汉语思维方式及写作经验在中国学生英语写作中的迁移现象

语言迁移现象会在语言学习的各个方面发生，正迁移对英语学习有促进作用，负迁移则有阻碍作用。写作教学是外语教学中的难点之一和薄弱环节，更容易发生负迁移。运用对比错误分析方法，对中国学生写作时容易发生的汉语负迁移现象进行了分析，试图对我国英语写作教学的改进提供一己之见。     

N、P、K三要素对水稻产量的效应分析

利用数学模型研究了N、P、K对水稻产量的影响，分析了单因素效应、双因素效应和边际效应，得出三要素对产量的贡献率大小依次为：N1．2081、P1．0527、K0．8499；N和P互作明显；当P处于高水平时，N的增产效果明显。说明高N、P配合适当的K是提高水稻产量的重要途径之一。     

当前农村土地流转的问题与思考

土地流转最终是为了增加农民收入，实现土地规模经营。为此，首先，要稳定土地承包关系，维护承包方土地流转的主体地位，其次，要刺激土地需求，扩大土地供应量。这样，一方而，土地转入户的收入能明显增加;另一方面，大量的农民能离开土地，另辟新业。同时，也要求政府应树立农业保护观念，切实改善农业基础设施，为土地流转提供物质条件。     

影响克隆牛生产效率之因素研究

为了提高牛体细胞克隆的效率,比较了不同融合电压对核移植胚发育的影响,其中1.7kv/cm电场强度,获得了较高的融合率、卵裂率和囊胚率,分别为67.14%,76.59%和29.16%。比较了血清饥饿处理体细胞对核移植效率的影响,血清饥饿处理体细胞后,融合率、卵裂率和囊胚率分别为68.91%,74.79%和28.26%,与非血清饥饿处理的相比没有明显差异(分别为60.96%,71.91%和20.31%,P>0.05)。而且胚胎移植后的怀孕率和产犊率也没有差异(分别为29.17%,8.33%和33.33%,16.66%,P>0.05)。另外,通过加强克隆牛的产后护理,可以提高克隆牛的成活率。总之,优化生产克隆牛的各环节因素,可以从整体上提高克隆牛的生产效率。     

和田绿洲蒸发能力预测的多因素GM(1,3)模型

在灰关联分析的基础上，找出了影响和田绿洲蒸发能力变化的主要影响因子为平均气温与相对湿度。根据灰色GM（1，N）建模原理，对和田绿洲蒸发能力建立了GM（1，3）预测模型，经检验模型预测结果较好，同时也说明了GM（1，N）模型在中长期水文预报中的适用性。     

羊胚胎生物技术研究进展及应用

阐述了胚胎移植、胚胎冷冻、胚胎分割、胚胎性别控制及体外受精等胚胎生物技术在养羊业的研究进展及应用现状。     

氮钾锌肥配施对玉米地上部分养分的积累与分配的影响

选用对玉米产量有重要作用的氮和被称作为品质元素且与氮有明显交互作用的钾, 以及在北方地区植物和人体共同缺乏的锌为肥源因子, 采用二次通用旋转回归组合设计的试验方法, 定量探讨了氮、钾、锌肥配施对玉米地上部分氮、钾、锌含量和分布的影响, 为北方地区玉米高产、优质提供合理施肥依据。     

Effects of nitrogen rate and ratio of base fertilizer and topdressing on uptake, translocation of nitrogen and yield in wheat

Application of nitrogen (N) fertilizer is one of the most important measures to increase grain yield and protein content in winter wheat (Triticum aestivum L.) production. However, misuse of N Tertilizer will not only affect gram yield and quality, but also cause the decline of economic benefits and related negative environmental effects. It is essential to study reasonable N application regimes for profitable yields, efficient N utilization and reduction in possible environmental pollution. The objective of this study was to determine the N uptake and translocation in wheat plants by using ¹⁵N isotope tracers in PVC cylinders (2.05 m long, ϕ 0.2 m, without bottom) in seven treatments: without N fertilizer application (N0); N application rate of 168 kg/hm² (0.527 g/pot), with ratios of base fertilizer to topdressing of 1:1 (N1), 1:2 (N2) and 0:1 (N3); N application rate of 240 kg/hm² (0.753 g/pot), with ratios of base fertilizer to topdressing of 1:1 (N4), 1:2 (N5) and 0:1 (N6). The ¹⁵N tracer experiment showed that the main basal N absorbed by plant from sowing to jointing stage accounted for 78.04%–89.67%; fertilizer N use efficiency (FNUE, N fertilizer accumulation in plant/N supplied) of topdressing was significantly higher than that of basal N; reducing basal N amount and increasing topdressing N amount could appropriately promote the plant’s absorption of more N fertilizer and enhance FNUE, of which treatment N2 had the highest values. Under the high-yield condition, when N fertilizer rate was increased from 168 to 240 kg/hm², there were no significant differences in the amount of N accumulation in plants and in grains between treatments with the same ratio of base fertilizer to topdressing; by reducing basal N amount and increasing topdressing N amount accordingly, the translocation efficiency (TE, accumulation amount from vegetative organs to gram/N accumulation in vegetative organs during anthesis) increased, and the amount of N assimilation to grains after anthesis and its contribution proportion (the amount of N assimilation to grains after anthesis/N accumulation in grain) also increased. In other words, grain N accumulation amount increased with increasing amount of topdressing N at the same N fertilizer rate. There were no significant differences among treatments N2, N3, N5 and N6 in grain N accumulation. Appropriate N fertilizer rate with a reduction in basal N amount and an increase in topdressing N amount such as in N2, N5 and N6 increased grain yield and protein content. In conclusion, under conditions used in this experiment, as far as grain yield, protein content and FNUE are concerned, the recommended appropriate N fertilizer application regime is treatment N2, with a N fertilizer rate of 168 kg/hm² and a ratio of base fertilizer to topdressing of 1:2. Translated from Journal of Acta Agronomica Sinica, 2006, 32(12): 1860–1866 [译自: 作物学报]     

竖直管道两种油品顺序输送的传质数值研究

通过建立顺序输送混油模型,并利用流体力学计算软件PHOENICS进行数值求解,分析了输送次序对竖直上坡管道与下坡管道混油的影响。研究结果表明,密度对竖直管道顺序输送过程中层流底层的影响比较明显,并且大于粘度影响,不可忽略。同时,发现粘度小的油品前行所形成的混油段长度不一定比输送次序相反所形成的混油段长度短。该研究结果对于研究我国西部地形复杂地区的顺序输送管道混油问题具有理论指导意义。     

埋地管道传热试验方案

根据相似理论设计埋地管道传热试验,并模拟沙箱底部及顶部环境、热油及沙子含水情况,研究热油管道周围沙体的温度分布,以解决实际生产中所遇到的热油管道稳态输送与停输后的非稳态温降场的问题。该试验装置可以模拟管道在不同状态下的温度分布情况。