Application of nuclear magnetic resonance technology to carbon capture,utilization and storage:A review

Carbon capture,utilization and storage (CCUS) is considered as a very important technology for mitigating global climate change.Carbon dioxide (CO2) injected into an underground reservoir will induce changes in its physical properties and the migration of CO2 will be affected by many factors.Accurately understanding these changes and migration characteristics of CO2 is crucial for selecting a CCUS project site,estimating storage capacity and ensuring storage security.In this paper,the basic principles of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technologies are briefly introduced in the context of laboratory experiments related to CCUS.The types of NMR apparatus,experimental samples and testing approaches applied worldwide are discussed and analyzed.Then two typical NMR core analysis systems used in CCUS field and a self-developed high-pressure,low-field NMR rock core flooding experimental system are compared.Finally,a summary of the current deficiencies related to NMR applied to CCUS field is given and future research plans are proposed.

Study on signal intensity of low field nuclear magnetic resonance via an indirect coupling measurement

We carry out an ultra-low-field nuclear magnetic resonance （NMR） experiment based on high-T c superconducting quantum interference devices （SQUIDs）. The measurement field is in a micro-tesla range （～10 μT-100 μT） and the experiment is conducted in a home-made magnetically-shielded-room （MSR）. The measurements are performed by the indirect coupling method in which the signal of nuclei precession is indirectly coupled to the SQUID through a tuned copper coil transformer. In such an arrangement, the interferences of applied measurement and polarization field to the SQUID sensor are avoided and the performance of the SQUID is not destroyed. In order to compare the detection sensitivity obtained by using the SQUID with that achieved using a conventional low-noise-amplifier, we perform the measurements using a commercial room temperature amplifier. The results show that in a wide frequency range （～1 kHz-10 kHz） the measurements with the SQUID sensor exhibit a higher signal-to-noise ratio. Further, we discuss the dependence of NMR peak magnitude on measurement frequency. We attribute the reduction of the peak magnitude at high frequency to the increased field inhomogeneity as the measurement field increases. This is verified by compensating the field gradient using three sets of gradient coils.

Analysis of quality-related proteins in golden pompano(Trachinotus ovatus)fillets with modified atmosphere packaging under superchilling storage

Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.

陆相砂岩油藏高含水阶段驱油效率再认识

涸洲11-4N油田涸洲组油藏已进入高、特高含水开发阶段,部分油组采出程度已经接近或超过已有探井实测驱油效率,在现有驱油效率认识下,油藏可挖潜潜力较小,需进一步开展酒洲组油藏高倍水驱下驱油效率研究。针对上述开发中存在的问题,开展了注入量为200PV下的岩心水驱油实验;设计制作了微观可视化水驱油模型,直观描述高倍水驱油过程及残余油的分布规律;结合核磁共振技术开展岩心在线驱替实验,量化大、中、小等不同尺度孔隙中的驱油效率。实验结果表明,长岩心驱油效率可达73.2%,远超原有认识下的驱油效率;当并联长岩心渗透率级差较大时,首次提出在高、低渗透岩心进口端存在伯努利效应;微观水驱油过程中,注入水沿着中、高渗透通道快速突破,模型无水采出程度仅为18.6%,200PV水驱后,低渗透区原油得到有效启动;核磁共振在线驱替实验结果表明,中孔隙对驱油效率的贡献最大,达45.63%。

Further discussion of CO_(2) huff-n-puff mechanisms in tight oil reservoirs based on NMR monitored fluids spatial distributions

Due to the poor physical properties of tight reservoirs,CO_(2) huff-n-puff(HNP)is considered a potential enhanced oil recovery(EOR)method after primary depletion.Optimization plays a critical role in the effective implementation of CO_(2) huff-n-puff.But the optimization requires a good understanding of the EOR mechanisms.In this work,the spatial distribution of oil saturation under different experimental conditions was analyzed by the NMR method to further discuss the HNP mechanisms.According to the variation of 1D frequency signal amplitude,we divided the core into the hardly movable area and movable area,the region with the obvious signal decline was defined as the movable area,and the hardly movable area was the region with limited signal decline.Based on that the recovery characteristics of different scenarios were evaluated.Firstly,the necessity of the soaking stage was studied,where three scenarios with different soaking times were carried out.Secondly,the injection pressure was adjusted to investigate the effect of the pressure gradient.The T_(2) spectra show that soaking has significantly improved the production of crude oil in small pores,and higher oil recovery in a single cycle is observed,but it is lower when the elapsed time(total operation time)is the same.31.03% of oil can be recovered after 3 cycles HNP,which increases to 33.8% and 37.06% for the 4 cycles and 6 cycles cases.As the pressure gradient increases,more oil is removed out of the matrix,and the oil in the deep part of the reservoir can be effectively recovered.During the CO_(2) huff-n-puff process,the oil distributions are similar to the solution gas drive,the residual oil is distributed at the close end of the core and the range that the oil can be efficiently recovered is limited.

Effects of Water-cement Ratio and Hydration Heat Regulating Materials on Hydration Process of Early-age Cementitious Materials

By means of low-field nuclear magnetic resonance(LF-NMR),the transverse relaxation time(T_(2))signals of physically bound water in cement paste were monitored to indicate water content change and characterize the early-age hydration process.With the curves of the T_(2)signals and hydration time obtained,the hydration process could be divided into four typical periods using the null points of the second derivative curve,and the influences of water-cement ratio(w/c)and hydration heat regulating materials(HHRM)on hydration process were analyzed.The experimental results showed that the hydration rate of pure cement paste in accelerated period presented a positive correlation with w/c.Compared to pure cement paste,the addition of HHRM extended all four periods,and led to a much faster hydration rate in initial period as well as a slower rate in accelerated period.Finally,according to the LFNMR test results,the early-age hydration model of cementitious materials was proposed considering w/c and HHRM content.

Classification of different walnut varieties using low-field nuclear magnetic resonance technology and cluster analysis

To classify different walnut varieties based on water and oil content of walnut,and determine their storage conditions,the low-field nuclear magnetic resonance(LFNMR)technology was used to obtain the NMR transverse relaxation time(T 2)of the samples based on the physical and chemical indicators of the walnut quality.The relationship between the relaxation time and phase state of the internal material of the sample was investigated,and the characteristic parameters of the NMR spectrum signals were statistically analyzed using cluster analysis to determine the different walnut varieties,and three different components,as well as their contents,were detected by a LFNMR spectrometer:firmly bound water,weakly bound water,and weakly bound oil.Test results indicated that the oil peak was dominant in the overall signal intensity compared to the water peaks,in which the firmly bound water phase contributed more to the overall water signal between the water peaks.Using the analytic hierarchy process of cluster analysis,21 walnut samples were classified into three different classes,based on the characteristic parameters of the water-content and oil-content spectrum signals.The first class contains four walnut varieties characterized by least water and highest oil contents;the third class contains two walnut varieties,with the highest water content and least oil content;whereas,the second class contains 15 walnut varieties,with both water and oil contents at medium levels.The results showed that LFNMR led to a rapid detection of moisture and oil contents in walnuts,while cluster analysis classified different walnuts varieties based on these parameters.This study also provided the basis for optimizing the storage methods and storage conditions of walnuts.

推进剂组分对聚醚聚氨酯粘合剂热氧降解的影响 (Ⅰ)硝酸酯增塑剂的影响

采用傅立叶红外光谱和核磁共振技术，研究了硝化甘油（ＮＧ）和１，２，４－丁三醇三硝酸酯（ＢＴＴＮ）两种硝酸酯增塑后的聚醚聚氨酯在空气中９０°Ｃ下的热氧降解。结果表明：ＮＧ，ＢＴＴＮ在聚氨酯粘合剂中的分解产物主要为醇类。这些小分子醇参与了聚氨酯硬段的重聚合反应，形成氨基甲酸酯结构；硝酸酯对聚氨酯粘合剂的热氧降解表现出某种稳定作用，并改变了软段产物结构，使甲酸酯和叔碳结构相对增加；硝酸酯分解产生的ＮＯ２自由基可能与软段降解产生的过氧化氢反应形成硝酸，从而加速了硝酸酯的水解。

基于核磁共振波谱的鼻咽癌患者血清代谢组研究

目的应用核磁共振氢谱(nuclearmagnetic resonance1H,1H NMR)和偏最小二乘法-判别分析(partialleast square-discriminant analysis,PLS-DA)研究鼻咽癌(NPC)患者血清中代谢物的代谢组变化。方法健康人血清10例和鼻咽癌患者血清21例,采用BRUKER 500 MHz超导核磁共振波谱仪进行检测,并运用PLS-DA分析方法,得出鼻咽癌患者血清代谢组的特征,探讨相关生化过程的改变。结果鼻咽癌患者血清中的丙氨酸、异亮氨酸、亮氨酸、苯丙氨酸、脂类和不饱和脂肪酸等含量升高,而乳酸、缬氨酸、谷氨酰胺以及胆碱类物质降低,与正常人血清代谢组比较差异有统计学意义(P<0.05)。结论基于核磁共振氢谱和偏最小二乘法-判别分析的代谢组学方法可为鼻咽癌的诊断提供分子水平上的代谢依据。

基于TEOS原位交联加固对土遗址水分运移行为影响研究

为了研究TEOS原位交联加固对土遗址水分运移行为的影响,采用低场核磁共振技术对TEOS加固重塑土样与未加固重塑土样中水分运移行为与孔隙结构变化规律进行系统研究。通过分析横向弛豫时间T2和孔隙谱峰面积发现:在水分运移过程中,重塑土样内部的水分以束缚水和自由水两种形态存在。吸水过程中,弛豫时间在0.01 ms^1.00 ms区间内的小孔先吸束缚水,而后10 ms^100 ms区间内大孔吸自由水;脱水时先脱大孔中的自由水后脱小孔中的束缚水。随着水分运移循环次数的增加,未加固重塑土样内部孔隙分布发生明显变化,大孔比例减小,小孔比例增大;而加固重塑土样内部孔隙结构保持稳定。这表明TEOS对土遗址土壤团粒起固定化作用,避免了土壤团粒因受水分溶胀、干缩作用而导致自身孔隙结构发生重组。

FCC油浆精制前后焦化蜡油产物的组成和结构分析

运用GC-FID/MS和NMR从分子水平表征FCC油浆加氢精制前后焦化蜡油产物的详细组成和结构。对其中121种芳烃单体化合物进行分子识别,基本实现该焦化蜡油中多环芳烃、氢化多环芳烃、噻吩和咔唑以及这些化合物的烷基取代物的定量,并考察了油浆精制前后焦化蜡油的结构及其变化。结果表明,尽管FCC油浆加氢精制前后焦化蜡油产物的烃族组成相近,但化合物组成和结构有较大变化。FCC油浆精制后再焦化,蜡油产物中无取代母核多环芳烃加氢转化及缩合减少,烷基桥链的多芳核结构裂化减少,硫、氮杂原子芳香化合物被较多地脱除,C_1和C_2取代芳烃、单环芳烃以及环烷芳烃含量增加,说明加氢精制对FCC油浆延迟焦化过程有利,其焦化蜡油产物的组成和结构得到改善。

碱性阶段起始F/U配比对UF最终结构影响的^(13)C-NMR研究

采用两种工艺[如传统工艺(记为A工艺)、低起始n(甲醛或F)∶n(尿素或U)比例工艺(记为B工艺)]合成脲醛树脂(UF),并用定量13C-NMR(核磁共振碳谱)法跟踪检测UF的结构变化。研究结果表明:当碱性阶段起始n(F)∶n(U)≥2.0∶1.0时,A工艺合成的UF最终结构中亚甲基醚键含量比B工艺高11%。这是由于前者在碱性缩聚阶段中醚键生成占优势,而后者因亚甲基桥键生成参与竞争反应而使醚键含量下降,并且两者在该阶段醚键含量差异贯穿整个树脂的合成过程中。由于空间位阻效应,碱性阶段N,N′-二羟甲基脲间的反应主要生成醚键,而含游离氨基的一羟甲基脲自聚或与其他羟甲基化合物的缩聚可生成亚甲基桥键。

催化裂化柴油和焦化柴油中烯烃类型及分布表征

采用固相萃取(SPE)技术,应用自行开发的Ag-SiO2固定相,分离出催化裂化柴油和焦化柴油中的烯烃,并用GC/MS和1 H NMR表征烯烃的类型和碳数分布。结果表明:催化裂化柴油和焦化柴油中的烯烃类型主要包括正构α-烯烃、内单烯烃、双烯烃和环烯烃;催化裂化柴油烯烃中的内烯氢摩尔分数为80.41%,而焦化柴油中的正构α-烯氢摩尔分数为53.32%;催化裂化柴油中的烯烃碳数集中在11～15,焦化柴油中的烯烃碳数集中在12～22。

基于非目标~1H NMR指纹图谱技术验证中国葡萄酒原产地

为了探讨非目标指纹图谱技术验证中国葡萄酒原产地的可行性,采用一维核磁共振氢谱(1H NMR)技术,对沙城、昌黎和昌吉三大特色原产地葡萄酒的224个样品进行分析。结果表明,主成分分析(principal component analysis,PCA)结合线性判别分析(linear discriminant analysis,LDA)建立的留一交叉验证模型,实现对沙城、昌黎和昌吉葡萄酒原产地样品准确识别率为92%,73%和68%;为避免PCA/LDA模型出现过拟合现象,采用外部重复双随机交叉验证方法对PCA/LDA模型的有效性进行验证。葡萄酒1H NMR指纹图谱包含葡萄酒原产地特征信息,通过多变量统计分析可以构建非目标1H NMR指纹图谱的中国葡萄酒产地验证技术模型。

Separation of liquefied product of Salix psammophila by column chromatography and structure analysis of its components

The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography （TLC） and column chromatography, and its structure was identified by nuclear magnetic resonance （NMR） spectra in our study. The separation result indicates that the sample of liquefied S. psammophila contained at least two categories of components. The structure of the main components was guaiacyl C-1, C-2 of the hydroxyphenyl propane, i.e., the aromatic nucleus protons of lignin. Degradation and polycondensation reactions occurred when the S. psammophila wood was liquefied in phenol. Polycondensation reactions occurred among the depolymerization products from cellulose, the aromatic depolymerization products from lignin and the products of the displacement reactions between phenoxide ion and cellulose.

应用核磁T_2谱与数字岩心技术计算粒度分布方法

提出一种利用核磁T2谱结合数字岩心技术计算岩石粒度分布的方法。岩石粒度分布近似符合Weibull分布,改变分布参数可得到不同粒度分布。给出初始Weibull分布后采用过程法构建数字岩心,并用随机行走法对构建的数字岩心进行核磁数值模拟,遍历分布参数区间使模拟得到T2谱与试验T2谱逼近,误差最小时获得的Weibull分布即为岩石粒度分布。最后根据实际核磁测井资料对井下岩石粒度进行连续计算,粒度计算结果与实验室粒度分析结果对比良好,验证了方法准确性。

易误诊的原发性肥厚型心肌病

目的：为了避免临床误诊而导致错误治疗，本文总结了３例易误诊的原发性肥厚型心肌病的病例。方法：所有病人均进行了心肌酶、心电图、胸部Ｘ光和超声心动图检查。结果：三例病人均显示有心肌酶不同项目的升高，心电图示心肌梗塞，Ｘ线示心脏扩大，超声心动图则显示为肥厚型心肌病的声像图改变。结论：原发性肥厚型心肌病在心电图上常表见为ＳＴ—Ｔ改变，左室肥厚，或左室高电压和异常Ｑ波，并由此而误诊为心肌梗塞或心肌炎。超声心动图可进行正确诊断。核磁共振更能描述本病的形态学特征。

Pore structure formation and hydration characteristics of cement paste with temperature rising inhibitor

The early-age thermal cracking easily generates and severely impairs the durability of concrete.The temperature rising inhibitor(TRI)was utilized to regulate the temperature evolution by controlling the cement hydration process.This paper aimed to investigate the pore structure formation and hydration characteristics of cement paste containing TRI by low-field nuclear magnetic resonance.The experiment showed that the T_(2) peak of cement paste shifted from 7.32 ms to 0.23 ms regardless of TRI addition.But the pattern of pore structure formation was changed with TRI addition,that is,the pore structure formation was delayed,and the pore successively shifted to left in two parts.In addition,TRI addition significantly prolonged the duration of gel pore formation and greatly decreased the increase rate of gel water,which implied that TRI introduction hindered the growth of C-S-H,and subsequently decreased the hydration rates and delayed the main hydration peak.Meanwhile,TRI dissolved and diffused rapidly at 40℃,delaying the hydration of cement paste seriously.Moreover,TRI brought about the C-S-H nucleation homogeneous and the ion concentration uniform,which might reduce the localized curvature occurring on the sheet of C-S-H,and then decreased the T_(2) intensity of capillary water and gel water.

Effect of Content and Fineness of GGBS on Pore Structure of Cement Paste

The effect of the content and specific surface area of the ground granulated blast furnace slag (GGBS) on the pore structure of the cement paste was determined through the low-field nuclear magnetic resonance (NMR).The Pearson correlation analysis method was used to calculate the correlation coefficient between the porosity and age of cement paste,the specific surface area of GGBS and the content of GGBS.The test results exhibited that the porosity of the cement paste with different ageing durations gradually decreased on increasing the content and specific surface area of GGBS.The content and specific surface area of GGBS had a negligible effect on the 1-10 nm size gel pores in the cement paste,whereas,had a significant effect on the 10-100 nm size capillary pores.In addition,these parameters did not affect the final most probable pore size of the cement paste.The correlation between age and porosity was the largest,and the correlation between GGBS content and porosity was greater than that between GGBS specific surface area and porosity.Moreover,a modified pore structure model was successfully developed to effectively predict the pore structure of the GGBS based cement paste.

Low-field NMR micro coils based on printed circuit board technology

Radiofrequency coil is one of the most important components for a nuclear magnetic resonance(NMR)instrument.In this article,some planar micro coils with an inner diameter of 2 mm and number of turns that varied from 1 to 11 were investigated based on the printed circuit board(PCB)technology.The electrical characterization of micro coils show that self-resonant frequencies are larger than 200 MHz.Then,an NMR measurement platform with a static magnetic field of 0.66 T was constructed and the signal to noise ratio(SNR)values of the NMR were analyzed.It was found that the SNR is optimal when the turn number of the micro coils is six and the excitation time of a 90°pulse is 0.8?s.Finally,we used the micro coil with six turns to study the transverse relaxation rate of copper sulfate pentahydrate aqueous solution with different concentrations.It was found that the transverse relaxation rate is proportional to the solution concentration.Results from the micro coil were verified by measurements using a Bruker Minispec MQ60.