Nitrate leaching in a silage maize field under different irrigation and nitrogen fertilizer rates

Quantification of the interactive effects of nitrogen (N) and water on nitrate (NO₃) loss provides an important insight for more effective N and water management. The goal of this study was to evaluate the effect of different irrigation and nitrogen fertilizer levels on nitrate-nitrogen (NO₃-N) leaching in a silage maize field. The experiment included four irrigation levels (0.7, 0.85, 1.0, and 1.13 of soil moisture depletion, SMD) and three N fertilization levels (0, 142, and 189 kg N ha⁻¹), with three replications. Ceramic suction cups were used to extract soil solution at 30 and 60 cm soil depths for all 36 experimental plots. Soil NO₃-N content of 0-30 and 30-60-cm layers were evaluated at planting and harvest maturity. Total N uptake (NU) by the crop was also determined. Maximum NO₃-N leaching out of the 60-cm soil layer was 8.43 kg N ha⁻¹, for the 142 kg N ha⁻¹ and over irrigation (1.13 SMD) treatment. The minimum and maximum seasonal average NO₃ concentration at the 60 cm depth was 46 and 138 mg l⁻¹, respectively. Based on our findings, it is possible to control NO₃ leaching out of the root zone during the growing season with a proper combination of irrigation and fertilizer management.     

第8届国际甜椒圃地试验报告

从6个方面对参试品种进行了比较分析，结论认为：除ISPN8#3在陕西岐山试验地表现差以外，其余品种（系）均表现优良。     

可信计算系统（TCG）

本文叙述了可信计算系统的概念并提出对可信计算系统的不足和改进     

美国黑人英语语言特征在电影对白中的表现及分析

屡次被贴上“蹩足英语”标签的美国黑人英语（AAVE）在美国文化发展中所起的作用不容质疑，黑人英语作为黑人文化的源泉一直受到语言学家及社会学家的关注。文中围绕美国黑人英语中BE不变体、否定、嘲讽及黑人俚语运用等典型语言特征，以系列好莱坞经典黑人电影对白为素材，分析了美国黑人英语的“黑人味”。指出作为一种成熟的英语变体，美国黑人英语独特的语言体系及其蕴含的丰富黑人文化元素对研究美国多元文化的变迁具有重要意义。     

二氯异氰脲酸钠处理对香石竹切花的保鲜效应

 就杀菌剂二氯异氰脲酸钠（Sodium dichloroisocyanurate，DICA）处理对瓶插香石竹(Dianthus caryphyllus L.) 切花的保鲜效应进行了初步探讨。结果表明：与对照（蒸馏水）相比，15.4和77.0 mg·L^-1 DICA处理可使香石竹切花的瓶插寿命分别延长6.0 d和6.8 d，但后者对观赏品质有不利影响；DICA处理有利于减缓切花茎基部水分导度下降, 维持花枝的水分吸收和鲜重，尤以15.4 mg·L^-1 DICA处理为佳；细菌计数试验和抑菌圈试验表明DICA处理可有效抑制瓶插液中微生物的生长。     

荷电喷雾改善烟气脱硫效果的机理及试验

为了研究荷电喷雾对湿法烟气脱硫的增益作用,探讨荷电雾滴表面特性、荷电特性及运动特性与传质的关系,采用石灰浆荷电雾化的方法进行了荷电喷雾烟气脱硫试验,获得了不同液气比、Ca/S摩尔比和荷电电压下的烟气脱硫效率.结果表明：脱硫效率随着液气比、Ca/S摩尔比、荷电电压的增大而提高,且提高的趋势都在逐渐变缓,提高幅度最大为10%.高压静电场的存在改善了雾滴的表面吸收特性,增加了雾滴表面Ca2＋的含量;荷电雾滴表面张力的减小降低了气体的传质阻力;雾滴带电及非过剩电荷感应极化作用,增加了雾滴吸收SO2的附加作用力;此外,高压静电作用下的二次雾化减小了雾滴粒径,增大了气液接触的总面积;带有同种电荷雾滴之间的相互排斥,雾滴在脱硫塔内部分布均匀.以上诸因素都有利于烟气脱硫效果的改善.     

Effect of ABA,arginine and sucrose on protein content of date palm somatic embryos

Abscisic acid (ABA), arginine and sucrose were evaluated for their effects on the morphology, germination rates and protein content of date palm somatic embryos (SE). Different concentrations of these supplements in the culture medium were used. The comparative study of SE length and thickness between treated and untreated SE revealed no differences, except for ABA (20 μM), which increased thickness. A decrease of water content (WC) in favor of an increase in dry weight (DW) was observed in all treated SE, especially with sucrose (90 g l⁻¹) and ABA (20 μM). Only ABA (20 and 4 μM) caused a proliferation rate of the cultures higher than those in the control. Although all the tested compounds increased protein content, ABA (20 μM) was more effective in protein enrichment than arginine and sucrose treatments. The SDS-PAGE protein profiles showed a significant difference between treated and untreated SE. A protein band of 22 kDa, identified as glutelin in a previous work, was accumulated after treatment with 20 μM ABA or 3 mM arginine. These findings may contribute to further understanding of the mechanisms involved in the accumulation of specific storage proteins in several plants.     

俄罗斯沙棘优良品种引种试验研究

“三北”地区和黄土高原是中国沙棘亚种的分布中心，现已有大面积人工沙棘林，但其果小、刺多，产果量低，采果难。为此，作者于1997－2006年承担水利部“948”沙棘引进项目，以解决该地区沙棘优良品种缺乏问题。通过8年试验研究，引进俄罗斯大果无刺沙棘优良品种、类型40余种，分别在“三北”和黄土高原地区的7个主要试验基地进行引种试验，从中初步筛选出效果较好的9个优良品种、类型。它们生长发育良好，抗性较强，具高产、优质特性，并已开始利用引进的俄罗斯沙棘与当地中国沙棘杂交，培育出第一代杂交种。在引种选育和对俄罗斯沙棘生物生态学特性进行试验研究的基础上，对其良种的集约栽培和繁育做了试验和示范推广工作，产生了良好的生态、经济效益。通过本项目实施，为做好沙棘引种选育工作提供了良种，这对大面积建造高产、优质人工沙棘林和沙棘果园，加速黄土高原和“三北”地区的环境治理、发展地方经济具重要意义。     

均匀设计法优化金线吊葫芦黄酮类化合物乙醇提取工艺

以提高金线吊葫芦提取液中黄酮类化合物质量浓度为考察指标，采用单因素试验方案探讨乙醇体积分数、提取温度及提取时间等对提取液中黄酮类化合物浓度的影响，应用均匀试验设计方案对影响提取液中黄酮类化合物浓度的主要因素水平进行优化．结果表明：优化的因素水平组合为乙醇体积分数55％，提取温度74℃，提取时间50min，黄酮类化合物质量浓度为0.106g·L^-1．     

土壤与植物根际磷的有效性研究

本文论述了影响土壤与植物根际磷的有效性的因素有其机理，为合理分配和施用磷肥提供了科学依据。