日本特殊胶合板农林标准(续1)

(4)冷热循环试验(冷热循环A、B、C、D试验) ①试件的制作 从各试验胶合板上分别截取2片边长150mm正方形试件,供冷热循环试验A的试件中心开直径3mm     

陕北红枣中多糖的提取与分离工艺优选

以多糖含量、多糖得率为指标，采用正交试验法对陕北红枣中多糖的提取与分离工艺进行优选。水煎煮提取的最佳工艺为：优化水平组合为A2B1C2,A2B3C1、A2B23、温度为80—900C、料水比为1：15最佳；分离的最佳工艺为：分级沉淀多糖时，采用浓缩液：无水乙醇（v／v）以1：3效果最好；当采用活性炭脱色时，活性炭用量为7g／L时，即可完全脱色。     

生物柴油副产物甘油发酵生产1,3-丙二醇的研究

对利用不同生物柴油副产物粗甘油发酵生产1,3-丙二醇的试验条件进行了研究。批次发酵试验结果表明:精制甘油(纯度98%)、生物柴油副产物粗甘油A(纯度83%)和B(纯度78%)及C(纯度68%)生成1,3-丙二醇的转化率分别为52.38%、48.08%、45.22%、39.95%;精制甘油、粗甘油A和B及C的流加补料发酵合成1,3-丙二醇的转化率分别为51.45%、44.63%、41.27%、35.39%。经济效益粗略评估分析表明,生物柴油副产物粗甘油A和B生产单位1,3-丙二醇较精制甘油成本低,生物柴油副产物粗甘油C却较精制甘油成本高。     

制绳用高强度镀锌钢丝生产工艺研究

从原料选择、生产工艺等方面研究制绳用高强度镀锌钢丝生产工艺。选用A厂家70#钢盘条生产2.35 mm待镀钢丝,扭转时偶尔出现劈裂,钢丝镀锌及捻制钢丝绳时出现少量断丝;选用B厂家82B盘条生产的待镀钢丝,扭转试验劈裂严重,镀锌及捻制钢丝绳时断丝频繁;选用C厂家90A盘条分别生产3.00、3.30 mm的待镀钢丝,断丝少、无扭转劈裂,性能均匀、稳定。结果表明:小规格的σb≥1 960 MPa级镀锌钢丝应选用70#、72A盘条生产;大规格σb≥1 960 MPa级镀锌钢丝选用90A优质热轧盘条生产;由于82B盘条生产的钢丝韧性差,因而不适合生产制绳用高强度镀锌钢丝。     

不同鞋底结构网球鞋的运动生物力学性能研究

基于网球技术动作特征，根据既有运动鞋生物力学研究成果，本文以止滑试验机、肌电仪、测力板对3种不同鞋底结构网球鞋(A、B、C)的运动生物力学性能差异进行了试验测试。结果发现，虽然不同鞋底结构的网球鞋止滑性与耐磨性不存在显著性差异，但A网球鞋最具止滑性，B网球鞋最具耐磨性；穿着不同鞋底结构的网球鞋时下肢肌肉在各个通道时的做功不存在显著性差异；稳定慢跑持续1 min时，穿着A网球鞋时总做功最大，穿着B网球鞋时次之，穿着C网球鞋时最小，说明C网球鞋可有效降低身体能量消耗，具备一定能量回归作用；穿着B网球鞋与C网球鞋时左右下肢肌肉总做功存在显著线性相关，且存在显著性差异；而穿着A、B、C 3款网球鞋时下肢肌肉总做功差异并不显著。     

米甜酒饮料中饭粒的悬浮稳定性研究

该试验通过对添加了增稠剂A、B、C及其不同组合的甜酒酿进行饭粒悬浮稳定性研究。结果表明:在密度不变的条件下,甜酒酿饭粒悬浮稳定所需的粘度值与增稠剂种类有关,且不能单靠增粘的方法来达到甜酒酿饭粒的悬浮稳定;添加增稠剂A或B或B C或B A可达到对甜酒酿饭粒的悬浮稳定;流动性大小为:B>B C>A>B A;热稳定性为:B>A>B C>B A;添加增稠剂C或A C达不到对甜酒酿饭粒的悬浮稳定效果。     

储存条件对啤酒花中α-酸含量的影响

研究香型啤酒花扎一(SA-1)和苦型啤酒花纳盖特(Nugget)、马可波罗(Marco Polo)、青岛大花(Tsingdao flower)4个啤酒花品种在不同的储藏条件下α-酸的变化。以α-酸为试验指标,采用正交试验法对时间(A)、残氧量(B)、温度(C)3个影响因素进行研究。青岛大花最佳储存方案是A1B2C1,扎一香花最佳储存方案是A1B3C1,纳盖特最佳储存方案是A2B2C1,马可波罗最佳储存方案是A3B3C1。     

中草药抗热应激剂对高温环境奶牛生产性能的影响

选用32头健康无病,体重、年龄、胎次、泌乳量、乳脂率、乳蛋白和乳固形物等相近的中国黑白花奶牛,对照组饲喂基础日粮,试验组在饲喂基础日粮的基础上分别添加50、100和150 g/(头·d)中草药抗热应激剂,进行中草药抗热应激剂缓解高温天气对奶牛的影响试验,试验期为40 d.结果表明,B、C和D组每头奶牛平均日产奶量比A组分别增加1.89、2.62和2.83 kg,提高幅度分别为11.91%、16.51%和17.83%,差异均极显著(P＜0.01).在乳脂率方面,B、C和D组比A组分别提高0.10、0.23和0.15个百分点,提高幅度分别为3.47%、7.99%和5.21%,其中C组差异显著(P＜0.05);在乳蛋白方面,B、C和D组比A组分别提高0.06、0.10和0.08个百分点,差异不显著(P＞0.05);B、C和D组乳固形物比A组分别提高0.39、0.42和0.38个百分点.B、C和D组比A组每头每日分别多收入2.64、3.08和2.53元.     

杂粮饭的预测与真实血糖指数差异性分析

为探究混合杂粮饭的真实血糖指数(GI)和血糖负荷(GL)与预测值的差异,从9种全谷豆类中选择4种食材组合成杂粮饭测试餐A1、A2、B和C,测定10名健康成年人进食后的血糖指数,计算血糖负荷及水解指数(HI)。结果表明:杂粮饭A2、B、C的GI值分别为60,66,48,GL值分别为23,23,16。采用电饭锅"杂粮饭"程序烹调时,杂粮饭A1的GI值和GL值均升高,分别为69和26。与用文献值计算法或体外碳水化合物水解法预测含豆类测试餐的GI值均有较大误差。     

流槽对筒仓双侧壁卸料动态压力分布影响研究

通过模型实验和离散元模拟,研究安装流槽对筒仓动态侧压力环向分布规律的影响,分析颗粒在普通筒仓双侧壁卸料和带流槽双侧壁卸料过程中的力学行为.研究表明:(1)在筒仓0.6～1.1 m深度范围内带流槽筒仓双侧壁卸料工况下侧压力均要小于普通筒仓双侧壁卸料;(2)与大偏心单侧壁卸料模式一样,双侧壁对称卸料模式下同一水平面环向侧压...     

半地下双层浅圆仓施工过程中力学性能的数值分析

作为一种新仓型,半地下双层浅圆仓具有节约用地、节约能源、机械化程度高的优势,并可保证储粮品质。论文采用实体单元建立数值模型,根据场地地质条件与实际状态设置边界条件,构建了半地下双层浅圆仓的数值分析方法;经与地下粮仓的足尺试验结果进行对比,验证了数值模拟方法的可行性。通过对半地下双层浅圆仓施工过程中回填前后的受力性能进行分析,研究表明：仓底在回填前距锥底2/3处径向、环向应力达到峰值;首层仓壁在回填后距锥底1/3处径向、环向应力达到峰值。该研究可为半地下双层浅圆仓工程设计与施工提供理论支持。     

外包钢板地下散装粮仓仓壁构造及受力分析

为加强地下钢筋混凝土圆形散装粮仓的防水效果,把外包钢板技术引入到地下仓的建造中,把防水与结构受力有机结合起来。在空仓与满仓工况下,利用ABAQUS有限元对筒仓进行分析,可知采用外包钢板地下粮仓形变分别为钢筋混凝土地下粮仓的25.8%与14.25%,通过对仓壁进行经济分析,与钢筋混凝土地下粮仓相比,外包钢板地下粮仓可节约混凝土用量28.19%,节约钢材用量75.20%,因此外包钢板地下粮仓具有良好的结构稳定性与经济性。     

一种新型行列布置立筒仓的结构力学设计要点

立筒仓以容量大、占地面积小、力学性能好等优势成为大仓容储粮的首选,但仓群中星仓积粮和容积小的问题一直以来没有得到很好解决.基于midas Gen2019软件,针对某港区综合码头工程项目立筒仓进行拉大排仓的间距,以短墙连接排仓形成了一种新型筒仓布置方式,通过对7种粮食荷载工况的整体有限元模拟分析,获得了短墙及相邻仓壁的内...     

Fiber-on-fiber friction measurement using hanging fiber method

Estimation and evaluation of frictional behavior of delicate materials such as textile fibers is contingent upon existence of accurate experimental methods. In this work, the effect of fiber fineness on frictional behavior of polypropylene fibers was investigated using a developed high-precision experimental setup based on hanging fiber method. Fiber fineness was varied by varying the spinning pump speed during production of melt-spun fibers on an industrial scale melt spinning machine. Data acquisition was achieved using Delphi programming software. A geometrical model capable of evaluating the frictional force between two in-contact identical fibers was proposed. Fiber-on-fiber frictional force was expressed by a third degree polynomial function of fiber diameter. The least value of frictional force was found to belong to fiber diameter of 49.1 μm which corresponds to linear density of 15.5 den. It was concluded that frictional behavior of fibers is influenced by factors such as contact point geometry, rate of fiber strain and profile of generated heat.     

Comparative analysis of the mycobiota and mycotoxins contaminating corn trench silos and silo bags

BACKGROUND: Silage is one of the most important feed sources for bovines. Mycotoxin contamination of feedstuffs is a worldwide concern. The aim of this study was to compare mycobiota and levels of aflatoxin B₁ (AFB₁), fumonisin B₁ (FB₁), deoxynivalenol (DON), zearalenone (ZEA) and patulin (PAT) in corn trench silos and silo bags. RESULTS: Dry matter was higher in trench silos. Counts varied from not detected to 10⁸ CFU g^?1 in both trench silos and silo bags. Isolation frequencies of Aspergillus spp. and Fusarium spp. were higher in trench silos, whereas Penicillium spp. was higher in silo bags. Silo bags showed less diversity than trench silos. Strains isolated produced AFB₁, FB₁ and PAT. In trench silos, AFB₁ was the only mycotoxin detected (1–160 µg kg^?1). In silo bags AFB₁ levels varied from 5.8 to 47.4 µg kg^?1. DON was detected in two silo bag samples. CONCLUSION: When handling is adequate the reduction of mould and mycotoxin contamination in silo bags is considerable. This study will enable estimation of the mycotoxicological risk of different ensiling practices and determination of the most adequate method to minimize economic losses and reduce hazard to animal and human health. Copyright © 2011 Society of Chemical Industry     

Effects of using wind exhausters on the quality and cost of soybean storage on a real scale

The objective of this study was to evaluate the effects of the wind exhaustion system (with and without natural lighting) during soybean storage (0, 3, and 6 months) on energy cost, mass temperature, mass loss, and soybean quality. During storage, the silo without exhaustion required more hours of aeration (191 h), higher energy consumption (9550 kW), and showed higher reduction in moisture content (2.07%) and loss of mass (105 t), when compared to silos with exhaustion and light and with exhaustion and no light. Fermented and moldy defects increased during storage, with a higher incidence of mold in the silo with exhaustion and no light when compared to the silo without exhaustion. Germination and soluble protein decreased during storage, but no difference was observed between silos. The acidity increased during storage, with the higher acidity being found in the silo with exhaustion and light when compared to the silo without exhaustion. The silo with exhaustion and light had an increase in electrical conductivity during storage, however, the lower electrical conductivity in 6 months was observed in the silo without exhaustion. The yellow coloration (b*-value) and the luminosity (L*-value) of the grains decreased during storage in silos with exhaustion and light and in the silo with exhaustion and no light. All silos had good conservability during storage, with acceptable values in all analyzed parameters. The excess of aeration promoted the soybean drying to safer levels of storage in the silo without exhaustion, however, the cost of storage was higher in that silo.     

筒仓中小麦密度分布值的有限元分析

筒仓中粮堆密度分布值是预测筒仓中粮食对仓壁的压力、确定粮食通风阻力、计算筒仓中粮食质量的关键参数.使用有限元方法求解小麦堆的修正剑桥模型计算出筒仓中小麦堆的密度分布值.结果 表明,筒仓中小麦堆的密度随着粮层深度的增加而逐渐增大,但在筒仓拐角处密度随着粮层深度的增加而逐渐减小.在上部粮层,粮块密度随着粮块与筒仓中心轴距离...     

Lining bunker walls with oxygen barrier film reduces nutrient losses in corn silages

The objective of this study was to evaluate 2 systems for covering corn silage in bunker silos. The first system consisted of a sheet of 45-μm-thick oxygen barrier film (OB, polyethylene + ethylene-vinyl alcohol) placed along the length of the sidewall before filling. After filling, the excess film was pulled over the wall on top of the silage, and a sheet of polyethylene was placed on top. The second system involved using a standard sheet (ST) of 180-μm-thick polyethylene film. Eight commercial bunker silos were divided into 2 parts lengthwise so that one-half of the silo was covered with OB and the other half with a ST system. During the filling, 3 net bags with chopped corn were buried in the central part (halfway between the top and bottom of the silo) of the bunkers (CCOR) in 3 sections 10 m apart. After filling, 18 net bags (9 per covering system) were buried 40 cm below the top surface of the 3 sections. These bags were placed at 3 distances from the bunker walls (0 to 50 cm, 51 to 100 cm, and 101 to 150 cm). During unloading, the bags were removed from the silos to determine the dry matter (DM) losses, fermentation end products, and nutritive value. The Milk2006 spreadsheet was used to estimate milk per tonne of DM. The model included the fixed effect of treatment (7 different locations in the bunker) and the random effect of the silo. Two contrasts were tested to compare silages in the top laterals (shoulders) with that in the CCOR (CCOR vs. OB and CCOR vs. ST). Three contrasts compared the corresponding distances of the silage covered by the 2 systems (OB50 vs. ST50, OB100 vs. ST100 and OB150 vs. ST150). Variables were analyzed with the PROC MIXED procedure of the SAS at the 5% level. The OB method produced well-fermented silages, which were similar to CCOR, whereas the OB system showed less lactic acid and greater pH and mold counts compared with CCOR. The ST method had 116.2 kg of milk/t less than the CCOR, as the OB system and the CCOR were similar (1,258.3 and 1,294.0 kg/t, respectively). Regarding the distances from the walls, the effects were more pronounced from 0 to 101 cm. The OB50 and OB100 silages had better quality and lower mold counts and DM losses than ST50 and ST100. The OB system reduced DM and nutrient losses at the shoulders in farm bunker corn silages compared with no sidewall plastic. The OB film should lap onto the crop for at least 200 cm so that 150 cm are covered outward from the wall.     

不同储粮粮仓稻谷品质及其霉菌数量的差异分析

对湖南省不同地区粮仓（金山仓、金牛仓、银光仓）及粮仓不同位置（上层、中层、下层）稻谷霉菌总数、水分含量、脂肪酸值和出糙率进行测定与比较,分析稻谷霉菌与品质变化的差异及相关性。结果表明,不同粮仓及取样层位间稻谷霉菌总数差异显著（P＜0.05）,银光仓＞金山仓＞金牛仓,上层＞中层＞下层。同一粮仓不同取样点位间稻谷霉菌总数差异不显著（P＞0.05）;金山仓与金牛仓稻谷品质相对较好,银光仓最差;同一粮仓不同层位稻谷水分含量与脂肪酸值均为上层＞中层＞下层,出糙率为下层＞中层＞上层,差异显著（P＜0.05）;同一粮仓不同点位稻谷水分含量、脂肪酸值与出糙率均存在显著性差异（P＜0.05）。霉菌总数与水分含量、脂肪酸值、出糙率均有一定相关性,脂肪酸值与水分含量无显著相关性（P＞0.05）。     

Persistence strategies of Bacillus cereus spores isolated from dairy silo tanks

Survival of Bacillus cereus spores of dairy silo tank origin was investigated under conditions simulating those in operational dairy silos. Twenty-three strains were selected to represent all B. cereus isolates (n = 457) with genotypes (RAPD-PCR) that frequently colonised the silo tanks of at least two of the sampled eight dairies. The spores were studied for survival when immersed in liquids used for cleaning-in-place (1.0% sodium hydroxide at pH 13.1, 75 °C; 0.9% nitric acid at pH 0.8, 65 °C), for adhesion onto nonliving surfaces at 4 °C and for germination and biofilm formation in milk. Four groups with different strategies for survival were identified. First, high survival (log 15 min kill ≤1.5) in the hot-alkaline wash liquid. Second, efficient adherence of the spores to stainless steel from cold water. Third, a cereulide producing group with spores characterised by slow germination in rich medium and well preserved viability when exposed to heating at 90 °C. Fourth, spores capable of germinating at 8 °C and possessing the cspA gene. There were indications that spores highly resistant to hot 1% sodium hydroxide may be effectively inactivated by hot 0.9% nitric acid. Eight out of the 14 dairy silo tank isolates possessing hot-alkali resistant spores were capable of germinating and forming biofilm in whole milk, not previously reported for B. cereus.