杨凌城区雨水资源利用潜力计算及其效益分析

应用径流系数法分析了杨凌示范区城区雨水资源利用潜力.2007年可直接收集利用的雨水总量为123.91万m3,占该年杨凌城区总用水量的28.3%;可处理后回用的雨水总量为367.15万m3,但目前仅有占城区总面积1.98%的绿地利用雨水12.93万m3,其它均未予利用;预计到2020年,以枯水年计算,可直接收集利用的雨水总量为3 233.03万m3;可处理后回用的雨水潜力巨大.并进一步对杨凌城区实施雨水利用后可能产生的经济、社会和生态效益进行了评价分析.     

不同灌水量对温室甜瓜生长和生理特性的影响

以"一品天下208" 甜瓜为试验品种,在日光温室内进行了灌溉试验,采用20蒸发皿的日水面蒸发量为灌溉水量控制指标,设置了不同蒸发量系数(K_p=0.45;0.6;0.75;0.9)的供水处理,探求不同灌溉水量对温室甜瓜生理指标、形态指标和光合生理指标的影响.结果表明:温室内外温度的变化趋势基本相似,温室内的温度能够满足甜瓜的正常生长.不同处理的灌溉水量比值始终为T1:T2:T3:T4=0.45:0.6:0.75:0.9;从甜瓜的株高、茎粗、总生物量、根冠比等指标综合分析,采用T2(K_p=0.6)处理均优于其它水分处理,且根冠比也处于一个较高的水平;叶绿素a、叶绿素b、叶绿素总量均以T2处理最高;各处理的细胞液浓度的变化呈单峰曲线,不同处理的叶片细胞液浓度表现为T1>T2>T3>T4处理.结果表明:采用T2处理的灌溉模式有利于甜瓜在获得较高产量的前提下降低灌溉用水量.     

杀虫剂混合使用的增效作用评判分析

用共毒因子重新评价共毒系数大于100的281个混配组合,发现有29.18%的混配组合没有增效作用。根据单剂的LC-P线和共毒因子公式,求出混剂的期望死亡率和"相加作用区间"(期望死亡率±20%期望死亡率),根据混剂的实测死亡率求出95%置信区间,画出期望LC-P线及"相加作用区间"和实测LC-P线及"95%置信区间",发现当共毒系数大于100、共毒因子小于20时,实测LC-P线和期望LC-P线彼此交缠,期望LC-P线的"相加作用区间"和实测LC-P线的"95%置信区间"能高度重叠,表明两条LC-P线之间没有毒力差异;当共毒系数大于100、共毒因子大于20,或者共毒系数小于100、共毒因子小于-20时,实测LC-P线的"95%置信区间"和期望LC-P线的"相加作用区间"只有少量重叠或完全不重叠,体现出了实测LC-P线和期望LC-P线对供试害虫的毒力差异。因此,为了获得有稳定增效作用的混配组合,共毒系数须大于100,同时共毒因子也要大于20。     

黔蔗自育品种(系)基础种质的分析

对贵州自育的黔糖1号、黔糖2号、果蔗2号、黔糖3号和黔糖4号等5个品种(系)的基础种质及亲缘系数进行了分析.结果表明:供试材料含16个基础种质,其中,热带种10个,割手密2个,印度种2个,中国种1个,高粱1个.热带种亲缘系数最大的是果蔗2号和黔糖3号,均为0.687 5;最小的是黔糖4号,为0.516 5.割手密亲缘系数最大的是黔糖4号,为0.171 8;印度种亲缘系数最大的是黔糖4号,为0.312 5.基础种质和亲缘系数一定程度上决定着甘蔗品种种性的优劣.     

土壤微生物量氮与玉米氮素养分利用关系研究

通过大田试验,研究了不同施氮量下土壤微生物量氮与玉米氮素养分利用的关系.结果表明,在同一生育期内,土壤微生物量氮含量随氮肥施用量的增加而增加;在不同生育期内,土壤微生物量氮在苗期达到最高,在拔节期、孕穗期明显降低,到成熟期又有增加的趋势;与玉米在各生育时期的吸氮量呈负相关关系,且施氮量越大,负相关程度越高.土壤微生物量氮的基础含量与玉米吸氮量基本吻合(土壤有效氮素养分校正系数为96.52% ),表明其能够表征土壤的供氮能力.     

UVSG950环保节能型上光机涂布压合系统的关键技术

基于UVSG950环保节能型上光机的关键技术,对涂布压合系统的涂布厚度变动系数、疵斑点率及剥离强度进行试验研究.上光涂布压合系统新增了三辊顺转涂布刮油压合机构、精细涂布计量调节装置及精细压力调节装置,可达到涂布厚度均匀、疵斑点率低、剥离强度满足标准要求的涂布压合效果.     

词汇语用学和多义词的语用充实

多义词语用充实的研究是词汇语用学的一个重要研究领域。多义词义项的确定是在具体的语境下实现的。笔者基于 Blutner 和 Wilson 词汇语用学理论,探讨了英汉多义词的选择和理解,发现多义词的本质是经过语用充实之后,其原型意义在一定语境下的收缩和扩充,以期表明词汇语用学和一词多义现象之间的互补性关系。     

Higher crop performance of rice hybrids than of elite inbreds in the tropics: 2. Does sink regulation,rather than sink size,play a major role?

Higher harvest index, widely reported as a main trait supporting major improvements in rice yield potential, also supports the higher performance of hybrids over inbreds. Although higher sink size is generally claimed for being the driver of higher grain filling in hybrid rice, it is relevant to question whether efficient sink regulation, that is timing and magnitude of the successive sink activities over crop growth from early stage, plays a role in supporting higher harvest index and is a key feature ensuring higher performance of hybrid rice. The partitioning coefficient (PC), as the increase in dry matter of one single organ over that of shoot, was calculated over short and successive periods to quantify the dynamics of dry matter partitioning. Four hybrid and four inbred genotypes of similar crop duration were grown under the same cropping management on the IRRI farm during a wet and a dry seasons. While PC to blade and sheath was similar for both plant types in both seasons at the early stage, PC to culm of hybrids was higher than that of inbreds, and PC to blade was lower, in the late vegetative and early reproductive phases. During the late reproductive phase, PC to panicle of hybrids was higher than that of inbreds, and PC to culm was lower whereas culm elongation was similar for both plant types. During grain filling, PC to culm was significantly more negative with hybrids which indicated stronger remobilization with hybrids. Specific culm length before anthesis, as low as 40 cm g⁻¹, accounted for storage ability, and at maturity, as high as 130 cm g⁻¹, for remobilization ability. Sink strength index, as a better indicator of dry matter partitioning efficiency than harvest index, and unfilled grain size, as an indicator of assimilate wastage, were suggested as key indices to account for the better sink regulation in hybrid rice and to improve screening protocols for increasing yield potential and tolerance to lodging.     

Optimization of air classification for the production of β-glucan-enriched barley flours

Barley grains contain a relevant amount of soluble fibre (i.e. β-glucans) and can be used for production of foods with healthy functions. To produce barley flours enriched in β-glucans, grain micronization and air classification of the flour was used, and a method to predict the relationship between the yield of the enriched flour and its β-glucan content was developed. This method is based on a series of sortings of micronized flour, with a progressive increase in the yield of a selected fraction; a curve for β-glucan enrichment vs. yield can then be calculated. Thus, the most suitable combination of yield and β-glucan content can be chosen. We tested this approach on two hull-less barleys with different starch type, and obtained barley flour fractions with twice the β-glucan concentration that the grain had. Enriched flour fractions with 11.2 and 15.6% β-glucans were obtained from cultivars Priora (hull-less) and CDC Alamo (waxy, hull-less), respectively, with a good flour yield (about 30%). We suggest that our method can be adopted for finely tuning the enrichment process to meet the industry's needs.     

中华绒螯蟹部分基因组文库构建和微卫星位点的筛选

利用磁珠富集和放射性杂交相结合构建了中华绒螯蟹基因组微卫星文库.并利用生物素标记的(GA)12探针进行微卫星片段的富集.将得到的片段与pGEM-T载体连接后转入DHSα大肠杆菌中,然后利用γ-32P同位素标记的(GA)12:探针进行第二次筛选.结果共获得微卫星基因组文库1 500个菌,杂交前菌落PCR检测阳性克隆率为62.5%;杂交后得到的阳性克隆为447个,占29.8%.经测序,有248个克隆含有重复次数大于5次的微卫星序列.在得到的微卫星序列中,重复单元除GA/CT外,还观察到三碱基、四碱基重复单元.根据侧翼序列没计引物164对,选择合成50对,通过优化PCR反应条件,结果有21对引物可扩增出清晰可重复的目的条带,15对具有多态性.本研究对中华绒螯蟹基因组资源的开发利用提供了相关资料.