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Mineral-mediated stability of organic carbon in soil and relevant interaction mechanisms

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Eco-Environment & Health 2024年第1期3卷 59-76页

作者： Zibo xu Daniel c.W.Tsang Department of civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of civil and Environmental Engineering The Hong Kong University of Science and TechnologyClear Water BayHong KongChina

Soil,the largest terrestrial carbon reservoir,is central to climate change and relevant feedback to environmental *** are the essential components that contribute to over 60%of soil carbon ***,how the interactions between minerals and organic carbon shape the carbon transformation and stability remains poorly ***,we critically review the primary interactions between organic carbon and soil minerals and the relevant mechanisms,including sorption,redox reaction,co-precipitation,dissolution,polymerization,and catalytic *** interactions,highly complex with the combination of multiple processes,greatly affect the stability of organic carbon through the following processes:(1)formation or deconstruction of the mineral–organic carbon association;(2)oxidative transformation of the organic carbon with minerals;(3)catalytic polymerization of organic carbon with minerals;and(4)varying association stability of organic carbon according to the mineral *** pieces of evidence related to the carbon turnover and stability during the interaction with soil minerals in the real eco-environment are then *** also highlight the current research gaps and outline research priorities,which may map future directions for a deeper mechanismsbased understanding of the soil carbon storage capacity considering its interactions with minerals.

关键词： carbon stability Mineral transformation carbon sequestration Bio-geochemistry Soil carbon management Sustainable waste management

Noncommutative analysis of Hermite expansions

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Science china Mathematics 2024年第10期67卷 2331-2356页

作者： Bang xu Department of Mathematics University of HoustonHoustonTX 77204USA Department of Mathematical Sciences Seoul National UniversitySeoul 08826Republic of Korea

This paper is devoted to the study of semi-commutative harmonic analysis associated with Hermite semigroups. In the first part, we establish the noncommutative maximal inequalities for Bochner-Riesz means associated with Hermite operators and then obtain the corresponding pointwise convergence theorems. In particular, we develop a noncommutative version of Stein's theorem of Bochner-Riesz means for Hermite operators. In the second part, we investigate two noncommutative multiplier theorems. Our approach in this part relies on a noncommutative analog of the classical Littlewood-Paley-Stein theory associated with Hermite semigroups.

关键词： noncommutative L_(p)-spaces Hermite semigroup maximal inequalities pointwise convergence multipliers

Highly Strong,Tough,and cryogenically Adaptive Hydrogel Ionic conductors via coordination Interactions

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Research 2024年第3期2024卷 703-713页

作者： Zhuomin Wang Siheng Wang Lei Zhang He Liu xu xu Institute of chemical Industry of Forestry Products Key Laboratory of Biomass Energy and MaterialJiangsu ProvinceKey Laboratory of Chemical Engineering of Forest ProductsNational Forestry and Grassland AdministrationNational Engineering Research Center of Low-Carbon Processing and Utilization of Forest BiomassJiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest ResourcesChinese Academy of ForestryNanjing 210042China college of chemical Engineering Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest ResourcesNanjing Forestry UniversityNanjing 210037China.

Despite the promise of high flexibility and conformability of hydrogel ionic conductors,existing polymeric conductive hydrogels have long suffered from compromises in mechanical,electrical,and cryoadaptive properties due to monotonous functional improvement strategies,leading to lingering ***,we propose an all-in-one strategy for the preparation of poly(acrylic acid)/cellulose(PAA/cel)hydrogel ionic conductors in a facile yet effective manner combining acrylic acid and salt-dissolved cellulose,in which abundant zinc ions simultaneously form strong coordination interactions with the two polymers,while free solute salts contribute to ionic conductivity and bind water molecules to prevent ***,the developed PAA/cel hydrogel simultaneously achieved excellent mechanical,conductive,and cryogenically adaptive properties,with performances of 42.5 MPa for compressive strength,1.6 MPa for tensile strength,896.9%for stretchability,9.2 MJ m^(−3)for toughness,59.5 kJ m^(−2)for fracture energy,and 13.9 and 6.2 mS cm^(−1)for ionic conductivity at 25 and−70°c,*** by these features,the resultant hydrogel ionic conductor is further demonstrated to be assembled as a self-powered electronic skin(e-skin)with high signal-to-noise ratio for use in monitoring movement and physiological signals regardless of cold temperatures,with hinting that could go beyond high-performance hydrogel ionic conductors.

关键词： Highly freezing salts

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基于温度相似性评价的机床热误差重构模型

机械工程学报 2024年第5期60卷 288-295页

作者：徐凯李喆裕李国龙苗恩铭庹军波重庆理工大学机械工程学院重庆400054 重庆大学机械传动国家重点实验室重庆400044 重庆工商大学机械工程学院重庆400067

数据驱动方法广泛用于热误差建模,然而缺乏机理支撑的开环黑箱运行模式难以保证模型在新工况中的鲁棒性,模型极易失效。为进一步提升机床热误差模型的精度和稳定性,提出了一种基于温度相似性评价的机床热误差重构模型。通过对预测组温... 详细信息

数据驱动方法广泛用于热误差建模,然而缺乏机理支撑的开环黑箱运行模式难以保证模型在新工况中的鲁棒性,模型极易失效。为进一步提升机床热误差模型的精度和稳定性,提出了一种基于温度相似性评价的机床热误差重构模型。通过对预测组温度均值向量与建模组温度均值向量的相似性评价,从原始建模批次中筛选出与预测组温度相似的特定批次,并基于偏最小二乘算法进行热误差模型重构。为验证重构模型的有效性,进行了累计31批次的热误差预测,结果表明重构模型在保证稳定性的前提下,可将预测结果的均方根误差均值进一步降低至2.2μm,相比常规的模糊聚类结合多元线性回归模型与偏最小二乘模型,预测精度可分别提高15%、35%,效果显著。方法对于评价数据驱动热误差模型的适用性,提高模型预测精度具有参考价值。

关键词：相似性评价重构模型偏最小二乘算法稳定性

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.xu T.W.Huang K.Jiang c.N.Wu H.Peng P.c.hen R.Li H.B.Zhuo c.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Enhanced photocatalytic hydrogen production from co-MOF/cN by nitrogen and sulfur co-doped coal-based carbon quantum dots

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Journal of Rare Earths 2024年第5期42卷 838-850,I0002页

作者： Shiyong xu Mei Li Yijun Wang caiyun Gao Rongsheng xu Zhiliang jin School of chemistry and chemical Engineering North Minzu UniversityYinchuan750021China Ningxia Key Laboratory of Solar chemical conversion Technology.North Minzu University.Yinchuan 750021China State Key Laboratory of National Ethnic Affairs commission chemical Technology.North Minzu University Yinchuan750021China

A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NScQDs)nanoparticles on the surface of sheet cobalt-based metal-organic framework(co-MOF)and graphitic carbon nitride(g-c_(3)N_(4),cN).The structure and properties of the obtained catalysts were systematically *** effectively broaden the absorption of co-MOF and cN in the visible *** new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254μmol/(g·h)at pH=*** the same time,NScQDs synergy co-MOF/cN composites have good *** four cycles of hydrogen production,the performance remains relatively *** tran sient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite *** semiconductor type(n-type semico nductor)of the single-phase catalyst was determined by the Mott-Schottky test,and the band structure was *** conductive and valence bands of cN are-0.99 and 1.72 eV,respectively,and the conduction and valence bands of co-MOF are-1.85 and 1.33 eV,*** e mechanism of the photocatalytic reaction can be inferred,that is,Z-type heterojunction is formed between cN an d co-MOF,and NScQDs was used as cocatalyst.

关键词： Nitrogen and sulfur co-doped coal-based carbon quantum dots co-MOF cN Photocatalytic hydrogen evolution Rare earths

Experimental investigation on the permeability of gap-graded soil due to horizontal suffusion considering boundary effect

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1072-1084页

作者： xuwei Wang Yeshuang xu State Key Laboratory of Ocean Engineering School of Naval ArchitectureOceanand Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure Department of Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

The boundary condition is a crucial factor affecting the permeability variation due to *** experimental investigation on the permeability of gap-graded soil due to horizontal suffusion considering the boundary effect is conducted,where the hydraulic head difference(DH)varies,and the boundary includes non-loss and soil-loss *** samples are filled into seven soil storerooms connected in *** evaluation,the variation in content of fine sand(ΔR_(f))and the hydraulic conductivity of soils in each storeroom(c_(i))are *** the non-loss test,the soil sample filling area is divided into runoff,transited,and accumulated areas according to the negative or positive ΔR_(f) values.ΔR_(f) increases from negative to positive along the seepage path,and ci decreases from runoff area to transited area and then rebounds in accumulated *** the soil-loss test,all soil sample filling areas belong to the runoff area,where the gentle-loss,strengthened-loss,and alleviated-loss parts are further divided.ΔR_(f) decreases from the gentle-loss part to the strengthened-loss part and then rebounds in the alleviated-loss part,and c_(i) increases and then decreases along the seepage *** relationship between ΔR_(f) and ci is different with the boundary *** exponentially decreases with ΔR_(f) in the non-loss test and increases with ΔR_(f) generally in the soil-loss test.

关键词： Suffusion Permeability Experimental investigation Boundary effect Horizontal seepage

Periodic Variation Studies of the Two Short Period W UMa-type Eclipsing Binaries: LX Lyn and V0853 Aur

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Research in Astronomy and Astrophysics 2024年第1期24卷 273-284页

作者： xu Zhang Bin Zhang School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550025China

In this paper,new light curves(Lcs) of contact eclipsing binary(cEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-Devinney(W-D) *** order to explain their asymmetric Lcs,cool starspots on the components were *** is suggested that their fill-out degrees are f=12.0%(LX Lyn) and f=26.3%(V0853 Aur).At the same time,we found that LX Lyn is a W-type eclipsing binary(EB) with an orbital inclination of i=84°.88 and a mass ratio of q=2.31.V0853 Aur is also a W-type cEB with a mass ratio of q=2.77 and an orbital inclination of i= 79°.*** on all available times of light minimum,their orbital period changes are studied by using the O-c *** O-c diagram of LX Lyn reveals a cyclic oscillation with a period of about 14.84 yr and an amplitude of 0.0019 days,which can be explained by the light-travel time effect(LTTE) due to the presence of a third body with a minimum mass of0.06M_⊙.For V0853 Aur,it is discovered that the O-c diagram of the system also shows a cyclic oscillation with a period of 9.64 yr and an amplitude of 0.03365 *** cyclic oscillation of V0853 Aur can be attributed to the LTTE by means of a third body with a mass no less than 3.77M_⊙.The third body may play an important role in the formation and evolution of these systems.

关键词： stars:activity (stars:)binaries(including multiple):close (stars:)binaries:eclipsing (stars:)brown dwarfs stars:evolution stars:formation

A Practical Predefined-Time Stability criterion and Its Application to Uncertain Nonlinear Systems

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Journal of Systems Science & complexity 2024年

作者： xu Hao YU Dengxiu SUI Shuai xu Bowen cHEN c.L.Philip Unmanned System Research Institute Northwestern Polytechnical University college of Science Liaoning University of Technology School of Artificial Intelligence Optics and Electronics Northwestern Polytechnical University School of computer Science and Engineering South China University of Technology and Pazhou Lab

In this paper, the singularity-free predefined-time fuzzy adaptive tracking control problem is studied for non-strict feedback(NSF) nonlinear systems considering mismatched external disturbances. An innovative practical predefined-time stability(PPTS) criterion is proposed to provide the theoretical basis for subsequent control design. compared to the existing predefined-time stability(PTS) criterion, this criterion has a broader application range and can solve the control design issues of nonlinear systems with system uncertainties. Fuzzy logic systems(FLSs) are employed to identify unknown nonlinear functions. Based on the backstepping control technology, a singularity-free predefined-time control(PTc) design method is proposed, in which the hyperbolic tangent function is utilized to avoid the singular problem, and the nature of fuzzy basis function is adopted to resolve the algebraic loop problem. The PPTS of the closed-loop NSF nonlinear system is proven with the Lyapunov theory and the proposed PPTS criterion. Ultimately, the efficiency of the presented PTc design method is verified by several sets of simulations on a single link manipulator system.

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