十二胺聚甘油醚表面活性剂的合成及光谱表征

十二胺与缩水甘油在碱催化下合成了不同聚合度的十二胺聚甘油醚表面活性剂,并以FTIR、ESI-MS、13CNMR进行了合成产品的光谱表征。用吊环法测定了该表面活性剂水溶液在25℃时的表面张力,考察了不同聚合度对其表面性质的影响。结果表明,十二胺二聚甘油醚、四聚甘油醚、六聚甘油醚水溶液的临界胶束浓度CMC(mmol/L)分别为0.32、0.055和0.20,先减小而后增大;最低表面张力γCMC(mN/m)分别为28.46、29.41和34.02,逐渐增大。

夜蓝在阴离子表面活性剂上Langmuir吸附及应用

在表面活性剂溶液中 ,活性剂分子长碳链相互缠绕折叠形成若干微电场 ,带异性电荷的染料分子被吸附 ,使溶液吸收光谱红移。本研究利用微相吸附—光谱修正 (MPASC)技术以十二烷基苯磺酸钠(SDBS)与染料夜蓝 (NB)结合反应为例研究表面活性剂在微量分析中的增效机理 ,结果表明二者的作用实质上是表面活性剂缠绕大分子内微电场对NB的Langmuir单分子层吸附。本报告测定了SDBS与NB结合产物性质 ,如结合比、单体摩尔吸光系数值等 ,而且定量分析了实际样品中的阴离子表面活性剂 ,回收率 97.9% ,RSD <3.1%。

提高某超级铁精矿制备过程中的反浮选回收率

以安徽某粉末冶金公司超级铁精矿生产线所用普通铁精矿为原料,将其再磨、弱磁再选后进行生产超级铁精矿的反浮选试验,通过添加调整剂Na2CO3、水玻璃、淀粉来解决现场单纯使用十二胺引起的反浮选回收率偏低问题,并探讨通过提高矿浆浓度来提高反浮选的生产效率。试验结果表明:将2 000 g/t Na2CO3、200 g/t水玻璃、100 g/t淀粉与130 g/t十二胺配合使用,在24%矿浆浓度下,反浮选所获超级铁精矿的作业回收率可由单纯使用十二胺时的44.61%(对原料为43.44%)提高到89.58%(对原料为89.27%);将矿浆浓度提高到28%,可使反浮选处理能力提高16.68%,而作业铁回收率仍达87.69%(对原料为87.38%)。

乙肝澳抗转阴一例

乙肝澳抗转阴一例屠金城王××，女，３６岁，初诊日用：１９７６年６目１日。〔病史〕慢性肝炎多年，肝功能异常，乙肝表面抗原阳性持续年余。［主证］肋痛绵绵，腹胀；午后浮肿，下肢明显，食欲欠佳。苔薄日，脉弦滑。当时化验ＧＰＴ为８００单位，ＴＴＴ为１６单位，澳...

亲水基团对十二烷基阴离子乳化剂在SiO_(2)表面吸附影响的分子动力学模拟与试验研究

乳化沥青破乳过程中,乳化剂分子亲水基团吸附于集料表面,亲油基团牵引沥青微滴向集料表面聚集,从而达到破乳。因此,为了探究乳化剂亲水基团对乳化沥青破乳过程的影响,通过分子动力学模拟和电导率试验探究了疏水基团为十二烷基碳链、亲水基团不同的5种阴离子乳化剂在玄武岩主要化学成分(SiO_(2))表面的吸附情况。模拟结果表明,亲水基团中的K+比Na+更能增强十二烷基阴离子乳化剂与水分子间的范德华相互作用,促进十二烷基阴离子乳化剂在SiO_(2)表面的聚集和吸附;在亲水基团中引入苯基官能团可提高十二烷基阴离子乳化剂与水分子间的范德华相互作用、十二烷基阴离子乳化剂在SiO_(2)表面的吸附能力,苯基官能团的引入率越高,十二烷基阴离子乳化剂与水分子间的范德华相互作用及十二烷基阴离子乳化剂在SiO_(2)表面的吸附能力越强;由于库仑力的作用,5种十二烷基阴离子乳化剂的疏水基团尾端C原子、亲水基团极性头S原子在SiO_(2)表面的扩散行为比十二烷基阴离子乳化剂自身在SiO_(2)表面的扩散行为弱。试验结果表明5种十二烷基阴离子乳化剂在SiO_(2)表面的吸附量随着乳化剂浓度和固/液比的增大而增加;5种阴离子乳化剂在SiO_(2)表面的吸附量大小排序与分子动力学模拟的结果一致,验证了结论的可靠性。

An experimental study on thermal characteristics of nanofluid with graphene and multi-wall carbon nanotubes

High-thermal conductivity enhancement of nanofluid is one of the promising topics of the nanoscience research field. This work reports the experimental study on the preparation of graphene(GN) and multi-walled carbon nanotubes(MWCNTs) based nanofluids with the assistance of sodium dodecyl benzene sulfonate(SDBS) and sodium dodecyl sulfate(SDS) surfactants, and their thermal behaviors. The present work suggests not a solution, but a solution approach and deduces a new conclusion by trying to resolve the agglomeration problem and improve the dispersibility of nanoparticles in the base fluid. The analysis results of FESEM, thermal conductivity, diffusivity, effusivity and heat transfer coefficient enhancement ratio of nanofluid with surfactants SDS and SDBS expose strong evidence of the dispersing effect of surfactant on the making of nanofluid.

EFFECT OF SURFACTANT SDS ON DETERMINATION OF NUCLEIC ACID WITH TERBIUM (III) FLUORESENCE

The effect of an anionic surfactant (sodium dodecyl sulfate, SDS) on the fluorescence properties of nucleic acid with terbium (III) is studied. Results show that ribonucleic acid (RNA) presents fluorescence reaction with Tb (III) directly, but deoxyribonucleic acid (DNA) presents similar fluorescence reaction only after its denaturation. In the presence of SDS, the fluorescence intensity is 4.0 times and 3.5 times greater than that of DNA and RNA without SDS.

Mass Transfer Enhancement of Propane Absorption into Dodecane-Water Emulsions

A one-dimensional unsteady heterogeneous parallel mass transfer(ODUHPMT) model was developed for the absorption enhancement of volatile organic compounds(VOC) by the dispersed droplets.An analytical solution for enhancement factor was obtained based on surface renewal theory and the Laplace domain transformation. The absorption rate of propane into water at different stirring speeds with the added micro dodecane droplets was investigated experimentally in a thermostatic stirred tank.The mass transfer flux across the gas-liquid interface and the enhancement factor were measured.The results showed that the dodecane has an obvious enhancement effect on propane absorption into water,the maximum enhancement factor reached 11.The enhancement factor increased with increasing dodecane volume fraction and decreased with increasing stirring speed.The experiment data agreed well with the model predictions and showed high prediction accuracy of ODUHPMT model.

Experimental Investigation on Promoting Effect of Composite Promoting Agents on Natural Gas Hydrate Formation

An experiment on effects of composite promoting agents composed of surfactants and liquid hydrocarbons on hydrate formation was conducted and the hydrate formation temperature,pressure,induction time and rate in the presence of different composite promoting agent packages were measured.The surfactants used covered sodium dodecyl sulfate(SDS),sodium dodecyl benzene sulfonate(SDBS) and 2-octyl sodium dodecyl sulfate(GC20S),and the liquid hydrocarbon additives utilized included cyclopentane(CP) and methyl cyclohexane(MCH).It appeared that all these combinations of composite promoting agents could promote hydrate formation.The type II hydrate formation conditions using composite promoting agents composed of CP and GC20S were the mildest and the induction time was the shortest;whereas the type H hydrates formation conditions using composite promoting agents composed of MCH and GC20S were the mildest and the induction time was also the shortest.

Performance of water-based foams affected by chemical inhibitors to retard spontaneous combustion of coal

The micelle generating process of the sodium dodecyl sulfate(SDS) solution with the addition of chemical inhibitors was elucidated using phase separation model, and the descending order of the capacity for the selected chemical inhibitors to reduce the critical micelle concentrations of the solution are Mg Cl_2, Ca Cl_2,NH_4HCO_3 and NH_4Cl. The data to quantitatively describe the foam decay process, including foaming ratio,foam life and decay behaviors, was obtained by pressure measuring system. The results indicate that chemical inhibitors can improve the solution foamability. The capacity of the inhibitors to enhance the solution foamability is sorted as NH_4 Cl, NH_4HCO_3, Mg Cl2 and Ca Cl_2 which can distinctly improve the foam stability as well. The capacity of the inhibitors to enhance the SDS foam stability can be arranged as Mg Cl_2, NH_4 Cl, NH_4HCO_3 and Ca Cl_2. It is observed that the gravity drainage plays a leading role in the increase of proportion of diffusion drainage. The oxidation dynamic parameters of the coal samples treated by inhibition foams were investigated using thermal analysis technique, and their synergistic effects on inhibiting coal oxidation were explored.

Effects of Ionic Surfactants on Bacterial Luciferase and α-Amylase

In order to study the effects of ionic surfactants on bacterial luciferase,the cationic surfactant dodecyltrimethylammonium biomide (DTAB) and anionic surfactant sodium dodecylsulfate (SDS) were chosen.For comparison with bacterial luciferase,α-amylase was used since these two enzymes have similar electrostatic potential and charged active sites.After the enzymes were treated with the surfactants,the catalytic properties of bacterial luciferase andα-amylase were assayed,and fluorescence spectroscopy and circular dichroism (CD) were used to analyze the alteration of the protein structure.The results showed that when the DTAB concentration was low,the cationic surfactant DTAB enhanced the enzymatic activities of bacterial luciferase andα-amylase.On the other hand,the anionic surfactant SDS did not alter the enzymatic activity.The main interaction of cationic surfactant DTAB and the negatively charged surface of the proteins was the ionic interaction,which could alter the environment for the enzyme to work when the DTAB/enzyme molar ratio was low.However,at high cationic surfactant concentration,the ionic interaction and hydrophobic interaction might destroy the secondary and tertiary structures of the proteins,leading to the loss of enzymatic activities.

Synthesis of Polyalphaolefins on AlCl_3/TiCl_4 Catalyst

The oligomerzation reactions on different catalysts were investigated and discussed. 1-Octene, 1-decene, 1-do- decene, a mixture of olefins （with a mass ratio of w（l-octene）： w（1-decenc）：w（1-dodecene） equating to 30：40：30）, and the products from paraffin cracking were oligomerized on the AlCl3/TiC14 catalyst. The results indicated that the AlCl3 catalyst led to severe coking reaction. With an increase in carbon number of alpha-olefins, the freezing point of oligomers increased and the kinematic viscosity decreased. The oligomers formed from the mixed olefins and the paraffin cracking products showed higher kinematic viscosity. Normal paraffins contained in the cracked products could increase the freezing point of oligomers. Furthermore, the distillation range of oligomers obtained from the cracked products was close to those of oligo- mers originated from 1-octene and 1-decene, while the oligomers obtained from the mixed olefins and 1-dodecene had simi- lar distillation ranges.

Unsedated ultrathin upper endoscopy is better than conventional endoscopy in routine outpatient gastroenterology practice:A randomized trial

AIM： to compare the feasibility and patients＇ tolerance of esophagogastroduodenoscopy （EGD） using a thin endoscope with those of conventional oral EGD and to determine the optimal route of introduction of smallcaliber endoscopes. METHODS： One hundred and sixty outpatients referred for diagnostic EGD were randomly allocated to 3 groups： conventional （C）-EGD （9.8 mm in diameter）, transnasal （TN）-EGD and transoral （TO）-EGD （5.9 mm in diameter）. Pre-EGD anxiety was measured using a 100-mm visual analogue scale （VAS）. After EGD, patients and endoscopists completed a questionnaire on the pain, nausea, choking, overall discomfort, and quality of the examination either using VAS or answering some questions. The duration of EGD was timed. Blood oxygen saturation （SaO2） and heart rate （HR） were monitored during EGD. RESULTS： Twenty-one patients refused to participate in the study. The 3 groups were well-matched for age, gender, experience with EGD, and anxiety. EGD was completed in 91.1% （41/45）, 97.5% （40/41）, and 96.2% （51/53） of cases in TN-EGD, TO-EGD, and C-EGD groups, respectively. TN-EGD lasted longer （3.11 ± 1.60 min） than TO-EGD （2.25 ± 1.45 min） and C-EGD （2.49 ± 1.64 rain） （P 〈 0.05）. The overall tolerance was higher （P 〈 0.05） and the overall discomfort was lower （P 〈 0.05） in TN-EGD group than in C-EGD group. EGD was tolerated ＂better than expected＂ in 73.2% of patients in TN-EGD group and 55% and 39.2% of patients in TO-EGD and C-EGD groups, respectively （P 〈 0.05）. Endoscopy was tolerated ＂worst than expected＂ in 4.9% of patients in TN-EGD group and 17.5% and 23.5% of patients in TO- EGD and C-EGD groups, respectively （P 〈 0.05）. TN-EGD caused mild epistaxis in one case, The ability to insuffiate air, wash the lens, and suction of the thin endoscope were lower than those of conventional instrument （P 〈 0,001）, All biopsies performed were adequate for histological assessment. CONCLUSION： Diagnostic TN-EGD is better tolerated than C-EGD, Narrow-diameter endoscope has a level of diagnostic accuracy comparable to that of conventional gastroscope, even though some technical characteristics of these instruments should be improved, Transnasal EGD with narrow-diameter endoscope should be proposed to all patients undergoing diagnostic EGD.

Trends in the eradication rates of Helicobacter pylori infection for eleven years

AIM:To evaluate the trends in the eradication rate of Helicobacter pylori(H.pylori) over the past 11 years in a single center.METHODS:This retrospective study covered the period from January 2000 to December 2010.We evaluated 5746 patients diagnosed with gastric ulcers(GU),duodenal ulcers(DU),GU + DU,or nonpeptic ulcers associated with an H.pylori infection.We treated them annually with the 2 wk standard first-line triple regimen,proton pump inhibitor(PPI) + amoxicilin + clarithromycin(PAC;PPI,clarithromycin 500 mg,and amoxicillin 1 g,all twice a day).The follow-up test was performed at least 4 wk after the completion of the 2 wk standard H.pylori eradication using the PAC regimen.We also assessed the eradication rates of 1 wk second-line therapy with a quadruple standard regimen(PPI b.i.d.,tripotassium dicitrate bismuthate 300 mg q.i.d.,metronidazole 500 mg t.i.d.,and tetracycline 500 mg q.i.d.) after the failure of the first-line therapy.Statistical analysis was performed with 95%CI for the differences in the annual eradication rates.RESULTS:A total of 5746 patients [2333 males(58.8%),1636 females(41.2%);mean age of males vs females 51.31 ± 13.1 years vs 52.76 ± 13.6 years,P < 0.05,total mean age 51.9 ± 13.3 years(mean ± SD)] were investigated.Among these patients,1674 patients were excluded:35 patients refused treatment;18 patients ceased H.pylori eradication due to side effects;1211 patients had inappropriate indications for H.pylori eradication,having undergone stomach cancer operation or chemotherapy;and 410 patients did not undergo the follow-up.We also excluded 103 patients who wanted to stop eradication treatment after only 1 wk due to poor compliance or the side effects mentioned above.Finally,we evaluated the annual eradication success rates in a total of 3969 patients who received 2 wk first-line PAC therapy.The endoscopic and clinical findings in patients who received the 2 wk PAC were as follows:gastric ulcer in 855(21.5%);duodenal ulcer in 878(22.1%);gastric and duodenal ulcer in 124(3.1%),erosive,atrophic gastritis and functional dyspepsia in 2055(51.8%);and other findings(e.g.,MALToma,patients who wanted to receive the therapy even though they had no abnormal endoscopic finding) in 57(0.5%).The overall eradication rate of the 2 wk standard firstline triple regimen was 86.5%.The annual eradication rates from 2000 to 2010 were 86.7%,85.4%,86.5%,83.3%,89.9%,90.5%,88.4%,84.5%,89.1%,85.8%,and 88.3%,sequentially(P = 0.06).No definite evidence of a significant change in the eradication rate was seen during the past eleven years.The eradication rates of second-line therapy were 88.9%,82.4%,85%,83.9%,77.3%,85.7%,84.4%,87.3%,83.3%,88.9%,and 84%(P = 0.77).The overall eradication rate of 1 wk quadruple second-line therapy was 84.7%.There was no significant difference in the eradication rate according to the H.pylori associated diseases.CONCLUSION:This study showed that there was no trend change in the H.pylori eradication rate over the most recent 11 years in our institution.

General Evaluation of Biocide （Bt-ASF-1） Produced from Iraqi Isolate of Bacillus thuringiensis

General evaluation of isolate Bacillus thuringiensis （Bt-ASF-1） used as biocide in meddle scale application was conducted. Some morphological and confirmation tests were achieved. The sensitivity tests had been accomplished by diffusion and dilution techniques to determine the response of isolate against the antibiotics. The results of diffusion tests showed to the sensitivity of bacteria to antibiotics of cefixime, erythromycin, gentamicin and tetracycline respectively. It was resistant to trimethoprim sulfonamide （TMP）, bacitracin, penicillin and all its generations, and moderate resistance to nalidixic acid. Minimum Inhibitory Concentration （MIC） for amoxicillin was ranged between 30-40 pg/mL and these results are an approximation of the universal findings. Curing experiments showed the effective role of sodium dodecyl sulfate （SDS） （1.5%） comparing with temperature. The bacterial cells became sensitive to amoxicillin and TMP. The curing by temperature did not differ significantly from control treatment in plasmid pattern or antibiotics response. Plasmid profile referring that curing by SDS has been caused disturbance in beta -lactamase genes through the sensitivity to amoxicillin and remaining resistance to ampicillin. Curing isolate by SDS also became more sensitive to nalidixic acid, erythromycin and tetracycline respectively. It was found from the curing treatments the complexity distribution of r-genes between different plasmid size and chromosome but not effect on their insecticidal ability.

The Effect of Casting Solvent on the Electrical Property of Polyaniline/Polyacrylonitrile

Blends of dodecylbenzene sulfonic acid doped polyaniline （PANI-DBSA） and polyacryionitrile （PAN） dissolved in either CHCh/DMF or CHCl3/DMSO mixture were solution cast. The conductivity of the blends with various compositions was measured and the doped ：xtent of PANI- DBSA in different casting solvent systems was studied. Solution blends prepared from CHCh/DMSO displayed higher conductivity than those obtained via CHCh/DMF. The dedoping reaction of PANI-DBSA in CHCl3/DMF identified by UV-Vis and FTIR analysis contributed to the lower conductivity of PANI-DBSA/PAN blend.

Diffusion-controlled Adsorption Kinetics of Surfactant at Air/Solution Interface

For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P（t） was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in this paper. From the measured dynamic surface tension of aqueous surfactant sodium dodecyl sulfate （SDS） solutions at 25 ℃, the adsorption kinetics of SDS at air/solution interface was studied. It was proved that for both of the short and long time limits, the adsorption process of SDS was controlled by diffusion.

Clinical characteristics of peptic ulcer perforation in Korea

AIM To elucidate the epidemiological characteristics and associated risk factors of perforated peptic ulcer(PPU).METHODS We retrospectively reviewed medical records of patients who were diagnosed with benign PPU from 2010 through 2015 at 6 Hallym university-affiliated hospitals.RESULTS A total of 396 patients were identified with postoperative complication rate of 9.1% and mortality rate of 0.8%. Among 174(43.9%) patients who were examined for Helicobacter pylori(H. pylori) infection, 78(44.8%) patients were positive for H. pylori infection, 21(12.1%) were on non-steroidal anti-inflammatory drugs(NSAIDs) therapy, and 80(46%) patients were neither infected of H. pylori nor treated by any kinds of NSAIDs. Multivariate analysis indicated that older age(OR = 1.09, 95%CI: 1.04-1.16) and comorbidity(OR = 4.11, 95%CI: 1.03-16.48) were risk factors for NSAID-associated PPU compared with non-H. pylori, non-NSAID associated PPU and older age(OR = 1.04, 95%CI: 1.02-1.07) and alcohol consumption(OR = 2.08, 95%CI: 1.05-4.13) were risk factors for non-H. pylori, non-NSAID associated PPU compared with solely H. pylori positive PPU.CONCLUSION Elderly patients with comorbidities are associated with NSAIDs-associated PPU. Non-H. pylori, non-NSAID peptic ulcer is important etiology of PPU and alcohol consumption is associated risk factor.

Investigation of Propene Oligomerization Catalyzed by Phosphotungstic Acid Catalysts

In this paper, the propene oligomerization reaction catalyzed by phosphotungstic acid supported on two kinds of silica gel was studied, it had been found out that the conversion of propene catalyzed by the type A silica gel-phosphotung- stic acid catalyst was 3.38 m%, while the conversion of propene catalyzed by the type B silica gel-phosphotungstic acid catalyst was 90.1 m% with a nonene selectivity of 42.33 m%, and a dodecene selectivity of 31.79 m%. The influence of reaction temperature, pressure and liquid hourly space velocity （LHSV） on the reaction catalyzed by the type B silica gel- phosphotungstic acid catalyst was investigated. It had been verified that when the reaction temperature increased from 170 ~C to 190 ~C, the conversion of propene increased while the selectivity of nonene and dodecene decreased; when the re- action pressure increased from 3.5 MPa to 4.5 MPa, the conversion of propene increased also, and the selectivity of nonene and dodecene changed very little. The conversion of propene at a space velocity of between 0.5 h-1 and 1.0 h-~ was higher than that achieved at 2.0 h-~, but the selectivity of nonene and dodecene did not show regular fluctuations. An optimum conversion of propene （91.05 m%） and an optimum selectivity of nonene and dodecene （89.51 m%） could be achieved at a reaction temperature of 170 ~C, a reaction pressure of 4.5MPa, and a LHSV of 1.0 fit. The experiments on catalyst life showed that the activity of the type B silica gel-phosphotungstic acid catalyst could be only maintained in 25 hours, and the reason was explained also.

Effect of chemical conditioning on the triboelectrification of coal and mineral particles

Chemical conditioning was used to modify the triboelectrification of coal and mineral particles.The chemicals tested included starch,lignin,kerosene,ethanol,acetic acid,salicylic acid,sodium oleate,Sodium Hexametaphosphate(SH),sodium silicate, Sodium Dodecylbenzenesulfonate(SDBS),Sodium Bicarbonate(SB) and ammonia.A high-speed,dry mixing method was employed.The charge-to-mass ratio of the coal and mineral samples,both untreated and treated,was tested using a Faraday cup. Dielectric constants were determined by measuring capacitance.It is found that the selectivity of the additives toward coal or minerals is not consistent.Salicylic acid is the optimal additive to enhance the triboelectrification performance of coal samples.Starch, lignin and sodium oleate are suitable for removal of pyrite.SH,sodium silicate,SDBS,SB and ammonia are suitable additives for the removal of ash-forming minerals.