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氨基功能化壳聚糖微球对Cr(VI)的吸附性能及其机理 被引量:2
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作者 蒋达 许倩倩 +2 位作者 吴雪兰 龙红明 张秋雨 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2024年第1期45-56,共12页
以壳聚糖(CS)为基材,在制备过程中用三聚磷酸钠(TPP)为固化剂,用戊二醛(GLA)交联以提高其耐酸性能,并使用二乙烯三胺(DETA)改性,制备出富含羟基和氨基的CS/DETA凝胶球用以吸附水体中的Cr(VI)。红外光谱表征结果证实了DETA的成功接枝;X... 以壳聚糖(CS)为基材,在制备过程中用三聚磷酸钠(TPP)为固化剂,用戊二醛(GLA)交联以提高其耐酸性能,并使用二乙烯三胺(DETA)改性,制备出富含羟基和氨基的CS/DETA凝胶球用以吸附水体中的Cr(VI)。红外光谱表征结果证实了DETA的成功接枝;X射线光电子能谱表征结果显示Cr(VI)被吸附到CS/DETA表面;Zeta电位表征揭示了CS/DETA的表面电负性,其在酸性条件下更易吸附Cr(VI)。通过动力学和热力学模型探究其吸附过程,结果表明,CS/DETA对Cr(VI)的吸附过程更符合拟一级动力学模型和Langmuir等温吸附模型,在318.15 K,pH=2时,对Cr(VI)的最大吸附量为370.92 mg/g,且该反应为自发的吸热反应。 展开更多
关键词 生物质 吸附剂 凝胶 改性 壳聚糖
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A Noise-Resistant Superpixel Segmentation Algorithm for Hyperspectral Images
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作者 Peng Fu qianqian xu +1 位作者 Jieyu Zhang Leilei Geng 《Computers, Materials & Continua》 SCIE EI 2019年第5期509-515,共7页
The superpixel segmentation has been widely applied in many computer vision and image process applications.In recent years,amount of superpixel segmentation algorithms have been proposed.However,most of the current al... The superpixel segmentation has been widely applied in many computer vision and image process applications.In recent years,amount of superpixel segmentation algorithms have been proposed.However,most of the current algorithms are designed for natural images with little noise corrupted.In order to apply the superpixel algorithms to hyperspectral images which are always seriously polluted by noise,we propose a noiseresistant superpixel segmentation(NRSS)algorithm in this paper.In the proposed NRSS,the spectral signatures are first transformed into frequency domain to enhance the noise robustness;then the two widely spectral similarity measures-spectral angle mapper(SAM)and spectral information divergence(SID)are combined to enhance the discriminability of the spectral similarity;finally,the superpixels are generated with the proposed frequency-based spectral similarity.Both qualitative and quantitative experimental results demonstrate the effectiveness of the proposed superpixel segmentation algorithm when dealing with hyperspectral images with various noise levels.Moreover,the proposed NRSS is compared with the most widely used superpixel segmentation algorithm-simple linear iterative clustering(SLIC),where the comparison results prove the superiority of the proposed superpixel segmentation algorithm. 展开更多
关键词 Superpixel segmentation hyperspectral images fourier transformation spectral similarity random noise
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Sipdroid平台下的信息隐藏功能设计与实现
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作者 徐茜茜 程开洋 +4 位作者 温兴杰 王壮 周玉欣 闫美玲 赵红光 《软件工程与应用》 2017年第6期163-171,共9页
网络电话具有资费低、易操作、平台兼容性高等优点,因此得到迅速发展并获得广大消费者的青睐。Sipdroid是一款开源且使用简便的网络电话软件,其采用的Sip协议具有结构简单、支持多媒体业务的开展、符合互联网网络结构、可扩展性好、应... 网络电话具有资费低、易操作、平台兼容性高等优点,因此得到迅速发展并获得广大消费者的青睐。Sipdroid是一款开源且使用简便的网络电话软件,其采用的Sip协议具有结构简单、支持多媒体业务的开展、符合互联网网络结构、可扩展性好、应用灵活等优点。基于的Android平台具有良好的开源性和兼容性。网络在为人们提供信息共享的同时,对信息的安全性也造成了一定的威胁。本文为了进一步提高传输信息的安全性,在Sipdroid系统的基础上进行分析设计,添加信息隐藏模块,在实时语音通话的同时,实现了隐藏信息的嵌入、传输与提取。测试结果表明,在加入信息隐藏功能之后Sipdroid仍具有良好的使用性。 展开更多
关键词 Sipdroid 分析与设计 信息隐藏
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Recent advances,challenges,and perspectives on carbon capture 被引量:2
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作者 Shihan Zhang Yao Shen +11 位作者 Chenghang Zheng qianqian xu Yifang Sun Min Huang Lu Li Xiongwei Yang Hao Zhou Heliang Ma Zhendong Li Yuanhang Zhang Wenqing Liu Xiang Gao 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2024年第6期75-104,共30页
Carbon capture,utilization and storage(CCUS)technologies play an essential role in achieving Net Zero Emissions targets.Considering the lack of timely reviews on the recent advancements in promising CCUS technologies,... Carbon capture,utilization and storage(CCUS)technologies play an essential role in achieving Net Zero Emissions targets.Considering the lack of timely reviews on the recent advancements in promising CCUS technologies,it is crucial to provide a prompt review of the CCUS advances to understand the current research gaps pertained to its industrial application.To that end,this review first summarized the developmental history of CCUS technologies and the current large-scale demonstrations.Then,based on a visually bibliometric analysis,the carbon capture remains a hotspot in the CCUS development.Noting that the materials applied in the carbon capture process determines its performance.As a result,the state-of-the-art carbon capture materials and emerging capture technologies were comprehensively summarized and discussed.Gaps between state-of-art carbon capture process and its ideal counterpart are analyzed,and insights into the research needs such as material design,process optimization,environmental impact,and technical and economic assessments are provided. 展开更多
关键词 Carbon capture utilization and storage Visualization analysis Research hotspots and trends CO_(2)capture technology
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Single-cell spatial transcriptomics in cardiovascular development,disease,and medicine
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作者 Songjie Han qianqian xu +6 位作者 Yawen Du Chuwei Tang Herong Cui Xiaofeng Xia Rui Zheng Yang Sun Hongcai Shang 《Genes & Diseases》 SCIE CSCD 2024年第6期192-204,共13页
Cardiovascular diseases(CVDs)impose a significant burden worldwide.Despite the elucidation of the etiology and underlying molecular mechanisms of cvDs by numerous studies and recent discovery of effective drugs,their ... Cardiovascular diseases(CVDs)impose a significant burden worldwide.Despite the elucidation of the etiology and underlying molecular mechanisms of cvDs by numerous studies and recent discovery of effective drugs,their morbidity,disability,and mortality are still high.Therefore,precise risk stratification and effective targeted therapies for CvDs are warranted.Recent improvements in single-cell RNA sequencing and spatial transcriptomics have improved our understanding of the mechanisms and cells involved in cardiovascular phylogeny and CvDs.Single-cell RNA sequencing can facilitate the study of the human heart at remarkably high res-olution and cellular and molecular heterogeneity.However,this technique does not provide spatial information,which is essential for understanding homeostasis and disease.Spatial tran-scriptomics can elucidate intracellular interactions,transcription factor distribution,cell spatial localization,and molecular profiles of mRNA and identify cell populations causing the disease and their underlying mechanisms,including cell crosstalk.Herein,we introduce the main methods of RNA-seq and spatial transcriptomics analysis and highlight the latest ad-vances in cardiovascular research.We conclude that single-cell RNA sequencing interprets dis-ease progression in multiple dimensions,levels,perspectives,and dynamics by combining spatial and temporal characterization of the clinical phenome with multidisciplinary tech-niques such as spatial transcriptomics.This aligns with the dynamic evolution of CVDs(e.g.,"angina-myocardial infarction-heart failure"in coronary artery disease).The study of pathways for disease onset and mechanisms(e.g.,age,sex,comorbidities)in different patient subgroups should improve disease diagnosis and risk stratification.This can facilitate precise individualized treatment of CVDs. 展开更多
关键词 Cardiovascular disease Precision medicine Single-cellspatial transcriptomics Single-cell transcriptome Spatial transcriptome TRANSCRIPTOMICS
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妊娠期运动干预对超重及肥胖孕妇Toll样受体4通路的下调作用 被引量:2
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作者 刘明慧 王晨 +6 位作者 马京梅 魏玉梅 张晓明 许芊芊 苏日娜 冯慧 杨慧霞 《中华围产医学杂志》 CAS CSCD 北大核心 2022年第6期461-469,共9页
目的:探讨妊娠期运动干预对超重及肥胖孕妇Toll样受体4(Toll-like receptor 4,TLR4)通路的调控作用。方法:本研究基于本课题组2014年12月至2016年7月于北京大学第一医院开展的随机对照试验,选取其中择期剖宫产分娩,且除外合并妊娠并发... 目的:探讨妊娠期运动干预对超重及肥胖孕妇Toll样受体4(Toll-like receptor 4,TLR4)通路的调控作用。方法:本研究基于本课题组2014年12月至2016年7月于北京大学第一医院开展的随机对照试验,选取其中择期剖宫产分娩,且除外合并妊娠并发症孕妇,最终纳入运动组12例、对照组11例。采用实时荧光定量聚合酶链反应、蛋白质印迹技术、流式细胞微珠法等检测方法比较2组孕妇外周血单个核细胞(peripheral blood mononuclear cell,PBMC)、腹直肌、网膜脂肪和皮下脂肪中 TLR4-髓样细胞分化因子(myeloid differentiation factor 8,MyD88)-核因子-κB(nuclear factor-κB,NF-κB)通路的表达情况,以及血浆中炎症因子的表达水平。采用独立样本 t检验、广义估计方程、 χ^(2)检验、Pearson相关分析等对数据进行统计学分析。 结果:(1)运动组孕妇中、晚孕期外周血浆中炎症因子TNF-α及IL-1β的表达呈现低于对照组的趋势,但差异均无统计学意义( P值均>0.05)。(2)运动组孕妇孕期PBMC中TLR4、MyD88和NF-κB的mRNA以及TLR4和NF-κB蛋白表达水平显著低于对照组(TLR4 mRNA:中孕期0.06±0.03与0.10±0.04,晚孕期0.05±0.02与0.11±0.05, χ^(2)=8.07;MyD88 mRNA:中孕期0.09±0.03与0.11±0.03,晚孕期0.10±0.04与0.17±0.06, χ^(2)=5.81;NF-κB mRNA:中孕期0.10±0.03与0.17±0.08,晚孕期0.08±0.03与0.20±0.08, χ^(2)=14.71;TLR4蛋白:中孕期1.7±0.5与1.9±0.8,孕晚期1.7±0.4与2.3±0.8, χ^(2)=5.83;NF-κB蛋白:中孕期1.0±0.4与1.5±0.4,晚孕期1.2±0.3与1.5±0.5, χ^(2)=4.73, P值均<0.05)。且随时间变化,运动组与对照组间PBMC中TLR4、MyD88和NF-κB的mRNA以及TLR4蛋白表达水平的差别逐渐增大。(3)运动组腹直肌、网膜脂肪组织中NF-κB(0.04±0.02与0.08±0.04, t=-3.72;0.25±0.05与0.63±0.21, t=-5.41;P值均<0.05)及皮下脂肪组织中TLR4和MyD88的mRNA水平明显低于对照组(0.12±0.03与0.30±0.10, t=-5.30;0.24±0.09与0.44±0.08, t=-5.38;P值均<0.05)。运动组网膜脂肪中MyD88和NF-κB及皮下脂肪中NF-κB蛋白水平明显低于对照组(1.1±0.5与2.0±0.8, t=-3.15;1.3±0.5与2.0±0.9, t=-2.23;1.2±0.5与1.9±0.8, t=-2.80;P值均<0.05)。(4)2组孕妇腹直肌中TLR4和NF-κB mRNA表达水平( r值分别为0.453和0.485)、网膜脂肪中NF-κB mRNA表达水平以及TLR4和MyD88蛋白水平( r值分别为0.539、0.437和0.527)与孕妇空腹血糖水平呈正相关( P值均<0.05)。 结论:妊娠期规律运动可以下调超重和肥胖孕妇TLR4-MyD88-NF-κB通路的表达和激活,且相关通路因子表达与空腹血糖水平具有一定相关性。 展开更多
关键词 妊娠期肥胖 TOLL样受体4 运动 妊娠结局
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Diagnostic value of combination of rapid on-site evaluation and radial endobronchial ultrasound for peripheral pulmonary infectious lesions 被引量:2
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作者 Min Li Jiaqi Cao +4 位作者 Qian He Ming Zhang qianqian xu Wenya Su Chunlai Feng 《Chinese Medical Journal》 SCIE CAS CSCD 2022年第23期2869-2871,共3页
Peripheral pulmonary lesions(PPLs)are surrounded by lung parenchyma and invisible under an endoscope.The detection rate of PPLs by routine bronchoscopy is low.Radial endobronchial ultrasound(R-EBUS)can overcome those ... Peripheral pulmonary lesions(PPLs)are surrounded by lung parenchyma and invisible under an endoscope.The detection rate of PPLs by routine bronchoscopy is low.Radial endobronchial ultrasound(R-EBUS)can overcome those limitations,as it can locate peripheral bronchial lesions through a characteristic ultrasound signal.Rapid on-site evaluation(ROSE)is a real-time rapid cytological interpretation technology accompanied by tissue sampling.ROSEis helpful in improving the diagnostic rate of R-EBUS for PPLs,especially lung cancer.[1]However,the utility of ROSE during R-EBUS for peripheral pulmonary infectious lesions(infectious PPLs)is unclear.This study aimed to analyze the diagnostic value and safety of R-EBUS combined with ROSE in infectious PPLs.The study was approved by the Ethics Committee of the Third Affiliated Hospital of Soochow University(No.2019-017).The informed consent form was signed by the patient or his or her authorized legal representative. 展开更多
关键词 LESIONS ROUTINE LEGAL
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Dynamically reconfigurable subwavelength optical device for hydrogen sulfide gas sensing 被引量:1
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作者 ZHENGJI WEN JIALIANG LU +11 位作者 WEIWEI YU HAO WU HAO XIE XIAOHANG PAN qianqian xu ZIJI ZHOU CHONG TAN DONGJIE ZHOU CHANG LIU YAN SUN NING DAI JIAMING HAO 《Photonics Research》 SCIE EI CAS CSCD 2021年第10期2060-2067,共8页
The importance of tunable subwavelength optical devices in modern electromagnetic and photonic systems is indisputable.Herein,a lithography-free,wide-angle,and reconfigurable subwavelength optical device with high tun... The importance of tunable subwavelength optical devices in modern electromagnetic and photonic systems is indisputable.Herein,a lithography-free,wide-angle,and reconfigurable subwavelength optical device with high tunability operating in the near-infrared regions is proposed and experimentally demonstrated,based on a reversible nanochemistry approach.The reconfigurable subwavelength optical device basically comprises an ultrathin copper oxide(CuO)thin film on an optical thick gold substrate by utilizing the reversible chemical conversion of CuO to sulfides upon exposure to hydrogen sulfide gas.Proof-of-concept experimental results show that the maximal modulation depth of reflectance can be as high as 90%at the wavelength of 1.79μm with the initial thickness of CuO taken as 150 nm.Partially reflected wave calculations combined with the transfer matrix method are employed to analytically investigate the optical properties of the structure,which show good agreement with experimental results.We believe that the proposed versatile approaches can be implemented for dynamic control management,allowing applications in tunable photonics,active displays,optical encryption,and gas sensing. 展开更多
关键词 RECONFIGURABLE OPTICAL TUNABLE
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Hydrogen-bonded metal-nucleobase frameworks for highly selective capture of ethane/propane from methane and methane/nitrogen separation
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作者 Ying Liu qianqian xu +7 位作者 Lihang Chen Changhua Song Qiwei Yang Zhiguo Zhang Dan Lu Yiwen Yang Qilong Ren Zongbi Bao 《Nano Research》 SCIE EI CSCD 2022年第8期7695-7702,共8页
The separation of light hydrocarbons,including C_(2)H_(6)and C_(3)H_(8),is essential to natural gas upgrading.Meanwhile,N_(2)removal from CH_(4)is also crucial to concentrating low-quality coalbed methane,but the adso... The separation of light hydrocarbons,including C_(2)H_(6)and C_(3)H_(8),is essential to natural gas upgrading.Meanwhile,N_(2)removal from CH_(4)is also crucial to concentrating low-quality coalbed methane,but the adsorption process is challenging because of the close kinetic diameter.This work reports two hydrogen-bonded metal-nucleobase frameworks(HOF-ZJU-201 and HOF-ZJU202)capable of efficiently separating C_(3)H_(8)/CH_(4),C_(2)H_(6)/CH_(4),and CH_(4)/N_(2).Due to strong affinity for C_(3)H_(8)and C_(2)H_(6),the lowpressure capacity for C_(3)H_(8)(5 kPa)and C_(2)H_(6)(10 kPa)of HOF-ZJU-201a exceeds most adsorbents.The ideal adsorbed solution theory(IAST)selectivity of C_(3)H_(8)/CH_(4)and C_(2)H_(6)/CH_(4)is 119 and 45 at ambient conditions.According to density functional theory calculations,surface polarization environments formed by electron-rich anions and electron-deficient purine heterocyclic rings contribute to the selective capture of C_(3)H_(8)and C_(2)H_(6)with greater polarizability.Furthermore,the high CH_(4)adsorption capacity(1.73 mmol/g for HOF-ZJU-201a and 1.50 mmol/g for HOF-ZJU-202a at 298 K and 1.0 bar)and excellent CH_(4)/N_(2)selectivity(6.0 for HOF-ZJU-201 at 298 K),as well as dynamic breakthrough experiments of binary CH_(4)/N_(2)gas mixture implied their efficacy in the concentration of low-quality coalbed methane. 展开更多
关键词 hydrogen-bonded frameworks METHANE natural gas adsorption separation
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Carbon dioxide fixation by Chlorella sp.USTB-01 with a fermentor-helical combined photobioreactor
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作者 xuan JIA Hai YAN +5 位作者 Zijing WANG Huanju HE qianqian xu Haiou WANG Chunhua YIN Liqin LIU 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2011年第3期402-408,共7页
A promising microalgal strain isolated from fresh water,which can grow both autotrophically on inorganic carbon under lighting and heterotrophically on organic carbon without lighting,was identified as Chlorella sp.US... A promising microalgal strain isolated from fresh water,which can grow both autotrophically on inorganic carbon under lighting and heterotrophically on organic carbon without lighting,was identified as Chlorella sp.USTB-01 with the phylogenetic analysis based on 18S ribosomal ribonucleic acid(rRNA)gene sequences.In the heterotrophic batch culture,more than 20.0 g·L^(-1)of cell dry weight concentration(DWC)of Chlorella sp.USTB-01 was obtained at day 5,and which was used directly to seed the autotrophic culture.A novel fermentor-helical combined photobioreactor was established and used to cultivate Chlorella sp.USTB-01 for the fixation of carbon dioxide(CO_(2)).It showed that the autotrophic growth of Chlorella sp.USTB-01 in the combined photobioreactor was more effective than that in the fermentor alone and the maximum DWC of 2.5 g·L^(-1)was obtained at day 6.The highest CO_(2)fixation of 95%appeared on day 1 in the exponential growth phases of Chlorella sp.USTB-01 and 49.8%protein was found in the harvested microalgal cells. 展开更多
关键词 Chlorella sp.USTB-01 carbon dioxide fixation combined photobioreactor
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