秦岭山区不同闭矿年限尾矿库植被恢复调查

[目的]对秦岭山区不同闭矿年限尾矿库植被恢复情况进行调查研究,可为矿区植被恢复与重建提供理论依据。[方法]以秦岭山区4个不同闭矿年限(2,3,6和14 a)的金尾矿库为研究对象,在尾矿库的库顶和边坡设置样方,对样方内植被种类、高度、密度、盖度、优势度进行调查。[结果]闭矿6 a的尾矿库植被种类最多,其次是闭矿14,3和2 a的植被种类;闭矿14 a的尾矿库植被相对高度最高,其次是闭矿6,3和2 a的植被相对较高;闭矿6 a的尾矿库植被相对密度最高,其次是闭矿14,3和2 a的植被相对密度;闭矿14 a的尾矿库植被盖度最高,其次是闭矿6,3和2 a的植被盖度;尾矿库植被主要为菊科植物和禾本科植物,闭矿6 a的尾矿库植被优势度最高,其次是闭矿14,3和2 a的植被优势度。[结论]金尾矿库区自然恢复植被生长情况与闭矿年限有密切关系;人工覆土可以显著增加尾矿库区自然恢复植被种类的多样性。     

单自由度四连杆取投苗机械臂设计

针对目前蔬菜穴盘苗自动取投苗机构结构复杂、制造成本较高等问题,该文设计了一种单自由度开式铰链四杆机构取投苗机械臂。首先通过对钵苗力学特性进行分析,为取苗爪的外形设计提供了依据。其次根据人工取投苗和现有取苗机构的作业过程,制定了取苗机构的设计要求。然后对机构的运动路径和各运动副的运动进行规划设计,最终设计出一种单自由度全机械式的取投苗机械臂,显著降低了成本。试验结果表明:取苗爪抓取点的运动轨迹和设计要求与理论仿真结果相一致,移栽试验中取苗成功率为96.7%,钵体破损率为3.13%,投苗成功率为97.74%,总体成功率为91.32%,机构的可靠性较高。该机构的设计提供了一种全自动取投苗方法,可为开展移栽装备的全自动化研究提供参考。     

Seed filling dynamic traits of oil flax in response to nitrogen and phosphorus

Crop yield is primarily seed-filling-limited in production system under field conditions.This study was aimed to determine whether seed filling traits of oil flax(Linum usitatissimum L.)could be controlled by phosphorus(P),nitrogen(N),and phosphorus and nitrogen(NP)supply.Effects on seed filling traits were investigated in 2 years including capsule diameter,capsule height,capsule dry matter(DM),seed DM per capsule,pericarp DM per capsule,protein content and oil content.DM translocation from pericarps to seed,translocation efficiency,and contribution of photoassimilates during seed filling period were also detected.In a randomized complete block design,cultivar'Longyaza 1'was grown under P(33 kg P/ha),N(75 kg N/ha),and NP(33 kg P/ha and 75 kg N/ha)along with a zerofertilizer(CK)treatment in 2013 and 2014.Results suggested that DM translocation efficiency and contribution efficiency increased to different extent due to P,N or NP application.At 42 DAA(days after anthesis),seed DM per capsule reached the greatest,while protein content and pericarp DM obtained the least level.However,the highest oil content was detected at 35 DAA.A significant positive linear relationship was observed between seed DM,capsule DM and DM translocation in both years.Protein content showed inconsistent relation with oil content.The results indicated that appropriate N and P management could be an effective approach to increase oil flax production.     

Identifying the spatial variability of soil constraints using multi-year remote sensing

In north-eastern Australia, soil attributes such as salinity, sodicity, acidity, and phytotoxic concentrations of chloride constrain the growth of crops. It is difficult to delineate constrained areas using conventional sampling methods. Alternatively, where crops fail, over multiple years, to pass a certain yield threshold, we might infer the presence of a soil constraint. For a wheat-growing farm over 10-year period we used remote sensing to obtain a large volume of surrogate yield data, by calibrating an archive of Normalised Difference Vegetation Index (NDVI) to an archive of (limited) ground-based observations. The model used was a generalised additive model that related wheat yield as a non-linear function of NDVI and a linear function of post-anthesis rainfall. Field locations where predicted yield consistently failed to reach the 75th percentile in a given year, over a number of years, we regarded as limited by at least one unknown soil constraint. Soil samples averaged for the constrained locations showed, compared with the unconstrained locations, relatively high concentrations of subsoil chloride, and, in the topsoil, relatively high exchangeable sodium percentage, and unused nitrate nitrogen. On-farm experiments suggested that, for constrained areas, preclusion of monoammonium phosphate (MAP) fertiliser application, coupled to gypsum amelioration, could potentially benefit the farm by A$32/ha/year (MAP) and A$207/ha/3 years (gypsum).     

小麦质膜Na+/H+逆转运蛋白TaSOS1的表达分析

为探讨小麦质膜Na⁺/H⁺逆转运蛋白TaSOS1在逆境条件下的生物学功能,采用荧光定量PCR（RTPCR）方法,对 TaSOS1基因在4种不同胁迫条件下（200 mmol·L^-1 NaCl、4℃低温、100 μmol·L^-1 ABA和15% PEG6000）的表达水平进行了定量分析。结果表明,在正常条件下,小麦根中 TaSOS1的mRNA表达量要高于叶中的表达量。盐胁迫处理下,根中 TaSOS1特异性上调表达,说明 TaSOS1基因在根中的功能更强,其表达与盐胁迫有关且具有组织特异性;在4℃低温处理下, TaSOS1在叶中上调表达;而在ABA和PEG6000两种处理条件下, TaSOS1的表达没有规律性,推测 TaSOS1的表达途径可能为非ABA依赖型且与盐离子的特异性有关。生物信息学分析的结果表明,小麦质膜Na⁺/H⁺逆转运蛋白TaSOS1与拟南芥和水稻的质膜Na⁺/H⁺逆转运蛋白AtSOS1和OsSOS1具有高度的同源性,由此可以推测小麦TaSOS1具有与AtSOS1和OsSOS1类似的功能,可以把植物体内Na⁺排出体外,以减轻Na⁺对植物的毒害。     

甘肃省高校数字化校园建设现状及对策

数字化校园建设是网络环境下高等教育适应信息社会的需求,也是实现自身与社会不断发展进化的必然选择。教育信息化作为高校建设的重要组成部分,数字化校园建设是其根本目标。目前,由于思想观念落后、缺乏有效的管理机制使得数字化校园建设无法取得应有的效益,通过对甘肃省11所高校数字化校园建设进行调研,对数字化校园建设的现状进行了分析,并提出具体的对策与建议。     

Insecticidal activities of crude extracts and phospholipids from Chenopodium ficifolium against melon and cotton aphid, Aphis gossypii

Several organic solvent extracts of Chenopodium ficifolium were tested for their insecticidal activity against melon and cotton aphid, Aphis gossypii, on cucumber plants. Both methanol and ethanol extracts, at 5000 μg ml⁻¹, were highly active giving over 80% control. The other crude extracts displayed moderate or weak insecticidal activity giving control in the range of 16–69%. Two phospholipids were isolated as insecticidal active substances from C. ficifolium. Their chemical structures were identified as 1-palmitoyl-2-(3-trans)-hexadecenoyl-sn-glycero-3-phosphoglycerol and 1-palmitoyl-2-linoleoyl-3-glycerophosphocholine by GC–MS, EDS, mass and NMR spectral analyses. Both compounds displayed a dose-dependent mortality of A. gossypii. Furthermore, the liquid formulation that was obtained by partitioning with n-hexane from the methanol extract of C. ficifolium controlled melon and cotton aphid on cucumber plants effectively. These results indicate that extracts of C. ficifolium have potential for development as botanical insecticides for controlling A. gossypii infesting cucumber plants.     

亚麻温敏雄性不育系F1、F2的优势分析

通过对以温敏亚麻雄性不育系1S为母本配制的6个杂交组合F1、F2代主要农艺性状和产量性状杂种优势的测定和分析,结果表明:不同杂交组合F1、F2代在株高和工艺长度上的平均优势均表现为负向超父本优势,而各产量性状上的平均优势均表现出很强的正向超父本优势;但与F1代相比,F2代平均优势明显下降.产量性状构成因素平均优势大小顺序为:单株产量＞单株果数＞千粒重＞每果粒数.不同组合间F1、F2代杂种优势表现差异较大,其中1S×黑亚15号组合产量性状的超父本优势最强,F1、F2代均表现出很强的杂种优势.     

3种野生茄和1个栽培茄的核型分析

分析3种野生茄和1个栽培茄品种染色体核型.结果表明:所有供试材料的染色体数目均为2n=24,核型类型均为"2A"型:染色体主要由中部着丝点和近中部着丝点染色体组成,属较对称核型.但它们的核型也具有明显差异, "04E28"的核型公式为2n=16m+6sm+2st,核不对称系数60.20%;04E42的核型公式为2n=14m+8sm+2T,核不对称系数65.91%;07E67的核型公式为2n=18m+6sm,核不对称系数59.68%;栽培品种.04E08"的核型公式为2n=22m+2sm.核不对称系数58.59%.     

Inverse identification of early- and latewood hydric properties using full-field measurements

The study and identification of the water diffusion properties of Abies alba Mill at the growth ring scale are investigated in this paper. A full-field measurement technique, the grid method, is used in the experimental tests in order to observe heterogeneities and to measure strain fields in the annual growth rings. In this case, the mechanical behaviour of latewood (LW) and earlywood (EW) is studied under the effect of water stress. This technique is coupled to an inverse method for parameter identification. It enables us to assess the diffusivity of EW and LW in the tangential diffusion direction (T) and their expansion coefficients in the radial direction (R) from strain maps obtained using the grid method. Thus the water diffusion phenomenon and its effect on the deformation of wood specimens are studied. A suitable experimental device is designed to provide direct contact with water on one side of the specimen, and strain maps are obtained over time on the other side. During the experiments, strain gradients that appear are clearly different between EW and LW, highlighting the different diffusion properties at the ring scale level. The results also show changes in the kinetics of the hydric deformation of the material.