Kinetics investigation on the combustion of waste capsicum stalks in Western China using thermogravimetric analysis

The combustion kinetics of waste capsicum stalk (WCS) in Western China is investigated through thermogravimetric analysis compared with sawdust and coal, and co-combustion of WCS with coal is also investigated. Results show that the ignition characteristics of WCS is better than that of sawdust and coal, and the activation energy E of WCS-volatile combustion and WCS-char combustion are 78.55?kJ?mol^?1 and 44.59?kJ?mol^?1. However, integrating the characteristics of ignition and burnout, the combustion characteristic factor (S _N) of WCS is lower than that of sawdust. With the increasing in the heating rate, the ignition of WCS is delayed. Oxygen concentration $ C_{{{\text{O}}_{2} }} $ affects E and k ₀ of volatile combustion largely under rich-oxygen condition, when $ C_{{{\text{O}}_{2} }} $ increases from 0.2 to 0.8, E has increased threefold and k ₀ also intensively increases from 10⁶ to 10¹³?C10²². Oppositely, effect of $ C_{{{\text{O}}_{2} }} $ on the E and k ₀ of char combustion is little, and there is an exponential relationship $ S_{\text{N}} = 7. 1 2 8 \times 10^{ - 9} \times { \exp }(C_{{{\text{O}}_{2} }} /0. 3 6 8) - 6. 1 2 6 \times 10^{ - 9} $ between S _N and $ C_{{{\text{O}}_{2} }} $ . For the tests of co-combustion, all the experimental and weighted-average curves coincide well, and there is no remarkable synergistic effect. With the increase of mixing ratio that WCS added, E and k ₀ of volatile combustion increase, but correspondingly E and k ₀ of char combustion decrease.     

A High－efficiency Preparation, Properties and Structure of （R, S ）－and （ S, S）－Pyrrolidine－2－carboxylic Acid 3,5－Dioxa－4－boracvclo.hepta [ 2,1－α; 3,4－α′] dinaphthalen－4－yl Esters

A highly-efficient preparative procedure for ( R, S )- and ( S, S)-pyrroHdine-2-carboxyHc acid 3,5-dioxa-4-boracyclohepta[2, 1-α ; 3,4-α′] dlnaphthalen-4-yl esters [ namely ( R, S )-BNBAP and (S, S )-BNBAP] is described and the crystal structure of (R, S )-BNBAP was obtained. The data indicate that ( R, S )-BNBAP is a spirocyclic inner borate salt with almost normal te-trahedral configuration. This structural form may be the basic reason for their high chemical, optical and thermodynamic sta-bility.     

KF-Al2O3催化合成2-甲基-1-苄基苯并咪唑

苯并咪唑类杂环化合物具有杀菌、消炎、抗癌、抗氧化的活性,广泛用于食品的防虫和防腐,用于动、植物病毒的防治,人体疾病和肿瘤的防治[1-3],本文用KF Al2O3作催化剂,用DMF为溶剂,利用2 甲基苯并咪唑与苄基溴反应合成2 甲基 1 苄基苯并咪唑的新型方法,考察了诸因素对产率的影响,找出了最佳的反应条件。合成路线如下:1　实验部分1 1　仪器与试剂Brurer AM 500超导核磁共振波谱仪(溶剂CDCl3);CarloErbal1106型元素分析仪,NicoletIm pact410型红外光谱仪,KBr压片,HP1100型和Finnigan FTMS 2000型质谱仪(以上均由华东理工大学分析…     

Gliding Arc Discharge for Decolorization and Biodegradability of Azo Dyes and Printing and Dyeing Wastewater

Gliding arc discharge process was used for the pretreatment of four azo dye solutions, which are classified to acidic, reactive and chemical indicator, as well as printing and dyeing wastewater with the objective of improving their overall biodegradability. The percentage color removal of all samples were found to be over 92% after 40?min treatment, and the color disappearance of four azo dyes followed the first-order kinetics completely. The biochemical oxygen demand (BOD₅)/chemical oxygen demand (COD) ratio increased from 0.02 to 0.46 for acid orange II (AO7), 0.173 to 0.55 for methyl orange, 0.019 to 0.4 for direct fast black, 0 to 0.65 for reactive red K-2BP. The decolorization of printing and dyeing wastewater achieved 97.5% and the COD removal efficiency was 76.6%. The BOD₅/COD ratio increased to 0.55 after 20?min treatment. The experimental results indicates it is possible to combine gliding arc discharge with conventional biological treatment for the remedy of wastewater containing generally non-biodegradable dye.     

Design,synthesis characterization and in vitro biological activity of a series of 3-aryl-6-(bromoarylmethyl)-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives as the novel acetylcholinesterase inhibitors

Bromination is used as a strategy to improve biological activity in medicinal chemistry.In order to study on the structure-activity relationships of the novel acetylcholinesterase inhibitors with 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one scaffold,based on our previous work and molecular modeling,a series of novel 3-aryl-6-(bromoarylrnethyl)-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives were designed by molecular docking,synthesized and characterized by mass spectra,infrared spectra,proton NMR and elemental analyses.The study of AChE inhibitory activity was carried out using the Ellman colorimetric assay with huperzine-A as the positive control.Most of all target compounds exhibited more than 45%inhibition at 10μmol/L.The preliminary structureactivity relationship was the bromine atoms and the hydroxyl group at the phenyl ring at the C6 position of the parent nucleus played significant roles in the AChE inhibitory activity of the target compounds.     

Xyloccensin L, a novel limonoid from Xylocarpus granatum

The isolation and structure elucidation of xyloccensin L from the stem bark of Xylocarpus granatum is described. Xyloccensin L is a highly oxidized heptacyclic A, B, D-seco limonoid with an α-8, 30-epoxy ring and a rare 1, 29 oxygen bridge.     

The Redox Coupling Effect in a Photocatalytic RuII‐PdII Cage with TTF Guest as Electron Relay Mediator for Visible‐Light Hydrogen‐Evolving Promotion

A nanocage coupling effect from a redox Ru^II‐Pd^II metal–organic cage (MOC‐16) is demonstrated for efficient photochemical H₂ production by virtue of redox–guest modulation of the photo‐induced electron transfer (PET) process. Through coupling with photoredox cycle of MOC‐16, tetrathiafulvalene (TTF) guests act as electron relay mediator to improve the overall electron transfer efficiency in the host–guest system in a long‐time scale, leading to significant promotion of visible‐light driven H₂ evolution. By contrast, the presence of larger TTF‐derivatives in bulk solution without host–guest interactions results in interference with PET process of MOC‐16, leading to inefficient H₂ evolution. Such interaction provides an example to understand the interplay between the redox‐active nanocage and guest for optimization of redox events and photocatalytic activities in a confined chemical nanoenvironment.     

Electron Configuration Modulation of Nickel Single Atoms for Elevated Photocatalytic Hydrogen Evolution

The emerging metal single‐atom catalyst has aroused extensive attention in multiple fields, such as clean energy, environmental protection, and biomedicine. Unfortunately, though it has been shown to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date owing to the lack of deep insight on electronic level. Now, partially oxidized Ni single‐atom sites were constructed in polymeric carbon nitride (CN), which elevates the photocatalytic performance by over 30‐fold. The 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons, which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation, and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.     

Synthesis and bioactivity of novel phthalimide derivatives

Novel phthalimide derivatives （4a, 4b and 6a-6e） were designed as hybrids of thalidomide and NO-ASA, and their chemical synthesis and in vitro biological activities were presented. The preliminary results showed that compared to thalidomide 4a and 4b exhibited enhanced activities against ECV304 and HepG2 cells, whereas 6e was more potent against HepG2 cells. 2007 Yi Hua Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.