化学打顶剂在甘肃棉花上的应用效果

2015年在甘肃敦煌植棉区,应用2种化学打顶剂进行不同施用时间和剂量的田间试验表明,土优塔化学打顶剂在6月28日前后、以900 mL·hm^－2的剂量使用,对棉花有较好的封顶效果,对产量及产量构成因子和纤维长度影响不大。2016年示范结果与2015年试验一致     

排种器振动种盘内种群质量实时监测方法

采用悬臂梁称重传感器测量排种器振动种盘内种群的冲击力,在分析不同参数下输出信号变化特征的基础上,设计了由加法器、精密半波整流、二阶巴特沃斯低通滤波和差动放大串联组成的信号处理电路,实现了振动状态下种群质量的实时监测。在振动种盘试验台上进行了性能试验,设定振幅为3、4、5mm,相应振动频率分别在11~13Hz、10~12Hz、9~11Hz范围,结果表明:当单位面积籽粒质量κ1.8 g/cm2时,信号处理电路输出电压Vout与κ的非线性误差小于5.5%;当κ2.0g/cm2时,由于种群振动运动的不稳定导致输出电压Vout的波动性增强,测量的非线性误差增大。信号处理电路零点输出电压随种盘振动强度的提高而增大,测量灵敏度随种盘振动频率的提高而降低,籽粒形状和力学特性差异对测量结果的影响可以被忽略,监测方法具有很好的适应性。     

基于数据包络分析的灌区农业生产综合效率评价与分析

为评价中国灌区农业生产综合效率的空间差异性,采用数据包络分析(Data envelopment analysis,DEA)方法对全国440个灌区2010年的农业生产综合相对效率进行评估,并基于不同区域灌区农业生产投入及其冗余状况对生产效率提升途径进行探索。结果表明,8个灌区的相对效率为1.000,达到DEA有效;灌区间农业生产效率差异显著,绝大部分(327个)不足0.300,省区尺度生产效率无明显空间分布规律;各投入指标对应存在冗余灌区个数分别为319(有效灌溉面积)、369(绿水)、155(蓝水)、298(化肥)及207(农业机械);非DEA有效灌区5个投入指标的可减少量占所有评价单元投入总量的比例分别为23.8%、39.2%、18.1%、29.0%以及19.9%。综上可知,各非DEA有效灌区应根据自身投入指标冗余状况优化配置和管理资源以提高区域综合农业生产效率,其中绿水资源高效利用是全国范围内广泛面临的问题;东北和西北地区需注重水土资源配置效率提升,而南方粮食主产区应注重水肥高效利用机制的研究与实践。     

Fabrication of hydrophobic/oleophilic cotton fabric by mussel-inspired chemistry for oil/water separation

A straightforward approach was proposed to modify cotton fabric for oil/water separation based on musselinspired reaction. The poly(DMA-Octadecyl acrylate) was designed to contain key chemical constituents present in mussel adhesive proteins by free radical polymerization of dopamine hydrochloride and octadecyl acrylate, which strongly adsorbed to fabric substrates, providing a special surface for fabric. The chemical structure, surface topography, and surface wettability of the fabric were characterized. The results showed that as-prepared cotton fabric displayed a high CA of >150° when dripped water droplets were on the modified fabric surface, and the oil contact angle (OCA) was close to 0°, it had excellent potential to be used in practical applications and has created a new method of fabric modification for oil/water separation.     

Optimization of curing process for polymer-matrix composites based on orthogonal experimental method

In this paper, the orthogonal experimental method was carried out to optimize the curing process of aeronautical composite X850/T800 in autoclave process. Four important curing parameters including curing pressure, heating rate, curing temperature and heat preservation time were taken into account, and sixteen samples were fabricated to study the effects of the four parameters mentioned above on the curing quality by interlaminar properties test and microstructure analysis. The interlaminar properties and the interfacial bonding quality of these samples were studied by the short-beam three points bending test and scanning electron microscopy, respectively. Results revealed that the optimal curing process of X850/T800 composite laminate should be as follows: curing pressure of 0.6 MPa, heating rate of 1.5 °C/min, curing temperature of 160 °C, and heat preservation time of 120 min.     

木麻黄与根系微生物关系研究进展

木麻黄是我国沿海防护林基干林带中的主栽树种,与土壤中的微生物可以形成共生关系,提高自身耐干旱、抗贫瘠、抗盐碱等适应恶劣环境的能力。土壤中的细菌和真菌能够与木麻黄根系形成稳定的相互作用的微生态系统,其中微生物主导的物质代谢循环是植物获取营养的主要来源之一,反之木麻黄的根系分泌物可以为微生物的生长提供养分。文中综述了木麻黄与根系微生物之间相互作用的相关研究,尤其是接种弗兰克氏菌（Frankia）及菌根菌提高木麻黄抗逆性方面的研究进展,对木麻黄与根系微生物体系的促生、抗逆机制进行了探讨和展望。     

A field experiment on stabilization of Cd in contaminated soils by surface-modified nano-silica (SMNS) and its phyto-availability to corn and wheat

Journal of Soils and Sediments - Cd-contaminated soil is a common environmental problem. Stabilization is an effective way of in situ remediation for Cd contamination in soils, but there is a lack...     

Composition of clay minerals and their pedogenetic and taxonomic implications for Stagnic Anthrosols derived from different parent materials in Hunan Province,China

Purpose

The aims of this study were to investigate the composition of clay minerals in soils derived from different parent materials and to elucidate how parent materials and pedogenic environment affect the distribution of clay minerals and reveal the implications for pedogenetics and taxonomy in Stagnic Anthrosols.

Materials and methods

Clay mineralogy and physicochemical properties of the Hydragric horizon of Stagnic Anthrosols derived from granite (GR), plate shale (PS), quaternary red clays (QRC), limestone (LS), purple sandy shale (PSS) and fluvial-lacustrine deposit (FLD) located in Hunan Province of China were analysed to explore the relationships between the conditions influencing the formation of the soil and the composition of clay minerals.

Results and discussion

Results indicated that the composition of clay minerals is closely related to both parent material and type of Stagnic Anthrosols: the soils derived from GR, PS and QRC, which are mostly classified as Fe-accumulic-Stagnic Anthrosols, are dominantly 1:1 type kaolinite and vermiculite and illite/vermiculite mixed layer minerals of widespread distribution. However, soils derived from LS, PSS and FLD were mainly classified as Hapli-Stagnic Anthrosols and are mainly composed of 2:1 type illite/smectite mixed layer minerals, where chlorite is commonly found. Illite is widely distributed and its content varies the least among different parent materials. An extremely significant relationship between pH and kaolinite, chlorite and mixed layer minerals was noted, and the two kinds of mixed layer minerals showed highly significant negative correlation.

Conclusions

This study revealed that the types and quantities of clay minerals in the soil are closely related to the types of parent material. This reflected better direction and degree of development in Stagnic Anthrosols, which is related to the physicochemical properties of parent material and can be used as one of the bases for the classification of soil groups and subgroups within the soil family for Stagnic Anthrosols in Chinese Soil Taxonomy.

     

天然棕色棉纤维色彩遗传特性的定量分析

将深棕色棉品种与白色棉杂交,观察F1代和自交F2代棉纤维的颜色表现,并且测定了各世代植株棉纤维中的色素含量。杂交F1代棉纤维的颜色介于两亲本之间,自交F2代可以分为3类:深棕色类型、中棕色类型和白色,F2代深棕色类型棉纤维的颜色和纤维中色素含量接近亲本棕色类型,F2代中棕色类型棉纤维的颜色和纤维中色素含量与F1代较一致,F2代3种类型经过卡平方检验符合1:2:1的比数(p>0.05),所以棉纤维棕色对白色为不完全显性遗传。讨论了质量性状与"修饰基因"的关系,有助于天然彩色棉的品种选育和新色彩品种的培养。     

Bt转基因抗虫棉田昆虫群落结构研究

选用3个转Bt基因抗虫棉品种DP99B、20B、1560BG和2个非抗虫棉对照品种鄂杂棉1号、湘杂棉2号,比较研究了不同棉花群体中昆虫群落结构特征。结果表明,在未采取任何防治措施的情况下,3个转Bt基因抗虫棉对棉铃虫种群,尤其是在棉花生育前期有很好的抑制作用;同时对其他鳞翅目害虫种群也有一定控制效果,这使得棉蚜、棉叶蝉、烟粉虱等刺吸式害虫上升为主要害虫。但抗虫棉棉田昆虫群落、害虫亚群落以及天敌亚群落的多样性、均匀性均较对照棉田小,而优势集中性比对照棉田高,反映出抗虫棉棉田昆虫群落结构稳定性较差。相对来说,DP99B和20B抗虫性能较好,其棉田昆虫群落结构也比较稳定。因此,转Bt基因抗虫棉的大面积应用中,除了要关注抗毒性棉铃虫的产生和危害以外,还应特别注意其他可能上升为主要害虫(如棉蚜、棉叶蝉、烟粉虱等)的防治工作。