As the number falls,alternatives to the Hagberg–Perten falling number method: A review

This review examines the application, limitations, and potential alternatives to the Hagberg–Perten falling number (FN) method used in the global wheat industry for detecting the risk of poor end-product quality mainly due to starch degradation by the enzyme α-amylase. By viscometry, the FN test indirectly detects the presence of α-amylase, the primary enzyme that digests starch. Elevated α-amylase results in low FN and damages wheat product quality resulting in cakes that fall, and sticky bread and noodles. Low FN can occur from preharvest sprouting (PHS) and late maturity α-amylase (LMA). Moist or rainy conditions before harvest cause PHS on the mother plant. Continuously cool or fluctuating temperatures during the grain filling stage cause LMA. Due to the expression of additional hydrolytic enzymes, PHS has a stronger negative impact than LMA. Wheat grain with low FN/high α-amylase results in serious losses for farmers, traders, millers, and bakers worldwide. Although blending of low FN grain with sound wheat may be used as a means of moving affected grain through the marketplace, care must be taken to avoid grain lots from falling below contract-specified FN. A large amount of sound wheat can be ruined if mixed with a small amount of sprouted wheat. The FN method is widely employed to detect α-amylase after harvest. However, it has several limitations, including sampling variability, high cost, labor intensiveness, the destructive nature of the test, and an inability to differentiate between LMA and PHS. Faster, cheaper, and more accurate alternatives could improve breeding for resistance to PHS and LMA and could preserve the value of wheat grain by avoiding inadvertent mixing of high- and low-FN grain by enabling testing at more stages of the value stream including at harvest, delivery, transport, storage, and milling. Alternatives to the FN method explored here include the Rapid Visco Analyzer, enzyme assays, immunoassays, near-infrared spectroscopy, and hyperspectral imaging.     

复杂型急倾斜煤层的开采技术探析

中国煤炭资源多处于中厚煤层中,伴随煤炭资源的不断开采,矿井深度日渐增加,煤层的开采环境也日渐复杂,其中复杂型急倾斜煤层对开采技术和开采施工工艺水平的要求较为突出。课题基于中国复杂型急倾斜煤层开发工艺的现状,深入分析了现有工艺在实际开采过程中存在的不足,提出了伪倾斜斜坡短臂采煤法,旨在为中国复杂型急倾斜煤层开采工艺的研究提供借鉴。     

降膜蒸发管内插往复螺旋强化传热实验研究

为有效解决降膜蒸发器加热管中传热效率与结垢问题，提出了一种降膜蒸发管内插往复螺旋强化传热技术，强化管内插螺旋运动与管壁碰撞过程。实验研究内插螺旋的结构参数、螺旋往复行程，以及热通量、蒸发压力以及溶液喷淋密度等工艺参数对降膜蒸发过程传热性能影响。实验结果表明，此技术的除垢防垢性能及传热性能优于空管及单纯的内插螺旋性能，在螺旋外径d=30 mm、螺距f=45 mm、丝径e=1.8 mm、往复行程H=100 mm时，其传热系数分别是空管和单纯的内插螺旋的2.08和1.26倍。通过对管内蒸发侧传热系数进行分析，总结得到与热通量、蒸发压力以及溶液喷淋密度相关的降膜蒸发传热系数关联式。     

46700m~2楼房一次爆破拆除

东北汽配城为框架结构,总建筑面积46700m2,周边环境非常复杂。该建筑物共有260根柱子,断面尺寸不尽相同。按建筑伸缩缝将楼房分为5个部分,分别采用了原地坍塌、定向倾倒、折叠倾倒一次控制爆破技术,并将土石方爆破的斜线起爆技术用于拆除爆破。由于爆破设计、施工及安全措施得当,爆破获得圆满成功。     

深基坑开挖塌方原因分析及处理方法

原定的施工方案存在缺陷以及施工环境隐伏的各种不利因素,促使“银团公寓”Ｂ２_栋基坑边坡发生局部坍塌。该文通过分析和论证,总结教训,积累经验,为从事专业工程技术人员提供有益的参考资料。     

采用异步机矢量控制的矿井提升机开机特性的分析及改进

分析了矢量控制的原理和数学模型，结合矿井提升机的工作特性，通过Matlab仿真，指出造成提升机下坠的根本原因及影响因素，并提出了相应的解决方案，即采用复合控制策略，在原有系统基础上增加给定前馈和扰动前馈环节.计算机仿真结果表明：此方案可大大减轻乃至消除提升机下坠现象.即使称重有误差，产生的下坠现象也非常轻微.     

孝义铝矿索道运输掉斗原因的分析和改进措施

孝义铝矿索道运输矿斗经常出现掉斗现象，严重影响山西铝厂的矿石供应。在对掉斗原因进行分析的基础上，提出了相应的改进措施，提高了矿斗零部件的可靠性和使用寿命，改善了矿斗的结构设计，实施后掉斗率由19％降至1.8％。     

某矿山冒顶片帮事故的事故树分析

运用事故树分析法，对引发冒项片帮事故的各种因素进行了定性分析，并提出了相应的预防措施。     

叉流平板式间接蒸发冷却过程数值模拟

建立了数学模型,对叉流平板式间接蒸发冷却过程进行了数值模拟分析,得到了分别沿一、二次空气流动方向一次空气干球温度和二次空气干湿球温度的分布,以及水膜温度的变化情况。     

重物高空坠落撞击多层钢筋混凝土楼板的仿真计算分析

本文针对重物高空坠落高速撞击钢筋混凝土楼（屋）盖时的结构损伤分析，根据弹塑性靶板理论以及动能守恒定理提出了一种计算板及周边梁中内力的简化手算算法。计算结果和现场实测资料吻合，说明该算法可以用于实际工程。