红外辐射联合回火与冷激杀菌技术对胡萝卜粉品质的影响

首先研究不同红外辐射温度(100,110,120℃)及辐射时间(2.5,5,10 min)对胡萝卜粉微生物及品质的影响,然后根据栅栏效应原理研究红外辐射-回火、红外辐射-冷激联合杀菌对胡萝卜粉微生物、色调值、类胡萝卜素含量等品质的影响。结果表明:100℃、10 min的红外辐射处理使细菌和真菌分别降低了1.9 lg(CFU/g)和2.32 lg(CFU/g),110℃、5 min的红外辐射处使细菌和真菌分别降低了1.58 lg(CFU/g)和2.57 lg(CFU/g)。在上述两种处理条件下胡萝卜粉的水分活度从0.238分别降至0.123和0.147,胡萝卜粉中总类胡萝卜素含量从308.8μg/g降至227.8μg/g和238.8μg/g,色差值(ΔE)为9.11和7.89。与红外辐射单独作用相比,联合回火后的处理没有显著影响细菌数目,处理后保持在5.40~5.80 CFU/g,霉菌、酵母数却在处理过程中显著减少,然而减少量较低,总数仍不低于4.5 lg(CFU/g)。红外辐射-冷激联合处理相比红外辐射单独处理,100℃、10 min联合冷激7 d处理可将细菌数量降低0.25 lg(CFU/g),可将霉菌与酵母数量降低0.28 lg(CFU/g),110℃、5 min联合冷激7 d处可将细菌数量降低0.26 lg(CFU/g),可将霉菌、酵母数量降低0.40 lg(CFU/g),且这些处理下胡萝卜粉的色调值、水分活度、类胡萝卜素含量变化不显著。本试验结果表明,红外辐射-冷激处理具有协同效应,且处理过程中胡萝卜粉的色调值及总类胡萝卜素含量不受影响,这为低水分粉体食品红外辐射联合杀菌提供了参考。     

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.     

KCl/NaCl/CPI复合盐阳离子聚合物钻井液在南海大斜度井段中的应用

为改善南海东部惠州25-8油田大斜度井因泥岩水化造浆而引起的井壁失稳和钻井液增稠影响携砂的问题,在现有成熟PLUS/KCl钻井液的基础上开展复合盐阳离子聚合物钻井液研究,对钻井液配方进行了优化,评价了优化后钻井液的流变性、抑制性、封堵性和润滑性,并在惠州油田进行了现场应用。结果表明,复合盐阳离子聚合物钻井液配方中,无机盐类抑制剂KCl和NaCl的适宜加量为3%和12%、有机阳离子聚合物抑制剂PF-CPI适宜的加量为2.0%。该钻井液抑制性强,防膨率高达93.32%,钻屑回收率87.56%;受到钻屑侵污后的钻井液流变性能波动小,仍具有较低的黏度和合适的切力,有利于大斜度井携砂;封堵性和润滑性均优于PLUS/KCl钻井液体系。现场应用2口井,钻井液流变性良好,平均起下钻速度提高,钻井过程顺利,无复杂情况发生。复合盐阳离子聚合物钻井液可改善南海大斜度井起下钻阻卡的问题。     

Optimization of room-temperature TCR of polycrystalline La0.9-xSrxK0.1MnO3 ceramics by Sr adjustment

High-density La_0.9-xSr_xK_0.1MnO₃ ceramics (LSKMO, A-site = La, Sr and K, 0 ≤ x ≤ 0.25) are successfully fabricated by using facile sol-gel method. Electrical properties are performed by using combination of phenomenological percolation (PP) model, double exchange (DE) mechanism, and Jahn-Teller (JT) effect. Moreover, X-ray diffraction and scanning electron microscopy are employed to analyze the structure and morphology of LSKMO ceramics. Valence states and ionic stoichiometry are assessed by using X-ray photoemission spectrometry. Results reveal that Sr²⁺ ions, substituting La³⁺ ions, significantly influenced DE mechanism and JT effect. In addition, Sr-doping plays essential role in improving electrical properties of LSKMO ceramics. At optimal doping content of x = 0.09, peak temperature coefficient of resistance (TCR) of the resistivity is found to be 11.56% K^?1 at 297.15 K, which is optimal TCR for A-site K-occupied perovskite manganese oxides. These results confirm that polycrystalline LSKMO ceramics render high room-temperature TCR values due to Sr-doping.     

物料堆场智能化管理经验分享

华润水泥（罗定）有限公司根据物料储存需求，共有三个长堆棚分为9个室内料场堆放原材料及混合材，厂内有4台铲车无规则轮流在这8个料场内作业，同时外来运料货车、公司化验及验收人员也会不间断地进入不同堆棚。由于料场内空间狭窄，驾驶员视线不好，如果堆棚料场内铲车在作业时，有其他人员或车辆进入铲车工作区域共同作业，在没有检测装置对进入的人、车进行识别，提醒铲车驾驶员的情况下，容易发生碾压进入人员或车辆碰撞的安全事故。公司根据现场实际，自2020年起决定实施从堆场出入口智能红外感应技术、装载机车载识别系统、智能声光语音提醒、实时监控显示、照明、堆场硬件设施等五方面实施物料堆场车辆智能化安全预警系统项目。     

一种利用生产动态资料确定水驱前缘的方法

针对长庆油田低渗透储集层岩性致密、注水受效不均衡、单井产量低、平面非均质性强等导致地下水驱不均的问题,依据低渗透油藏水驱理论建立基础模型,并考虑注采井网中生产井的干扰,根据势的叠加原理,引入生产井影响因子系数,建立了井组单元内水驱前缘的简易确定方法。将该方法应用于鄂尔多斯盆地某超低渗透油藏加密调整部署,通过生产实例验证,该方法简便易行,计算结果可靠。     

自动垂直钻井工具分类及发展现状

从石油钻井和地质钻探两方面阐述了自动垂直钻井技术的原理及优点,按照不同结构及工作原理对自动垂直钻井工具做出分类,并简要分析了各类工具的优缺点。随后在上述分类基础上系统归纳了国内外现有垂直钻井工具及其技术特点,剖析了国内外自动垂直钻井工具之间的技术差距。最后总结出自动垂直钻井工具存在的问题,指出工具今后的发展趋势为小型化、可取心、高精度和长寿命,并对其未来的研究思路与方法提出建议:对执行机构零部件结构和布局进行优化,在减小工具外径的同时增大工具内部空间,使工具在小口径井眼垂直钻进的同时还能进行取心作业;对电控式垂直钻井工具的测控传感器及其密封系统进行优化改进,使工具整体耐温耐压性能得到提高;对机械式垂直钻井工具的偏重平台在井下复杂环境下的响应规律进行研究,并探索相应的误差抑制补偿方法,以提高工具的井斜控制精度。     

Study of macromolecular interactions in low‐fat brined cheese modified with Zedu gum

The functionality of Zedu gum as a fat mimetic in low‐fat brined cheese was studied. The physicochemical, textural, rheological, microstructural and sensory properties of cheese samples modified with 0.1% and 0.25% of Zedu gum were compared to those of control cheeses (low‐fat and full‐fat cheeses with no fat mimetic) during ripening. To obtain further information about the cheeses' structure and interactions between macromolecules (casein protein and Zedu gum), other parameters were analysed by differential scanning calorimetry and Fourier transform infrared (FTIR) spectroscopy. Incorporation of Zedu gum into low‐fat cheese caused an open microstructure and softer texture in comparison with the control low‐fat cheese. The thermal properties and FTIR spectra of the cheeses were influenced by both fat mimetic and ripening time. On days 1 and 60 of ripening time, the lower value of enthalpy of the low‐fat cheese with 0.25 g of Zedu gum/kg of milk (AS 0.25) in comparison with control low‐fat cheese could have been due to the electrostatic nature of the interactions between Zedu gum and casein protein. On both days, the FTIR spectrum of AS 0.25 showed a well separated absorption at 1746 cm^?1 possibly due to the formation of ester groups as a result of the interaction of the carbonyl groups in Zedu gum with the hydroxyl groups of some amino acids in casein.