期刊文献+
共找到420篇文章
< 1 2 21 >
每页显示 20 50 100
Boosting Lean Electrolyte Lithium-Sulfur Battery Performance with Transition Metals: A Comprehensive Review 被引量:3
1
作者 Hui Pan Zhibin Cheng +8 位作者 Zhenyu Zhou Sijie Xie Wei Zhang Ning Han Wei Guo Jan Fransaer Jiangshui Luo Andreu Cabot Michael Wübbenhorst 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第10期53-100,共48页
Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyze... Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyzes the effect of the electrolyte-to-sulfur(E/S) ratios on battery energy density and the challenges for sulfur reduction reactions(SRR) under lean electrolyte conditions. Accordingly, we review the use of various polar transition metal sulfur hosts as corresponding solutions to facilitate SRR kinetics at low E/S ratios(< 10 μL mg~(-1)), and the strengths and limitations of different transition metal compounds are presented and discussed from a fundamental perspective. Subsequently, three promising strategies for sulfur hosts that act as anchors and catalysts are proposed to boost lean electrolyte Li–S battery performance. Finally, an outlook is provided to guide future research on high energy density Li–S batteries. 展开更多
关键词 transition metals Lean electrolyte sulfur reduction reactions Li–s batteries
下载PDF
Transitivity Analysis of the Energy in China’s New Era
2
作者 SHAN Ting WANG Yu 《Journal of Literature and Art Studies》 2024年第2期170-176,共7页
At present,with the steady development of the global economy,more and more countries begin to pay attention to the impact of ecological environment on economic development and human society,so the ecological environme... At present,with the steady development of the global economy,more and more countries begin to pay attention to the impact of ecological environment on economic development and human society,so the ecological environment has become a global issue that cannot be ignored in today’s era.Therefore,from the perspective of the ecological philosophy of Diversity&Harmony as well as Interaction&Co-existence,this paper will conduct ecological discourse analysis on the Energy in China’s New Era based on the transitivity system of systemic-functional grammar,and use the Corpus analysis software UAM Corpus Tool 3.3x to label and make statistics on the transitivity system,aiming to explore the distribution characteristics of the transitivity system in this white paper.Through the transitivity analysis of the white paper,this study helps readers to have a deeper understanding of the positive significance contained in the white paper.To a certain extent,it enables readers at home and abroad to understand China’s stance on energy issues and the positive image of China in energy ecology.It also awaken readers’awareness of environmental protection and acquire good habits of resource conservation to be in harmony between human and nature for sustainable development. 展开更多
关键词 transitIVITY Ecological discourse analysis Energy in China’s new era
下载PDF
Ⅰ导联R/(R+S)对胸前V3导联移行流出道室性心律失常起源部位的鉴别价值
3
作者 秦奋 赵雨薇 +4 位作者 赵江涛 朱揆 王攀基 宋盼 陶海龙 《郑州大学学报(医学版)》 CAS 北大核心 2024年第5期686-690,共5页
目的:探索鉴别胸前V3导联移行流出道室性心律失常(OT-VA)起源部位的体表心电图指标。方法:连续选择2017年1月至2022年8月行导管射频消融术的胸前V3导联移行OT-VA患者65例。比较左室流出道起源组(LVOT组)和右室流出道起源组(RVOT组)室性... 目的:探索鉴别胸前V3导联移行流出道室性心律失常(OT-VA)起源部位的体表心电图指标。方法:连续选择2017年1月至2022年8月行导管射频消融术的胸前V3导联移行OT-VA患者65例。比较左室流出道起源组(LVOT组)和右室流出道起源组(RVOT组)室性心律失常发作时体表心电图QRS波振幅及相关指标的差异,选择差异有统计学意义的指标,绘制ROC曲线评价所选取指标鉴别OT-VA起源部位的效能。结果:LVOT组11例,RVOT组54例,两组间差异有统计学意义且ROC曲线下面积(AUC)最大的指标为Ⅰ导联R波/(R+S)波振幅比[R/(R+S)],其鉴别OT-VA起源部位的AUC(95%CI)为0.949(0.894~1.000),截断值为0.50。Ⅰ导联R/(R+S)<0.50诊断胸前V3导联移行LVOT起源OT-VA的敏感度、特异度和准确度分别为0.909、0.944和0.938。结论:Ⅰ导联R/(R+S)<0.50可准确鉴别LVOT起源的胸前V3导联移行OT-VA。 展开更多
关键词 Ⅰ导联 室性心律失常 胸前导联移行 左室流出道 右室流出道
下载PDF
纳米碳片负载Mott-Schottky型Co/Co_(9)S_(8)异质结的原位合成及电催化性能研究 被引量:1
4
作者 方瑜 李靖 +4 位作者 孔维超 周雪 徐林 孙冬梅 唐亚文 《材料导报》 EI CAS CSCD 北大核心 2024年第8期44-50,共7页
以K_(3)[Co(CN)_(6)]为Co源,硫脲为S源,富含-OH和-NH_(2)的天然亲水性高分子壳聚糖为碳源,通过形成CS-K_(3)[Co(CN)_(6)]水凝胶将Co前驱体和S源均匀分布于C前驱体中。水凝胶形成的主要驱动力来自金属Co离子与壳聚糖中-NH_2的配位交联以... 以K_(3)[Co(CN)_(6)]为Co源,硫脲为S源,富含-OH和-NH_(2)的天然亲水性高分子壳聚糖为碳源,通过形成CS-K_(3)[Co(CN)_(6)]水凝胶将Co前驱体和S源均匀分布于C前驱体中。水凝胶形成的主要驱动力来自金属Co离子与壳聚糖中-NH_2的配位交联以及Co离子之间通过-CN的桥接作用。得益于均匀分散的前驱体和后续热解处理初期形成的Co的催化作用,通过简单地调控Co与S的原子比,原位构建出均匀镶嵌有Co/Co_(9)S_(8)异质结的N,S共掺杂富含微孔的碳纳米片(Co/Co_(9)S_(8)@N,S-CNSs)。采用SEM、TEM、BET、XRD、Raman、XPS和电化学工作站等方法对所制备催化剂的形貌、组成和结构以及电催化性能进行了表征。结果表明,形成的Mott-Schottky型Co/Co_(9)S_(8)异质界面有效地调控了活性中心的电子结构和电荷传输特性;二维掺杂多孔碳纳米片的负载使活性位点更加均匀分散,同时提供了高速的电子和传质通道,也避免了活性位点在催化过程中的迁移聚集。两者的协同作用使合成的Co/Co_(9)S_(8)@N,S-CNSs复合催化剂具有了更优的催化性能,在10 mA·cm^(-2)的电流密度下,其催化碱性析氧反应/OER的过电位仅为304 mV,优于商业化的RuO_(2)催化剂。该研究为发展具有优异电催化性能的廉价过渡金属催化剂提供帮助。 展开更多
关键词 Co/Co_(9)s_(8) Mott-schottky N s共掺杂碳纳米片 过渡金属电催化剂
下载PDF
Chronological age when health care transition skills are mastered in adolescents/young adults with inflammatory bowel disease 被引量:3
5
作者 Natalie Stollon Yi Zhong +6 位作者 Maria Ferris Suneet Bhansali Brian Pitts Eniko Rak Maureen Kelly Sandra Kim Miranda AL van Tilburg 《World Journal of Gastroenterology》 SCIE CAS 2017年第18期3349-3355,共7页
To describe the longitudinal course of acquisition of healthcare transition skills among adolescents and young adults with inflammatory bowel diseases.METHODSWe recruited adolescents and young adults (AYA) with inflam... To describe the longitudinal course of acquisition of healthcare transition skills among adolescents and young adults with inflammatory bowel diseases.METHODSWe recruited adolescents and young adults (AYA) with inflammatory bowel diseases (IBD), from the pediatric IBD clinic at the University of North Carolina. Participants completed the TR<sub>x</sub>ANSITION Scale™ at least once during the study period (2006-2015). We used the electronic medical record to extract participants’ clinical and demographic data. We used ordinary least square regressions with robust standard error clustered at patient level to explore the variations in the levels and growths of healthcare transition readiness.RESULTSOur sample (n = 144) ranged in age from 14-22 years. Age was significantly and positively associated with both the level and growth of TR<sub>x</sub>ANSITION Scale™ scores (P < 0.01). Many healthcare transition (HCT) skills were acquired between ages 12 and 14 years, but others were not mastered until after age 18, including self-management skills.CONCLUSIONThis is one of the first studies to describe the longitudinal course of HCT skill acquisition among AYA with IBD, providing benchmarks for evaluating transition interventions. 展开更多
关键词 Inflammatory bowel disease Crohn’s disease Ulcerative colitis PEDIATRICs Healthcare transition
下载PDF
Outcomes and patients' perspectives of transition from paediatric to adult care in inflammatory bowel disease 被引量:4
6
作者 Alice L Bennett David Moore +2 位作者 Peter A Bampton Robert V Bryant Jane M Andrews 《World Journal of Gastroenterology》 SCIE CAS 2016年第8期2611-2620,共10页
AIM: To describe the disease and psychosocial outcomes of an inflammatory bowel disease (IBD) transition cohort and their perspectives.METHODS: Patients with IBD, aged &#x0003e; 18 years, who had moved from paedia... AIM: To describe the disease and psychosocial outcomes of an inflammatory bowel disease (IBD) transition cohort and their perspectives.METHODS: Patients with IBD, aged &#x0003e; 18 years, who had moved from paediatric to adult care within 10 years were identified through IBD databases at three tertiary hospitals. Participants were surveyed regarding demographic and disease specific data and their perspectives on the transition process. Survey response data were compared to contemporaneously recorded information in paediatric service case notes. Data were compared to a similar age cohort who had never received paediatric IBD care and therefore who had not undergone a transition process.RESULTS: There were 81 returned surveys from 46 transition and 35 non-transition patients. No statistically significant differences were found in disease burden, disease outcomes or adult roles and responsibilities between cohorts. Despite a high prevalence of mood disturbance (35%), there was a very low usage (5%) of psychological services in both cohorts. In the transition cohort, knowledge of their transition plan was reported by only 25/46 patients and the majority (54%) felt they were not strongly prepared. A high rate (78%) of discussion about work/study plans was recorded prior to transition, but a near complete absence of discussion regarding sex (8%), and other adult issues was recorded. Both cohorts agreed that their preferred method of future transition practices (of the options offered) was a shared clinic appointment with all key stakeholders.CONCLUSION: Transition did not appear to adversely affect disease or psychosocial outcomes. Current transition care processes could be optimised, with better psychosocial preparation and agreed transition plans. 展开更多
关键词 transition care Crohn’ s disease Ulcerative colitis Chronic illness Inflammatory bowel disease Patient perspectives Disease outcomes
下载PDF
Total flavone of Abelmoschus manihot suppresses epithelial-mesenchymal transition via interfering transforming growth factor-β1 signaling in Crohn's disease intestinal fibrosis 被引量:8
7
作者 Bo-Lin Yang Ping Zhu +5 位作者 You-Ran Li Min-Min Xu Hao Wang Li-Chao Qiao Hai-Xia Xu Hong-Jin Chen 《World Journal of Gastroenterology》 SCIE CAS 2018年第30期3414-3425,共12页
AIM To explore the role and mechanism of total flavone of Abelmoschus manihot(TFA) on epithelial-mesenchymal transition(EMT) progress of Crohn's disease(CD) intestinal fibrosis.METHODS First,CCK-8 assay was perfor... AIM To explore the role and mechanism of total flavone of Abelmoschus manihot(TFA) on epithelial-mesenchymal transition(EMT) progress of Crohn's disease(CD) intestinal fibrosis.METHODS First,CCK-8 assay was performed to assess TFA on the viability of intestinal epithelial(IEC-6) cells and select the optimal concentrations of TFA for our further studies.Then cell morphology,wound healing and transwell assays were performed to examine the effect of TFA on morphology,migration and invasion of IEC-6 cells treated with TGF-β1.In addition,immunofluorescence,real-time PCR analysis(q RT-PCR) and western blotting assays were carried out to detect the impact of TFA on EMT progress.Moreover,western blotting assay was performed to evaluate the function of TFA on the Smad and MAPK signaling pathways.Further,the role of co-treatment of TFA and si-Smad or MAPK inhibitors has been examined by q RTPCR,western blotting,morphology,wound healing andtranswell assays.RESULTS In this study,TFA promoted transforming growth factor-β1(TGF-β1)-induced(IEC-6) morphological change,migration and invasion,and increased the expression of epithelial markers and reduced the levels of mesenchymal markers,along with the inactivation of Smad and MAPK signaling pathways.Moreover,we revealed that si-Smad and MAPK inhibitors effectively attenuated TGF-β1-induced EMT in IEC-6 cells.Importantly,co-treatment of TFA and si-Smad or MAPK inhibitors had better inhibitory effects on TGF-β1-induced EMT in IEC-6 cells than either one of them.CONCLUSION These findings could provide new insight into the molecular mechanisms of TFA on TGF-β1-induced EMT in IEC-6 cells and TFA is expected to advance as a new therapy to treat CD intestinal fibrosis. 展开更多
关键词 Crohn’s disease Intestinal fibrosis Epithelialto-mesenchymal transition Total FLAVONE of Abelmoschus MANIHOT TRANsFORMING GROWTH factor-β1/smad sIGNALING TRANsFORMING GROWTH factor-β1/non-smad sIGNALING
下载PDF
Hsa_circRNA_102610 upregulation in Crohn’s disease promotes transforming growth factor-β1-induced epithelial-mesenchymal transition via sponging of hsa-miR-130a-3p 被引量:2
8
作者 Juan Yin Yu-Lan Ye +7 位作者 Tong Hu Li-Juan Xu Li-Ping Zhang Ru-Ning Ji Ping Li Qian Chen Jian-Yun Zhu Zhi Pang 《World Journal of Gastroenterology》 SCIE CAS 2020年第22期3034-3055,共22页
BACKGROUND The incidence of inflammatory bowel disease,a chronic intestinal inflammatory disorder that includes Crohn’s disease(CD)and ulcerative colitis,is rising.Circular RNAs are considered valuable diagnostic bio... BACKGROUND The incidence of inflammatory bowel disease,a chronic intestinal inflammatory disorder that includes Crohn’s disease(CD)and ulcerative colitis,is rising.Circular RNAs are considered valuable diagnostic biomarkers for CD.Current evidence supports the views that epithelial-mesenchymal transition(EMT)plays an important role in CD pathogenesis,and that hsa-miR-130a-3p can inhibit transforming growth factor-β1(TGF-β1)-induced EMT.Our previous study revealed that hsa_circRNA_102610 was upregulated in CD patients.Moreover,we predicted an interaction between hsa_circRNA_102610 and hsa-miR-130a-3p.Thus,we hypothesized that hsa_circRNA_102610 may play roles in the proliferation and EMT of intestinal epithelial cells by sponging hsa-miR-130a-3p to participate in the pathogenesis of CD.AIM To explore the mechanism of hsa_circRNA_102610 in the pathogenesis of CD.METHODS The relative expression levels of hsa_circRNA_102610 and hsa-miR-130a-3p in patients were detected by quantitative reverse transcription-polymerase chain reaction.The proliferation of human intestinal epithelial cells(HIECs)and normal-derived colon mucosa cell line 460(NCM460)cells was detected by cell counting kit-8,5-ethynyl-2’-deoxyuridine staining and cell cycle assays following overexpression or downregulation of hsa_circRNA_102610.Cell proliferation assays were performed as described above in a rescue experiment with hsa-miR-130a-3p mimics.The interaction of hsa_circRNA_102610 and hsa-miR-130a-3p was verified by fluorescence in situ hybridization and dual luciferase reporter assays.The relative expression levels of CyclinD1,mothers against decapentaplegic homolog 4(SMAD4),E-cadherin,N-cadherin and Vimentin were detected by western blotting following hsa_circRNA_102610 overexpression,TGF-β1-induced EMT or hsa-miR-130a-3p mimic transfection(in rescue experiments).RESULTS Upregulation of hsa_circRNA_102610 was determined to be positively correlated with elevated fecal calprotectin levels in CD(r=0.359,P=0.007)by Pearson correlation analysis.Hsa_circRNA_102610 promoted the proliferation of HIECs and NCM460 cells,while hsa-miR-130a-3p reversed the cell proliferationpromoting effects of hsa_circRNA_102610.Fluorescence in situ hybridization and dual luciferase reporter assays showed that hsa_circRNA_102610 directly bound hsa-miR-130a-3p in NCM460 and 293T cells.An inverse correlation between downregulation of hsa-miR-130a-3p and upregulation of hsa_circRNA_102610 in CD patients was observed(r=-0.290,P=0.024)by Pearson correlation analysis.Moreover,overexpression of hsa_circRNA_102610 promoted SMAD4 and CyclinD1 protein expression validated by western-blotting.Furthermore,overexpression of hsa_circRNA_102610 promoted TGF-β1 induced EMT in HIECs and NCM460 cells via targeting of hsa-miR-130a-3p,with increased expression of Vimentin and N-cadherin and decreased expression of E-cadherin.CONCLUSION Hsa_circRNA_102610 upregulation in CD patients could promote the proliferation and EMT of intestinal epithelial cells via sponging of hsa-miR-130a-3p. 展开更多
关键词 Hsa_circRNA_102610 Hsa-miR-130a-3p Epithelial-mesenchymal transition Crohn’s disease Mothers against decapentaplegic homolog 4 Transforming growth factor-β1
下载PDF
基于TS-DBN的地铁牵引系统可靠性分析
9
作者 席欢 钟倩文 +2 位作者 柴晓冬 郑树彬 文静 《计算机与数字工程》 2024年第5期1310-1316,共7页
论文提出一种结合连续时间T-S动态故障树和贝叶斯网络(TS-DBN)的可靠性评估方法来模拟实际运营过程中牵引系统的动静态失效行为。首先,构建基于牵引系统单元结构的故障树模型;然后,通过应用T-S动态门的时序规则,给出T-S门的逻辑定义,进... 论文提出一种结合连续时间T-S动态故障树和贝叶斯网络(TS-DBN)的可靠性评估方法来模拟实际运营过程中牵引系统的动静态失效行为。首先,构建基于牵引系统单元结构的故障树模型;然后,通过应用T-S动态门的时序规则,给出T-S门的逻辑定义,进而计算子节点后验概率及重要度参数;将敏感节点进行排序,建立系统连续时间状态下的稳定度函数数学模型。该方法能够直观地反映牵引系统结构单元的敏感薄弱环节,可以为后续维修策略优化提供理论参考。 展开更多
关键词 轨道交通 牵引系统 T-s动态门 贝叶斯网络 可靠性分析
下载PDF
Brownian Motion of Decaying Particles: Transition Probability, Computer Simulation, and First-Passage Times 被引量:2
10
作者 M. P. Silverman 《Journal of Modern Physics》 2017年第11期1809-1849,共41页
Recent developments in the measurement of radioactive gases in passive diffusion motivate the analysis of Brownian motion of decaying particles, a subject that has received little previous attention. This paper report... Recent developments in the measurement of radioactive gases in passive diffusion motivate the analysis of Brownian motion of decaying particles, a subject that has received little previous attention. This paper reports the derivation and solution of equations comparable to the Fokker-Planck and Langevin equations for one-dimensional diffusion and decay of unstable particles. In marked contrast to the case of stable particles, the two equations are not equivalent, but provide different information regarding the same stochastic process. The differences arise because Brownian motion with particle decay is not a continuous process. The discontinuity is readily apparent in the computer-simulated trajectories of the Langevin equation that incorporate both a Wiener process for displacement fluctuations and a Bernoulli process for random decay. This paper also reports the derivation of the mean time of first passage of the decaying particle to absorbing boundaries. Here, too, particle decay can lead to an outcome markedly different from that for stable particles. In particular, the first-passage time of the decaying particle is always finite, whereas the time for a stable particle to reach a single absorbing boundary is theoretically infinite due to the heavy tail of the inverse Gaussian density. The methodology developed in this paper should prove useful in the investigation of radioactive gases, aerosols of radioactive atoms, dust particles to which adhere radioactive ions, as well as diffusing gases and liquids of unstable molecules. 展开更多
关键词 BROWNIAN Motion Random Walk Diffusion Radioactivity transition Probability FOKKER-PLANCK EQUATION LANGEVIN EQUATION First Passage Fick’s Law WIENER Process
下载PDF
Effect of Magnesium on the C-S-H Nanostructure Evolution and Aluminate Phases Transition in Cement-Slag Blend 被引量:4
11
作者 丁庆军 YANG Jun +1 位作者 张高展 HOU Dongshuai 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第1期108-116,共9页
The microstructural study was conducted on cement and cement-slag pastes immersed in different concentrations of Mg(NO3)2 solutions utilizing ^29Si, ^27Al NMR spectroscopy and XRD techniques. The results show that t... The microstructural study was conducted on cement and cement-slag pastes immersed in different concentrations of Mg(NO3)2 solutions utilizing ^29Si, ^27Al NMR spectroscopy and XRD techniques. The results show that the hydration of both the cement and cement-slag pastes is delayed when the pastes are cured in Mg(NO3)2 solutions as compared to the pastes cured in water. Moreover, Mg^2+ ions also exhibit an decalcifying and dealuminizing effect on the C-A-S-H in cement and cement-slag pastes, and thereby decrease Ca/Si and Al[4]/Si ratios of the C-A-S-H. The dealuminization of C-A-S-H is mitigated for cement-slag paste as compared to pure cement paste. The depolymerized calcium and aluminum ions from C-A-S-H gel mainly enter the pore solution to maintain the pH value and form Al^[6] in TAH, respectively. On the other hand, Mg^2+ ions exert an impact on the intra-transition between Al^[6] species, from AFm and hydrogarnet to hydrotalcite-like phase. NO3^-ions are interstratified in the layered Mg-Al structure and formed nitrated hydrotalcite-like phase(Mg1-xAlx(OH)2(NO3)x·nH2O). Results from both ^27Al NMR and XRD data show that ettringite seems not to react with Mg^2+ ions. 展开更多
关键词 ^29si and ^27Al NMR magnesium ion C-A-s-H microstructure aluminate phases transition hydration slag incorporation
下载PDF
No basalt accumulation and segregation atop the 660-km discontinuity beneath the Sea of Okhotsk
12
作者 BingXin Zhou XiaoBo He 《Earth and Planetary Physics》 EI CAS CSCD 2024年第4期621-631,共11页
Recent seismic evidence shows that basalt accumulation is widespread in the mantle transition zone(MTZ),yet its ubiquity or sporadic nature remains uncertain.To investigate this phenomenon further,we characterized the... Recent seismic evidence shows that basalt accumulation is widespread in the mantle transition zone(MTZ),yet its ubiquity or sporadic nature remains uncertain.To investigate this phenomenon further,we characterized the velocity structure across the 660-km discontinuity that separates the upper mantle from the lower mantle beneath the Sea of Okhotsk by modeling the waveform of the S660P phase,a downgoing S wave converting into a P wave at the 660-km interface.These waves were excited by two regional>410-km-deep events and were recorded by stations in central Asia.Our findings showed no need to introduce velocity anomalies at the base of the MTZ to explain the S660P waveforms because the IASP91 model adequately reproduced the waveforms.This finding indicates that the basalt accumulation has not affected the bottom of the MTZ in the study area.Instead,this discontinuity is primarily controlled by temperature or water content variations,or both.Thus,we argue that the basalt accumulation at the base of the MTZ is sporadic,not ubiquitous,reflecting its heterogeneous distribution. 展开更多
关键词 660-km discontinuity s660P basalt segregation mantle transition zone western Pacific subduction zone
下载PDF
Microscopic growth mechanism and edge states of monolayer 1T'-MoTe_(2)
13
作者 赵海鹏 刘隐 +7 位作者 杨胜国 林陈昉 陈明星 Kai Braun 罗心仪 李思宇 潘安练 王笑 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期605-611,共7页
Transition metal ditellurides(TMTDs)have versatile physical properties,including non-trivial topology,Weyl semimetal states and unique spin texture.Controlled growth of high-quality and large-scale monolayer TMTDs wit... Transition metal ditellurides(TMTDs)have versatile physical properties,including non-trivial topology,Weyl semimetal states and unique spin texture.Controlled growth of high-quality and large-scale monolayer TMTDs with preferred crystal phases is crucial for their applications.Here,we demonstrate the epitaxial growth of 1T'-MoTe_(2) on Au(111)and graphitized silicon carbide(Gr/SiC)by molecular beam epitaxy(MBE).We investigate the morphology of the grown1T'-MoTe_(2) at the atomic level by scanning tunnelling microscopy(STM)and reveal the corresponding microscopic growth mechanism.It is found that the unique ordered Te structures preferentially deposited on Au(111)regulate the growth of monolayer single crystal 1T'-MoTe_(2),while the Mo clusters were preferentially deposited on the Gr/SiC substrate,which impedes the ordered growth of monolayer MoTe_(2).We confirm that the size of single crystal 1T'-MoTe_(2) grown on Au(111)is nearly two orders of magnitude larger than that on Gr/SiC.By scanning tunnelling spectroscopy(STS),we observe that the STS spectrum of the monolayer 1T'-MoTe_(2) nano-island at the edge is different from that at the interior,which exhibits enhanced conductivity. 展开更多
关键词 transition metal ditellurides 1T'-MoTe_(2) microscopic growth mechanism scanning tunneling microscopy/spectroscopy(sTM/s)
下载PDF
Modulating Co-Co bonds average length in Co_(0.85)Se_(1-x)S_(x) to enhance conversion reaction for potassium storage
14
作者 Daming Chen Yuchun Liu +5 位作者 Pan Feng Xiao Tao Zhiquan Huang Xiyu Zhang Min Zhou Jian Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期111-121,共11页
While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,... While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,we study the influence of dopant concentration on the chemical bonds in TMC and reveal the associated stepwise conversion reaction mechanism for potassium ion storage.According to density function theory calculations,appropriate S-doping in Co0.85Se(Co_(0.85)Se_(1-x)S_(x))can reduce the average length of Co-Co bonds because of the electronegativity variation,which is thermodynamically favourable to the phase transition reactions.The optimal Se/S ratio(x=0.12)for the conductivity has been obtained from experimental results.When assembled as an anode in potassium-ion batteries(PIBs),the sample with optimized Se/S ratio exhibits extraordinary electrochemical performance.The rate performance(229.2 mA h g^(-1)at 10 A g^(-1))is superior to the state-of-the-art results.When assembled with Prussian blue(PB)as a cathode,the pouch cell exhibits excellent performance,demonstrating its great potential for applications.Moreover,the stepwise K+storage mechanism caused by the coexistence of S and Se is revealed by in-situ X-ray diffraction and ex-situ transmission electron microscopy techniques.Hence,this work not only provides an effective strategy to enhance the electrochemical performance of transition metal chalcogenides but also reveals the underlying mechanism for the construction of advanced electrode materials. 展开更多
关键词 Co_(0.85)se_(1-x)s_(x) Co-Co bonds Phase transition reactions Optimal se/s Potassium ion batteries
下载PDF
Far Infrared Resonance Transition Study of the Chain-End S=1/2 Modes in an S=1 Antiferromagnetic Chain
15
作者 LU Wei SHEN Xuechu +4 位作者 LIU Pulin M.von Ortenberg J.Tuchendler J.P.Renard ZHENG Fen 《Chinese Physics Letters》 SCIE CAS CSCD 1995年第5期313-316,共4页
The unpaired spin S=1/2 states which occur at the ends of an S=1 Heisenberg-like antiferromagnetic chain,have been observed recently in low-temperature electron spin-resonance measurements of Ni(C_(2)H_(8)N_(2))_(2)NO... The unpaired spin S=1/2 states which occur at the ends of an S=1 Heisenberg-like antiferromagnetic chain,have been observed recently in low-temperature electron spin-resonance measurements of Ni(C_(2)H_(8)N_(2))_(2)NO_(2)ClO_(4) containing selected impurities.We present here a further study on this topic by far infrared transmission spectra under the magnetic field.The splitting of S=1/2 modes was clearly observed and explained by the interaction of S=1/2 modes at two nearby chains,which can be separated by vacancy-like defect. 展开更多
关键词 s=1/2 field. transition
下载PDF
Magic Wavelengths for the 1S-2S and 1S-3S Transitions in Hydrogen Atoms
16
作者 尹东 张永慧 +1 位作者 李承斌 张现周 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期59-62,共4页
The dynamic dipole polarizabilities for 1S, 2S and 3S states of the hydrogen atom are calculated using the finite B-spline basis set method, and the magic wavelengths for 1S-2S and 1S-3S transitions are identified. In... The dynamic dipole polarizabilities for 1S, 2S and 3S states of the hydrogen atom are calculated using the finite B-spline basis set method, and the magic wavelengths for 1S-2S and 1S-3S transitions are identified. In comparison of the solutions from the Schr6dinger and Dirac equations, the relativistic corrections on the magic wavelengths are of the order of 10-2 nm. The laser intensities for a 300-Er-deep optical trap and the heating rates at 514 and 1371 nm are estimated. The reliable prediction of the magic wavelengths would be helpful for the experimental design on the optical trapping of the hydrogen atoms, and in turn, it would be helpful to improve the accuracy of the measurements of the hydrogen 1S-2S and 1S-3S transitions. 展开更多
关键词 of Is for Magic Wavelengths for the 1s-2s and 1s-3s transitions in Hydrogen Atoms in
下载PDF
Hofstadter's Butterfly and Phase Transition of Checkerboard Superconducting Network in a Magnetic Field
17
作者 侯净敏 田立君 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第3期587-590,共4页
We study the magnetic effect of the checkerboard superconducting wire network. Based on the de Gennes- Alexader theory, we obtain difference equations for superconducting order parameter in the wire network. Through s... We study the magnetic effect of the checkerboard superconducting wire network. Based on the de Gennes- Alexader theory, we obtain difference equations for superconducting order parameter in the wire network. Through solving these difference equations, we obtain the eigenvalues, linked to the coherence length, as a function of magnetic field. The diagram of eigenvalues shows a fractal structure, being so-called Hofstadter's butterfly. We also calculate and discuss the dependence of the transition temperature of the checkerboard superconducting wire network on the applied magnetic field, which is related to up-edge of the Hofstadter's butterfly spectrum. 展开更多
关键词 superconducting wire network checkerboard lattice Hofstadter's butterfly phase transition
下载PDF
Thickness-dependent magnetic order and phase transition in V5S8
18
作者 Rui-Zi Zhang Yu-Yang Zhang Shi-Xuan Du 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第7期516-520,共5页
V5S8 is an ideal candidate to explore the magnetism at the two-dimensional(2D)limit.A recent experiment has shown that the V5S8 thin films exhibit an antiferromagnetic(AFM)to ferromagnetic(FM)phase transition with red... V5S8 is an ideal candidate to explore the magnetism at the two-dimensional(2D)limit.A recent experiment has shown that the V5S8 thin films exhibit an antiferromagnetic(AFM)to ferromagnetic(FM)phase transition with reducing thickness.Here,for the first time,using density functional theory calculations,we report the antiferromagnetic order of bulk V5S8,which is consistent with the previous experiments.The specific antiferromagnetic order is reproduced when Ueff=2 eV is applied on the intercalated vanadium atoms within LDA.We find that the origin of the magnetic ordering is from superexchange interaction.We also investigate the thickness-dependent magnetic order in V5S8 thin films.It is found that there is an antiferromagnetic to ferromagnetic phase transition when V5S8 is thinned down to 2.2 nm.The main magnetic moments of the antiferromagnetic and ferromagnetic states of the thin films are located on the interlayered vanadium atoms,which is the same as that in the bulk.Meanwhile,the strain in the thin films also influences the AFM-FM phase transition.Our results not only reveal the magnetic order and origin in bulk V5S8 and thin films,but also provide a set of parameters which can be used in future calculations. 展开更多
关键词 V5s8 superexchange interaction AFM-FM phase transition
下载PDF
Effects of bisphenol compounds on the growth and epithelial mesenchymal transition of MCF-7 CV human breast cancer cells 被引量:3
19
作者 Ji-Youn Kim Ho-Gyu Choi +3 位作者 Hae-Miru Lee Geum-A Lee Kyung-A Hwang Kyung-Chul Choi 《The Journal of Biomedical Research》 CAS CSCD 2017年第4期358-369,共12页
Bisphenol-A(BPA) has been considered as an endocrine disrupting chemical(EDC) because it can exert estrogenic properties.For bisphenol-S(BPS) and bisphenol-F(BPF) that are BPA analogs and substitutes,their ris... Bisphenol-A(BPA) has been considered as an endocrine disrupting chemical(EDC) because it can exert estrogenic properties.For bisphenol-S(BPS) and bisphenol-F(BPF) that are BPA analogs and substitutes,their risk to estrogendependent cancer has been reported rarely compared with the numerous cases of BPA.In this study,we examined whether BPA,BPS,and BPF can lead to the proliferation,migration,and epithelial mesenchymal transition(EMT) of MCF-7 clonal variant(MCF-7 CV) breast cancer cells expressing estrogen receptors(ERs).In a cell viability assay,BPA,BPS,and BPF significantly increased proliferation of MCF-7 CV cells compared to control(DMSO) as did17β-estradiol(E2).In Western blotting assay,BPA,BPS,and BPF enhanced the protein expression of cell cycle progression genes such as cyclin D1 and E1.In addition,MCF-7 CV cells lost cell to cell contacts and acquired fibroblast-like morphology by the treatment of BPA,BPS,or BPF for 24 hours.In cell migration assay,BPA,BPS,and BPF accelerated the migration capability of MCF-7 CV cells as did E2.In relation with the EMT process,BPA,BPS,and BPF increased the protein expression of N-cadherin,while they decreased the protein expression of Ecadherin.When BPA,BPS,and BPF were co-treated with ICI 182,780,an ER antagonist,proliferation effects were reversed,the expression of cyclin D1 and cyclin E1 was downregulated,and the altered cell migration and expression of N-cadherin and E-cadherin by BPA,BPS,and BPF were restored to the control level.Thus,these results imply that BPS and BPF also have the risk of breast cancer progression as much as BPA in the induction of proliferation and migration of MCF-7 CV cells by regulating the protein expression of cell cycle-related genes and EMT markers via the ER-dependent pathway. 展开更多
关键词 human breast cancer cells endocrine disrupting chemicals bisphenol-A bisphenol-s bisphenol-F epithelial-mesenchymal transition migration
下载PDF
Pressure-induced phase transitions in single-crystalline Cu_4Bi_4S_9 nanoribbons
20
作者 胡靖宇 李劲 +13 位作者 张思佳 赵豪飞 张庆华 姚湲 赵清 石丽洁 邹炳锁 李延春 李晓东 刘景 朱恪 刘玉龙 靳常青 禹日成 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第11期440-444,共5页
In situ angle dispersive synchrotron X-ray diffraction and Raman scattering measurements under pressure are em- ployed to study the structural evolution of Cu4Bi4S9 nanoribbons, which are fabricated by using a facile ... In situ angle dispersive synchrotron X-ray diffraction and Raman scattering measurements under pressure are em- ployed to study the structural evolution of Cu4Bi4S9 nanoribbons, which are fabricated by using a facile solvothermal method. Both experiments show that a structural phase transition occurs near 14.5 GPa, and there is a pressure-induced re- versible amorphization at about 25.6 GPa. The electrical transport property of a single Cu4Bi4S9 nanoribbon under different pressures is also investigated. 展开更多
关键词 Cu4Bi4s9 nanoribbon high pressure amorphization phase transition
下载PDF
上一页 1 2 21 下一页 到第
使用帮助 返回顶部