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
This study investigated the effects of periodic high-frequency stress disturbances on the creep behavior of sandstone and analyzed the microstructural changes using nuclear magnetic resonance(NMR)technology.High-frequ...This study investigated the effects of periodic high-frequency stress disturbances on the creep behavior of sandstone and analyzed the microstructural changes using nuclear magnetic resonance(NMR)technology.High-frequency disturbance creep experiments were conducted on sandstone under different disturbance frequencies,disturbance cycles and loading stresses,and the following findings were obtained.Firstly,with the increase of loading stress and disturbance cycles,the total porosity increments,and damage value of sandstone increase,while the fractal dimension of sandstone pore structure presents the opposite trend.Secondly,during the disturbance creep process,the volumes of all three types of pores increase,but the proportion of micropores(T_(2)<10 ms)decreases,while the proportion of mesopores(10 ms<T_(2)<100 ms)and macropores(T_(2)>100 ms)increases.Thirdly,the fractal dimension difference has a good linear relationship with the damage,strain and porosity increment of sandstone during the disturbance creep process.Finally,the higher the disturbance frequency,the smaller the creep strain and creep strain rate during the steady-state creep stage.The study offers valuable theoretical insights for understanding rock creep behavior in complex stress environments.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
With the energy problem becoming increasingly severe,industrial energy efficiency issues need to be solved urgently.The tube and shell heat exchanger,as the most widely used device for energy recovery and utilisation,...With the energy problem becoming increasingly severe,industrial energy efficiency issues need to be solved urgently.The tube and shell heat exchanger,as the most widely used device for energy recovery and utilisation,its optimal design has become a significantly important research topic.Optimal design solves the tediousness of traditional design and can easily and accurately give the desired design results.Several industrial heat duty targets and pressure drop limitations for the design of shell-and-tube heat exchangers,such as high heat transfer efficiency,large temperature correction coefficient,and high capacity,cannot be met by single-shell units and require series or parallel arrangements.This paper uses Set Trimming to optimize the design of double shell and tube heat exchangers,assuming the possibility of series,parallel,or series-parallel arrangements.Minimum heat transfer area and minimum total annualized cost are used as objective functions to optimize the design of a single or double-shell heat exchanger that better meets the objectives.展开更多
电解水技术是一种生产高纯氢燃料的方法,能够增强可再生能源发电系统的消纳能力.相较于质子交换膜(PEM)电解槽,碱性(ALK)电解槽可以使用非贵金属基催化电极,拥有更高的经济效益和市场占有率.然而,由于ALK电解槽处于质子稀缺环境,阴极氢...电解水技术是一种生产高纯氢燃料的方法,能够增强可再生能源发电系统的消纳能力.相较于质子交换膜(PEM)电解槽,碱性(ALK)电解槽可以使用非贵金属基催化电极,拥有更高的经济效益和市场占有率.然而,由于ALK电解槽处于质子稀缺环境,阴极氢气演化反应(HER)动力学变得更加复杂,需要快速解离水分子提供动态质子微环境.硫化钼(MoS_(2))纳米片边缘具有合适的质子吸附和演化的活性位点,是制备HER催化剂的潜力材料.但其二维基面原子由于配位饱和,显示出较弱的质子吸附能力.如何调控MoS_(2)基面以实现水解动力与质子吸附演化动力的集成,提升MoS_(2)纳米片的碱性HER活性,具有重要的科学和应用意义.本文提出了一种Co/O双原子植入策略,精准调控双活性位点及其电子结构,实现了水解离动力和质子吸附演化动力的高效耦联.首先,利用刻蚀和电沉积的两步实验法,在MoS_(2)基面上成功引入O和Co原子;随后,结合高分辨透射电镜、高角环形暗场-扫描透射电子显微镜、同步辐射X射线吸收精细结构谱等表征分析技术,精准识别了掺杂Co/O原子的位置和配位情况:O原子替换部分S原子,Co原子占据Mo原子的上方,构建出立体凸起的“O-Co-S_(2)”配位构型.催化在线的原位表征分析结果表明:该独特的“O-Co-S_(2)”原子基序发挥着水解离与氢演化反应协同催化效应.密度泛函理论计算结果也证实了该协同机制,其中Co位点促进水的解离反应,而S位点则有助于质子的转化生成氢气.因此,Co/O掺杂MoS_(2)催化剂(Co-O@MoS_(2))表现出较好的碱性HER活性:仅需81 mV的过电位,即可达到100 mA cm^(‒2)的电流密度,Tafel斜率低至42 mV dec^(‒1),在600 mA cm^(‒2)的高电流密度测试中运行300 h活性无衰减.上述碱性HER性能不仅远高于原始的MoS_(2)纳米片,而且也领先于部分已报道结果.综上所述,本文在MoS_(2)基面上构筑了原子级协同催化活性中心,显著促进了碱性HER反应性能,为原子活化工程开发先进催化剂提供参考,在原子级基序构造、表征和功能分析方面提供借鉴.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
AIM:To study the clinicopathological features of gastric glomus tumor and review the related Chinese literature published in 1990-2010.METHODS:A case of gastric glomus tumor was re-ported.Clinicopathological findings ...AIM:To study the clinicopathological features of gastric glomus tumor and review the related Chinese literature published in 1990-2010.METHODS:A case of gastric glomus tumor was re-ported.Clinicopathological findings in 56 cases of gastric glomus tumor were analyzed.RESULTS:Gastric glomus tumor was far more common in women than in men with a female to male ratio of 1.6:1.The median age of the patients was 45 years(range 28-79 years).The patients often complained of epigastric pain and bloody stool.The tumor was located in antrum of the stomach.The greatest diameter of the tumor was 0.8-11cm.Histologically,the tumor was comprised of nests of glomus cells surrounding the capillaries.Glomus cells were small,uniform and round.Vimentin,smooth muscle actin and actin were expressed in the tumor.Other markers,including S-100 protein,CD34,CD117,desmin,CD56,synaptophysin,chromo-granin A,neuron specific enolase and cytokeratin were all negative.CONCLUSION:Gastric glomus tumor is a rare benign mesenchymal neoplasm.Its diagnosis depends on pathologic examination.Differential diagnosis includes gastrointestinal stromal tumor,paraganglioma and carcinoid tumor.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
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 National Natural Science Foundation of China(Grant No.52404074)the National Key Research and Development Program(Fund for Young Scientists)(Grant No.2021YFC2900400)Postdoctoral Science Foundation of China(Grant No.2024M761706).
文摘This study investigated the effects of periodic high-frequency stress disturbances on the creep behavior of sandstone and analyzed the microstructural changes using nuclear magnetic resonance(NMR)technology.High-frequency disturbance creep experiments were conducted on sandstone under different disturbance frequencies,disturbance cycles and loading stresses,and the following findings were obtained.Firstly,with the increase of loading stress and disturbance cycles,the total porosity increments,and damage value of sandstone increase,while the fractal dimension of sandstone pore structure presents the opposite trend.Secondly,during the disturbance creep process,the volumes of all three types of pores increase,but the proportion of micropores(T_(2)<10 ms)decreases,while the proportion of mesopores(10 ms<T_(2)<100 ms)and macropores(T_(2)>100 ms)increases.Thirdly,the fractal dimension difference has a good linear relationship with the damage,strain and porosity increment of sandstone during the disturbance creep process.Finally,the higher the disturbance frequency,the smaller the creep strain and creep strain rate during the steady-state creep stage.The study offers valuable theoretical insights for understanding rock creep behavior in complex stress environments.
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.
基金Financial support from the National Natural Science Foundation of China under Grant(22393954)is gratefully acknowledged。
文摘With the energy problem becoming increasingly severe,industrial energy efficiency issues need to be solved urgently.The tube and shell heat exchanger,as the most widely used device for energy recovery and utilisation,its optimal design has become a significantly important research topic.Optimal design solves the tediousness of traditional design and can easily and accurately give the desired design results.Several industrial heat duty targets and pressure drop limitations for the design of shell-and-tube heat exchangers,such as high heat transfer efficiency,large temperature correction coefficient,and high capacity,cannot be met by single-shell units and require series or parallel arrangements.This paper uses Set Trimming to optimize the design of double shell and tube heat exchangers,assuming the possibility of series,parallel,or series-parallel arrangements.Minimum heat transfer area and minimum total annualized cost are used as objective functions to optimize the design of a single or double-shell heat exchanger that better meets the objectives.
文摘电解水技术是一种生产高纯氢燃料的方法,能够增强可再生能源发电系统的消纳能力.相较于质子交换膜(PEM)电解槽,碱性(ALK)电解槽可以使用非贵金属基催化电极,拥有更高的经济效益和市场占有率.然而,由于ALK电解槽处于质子稀缺环境,阴极氢气演化反应(HER)动力学变得更加复杂,需要快速解离水分子提供动态质子微环境.硫化钼(MoS_(2))纳米片边缘具有合适的质子吸附和演化的活性位点,是制备HER催化剂的潜力材料.但其二维基面原子由于配位饱和,显示出较弱的质子吸附能力.如何调控MoS_(2)基面以实现水解动力与质子吸附演化动力的集成,提升MoS_(2)纳米片的碱性HER活性,具有重要的科学和应用意义.本文提出了一种Co/O双原子植入策略,精准调控双活性位点及其电子结构,实现了水解离动力和质子吸附演化动力的高效耦联.首先,利用刻蚀和电沉积的两步实验法,在MoS_(2)基面上成功引入O和Co原子;随后,结合高分辨透射电镜、高角环形暗场-扫描透射电子显微镜、同步辐射X射线吸收精细结构谱等表征分析技术,精准识别了掺杂Co/O原子的位置和配位情况:O原子替换部分S原子,Co原子占据Mo原子的上方,构建出立体凸起的“O-Co-S_(2)”配位构型.催化在线的原位表征分析结果表明:该独特的“O-Co-S_(2)”原子基序发挥着水解离与氢演化反应协同催化效应.密度泛函理论计算结果也证实了该协同机制,其中Co位点促进水的解离反应,而S位点则有助于质子的转化生成氢气.因此,Co/O掺杂MoS_(2)催化剂(Co-O@MoS_(2))表现出较好的碱性HER活性:仅需81 mV的过电位,即可达到100 mA cm^(‒2)的电流密度,Tafel斜率低至42 mV dec^(‒1),在600 mA cm^(‒2)的高电流密度测试中运行300 h活性无衰减.上述碱性HER性能不仅远高于原始的MoS_(2)纳米片,而且也领先于部分已报道结果.综上所述,本文在MoS_(2)基面上构筑了原子级协同催化活性中心,显著促进了碱性HER反应性能,为原子活化工程开发先进催化剂提供参考,在原子级基序构造、表征和功能分析方面提供借鉴.
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AIM:To study the clinicopathological features of gastric glomus tumor and review the related Chinese literature published in 1990-2010.METHODS:A case of gastric glomus tumor was re-ported.Clinicopathological findings in 56 cases of gastric glomus tumor were analyzed.RESULTS:Gastric glomus tumor was far more common in women than in men with a female to male ratio of 1.6:1.The median age of the patients was 45 years(range 28-79 years).The patients often complained of epigastric pain and bloody stool.The tumor was located in antrum of the stomach.The greatest diameter of the tumor was 0.8-11cm.Histologically,the tumor was comprised of nests of glomus cells surrounding the capillaries.Glomus cells were small,uniform and round.Vimentin,smooth muscle actin and actin were expressed in the tumor.Other markers,including S-100 protein,CD34,CD117,desmin,CD56,synaptophysin,chromo-granin A,neuron specific enolase and cytokeratin were all negative.CONCLUSION:Gastric glomus tumor is a rare benign mesenchymal neoplasm.Its diagnosis depends on pathologic examination.Differential diagnosis includes gastrointestinal stromal tumor,paraganglioma and carcinoid tumor.
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.
