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Derivative Spectroscopy and its Application at Detecting the Weak Emission/Absorption Lines

Research in Astronomy and Astrophysics 2024年第3期24卷 205-223页

作者： Lihuan yu Jiangdan Li Jinliang Wang Jiajia Li Jiao Li qiang Xi Zhanwen Han yunnan Observatories Chinese Academy of Sciences(CAS)Kunming 650011China Key Lab of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

The development of spectroscopic survey telescopes like Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST),Apache Point Observatory Galactic Evolution Experiment and Sloan Digital Sky Survey has opened up unprecedented opportunities for stellar *** types of stars,such as early-type emission-line stars and those with stellar winds,can be distinguished by the profiles of their spectral *** this paper,we introduce a method based on derivative spectroscopy(DS)designed to detect signals within complex backgrounds and provide a preliminary estimation of curve *** method exhibits a unique advantage in identifying weak signals and unusual spectral line profiles when compared to other popular line detection *** validated our approach using synthesis spectra,demonstrating that DS can detect emission signals three times fainter than Gaussian ***,we applied our method to 579,680 co-added spectra from LAMOST Medium-Resolution Spectroscopic Survey,identifying 16,629 spectra with emission peaks around the Hαline from 10,963 *** spectra were classified into three distinct morphological groups,resulting in nine subclasses as follows.(1)Emission peak above the pseudo-continuum line(single peak,double peaks,emission peak situated within an absorption line,P Cygni profile,Inverse P Cygni profile);(2)Emission peak below the pseudo-continuum line(sharp emission peak,double absorption peaks,emission peak shifted to one side of the absorption line);(3)Emission peak between the pseudo-continuum line.

关键词： line identification-line profiles-methods data analysis-techniques spectroscopic-techniques radial velocities

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多片弹性块周向紧箍带力学性能分析

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科学技术与工程 2016年第35期16卷 162-166页

作者：马长林于传强郝琳火箭军工程大学203教研室西安710025

针对多片分离结构弹性块在大型圆柱外圆周上的紧箍问题,根据力学平衡原理,建立了理想情况下紧箍带受力计算基础模型,分别推导了考虑弹性块重力、紧箍带与弹性块之间摩擦力等因素时紧箍带受力计算修正模型。以某弹性块的紧箍为例进行了... 详细信息

针对多片分离结构弹性块在大型圆柱外圆周上的紧箍问题,根据力学平衡原理,建立了理想情况下紧箍带受力计算基础模型,分别推导了考虑弹性块重力、紧箍带与弹性块之间摩擦力等因素时紧箍带受力计算修正模型。以某弹性块的紧箍为例进行了数据验算,比较分析了弹性块重力、摩擦力、紧箍操作方式等因素对紧箍带受力与角度关系的影响,从工程应用角度揭示了多片弹性块周向紧箍过程中紧箍带的受力规律。研究结果可为多片弹性块周向紧箍带的选材与设计提供理论依据。

关键词：工程力学弹性块紧箍带受力分析

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Inter-stage performance and energy characteristics analysis of electric submersible pump based on entropy production theory

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Petroleum Science 2024年第2期21卷 1354-1368页

作者： Hui Wang Yang Yang Bin Xi Wei-Dong Shi chuan Wang Lei-Lei Ji Xiang-yu Song Zhao-Ming He College of Hydraulic Science and Engineering Yangzhou UniversityYangzhou225009JiangsuChina College of Electrical and Mechanical Engineering Nanchang Institute of TechnologyNanchang330044JiangxiChina College of Mechanical Engineering Nantong UniversityNantong226019JiangsuChina National Research Center of Pumps Jiangsu UniversityZhenjiang212013JiangsuChina Zhejiang Zhenxing Petrochemical Machinery Co. Ltd.Ruian325204ZhejiangChina Department of Mechanical Engineering of Texas Tech University Lubbock79411TXUSA

The electric submersible pump(ESP) is a crucial apparatus utilized for lifting in the oil extraction *** lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristics and internal flow across stages are also introduced. In this study, the inter-stage variability of energy characteristics in ESP hydraulic systems is investigated through entropy production(EP) analysis,which incorporates numerical simulations and experimental validation. The EP theory facilitates the quantification of energy loss in each computational subdomain at all ESP stages, establishing a correlation between microscopic flow structure and energy dissipation within the system. Furthermore, the underlying causes of inter-stage variability in ESP hydraulic systems are examined, and the advantages and disadvantages of applying the EP theory in this context are evaluated. Consistent energy characteristics within the ESP, aligned with the distribution of internal flow structure, are provided by the EP theory, as demonstrated by our results. The EP theory also enables the quantitative analysis of internal flow losses and complements existing performance analysis methods to map the internal flow structure to hydraulic losses. Nonetheless, an inconsistency between the energy characterization based on EP theory and the traditional efficiency index when reflecting inter-stage differences is identified. This inconsistency arises from the exclusive focus of the EP theory on flow losses within the flow field, disregarding the quantification of external energy input to the flow field. This study provides a reference for the optimization of EP theory in rotating machinery while deeply investigating the energy dissipation characteristics of multistage hydraulic system, which has certain theoretical and practical significance.

关键词： Electric submersible pump(ESP) Entropy production theory Energy characteristics Inter-stage differences

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A Plasma Membrane Polarity Sensor Harnessing Conjoined Twisted Intramolecular Charge Transfer Modulation and Charge Number Control Strategy

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CCS Chemistry 2024年第3期6卷 733-748页

作者： yu-qiang Zhao Le yu Liping Zhu Jinsong Liang Ying Zhou Jong Seung Kim College of Chemical Science and Technology Yunnan UniversityKunming 650091 Department of Chemistry Korea UniversitySeoul 02841 TheranoChem Incorporation Seoul 02856

Polarity is a critical microenvironmental factor of the plasma membrane,which can offer valuable insights into various biological ***,we proposed a novel strategy for the construction of fluorescent agents to measure plasma membrane polarity by conjoining twisted intramolecular charge transfer(TICT)modulation and charge number *** is shown that compounds with a stronger TICT tendency are more sensitive to polarity shifts due to the number of dialkylated amino groups present(from 1 to 3),and the molecules with two or more charged centers remain in the plasma ***,we developed two fluorescent agents with high polarity sensitivity,excellent turn-on ratios,and superior ability,to target the plasma *** the wash-free fluorescence imaging and fluorescence lifetime tests,our designed agent could detect plasma membrane polarity with high precision,allowing effective distinction between cancer cells and normal cells based on their differences in plasma membrane ***,both fluorescence and fluorescence lifetime changes of the plasma membrane in the ferroptosis model established by Sorafenib confirmed an increase in plasma membrane polarity during cell ferroptosis.

关键词： membrane polarity fluorescence agents fluorescence imaging fluorescence lifetime imaging

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NbN quantum dots anchored hollow carbon nanorods as efficient polysulfide immobilizer and lithium stabilizer for Li-S full batteries

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Journal of Energy Chemistry 2024年第1期88卷 260-271,I0007页

作者： Fei Ma Zhuo Chen Katam Srinivas Ziheng Zhang yu Wu Dawei Liu Hesheng yu yue Wang Xinsheng Li Ming-qiang Zhu Qi Wu yuanfu Chen School of Integrated Circuit Science and Engineering and State Key Laboratory of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and TechnologyChengdu 610054SichuanChina College of Science and Institute of Oxygen Supply Center of Tibetan Studies(Everest Research Institute)Tibet UniversityLhasa 850000TibetChina College of Mechanical and Electronic Engineering Northwest A&F UniversityXianyang 712100ShaanxiChina

The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)*** simultaneously address such issues,monodispersed Nb N quantum dots anchored on nitrogen-doped hollow carbon nanorods(NbN@NHCR)are elaborately developed as efficient Li PSs immobilizer and Li stabilizer for high-performance Li-S full *** functional theory(DFT)calculations and experimental characterizations demonstrate that the sulfiphilic and lithiophilic NbN@NHCR hybrid can not only efficiently immobilize the soluble Li PSs and facilitate diffusion-conversion kinetics for alleviating the shuttling effect,but also homogenize the distribution of Li+ions and regulate uniform Li deposition for suppressing Li-dendrite *** a result,the assembled Li-S full batteries(NbN@NHCR-S||Nb N@NHCR-Li)deliver excellent long-term cycling stability with a low decay rate of 0.031%per cycle over 1000 cycles at high rate of 2 *** at a high S loading of 5.8 mg cm^(-2)and a low electrolyte/sulfur ratio of 5.2μL mg^(-1),a large areal capacity of 6.2 mA h cm^(-2)can be achieved in Li-S pouch cell at 0.1 *** study provides a new perspective via designing a dual-functional sulfiphilic and lithiophilic hybrid to address serious issues of the shuttle effect of S cathode and dendrite growth of Li anode.

关键词： Dual-functional host NbN quantum dots Shuttle effect Dendrite-free Li anode Li-S full batteries

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Dynamic Crosslinked Phosphorescent Poly(vinyl alcohol)-Terpyridine Films with Enhanced Mechanical Properties and Tunable Shape Memory

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Chinese Journal of Polymer Science 2024年第10期42卷 1595-1601页

作者： Meng Wei Wei-Hao Feng Chen yu Zhen-Yi Jiang Guang-qiang Yin Wei Lu Tao Chen Key Laboratory of Advanced Marine Materials Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences School of Chemical Sciences University of Chinese Academy of Sciences School of Materials Science and Chemical Engineering.Ningbo University

Achieving versatile room temperature phosphorescence （RTP） materials, especially with tunable mechanical properties and shape memory is attractive and essential but rarely reported. Here, a strategy was reported to realize multi-functional RTP films with multicolor fluorescence, ultralong afterglow, adjustable mechanical properties, and shape memory through the synergistic dynamic interaction of lanthanide（LnⅢ）-terpyridine coordination, borate ester bonds, and hydrogen bondings in a poly（vinyl alcohol）(PVA) matrix. By varying the amount of borax,the mechanical properties of the films could be finely controlled due to the change of crosslinking degree of dynamic borate ester bonds in *** assembly and disassembly of borate ester bonds upon the trigger of borax and acid were applied as reversible linkage to achieve programmable shape memory behavior. In addition, the films displayed both fascinating multicolor fluorescence and ultralong afterglow characteristics due to the presence of Ln III doping and confinement of terpyridine in PVA. This study provides a new avenue to impart modulable mechanical strength and shape memory to RTP materials.

关键词： Dynamic bonds Multicolor fluorescent Room temperature phosphorescence materials Shape memory Tunable mechanical properties

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Unravelling the nature of the active species as well as the Mn doping effect over gamma-Al_(2)O_(3) catalyst for eliminating AsH_(3) and PH_(3)

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Journal of Environmental Sciences 2024年第2期136卷 213-225页

作者： Bowen Xu Jiaxin Qu Xueqian Wang Langlang Wang yu Pu Ping Ning Yibing Xie Yixing Ma qiang Ma Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China School of Architecture and Civil Engineering Chengdu UniversityChengdu 610106China

To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3)catalysts were *** characteristics of the catalysts showed that Mn reduced the crystallinity of the active CuO component,increased the number of oxygen vacancies and acidic sites on the catalyst surface,enhanced the mobility of surface oxygen,and the interaction between copper and manganese promoted the redox cycling ability of the catalysts and improved their oxidation performance,which increased the conversion frequency(TOF)by 2.54×10^(-2)to 3.07×10^(-2)sec^(-1).On the other hand,the introduction of Mn reduced the production of phosphate and As_(2)O_(3)on the catalyst surface by30.96%and 44.9%,which reduced the coverage and inerting of the active sites by phosphate and As_(2)O_(3),resulting in an 8 hr(6 hr)improvement in the stability of PH_(3)(AsH_(3))removal.

关键词： AsH_(3)-PH_(3)removal Oxygen activation Mn doping Stability enhancement

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Preoperative prediction of perineural invasion of rectal cancer based on a magnetic resonance imaging radiomics model:A dual-center study

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World Journal of Gastroenterology 2024年第16期30卷 2233-2248页

作者： Yan Liu Bai-Jin-Tao Sun chuan Zhang Bing Li Xiao-Xuan yu Yong Du Department of Radiology The Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina Department of Radiology The Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina.duyong@***

BACKGROUND Perineural invasion(PNI)has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer(RC).Preoperative prediction of PNI status is helpful for individualized treatment of ***,several radiomics studies have been used to predict the PNI status in RC,demonstrating a good predictive effect,but the results lacked *** preoperative prediction of PNI status is still challenging and needs further *** To establish and validate an optimal radiomics model for predicting PNI status preoperatively in RC *** This retrospective study enrolled 244 postoperative patients with pathologically confirmed RC from two independent *** patients underwent preoperative high-resolution magnetic resonance imaging(MRI)between May 2019 and August *** radiomics features were extracted and selected from oblique axial T2-weighted imaging(T2WI)and contrast-enhanced T1WI(T1CE)*** radiomics signatures were constructed using logistic regression analysis and the predictive potential of various sequences was compared(T2WI,T1CE and T2WI+T1CE fusion sequences).A clinical-radiomics(CR)model was established by combining the radiomics features and clinical risk *** internal and external validation groups were used to validate the proposed *** area under the receiver operating characteristic curve(AUC),DeLong test,net reclassification improvement(NRI),integrated discrimination improvement(IDI),calibration curve,and decision curve analysis(DCA)were used to evaluate the model *** Among the radiomics models,the T2WI+T1CE fusion sequences model showed the best predictive performance,in the training and internal validation groups,the AUCs of the fusion sequence model were 0.839[95%confidence interval(CI):0.757-0.921]and 0.787(95%CI:0.650-0.923),which were higher than those of the T2WI and T1CE sequence *** CR model constructed by combinin

关键词： Rectal cancer Perineural invasion Magnetic resonance imaging Radiomics Nomogram

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Electro-reductive carboxylation of acyclic C（sp3）–C（sp3） bonds in aromatic hydrocarbons with CO2

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Science China Chemistry 2024年第10期67卷 3366-3372页

作者： chuan-Kun Ran Quan Qu Yang-Yi Tao Yi-Fei Chen Li-Li Liao Jian-Heng Ye Da-Gang yu Key Laboratory of Green Chemistry & Technology of Ministry of Education College of ChemistrySichuan University West China School of Public Health and West China Fourth Hospital Sichuan University

Despite the recent advances in the selective functionalization of C–C bonds in specific substrates,cleavage and functionalization of C–C bonds in acyclic substrates,such as ethane derivatives,remains *** contrast to the well-developed functionalization of one carbon fragment after C–C bond cleavage,herein,we report a novel electro-reductive carboxylation of C（sp3）–C（sp3） bond in multi-aryl ethanes with carbon dioxide（CO2） by utilizing both carbon ***,this reaction exhibits an atom-,step-economic approach for the synthesis of carboxylic acids,fulfilling principal aspirations of organic ***,this method features mild reaction conditions,broad substrate scope,and good functional group *** and asymmetric substrates bearing primary,secondary,or tertiary C（sp3）–C（sp3） bonds are all amenable to this strategy,enabling one or two structurally different carboxylic acids to be facilely constructed at the same *** investigations indicate that carbanions might be the key intermediates in this reaction,which could be captured by CO2efficiently.

关键词： carbon dioxide electrochemistry C(sp3)–C(sp3) bonds cleavage reductive carboxylation

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Mismatch analysis of all-fiber coherent beam combiners based on the self-imaging effect

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High Power Laser Science and Engineering 2024年第2期12卷 1-15页

作者： yuefang Yan yu Liu Haoyu Zhang yuwei Li Chao Guo qiang Shu Wenhui Huang Feng Jing Rumao Tao Laser Fusion Research Center China Academy of Engineering PhysicsMianyangChina Key Laboratory of Particle&Radiation Imaging(Tsinghua University) Ministry of EducationBeijingChina

All-fiber coherent beam combiners based on the self-imaging effect can achieve a near-perfect single laser beam,which can provide a promising way to overcome the power limitation of a single-fiber *** of the key points is combining efficiency,which is determined by various mismatches during fabrication.A theoretical model has been built,and the mismatch error is analyzed numerically for the first *** mismatch errors have been numerically studied with the beam quality and combining efficiency being chosen as the evaluation *** tolerance of each mismatch error for causing 1%loss is calculated to guide the design of the beam *** simulation results are consistent with the experimental results,which show that the mismatch error of the square-core fiber is the main cause of the efficiency *** results can provide useful guidance for the fabrication of all-fiber coherent beam combiners.

关键词： all-fiber coherent beam combination mismatch analysis self-imaging

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