Reaction of 3-Benzoyl-2,3-dibromopropionic Acid with Substituted ortho-Phenylenediamines

3-Benzoyl-2,3-dibromopropionic acid reacts with 4-substituted o-phenylenediamines to give 3-aryl-2-carboxymethylene-1,2-dihydroquinoxalines.     

A New Efficient Synthesis of p-Nitrocalix[4]arene

A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described.The compound is an useful intermediates for the introduction of other functional groups to obtain N containing substituted calix[4]arene.The reaction mechanism is briefly discussed.     

Synthesis of diaminohydroxyethersvia 3-(ω-haloalkoxy)-2-hydroxypropyl sulfamates

Reactions of 3-(ω-haloalkoxy)-2-hydroxypropyl sulfamates with amines or ammonia followed by acid hydrolysis give the corresponding diaminohydroxyethers. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1663–1665, August, 1998.     

Oxidation of 2-dialkylaminomethyl-4,6-di-tert-butylphenols

Oxidative transformations of 2-dialkylaminomethyl-4,6-di-tert-butylphenols depend on the nature of the oxidant, the character of the substituents at the nitrogen atom, and the medium. A mechanism of the oxidation of these compounds is suggested. The molecular structure of the compound obtained as a result of oxidative trimerization of 2-dimethylaminomethyl-4,6-di-tert-butylphenol was established by X-ray structural analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1328–1335, July, 1997.     

2-（2＇-羟基-3’-甲氧基苯基）-5，6-二硝基苯并咪唑的阴离子识别

设计并合成了2-（2’-羟基-3’-甲氧基苯基）-5，6-二硝基苯并咪唑化合物（1），通过X射线单晶衍射研究了该化合物的固态结构．利用紫外-可见光谱技术研究了其对阴离子的识别，发现化合物1能够在DMSO中对AcO^-，H2PO4^-，OH^-的3种离子进行有效识别，同时溶液由原来的黄色变成红色，实现裸眼检测．     

Uncoupled metabolism stimulated by chemical uncoupler and oxic-settling-anaerobic combined process to reduce excess sludge production

The effects of three uncoupled metabolic systems (conventional activated sludge process with the addition of 3,3′,4′,5-tetrachlorosalicylanilide [TCS], oxic-settling-anaerobic [OSA] process modified by insertion of a sludge-holding tank in the sludge return line, and TCS and OSA combined process) on reducing excess sludge production were studied. Compared with the control conventional activated sludge process, the most effective system was the combined process, which could reduce excess sludge production by 46.90%. The 180-d operation results confirmed that TCS is an effective chemical uncoupler in reducing the sludge yield but that it had an adverse effect on substrate removal capability, effluent nitrogen concentration, and sludge settleability. The OSA process decreased excess sludge production by only 26% but had less adverse effect on effluent quality and could improve sludge settleability. The effluent total phosphorous concentration of the three systems was slightly lower than of the control unit. Microbial populations were monitored by both microscopic and molecular biologic analysis method (polymerase chain reaction [PCR]-denaturing gradient gel electrophoresis [DGGE]). The presence of TCS caused metazoans to disappear and decreased the number and activity of protozoa. PCR amplification of 16S rRNA and sequent DGGE analysis found a shift in the diversity of the predominant species. The results imply that OSA combined with the chemical uncoupler process may effectively reduce excess sludge yield and not affect process performance significantly.     

Effects of processing on the structure of zein/oleic Acid films investigated by x-ray diffraction

Zein films plasticized with oleic acid were formed by solution casting, by the stretching of moldable resins, and by blown film extrusion. The effects of the forming process on film structure were investigated by X-ray diffraction. Wide-angle X-ray scattering (WAXS) patterns showed d-spacings at 4.5 and 10 A, which were attributed to the zein alpha-helix backbone and inter-helix packing, respectively. The 4.5 A d-spacing remained stable under processing while the 10 A d-spacing varied with processing treatment. Small-angle X-ray scattering (SAXS) detected a long-range periodicity for the formed films but not for unprocessed zein, which suggests that the forming process-promoted film structure development is possibly aided by oleic acid. The SAXS d-spacing varied among the samples (130-238 A) according to zein origin and film-forming method. X-ray scattering data suggest that the zein molecular structure resists processing but the zein supramolecular arrangements in the formed films are dependent on processing methods. Structural model for a zein molecular aggregate (based on Matsushima et al.10). Rectangular prisms of individual zein molecules are hexagonally aligned parallel to each other.     

Na＋-丙氨酸二肽络合离子结构的密度泛函理论研究

运用密度泛函理论B3LYP方法在6-311＋＋G**基组水平下研究了Na^＋与丙氨酸二肽(AD)分子结合形成的6种Na^＋-AD 络合离子, 其中包括2种双齿结构和4种单齿结构. 考察了6种Na^＋-AD络合离子的相对稳定性, 分析了丙氨酸二肽分子与Na^＋作用过程中分子骨架Ramachandran角f和Ψ以及分子内氢键的变化.     

Synthesis and Crystal Structure of Metronidazole-derived Compound

A MET-OH derivative,MET-OTs 1,was designed,prepared and structurally charac-terized by single-crystal X-ray diffraction. X-ray structure analysis reveals that 1 crystallizes in the monoclinic system,space group P21/c,with a=16.1178(14),b=7.5473(6),c=13.4161(11),V= 1520.3(2)3,β=111.3210(10)o,Z=4,Dc=1.421 g/cm3 and F(000)=680.