Local trimer orbital ordering in LiNiO2 studied by quantitative convergent beam electron diffraction technique

A local trimer orbital ordering model of LiNiO₂ was studied by means of theoretical calculation and experimental measurement of electron structure factors. Based on the trimer model, the electron structure factors were calculated by using the scattering factor of non-spherical Ni³⁺ ion. From these results, it is found that the effect of local orbital ordering on the electron structure factors of several subtle reflections, such as (202) and (107), is very large. The electron structure factors of these subtle reflections were measured by quantitative convergent beam electron diffraction method. The experimentally measured electron structure factor values of these reflections indicate that the trimer orbital ordering model is more close to the true structure of LiNiO₂.     

The Schiff Base Probe With J-aggregation Induced Emission for Selective Detection of Cu2+

Here, three Schiff bases 3a-c, differing by the substitutions (–H, –Cl, and –N(CH₃)₂) on the phenyl ring, have been designed and synthesized via the reaction of ortho-aminophenol with benzaldehyde, 2,4-dichlorobenzaldehyde and para-dimethylamine benzaldehyde in 1:1 molar ratio with favourable yields of 89–92%, respectively. Their structural characterizations were studied by FT-IR, NMR, MALDI-MS and elemental analysis. The fluorescence behaviours of compounds 3a and 3b exhibited a severe aggregation caused quenching (ACQ) effect in EtOH/water system. On the contrary, compound 3c had an obvious J-aggregation induced emission (AIE) feature in EtOH/water mixture (v/v?=?1:1), and exhibited excellent sensitivity and anti-interference towards Cu²⁺ with the limit of detection (LOD) of 1.35?×?10^–8 M. Job’s plot analysis and MS spectroscopic study revealed the 2:1 complexation of probe 3c and Cu²⁺. In addition, probe 3c was successfully applied to the determination of Cu²⁺ in real aqueous samples.

     

New sesquiterpenoid glycoside from the rhizomes of Atractylodes lancea

Abstract

Six sesquiterpenoids and four lignans (1–10) were isolated from the n-BuOH extract of the rhizomes of Atractylodes lancea. Among them, the new sesquiterpenoid glycoside named (4?R, 5S, 7R)-hinesolone-11-O-β-?-glucopyranoside (1), along with three known compounds (2–4) were first obtained from this genus. All the isolates were elucidated by spectroscopic analyses and chemical methods, and the absolute configurations were assigned by electronic circular dichroism spectroscopy technique. In addition, the cytotoxic bioassay of compound 1 was evaluated and results showed it had no significant antitumor activity against human cancer cell lines MCF-7, HepG-2 and Hela.     

Effects of the chemical structure of surfactants on the stability of naphthenic oil-based metalworking fluids

In this study,various nonionic surfactants(NS) with different ethylene oxide(EO) numbers and tail lengths and its binary blends with anionic surfactants(AS) were used as emulsifiers for naphthenic oil to form the microemulsion metalworking fluids(MWFs),and the effects of them on the stability of the emulsion system were investigated by formulation triangle method.The results indicated that binary complex surfactants of NS and AS as emulsifiers exhibited better emulsifying effect than that of single NS.NS with different EO numbers and tail lengths presented various emulsifying effects.NS(EO=10)exhibited the greatest number of stable formulations,especially the TX-10,but no linear relationship existed between the number of stable formulations and the tail length of NS.In addition,aromatic primary alcohol ethoxy late(APAE) series surfactants containing benzene groups similar to the cycloalkanes in the naphthenic oil so that presented the best emulsifying affect and the greatest number of stable formulations.The co-surfactant of sodium dodecyl benzene sulfonate(SDBS) binary blends with NS exerted the best synergistic effect,and the stable formulations numbers were ranged from 5 to 7,next sodium stearate(SS) comes last followed by sodium dodecyl sulfate(SDS-1) and sodium dodecyl sulfonate(SDS-2).     

2,2′-二取代-1,1′-联萘化合物的NMR研究

用二维核磁共振谱（ＣＯＳＹ、ＨＭＱＣ、ＨＭＢＣ、ＦＧ＿ＨＭＢＣ）进一步研究了２，２′－二羟基－１，１′－联萘（１）、２，２′－二甲氧基－１，１′－联萘（２）、２，２′－亚甲二氧基－１，１′－联萘（３）、２，２′－亚乙二氧基－１，１′－联萘（４）、２－羟基－２′－甲氧基－１，１′－联萘（５）、２－羟基－２′－乙氧基－１，１′－联萘（６）、２－羟基－２′－异丙氧基－１，１′－联萘（７）、２－羟基－２′－丁氧基－１，１′－联萘（８）和２－羟基－２′－氧乙酸基－１，１′－联萘（９）等９个２，２′－二取代－１，１′－联萘化合物，确定了它们的氢谱和碳谱谱峰的归属，指出联萘化合物的立体结构、萘环的磁各向异性对质子谱有明显的影响，特别是Ｈ８（Ｈ８′）；而其对环碳的影响可以忽略。     

Phase behaviors of Gemini cationic surfactants/n-butanol/water systems

Phase diagrams for ternary system of the Gemini cationic surfactants, N,N-long chain alkyl-2-hydroxyl-N,N,N,N-tetramethyl diammonium dichloride (G_nCl₂) with butanol and water have been drawn based on experimental data at 25 °C. The phase diagrams show that L phase and different liquid crystalline phases are existent in the ternary system at different components. Electric conductivity of the L phase has been studied. Small-angle X-ray scattering (SAXS), ²H (deuterium) quadrupolar splitting (²H NMR) and the polarizing-light microscope were employed to confirm the characteristic texture structures and the microstructure of three different liquid crystalline phases.     

精密角度传感器及其标定技术的研究

介绍了精密角度传感器和不使用任何精密参考仪器的角度传感器的自标定方法。采用补偿技术制作了一对角度传感器,可以克服光源热漂移带来的影响,并进行了标定。两个角度传感器的测量范围为180″,分辨率分别为0．003″,0．004″。平均灵敏度标定的重复性误差为0．015％,线性误差的标定重复性误差为0．015″。     

A new sesquiterpenoid glycoside from Saussurea involucrata

Abstract

Saussurea involucrata, known for the abundant bioactive components, is a precious traditional Chinese medicine. In this study, a novel guaiane sesquiterpenoid glycoside named (1R, 5R, 6R, 7R, 8S, 11S)-11, 13-dihydrodehydrocostuslactone-8-O-6'-2''(E)-butenoyl-β-D-glucopyranoside (1), together with seven known compounds (2–8) were isolated from the dried aerial part of S. involucrata. Their structures were elucidated by spectroscopic and physico-chemical analyses. The antioxidant and anti-inflammatory activities of compound 1 were investigated. And compound 1 showed weak radical scavenging activity and low inhibitory activity on nitric oxide (NO) production.     

Study on dynamic interfacial tension of 3-dodecyloxy-2-hydroxypropyl trimethyl ammonium bromide at liquid/liquid interface

Dynamic interfacial tension between aqueous solutions of 3-dodecyloxy-2-hydroxypropyl trimethyl ammonium bromide (R₁₂HTAB) and n-hexane were measured using the spinning drop method. The effects of the R₁₂HTAB concentration (the concentration below the CMC) and temperature on the dynamic interfacial tension have been investigated; the reason of the change of dynamic interfacial tension with time has been discussed. The effective diffusion coefficient, D_a, and the adsorption barrier, _a, have been obtained from the experimental data using the extended Word–Tordai equation. The results show that the dynamic interfacial tension becomes smaller while _a becomes higher with increasing R₁₂HTAB concentration in the bulk aqueous phase. D_a decreases from 5.56 × 10⁻¹² m⁻² s⁻¹ to 0.87 × 10⁻¹² m⁻² s⁻¹ while _a increases from 5.41 kJ mol⁻¹ to 7.74 kJ mol⁻¹ with the increase of concentration in the bulk solution of R₁₂HTAB from 0.5 × 10⁻³ mol dm⁻³ to 4 × 10⁻³ mol dm⁻³. Change of temperature affects the adsorption rate through altering D_a and _a. The value of D_a increases from 5.56 × 10⁻¹² m⁻² s⁻¹ to 13.98 × 10⁻¹² m⁻² s⁻¹ while that of _a decreases from 5.41 kJ mol⁻¹ to 5.07 kJ mol⁻¹ with temperature ascending from 303 K to 323 K. The adsorption of surfactant from the bulk phase into the interface follows a mixed diffusion–activation mechanism, which has been discussed in the light of interaction between surfactant molecules, diffusion and thermo-motion of molecules.     

Convection and heat transfer of elliptical tubes

Convection heat transfer (including natural and forced convection) of elliptical tubes had been studied system-atically. The experienced formula of heat transfer had been given. It presents fin efficiency of rectangular finned elliptical tube and optimized fin geometry (i.e. length/width ratio) and fin spacing for rectangular fin.

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Konvektion und Wärmeübergang an elliptischen Rohren

Zusammenfassung Konvektion und Wärmeübergang (sowohl bei freier als auch bei erzwungener Konvektion) an elliptischen Rohren wurden systematisch untersucht. Es wird eine aus dem Experiment abgeleitete Beziehung für den Wärmeübergang angegeben, die den Gütegrad elliptischer Rohre mit Rechteckrippen unter optimierter Rippengeometrie (Längen- zu Breitenverhältnis und Rippenabstand) beinhaltet. Stichworte: Konvektiver Wärmeübergang, Rippengütegrad, Elliptische Rohre mit Rechteckrippe.

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Nomenclature A length of a rectangular fin - A _F area of a fin - A _f overall fin area of per length - A _r tube surface of per length - B width of a rectangular fin - Gr Grashof number - N fin number of per length - Nu =hl/ Nusselt number - Pr Prandtl number - Ra =Gr·Pr Rayleigh number - Re =wl/ Reynolds number - S ₁ transverse tube pitch - S ₂ longitudinal tube pitch - w fluid velocity - a long axis of a ellipse - b short axis of a ellipse - c =a/b shape factor - d _e equivalent diameter - g acceleration of gravity - h heat exchange coefficient - l characteristic length - t fin spacing Greek symbols coefficient of thermal expansion - fin thickness - _fm area average fin efficiency - coefficient of fluid thermal conductivity - _f fin's thermal conductivity - kinematic viscosity