得出了制备碱式碳酸铅的最佳工艺条件：pH=6．5时停止通入二氧化碳，反应温度25～30℃，二氧化碳流量控制在0．5～3L／min，把河水或自来水经过离子交换处理，溶液中总铅质量分数控制在2％～5％。     

纳米碳酸钙在涂料中的应用研究

探究纳米碳酸钙先在溶剂中分散再与树脂进行调配的方法。利用正交设计法对其中高速搅拌法进行优惠条件实验，发现搅拌时间并非越长越好，优惠条件下涂料中纳米碳酸钙分散到原始粒径，涂料质量有较大提高。