Phase-field simulation of forced flow effect on random preferred growth direction of multiple grains

The random distribution problem of dendrite preferred growth direction was settled by random grid method.This method was used to study the influence of forced laminar flow effect on multiple grains during solidification.Taking high pure succinonitrile （SCN） undercooled melt as an example,the forced laminar flow effect on multiple grains was studied by phase-field model of single grain which coupled with flow equations at non-isothermal condition.The simulation results show that the random grid method can reasonably settle the problem of random distribution and is more effective.When the solid fraction is relatively low,melt particles flow around the downstream side of dendrite,and the flow velocity between two dendrite arms becomes high.At the stage of solidification time less than 1800Δt,every dendrite grows freely;the upstream dendrites are stronger than the downstream ones.The higher the melt flow rate,the higher the solid fraction.However,when the solid fraction is relatively high,the dendrite arm intertwins and only a little residual melt which is not encapsulated can flow;the solid fraction will gradually tend to equal to solid fraction of melt without flow.

Phase-field model of isothermal solidification with multiple grain growth

This paper develops a new phase-field model for equiaxed dendrite growth of multiple grains in multicomponent alloys based on the Ginzberg-Landau theory and phase-field model of a single grain. Taking Al-Cu and Al-Cu-Mg alloys for example, it couples the concentration field and simulates the dendrite growth process of multiple grains during isothermal solidification. The result of the simulation shows dendrite competitive growth of multiple grains, and is reapplied to the process of dendrite growth in practical solidification.

Multiple time step molecular dynamics simulation for interaction between dislocations and grain boundaries

A multiple time step algorithm, called reversible reference system propagator algorithm, is introduced for the long time molecular dynamics simulation. In contrast to the conventional algorithms, the multiple time method has better convergence, stability and efficiency. The method is validated by simulating free relaxation and the hypervelocity impact of nano-clusters. The time efficiency of the multiple time step method enables us to investigate the long time interaction between lattice dislocations and low-angle grain boundaries.

Effect of Multiple Forging on Microstructure and Mechanical Properties of Powder Metallurgy FGH4096 Superalloy

FGH4096 is an important damage-tolerance-type powder metallurgy （PM） superalloy, which is also the optimized turbine material for high performance aero-engine. To turbine disc, bore and rim are used in high temperature-low stress condition and low temperature-high stress condition, and dual-microstructure is introduced. Coarse-grained microstructure is suit for rim region and fine-grained is no doubt most suitable for bore region. But fine-grained ingot can not make by PM technique, so that gradient heat treatment can not be developed to coarsen the grain of rim region. Under the confine of PM technique, several treatment processir, g should be taken place to refine the coarse grains of PM alloy. Multiple forging with large accumulate deformation was carried cat on PM FGH4096 superalloy, and fine grains of 3.5 μm were obtained by this treatment processing. Mechanical properties testing were ake carried out on both fine-grained and other statuses alloys, Microstrucmre evolution was observed by optical microscopy, scanning electron microscopy and transmission electron microscopy. As a result of repeated dynamic recrystallizafion, coarse grains could be completely refined into fine grains. And the increase of strength was mainly attributed to refinement effect and improvement of defects such as previous particle boundaries. Successful development of fine-grained treatment processing will promote the research of dual-microstructure turbine disc.

Production and Evaluation of the Nutritional and Functional Qualities of “Adakwa” Enriched with Waste Biomass of Traditional Brewer’s Spent Grain as a Functional Staple Food

Brewers’ spent grains constitute a nutrient-rich valuable and highly under-utilized by-product of the beer industry produced in large amounts all through the year. This bio-resource is a very good candidate for valorization, due to environmental and economic concerns, using biotechnological processing, particularly for food enrichment. This study was undertaken to evaluate the effect of fortification of Adakwa with traditional brewers’ spent grains (TBSG) on its physicochemical and nutritional properties as well as its acceptability using an experimental design. Four (4) samples of Adakwa were produced with TBSG incorporated rates of 0% (control sample), 10%, 20%, and 30% and evaluated. Using an experimental design, the effect of process parameters, including the TBSG incorporation rate, cooking time, and cooking temperatures on the physicochemical and nutritional properties of the Adakwa were evaluated while the 9-point hedonic scale was used to evaluate the sensory properties and its overall acceptability: carbohydrate, protein, crude fibre, cellulose, polyphenol, antioxidant activity (FRAP and DPPH). The water absorption activity values were 81.2 ± 0.04, 4.55 ± 0.05, 9.73 ± 0.23, 3.31 ± 0.05, 6.73 ± 0.23, 1.60 ± 0.09, 28.85 ± 0.8 and 117 ± 3.54 respectively for 0% TBSG (control);86.8 ± 0.01, 1.81± 0.20, 16.22 ± 0.16, 5.54 ± 0.69, 6.01 ± 0.16, 6.59 ± 0.03, 25.89 ± 0.94 and 475.0 ± 21.21 respectively for 30% TBSG. The sample with a high nutrient content was further produced using a central composite design and the factors studied were temperature and time, with responses, crude fiber, and FRAP content. The optimum production condition was: % TBSG: 47.06%;temperature: 123.17℃;Time: 30.34 mins. The sample with 47% TBSG had the best overall acceptability after sensory evaluation with sensory scores of: 5.45 ± 0.76, 7.9 ± 0.79, 8.0 ± 1.0, 7.10 ± 0.16, 8.5 ± 1.6, 7.6 ± 0.98 for color, taste, aroma, mouthfeel, texture and overall acceptability respectively. Thus TBSG can be used to improve the physicochemical and nutritional properties of adakwa.

基于动态定位和特征融合的多分支细粒度识别方法

为了解决细粒度分类类间差异小、类内差异大的分类难点,在Swin Transformer基础上,提出了一种改进的端到端的细粒度分类模型(TBformer)。针对复杂背景对网络识别产生的干扰,使用ECA、Resnet50、SCDA相结合的动态定位模块(DLModule)捕获关键物体,并设计了基于DLModule的三分支特征提取模块,提高对目标判别性特征的提取能力。为了充分挖掘三分支特征蕴含的丰富细粒度信息,提出了基于ECA的特征融合方法,增强特征的全面性、精确性,提高网络对细粒度分类的鲁棒性。实验结果表明:相比基础方法,TBformer在CUB-200-2011上的准确率提升了3.19%,在Stanford Dogs上的准确率提升了3.47%,在NABirds上的准确率提升了1.09%。

酿酒专用小麦籽粒品质特性研究

为探明酿酒专用小麦的主要籽粒品质特征,对12个常用酿酒小麦品种及6个非酿酒小麦品种的主要籽粒品质指标进行了分析与比较。结果表明,12个酿酒小麦品种的硬度指数均小于45%,角质率均小于70%,平均总淀粉含量大于60%,其中支链淀粉占比大于70%;籽粒硬度指数、角质率、饱满度及淀粉含量与弱筋小麦皖西麦0638相近;蛋白质、湿面筋含量显著低于非酿酒小麦西农20、周麦36,符合中国中筋小麦标准。相关性分析表明,酿酒小麦籽粒硬度指数与角质率呈极显著正相关,与千粒重呈极显著负相关;支链淀粉含量与千粒重呈显著正相关。通过聚类分析将12种酿酒小麦分为3个类群,类群Ⅰ包括9个品种,较其他2个类群总淀粉含量、支链淀粉含量高,硬度、蛋白质含量适中。综上所述,供试酿酒小麦籽粒具有软质、饱满、胚乳呈粉质-半角质、蛋白质含量适中、支链淀粉含量高等特点;籽粒特性和淀粉含量接近弱筋小麦并具备中筋小麦的蛋白质、湿面筋含量的小麦品种具有更大优势成为酿酒小麦。

复种指数视角下湖南省域及典型县域粮食增产潜力时序特征分析

分析1972—2021年湖南省域及4个典型县域的耕地和农作物种植时序特征,探讨复种指数时序特征及粮食增产潜力。结果表明,复种指数提升潜力的时序特征具有明显区域差异性,位于山区与毗邻城市群的县域(芷江侗族自治县、浏阳市)耕地复种指数提升潜力未随粮食作物播种面积占农作物总播种面积的比例减少而大幅增加,其平均值范围为0.12~0.50,复种指数提升潜力有限;粮食主产县域(湘阴县、祁阳市)耕地与粮食作物复种指数提升潜力变化趋势基本一致,其平均值范围为0.23~0.79,复种指数提升潜力较大。全省基于耕地与粮食作物复种指数的粮食年均最大增产潜力分别为454.50万、208.70万t,对应时期分别为1984—1988年、2002—2003年;典型县域的粮食增产潜力时空差异明显,基于耕地与粮食作物复种指数的粮食增产潜力平均值范围分别为0.69万~10.32万t、1.33万~12.56万t,在基于粮食作物复种指数的粮食增产潜力方面,湘阴县的粮食增产潜力最大,其次是祁阳市与浏阳市,粮食增产潜力最小的为芷江侗族自治县。

洒酒尾在高温堆积发酵工艺中的应用

高温堆积是金种子馥合香白酒酿造过程中的重要环节,其堆积效果直接影响到酒的品质和口感。洒酒尾作为一种常见的工艺方法,在防止堆积粮糟结板、调节物料水分和温度、促进微生物生长和代谢等方面具有显著作用。本文详细探讨了高温堆积过程中洒酒尾的意义,并通过实验研究和理论分析,深入阐述了其对白酒酿造的影响和机制。研究结果为白酒酿造工艺的改进和优化提供了理论支持和实践指导。

呕吐毒素污染对小麦质量安全和品质指标及利用价值的影响

本研究选取17个呕吐毒素污染的小麦籽粒样本,对其容重、面筋吸水量、粗蛋白质含量、不完善粒含量、生芽粒含量、赤霉病粒含量、虫蚀粒含量等质量安全和品质指标、呕吐毒素和重金属污染状况进行分析;并进一步分析小麦籽粒呕吐毒素含量与其他参数之间的关系;考察在将皮磨粉和心磨粉制备成为面筋和淀粉的加工过程对呕吐毒素污染水平的影响。结果表明:小麦籽粒中呕吐毒素的污染水平与容重、面筋吸水量、粗蛋白质、不完善粒含量、生芽粒、赤霉病粒、虫蚀粒能够建立良好的线性相关性。而其中面筋吸水量与呕吐毒素含量相关性不明显,说明呕吐毒素含量高低不会影响小麦的储存品质;考察营养物质、重金属与小麦粗麸、细麸、皮磨粉、心磨粉、全麦粉中呕吐毒素含量的相关性时发现,重金属As和Cd、元素Ca和P与呕吐毒素含量无相关性,仅全麦粉中的Ca与呕吐毒素含量存在相关性;进一步将皮磨粉和心磨粉制备为面筋和淀粉,测得其呕吐毒素水平均低于200μg/kg,说明呕吐毒素超标小麦可以通过制备面筋或淀粉实现商业化应用。

绿肥对减量施氮小麦籽粒产量和氮素利用的补偿机制

针对西北绿洲灌区小麦连作普遍、化肥施用量较大及氮素利用率低等问题,探究麦后复种绿肥对减量施氮小麦籽粒产量和氮素利用的补偿效应,以期为构建减氮小麦高效生产技术提供理论依据。本研究依托始于2018年的定位试验进行,2020-2022年期间采集数据。试验采用裂区设计,主区设4种绿肥种植模式,即麦后分别复种毛叶苕子混播箭筈豌豆(HCV)、箭筈豌豆(CV)、油菜(R)和麦后休闲(F);副区为3种施氮水平:试区习惯施氮量(N3,180 kg hm^(–2))、习惯施氮减量20%(N2,144 kg hm^(-2))、习惯施氮减量40%(N1,108 kg hm^(-2))。研究表明,习惯施氮减量20%和40%显著降低了小麦籽粒产量和氮素吸收,但麦后复种毛叶苕子混播箭筈豌豆可补偿因减量施氮40%造成的籽粒产量和氮素吸收损失,且麦后复种毛叶苕子混播箭筈豌豆结合减量施氮20%提高小麦籽粒产量21.4%和氮素吸收6.9%(P<0.05)。麦后复种毛叶苕子混播箭筈豌豆可补偿因减量施氮40%造成的氮素利用率损失,且其结合减量施氮20%氮素利用率提高13.4%(P<0.05)。其补偿机制归因于:(1)麦后复种毛叶苕子混播箭筈豌豆在减量施氮40%条件下可补偿小麦氮素吸收速率,提高氮素净同化速率34.3%(P<0.05),维持穗部氮素分配,增加茎氮素转运率6.6%(P<0.05)。(2)与麦后休闲传统施氮量相比,麦后复种毛叶苕子混播箭筈豌豆结合减量施氮20%提高氮素平均吸收速率和氮素净同化速率7.2%和34.1%(P<0.05),增加灌浆初期至成熟期穗氮素分配6.7%(P<0.05),提高叶、茎氮素对穗的转运贡献率17.8%、8.9%(P<0.05)。因此,在干旱绿洲灌区,麦后复种毛叶苕子混播箭筈豌豆是实现小麦减氮40%的可行措施,麦后复种毛叶苕子混播箭筈豌豆结合减氮20%可通过提高小麦氮素吸收速率和氮素净同化率,提高叶、茎对穗的转运贡献率从而促进穗部氮素分配,实现小麦产量和氮素利用率双提升。

Dissecting the Genetic Basis of Grain Shape and Chalkiness Traits in Hybrid Rice Using Multiple Collaborative Populations

Dear Editor Through the efficient use of heterosis, hybrid rice varieties generally have higher grain yield potential than inbred varieties. With the significant advantage in grain yield, over the past 30 years approximately half of China＇s total rice-growing area is planted with rice hybrids. However, grain quality has now become one of the most important targets in hybrid rice breeding for meeting consumer demands. Grain shape and chalkiness are two important components of rice grain quality, in which slender grains （typically, grain length-to-width ratio 〉3） with low chatkiness are preferred by most consumers of hybrid rice.

川法小曲酒泡粮废水的水质和有机组分的检测分析

泡粮作为川法小曲酒生产过程中必不可少的一道工序,能使粮食吸水膨胀,使淀粉结构松弛,为蒸煮糊化创造条件。泡粮废水作为酿酒废水的主要部分之一,对其进行分析检测是开发高效处理手段和资源化利用的必要步骤。本文对泡粮废水的水质经行了检测分析,并利用傅里叶红外光谱、元素分析、紫外分光光度法等对泡粮水中的具体有机组分进行了检测分析。水质分析结果显示泡粮水是一种COD_(Cr)和BOD_5含量高、总氮和总磷含量高的“三高”工业废水,指标远高出了国家废水的排放标准。有机组分分析结果表明,泡粮废水是富氧有机物,含有较多的可溶性多糖和酸类物质,具有资源化回收利用的价值。

种植结构“趋粮化”:劳动力外流的影响及其异质性

已有关于农业种植结构“趋粮化”研究忽视粮食作物的品种结构差异和区域差异,存在以户为单位度量劳动力外流的选择差错及要素替代发生主体不一致带来的行为逻辑分析偏误。基于全国农村固定观察点2004—2018年村级面板数据,实证分析劳动力外流对农业种植结构“趋粮化”的影响及其异质性。结果表明:相悖于现有文献的主流观点,整体上农村劳动力外流对粮食种植比例的影响不显著,水稻主产区农村劳动力外流甚至会显著抑制种植结构“趋粮化”,这一结论经过多重稳健性检验依然成立。原因在于,劳动力外流显著促进了土地流转和规模经营,强化了水稻种植“双改单”和复种指数下降的趋势。

The rational design of multiple molecular module-based assemblies for simultaneously improving rice yield and grain quality

Rice is one of the most important staple food for over half of the world＇s population,and a substantial increase in productivity and quality of rice grain will be required to feed a growing human population.Grain size and shape are the two important components contributing to grain yield and quality,because they impact both yield potential and end-use quality.

深冷条件下多重旋转碾压超细晶铜的组织与磨损性能

通过碾压式搅拌头在深冷条件下对铜板进行多重旋转碾压,采用超景深显微镜、光学显微镜、摩擦磨损仪对碾压后样品的表面形貌、组织和性能进行了分析。结果表明,在深冷条件下多重旋转碾压后,样品表面成形良好,表层出现明显的超细晶区;在转速为50 r/min时,超细晶成形机制为晶粒的剪切破碎;在转速为500 r/min时,晶粒细化机制为动态再结晶和强制冷却抑制再结晶晶粒的长大;在深冷条件下多重旋转碾压制备的超细晶层可提高材料的耐磨性。

籽粒苋的营养价值及其在酒行业中的研究进展

主要介绍了籽粒苋的营养成分特点,从基本营养成分淀粉、蛋白质、脂肪到生物活性物质角鲨烯、多肽,证明籽粒苋确实具有很高的营养价值。简要讨论了当前籽粒苋在酿酒行业应用的可行性分析,包括对籽粒苋主要成分淀粉、蛋白质和脂肪含量的分析,以淀粉含量来看,籽粒苋有望成为一种酿酒原料并得到大力推广,并就其在白酒、米酒及啤酒中的应用情况做了详细介绍。

不同工艺酿造黄酒对料酒品质的影响研究

研究比较了不同料水比(1∶3、1∶2)和不同曲(红曲、麦曲)黄酒的理化性质和风味成分差异,并与纯酿料酒标准进行比较。结果表明,低料水比(1∶3)发酵的黄酒出现了酒精度、固形物等指标偏低,无法满足高等级纯酿料酒标准的问题,需适当提高料水比;红曲和麦曲作为发酵剂得到的高度黄酒(料水比1∶2),红曲酒的β-苯乙醇不满足纯酿料酒的标准要求,麦曲高度工艺发酵黄酒可以更好地满足不同等级纯酿料酒的生产。

多菌种发酵芝麻香型丢糟生产饲料的工艺条件优化

为了优化多菌发酵芝麻香型丢糟生产饲料的工艺条件,试验以芝麻香型丢糟为原料,添加辅料麸皮,同时接种枯草芽孢杆菌D、酿酒酵母菌SY和植物乳杆菌2-41进行发酵。采用正交试验设计,测定粗蛋白含量、细胞计数和感官评价指标。最佳工艺条件:麸皮添加量15%,菌种接种量17%,发酵温度30℃,发酵时间8 d,初始酸度1.2 mmol/10 g NaOH,该发酵条件下产物粗蛋白含量(25.31±0.41)%,细胞计数6.4×10^(8)个/g,发酵香突出,饲料评分95分,等级为1级。

Achieving Large-area Bulk Ultrafine Grained Cu via Submerged Multiple-pass Friction Stir Processing

Large-area bulk ultrafine grained （UFG） pure Cu was successfully prepared by multiple-pass overlapping friction stir processing （FSP） under additional rapid cooling. Overlapping FSP did not exert a significant effect on the microstructure and mechanical properties of the FSP UFG Cu. Similar average grain size was achieved in the transitional zone （TZ） of the multiple-pass FSP sample compared to that in the nugget zone of the single-pass FSP sample, and the TZ exhibited a strong {111}（112） type A fiber shear texture, Very weak softening occurred in the TZ of the multiple-pass FSP UFG Cu, resulting in a relatively uniform hardness distribution throughout the whole processed zone. A high yield strength of - 310 MPa and a uniform elongation of - 13% were achieved in the bulk FSP UFG Cu. This study provides an effective strategy to prepare large-area bulk IUFG materials.