黄原酸钾含量的示波滴定

报道了用示波滴定法测定黄原酸钾含量 ,在 p H5～ 6的 HAc- Na Ac缓冲底液中 ,加入四苯硼钠 ( Na- TPB)沉淀 K+ ,过量的 Na- TPB用氯化四乙基铵标准溶液滴定 ,滴至 Na- TPB示波图切口消失为终点 ,终点直观敏锐 ,方法快速简便 ,准确度、精密度均高。标准加入回收率在 99.8%～1 0 0 .2 % ,RSD<0 .2 %     

结晶法净化湿法磷酸生产磷酸二氢钾研究

研究了三聚氰胺结晶法净化湿法磷酸复分解生产精细磷酸二氢钾工艺中磷酸三聚氰胺与氯化钾反应生产磷酸二氢钾的工艺条件。采用二次正交组合实验设计，对反应过程中反应温度，反应时间，搅拌速度，氯化钾用量，氯化钾初始浓度等诸因素的一次作用，二次作用及交互作用对五氧化二磷转化率的影响进行了研究，得到了适宜的工艺条件，所得磷酸二氢钾达到HG2321－91质量标准。     

铜掺杂对(Na0.5K0.5)NbO3无铅压电陶瓷性能的影响

采用传统固相反应法对(Na0.5K0.5)NbO3压电陶瓷进行铜掺杂改性研究。使用SEM、XRD并结合常规压电陶瓷性能测试手段对该体系的显微结构、压电性能等进行表征。研究结果表明:CuO的掺入使材料出现“硬化”现象,即材料的压电系数d33、平面机电耦合系数Kp和介电损耗tanδ下降了,机械品质因子Qm大大提高;CuO掺入量在1%mol时各项性能最佳。另外,从SEM图片中可以看出:(Na0.5K0.5)NbO3压电陶瓷材料的平均晶粒尺寸随着CuO掺入量的增加明显变大。这表明CuO有烧结助熔作用,能降低烧成温度。     

青岗钾肥厂试车小结

为满足农业生产上对硫酸钾的需求，化工部上海化工研究院复肥所着重开发了硫铵转化法的生产工艺，并在推广过程中，针对操作工艺和设备上所存在的问题，继续探索，取得了新的结果。该技术已用于青岗钾肥厂万吨级硫酸钾生产装置。本文着重介绍了该装置在试车过程中所发生的问题及处理方法。     

复分解四步循环法制取硫酸钾新工艺

介绍了制取硫酸钾的一种新工艺－－复分解四步循环法，即氯化钾与硫酸铵反应生成硫酸钾铵与氯化铵钾，硫酸钾铵再与氯化钾溶液反应生成硫酸钾，氯化铵钾再与硫酸铵溶液反应生成氯化铵。整个工艺全封闭循环生产，产品硫酸钾K2O质量分数≥50％，钾收率达92％。     

复分解法制备磷酸二氢钾的研究

介绍了以工业氯化钾和工业磷酸为基本原料，采用复分解法，在氯化钾过量的情况下，加入氨水作为pH值调节剂，制备磷酸二氢钾（KH2PO4）的研究。产品含量大于92％，原料转化率（以磷酸计）大于85％，无三废产生。     

Crystallography and equilibrium solubility for ammonium and potassium orthophosphites and hypophosphites

The composition and solubility properties of eight ammonium and potassium orthophosphites and hypophosphites were determined to evaluate the potential of these classes of materials for increasing the plant nutrient content of liquid fertilizers. Phase relationships for the systems (NH₄)₂O-P₂O₃-H₂O, K₂O-P₂O₃-H₂O, (NH₄)₂O-P₂O-H₂O, and K₂O-P₂O-H₂O were determined along with the crystallographic properties (X-ray and optical) of the solid phases. Toxicity and phosphite response was tested in greenhouse experiments for the compounds.     

Balanced pasture fertilization in the Basque Country: I. Phosphorus and potassium budgets on dairy farms

Dairy farming is the main agricultural activity of the Basque Country. A dairy farm is characterized as a system with soils and crops, forage, cattle and manure as main components, and in such a system, nutrient cycling is very important to maintain soil fertility and optimize forage production. To quantify nutrient transfers in the cycle, a simple system was developed and has been applied to seventeen farms to examine its ability to achieve a balanced P and K fertilization. These farms have provided data on inputs (fertilizer, feeds, concentrates), pasture and manure management, and outputs (milk production), and soil samples have been taken from farm pastures. Phosphorus and K in excreta and uneaten pasture is used with a relatively high efficiency as suggested by the relatively high efficiency of P and K utilization by the pasture that usually ranges from 70 to 90%. Concentrate feeding (3000 kg cow^–1 yr^–1) represents one of the main P and K inputs in Basque Country dairy farms, averaging 26 and 66 kg ha^–1, respectively. Besides, release of K in the soil through slow liberation from non-exchangeable sites was estimated as 30 kg ha^–1. Thus, a high efficiency in excreta recycling would diminish substantially P and K mineral fertilizer needs. Farm nutrient budgets appear to be a convenient tool for determining nutrient shortages and surpluses at farm level, and thus they are considered as a first step to support a better management of maintenance fertilization of permanent pastures.     

Yb3+掺杂KLa(WO4)2激光晶体生长与光谱分析

采用提拉法生长出掺镱钨酸镧钾[Yb:KLa(WO4)2,Yb:KLW]晶体,测试了晶体的红外光谱和Raman光谱,对出现的振动模式进行了归属.从X射线衍射分析得到晶胞参数a=b=0.532 nm,c=1.189 nm.通过热重-差热分析得到晶体的熔点为1 119 ℃,在熔点以下没有相变.测试了晶体的吸收光谱和荧光光谱,计算了相应的光谱参数.结果表明:该晶体发射波长为1 021 nm,在931,981 nm附近有较强、较宽的吸收峰,适合用InGaAs半导体激光泵浦.     

催化动力学光度法测定痕量钒(Ⅴ)的研究

研究了在 p H=4及没食子酸存在下 ,微量钒 ( )催化溴酸钾氧化邻苯二胺的动力学条件 ,建立了催化动力学光度法测定痕量钒 ( )的新方法。方法的测定范围为 0～ 0 .0 2 5 μg· 2 5 m L- 1 ,检出限为 1.18× 10 - 6 g·L- 1 ,相对标准偏差为 4 .6 3% (n=10 ) ,线性回归方程为△ A=2 5 .6 6 c(μg· 2 5 m L- 1 ) - 0 .0 15 7(r=0 .9997) ,表观摩尔吸光系数ε4 6 0 nm=3.2 7× 10 7L· m ol- 1 · cm- 1 。该法灵敏度高 ,选择性好 ,直接应用于水样和食品样中痕量钒( )的测定 ,结果满意