切-双纵流脱分装置试验研究与分析

阐述了切-双纵轴流脱粒分离装置的结构组成及工作原理,基于切-双纵流联合收获机,以喂入量、切流滚筒间隙及滚筒转速为影响因子,脱粒破碎率及脱粒损失率为指标,进行田间性能试验,并利用极差分析分别对破碎率、脱粒损失率单影响因子进行分析。结果表明:对脱粒破碎率影响的主次因素为BCA,即切流滚筒转速纵轴流滚筒转速喂入量,最佳组合为切流滚筒间隙25/30mm、滚筒转速907/1 043r/min、喂入量10.2 kg/s;对脱粒损失率影响的主次因素为BAC,即切流滚筒间隙喂入量滚筒转速,最佳组合为切流滚筒间隙25/30mm、喂入量10.2kg/s、滚筒转速953/1 096r/min。     

水肥耦合对当归产量和品质的影响效应研究

探索水肥耦合对当归品质和产量的影响效应,为当归GAP规范化种植中的水肥调控提供理论依据。采用水肥双因素试验,通过二元二次多项式拟合灌水量、施肥量与当归产量和主要品质指标（阿魏酸含量）的关系,建立影响效应模型,并对其进行检验分析和相关性分析。结果表明：在灌水一定的情况下,随着施肥量的增加,当归的产量先增加后减少;在施肥一定情况下,随着灌水量的增加,当归的产量也是先增加后减少,当归的最高产量出现在中水中肥区,即灌水量1073.97 m3/hm2,施肥量808.97 kg/hm2,最大产量为15804.36 kg/hm2;在灌水量一定的条件下,随着施肥的增加当归的阿魏酸含量先增加后降低,在施肥量一定的条件下,随着灌水量的增加当归的阿魏酸含量也是先增加后降低,当归的阿魏酸含量最高出现在中高水中高肥区,即灌水量1491.42 m3/hm2,施肥量863.55 kg/hm2,阿魏酸最高含量为2.41 mg/g。合理有效的灌溉施肥使当归达到优质高产。     

基于高光谱图像技术预测苹果大小

以新疆红富士苹果为研究对象,探讨应用高光谱图像技术和最小外接矩形法预测其大小的研究方法。提取苹果高光谱图像中可见红色区域受色度影响较小的713nm以及近红外区域793和852nm的3个波长图像,做双波段比运算处理。比较所得双波段比图像可知,852/713双波段比图像中背景和前景灰度对比度最大。对该图像做阈值分割以及形态闭运算去除果梗区域,使用8邻接边界跟踪法得到二值图像的轮廓坐标序列,采用最小外接矩形法求苹果的大小,与实测值建立回归方程。结果表明,基于高光谱图像技术采用波段比算法,结合最小外接矩形法,能够有效地检测苹果大小,预测值与实际值最大绝对误差为3.06mm,均方根误差为1.21mm。     

苹果图像的背景分割与目标提取

水果的缺陷、大小和颜色差异以及光照等因素影响图像背景分割与目标提取精度.以苹果为研究对象,针对4种不同光照强度条件下采集的280幅不同姿态的苹果图像,将彩色图像的R、G、B分量进行算术运算,然后采用形态学开运算进行消噪处理,采用线性空间滤波消除锯齿状边界,采用自动阈值分割方法进行背景分割与目标提取.结果显示,203幅图像的分割偏差小于1％,占总量的72.5％;70幅图像的分割偏差大于1％而小于2％,占总量的25％;偏差大于2％的有7幅,占总量的2.5％.最大分割偏差为2.83％.     

Interaction of curcumin with phosphatidylcholine: A spectrofluorometric study

Curcumin [1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3, 5-dione], the main constituent of the rhizomes of the plant Curcume longa L. (turmeric), is a powerful antioxidant in both enzymatic and nonenzymatic systems. The interactions of curcumin with egg and soy phosphatidylcholine were followed by fluorescence spectroscopy. Curcumin had very weak fluorescence in aqueous system, which was enhanced in apolar environments. Curcumin emitted at 490 nm after being excited at 451 nm in phosphatidylcholine micelles. The equilibrium constants for the interaction of curcumin with egg and soy phosphatidylcholine were (3.26 +/- 0.2) x 10(5) and (2.64 +/- 0.2) x 10(5) M(-1), respectively. From the Scatchard plot of the fluorometric data, it was inferred that one molecule of curcumin could bind six molecules of phosphatidylcholine. The equilibrium constant for the phosphatidylcholine-curcumin interaction decreased with temperature, indicating the amphiphilic nature of curcumin. The DeltaG, DeltaH, and DeltaS values obtained for the interaction of egg phosphatidylcholine-curcumin were -7.8 +/- 0.3 kcal/mol, -9.6 +/- 0.4 kcal/mol, and -6.8 +/- 0.2 cal/mol/K, respectively. The fluorescence anisotropy measurements of curcumin with phosphatidylcholine suggested that the anisotropy of the curcumin molecule did not change in phosphatidylcholine. The interaction of divalent metal ions with phosphatidylcholine-curcumin in comparison with phosphatidylcholine-1-anilino-8-naphathalenesulfonic acid complex suggested the strong binding of curcumin to metal ions.     

Response of the pigeonpea-Rhizobium symbiosis to salinity stress: variation among Rhizobium strains in symbiotic ability

Summary There were significant differences among pigeonpea [Cajanus cajan (L.) Millsp] Rhizobium sp. strains (IC 3506, IC 3484, IC 3195, and IC 3087) in their ability to nodulate and fix N₂ under saline conditions. Pigeonpea plants inoculated with IC 3087 and IC 3506 were less affected in growth by salinity levels of 6 and 8 dS m^-1 than plants inoculated with the other strains. For IC 3506, IC 3484, and IC 3195, there was a decrease in the number of nodules with increasing salinity, while the average nodule dry weight and the specific nitrogenase activity remained unaffected. However, in IC 3087, the number of nodules increased slightly with increasing salinity. Leaf-P concentrations increased with salinity in the inoculated plants irrespective of the Rhizobium sp. strain, and leaf-N concentrations decreased with increasing salinity in IC 3484 and IC 3195 only. Shoot-Na and-Cl levels were further increased in these salt-sensitive strains only at 8 dS m^-1. Therefore there may be scope for selecting pigeonpea Rhizobium sp. symbioses better adapted to saline conditions. The Rhizobium sp. strains best able to form effective symbioses at high salinity levels are not necessarily derived from saline soils.Submitted as JA No. 919 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)     

干旱地区喷洒水利用系数的田间试验研究

为了科学地评价喷灌在干旱地区的适宜性,在内蒙古包头春小麦生育期内对喷洒水利用系数进行了监测,结果指出,通过选择适宜的灌溉时间,喷洒水利用系数可以达到0.85以上。对影响喷洒水利用系数的环境因素进行分析后得出,风速的影响最大,相对湿度次之,气温的影响很小;在此基础上建立了喷洒水利用系数与上述3因子之间的回归模型。为了估算整个灌溉季节的喷洒水利用系数,对所研究地区1991～2001年灌溉季节(4～9月份)内的日平均风速进行了统计分析,发现不大于3m/s的日数占灌溉季节总日数的90%以上,因此,选择日平均风速不大于3m/s的时间灌溉可以满足作物的需水要求,这种情况下,整个灌溉季节的喷洒水利用系数可以达到0.83。由此可见,在条件与包头类似的干旱地区,从提高水的利用率的角度出发,发展喷灌也是适宜的     

Soil management for Alfisols in the semiarid tropics: erosion, enrichment ratios and runoff

Abstract. Continuous cultivation of soils of the semiarid tropics has led to significant land degradation. Soil erosion and nutrient loss caused by high runoff volumes have reduced crop yields and contributed to offsite damage. We compared a number of soil management practices (tillage, mulch and perennial/annual rotational based systems) for their potential to improve crop production and land resource protection in an Alfisol of the semiarid tropics of India. Runoff and soil erosion were monitored and surface soil and sediment were analysed for nitrogen and carbon to determine enrichment ratios. Amelioration of soils with organic additions (farmyard manure, rice straw) or rotating perennial pasture with annual crops increased soil carbon and nitrogen contents and reduced runoff, soil erosion and nutrient loss. Soil erosion totalled less than 7 t ha^–1, but enrichment ratios were often greater than 2 resulting in up to 27 kg N ha^–1 and 178 kg C ha^–1 being lost in sediment. Up to an extra 250 mm of water per year infiltrated the soil with organic additions and was available for crop water use or percolation to groundwater. The results show that there are good opportunities for reducing degradation and increasing productivity on farms.     

赤霉素对‘粉红朱砂’和‘虎丘晚粉’开花的影响

该文研究了不同时间、不同浓度的赤霉素处理对‘粉红朱砂’和‘虎丘晚粉’两种露地栽培梅花的花期、展叶期和落蕾率的影响。结果表明 :2 0 0 0mg L的赤霉素在 10月底至 11月处理可使‘粉红朱砂’的花期提前约 1个月 ,展叶期提前 30～ 4 1d ,但同时出现明显的落蕾效应 ;而 1月处理使‘虎丘晚粉’始花期、末花期均延迟 ,同时开花量增加 ,且观赏期延长。研究还探讨了温度作为梅花开花的主导因子对试验研究的影响。     

Contributions of the visual ventral pathway to long-range apparent motion

Objects displaced intermittently across the visual field will nonetheless give an illusion of continuous motion [called apparent motion (AM)] under many common conditions. It is believed that form perception is of minor importance in determining AM, and that AM is mediated by motion-sensitive areas in the "where" pathway of the cortex. However, form and motion typically interact in specific ways when natural objects move through the environment. We used functional magnetic resonance imaging to measure cortical activation to long-range AM, compared to short-range AM and flicker, while we varied stability of structural differences between forms. Long-range AM activated the anterior-temporal lobe in the visual ventral pathway, and the response varied according to the form stability. The results suggest that long-range AM is associated with neural systems for form perception.