加热非燃烧状态下烟草制品的TSNAs释放规律

为了解加热非燃烧烟草制品加热时TSNAs的释放情况,以烟草薄片颗粒（RTPs）为原料,研究甘油含量、加热温度等对TSNAs释放的影响,并探究了其中NNN与NNK释放之间的关系。NNK和NNN释放量随加热温度升高而增加,达到240℃之后增量变小;NAB的释放量随温度升高不断上升;NAT的释放量先随温度升高而增加,达到240℃后基本稳定。同时,原料中添加甘油会不同程度地减少TSNAs的释放量。因此,烟草薄片颗粒中的甘油含量、加热温度显著影响TSNAs释放行为,合理的甘油含量和低温加热均可有效减少TSNAs的释放。原料中添加NNN后,NNK的释放量显著增加,推测原料中NNN含量增加可能促进气溶胶中NNK的释放。     

服装热缩膜皱缩成形工艺及其原理

热缩膜成形织物是在热缩膜成形皱缩服装独特的生产加工过程形成的一种具有特殊肌理特征的起皱织物,形成这种织物肌理特征的工艺过程包括附膜、绣缝、皱缩3步.通过分析肌理纹样的形成原理,得出上述3种影响服装面料肌理图案效果的工艺过程,通过选择不同的工艺组合方式,可以得到不同风格特征的皱缩肌理.     

炭化三维间隔棉织物的制备及其电加热性能

为开发一种结构稳定可应用于压阻传感和电加热的功能型纺织品,研制出一种机织三维间隔织物基体,通过在惰性气体高温环境制备炭化三维间隔棉织物,应用扫描电子显微镜、傅里叶红外光谱和拉曼光谱对制备炭化棉织物纤维结构进行表征,研究其电加热性能。结果表明：炭化三维间隔棉织物具有很好的导电性,可视为均匀的电阻介质,且电阻变化率随着织物炭化温度升高呈指数降低;在较低炭化温度情况下电阻变化率较大,随着炭化温度升高,电阻变化率逐步降低。通过对织物升温效果与加热性能分析可知,织物在低于62.4℃时,其理论加热效率与升温温度呈等比关系,可应用于温度精准可控的电加热织物。     

Synthesis of dense MoSi2 by high-frequency induction heated combustion and its mechanical properties

Dense MoSi₂ compound was synthesized with the high-frequency induction heated combustion synthesis method in one step from elemental powders of Mo and Si within 2 min. Simultaneous combustion synthesis and densification were carried out under the combined effects of induced current and mechanical pressure. A highly dense MoSi₂ with a relative density of up to 98% was produced with simultaneous application of 60 MPa pressure and induced current. The percentages of the total shrinkage occurring before and during the synthesis reaction were 16% and 53%, respectively. The average grain size was about 15 μm and a slight amount of Mo₅Si₃ was observed at the boundaries of the MoSi₂ grains. The fracture toughness and hardness values obtained were 3.5 MPa·m^1/2 and 1050 kg/mm², respectively. These values were similar to those of commercial ones.     

Analysis of thermal strains and stresses in heated fibre metal laminates

Current trends in aircraft design are to increase the economic efficiency by integrating different features in multifunctional materials. One strategy is to embed resistance heater elements between glass‐fibre epoxy layers in (heated) fibre metal laminates and to use them as anti or de‐icing devices in leading edges of wings. Heated glass fibre reinforced aluminium (GLARE) is an example of such a multifunctional material where heating functionality was added to the (certified) structural feature of GLARE. As heated fibre metal laminates are an innovative and rather new material, the possible (local) effects of embedded heating on the stress–strain state have not yet been investigated. This research couples experimental characterisation of heated GLARE surface behaviour and numerical modelling analysis to investigate the surface and the through‐the‐thickness strain‐stress state and temperature distributions due to the embedded heating. For the experimental part, the surface strains and the temperatures of a developed specimen were measured in a slow heating regime (temperature increase from 22.7 to 39.4 °C within 120 s) using, respectively, a developed shearography instrument and thermocouples with an infrared camera. Then a numerical model of heated GLARE was developed and verified with experimental results. Further, the numerical model was used to predict strains, stresses, and temperatures during a temperature increase similar to that used for de‐icing in a real operation (temperature increase from −25 to 86.7 °C within 4.8 s).     

对热压复合PVC塑料地板砖加热长度变化率的探讨

加热长度变化率是国家标准规定的塑料地板砖的物理性能指标之一,目前不少产品此项指标未能达到国家标准。分析了原因,提出了从工艺着手降低加热长度变化率的方法,以及加热长度变化率的简易鉴定方法。     

An analytical approach to reveal the addition of heat-denatured whey proteins in lab-scale cheese making

A simple analytical procedure for the detection of self-aggregated heat-denatured whey proteins (HDWP) in model cheeses was developed. The principle of the approach lies in the solubilization of the cheese matrix by a sodium citrate solution (0.2 M, pH 7.0) resulting in the dissociation of the casein micelles and the insolubilization of HDWP aggregates, which are collected in the pellet after a centrifugation step. The reliability of the procedure was tested in lab-scale cheeses from peroxidase-positive pasteurized milk with different protein-based ingredients (microparticulated whey protein concentrate, milk protein concentrate, whey protein isolate and Ricotta cheese) at concentrations ranging from 0.2 to 1.2% protein (w/v on cheese milk). A linear relationship between the amount of the HDWP added to cheese milk and that recovered from model cheeses was observed. Heat-damage indicators, furosine and lysinoalanine, showed levels in the experimental cheese samples not related with added HDWP, but represented a source of information on the ingredients other than liquid milk. Overall, in the model cheeses, the proposed method was an easy-to-apply and reliable tool for the evaluation of the presence of HDWP-based products. Further investigation is required for the application to real cheeses and for the evaluation of possible interferences from proteolysis during ripening.     

不同加热轧制AZ91镁合金带材数值模拟及试验验证

利用有限元法研究了热辊热带(HSR-HR)、热辊冷带(NSR-HR)和冷辊热带(HSR-NR)3种不同加热方式下AZ91镁合金轧制过程热-力行为,并进行了大压下率热辊冷带工艺试验和组织性能分析.结果表明,HSR-HR、NSR-HR及HSR-NR 3种加热轧制方式的应力三轴度依次增大,中性点附近应力状态软性系数依次减小....     

电加热气体干燥装置的PLC控制

介绍了电加热再生式气体干燥装置的ＰＬＣ控制系统的软硬件组成和工作原理,实践表明用ＰＬＣ控制可显著提高系统工作可靠性。     

广西某锑锌银钨多金属矿选矿工艺研究

经过全面详细的工艺矿物学研究和选矿试验研究,针对广西某锑锌银钨多金属矿的矿石特点,提出了"先浮辉锑矿—后浮铁闪锌矿—再浮白钨矿—白钨粗精矿加温精选—浮选尾矿重选回收黑钨矿"的合理工艺流程,锑锌银钨均得到较好回收。