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Petroleum Science 2023年第5期20卷 3210-3222页

作者： wei Xiong lie-Hui Zhang Yu-Long Zhao Qiu-Yun Hu Ye Tian xiao He Rui-Han Zhang Tao Zhang National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengduSichuan610500China Engineering Technology Research Institute Southwest Oil and Gas Field CompanyChengduSichuan610031China PetroChina Southwest Oil&Gasfield Company ChengduSichuan610051China

Eighteen models based on two equations of state(EoS),three viscosity models,and four mixing rules were constructed to predict the viscosities of natural gases at high temperature and high pressure(HTHP)*** pure substances,the parameters of free volume(FV)and entropy scaling(ES)models were found to scale with molecular weight,which indicates that the ordered behavior of parameters of Peng-Robinson(PR)and Perturbed-Chain Statistical Associating Fluid Theory(PC-SAFT)propagates to the behavior of parameters of viscosity *** the viscosities of natural gases showed that the FV and ES models respectively combined with MIX4 and MIX2 mixing rules produced the best ***,the FV models were more accurate for predicting the viscosities of natural gases than ES models at HTHP conditions,while the ES models were superior to PRFT *** average absolute relative deviations of the best accurate three models,i.e.,PC-SAFT-FV-MIX4,tPR-FVMIX4,and PC-SAFT-ES-MIX2,were 5.66%,6.27%,and 6.50%,respectively,which was available for industrial *** with the existing industrial models(corresponding states theory and LBC),the proposed three models were more accurate for modeling the viscosity of natural gas,including gas condensate.

关键词： Viscosity Friction theory Free volume theory Entropy scaling PC-SAFT Equation of state

Unveiling an ancient whole-genome duplication event in Stentor,the model unicellular eukaryotes

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Science China Life Sciences 2025年

作者： weibo Zheng Chao Li Zhaorui Zhou xiao Chen Michael Lynch Ying Yan School of Life Sciences Ludong University Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education) and Institute of Evolution & Marine Biodiversity Ocean University of China Biodesign Center for Mechanisms of Evolution Arizona State University Marine College Shandong University

Whole-genome duplication(WGD) events are widespread across eukaryotes and have played a significant role in moulding the genetic architectures of diverse organisms. In the present study, the newly sequenced genome of a giant ciliated protist, Stentor roeselii, provides an opportunity for the analysis of the collinearity and retention of reciprocal best-hit genes between two Stentor species. As a main result, we have unveiled a previously undetected ancient WGD event shaping the genome of its congener, Stentor coeruleus, a model protist used in cytological and evolutionary studies. Genomes of two congeners, S. coeruleus and S. roeselii, are compared and analyzed, revealing that:(i)the former exhibits a much higher retention rate of colinear-gene pairs(28%) than does S. roeselii, and in S. coeruleus, 75% of genes that have a RBH hit in S. roeselii, have paralogs with high amino-acid identity, consistent with a WGD event in the lineage leading to S. coeruleus;(ii) the S. roeselii genome possesses extremely short intergenic regions, implying that the lengths of intergenic regions are under strong selection;(iii) the unique characteristics of introns may have been shaped in the common ancestor of heterotrichs;(iv) gene families that play a role in activities of multiple protein kinases and voltage-gated ion channels expanded rapidly in the ancestor of both taxa, possibly relating to the remarkable regenerative ability in Stentor. This study offers new insights into the evolutionary dynamics of ciliate genomes,with implications for understanding of the processes underlying the evolution of genomic complexity.

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Rise of β-furanosyl ribonucleosides as the extant RNA component facilitated by simple divalent transition-metal minerals

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Science China Chemistry 2025年

作者： Qianqian Chen Haoxing Xu Bingyue Zhao Yeersen Patehebieke Zerun Zhao xiao Wang School of Chemistry and Chemical Engineering Nanjing University Frontiers Science Center for Critical Earth Material Cycling Nanjing University

The selective nucleoside synthesis through direct condensation between nucleobase and unactivated sugar in aqueous media has long been a formidable obstacle for the early chemical transformations hypothesized to construct the RNAWorld, due to product complexity and the low selectivity of the desired isomer. The preference of β-furanoside, the extant RNA component, has never been documented. Here we report an aqueous ribosylation mediated by divalent transition-metal ions, which unprecedentedly enhances the selectivity of furanosyl ribonucleosides as opposed to the traditionally predominating pyranosyl ones, with the furanoside/pyranoside ratio reaching up to 9/1. Furthermore, β-furanoside stands out for the first time as the most prevalent isomer in the presence of zinc and ammonium salts. The mechanism of this selectivity is elucidated with density functional theory calculations. The selectivity for β-furanoside can be further elevated via the adsorption on a zinc mineral. These findings exhibit as the first example that the selection of nucleosides with the desired, canonical configuration might be completed in the early stage of the RNA-forming process as opposed to later evolution, promoted by simple and widespread transition-metal minerals. The study may also find its value in synthetic chemistry as a guideline for developing a sustainable and selective glycosylation process.

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Development of a general circumferentially nonuniform heat transfer fuel rod model for subchannel analysis and application to helical fuel rods

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Science China Technological Sciences 2025年

作者： Junsen FU Junlong LI xiaowen WANG Qi ZHANG Yao xiao Hanyang GU School of Mechanical Engineering Shanghai Jiao Tong University Key Laboratory of Nuclear Power Systems and Equipment of the Ministry of Education Shanghai Jiao Tong University National Key Laboratory of Nuclear Reactor Technology Nuclear Power Institute of China State Key Laboratory of Nuclear Power Safety Technology and Equipment Shanghai Jiao Tong University

The subchannel analysis method is one of the most crucial transient safety analysis methods in the thermal design of nuclear reactors. The nonuniformity of circumferential heat transfer is slight in conventional pressurized water reactor (PWR)cores, but it is significant in advanced reactors with wire-wrapped or helical fuel rods. Predicting circumferentially nonuniform heat transfer behavior can be challenging owing to the complex geometry of helical fuel rods. In this study, a general circumferentially nonuniform heat transfer fuel rod (GCNF) model is developed to predict the fuel central temperature and circumferential heat flux and wall temperature. This model incorporates a refined two-dimensional fuel conduction model and circumferential nonuniform shape factor, addressing the dual factors contributing to the circumferential nonuniformity of helical fuel rods. An empirical correlation for the nonuniform shape factor is developed based on the computational fluid dynamics (CFD) results, and it is implemented to the subchannel code. The newly developed model is applied to a helical fuel annulus and validated by comparing the prediction results with CFD data. The maximum wall temperature predicted by the code is 1.15°C lower than the value calculated through CFD. In terms of the heat flux, the maximum value at the inner corner is22 kW lower than that obtained from the CFD prediction. The accurate prediction of circumferentially nonuniform heat transfer in helical fuel, concerning the surface heat flux and cladding temperature, addresses existing shortcomings in helical fuel subchannel analysis methods. Additionally, the capability to predict the fuel central temperature is essential for the safety analysis to determine whether fuel rods are melting. The generality of the model framework allows it to be used for the prediction of circumferential nonuniform heat transfer behavior in other types of fuel assemblies.

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Isospin dependence of nucleon effective masses in neutron-rich matter

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Nuclear Science and Techniques 2016年第6期27卷 25-32页

作者： Bao-An Li Bao-Jun Cai lie-Wen Chen xiao-Hua Li Department of Physics and Astronomy Texas A&MUniversity-Commerce Department of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University School of Nuclear Science and Technology University of South China

In this talk,we first briefly review the isospin dependence of the total nucleon effective mass M Jinferred from analyzing nucleon-nucleus scattering data within an isospin-dependent non-relativistic optical potential model,and the isospin dependence of the nucleon E-mass M;E J obtained from applying the Migdal–Luttinger theorem to a phenomenological single-nucleon momentum distribution in nuclei constrained by recent electron-nucleus *** information about the isospin dependence of both the nucleon total effective mass and E-mass,we then infer the isospin dependence of nucleon k-mass using the well-known relation M_J~*=M_ J^(*1E).Implications of the results on the nucleon mean free path in neutron-rich matter are discussed.

关键词：同位旋相关有效质量单核子核物质丰中子平均自由程非相对论分析数据

Pharicin A,a novel natural ent-kaurene diterpenoid,induces mitotic arrest and mitotic catastrophe of cancer cells by perturbing BubR1 functions

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Pharicin A,a novel natural ent-kaurene diterpenoid,induces m...

Soil Microbial Community Composition During Natural Recovery in the Loess Plateau, China

第六届全国化学生物学学术会议

作者： Han-Zhang XU~1,Ying HUANG~(1,2),Ying-Li WU~1,Yong ZHAO~3,wei-lie xiao~3,Yixin Yao~2, Han-Dong SUN~3,wei DAI~2,and Guo-Qiang CHEN~(1*) 1 Department of Pathophysiology,Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education,Shanghai Jiao-Tong University School of Medicine,Shanghai 200025,CHINA. 2 Department of Environmental Medicine and Pharmacology,New York University School of Medicine, Tuxedo,New York 10987,United States. 3 State Key Laboratory of Phytochemistry and Plant Resources in West China,Kunming Institute of Botany,Chinese Academy of Sciences,Yunnan,CHINA.

＜正＞Paclitaxel represents a potent and effective class of anticancer compounds by causing mitotic arrest and mitotic *** the past decades,great efforts have been directed to the identification of novel natural produ...

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Journal of Integrative Agriculture 2013年第10期12卷 1872-1883页

作者： xiao lie LIU Guo-bin XUE Sha ZHANG Chao State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F University Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resource

This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess *** soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids（PLFAs） of eight croplands abandoned for 1,3,5,10,13,15,20,and 30 yr in the Dunshan watershed,northern Loess Plateau,*** results showed that soil organic carbon,total nitrogen,soil microbial biomass carbon,and soil microbial biomass nitrogen significantly increased with the abandonment duration,whereas the metabolic quotient significantly *** Shannon richness and Shannon evenness of PLFAs significantly increased after 10 yr of ***-negative,Gram-positive,bacterial,fungal,and total PLFAs linearly increased with increased abandonment *** analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community *** soil microbial PLFAs changed from anteiso-to iso-,unsaturated to saturated,and short-to long-chain during natural ***,in the Loess Plateau,cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.

关键词： abandoned cropland microbial diversity phospholipid fatty acid(PLFA) redundancy analysis(RDA) Loess Plateau

Effect of Different Vegetation Types on the Rhizosphere Soil Microbial Community Structure in the Loess Plateau of China

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Journal of Integrative Agriculture 2013年第11期12卷 2103-2113页

作者： ZHANG Chao LIU Guo-bin XUE Sha xiao lie State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources

The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understanding the microbial community structure is essential for the sustainability of ecosystems and for the reclamation of degraded arable land. This study aimed to determine the effect of different vegetation types on microbial processes and community structure in rhizosphere soils in the Loess Plateau. The six vegetation types were as follows：two natural grassland （Artemisia capillaries and Heteropappus altaicus）, two artificial grassland （Astragalus adsurgens and Panicum virgatum）, and two artificial shrubland （Caragana korshinskii and Hippophae rhamnoides） species. The microbial community structure and functional diversity were examined by analyzing the phospholipid fatty acids （PLFAs） and community-level physiological profiles. The results showed that rhizosphere soil sampled from the H. altaicus and A. capillaries plots had the highest values of microbial biomass C, average well color development of carbon resources, Gram-negative （G-） bacterial PLFA, bacterial PLFA, total PLFA, Shannon richness, and Shannon evenness, as well as the lowest metabolic quotient. Soil sampled from the H. rhamnoides plots had the highest metabolic quotient and Gram-positive （G＋） bacterial PLFA, and soil sampled from the A. adsurgens and A. capillaries plots had the highest fungal PLFA and fungal：bacterial PLFA ratio. Correlation analysis indicated a signiifcant positive relationship among the microbial biomass C, G- bacterial PLFA, bacterial PLFA, and total PLFA. In conclusion, plant species under arid climatic conditions signiifcantly affected the microbial community structure in rhizosphere soil. Among the studied plants, natural grassland species generated the most favorable microbial conditions.

关键词： soil microbial biomass microbial community structure PLFA community-level physiological profiles,vegetation types

Hybrid Scenario Generation Method for Stochastic Virtual Bidding in Electricity Market

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CSEE Journal of Power and Energy Systems 2021年第6期7卷 1312-1321页

作者： Dongliang xiao wei Qiao the School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China the Power and Energy Systems Laboratory Department of Electrical and Computer EngineeringUniversity of Nebraska-LincolnLincolnNE 68588-0511 USA

Stochastic optimization can be used to generate optimal bidding strategies for virtual bidders in which the uncertain electricity prices are represented by using *** paper proposes a hybrid scenario generation method for electricity price using a seasonal autoregressive integrated moving average(SARIMA)model and historical *** electricity price spikes are first identified by using an outlier detection ***,the historical data are decomposed into base and spike ***,the base and spike component scenarios are generated by using the SARIMA-and historical data-based methods,***,the electricity price scenarios are obtained by combining the base and spike component *** studies are carried out for a virtual bidder in the PJM electricity market to validate the proposed *** optimal bidding strategies of the virtual bidder are generated by solving a stochastic optimization problem using the electricity price scenarios generated by the proposed method,the SARIMA method,and a historical data-based method,*** study results show that the proposed method is better than the SARIMA method in preserving statistical properties of the electricity price in the generated scenarios and is better than the historical data-based method in predicting the future trend of the electricity price and,therefore,can help the virtual bidder earn more profit in the electricity market.

关键词： Electricity market electricity price scenario generation stochastic optimization virtual bidding

Differential-operator representations of Weyl group and singular vectors in Verma modules

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Science China Mathematics 2018年第6期61卷 1013-1038页

作者： wei xiao College of Mathematics and Statistics Shenzhen University

Given a suitable ordering of the positive root system associated with a semisimple lie algebra,there exists a natural correspondence between Verma modules and related polynomial algebras. With this, the lie algebra action on a Verma module can be interpreted as a differential operator action on polynomials, and thus on the corresponding truncated formal power series. We prove that the space of truncated formal power series gives a differential-operator representation of the Weyl group W. We also introduce a system of partial differential equations to investigate singular vectors in the Verma module. It is shown that the solution space of the system in the space of truncated formal power series is the span of {w(1) | w ∈ W }. Those w(1) that are polynomials correspond to singular vectors in the Verma module. This elementary approach by partial differential equations also gives a new proof of the well-known BGG-Verma theorem.

关键词： Verma module singular vector differential equation differential operator Weyl group