High performance flame-retardant composite yarns with oxidized fiber

This study employed a SKF draft system equipped with an additional spreading device to form a high performance flame-retardant composite yarn. For mixing the spread Technora® filaments and Stretch-Broken oxidized fibers, nip of the front rollers was arranged for best dispersion. The yarn unevenness (CV %), strength, abrasion-resistance, and Limited Oxygen Index (LOI) of the composite yarn were evaluated. The cross-sections of the actual composite yarn were observed to assess its structure and the effect on yarn performance. The experimental results showed that the yarn CV% is worse as the yarn count (Tex) tend to be finer. This would be an optimum condition adopting 30 TM for the yarn evenness and yarn strength. After abrasion test, the residual strength of composite yarns remains above 80 %. The LOI value depends on the coverage degree of oxidized fiber outside the yarn surface, and there tended to be a lower LOI value with finer yarn count (Tex). Overall, the T/O composite yarn with uniform distribution structure can provide high performance and flame-retardancy.     

槟榔基因组DNA提取方法及RAPD分析体系的初步优化

采用CTAB法、改良CTAB法和高盐低pH法等3种不同的方法比较了槟榔基因组DNA提取的效果,其中改良CTAB法最优,提取的DNA质量高,DNA降解少,杂质含量少。通过对退火温度、DNA模板用量、TaqDNA聚合酶浓度等因素的优化实验,建立了槟榔RAPD分析体系,从PCR扩增程序和反应体系两个方面对槟榔RAPD分析体系进行了优化并验证了优化后的体系扩增谱带清晰、多态性强稳定性好。     

Nitrous oxide emissions from paddy fields under different water managements in southeast China

Water management is recognized as one of the most important factors in regulating nitrous oxide (N₂O) emissions from paddy fields. In China, controlled irrigation (CI) is widely applied because it has been proved highly effective in saving water. During the rice-growing season, the soil in CI paddy fields remains dry 60–80% of the time compared with soil irrigated by traditional methods. This study aims to assess N₂O emissions from paddy fields under CI, with traditional irrigation (TI) as the control. The cumulative N₂O emission from CI paddy fields was 2.5 kg N ha⁻¹, which was significantly greater than that from TI paddy fields (1.0 kg N ha⁻¹) (P < 0.05). Soil drying caused substantial N₂O emissions. The majority (73.9%) of the cumulative N₂O emission from CI paddy fields was observed during the drying phase, whereas no substantial N₂O emissions were observed when the soil was re-wetted after the drying phase. More and significantly higher peaks of N₂O emissions from CI paddy fields (P < 0.05) were also detected. These peaks were observed ~8 days after fertilizer application at water-filled pore spaces (WFPS) ranging from 78.0 to 83.5%, soil temperature ranging from 29.1 to 29.4°C, and soil redox potential (Eh) values ranging from +207.5 to +256.7 mV. The highest N₂O emission was measured 8 days after the application of base fertilizer at a WFPS of 79.0%, soil temperature of 29.1°C, and soil Eh value of +207.5 mV. These results suggest that N₂O emissions may be reduced obviously by keeping the WFPS higher than 83.5% within 10 days after each fertilizer application, especially when the soil temperature is suitable.     

海南部分荔枝种质的ISSR分析

从74条引物中筛选出23条多态性引物,用ISSR方法对80份海南荔枝(Litchi chinensis Sonn)种质进行分子标记分析和遗传多样性研究。结果表明,大多数种质的遗传距离在0.2￣0.5之间,说明它们的亲缘关系较近。在遗传距离为0.55的水平上,80份荔枝种质被分为7组,海垦8号、琼山3号与永25单独为一组,可能属于海南的地方种质。另外,通过与SSR,RAPD等方法对比,ISSR方法应用前景较好。     

非洲菊头状花序发育时期的划分与最佳采切期

对非洲菊(Gerbera jamesonii)3个品种‘Red-Tube’(红色单瓣),‘Cora’(红色复瓣),‘Delphi’(白色复瓣)花序发育过程、维管束结构进行研究,同时结合切花保鲜试验,确定3个品种的最佳采摘期。结果表明:3个品种非洲菊花序的发育过程可分为9个时期;品种‘Red-Tube’最佳采切期为开花期的一轮露药开花期(即Ⅵ期),品种‘Cora’与‘Delphi’最佳采切期均为开花期的隐药开花期(即Ⅴ期)。这2个时期切花外观上具有较好的观赏价值,单个维管束平均面积大,韧皮纤维厚,导管数目多,具有较强的输导功能与机械支持作用。     

菜地重金属污染的标准值分析与治理对策

参照通用标准值,检测与评价福州市郊22个蔬菜地土样的镉(Cd)、铅(Pb)、汞(Hg)、砷(As)4种重金属,从污染范围和程度上阐明蔬菜基地污染现状。结果表明,Pb,As未超标,污染指数分别为0.01～0.64和0.02～0.11;Cd的污染指数为0.17～29.0,但大多在6～10之间,表现出污染面广、污染程度重;Hg的污染指数为0.47～9.0,但大多为1.5,虽表现出污染面广,但污染程度相对较轻。由于这4种重金属之间并无显著的相关性(r<0.4),说明菜地重金属污染源的复杂性。灰色关联分析结果表明,菜体Cd含量与土壤Cd总量关联度最大(0.75067),菜体Pb含量与土壤pH关联度最大(0.70949),而菜体Hg,As含量与土壤有机质关联度最大(0.67921,0.76537),表明菜体某种重金属污染与否,除与土壤重金属含量有关外,还与不同土壤类型及其相关的理化性状有关。菜地污染标准值应以是否造成菜体污染为依据,即要将土壤重金属污染标准值与菜体重金属污染指标有机结合起来,并以此来合理评价菜地污染状况,提出因地制宜的治理菜体重金属污染方法。     

Application of system dynamics approach for time varying water balance in aerobic paddy fields

Increasing water scarcity has necessitated the development of irrigated rice systems that require less water than the traditional flooded rice. The cultivation of aerobic rice is an effort to save water in response to growing worldwide water scarcity with the pressure to reduce water use and increase water productivity. An accurate estimation of different water balance components at the aerobic rice fields is essential to achieve effective use of limited water supplies. Some field water balance components, such as percolation, capillary rise and evapotranspiration, can not be easily measured; therefore a soil water balance model is required to develop and to test water management strategies. This paper presents results of a study to quantify time varying water balance under a critical soil water tension based irrigation criteria for the cultivation of non-ponded “aerobic rice” fields along the lower parts of the Yellow River. Based on the analysis and integration of existing field information on the hydrologic processes in an aerobic rice field, this paper outlines the general components of the water balance using a conceptual model approach. The time varying water balance is then analyzed using the feedback relations among the hydrologic processes in a commercial dynamic modeling environment, Vensim. The model simulates various water balance components such as actual evapotranspiration, deep percolation, surface runoff, and capillary rise in the aerobic rice field on a daily basis. The model parameters are validated with the observed experimental field data from the Huibei Irrigation Experiment Station, Kaifeng, China. The validated model is used to analyze irrigation application soil water tension trigger under wet, dry and average climate conditions using daily time steps. The scenario analysis show that to conserve scarce water resources during the average climate years the irrigation scheduling criteria can be set as −30 kPa average root zone soil water tension; whereas it can be set at −70 kPa during the dry years, however, the associated yields may reduce. Compared with the flooded lowland rice and other upland crops, with these two alternatives irrigation event triggers, aerobic rice cultivation can lead to significant water savings.     

水稻中413的广亲恢性及其系列组合

 中413是从50465中经系统选育而成的广亲和恢复系。与籼型测验种IR36，南京11测交，F₁结实率分别为75.5%和80.0%；与粳型测验种秋光，Balilla测交，结实率分别为71.4%和53.2%。对野败，矮败，Dissi，马尾粘等胞质不育系均具有较强的恢复能力。以中413为广亲恢系而配制的系列组合均有较强的杂种优势，在不同地区，不同季节种植均比对照汕优63和汕优10号增产或极显著增产。作单季种植，亩产可达700 kg以上；作双晚栽培，亩产可达600 kg左右。表现为秧苗素质号，生长势旺，耐肥抗倒，穗大，叶面积系数大，物质生产力高，穗多，库源关系协调。中413系列组合不仅表现较强的杂种优势，而且较好地克服了籼粳亚种间优势利用种F1结实率偏低，籽粒不饱满，植株偏高和生育期偏长等障碍。     

原糖厂滤泥燃烧特性测定

为了了解原糖厂滤泥作为能源资源利用的可行性,根据煤的工业分析方法,测定了该滤泥的空气干燥基含水分、挥发分、固定碳、灰分含量,以及50％含水量时,收到基低位发热量.作为比较,测定了同等含水量的亚硫酸法糖厂滤泥的收到基低位发热量.测定结果为,滤泥的空气干燥基含水量为9.05％、挥发分含量60.58％、灰分含量19.58％、固定碳含量为10.78％;湿基含水量为50％的原糖厂滤泥和亚硫酸法糖厂滤泥的低位发热量分别为8700kJ/kg和7200kJ/kg,显示原糖厂滤泥具有高于水分为50％的蔗渣发热量.实验结果表明,经一定干燥后,原糖厂滤泥不失为一种低灰分、高挥发分的优良固体燃料.     

甘蔗杂交后代主要荧光性状的遗传力及配合力分析

以6×3不完全双列杂交NCⅡ）衍生的18个家系实生苗为材料,对主要荧光性状PSIⅡ原初光能转换率（FvFo）、PS Ⅱ潜在活性（FvFm）、光合量子产额（Y）、光化学猝灭系数（qP）、非光化学猝灭系数（qN）的遗传力和配合力进行分析。结果表明∶FvFo,FvFm、Y、qN、qP的遗传主要受基因的非加性效应所制约,这些荧光性状的广义遗传力（h?）变幅为27.46%个44.38%;亲本赣75-65和崖84-153各荧光性状一般配合力为正值且较大,是配合力较好的高光效亲本;根据配合力总效应,综合表现较好的高光效组合有赣75-65崖84-153,,,桂69-156×崖84-153、CP81-1254崖 84-153,CP65-357崖82-96。