THE PREPARATION OF ISOPOLYMOLYBDIC ACID-POLYANILINE FILM MODIFIED ELECTRODE AND ITS CATALYTIC EFFECTS ON CHLORATE IONS

The preparation method of H_4MoO_(26)-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.

Experimental constraints on the formation of oxychlorine species by UV irradiation and mechanical pulverization on the lunar surface

Perchlorate and chlorate are present in various extraterrestrial celestial bodies throughout the solar system,such as Mars,the moon,and asteroids.To date,the origin mechanisms of perchlorate and chlorate on the Martian surface have been well-established;however,relatively little attention has been cast to airless bodies.Here,we experimentally investigated the potential oxidation mechanisms of chloride to chlorate and perchlorate,such as ultraviolet irradiation under H_(2)O-and O_(2)-free conditions and mechanical pulverization processes.Individual minerals,olivine,pyroxene,ilmenite,magnetite,TiO_(2)and anhydrous ferric sulfate,and lunar regolith simulants(low Ti,CLRS-1;high-Ti,CLRS-2)and their metallic iron(Fe^( 0))bearing counterparts were examined.We found that pulverization of dry matrix material-halite mixtures,even in the presence of O_(2),does not necessarily lead to perchlorate and chlorate formation without involving water.Under photocatalytic and H_(2)O and O_(2)-free conditions,olivine and pyroxene can produce oxychlorine(ClO_(x)^(−))species,although the yields were orders of magnitude lower than those under Martian-relevant conditions.Nanophase-Fe^(0)particles in the lunar regolith and the common photocatalyst TiO_(2)can facilitate the ClO_(x)^(−)formation,but their yields were lower than those with olivine.The oxides ilmenite and magnetite did not efficiently contribute to ClO_(x)^(−)production.Our results highlight the critical role of H_(2)O in the oxidation chloride to chlorate and perchlorate,and provide essential insights into the environmental influence on the formation of oxychlorine species on different celestial bodies.

Genome-wide association study of seedling nitrogen-use efficiency-associated traits in common wheat(Triticum aestivum L.)

Nitrogen(N)fertilizer application is essential for crop-plant growth and development.Identifying genetic loci associated with N-use efficiency(NUE)could increase wheat yields and reduce environmental pollution caused by overfertilization.We subjected a panel of 389 wheat accessions to N and chlorate(a nitrate analog)treatments to identify quantitative trait loci(QTL)controlling NUE-associated traits at the wheat seedling stage.Genotyping the panel with a 660K single-nucleotide polymorphism(SNP)array,we identified 397 SNPs associated with N-sensitivity index and chlorate inhibition rate.These SNPs were merged into 49 QTL,of which eight were multi-environment stable QTL and 27 were located near previously reported QTL.A set of 135 candidate genes near the 49 QTL included TaBOX(F-box family protein)and TaERF(ethylene-responsive transcription factor).A Tabox mutant was more sensitive to low-N stress than the wild-type plant.We developed two functional markers for Hap 1,the favorable allele of TaBOX.

Stress Effects of Chlorate on Longan(Dimocarpus longan Lour.)Trees: Changes in Nitrogen and Carbon Nutrition

Three-year-old potted longan(Dimocarpus longan Lour.cv.Shixia)trees were treated with potassium chlorate and effects on nitrogen and carbon nutrition were examined.The results showed that potassium chlorate at 10 and 20 g per pot failed to induce flower but suppressed shoot growth and caused leaf chlorosis and drop.The treatment significantly inhibited nitrate reductase but increased nitrogen concentration in the leaves and buds.Concentration of soluble amino acids in the leaves of treated trees increased within 14 days and then declined to the control level,while it increased constantly in buds.In both organs,the amino acid increase was an all-round one,with all the tested 21 amino acids increased.However,soluble proteins in the leaves were slightly increased by chlorate,indicating that de novo synthesis of amino acids was activated.Chlorate reduced photosynthetic rate and stomatal conductance but slightly increased CO2 concentration in the mesophyll,suggesting that chlorate treatment damaged photosynthetic apparatus.The damage was reflected by the destruction of thylakoids and grana in the chloroplasts.Chlorate also caused depletion of starch with significant accumulation of soluble sugars in the leaves.Accumulation of sugars and soluble amino acids indicates osmotic adjustment in response to the stress caused by chlorate treatment.

Misconceptions in global reactions and formula writing

The frequently used concept of "global reaction" is discussed and the reason for the confusion behind explained. The misconception is cleared by formula writing based on the donor–acceptor(donac) reaction concept and by applying the Grand Rule of Formula Writing that is based on it.

有机金属盐VC-Ca的合成初探

有机金属盐ＶＣ－Ｃａ的合成初探高远浩（平顶山师专化学系）１引言维生素Ｃ［１］和活性钙都是人体生命不可缺少的物质，其医疗和保健作用早已为人类所熟知．但同时具有维生素Ｃ和活性钙双重功效的新物质国内尚无报道．本文在分析了维生素Ｃ结构特征的基础上，以自然界富...

A new method of NMR technique in the study of active center structure of metalloenzyme

UP until now, all methods using NMR technique to study the coordinated structure of activecenter in metalloenzyme are to reconstitute the diamagnetic ions [i. e. Zn(Ⅱ), etc.] in metal-loenzyme or its paramagnetic ions [i. e. Cu(Ⅱ), etc] whose electronic relaxation times are notshort enough to substitute the metal ions of active center in enzyme with [Co(Ⅱ), Ni(Ⅱ)],which are paramagnetic and whose electronic relaxation time is shorter, so that the ~1H NMRspectra of the coordinated structure of active center are separated from those of the rest of en-

The role of metal oxides on oxidant decay and disinfection byproduct formation in drinking waters: Relevance to distribution systems

Maintaining a residual disinfectant/oxidant(e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid(HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts(DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogencontaining oxidants via three pathways:(1) catalytic disproportionation to yield an oxidized form of halogen(i.e., halate) and reduced form(halide for chlorine and bromine or chlorite for chlorine dioxide),(2) oxygen formation, and(3) oxidation of a metal in a reduced form(e.g., cuprous oxide) to a higher oxidation state. Cupric oxide(Cu O) and nickel oxide(Ni O)showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of Cu O on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important(exceeding 10 μg/L) when initial bromide concentration is above 400 μg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at p H8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.