BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly aff...BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly affect the patient’s exercise habits and lifestyle.X-ray,computed tomography(CT)and magnetic resonance imaging(MRI)were used in this examination.X-rays are relatively new and easy to operate.However,there are some errors in the observation of fracture collapse and fracture displacement.In recent years,CT and MRI have been actively used to diagnose various types of clinical fractures.They have more diagnostic power than X-ray film.However,some scholars believe that CT is also prone to errors in clinical application.The volume effect leads to missed diagnosis and misdiagnosis in some cases,while the multidirection scanning of MRI technology can effectively overcome the shortcomings of CT.To facilitate the selection of clinical examination regimens,this study further observed the diagnostic ability of these two regimens in the diagnosis of tibial plateau fractures.AIM To explore the value of nuclear MRI and CT in the clinical diagnosis of tibial plateau fractures.METHODS A total of 120 patients with tibial plateau fractures admitted from September 2017 to August 2019 were included.All patients were examined by nuclear MRI and CT scanning.The results were sent to senior physicians in our hospital to complete the diagnosis.RESULTS Nuclear magnetic resonance showed the same effects as CT in four aspects:fracture displacement,bone defect,fracture site and fracture comminution.There was no significant difference in the score data(P>0.05).Nuclear magnetic resonance and CT tended to be consistent in the B3,C2 and C3 fracture diagnosis coincidence rate,combined injury detection rate and fracture detection rate.The diagnostic coincidence rate of type B1,B2 and C1 fractures and the accuracy rate of overall fracture classification indicated that the MRI technique was significantly better than that of CT(P>0.05).CONCLUSION MRI and CT have good diagnostic typing in the diagnosis of tibial plateau fractures,but MRI is more accurate and may be preferred.展开更多
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 re...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.展开更多
Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its goo...Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.展开更多
我国煤层普遍具有低透气性、高瓦斯含量的特性,在低透气性煤层增透方面,煤层注水、水力压裂、水力割缝等水力化技术得到了广泛应用,并取得了良好的瓦斯治理效果。然而水作为外侵液进入煤体,堵塞了瓦斯流动通道,降低了瓦斯解吸量,产生了...我国煤层普遍具有低透气性、高瓦斯含量的特性,在低透气性煤层增透方面,煤层注水、水力压裂、水力割缝等水力化技术得到了广泛应用,并取得了良好的瓦斯治理效果。然而水作为外侵液进入煤体,堵塞了瓦斯流动通道,降低了瓦斯解吸量,产生了水锁效应。为分析水力化技术造成水锁效应的内在机理,利用压汞实验分析了煤样孔容分布规律,以及利用扫描电镜分析了原始、饱水、饱CMC溶液煤样的微观结构,基于低场核磁共振技术研究了煤样在饱水状态以及饱CMC溶液状态下的液相滞留效应,并根据曲线相似度法分析了孔径与束缚流体饱和度的相似度。研究结果表明:CMC溶液可以溶解煤中的矿物质增加煤孔隙裂隙以及降低水在煤体表面的表面张力,从而达到解除水锁效应的目的;随着煤变质程度的增大,T 2截止值在逐渐减小,T 2截止值的数值与煤样孔径大小呈负相关;煤样的束缚流体饱和度远大于自由流体饱和度,煤样在饱水状态下的束缚流体饱和度比饱CMC溶液状态下高;高变质程度的煤大孔孔容少、微孔孔容多,使得水在煤孔隙中的毛细管力大,最终造成高阶煤的水锁效应严重;大孔孔容是影响束缚流体饱和度的主控因素,微孔起到正向促进作用,得到束缚流体饱和度S与大孔孔容V A、微孔孔容V D的耦合关系式:S=94.86-1078.96 V A+261.24 V D。滞留在煤体内的束缚水阻塞了瓦斯流动通道,是造成水锁效应的根本原因,增加煤层的孔隙裂隙以及选用合适的表面活性是减缓煤层水锁效应的有效措施。展开更多
文摘BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly affect the patient’s exercise habits and lifestyle.X-ray,computed tomography(CT)and magnetic resonance imaging(MRI)were used in this examination.X-rays are relatively new and easy to operate.However,there are some errors in the observation of fracture collapse and fracture displacement.In recent years,CT and MRI have been actively used to diagnose various types of clinical fractures.They have more diagnostic power than X-ray film.However,some scholars believe that CT is also prone to errors in clinical application.The volume effect leads to missed diagnosis and misdiagnosis in some cases,while the multidirection scanning of MRI technology can effectively overcome the shortcomings of CT.To facilitate the selection of clinical examination regimens,this study further observed the diagnostic ability of these two regimens in the diagnosis of tibial plateau fractures.AIM To explore the value of nuclear MRI and CT in the clinical diagnosis of tibial plateau fractures.METHODS A total of 120 patients with tibial plateau fractures admitted from September 2017 to August 2019 were included.All patients were examined by nuclear MRI and CT scanning.The results were sent to senior physicians in our hospital to complete the diagnosis.RESULTS Nuclear magnetic resonance showed the same effects as CT in four aspects:fracture displacement,bone defect,fracture site and fracture comminution.There was no significant difference in the score data(P>0.05).Nuclear magnetic resonance and CT tended to be consistent in the B3,C2 and C3 fracture diagnosis coincidence rate,combined injury detection rate and fracture detection rate.The diagnostic coincidence rate of type B1,B2 and C1 fractures and the accuracy rate of overall fracture classification indicated that the MRI technique was significantly better than that of CT(P>0.05).CONCLUSION MRI and CT have good diagnostic typing in the diagnosis of tibial plateau fractures,but MRI is more accurate and may be preferred.
基金This project was supported by National Natural Science Foundation of China(Grant Nos.31701318 and 31601216)National Natural Science Foundation of China Projects of International Cooperation and Exchanges(Grant No.31811540396)+1 种基金National Key Research and Development Program of China(Grant No.2017YFD0701205)Doctoral Research Fund of Liaoning Province,China(Grant No.20170520202).
文摘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.
基金supported by the National Natural Science Foundation of China(No.21974007).
文摘Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.
文摘我国煤层普遍具有低透气性、高瓦斯含量的特性,在低透气性煤层增透方面,煤层注水、水力压裂、水力割缝等水力化技术得到了广泛应用,并取得了良好的瓦斯治理效果。然而水作为外侵液进入煤体,堵塞了瓦斯流动通道,降低了瓦斯解吸量,产生了水锁效应。为分析水力化技术造成水锁效应的内在机理,利用压汞实验分析了煤样孔容分布规律,以及利用扫描电镜分析了原始、饱水、饱CMC溶液煤样的微观结构,基于低场核磁共振技术研究了煤样在饱水状态以及饱CMC溶液状态下的液相滞留效应,并根据曲线相似度法分析了孔径与束缚流体饱和度的相似度。研究结果表明:CMC溶液可以溶解煤中的矿物质增加煤孔隙裂隙以及降低水在煤体表面的表面张力,从而达到解除水锁效应的目的;随着煤变质程度的增大,T 2截止值在逐渐减小,T 2截止值的数值与煤样孔径大小呈负相关;煤样的束缚流体饱和度远大于自由流体饱和度,煤样在饱水状态下的束缚流体饱和度比饱CMC溶液状态下高;高变质程度的煤大孔孔容少、微孔孔容多,使得水在煤孔隙中的毛细管力大,最终造成高阶煤的水锁效应严重;大孔孔容是影响束缚流体饱和度的主控因素,微孔起到正向促进作用,得到束缚流体饱和度S与大孔孔容V A、微孔孔容V D的耦合关系式:S=94.86-1078.96 V A+261.24 V D。滞留在煤体内的束缚水阻塞了瓦斯流动通道,是造成水锁效应的根本原因,增加煤层的孔隙裂隙以及选用合适的表面活性是减缓煤层水锁效应的有效措施。
