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Al-containing Ge-rich IWV:rapid synthesis via interzeolite transformation and application in Baeyer-Villiger oxidation

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Science China Chemistry 2024年第7期67卷 2282-2291页

作者： Meichen jiao Chunmin Jia Hao Xu Peng Wu Xian-ming Zhang School of Chemistry&Material Science Shanxi Normal UniversityTaiyuan 030006China Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China School of Chemistry Taiyuan University of TechnologyTaiyuan 030024China

Ge-containing Lewis acidic zeolites are typically synthesized using a conventional hydrothermal strategy from amorphous silica sources,through a long time-and energy-consuming approach limiting their wide *** study reports a rapid synthesis strategy for a series of IWV aluminogermanosilicate zeolites(T-x-Al)with a wide range of Si/Ge molar ratios(5–15)by interzeolite transformation of dealuminated FAU(da-FAU).Notably,Ge-rich IWV could be obtained with crystallization time as short as one day by the equimolecular Si/Ge ratio *** effect of synthetic parameters was investigated and the obtained T-x-Al samples were characterized by XRD,SEM,EDS,ICP,^(29)Si and^(27)Al MAS NMR,FTIR,and N_(2)physisorption *** with a previously reported IWV germanosilicate(H-3),T-x-Al displayed a better catalytic activity in Baeyer-Villiger(BV)oxidation,attributed to the presence of the active framework Ge sites with the assistance of the extraframework Al *** cyclic catalysis tests revealed that the presence of framework Al species contributed to the stability of the ***,T-x-Al,with 14-membered ring(MR)supercages,outperformed the typical 12-MR Sn-beta catalyst in the BV oxidation of large ketone-like 2-admantanone,indicating a promising potential application in the macromolecular catalytic process.

关键词： Ge-rich IWV interzeolite transformation Al assistance Baeyer-Villiger oxidation

Patterns and drivers of seasonal water sources for artificial sand-fixing plants in the northeastern Mu Us sandy land,Northwest China

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Pedosphere 2024年第1期34卷 63-77页

作者： Yanwu PEI Laiming HUANG ming'an SHAO jiao WANG Yinglong ZHANG Yellow River Delta Modern Agricultural Engineering Laboratory Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Natural Resources and Environment Northwest Agriculture and Forestry UniversityYangling 712100China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences of Chinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Shenmu Ecological Association Shenmu 719399China

Understanding plant water-use patterns is important for improving water-use efficiency and for sustainable vegetation restoration in arid and semi-arid regions. However, seasonal variations in water sources and their control by different sand-fixing plants in water-limited desert ecosystems remain poorly understood. In this study, stable isotopic ratios of hydrogen(δ^(2)H) and oxygen(δ^(18)O) in precipitation, soil water, groundwater, and xylem water were determined to document seasonal changes in water uptake by three representative plant species(Pinus sylvestris var. mongolica Litv., Amygdalus pedunculata Pall., and Salix psammophila) in the northeastern Mu Us sandy land, Northwest China. Based on the depth distribution and temporal variation of measured gravimetric soil water content(SWC), the soil water profile of the three species stands was divided into active(0.01 g g^(-1)45%) layers. Annually, P. sylvestris, A. pedunculata, and S. psammophila obtained most water from deep(59.2%±9.7%, moist layer and groundwater),intermediate(57.4%±9.8%, stable and moist layers), and shallow(54.4%±10.5%, active and stable layers) sources, respectively. Seasonally, the three plant species absorbed more than 60% of their total water uptake from the moist layer and groundwater in the early(June) dry season;then, they switched to the active and stable layers in the rainy season(July–September) for water resources(50.1%–62.5%). In the late(October–November) dry season, P. sylvestris(54.5%–66.2%) and A. pedunculata(52.9%–63.6%) mainly used water from stable and moist layers, whereas S. psammophila(52.6%–70.7%) still extracted water predominantly from active and stable layers. Variations in the soil water profile induced by seasonal fluctuations in precipitation and groundwater levels and discrepancies in plant pheno

关键词： desert ecosystem MixSIAR model plant water uptake soil moisture stable isotopes vegetation restoration water-use efficiency

Buckling Properties of Water-Drop-Shaped Pressure Hulls with Various Shape Indices Under Hydrostatic External Pressure

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China Ocean Engineering 2024年第1期38卷 1-17页

作者： DING Xiao-de ZHANG Jian WANG Fang jiao Hui-feng WANG ming-lu School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Shanghai Engineering Research Center of Marine Renewable Energy College of Engineering Science and Technol-ogyShanghai Ocean UniversityShanghai 201306China China Ship Scientific Research Center Wuxi 214082China

The water-drop-shaped pressure hull has a good streamline,which has good application prospect in the underwater ***,this study conducted analytical,experimental and numerical investigation of the buckling properties of water-drop-shaped pressure hulls under hydrostatic pressure.A water-drop experiment was conducted to design water-drop-shaped pressure hulls with various shape *** critical loads for the water-drop-shaped pressure hulls were resolved by using Mushtari’s *** numerical simulations including linear buckling analysis and nonlinear buckling analysis including eigenmode imperfections were *** results indicated that the critical loads resolved by Mushtari's formula were in good agreement with the linear buckling loads from the numerical *** formula can be extended to estimate the buckling capacity of water-drop-shaped pressure *** addition,three groups of pressure hulls were fabricated by using stereolithography,a rapid prototyping ***,three groups of the pressure hulls were subjected to ultrasonic measurements,optical scanning,hydrostatic testing and numerical *** experimental results were consistent with the numerical *** results indicate that the sharp end of the water-drop-shaped pressure hulls exhibited instability compared with the blunt *** paper provides a new solution to the limitations of experimental studies on the water-drop-shaped pressure hulls as well as a new configuration and evaluation method for underwater observatories.

关键词： buckling pressure hull water drop underwater observatory

Drainage of paddy terraces impacts structures and soil properties in the globally important agricultural heritage of Hani Paddy Terraces,China

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International Soil and Water Conservation Research 2024年第1期12卷 64-76页

作者： ming Wang Li Rong Yanbo Li Jiangcheng Huang Yuanmei jiao Xiaoyan Wei Institute of International Rivers and Eco-Security Kunming650500China Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Kunming650500China Power China Kunming Engineering Corporation Limited Kunming650051China Department of Geography Yunnan Normal UniversityKunming650500China Yunnan Provincial Archives of Surveying and Mapping(Yunnan Provincial Geomatics Centre) Kunming650032China

Marginalization and abandonment of paddy terraces are widespread,but their effects on the sustainability of subsequent agricultural production are still *** Paddy Terraces,included in Globally Important Agriculture Heritage Systems,are threatened by paddy fields ***,changes in terrace structure,the productivity of topsoil(0-20 cm),and soil water holding capacity at 0-70 cm depth were determined in a case study of Hani Paddy Terraces in Amengkong River Basin in Yuanyang County in Southwestern China,which had been converted into dryland terraces for 2-14 *** results showed that:(1)The degree of terrace structures degradation exhibited a U-shaped curve with increasing time since draining,with those drained for 5-9 years having the best structure;(2)Soil productivity index decreased first and then increased with time after conversion;(3)Maximum water holding capacity at 0-70 cm soil depth dramatically decreased after conversion and such trend became increasingly obvious with increasing time since *** study revealed that drainage of paddy terraces along with associated changes in crop and field management led to an increase in soil productivity,but degradation of terrace structures and a decrease in water holding capacity will inhibit restoration to paddy *** findings enhance the understanding of the biophysical changes due to marginalization in paddy terraces.

关键词： Hani paddy terraces Terraces marginalization Terrace structure degradation Soil productivity Water holding capacity

Biocrusts impact soil properties and ecological stoichiometry characteristics in frozen ground regions on the Qinghai-Tibet Plateau

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Soil Ecology Letters 2024年第3期6卷 151-162页

作者： jiao ming Yunge Zhao Yingying Sun Zhe Liu The Research Center of Soil and Water Conservation and Ecological Environment Chinese Academy of Sciences and Ministry of EducationYangling 712100China College of Soil&Water Conservation Science and Engineering(Institute of Soil and Water Conservation) Northwest A&F UniversityYangling 712100China Institute of Soil and Water Conservation Chinese Academy of Sciences&Ministry of Water ResourcesYangling 712100China Shaanxi Provincial Land Engineering Construction Group Co. Ltd.Xi'an 710075China

Biocrusts(BSCs)are widely distributed in frozen ground regions on the Qinghai-Tibet Plateau,and they are considered an important component of cold ***,the specific impacts of BSCs on frozen soil remains relatively *** aim of our study was to clarify the influence of BSCs(light BSCs and dark BSCs in two different succession stages)on the physical properties and ecological stoichiometry characteristics of frozen *** results showed that BSCs increased the silt particle content in 20–40 cm soil layer,leading to a decrease in soil bulk *** the field water capacity increased about 10%–40%compared to bare ***,BSCs significantly increased the contents of soil organic carbon(SOC,22.6–30.8 g kg^(-1))and total nitrogen(TN,2.1–2.8 g kg^(-1))in the upper 40 cm soil layer,both of them were approximately 1.3–2.0 and 1.3–4.0 times higher than those observed in bare ***,BSCs did not have significant influence on soil total phosphorus(TP).BSCs had a significant impact on the stoichiometric ratios within 40 *** C/N ratios of the two types of BSCs ranged from 8.8 to 13.5,the C/P ratios ranged from 6.6 to 13.8,and the N/P ratios ranged from 0.6 to 1.2,which were all higher than those of the bare *** were no significant differences among the C/N,C/P,and N/P ratios between two types of ***,the increment of C/P and N/P ratios of dark BSCs were significantly higher than those of light BSCs within 0–30 cm,which indicated that a reduction in the availability of phosphorus during the later stages of BSCs *** findings provided a theoretical basis for further research on the ecological functions of BSCs in frozen ground regions.

关键词： biocrusts frozen soil soil properties stoichiometry characteristics Qinghai-Tibet Plateau

Identification,Characterization,and Probiotic Potentials of Lactobacillus pentosus SF-1

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Journal of Ocean University of China 2024年第2期23卷 509-517页

作者： jiao Lin LIANG Shufei CHU Ruixia WANG Wentao MAI Kangsen LIU ming WAN Min Key Laboratory of Aquaculture Nutrition and Feed Ministry of Agriculture&Key Laboratory of MaricultureMinistry of EducationCollege of FisheriesOcean University of ChinaQingdao 266003China Engineering Research Center of Mariculture Ministry of EducationOcean University of ChinaQingdao 266003China

In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in *** the present study a strain of Lactobacillus pentosus,named as *** SF-1,was isolated from waters in *** species identification of this strain was conducted by 16S rRNA sequence,and the physiological and biochemical characteristics of this strain were ***,the virulence,antibiotic sensitivity,cell surface characteristics and acid/base-resistance of *** SF-1 were determined to evaluate the probiotic potentials of this ***,*** SF-1 is sensitive to most common antibiotics,and no hemolysin was generated from it,indicating the safety of this strain to *** addition,*** SF-1 was able to tolerate the artificial gastric juice at pH 3 for 4 h and the artificial intestinal fluid at pH 6.8 or 8.0 for 6 ***,the analysis of self-aggregation and the adhesion of *** SF-1 to organic solvents suggested a high potential of *** SF-1 to inhabit the hosts,which was confirmed by testing the colonization of *** SF-1 in germ-free ***,*** SF-1 displayed a high bactericidal activity against several bacterial ***,the incubation of *** SF-1 significantly promoted the expression of antimicrobial components in zebrafish,contributing to the protection of the fish from *** infection in *** together,the probiotic strain *** SF-1 could be applied as anti-infection reagent in aquaculture.

关键词： Lactobacillus pentosus probiotics antibiotics hemolysis cell surface characteristics bactericidal activity infection

Evolution model and failure mechanisms of rainfall-induced cracked red clay slopes:insights from Xinshao County,China

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Journal of Mountain Science 2024年第3期21卷 867-881页

作者： jiao Weizhi ZHANG ming LI Peng XIE Junjin PANG Haisong LIU Fuxing YANG Long Faculty of Engineering China University of GeosciencesWuhan 430074China

Red clay landslides are widely distributed worldwide,resulting in severe loss of life and *** rainfall-induced red clay slopes have received extensive attention,the role of cracks in the evolutionary process of red clay slopes and their connection to failure mechanisms is still poorly understood.A comprehensive approach integrating field investigation,laboratory tests,and numerical simulations was conducted to study the 168 red clay landslides in Xinshao County,*** results show that red clay is prone to forming cracks at high moisture content due to its low swelling and high shrinkage *** failure mode of red clay slopes can be summarized in three stages:crack generation,slope excavation,and slope ***,the retrospective analysis and numerical simulations of the typical landslide in Guanchong indicated that intense rainfall primarily impacts the shallow layer of soil within approximately 0.5 m on the intact ***,cracks change the pattern of rainfall infiltration in the *** infiltrates rapidly through the preferential channels induced by the cracks rather than uniformly and slowly from the slope *** results in a significant increase in both the depth of infiltration and the saturated zone area of the cracked slope,reaching 3.8 m and 36.2 m^(2),***,the factor of safety of the slope decreases by 13.4%compared to the intact slope,ultimately triggering *** study can provide valuable insights into understanding the failure mechanisms of red clay slopes in China and other regions with similar geological settings.

关键词： Red clay slopes Cracks Preferential flow Failure mechanism

Enhanced preparation of dendritic metallic vanadium in recyclable NaCl-KCl-VCl_(2) molten salt by V_(2)CO electrolysis

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Rare Metals 2024年第8期43卷 3961-3973页

作者： Jia-Liang An ming-Yong Wang Yong-Zheng Jia Jin-Tao Zhang Bao-Yan Feng Shu-Qiang jiao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China College of Material Science and Engineering Hebei Province Laboratory of Inorganic Nonmetallic MaterialsNorth China University of Science and TechnologyTangshan 063210China

A promising method for the preparation of pure metallic vanadium via V_(2)CO anode electrolysis was proposed and *** simple and controllable synthesis of a molten chloride salt containing VCl_(2) by an insitu reaction between VCl_(3) and metallic vanadium was verified through thermodynamic analysis and ***-KCl-VCl_(2) molten salt exhibited excellent recycling performance and could be repetitively used to prepare metallic vanadium by V_(2)CO *** V^(2+) ions remained in the molten salt after *** electrolysis conditions,such as the cathode diameter,current density,V^(2+) ion concentration,and temperature,were optimised to maximise the current *** was also simulated to reveal the regulatory *** highest current efficiency was 85%.The purity of metallic vanadium was up to 99.8%.In this study,an easy and efficient preparation of pure metallic vanadium was achieved.

关键词： V_(2)CO Metallic vanadium Current efficiency Molten salt electrolysis

Single-wall carbon nanotube fiber non-woven fabrics with a high electrothermal heating response

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Nano Research 2024年第6期17卷 5621-5628页

作者： Xinyu jiao Lele Xu Xinyang Sun Chao Shi Peng-Xiang Hou Chang Liu Hui-ming Cheng Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Carbon nanotube(CNT)fibers have great promise for constructing multifunctional fabrics with high electrical conductivity,good electro-heating ability,excellent flexibility,and a low ***,the inter-fiber contacts in the fabric greatly reduce these advantages and limit their ***,a simple pressure-fusing method to fabricate single-wall CNT(SWCNT)fiber non-woven fabrics(NWFs)that are composed of interconnected SWCNT fibers with fused joints is reported,which have good flexibility,a low density of 0.46 g/cm^(3),a high electrical conductivity of 3.7×10^(5)S/m,and a record high specific electrical conductivity of 803(S·m^(2))/*** also showed excellent electrical heating ability,so that a temperature of~160℃was rapidly reached at a low voltage of 2 *** with their low density,the SWCNT fiber NWFs are promising for use as a heating unit for low temperature battery protection and de-icing applications.

关键词： carbon nanotube fiber nonwoven fabrics fusing electrothermal heating