离子色谱法同时测定水中7种阴离子的研究

[目的]为了检测水中F-、Cl-、NO-2、Br-、NO-3、PO3-4、SO2-4,建立了一种快速、灵敏的采用离子色谱同时测定水中7种阴离子的方法。[方法]以4.5×10-3mol/L Na2CO3+8.0×10-4mol/L Na HCO3为淋洗液,流速为1 ml/min。[结果]在系列浓度范围内,7种阴离子峰面积与浓度之间具有良好的线性关系(r2≥0.997 9),加标回收率为82.39%~109.19%。[结论]采用该方法,在25 min内7种阴离子能够完全分离。该方法具有准确、快速、重复性好的特点。     

赣江水体无机氮分布特征

于2013年1月（枯水期）、6月（丰水期）对赣江干流及主要支流的24个采样点进行水样采集,分析研究了赣江水体NO3--N、NH4＋-N以及NO,--N的时空分布特征.结果表明,赣江水体无机氮的主要形式为NO3--N,约占78％,其次为NH4＋-N,NO2--N含量很小,平均浓度低于0.02 mg/L.赣江枯水期NO3--N平均含量为1.86 mg/L,略高于丰水期的1.74 mg/L;枯水期NH4＋-N含量为0.59mg/L,高于丰水期的0.45 mg/L.枯水期赣江流域上游到下游NO3--N和DIN含量呈现先下降后逐渐上升的趋势,NH4＋-N含量在赣州附近出现最大值,其次在南昌下游赣江南支,其他地区含量较小,反映了城市污水排放对NH4＋-N的影响.丰水期上游至下游NO3--N含量呈逐渐下降趋势,但降幅不大,NH4＋-N含量变化趋势与枯水期相似.主要支流中枯、丰水期以S06样点（桃江）的DIN含量和NO3--N含量最高,主要原因为桃江流域农业化肥的氮输入;其次为S18样点（袁水）,可能与新余市大量排放工业废水有关.     

西藏自治区灌木林碳储量估算

青藏高原独特的地形地貌和高、旱、寒的自然特征促进了灌木的生长和广泛分布,作为森林资源不可或缺的组成部分,灌木林在林业生态建设和应对气候变化中发挥了重要作用。近年来西藏自治区加大了生态保护的力度,采取了封山育林等措施保护和促进灌木林资源发展。估算灌木林碳库及碳汇,对于充分认识灌木林的重要地位,发挥灌木林在固碳增汇中的重要作用及评估西藏自治区生态建设成效都具有积极意义。     

Dietary phytase supplementation and the utilisation of phosphorus by Atlantic salmon (Salmo salar L.) fed a canola-meal-based diet

The effect of phytase supplementation to a canola-meal-based diet on phosphorus utilisation in Atlantic salmon was studied in a two-by-two factorial design. Diets were prepared without phytase or inorganic phosphorus supplementation, with phytase, with supplemental inorganic phosphorus and with both phytase and supplemental inorganic phosphorus. Available phosphorus was set below requirement and the total phosphorus set to meet requirements for salmonids. After 12 weeks, there were no significant differences in survival, feed intake and weight gain between diets. There was an interaction effect between supplements on bone ash, bone phosphorus and whole-body phosphorus so that adding phytase, inorganic phosphorus, or both resulted in significantly (P<0.05) higher values for these parameters. An interaction effect was also observed for phosphorus digestibility, phosphorus retention efficiency and phosphorus load. Phosphorus digestibility and retention efficiency were significantly (P<0.05) higher, and phosphorus load was significantly (P<0.05) lower in fish fed the phytase supplemented diet compared with diets containing supplemental inorganic phosphorus. In conclusion, phytase increased phosphorus availability, therefore reducing the need to add inorganic phosphorus and reducing phosphorus waste from plant-meal-based diets for Atlantic salmon.     

青海高原早熟禾有益内生真菌营养生理特性的初步研究

禾草有益内生真菌是一种极具开发潜力的真菌,本实验从碳源、氮源、无机盐(Na Cl、Mg SO4·7H2O)、生长因子,单因子、正交这五个实验对禾草内生真菌进行摇床培养,p H均为自然。单因子实验培养选出最佳碳源为可溶性淀粉,其次为蔗糖、麦芽糖、山梨醇;最佳氮源为蛋白胨,其次为酵母膏、硝酸钾、硫酸铵;无机盐中Na Cl最佳浓度为2.5g/L,Mg SO4·7H2O最佳浓度为0.75g/L,最适生长因子是麸皮;通过正交实验研究了有益内生真菌营养生理特性液体培养基配方,筛选出适宜有益内生真菌菌丝体生长的最佳液体培养基配方为可溶性淀粉25 g/L,蛋白胨6g/L,Na Cl2.5 g/L,Mg SO4·7H2O0.5g/L。     

陆地棉高品质纤维种质基因库的拓建

采用远缘杂交,开展了棉属野生种的高强纤维潜力基因向陆地棉品种转育研究,以构建高纤维品质的种质基因库.在适宜的自然条件和人工条件下,陆地棉分别与异常棉(Gossypium anomalum)、辣根棉(G.armourianum)、雷蒙德氏棉(G.raimondii)等杂交,克服杂交不可交配性、杂种一代的高度不育性等,通过多年的回交选择和纤维品质测定筛选,     

EXPERIMENTAL INVESTIGATION ON BOILING HEAT TRANSFER OUTSIDE THE LOW FINNED TUBE WITH SHROUD

Based on analysis of pool boiling characteristics outside low finned tube, this paper describes a simple method, using enhancing shroud to improve the performance of boiling heat transfer outside the low finned tube. The experiment results show that the boiling heat transfer coefficient can be 7-up to 10-fold enhanced by using shroud. The efficiency of a shroud is related to the size of two windows, heat flux and physical characteristics of test fluids.     

Genetic diversity of Brassica carinata with emphasis on the interspecific crossability with B. rapa

Brassica carinata (BBCC, 2n = 34) possesses many good agronomic characters and, to provide more genetic information about this species and utilize it further, 110 accessions of B. carinata were tested for genetic variation by using 233 amplified fragment length polymorphism markers, so that a dendrogram could be constructed. To combine the good traits of B. carinata and B. rapa (AA, 2n = 20) with those of B. napus (AACC, 2n = 38) which is the major rapeseed variety in China, interspecific crosses between these two species have been made which have resulted in 276 doubled hybrids (AABBCC). These hexaploids combine positive characters and can be used for crossing with B. napus . Brassica carinata as the female parents exhibited extensive differences in interspecific crossability and 20 high crossability accessions were identified. The Poisson Regression Model analysis result (P < 0.0255) indicated that such differences were due to the genotype of the accessions. Accessions with high crossability could promote gene flow within the genus Brassica .     

Variation in relation to geographical distribution of wild oats-seed traits

Summary A sample of 457 wild oats (Avena sterilis L.) from the world collection maintained at the Germplasm Laboratory, Beltsville, Maryland, USA, was studied for variation of six seed characters via means, ranges, variances, and frequencies from various geographical areas. It was concuded that region-specific adaptations are responsible for occurrence of certain trait(s) in specific geographical regions; e.g., Libyan and Iraqi collections had high protein percentage, Israeli strains had high oil percentage, and the Middle East and Central Asian lines had a high number of spikelets per panicle. The main conclusion of interest here is that, within the same species, estimates of the amount of variation may vary widely, depending upon the area sampled, geographical scale of sampling, etc., presumably due to the complex interrelationship between genetic and ecological factors.Journal Paper No. J-12670 of the Iowa Agric. and Home Econ. Exp. Stn., Amers, Iowa, Project 2447.     

Genetic diversity of wheat gene pool of recurrent selection assessed by microsatellite markers and morphological traits

Abstact An agronomic gene pool of wheat (Triticum aestivum L.) was constructed through recurrent selection. In present research, 24 wheat SSR markers determining 25 loci on 14 different chromosomes were used to evaluate the gene pool. Thirty parents used as original materials in recurrent selection were also assessed. In total, 115 alleles were detected in gene pool with an average of 4.6, ranging from 2 to 9 alleles per locus. Statistical test showed that genetic diversities had no significant difference between the gene pool and the 30 parents. Principle coordinates analysis revealed that the individuals of the gene pool were mainly divided into three groups, which was consistent with the result of cluster analysis based on genetic distance matrix of the gene pool. Cluster analysis was carried out based on Euclidian distance calculated upon five morphological trait values and the results showed that most individuals were in a group while the others scattered. Correlation analysis of genetic distance matrix and Euclidian distance matrix showed no significant correlation between two matrices. The results suggest that the gene pool is improved after several cycles of selection, while genetic variation is still maintained. Therefore, the gene pool is suitable for further breeding program.