螺旋挤搓式自动玉米脱粒机的设计

目前玉米脱粒机均为人工控制上料工作,其上料速度的不均匀直接影响脱粒机的寿命及玉米脱粒程度,同时传统的脱粒机都是采用打击原理设计,对玉米籽粒伤害很大。针对上述情况,提出一种基于STM32传感器控制的自动螺旋挤搓式玉米脱粒机的自动控制系统。该系统在STM32的控制下通过步进电机实现自动上料、螺旋挤压式玉米脱粒系统完成玉米的脱粒及籽粒与玉米芯的分离,采用全自动化控制,同时能有效地降低玉米籽粒的损伤率,提高玉米的脱净率及玉米芯的完整度。     

不同温度条件下玉米穗红外干燥试验研究

针对玉米收获后由于气候原因导致霉变发芽、公路晾晒造成严重污染,或采用“先脱粒后干燥”工艺导致籽粒破碎严重等问题,按照“玉米穗干燥→脱粒→玉米籽粒干燥”分段干燥工艺设计了一种玉米穗红外干燥试验台.试验结果表明,采用等温干燥时,较佳的干燥温度为58℃左右;采用变温干燥时,宜选用“先低后高”的变温方式,且在保证干玉米品质的前提下,应尽量选用较高的起始干燥温度;无论采用等温干燥还是变温干燥,其干燥温度均不得高于60℃.该玉米穗红外干燥试验台干燥均匀性好、设备的空间利用率高,解决了收获期玉米霉变或采用“先脱粒后干燥”工艺而导致的籽粒破碎率严重等问题,为玉米穗红外干燥机的研制提供了参考.     

HSCC-0．7甜玉米脱粒机

由农业部规划设计研究院研制的HSCC-0．7甜玉米脱粒机借鉴了国外最新甜玉米切粒技术，采用包容玉米籽粒根部的切削技术，切刀与玉米籽粒根部（玉米芯外缘）成弹性接触，刀盘内部设有弹簧，刀刃孔可随玉米芯轴直径的不同而作自动调整，保证切刀刃部始终贴近玉米籽粒根部，因此在设计上保证了切净率指标。 该设备专门用于鲜嫩甜玉米脱粒。     

不同温度条件下红外玉米穗干燥试验研究

针对玉米收获后由于气候原因导致霉变发芽、公路晾晒造成严重污染,或采用“先脱粒后干燥”工艺导致籽粒破碎严重等问题,按照“玉米穗干燥—脱粒—玉米籽粒干燥”分段干燥工艺设计了一种红外玉米穗干燥试验台。试验结果表明,采用等温干燥时,较佳的干燥温度为58℃左右;采用变温干燥时,宜选用“先低后高”的变温方式,且在保证干玉米品质的前提下,应尽量选用较高的干燥温度;无论采用等温干燥还是变温干燥,其干燥温度均不得高于60℃。本文研究的红外玉米穗干燥试验台干燥均匀性好、设备的空间利用率高,彻底解决了收获期玉米霉变或采用“先脱粒后干燥”工艺而导致的籽粒破碎率严重等问题,为红外玉米穗干燥机的研制奠定了坚实基础。     

不同温度条件下玉米穗红外干燥试验研究

针对玉米收获后由于气候原因导致霉变发芽、公路晾晒造成严重污染,或采用“先脱粒后干燥”工艺导致籽粒破碎严重等问题,按照“玉米穗干燥→脱粒→玉米籽粒干燥”分段干燥工艺设计了一种玉米穗红外干燥试验台。试验结果表明,采用等温干燥时,较佳的干燥温度为58℃左右;采用变温干燥时,宜选用“先低后高”的变温方式,且在保证干玉米品质的前提下,应尽量选用较高的起始干燥温度;无论采用等温干燥还是变温干燥,其干燥温度均不得高于60℃。该玉米穗红外干燥试验台干燥均匀性好、设备的空间利用率高,解决了收获期玉米霉变或采用“先脱粒后干燥”工艺而导致的籽粒破碎率严重等问题,为玉米穗红外干燥机的研制提供了参考。     

玉米籽粒缓苏干燥过程动力学分析

对玉米籽粒的缓苏干燥过程进行了理论分析,并假设玉米籽粒为轴对称结构、各向同性的均匀物质,建立了玉米籽粒的缓苏干燥数学模型,利用COMSOL Multiphysics模块进行了热质传递过程的模拟研究。结果表明,该模型可较好地模拟玉米籽粒的干燥过程。利用该模型模拟研究了不同干燥条件下玉米籽粒温度、干燥时间、缓苏时间、缓苏度的变化及其对干燥速度的影响。结果表明,玉米籽粒内外温度在3~5 min内即可达到热风温度,玉米籽粒内部最大水分梯度出现在热风干燥5~10 min后,不同干燥阶段不同初始含水率对缓苏度的影响很小,缓苏60 min水分梯度可以基本消除。利用该优化工艺参数对玉米籽粒交替进行热风干燥和缓苏干燥,可使总的热风干燥时间最少,实现节能目的。     

微波干燥玉米的试验研究

以玉米籽粒为试验材料,研究了微波处理对玉米品质的影响,分析了微波干燥玉米籽粒的干燥特性、温度特性以及单位质量功耗、温度、平均失水速率与玉米籽粒发芽率、爆腰率和淀粉得率的关系,提出了干燥玉米的最优工艺流程,并确定了影响微波干燥玉米的工艺参数。     

籽粒玉米脱粒装置的对比试验

本文是西德斯图特嘎尔特—霍恩海姆大学的阿瑙尔杜恩·洛等人写的。文中论述了籽粒玉米收获中使用的两种不同的脱粒装置,即切流式纹杆脱粒装置和轴流式钉齿脱粒装置,在实验室不同条件下所作的试验,并且探讨了滚筒圆周速度、籽粒喂入量和含水量对脱粒损失、分离损失、分离率和损失率的影响。     

5TYX-855型新式玉米脱粒清选机

目前国外玉米脱粒多为大型脱粒清选、分级机组,不适于我国农村的生产经营规模。国内目前玉米脱粒机又多为脱粒、风吹、筛选,不能清除同玉米籽粒大小相当的玉米芯及杂物。尤其是我国现阶段使用的玉米脱粒机(下称老式脱粒机),一直采用传统的奶头针齿、封闭式滚筒,存在着脱净率低(特别     

不同浓度NaCl处理对发芽玉米中类胡萝卜素富集的影响

本文旨在研究不同浓度NaCl处理对发芽玉米籽粒中类胡萝卜素富集、抗氧化能力及其合成途径中关键酶基因表达量的影响。结果表明,NaCl胁迫下,发芽3 d玉米籽粒的发芽率和芽长显著下降,呼吸强度显著增加。随NaCl浓度升高,发芽玉米籽粒中类胡萝卜素含量及其合成途径中关键酶基因表达量先上升后下降,300 mmol/L NaCl处理下均达到最大值,其中叶黄素和玉米黄质含量分别为对照的1.19和1.30倍。同时,其超氧化物歧化酶、过氧化物酶活性及总抗氧化能力显著增加。NaCl浓度大于300mmo/L时,关键酶基因相对表达量均下降,类胡萝卜素的合成被抑制。NaCl处理可提高类胡萝卜素合成相关酶基因表达量,促进叶黄素、玉米黄质等类胡萝卜素富集,同时其抗氧化能力有所提高。研究结果为玉米籽粒富集类胡萝卜素开创了新思路,并为开发玉米籽粒保健功能食品提供理论依据和技术支撑。     

干燥后玉米水分不均匀度影响因素的分析与建议

本文根据对顺流式、顺逆流式、混流式、横流式、双塔玉米干燥机及小型玉米干燥机进行全面技术性能测试结果，分析影响玉米干燥后水分不均匀度高的因素。通过对工艺结构的研究分析和实际测试结果的线性分析，认为玉米干燥机工艺结构、穿越粮层风速和粮层厚度是影响干燥后玉米水分不均匀度的主要因素，并针对已有玉米干燥机及新建玉米干燥机，分别提出解决问题的方法。     

圆球导热法测定粮食导热系数研究

采用圆球导热法测定了稻谷、小麦、玉米和大豆的导热系数,并对稳态时间、装样均匀性和水分迁移等影响试验准确性的因素进行了分析.结果表明,该方法测定粮食导热系数的稳定时间至少需要8～10h,通过内外球壁多个热电偶的电势差能确保装样均匀,水分含量分别为10.9%、10.1%、11.0%、6.9%的稻谷、小麦、玉米和大豆的导热系数分别为0.105 4、0.141 8、0.136 2、0.127 4 W/(m·℃),水分迁移对低水分粮食导热系数测定结果的影响可以忽略.     

Corn grain endosperm type and brown midrib 3 corn silage: site of digestion and ruminal digestion kinetics in lactating cows

Interactions of endosperm type of corn grain and the brown midrib 3 (bm3) mutation in corn silage on ruminal kinetics and site of nutrient digestion of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous) and corn silage type (bm3 or isogenic normal). Diets contained 26% neutral detergent fiber (NDF) and 30% starch. Interactions of treatments were not observed for any measure of digestibility, but digestion kinetics of starch and fiber did interact to affect digestible organic matter intake by affecting dry matter intake. Rate of ruminal starch digestion was faster and rate of ruminal starch passage tended to be slower in diets containing corn grain with floury vs. vitreous endosperm, resulting in a mean increase of 22 units for ruminal starch digestibility. Although compensatory postruminal starch digestion decreased differences among treatments for total tract starch digestibility, starch entering the duodenum was more digestible for grain with floury endosperm compared with vitreous grain, resulting in greater total tract starch digestibility for floury compared with vitreous corn grain. Fermentation rate of potentially digestible NDF was not affected by either bm3 corn silage or greater ruminal starch digestion of floury grain. Brown midrib corn silage increased total tract NDF digestibility vs. control silage by numerically increasing ruminal and postruminal digestibility of NDF. Endosperm type of corn grain greatly influences site of starch digestion and should be considered when formulating diets.     

Effects of corn grain endosperm type and conservation method on site of digestion,ruminal digestion kinetics,and flow of nitrogen fractions to the duodenum in lactating dairy cows

Our objective was to evaluate the relative effects of endosperm type and conservation method of corn grain on ruminal kinetics, site of nutrient digestion, and flow of nitrogen fractions to the duodenum in lactating dairy cows. Seven ruminally and duodenally cannulated Holstein cows (73 ± 39 d in milk; mean ± SD) were used in a duplicated 4 × 4 Latin square design with 21-d periods. A 2 × 2 factorial arrangement of treatments was used, with main effects of corn grain endosperm type (floury or vitreous) and conserved as dry ground corn (DGC) or high-moisture corn (HMC). Rations were formulated to contain 27.0% starch, 26.6% neutral detergent fiber (NDF), 19.1% forage NDF, and 16.5% crude protein. Corn grain treatments supplied 86.6% of dietary starch, and alfalfa silage was the sole forage. True ruminal starch digestibility was increased by HMC compared with DGC (87.2 vs. 64.3%) and by floury compared with vitreous corn grain (83.7 vs. 67.7%). The increase for HMC compared with DGC was because of an increase in the degradation rate (33.8 vs. 23.1%/h) and a decrease in passage rate of starch (7.6 vs. 15.2%/h). The increase for floury compared with vitreous corn grain was because of an increase in the degradation rate (31.5 vs. 25.4%/h) and a decrease in rate of starch passage from the rumen (7.9 vs. 14.9%/h). Apparent total-tract starch digestibility was increased by HMC compared with DGC and by floury compared with vitreous corn, but the increase for floury corn was greater for the DGC treatment. Dry ground corn compared with HMC tended to increase nonammonia N flow to the duodenum (466 vs. 431 g/d) by increasing flow of nonammonia nonmicrobial N (211 vs. 111 g/d) despite a decrease in microbial N flow (255 vs. 320 g/d). Vitreous corn increased nonammonia nonmicrobial N flow to the duodenum (187 vs. 135 g/d) compared with floury corn, but microbial N flow to the duodenum was not affected by endosperm type. Efficiency of microbial N production was not affected by treatment. Endosperm type and conservation method of corn grain greatly affect digestion kinetics and ruminal digestibility of starch as well as flow of N fractions to the duodenum and should be considered during diet formulation for lactating cows.     

Corn grain endosperm type and brown midrib 3 corn silage: feeding behavior and milk yield of lactating cows

Interactions of endosperm type of corn grain and the brown midrib 3 mutation (bm3) in corn silage on feeding behavior, productivity, energy balance, and plasma metabolites of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous), and corn silage type (bm3 or isogenic control). Diets contained 26% neutral detergent fiber (NDF) and 30% starch. Floury endosperm grain decreased dry matter intake (DMI) 1.9 kg/ d compared with vitreous grain when combined with control corn silage but did not affect DMI when combined with bm3 corn silage. This interaction of treatments occurred because of changes in meal size; floury endosperm grain decreased meal size in control silage diets but increased meal size in bm3 corn silage diets. Ruminal pool sizes reflected DMI differences among diets, suggesting that ruminal fill was not the primary limitation on intake. Brown midrib 3 corn silage reduced rumination time per day and number of rumination bouts per day. Floury endosperm grain decreased 3.5% fat-corrected milk by 1.2 kg/d when combined with control silage but increased 3.5% fat-corrected milk by 2.1 kg/d when combined with bm3 corn silage. Starch and fiber digestibility interact to affect feeding behavior and milk production and production response to bm3 corn silage depends on the grain source that is fed.     

基于表面诱捕装置的不同食料引诱嗜卷书虱效果比较研究

及时检查监测常见微小害虫书虱的发生动态有利于其早防早治和避免危害，谷物食料诱捕害虫具有取材方便、有利于提高诱捕效率以及对书虱类害虫的种群控制。在20、24和28℃温度下，研究了粮堆表面波纹板诱捕器内置小麦粉、玉米粉、稻谷粉、酵母粉、发霉小麦粉、发霉玉米粉以及发霉稻谷粉等食料后不同时间引诱嗜卷书虱Liposcelis bostrychophila的数量动态。温度28℃时，实验食料中引诱效果最好的酵母粉在14 d内可引诱嗜卷书虱数量达827头，同时发霉小麦粉、发霉玉米粉和发霉稻谷粉中引诱嗜卷书虱的数量分别达662、605和604头，未霉变小麦粉、玉米粉和稻谷粉引诱嗜卷书虱数量分别为479、460和451头。20℃和24℃温度下，以上不同食料同时引诱嗜卷书虱的数量随温度降低相应减少，如酵母粉在对应温度下引诱嗜卷书虱的数量分别降至450和628头。采用GC-MS法测定出小麦粉、玉米粉、稻谷粉、酵母粉、发霉小麦粉、发霉玉米粉以及发霉稻谷粉的挥发物种类数量分别为17、24、20、20、20、23和25种，引诱效果最好的酵母粉的挥发物中芳樟醇、异戊醇、2-甲基丁酸乙酯以及正己醇相对含量较高，同样谷物粉发霉后引诱效果显著增加且这几种挥发物含量也明显增加，初步分析桧烯、1-辛烯-3-醇、2-戊基呋喃、肉桂醛等一定量的存在可能与较好的引诱效果有关，它们对嗜卷书虱的引诱作用值得进一步关注和研究。     

Hydration of grain kernels and its effect on drying

Different hydration methods have been considered and their effect on the drying characteristics of corn and amaranth grains have been studied at different drying temperatures and the results compared with those for the fresh materials. The effect of hydration on drying was found to depend on the type of grain. In general, for corn hydrated grain particles the moisture content was found to be in a looser condition than it was in the fresh grains, and hence, smaller effective diffusion coefficients where found for the latter. Such differences were found to increase with increasing drying temperature. Also a first-order irreversible kinetic model was applied to the drying data for hydrated and fresh corn and a reduction on the drying activation energy was observed by the humidification process. In contrast, for the relatively small amaranth grains, both hydrated and fresh particles showed similar drying characteristics. The results suggest that drying kinetics and transport properties obtained for rehydrated grains can overestimate drying rates for the corresponding freshly harvested material, especially at relatively high moisture contents and for relatively large grain particles like corn.     

Corn grain endosperm type and brown midrib 3 corn silage: ruminal fermentation and N partitioning in lactating cows

Interactions of endosperm type of corn grain and the brown midrib 3 mutation (bm3) in corn silage on ruminal fermentation and microbial efficiency of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous) and corn silage type (bm3 or isogenic normal). Diets contained 26% neutral detergent fiber and 30% starch. Increasing ruminal starch digestibility by replacing vitreous corn grain with floury grain reduced mean and minimum ruminal pH. Brown midrib 3 corn silage reduced mean and minimum ruminal pH and increased total volatile fatty acid concentration. Ruminal pH was positively associated with rate of valerate absorption. Although floury endosperm reduced acetate:propionate ratio in both control and bm3 corn silage diets, it had a greater effect on reducing acetate:propionate ratio for control silage compared with bm3 corn silage. Nonammonia N flow to the duodenum did not differ among treatments and no effects of treatment were detected for microbial N and nonammonia, nonmicrobial N flow. Although treatment effects on ruminal fermentation and ruminal pH were observed, few interactions of treatment were detected and treatments did not affect flow of N fractions to the intestines.     

Effects of corn grain endosperm type and fineness of grind on feed intake,feeding behavior,and productive performance of lactating dairy cows

Our objective was to evaluate effects of corn grain endosperm type and fineness of grind on feed intake, feeding behavior, ruminal fermentation, and productive performance of lactating cows. Eight ruminally and duodenally cannulated Holstein cows in mid lactation (130 ± 42 d in milk; mean ± standard deviation) were used in a duplicated 4 × 4 Latin square design with 21-d periods. A 2 × 2 factorial arrangement of treatments was used with main effects of corn grain endosperm type (floury or vitreous) and fineness of grind of corn grain (fine or medium). Rations were formulated to contain 29% starch, 27% neutral detergent fiber, 18.2% forage neutral detergent fiber, and 18% crude protein. Corn grain treatments supplied 86.2% of dietary starch. Endosperm was 25% vitreous for floury corn and 66% vitreous for vitreous corn. Fineness of grind did not affect dry matter intake (DMI), but floury corn tended to reduce DMI (23.8 vs. 25.1 kg/d) compared with vitreous corn. Floury corn increased meal frequency more for fine grind size (9.57 vs. 9.41 meals/d) than medium grind size (9.78 vs. 9.75 meals/d). However, there were no effects of treatment on any other measure of feeding behavior. Endosperm type did not affect yields of milk or milk components or milk composition except that vitreous corn tended to decrease milk lactose concentration compared with floury corn. Finely ground corn decreased yields of milk (31.1 vs. 33.1 kg/d), 3.5% fat-corrected milk (33.1 vs. 35.1 kg/d), milk fat (1.22 vs. 1.32 kg/d), milk lactose (1.48 vs. 1.59 kg/d), and solids not fat (2.46 vs. 2.63 kg/d) compared with medium grind size. However, fineness of grind did not affect milk composition. Treatments had no effect on change in body weight or body condition score or efficiency of milk production (kg of 3.5% fat-corrected milk/kg of DMI). Mean ruminal pH was not affected by treatment, but pH variance was decreased by vitreous compared with floury corn. Total volatile fatty acids and propionate concentrations in the rumen were increased by floury compared with vitreous corn but were not affected by fineness of grind. Effects of fineness of grind on yield of milk and milk components were greater than the effects of corn grain vitreousness.