高取代度阳离子淀粉作为阴离子垃圾捕集剂在高得率浆中的应用

含有阴离子垃圾的高得率浆(HYP)和回收纤维作为纸张生产原料的应用正不断增加。PEI、CPAM和PDADMAC都是传统的阴离子垃圾捕集剂(ATCs)。本文研究一种选择性的ATC,即高取代度的阳离子淀粉(HS-CS)。在含溶解物与胶体物(DCS)纸料中评价不同取代度(0.57～0.97)阳离子淀粉的阴离子垃圾捕集效率。结果表明:HS-CS是一种非常好的阴离子垃圾捕集剂。加入HS-CS后,DCS在微粒助留系统中的不利影响被减小,且助留剂的助留效果也被提高。动态絮凝实验中也能得到相同的结论。     

高取代度阳离子淀粉对阔叶材BCTMP纸料中DCS的控制

本研究主要探讨高取代度阳离子淀粉在消除漂白化学热磨机械浆(BCTMP)在高附加值纸种中应用过程阴离子垃圾不良影响中的作用.在含溶解性胶体物质纸料中评价不同取代度(0.57～0.97)阳离子淀粉的作用效率;并在微粒助留体系(CPAM/膨润土)前采用高取代度阳离子淀粉,优化体系的填料留着.结果表明:高取代度阳离子淀粉是一种非常好的阴离子垃圾捕集剂,通过添加高取代度阳离子淀粉,溶解性胶体物质对微粒助留系统的负面影响可被消除,助留剂的作用效果得到大大改善.     

非晶颗粒态马铃薯淀粉改性研究

将非晶颗粒态淀粉和原淀粉在阴离子、阳离子、醋酸酯及羟丙基醚化剂条件下进行淀粉改性反应,取代度随醚化剂量的改变而改变,但由于整个颗粒处于非晶状态,导致非晶淀粉取代度和原淀粉相比有不同程度的提高,对羧甲基化,取代度平均提高9.15%,最高达10.72%,对阳离子化来说,取代度平均提高9.65%,最高达13.18%,对醋酸酯化,取代度平均提高47.49%,最高达64.82%,对羟丙基化,取代度平均提高22.78%,最高达27.48%.     

氨基甲酸酯淀粉浆料抗老化性分析

探讨氨基甲酸酯淀粉浆料的抗老化性能.通过改变尿素对玉米淀粉的投料比,制备出一系列具有不同取代度的氨基甲酸酯淀粉,测试了淀粉浆液的黏度、透明度和沉降积,研究了氨基甲酸酯化变性程度与淀粉浆液抗老化性能之间的关系.结果表明:当取代度不超过0.054时,随着氨基甲酸酯化程度的提高,浆液的冷热黏度差值变小,透明度得到明显改善,沉降积增加.指出:当取代度不超过0.054时,氨基甲酸酯淀粉随取代度的提高,浆液的老化速度降低,抗老化性能明显改善.     

磷酸型两性淀粉制备研究

用阳离子淀粉为中间体,三聚磷酸钠为酯化剂,尿素为催化剂,制备了磷酸型两性淀粉.用三因子的二次回归正交设计实验方案,确定了制备低取代度两性淀粉的最佳工艺.当阳离子淀粉用量为50 g(取代度0.038 12)时,尿素用量为1 g,三聚磷酸钠(STP)用量为2 g,反应温度128.2℃,反应pH5.90,反应时间4.2 h,产品的阴离子取代度为0.0135,反应效率达到70.32%.     

阴离子垃圾捕集剂在含机木浆新闻纸浆料系统中的应用

本文对含机木浆新闻纸浆料系统的阴离子垃圾问题进行了分析,并对阴离子垃圾捕集剂处理纸浆料的效果进行了研究,结果表明使用ＡＴＣ能明显提高阳离子淀粉的增强作用,并可适当减少硫酸铝的用量。     

阴离子垃圾捕集剂在含机木浆新闻纸浆料系统中的应用

本文对含机木浆新闻纸浆料系统的阴离子垃圾问题进行了分析,并对阴离子垃圾捕集剂（ＡＴＣ） 处理纸浆料的效果进行了研究。结果表明使用ＡＴＣ能明显提高阳离子淀粉的增强作用,并可适当减少硫酸铝的用量。     

阴离子垃圾捕集剂在AKD施胶中的应用

阴离子垃圾的积累给纸机网部抄造及纸的性质带来很多影响,尤其是纸张施胶效果.为更好地解决阴离子垃圾对施胶效果的影响,尤其是改善AKD中性施胶的施胶效果,采用电荷密度更高的聚合物(PEI、PDADMAC)代替阳离子淀粉对阴离子垃圾进行捕集.结果表明:使用电荷密度较大、聚合度较小的有机阳离子聚合物对纸张的施胶效果有明显的改善,可在一定程度上减轻抄纸系统积累阴离子垃圾对施胶的影响.     

半干法制备羧基型两性淀粉及其应用

以玉米淀粉为原料、氢氧化钠为催化剂,与氯乙酸、3-氯-2-羟丙基三甲基氯化铵采用半干法工艺合成羧基型两性淀粉,产品的阳离子取代度为0.050,阴离子取代度为0.024,可用于废纸生产箱纸板,增强效果显著。     

淀粉黄原酸酯的合成及捕集重金属离子性能研究

以天然木薯淀粉为主要原料,环氧氯丙烷为交联荆制备交联淀粉,然后与CS2在碱性条件下发生黄原酸化反应制备改性淀粉黄原酸酯捕集荆,考察环氧氯丙烷用量、氢氧化钾用量、CS2浓度及反应温度、时间等诸因素对反应过程及产物捕集Cu2+性能的影响,确定了最佳的合成工艺条件.实验结果显示,合成捕集荆的最佳工艺务件为:环氧氯丙烷的用量为1.6 ml,KOH的用量为1.6 g.CS2用量11 ml,反应温度为35℃,反应时间为1.5 h.产物的舍硫量可达9.02%,Cu2+去除率可达96.95%.     

数字陷印技术分析(三)

(一)在QuarkXPress中陷印 在QuarkXPress中陷印可以用3种方法进行控制. ①自动陷印.这就意味着可以简单地让QuarkXPress在输出的时候实施陷印,这种方法需要在陷印的选择对话框中进行设置.     

数字陷印技术分析(一)

编者按 从本期开始将分三期连载"数字陷印技术分析"一文,作者将从各个方面对数字陷印技术做详尽分析,读者可从中受益.     

Novel amorphous functional materials for trapping nitrosamines

Novel amorphous functional materials are designed to modify amorphous silica with alumina. They are first presented as efficient adsorbents to trap both volatile nitrosamines and bulky tobacco specific nitrosamines in the environment. Selective adsorption, temperature programmed surface reaction (TPSR), and FTIR methods are employed to study the impact of alumina modification on the ability of silica to adsorb and catalytically degrade nitrosamines. Due to the special interaction between the N-NO group of nitrosamines and the aluminum ion in the composite, nitrosamines can be very easily trapped by the composite. Moreover, this cost-efficient material first shows a remarkable adsorptive capability and catalytic activity in reduction of NNN (N-nitrosonornicotine) in the liquid phase. The new concept of designing a multifunctional trap for carcinogenic pollutants, which combines the amorphous silica's pore structure with the specific adsorbing/catalyzing features of metal ions, proves feasible.     

Isolation of single yeast cells by optical trapping

Individual yeast cells can be successfully isolated and recultured on plates with a new isolation method making use of optical trapping with infrared laser light. The cells can be selected on morphological criteria by high resolution microscopy. The isolation device is constructed from two coverslips separated by spacers, in which selected cells are transferred to a plastic capillary, using the optical trap. To test the procedure, selection experiments were done with a mixture of two Saccharomyces cerevisiae strains, distinguishable both in fluorescence microscopy and on agar plates. These experiments showed that only selected cells were isolated, and close to 100% of the isolated stationary-phase cells formed colonies on agar plates, indicating a high recovery. A lower recovery was obtained with exponential-phase cells, possibly because of a higher sensitivity to laser irradiation. Applications for this method may include the isolation of mutants with altered morphology and the isolation of subpopulations of yeast cultures, for their separate investigation or for the initiation of pure cultures.     

储粮害虫诱集技术研究进展

诱集技术是储粮害虫监测和防治的一种重要的非化学手段,受到国内外的普遍关注。综述了基于储粮害虫的视觉、嗅觉、以及信息素等生理特征及生活习性而建立的诱集技术的研究进展概况,为促进各项诱集技术的进一步发展,更好地应用于储粮害虫的防治提供参考。     

Efficiency of trapping methylglyoxal by phenols and phenolic acids

The carbonyl stress that leads to the formation of advanced glycation end products (AGEs) has drawn much attention recently because of its micro- and macrovascular implications. During monitoring of methylglyoxal (MG), the efficiency of phenolics to directly trap MG can be demonstrated. Twenty compounds consisting of a single benzene ring structure with the addition of at least one hydroxyl group were allowed to react with MG at 37 °C for 1 h under physiological conditions in pH 7.4 phosphate buffer solution. Compounds composed of a benzene structure with a mono-hydroxyl substitute cannot react with MG. Among benzenediols and di-hydroxyl benzoic acids, only hydroquinone reacted with MG and showed a 13% decrease in MG. Nevertheless, high reactivity was shown for 3 benzenetriols. The percentages of MG remaining were 45%, 51%, and 36% for pyrogallol, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene, respectively. When a carboxyl group is added to the benzenetriols, steric hindrance and carbon electron charges on benzene ring are the influential factors in reactivity. Using computational chemistry calculations, a carbon electron charge of -0.24 was the minimum value for high reactivity.     

Peroxyl radical‐trapping capacity of germinated legume seeds

The legume seeds of lentil (Lens culinaris( vetch (Vicia sativa) and soybean (Glycine max, cv. Mazowia) were germinated in the dark at a constant temperature of 25°C up to 168 h (24 h×7 d). The changes in peroxyl radical‐trapping capacity (PRTC) of the processed seeds were measured and compared to those of the raw seeds. A simple method of determining the peroxyl radical‐trapping capacity based on the use of 2,2′‐azobis(2‐amidopropane) hydrochloride (ABAP) decomposition as a free radical source and the use of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) oxidation as the reaction indicator was employed to express antioxidant properties of germinated seeds. The data show that the germinated lentil and vetch seeds were more effective than germinated soybean when their peroxyl radical‐trapping capacity was compared.     

A new technique for trapping and sensory evaluation of flavour volatiles

Procedures are described whereby volatile components of flavour concentrates may be trapped upon elution from either packed or capillary gas chromatographic columns on short lengths of glass porous layer open tubular (PLOT) capillaries containing a layer of alumina or Celite 545. The trapped compounds are subsequently released and their aromas evaluated by grinding up the traps in a small quantity of water. Using a multicomponent “synthetic essence” the best results for the combined trapping and release of compounds were obtained with capillaries containing acid-washed Celite 545. Although the technique is complementary to the conventional method of “sniffing” eluted peaks it is considerably more versatile than the latter, as it may be used to assess the sensory properties of different separated regions of complete chromatograms after recombination and thus detect interactive and blending effects.     

Characteristics of trapping copper ions with scrolled ferritin reactor in the flowing seawater

Native liver ferritin of Dasyatis akajei (DALF), apoDALF, and reconstituted DALF were employed to construct a ferritin reactor, respectively. An apparatus consisting of a mixer, a ferritin reactor, and a magnetic stirrer was constructed to study capacity and feasibility of trapping Cu2+ in the flowing seawater. The experimental results showed that the numbers of trapping Cu2+ with DALF reactor were higher than these with the reactors of apoDALF and reconstituted DALF, respectively, giving the maximal numbers of 98 +/- 5 Cu2+ per molecular DALF in 120 h. We found that the iron layer with a high ratio of phosphate to ion on the surface of the ferritin core played an important role in increasing numbers of trapping Cu2+. In addition, we found two positive relations of dependence of trapping Cu2+ numbers with the reactor on the incubation time and on the Cu2+ concentration in the flowing seawater. Another apparatus consisting of a buoyage, an isolation basket equipped with griddling, and a scrolled ferritin reactor was constructed to study the feasibility of trapping Cu2+ in the sea area. Moreover, the present studies indicated that this apparatus had been used to not only analyze and evaluate the concentration variety of various heavy metal ions such as Cu2+ and Pb2+ diluting by the seawater but also monitor the formation of pollution degree by various small organic molecules during the climax and the neap.