Chemical examination of Tylophora asthmatica—V Structure of tylophorinine

Tylophorinine, the minor alkaloid of Tylophora asthmatica, has been oxidized to yield 2,3,6-trimethoxyphenanthrene-9,10-dicarboxylic acid. A synthesis of the corresponding imide has been achieved. Desoxytylophorinine, obtained by hydrogenolysis of the alkaloid, has been synthesized. These results in conjunction with other degradation experiments have enabled the assignment of the structure XIV to tylophorinine.     

Effect of prior mechanical and thermal treatment on the thermal decomposition and sublimation of cubic ammonium perchlorate

The thermal decomposition of ammonium perchlorate (AP) in its cubic modification has been studied in the temperature range 300–390°C. Two distinct regions of temperature dependence are observed for the rate constants of the decomposition. The activation energies in the two regions are found to be 20 ± 2 kcals/mole and 60 ± 2 kcals/mole. Prior mechanical and thermal treatment of the materials is seen to result in a marked increase in the thermal reactivity of AP in the range 300–370°C. Differential thermal analysis of pre-compressed AP shows pronounced changes in the exothermic characteristics of the material. Prior compression of AP in addition enhances the sublimation of the material. The activation energies are not altered by the pretreatment. The results are explained in terms of crystal imperfections and the role of dislocations in the thermal decomposition of AP.     

Thermocouple measurement of metal temperature under pulsed deformation conditions

Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 137–143, January–February, 1991.     

2′,5,6,7-tetramethoxyflavone and the structure of zapotin

2′,5,6,7-Tetramethoxyflavone, synthesized by two methods has been found to be different from zapotin.     

Synthesis of novel diastereomeric diphosphine ligands and their applications in asymmetric hydrogenation reactions

[structure: see text] Diastereomeric biaryl diphosphine ligands 10 and 11 with added chiral centers on the backbone were synthesized. Substrate-directed asymmetric synthesis occurred in the coupling step of the preparation of the diastereomeric diphosphine oxides. The diastereomeric diphosphine oxides were easily separated by column chromatography with silica gel. Ruthenium catalysts containing these ligands were highly effective in the hydrogenation of 2-(6'-methoxy-2'-naphthyl)propenoic acid and beta-ketoesters. The additional chiral centers had a significant influence on the enantioselectivity and activity of the catalysts.     

Modelling the steady-state effluent characteristics of the TNCU process under different return mixed liquid

The Activated Sludge Model No. 2d (ASM2d) was employed and modified to predict the effluent qualities of the modified enhanced biological phosphate removal (EBPR) system – TNCU. The TNCU process was composed of anaerobic/anoxic/oxide (A2O) process and rotating biological contactors (RBC) in each reactor. There were three modifications for the model in this study: (1) the biosorption effect of the soluble COD, (2) the ammonification of the organic nitrogen in influent wastewater, and (3) the growth of the heterotrophic organisms in the anaerobic tank. The influent wastewater qualities were fixed, the ratios of return sludge and SRT were 0.5 and 11 days, and the model plant was operated at three different mixed liquid recycling ratios (MLRR, 0.5, 1.25, 2). When a steady state was reached, the comparisons between the measured values and the model predicted values in each test were made. It shows a good consistency between them. According to the consistent results, the biosorption effect of the soluble COD and the ammonification of the organic nitrogen in influent wastewater were the important effects in activated sludge system. Additionally, the heterotrophic organisms might grow in the anaerobic tank. The heterotrophic organisms, phosphorus accumulating organisms and autotrophic organisms would decrease in the anaerobic tanks because the lysis reactions were the major reactions in the anaerobic tanks. They would increase in the aerobic tanks. Furthermore, it was indirectly proved that the denitrifying PAOs existed in the EBPR system.     

Physical‐chemical Test Platform for Room Temperature,Far‐infrared Ray Emitting Ceramic Materials (cFIR)

Ceramic far‐infrared (cFIR) emitting materials are sources of room temperature FIR radiation that allow non‐thermal irradiation of biological tissue. In this study, we explored some interesting physical and chemical effects that have not been reported. We investigated the effects of cFIR irradiation of sorghum wine using gas chromatography with solid‐phase micro‐extraction (GC‐SPME) to demonstrate enhancement on volatility; monitored pH changes resulting from irradiation on acetic acid; and used UV spectroscopy to identify and quantify chemical changes. On the basis of the results, we deduced that cFIR possesses the ability of weakening hydrogen bond and exhibits chemical reduction change. The methods above provide a relatively convenient and cost‐effective test platform to demonstrate the application of cFIR as an effective alternative to biological assay.     

Determination of the effect of final state energy loss on the acoplanarity and momentum imbalance in jets

The energy loss of partons leaving the hot media created in the heavy ion collisions has been at the center of the interest of the experimental and theoretical communities of the field. Hence an increase in the transverse momentum imbalance and acoplanarity of dijets may be a way to study the parton energy loss. In order to study the effect, we have made simulations of dijet events where the intrinsic k _T of the partons, the initial and final state radiation are taken into account. The results of these simulations for p + p and Pb + Pb collisions, as a function of the center of mass energy of collision will be presented.