基于响应面法的玉米秸秆成型工艺优化

为了研究玉米秸秆成型过程中各参数之间的交互作用,获得最佳的工艺参数,该文采用5因素的响应面试验设计研究了原料水分(8%~24%)、温度(50~150℃)、压缩速度(10~50 mm/min)、压力(51.0~127.4 MPa)、保压时间(10~50 s)5个成型参数对玉米秸秆成型颗粒的松弛密度、Meyer强度以及压缩比能耗3个成型技术指标的影响,建立了响应面模型,结合成型燃料标准,获得了最佳的工艺参数,并对优化后的试验参数进行了试验验证。试验结果表明:在选取试验参数范围内,温度、原料水分、压力均会对技术指标产生较大影响;而压缩速度和保压时间所产生的影响相对较小。最优化的工艺参数(压力、温度、水分)为:4 k N(51.0 MPa)、110.8℃、17%,在该参数组合下的验证试验结果为:松弛密度为1031 kg/m~3,Meyer强度为27.1 N/m~2,比能耗为10.03 k J/kg。该研究可为秸秆生物质成型燃料制备产业提供参考。     

云南铁壳麦籽粒硬度及其单粒硬度的频率分布

为了明确云南铁壳麦亚种在小麦品质改良中的作用,用单籽粒谷糖硬度测定仪对36份云南铁壳麦的籽粒硬度及其单籽粒硬度的频率分布进行了分析.结果表明,云南铁壳麦籽粒硬度变幅为7.3±15.9～70.9±19.6,其中硬质麦31份(1级17份、2级14份)、混合麦2份(2级1份,3级1份)、软质麦3份(均为5级),硬质、混合和软质麦类型比例分别为86.1%、5.6%和8.3%;硬质类型云南铁壳麦的平均硬度为62.0,没有极硬的类型;有2份临沧铁壳麦(A14,A21)属极软类型.籽粒硬度的分类与不同硬度范围单籽粒频率分布及硬度均值有关,硬质云南铁壳麦硬度低于46的籽粒占5%～20%,高于47的籽粒比例为74%～95%,硬度均值55.7±14.0～70.9±19.6,绝大部分一致性较好;2份混合型云南铁壳麦(云0005、云0007)硬度指数低于46的籽粒分别占29%和30%,高于47的籽粒分别占70%和71%,硬度值为53.7±17.2和55.7±17.8,一致性最差;软质麦硬度指数低于46的籽粒占98%～100%,高于47的籽粒占0～2%,硬度均值为7.3±15.9～16.6±13.5,一致性最好.籽粒硬度分析表明,云南铁壳麦中既具有加工优质面条、馒头等所需的硬度等级,又具有软质小麦改良的亲本材料.     

扫描间距对45钢激光熔凝强化组织性能的影响

为了研究扫描间距对45钢激光熔凝强化组织性能的影响,采用HLD1001-5 型固体激光器对45钢表面进行了多条带等间距激光熔凝处理,分别利用扫描电镜、洛氏硬度计、磨损试验机观察和测量了不同扫描间距下硬化层的显微组织及性能。结果表明：激光熔凝处理的硬化层由熔化区、相变硬化区和热影响区组成,组织为马氏体;多条带等间距激光熔凝处理在垂直于熔凝条带方向上的硬度分布由左高硬度区、左过渡区、低硬度区、右过渡区和右高硬度区组成,高硬度区的硬度为58.1～59.6 HRC,低硬度区的硬度约16 HRC;在试验范围内,经激光扫描间距为4.5 mm 熔凝处理的试样具有最好的耐磨性。     

The influence of mechanical impact and storage conditions on subsurface hardening in pre-peeled potatoes (Solanum tuberosum L.)

Summary In investigating the effect of mechanical impact and storage conditions on subsurface hardening in boiled pre-peeled potatoes, potatoes (cv. Sava) were peeled using an industrial peeler, a laboratory knife peeler or a hand knife peeler, packed in polymer bags and stored at 4 to 18 °C for 6 days. Industrially peeled potatoes were significantly harder than potatoes peeled by hand or using a laboratory knife peeler. Potato hardening was not related to pectin methyl esterase activity (EC 3.1.1.11.). However, it was significantly correlated with mechanical impact from the peeler knives and by treatment in a damage barrel. Blunt knives resulted in harder potatoes than when sharp knives were used. An increase in storage temperature from 4 to 18 °C also increased subsurface hardening significantly. Maximum hardness was found below the wounded surface at a depth of 2–8 mm (average 4 mm).     

Disease and pest resistance in grains of sorghum and millets

In this review available information on the mechanisms of resistance to insect pests and fungal pathogens in sorghum and millets is discussed. The primary source of resistance lies in the chemical and physical make up of the grain. Phenolic compounds such as ferulic acid and tannins present in some sorghums are potent inhibitors of pests and pathogens. Grain hardness is a major deterrent to infection and infestation in low tannin grains. The prolamins, the grain storage proteins of sorghum, are organized into protein bodies and provide a physical and a nutritional barrier since they are resistant to digestion by insect and fungal proteases. A plethora of proteins that belong to the ‘pathogenesis related protein’ group are distributed in various parts of the grain. Some of them are located in protein bodies. Notwithstanding, sorghum is still susceptible to insect pests and fungal pathogens. An understanding of the natural mechanisms of resistance in the grain is paramount for the development of durable resistance against pests and pathogens. The pyramiding of resistance genes and the development of transgenic lines based on this understanding are two sources of hope for the future protection of sorghum and millets.     

Research on wind erosion processes and controlling factors based on wind tunnel test and 3D laser scanning technology

The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion. In this study, three structurally intact soil samples were collected from the steppe of Inner Mongolia Autonomous Region, China and placed in a wind tunnel where they were subjected to six different wind speeds (10, 15, 17, 20, 25, and 30 m/s) to simulate wind erosion in the wind tunnel. After each test, the soil surfaces were scanned by a 3D laser scanner to create a high-resolution Digital Elevation Model (DEM), and the changes in wind erosion mass and microtopography were quantified. Based on this, we performed further analysis of wind erosion-controlling factors. The study results showed that the average measurement error between the 3D laser scanning method and weighing method was 6.23% for the three undisturbed soil samples. With increasing wind speed, the microtopography on the undisturbed soil surface first became smooth, and then fine stripes and pits gradually developed. In the initial stage of wind erosion processes, the ability of the soil to resist wind erosion was mainly affected by the soil hardness. In the late stage of wind erosion processes, the degree of soil erosion was mainly affected by soil organic matter and CaCO₃ content. The results of this study are expected to provide a theoretical basis for soil wind erosion control and promote the application of 3D laser scanners in wind erosion monitoring.     

甘肃冬小麦品种(系)面粉品质性状相关基因分析

为了解甘肃省近20年育成的106份冬小麦品种(系)中加工品质性状相关基因分布情况,用22个分子标记对供试材料的HMW-GS、LMW-GS、面粉色泽及籽粒硬度等品质性状相关基因进行了分析。结果发现,供试品种(系)的HMW-GS相关基因中,在Glu-A1位点检测到34份品种(系)含有AxNull,频率为32.08%;在Glu-B1位点检测到Bx7+By8和Bx14+By15共2种基因组合,分别占17.92%和25.47%;在Glu-D1位点检测到11份品种(系)含有Dx5+Dy10,占10.38%。对LMW-GS鉴定结果显示,29份品种(系)含Glu-A3d基因,分布频率为27.36%。HMW-GS和LMW-GS亚基组合中,含有4个、3个和2个位点优质亚基基因组合的品种(系)分别占0.94%、8.49%和3.77%。对面粉色泽相关基因Ppo-A1、Ppo-D1、Psy-A1、Lox-B1和TaPod-A1位点的检测发现,优异等位变异占比分别为39.62%、50.94%、31.13%、30.19%和38.68%。对籽粒硬度相关基因检测发现,在Pina、Pinb和Pinb-2等位变异位点的检测...     

Analysis of Pina and Pinb alleles in the micro-core collections of Chinese wheat germplasm by Ecotilling and identification of a novel Pinb allele

Kernel hardness is mainly conditioned by allelic variations of Pina-D1 and Pinb-D1 genes located on the short arm of chromosome 5D. In this work, the Ecotilling approach was optimized to investigate Pina and Pinb alleles in the micro-core collections of Chinese wheat germplasm, and three Pina and eight Pinb alleles were found. Generally, more Pinb alleles were detected in the accessions coming from the regions that grow winter or a mixture of spring and winter wheats. This was particularly evident for the Southwestern winter wheat, Xinjiang winter–spring wheat and Yellow and Huai River Valley winter wheat regions. A novel variant (designated as Pinb-D1x) was discovered in one of the accessions from the Xinjiang winter–spring wheat region. Compared to wild type (WT) allele Pinb-D1a, two nucleotide substitutions occurred in the coding region of Pinb-D1x, one (at nucleotide position 257) resulting in the replacement of a WT cysteine residue by tyrosine and the other (at nucleotide position 382) creating a premature stop codon. The implications of our data to understanding the diversity of Pina and Pinb alleles in wheat and to future molecular breeding of wheat kernel hardness are discussed.     

CIMMYT普通小麦籽粒硬度等位变异的检测

籽粒硬度主要由5D染色体短臂的一对主效基因Ha控制,研究籽粒硬度等位变异有助于提高小麦的磨粉和食品加工品质。本试验对国际玉米小麦改良中心（CIMMYT）的138份历史品种和代表性高代品系的硬度基因型进行了研究。在用SDS-PAGE鉴定Pina-D1b/Pinb-D1a时,用10%甘油代替水配制分离胶,用PDA代替甲叉配制分离胶和浓缩胶,增强了PINA和PINB两种蛋白带型的分辨率。结果表明,与其他国家硬质麦中Pina-D1a/Pinb-D1b类型偏多的特点明显不同,CIMMYT硬质小麦中puroindoline a（PINA）蛋白缺失类型（或称Pina-D1b/Pinb-D1a）较多,为118个,占85.5%;Pina-D1a/Pinb-D1a（野生型）为11个,占8.0%;Pina-D1a/Pinb-D1b类型有9个,占6.5%。其中,PINA缺失对小麦籽粒硬度的影响最大,与其他2种基因型硬度值之间差异达5%显著水平。先前研究结果表明,PINA蛋白缺失类型的磨粉品质和面包烘烤品质均劣于Pina-D1a/Pinb-D1b类型,因此,建议CIMMYT多引进一些其他硬度变异类型的小麦种质,如Pina-D1a/Pinb-D1b类型等,以改善其硬度基因型过度单一的局面,从而减少PINA蛋白缺失带来的不利影响。同时,也提醒我国以其他用途如抗病、抗旱等为目的,引种CIMMYT小麦时,还应充分考虑PINA蛋白缺失对磨粉和加工品质的不利影响,以更合理引进和有效利用CIMMYT种质资源。     

红宝石海棠生长适应性综合指标排序及其分析

红宝石海棠是一个叶、花、果、枝同观共赏的彩色观赏树种.通过引进红宝石海棠对其进行抗寒性、抗旱性、耐盐碱性、观赏性试验研究,建立生长适应性评价体系,以红宝石海棠在新疆正常生长的关键因子为评价指标,根据每个关键因子相对重要程度,利用判断矩阵算出各项指标所占的权重,进行层次排序.结果表明:红宝石海棠在新疆适应性强,叶色艳丽悦目具有较高的观赏价值,是新疆乃至西北地区大力推广的彩化、美化树种.