Response of broiler chicks to non-steam- or steam-pelleted diets containing raw,full-fat soybean meal

The objective of this study was to evaluate the effects of steam pelleting of diets containing graded levels of raw, full-fat soybean meal (RSBM) on the chemical properties and feeding values of the diets. Samples of diets with steam- or non-steam-pelleted as well as the mash containing varying levels of RSBM were subjected to detailed chemical analysis. As a result of this study, trypsin inhibitor (TI) concentrations in the diets ranged between 4,153 and 10,484 TIU/g. Amino acid concentrations were higher in the non-steam-pelleted and mash diets than the steam-pelleted diets. A 4 × 2 factorial arrangement (RSBM: zero, 10, 20 or 30%, equivalent to zero, 30, 60, and 90 g/kg of diet, respectively, and non-steam- or steam-pelleted diets) was used while feeding broiler chicks (zero to 14 d of age). Each treatment was replicated 6 times with 8 birds per replicate. As a result of this study, there was no difference (P > 0.05) in mortality of birds among the groups. Feed intake (FI) (P < 0.05) and body weight gain (BWG) (P < 0.001) decreased with increasing levels of RSBM. Birds fed on steam-pelleted diets gained less (P < 0.001) weight than birds on the non-steam-pelleted diets, but the FI was not significantly (P > 0.05) different. The FCR was negatively affected (P < 0.05) by increasing levels of RSBM. There was no interaction effect between RSBM and pelleting method on the FI, BWG, or FCR of birds. The weight of the pancreas (P < 0.001) and duodenum (P < 0.01) increased with a rise in the level of RSBM in diets. Non-steam pelleting increased (P < 0.05) the pancreatic protein content, whereas the activity of chymotrypsin was reduced (P < 0.01) when the RSBM level was increased. Birds fed with RSBM-free diets had thicker muscle, longer villi, wider villus surface area, and higher villus to crypt depth ratios than birds on the other diets, but these differences were not significant. It can be concluded that steam pelleting of diets containing RSBM is inadequate to reduce the adverse impact of TI on chicks.     

烟气中挥发性羰基化合物与卷烟味觉特性相关性研究

[目的]研究烟气中挥发性羰基化合物与卷烟味觉特性的相关性.[方法]通过简单相关分析、偏相关分析和通径分析方法分析了48个烟叶样本中8种挥发性羰基化合物释放量对卷烟味觉特征的影响.[结果]试验表明,甲醛、丙酮、丙烯醛与烟气味觉特征各指标基本都呈显著或极显著正相关,丁醛等与味觉特征没有显著相关性,其中甲醛与苦味,丙烯醛、丙酮与甜味呈良好线性相关,乙醛、丙醛与味觉特征相应显著性指标呈多元线性相关.[结论]研究确定了挥发性羰基化合物对烟气口感特征的影响规律,可为卷烟生产开发更适消费者喜好的产品提供参考依据.     

提高烟片加料回潮机出口含水率CPK值

滚筒式烟片加料回潮机由于料尾部分流量的减少,造成筒体内容积比发生明显的变化,因此料尾部分烟片存在含水率不稳定、料尾含水率超标的烟片量偏大等问题,在一定程度上影响了加料后烟片含水率的均匀性。为此,通过设计改进试验方案,调节料尾阶段蒸汽阀门开度和关闭顺序及时间,最终确定了最佳改进方案。实际运行结果表明,该控制方式稳定可靠,满足了生产的实际需要和质量部门提高过程精度的要求,烟片加料含水率CPK值可以保持在1．33以上,满足了技术指标。     

南美蟛蜞菊叶挥发油化学成分分析

采用水蒸汽蒸馏法提取南美蟛蜞菊叶的挥发油,应用气相色谱-质谱联用(GC-MS)的方法对其挥发油的化学成分进行测试分析,运用气相色谱峰面积归一法确定各个成分的相对百分含量。共分离鉴定出56个化学成分,主要成分为:α-蒎烯(30.35%)、a-水芹烯(16.67%)、D-柠檬烯(15.92%)、1,2,3,4,4a,5,6,8a-八氢-7-甲基-4-亚甲基-1-(1-甲基乙基)-萘(4.71%)、1-乙烯基-1-甲基-2-(1-甲基乙烯基)-4-(1-乙缩醛甲基)-环己烷(4.08%)、石竹烯(3.45%)、1-甲基-2-(1-甲基乙基)-苯(3.37%)等。     

高温短时蒸汽处理对玛咖黑芥子酶活性及品质的影响

【目的】为了提高玛咖贮藏和加工后芥子油苷的含量及改善品质,探讨高温蒸汽烫漂在玛咖块根黑芥子酶钝化上的应用效果。【方法】通过单因素试验考察蒸汽压力、蒸汽处理时间和载料量3个主要因素对玛咖块根黑芥子酶活性及芥子油苷含量的影响,在单因素试验的基础上,以黑芥子酶活性以及芥子油苷含量为响应值,进行Box-Behnken中心组合试验。【结果】利用响应曲面法分析优化最佳蒸汽处理工艺条件为：蒸汽压力0.35 MPa,蒸汽处理时间50 s,载料量为240 g,在此条件下玛咖块根黑芥子酶相对酶活性降低到1.96%,且保留的芥子油苷含量达到0.98%。在达到烫漂终点的要求下,高温短时蒸汽处理的最佳工艺与热水烫漂、微波烫漂相比,营养成分保留较多。【结论】高温短时蒸汽处理能有效钝化玛咖块根黑芥子酶活性,且处理后感官品质较佳,与常规烫漂工艺相比,优势较明显。     

高温高压蒸汽改性落叶松木材力学性能预测模型的建立

利用RBF神经网络和支持向量机两种算法建模,分析落叶松高温高压蒸汽改性工艺参数与其力学性能关系;以落叶松热处理的温度、相对湿度、处理时间3个主要工艺参数作为网络输入,建立了RBF神经网络和支持向量机预测模型,并对两者进行比较。结果表明:支持向量机模型,在网络建立结构、收敛速度和泛化能力上更具优势。     

Steam explosion of crop straws improves the characteristics of biochar as a soil amendment

Five crop straws(wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210°C, 2.5 MPa and then pyrolyzed at 500°C for 2 h. Steam explosion(SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area(SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity(AEC)(6.88–11.44 cmol kg~(–1)) and point of zero net charges(PZNC)(pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.     

高温高压过热蒸汽处理木材的力学特性及化学成分变化

以日长柳杉为试材，经温度80～180℃，相对湿度0～100％的不同条件过热蒸汽处理后的试件，用万能试验机进行横纹压缩试验，探讨不同温度、不同相对湿度条件对木材力学特性的影响；实验同时考察了经不同温度和相对温度处理后的木材化学组分的变化。结果表明：高温高压过热蒸汽处理后，木材的抗压强度没有发生明显变化，其化学成分发生了微小的变化。     

蒸汽爆破参数对菜籽粕中总硫苷脱毒效果的影响

本试验旨在研究蒸汽爆破参数(水料比、蒸汽压强、维压时间)对菜籽粕中总硫苷脱毒效果的影响,并用体外仿生法对脱毒菜籽粕的营养物质消化率进行评价。试验均采用单因素试验设计,分别筛选出最适的水料比、维压时间与蒸汽压强,每个试验处理设4个水平,每个水平3个重复。结果表明:蒸汽爆破处理对菜籽粕中总硫苷的脱毒效果明显,总硫苷脱毒率达73.71%~86.98%。以总硫苷脱毒率为筛选指标,按单因素试验设计,分别筛选出最适的水料比为25%,最适的维压时间为60 s,最适的蒸汽压强为2.0 MPa。以菜籽粕营养物质消化率筛选指标时发现,与未处理组相比,1.0、1.5 MPa(固定水料比为25%、维压时间为60 s)蒸汽压强对菜籽粕营养物质消化率无显著影响(P0.05),2.0 MPa蒸汽压强时可显著或极显著降低粗蛋白质、赖氨酸、精氨酸的消化率(P0.05或P0.01),提高蒸汽压强可极显著降低总硫苷、异硫氰酸酯的含量(P0.01)。综合考虑总硫苷脱毒率与营养物质消化率指标,当固定水料比为25%、维压时间为60 s时,适宜的蒸汽压强以不大于2.0 MPa为宜。     

A review of non-chemical weed control on hard surfaces

Weed control research to date has mainly focused on arable land, especially regarding herbicides, but also regarding non‐chemical methods. Some of these experiences can be applied to hard surface areas. However, weeds on hard surface areas cause problems that are different from those on arable land. Additionally, crop tolerance does not need to be considered when choosing an appropriate weed control method on these areas. The aim of this review is to describe current knowledge of weeds and weed control methods on hard surface areas and reveal potential ways of advancement. One of the shortcomings of non‐chemical weed control on hard surfaces thus far, is a lack of proper definition of efficiency of the weed control methods. To obtain effective control, more frequently repeated treatments are required than chemical weed management, thereby increasing the costs of labour and fuel. One way to reduce costs can be by adjusting the level of control to the required visual street quality. Weeds are adapted to the hard surface environment and may be less susceptible to certain control methods. This review indicates that for efficient weed control on hard surfaces there is a need for combining weed control techniques, applying sensors for detecting weeds, adapting the energy dose to type of weed flora and prevention of weeds by improved construction of new surfaces.