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Topsoil organic carbon mineralization and CO_2 evolution of three paddy soils from South China and the temperature dependence

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Journal of Environmental Sciences 2007年第3期19卷 319-326页

作者： ZHANG Xu-hui li lian-qing pan Gen-xing Institute of Resources Ecosystem and Environment of Agriculture Nanjing Agricultural University Nanjing 210095 China.

Carbon mineralization and its response to climatic warming have been receiving global attention for the last decade. Although the virtual influence of temperature effect is still in great debate, little is known on the mineralization of organic carbon （SOC） of paddy soils of China under warming. SOC mineralization of three major types of China＇s paddy soils is studied through laboratory incubation for 114 d under soil moisture regime of 70% water holding capacity at 20℃ and 25℃ respectively. The carbon that mineralized as CO2 evolved was measured every day in the first 32 d and every two days in the following days. Carbon mineralized during the 114 d incubation ranged from 3.51 to 9.22 mg CO2-C/gC at 20℃ and from 4.24 to 11.35 mg CO2-C/gC at 25℃ respectively; and a mineralizable C pool in the range of 0.24 to 0.59 gC/kg, varying with different soils. The whole course of C mineralization in the 114 d incubation could be divided into three stages of varying rates, representing the three subpools of the total mineralizable C： very actively mineralized C at 1-23 d, actively tnineralized C at 24--74 d and a slowly mineralized pool with low and more or less stabilized C mineralization rate at 75-114 d. The calculated Q10 values ranged from 1.0 to 2.4, varying with the soil types and N status. Neither the total SOC pool nor the labile C pool could account for the total mineralization potential of the soils studied, despite a well correlation of labile C with the shortly and actively mineralized C, which were shown in sensitive response to soil warming. However, the portion of microbial C pool and the soil C/N ratio controlled the C mineralization and the temperature dependence. Therefore, C sequestration may not result in an increase of C mineralization proportionally. The relative control of C bioavailability and microbial metabolic activity on C mineralization with respect to stabilization of sequestered C in the paddy soils of China is to be further studied.

关键词： C mineralization carbon pool laboratory incubation paddy soil soil warming

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Martensitic transformation and magnetic properties in Mn_(49-x)Cu_(x)Ni_(41)Sn_(10)(x=0-2)

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Rare Metals 2023年第7期42卷 2433-2438页

作者： Meng-Zhe Zhao Hong-Mei Qiu Ze-Ya Zhu Yun-li Xu Zhu-Hong liu li-qing pan Department of Applied Physics University of Science and Technology BeijingBeijing100083China College of Science China Three Gorges UniversityYichang443002China

The crystal structure,phase transition,metamagnetic behavior and magnetic entropy change(ΔS_(M))of the Mn_(49-x)Cu_(x)Ni_(41)Sn_(10)(x=0-2)alloys were systematically *** results of experiment about crystal structure confirm that Mr_(49-x)Cu_(x)Ni_(41)Sn_(10)alloys have a highly ordered cubic L2_(1)Heusler *** Cu element improving,all samples have a martensitic transformation and inverse martensitic transformation by analyzing the result of magnetic *** saturation magnetization of samples decreases gradually,the martensitic transformation temperature(T_(M))of as-annealed samples increases to a high-temperature area,and the Curie temperature(T_(C))of samples moves to a low-temperature area with the content of Cu element increasing from x=0 to x=*** positive values of magnetic entropy change(ΔS_(M))of all alloys were investigated near the martensitic *** the applied magnetic field is 3 T,a worthwhile value ofΔS_(M)can reach up to 32.0 J·kg^(-1)·K^(-1)in Mn_(47)Cu_(2)Ni_(41)Sn_(10)alloy.

关键词： Heusler alloys Arc melting X-ray diffraction Magnetic properties

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Recent progress in Heusler-type magnetic shape memory alloys

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Rare Metals 2015年第8期34卷 527-539页

作者： Guang-Hua Yu Yun-li Xu Zhu-Hong liu Hong-Mei Qiu Ze-Ya Zhu Xiang-Ping Huang li-qing pan Department of Materials Physics and Chemistry University of Science and Technology Beijing College of Science China Three Gorges University Department of Physics University of Science and Technology Beijing

Magnetic shape memory alloys(MSMAs), both in condensed matter physics and in material science, are one of the most extensive research subjects. They show prompt response to the external magnetic field and give rise to large strain and have fine reversibility. The well-known example is Heusler-type MSMAs, which possess excellent multifunctional properties and have potential applications in energy transducer, actuator, sensor, microelectromechanical system, and magnetic refrigerator. In this paper, it is shown the recent progress in magnetostructural transformation, magnetic properties, shape deformation, magnetocaloric effect as well as magnetic field-induced shape memory effect in Ni–Mn–Ga, Ni Mn Z(Z = In, Sn, Sb),and Ni Co Mn Z(Z = In, Sn, Sb, Al) Heusler-type *** remaining issues and possible challenges are briefly discussed.

关键词： Heusler alloy Magnetic shape memory alloy Martensi

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Spatiotemporal variation and influencing factors of desertification sensitivity on the qinghai-Xizang Plateau,China

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Journal of Arid Land 2025年第1期17卷 58-73页

作者： pan Meihui CHEN qing li Chenlu li Na GONG Yifu College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal UniversityLanzhou 730070China

Due to irrational human activities and extreme climate,the qinghai-Xizang Plateau,China,faces a serious threat of *** has a detrimental effect on the ecological environment and socioeconomic *** this study,the desertification sensitivity index(DSI)model was established by integrating the spatial distance model and environmentally sensitive area index evaluation method,and then the model was used to quantitatively analyze the spatial and temporal characteristics of desertification sensitivity of the qinghai-Xizang Plateau from 1990 to *** results revealed that:(1)a general increasing tendency from southeast to northwest was identified in the spatial distribution of desertification *** low-sensitivity areas were mostly concentrated in the Hengduan and Nyaingqêntanglha mountains and surrounding forest and meadow *** high-sensitivity areas were located mainly in the Kunlun and Altun mountains and surrounding decertified *** center of gravity of all types of desertification-sensitive areas moved to the northwest,and the desertification sensitivity showed a decreasing trend as a whole;(2)the area of highly sensitive desertification areas decreased by 8.37%,with extreme sensitivity being the largest change among the sensitivity *** desertification sensitivity transfer was characterized by a greater shift to lower sensitivity levels(24.56%)than to higher levels(2.03%),which demonstrated a declining trend;(3)since 1990,the change in desertification sensitivity has been dominated by the stabilizing type Ⅰ(29.30%),with the area of continuously increasing desertification sensitivity accounting for only 1.10%,indicating that the management of desertification has achieved positive results in recent years;and(4)natural factors have had a more significant impact on desertification sensitivity on the Xizang Plateau,whereas socioeconomic factors affected only localized *** main factors influencing deserti

关键词： desertification sensitivity geodetector gravity center transfer model spatiotemporal change qinghai-Xizang Plateau

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A Decoupling-Type Strategy for the Allen-Cahn Equation on Curved Surfaces

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Journal of Mathematical Research with Applications 2025年第1期45卷 73-83页

作者： Xiaoman XIE qing pan School of Computer and Communication Engineering Changsha University of Science & Technology

In this paper, we construct an efficient decoupling-type strategy for solving the Allen-Cahn equation on curved surfaces. It is based on an FEM-EIEQ(Finite Element Method and explicit-Invariant Energy Quadratization) fully discrete scheme with unconditional energy stability. Spatially the FEM is adopted, using a triangular mesh discretization strategy that can be adapted to complex regions. Temporally, the EIEQ approach is considered, which not only linearizes the nonlinear potential but also gives a new variable that we combine with the nonlocal splitting method to achieve the fully decoupled computation. The strategy can successfully transform the Allen-Cahn system into some completely independent algebraic equations and linear elliptic equations with constant coefficients, we only need to solve these simple equations at each time step. Moreover, we conducted some numerical experiments to demonstrate the effectiveness of the strategy.

关键词： FEM-EIEQ Allen-Cahn equation surface

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Holographic images of a charged black hole in Lorentz symmetry breaking massive gravity

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 59-72页

作者： Xiao-Xiong Zeng li-Fang li pan li Bo liang Peng Xu College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Department of Mechanics Chongqing Jiaotong UniversityChongqing 400074.China Center for Gravitational Wave Experiment National Microgravity LaboratoryInstitute of MechanicsChinese Academy of SciencesBeijing 100190China Lanzhou Center of Theoretical Physics Lanzhou UniversityLanzhou 730000China

Using the AdS/CFT correspondence,this paper investigates the holographic images of a charged black hole within the context of Lorentz symmetry breaking massive *** photon rings,luminosity-deformed rings,or light points from various observational perspectives are *** also study the influences of both the chemical potential and temperature on the Einstein *** the previous work,which primarily examines the effect of chemical potential on ring radius at high temperatures and find no change in the radius with varying chemical potential,we also investigate the effect of chemical potential on the ring radius at low temperature besides at high *** findings indicate that at low temperatures,the photon ring radius decreases with increasing of chemical potential,while at high temperatures,the results are consistent with previous ***,we explore the impact of the model parameterλon the Einstein ring radius and find the the ring radius increases as the model parameterλ*** interestingly,for the large chemical potential,u=1,the temperature dependence of the photon ring radius is reversed forλ=2 andλ=***,for a small chemical potential u=0.1,the temperature dependence of the Einstein ring stays the same asλ=2 andλ=4.

关键词： AdS/CFT correspondence holographic images massive gravity black holes

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Topologically close-packed intermetallic alloy electrocatalysts for CO_(2) reduction towards high value-added multi-carbon chemicals

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Chinese Chemical Letters 2025年第1期36卷 6-7页

作者： Qiyan Wu qing li State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The continuous combustion of unsustainable carbon-based fossil fuels has dramatically accelerated the increase in carbon dioxide(CO_(2))concentration in the atmosphere(from approximately278.3 ppm in 1750 to 417.9 ppm in 2023),which would exacerbate environmental problems such as greenhouse effect[1].The effective electrosynthesis of high value-added multi-carbon(C_(2+))chemicals(e.g.,ethanol,ethylene)from CO_(2) reduction reaction(CO_(2)RR)is a promising strategy to mitigate these environmental issues mentioned above but remains highly challenging due to the competition of hydrogen evolution reaction(HER)and low selectivity of target products.

关键词： intermetallic alloy carbon

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Engineering atomic Rb-N configurations to tune radical pathways for highly selective photocatalytic H_(2)O_(2) synthesis coupled with biomass valorization

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Journal of Energy Chemistry 2025年第1期100卷 215-225页

作者： Jiaye li Shuang pan Yihuang Chen Qiong liu College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035ZhejiangChina Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology(China) Institute of AnalysisGuangdong Academy of Sciences(China National Analytical CenterGuangzhou)Guangzhou 510070GuangdongChina

Photocatalytic oxygen reduction for hydrogen peroxide(H_(2)O_(2))synthesis presents a green and costeffective production ***,achieving highly selective H_(2)O_(2)synthesis remains challenging,necessitating precise control over free radical reaction pathways and minimizing undesirable oxidative ***,we report for the visible light-driven simultaneous co-photocatalytic reduction of O2to H_(2)O_(2)and oxidation of biomass using the atomic rubidium-nitride modified carbon nitride(CNRb).The optimized CNRb catalyst demonstrates a record photoreduction rate of 8.01 mM h^(-1)for H_(2)O_(2)generation and photooxidation rate of 3.75 mM h^(-1)for furfuryl alcohol to furoic acid,achieving a remarkable solar-to-chemical conversion(SCC)efficiency of up to 2.27%.Experimental characterizations and DFT calculation disclosed that the introducing atomic Rb–N configurations allows for the high-selective generation of superoxide radicals while suppressing hydroxyl free radical *** is because the Rb–N serves as the new alternative site to perceive a stronger connection position for O2adsorption and reinforce the capability to extract protons,thereby triggering a high selective redox product *** study holds great potential in precisely regulating reactive radical processes at the atomic level,thereby paving the way for efficient synthesis of H_(2)O_(2)coupled with biomass valorization.

关键词： Atomic economy Radical pathway regulation Photocatalytic H_(2)O_(2)synthesis Rubidium atom coordination Biomass valorization

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Unconventional room-temperature negative magnetoresistance effect in Au/n-Ge:Sb/Au devices

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Chinese Physics B 2024年第3期33卷 602-608页

作者：何雄杨凡黎牛浩峪王立峰易立志许云丽刘敏潘礼庆夏正才 Hubei Engineering Research Center of Weak Magnetic-field Detection College of ScienceChina Three Gorges UniversityYichang 443002China Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China

Non-magnetic semiconductor materials and their devices have attracted wide attention since they are usually prone to exhibit large positive magnetoresistance(MR)effect in a low static magnetic field environment at room ***,how to obtain a large room-temperature negative MR effect in them remains to be *** this paper,by designing an Au/n-Ge:Sb/Au device with metal electrodes located on identical side,we observe an obvious room-temperature negative MR effect in a specific 50 T pulsed high magnetic field direction environment,but not in a static low magnetic field *** the analysis of the experimental measurement of the Hall effect results and bipolar transport theory,we propose that this unconventional negative MR effect is mainly related to the charge accumulation on the surface of the device under the modulation of the stronger Lorentz force provided by the pulsed high magnetic *** theoretical analytical model is further confirmed by regulating the geometry size of the *** work sheds light on the development of novel magnetic sensing,magnetic logic and other devices based on non-magnetic semiconductors operating in pulsed high magnetic field environment.

关键词： magnetoresistance germanium-based devices pulsed high magnetic fields

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Recent progress in flexible sensors based on 2D materials

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Journal of Semiconductors 2025年第1期46卷 130-142页

作者： Xiang li Guancheng Wu Caofeng pan Rongrong Bao School of Physics Beihang UniversityBeijing 100191China Institute of Atomic Manufacturing Beihang UniversityBeijing 100191China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049China

With the rapid development of the internet of things(IoT)and wearable electronics,the role of flexible sensors is becoming increasingly irreplaceable,due to their ability to process and convert information ***-dimensional(2D)materials have been widely welcomed by researchers as sensitive layers,which broadens the range and application of flexible sensors due to the advantages of their large specific surface area,tunable energy bands,controllable thickness at the atomic level,stable mechanical properties,and excellent optoelectronic *** review focuses on five different types of 2D materials for monitoring pressure,humidity,sound,gas,and so on,to realize the recognition and conversion of human body and environmental ***,the main problems and possible solutions of flexible sensors based on 2D materials as sensitive layers are summarized.

关键词： 2D materials flexible sensors layered structure solution method

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