超声-硝酸联合法提取褐煤腐植酸工艺

实验考察了超声、硝酸预处理、酸化程度、碱液浓度、反应温度、液固比、反应时间等对腐植酸提取率的影响,并通过正交设计选择最佳预氧化条件和褐煤腐植酸的最佳提取条件.结果表明;超声硝酸联合氧化法提取腐植酸的最佳条件为：超声频率80kHz,氧化温度50℃,硝酸液固比（mL/g）为5∶1,氧化时间90min,硝酸浓度1.5mol/L.     

腐植酸增值尿素的多谱学分子结构表征

尿素生产过程中加入腐植酸生产腐植酸增值尿素,可以有效延缓尿素水解,提高作物产量与氮肥利用效率,然而在此过程中腐植酸（HA）与尿素（U）主要发生什么反应还未见报道。利用风化煤源HA生产含腐植酸5%,10%及20%的腐植酸增值尿素（HAU5,HAU10及HAU20）,采集并分析了HAU5,HAU10,HAU20及U的红外谱图及其二阶导数谱图,用XPS与O(1s)NEXAFS分别对HAU20,HA及U进行表征;通过无水乙醇溶解HAU20的方式去除了HAU20中的尿素,并利用FTIR与XPS对醇不溶物（UHA）进行表征。结果表明：（1）FTIR原谱图及二阶导数谱图表明,腐植酸增值尿素伯胺C—N振动强度低于普通尿素,且振动强度随着HA添加量的提高而降低,XPS N(1s)与O(1s)NEXAFS检测到HAU20中分别存在较多仲胺氮与非羰基氧,且FTIR发现UHA酰胺特征明显,表明腐植酸增值尿素制备过程中HA与U发生了反应。（2）XPS C(1s)表明,HAU20与UHA羧基碳比例少于HA,FTIR结果表明,UHA中不存在HA中检测到的羧酸C—O—H面内弯曲振动,羧基C═O伸缩振动位置发生偏移且伯胺氮特征明显,表明腐植酸的羧基参与了HA与U的反应,且反应方式为腐植酸羧基C—OH化学键断裂,与尿素胺基结合,脱水形成R—CO—NH—CO—NH₂。因此,采用光谱分析明晰了腐植酸增值尿素制备过程中,腐植酸与尿素的主要反应方式,这将为腐植酸增效尿素机理揭示以及增值尿素研制提供基础资料。     

液体酸对碱溶酸析法提取泥炭腐植酸光谱学变化特征的影响

研究不同液体酸酸析对碱溶酸析法提取腐植酸的光谱学特性的影响,进而优选酸析液体酸,解析泥炭甲烷发酵、腐植酸提取耦合的泥炭利用新工艺机理。泥炭甲烷发酵,将发酵后泥炭残渣和未发酵的泥炭,采用碱溶酸析法提取腐植酸,提取时采用不同液体酸酸析,对得到的腐植酸进行傅里叶红外光谱分析、荧光光谱分析、E_4/E_6的表征。碱溶酸析法提取泥炭腐植酸, PHA1腐植酸产率最高, PHA2腐植酸产率有所降低。PHA1和PHA2硝酸酸析腐植酸产率为45.30%和35.00%,且硝酸酸析腐植酸纯度较大, PHA1是54.83 mg·L~(-1), PHA2为61.03 mg·L~(-1),综合产率与纯度,硝酸是碱溶酸析法提取泥炭腐植酸的最佳液体酸。傅里叶红外光谱分析显示,硝酸酸析得到的腐植酸含O—H基团最多,存在较多的脂肪碳链结构、烷基、醇羟基。PHA1和PHA2腐植酸的红外谱图相似, PHA1腐植酸饱和碳明显高于PHA2, PHA2腐植酸羰基、苯环较多。三键和累积双键、羟基、 PHA1和PHA2差别不大。荧光光谱分析表明,泥炭腐植酸均在450 nm附近出现峰值,以PHA1腐植酸峰值最高, PHA2峰值最低。磷酸酸析腐植酸峰值最高,硝酸酸析峰值次之,表明不同液体酸酸析得到的腐植酸官能团数目不同。E_4/E_6分析显示, PHA1腐植酸的E_4/E_6比值均较大,芳香缩合程度低,发酵后PHA2的E_4/E_6均降低,芳香缩合程度高。表明甲烷发酵会消耗低芳香缩合度的腐植酸,而复杂芳香结构无法被降解,提取的腐植酸芳香缩合程度明显增大。碱溶酸析法提取泥炭腐植酸光谱学变化特征研究表明,不同液体酸、甲烷发酵对碱溶酸析法提取泥炭腐植酸产率、纯度、官能团有明显影响,泥炭联产甲烷和腐植酸的工艺可行。     

腐植酸溶液的声化学降解研究

采用频率为1.8MHz的超声波在固定式声化学反应器内研究了声化学降解腐植酸的自由基氧化历程。通过采用TA溶液作为OH自由基捕获剂,吡啶溶液作HO2自由基捕获剂,以及KI溶液的I2释放法分别确定出实验条件下反应溶液中OH自由基的浓度为10^-7M,HO2自由基浓度为10^-5M及H2O2浓度为10^-5M。在此基础上研究了均相与多相催化条件下声化学降解腐植酸溶液的TOC削减情况。发现CeO2和Cu2O催化作用下腐植酸的降解效率分别较均相条件下提高40％和20％。并就反应机理和反应动力学过程进行了描述。     

南瓜多糖的性质及光谱分析

采用热水浸提和乙醇沉淀的方法提取南瓜多糖,Sevage法除蛋白,活性炭脱色,对南瓜多糖的理化性质、提取率、含量、组成和结构进行了研究,南瓜多糖呈灰白色粉末,溶于水,不溶于有机溶剂。碘-碘化钾反应呈阴性,说明提取物为非淀粉性多糖。提取率5.34%,总糖含量为97.93%,紫外光谱扫描结果表明南瓜多糖几乎不含核酸和蛋白质;红外吸收光谱检测表明,在3433、2949、1749、1612、1416、1333、1238、1147、1101、1018、833、763、637、536、427cm^-1处表现为典型的多糖特征吸收峰;南瓜多糖是一种酸性多糖,同时存在呋喃环和吡喃环,该多糖是以α型糖苷键相连结的杂多糖。     

静电场协同超声提取甘草中甘草酸的研究

本文以甘草中甘草酸为研究对象,采用静电场协同超声方法提取,对其影响因素和强化效果进行了研究。通过一系列的单因素实验和响应曲面方法,本项目考察了浸泡时间,液固比,超声电功率,提取时间,超声频率和静电压对甘草酸提取率的影响。运用曲面响应法得出甘草中甘草酸的最优化反应条件为:液固比为30 mL/g,提取时间为29 min,超声电功率为100 W,静电压为9 kV;在该条件下甘草酸的提取率为11.02%。影响提取率最显著的因素是液固比,其次是超声电功率。实验结果表明超声与静电场存在协同作用。     

半叶马尾藻多糖的提取和分析

采用热水浸提法提取半叶马尾藻多糖 [Sargassumhemiphyllum (Turner)C Ag polysaccharides ,SHP],并对其理化性质、提取率、含量、组成和性质进行了研究。SHP呈灰白色粉末状 ,溶于水 ,不溶于有机溶剂。碘 碘化钾反应呈阴性 ,说明提取物为非淀粉性多糖。提取率为 7 0 4 % ,总糖含量为 82 9%。紫外扫描结果表明多糖几乎不含核酸和蛋白质。红外光谱显示SHP主要为吡喃多糖 ,并显示多糖分子结构中存在 β 糖苷键。薄层层析结果提示该多糖可能为木聚糖。上述结果不仅说明该方法提取的物质是多糖 ,而且纯度好 ,提取效率高。     

类硼烯HBNaX（X=F,Cl）的构型及异构化反应的理论研究

用ＲＨＦ／６－３１Ｇ＾＊解析梯摭方法研究了类硼烯ＨＢＮａＦ和ＨＢＮａＣｌ的结构２，均得到了３个平衡构型和２个异构化反应的过渡态构型，经动力学分析表明，其中两种平衡要型是它们存在和参加化学反应的基本构型，分子各平衡构型的结构特点及稳定性，给出了各构型的Ｍｕｌｌｉｋｅｎ集居数和基本构型的前线分子轨道，并讨论了基本构型的反应活性及卤素原子（Ｆ，Ｃｌ）对构型稳定性和基本的构型反应活性的影响。     

超声波强化提取对茯苓水溶性多糖结构影响的研究

以茯苓菌核为原料,采用正交实验法确定超声波辅助热水浸提茯苓水溶性多糖的最佳提取条件,并对超声波辅助提取中药多糖的机理进行初步研究。用苯酚硫酸法测定糖含量,傅立叶变换红外光谱仪(FTIR)分析糖类官能团,气相色谱法测定单糖组成,原子力显微镜观察多糖结构,并将测定结果与传统热水法浸提所得茯苓多糖进行对比。实验结果表明:采用超声波辅助热水浸提可以使水溶性茯苓多糖的提取率达到2.71%(传统热水浸提法提取率为1.49%),传统热水浸提得茯苓多糖(PPTH)与超声波辅助热水浸提得茯苓多糖(PPUH)具有相同的单糖组成,都包含核糖、木糖、甘露糖、果糖、半乳糖和葡萄糖,二者的红外吸收谱也基本相同,原子力显微镜扫描分析显示,PPTH整体呈现网状结构,而PPUH主要以长短不一的近棒状结构存在。     

微波辅助提取参芪胶囊中五味子甲素

研究了参芪胶囊中五味子甲素最佳提取工艺。采用正交试验以提取率为评价指标,确定最佳因素为:微波功率160W、料液比1:20(g/mL)、微波时间12min。与传统水提法比较,该方法耗时短,五味子甲素提取率较高。     

Physicochemical,structural, and digestive properties of pea starch obtained via ultrasonic-assisted alkali extraction

As a new and clean extraction technology, ultrasonic extraction has been demonstrated with great potential in the preparation of modified starch. In order to increase its added value, it is necessary to modify pea starch to enlarge its application. In this study, the efficiency of combining ultrasonic with alkali in the extraction of pea starch was evaluated and compared to conventional alkali extraction. Ultrasonic-assisted alkali extraction conditions were optimized using single-factor experiments and response surface methodology. The results revealed that maximum yield of pea starch (54.43 %) was achieved using ultrasound-assisted alkali extraction under the following conditions: sodium hydroxide solution with a concentration of 0.33 %, solid/alkali solution ratio of 1:6 (w/v), ultrasonic power of 240 W, temperature of 42 °C, and extraction time of 22 min. The ultrasound-assisted alkali extraction yielded 13.72 % greater pea starch than conventional alkali extraction. On the other hand, morphological, structural, and physicochemical properties of the obtained starch isolates were evaluated. The ultrasound-assisted alkali extraction resulted in pea starch with greater amylose content, water-solubility, swelling power, and viscosity compared with conventional alkali extraction. Furthermore, ultrasonication influenced the morphological properties of pea starch granules, while the molecular structure and crystal type were not affected. Moreover, the ultrasonic-assisted extraction produced starch with a slightly greater resistant starch content. Therefore, ultrasonic-assisted extraction can be suggested as a potential method for extracting pea starch with improved functional properties.     

响应面法优化超声提取熟地黄中5-羟甲基糠醛的工艺

采用响应面法优化了超声提取熟地黄中5-羟甲基糠醛的工艺.选取提取时间、溶剂浓度和温度3个因素为随机因子,在单因素的基础上进行3因素3水平Box-Behnken中心组合试验设计,以5-羟甲基糠醛得率为响应值进行响应面分析.优化后的超声提取熟地黄中5-羟甲基慷醛的条件为:在提取时间61.6min,溶剂体积分数90.5%,提...     

Effect of ultrasound on the dissolution of copper from copper converter slag by acid leaching

This work presents the optimum conditions of dissolution of copper in copper converter slag in sulphuric acid ferric sulphate mixtures in the presence and absence of ultrasound. The Taguchi method was used to determine the optimum conditions. The parameters investigated were the reaction temperature, acid concentration, ferric sulphate concentration and reaction time. The optimum conditions for the maximum dissolution of copper were determined as follows: reaction temperature, 65 °C; acid concentration, 0.2 M; ferric sulphate concentration, 0.15 M; reaction time 180 min. Under these conditions, extraction efficiency of copper, zinc, cobalt, and iron from slag were 89.28%, 51.32%, 69.87%, and 13.73%, respectively, in the presence of ultrasound, while they are 80.41%, 48.28%, 64.52%, and 12.16%, respectively, in the absence of ultrasound. As seen from the above results, it is clear that ultrasound enhances on the dissolution of Cu, Zn, Co and Fe in the slag.     

广藿香挥发油提取工艺的优化选择

采用正交试验探讨了不同提取温度、提取剂用量、提取时间以及提取次数对广藿香中挥发油提取率的影响,最终确定了广藿香挥发油的最佳提取工艺,即采用5倍量的石油醚在40℃下浸提4次,提取时间为24h.     

Ultrasound-assisted cyanide extraction of gold from gold concentrate at low temperature

A sonochemical reactor was developed to study the ultrasound-assisted cyanide extraction of gold from gold ore at low temperature. The effects of ultrasound on gold leaching in low temperature and conventional conditions were investigated. At the low temperature of 10 °C, ultrasound-assisted extraction increased extraction rate of gold by 0.6%–0.8% and reduced the gold content of cyanide tailings to 0.28 g/t in the leaching of gold concentrate and cyanide tailings, respectively. At the conventional temperature of 25 °C, ultrasound-assisted extraction obtained a 0.1% higher extraction rate of gold compared with conventional extraction, with the unit consumption of NaCN reduction of 15%. The analysis of kinetic model also demonstrated that sonication indeed improved the reaction of gold leaching greatly. The mineralogy and morphology of ore were further analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and particle size analyzer to explore the strengthening mechanism of gold leaching. The results showed that the ore particles were smashed, the ore particle surface was peeled, the passive film was destroyed and the reaction resistance decreased under ultrasonic processing. Therefore, the extraction rate of gold was improved and the extraction time was shortened significantly in ultrasound-assisted cyanide extraction.     

超声辅助提取栀子果总黄酮的工艺

以栀子果为原料,超声辅助提取总黄酮.用分光光度法测定栀子果中总黄酮含量,用正交试验探讨提取条件.结果表明：当溶剂乙醇浓度为70％,溶剂量为15mL/g,提取时间为20 min,提取温度为30℃时,黄酮提取率可达14.45％.     

Hyaluronan in the epidermal and the dermal extracellular matrix: its role in cutaneous hydric balance and integrity of anuran integument

New researches have revealed that hyaluronan (HA) is not a passive molecule. HA has being pointed out to participate in many processes, such as cell interactions, proliferating and migrating cell events and function as hydrate agent. The present study was undertaken to localize HA in Bufo ictericus integument providing a better understating for the role of cutaneous HA. Paraffinized sections were stained with haematoxylin-eosin and with 1% Alcian blue 8GX at pH 1.0 and 2.5. Alcianophilic reaction was visualized in both spongious dermis and Eberth-Katschenko layer. The mucus cells of mucus glands were also stained with AB methods. Besides these histological techniques, the localization of HA was performed using the FITC-labeled HA probe labeled with fluorescein isothiocyanate. In the extracellular matrix of spongious dermis, the reaction for HA was evident, being less intense in hypodermis and in pericellular keratinocyte matrix of the cornified tubercles regions. Thus, since HA was localized in the pericellular epidermal matrix and in the spongious dermis of anuran integument, it plays an important role in hydric balance, and is essential for integument integrity and functionality.     

Biomedical properties of laser prepared silver-doped hydroxyapatite

Thin films of hydroxyapatite (HA) and silver-doped HA were synthesized using KrF excimer laser deposition. Material was ablated from one target composed from silver and HA segments. Layers properties as silver content, structure, color, FTIR spectra and antibacterial properties (Gram-positive Bacillus subtilis) were measured. Silver concentration in HA layers of 0.06, 0.3, 1.2, 4.4, 8.3, and 13.7 at % was detected. The antibacterial efficacy changed with silver dopation from 71.0 to 99.9%. The focus is on investigation of minimum Ag concentration needed to reach a high antibacterial efficacy.     

Optimization of ultrasound-assisted extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant (Solanum melongena L.) peel

The present study describes the extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant peel using ultrasonic treatments and methanol and 2-propanol as extraction solvents. The extraction yields were optimized by varying the solvent concentration, ultrasonic frequency, temperature and time of ultrasonic treatment. Box–Behnken design was used to investigate the effect of process variables on the ultrasound-assisted extraction. The results showed that for TPC extraction the optimal condition were obtained with a methanol concentration of 76.6%, 33.88 kHz ultrasonic frequency, a temperature of 69.4 °C and 57.5 min extraction time. For TMA the optimal condition were the following: 54.4% methanol concentration, 37 kHz, 55.1 °C and process time of 44.85 min.