Autolysis and the endogenous proteinases characterised in beardless barb (Anematichthys apogon) muscle

Beardless barb is a common fish species used in fermentation of fish paste Ka-pi-plaa. Autolytic profile of beardless barb muscle showed the maximum autolysis was at 50 °C, at both acidic and alkaline pH values. With augmentation concentration of NaCl, autolytic activity slightly decreased. Endogenous proteinases isolated from fish muscle in crude extract forms were also characterised. The acidic proteinases had optimum activity at pH 3.0 and 50°C, and they showed higher proteolytic activity than the alkaline proteinases which were optimally active at pH 9.0 and 50 °C. Proteinases in peak at pH 3.0 were inhibited by pepstatin A, but those in peak at pH 9.0 were highly inhibited by PMSF, TLCK and soybean trypsin inhibitor, suggesting that both aspartic and serine proteinases were existed in beardless barb muscle. The proteinases were stable in pH range of 2.0-5.0 but unstable at the temperatures higher than 40 °C. NaCl suppressed the proteolytic activity, ATP activated the proteinase activity, while CaCl₂, MgCl₂ and CoCl₂ exhibited no influence on the activity. The results implied that cathepsin D is the predominant proteinase responsible for autolysis in beardless barb. The findings were useful to improve the processing and qualities of Ka-pi-plaa product using beardless barb as raw material.     

Effect of the type of superplasticizer on the properties of cementitious systems incorporating slag

Superplasticizers have become an integral ingredient in the formulation of concretes. After 40?years, their use and dosage remain uncertain due to variations in their compositions and those of cement. In addition, the substitution of cement by supplementary cementitious materials having different chemical compositions exacerbates the problem without counting the multiplicity of superplasticizers to choose from. The present work consists of a study of the rheological and mechanical properties of cementitious systems containing slag and various types of superplasticizers. The tests were carried out on pastes, mortars and concretes incorporating slag in partial cement replacement and four superplasticizers types, polynaphthalene sulphonate (PNS) and three polycarboxylates (PC). The results of this study demonstrate that the viscosity and the yield stress increase with the rate of incorporation of the slag. The air increases with the polycarboxylates but this effect is less perceptible in the presence of the slag. Polycarboxylates improve workability more than PNS. The use of polycarboxylates reduces the viscosity and the yield stress. The compressive strength of concretes containing slag is low at early age but high at long run. They exhibit good resistances to scaling. The permeability to chloride ions is considerably reduced in the presence of the slag independently of the type of superplasticizer, suggesting good durability of these concretes in potentially aggressive external environments.     

豆基杂粮米稀挤压膨化工艺优化

以豆渣为主要原料，复配杂粮及药食同源食材制备豆基杂粮米稀，以物料加水量、螺杆转速、Ⅲ区机筒温度为响应因素，糊化度为考察指标，在单因素试验的基础上，利用Design-Expert 8.0.6设计试验得到挤压膨化技术制备豆基杂粮米稀的最佳工艺条件。结果表明，在物料加水量12.5%、螺杆转速330 r/min、Ⅲ区机筒温度160 ℃的条件下，制备的豆基杂粮米稀具有较高的糊化度（91.47%），冲调时口感细腻、香味浓郁、不易结块。     

碘化多壁碳纳米管制备含有Ag/MWCNTs复合材料的银-环氧树脂浆料

提出一种将多壁碳纳米管碘化后制备银/多壁碳纳米管（Ag/MWCNTs）复合材料的方法。通过球磨对碘化多壁碳纳米管进行了功能化，并通过透射电子显微镜（TEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、拉曼光谱和热重分析（TG）对其进行了表征。结果表明，经碘化处理后，银纳米粒子（Ag-NPs）能更好地粘附在碳纳米管表面，改善了银纳米粒子与碳纳米管之间的连接。羟基（-OH）基团的伸缩振动明显增强，激活了碳纳米管的表面，增加了碳纳米管表面Ag⁺形核的数量。在260 ℃以下，Ag/MWCNTs复合材料的质量损失小于MWCNTs的质量损失。最后，制备了银-环氧树脂浆料，发现使用Ag/MWCNTs复合物制备的浆料具有最低的电阻率和最高的热导率。     

The Photomontage Activity of Postmodernism

For decades now, Douglas Crimp’s landmark 1980 essay ‘The Photographic Activity of Postmodernism’ has shaped our understanding of modernism’s aftermath, at least as it unfolded in North America and Western Europe. Less remembered, however, is the degree to which the procedures of disjunction, copying, appropriation, and outright theft that he highlighted were epitomised not just by contemporary photography, but by photomontage in particular. This article recovers the debates that led critics such as Crimp, Abigail Solomon-Godeau, Christopher Phillips, Benjamin Buchloh and others to turn to photomontage as one of their principal objects of concern in what became known as the postmodern critique of photography. Why was montage tasked to perform this critical function, particularly by people around the journal October who had not otherwise devoted the balance of their writing to photography’s history? The article suggests that these men and women, along with the contemporary artists they foregrounded, manifested what Mary Anne Doane has called a ‘desire for signification’, a reaction in the late 1970s against the mute theatricality of minimalist and conceptual art. Photomontage reintroduced representation to contemporary art and to the canon of art history. But unlike the reemerging illusionism in painting that also manifested this desire, montage guarded against an uncomplicated realism by highlighting and critiquing operations of representation in a manner that painting no longer could.     

双酶水解鸡骨泥的工艺优化

对鸡骨泥进行酶水解,经筛选确定中性蛋白酶和Flavourzyme复合风味酶的组合能有效酶解鸡骨泥。经正交试验分析,确定酶解的最佳工艺为:酶解温度50℃、pH值8.5、中性蛋白酶和Flavourzyme复合风味酶的添加量分别为0.75%和1.50%、底物浓度5%、水解时间2.5h。在该条件下酶解效率最高,水解度和氮收率分别为37.11%和92.50%,酶解产物澄清无苦味及腥味,且游离氨基酸含量显著增加。     

西瓜豆瓣酱研制及其亚硝酸盐含量研究

首先在传统西瓜豆瓣酱制作的工艺基础上,设定西瓜、花生油的添加量为150,10 g,通过将影响西瓜豆瓣酱风味的主要因素豆曲、盐、花椒、八角、小茴香、葱、姜、蒜的添加量进行单因素和正交试验,确定自制西瓜豆瓣酱的较优配方。试验结果表明,西瓜150 g、豆曲30 g、盐10 g、花椒1 g、八角2 g、小茴香1 g、葱8 g、姜12 g、蒜8 g为最佳配方。另外,研究了西瓜与豆曲的比例对亚硝酸盐的影响及西瓜豆瓣酱发酵成熟后随放置时间增加亚硝酸盐含量的变化。研究表明,在相同食盐添加量下,亚硝酸盐含量随着西瓜添加量的下降而降低,自制豆瓣酱亚硝酸盐含量随着放置时间的增加而降低并逐渐接近于平稳。根据GB 2762-2017《食品安全国家标准食品中污染物限量》对于蔬菜类食品规定亚硝酸盐含量不得超过20 mg/kg[1],食用不会对人体产生危害,为人们在加工西瓜豆瓣酱时提供了参考。     

北洺河铁矿全尾砂胶结充填治理塌陷区的可行性研究

北洺河铁矿为践行“绿水青山就是金山银山”的绿色发展理念,探索利用选厂尾矿治理地表塌陷区方案。通过对北洺河铁矿塌陷区稳定性分析以及对全尾砂膏体制备、输送、胶结充填技术可行性试验研究,并结合经济估算、环境和社会效益等综合分析,认为全尾砂胶结充填治理塌陷区的方案可行。     

豆瓣酱加工过程中产生的危害物分析及控制措施研究

近年来,随着我国食品行业的不断创新与发展,豆瓣酱产业也随之呈现稳固上升的趋势,然而开放式的豆瓣制作环境和复杂繁长的制作工序也使得豆瓣酱在生产加工过程中存在某些食品安全隐患。本文探讨了豆瓣酱用料、制曲、发酵和贮藏等环节可能产生的危害物,如黄曲霉毒素B1、肉毒毒素、微生物、生物胺等,以及减少和控制这些有害物质的措施,为豆瓣酱生产过程中的安全控制提供有效借鉴。     

Product design: Formulation of a screen-printable sintering-type conductive paste

Due to the complexity of the screen-printing operation and the rheological behaviors of the screen-printable paste, such a paste is usually formulated by trial-and-error. In this report, a systematic procedure, based on heuristics and mechanistic models, for the design of a screen-printable paste is developed. The procedure is demonstrated by a case study of the formulation of a conductive paste of copper particles.