基于半导体压力传感原理的钐一硫化物在冻土区压力测量中的应用(英文)

提出了利用半导体压力传感器自动化装置进行冻土区压力测量的方法。传感器的运行原理是依靠半导体导电层电阻变化与压力和温度变动之间的相关关系,从而在传感器温度已知的条件下,对压力进行估算。实验结果验证了这种方法的可行性。

新疆若羌县坡一岩浆硫化物矿床地质特征及成因初探

坡一岩浆硫化物矿床赋矿岩石主要为华力西中期第一侵入次第二阶段纯橄榄岩、辉石橄榄岩、橄榄辉石岩、辉石岩。镍矿体主要分布于超基性岩体中部、底部。矿石类型以星散浸染状为主,次为稀疏浸染状、少量稠密浸染状、海绵陨铁状,半块状-块状、脉状。金属硫化物主要为镍黄铁矿、磁黄铁矿及黄铜矿,次为黄铁矿、白铁矿。通过对坡一岩浆硫化物矿床岩相学、岩石化学、稀土微量元素特征、成矿作用总结分析,初步探讨矿床成因。

大蒜有效成分的药理作用研究进展

大蒜含有多种化学成分,目前发现其主要的生物活性物质是二烯丙基一硫化物、二烯丙基二硫化物、二烯丙基三硫化物和蒜氨酸等硫化物,这些有效成分具有抗氧化、抗肿瘤、抗感染、防治心脑血管疾病、调节肝脏药物代谢酶、抗神经变性和调节细胞内Ca^(2+)水平等广泛的药理学作用。

Fabrication and characterization of tungsten-containing mesoporous silica for heterogeneous oxidative desulfurization

A series of functional,tungsten-containing mesoporous silica materials（W-SiO2） have been fabricated directly from an ionic liquid that contained imidazole and polyoxometalate,which acted as mesoporous template and metal source respectively.These materials were then characterized through X-ray diffraction（XRD）,transmission electron microscopy（TEM）,Raman spectroscopy,Fourier transform infrared spectra（FTIR）,diffuse reflectance spectra（DRS）,and N2 adsorption-desorption,which were found to contain tungsten species that were effectively dispersed throughout the structure.The as-prepared materials W-SiO2 were also found to possess a mesoporous structure.The pore diameters of the respective sample W-SiO2-20 determined from the TEM images ranged from 2 to 4 nm,which was close to the average pore size determined from the nitrogen desorption isotherm（2.9 nm）.The materials were evaluated as catalysts for the heterogeneous oxidative desulfurization of dibenzothiophene（DBT）,which is able to achieve deep desulfurization within 40 min under the optimal conditions（Catalyst（W-SiO2-20）= 0.01 g,temperature = 60℃,oxidant（H2O2）= 20 μL）.For the removal of different organic sulfur compounds within oil,the ability of the catalyst（W-SiO2-20） under the same conditions to remove sulfur compounds decreased in the order：4,6-dimethyldibenzothiophene Dibenzothiophene Benzothiophene 1-dodecanethiol.Additionally,they did not require organic solvents as an extractant in the heterogeneous oxidative desulfurization process.After seven separate catalytic cycles,the desulfurization efficiency was still as high as 90.3%.From the gas chromatography-mass spectrometer analysis,DBT was entirely oxidized to its corresponding sulfone DBTO2 after reaction.A mechanism for the heterogeneous desulfurization reaction was proposed.

Iron Monosulfide Distribution in Three Coastal Floodplain Acid Sulfate Soils, Eastern Australia

The distribution of iron monosulfide (quantified as acid volatile sulfur: SAV) was compared with geo- chemical properties that are known to affect its formation and accumulation in three coastal Holocene acid sulfate soils (ASS) at Tuckean Swamp, McLeods Creek and Bungawalbyn Swamp respectively. These properties included PH, reactive iron (FeR), pore-water sulfate (SO:42-) and organic carbon (OC). Iron monosulfide was concentrated at the oxic/anoxic boundary. The Tuckean Swamp and McLeods Creek sites are Holocene sediments, whereas the Bungawalbyn Swamp is a Holocene peat. The concentration of SAV averaged 0.2 g kg-l in a 0.5 m thick soil layer at the Tuckean Swamp, but was an order of magnitude lower in the oxic/anoxic transition layers at McLeods Creek and Bungawalbyn Swamp. The SAV mineral greigite (Fe3S4) was identified in the Tuckean Swamp by X-ray diffraction and scanning electron microscopy with quantitative energy dispersive X-ray analysis (SEM-EDX). Very small concentrations of greigite were also observed in the McLeods Creek, based on crystal morphology and elemental composition. The concentration of SAV was a small fraction of the total reduced sulfur, representing at most 3% of the Pyrite sulfur. However, the presence of this highly reactive sulfide mineral, distributed within pores where oxygen diffusion is most rapid, has important implications to the potential rate of acid production from these sediments.

Peroxymonosulfate activation by Mn_3O_4/metal-organic framework for degradation of refractory aqueous organic pollutant rhodamine B

An environmentally friendly Mn‐oxide‐supported metal‐organic framework(MOF),Mn3O4/ZIF‐8,was successfully prepared using a facile solvothermal method,with a formation mechanism proposed.The composite was characterized using X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,X‐ray photoelectron microscopy,and Fourier‐transform infrared spectroscopy.After characterization,the MOF was used to activate peroxymonosulfate(PMS)for degradation of the refractory pollutant rhodamine B(RhB)in water.The composite prepared at a0.5:1mass ratio of Mn3O4to ZIF‐8possessed the highest catalytic activity with negligible Mn leaching.The maximum RhB degradation of approximately98%was achieved at0.4g/L0.5‐Mn/ZIF‐120,0.3g/L PMS,and10mg/L initial RhB concentration at a reaction temperature of23°C.The RhB degradation followed first‐order kinetics and was accelerated with increased0.5‐Mn/ZIF‐120and PMS dosages,decreased initial RhB concentration,and increased reaction temperature.Moreover,quenching tests indicated that?OH was the predominant radical involved in the RhB degradation;the?OH mainly originated from SO4??and,hence,PMS.Mn3O4/ZIF‐8also displayed good reusability for RhB degradation in the presence of PMS over five runs,with a RhB degradation efficiency of more than96%and Mn leaching of less than5%for each run.Based on these findings,a RhB degradation mechanism was proposed.

Lattice Dynamics Study of Magnesium Chalcogenides

First-principles calculations,which are based on the plane-wave pseudopotential approach to density functional perturbation theory within the local density approximation,have been performed to investigate the structural,lattice dynamical and thermodynamic properties of zinc blende(B3) structure magnesium chalcogenides:MgS,MgSe and MgTe.The results of ground state parameters and phonon dispersion are compared and agree well with the experimental data available and other calculations.We obtain the change of Born effective charge and LO-TO splitting under hydrostatic pressure.Finally,by the calculations of phonon frequencies,some thermodynamic properties such as the entropy,heat capacity,internal energy,and free energy are also successfully obtained.