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How to estimate isotope fractionations of a Rayleigh-like but diffusion-limited disequilibrium process?

Acta Geochimica 2023年第1期42卷 24-37页

作者： Zi Xuan Guan Yun liu School of Earth and Space Science Peking UniversityBeijing 100871China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China International Center for Planetary Science College of Earth ScienceChengdu University of TechnologyChengdu 610059China CAS Center for Excellence in Comparative Planetology Hefei 230026China

The Rayleigh distillation isotope fractionation(RDIF) model is one of the most popular methods used in isotope geochemistry. Numerous isotope signals observed in geologic processes have been interpreted with this model. The RDIF model provides a simple mathematic solution for the reservoir-limited equilibrium isotope fractionation effect. Due to the reservoir effect, tremendously large isotope fractionations will always be produced if the reservoir is close to being depleted. However, in real situations, many prerequisites assumed in the RDIF model are often difficult to meet. For instance, it requires the relocated materials, which are removed step by step from one reservoir to another with different isotope compositions(i.e., with isotope fractionation), to be isotopically equilibrated with materials in the first reservoir simultaneously. This ‘‘quick equilibrium requirement’’ is indeed hard to meet if the first reservoir is sufficiently large or the removal step is fast. The whole first reservoir will often fail to re-attain equilibrium in time before the next removal *** problem led the RDIF model to fail to interpret isotope signals of many real situations. Here a diffusion-coupled and Rayleigh-like(i.e., reservoir-effect included) separation process is chosen to investigate this problem. We find that the final isotope fractionations are controlled by both the diffusion process and the reservoir effects via the disequilibrium separation process. Due to its complexity, we choose to use a numerical simulation method to solve this problem by developing specific computing codes for the working *** to our simulation results, the classical RDIF model only governs isotope fractionations correctly at the final stages of separation when the reservoir scale(or thickness of the system) is reduced to the order of magnitude of the quotient of the diffusivity and the separation rate. The RDIF model fails in other situations and the isotope fractionations

关键词： Isotope fractionation Reservoir isotope effect Rayleigh-like distillation process Diffusional isotope effect Numerical modeling Disequilibrium process

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Asymmetric Schottky Contacts in van der Waals Metal-Semiconductor-Metal Structures Based on Two-Dimensional Janus Materials

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Research 2020年第1期2020卷 1108-1115页

作者： Jia liu Ji-Chang Ren Tao Shen Xinyi liu Christopher J.Butch Shuang Li Wei liu Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Biomedical Engineering Nanjing UniversityNanjingChina Blue Marble Space Institute of Science SeattleWashingtonUSA

Physical and electronic asymmetry plays a crucial role in rectifiers and other devices with a directionally variant current-voltage(I-V)*** strategies for practically creating asymmetry in nanoscale components have been demonstrated,but complex fabrication procedures,high cost,and incomplete mechanistic understanding have significantly limited large-scale applications of these *** this work,we present density functional theory calculations which demonstrate asymmetric electronic properties in a metal-semiconductor-metal(MSM)interface composed of stacked van der Waals(vdW)*** MoSSe has an intrinsic dipole due to its asymmetric structure and,consequently,can act as either an n-type or p-type diode depending on the face at the interior of the stacked structure(SeMoS-SMoS ***-SMoS).In each configuration,vdW forces dominate the interfacial interactions,and thus,Fermi level pinning is largely *** transport calculations show that not only does the intrinsic dipole cause asymmetric I-V characteristics in the MSM structure but also that different transmission mechanisms are involved across the S-S(direct tunneling)and S-Se interface(thermionic excitation).This work illustrates a simple and practical method to introduce asymmetric Schottky barriers into an MSM structure and provides a conceptual framework which can be extended to other 2D Janus semiconductors.

关键词： Schottky asymmetric dipole

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Sepsis heterogeneity

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World Journal of Pediatrics 2023年第10期19卷 919-927页

作者： Wei Wang Chun-Feng liu Department of Pediatrics ShengJing Hospital of China Medical UniversityNo.36SanHao StreetShenyang CityLiaoning Province 110004China

Background Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection,with extremely high ***,sepsis is a heterogeneous syndrome characterized by a vast,multidimensional array of clinical and biologic features,which has hindered advances in the therapeutic field beyond the current *** sources We used PubMed to search the subject-related medical literature by searching for the following single and/or combination keywords:sepsis,heterogeneity,personalized treatment,host response,infection,epidemiology,mortality,incidence,age,children,sex,comorbidities,gene susceptibility,infection sites,bacteria,fungi,virus,host response,organ dysfunction and *** We found that host factors(age,biological sex,comorbidities,and genetics),infection etiology,host response dysregulation and multiple organ dysfunctions can all result in different disease manifestations,progression,and response to treatment,which make it difficult to effectively treat and manage sepsis *** Herein,we have summarized contributing factors to sepsis heterogeneity,including host factors,infection etiology,host response dysregulation,and multiple organ dysfunctions,from the key elements of pathogenesis of *** in-depth understanding of the factors that contribute to the heterogeneity of sepsis will help clinicians understand the complexity of sepsis and enable researchers to conduct more personalized clinical studies for homogenous patients.

关键词： Heterogeneity Host response Infection Personalized treatment Sepsis

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Balancing free and confined metallic Ni for an active and stable catalyst——A case study of CO methanation over Ni/Ni–Al2O3

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Journal of Energy Chemistry 2020年第11期29卷 73-84页

作者： Yong-Shan Xiao Yong-Hong Song Chang liu Xian-Ying Shi Han-Qing Ge Min-Li Zhu Zhao-Tie liu Zhong-Wen liu Key Laboratory of Syngas Conversion of Shaanxi Province School of Chemistry&Chemical EngineeringShaanxi Normal UniversityXi'an 710119ShaanxiChina

We propose a new strategy to make an active and stable Ni-based catalyst which can be operated in a wide range of reaction temperatures. The ordered mesoporous alumina(OMA) with confined Ni in the pore wall(Ni-OMA) was prepared via the one-pot evaporation induced self-assembly method. By using the incipient impregnation method, different amounts of free Ni were loaded over Ni-OMA(Ni/NiOMA) at a fixed total NiO content of 15 wt%. Characterization results confirmed the formation of wellstructured Ni-OMA, and the ordered structure was still well preserved even after impregnating NiO at a content of as high as 12 wt%. The catalysts were evaluated for the CO methanation as a model reaction under varied conditions. Importantly, the activity and stability of Ni/Ni-OMA for the titled reaction were significantly regulated by simply changing the ratio of the confined to free Ni. Over the optimum catalyst of NiO(2 wt%)/NiO(13 wt%)-OMA, the high activity at a temperature of as low as 300 ℃ was achieved with the space-time yield of methane over 7.6 g gcat-1 h-1 while a long-term stability for a time-onstream of 400 h was confirmed without an observable deactivation under the conditions of 600 ℃ and an extremely high gas hourly space velocity of 120,000 mL g-1 h-1. The results were well explained as the integrated merits of the free Ni for a high dispersion and the confined Ni in OMA for the anti-sintering property.

关键词： CO methanation Ni Ordered mesoporous alumina Evaporation induced self-assembly Ni-support interactions

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Manipulating cavity photon dynamics by topologically curved space

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Light(Science & Applications) 2022年第11期11卷 2738-2747页

作者： Yongsheng Wang Yuhao Ren Xiaoxuan Luo Bo Li Zaoyu Chen Zhenzhi liu Fu liu Yin Cai Yanpeng Zhang Jin liu Feng Li Key Laboratory for Physical Electronics and Devices of the Ministry of Education&Shaanxi Key Lab of Information Photonic Technique School of Electronic Science and EngineeringFaculty of Electronic and Information EngineeringXi'an Jiaotong UniversityXi'an 710049China State Key Laboratoy of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhouChina

Asymmetric microcavities supporting Whispering-gallery modes(WGMs)are of great significance for on-chip optical information *** establish asymmetric microcavities on topologically curved surfaces,where the geodesic light trajectories completely reconstruct the cavity mode *** curvature-mediated photon-lifetime engineering enables the enhancement of the quality factors of periodic island modes by up to 200 *** and weak coupling between modes of very different origins occurs when the space curvature brings them into resonance,leading to fine tailoring of the cavity photon energy and lifetime and the observation of non-Hermitian exceptional point(EP).At large space curvatures,the role of the WGMs is replaced by high-Q periodic modes protected by the high stability of island-like light *** work demonstrates interesting physical mechanisms at the crosspoint of optical chaotic dynamics,non-Hermitian physics,and geodesic optical devices,and would initiate the novel area of geodesic microcavity photonics.

关键词： topological curved curvature

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Software debugging analysis based on developer behavior data

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Frontiers of Computer Science 2021年第1期15卷 233-235页

作者： Bo YANG Qian YU Huai liu Yuze HE Chao liu School of Information Science and Technology North China University of TechnologyBeijing 100144China Department of Computer Science and Software Engineering Swinburne University of TechnologyHawthorn VIC 3122Australia School of Computer Science and Engineering Beihang UniversityBeijing 100191China

1 Introduction Software debugging is one of the most costly activities in sof-ware development *** mainly consists of four core tasks,namely fault detection,fault localization,fault understanding and fault *** them,fa... 详细信息

关键词： fault process. Software

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Stochastic Fubini Theorem for Jump Noises in Banach Spaces

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Acta Mathematica Sinica,English Series 2021年第3期37卷 423-435页

作者： Jia Hui ZHU Wei liu School of Science Zhejiang University of TechnologyHangzhou 310019P.R.China School of Mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116P.R.China

We prove a general version of the stochastic Fubini theorem for stochastic integrals of Banach space valued processes with respect to compensated Poisson random measures under weak integrability assumptions, which ext... 详细信息

关键词： Stochastic Fubini theorem martingale type p Banach space Poisson random measure stochastic integration

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Study and design of cladding power stripper for high power fiber laser systems

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High Power Laser Science and Engineering 2016年第3期4卷 71-73页

作者： Haixia An Xiaogang liu Zhiyue Bi Institute of Systems Engineering CAEP

Heat handling has been a significant problem of the high power fiber laser systems as the output power increases *** power stripper(CPS) which is used to deal with the unwanted optical power and light is required for higher cooling ability. So the methods of stripping the unwanted light attracted much attention recently, and the thermal effect is given. However, few investigations focus on the dissipation of the heat converted from the unwanted light. In this paper,an approach of active cooling for CPS is demonstrated. This is achieved by using microchannel cooling technology in heat sinking in CPS to improve the efficiency of heat exchange. In order to explain the mechanism of CPS the function of it and consistence of categories of the unwanted light are detailed firstly. Then microchannel heat sinking is proposed and verified by the heat exchange theory. At last, the design of the CPS with microchannel heat sinking is shown and following experiment is conducted. The final temperature of the device with 1000 W cladding power was demonstrated at last to verify the ability of heat distribution of the CPS component. This suggests that these CPSs can be used to stripe a thousand of watts of light in high power double cladding fiber lasers.

关键词： cladding power stripper double cladding fiber high power laser system microchannel

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A TICS-fluorophore based probe for dual-color GSH imaging

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Chinese Chemical Letters 2022年第11期33卷 4943-4947页

作者： Wenjuan liu Jie Chen Qinglong Qiao Xiaogang liu Zhaochao Xu CAS Key Laboratory of Separation Science for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China Fluorescence Research Group Singapore University of Technology and DesignSingapore 487372Singapore

Cascading reactions in fluorophores accompanied by the replacement of different fluorescence wavelengths can be used to develop luminescent materials and reactive fluorescent *** on multiple signal channels,the selectivity of probes can be improved and the range of response to guest molecule recognition can be *** regulating the position,number,and activity of active sites in fluorophores,fluorescent probes that successively react with thiol and amino groups in cysteine(Cys),homocysteine(Hcy)have been developed,which can only react with the thiol group of GSH,In this paper,we report the first probe capable of cascading nucleophilic substitution reaction with the thiol group and amino group of GSH at a single reaction site,and showed the dual-color recognition of GSH,which improved the selectivity of GSH also was an extension of GSH *** probe Rho-DEA was based on a TICS fluorophore,and the intramolecular cascade nucleophilic substitution reaction occurs with Cys/*** thiol substitution of the first step reaction with Cys/Hcy was quenched due to intersystem crossing to triplet state,so GSH can be selectively recognized from the fluorescence ***-DEA has the ability of mitochondrial localization,and finally realized in situ dual-color fluorescence recognition of GSH in mitochondria.

关键词： TICS Reactive fluorescent probe GSH imaging Dual-color Cascading reaction

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Candidate genes involved in the biosynthesis of lignan in Schisandra chinensis fruit based on transcriptome and metabolomes analysis

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Chinese Journal of Natural Medicines 2020年第9期18卷 684-695页

作者： CHEN Chun-Yu liu Shu-Ying YAN Yan YIN Le DI Peng liu Hui-Min liu Hong-Zhang College of life Science Jilin Agricultural UniversityChangchun 130118China College of Chinese Medicinal Materials Jilin Agricultural UniversityChangchun 130118China

Schisandra chinensis Turcz.(Baill.) is a plant species with fruits that have been well known in Far Eastern medicine for a long time. It has traditionally been used as a stimulating and fortifying agent in cases of physical exhaustion and to inhibit *** major bioactive compounds found in S. chinensis are lignans with a dibenzocyclooctadiene skeleton, but little is known about their biosynthesis in plants. S. chinensis is the ideal medicinal plant for studying the biosynthesis of lignans, especially the dibenzocyclooctadiene skeleton. Genomic information for this important herbal plant is unavailable. To better understand the lignan biosynthesis pathway, we generated transcriptome sequences from the fruit during ripening and performed de novo sequence assembly, yielding136 843 unique transcripts with N50 of 1778 bp. Putative functions could be assigned to 41 824 transcripts(51.57%) based on BLAST searches against annotation databases including GO(Gene ontology) and KEGG(Kyoto Encyclopedia of Genes and Genomes). Furthermore, 22 candidate cytochrome P450 genes and 15 candidate dirigent proteins genes that were most likely involved in the lignan biosynthesis pathway were discovered based on transcriptome sequencing of S. chinensis. The genomic data obtained from S. chinensis, especially the identification of putative genes involved in the lignan biosynthesis pathway, will facilitate our understanding of lignan biosynthesis at the molecular level. The lignan metabolite profiles were analyzed by metabolomes, the accumulation patterns of 30 metabolites involved in the lignan pathway were studied. Co-expression network of lignan contents and transcriptional changes showed355 strong correlations(correlation coefficient, R^2 > 0.9) between 21 compounds and 153 transcripts. Furthermore, the comprehensive analysis and characterization of the genes involved in lignan pathways and the metabolite profiles of lignans are expected to provide better insight regarding the dive

关键词： Schisandra chinensis Transcriptome Metabolome Biosynthetic pathways Lignan

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