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Dynamic Variation of Vegetation NPP and Its Driving Forces in the Yellow River Basin, China

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Chinese Geographical Science 2025年第1期35卷 24-37页

作者： WANG Shimei MA Yutao gong Jie jin Tiantian Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Center for Remote Sensing of Ecological Environments in Cold and Arid Regions Lanzhou UniversityLanzhou 730000China

The productivity of vegetation is influenced by both climate change and human *** the specific contributions of these influencing factors is crucial for ecological conservation and regional *** study utilized a combination of multi-source data to examine the spatiotemporal patterns of Net Primary Productivity(NPP)in the Yellow River Basin(YRB),China from 1982 to ***,a scenario-based approach was employed to compare Potential NPP(PNPP)with Actual NPP(ANPP)to determine the relative roles of climatic and human factors in NPP *** PNPP was estimated using the Lund-Potsdam-Jena General Ecosystem Simulator(LPJ-GUESS)model,while ANPP was evaluated by the Carnegie-Ames-Stanford Approach(CASA)model using different NDVI data *** model simulations revealed that significant greening occurring in the YRB,with a gradual decrease observed from southeast to *** to the LPJ_GUESS model simulations,areas experiencing an increasing trend in NPP accounted for 86.82% of the *** using GIMMS and MODIS NDVI data with CASA model simulations,areas showing an increasing trend in NPP accounted for 71.42% and 97.02%,***,both climatic conditions and human factors had positive effects on vegetation restoration;approximated 41.15% of restored vegetation areas were influenced by both climate variation and human activities,while around 31.93% were solely affected by climate ***,it was found that human activities served as the principal driving force of vegetation degradation within the YRB,impacting 26.35% of degraded areas solely due to human ***,effective management strategies encompassing both human activities and climate change adaptation are imperative for facilitating vegetation restoration within this *** findings will valuable for enhancing our understanding in NPP changes and its underlying factors,thereby contributing to improved ecological man

关键词： Net Primary Productivity(NPP) vegetation greening Carnegie-Ames-Stanford Approach(CASA) Lund-Potsdam-Jena General Ecosystem Simulator(LPJ_GUESS) Yellow River Basin(YRB),China

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Crevice corrosion of reinforcing steel in carbonated simulated concrete pore solutions contaminated by chloride

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Journal of Iron and Steel Research International 2025年第1期32卷 293-311页

作者： Peng-peng Wu Yuan-pei gong Shao-hua Zhang Yue-zhong Zhang Bao-sheng Liu Guang-ling Song College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina College of Chemical Engineering and Technology Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen518055GuangdongChina School of Mechanical and Mining Engineering Centre for Advanced Materials Processing and Manufacturing(AMPAM)The University of QueenslandSt LuciaQLD4072Australia State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamen361005FujianChina

The crevice corrosion of the reinforcing steel in the carbonated simulated concrete pore solutions(SCPSs)containing 0.04 mol/L chloride was *** comparison,the steel without crevice covered on its surface was also *** showed that the crevice corrosion in the uncarbonated SCPS was not triggered and the steel remained passivity by suppressing the anodic dissolution in the crevice *** SCPS was carbonated to have pH values of 10.5 and 11.5,the crevice corrosion was easier to be activated than the widely reported pitting corrosion owing to the rapid oxygen depletion within the crevice,but the crevice corrosion damage might be alleviated to a certain extent due to the relative compact surface film formed inside the *** further carbonation led to the activation dissolution of both the crevice interior and exterior,causing the more serious corrosion *** process of the crevice corrosion was systematically analyzed by combining the electrochemical measurement results and Evens polarization diagram.

关键词： Crevice corrosion Reinforcing steel Carbonation Electrochemical test Rust Evens polarization diagram

Thickness and sp3 bond modulation of（Ti/tetrahedral amorphous carbon）_n multilayer coatings

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Tungsten 2025年第1期7卷 152-160页

作者： Zhi-Jun Xie Jia-Lin Li Ling gong Xiang-Li Zhong Hong-Jia Song jin-Bin Wang National-Provincial Laboratory of Special Function Thin Film Materials School of Materials Science and Engineering Xiangtan University

The durability of wear-resistant tetrahedral amorphous carbon（ta-C） coatings is intimately linked to their thickness and the concentration of *** enhance the lifespan of the coatings,we have prepared a multilayer coating consisting of alternating layers of Ti and ta-C,denoted as（Ti/ta-C）_n,using arc ion plating.A multi-layer structure in conjunction with stage cooling is employed to enhance the thickness and promote *** results indicate that the ID/IGvalue,representing the ratio of the intensity of the D peak to that of the G peak in Raman spectroscopy,decreases from 0.85 when no stage cooling is applied to 0.35 when stage cooling is employed,suggesting an enhancement in the fraction of sp3bonds within the *** obtained（Ti/ta-C）_n multilayer coating without peeling off has a maximum thickness of 1.14 μm,which is almost double that of the ta-C coating single layer *** the same time,the coating has a low coefficient of friction,down to 0.069,and maintains excellent friction properties with a wear rate of 3.4×10-6mm3·N-1·*** results conclusively show that the preparation technology can enhance both thickness and sp3bonding in ta-C coatings,significantly expanding their utility across tools,molds,and precision engineering components.

关键词： Arc ion plating Multilayer structure sp3 bond Ta-C coating Wear resistance

Chiral phosphoramidite ligand-modulated palladium auto-tandem catalysis for asymmetric dehydrogenative dienylation of imines with α-alkenes

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Science China Chemistry 2025年

作者： Zhong-sheng Nong Hao-Fan Qian Ying-Chun Chen Pu-sheng Wang Liu-Zhu gong Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of China Key Laboratory of Drug Targeting and Drug Delivery System (Sichuan University) Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University School of Materials and Chemistry Southwest University of Science and Technology

The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community. Transition metal-catalyzed asymmetric functionalization of allylic C–H bond represents a unique alternative toward this goal. However, enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered. Here, we report a highly enantioselective dehydrogenative dienylation of imines with unactivated α-alkenes driven by the synergistic action of palladium complex and carboxylic acid. Chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range of α-alkenes and imines to be transformed into chiral dienylamines. Mechanistic studies suggest that the dienes could be in situ generated from α-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants, and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst. Notably, the second β-H elimination occurring in the dienylation event might be the turnover-limiting step.

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Recent progress on photoactive nonprecious transition-metal complexes

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Science China Chemistry 2025年第1期68卷 46-95页

作者： Zhong-Liang gong Hong-Jie Zhang Yan Cheng Jianxun Liu Yuhan Ai Yaqin Li Zhihui Feng Qiong Zhang Shaolong gong Yong Chen Chang-Jiang Yao Yuan-Yuan Zhu Liang-jin Xu Yu-Wu Zhong CAS Key Laboratory of Photochemistry Institute of ChemistryChinese Academy of SciencesBeijing 100190China State Key Laboratory of Structural Cemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China School of Chemistry and Chemical Engineering Anhui Key Laboratory of Advanced Catalytic Materials and Reaction EngineeringHefei University of TechnologyHefei 230009China State Key Laboratory of Explosion Science and Safety Protection School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China College of Chemistry and Molecular Sciences Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsWuhan UniversityWuhan 430072China School of Chemistry and Chemical Engineering Anhui UniversityHefei 230601China Key Laboratory of Photochemical Conversion and Optoelectronic Materials&CAS-HKU Joint Laboratory on New Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Photoactive complexes of nonprecious transition metals,mainly including those in the first-row and partially the second-row of the Periodic table of elements,have received increasing attention in view of their low cost and long-term *** are recognized as promising alternatives to noble transition metal complex congeners that have been extensively studied in optoelectronic devices,artificial photosynthesis,photocatalysis,biodiagnostics,and therapeutics,*** review is devoted to a comprehensive summary on the classical and recent advances on photoactive nonprecious transition metal complexes,including photoactive Zr,V,Cr,Mo,and W complexes,Mn complexes and hybrids,Fe,Co,Ni,and Cu complexes,and Zn and Cd complexes and hybrids.A particular focus is given on the molecular design,modulation of photophysical and photochemical properties,and applications of the representative and lately-developed nonprecious metal *** addition,a perspective on the future development in this field is provided at the end of this review.

关键词： photoactive metal complexes earth-abundant metals nonprecious metal complexes luminescence photochemistry

Long-read sequencing reveals novel genetic polymorphisms in the major histocompatibility complex region and their impacts on the Han Chinese population

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Science China Life Sciences 2025年

作者： Cong Zhou Tingting gong Shuhang Li Li jin Shaohua Fan State Key Laboratory of Genetic Engineering Lab for Evolutionary Synthesis School of Life Sciences Human Phenome Institute Fudan University Research Unit of Dissecting the Population Genetics and Developing New Technologies for Treatment and Prevention of Skin Phenotypes and Dermatological Diseases (2019RU058) Chinese Academy of Medical Sciences

Human leukocyte antigen(HLA) genes in the major histocompatibility complex(MHC) region are crucial for immunity and are associated with numerous diseases and phenotypes. The MHC region's complexity and high genetic diversity make it challenging to analyze using short-read sequencing(SRS) technology. We sequence the MHC region of 100 Han Chinese individuals using both long-read sequencing(LRS) and SRS platforms at approximately 30X coverage to study genetic alterations and their potential functional impacts. LRS provides significantly greater coverage of the MHC region and eight classical HLA genes, particularly at the HLA-DRB1 locus, compared with SRS. We detect 78,249 single nucleotide polymorphisms(SNPs) using LRS, with 26.0% undetectable by SRS. Based on SNP and inferred HLA allele types, we construct an LRS-based MHC reference panel for the Han Chinese, containing approximately 2.6 times more genetic variants than the SRS-based Han-MHC reference panel. A phenome-wide association study assessing 26,024 phenotypes across 15 categories identifies significant associations for 7,879 independent variants(including 809 LRS-specific SNPs) with 409 phenotypes in nine categories. This analysis reveals 24 unreported HLA allele associations in the bioelectric and cellular categories. The conditional analysis identifies 530independent signals across the 409 phenotypes, including 28 previously unreported signals of eight classical HLA genes associated with 33phenotypes. Of the top-associated SNPs, 191 are detected by LRS only. Fine-mapping identifies 126 independent candidate causal SNPs for three immune-related cellular phenotypes, with 17 detected exclusively by LRS. Our study reveals previously unreported variants and their functional impacts in the MHC region, enhancing our understanding of genetic diversity and its potential biological implications in the Han Chinese population.

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Impact of Hard Segment Structures on Fatigue Threshold of Casti

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Chinese Journal of Polymer Science 2025年第2期43卷 303-315页

作者： Guang-Zhi jin Le-Hang Chen Yu-Zhen gong Peng Li Run-Guo Wang Fan-Zhu Li Yong-Lai Lu State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China Engineering Research Center of Elastomer Materials Energy Conservation and Resources Ministry of EducationBeijing100029China Key Laboratory of Carbon Fiber and Functional polymers Beijing University of Chemical TechnologyBeijing100029China Center of Advanced Elastomer Materials College of Material Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China

The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive *** its importance,no studies have reported on the fatigue threshold of *** study employed an advanced Intrinsic Strength Analyzer(ISA)to evaluate the fatigue threshold of CPUs,systematically exploring the effects of three types of isocyanates(PPDI,NDI,TDI)that contribute to hard segment structures based on the cutting *** multiple advanced characterization techniques(XRD,TEM,DSC,AFM),the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold(182.89 J/m^(2))due to a highest phase separation and a densely packed spherulitic structure,although the hydrogen bonding degree is the lowest(48.3%).Conversely,NDI-based polyurethane,despite having the high hydrogen bonding degree(53.6%),exhibits moderate fatigue performance(122.52 J/m^(2)),likely due to a more scattered ***-based polyurethane,with the highest hydrogen bonding degree(59.1%)but absence of spherulitic structure,shows the lowest fatigue threshold(46.43 J/m^(2)).Compared to common rubbers(NR,NBR,EPDM,BR),the superior fatigue performance of CPU is attributed to its well-organized microstructure,polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.

关键词： Casting polyurethane Fatigue threshold Cutting method Hard segment structures Materials characterization

Platinum oxide redefined: a thermally stable two-dimensional crystallineform

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Science China Materials 2025年第2期68卷 683-684页

作者： Bixuan Li Yongji gong Tianmushan Laboratory Hangzhou 310023China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Catalysis,as a core technology in the chemical industry,plays a pivotal role in numerous fields,including energy,environmental science,and materials ***(Pt),a ubiquitous and indispensable catalyst,has been extensively employed in diverse applications,including industrial chemical transformations and automotive emission control systems[1].However,it was believed to suffer from deactivation under severe operating conditions,particularly in high-temperature and oxidizing *** concept suggests that platinum oxides,decompose or sublimate at elevated temperatures,typically above 700 K[2].Consequently,researchers frequently employ encapsulation techniques for metal particles,utilizing materials such as mesoporous silica[3],zeolites[4],two-dimensional(2D)layered materials[5],and various other protective *** approach necessitates a delicate balance between activity and stability,often resulting in enhanced stability at the expense of catalytic efficiency.

关键词： stability crystalline utilizing

Comprehensive Assessment of Transient Stability for Grid-Forming Converters Considering Current Limitations,Inertia and Damping Effects

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CSEE Journal of Power and Energy Systems 2025年第1期11卷 1-12页

作者： jinlei Chen Qingyuan gong Yawen Zhang Muhammad Fawad sheng Wang Chuanyue Li Jun Liang School of Engineering Cardiff UniversityCF243AACardiffU.K Compound Semiconductor Applications Catapult NP108BE NewportU.K.

This paper presents a quantitative assessment of the transient stability of grid-forming converters,considering current limitations,inertia,and damping *** contributions are summarized in two main aspects:First,the analysis delves into transient stability under a general voltage sag scenario for a converter subject to current *** the voltage sag exceeds a critical threshold,transient instability arises,with its severity influenced by the inertia and damping coefficients within the swing ***,a comprehensive evaluation of these inertia and damping effects is conducted using a model-based phase-portrait *** method allows for an accurate assessment of critical clearing time(CCT)and critical clearing angle(CCA)across varying inertia and damping *** data obtained from the phase portrait,an artificial neural network(ANN)method is presented to model CCT and CCA *** precise estimation of CCT enables the extension of practical operation time under faults compared to conservative assessments based on equal-area criteria(EAC),thereby fully exploiting the system's low-voltage-ride-through(LVRT)and fault-ride-through(FRT)*** theoretical transient analysis and estimation method proposed in this paper are validated through PSCAD/EMTDC simulations.

关键词： Current limitation damping effects gridforming converters transient stability analysis virtual inertia