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Influence of Evaporating Under the Clouds on the Precipitation Stable Isotope in the Transition zone Between Tibetan Plateau and Arid Region of China

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Chinese Geographical Science 2023年第4期33卷 764-778页

作者： GUI Juan li zongxing DU Fa zHANG Baijuan XUE Jian CUI Qiao Observation and Research Station of Eco-Hydrology and National Park by Stable Isotope Tracing in Alpine Region Gansu Qilian Mountains Ecology Research CenterChinese Academy of SciencesLanzhou 730000China National Key Laboratory of Ecological Security and Sustainable Development in Arid Region Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Consideration of stable isotopes in precipitation is valuable for investigating hydrological ***,correcting the measured isotopic composition of precipitation under below-cloud evaporation is *** accurate description of the underlying processes affecting stable isotopic composition of precipitation could help improve our understanding of the water *** transitivity between monsoonal and arid climates was reflected by the evaporation rate of falling raindrops in precipitation in the Qilian Mountains,a typical transition zone between Tibetan Plateau and arid region of *** 1310 precipitation event-scale samples,based on stable isotope analysis method,the mean below-cloud evaporation rate(f)in the study area was measured as 12.00%during the summer half-year(May-October).The evaporation rate on the northern slopes(12.70%)of the Qilian Mountains in China was significantly higher than that on the southern slopes(9.98%).The transition between monsoonal and arid climates was reflected in the evaporation rate of falling raindrops during precipitation in the Qilian Mountains of ***-cloud evaporation contributed to a noticeable enrichment of stable isotopes in the precipitation in the study *** monthly precipitationδ^(18)O enrichment rate in the Qilian Mountains of China from May to October was 29.18%,23.35%,25.60%,22.99%,31.64%,and 14.72%,*** every 1.00%increase in the evaporation rate of raindrops in Qilian Mountains of China,the changes in the concentration of oxygen isotopes from the bottom of the clouds to the ground increased by 0.92‰;however,with an evaporation rate of<5.00%,for every 1.00%increase in the evaporation rate of raindrops the changes in the concentration of oxygen isotopes from the bottom of the clouds to the ground increased by 1.00‰could also be ***,altitude was an important factor affecting below-cloud evaporation in the study area.

关键词： below-cloud evaporation stable isotopes transition zone Qilian Mountains of China

Carbon-carbon double bond in pillar[5]arene cavity:Selective binding of cis/trans-olefin isomers

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Chinese Chemical Letters 2020年第12期31卷 3230-3232页

作者： Xue zhang Xiaoyang Wang Bin Wang zhi-Jun Ding Chunju li Key Laboratory of lnorganic-Organic Hybrid Functional Material Chemistry Ministry of EducationTianjin Key Laboratory of tructure and Performane forFunctional MoleculesCollege of ChemistryTianjin Norrmal UniversityTianjin 300387China Center for Supramolecular Chemistry and Catalysis and Department of Chemistry Sshanghai UniversitySshanghai 20044China Srare Key Laboratory of NBC Protecrion for Civilian Beijing 102205China

The binding behavior of pillar[5]arenes(P5 As)towards a series of olefin guests((E)-1,4-dichlo robut-2-ene(1 E),(z)-1,4-dichlo robut-2-ene(1 z),(E)-but-2-ene-1,4-diol(2 E),and(z)-but-2-ene-1,4-diol(2 z),as well as an alkyne derivative 1,4-dichlorobut-2-yne(3))have been studied in organic solution.P5 As exhibit considerable selectivities for the trans-olefin isomers(1 E and 2 E)over their cis-isomers(1 z and 2 z).The cis/trans-selective interactions hold the potential of utilizing P5 As to separate olefin isomers.

关键词： Pillararenes Molecular recognition Supramolecular chemistry Olefin Isomers

Mechanical properties and influence mechanism of confined concrete arches in high-stress tunnels

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International Journal of Mining Science and Technology 2023年第7期33卷 829-841页

作者： Bei Jiang zhongxin Xin Xiufeng zhang Yusong Deng Mingzi Wang Shidong li Wentao Ren State Key Laboratory for Geo-mechanics and Deep Underground Engineering China University of Mining and Technology-BeijingBeijing 100083China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Research Center of Geotechnical and Structural Engineering Shandong UniversityJinan 250061China Shandong Energy Group Co. Ltd.Jinan 250014China

Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,which makes it difficult to meet the requirements of ground control under complex conditions. As a new support form with high strength and rigidity, the confined concrete arch plays an important role in controlling the rock deformation under complex conditions. The section shape of the tunnel has an important impact on the mechanical properties and design of the support system. However, studies on the mechanical properties and influence mechanism of the new confined concrete arch are rarely reported. To this end, the mechanical properties of traditional U-shaped steel and new confined concrete arches are compared and comparative tests on arches of circular and straight-leg semicircular shapes in deep tunnels are conducted. A large mechanical testing system for underground engineering support structure is developed. The mechanical properties and influence mechanism of confined concrete arches with different section shapes under different loading modes and cross-section parameters are systematically studied. Test results show that the bearing capacity of the confined concrete arch is 2.10 times that of the U-shaped steel arch, and the bearing capacity of the circular confined concrete arch is 2.27 times that of the straight-leg semicircular arch. Among the various influencing factors and their engineering parameters,the lateral stress coefficient has the greatest impact on the bearing capacity of the confined concrete arch,followed by the steel pipe wall thickness, steel strength, and core concrete strength. Subsequently, the economic index of bearing capacity and cost is established, and the optimization design method for the confined concrete arch is proposed. Finally, this design method is applied to a high-stress tunnel under complex conditions, and the d

关键词： High-stress tunnel Confined concrete arch Section shape Mechanical properties Design method

Microstructures and magnetic properties of Sm(Co_(bal)Fe_(0.245)Cu_(0.07)zr_(0.02))_(7.8)sintered magnet solution-treated at high temperature

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Rare Metals 2022年第12期41卷 4230-4234页

作者： Wei Sun Ming-Gang zhu Yi-Kun Fang zhao-Hui Guo Wei li Functional Materials Research Institute Central Iron and Steel Research InstituteBejing 100081China Beijing Engineering Laboratory of Advanced Metallic Magnetic Materials and Preparation Techniques Beijing 100081China

Sm(CoFeCuzr)zsintered permanent magnet has been attracting a great deal of attention by virtue of its high-temperature magnetic properties,low temperature coefficient and good corrosion and oxidation *** microstructures and magnetic properties of Sm(Co_(ba1)Fe_(0.245)Cu_(0.07)zr_(0.02))_(7.8)sintered permanent magnet prepared by a traditional powder metallurgy method were *** magnetic properties,especially the maximum magnetic energy product,(BH)max,were obtained through adjusting solution-treated *** solution-treated temperature increasing from 1155 to 1195℃,remanence(Br)almost keeps constant and knee point coercivity(Hk),magnetic induction coercivity(H_(cb))and(B_(H))maxfirst increase and then *** intrinsic coercivity(H_(cj))of magnet solution-treated at 1195℃is 738 kA·m^(-1),which is less than 2/5 that of magnet solution-treated at 1183℃(>1927 kA·m^(-1)).The reason that magnet solution-treated at 1195℃shows lower Hcjthan magnet solution-treated at 1183℃is considered to be mainly related to the fact that there are a lot of cells with abnormally small *** addition,the lattice constant of Sm(Co_(bal)Fe_(0.245)Cu_(0.07)zr_(0.02))_(7.8)sintered permanent magnet solution-treated at 1195℃,given by indexing highresolution transition electron microscope(HRTEM)results,is considered to be related to the formation of cells with abnormally small size which decreases H_(cj).

关键词： Microstructures Magnetic properties Sm(CoFeCuzr)_(z)sintered magnet High solution-treated temperature

Poly(methyl methacrylate)-induced Microstructure and Hydrolysis Behavior Changes of Poly(L-lactic acid)/Carbon Nanotubes Composites

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Chinese Journal of Polymer Science 2020年第2期38卷 195-204,I0008页

作者： Xu Yu Xin-zheng Jin Ting Huang Nan zhang Xiao-Yu li Yong Wang School of Materials Science&Engineering Key Laboratory of Advanced Technologies of Materials(Ministry of Education)Southwest Jiaotong UniversityChengdu 610031China College of Polymer Science and Engineering Sichuan UniversityChengdu 610065China

Poly(L-lactic acid)(PLLA)-based composites exhibit wide applications in many ***,most of hydrophilic fillers usually accelerate the hydrolytic degradation of PLLA,which is unfavorable for the prolonging of the service life of the *** this work,a small quantity of poly(methyl methacrylate)(PMMA)(2 wt%-10 wt%)was incorporated into the PLLA/carbon nanotubes(CNTs)*** effects of PMMA content on the dispersion of CNTs as well as the microstructure and hydrolytic degradation behaviors of the composites were systematically *** results showed that PMMA promoted the dispersion of CNTs in the *** PLLA was obtained in all the *** enhanced hydrolytic degradation resistance was achieved by incorporating PMMA,especially at relatively high PMMA *** 10 wt%PMMA led to a dramatic decrease in the hydrolytic degradation rate from 0.19%/h of the PLLA/CNT composite sample to 0.059%/h of the PLLA/PMMA-10/CNT composite *** microstructure evolution of the composites was also detected,and the results showed that no crystallization occurred in the PLLA *** results based on the interfacial tension calculation showed that the enhanced hydrolytic degradation resistance of the PLLA matrix was mainly attributed to the relatively strong interfacial affinity between PMMA and CNTs,which prevented the occurrence of hydrolytic degradation at the interface between PLLA and *** work provides an alternative method for tailoring the hydrolytic degradation ability of the PLLA-based composites.

关键词： Poly(L-lactic acid)composites Poly(methyl methacrylate) Microstructure Hydrolytic degradation

Sandwich Structure Design of a Cooling Fin for Battery Modules Against Impact Loads

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Automotive Innovation 2020年第3期3卷 260-269页

作者： zitong Shi Guanhua Chen lingxiao zhu Jie li Yong Xia State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China State Key Laboratory of Vehicle NVH and Safety Technology Chongqing 401120China

lithium-ion batteries(liBs)are widely employed in electric vehicles owing to their high power density,long cycle life,and environmental ***,liBs are hazardous in the event of a crash,leading to thermal *** this study,the basic structure of a battery module is analyzed to improve the crashworthiness of liBs.A simplified finite element model of the battery module structure,which is a battery unit composed of two pouch cells and a cooling fin,is set up and verified by conducting module-level *** simulation results reveal that the cooling fin in the battery module has the potential to absorb *** sandwich configurations are introduced to modify the cooling *** a unidirection-ally stiffened double hull USDH structure serving as an example,a parametric analysis is conducted,demonstrating that the sandwich height does not influence the areal density;a small height of 3 mm can make the material work sufficiently while avoiding early buckling of the ***,the crashworthiness of different sandwich configurations with the same areal density and height is compared,leading to three deformation *** and circular core structures are found to be able to effectively reduce the peak force and improve the energy absorption ability.

关键词： lithium-ion battery Impact protection Sandwich configuration Cooling fin

Synergistic effects of Cu species and acidity of Cu-zSM-5 on catalytic performance for selective catalytic oxidation of n-butylamine

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Journal of Environmental Sciences 2020年第10期32卷 55-63页

作者： Xin Xing Na li Jie Cheng Yonggang Sun zhongshen zhang Xin zhang zhengping Hao Key Laboratory of Environmental Nanotechnology and Health Effects Research Center for Eco-Enuironmental SciencesChinese Academy of SciencesBeijing 100085China National Engineering Laboratory/or VOCs Pollution Control Material&Technology Research Center/or Environmental Material and Pollution Control TechnologyUniversity of Chinese Academy of SciencesBeijing 101408China

In this work, a series of Cu-zSM-5 catalysts with different SiO2/Al2O3 ratios(25, 50, 100 and200) were synthesized and investigated in n-butylamine catalytic degradation. The n-butylamine can be completely catalytic degradation at 350 ℃ over all Cu-zSM-5 catalysts. Moreover, Cu-zSM-5(25) exhibited the highest selectivity to N2, exceeding 90% at 350 ℃. These samples were investigated in detail by several characterizations to illuminate the dependence of the catalytic performance on redox properties, Cu species, and acidity. The characterization results proved that the redox properties and chemisorption oxygen primarily affect n-butylamine conversion. N2 selectivity was impacted by the Bronsted acidity and the isolated Cu^2+ species. Meanwhile, the surface acid sites over Cu-zSM-5 catalysts could influence the formation of Cu species. Furthermore, in situ diffuse reflectance infrared Fourier transform spectra was adopted to explore the reaction mechanism. The Cu-zSM-5 catalysts are the most prospective catalysts for nitrogen-containing volatile organic compounds removal, and the results in this study could provide new insights into catalysts design for VOC catalytic oxidation.

关键词： CH3CH2CH2CH2NH2 Selective oxidation Cu-zSM-5 Cu species Acid sites

Spaceflight and simulated microgravity suppresses macrophage development via altered RAS/ERK/NFκB and metabolic pathways

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Cellular & Molecular Immunology 2021年第6期18卷 1489-1502页

作者： Lu Shi Hongling Tian Peng Wang ling li zhaoqi zhang Jiayu zhang Yong zhao State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijingChina

Spaceflight-associated immune system weakening ultimately limits the ability of humans to expand their presence beyond the earth's orbit. A mechanistic study of microgravity-regulated immune cell function is necessary to overcome this challenge. Here, we demonstrate that both spaceflight (real) and simulated microgravity significantly reduce macrophage differentiation, decrease macrophage quantity and functional polarization, and lead to metabolic reprogramming, as demonstrated by changes in gene expression profiles. Moreover, we identified RAS/ERK/NFκB as a major microgravity-regulated pathway. Exogenous ERK and NFκB activators significantly counteracted the effect of microgravity on macrophage differentiation. In addition, microgravity also affects the p53 pathway, which we verified by RT-qPCR and Western blot. Collectively, our data reveal a new mechanism for the effects of microgravity on macrophage development and provide potential molecular targets for the prevention or treatment of macrophage differentiation deficiency in spaceflight.

关键词： Microgravity Hematopoietic progenitor cells Macrophage differentiation Macrophage polarization RAS/ERK/NFκB pathway

Electrostatic self-assembly of 2D/2D CoWO_(4)/g-C_(3)N_(4)p-n heterojunction for improved photocatalytic hydrogen evolution:Built-in electric field modulated charge separation and mechanism unveiling

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Nano Research 2022年第8期15卷 6987-6998页

作者： Haiyang Wang Ranran Niu Jianhui liu Sheng Guo Yongpeng Yang zhongyi liu Jun li Henan Institute of Advanced Technology College of ChemistryZhengzhou UniversityZhengzhou 450052China School of Chemistry and Environmental Engineering Wuhan Institute of TechnologyWuhan 430205China

Two-dimensional(2D)semiconductor heterojunctions are considered as an effective strategy to achieve fast separation of photoinduced ***,a novel CoWO_(4)/g-C_(3)N_(4)(CWO/CN)p–n junction was synthesized using an electrostatic selfassembly *** constructed 2D/2D p–n heterostructure had a rich hetero-interface,increased charge density,and fast separation efficiency of photoinduced *** in-situ Kelvin probe force microscopy confirmed that the separation pathway of photoinduced carriers through the interface obeyed an II-scheme charge transfer *** results and density functional theory calculations indicated the differences of work function between CWO and CN induced the generation of built-in electric field,ensuring an efficient separation and transfer process of photoinduced *** the optimized conditions,the CWO/CN heterojunction displayed enhanced photocatalytic H_(2)generation activity under full spectrum and visible lights irradiation,*** study provides a novel approach to design 2D/2D hetero-structured photocatalysts based on p–n type semiconductor for photocatalytic H_(2)generation.

关键词： p-n junction interfacial charge transfer two-dimensional/two-dimensional photocatalytic H_(2)generation CoWO_(4)/g-C_(3)N_(4)heterojunction