纳米SiO_2添加量对水性木器涂料漆膜质量的影响

本实验在水性丙烯酸面漆涂料中加入纳米SiO_2并对其改性,旨在保证光泽度的前提下提升其硬度和耐磨性等理化性能。试验测试结果表明,当纳米SiO_2添加量高于5%时,试液结团严重;当添加量在0.5%~1.5%时,漆膜光泽度符合产品需求且附着力较佳;当添加量在0.5%~3%时,漆膜硬度达到国标要求,且在3%时硬度最好;随着添加量的增加,漆膜耐磨性增强,但当添加量达到3%时,漆膜耐磨性最低。笔者综合评定光泽度、硬度、耐磨性、附着力、施工粘度、成本这几项因素,确定1%为改性剂纳米SiO_2的最佳添加量,     

谷氨酰胺转胺酶和磷酸盐对鱿鱼鱼糜凝胶性能的影响

研究添加谷氨酰胺转胺酶(TGase)和磷酸盐对鱿鱼鱼糜凝胶硬度和弹性的影响。结果表明:TGase和磷酸盐在鱼糜凝胶化过程中起重要作用,且不同添加量的TGase和磷酸盐均可提高鱿鱼鱼糜的硬度和弹性;单因素试验确定最佳添加量为(以鱼糜质量为基本):TGase(100U/g)0.50%、焦磷酸钠0.30%、六偏磷酸钠0.30%、三聚磷酸钠0.30%;采取二段加热法(60℃保温1h),鱼糜的硬度、弹性达到最大。     

纳米二氧化钛对木器硝基涂料性能的影响研究

采用纳米TiO_2对硝基涂料进行改性,并对改性后的木器硝基涂料涂层的力学性能(耐磨性、硬度、附着力和抗冲击性能)和光学性能进行测试,探究纳米TiO_2对涂膜的力学性能与光学性能的影响。结果表明:实验中纳米TiO_2添加量的不同对涂膜硬度和附着力没有产生显著影响,添加量为0.1 g时涂膜耐磨性较好并处于亚光状态,此时纳米TiO_2与涂料的质量比为1:30。当进一步使用0.01 g烷基烯酮二聚体对0.1 g纳米TiO_2进行表面修饰后,得到的涂膜性能达到最佳,此时涂膜硬度为HB、附着力为1级、磨耗值为0.024 g、光泽度为19%。该研究丰富了无机纳米粒子(TiO_2)改性硝基涂料的应用范围。     

对AZ31B镁合金固相再生后的力学性能研究

伴随着科学技术的迅速发展,我们能够在很多领域看到镁合金的使用,比如在航天、交通、信息、日常生活等,但是在使用镁合金的过程中我们会发现废弃的大量零部件无法处理从而导致很多浪费,怎么合理处理这些废料成了我们的当务之急。针对这个问题深入研究屑尺寸、挤压温度和挤压比三种因素对固相再生AZ31B镁合金力学性能的影响,通过实验发现固相再生工艺参数对AZ31B镁合金力学性能有着重要的影响,利用镁合金再生技术回收废料是可行的,对于保护环境资源和产业发展具有十分重要的技术价值。     

卡拉胶对南酸枣糕质构性质的影响

通过质构仪分析,研究卡拉胶添加量对南酸枣糕质构性质的影响,并利用扫描电镜分析其内部结构,比较不同卡拉胶添加量,各参数(硬度、弹性、咀嚼性、黏性)的差异性和相关性。结果表明:卡拉胶添加量为0.0%～0.6%时,南酸枣糕的硬度、咀嚼性基本不变,而添加量为0.6%～1.0%时,硬度、咀嚼性增加比较显著,且硬度和咀嚼性之间具有良好的线性相关性。弹性随着卡拉胶添加量的增加而增加,而黏性随着卡拉胶的增加先增加后降低,且在卡拉胶添加量为0.8%时达到最大值。从电镜扫描图中可看出,随着卡拉胶的增加,南酸枣糕能形成较厚实的凝胶,质地更紧密,外观特征更均匀。     

超高强度气门簧用线材的开发

介绍日本超高强度气门簧用线材的发展过程:在SAE9254钢的基础上增加C含量,同时添加V元素,开发出KHV7钢,经过渗氮处理后,钢丝的疲劳强度提高到SAE9254钢的1.3倍;为减少回火造成的抗拉强度降低,使Si元素的质量分数达到2.0%,开发出KHV10N钢,经过渗氮处理和喷丸处理后,钢丝疲劳强度可以达到SAE9254钢的1.4倍;加大Cr,V的添加量,生产出超高强度的KHV12N钢,钢丝疲劳强度可以达到SAE9254钢的1.55倍。分析钢中各添加元素的作用机制和夹杂物对疲劳强度影响及控制方法,给出各钢种的化学成分组成、油淬火后钢丝的力学性能、退火后的钢丝力学性能及金相组织照片。     

纳米纤维素对豌豆淀粉糊化特性和质构特性影响

该文研究了小麦纳米纤维素对豌豆淀粉糊化特性和质构特性的影响。快速黏度分析仪(RVA)分析表明:小麦纳米纤维素添加量为0%²0%时,豌豆淀粉的糊化温度无明显变化,峰值黏度、谷值黏度、末值黏度、衰减值和回生值均随小麦纳米纤维素添加量的增加而升高。TA.XT Plus物性测定仪(TPA)结果表明:小麦纳米纤维素的添加对豌豆淀粉凝胶的弹性无影响,小麦纳米纤维素的添加量为5%时,豌豆淀粉的凝胶硬度下降;添加量为10%20%时,豌豆淀粉的糊化温度无明显变化,峰值黏度、谷值黏度、末值黏度、衰减值和回生值均随小麦纳米纤维素添加量的增加而升高。TA.XT Plus物性测定仪(TPA)结果表明:小麦纳米纤维素的添加对豌豆淀粉凝胶的弹性无影响,小麦纳米纤维素的添加量为5%时,豌豆淀粉的凝胶硬度下降;添加量为10%²0%,豌豆淀粉的凝胶硬度增加,最大达到927.29 g。     

谷氨酰胺转氨酶对鸡蛋全蛋液热凝固性的影响

通过物性测定仪分析的方法,探讨NaCl添加量、pH值、谷氨酰胺转氨酶(TGase)添加量、酶作用温度、酶作用时间对鸡蛋全蛋液热处理后的凝胶硬度的影响,旨在拓展TGase在蛋品行业的应用,为传统蒸蛋的工业化生产提供一定的数据支持。结果表明:TGase处理全蛋液提高了全蛋液在加热后的凝胶硬度。且在NaCl添加量为2%,pH值为7.00,TGase添加量为1.2U/mL·全蛋液,酶作用温度为30℃,酶作用时间为4h时,所得全蛋液在加热后凝胶硬度达到最大(52.375g)。     

藜麦粉对小麦面团、面包质构特性及品质的影响

研究藜麦粉对小麦面团及面包质构特性的影响,为开发藜麦焙烤食品提供理论依据。在对藜麦粉中蛋白组分含量系统研究的基础上,利用质构仪的TPA模式测定添加藜麦粉对小麦面团硬度、弹性和黏性的影响,藜麦粉对面包硬度和弹性的影响。结果表明,随着藜麦粉添加量的增加,面团的硬度呈先减小后增加的趋势,添加量为15%时硬度最小;弹性呈先增大后减小的趋势,在藜麦粉添加量15%时达到最大值,黏性呈逐渐增大的趋势。随着藜麦粉添加量的增加,面包的硬度逐渐增大,弹性逐渐减小,感官评分先增大后减小,在15%时达到最大值。因此,藜麦粉的添加改变了小麦面团和面包的质构特性,且面团的质构特性与面包质构特性、面包感官品质间具有一定相关性。     

全氟庚烷对木材表面环氧生漆性能的影响

通过测试附着力、涂膜硬度、涂膜光泽度、涂膜色差和涂膜耐水性能等,研究了全氟庚烷的添加量对天然生漆性能的影响。研究结果表明全氟庚烷的添加量对天然生漆的干燥时间和附着力没有明显影响,当全氟庚烷的添加量在2%以下时,天然生漆涂膜的硬度为2H;当添加量为4%时,涂膜光泽度提升最多,达到17.3%。另一方面,全氟庚烷的添加量在3%时,涂膜的耐水性最差。当全氟庚烷含量为2%时,天然生漆综合性能最佳。     

AZ31B镁合金复合陶瓷涂层在SBF溶液中的应力腐蚀研究

为了研究微弧氧化-电泳沉积复合陶瓷涂层对镁合金在模拟体液(SBF)中的应力腐蚀行为的影响程度,采用微弧氧化-电泳沉积的复合处理方法在AZ31B镁合金表面制备复合陶瓷涂层,使用电化学实验和慢应变速率拉伸试验研究有无复合陶瓷涂层在SBF溶液中的腐蚀和应力腐蚀行为。研究结果表明:复合陶瓷涂层能提高AZ31B镁合金在SBF溶液的耐蚀性能,但是对AZ31B镁合金在SBF溶液中的应力腐蚀敏感性影响甚微。     

响应面法优化玛咖全粉直接压片法研究

通过粉体性质筛选玛咖粉直接压片适宜辅料;通过单因素试验探究水分含量及辅料用量对片剂硬度、崩解时间、脆碎度和片重差异的影响;进行4因素3水平响应面设计,建立回归方程,筛选出最优工艺配方。结果表明,玛咖直接压片的适宜辅料为微晶纤维素SH102、直压乳糖和硬脂酸镁;最优压片工艺为:水分含量7.65%,硬脂酸镁含量0.85%,微晶纤维素含量12.34%,直压乳糖含量8.34%,玛咖粉含量78.47%。全粉直压法可用于高纯度玛咖压片的生产,研究结果可为玛咖压片成型和生产加工过程提供参考。     

麦麸膳食纤维咀嚼片配方优化及其体外抗氧化能力

以食用菌秀珍菇发酵麦麸膳食纤维复合产物为主要原料,采用全粉末直接压片技术,选取片质量差异、崩解时限、硬度及脆碎度的综合评定值为评价指标,通过响应面法确定麦麸膳食纤维咀嚼片最佳配方,并分析其体外抗氧化能力。结果表明:麦麸膳食纤维咀嚼片的最佳配方为硬脂酸镁用量2%、黄秋葵超细粉用量34%和麦麸膳食纤维复合菌粉用量64%,制成的咀嚼片表面光滑、色泽均一、硬度适中;体外抗氧化能力的测定显示,麦麸膳食纤维咀嚼片具有较高的脂质过氧化抑制作用和羟自由基清除能力,脂质过氧化抑制率的IC50值为8 mg/mL,羟自由基清除率的IC50值达20 mg/mL。研究通过辅助强制加料配合直接压片的技术,对麦麸膳食纤维咀嚼片的配方工艺和体外抗氧化性进行研究,旨在为产品的功能营养价值提供一定理论支持。     

Texture of Pecans Measured by Sensory and Instrumental Means

The texture of pecans (Carya illinoensis) from four cuhivars (Barton, Mahan, Western and Wichita) was analyzed using sensory and instrumental methods. Sensory hardness, flexibility and crispness were rated by trained panelists. Ranking of hardness and crispness was also carried out. A Texture Analyser TAXT2 was used for 50% compression, texture profile analysis (TPA), puncture and bending. Puncture and 50% compression gave best reproducibility, least variability and agreement with sensory data. The most relevant TPA parameters were cohesiveness, elasticity and fracturabihty. Parameters from the bending test did not indicate texture of the pecans suitably.     

The influence of compression failure on the bending, impact bending and tensile strength of spruce wood and the evaluation of non-destructive methods for early detection

Bending strength (MOR) and bending Young’s modulus (MOE) according to DIN 52186 and MOE calculated on the basis of eigenfrequency and sound velocity were tested on small clear wood specimens of Norway spruce wood with and without compression failure. One group of specimens was climatised in a normal climate of 20°C and 65% relative humidity, while the other group was stored for one month under water before testing. The MOR of specimens with compression failure decreased about 20% on average (normal climate and wet) compared with the specimens without compression failure. The MOE of the specimens with compression failure was reduced only minimally compared with the specimens without compression failure stored in a normal climate, but very distinct differences (more then 30%) were found under wet conditions. The MOE of the specimens with compression failure calculated on the basis of eigenfrequency and sound velocity were not reduced or only minimally compared with the specimens without compression failure. It is therefore not possible to detect compression failure and to determine reduction in MOR using eigenfrequency or sound velocity. In addition, impact bending (DIN 52189), tensile strength and tensile MOE (DIN 52188) were tested on small clear wood specimens of Norway spruce wood with and without compression failure. The specimens with compression failure revealed an average reduction in impact strength of about 40% and an average reduction in tensile strength of about 20% compared with the specimens without compression failure, whereas tensile MOE of the specimens with compression failure was not reduced compared with the specimens without compression failure. The detection of compression failure by computer tomography (CT) was tested on Norway spruce wood boards 10 cm in thickness, and detection by optical scanner was tested on planed Norway spruce wood boards. CT recognised large compression failures easily, whereas the scanner was not able to detect them.     

五种苹果质构测定方法的比较及与感官评价的相关性分析

为比较5种苹果质构不同测定方法,采用剪切法、穿刺法和TPA压缩法测定了辽宁地区5种主栽苹果的质构特征,同时研究了不同测试条件对测定指标的影响,并分析了仪器测定与感官评价结果的相关性。结果表明剪切、穿刺和TPA压缩均能测得苹果的硬度特征,并区分不同品种间的差异,去皮果肉硬度大小依次为王林 > 红富士 > 国光 > 乔纳金 > 黄元帅;穿刺法检测显示果皮对苹果质构有显著影响(P<0.05),且不同穿刺部位的质构差异显著(P<0.05),其中果顶部位穿刺硬度值最大,其次为果肩和赤道;与感官评价相关性分析显示最大穿刺模量与感官脆性极显著相关(r=0.638,P<0.01),可作为苹果脆性的表征指标;对TPA法,随着压缩形变量增加,苹果硬度测定值显著增加(P<0.05),而内聚性显著减小(P<0.05),且形变量为25%时与感官评价相关性最好。本研究表明穿刺法和TPA法均适用于苹果质构的测定,果皮及穿刺位点对穿刺影响显著,最大穿刺模量可用于表征苹果脆性指标;压缩形变量为25%时TPA法所测得质构参数与感官评价结果相关性最好。     

基于高光谱散射图像的苹果压缩硬度和汁液含量无损检测

压缩硬度和汁液含量是衡量苹果内部品质的两项重要指标。采用高光谱散射图像技术对苹果压缩硬度和汁液含量进行预测。已有研究表明,高光谱图像含有丰富的波谱信息,光谱值与测量值之间存在严重的非线性关系,简单的线性建模方法不能达到较高的预测精度。最小二乘支持向量机(Least Squares Support Vector Machine,LS_SVM)作为一种非线性建模工具,已用于解决小样本、非线性和高维数等实际问题。针对580个‘RedDelicious’苹果的高光谱散射图像,提取600～1000nm范围内的波谱信息,采用LS_SVM建立苹果的压缩硬度和汁液含量模型。研究结果表明,LS_SVM压缩硬度预测模型的相关系数为Rp=0.795,预测均方差为RMSEP=10.4KN/m,汁液含量的相关系数为Rp=0.568,预测均方差为RMSEP=1.20cm2,高于传统的偏微分最小二乘(PartialLeastSquares,PLS)建立的压缩硬度,模型精度Rp=0.744,RMSEP=11.4KN/m,汁液含量模型精度Rp=0.539,RMSEP=1.23cm2。     

黑果枸杞超微粉全粉压片工艺优化

对黑果枸杞超微粉全粉压片最佳工艺进行探究。通过粉体性质筛选适宜辅料;采用单因素试验探究各辅料添加量对片剂硬度、崩解时间、脆碎度的影响;随后进行三因素三水平响应面设计,建立回归方程,筛选最佳工艺配方,同时探究在不同环境下压片对片剂质量的影响。结果表明:黑果枸杞粉末最适辅料为微晶纤维素SH102型、无水乳糖、微粉硅胶,最佳工艺条件为微晶纤维素添加量29.56%,无水乳糖添加量26.91%,微粉硅胶添加量6.24%。低温低湿状态下制成的片剂质量评分(0.806)最佳,加入辅料后的片不加辅料的在贮存运输中更具有优势。     

Influence of temperature of thermal treatment on surface densification of spruce

Spruce (Picea abies L. Karst) wood lamellae, thermally treated at 170, 190, 210 and 230 °C were surface densified by compression at a temperature of 150 °C to three degrees of compression. Immediate springback, set recovery, mechanical properties in 3-point flexure, Brinell hardness and density profiles measurements were used to determine the effect of thermal treatment on the properties of surface densified wood. The highest immediate springback occurred in wood specimens thermally treated at the highest temperature (230 °C) and decreased with decreasing thermal treatment temperature. The untreated samples had the highest set recovery, which decreased with the temperature of thermal treatment. The surface densification increased hardness and bending strength. The highest increase was in the case of untreated wood and decreased with the temperature of thermal treatment. The modulus of elasticity (MOE) and modulus of rupture (MOR) of surface densified wood decreased with increasing thermal treatment temperature. The trend was similar for specimens which were thermally treated but not surface densified. Surface densification increased the density of the specimens in the first few millimetres below the surface. The highest density was achieved in untreated specimens and the lowest in specimens thermally treated at the highest temperature.     

Poured feed blocks using distillery by-products as supplements for ruminants

A technique was developed in this study for preparing solid poured feed blocks as supplements for ruminants. Blocks containing liquid condensed solubles and dried distillers grain with solubles as the base material and protein source were prepared with different cementing agents. A method for testing the hardness of blocks, an index of the physical durability, was also developed. The hardness of blocks was positively related to the concentration of magnesium oxide and to the length of storage time. Ferrous sulphate, on the other hand, had a synergistic effect with magnesium oxide which accelerated the setting of blocks after 24 h. A feeding trial revealed a negative relationship between daily intake by cattle and hardness of blocks. Blocks prepared with about 4% magnesium oxide and 3% ferrous sulphate provide a dry, weather-resistant supplement with a degree of hardness that allows an optimum rate of intake.