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石墨烯负载磷-氮复合阻燃剂的合成及其在聚乳酸改性中的应用 被引量:2
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作者 马文静 王瀚文 +4 位作者 徐菲 安世杰 朱志国 王文庆 王锐 《高分子材料科学与工程》 北大核心 2025年第1期43-52,共10页
聚乳酸(PLA)是一种典型的生物降解绿色高分子材料,但其极限氧指数(LOI)仅为20%,高的可燃性限制了其应用安全性。文中以2-羧乙基苯基次磷酸、碳酰胺和还原氧化石墨烯(rGO)为原料合成了一种石墨烯负载磷-氮复合高效阻燃剂(CN-rGO),采用熔... 聚乳酸(PLA)是一种典型的生物降解绿色高分子材料,但其极限氧指数(LOI)仅为20%,高的可燃性限制了其应用安全性。文中以2-羧乙基苯基次磷酸、碳酰胺和还原氧化石墨烯(rGO)为原料合成了一种石墨烯负载磷-氮复合高效阻燃剂(CN-rGO),采用熔融共混法制备了PLA/CN-rGO复合物,对其阻燃性能及其作用机理进行了研究分析。极限氧指数、垂直燃烧等级和锥形量热等测试结果表明,CN-rGO是一种高效阻燃剂,其质量分数为1%时,PLA/CN-rGO的LOI明显提升至37%,达到难燃级别;垂直燃烧等级为V-0级,能够离火自熄;最大热释放速率(PHRR)和总热释放量(THR)分别降低了40.2%和23.1%。机理研究表明,CN-rGO在凝聚相和气相均产生阻燃作用,综合提高了阻燃性能。另外,PLA/CN-rGO的表面电阻达到抗静电性级别,说明CN-rGO具有多功能性。 展开更多
关键词 聚乳酸 还原氧化石墨烯 磷-氮复合阻燃剂 阻燃性能 抗静电性能
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轻工学科课程知识图谱的建立及其在实现碎片化知识重构中的应用研究 被引量:2
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作者 李尧 费旭 +1 位作者 马子豪 孙广卫 《造纸技术与应用》 2025年第2期40-44,共5页
随着学科交叉的深入发展,原有的研究生基础科学类课程已无法全面覆盖所有研究方向,这导致了课程教学环节对于研究生开展科学研究工作的助力严重不足。文章基于轻工技术与工程学科的研究生基础课程《高分子化学与物理》,探索了引导研究... 随着学科交叉的深入发展,原有的研究生基础科学类课程已无法全面覆盖所有研究方向,这导致了课程教学环节对于研究生开展科学研究工作的助力严重不足。文章基于轻工技术与工程学科的研究生基础课程《高分子化学与物理》,探索了引导研究生对课程内知识点与课程外相关知识点进行碎片化重构处理的路径,帮助研究生构建适应自身研究方向的课程、学科及相关前沿研究课题知识点的可视化知识图谱。同时,通过对适应研究生自身研究方向的知识图谱的建立,实现多学科知识点的交叉融合,帮助研究生在碎片化知识学习过程中跟踪科技前沿、选择科研方向、开展知识管理与辅助科研决策。 展开更多
关键词 知识图谱 碎片化知识重构 高分子化学与物理
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Association between blood pressure traits,hypertension,antihypertensive drugs and calcific aortic valve stenosis:a mendelian randomization study
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作者 Wen-Hua LEI Jia-Liang ZHANG +7 位作者 Yan-Biao LIAO Yan WANG fei xu Yao-Yu ZHANG Yanjiani xu Jing ZHOU Fang-Yang HUANG Mao CHEN 《Journal of Geriatric Cardiology》 2025年第3期351-360,共10页
Background Hypertension is associated with an increased risk of calcific aortic valve stenosis(CAVS).However,the directionality of causation between blood pressure traits and aortic stenosis is unclear,as is the benef... Background Hypertension is associated with an increased risk of calcific aortic valve stenosis(CAVS).However,the directionality of causation between blood pressure traits and aortic stenosis is unclear,as is the benefit of antihypertensive drugs for CAVS.Methods Using genome-wide association studies(GWAS)summary statistics,we performed bidirectional two-sample univariable mendelian randomization(UVMR)to assess the causal associations of systolic blood pressure(SBP),diastolic blood pressure(DBP),and pulse pressure(PP)with CAVS.Multivariable mendelian randomization(MVMR)was conducted to evaluate the direct effect of hypertension on CAVS,adjusting for confounders.Drug target mendelian randomization(MR)and summary-level MR(SMR)were used to estimate the effects of 12 classes of antihypertensive drugs and their target genes on CAVS risk.Inverse variance weighting was the primary MR method,with sensitivity analyses to validate results.Results UVMR showed SBP,DBP,and PP have causal effects on CAVS,with no significant reverse causality.MVMR confirmed the causality between hypertension and CAVS after adjusting for confounders.Drug-target MR analyses indicated that calcium channel blockers(CCBs),loop diuretics,and thiazide diuretics via SBP lowering exerted protective effects on CAVS risk.SMR analysis showed that the CCBs target gene CACNA2D2 and ARBs target gene AGTR1 were positively associated with CAVS risk,while diuretics target genes SLC12A5 and SLC12A1 were negatively associated with aortic stenosis risk.Conclusions Hypertension has a causal relationship with CAVS.Managing SBP in hypertensive patients with CCBs may prevent CAVS.ARBs might exert protective effects on CAVS independent of blood pressure reduction.The relationship between diuretics and CAVS is complex,with opposite effects through different mechanisms. 展开更多
关键词 antihypertensive drugs blood pressure blood pressure traits aortic stenosis calcific aortic valve stenosis calcific aortic valve stenosis cavs Mendelian randomization HYPERTENSION
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Nuclear FGF2 orchestrates phase separation-mediated rDNA chromatin architecture to control BMSCs cell fate
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作者 Hengguo Zhang Zifei Wang +11 位作者 Zhenqing Liu xuan Li Wansu Sun Wenyu Zhen fei xu Rui Wang Qi Yin Shuqin CaoMingyue Wu Jiacai He Jianguang xu Yang Li Quan Yuan 《Bone Research》 2025年第5期1266-1281,共16页
Ribosomal RNA(rRNA)synthesis is intricately tied to cellular growth and proliferation.Basic fibroblast growth factor(FGF2),a pivotal factor for bone marrow mesenchymal stem cells(BMSCs),can stimulates rRNA transcripti... Ribosomal RNA(rRNA)synthesis is intricately tied to cellular growth and proliferation.Basic fibroblast growth factor(FGF2),a pivotal factor for bone marrow mesenchymal stem cells(BMSCs),can stimulates rRNA transcription,though the underlying mechanism remains unknown.Here,we demonstrate that the cytoplasm-nucleus translocation of FGF2 is determined by the stable nuclear localization motif.Meanwhile,the nuclear FGF2 regulates rRNA expression and BMSCs proliferation via phase separation.Next,through FGF2 related epigenomics and 3D genomes analysis,we identified chromatin architectures during BMSCs differentiation and aging.In the process,topologically associating domains(TADs)and chromatin loops profiling revealed the attenuated genomic interaction among proximal chromosomes 13,14,15,21,and 22,where phase-separated FGF2 facilitates rDNA transcription depend on specific super-enhancers(SEs).Furthermore,we validated that FGF2 orchestrates rDNA chromatin architecture in coordination with STAT5.Together,these findings underscore the pivotal role of FGF2 in rDNA chromatin architectures,which determines BMSCs cell fate. 展开更多
关键词 bone marrow mesenchymal stem cells bmscs can stimulates rrna bone marrow mesenchymal stem cells ribosomal RNA synthesis nuclear localization phase separationnextthrough chromatin architecture fibroblast growth factor fgf
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Laparoscopic microwave ablation for giant cavernous hemangioma coexistent with diffuse hepatic hemangiomatosis:Two case reports
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作者 fei xu Jian Kong +4 位作者 Shu-Ying Dong Li xu Shao-Hong Wang Wen-Bing Sun Jun Gao 《World Journal of Gastrointestinal Surgery》 2025年第3期398-405,共8页
BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs interve... BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma. 展开更多
关键词 Giant cavernous hemangioma Diffuse hepatic hemangiomatosis Manage-ment Microwave Thermal ablation Case report
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Agricultural Drought Vulnerability in the Middle Reaches of Yangtze River Basin under Environmental Change
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作者 Peng Yang fei xu +3 位作者 Jun Xia Jiang Li Libo Zhou Cai Fu 《Journal of Earth Science》 2025年第1期184-196,共13页
Climate change and economic development impact the population expansion and water shortage in the middle reaches of the Yangtze River Basin(MYRB),leading directly to drought aggravation-expansion and impacting agricul... Climate change and economic development impact the population expansion and water shortage in the middle reaches of the Yangtze River Basin(MYRB),leading directly to drought aggravation-expansion and impacting agricultural production in the MYRB.Therefore,this study quantitatively evaluated agricultural drought vulnerability in the MYRB based on the variable fuzzy evaluation model(VFEM).The main conclusions are as follows:(1)The arable land in the MYRB gradually decreased between 2005 and 2020,whereas the forest cover decreased and then increased;(2)precipitation and evapotranspiration were the key factors affecting the agricultural drought vulnerability(e.g.,weights of 0.24 and 0.21),whereas arable land density and gross domestic product(GDP)per capita played less significant roles;and(3)the agricultural drought vulnerability in the MYRB during 2005-2020 was mainly at level 3 and below,with higher drought vulnerability in the western and northern regions,which had a higher drought risk potential. 展开更多
关键词 MYRB agricultural drought vulnerability variable fuzzy evaluation quantitative evaluation agricultural production
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Ultrasmall PtCu nanosheets as a broadband phototheranostic agent in near-infrared biowindow
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作者 Ying Zhang Chuang Shen +7 位作者 Jiaxu Zhang Qi Shen fei xu Shengheng Wang Jiuyi Hu Faisal Saleem Feng Huang Zhimin Luo 《Chinese Chemical Letters》 2025年第6期387-391,共5页
Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are syn... Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo,which show strong light absorption from NIR-I to NIR-II biowindows with the photothermal conversion efficiencies of 20.4%under 808 nm laser and 32.7%under 1064 nm laser.Pt Cu nanosheets functionalized with folic acidmodified thiol-poly(ethylene glycol)(SH-PEG-FA)present good biocompatibility and 4T1 tumor-targeted effect,which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-I and NIR-II biowindows.Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties. 展开更多
关键词 Noble metal nanostructures PtCu nanosheets Photothermal therapy Photoacoustic imaging Broadband phototheranostics
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Clinical features of abnormalα-fetoprotein in 15 patients with chronic viral hepatitis B after treatment with antiviral drugs
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作者 Man-Lei Jiang fei xu +3 位作者 Jin-Long Li Jia-Yu Luo Jiang-Ling Hu Xian-Qiang Zeng 《World Journal of Hepatology》 2025年第1期47-54,共8页
BACKGROUND Liver function of chronic hepatitis B(CHB)patients is essentially normal after treatment with antiviral drugs.In rare cases,persistently abnormally elevatedα-fetoprotein(AFP)is seen in CHB patients followi... BACKGROUND Liver function of chronic hepatitis B(CHB)patients is essentially normal after treatment with antiviral drugs.In rare cases,persistently abnormally elevatedα-fetoprotein(AFP)is seen in CHB patients following long-term antiviral treatment.However,in the absence of imaging evidence of liver cancer,a reasonable expla-nation for this phenomenon is still lacking.AIM To explore the causes of abnormal AFP in patients with CHB who were not diag-nosed with liver cancer.METHODS From November 2019 to May 2023,15 patients with CHB after antiviral treatment and elevated AFP were selected.Clinical data and quality indicators related to laboratory testing,imaging data,and pathological data were obtained through inpatient medical records.RESULTS All patients had increased AFP and significantly elevated IgG.Cancer was excluded by imaging examination.Only four patients had elevated alanine ami-notransferase,10 had elevated aspartate aminotransferase,nine had elevated total bilirubin,and two had antinuclear antibodies.The liver biopsy and histopatho-logical examination indicated that 14 patients had rosette,moderate,or higher interfacial inflammation,lymphocyte infiltration,and severe hepatic fibers(11 cases),which was consistent with the pathological features of autoimmune hepa-titis(AIH).After 8-12 week of hormone therapy,the levels of AFP and IgG,and liver function returned to normal(P<0.05).CONCLUSION For patients with CHB and elevated AFP after antiviral treatment,autoimmune hepatitis should be considered.CHB with AIH is clinically insidious and difficult to detect,and prone to progression to cirrhosis.Liver puncture pathological examination should be performed when necessary to confirm diagnosis. 展开更多
关键词 Abnormalα-fetoprotein Chronic viral hepatitis B Antiviral treatment Autoimmune hepatitis Hepatic pathology
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Blocking thermal runaway propagation in large-format sodium-ion battery system through localized energy release
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作者 Yongchun Dang Yongchao Yu +6 位作者 Zhenpo Wang Peng Liu xunli Zhou Yongjie Zhao Peipei Qi fei xu Lei Li 《Journal of Energy Chemistry》 2025年第5期514-526,共13页
Cascading thermal runaway(TR)propagation poses a critical safety concern for large-format sodium-ion battery(SIB)systems because of the heightened risks of fires or explosions.However,effectively suppressing TR propag... Cascading thermal runaway(TR)propagation poses a critical safety concern for large-format sodium-ion battery(SIB)systems because of the heightened risks of fires or explosions.However,effectively suppressing TR propagation without introducing unintended side effects remains a significant challenge.Herein,we demonstrate a localized energy release method to mitigate TR,by reducing the state of charge(SOC)of cells adjacent to the thermally runaway unit.We discover that as the SOCs decreased from 100%to 25%,the TR trigger temperature decreased significantly,and the maximum temperature decrease from 367 to 229℃.Meanwhile,the volume of gas decreased to one-third of its original value,while the range of explosion limits significantly narrowed.The analysis of the morphology of the debris further confirms that the structural damage is greater at higher SOC levels.Moreover,an Entropy Weight and Technique for Order Preference by Similarity to an Ideal Solution(EW-TOPSIS)method has been established to assess the safety status of SIBs,showing that the TR possibility is nearly linear with the SOCs,and the TR hazard is exponentially related to the SOCs.Finally,when the SOC of cells adjacent to the TR cell is reduced to 25%,TR can be directly blocked without the need for additional cooling or thermal insulation methods.This study not only advances the understanding of TR behavior in SIBs but also offers a straightforward approach to mitigating the TR risk in SIB systems. 展开更多
关键词 Sodium-ion battery Thermal runaway Safety assessment Localized energy release
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Research progress on the mechanism of acupuncture-moxibustion in promoting the rehabilitation of sequelae of ischemic stroke
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作者 Chang-long ZHANG Yang LI +1 位作者 fei xu Li-li SHANG 《World Journal of Acupuncture-Moxibustion》 2025年第2期96-102,共7页
Acupuncture-moxibustion can promote recovery from the sequelae of ischemic stroke.However,its mechanism of action has not yet been fully elucidated.This paper introduces the mechanism of acupuncture-moxibustion in all... Acupuncture-moxibustion can promote recovery from the sequelae of ischemic stroke.However,its mechanism of action has not yet been fully elucidated.This paper introduces the mechanism of acupuncture-moxibustion in alleviating rehabilitation of ischemic stroke sequelae.The regulatory mechanism of acupuncture-moxibustion was analyzed for limb movement disorders,cognitive impairment,depression,epilepsy,dysphagia,and insomnia after stroke from four aspects(promoting neuronal growth and cell proliferation,regulating cerebral blood flow,modulating neurochemicals,and suppressing cell apoptosis).This study provides theoretical support for the wide application of acupuncture-moxibustion in rehabilitation after ischemic stroke. 展开更多
关键词 Ischemic stroke ACUPUNCTURE REHABILITATION MECHANISM
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Break the capacity limit of Li_(4)Ti_(5)O_(12) anodes through oxygen vacancy engineering
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作者 Jianjun Fang Kunchen Xie +9 位作者 Yongli Song Kangyi Zhang fei xu Xiaoze Shi Ming Ren Minzhi Zhan Hai Lin Luyi Yang Shunning Li Feng Pan 《Chinese Journal of Structural Chemistry》 2025年第2期34-40,共7页
The zero-strain spinel Li_(4)Ti_(5)O_(12)stands out as a promising anode material for lithium-ion batteries due to its outstanding cycling stability.However,the limited theoretic specific capacity,low Li^(+) diffusion... The zero-strain spinel Li_(4)Ti_(5)O_(12)stands out as a promising anode material for lithium-ion batteries due to its outstanding cycling stability.However,the limited theoretic specific capacity,low Li^(+) diffusion coefficient and electronic conductivity severely hinder its practical application.In this study,we demonstrate a strategy of introducing abundant oxygen vacancies not only on the surface and but also inside the bulk of Li_(4)Ti_(5)O_(12)particles via reductive thermal sintering.The oxygen vacancies can significantly enhance the electronic conductivity and lithium-ion diffusion coefficient of Li_(4)Ti_(5)O_(12),leading to a remarkable improvement in rate performance and a reduction in polarization.Moreover,additional lithium-ion accommodation sites can be created at the defective surface,contributing to a high specific capacity of over 200 mAh g^(-1). 展开更多
关键词 Li_(4)Ti_(5)O_(12) Oxygen vacancies Anode Excess capacity
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Research on the Influence of Financial Status of Benxi Steel Sheet Material on Stock Price Under the Perspective of Big Data
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作者 Rui Gao Wenli Bao +2 位作者 fei xu Junchi Liu Meihang Li 《Proceedings of Business and Economic Studies》 2025年第6期68-73,共6页
Based on the financial data and stock price information of Bengang Steel Plates Co.Ltd.from 2004 to 2023,this paper uses SPSS 26 software,combined with DuPont Analysis and Wall Score Method,to explore the correlation ... Based on the financial data and stock price information of Bengang Steel Plates Co.Ltd.from 2004 to 2023,this paper uses SPSS 26 software,combined with DuPont Analysis and Wall Score Method,to explore the correlation between stock price and nine key financial indicators selected from three dimensions:profitability,development capability,and operating capability,including fixed asset growth rate,price-to-book ratio(P/B ratio),and gross profit margin.Through correlation analysis,multiple regression analysis,and curve fitting,the study finds that:fixed asset growth rate,P/B ratio,and gross profit margin show a significant positive correlation with stock price;return on equity(ROE),operating income,and accounts receivable turnover days show a significant negative correlation with stock price;earnings per share(EPS)and net profit growth rate do not show a significant correlation with stock price.The research results indicate that the stock price of Bengang Steel Plates Co.Ltd.is greatly affected by its asset scale and market valuation,while some profitability indicators have not been effectively transmitted to the stock price.Finally,countermeasures and suggestions are put forward from the aspects of cost control,technological innovation,market expansion,and financial structure optimization,so as to provide references for corporate operation and investment decisions. 展开更多
关键词 Bengang Steel Plates Co.Ltd. Financial indicators Stock price impact
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矿物药的理化鉴别与含量测定实验教学改进设计 被引量:2
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作者 邵江娟 李璇 +5 位作者 翁婧丹 陈晓蕾 徐飞 马瑜璐 李念光 郑仕中 《大学化学》 CAS 2024年第10期137-142,共6页
对本科无机化学教学实验中“矿物药的鉴别”实验进行了改进,选用6种外观难以区分、类白色的矿物药粉末作为实验对象,创新地设计了矿物药鉴别的盲盒实验,并增加了含量测定内容,优化了部分离子的鉴别方法,能够让学生体会无机化学反应在药... 对本科无机化学教学实验中“矿物药的鉴别”实验进行了改进,选用6种外观难以区分、类白色的矿物药粉末作为实验对象,创新地设计了矿物药鉴别的盲盒实验,并增加了含量测定内容,优化了部分离子的鉴别方法,能够让学生体会无机化学反应在药物鉴别和分析中的现实意义,并强化了本科生灵活运用理化反应原理解决实际问题的能力。 展开更多
关键词 矿物药 无机化学实验 鉴别分析 教学改进
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虚拟仿真实验室在仪器分析教学中的应用 被引量:1
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作者 费旭 李尧 +3 位作者 王秀英 王聪 李晓佩 薛丽贞 《造纸技术与应用》 2024年第4期57-59,62,共4页
仪器分析是化学相关专业一门非常重要的理论和实际操作相结合的课程,在实验环节需要操作使用大型精密仪器,与传统的实验教学相比,虚拟仿真实验能够保证每个学生都独立操作并可以反复演练,对培养学生的实际操作能力有很好的辅助作用,同... 仪器分析是化学相关专业一门非常重要的理论和实际操作相结合的课程,在实验环节需要操作使用大型精密仪器,与传统的实验教学相比,虚拟仿真实验能够保证每个学生都独立操作并可以反复演练,对培养学生的实际操作能力有很好的辅助作用,同时能够提升实验教学效果。文章通过几种大型仪器虚拟仿真实验过程介绍仪器的原理、操作和结果分析。 展开更多
关键词 仪器分析 虚拟仿真实验室 光谱分析
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In-situ analysis and genetic investigation of Li-bearing minerals in McDermitt clay-type lithium deposit,Nevada,USA 被引量:3
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作者 Yi Cui Hanjie Wen +4 位作者 Zhengbing Zhou Kunyue Ling Lin xu Shirong Liu fei xu 《Acta Geochimica》 EI CAS CSCD 2024年第3期478-488,共11页
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
关键词 McDermitt caldera Lithium occurrence Tuffaceous sediments MINERALOGY Hectorite neoformation
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Comparative analysis of thermodynamic and mechanical responses between underground hydrogen storage and compressed air energy storage in lined rock caverns 被引量:2
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作者 Bowen Hu Liyuan Yu +5 位作者 Xianzhen Mi fei xu Shuchen Li Wei Li Chao Wei Tao Zhang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第4期531-543,共13页
Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar power.Therefore,it is meaningful to comp... Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar power.Therefore,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage processes.This study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock caverns.Gas thermodynamic responses are validated using additional simulations and the field test data.Temperature and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation modes.Hydrogen reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and pressure.Unlike steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing layer.In CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same areas.Our present research can provide references for the selection of energy storage methods. 展开更多
关键词 Underground hydrogen storage Compressed air energy storage Mechanical response Thermodynamic response Lined rock caverns
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Optical scanning endoscope via a single multimode optical fiber 被引量:3
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作者 Guangxing Wu Runze Zhu +2 位作者 Yanqing Lu Minghui Hong fei xu 《Opto-Electronic Science》 2024年第3期1-32,共32页
Optical endoscopy has become an essential diagnostic and therapeutic approach in modern biomedicine for directly observing organs and tissues deep inside the human body,enabling non-invasive,rapid diagnosis and treatm... Optical endoscopy has become an essential diagnostic and therapeutic approach in modern biomedicine for directly observing organs and tissues deep inside the human body,enabling non-invasive,rapid diagnosis and treatment.Optical fiber endoscopy is highly competitive among various endoscopic imaging techniques due to its high flexibility,compact structure,excellent resolution,and resistance to electromagnetic interference.Over the past decade,endoscopes based on a single multimode optical fiber(MMF)have attracted widespread research interest due to their potential to significantly reduce the footprint of optical fiber endoscopes and enhance imaging capabilities.In comparison with other imaging principles of MMF endoscopes,the scanning imaging method based on the wavefront shaping technique is highly developed and provides benefits including excellent imaging contrast,broad applicability to complex imaging scenarios,and good compatibility with various well-established scanning imaging modalities.In this review,various technical routes to achieve light focusing through MMF and procedures to conduct the scanning imaging of MMF endoscopes are introduced.The advancements in imaging performance enhancements,integrations of various imaging modalities with MMF scanning endoscopes,and applications are summarized.Challenges specific to this endoscopic imaging technology are analyzed,and potential remedies and avenues for future developments are discussed. 展开更多
关键词 multimode optical fiber ENDOSCOPE scanning imaging FOCUSING wavefront shaping
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Acupuncture for chronic nonspecific low back pain in middle-aged and older patients:A randomized controlled trial 被引量:1
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作者 fei xu Kai-qiong JIAO +1 位作者 Lin-peng WANG Fan ZHANG 《World Journal of Acupuncture-Moxibustion》 CAS CSCD 2024年第4期300-305,共6页
Objective:To observe the specific effects of acupuncture in middle-aged and older patients with chronic nonspecific low back pain(CNSLBP).Methods:Sixty-six patients with CNSLBP were randomized into the acupuncture or ... Objective:To observe the specific effects of acupuncture in middle-aged and older patients with chronic nonspecific low back pain(CNSLBP).Methods:Sixty-six patients with CNSLBP were randomized into the acupuncture or sham acupuncture groups(n=33).In the acupuncture group,penetrating acupuncture with a long needle was delivered at Ashi points(painful/sensitive points),and the needles were manipulated by rotating technique after deqi till patients felt distending pain.The needles were retained in place for 30 min.Acupuncture was given three times per week for 4 weeks.In the sham acupuncture group,shallow needling was performed at non-meridian,non-acupoint,non-painful,and non-sensitive points.The needle retention and duration of treatment were the same as those of the acupuncture group before treatment,after the first intervention,after the whole treatment,and in follow-up visit(4 weeks after the whole treatment).The scores of the visual analog scale(VAS)for pain,range of movement(ROM)of the spine,and simplified Oswestry Dysfunction Index(ODI)were observed separately.Results:Compared to the outcomes before treatment,the VAS score,spinal ROM,and simplified ODI score were lower after the first intervention,after treatment,and in follow-up visits in the acupuncture group,indicating the statistical significance(P<0.05).When compared with the sham acupuncture group,the VAS score,spinal ROM,and simplified ODI score were significantly lower in the acupuncture group after the first intervention,after treatment,and in follow-up visit(P<0.05).The total effective rate was 90.9%in the acupuncture group,which was significantly higher than that(75.76%)in the sham acupuncturegroup(P<0.05).Conclusion:Acupuncture has a specific effect on CNSLBP in middle-aged and older patients and a superior effect on immediate analgesia. 展开更多
关键词 Low back pain ACUPUNCTURE Sham-acupuncture Elongated needle Long needle Specific effect
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大型仪器分析实验教学的困境及虚拟仿真技术的应用 被引量:4
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作者 李晓佩 张勇杰 +3 位作者 费旭 王佳 岳向丽 薛丽珍 《广州化工》 CAS 2024年第9期167-169,共3页
仪器分析实验是仪器分析类课程的重要实践环节,是高校培养高素质实践型人才的重要途径。然而,受制于仪器价格、运行维护成本、实验周期等因素,大型仪器分析实验教学面临困境。虚拟仿真技术是助力大型仪器分析实验教学走出困境的有效工... 仪器分析实验是仪器分析类课程的重要实践环节,是高校培养高素质实践型人才的重要途径。然而,受制于仪器价格、运行维护成本、实验周期等因素,大型仪器分析实验教学面临困境。虚拟仿真技术是助力大型仪器分析实验教学走出困境的有效工具。本文探讨了大型仪器分析实验教学所面临的困境,并对虚拟仿真技术在大型仪器分析实验教学中的应用进行了总结和分析。 展开更多
关键词 大型仪器分析实验教学 虚拟仿真技术 虚实结合
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Hybrid hard carbon framework derived from polystyrene bearing distinct molecular crosslinking for enhanced sodium storage
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作者 Yuqian Qiu Guangshen Jiang +8 位作者 Yanxia Su Xinren Zhang Yuxuan Du Xiaosa xu Qian Ye Jinbo Zhang Miaohan Ban fei xu Hongqiang Wang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第7期178-190,共13页
Exploiting high-performance yet low-cost hard carbon anodes is crucial to advancing the state-of-the-art sodium-ion batteries.However,the achievement of superior initial Coulombic efficiency(ICE)and high Na-storage ca... Exploiting high-performance yet low-cost hard carbon anodes is crucial to advancing the state-of-the-art sodium-ion batteries.However,the achievement of superior initial Coulombic efficiency(ICE)and high Na-storage capacity via low-temperature carbonization remains challenging due to the presence of tremendous defects with few closed pores.Here,a facile hybrid carbon framework design is proposed from the polystyrene precursor bearing distinct molecular bridges at a low pyrolysis temperature of 800℃ via in situ fusion and embedding strategy.This is realized by integrating triazine-and carbonylcrosslinked polystyrene nanospheres during carbonization.The triazine crosslinking allows in situ fusion of spheres into layered carbon with low defects and abundant closed pores,which serves as a matrix for embedding the well-retained carbon spheres with nanopores/defects derived from carbonyl crosslinking.Therefore,the hybrid hard carbon with intimate interface showcases synergistic Na ions storage behavior,showing an ICE of 70.2%,a high capacity of 279.3 mAh g^(-1),and long-term 500 cycles,superior to carbons from the respective precursor and other reported carbons fabricated under the low carbonization temperature.The present protocol opens new avenues toward low-cost hard carbon anode materials for high-performance sodiumion batteries. 展开更多
关键词 closed pores hybrid hard carbons hypercrosslinking polystyrenes low-temperature carbonization sodium storage
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