我国主要类型土壤的有效态硒及其与某些土壤性质的关系

Forty-eight soil profiles were sampled from different ecological and pedogeochemical areas of China and their available selenium (Av-Se) contents were determined. Results showed that the content of Av-Se in the profiles of soils in China ranged within 2.49~18.10 μg kg^-1, with a mean value of 10.01 μg kg^-1, and was in the sequence of Ferralisols > Luvisols > Isohumisols > Aridisols. The correlation analysis between Av-Se and the soil physical-chemical properties revealed that the correlations between Av-Se and O.M., CEC, Fe₂O₃, Al₂O₃, ignition loss, Co and Zn were positive at a highly significant level, but those between Av-Se and pH, base saturation, CaO, Ba and Sr were all negative at a highly significant level. The reason of some diseases related to the Se deficiency might be the leaching loss of selenium in some soils.     

水稻施用硅肥方法的研究

水稻施用硅肥试验表明,氮磷硅肥配合施用比单施氮肥生育期提前3d,分蘖率提高86．5％,增产19．4％;比氮磷肥配合施用生育期提前4d,分蘖率提高115．5％,增产10．6％;比氮硅肥配合施用生育期提前1d,分蘖率提高70．5％,增产6．0％。     

江西省农田土壤有效硫现状研究

采集了江西１６个县市９种主要母质的６０９个农田耕层土样进行了土壤有效硫含量测定。统计结果表明：平均值为２６．７１ｍｇ／ｋｇ,缺硫和潜在缺硫样点占３９．１０％。按地区分,以赣南、赣东北山区缺硫最严重,有效硫小于１２ｍｇ／ｋｇ的样点占２６．６０％～４４．７０％,其次是丘陵地区,有效硫小于１２ｍｇ／ｋｇ的样点占１０．００％～１９．００％。按母质分,母质中以石英岩、花岗岩发育的土壤最缺,约占５０％～６０％,其次是红砂岩、泥质岩,缺硫为３０％～４０％,这些是江西省急需施用硫肥的土壤。水稻土以黄砂泥田、麻砂泥田、红砂泥田、鳝泥田等土属缺硫面积最多,全省缺硫水稻土面积约为１０３．８万ｈｍ２,约占水稻土面积的３４％。     

纳米晶须的系列倾衍射及带轴夹角的精确测定

通过对以纳米碳管为媒介生长的一未知纳米晶须进行的系列倾电子衍射实验,测定了该晶须为正交结构的Ｓｉ２Ｎ２Ｏ;针对常用的系列倾电子衍射实验的倾角计算公式,讨论了带轴间夹角与膜面法线转角的差异,并推导了其精确表达式。     

漂白粉有效氯在水中衰减规律及鱼对其耐受性的研究

在室内外不同条件下,研究了ＣＯＤ、温度、有效氯含量、ｐＨ和光照对漂白粉有效氯衰减的影响,以及鲤和链对有效氯的耐受能力。结果表明：１）漂白粉有效氯在水中按ρ＝α＋ｂｅ＾ｋｔ规律衰减,衰减速率常数（ｋ）随初始有效氯浓度的减小、温度的升高和ＣＯＤ的增大而加快,随ｐＨ的下降和光照强度的增加而增加。且温度和ＣＯＤ对衰减的影响有交互作用;２）在本实验条件下,小于０．３ｍｇ／Ｌ的有效氯２４ｈ内基本衰减完毕,大于     

毛竹施用硅肥的效应研究

探讨了在有效硅含量水平较低的流纹岩风化物发育的土壤上，中、低产毛竹林施用硅肥的效应。试验结果表明，在中、低产毛竹林中施用硅肥是没有增产效果的；土壤中有效硅的含量管较低，但足够毛竹生长对硅素的需要。综合诊断施肥法（DRIS）对硅素营养的诊断结果提示，即使在具有较高竹材产量的竹林中，无论施用N、P、K三要素肥料与否，硅的营养况仍然是接近适宜水平的。鉴于中因大多数竹林的实际情况，认为目前生产上尚无施用硅肥的必要。     

Lithium chloride solution as an extraction agent for soils

The author proposes the extraction of mobile (”︁available”) ions including heavy metals by means of a 0.4 M solution of LiCl. The accuracy and precision of the method are demonstrated and the results compared with the CaCl₂ and BaCl₂ extraction. The suspension pH of non-calcareous samples remains almost constant during LiCl-extraction but changes considerably with NH₄NO₃- and NH₄-acetate. The results of the LiCl- and the CaCl₂-extraction were closely correlated. The same was true for the relative cation distribution on the sorption complex compared to the BaCl₂-extraction. A series of arguments emphasize and substantiate the advantages of the use of neutral salts, especially LiCl, for extraction.     

酸性土壤有效砷提取方法研究

采用0.5mol·L-1NaHCO3(pH8.5),0.5mol·L-1NaH2PO4和0.1mol·L-1HCl等3种浸提剂,对福建省酸性水稻土和酸性菜地土壤有效砷的提取效果以及相关的提取条件进行了研究。结果表明,3种浸提剂所提取的土壤有效砷与作物可食用部分砷含量之间均存在显著相关,其中0.5mol·L-1NaH2PO4提取的有效砷与糙米和蔬菜地上部砷含量的相关性最高,相关系数分别是0.628和0.824,是三者中最佳的浸提剂。对NaH2PO4的提取条件的研究表明,在15∶1的液土比条件下以250r·min-1的速度振荡120min是最佳的酸性土壤有效砷的提取方法。     

Si3N4/TiCnano制备中Y2O3-Al2O3的影响机理研究

采用Y2O3-Al2O3复合烧结助剂制备Si3N4／TiCnano复合陶瓷材料,研究了Y2O3与Al2O3的配比、烧结助剂体积分数对纳米复合陶瓷材料力学性能、致密化进程和显微结构的影响,并利用SEM等手段对其影响机理作了探讨。研究结果表明：烧结助剂的配比、体积分数影响到烧结体中液相的量和粘度等,并进一步影响到材料的致密化进程和显微组织,材料致密化程度的提高和显微结构的改善是其力学性能提高的根本原因。