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Thermal stability of permafrost under U-shaped crushed rock embankment of the Qinghai-Tibet Railway

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Advances in Climate Change Research 2024年第1期15卷 158-169页

作者： Kun-Ming xu Guan-li JIANG Ji chen Qing-Bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Beiluhe Observation Station of Frozen Soil Environment and Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China

The U-shaped crushed rock embankment(UCRE),of which widely utilized in the permafrost regions along the Qinghai-Tibet Railway,has the capability to rapidly reduce the ground temperature of the underlying ***,there remains uncertainty regarding the adaptation of UCRE to climate change and its long-term cooling *** study focuses on nine UCRE monitoring sites along the Qinghai-Tibet Railway to analyze the dynamic variations of the ground temperature underlying permafrost from 2006 to *** efficiency of UCRE in stabilizing permafrost temperature in different permafrost zones is evaluated by considering the permafrost table,ground temperature,and MAGT,as well as the temperature difference between the top and bottom of the crushed rock layer and the ground temperature variation index(GTVI).The results show that UCRE is suitable for application in extremely unstable warm permafrost regions where the MAGT is higher than-0.5℃.Moreover,UCRE effectively diminishes the disparity in permafrost thermal stability between the sunny and shaded shoulders of the *** short-term and long-term effect of cooling permafrost is experiencing a change related with permafrost ***,in stable cold permafrost regions with MAGT lower than-1.5℃,the long-term cooling effect of UCRE on permafrost seems to gradually di-minishes,but UCRE continues to fulfill the role of stabilizing the underlying permafrost thermal state over the *** results show that UCRE can quickly restore and stabilize the thermal state of permafrost in the early stages of construction,and adapt to the influence of future climate *** findings provide important guidance for understanding the variations of permafrost thermal stability beneath the embankment in permafrost regions,as well as for improving the embankment stability and operational safety of the Qinghai-Tibet Railway.

关键词： Qinghai-Tibet Railway U-shaped crushed rock embankment Climate change Permafrost zone Ground temperature variation index Long-term coolingrole

Enhanced hydrogen evolution performance by 3D ordered macroporous Ru-CoP@NC electrocatalysts

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Rare Metals 2024年第3期43卷 1095-1107页

作者： chen-chen Zhang Sheng Wei li-Xian Sun Yi-Fang Ouyang Fen xu Hai-liang Chu Hong-GePan li-Xin chen xue-Zhang Xiao School of Material Science and Engineering Guilin University of Electronic TechnologyGuilin541004China School of Chemistry and Chemical Engineering Guangxi UniversityNanning530004China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen518055GuangdongChina Institute of Science and Technology for New Energy Xi'an Technological UniversityXi'an710021China School of Materials Science and Engineering Zhejiang UniversityHangzhou310058China

Electrocatalytic water splitting coupled with sustainable energies is identified as an environmentally friendly and renewable strategy to generate high-quality hydrogen for the fuel ***,the main challenge is to develop high performance,low cost and chemically stable electrocatalysts to decline the energy barriers and enhance the sluggish kinetics of hydrogen evolution reaction(HER).Herein,a three-dimensional hierarchically ordered macroporous Ru-CoP@NC electrocatalyst(3DOM Ru-CoP@NC)derived from ordered macro-microporous metal-organic frameworks has been prepared using the precursor@template and double-solvent *** prepared 3DOM Ru-CoP@NC catalyst exhibits an overpotential of 15 mV(j=10 mA·cm^(-2))and a reaction Tafel slope of 38 mV·dec^(-1)in alkaline electrolyte,which are superior to commercial Pt@C ***,the overpotential and reaction Tafel slope of this catalyst in acidic media are 45 mV and 50 mV·dec^(-1),*** outstanding HER activities of 3DOM Ru-CoP@NC catalysts are ascribed to the 3D highly interconnectedreticular nanospaces that can increase effective reaction active *** N dope d carbon framework improves the electronic properties and ***,the strong interaction of Ru and CoP nanoparticles also boosts the HER *** results indicate that 3DOM Ru-CoP@NC catalysts with high catalytic activities have a broad application prospect in the future.

关键词： Hydrogen evolution reaction Template method 3D ordered macroporous Ru-CoP@NC

A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study

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World Journal of Emergency Medicine 2024年第1期15卷 16-22页

作者： Jing Yang Hanqi Tang Shihuan Shao Feng xu Yangyang Fu Shengyong xu chen li Yan li Yang liu Joseph Harold Walline Huadong Zhu Yuguo chen xuezhong Yu Jun xu Emergency Department State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing 100730China Emergency Department Peking University People’s HospitalBeijing 100044China Department of Emergency and Chest Pain Center Shandong Provincial Clinical Research Center for Emergency and Critical Care MedicineKey Laboratory of Emergency and Critical Care Medicine of Shandong ProvinceQilu Hospital of Shandong UniversityJinan 250012China Emergency Department Beijing Jishuitan HospitalBeijing 100035China Emergency Department Tianjin Medical University General HospitalTianjin 300052China Department of Emergency Medicine Penn State Health Milton S.Hershey Medical Center and Penn State College of MedicineHershey 17033USA

BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest *** study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysmogram(POP)parameters can be used to identify unsustained ***:We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to ***’general information,ETCO_(2),and POP parameters were collected and statistically ***:The included 105 ROSC episodes(from 80 cardiac arrest patients)comprised 51 sustained ROSC episodes and 54 unsustained ROSC *** 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group(29.2%vs.9.4%,P<0.05).The logistic regression analysis showed that the difference between after and before ROSC in ETCO_(2)(ΔETCO_(2))and the difference between after and before ROCS in area under the curve of POP(ΔAUCp)were independently associated with sustained ROSC(odds ratio[OR]=0.931,95%confi dence interval[95%CI]0.881-0.984,P=0.011 and OR=0.998,95%CI 0.997-0.999,P<0.001).The area under the receiver operating characteristic curve ofΔETCO_(2),ΔAUCp,and the combination of both to predict unsustained ROSC were 0.752(95%CI 0.660-0.844),0.883(95%CI 0.818-0.948),and 0.902(95%CI 0.842-0.962),***:Patients with unsustained ROSC have a poor *** combination ofΔETCO_(2) andΔAUCp showed signifi cant predictive value for unsustained ROSC.

关键词： Return of spontaneous circulation Pulse oximetry photoplethysmogram End-tidal carbon dioxide Cardiac arrest Cardiopulmonary resuscitation

Efficient recovery of tungsten from scheelite concentrates using a sulfur-phosphorus mixed acid leaching system

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Tungsten 2024年第4期6卷 821-832页

作者： Jiang-Tao li li-li Gao Zhong-Wei Zhao xu-Heng liu Xing-Yu chen School of Metallurgy and Environment Central South University Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals

In recent years,a new process for leaching scheelite concentrates with sulfur-phosphorus mixed acid has been successfully *** process suffers from the elimination of the retarding effect of calcium sulfate,the selective extraction of tungsten from the H3PW12O40-H2SO4-H3PO4mixture solution,and the removal of introduced ***,in this paper,we investigated the inhibition measures of a calcium sulfate-blocking membrane,the selective extraction of tungsten by ion exchange,and the removal of phosphorus by the magnesium ammonium salt *** results showed that the addition of calcium sulfate whisker seeds and a higher H3PO4concentration inhibited spontaneous diffuse nucleation,promoted crystal growth,and avoided the formation of a dense blocking *** 98 wt.% of the scheelite concentrate was digested by *** selective adsorption of PW12O403-was realized using D301 resin,and the extraction efficiency of tungsten exceeded 99.9%.After desorption with ammonia water,PW12O403-was depolymerized into WO42-and PO43-.99.9 wt.% of phosphorus was removed in the form of MgNH4PO4by the magnesium ammonium salt method,and the residual phosphorus concentration in the solution was lower than 10 mg·*** purification,the highest-grade ammonium paratungstate product was prepared by evaporative crystallization.

关键词： Calcium sulfate Ion exchange Scheelite concentrates Sulfur-phosphorus mixed acid Tungsten

Synthesis and Properties of Ferrocene Conjugated Macrocycles with Illusory Topology of the Penrose Stairs

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Chemical Research in Chinese Universities 2024年第5期40卷 881-886页

作者： xu Jindong LAN Bin ZHU lingyun xu Hui chen Xinyu li Wenjuan YUAN Yaofeng YAN Jianfeng li Yuanming Key Laboratory of Molecule Synthesis and Function Discovery(Fujian Province University) College of ChemistryFuzhou UniversityFuzhou350108P.R.China Henan Key Laboratory of Biomolecular Recognition and Sensing College of Chemistry and Chemical EngineeringShangqiu Normal UniversityShangqiu476000P.R.China

Polyferrocene macrocycles hold immense potential in the fields of molecular electronics and electrochemistry,primarily due to their multiple metal ***,developing highly efficient synthetic strategies for constructing these rings remains a significant *** this study,we successfully synthesized triferrocenyl macrocycles using Pt-mediated coupling strategy and determined their configuration using single-crystal X-ray diffraction analysis,revealing a structure reminiscent of the Penrose *** comprehensively investigated the macrocycle’s structure,photophysical properties,and employed density functional theory(DFT)calculations to gain further ***,this macrocycle exhibits several advantageous features,including a flexible structure,good solubility,and a highly efficient synthetic pathway.

关键词： Conjugated macrocycle Organometallic macrocycle Pt-template method

3D digital-image correlation insight into generalized relaxation behavior of sandstone under stress and pore pressure coupling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2516-2536页

作者： Cancan chen Heping Xie Jiang xu Seisuke Okubo Shoujian Peng Cunbao li Minghui li State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen518060China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and GreenEnergyCollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen518060China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400044China

The occurrence of geological hazards and the instability of geotechnical engineering structures are closely related to the time-dependent behavior of ***,the idealization boundary condition for constant stress in creep or constant strain in relaxation is not usually attained in natural geological ***,generalized relaxation tests that explore the simultaneous changes of stress and strain with time under different stress levels with constant pore-water pressure are conducted in this *** results show that in area Ⅰ,area Ⅱ,and area Ⅲ,the stress and strain both change synchronously with time and show similar evolutionary laws as the strain-time curve for creep or the stress-time curve for *** the applied stress level surpasses the δ_(ci) or δ_(cd) threshold,the variations in stress and strain and their respective rates of change exhibit a significant *** radial deformation and its rate of change exhibit greater sensitivity in response to stress *** apparent strain deforms homogeneously at the primary stage,and subsequently,gradually localizes due to the microcrack development at the secondary ***,interconnection of the microcracks causes the formation of a shear-localization zone at the tertiary *** strain-time responses inside and outside the localization zone are characterized by local strain accumulation and inelastic unloading during the secondary and tertiary stages,*** width of the shear-localization zone is found to range from 4.43 mm to 7.08 mm and increased with a longer *** electron microscopy(SEM)reveals a dominant coalescence of intergranular cracks on the fracture surface,and the degree of physiochemical deterioration caused by water-rock interaction is more severe under a longer *** brittle sandstone’s time-dependent deformation is essentially controlled by microcrack development during generalized relaxation,and its expectancy-life is dete

关键词： Generalized relaxation Stress level Direction coefficient Major-strain field Microcrack damage Stress threshold

Organic stoichiometric cocrystals with a subtle balance of charge-transfer degree and molecular stacking towards high-efficiency NIR photothermal conversion

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Chinese Chemical Letters 2024年第10期35卷 180-186页

作者： Jieqiong xu Wenbin chen Shengkai li Qian chen Tao Wang Yadong Shi Shengyong Deng Mingde li Peifa Wei Zhuo chen Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationAnhui Graphene Engineering LaboratoryAnhui UniversityHefei 230601China Molecular Science and Biomedicine Laboratory(MBL).State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringCollege of BiologyAptamer Engineering Center of Hunan ProvinceHunan UniversityChangsha 410082China Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou515063China

Charge-transfer(CT)stoichiometric cocrystals are promising choice of organic materials for unveiling the structure-property ***,due to the contradiction between large CT degree required for strong NIR absorption and flexible molecular stacking,construction of stoichiomorphism-based cocystals with near-infrared(NIR)photothermal property remains ***,the first example of stoichiomorphism-based photothermal cocrystals were accomplished through the adaptive assembly of 3,3,5,5-tetramethylbenzidine(TMB)donor and 1,2,4,5-tetracyanobenzene(TCNB)*** selective cocrystallization could be controlled by varying the donor-acceptor stoichiometries via a surfactantassisted method,resulting in two cocrystals with 1:1(T1C1)and 1:2(T2C1)*** absorbance intensity of T1C1 at 808 nm was nearly twice that of T2C1,while the photothermal conversion efficiency(PCE)of the former was 60.3%±0.6%,approximately 80%of that for the latter(75.5%±2.6%),which might be caused by the different intermolecular interactions in distinct molecular stacking ***,both excellent PCEs of stoichiometric cocrystals were attributed to the nonradiative transition process,including internal conversion and charge dissociation processes,as elucidated by femtosecond transient absorption spectroscopy ***,T1C1 was used as an NIR heater for preparing agarose-based photothermal hydrogel,showing great potential for light-controlled in-situ *** strategy of balancing the CT degree and molecular packing orientation not only uncovered the relationship between stoichiometric stacking and photothermal property,but also provided an opportunity to develop advanced organic optoelectronic materials.

关键词： Charge-transfer cocrystal Stoichiometric stacking Crystal growth Photothermal conversion In-situ gelation

Andrias davidianus bone peptides alleviates hyperuricemia-induced kidney damage in vitro and in vivo

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Food Science and Human Wellness 2024年第4期13卷 1886-1905页

作者： Wei li Haihong chen Hongliang chen Ziyin li Wei Hu Qinxuan Zhou Bing xu Yi Wang Xinhui Xing Institute of Biopharmaceutical and Health Engineering Tsinghua Shenzhen International Graduate SchoolShenzhen 518055China Institute of Biomedical Health Technology and Engineering Shenzhen Bay LaboratoryShenzhen 440300China Key Laboratory for Industrial Biocatalysis Ministry of EducationInstitute of Biochemical EngineeringDepartment of Chemical EngineeringBeijing 100084China Center for Synthetic and Systems Biology Tsinghua UniversityBeijing 100084China Affiliated Dongguan Hospital Southern Medical University(Dongguan People’s Hospital)Dongguan 523059China

Hyperuricemia(HUA)is a vital risk factor for chronic kidney diseases(CKD)and development of functional foods capable of protecting CKD is of *** paper aimed to explore the amelioration effects and mechanism of Andrias davidianus bone peptides(ADBP)on HUA-induced kidney *** the present study,we generated the standard ADBP which contained high hydrophobic amino acid and low molecular peptide *** vitro results found that ADBP protected uric acid(UA)-induced HK-2 cells from damage by modulating urate transporters and antioxidant *** vivo results indicated that ADBP effectively ameliorated renal injury in HUA-induced CKD mice,evidenced by a remarkable decrease in serum UA,creatinine and blood urea nitrogen,improving kidney UA excretion,antioxidant defense and histological kidney *** analysis highlighted 14 metabolites that could be selected as potential biomarkers and attributed to the amelioration effects of ADBP on CKD mice kidney ***,ADBP restored the gut microbiome homeostasis in CKD mice,especially with respect to the elevated helpful microbial abundance,and the decreased harmful bacterial *** study demonstrated that ADBP displayed great nephroprotective effects,and has great promise as a food or functional food ingredient for the prevention and treatment of HUA-induced CKD.

关键词： Andrias davidianus bone peptides Hyperuricemia Uric acid Chronic kidney disease Gut microbiota

Sources appointment and health risks of PM_(2.5)-bound trace elements in a coastal city of southeastern China

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Journal of Environmental Sciences 2024年第4期138卷 561-571页

作者： Ziyi lin Xiaolong Fan Gaojie chen Youwei Hong Mengren li lingling xu Baoye Hu chen Yang Yanting chen Zhiqian Shao Jinsheng chen Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy ofSciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Minnan Normal University Zhangzhou 363000China

To gain a comprehensive understanding of sources and health risks of trace elements in an area of China with high population densities and low PM_(2.5)concentrations,15 trace elements(Al,K,Ca,Ti,V,Cr,Mn,Fe,Ni,Cu,Zn,As,Sn,Ba,Pb)in PM_(2.5)were monitored from December 2020 to November 2021 in a representative city,*** concentrations of trace elements in Xiamen displayed an obvious seasonal variation and were dominated by K,Fe,Al,Ca and *** on Positive Matrix Factorization analysis,source appointment revealed that the major sources of trace elements in Xiamen were traffic,dust,biomass and firework combustion,industrial manufacture and shipping *** to health risk assessment combined with the source appointment results,it indicated that the average noncarcinogenic risk was below the threshold and cancer risk of four hazardous metals(Cr,Ni,As,Pb)exceeded the threshold(10^(-6)).Traffic-related source had almost half amount of contribution to the health risk induced by PM_(2.5)-bound trace *** the dust transport period or Spring Festival period,the health risks exceeded an acceptable threshold even an order of magnitude higher,suggesting that the serious health risks still existed in low PM_(2.5)environment at certain *** risk assessment reminded that the health risk reduction in PM_(2.5)at southeastern China should prioritize traffic-related hazardous trace elements and highlighted the importance of controlling vehicles emissions in the future.

关键词： PM_(2.5)-bound trace elements Seasonal variations Source appointment Health risks Traffic-related source