Who/what inspires you to the field of energy and nanomaterials?My Ph.D advisor Professor Charles Lieber has been a big inspiration to me since my graduate school study.I was later influenced quite a bit by my postdoct...Who/what inspires you to the field of energy and nanomaterials?My Ph.D advisor Professor Charles Lieber has been a big inspiration to me since my graduate school study.I was later influenced quite a bit by my postdoctoral mentor Professor Paul Alivisatos.By the end of my postdoctoral study in 2005,I was also influenced by Professor Steven Chu,who is a major figure to excite me to go into the energy area.I have many on‐going collaborations with Professor Chu.展开更多
Deconfined quantum critical points(DQCPs)have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns,beyond the conventional fram...Deconfined quantum critical points(DQCPs)have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns,beyond the conventional framework of Landau-Ginzburg-Wilson(LGW)theory.At the DQCP,the system exhibits emergent gauge fields,fractionalized excitations,and enhanced symmetries.展开更多
Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indiu...Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.展开更多
The composition and isotopic characteristics of coalbed methane(CBM), as well as the genesis of CH_(4)and CO_(2), associated geological process and migration-accumulation model of CBM in typical mid-to low-rank coal-b...The composition and isotopic characteristics of coalbed methane(CBM), as well as the genesis of CH_(4)and CO_(2), associated geological process and migration-accumulation model of CBM in typical mid-to low-rank coal-bearing basins were studied. The genesis of CBM is jointly influenced by the degree of coalification and biochemical processes, which in turn determine the composition and isotopic characteristics of CBM.Biogenic gas is extensively developed in mid-to low-rank coal-bearing basins, but its genesis varies. In the Baode area, China, and the San Juan Basin, USA, CBM is mainly secondary biogenic gas and thermogenic gas. In the Miquan area, China, CBM is characterized by primary biogenic gas. However, CBM in the Jiergalangtu area, China, Surat Basin, Australia, and Power River Basin, USA, are characterized by secondary biogenic gas. Microbial CO_(2)reduction occurs in these coal-bearing basins, but with significant gas generation by acetate fermentation in some areas of these basins. Moreover, CO_(2)in the Power River Basin, Surat Basin, and Jiergalangtu area mainly originates from microbial degradation of organic matter.However, in other basins studied, CO_(2)initially derives from coal pyrolysis and is subsequently supplemented by CO_(2)from microbial methanogenesis. The generation and isotope fractionation of CBM are affected and controlled by associated geological processes. Additionally, under the control of tectonic morphology and hydrogeological conditions, the genesis and migration-accumulation models of CBM in mid-to low-rank coal-bearing basins can be summarized into two models-the hydrodynamic active monoclinic model and the hydrodynamic differential syncline model-or a combination of the two.展开更多
Currently,regression prediction methods based on logging data is one of the main methods for analyzing gas content of coal seams.However,the complexity of logging parameters for deep coal seams and the scarcity of mea...Currently,regression prediction methods based on logging data is one of the main methods for analyzing gas content of coal seams.However,the complexity of logging parameters for deep coal seams and the scarcity of measured gas content data signifcantly afects the accuracy and generalizability of data regression models.Accurately predicting the gas content of coal seams under small-sample condition become a difcult point in deep coalbed methane(CBM)exploration.The ModelAgnostic Meta-Learning(MAML)and Support Vector Regression(SVR)algorithms are among the few suitable for smallsample learning,exhibiting strong adaptability under limited sample conditions.In this study,logging parameters are used as input variables to construct MAML and SVR models,and their performance in predicting gas content of deep coal seams across diferent regions and layers is compared.The results demonstrate that the MAML algorithm efectively addresses the complex relationships between gas content of deep coal seam and logging parameters.The prediction errors for test dataset and new samples are merely 3.61%and 4.52%respectively,indicating exceptional adaptability,robust generalization capability,and stable model performance.In contrast,the dependency of SVR model on input parameters restricts its accuracy and generalizability in predicting gas content in deep coal seams with varying geological conditions.Although achieving a test dataset error of 4.71%,the SVR model demonstrates substantially degraded performance when applied to novel samples,with prediction errors escalating to 12.46%.Therefore,the MAML model is selected to predict gas content in the unknown areas of the Baijiahai region.The prediction results reveal that the gas content of coal seams in the Xishanyao formation(J2x)ranges from 1.32 m^(3)/t to 16.11 m^(3)/t,while that in the Badaowan Formation(J1b)varies between 1.73 m^(3)/t and 11.27 m^(3)/t.Notably,the gas enrichment areas are predominantly distributed in well blocks adjacent to fault systems,such as wells C31 and BJ8,etc.,which align with the favorable geological conditions for deep CBM accumulation in the Baijiahai region.These spatial distribution patterns not only corroborate existing geological insights but also further validate the reliability of the MAML model in predicting gas content within deep coal seams.展开更多
AIM:To compare the efficacy of modified percutaneous transhepatic variceal embolization(PTVE)with 2-octyl-cyanoacrylate(2-OCA)and endoscopic variceal obturation(EVO)with an injection of 2-OCA for prophylaxis of gastri...AIM:To compare the efficacy of modified percutaneous transhepatic variceal embolization(PTVE)with 2-octyl-cyanoacrylate(2-OCA)and endoscopic variceal obturation(EVO)with an injection of 2-OCA for prophylaxis of gastric variceal rebleeding. METHODS:In this retrospective study,the medical records of liver cirrhosis patients with gastric variceal bleeding who underwent either endoscopic 2-OCA(EVO) or modified PTVE using 2-OCA at Shandong Provincial Hospital from January 2006 to December 2008 were reviewed.Patient demographics,rebleeding rate,survival rate,and complications were compared between the two groups(PTVE and EVO).All results were expressed as mean±SD,or as a percentage.Quantitative variables were compared by two sample Student t tests, and qualitative variables were compared by the Fisher exact test or theχ 2 test(with Yates correction)where appropriate.A P value less than 0.05 was considered significant.Statistical computation was performed using SPSS 13.0 software. RESULTS:A total of 77 patients were included;45 patients who underwent EVO and 32 patients who received PTVE.During the follow-up(19.78±7.70 mo in the EVO group,vs 21.53±8.56 mo in the PTVE group) rebleeding occurred in 17 patients in the EVO group and in 4 patients in the PTVE group(37.78%vs 12.5%, P=0.028).The cumulative rebleeding-free rate was 75%,59%,and 49%in 1,2,and 3 years respectively for EVO,and 93%,84%,and 84%for PTVE(P=0.011). Cox analysis was used to identify independent factors that predicted rebleeding after treatment.Variables including age,gender,cause,Child-Pugh classification, size of gastric varices(GV),location of GV,and treatment methods were analyzed.It was revealed that Child-Pugh classification[risk ratio(RR)2.10,95%CI:1.03-4.28,P=0.040],choice of treatment(RR 0.25, 95%CI:0.08-0.80,P=0.019),and size of GV(RR 2.14, 95%CI:1.07-4.28,P=0.032)were the independent factors for predicting rebleeding.Follow-up computed tomography revealed that cyanoacrylate was retained in the varices and in the feeding veins of PTVE patients. During the follow-up,eight patients in the EVO group and four patients in the PTVE group died.The cumulative survival rates at 1,2,and 3 years were 93%,84%, and 67%respectively in the EVO group,and 97%, 88%,and 74%respectively in the PTVE group.The survival rates were not significantly different between the two groups(P=0.432).Cox analysis showed that the Child-Pugh classification was the most significant prognostic factor of survival(RR 2.77,95%CI:1.12-6.80,P=0.027).The incidence of complications was similar in both groups. CONCLUSION:With extensive and permanent obliteration of gastric varices and its feeding veins,PTVE with 2-OCA is superior to endoscopic 2-OCA injection for preventing gastric variceal rebleeding.展开更多
Personal thermal management is emerging as a promising strategy to provide thermal comfort for the human body while conserving energy.By improving control over the heat dissipating from the human body,personal thermal...Personal thermal management is emerging as a promising strategy to provide thermal comfort for the human body while conserving energy.By improving control over the heat dissipating from the human body,personal thermal management can provide effective personal cooling and warming.Here,we propose a facile surface modification approach to tailor the thermal conduction and radiation properties based on commercially available fabrics,to realize better management of the whole heat transport pathway from the human body to the ambient.A bifunctional asymmetric fabric(BAF)offering both a cooling and a warming effect is demonstrated.Due to the advantages of roughness asymmetry and surface modification,the BAF demonstrates an effective cooling effect through enhanced heat conduction and radiation in the cooling mode;in the warming mode,heat dissipation along both routes is reduced for personal warming.As a result,a 4.6℃ skin temperature difference is measured between the cooling and warming BAF modes,indicating that the thermal comfort zone of the human body can be enlarged with one piece of BAF clothing.We expect this work to present new insights for the design of personal thermal management textiles as well as a novel solution for the facile modification of available fabrics for both personal cooling and warming.展开更多
AIM:To investigate the therapeutic effects of four strains of probiotics(E.feacalis,L.acidophilus,C.butyricum and B.adolescentis) on dextran sulphate sodium(DSS)-induced experimental colitis in Balb/c mice.METHODS:Eig...AIM:To investigate the therapeutic effects of four strains of probiotics(E.feacalis,L.acidophilus,C.butyricum and B.adolescentis) on dextran sulphate sodium(DSS)-induced experimental colitis in Balb/c mice.METHODS:Eighty Balb/c mice were randomly divided into 8 groups.Weight-loss,fecal character,fecal occult blood and hematochezia were recorded daily.Disease activity index(DAI) scores were also evaluated everyday.Length of colon was measured and histological scores were evaluated on the 13th day.Myeloperoxidase(MPO) activity was detected.Interleukin-1(IL-1) and IL-4 expression was detected by ELISA and RT-PCR.RESULTS:The four strains of probiotics relieved the inflammatory condition of DSS-induced experimental colitis in mice.Weight loss was slowed down in all probiotics-treated mice.Even weight gain was observed by the end of probiotics treatment.The DAI and histological scores of probiotics-treated mice were lower than those of mice in the control group(1.9 ± 0.2 vs 8.6 ± 0.4,P < 0.05 for E.faecalis).The length of colon of probiotics-treated mice was longer than that of mice in the control group(10.3 ± 0.34 vs 8.65 ± 0.77,P < 0.05 for E.faecalis).The four strains of probiotics decreased the MP activity and the IL-1 expression,but increased the IL-4 expression.E.faecalis had a better effect on DSS-induced experimental colitis in mice than the other three strains.CONCLUSION:The four strains of probiotics have beneficial effects on experimental colitis in mice.E.faecalis has a better effect on DSS-induced experimental colitis in mice than the other three strains.Supplement of probiotics provides a new therapy for UC.展开更多
Intraspinal inflammatory and immune responses are considered to play central roles in the pathological development of spinal cord injury.This study aimed to decipher the dynamics of systemic immune responses,initiated...Intraspinal inflammatory and immune responses are considered to play central roles in the pathological development of spinal cord injury.This study aimed to decipher the dynamics of systemic immune responses,initiated by spinal cord injury.The spinal cord in mice was completely transected at T8.Changes in the in vivo inflammatory response,between the acute and subacute stages,were observed.A rapid decrease in C-reactive protein levels,circulating leukocytes and lymphocytes,spleen-derived CD4~+interferon-γ+T-helper cells,and inflammatory cytokines,and a marked increase in neutrophils,monocytes,and CD4~+CD25~+FOXP3~+regulatory T-cells were observed during the acute phase.These systemic immune alterations were gradually restored to basal levels during the sub-acute phase.During the acute phase of spinal cord injury,systemic immune cells and factors showed significant inhibition;however,this inhibition was transient,and the indicators of these serious disorders gradually returned to baseline levels during the subacute phase.All experiments were performed in accordance with the institutional animal care guidelines,approved by the Institutional Animal Care and Use Committee of Experimental Animal Center of Drum Tower Hospital,China(approval No.2019 AE01040)on June 25,2019.展开更多
To obtain intrinsic overcharge boundary and investigate overcharge mechanism,here we propose an innovative method,the step overcharge test,to reduce the thermal crossover and distinguish the overcharge thermal behavio...To obtain intrinsic overcharge boundary and investigate overcharge mechanism,here we propose an innovative method,the step overcharge test,to reduce the thermal crossover and distinguish the overcharge thermal behavior,including 5%state of charge(SOC)with small current overcharge and resting until the temperature equilibrium under adiabatic conditions.The intrinsic thermal response and the self-excitation behaviour are analysed through temperature and voltage changes during the step overcharge period.Experimental results show that the deintercalated state of the cathode is highly correlated to self-heating parasitic reactions.Before reaching the upper limit of Negative/Positive(N/P)ratio,the temperature changes little,the heat generation is significantly induced by the reversible heat(endothermic)and ohmic heat,which could balance each other.Following that the lithium metal is gradually deposited on the surface of the anode and reacts with electrolyte upon overcharge,inducing selfheating side reaction.However,this spontaneous thermal reaction could be“self-extinguished”.When the lithium in cathode is completely deintercalated,the boundary point of overcharge is about 4.7 V(~148%SOC,>40℃),and from this point,the self-heating behaviour could be continuously triggered until thermal runaway(TR)without additional overcharge.The whole static and spontaneous process lasts for 115 h and the side reaction heat is beyond 320,000 J.The continuous self-excitation behavior inside the battery is attributed to the interaction between the highly oxidized cathode and the solvent,which leads to the dissolution of metal ions.The dissolved metal ions destroy the SEI(solid electrolyte interphase)film on the surface of the deposited Li of anode,which induces the thermal reaction between lithium metal and the solvent.The interaction between cathode,the deposited Li of anode,and solvent promotes the temperature of the battery to rise slowly.When the temperature of the battery reaches more than 60℃,the reaction between lithium metal and solvent is accelerated.After the temperature rises rapidly to the melting point of the separator,it triggers the thermal runaway of the battery due to the short circuit of the battery.展开更多
AIM： To analyze the microbiota shift in the dista esophagus of Sprague-Dawley rats fed a high-fat diet. METHODS： Twenty Sprague-Dawley rats were divided into high-fat diet and normal control groups of 10 rats each. ...AIM： To analyze the microbiota shift in the dista esophagus of Sprague-Dawley rats fed a high-fat diet. METHODS： Twenty Sprague-Dawley rats were divided into high-fat diet and normal control groups of 10 rats each. The composition of microbiota in the mucosa from the distal esophagus was analyzed based on se- lective culture. A variety of Lactobacillus species were identified by molecular biological techniques. Bacterial DNA from Lactobacillus colonies was extracted, and 165 rDNA was amplified by PCR using bacterial uni- versal primers. The amplified 16S rDNA products were separated by denaturing gradient gel electrophoresis （DGGE）. Every single band was purified from the gel and sent to be sequenced. RESULTS： Based on mucosal bacterial culturing in the distal esophagus, Staphylococcus aureus was absent, and total anaerobes and Lactobacillus species were de- creased significantly in the high-fat diet group compared with the normal control group （P 〈 0.01）. Detailed DGGE analysis on the composition of Lactobacillus species in the distal esophagus revealed that Lactobacillus crispa- tus, Lactobacillus gasseri （L. gasser/] and Lactobacillus reuteri （L. reuterl] comprised the Lactobacillus species in the high-fat diet group, while the composition of Lactobacillus species in the normal control group consisted of L. gasseri, Lactobacillus jensenii and L. reuteri. CONCLUSION： High-fat diet led to a mucosal micro- flora shift in the distal esophagus in rats, especially the composition of Lactobacillus species.展开更多
Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted...Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,respectively.However,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous research.Here,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic resonance.Our results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic minerals.Within the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay minerals.Owing to the octahedral sites of Mg-smectite bounded in Li,it is referred to be hectorite.We interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt tuffdissolution.This conclusion can be supported by the coexistence of spherulitic calcite and hectorite.Overall,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.展开更多
A new constant false alarm rate （CFAR） target detector for synthetic aperture radar （SAR） images is developed. For each pixel under test, both the local probability density function （PDF） of the pixel and the cl...A new constant false alarm rate （CFAR） target detector for synthetic aperture radar （SAR） images is developed. For each pixel under test, both the local probability density function （PDF） of the pixel and the clutter PDF in the reference window are estimated by the non-parametric density estimation. The target detector is defined as the mean square error （MSE） distance between the two PDFs. The CFAR detection in SAR images having multiplicative noise is achieved by adaptive kernel bandwidth proportional to the clutter level. In addition, for obtaining a threshold with respect to a given probability of false alarm （PFA）, an unsupervised null distribution fitting method with outlier rejection is proposed. The effectiveness of the proposed target detector is demonstrated by the experiment result using the RADATSAT-2 SAR image.展开更多
Flexible electrochemical power sources are attracting increasing attentions for their unique advantages like flexibility, shape diversity, light weight and excellent mechanical properties. In this research, we discove...Flexible electrochemical power sources are attracting increasing attentions for their unique advantages like flexibility, shape diversity, light weight and excellent mechanical properties. In this research, we discover that the current collector can dramatically affect the performance of flexible electrochemical power sources with large size. For flexible air-breathing proton exchange membrane fuel cell (PEMFC), the performance could have more than 8 times increase by only adjusting the directions of current collectors. The different performances of different current collection types are mainly attributed to the diverse lengths of the electron transfer pathways. In addition, the conductivity of current collector can dramatically affect the capability of flexible PEMFCs with large-size. The flexible PEMFCs with thicker carbon nanotube membrane as current collector (low electric resistance) show higher ability. A mathematic model is successfully built in this work to further understand the performance. Moreover, the model and simulation are also applicable to other flexible power sources, such as flexible Li-ion battery and supercapacitor.展开更多
Despite the recent discovery of superconductivity in Nd_(1-x)Sr_(x)NiO_(2) thin films,the absence of superconductivity and antiferromagnetism in their bulk materials remains a puzzle.Here we report the 1H NMR measurem...Despite the recent discovery of superconductivity in Nd_(1-x)Sr_(x)NiO_(2) thin films,the absence of superconductivity and antiferromagnetism in their bulk materials remains a puzzle.Here we report the 1H NMR measurements on powdered Nd0.85Sr0.15NiO2 samples by taking advantage of the enriched proton concentration after hydrogen annealing.We find a large full width at half maximum of the spectrum,which keeps increasing with decreasing the temperature T and exhibits an upturn behavior at low temperatures.The spin-lattice relaxation rate ^(1)T_(1)^(-1) is strongly enhanced when lowering the temperature,developing a broad peak at about 40 K,then decreases following a spin-wave-like behavior ^(1)T_(1)^(-1)∝T^(2) at lower temperatures.These results evidence a short-range glassy antiferromagnetic ordering of magnetic moments below 40 K and dominant antiferromagnetic fluctuations extending to much higher temperatures.Our findings reveal the strong electron correlations in bulk Nd_(0.85)Sr_(0.15)NiO_(2),and shed light on the mechanism of superconductivity observed in films of nickelates.展开更多
文摘Who/what inspires you to the field of energy and nanomaterials?My Ph.D advisor Professor Charles Lieber has been a big inspiration to me since my graduate school study.I was later influenced quite a bit by my postdoctoral mentor Professor Paul Alivisatos.By the end of my postdoctoral study in 2005,I was also influenced by Professor Steven Chu,who is a major figure to excite me to go into the energy area.I have many on‐going collaborations with Professor Chu.
基金supported by the National Natural Science Foundation of China(Grant Nos.12134020 and 12374156)the National Key Research and Development Program of China(Grant No.2023YFA1406500)。
文摘Deconfined quantum critical points(DQCPs)have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns,beyond the conventional framework of Landau-Ginzburg-Wilson(LGW)theory.At the DQCP,the system exhibits emergent gauge fields,fractionalized excitations,and enhanced symmetries.
基金supported by the Young Cross Team Project of CAS(No.JCTD-2021-14)the National Natural Science Foundation of China(51925206)Gusu Innovation and Entrepreneur Leading Talents(ZXL2022466)。
文摘Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.
基金supported by the National Natural Science Foundation of China(No.42272200)The Science and Technology Major Project of China National Petroleum Corporation(No.2023ZZ18-03)+1 种基金The Science and Technology Major Project of Changqing Oilfield(No.2023DZZ01)The Technology project of Huaneng Group Headquarters(Medium-deep Low-Rank Coalbed Methane Resource Potential Evaluation and Key Development Technologies of Zhalainuoer Coalfield,No.HNKJ23-H51).
文摘The composition and isotopic characteristics of coalbed methane(CBM), as well as the genesis of CH_(4)and CO_(2), associated geological process and migration-accumulation model of CBM in typical mid-to low-rank coal-bearing basins were studied. The genesis of CBM is jointly influenced by the degree of coalification and biochemical processes, which in turn determine the composition and isotopic characteristics of CBM.Biogenic gas is extensively developed in mid-to low-rank coal-bearing basins, but its genesis varies. In the Baode area, China, and the San Juan Basin, USA, CBM is mainly secondary biogenic gas and thermogenic gas. In the Miquan area, China, CBM is characterized by primary biogenic gas. However, CBM in the Jiergalangtu area, China, Surat Basin, Australia, and Power River Basin, USA, are characterized by secondary biogenic gas. Microbial CO_(2)reduction occurs in these coal-bearing basins, but with significant gas generation by acetate fermentation in some areas of these basins. Moreover, CO_(2)in the Power River Basin, Surat Basin, and Jiergalangtu area mainly originates from microbial degradation of organic matter.However, in other basins studied, CO_(2)initially derives from coal pyrolysis and is subsequently supplemented by CO_(2)from microbial methanogenesis. The generation and isotope fractionation of CBM are affected and controlled by associated geological processes. Additionally, under the control of tectonic morphology and hydrogeological conditions, the genesis and migration-accumulation models of CBM in mid-to low-rank coal-bearing basins can be summarized into two models-the hydrodynamic active monoclinic model and the hydrodynamic differential syncline model-or a combination of the two.
基金supported by the National Natural Science Foundation of China(42272200)The Science and Technology Major Project of China National Petroleum Corporation(2023ZZ18-03)+1 种基金The Science and Technology Major Project of Changqing Oilfeld(2023DZZ01)The Technology project of Huaneng Group Headquarters(Medium-deep Low-Rank Coalbed Methane Resource Potential Evaluation and Key Development Technologies of Zhalainuoer Coalfeld,HNKJ23-H51).
文摘Currently,regression prediction methods based on logging data is one of the main methods for analyzing gas content of coal seams.However,the complexity of logging parameters for deep coal seams and the scarcity of measured gas content data signifcantly afects the accuracy and generalizability of data regression models.Accurately predicting the gas content of coal seams under small-sample condition become a difcult point in deep coalbed methane(CBM)exploration.The ModelAgnostic Meta-Learning(MAML)and Support Vector Regression(SVR)algorithms are among the few suitable for smallsample learning,exhibiting strong adaptability under limited sample conditions.In this study,logging parameters are used as input variables to construct MAML and SVR models,and their performance in predicting gas content of deep coal seams across diferent regions and layers is compared.The results demonstrate that the MAML algorithm efectively addresses the complex relationships between gas content of deep coal seam and logging parameters.The prediction errors for test dataset and new samples are merely 3.61%and 4.52%respectively,indicating exceptional adaptability,robust generalization capability,and stable model performance.In contrast,the dependency of SVR model on input parameters restricts its accuracy and generalizability in predicting gas content in deep coal seams with varying geological conditions.Although achieving a test dataset error of 4.71%,the SVR model demonstrates substantially degraded performance when applied to novel samples,with prediction errors escalating to 12.46%.Therefore,the MAML model is selected to predict gas content in the unknown areas of the Baijiahai region.The prediction results reveal that the gas content of coal seams in the Xishanyao formation(J2x)ranges from 1.32 m^(3)/t to 16.11 m^(3)/t,while that in the Badaowan Formation(J1b)varies between 1.73 m^(3)/t and 11.27 m^(3)/t.Notably,the gas enrichment areas are predominantly distributed in well blocks adjacent to fault systems,such as wells C31 and BJ8,etc.,which align with the favorable geological conditions for deep CBM accumulation in the Baijiahai region.These spatial distribution patterns not only corroborate existing geological insights but also further validate the reliability of the MAML model in predicting gas content within deep coal seams.
文摘AIM:To compare the efficacy of modified percutaneous transhepatic variceal embolization(PTVE)with 2-octyl-cyanoacrylate(2-OCA)and endoscopic variceal obturation(EVO)with an injection of 2-OCA for prophylaxis of gastric variceal rebleeding. METHODS:In this retrospective study,the medical records of liver cirrhosis patients with gastric variceal bleeding who underwent either endoscopic 2-OCA(EVO) or modified PTVE using 2-OCA at Shandong Provincial Hospital from January 2006 to December 2008 were reviewed.Patient demographics,rebleeding rate,survival rate,and complications were compared between the two groups(PTVE and EVO).All results were expressed as mean±SD,or as a percentage.Quantitative variables were compared by two sample Student t tests, and qualitative variables were compared by the Fisher exact test or theχ 2 test(with Yates correction)where appropriate.A P value less than 0.05 was considered significant.Statistical computation was performed using SPSS 13.0 software. RESULTS:A total of 77 patients were included;45 patients who underwent EVO and 32 patients who received PTVE.During the follow-up(19.78±7.70 mo in the EVO group,vs 21.53±8.56 mo in the PTVE group) rebleeding occurred in 17 patients in the EVO group and in 4 patients in the PTVE group(37.78%vs 12.5%, P=0.028).The cumulative rebleeding-free rate was 75%,59%,and 49%in 1,2,and 3 years respectively for EVO,and 93%,84%,and 84%for PTVE(P=0.011). Cox analysis was used to identify independent factors that predicted rebleeding after treatment.Variables including age,gender,cause,Child-Pugh classification, size of gastric varices(GV),location of GV,and treatment methods were analyzed.It was revealed that Child-Pugh classification[risk ratio(RR)2.10,95%CI:1.03-4.28,P=0.040],choice of treatment(RR 0.25, 95%CI:0.08-0.80,P=0.019),and size of GV(RR 2.14, 95%CI:1.07-4.28,P=0.032)were the independent factors for predicting rebleeding.Follow-up computed tomography revealed that cyanoacrylate was retained in the varices and in the feeding veins of PTVE patients. During the follow-up,eight patients in the EVO group and four patients in the PTVE group died.The cumulative survival rates at 1,2,and 3 years were 93%,84%, and 67%respectively in the EVO group,and 97%, 88%,and 74%respectively in the PTVE group.The survival rates were not significantly different between the two groups(P=0.432).Cox analysis showed that the Child-Pugh classification was the most significant prognostic factor of survival(RR 2.77,95%CI:1.12-6.80,P=0.027).The incidence of complications was similar in both groups. CONCLUSION:With extensive and permanent obliteration of gastric varices and its feeding veins,PTVE with 2-OCA is superior to endoscopic 2-OCA injection for preventing gastric variceal rebleeding.
文摘Personal thermal management is emerging as a promising strategy to provide thermal comfort for the human body while conserving energy.By improving control over the heat dissipating from the human body,personal thermal management can provide effective personal cooling and warming.Here,we propose a facile surface modification approach to tailor the thermal conduction and radiation properties based on commercially available fabrics,to realize better management of the whole heat transport pathway from the human body to the ambient.A bifunctional asymmetric fabric(BAF)offering both a cooling and a warming effect is demonstrated.Due to the advantages of roughness asymmetry and surface modification,the BAF demonstrates an effective cooling effect through enhanced heat conduction and radiation in the cooling mode;in the warming mode,heat dissipation along both routes is reduced for personal warming.As a result,a 4.6℃ skin temperature difference is measured between the cooling and warming BAF modes,indicating that the thermal comfort zone of the human body can be enlarged with one piece of BAF clothing.We expect this work to present new insights for the design of personal thermal management textiles as well as a novel solution for the facile modification of available fabrics for both personal cooling and warming.
文摘AIM:To investigate the therapeutic effects of four strains of probiotics(E.feacalis,L.acidophilus,C.butyricum and B.adolescentis) on dextran sulphate sodium(DSS)-induced experimental colitis in Balb/c mice.METHODS:Eighty Balb/c mice were randomly divided into 8 groups.Weight-loss,fecal character,fecal occult blood and hematochezia were recorded daily.Disease activity index(DAI) scores were also evaluated everyday.Length of colon was measured and histological scores were evaluated on the 13th day.Myeloperoxidase(MPO) activity was detected.Interleukin-1(IL-1) and IL-4 expression was detected by ELISA and RT-PCR.RESULTS:The four strains of probiotics relieved the inflammatory condition of DSS-induced experimental colitis in mice.Weight loss was slowed down in all probiotics-treated mice.Even weight gain was observed by the end of probiotics treatment.The DAI and histological scores of probiotics-treated mice were lower than those of mice in the control group(1.9 ± 0.2 vs 8.6 ± 0.4,P < 0.05 for E.faecalis).The length of colon of probiotics-treated mice was longer than that of mice in the control group(10.3 ± 0.34 vs 8.65 ± 0.77,P < 0.05 for E.faecalis).The four strains of probiotics decreased the MP activity and the IL-1 expression,but increased the IL-4 expression.E.faecalis had a better effect on DSS-induced experimental colitis in mice than the other three strains.CONCLUSION:The four strains of probiotics have beneficial effects on experimental colitis in mice.E.faecalis has a better effect on DSS-induced experimental colitis in mice than the other three strains.Supplement of probiotics provides a new therapy for UC.
基金the National Natural Science Foundation of China,Nos.81571213(to BW),81800583(to YYX),81601539(to DM)and 81601084(to YC)+3 种基金the National Key Research and Development Program of China,No.2017YFA0104304(to BW)the Nanjing Medical Science and Technique Development Foundation of China,Nos.QRX17006(to BW),QRX17057(to DM)the Key Project Medical Science and Technology Development Foundation,Nanjing Department of Health and the Nanjing Medical Science of China,No.201803024(to TYG)Innovation Platform,No.ZDX16005(to BW)。
文摘Intraspinal inflammatory and immune responses are considered to play central roles in the pathological development of spinal cord injury.This study aimed to decipher the dynamics of systemic immune responses,initiated by spinal cord injury.The spinal cord in mice was completely transected at T8.Changes in the in vivo inflammatory response,between the acute and subacute stages,were observed.A rapid decrease in C-reactive protein levels,circulating leukocytes and lymphocytes,spleen-derived CD4~+interferon-γ+T-helper cells,and inflammatory cytokines,and a marked increase in neutrophils,monocytes,and CD4~+CD25~+FOXP3~+regulatory T-cells were observed during the acute phase.These systemic immune alterations were gradually restored to basal levels during the sub-acute phase.During the acute phase of spinal cord injury,systemic immune cells and factors showed significant inhibition;however,this inhibition was transient,and the indicators of these serious disorders gradually returned to baseline levels during the subacute phase.All experiments were performed in accordance with the institutional animal care guidelines,approved by the Institutional Animal Care and Use Committee of Experimental Animal Center of Drum Tower Hospital,China(approval No.2019 AE01040)on June 25,2019.
基金funded by the National Key Research and Development Program of China(2018YFB0104400)supported by the Beijing Natural Science Foundation(2214066)。
文摘To obtain intrinsic overcharge boundary and investigate overcharge mechanism,here we propose an innovative method,the step overcharge test,to reduce the thermal crossover and distinguish the overcharge thermal behavior,including 5%state of charge(SOC)with small current overcharge and resting until the temperature equilibrium under adiabatic conditions.The intrinsic thermal response and the self-excitation behaviour are analysed through temperature and voltage changes during the step overcharge period.Experimental results show that the deintercalated state of the cathode is highly correlated to self-heating parasitic reactions.Before reaching the upper limit of Negative/Positive(N/P)ratio,the temperature changes little,the heat generation is significantly induced by the reversible heat(endothermic)and ohmic heat,which could balance each other.Following that the lithium metal is gradually deposited on the surface of the anode and reacts with electrolyte upon overcharge,inducing selfheating side reaction.However,this spontaneous thermal reaction could be“self-extinguished”.When the lithium in cathode is completely deintercalated,the boundary point of overcharge is about 4.7 V(~148%SOC,>40℃),and from this point,the self-heating behaviour could be continuously triggered until thermal runaway(TR)without additional overcharge.The whole static and spontaneous process lasts for 115 h and the side reaction heat is beyond 320,000 J.The continuous self-excitation behavior inside the battery is attributed to the interaction between the highly oxidized cathode and the solvent,which leads to the dissolution of metal ions.The dissolved metal ions destroy the SEI(solid electrolyte interphase)film on the surface of the deposited Li of anode,which induces the thermal reaction between lithium metal and the solvent.The interaction between cathode,the deposited Li of anode,and solvent promotes the temperature of the battery to rise slowly.When the temperature of the battery reaches more than 60℃,the reaction between lithium metal and solvent is accelerated.After the temperature rises rapidly to the melting point of the separator,it triggers the thermal runaway of the battery due to the short circuit of the battery.
文摘AIM： To analyze the microbiota shift in the dista esophagus of Sprague-Dawley rats fed a high-fat diet. METHODS： Twenty Sprague-Dawley rats were divided into high-fat diet and normal control groups of 10 rats each. The composition of microbiota in the mucosa from the distal esophagus was analyzed based on se- lective culture. A variety of Lactobacillus species were identified by molecular biological techniques. Bacterial DNA from Lactobacillus colonies was extracted, and 165 rDNA was amplified by PCR using bacterial uni- versal primers. The amplified 16S rDNA products were separated by denaturing gradient gel electrophoresis （DGGE）. Every single band was purified from the gel and sent to be sequenced. RESULTS： Based on mucosal bacterial culturing in the distal esophagus, Staphylococcus aureus was absent, and total anaerobes and Lactobacillus species were de- creased significantly in the high-fat diet group compared with the normal control group （P 〈 0.01）. Detailed DGGE analysis on the composition of Lactobacillus species in the distal esophagus revealed that Lactobacillus crispa- tus, Lactobacillus gasseri （L. gasser/] and Lactobacillus reuteri （L. reuterl] comprised the Lactobacillus species in the high-fat diet group, while the composition of Lactobacillus species in the normal control group consisted of L. gasseri, Lactobacillus jensenii and L. reuteri. CONCLUSION： High-fat diet led to a mucosal micro- flora shift in the distal esophagus in rats, especially the composition of Lactobacillus species.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.92162214,41773015,and U1812402)the Key Research and Development Program of Yunnan Province(202103AQ100003).
文摘Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,respectively.However,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous research.Here,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic resonance.Our results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic minerals.Within the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay minerals.Owing to the octahedral sites of Mg-smectite bounded in Li,it is referred to be hectorite.We interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt tuffdissolution.This conclusion can be supported by the coexistence of spherulitic calcite and hectorite.Overall,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.
基金supported by the National Natural Science Foundation of China (40871157 41171317)the Foundation of Advance Research of Science and Technology for Chinese National Defence(9140C620201902)
文摘A new constant false alarm rate （CFAR） target detector for synthetic aperture radar （SAR） images is developed. For each pixel under test, both the local probability density function （PDF） of the pixel and the clutter PDF in the reference window are estimated by the non-parametric density estimation. The target detector is defined as the mean square error （MSE） distance between the two PDFs. The CFAR detection in SAR images having multiplicative noise is achieved by adaptive kernel bandwidth proportional to the clutter level. In addition, for obtaining a threshold with respect to a given probability of false alarm （PFA）, an unsupervised null distribution fitting method with outlier rejection is proposed. The effectiveness of the proposed target detector is demonstrated by the experiment result using the RADATSAT-2 SAR image.
基金financial support granted by Ministry of Science and Technology of China(Nos. 2016YFE0105700, 2016YFA0200700)the National Natural Science Foundation of China (Nos. 21373264, 21573275)+2 种基金China Postdoctoral Science Foundation(No. 2018M632406)the Science and Technology Project of Nanchang(No. 2017-SJSYS-008)the Collaborative Innovation Center of Suzhou Nano Science and Technology
文摘Flexible electrochemical power sources are attracting increasing attentions for their unique advantages like flexibility, shape diversity, light weight and excellent mechanical properties. In this research, we discover that the current collector can dramatically affect the performance of flexible electrochemical power sources with large size. For flexible air-breathing proton exchange membrane fuel cell (PEMFC), the performance could have more than 8 times increase by only adjusting the directions of current collectors. The different performances of different current collection types are mainly attributed to the diverse lengths of the electron transfer pathways. In addition, the conductivity of current collector can dramatically affect the capability of flexible PEMFCs with large-size. The flexible PEMFCs with thicker carbon nanotube membrane as current collector (low electric resistance) show higher ability. A mathematic model is successfully built in this work to further understand the performance. Moreover, the model and simulation are also applicable to other flexible power sources, such as flexible Li-ion battery and supercapacitor.
基金Supported by the National Natural Science Foundation of China(Grant Nos.51872328,11674392,11774401,and A0402/11927809)the National Key R&D Program of China(Grant Nos.2016YFA0300504 and 2016YFA0300401)+2 种基金China Postdoctoral Science Foundation(Grant No.2020M680797)the Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China(Grant Nos.18XNLG24,20XNLG19,and 21XNLG18)。
文摘Despite the recent discovery of superconductivity in Nd_(1-x)Sr_(x)NiO_(2) thin films,the absence of superconductivity and antiferromagnetism in their bulk materials remains a puzzle.Here we report the 1H NMR measurements on powdered Nd0.85Sr0.15NiO2 samples by taking advantage of the enriched proton concentration after hydrogen annealing.We find a large full width at half maximum of the spectrum,which keeps increasing with decreasing the temperature T and exhibits an upturn behavior at low temperatures.The spin-lattice relaxation rate ^(1)T_(1)^(-1) is strongly enhanced when lowering the temperature,developing a broad peak at about 40 K,then decreases following a spin-wave-like behavior ^(1)T_(1)^(-1)∝T^(2) at lower temperatures.These results evidence a short-range glassy antiferromagnetic ordering of magnetic moments below 40 K and dominant antiferromagnetic fluctuations extending to much higher temperatures.Our findings reveal the strong electron correlations in bulk Nd_(0.85)Sr_(0.15)NiO_(2),and shed light on the mechanism of superconductivity observed in films of nickelates.
