甜菜碱/AOS/Gemini季铵盐三元复合型泡排剂的研制与性能评价

泡沫排液技术是保障气井产量的重要手段,研发高性能的泡排剂极其关键。为适应高矿化度、高凝析油含量及高温等苛刻气井环境,以椰油酰胺丙基羟基磺基甜菜碱(CHSB)作为主剂,α-烯基磺酸钠(AOS)和合成的Gemini阳离子表面活性剂CAGB作为辅剂制备了一种高效环保的三元泡排体系。结果表明,三元复配体系AOS/CAGB/CHSB在摩尔比为12∶3∶35、总量为20 mmol/L时性能最优,泡沫体积和半衰期分别达到360 mL和30.27 min;在含有30%甲醇的泡排剂溶液中,测得的携液率最高可达31%,发泡率为95%;在含有0%~50%凝析油的泡排剂溶液中,三元泡沫体系表现出良好的性能,其中在凝析油含量为20%时,测得的携液率最高可达38%,发泡率为95%;优选的三元复配体系AOS/CAGB/CHSB对盐离子耐受性较差,加入螯合剂(氨三乙酸三钠(NTA))后,三元复配体系在矿化度为150 g/L的溶液中仍能稳定发泡和携液;温度大于50℃时,泡沫的携液率也逐渐增加,温度在90℃时,携液率在95%以上。此外,通过表面张力测试、泡沫微观结构观察也证实了该泡排剂体系存在的协同效应使其起泡、稳泡和泡沫携液能力得到有效提升。

Accurate method based on data filtering for quantitative multi-element analysis of soils using CF-LIBS

To obtain more stable spectral data for accurate quantitative analysis of multi-element,especially for the large-area in-situ elements detection of soils, we propose a method for a multielement quantitative analysis of soils using calibration-free laser-induced breakdown spectroscopy(CF-LIBS) based on data filtering. In this study, we analyze a standard soil sample doped with two heavy metal elements, Cu and Cd, with a specific focus on the line of Cu I324.75 nm for filtering the experimental data of multiple sample sets. Pre-and post-data filtering,the relative standard deviation for Cu decreased from 30% to 10%, The limits of detection(LOD)values for Cu and Cd decreased by 5% and 4%, respectively. Through CF-LIBS, a quantitative analysis was conducted to determine the relative content of elements in soils. Using Cu as a reference, the concentration of Cd was accurately calculated. The results show that post-data filtering, the average relative error of the Cd decreases from 11% to 5%, indicating the effectiveness of data filtering in improving the accuracy of quantitative analysis. Moreover, the content of Si, Fe and other elements can be accurately calculated using this method. To further correct the calculation, the results for Cd was used to provide a more precise calculation. This approach is of great importance for the large-area in-situ heavy metals and trace elements detection in soil, as well as for rapid and accurate quantitative analysis.

Research on batch multielement rapid quantitative analysis based on the standard curve-assisted calibration-free laserinduced breakdown spectroscopy method

This study proposes a batch rapid quantitative analysis method for multiple elements by combining the advantages of standard curve(SC)and calibration-free laser-induced breakdown spectroscopy(CF-LIBS)technology to achieve synchronous,rapid,and accurate measurement of elements in a large number of samples,namely,SC-assisted CF-LIBS.Al alloy standard samples,divided into calibration and test samples,were applied to validate the proposed method.SC was built based on the characteristic line of Pb and Cr in the calibration sample,and the contents of Pb and Cr in the test sample were calculated with relative errors of 6%and 4%,respectively.SC built using Cr with multiple characteristic lines yielded better calculation results.The relative contents of ten elements in the test sample were calculated using CF-LIBS.Subsequently,the SC-assisted CF-LIBS was executed,with the majority of the calculation relative errors falling within the range of 2%-5%.Finally,the Al and Na contents of the Al alloy were predicted.The results demonstrate that it effectively enables the rapid and accurate quantitative analysis of multiple elements after a single-element SC analysis of the tested samples.Furthermore,this quantitative analysis method was successfully applied to soil and Astragalus samples,realizing an accurate calculation of the contents of multiple elements.Thus,it is important to advance the LIBS quantitative analysis and its related applications.

Isoforsythiaside confers neuroprotection against Alzheimer's disease by attenuating ferroptosis and neuroinflammation in vivo and in vitro

Ferroptosis and neuroinflammation contribute to the development of Alzheimer's disease(AD). Isoforsythiaside(IFY)is a phenylethanoid glycoside isolated from the dried fruit of Forsythia suspensa(Thunb.)Vahl that has been confirmed to improve the memory and cognitive abilities of APP/PS1 mice in our previous study. The purpose of this study was to explore the anti-ferroptosis and anti-neuroinflammatory properties of IFY-mediated neuroprotection. In APP/PS1 mice, erastin-damaged HT22 cells, and LPS-exposed BV2 cells, the neuroprotective effects against ferroptosis and neuroinflammation were investigated using immunohistochemistry, label-free proteomics, western blot, ELISA, MTT, fluorescence, and TEM. IFY alleviated the expression levels of NO, IL-6, and IL-1β in LPS-exposed BV2 cells and improved the morphology of mitochondria in erastin-damaged HT22 cells. Additionally, IFY upregulated the expression levels of GPX4, FTH, FTL, p-GSK-3β, Nrf2, and NQO1, and downregulated the expression of TFR1, DMT1, p-Fyn, GFAP, p-IKKα+β, p-IκBα, p-NF-κB, and pro-inflammatory factors in the brains of APP/PS1 mice and erastin-damaged HT22 cells. In conclusion, IFY inhibits ferroptosis and neuroinflammation in erastin-damaged HT22 cells and APP/PS1 mice, at least partially by regulating the activation of Nrf2 and NF-κB signaling. IFY may prevent ferroptosis and neuroinflammation in AD and provide a new treatment strategy for AD.

Analysis of metallic elements dissolution in the Astragalus at different decocting time by using LIBS technique

Astragalus is an important traditional Chinese herb that has therapeutic potential in the treatment of diseases. In this study, the dissolution of metallic elements during the material decoction process was investigated using laser-induced breakdown spectroscopy(LIBS). The Ca, Mg, Al, and Fe in the drug residues, liquid, and vapor were selected for the study of the transfer of elements after different decocting times. It was found that the intensities of the spectral lines for these elements in the drug liquid increased with increasing decocting times.The contrast trend was observed in the residues and only calcium was detected in the vapor.Furthermore, the relative mass concentrations of Ca, Mg, Al, and Fe in the liquid were quantitatively determined by a combination of the standard addition method and calibrationfree-LIBS method by adding the standard concentration solution of Cu and Cd elements into the drug liquids, it can be found that the maximum error between Cd concentration calculated by internal CF-LIBS and the standard is within 10%. This provides a new method of achieving the on-line monitoring and analysis of metallic elements in the production of traditional Chinese medicines.

Robust ZnS interphase for stable Zn metal anode of high-performance aqueous secondary batteries

Although Zn metal is an ideal anode candidate for aqueous batteries owing to its high theoretical capacity,lower cost,and safety,its service life and efficiency are damaged by severe hydrogen evolution reaction,self-corrosion,and dendrite growth.Herein,a thickness-controlled ZnS passivation layer was fabricated on the Zn metal surface to obtain Zn@ZnS electrode through oxidation–orientation sulfuration by the liquid-and vapor-phase hydrothermal processes.Benefiting from the chemical inertness of the ZnS interphase,the as-prepared Zn@ZnS electrode presents an excellent anti-corrosion and undesirable hydrogen evolution reaction.Meanwhile,the thickness-optimized ZnS layer with an unbalanced charge distribution represses dendrite growth by guiding Zn plating/stripping,leading to long service life.Consequently,the Zn@Zn S presented 300 cycles in the symmetric cells with a 42 mV overpotential,200 cycles in half cells with a 78 mV overpotential,and superb rate performance in Zn||NH;V;O;full cells.

Improved sensitivity on detection of Cu and Cr in liquids using glow discharge technology assisted with LIBS

Laser-induced breakdown spectroscopy-assisted glow discharge(LIBS-GD)for analysis of elements in liquid was proposed,and it was applied to detect heavy metals in highly sensitive mixed solutions of Cu and Cr.During the experiments of GD and LIBS-GD,the experimental parameters have been optimized and the optimal voltage is 450 V,laser energy is 60 mJ,and the delay time is 4000 ns.Furthermore,the calibration curves of Cu and Cr under GD and LIBS-GD experiments have been established,and the limits of detection(LODs)of Cu and Cr were obtained with the method of GD and LIBS-GD,respectively.The LOD of Cu decreased from3.37(GD)to 0.16 mg l(LIBS-GD),and Cr decreased from 3.15 to 0.34 mg l.The results prove that the capability of elemental detection under LIBS-GD has improved compared with the GD method.Therefore,LIBS-GD is expected to be developed into a highly sensitive method for sewage detection.

Influence of heating effect in Thomson scattering diagnosis of laser-produced plasmas in air

A state diagnosis of laser-produced plasma in air generated by a 1064 nm pulse laser was investigated by the Thomson scattering(TS)method.The evolutions of the electron temperature and electron density were obtained as a function of the time delay which ranged from 300-3200 ns.The heating effect produced by the 532 nm probe beam with different energies on the air plasma at different interaction times was further studied using a time-resolved optical emission spectroscopy technique.The influence of the probe beam on the electron density was found to be negligible,whereas its influence on electron temperature is evident.In addition,the heating effect of the probe beam on the plasma strongly depends on the energy of the probe beam,and gradually weakens with increasing time delay.Our results are helpful for further understanding the TS method and its application in plasma diagnostics.

Optimizing electronic structure of NiFe LDH with Mn-doping and Fe_(0.64)Ni_(0.36)alloy for alkaline water oxidation under industrial current density

Alkaline electrolyzers for water splitting under the industrial current densities are always burdened with huge energy consumption due to the high overpotential and poor stability of the anode nanocatalysts for oxygen evolution reaction(OER).Inspired by the interfacial charge transfer for enhancing the performance,a series of in-situ grown interfacial Mn-NiFe lactate dehydrogenase(LDH)was designed on the Fe_(0.64)Ni_(0.36)/NM(nickel mesh)alloy layer.The optimized Mn_(0.15)-NiFe LDH/Fe_(0.64)Ni_(0.36)/NM exhibited an ultralow overpotential of 295 mV to drive 500 mA·cm^(-2)and an incredible stability under large current density.The interfacial space and heteroatom doping synergistically triggered the electronic structure optimization to promote electron transfer and ensure the durability of the high-current reaction.Notably,the designed Mn_(0.15)-NiFe LDH/Fe_(0.64)Ni_(0.36)/NM as an anode in an integral alkaline electrolyzer exhibited a cell voltage of 1.78 V at 500 mA·cm^(-2) with a stability of 366 h.Density functional theory(DFT)calculations further demonstrated the synergistic effect of alloy layer introduction and Mn doping could accelerate electron transfer and stabilize the charged active center to activate the NiFe LDH and reduce the OER energy barrier.Our work offers new insights into developing efficient self-supported catalysts for high-current alkaline water oxidation.

火焰法制备碳纳米管研究进展

火焰法是近20年来兴起的一种新颖、高能效、低成本的碳纳米管制备方法。火焰法能同时提供制备碳纳米管所需的碳源和热源,具有大规模制备碳纳米管的潜力。由于火焰中环境极其复杂,控制火焰中碳纳米管的合成仍是巨大的挑战。本工作介绍了碳纳米管的结构及其性能,综述了扩散火焰(同轴扩散火焰、反扩散火焰和对冲扩散火焰)和预混火焰(单面滞止火焰和双面滞止火焰)制备碳纳米管的研究进展,并对碳纳米管的vapor-liquid-solid、顶部和底部及空心和实心生长机理作了简要阐述,介绍了本课题组基于甲烷/空气同轴射流火焰制备碳纳米管的研究进展。分析表明,金属镍起催化作用,催化剂颗粒包覆在碳纳米管内部,火焰合成的碳纳米管基于vapor-liquid-solid生长机制,碳纳米管直径为50～90 nm,平均直径为65 nm。对火焰法制备碳纳米管的发展方向进行了展望。

Asymmetric Synthesis and Antitumor Activity of Spiro- Oxadiazole Derivatives from 1,4：3,6-Dianhydro-D-fructose

A series of spiro-oxadiazoles were synthesized from 1,4：3,6-dianhydro-D-fructose and hydrazides via a stereoselective two-step reaction sequence. The structures of newly synthesized compounds were established by spectral analysis. The absolute configuration of compound 2a was further confirmed by single crystal X-ray analysis. All the synthesized compounds were screened for their in vitro antitumor activity, showing that these compounds have poor inhibitory activities against A549, MGC-803 tumor cells.