催化剂对造纸污泥热解特性的影响

研究了Na2CO3、Na2SO4、NaCl、K2CO3、K2SO4、KCl 6种化合物对造纸污泥热解的催化作用,利用热天平分别将其按一定比例与污泥混合后进行热重实验,对加入催化剂的污泥与空白污泥的DTG曲线进行了分析比较,探讨了催化剂的种类、用量等因素对污泥热解特性的影响。研究结果表明：钠化合物的催化作用大小依次为Na2CO3〉Na2SO4〉NaCl,而钾化合物的催化作用依次为K2CO3〉K2SO4〉KCl,两类化合物中碳酸盐的催化作用显著;6种催化剂均使污泥热解反应向低温区移动,其中碳酸盐最显著,且最大失重速率最大;催化剂用量5%（以催化剂中Na或K元素对污泥质量分数计）时为理想用量。     

超低载量贵金属催化氢电极的活性

利用恒流极化方法，求出超低载量贵金属催化氢电极反应的交换电流，并以此来反映其电极活性；同时也选择出氢气体扩散电极催化剂（贵金属）的最佳用量为１．９ｍｇ／ｃｍ￣２．     

稀土复合固体超强酸催化合成食用香料乳酸正丁酯

研究了以纳米稀土复合固体超强酸SO4^2/ZrO2Nd2O3为催化剂，以乳酸和正丁醇为原料合成乳酸正丁酯。通过正交试验考察了影响酯化反应的主要因素，确定的最佳合成条件为：乳酸用量为0．1mol时，正丁醇与乳酸物质量之比为3．0：1，催化剂用量为0．55g，带水剂环己烷15mL，回流反应2．0h，酯化率可达98．7％。该催化剂回收简单，重复使用7次后酯化率仍超过96％。     

纳米固体超强酸SO42-/TiO2催化合成酒用香料丁酸异戊酯

以纳米固体超强酸SO4^2-／TiO2为催化剂，通过丁酸和异戊醇反应合成丁酸异戊酯。实验结果表明，纳米固体超酸SO4^2-／TiO2是合成丁酸异戊酯的良好催化剂，最佳反应条件为：酸醇物质的量比为1：1．3，催化剂用量为0．4g／0．2mol丁酸，反应时间为2h。此时酯化率可达98．2％，并且催化剂可以多次重复使用。     

硫氰酸根离子电极的研究与应用

通过合成水杨醛缩4-氨基安替比林Schiff碱金属配合物,并以此为载体研究该电极对阴离子的电位响应特性,同时采用紫外光谱技术和交流阻抗研究电极的响应机理。发现以水杨醛缩4-氨基安替比林合铜（[Cu（Ⅱ）-SAMT]）为载体的离子选择性电极对硫氰酸根离子呈现优良的电位响应和反Hofmeister选择性序列：SCN^-〉Sal^-〉ClO4^-〉NO3^-〉Cl^-〉Br^-〉I^-〉SO3^2-〉No2^-〉SO4^2-。在pH=4．0的磷酸盐缓冲体系中,硫氰酸根离子在1．0×10～1．0×10^-6 mol／L浓度范围内呈近能斯特响应,斜率为-55．64mV／pSCN^-（26℃）,检测下限为6．3×10^-7 mol／L。并将电极应用于蔬菜中硫氰酸盐的测定,结果比较满意。     

固体酸Ti(SO_4)_2/硅藻土催化合成香料己酸正丙酯

以固体酸Ti(SO4)2/硅藻土为催化剂,己酸和正丙醇为原料,催化合成己酸正丙酯。考察了催化剂制备条件对催化剂性能的影响,得出适宜的催化剂制备条件为m(Ti(SO4)2)︰m(硅藻土)=6︰4,焙烧时间2 h,焙烧温度400℃。以正交试验优化固体酸Ti(SO4)2/硅藻土催化合成己酸正丙酯的反应工艺条件,得出了适宜的酯化反应条件为n(己酸)︰n(正丙醇)=1︰1.75,催化剂用量为0.6 g,反应时间为2 h,带水剂量为3 m L。在该反应条件下,己酸正丙酯的酯化率为99.6%。     

无机盐对乙酸正丁酯催化研究

以乙酸和正丁醇为原料，以无机盐为催化剂合成乙酸正丁酯。文章探讨了催化剂种类、催化剂用量、醇酸比、反应时间等对酯化率的影响。结果表明：Fe2（SO4）3、Al2（SO4）3·18H2O、NaHSO4·H2O为较好的催化剂，且当醇酸比为1：1.15，催化剂用量为0.8g，反应时间为30-60min时，酯化率较高。     

微波协同固体超强酸催化合成香料肉桂酸环己酯

以肉桂酸和环己醇为原料,用微波协同固体超强酸SO2-4/Ti O2/La3+催化合成了肉桂酸环己酯。通过单因素实验和正交实验考察催化剂种类、催化剂用量、肉桂酸与环己醇物质的量比、微波功率、微波时间对肉桂酸环己酯产率的影响。实验结果表明,肉桂酸环己酯最佳合成条件为:催化剂固体超强酸SO2-4/Ti O2/La3+用量为1.0g,肉桂酸与环己醇物质的量比1∶4,微波功率为600W,微波时间为15min,肉桂酸环己酯产率可达到97.5%。该工艺操作简单,反应条件温和,节约时间,产品纯度高,是一种高效环保的合成工艺。     

亚硫酸铵和卤水制无水亚硫酸钠工艺研究

亚硫酸铵和卤水在60℃下，n（NaCl）／n[（NH4）2SO3]：2．0～2．1的条件下反应得Na2SO3晶体，经分离、洗涤、干燥后得无水亚硫酸钠产品。分离Na2SO3后的母液Ⅰ冷至20℃，析出NH4Cl晶体，将分离NH4Cl后的母液Ⅱ浓缩结晶得Na2SO3晶体，分出Na2SO3后的残液与母液Ⅱ混合，送去浓缩结晶。将分出的NH4Cl干燥得氯化铵副产品。该工艺的优点是原料成本低，副产氯化铵，经济效益好，无污染。     

稀土复合固体超强酸SO4^2-／ZrO2-Nd2O3催化合成乳酸正丁酯

研究了以纳米稀土复合固体超强酸SO4^2-／ZrO2-Nd2O3为催化剂,以乳酸和正丁醇为原料合成乳酸正丁酯。通过正交实验考察了影响酯化反应的主要因素,确定的最佳合成条件为：乳酸用量为0．1mol时,正丁醇与乳酸物质的量之比为3．0：1,催化剂用量为0．55g,带水剂环己烷15mL,回流反应2．0h,酯化率可达98．7％。该催化剂回收简单,重复使用7次后,酯化率仍在96％以上。     

钝顶螺旋藻多糖的分离纯化及组成分析

目的：对钝顶螺旋藻多糖进行提取、分离纯化和热降解,并对不同多糖组分的基本化学性质和糖链的精细组成进行分析。方法：采用蛋白酶酶解、醇沉、阴离子交换色谱法和热降解,从钝顶螺旋藻中提取和分离纯化出P0、P0.2、P0.4、P0.6、P0.8五种多糖组分及其热降解产物。采用高效凝胶排阻色谱法、离子色谱法、1-苯基-3-甲基-5-吡唑啉酮柱前衍生-高效液相色谱法和亲水液相色谱-高分辨傅里叶转换质谱（hydrophilic interaction liquid chromatography-Fourier transform mass spectrometry,HILIC-FTMS）联用技术,分析比较不同多糖组分的化学性质和糖链精确组成。结果：钝顶螺旋藻多糖中P0、P0.2、P0.4和P0.6组分硫酸根质量分数在6%～7%,而P0.8组分硫酸根质量分数最高（14.46%）。单糖组成分析结果说明,P0组分是1 种葡聚糖,P0.2组分是主要由葡萄糖、半乳糖、鼠李糖、岩藻糖等中性糖组成的杂多糖;而P0.4、P0.6和P0.8组分主要是由鼠李糖、葡萄糖醛酸、葡萄糖、木糖和半乳糖组成的结构非常复杂的硫酸鼠李聚糖。采用HILIC-FTMS分析多糖组分热降解产物中的寡糖组成,发现P0.2糖链主要是由己糖单糖、戊糖二糖、脱氧己糖-戊糖寡糖、脱氧己糖-糖醛酸的寡糖片段组成,硫酸根在脱氧己糖、戊糖和己糖上,糖链组成复杂。而P0.4和P0.6组成相似,主要鼠李糖-戊糖寡糖、鼠李糖-葡萄糖醛酸寡糖、戊糖二糖和三糖寡糖片段组成,硫酸根连接在鼠李糖和戊糖上。结论：钝顶螺旋藻中有多种不同结构的复杂硫酸多糖,其中葡萄糖醛酸-鼠李聚糖是钝顶螺旋藻中特有的一种硫酸多糖。     

Challenges and constraints of using oxygen cathodes in microbial fuel cells

The performance of oxygen reduction catalysts (platinum, pyrolyzed iron(ll) phthalocyanine (pyr-FePc) and cobalt tetramethoxyphenylporphyrin (pyr-CoTMPP)) is discussed in light of their application in microbial fuel cells. It is demonstrated that the physical and chemical environment in microbial fuel cells severely affects the thermodynamics and the kinetics of the electrocatalytic oxygen reduction. The neutral pH in combination with low buffer capacities and low ionic concentrations strongly affect the cathode performance and limit the fuel cell power output. Thus, the limiting current density in galvanodyanamic polarization experiments decreases from 1.5 mA cm(-2) to 0.6 mA cm(-2) (pH 3.3, E(cathode) = 0 V) when the buffer concentration is decreased from 500 to 50 mM. The cathode limitations are superposed by the increasing internal resistance of the MFC that substantially contributes to the decrease of power output. For example, the maximum power output of a model MFC decreased by 35%, from 2.3 to 1.5 mW, whereas the difference between the electrode potentials (deltaE = E(anode) - E(cathode)) decreased only by 10%. The increase of the catalyst load of pyr-FePc from 0.25 to 2 mg cm(-2) increased the cathodic current density from 0.4 to 0.97 mA cm(-2) (pH 7, 50 mM phosphate buffer). The increase of the load of such inexpensive catalyst thus represents a suitable means to improve the cathode performance in microbial fuel cells. Due to the low concentration of protons in MFCs in comparison to relatively high alkali cation levels (ratio C(Na+,K+)/C(H+) = 5 x E5 in pH 7, 50 mM phosphate buffer) the transfer of alkali ions through the proton exchange membrane plays a major role in the charge-balancing ion flux from the anodic into the cathodic compartment. This leads to the formation of pH gradients between the anode and the cathode compartment.     

Antimicrobial Effect of Cetylpyridinium Chloride on Listeria monocytogenes V7 Growth on the Surface of Raw and Cooked Retail Shrimp

ABSTRACT:  This study examined the concentration of cetylpyridinium chloride (CPC) required to control Listeria monocytogenes on the surfaces of raw and cooked, peeled and shell-on shrimp. Shrimp (5 g) were inoculated by immersion into a 24 h culture of L. monocytogenes (decimally diluted in PBS) for 1 min, followed by air drying for 1 h, to yield between 6.2 log and 7.0 log CFU/g. The raw and cooked shell-on samples had higher L. monocytogenes counts than the peeled shrimp groups after this inoculation process. The shrimp samples were treated by soaking in different concentrations of CPC (0.05, 0.1, 0.2, 0.4, 0.6, 0.8, or 1.0%) solutions for 1 min, with or without a water rinse for 1 min. The samples were bagged, stored at 4 °C for 24 h, and then plated onto Oxford selective media for determination of log CFU/g. All CPC treatments (0.05% to 1.0%) that were followed by a water rinse reduced L. monocytogenes counts on cooked shrimp by about 2.5 log CFU/g. Conversely, treatments not followed by a water rinse reduced L. monocytogenes counts on cooked shrimp by 3 log CFU/g with 0.1, 0.2, or 0.4% CPC, 5 log CFU/g with 0.6% CPC, 6 log CFU/g with 0.8% CPC, and 7.0 log CFU/g with 1.0% CPC. These results indicate that a soaking treatment of CPC has a strong potential to eliminate or reduce L. monocytogenes on the surfaces of shrimp.     

外源蔗糖对萝卜幼苗品质及代谢酶活性的影响

以“满堂红”品种的萝卜为材料,探究不同质量浓度的外源蔗糖喷洒处理对不同生长天数的萝卜幼苗营养品质（花青素、叶绿素、类胡萝卜素、总酚和芥子油苷等含量）及代谢酶（过氧化物酶（peroxidase,POD）和苯丙氨酸解氨酶（phenylalanine ammonialyase,PAL））活性的影响。结果表明：对于生长3、5 d和7 d的萝卜幼苗,0.4 g/100 mL和0.6 g/100 mL蔗糖处理均能够显著提高其花青素、叶绿素、类胡萝卜素、总酚、芥子油苷含量及POD、PAL活性（P＜0.05）,而0.2 g/100 mL蔗糖处理对其营养物质含量及抗氧化性的影响不显著（P＞0.05）;0.4 g/100 mL和0.6 g/100 mL蔗糖处理在改善其营养价值方面的差别不大。因此,在农业生产中,可采用质量浓度0.4 g/100 mL蔗糖喷洒处理萝卜幼苗来提高其营养价值。     

Bifunctional silver nanoparticle cathode in microbial fuel cells for microbial growth inhibition with comparable oxygen reduction reaction activity

Organic contamination of water bodies in which benthic microbial fuel cells (benthic MFCs) are installed, and organic crossover from the anode to the cathode of membraneless MFCs, is a factor causing oxygen depletion and substrate loss in the cathode due to the growth of heterotrophic aerobic bacteria. This study examines the possible use of silver nanoparticles (AgNPs) as a cathodic catalyst for MFCs suffering from organic contamination and oxygen depletion. Four treated cathodes (AgNPs-coated, Pt/C-coated, Pt/C+AgNPs-coated, and plain graphite cathodes) were prepared and tested under high levels of organics loading. During operation (fed with 50 mM acetate), the AgNPs-coated system showed the highest DO concentration (0.8 mg/L) in the cathode area as well as the highest current (ranging from 0.04 to 0.12 mA). Based on these results, we concluded that (1) the growth of oxygen-consuming heterotrophic microbes could be inhibited by AgNPs, (2) the function of AgNPs as a bacterial growth inhibitor resulted in a greater increase of DO concentration in the cathode than the other tested cathode systems, (3) AgNPs could be applied as a cathode catalyst for oxygen reduction, and as a result (4) the MFC with the AgNPs-coated cathode led to the highest current generation among the tested MFCs.     

正交试验法分散碳纳米管的初步研究

运用正交试验法初步探索了十二烷基苯磺酸钠（SDBS）、十二烷基硫酸钠（SDS）两种表面活性剂作为分散剂分散碳纳米管的最佳工艺条件,同时讨论了两种表面活性剂复配对碳纳米管分散性能的影响。结果表明,十二烷基苯磺酸钠与十二烷基硫酸钠作为分散剂的最佳分散工艺条件：超声时间、超声温度、超声功率、分散剂用量分别为30min、60℃、450W、0.8g/L和20min、60℃、360W、0.6g/L。在两种最佳分散工艺条件下,分散效果最优的复配量：十二烷基苯磺酸钠、十二烷基硫酸钠分别是0.8g/L、0.64g/L和0.36g/L、0.6g/L。     

Optimization of trans-resveratrol concentration and sensory properties of peanut kernels by slicing and ultrasound treatment, using response surface methodology

ABSTRACT:  Effect of postharvest stress application by slicing at 0.2, 0.4, and 0.6 cm, exposure to ultrasound (power density of 39.2 mW/cm³) for 4 min at 25 °C and subsequent incubation for 24, 36, 42, and 48 h on trans -resveratrol concentrations, and sensory attributes were evaluated using response surface methodology. Peanuts sliced 0.4 and 0.6 cm, exposed to ultrasound, and incubated for 42 h had trans -resveratrol concentrations above 1.0 μg/g, as did all samples incubated for 48 h. The optimized area was bound by peanut size of 0.89, 0.72, and 0.64 and incubation time of 48, 41.5, and 48 h, respectively. Combinations of treatments that fall within the optimized area were predicted to result in a peanut with a trans -resveratrol ≥1.0 μg/g; slightly lower roasted peanut aroma (>24) and flavor (>43); peanut butter aroma (>14), and flavor (>31) compared to controls with attribute ratings of 33, 78, 38, and 51, respectively; and slightly higher oxidized aroma (<6), and painty (<0.5), fishy (<6), and cardboard flavor (>4) compared to controls rated 0 for all attributes.     

Inhibitory effect of marinades with hibiscus extract on formation of heterocyclic aromatic amines and sensory quality of fried beef patties

Heterocyclic aromatic amines (HAA) are carcinogenic compounds found in the crust of fried meat. The objective was to examine the possibility of inhibiting HAA formation in fried beef patties by using marinades with different concentrations of hibiscus extract (Hibiscus sabdariffa) (0.2, 0.4, 0.6, 0.8 g/100 g). After frying, patties were analyzed for 15 different HAA by HPLC-analysis. Four HAA MeIQx (0.3–0.6 ng/g), PhIP (0.02–0.06 ng/g), co-mutagenic norharmane (0.4–0.7 ng/g), and harmane (0.8–1.1 ng/g) were found at low levels. The concentration of MeIQx was reduced by about 50% and 40% by applying marinades containing the highest amount of extract compared to sunflower oil and control marinade, respectively. The antioxidant capacity (TEAC-Assay/Folin–Ciocalteu-Assay) was determined as 0.9, 1.7, 2.6 and 3.5 μmol Trolox antioxidant equivalents and total phenolic compounds were 49, 97, 146 and 195 μg/g marinade. In sensory ranking tests, marinated and fried patties were not significantly different (p > 0.05) to control samples.     

Electricity generation using an air-cathode single chamber microbial fuel cell in the presence and absence of a proton exchange membrane

Microbial fuel cells (MFCs) are typically designed as a two-chamber system with the bacteria in the anode chamber separated from the cathode chamber by a polymeric proton exchange membrane (PEM). Most MFCs use aqueous cathodes where water is bubbled with air to provide dissolved oxygen to electrode. To increase energy output and reduce the cost of MFCs, we examined power generation in an air-cathode MFC containing carbon electrodes in the presence and absence of a polymeric proton exchange membrane (PEM). Bacteria present in domestic wastewater were used as the biocatalyst, and glucose and wastewater were tested as substrates. Power density was found to be much greater than typically reported for aqueous-cathode MFCs, reaching a maximum of 262 +/- 10 mW/m2 (6.6 +/- 0.3 mW/L; liquid volume) using glucose. Removing the PEM increased the maximum power density to 494 +/- 21 mW/m2 (12.5 +/- 0.5 mW/L). Coulombic efficiency was 40-55% with the PEM and 9-12% with the PEM removed, indicating substantial oxygen diffusion into the anode chamber in the absence of the PEM. Power output increased with glucose concentration according to saturation-type kinetics, with a half saturation constant of 79 mg/L with the PEM-MFC and 103 mg/L in the MFC without a PEM (1000 omega resistor). Similar results on the effect of the PEM on power density were found using wastewater, where 28 +/- 3 mW/m2 (0.7 +/- 0.1 mW/L) (28% Coulombic efficiency) was produced with the PEM, and 146 +/- 8 mW/m2 (3.7 +/- 0.2 mW/L) (20% Coulombic efficiency) was produced when the PEM was removed. The increase in power output when a PEM was removed was attributed to a higher cathode potential as shown by an increase in the open circuit potential. An analysis based on available anode surface area and maximum bacterial growth rates suggests that mediatorless MFCs may have an upper order-of-magnitude limit in power density of 10(3) mW/m2. A cost-effective approach to achieving power densities in this range will likely require systems that do not contain a polymeric PEM in the MFC and systems based on direct oxygen transfer to a carbon cathode.     

Ion exchange membrane cathodes for scalable microbial fuel cells

One of the main challenges for using microbial fuel cells (MFCs) is developing materials and architectures that are economical and generate high power densities. The performance of two cathodes constructed from two low-cost anion (AEM) and cation (CEM) exchange membranes was compared to that achieved using an ultrafiltration (UF) cathode, when the membranes were made electrically conductive using graphite paint and a nonprecious metal catalyst (CoTMPP). The best performance in single-chamber MFCs using graphite fiber brush anodes was achieved using an AEM cathode with the conductive coating facing the solution, at a catalyst loading of 0.5 mg/cm2 CoTMPP. The maximum power densitywas 449 mW/ m2 (normalized to the projected cathode surface area) or 13.1 W/m3 (total reactor volume), with a Coulombic efficiency up to 70% in a 50 mM phosphate buffer solution (PBS) using acetate. Decreasing the CoTMPP loading by 40-80% reduced power by 28-56%, with only 16% of the power (72 mW/m2) generated using an AEM cathode lacking a catalyst. Using a current collector (a stainless steel mesh) pressed against the inside surface of the AEM cathode and 200 mM PBS, the maximum power produced was further increased to 728 mW/m2 (21.2 W/m3). The use of AEM cathodes and brush anodes provides comparable performance to similar systems that use materials costing nearly an order of magnitude more (carbon paper electrodes) and thus represent more useful materials for reducing the costs of MFCs for wastewater treatment applications.