Influence of Soil pH and Temperature on Atrazine Bioremediation

Present study was conducted to clarify soil pH and temperature influence on different atrazine bioremediation techniques. For this purpose, sodium citrate, Arthrobactor sp. strain DNS10, sawdust and animal manure were selected to clarify their atrazine remediation efficiency under pH 5, 7 and 9 and temperatures 20, 30 and 40℃, respectively. Results showed that atrazine remediation was generally optimized at pH 7 and 30℃ for all the treatments except sodium citrate as soil treated with sawdust was not temperature dependant, but at pH 5 remediation process was determined slower. Atrazine remediation in soil with no additional amendment was only 34%, while in soil treated with sawdust, DNS10, sodium citrate and animal manure were 75.17%, 89%, 74.17% and 76.83% at optimized pH and temperature. Overall atazine removal rate was significantly（≥0.01） higher with increasing in temperature at all the selected pH.

Thermoreversible Thickening and Self-assembly Behaviors of pH/Temperature Dually Responsive Microgels with Interpenetrating Polymer Network Structure

The pH /temperature dually responsive microgels of interpenetrating polymer network( IPN) structure composed of poly( N-isopropylacrylamide)( PNIPAM) network and poly( acrylic acid)( PAA) network( PNIPAM /PAA IPN microgels) were synthesized by seed emulsion polymerization. The results obtained by dynamic laser light scattering( DLLS) show that the microgels have good pH /temperature dual sensitivities. The temperature sensitive component and the pH sensitive component inside the microgels have little interference with each other. The rheological properties of the concentrated PNIPAM /PAA IPN microgel dispersions as a function of temperature at pH 4. 0 or 7. 0 were investigated by viscometer,and the results displayed that only at pH 7. 0 the dispersions presented thermoreversible thickening behavior. Then the PNIPAM /PAA fibers were prepared by self-assembly of the PNIPAM /PAA IPN microgels in the ice-crystal templates formed by unidirectional liquid nitrogen freezing method. Field emission scanning electron microscopy( FESEM) images indicate that the PNIPAM /PAA fibers are rounded,randomly orientated and interweaved.

Effects of temperature and pH on the inhibition of Bensulfuron-Methyl(BSM)

Bensulfuron-Methyl(BSM)is a highly active sul-fonylurea herbicide that effectively controls most an-nual and perennial broadleaf or sedge weeds in paddyfield.However,the activity of BSM is affected byseveral evironmental factors.Using corn seedlings asmaterial,we found that under different temperatures

Thermodynamic Foundation for High Temperature Electrochemistry

Thermodynamic concepts required for the thermodynamic calculation of the potentials of electrodes for high temperature applications are briefly reviewed. A thermodynamic approach to the calculation of half cell potentials and the standard chemical potential of an electron at high temperatures which are related to the Standard Hydrogen Electrode(SHE) is discussed. As examples, an external Ag/AgCl reference electrode and a YSZ(Ag|O_2) pH sensor for high temperature applications are analyzed by using the thermodynamic approach to derive a high temperature pH measurement equation. The two electrodes are employed to measure high temperature pH and the measured pH was compared with the calculated pH by using a solution chemistry method. Concepts and principles for electrode kinetics are also briefly introduced and a modification to the Tafel equations is suggested.

Chemical stability of simulated waste forms Zr1–xNdxSiO4–x/2： Influence of temperature, pH and their combined effects

The chemical stability of simulated waste forms Zr_（1–x）Nd_xSiO_（4–x/2） was investigated using the static leach test（MCC-1） with lixiviants of three pH values（pH=4, 6.7 and 10） at three temperature points（40, 90 and 150 oC） for periods ranging from 1 to 42 d, and the influence of temperature, pH, as well as their combined effects were explored in detail. The results showed that all the normalized release rate of Nd firstly decreased with leaching time and closed to equilibrium after 14 d. As the temperature increased, the normalized release rate of Nd also increased, but it was no more than 3×10^（–5） g/（m^2·d）. And, the normalized release rate of Nd reached the highest values（~5×10^（–5） g/（m^2·d）） when pH=4, whilst the normalized release rate of Nd remained the lowest value（~1×10^（–5） g/（m^2·d）） near neutral environment（pH=6.7）.

Degradation kinetics of larotaxel and identification of its degradation products in alkaline condition

Larotaxel, a new taxane compound prepared by partial synthesis from 10-deacetyl baccatin III, is active against tumors. In this research, a selective LC–MS method was developed and validated for the study of degradation kinetics of larotaxel, which was carried out in aqueous solutions with different pH（1.5, 3.0, 5.0, 6.5, 7.4, 9.0, 10 and 11.0） and temperature（0, 25, 37 and 45 °C）. The linear range was 0.5–25 μg/mL, the intra-and inter-day precisions were less than 7.0%, and accuracy ranged from 97.4–104.5% for each analyte. The observed rate obtained by measuring the remaining intact larotaxel was shown to follow first-order kinetics. The activation energies for degradation were 126.7 and 87.01 k J/mol at pH 1.5 and 11, respectively. Although larotaxel was stable in pH 5, 6.5 and 7.4 buffers at 37 °C for 24 h during our study, increasing or decreasing the pH of the solutions would decrease its stabilities. Moreover, three main degradation products in alkaline condition were separated by HPLC and identified by Q–TOF–MS. The three degradation products were confirmed as 10-deacetyl larotaxel, 7, 8-cyclopropyl baccatin Ⅲ and 10-deacetyl-7, 8-cyclopropyl baccatin Ⅲ.

Synthesis of novel tempera-ture/pH responsive polymer via oxyanionic polymerization

Hyperbranched poly(3-ethyl-3-oxetanemetha-nol)-graft-poly(2-dimethylaminoethyl methacrylate) (HP-g-DMA) with a three-demensional structure was synthesized via oxyanionic polymerization. The hydroxyl groups of hyper-branched poly(3-ethyi-3-oxetanemethanol) (HP) reacted with KH and conversed into potassium alcoholate macroinitiators with high initiating efficiencies. High monomer conversion (】95%) was obtained and no residual macroinitiators or monomer was observed. UV-visible spectra indicate that the aqueous solution of the HP-g-DMA exhibited the lowermost critical solution temperature (LCST). The LCST was influ-enced by the chain length of DMA and pH condition of solu-tion. It is found that LCST decreased with increasing DMA chain length or increasing pH value of solution.

A smart MXene-copolymeric molecularly imprinted hydrogel with dual-response and photothermal conversion performance for specific recognition of cis-diol compounds

In this work,a novel MXene-copolymeric molecularly imprinted hydrogel(FMMIH)with temperature/pH dual response and photothermal conversion performance for selective recognition of cis-diol compounds is successfully prepared.Functionalized MXene becomes an important part of the hydrogel’s skeleton by participating in the free radical polymerization reaction.Therefore,FMMIH exhibits improved mechanical properties and great photothermal conversion performance.Furthermore,based on the temperature/pH dual response,FMMIH can realize the controllable capture and release of ginsenoside Rb1 with cis diol structures through dual recognitions of functional groups and geometric space.Under the conditions of pH 8.5 and 25℃,the adsorption capacity of FMMIH is 26.3 mg·g^(-1) and the imprinting factor is 16.4,showing a good imprinting effect.It is worth noting that the volume shrinkage caused by photothermal conversion of the hydrogel is conducive to the elution of template molecules and greatly saves the time of desorption(the desorption efficiency is as high as 89.4%under light conditions for 30 min,which is 3.7 times in dark conditions).These excellent properties make it possible to have broad prospects in many fields such as separation of cis-diol compounds,drug delivery systems,and biosensors.