磺氧化反应的机理探讨

本文探讨了以石蜡烃、二氧化硫、氧为起始反应物，在紫外线的引发下的磺氧化反应的机理。

水—光法磺氧化制取仲链烷磺酸盐

使用了几种高、低压汞灯，制得了质量较好的SAS。使用高压汞灯时，将反应器中的磺酸浓度控制在2％左右，气体的空塔线速度提高到23～25毫米/秒以上，灯耗每度电的磺酸产率可达2.17公斤。

苯磺酰基呋咱氮氧化物与双氯芬酸偶联化合物的合成及抗炎活性

目的 研究高效低毒的双氯芬酸 (DC)偶联化合物。方法 以酯键或酰胺键将一氧化氮 (NO)供体 3 ,4 二苯磺酰基呋咱氮氧化物与DC偶联 ,观察偶联物对二甲苯致炎小鼠和角叉菜胶致炎大鼠的抗炎活性及对大鼠胃肠道反应 ,研究体内外偶联物的NO释放。结果 合成了 11个新化合物 (I1 - 1 1 ) ,其结构经MS ,IR ,1 HNMR和元素分析确证。I1 - 5,I9显示抗炎活性 ,其中I4 和I5活性与DC相当 ,胃肠道副作用显著小于DC ,体内外均释放NO。结论 苯磺酰基呋咱氮氧化物与DC偶联的化合物可保留DC抗炎活性 ,降低DC胃肠道不良反应。

仲烷基磺酸钠(SAS)研究进展

综述了一种重要的表面活性剂仲烷基磺酸钠的国内外研究现状、制备方法及产品特性。

Ф-磺基脂肪酸甲酯磺酸盐的生产工艺

Ф-脂肪酸甲酯磺酸盐(Ф-MES)是由脂肪酸甲酯(FAME)与SO2/O2混合气体在适宜波长的紫外光(UV)照射下发生磺氧化反应得到的阴离子表面活性剂。与烷基苯磺酸钠(LAS)、脂肪醇醚硫酸酯盐(AES)一样,该产品可用于重垢洗涤剂及餐具洗涤剂等液体洗涤剂中,并有可能用于洗衣粉及洗浴用品中。本文介绍了ф-MES的合成方法、反应机理、分离方法,并用GC-MS对产品组成进行了结构鉴定。

碘仿氢氧化钙糊剂在感染根管内的应用疗效分析

根管消毒是根管治疗的一个重要步骤。患牙经过根管预备和传统的根管内封药后大部分能够治愈,但是对于一些病程长、长期渗出的有瘘型根尖周炎病例疗效不理想。良好的根管消毒药物可以更好的消除根管内的细菌和毒素,减少患者封药后的疼痛和复诊的次数[1]。以往的相关临床实践和报道结果显示碘仿氢氧化钙(Vitapex)糊剂在治疗慢性根尖周炎的过程中具有重要的临床实践意义。

低温发泡剂OBSH与BK并用活化机理及其对NBR/PVC材料性能的影响

研究了发泡剂4,4-氧代双苯磺酰肼(OBSH)与尿素脂(BK)的相互促进机理,以及两者的用量及质量比对丁腈橡胶/聚氯乙烯(NBR/PVC)海绵橡胶发泡材料泡孔结构及性能的影响。结果表明,发泡剂OBSH和尿素脂BK并用能明显改善发泡剂OBSH的分解历程,将发泡剂OBSH的最快分解温度降低到149.2℃。当发泡剂OBSH与BK质量比为2∶1时,发泡材料的密度最低,真空吸水率最低,泡孔结构最均匀,发泡效果最好。

为古战船换骨

作为瑞典的国宝，VASA皇家战船被人称为是21世纪的传奇老帆船。这艘目前世界上保存最好的17世纪木质船在海底时，船体内的铁钉生锈并形成硫磺，硫磺氧化形成的硫酸会腐蚀木材，因此在延续VASA生命的整体计划中，第一步就是更换船身内所有的钢制螺栓。

Nutritional Analysis and Physiological Activity Evaluation of Pneumatophorus japonicus Sauce

The nutritional composition of Pneumatophorus japonicus sauce was analyzed and compared with other fish sauces. The sodium chloride content of the sample Pneumatophorus japonicus sauce was greater than 25%. The total soluble nitrogen content was greater than 2.1 g/100mL, and the amino nitrogen content was greater than 1.2 g/100mL. The mineral content was abundant in the Pneumatophorus japonicus sauce, the calcium content and the magnesium content were 391.50±0.03 and 375.00±0.02 mg/L respectively, much higher than those in other samples. The iron content and the zinc content were 22.30±0.04 and 2.80±0.03 mg/L, respectively. The content of free amino acids was 5 552.17 mg/100mL, the content of essential amino acids was 2 666.00 mg/100mL,The taurine content was 113.05 mg/100mL. The antioxidant activity of the fermentation broth was 90.48%, while the TCA soluble peptide content was 29.04 mg/mL. Pneumatophorus japonicus sauce is nutritionally rich and has special physiological activity.

Effect of grinding with sulfur on surface properties and floatability of three nonferrous metal oxides

Co-grinding three nonferrous metal oxides(CuO,PbO and ZnO)with element sulphur under mild conditions and flotation of the ground samples were conducted to investigate the surface properties and floatability of the oxides.Phase transition,morphological features,electrochemical properties and surface chemical compositions of ground samples were studied.The results show that the floatability of CuO is improved after grinding with sulfur,by the formation of surface layer with properties similar to CuS due to the Cu-S bonding.The floatability of PbO is deteriorated after mechanochemical processing due to surface carbonation and the formation of PbS and PbSO4by disproportionation reaction with sulfur.ZnO shows no evident response to mechanochemical sulfidation.

Synthesis of Petroleum Sulfonate Surfactant by Different Sulfonating Agent with Application of HIGEE Technology

With the application of HIGEE process intensification technology, petroleum sulfonate surfactant used for enhanced oil recovery was synthesized from petroleum fraction of Shengli crude oil with three sulfonating agents, including diluted liquid sulfur trioxide, diluted gaseous sulfur trioxide and fuming sulfuric acid. For each sulfonating agent, different operation modes (liquid-liquid or gas-liquid reaction with semi-continuous or continuous operation) were applied. The effects of various experimental conditions, such as solvent/oil mass ratio, sulfonating agent/oil mass ratio, gas/liquid ratio, gas concentration, reaction temperature, rotating speed, circulation ratio, reaction time and aging time, on the content of active matter and unsulfonated oil were investigated. Under relatively optimal reaction conditions, the target product was prepared with high mass content of active matter (up to 45.3%) and extremely low oil/water interfacial tension (4.5×10 –3 mN·m –1 ). The product quality and process efficiency are higher compared with traditional sulfonation technology.

Juvenile ferric iron prevents microbiota dysbiosis and colitis in adult rodents

AIM: To assess whether juvenile chronic ferric iron ingestion limit colitis and dysbiosis at adulthood in rats and mice. METHODS: Two sets of experiments were designed. In the first set, recently weaned mice were either orally administered ferrous (Fe2+) iron salt or ferric (Fe3+) microencapsulated iron for 6 wk. The last week of experiments trinitrobenzene sulfonic acid (TNBS) colitis was induced. In the second set, juvenile rats received the microencapsulated ferric iron for 6 wk and were also submitted to TNBS colitis during the last week of experiments. In both sets of experiments, animals were sacrificed 7 d after TNBS instillation. Severity of the inflammation was assessed by scoring macroscopic lesions and quantifying colonic myeloperoxidase (MPO) activity. Alteration of the microflora profile was estimated usingquantitative polymerase chain reaction (qPCR) by measuring the evolution of total caecal microflora, Bacteroidetes, Firmicutes and enterobacteria. RESULTS: Neither ferrous nor ferric iron daily exposures at the juvenile period result in any effect in control animals at adulthood although ferrous iron repeated administration in infancy limited weight gain. Ferrous iron was unable to limit the experimental colitis (1.71 ± 0.27 MPO U/mg proteinvs 2.47 ± 0.22 MPO U/mg protein in colitic mice). In contrast, ferric iron significantly prevented the increase of MPO activity (1.64 ± 0.14 MPO U/mg protein) in TNBS-induced colitis. Moreover, this positive effect was observed at both the doses of ferric iron used (75 and 150 mg/kg per day po - 6 wk). In the study we also compared, in both rats and mice, the consequences of chronic repeated low level exposure to ferric iron (75 mg/kg per day po - 6 wk) on TNBS-induced colitis and its related dysbiosis. We confirmed that ferric iron limited the TNBS-induced increase of MPO activity in both the rodent species. Furthermore, we assessed the ferric iron incidence on TNBS-induced intestinal microbiota dysbiosis. At first, we needed to optimize the isolation and quantify DNA copy numbers using standard curves to perform by qPCR this interspecies comparison. Using this approach, we determined that total microflora was similar in control rats and mice and was mainly composed of Firmicutes and Bacteroidetes at a ratio of 10/1. Ferric juvenile administration did not modify the microflora profile in control animals. Total microflora numbers remained unchanged whichever experimental conditions studied. Following TNBS-induced colitis, the Firmicutes/Bacteroidetes ratio was altered resulting in a decrease of the Firmicutes numbers and an increase of the Bacteroidetes numbers typical of a gut inflammatory reaction. In parallel, the subdominant population, the enterobacteria was also increased. However, ferric iron supplementation for the juvenile period prevented the increase of Bacteroidetes and of enterobacteria numbers consecutive to the colitis in both the studied species at adulthood.CONCLUSION: Rats and mice juvenile chronic ferric iron ingestion prevents colitis and dysbiosis at adulthood as assessed by the first interspecies comparison.

Effect of temperature,oxygen partial pressure and calcium lignosulphonate on chalcopyrite dissolution in sulfuric acid solution

The pressure leaching mechanism of chalcopyrite was studied by both leaching tests and in-situ electrochemical measurements. The effects of leaching temperature, oxygen partial pressure, and calcium lignosulphonate, on copper extraction and iron extraction of chalcopyrite pressure leaching were investigated. The leaching rate is accelerated by increasing the leaching temperature from 120 to 150 ℃ and increasing oxygen partial pressure to 0.7 MPa. The release of iron is faster than that of copper due to the formation of iron-depleted sulfides. Under the optimal leaching conditions without calcium lignosulphonate, the copper and iron extraction rates are 79% and 81%, respectively. The leaching process is mixedly controlled by surface reaction and product layer diffusion with an activation energy of 36.61 k J/mol. Calcium lignosulphonate can effectively remove the sulfur passive layer, and the activation energy is 45.59 k J/mol, suggesting that the leaching process with calcium lignosulphonate is controlled by surface chemical reactions. Elemental sulfur is the main leaching product, which is mixed with iron-depleted sulfides and leads to the passivation of chalcopyrite. Electrochemical studies suggest that increasing the oxygen partial pressure leads to increasing the cathodic reaction rate and weakening the passivation of chalcopyrite.

Fabrication of a solid superacid with temperature-regulated silica-isolated biochar nanosheets

This paper reports a new strategy for the structural reconstruction of biomass carbon sulfonic acid(BCSA)to its solid superacid counterpart.In this approach,a cheap layered biomass carbon(BC)source is chemically exfoliated by cetyltrimethyl ammonium bromide and then converted to silica-isolated carbon nanosheets(CNSs)by a series of conversion steps.The state of the silica-isolated CNSs and the stacking density of their nanoparticles are regulated by the dehydration temperature.Only the highly isolated and non-crosslinked CNSs with loose particle stacking structures obtained upon dehydration at 250℃ can be turned into superacid sites(with stronger acidity than that of 100%H2 SO4)after sulfonation.This is accompanied by the creation of abundant hierarchical slit pores with high external surface area,mainly driven by the strong hydrogen bonding interactions between the introduced sulfonic acid groups.In typical acid-catalyzed esterification,etherification,and hydrolysis reactions,the newly formed superacid exhibits superior catalytic activity and stability compared to those of common BCSA and commercial Amberlyst-15 catalysts,owing to its good structural stability,highly exposed stable superacidic sites,and abundance of mesoporous/macroporous channels with excellent mass transfer rate.This groundbreaking work not only provides a novel strategy for fabricating bio-based solid superacids,but also overcomes the drawbacks of BCSA,i.e.,unsatisfactory structural stability,acidity,and porosity.

Alkanesulfonate monooxygenase SsuD and its chemicalbiomimetic system

Atkanesulfonate monooxygenase SsuD facilitates the desulfonation reaction of alkane sulfonates to release sulfite and corresponding aldehydes/ketones. Oxygen is activated by the reduced flavin. One oxygen atom is to fi＇om water and the other oxygen atom is to from aldehydes/ketones. The oxidized flavin is regenerated after water is formed. The chemical biomimetic system was established according to the preliminary mechanism of alkanesulfonate monooxygenase and the cyclic mechanism was proposed for the formation ofaldehydes/ketones. Two oxygen atoms from the reduced flavin to form C（4a）-peroxy-flavin. The oxygen atom connected with C（4a） abstracts one electron from the neighbouring oxygen to transfer one oxygen atom to C1 ofalkanesulfonates and abstracts one hydrogen from C1 ofalkanesulfonates to break C 1-H bond. Hydroxy-flavin was produced by the above cyclic mechanism. Alkansulfonate monooxygenase SsuD does not directly involve in the reaction. It only supplies some comfortable environment to facilitate the target reactiorL

Visible-light-induced deoxygenative C2-sulfonylation of quinoline N-oxides with sulfinic acids for the synthesis of 2-sulfonylquinoline via radical reactions

A simple and efficient method for the synthesis of 2-sulfonylquinoline from deoxygenative C2-sulfonylation of quinoline N-oxides with sulfinic acid induced by visible light is presented.This protocol shows a broad substrate scope,and desired products with various substituents can be formed in moderate to high yields at room temperature.

PREPARATION OF POLYSULFONAMIDE/TiO_2 NANOCOMPOSITES BY SOL-GEL

Polysulfonamide(PSA)was synthesized at room temperature,the polymerization based on terephthaloyl chloride and 3,3’-diaminodiphenylsulfone in the common solvent N,N-Dimethyl-acetamide(DMAc).Polysulfonamide/titanium oxide nanocomposites were prepared by sol-gel method.Tetrabutyl titanate(TBT)was added into the polysulfonamide solution,at the same time,some water was mixed to make the TBT hydrolyze.In the process,hydrochloric acid was used to catalyze the reaction.The polysulfonamide chemistry structure was characterized by FT-IR spectrum.Atomic force microscopy(AFM)was employed to observe the microstructure of the composite film.The thermal property was investigated by TGA.The results show that we have succeeded to synthesize the polysulfonamide,TiO2 particles were well distributed in the composite film and average size was about 20 nm on average,the heat-resistance of nanocomposite was batter than the pure polysulfonamide.

Synthesis of 3-O-Benzoyl-1 ,2-O-isopropylidene-a-D-allofuranose and Its Dimesylated Derivative

Diisopropylidenated α-D-glucofuranose （1） was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose （ 3）. The yield of 3 increased by 8% than that with only oxidated product as reduction substrate. Benzoylated derivative of 3 was selectively nydrolyzed and dimesylated to synthesize 3-O-benzoyl-1 .2- O- isopropylidene-α-D-allofuranose （ 5 ） and its dimesylated derivative respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by ^1H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81.8%. Oxidation. reduction and other procedures were practical and had application potential.

PREPARATION OF POLYSULFONAMIDE AND MODIFIED TITANIUM OXIDE NANOCOMPOSITES BY IN-SITU POLYMERIZATION

A kind of new nano composite with ultraviolet （UV） ray resistance and high temperature stability was prepared by in-situ polymerization in low temperature. Polysulfonamide （PSA） was synthesized with 4, 4＇-diaminodiphenyl sulfone （DDS） and terephthaloyl chloride （TPC） in the common solvent N, N-Dimethyl- -acetamide （DMAc）. Nano filler is a certain nano titanium oxide modified by silicon oxide （TMS）, which plays the role of UV resistance additives. Properties of the novel composite materials were characterized by Atomic Force microscopy （AFM）, thermal gravimetric Analysis （TGA） and Ultraviolet Spectroscopy. AFM had showed the sizes and distributions of TMS particles in the nanocomposite. Ultraviolet Spectroscopy for the nanocomposites showed a large absorption in UV band. TGA showed the decomposition temperature was increased over ten degrees with 0.5% wt TMS for this nanocomposite compared with pure PSA.