一种具有识别Hg^(2+)和ClO^(-)荧光探针的设计和应用

设计合成了一种含双酯基的1,2,3-三氮唑化合物,与罗丹明B酰肼结合生成了具有“开-关”性质的荧光探针(简称L_(2)),应用光谱学表征了L_(2)的物理化学参数。L_(2)分别在DMF/Tris-HCl(1:1,v/v,pH=6.0,20μmol/L)和MeOH(20μmol/L)溶液中对Hg^(2+)和ClO^(-)显示出高选择性和灵敏性;利用荧光和紫外光谱分别测定了L_(2)对19种金属离子和14种阴离子的光学性能。实验表明,Hg^(2+)和ClO^(-)的存在使得L_(2)在585 nm和576 nm均有一个新的发射峰出现;同时伴随着荧光强度明显的增强,溶液体系发生了裸眼能识别的显色变化,表明Hg^(2+)可以将罗丹明分子的酰肼闭环结构转换为开环结构,并以1:2的比例方式生成了一种新配合物,这也被质谱、工作曲线、核磁滴定和TD-DFT计算的结果所证实;L_(2)对Hg^(2+)和ClO^(-)的检测限分别为7.45 nmol/L和0.67μmol/L。此外,生物活性测定显示L_(2)对HeLa细胞有非常低的毒性,并且可用于HeLa细胞中Hg^(2+)和ClO^(-)的细胞成像,表明L_(2)在体内可进行微测定Hg^(2+)和ClO^(-)的巨大潜力。

1,3-氧硫戊环为受体的Hg^(2+)荧光探针的设计、合成及性能

Hg^(2+)是毒性最强的重金属离子之一,会造成空气、土壤和水的污染,严重损害人体健康,开发有效的分析方法检测环境体系中的Hg^(2+)尤为重要。荧光探针因其灵敏度高、选择性好、响应速度快、可实时在线检测等优点,已广泛应用于Hg^(2+)检测。以Hg^(2+)促进硫代缩醛的去保护反应设计合成了一种全新的以1,3-氧硫戊环为受体的开启型Hg^(2+)荧光探针[2-(pyren-1-yl)-1,3-oxathiolane,POX],通过^(1)H NMR、^(13)C NMR和HRMS对POX结构进行表征,考察了POX在CH_(3)CH_(2)OH/H_(2)O中对Hg^(2+)的选择性、竞争性、浓度滴定、pH滴定、时间依赖性、检出限和识别机理等。研究结果表明,POX可在较宽的pH范围内对Hg^(2+)快速识别,并表现出高度的选择性和灵敏度;向POX中加入Hg^(2+)后,在386 nm处出现明显的荧光发射峰,表明POX对Hg^(2+)呈现出显著的荧光“开启”效应,其识别过程几乎不受其他金属离子干扰;荧光滴定实验表明POX在Hg^(2+)浓度为0~6.5μmol·L^(-1)范围内具有良好的线性响应(R^(2)=0.9994),检出限为0.168μmol·L^(-1),在实际水样中检测Hg^(2+)的RSD小于2.92%。由于POX合成简单、原料易得且pH适用范围较广,可作为定性和定量检测环境中Hg^(2+)的潜在工具。

氨基酸基氮掺杂荧光碳点的制备及饮料中Hg^(2+)的检测

汞离子是一种高毒性的重金属污染物,人体摄入后会带来健康危害,因此控制食品中的汞离子含量非常重要。以柠檬酸为碳源,不同的氨基酸为氮源掺杂,采用一步水热法制备高性能荧光的碳点(CDs),探究不同氨基酸基氮掺杂对碳点荧光量子产率(QY)的影响,以及这些氨基酸基氮掺杂碳点对汞离子的响应。结果显示,不同氨基酸的碳链长度和官能团对CDs的QY有一定的影响。Hg^(2+)能高效猝灭以甘氨酸(Gly)为氮源掺杂的Gly-CDs的荧光,Gly-CDs具有良好的荧光稳定性,在优化的试验条件下,用于Hg^(2+)检测的线性范围为0.00~7.00μmol/L和8.00~60.00μmol/L,检出限为0.20μmol/L。据此构建的荧光探针用于检测实际饮料样品中的Hg^(2+),回收率在90.08%~107.90%。该方法简便、快速、灵敏、适用于饮料中Hg^(2+)的测定。

Recent advances and future prospects on Ni_(3)S_(2)-Based electrocatalysts for efficient alkaline water electrolysis

Green hydrogen(H_(2))produced by renewable energy powered alkaline water electrolysis is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.However,efficient and economic H_(2) production by alkaline water electrolysis is hindered by the sluggish hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Therefore,it is imperative to design and fabricate high-active and low-cost non-precious metal catalysts to improve the HER and OER performance,which affects the energy efficiency of alkaline water electrolysis.Ni_(3)S_(2) with the heazlewoodite structure is a potential electrocatalyst with near-metal conductivity due to the Ni–Ni metal network.Here,the review comprehensively presents the recent progress of Ni_(3)S_(2)-based electrocatalysts for alkaline water electrocatalysis.Herein,the HER and OER mechanisms,performance evaluation criteria,preparation methods,and strategies for performance improvement of Ni_(3)S_(2)-based electrocatalysts are discussed.The challenges and perspectives are also analyzed.

Electrokinetic-mechanism of water and furfural oxidation on pulsed laser-interlaced Cu_(2)O and CoO on nickel foam

The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.

Analysis of the effect of the 2021 Semeru eruption on water vapor content and atmospheric particles using GNSS and remote sensing

Mount Semeru,an active volcano in East Java,Indonesia,erupted on December 4,2021,following extreme rainfall that caused an avalanche of hot pyroclastic flows and lava.The tropospheric conditions and dominant particle components in the atmosphere can be monitored using Global Navigation Satellite System(GNSS)technology and remote sensing satellites.GNSS signal propagation delay in Precise Point Positioning(PPP)processing can be used to determine Zenith Tropospheric Delay(ZTD)and Precipitable Water Vapor(PWV)variables so that atmospheric conditions can be generated.In addition,by using remote sensing satellite data,it is possible to obtain rainfall data with high temporal resolution as well as the dominant particle and gas content values during eruptions.During the eruption period,the high value of PWV was dominated by the high intensity of precipitation during the rainy season.High rainfall before the eruption caused activity inside the mountain to increase,which occurred in avalanche type eruption.Apart from that,the atmosphere around Semeru was also dominated by SO_(2)content,which spreaded for tens of kilometers.SO_(2)content began to be detected significantly by remote sensing sensors on December 7,2021.In this study,deformation and atmospheric monitoring were also carried out using low-cost GNSS at the Semeru Monitoring Station on September 9-15,2022.The results of the ZTD and ZWD values show the dominance of the wet component,which is directly proportional to rainfall activity in this period.

氮掺杂碳点的制备及其在Hg^(2+)测定中的应用研究

以柠檬酸为碳源,尿素、邻菲罗啉、氨水、硫脲、精氨酸为氮源,通过水热法合成了5种氮掺杂荧光碳点。对合成的碳点进行荧光性能表征,测定了每种碳点的最佳激发和发射波长,在最佳发射波长下,利用荧光猝灭对Hg^(2+)进行检测。结果表明,以精氨酸为氮源制备的碳点对Hg^(2+)检测具有较灵敏的响应,其线性范围为0.25~1.5μmol/L。

磁性聚氨基噻唑吸附剂脱除水体Hg^(2+)性能

聚多巴胺(PDA)辅助负载聚氨基噻唑(PAT)法制备了磁性颗粒吸附剂Fe_(3)O_(4)@SiO_(2)@PDA-PAT。对吸附剂进行了XRD、VSM、TG、SEM、XPS、EDS和Zeta电位等表征分析,考察了吸附剂对Hg^(2+)的吸附性能。结果表明,Fe_(3)O_(4)@SiO_(2)@PDA-PAT具有超顺磁性,在pH小于2时Zeta电位为正,pH大于2时Zeta电位为负。在303 K和Hg^(2+)浓度为50 mg/L模拟废水中,当pH为1.3和5.0时,Hg^(2+)的平衡吸附量分别为121.9 mg/g和153.1 mg/g。在强酸(如pH 1.3)和弱酸(如pH 5.0)环境下Fe_(3)O_(4)@SiO_(2)@PDA-PAT吸附Hg^(2+)的过程均是自发过程,且符合二级动力学模型和Langmuir等温吸附模型。强酸环境下(如pH 1.3)Fe_(3)O_(4)@SiO_(2)@PDA-PAT吸附Hg^(2+)是焓驱动的放热过程,弱酸(如pH 5.0)环境下是熵驱动的吸热过程。用2 mol/L混酸(盐酸和硝酸摩尔比为1∶1)作为解吸液可使Hg^(2+)解吸率达91%以上。在303 K、pH 1.3、Hg^(2+)浓度20 mg/L条件下,当Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)、Cu^(2+)、Zn^(2+)、Ni^(2+)质量浓度为Hg^(2+)的20倍时,Fe_(3)O_(4)@SiO_(2)@PDA-PAT的Hg^(2+)平衡吸附量分别下降了33.2%、32.1%、20.6%、26.7%、21.2%、29.6%、17.8%。在模拟海水下,Hg^(2+)吸附量下降40.9%。Fe_(3)O_(4)@SiO_(2)@PDA-PAT具有较好的Hg^(2+)选择性,具有净化海水脱除重金属的应用潜力。

Transcriptomics integrated with metabolomics reveals the mechanism of CaCl_(2)-HCl electrolyzed water-induced glucosinolate biosynthesis in broccoli sprouts

Glucosinolates are important phytochemicals in Brassicaceae.We investigated the effect of CaCl_(2)-HCl electrolyzed water(CHEW)on glucosinolates biosynthesis in broccoli sprouts.The results showed that CHEW treatment significantly decreased reactive oxygen species(ROS)and malondialdeh yde(MDA)contents in broccoli sprouts.On the the 8^(th)day,compared to tap water treatment,the the total glucosinolate content of broccoli sprouts with CHEW treatment increased by 10.6%and calcium content was dramatically enhanced from 14.4 mg/g DW to 22.7 mg/g DW.Comparative transcriptome and metabolome analyses revealed that CHEW treatment activated ROS and calcium signaling transduction pathways in broccoli sprouts and they interacted through MAPK cascades.Besides,CHEW treatment not only promoted the biosynthesis of amino acids,but also enhanced the expression of structural genes in glucosinolate synthesis through transcription factors(MYBs,bHLHs,WRKYs,etc.).The results of this study provided new insights into the regulatory network of glucosinolates biosynthesis in broccoli sprouts under CHEW treatment.

Experimental investigation on using CO_(2)/H_(2)O emulsion with high water cut in enhanced oil recovery

CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility reduction.However,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fraction),while CO_(2) emulsion with high water cut has been rarely researched.In this paper,we carried out a comprehensive experimental study of using high water cut CO_(2)/H_(2)O emulsion for enhancing oil recovery.Firstly,a nonionic surfactant,alkyl glycosides(APG),was selected to stabilize CO_(2)/H_(2)O emulsion,and the corresponding morphology and stability were evaluated with a transparent PVT cell.Subsequently,plugging capacity and apparent viscosity of CO_(2)/H_(2)O emulsion were measured systematically by a sand pack displacement apparatus connected with a 1.95-m long capillary tube.Furthermore,a high water cut(40 vol%) CO_(2)/H_(2)O emulsion was selected for flooding experiments in a long sand pack and a core sample,and the oil recovery,the rate of oil recovery,and the pressure gradients were analyzed.The results indicated that APG had a good performance on emulsifying and stabilizing CO_(2) emulsion.An inversion from H_(2)O/CO_(2) emulsion to CO_(2)/H_(2)O emulsion with the increase in water cut was confirmed.CO_(2)/H_(2)O emulsions with lower water cuts presented higher apparent viscosity,while the optimal plugging capacity of CO_(2)/H_(2)O emulsion occurred at a certain water cut.Eventually,the displacement using CO_(2)/H_(2)O emulsion provided 18.98% and 13.36% additional oil recovery than that using pure CO_(2) in long sand pack and core tests,respectively.This work may provide guidelines for EOR using CO_(2) emulsions with high water cut.

聚丙烯腈改性及其对Hg^(2+)吸附研究

Hg^(2+)是生态环境中存在的对人体健康危害最大的重金属离子之一。吸附法是一种去除Hg^(2+)最简单高效的方法。因此设计成本低廉、吸附性能好且能循环利用的吸附剂是非常重要的。采用乳液自由基聚合技术制备聚丙烯腈,然后用三乙烯四胺对聚丙烯腈进行改性,得到改性后的聚丙烯腈。以废水中Hg^(2+)为吸附对象,考察不同的实验条件下,改性后的聚丙烯腈对Hg^(2+)的吸附性能。在pH值为6,Hg^(2+)浓度为40 mg/L,即时吸附量q_(t)达到最大;吸附30 min后吸附基本达到饱和。分别用伪一级吸附和伪二级吸附方程动力学模型对实验数据进行拟合,结果表明,用伪二级动力学方程可以更好描述吸附过程,说明三乙烯四胺改性聚丙烯腈对Hg^(2+)的吸附过程受Hg^(2+)扩散和-NH_(2)与Hg^(2+)的配位反应影响,为化学吸附。

Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.

基于适配体的荧光生物传感器对Hg^(2+)的检测技术研究

工业迅速发展所带来的重金属污染,是目前威胁人类健康的重要环境问题之一。Hg^(2+)是一种毒性强且污染较为普遍的重金属离子,较低浓度Hg^(2+)就会对人体造成很大危害。基于核酸适配体错配结合Hg^(2+)的原理,以特异性双链核酸染料SYBR GreenⅠ为荧光指示探针,构建了新型的无标记核酸适配体荧光生物传感器,建立了一种高灵敏度、快速检测Hg^(2+)的方法,实现了Hg^(2+)高效检测。在优化条件下,传感器对Hg^(2+)的检测线性范围为10 nmol/L~1μmol/L,相关系数(r^(2))为0.99,检出限为1 nmol/L。5种干扰离子(Ca^(2+)、Fe^(2+)、Cu^(2+)、Ni^(2+)、Ag^(+))的存在不影响Hg^(2+)检测,表明该方法对Hg^(2+)检测具有较好的特异性。在自来水样的Hg^(2+)加标检测实验中,平均回收率达到95.8%,具备分析实际样品的能力。

聚(N-异丙基丙烯酰胺-共聚-烯丙基硫脲)智能微凝胶的制备及其Hg^(2+)响应性能的研究

以N-异丙基丙烯酰胺(NIPAM)和烯丙基硫脲(ATU)为共聚单体,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂,2,2′-偶氮二(2-甲基丙基咪)二盐酸盐(V50)为引发剂,通过沉淀聚合法制备了一种可用于Hg^(2+)检测与去除的聚(N-异丙基丙烯酰胺-共聚-烯丙基硫脲)(PNA)智能微凝胶。利用傅里叶变换红外光谱仪(FT-IR)、X射线光电子能谱仪(XPS)和扫描电镜(SEM)对微凝胶进行了化学成分和形貌表征。利用动态光散射纳米粒度分析仪(DLS)对微凝胶的粒径分布及温度响应性进行了研究。探究了干扰离子、pH和温度对微凝胶Hg^(2+)响应性能的影响。利用原子吸收光谱仪(AAS)探究了PNA微凝胶对Hg^(2+)的吸附去除效果。结果显示,PNA微凝胶具有良好的温敏性以及对Hg^(2+)的特异响应性,响应Hg^(2+)后引起的收缩比(RD)随着ATU单体比例的增加而减小,并确定了最佳检测温度为30℃。随着Hg^(2+)浓度的增加,RD值逐渐减小,根据Hg^(2+)浓度与RD之间的对应关系拟合出相应的Hg^(2+)浓度计算公式。该PNA微凝胶最低检测浓度可达10^(-8)mol·L^(-1)。在吸附实验中,PNA微凝胶的吸附容量随着Hg^(2+)浓度的增加而增加,对10^(-4)mol·L^(-1)以下的Hg^(2+)溶液,吸附率可达80%以上,最低可使Hg^(2+)浓度降至0.0005 mg·L^(-1)。相比Zn^(2+)、Cd^(2+)和Pb^(2+),微凝胶对Hg^(2+)的吸附率是其他金属离子的7倍左右。研究结果为有害金属Hg^(2+)的检测和去除提供了新方法。

基于时序Sentinel-2影像的引黄灌区作物结构提取和供需水分析

在黄河流域用水指标严格控制的背景下,以山东省东营市垦利区引黄灌区为例,利用2022年时序Sentinel-2遥感影像构建作物生育期的NDVI时间序列,采用决策树分类方法提取灌区作物种植结构,基于垦利站气象资料和Penman-Monteith公式,分析了1973—2022年各作物的需水特性,利用遥感影像解译的各作物种植面积,计算了2022年灌区作物在不同降水保证率(5%、25%、50%、75%、95%)条件下的灌溉总需水量,结合2023年分配给灌区作物的灌溉水指标探究了灌溉水资源供需之间的平衡。结果表明:基于NDVI时间序列构建决策树分类方法可有效提取作物的种植结构,总体分类精度为85.07%,Kappa系数为0.819,能够满足作物灌溉需水量的研究。作物净灌溉需水量年际波动较大,水稻和冬小麦补充灌溉水量在所有作物中位列前两位,均值分别为913 mm和410 mm;处于雨季生长的夏玉米、夏大豆补充灌溉水量较小且灌溉需求均值较小。研究区2023年分配的灌溉水指标在降水保证率为50%时研究区灌溉水亏缺量为235.5万m^(3),在降水保证率为75%和95%时灌溉水亏缺量分别为1 754.5万m^(3)和2 261.5万m^(3)。

“哨兵-2”卫星影像及C2RCC算法在太湖冬春季水色分析中的应用

利用太湖2019—2022年冬春季“哨兵-2”卫星10 m分辨率的MSI影像和SNAP软件C2RCC(Case 2 Regional CoastColour)模块,以适合浑浊、富营养程度较高、光学复杂的“二类水体”的C2X-nets为模式,开展太湖叶绿素a、总悬浮物浓度、透明度等水色参数反演。结果表明:冬春季太湖各湖区叶绿素a浓度处于较低水平,但4月中旬起有明显抬升;太湖西部沿岸区、南部沿岸区和湖心区总悬浮物浓度较高,表明这些湖区易受风浪影响,造成沉积物再悬浮;太湖东部沿岸区、北部湖湾及东太湖遥感反演的水体清澈度较高,可能与这些湖区冬春季沉水植物菹草的分布有关,菹草生长对水质有较好的净化效果。总体来看,基于C2X-nets模式的C2RCC反演算法从较高分辨率卫星遥感影像中提取的水色信息,能有效反映太湖冬春季水色指标的空间分布特征,可为湖体生态状况及动态变化的长期监测评估提供有价值的参考。

衰竭底水气藏注CO_(2)提高天然气采收率与碳封存机理

气藏注CO_(2)提高天然气采收率并实现碳封存有望成为大幅度提高天然气产量与碳减排协同的潜在关键技术。为了给底水气藏注CO_(2)高效开发提供指导,针对地层水盐度对CO_(2)-CH_(4)-H_(2)O-NaCl体系相平衡影响、气藏注气过程中压力变化对CO_(2)-CH_(4)-H_(2)O-NaCl体系相平衡影响、注采方案对注CO_(2)提高气藏采收率影响、盐度对注CO_(2)提产及封存影响等目前认识不清的问题开展了CO_(2)-CH_(4)-H_(2)O-NaCl体系相平衡规律及注CO_(2)提采与封存数值模拟研究。研究结果表明:①随着盐度增加,CO_(2)和CH_(4)在盐水中的溶解度降低,液相的密度和黏度增加,盐度对气相性质几乎没有影响;②随着压力增加,CO_(2)和CH_(4)在液相中的溶解度均增加,气相、液相密度和黏度均增加,液相偏差因子随压力增加而增加,气相偏差因子先减小后增加;③同注同采方案CH_(4)产量更稳定且产出的CO_(2)少,而先注后采方案则会加速CO_(2)与CH_(4)的混合,CO_(2)封存量低,前者更适合注CO_(2)提采及封存;④在不考虑盐析效应的前提下,盐度对CH_(4)采收率和CO_(2)封存量的影响几乎可以忽略不计,不同盐度的衰竭底水气藏中CH_(4)采收率均超过80%、CO_(2)封存率均超过99%,短期注CO_(2)过程中,CO_(2)主要以气态或超临界态的形式被封存,少部分CO_(2)溶解在液相中,100年后CO_(2)在液相中的溶解质量分数约为5%。结论认为,衰竭底水气藏注CO_(2)能增压补能、驱替置换残余天然气,提高采收率并实现碳封存。

SCCO_(2)作用下不同含水性煤孔裂隙结构变化机制

深部煤层封存CO_(2)增产CH_(4)产出过程中,处于超临界状态的CO_(2)(SCCO_(2))与煤中矿物质发生反应,改变煤的孔隙性,进而影响煤层封存CO_(2)的效果和甲烷增产效果。为发现SCCO_(2)–H_(2)O–煤岩作用对煤中孔隙的影响特征,以焦煤为研究对象,开展了不同含水条件下的超临界CO_(2)改造煤实验,基于矿物组成和孔隙性测定结果,对比煤中主要矿物质和不同尺度的孔裂隙变化的差异,探讨了不同含水状态下SCCO_(2)流体对孔裂隙性的作用机制。研究表明:①SCCO_(2)作用后,煤体表面粗糙、疏松,且由于矿物溶蚀使得一些裂隙得到贯通,微裂隙连通性增强。②SCCO_(2)流体对煤具有“扩孔”作用,表现为微、小孔含量下降,中、大孔占比升高,也即微、小孔隙向大孔隙的转化,且孔隙连通性改善;进一步发现,萃余煤吸附孔的分形维数稍微增加,粗糙度增大,而渗流孔的分形维数显著降低,复杂性和非均质性降低。③SCCO_(2)对煤中碳酸盐类矿物的溶解性最好,其次是黏土矿物,且随着含水率增加,萃余煤中的碳酸盐矿物占比先增加后减小。SCCO_(2)使干燥基态、饱和水态煤样中碳酸盐矿物显著溶解,有效改善了孔隙结构,且对饱和水态煤样作用效果更好。空气干燥基态煤样经SCCO_(2)作用后,新生成的白云石矿物聚集在孔喉中造成堵孔效应,缩小原有大孔隙尺寸,是引起不同含水性煤孔隙差异性变化的主要原因。

潮湿环境下金红石型纳米TiO_(2)掺杂聚乙烯的分子动力学模拟

为了从微观角度分析金红石型纳米TiO_(2)掺杂对聚乙烯(polyethylene,PE)材料性能的影响,采用分子动力学模拟方法,构建不同水分子质量分数的PE和TiO_(2)/PE复合模型,以温度为变量研究分析纳米TiO_(2)改性PE材料前后的热力学性能和微观结构以及水分子在复合体系中的扩散能力。结果表明:纳米TiO_(2)的掺杂使PE体系的玻璃化转变温度提高了33 K,杨氏模量提升了428.17%,剪切模量提升了338.62%。纳米TiO_(2)极大抑制了PE分子链的运动和水分子的扩散,增强了复合体系的稳定性。水分子的加入和温度的升高降低了复合体系的热力学性能,这两者均破坏了复合体系的稳定性。

CO_(2)-EOR过程中油藏储层构造封存能力的模拟

为应对日益严峻的能源危机和温室效应,CO_(2)提高采收率技术脱颖而出,因此CO_(2)提高采收率后的地质封存安全性和相应的封存能力评估引起了广泛关注。借助数值模拟方法,基于吉林油田某区块油藏的实际储层条件,构建了注入CO_(2)含量为10%~90%的9个模型,分别探究了含水饱和度为30%,50%和90%以及储层压力为10 MPa,20 MPa和30 MPa时油藏各相组分的分布规律;基于前人对封存CO_(2)安全储存状态划分的研究,最终明确了CO_(2)的安全封存量。结果表明:1)当含水饱和度(30%)和压力(10 MPa)一定时,增加CO_(2)含量(10%~90%)可大幅提高CO_(2)的有效封存体积分数(26%~93%);2)压力的提升(10~30 MPa)促进了CO_(2)在油相中的溶解,从而略微降低了储层的封存能力(18%~7%);3)含水饱和度对储层封存CO_(2)的能力的影响微乎其微。该研究旨在阐明不同条件下CO_(2)的构造埋存量,为相关研究提供借鉴。