过氧化氢氧化氨基黑10B催化光度法测定痕量铁的研究

研究了在稀硫酸介质中,痕量铁(Ⅲ)对过氧化氢氧化氨基黑10B的催化褪色作用,建立了催化动力学光度法测定痕量铁的新方法,并探讨了动力学条件。方法的线性范围为10mL溶液中0～0 2μg铁,检出限为7 04×10-10g/mL,用于自来水中铁的测定,结果满意。

过氧化氢异丁烷的研制

利用叔丁醇为原料，在硫酸氧化下生成过氧化氢异丁烷产物，其最佳操作条件是：维持在液相条件下进行反应，反应温度为１４～１８℃，反应时间为９０ｍｉｎ，静止分层时间为１５ｈ。所用氧化剂的浓度为７０％，引发剂的浓度为３０％，而原料叔丁醇的浓度为８５％。

蒽醌法双氧水生产中安全事故分析及措施

根据双氧水的化学特性及惠醌法双氧水生产工艺，对影响双氧水稳定性因素、生产中的安全隐患进行了分析，提出了在装置建设、生产及产品浓缩过程中的安全措施。

Responses of soil enzymes to long-term CO_2 enrichment in forest ecosystems of Changbai Mountains

A study was conducted to determine the responses of soil enzymes （invertase, polyphenol oxidase, catalase, and dehydrogenase） to long-term CO2 enrichment at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences （42°24＇N, 128°28＇E; 738 m in elevation） in the northeast China during 1999-2006. Three treatments of the CO2 enrichment, designed as 500 μmol·mol-1 CO2 open-top chamber （OTC）, ambient control chamber and unchambered field （approx. 370 μmol·mol^-1CO2）, were conducted with Pinus koraiensis and Pinus sylvestriformis tree species. Soil sampling was made and analyzed separately in spring, summer and autumn in 2006 after the soil enzymes were exposed to elevated CO2 concentration （500 μmol·mol^-1） for eight growing seasons. Results showed that, at elevated CO2 concentration （500 μmol·mol^-1）, the activities of invertase （except for the summer samples of P. koraiensis） presented a remarkable decline in all growing seasons, while the activities of dehydrogenase had an increase but only part of the results was remarkable; the activities of polyphenol oxidase in P. sylvestriformis rhizosphere showed a remarkable decrease; the catalase activities increased in spring, while in turn were decline in other seasons. This study also revealed that the soil enzyme activities are significantly correlated with the tree species under the CO2 enhancement.

Bicarbonate activation of hydrogen peroxide: A new emerging technology for wastewater treatment

The serious limitations of available technologies for decontamination of wastewater have compelled researchers to search for alternative solutions. Catalytic treatment with hydrogen peroxide, which appears to be one of the most efficient treatment systems, is able to degrade various organics with the help of powerful ·OH radicals. This review focuses on recent progress in the use of bicarbonate activated hydrogen peroxide for wastewater treatment. The introduction of bicarbonate to pollutant treatment has led to appreciable improvements, not only in process efficiency, but also in process stability. This review describes in detail the applications of this process in homogeneous and heterogeneous systems. The enhanced degradation, limited or lack of leaching during heterogeneous degradation, and prolonged catalysts stability during degradation are salient features of this system. This review provides readers with new knowledge regarding bicarbonate, including the fact that it does not always harm pollutant degradation, and can significantly benefit degradation under some conditions.

Synergistic degradation of phenols by bimetallic CuO-Co_3O_4@γ-Al_2O_3 catalyst in H_2O_2/HCO_3^- system

The development of new catalytic techniques for wastewater treatment has long attracted much attention from industrial and academic communities.However,because of catalyst leaching during degradation,catalysts can be short lived,and therefore expensive,and unsuitable for use in wastewater treatment.In this work,we developed a bimetallic CuO-Co3O4@γ-Al2O3 catalyst for phenol degradation with bicarbonate-activated H2O2.The weakly basic environment provided by the bicarbonate buffer greatly suppresses leaching of active Cu and Co metal ions from the catalyst.X-ray diffraction and X-ray photoelectron spectroscopy results showed interactions between Cu and Co ions in the CuO-Co3O4@γ-Al2O3 catalyst,and these improve the catalytic activity in phenol degradation.Mechanistic studies using different radical scavengers showed that superoxide and hydroxyl radicals both played significant roles in phenol degradation,whereas singlet oxygen was less important.

Simultaneous hydrogen and peroxide production by photocatalytic water splitting

Photocatalytic oxidation of water is a promising method to realize large-scale H2O2 production without a hazardous and energy-intensive process. In this study, we introduce a Pt/TiO2(anatase) photocatalyst to construct a simple and environmentally friendly system to achieve simultaneous H2 and H2O2 production. Both H2 and H2O2 are high-value chemicals, and their separation is automatic. Even without the assistance of a sacrificial agent, the system can reach an efficiency of 7410 and 5096 μmol g^-1 h^–1 (first 1 h) for H2 and H2O2, respectively, which is much higher than that of a commercial Pt/TiO2(anatase) system that has a similar morphology. This exceptional activity is attributed to the more favorable two-electron oxidation of water to H2O2, compared with the four-electron oxidation of water to O2.

Advances in the production technology of hydrogen peroxide

This article mainly summarizes various aspects of hydrogen peroxide(H2O2)production through the anthraquinone route,including hydrogenation catalysts,working solution,regeneration technique,hydrogenation reactors,and environmental protection.The advances and breakthrough of SINOPEC in the production of H2O2 through the anthraquinone route is presented in this review,highlighting recent innovative technology on these aspects developed independently.The technical prospect and scientific challenges associated with the direct synthesis method from hydrogen and oxygen are also briefly discussed.

Role of hydrazine and hydrogen peroxide in aluminium hydroxide precipitation from sodium aluminate solution

Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while higher amount of hydrogen peroxide is required to generate similar effect. XRD data confirm the product phase to be gibbsitic by nature. The scanning electron micrographs （SEM） show that agglomerated products form in the presence of hydrazine while fine discrete particles are produced with hydrogen peroxide. The probable mechanism of precipitation in the presence of hydrazine and hydrogen peroxide is also discussed.

Layered transition-metal hydroxides for alkaline hydrogen evolution reaction

Hydrogen is a promising sustainable energy to replace fossil fuels owning to its high specific energy and environmental friendliness.Alkaline water electrolysis has been considered as one of the most prospective technologies for large scale hydrogen production.To boost the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline media,abundant materials have been designed and fabricated.Herein,we summarize the key achievements in the development of layered transition-metal hydroxides[TM(OH)x]for efficient alkaline HER.Based on the structure of TM(OH)x,the mechanism of synergistic effect between TM(OH)x and HER active materials is illuminated firstly.Then,recent progress of TM(OH)x-based HER catalysts to optimize the synergistic effect are categorized as TM(OH)x and active materials,including species,structure,morphology and interaction relationship.Furthermore,TM(OH)x-based overall water splitting electrocatalysts and electrodes are summarized in the design principles for high activity and stability.Finally,some of key challenges for further developments and applications of hydrogen production are proposed.

Tentative Research of Short Process of Jute Degumming and Bleaching

The feasibility of combination process of jute degumming and bleaching with alkali-hydrogen peroxide in one-step-one-bath was discussed. The combination process basically has the similar function as the traditional two-step-two-bath method. The factors such as hydrogen peroxide concentration, CBI concentration, sodium hydroxide concentration, treatment time and temperature were studied respectively, and then an orthogonal experiment was designed to study the interactions among the hydrogen peroxide concentration, CBI concentration, sodium hydroxide concentration. After the designed experiments, the optimum treatment conditions were obtained as follows: hydrogen peroxide of 12g/L, sodium hydroxide of 4g/L, CBI of 4g/L, JFC of 1g/L, treatment time of 60min and temperature of 75℃.

High glucose augments stress-induced apoptosis in endothelial cells.

Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. EAhy 926 endothelial ceils were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide （HzO2） or tumour necrosis factor- α （TNF- α ）, following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of EAhy 926 cells to apoptosis in the presence of 500 gmol/L H2O2 , above that induced in normal glucose （P〈0.02）. A reduction of H2O2- and TNF- a -induced apoptosis occurred in both high and low glucose after treatment with dexamethasone （P〈0.05）. Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.

Physical-Chemical Aggressiveness of Solutions of Medicines as a Factor in the Rheology of the Blood inside Veins and Catheters

In experiments in vitro and observations in the clinic in vivo studied the state of the lumen of subcutaneous veins and blood rheology of patients after their interaction with vascular catheters and solutions of medicines based on the values of temperature, volume, concentration, osmotic activity and pH. It is shown that heparin injection in blood not prevent, but solution of 4% sodium bicarbonate injection prevents blood clotting, blood clots and blockage blood clots of veins and of catheters. It is shown that the heating to a temperature of＋42 ℃ with the solution of 4% sodium bicarbonate provides softening action on old dry blood clots in 1 min, and their subsequent irrigation with a warm solution of 4% sodium bicarbonate and 3% hydrogen peroxide provides complete destruction and discoloration of the remaining spots of blood during 2 s. Proposed new medicines and hygiene products for the protection of the veins and installed in them vascular catheters from blockage of blood clots, and for removing blood stains from clothes and body surface patients.

Inhibitory effect of Cr(Ⅵ) on activities of soil enzymes

To evaluate the influence of various Cr(Ⅵ) concentrations (0.05, 0.25, 0.50, 1.00 and 2.00 g/kg) on the activity of soil enzymes, the activities of catalase, polyphenol oxidase, dehydrogenase, alkaline phosphatase in soils were investigated in the incubation experiment with a period of 35 d. The results indicate that all the tested Cr(Ⅵ) concentrations significantly inhibit dehydrogenase activity by over 70% after 35 d. The activity of alkaline phosphatase is slightly inhibited during the whole experiment except for on the day 7. Cr(Ⅵ) has no obvious effect on the activity of catalase in soil. On the contrary, Cr(Ⅵ) stimulates the activity of polyphenol oxidase. The results suggest that dehydrogenase activity can be used as an indicator for assessing the severity of chromium pollution.

Therapeutic effects of flavonoids from Ceylon green tea on hypoxic human brain epithelial cells

We have extracted and purified flavonoids as active ingredients from Ceylon green tea （Dilmah）. In this project, an in vitro hypoxic model using human brain epithelial cells （HBEC） was studied with treatment of the tea extract before inducing hypoxia. We have tested the hypothesis that flavonoids extracted from Ceylon green tea act as potential therapeutic ingredient （s） to reduce oxidative stress in hypoxic cells through its antioxidant properties and its ability to reduce cerebral cellular death. The biochemical antioxidant tests show that the Ceylon green tea has 68% ± 2.8% inhibition property of scavenging of ABTS. The inhibition of pyrogallol red bleaching by HOCI from Ceylon tea was 79% ± 4.5%. After exposing to hypoxia, the cell viability was 29% ± 2.3% in the hypoxia control group but 41% ± 4.7% for flavonoids extract treated group. In LDH assay, flavonoids extract treated group had 75% ± 3.7% reducing of LDH release. The flavonoids extract treated groups significantly increased in antioxidant enzyme activity assays： the activity level of SOD [（1.5 ± 0.6） μmol/min/mg protein], CAT [（0.61 ± 0.06） μmol/min/mg protein], GPx [（2.6 ± 0.41） μmol/min/mg protein] and GST [（6.0 ± 2.4） μmol/min/mg protein] are significantly increased as compared with hypoxic control [（0.5 ± 0.52, 0.51 ± 0.04, 1.2 ± 0.35 and 3.1 ± 1.6） μmol/min/mg protein, respectively]. The study demonstrated a great clinical potential and opened a new avenue to prevent stroke by drinking Ceylon tea.

Interconnected 1D Co3O4 nanowires on reduced graphene oxide for enzymeless H2O2 detection

Enzymeless hydrogen peroxide （H2O2） detection with high sensitivity and excellent selectivity is desirable for clinical diagnosis. Herein, one-dimensional Co3O4 nanowires have been successfully constructed on reduced graphene oxide （rGO） via a simple hydrothermal procedure and subsequent thermal treatment. These Co3O4 nanowires, assembled by small nanoparticles, are interlaced with one another and make a spider web-like structure on rGO. The formation of Co3O4-rGO hybrids is attributed to the structure-directing and anchoring roles of DDA and GO, respectively. The resulting structure possesses abundant active sites, the oriented transmission of electrons, and unimpeded pathways for matter diffusion, which endows the Co3O4-rGO hybrids with excellent electrocatalytic performance. As a result, the obtained Co3O4-rGO hybrids can serve as an efficient electrochemical catalyst for H2O2 oxidation and high sensitivity detection. Under physiological conditions, the oxidation current of H2O2 varies linearly with respect to its concentration from 0.015 to 0.675 mM with a sensitivity of 1.14 mA.mM^-1.cm^-2 and a low detection limit of 2.4 μM. Furthermore, the low potential （-0.19 V） and the good selectivity make Co3O4-rGO hybrids suitable for monitoring H2O2 generated by liver cancer HepG2 cells. Therefore, it is promising as a non-enzymatic sensor to achieve real-time quantitative detection of H2O2 in biological applications.

Epoxidation of olefins with hydrogen peroxide catalyzed by a reusable lacunary-type phosphotungstate catalyst

Olefins and allylic alcohols have been epoxidized with commercially available hydrogen peroxide (30% H2O2) using a phase transfer catalyst,composed of cetyltrimethylammonium cations and a lacunary-type phosphotungstate anion [PW11O39]7-or the complete Keggin-type heteropolyanion [PW12O40]3-,under two-phase conditions using ethyl acetate as the solvent. It was found that the lacunary-type catalyst showed higher activity and better recyclability than the complete Keggin-type catalyst under the same reaction conditions. 31P NMR spectroscopy and solubility measurements for the two catalysts revealed that the [PW11O39]7-anion had a much faster degradation rate than the [PW12O40]3-anion in an excess of H2O2,which resulted in the formation of more catalytically active species. As a result,the lacunary-type phosphotungstate anion-based catalyst gave a better catalytic performance than the complete Keggin-type anion in ethyl acetate.