UASB/MBR组合工艺处理抗生素废水的研究

采用UASB/MBR组合工艺处理抗生素废水,考察了其处理效果及影响因素.结果表明,当UASB的水力停留时间(HRT)为13 h、MBR的HRT为7.5 h时,系统对COD的去除效果最好,在进水COD为1 000～9 000 mg/L的条件下,出水COD可降至199 mg/L,对COD的总去除率可达80%以上.     

Field measurements on a district heating pipe with vacuum insulation panels

In Swedish district heating networks, around 10% of the supplied thermal energy is lost in the distribution system. One solution to decrease the losses is to use hybrid insulation district heating pipes, a concept where the innermost part of the thermal insulation consists of vacuum insulation panels, held in place by polyurethane foam. One problem with vacuum insulation panels are their sensitivity to high temperatures. This paper presents field measurements on a hybrid insulation district heating pipe where the temperatures have been measured continuously at various positions of a pipe section. The measurements show consistency and a large difference between hybrid insulation parts and reference parts without vacuum insulation panels. A superposition model has been used to calculate the temperature in a point and compare it to the measurement. The results are compared to the same calculation on the results from finite element simulations. The results show clearly that the vacuum panels in the pipes have not collapsed. A slow deterioration of the panels is harder to find with this model. Changes in the system, such as a return temperature which decreases over time, can give a larger impact, concealing the change in the panel performance.     

牡丹花纯露营养酸奶的研制及品质分析

以牡丹花纯露添加量、发酵剂接种量、白砂糖添加量为单因素指标,牡丹花纯露酸奶的酸度、pH、持水力、质构特性及感官评分为考核指标,利用响应面分析法对牡丹花纯露酸奶发酵配方进行优化,并对产品的理化指标、微生物指标及抗氧化活性进行分析。结果表明,牡丹花纯露酸奶的最佳发酵配方为牡丹花纯露添加量4.0%,发酵剂接种量0.2%,白砂糖添加量7%,在此优化工艺条件下牡丹酸奶的感官评分为96分,与预测值（96.242分）相近;牡丹花纯露酸奶的硬度3.892 N,弹性0.9985 mm,胶黏性3.275 N,凝聚性0.851,粘度1.43 mJ,均优于未添加牡丹花纯露的酸奶;牡丹花纯露酸奶持水力为81.5%,pH4.23,蛋白质含量3.01 g/100 g,脂肪含量2.88 g/100 g,酸度78.85°T,乳酸菌数为1.5×108 CFU/mL,大肠杆菌未检出,检测结果均符合食品安全国家标准;牡丹花纯露酸奶（浓度为25 mg/mL时）对DPPH和羟自由基的清除率分别为63.2%、59.5%,抗氧化能力显著优于原味酸奶。牡丹花纯露酸奶具有更好的品质和较强的抗氧化活性。     

动物尿液中沙丁胺醇残留快速检测

探索一种动物尿液样品沙丁胺醇残留的快速检测方法。分别研究提取溶剂、β-环糊精与小分子醇的协同增敏作用和pH值对检测结果的影响,对该方法的选择性、线性方程、精密度和回收率以及检出限进行考察。结果表明：最佳提取溶剂为异丁醇,β-环糊精浓度为5mmoL/L,添加4%(V/V)的乙醇之后,能够明显增加沙丁胺醇荧光强度,最佳pH9;该方法的精密度相对标准偏差、回收率以及检出限分别为0.13%、96.57%、0.8μg/L。该动物尿液中沙丁胺醇残留的荧光光度检测方法,整个过程只需10～15min,操作方便,适合于现场检测。     

水酶法从红花籽中提取油脂与水解蛋白的工艺优化

以水酶法从红花籽中提取油脂和水解蛋白为目的,采用单因素和正交实验的方法,确定最佳的工艺条件:碱提温度为60 ℃,碱提时间为60 min,在水解蛋白酶Alcalase 2.4L、果胶酶和纤维素酶(1:1:1)共同作用下,酶解温度为55 ℃,酶解时间为3 h,料液比为1:5 (w/w),酶总添加量为4.5%,此时,红花籽游离油得率为58.21%,水解蛋白得率为41.32%。对于酶解后得到的乳状液选取最佳破乳方法为冷冻破乳,离心转速为8000 r/min,此时的破乳率为35.28%,总油得率为63.94%。     

不同采收期香椿茶发酵前后活性成分、降糖活性及其挥发性成分比较分析

以4～6月香椿嫩芽制备的香椿发酵茶为研究材料,探讨不同采收期香椿茶发酵前后6个样品中主要活性成分、抗氧化活性、降糖活性及挥发性成分的差异,揭示香椿发酵茶品质随采收期的变化规律,确定香椿发酵茶最适的采收期.结果表明:6个样品的主要活性成分、抗氧化和降糖活性具有显著性差异,挥发性成分各有特色.随着采收期的延长,香椿茶发酵前...     

Pressureless consolidation of boron nitride fiber ceramics via a chemical bonding approach

Hexagonal boron nitride (h-BN) materials with excellent physicochemical stability and processibility have been considered as promising engineering materials. However, their practical applications are rather limited by the difficulty in constructing the well-bonded h-BN ceramic. Herein, we present a reaction welding strategy for facile preparation of well-bonded h-BN fibers (BNFs) network by using ethanolamine (ETA) containing alcoholic hydroxyl and primary amine groups as crosslinking agent. The formed >B-O-H₂C-H₂C-H₂N|→B< bond bridges through the esterification and intramolecular coordination (N|→B) reactions between ETA molecules and BNFs containing surface hydroxyls, play an essential role in the construction of the thermodynamically stable >B-N-B< covalent bond between BNFs. Based on this synthetic strategy and a room-temperature molding process followed by a calcination step, a series of resilient BNFs ceramics with high processibility, typical diamagnetism, low dielectric constant (∼ 2.1) and loss, good resistance to temperature different, corrosion, oxidation and abrasion are produced. Besides, they also exhibit excellent strain and damage tolerance, the maximum compression strain and strength can reach up to 38% and ∼ 33 MPa, respectively. Significantly, the deliberately designed BNFs vessel can be successfully used for the alloying of high melting point metals, showing both structural/chemical robustness and good reusability. This ingenious design for well-bonded BNFs network not only is a good model for exploring the welding way for h-BN powders, but also opens up numerous opportunities for practical applications.