Anodic oxidation of salicylic acid at Ta/BDD electrode

Boron-doped diamond （BDD） film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid （SA）. The effects of operational variables including initial concentration, current density, temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect ofpH on SA degradation. The current efficiency （CE） ,aas fbund to be dependent mainly on the initial SA concentration, current density and temperature. Chemical oxygen demand （COD） was reduced from 830 mg/L to 42 mg/L under a current density of200A/m^2 at 30℃.     

超声波降解水中有机污染物的研究进展

综述了超声波降解水污染物的机理、影响因素，并介绍了国外超声波降解有机污染物的研究概况及后续研究方向．     

A novel way of liver preservation improves rat liver viability upon reperfusion

Background/aim： Currently, the liver is cold-preserved at 0-4 ℃ for experimental and clinical purposes. Here, we investigated whether milder hypothermia during the initial phase of the preservation period was beneficial for liver viability upon reperfusion. Methods： In the first set of experiments, rat livers were preserved either conventionally in clinically used histidine-trypthopan-ketoglutarate （HTK） solution （Group A： 45 min and Group B： 24 h） or by slow cooling HTK solution （from 13 ℃ to 3 ℃） during the initial 45 min of preservation （Group C： 24 h）. In the second set of experiments, additional groups of livers were evaluated： Group BB-preservation according to Group B and Group CC-preservation according to Group C. Further, some livers were preserved at 13 ℃ for 24 h. Livers were then reperfused using a blood-free perfusion model. Results： Bile production was approximately 2-fold greater in Group C compared to Group B. Alanine transaminase （ALT） and aspartate transaminase （AST） release into perfusate were 2-3-fold higher in Group B compared to Group C. No significant differences were found in ALT and AST release between Group C and Group A. Livers in Group CC compared to Group BB exhibited significantly lower portal resistance, greater oxygen consumption and bromosulfophthalein excretion into bile and lower lactate dehydrogenase （LDH） release into perfusate. Histological evaluation of tissue sections in Group BB showed parenchymal dystrophy of hepatocytes, while dystrophy ofhepatocytes was absent in Group CC. Livers preserved at 13 ℃ for 24 h exhibited severe ischemic injury Conclusion： These results suggest that the conventional way of liver preservation is not suitable at least for rat livers and that slow cooling of HTK solution during the initial phase of cold storage can improve liver viability during reperfusion.     

基于Powell算法的改进微粒群算法

提出一种与Powell算法相结合的新型改进微粒群算法——Powell-PSO.改进算法将粒子的搜索过程分为两阶段,第一阶段,将标准微粒群算法的速度公式加以改进进行搜索;第二阶段,将第一阶段的最后一代粒子作为Powell算法的初始点,让Powell算法与PSO算法交替进行.这样既克服了微粒群算法陷入局优的缺点,也大大提高了算法的求解精度,同时提高了收敛速度并保持了微粒的多样性.仿真结果表明：与标准微粒群算法相比,Powell-PSO具有较高求解精度和较强寻优能力,并且不论是对单峰还是多峰函数都能取得较好的优化效果.     

Process Optimization of Coke Oven Gas to Methanol Based on the Downgrade of By-Product Steam

In the coke oven gas to methanol(CTM) process, boiling water(above 200 ℃) is generally used as the coolant in the methanol synthesis reactor, and thus, medium-pressure steam is generated as a by-product. In this paper, the influence of the coolant temperature on the CTM process is investigated from two aspects, which are the performance analyses of the reactor and the overall process and the energy integration of by-product steam. The results reveal that the coolant temperature plays a key role in the CTM process optimization. When the coolant temperature is reduced to 187 ℃, though low-pressure steam is generated, the techno-economic performance of the whole process is greatly improved: the energy/exergy efficiency is increased by 4-9%, energy cost is saved by 37.1%, income is increased by 5.4 M$/year, and the C02 emission is reduced by 21.3%.     

Experimental Study on Decolorization and Degradation of Reactive Brilliant Red X—3B in a White Rot Fungal Biofilm Reacor

Experimental results of an azo dye(reactive brilliant red X-3B,RBR X-3B) decolorization and degradation in a white rot fungal biofilm reactor were introduced and discussed.The fungal biofilm reactor is highly potential for dye decolorization and degradation with the highest decoloring rate of 95% within 96 hours reaction time at initial pH 4.5 under high nirogen level (HN) (24mmol/L ammonium tartrate)condition.Experimental conditions.such as nutrient nitrogen levels in reaction mixture and initial pH,significantly affected dye decolorization and degradation.Effluents from this bioilm reactor can be well treated to meet the discharging requirements by use of chemical flocculation.RBR X-3B was first absorbed onto fungal biomass and then degraded gradually,The SH-13 fungus monopolized the biofilm throughout the experiments,though the reactor was exposed to open air for 4 months.     

纳米Ti0_2光催化氧化法处理碱性紫5BN染料废水的研究

以脱色率为主要考察指标,研究了纳米TiO2光催化氧化法处理三苯甲烷染料碱性紫5BN的最佳工艺条件。试验结果表明,采用紫外光源为20 W的KL-1型光催化反应器,在平均粒径为30 nm的TiO2悬浮体系中,TiO2能够高效脱除碱性紫5BN的色度。纳米TiO2光催化降解碱性紫5BN、活性艳红K-2BP,在KL-1型紫外光实验装置上的最佳工艺条件为:碱性紫5BN在初始浓度80 mg/L时,TiO2用量1.0 g/L,pH值为3,外加催化剂H2O2加入量为2.5 ml/L,反应2.5 h,碱性紫5BN最大脱色率为98%。本试验为进一步进行碱性紫5BN的工业化处理提供了科学依据,并为纳米TiO2光催化氧化法处理其他染料废水提供借鉴。     

辣根过氧化物酶催化H2O2氧化橙黄Ⅱ的降解研究

研究了pH值、温度、反应时间、过氧化氢用量、染料初始浓度等对辣根过氧化物酶（HRP）催化过氧化氢氧化降解橙黄Ⅱ染料溶液的影响.结果表明在pH值为2、温度为43℃、反应时间为12 min、H2 O2用量为2.0 mmol·L-1、染料初始浓度0.8 mmol·L-1时橙黄Ⅱ的降解最为理想,脱色率可达到83.7％.     

Optimization of elastolysis conditions and elastolytic kinetic analysis with elastase from Bacillus licheniformis ZJUEL31410

INTRODUCTION Elastases are heterogeneous with differing sub-strate specificities and catalytic mechanisms. In fact, enzymes with elastolytic activity can be found in most of the major proteolytic families, including serine, thiol, aspartic, and metallo-enzymes. Despite the differences in catalytic mechanisms, all of these elastases share a common specificity for cleaving peptide bonds associated with hydrophobic or aro-matic amino acids (Hall and Czerkawaki, 1961). Bacterial elastases b…     

佐匹克农测定方法研究

首次用碳糊电极吸附伏安法测定了Zopiclone的浓度 .对底液、PH值、电极组成等进行了研究 ,在PH为 3.17的HAC -NaAC中 ,Zopiclone产生两对可逆峰 ,峰高与浓度在 1.3× 10 - 8～ 1.3×10 - 7mol/L间呈线性关系 ,相关系数为 0 .9996 ,下限为 3.9× 10 - 9mol/L ,并对顺德制药厂产的Zopi clone片剂进行了应用分析 .     

苯酚光催化降解过程中的浓度测定

在强碱性环境中高锰酸钾和苯酚反应后的溶液在800～900mm范围内的吸收与苯酚初始浓度正相关,该范围内的吸收几乎全部来自于反应后生成的MnO4^2-反应后溶液在845nm处的吸收与苯酚初始浓度之间具有良好的线性关系：Abs=0．03292C＋0．07034（R=0．9954）。该法能直接用于测定苯酚光催化降解过程中的浓度变化。     

水中2,4-二氯苯酚和五氯苯酚电子束辐射降解的研究

用电子束辐射降解水中的2, 4-二氯苯酚(2, 4-DCP)和五氯苯酚(PCP), 研究辐照剂量对溶液初始质量浓度各为50 mg/L的2种氯代苯酚辐射降解和去除有机氯的影响. 同时研究了溶液不同的初始质量浓度、pH值和去氧状态等条件对辐射降解的影响. HPLC的测试结果表明: 随着辐照剂量的增加,氯代苯酚的降解率增加, 溶液中的氯离子增加, 但辐照后溶液中仍有2, 4-DCP和PCP的残余物. 试验结果表明: 有机氯辐射降解的速度要比无机氯生成的速度快得多; 溶液的去氧也能加快氯代苯酚的降解; 在酸性到中性条件下比碱性条件下更利于有机氯裂解.     

Fe^3＋、Cu^2＋掺杂TiO2光催化降解日落黄的研究

通过溶胶-凝胶法分别制备了掺杂Fe^3＋、Cu^2＋的TiO2.以日落黄为目标降解物,研究Fe^3＋、Cu^2＋掺杂TiO2为催化剂的紫外光催化反应,考察了金属离子的掺杂量、催化剂的加入量、光照时间、溶液pH值、溶液初始浓度对脱色率的影响.结果表明：Fe3＋掺杂对提高TiO2光催化活性的效果优于Cu^2＋掺杂.在Fe^3＋、Cu^2＋掺杂比为1.5%,Fe^3＋、Cu^2＋掺杂催化剂用量分别为0.04、0.1 g/L,紫外光催化降解2 h,pH为10,初始浓度为6 mg/L的日落黄100 mL的条件下,Fe^3＋、Cu^2＋掺杂的催化剂脱色率分别达92.14%、58.68%.     

纳米二氧化钛制备方法的对比及其降解间苯二酚的研究

采用溶胶-凝胶法、超声水解法制备纳米TiO2,用XRD对两种方法制得粉体进行了表征,对比了两种方法的优缺点。结果表明:超声水解法制得粉体的光催化效果好,且制备工艺简单,对间苯二酚光催化降解符合假一级动力学,速率常数为0.0928min-1,是溶胶-凝胶法速率常数的5.4倍。以超声水解法制得粉体对间苯二酚进行了降解研究,考察催化剂投加量、有机物浓度、溶液pH等因素对间苯二酚降解效果的影响。在最佳实验条件下反应60min,UV-Vis及HPLC均显示间苯二酚降解完全。     

辉光放电等离子体降解生物染料橙黄G

利用辉光放电等离子体技术降解橙黄G偶氮染料废水,借助紫外光谱分析了其降解过程,考察了多种因素对其降解效果的影响.结果表明,提高染料初始浓度和电解质浓度可提高橙黄G的降解率.改变溶液的初始pH值,橙黄G的降解率随溶液的初始pH值升高而增加.橙黄G降解60min后,无催化剂时,降解率达到71.68%;在催化剂Fe^2＋和Mn^2＋存在时降解率达到92.48%和89.69%,COD去除率为95.85%和63.44%;H2O2存在时,降解率达到78.91%.     

Science Letters:Anodic oxidation of salicylic acid at Ta/BDD electrode

Boron-doped diamond (BDD) film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid (SA). The effects of operational variables including initial concentration,current density,temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect of pH on SA degradation. The current efficiency (CE) was found to be dependent mainly on the initial SA concentration,current density and temperature. Chemical oxygen demand (COD) was reduced from 830 mg/L to 42 mg/L under a current density of 200 A/m2 at 30 °C.     

Low-Temperature Plasma Induced Grafting of 2-Methacryloyloxyethyl Phosphorylcholine onto Poly（tetrafluoroethylene） Films

Modification of poly(tetrafluoroethylene) (PTFE) films with 2-methacryloyloxyethyl phosphorylcholine (MPC) was performed by low-temperature plasma treatment and grafting polymerization. Surface properties of PTFE were characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra, X-ray photoelectron spectroscopy (XPS), and static contact angle. The results show that MPC has been grafted onto PTFE film surface successfully. Contact angle for the modified PTFE films in the water decreased from 108° to 58.25°, while surface energy increased from 17.52 mN/m to 45.47 mN/m. The effects of plasma treatment time, monomer concentration and grafting time on degree of grafting were determined. In the meanwhile, blood compatibility of the PTFE films was studied by checking thrombogenic time of blood plasma.     

Biosynthesis of (<Emphasis Type="Italic">R</Emphasis>)-2-hydroxy-3-phenylpropionic acid using whole recombinant <Emphasis Type="Italic">Escherichia coli</Emphasis> cells in an aqueous/<Emphasis Type="Italic">n</Emphasis>-octane biphasic system

(R)-2-hydroxy-3-phenylpropionic acid (PLA) is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate (PPA) to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6:4, 40 °C, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor (2-L scale). Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.     

TiO2光催化氧化降解偶氮染料

研究了催化剂、光源、溶液初始浓度、溶液初始pH值等因素对甲基橙光催化氧化降解反应的影响．实验结果表明,最佳实验条件为：以灼烧的TiO2为催化剂,催化剂的投加量为0,8g·L^-1,采用浸波式紫外灯作光源,甲基橙初始浓度为20mg·L^-1,溶液初始pH=3．该实验条件下,甲基橙一小时脱色率可达81．3％．该研究可为偶氮染料降解提供新的思路．     

罗丹明B的电化学降解工艺研究

探讨了罗丹明B在FTO导电玻璃上的电化学降解工艺,考察了支持电解质、缓冲体系类型、酸度、外加电压、初始浓度等因素对染料去除率的影响.结果表明,控制外加电压为10 V,在含0.15 mg·L-1氯化钠的硼酸盐缓冲溶液（pH7.0）中,电化学降解罗丹明B溶液（4.0mol·L-1）6 min后,罗丹明B的去除率可达到92％以上.