中纤板热压机微机测控系统的研究

采用单片机与台式微机结合构成中纤板热压机微机测控系统，用MCS-51汇编语言和基于Windows98的Visual Basic6.0分别编写单片机数据采集与控制程序和微机主控程序，具有数据处理能力强、数据存储量大、操作界面直观方便等优点。系统设计中考虑了系统的可扩展性和通用性，便于系统扩展和移植。     

防霉中密度纤维板的研制

在湿度较大的地区和潮湿的场所,中密度纤维板(下称中纤板)因长期受潮而产生霉变,使其性能受损,更为严重的是污染了居住环境。因此,研究如何防止中纤板霉变,使其具有防霉性能应作为一项重要的课题。笔者通过对防霉剂选择、优化热压工艺参数、防霉效果测试等方面进行了试验研究,确定了适当的防霉剂及其添加量,得出了压制防霉中纤板的优化热压工艺。     

Technological properties and fire performance of medium density fibreboard (MDF) treated with selected polyphosphate-based fire retardants

ABSTRACT

The objective of the work was to evaluate the efficacy of two new polyphosphate-based fire retardants (FRs) and one commercial product named Siriono^® on the fire performance and physical–mechanical properties of medium density fibreboard (MDF) fabricated in the laboratory from Scots pine (Pinus sylvestris L.) wood. The fibres were treated with aqueous solutions of fire retardants, at 12% loading (dry salt on dry wood), and bonded with a melamine urea formaldehyde (MUF) adhesive. The physical and mechanical properties of panels were assessed using the European standards, whereas their fire performance was evaluated using an in-house method and the Cone calorimeter. In overall, the chemicals added enhanced the fire and smoke properties of the panels to varying degrees. Critical FR parameters such as peak heat release rate (peak HRR), total heat release (THR) and total smoke production (TSP) were significantly improved in the FR-treated panels, as exhibited in cone calorimeter tests. However, the internal bond strength of treated panels largely decreased by the addition of fire retardants, while thickness swell and water absorption negatively affected to a significant extent. In contrast, the formaldehyde release of the panels was considerably decreased at the E1 class level, with the incorporation of the polyphosphate-based additives.     

树木盆景无土培育技术探讨

通过采用6种基质，栽培7种树桩盆景，并对结果进行分析。结果表明：a1、a2长势最好，可作树桩盆景无性繁殖的基质，也是树木盆景上盆、换盆的好基质，用其栽培的树木盆景病虫少，能达到出境要求；a3、a4、a5只是盆景繁育的基质，用其培育的盆景若在出口前3－5个月换成a1或a2也能达到出境要求；a6是花卉、蔬菜无土培育液体基质，在中小型盆景中也有运用，在大型盆景中因难以固定而较少使用。     

玉米蛋白粉与豆粕在反刍动物瘤胃内降解动力学评定分析

对玉米蛋白粉(CGM)及豆粕(SBM)的干物质(DM)、有机物(OM)及粗蛋白质(CP)在反刍动物瘤胃内的有效降解率及瘤胃降解前后色氨酸(Trp)的质量分数变化进行比较评定。选用3只装有永久性瘤胃瘘管的平均体质量28kg的育肥哈萨克公羊作为试验动物,采用尼龙袋技术对2种饲料的DM、OM及CP在育肥羊瘤胃内的有效降解率、瘤胃停留时间及降解前后的Trp质量分数进行测定。结果表明:在瘤胃固相食糜的平均外流速度为1.84%·h-1条件下,豆粕和玉米蛋白粉DM、OM及CP的有效降解率(ED)分别为72.86%、66.16%、55.27%和59.66%、59.19%、48.10%,瘤胃停留时间(RRT)分别为14.75h和21.93h。随着豆粕在瘤胃内培养时间的延长,色氨酸质量分数显著降低(P0.05),玉米蛋白粉的色氨酸在降解前后无明显变化(P0.05)。     

Growth performance and feed utilization of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) and tilapia galilae Sarotherodon galilaeus (Linnaeus, 1758) fingerlings fed plant protein-based diets

This study was designed to determine the effect of complete substitution of fish meal (FM) by three plant protein sources including extruded soybean meal (SBM), extruded full‐fat soybean (FFSB) and corn gluten meal (CGM) on growth and feed utilization of Nile tilapia Oreochromis niloticus and tilapia galilae Sarothrodon galilaeus. Four isonitrogenous of crude protein (ca. 28.0%) and isocaloric (ca. 19 MJ kg⁻¹) experimental diets were formulated. The control diet (diet 1) was prepared with FM as the main protein sources. Diets 2–4, each FM control diet, were completely substituted with SBM (diet 2), FFSB (diet 3) and CGM (diet 4). l ‐lysine and dl ‐methionine were added to plant protein diets to cover the nutritional requirements of tilapia. Each treatment was allocated to three net pens and fed for 17 weeks. Nile tilapia fed the control diet showed significantly higher (P≤0.05) values for final body weight (FBW), feed intake (FI), weight gain (WG) and specific growth rate (SGR), whereas fish fed the diet with CGM achieved the lowest values. Tilapia galilae fed SBM diet recorded the highest (P≤0.05) values for growth performance. Better feed conversion ratio (FCR) for both Oreochromis niloticus and Sarothrodon galilaeus was observed when fish were fed SBM diet, whereas the worse FCR was recorded for FFSB diet. Feed utilization parameters including protein productive value (PPV), fat retention (FR) and energy retention (ER) showed significant differences (P≤0.05) for both the species fed different dietary protein sources. The present results suggest that, for Nile tilapia, both SBM and FFSB supplemented with dl ‐methionine and l ‐lysine can completely replace dietary FM. Meanwhile, S. galilaeus fed SBM diet exhibited comparable growth and feed utilization with those fish fed a fish‐meal‐based diet.     

Incorporation of Maize Gluten in Supplementary Feed and its Impact on Growth and Flesh Quality of Some Carps

Maize gluten (a byproduct from the starch industry) was used at four different levels (5, 10, 15 and 20% w/w) replacing the fish meal, a component of supplementary diet, under a semi-intensive culture system. The impact of different diets on the physico-chemical parameters of water, growth and flesh quality of catla, Catla catla; rohu, Labeo rohita; and mrigal, Cirrhina mrigala was studied. Growth in terms of body weight gain was highest when fed a diet having 5% maize gluten (replacing fish meal at 25% level) for all the fish species. However, incorporation of maize gluten at higher levels led to decline in growth, since maize gluten is deficient in essential amino acids like methionine, lysine and threonine, etc. The flesh quality in terms of total protein, total lipid, total sugar, moisture and total ash was also determined at the termination of the experiment to see whether there was any significant variation with the incorporation of maize gluten or not.     

Suitability of enzymatic hydrolyzates of extracted gluten from fresh pasta by-product used as bread improvers

Gluten extracted from fresh pasta by-products (PG) was enzymatically hydrolyzed by two different commercial proteases (Alcalase 2.4 L and Pancreatin) to different degrees of hydrolysis (DH 2.0, 4.0 and 8.0%). Commercial gluten (CG) was used as reference. The evaluation of functional properties of hydrolyzates from pasta gluten (PGH) and commercial gluten (CGH) showed that Pancreatin hydrolyzates had the highest emulsifying capacities. Regarding the foaming activity, all hydrolyzates performed better than unhydrolyzed gluten. PGH and CGH were added to wheat flour (1%) and their effects on dough rheology were studied. Most hydrolyzates with DH 8% increased dough thermal stability and elasticity during mixing, accelerated the denaturation rate of the protein network, and delayed the gelatinization speed of starch as the temperature increased. Texture profiles and specific volumes of breads from low quality wheat flour with added Pancreatin hydrolyzates (DH 8%) were comparable to those of breads from high quality flour. This showed the potential suitability of PGH and CGH as bread improvers.     

基于主成分分析的强筋小麦加工品质综合评价

为有效评价不同强筋小麦品种加工品质的差异,以65个强筋小麦品种（系）为研究对象,对其籽粒、面粉及面团品质特性进行分析,在主成分分析基础上,利用综合得分对供试材料进行品质评价,并利用聚类分析法对其分类。结果表明,在20个品质评价指标中,容重的变异系数最小（1.36%）,面团形成时间的变异系数最大（62.90%）。千粒重与稳定时间、拉伸面积等参数呈极显著负相关;湿面筋含量与籽粒蛋白含量、沉降值呈极显著正相关,与面筋指数呈极显著负相关;面筋指数与面团参数（弱化度除外）呈极显著正相关。通过主成分分析将20个性状综合成5个主成分因子,累计贡献率达到82.437%;其中,第1、2主成分的贡献率较高 （33.083%、25.111%）,分别代表了面团及蛋白质因子。综合评价得分高的品种（系）有6个,为师栾02-1、新麦26、藁优5766、科兴3302、鲁研1403、陕农33,可作为品质改良的亲本材料加以利用。65个材料可分为5个类群,第Ⅰ、Ⅱ类群的籽粒品质较好;第Ⅲ类群的面团品质最佳;第Ⅳ类群的籽粒、面粉及面团的综合性状较好;第Ⅴ类群的籽粒蛋白与面筋含量最高。     

中小河道非法采砂的成因、危害及治理对策--基于桐城市大沙河的实证研究

近年来,对于长江、淮河等重要干支流河道非法采砂的治理,取得了一定的成效,但中小河道非法采砂屡禁不止,严重影响着行洪安全及流域生态环境。该文以桐城市大沙河为例,分析了中小河道非法采砂的成因及危害,并初步探究了治理对策。