Self-separation ionic liquid catalyst for the highly effective conversion of H_(2)S by α,β-unsaturated carboxylate esters under mild conditions

The deep-processing utility of pure hydrogen sulfide (H_(2)S) is a significant direction in natural gas chemical industry.Herein,a brand-new strategy of H_(2)S conversion by a,β-unsaturated carboxylate esters into thiols or thioethers using task-specific carboxylate ionic liquids (ILs) as catalyst has been developed,firstly accomplishing the phase separation of product and catalyst without introducing the third component.It can be considered as a cascade reaction in which the product selectivity can be controlled by adjusting the molar ratio of H_(2)S to a,β-unsaturated carboxylate esters.Also,the effects of ILs with different anions and cations,intermittent feeding operations,as well as pressure-time kinetic behaviors on cascade reaction were investigated.Furthermore,the proposed interaction mechanism of H_(2)S conversion using butyl acrylate catalyzed by[Emim][Ac]was revealed by DFT-based theoretical calculation.The approach enables the self-phase separation promotion of catalyst and product and achieves 99%quantitative conversion under mild conditions in the absence of solvent,making the entire process ecologically benign.High-efficiency reaction activity can still be maintained after ten cycles of the catalyst.Therefore,the good results,combined with its simplicity of operation and the high recyclability of the catalyst,make this green method environmentally friendly and cost-effective.It is anticipated that this self-separation method mediated by task-specific ILs will provide a feasible strategy for H_(2)S utilization,which will guide its application on an industrial scale.

Fine quantitative characterization of high-H2S gas reservoirs under the influence of liquid sulfur deposition and adsorption

In order to clarify the influence of liquid sulfur deposition and adsorption to high-H2S gas reservoirs,three types of natural cores with typical carbonate pore structures were selected for high-temperature and high-pressure core displacement experiments.Fine quantitative characterization of the cores in three steady states(original,after sulfur injection,and after gas flooding)was carried out using the nuclear magnetic resonance(NMR)transverse relaxation time spectrum and imaging,X-ray computer tomography(CT)of full-diameter cores,basic physical property testing,and field emission scanning electron microscopy imaging.The loss of pore volume caused by sulfur deposition and adsorption mainly comes from the medium and large pores with sizes bigger than 1000μm.Liquid sulfur has a stronger adsorption and deposition ability in smaller pore spaces,and causes greater damage to reservoirs with poor original pore structures.The pore structure of the three types of carbonate reservoirs shows multiple fractal characteristics.The worse the pore structure,the greater the change of internal pore distribution caused by liquid sulfur deposition and adsorption,and the stronger the heterogeneity.Liquid sulfur deposition and adsorption change the pore size distribution,pore connectivity,and heterogeneity of the rock,which further changes the physical properties of the reservoir.After sulfur injection and gas flooding,the permeability of TypeⅠreservoirs with good physical properties decreased by 16%,and that of TypesⅡandⅢreservoirs with poor physical properties decreased by 90%or more,suggesting an extremely high damage.This indicates that the worse the initial physical properties,the greater the damage of liquid sulfur deposition and adsorption.Liquid sulfur is adsorbed and deposited in different types of pore space in the forms of flocculence,cobweb,or retinitis,causing different changes in the pore structure and physical property of the reservoir.

Perfluoropentane-based oxygen-loaded nanodroplets reduce microglial activation through metabolic reprogramming

Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s disease.Nanoscale perfluorocarbon droplets have been reported to not only possess a high oxygen-carrying capacity,but also exhibit remarkable anti-inflammatory properties.However,the role of perfluoropentane in microglia-mediated central inflammatory reactions remains poorly understood.In this study,we developed perfluoropentane-based oxygen-loaded nanodroplets(PFP-OLNDs)and found that pretreatment with these droplets suppressed the lipopolysaccharide-induced activation of M1-type microglia in vitro and in vivo,and suppressed microglial activation in a mouse model of Parkinson’s disease.Microglial suppression led to a reduction in the inflammatory response,oxidative stress,and cell migration capacity in vitro.Consequently,the neurotoxic effects were mitigated,which alleviated neuronal degeneration.Additionally,ultrahigh-performance liquid chromatography–tandem mass spectrometry showed that the anti-inflammatory effects of PFP-OLNDs mainly resulted from the modulation of microglial metabolic reprogramming.We further showed that PFP-OLNDs regulated microglial metabolic reprogramming through the AKT-mTOR-HIF-1αpathway.Collectively,our findings suggest that the novel PFP-OLNDs constructed in this study alleviate microglia-mediated central inflammatory reactions through metabolic reprogramming.

高效液相色谱法测定纺织品中四溴双酚S

建立了一种以磁固相萃取纺织品中四溴双酚S,再利用高效液相色谱分析的方法。试验以Fe_(3)O_(4)-GO磁性材料为磁性固相吸附剂,并采用正交试验对萃取过程中的萃取剂用量、温度和时间等因素进行优化,再以0.1 mmol甲酸-乙腈(V∶V=30∶70)为流动相,采用Athena C18-WP柱(2.1 mm×100.0 mm,5.00μm)分离,检测波长214 nm,外标法定量。结果表明,在0.01~50.00 mg/L范围内四溴双酚S线性良好,相关系数R^(2)>0.999,加标回收率达到98.6%~101.5%,相对标准偏差(RSD)小于5.0%(n=6)。该方法高效、简单、灵敏,能够满足纺织品中四溴双酚S的检测。

Effects of huoxiangzhengqi liquid on enteric mucosal immune responses in mice with Bacillus dysenteriae and Salmonella typhimurium induced diarrhea

AIM： To explore effects of huoxiangzhengqi liquid （HXZQ） on enteric mucosal immune responses in mice with Bacillus dysenteriae and Salmonella typhimurium induced diarrhea （BSD）. METHODS： BSD was induced in Balb/c mice by oral administration with Bacillus dysenteriae and Salmonella typhimurium. HXZQ was administrated from the day of diarrhea induction at dosages of 5.21 g/kg and 0.52 g/kg, respectively. The onset of diarrhea and lasting time were recorded. Peyer＇s patches and peripheral lymphocytes were prepared for flow cytometry, and levels of TNF-α in peripheral blood and enteric tissue homogenates were determined with ELISA. Student＇s t test was employed for statistics. RESULTS： Mice in BSD group started showing continuous diarrhea on the day of induction until the fourth day when they were sacrificed. Diarrhea in the mice of HXZQ high and low dose groups lasted for 36 and 54 h, respectively. There were more CD4^＋ and CD8^＋ cells in peripheral blood, fewer CD4^＋ cells in Peyer＇s patches in BSD mice compared to normal mice. Fewer CD4^＋ and CD8^＋ cells was shown in the mice in HXZQ high group compared to BSD mice. In Peyer＇s patch, there were more CD8^＋ cells in mice in HXZQ high and low dose groups and more CD4^＋ in mice in HXZQ high group. Higher levels of TNF-α in peripheral blood and intestinal tissue homogenates in BSD group were observed. Mice in HXZQ high group showed decreased levels of TNF-α in peripheral blood and enteric tissue homogenates. CONCLUSION： The immune regulation of CD4^＋ and CD8^＋ cells in Peyer＇s patch and suppression of TNF-α levels in enteric homogenates may partially explain the effect of HXZQ on improvement of BSD.

Swelling acidic poly(ionic liquid)s as efficient catalysts for the esterification of cyclohexene and formic acid

Acidic poly(ionic liquid)s(PILs)with swelling ability were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,divinylbenzene(DVB)and sodium acrylate(NaAA),and further acidification by sulfuric acid.The swelling ability of acidic PILs was greatly affected by cross-linker content and chain length of 3-alkyl-substituents on imidazolium.Cross-linked network structures could be observed from the cryogenic scanning electron microscopy(cryo-SEM)images of the swollen acidic PILs in formic acid.Acidic PILs with network structures in swollen state exhibited excellent activities in the esterification of cyclohexene and formic acid,and the catalytic activities were in positive correlation with their swelling abilities.Acidic PIL with 3-octyl-substituent and 2.5 mol%DVB(PIL-C8-2.5DVB-HSO4)had the highest swelling ability in formic acid and exhibited comparable catalytic activities with homogeneous catalysts such as sulfuric acid and p-toluenesulfonic acid.

Ionic liquids/deep eutectic solvents for CO_(2) capture:Reviewing and evaluating

The CO_(2)solubilities(including CO_(2)Henry’s constant)in physical-and chemical-based ILs/DESs and the COSMO-RS models describing these properties were comprehensively collected and summarized.The summarized results indicate that chemical-based ILs/DESs are superior to physical-based ILs/DESs for CO_(2)capture,especially those ILs have functionalized cation and anion,and superbase DESs;some of the superbase DESs have higher CO_(2)solubilities than those of ILs;the best physical-and chemical-based ILs,as well as physical-and chemicalbased DESs are[BMIM][BF4](4.20 mol kg^(-1)),[DETAH][Im](11.91 mol kg^(-1)),[L-Arg]-Gly 1:6(4.92 mol kg^(-1))and TBD-EG 1:4(12.90 mol kg^(-1)),respectively.Besides the original COSMO-RS mainly providing qualitative predictions,six corrected COSMO-RS models have been proposed to improve the prediction performance based on the experimental data,but only one model is with universal parameters.The newly determined experimental results were further used to verify the perditions of original and corrected COSMO-RS models.The comparison indicates that the original COSMO-RS qualitatively predicts CO_(2)solubility for some but not all ILs/DESs,while the quantitative prediction is incapable at all.The original COSMO-RS is capable to predict CO_(2)Henry’s constant qualitatively for both physical-based ILs and DESs,and quantitative prediction is only available for DESs.For the corrected COSMO-RS models,only the model with universal parameters provides quantitative predictions for CO_(2)solubility in physical-based DESs,while other corrected models always show large deviations(>83%)compared with the experimental CO_(2)Henry’s constants.

Poly(ionic liquid)-crosslinked graphene oxide/carbon nanotube membranes as efficient solar steam generators

Graphene oxide(GO)is regarded as a promising candidate to construct solar absorbers for addressing freshwater crisis,but the easy delamination of GO in water poses a critical challenge for practical solar desalination.Herein,we improve the stability of GO membranes by a self-crosslinking poly(ionic liquid)(PIL)in a mild condition,which crosslinks neighbouring GO nanosheets without blemishing the hydrophilic structure of GO.By further adding carbon nanotubes(CNTs),the sandwiched GO/CNT@PIL(GCP)membrane displays a good stability in pH=1 or 13 solution even for 270 days.The molecular dynamics simulation results indicate that the generation of water nanofluidics in nanochannels of GO nanosheets remarkably reduces the water evaporation enthalpy in GCP membrane,compared to bulk water.Consequently,the GCP membrane exhibits a high evaporation rate(1.87 kg m^(-2)h^(-1))and displays stable evaporation rates for 14 h under 1 kW m^(-2)irradiation.The GCP membrane additionally works very well when using different water sources(e.g.,dye-polluted water)or even strong acidic solution(pH=1)or basic solution(pH=13).More importantly,through bundling pluralities of GCP membrane,an efficient solar desalination device is developed to produce drinkable water from seawater.The average daily drinkable water amount in sunny day is 10.1 kg m^(-2),which meets with the daily drinkable water needs of five adults.The high evaporation rate,long-time durability and good scalability make the GCP membrane an outstanding candidate for practical solar seawater desalination.

Efficacy and safety of liquid nitrogen cryotherapy for treatment of Barrett's esophagus

AIM To evaluate the efficacy and safety of liquid nitrogen cryotherapy as a primary or rescue treatment for BE,with and without dysplasia,or intramucosal adenocarcinoma (IMC).METHODS This was a retrospective,single-center study carried out in a tertiary care center including 45 patients with BE who was treatment-na?ve or who had persistent intestinal metaplasia(IM),dysplasia,or IMC despite prior therapy.Barrett's mucosa was resected via EMR when clinically appropriate,then patients underwent cryotherapy until eradication or until deemed to have failed treatment.Surveillance biopsies were taken at standard intervals.RESULTS From 2010 through 2014,33 patients were studied regarding the efficacy of cryotherapy.Overall,29 patients (88%) responded to cryotherapy,with 84% having complete regression of all dysplasia and cancer.Complete eradication of cancer and dysplasia was seen in 75% of subjects with IMC; the remaining two subjects did not respond to cryotherapy.Following cryotherapy,15 patients with high-grade dysplasia (HGD) had 30% complete regression,50% IM,and 7% low-grade dysplasia (LGD); one subject had persistent HGD.Complete eradication of dysplasia occurred in all 5 patients with LGD.In 5 patients with IM,complete regression occurred in 4,and IM persisted in one.In 136 cryotherapy sessions amongst 45 patients,adverse events included chest pain (1%),stricture (4%),and one gastrointestinal bleed in a patient on dual antiplatelet therapy who had previously undergone EMR.CONCLUSION Cryotherapy is an efficacious and safe treatment modality for Barrett's esophagus with and without dysplasia or intramucosal adenocarcinoma.

LPS'S CRITERION FOR INCOMPRESSIBLE NEMATIC LIQUID CRYSTAL FLOWS

In this paper we derive LPS＇s criterion for the breakdown of classical solutions to the incompressible nematic liquid crystal flow, a simplified version of Ericksen-Leslie system modeling the hydrodynamic evolution of nematic liquid crystals in R^3. We show that if 0 〈 T 〈 ＋∞ is the maximal time interval for the unique smooth solution u ∈ C^∞（[0, T）,R^3）,then ｜u｜＋｜△d｜∈L^q（[0,T],L^p（R^3））,where p and q satisfy the Ladyzhenskaya-Prodi-Serrin＇s condition：3/p＋2/q=1 and p∈（3,＋∞].

Liquid Crystalline Polymers XIII Main Chain Thermotropic Copoly (Arylidene-Ether)s Containing 4-Teriary Butyl-Cyclohexanone Moiety Linked with Polymethylene Spacers

A new homologous series of thermotropic liquid crystalline copoly(arylidene-ether)s based on 4-teriary butyl cyclohexanone moiety were synthesized by solution polycondensation of 4,4’-diformyl-α,ω-diphenoxyalkanes, Ia-d or 4,4’- diformyl-2,2’-dimethoxy-α,ω-diphenoxyalkanes IIa-d with the 4-teriary butyl-cyclohexanone III and cyclopentanone. A model compound IV was synthesized from the monomer III with benzaldehyde and characterized by elemental and spectral analyses. The inherent viscosities of the resulting polymers were in the range 0.22 - 0.92 dI/g. All the copoly(arylidene-ether)s were insoluble in common organic solvents but dissolved completely in concentrated H2SO4 and formic acid. The mesomorphic properties of these polymers were studied as a function of the diphenoxyalkane space length. Their thermotropic liquid crystalline properties were examined by DSC and optical polarizing microscopy and demonstrated that the resulting polymers form nematic mesophases over wide temperature ranges. The thermogravimetric analyses of those polymers were evaluated by TGA and DSC measurements and correlated to their structural units. X-Ray analysis showed that copolymers having some degree of crystallinity in the region 2q = 5° -60°. In addition, the morphological properties of selected examples were tested by Scanning electron microscopy.

Synthesis and mesomorphic properties of fluorinated Schiff's base liquid crystals containing vinyl end groups

Three kinds of fluorinated Schiff＇s base esters, 4-allyloxy-2-X-6-X-benzoic acid 4-[（2, 3, 4-trifluorophenylimino）methyl]phenyl ester, where X=H or F, were synthesized and characterized. Their chemical structures were identified by Fourier transform infrared spectroscopy （FTIR） and ^1H nuclear magnetic resonance （^1H NMR）. Their mesomorphic properties were studied by polarized optical microscopy （POM） and differential scanning calorimetry （DSC）. It was found that all the three compounds exhibited enantiotropic nematic phases only. And their cleating point temperature and thermal range of mesophase decreased with the number of fluorine atoms on the rigid core of the compounds; while their melting point temperature showed no distinct regularity.

QuEChERS-液相色谱-串联质谱法测定乳及乳制品中活化酯及其代谢物阿拉酸式苯含量

该文研究了高效液相色谱-三重四级杆质谱法(HPLC-MS/MS)测定乳及乳制品中活化酯和阿拉酸式苯的测试方法。样品经甲酸乙腈(含1%甲酸(V/V))涡旋提取,分析液经QuEChERSdSPE EMR-Lipid除脂专用管净化,离心后过膜上机检测。测试方法以甲醇-0.1%甲酸水(V/V)为流动相,流速设置为0.2 mL/min,应用梯度洗脱程序,采用ACQUITY UPLC HSS T3色谱柱进行分离,电喷雾正、负离子模式(活化酯为ESI+、阿拉酸式苯为ESI-),多反应离子监测模式(MRM)检测,基质匹配外标法进行定量。对于乳及乳制品基质,活化酯和阿拉酸式苯在1~30 ng/mL的质量浓度与其相对应的峰面积之间线性关系良好,R^(2)均大于0.996,在0.01、0.02和0.1 mg/kg 3种不同浓度添加水平下,活化酯和阿拉酸式苯的平均回收率在91.8%~109.6%之间,相对标准偏差在1.3%~11.5%之间。该方法可满足残留检测的准确度、精密度和灵敏度的要求。

液压成形对液体火箭发动机多层增强S型波纹管结构疲劳寿命的影响

完善液体火箭发动机燃气摇摆装置中增强S型波纹管组件的疲劳寿命评估方法,提高其疲劳寿命预测精度,是发展可重复使用液体火箭发动机的重要课题之一。针对多层增强S型波纹管,为了计算其液压成形后的实际寿命数据,了解成形工艺对其疲劳寿命的影响,提出一种充分考虑成形制备过程对结构不同区域几何构型和材料力学性能造成差异化影响后的波纹管疲劳寿命分析方法。该方法基于成形仿真和材料拉伸试验结果,构建实际波纹管有限元模型并进行三维仿真分析,得到其在高内压和不同摆动工况下结构危险点的循环载荷信息,并根据波纹管结构的低周疲劳失效特点采用子午向应力应变数据,以及经过平均应力应变修正的Manson-Coffin(M-C)公式对波纹管的循环寿命进行估算和对比分析。结果表明:波纹管疲劳寿命薄弱点位置和大小均与循环摆角有关;在预测计算中考虑液压成形作用影响更接近实际场景,所得结构疲劳寿命大小和所在区域均与理论模型值存在差异,在结构设计、优化和健康监测中不应忽视其影响。

Progress in Technology of Main Liquid Rocket Engines of Launch Vehicles in China

Liquid propellant rocket engines for a launch vehicle are an essential aerospace technology, representing the advanced level of hi-tech in a country. In recent years, China’s aerospace industry has made remarkable achievements, and liquid rocket engine technology has also been effectively developed. In this article, the development processes of China’s liquid rocket engines are discussed. Then, the performance features of China’s new generation liquid rocket engines as well as the flight tests of the new-generation launch vehicles are introduced. Finally, the development direction and the most recent progress of the next generation large-thrust liquid rocket engine is presented.

H_(2)S/CO_(2)共存体系气液相中P110钢的腐蚀行为

为了研究油套管在H_(2)S/CO_(2)共存体系高温高压环境气液相中的腐蚀行为及腐蚀机理,利用高温高压反应釜展开了油套管P110钢在CO_(2)/H_(2)S共存体系中的动态腐蚀模拟试验。采用失重法计算了试样的均匀腐蚀速率和点腐蚀速率,采用XRD、SEM/EDS、三维光学轮廓显微镜等手段研究了CO_(2)/H_(2)S共存体系中P110钢处于液相和气相中的腐蚀行为特征。结果表明:液相中P110钢的均匀腐蚀速率和点腐蚀速率分别为0.0263 mm/a和0.2081 mm/a,均大于在气相环境中P110钢的均匀腐蚀速率(0.0148 mm/a)和点蚀速率(0.1569 mm/a)。液相中P110钢表面生成的腐蚀产物主要为红褐色粉状疏松的FeCO_(3),气相中P110钢表面所形成的腐蚀产物主要为FeCO_(3)和黑褐色致密均匀的FeS,FeS能抑制环境介质中CO_(2)、H_(2)S及Cl-对基体材料的进一步腐蚀。P110钢在液相和气相中发生的腐蚀主要为均匀腐蚀,局部区域有点蚀,存在局部腐蚀倾向。

THERMODYNAMICS AND PHASE EQUILIBRIUM OF Cu－Y－O，Cu－Y－S，Cu－Y－O－S LIQUID SOLUTIONS

ＴＨＥＲＭＯＤＹＮＡＭＩＣＳＡＮＤＰＨＡＳＥＥＱＵＩＬＩＢＲＩＵＭＯＦＣｕ－Ｙ－Ｏ，Ｃｕ－Ｙ－Ｓ，Ｃｕ－Ｙ－Ｏ－ＳＬＩＱＵＩＤＳＯＬＵＴＩＯＮＳ￥Ｄｕ，Ｔｉｎｇ；Ｌｉ，Ｇｕｏｄｏｎｇ（ＣｅｎｔｒａｌＩｒｏｎａｎｄＳｔｅｅｌＲｅｓｅａｒｃｈｉｎｓｔｉｔ...

A NEW STRATEGY FOR THE DESIGN OF LIQUID CRYSTALLINE POLYMERS WITH FLEXIBLE AND APOLAR BUILDING BLOCKS

The synthesis and characterization of a new series of liquid crystalline polymers, poly(dicycloalkylvinylterephthalate)s, are reported. The basic building blocks of these polymers are not mesogenic by themselves. However,very stable mesophases can be generated by self-assembly of the polymer molecules. This approach suggests a novel designstrategy of liquid crystalline polymers with flexible and apolar building blocks.

Immobilization of Functionalized Ionic Liquid on Sol-Gel Derived Silica for Efficient Removal of H_2S

An innovative approach to H2 S capture has been developed using several metal-based ionic liquids([Bmim]Cl·CuCl_2, [Bmim]Cl·FeCl_3, [Bmim]Cl·ZnCl_2, [Bmim]Br·CuCl_2, and [Bmim]Br·FeCl_3) immobilized on the sol-gel derived silica, which is superior to purely viscous ionic liquid with a crucial limit of high temperature, low mass transfer rate,and mass loss. The adsorbents were characterized by the Fourier transform infrared spectrometer, transmission electron microscope, N_2 adsorption/desorption, X-ray photoelectron spectroscopy, and thermal analysis techniques. The effects of the metal and halogen in IL, the loading amount of IL, and the adsorption temperature were studied by dynamic adsorption experiments at a gas flow rate of 100 mL/min. The H2 S adsorption results have showed that the optimal adsorbent and adsorption temperature are 5% [Bmim]Cl·CuCl_2/silica gel and 20—50 ℃, respectively. H_2 S can be captured and oxidized to elemental sulfur, and [Bmim]Cl·CuCl_2/silica gel can be readily regenerated by air. The excellent efficiency of H2 S removal may be attributed to the formation of nano-scaled and high-concentration [Bmim]Cl·CuCl_2 confined in silica gel, indicating that the immobilization of [Bmim]Cl·CuCl_2 on the sol-gel derived silica can be used for H2 S removal promisingly.

P-wave velocity prediction in porous medium with liquid-pocket patchy saturation

It becomes increasingly clear that non-uniform distribution of immiscible fluids in porous rock is particularly relevant to seismic wave dispersion. White proposed a patchy saturation model in 1975, in which spherical gas pockets were located at the center of a liquid saturated cube. For an extremely light and compressible inner gas, the physical properties can be approximated by a vacuum with White＇s model. The model successfully analyzes the dispersion phenomena of a P-wave velocity in gas-water- saturated rocks. In the case of liquid pocket saturation, e.g., an oil-pocket surrounded by a water saturated host matrix, the light fluid-pocket assumption is doubtful, and few works have been reported in White＇s framework. In this work, Poisson＇s ratio, the bulk modulus, and the effective density of a dual-liquid saturated medium are formulated for the heterogeneous porous rocks containing liquid-pockets. The analysis of the difference between the newly derived bulk modulus and that of White＇s model shows that the effects of liquid-pocket saturation do not disappear unless the porosity approaches zero. The inner pocket fluid can no longer be ignored. The improvements of the P-wave velocity predictions are illustrated with two examples taken from experiments, i.e., the P-wave velocity in the sandstone saturated by oil and brine and the P-wave velocity for heavy oils and stones at different temperatures.