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Experimental studies on the pore structure and mechanical properties of anhydrite rock under freeze-thaw cycles

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 781-797页

作者： Chao Hou Xiaoguang Jin jie he Hanlin Li School of Civil Engineering Chongqing UniversityChongqing400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area of the Ministry of Education Chongqing UniversityChongqing400045China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400045China

To study the deterioration mechanisms of anhydrite rock under the freeze-thaw weathering process,the physico-mechanical characteristics and microstructure evolutions of anhydrite samples were determined by a series of laboratory ***,a descriptive-behavioral model was used to measure the integrity loss in anhydrite samples caused by cyclic ***,the freeze-thaw damage mechanisms of anhydrite rock were revealed from the macro and micro *** results show that the pore size of the anhydrite rock is mainly concentrated in the range of 0.001-10μ*** the number of freeze-thaw cycles increases,there is a growth in the proportion of macropores and ***,the proportion of micropores shows a declining *** relations of the uniaxial compressive strength,triaxial compressive strength,cohesion,and elastic modulus versus freeze-thaw cycles can be fitted by a decreasing exponential function,while the internal friction angle is basically unchanged with freezethaw *** the increase of confining pressure,the disintegration rates of the compressive strength and the elastic modulus decrease,and the corresponding half-life values increase,which reveals that the increase of confining pressures could inhibit freeze-thaw damage to ***,it has been proven that the water chemical softening mechanism plays an essential role in the freeze-thaw damage to anhydrite ***,it is concluded that the freeze-thaw weathering process significantly influences the macroscopic and microscopic damages of anhydrite rock.

关键词： Anhydrite rock Freeze-thaw cycles Physico-mechanical characteristics Microstructure evolution Deterioration mechanisms

Total spinal involvement due to delayed diagnosis and treatment of noncontiguous brucellar spondylitis

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Asian Pacific Journal of Tropical Medicine 2021年第1期14卷 44-46页

作者： jie he Qiang Zhang Department of Orthopedics Beijing Ditan HospitalCapital Medical University100015China

Rational:Brucellosis is a globally prevalent zoonotic *** part of the body can be affected by active brucellosis but osteoarticular involvement are the most common symptoms which was reported to vary from 10%to 85%.The spine is the most common site of brucellosis in the ***,noncontiguous brucellar spondylitis is rare,only few cases have been reported in the *** concerns:A 62-year-old woman with brucellar spondylitis presented with lower back pain and pain in the right lower extremity for six ***:Brucella agglutination test(1:320)and the result of polymerase chain reaction(PCR)confirmed the diagnosis of noncontiguous brucellar ***:During hospital stay,the women received intravenous treatment for brucellosis(A combination of doxycycline 200 mg/d,rifampicin 900 mg/d,levofloxacin 0.5 g/QD,and ceftriaxone 2 g/QD was administered for 1 week),The L4-S1 vertebral body was fixed by posterior lumbar ***:Six months after discharge,the follow-up radiographic images showed stable vertebral height and good lumbar *** complained no ***:Multi-level involvement is an exceptional form of brucellar *** the best of our knowledge,only few similar cases have been *** and bacterial culture is necessary for confirmed diagnosis.

关键词： Brucella Spondylitis Tuberculosis Polymerase chain reaction Radiology

Effect of micro-alloying La on precipitation behavior, mechanical properties and electrical conductivity of Al-Mg-Si alloys

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Science China(Technological Sciences) 2021年第9期64卷 2012-2022页

作者： ZheNG QiuJu JIANG HongXiang he jie ZHANG LiLi ZHAO JiuZhou Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The rapid industrial development calls for alloys that possess higher comprehensive properties. In this study, the effect of microalloying La addition on the precipitation behavior during artificial aging as well as the mechanical properties and electrical conductivity of Al-Mg-Si alloys were investigated by thermal analysis, microstructural characterizations and properties *** results demonstrated that micro-alloying La addition does not change the whole precipitation sequence during the artificial aging of Al-Mg-Si alloys as well as the atomic structure of the precipitates. However, the higher La-vacancy binding energy as well as the strong La-Si and La-Mg interactions can decrease the solubility of Si and Mg in the Al matrix and the β″ precipitation activation energy from 89.9 to 76.7 kJ/mol, leading to the improvement of the strength and electrical conductivity of Al-Mg-Si alloys simultaneously. The microstructural features affecting the strength and electrical conductivity were theoretically discussed in terms of the La addition.

关键词： aluminum alloys micro-alloying La precipitation behavior hardness electrical conductivity

Using chloramine as a coagulant aid in enhancing coagulation of Yellow River water in China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第9期8卷 1475-1481页

作者： YANG Wei CheN jie LI Xing LIANG heng he Wen-jie LI Gui-bai Department of Environmental Engineering. Harbin University ofCommerce Harbin 150076. China School of Municipal and Environmental Engineering ttarbin Institute of Technology Harbin 150090 China Suzhou Litree Ultra-filtration Membrane Technology Co. Ltd. Suzhou 215152 China College of Civil Engineering and Archltecture Beijing University of Technology Beijing 100023 China Tianjin Waterworks Group Company Ltd Tianjin 300040 China

Considering that contaminated raw water mostly contains high Ammonia-N and a majority of water treatment plants use prechlorination process in China, efficiency of chloramines as a coagulant aid in enhancing coagulation was investigated by Jar stirring and pilot-scale tests, using Yellow River water containing high concentration of natural organic matters （NOM） and bromide in winter. The jar tests results showed that, compared with no preoxidation, preformed chloramine apparently decreased the turbidity of settled and filtered water with low dosage （2.0 rag/L）, and the aid-coagulation efficiency was further enhanced with the increase of chlorine （Cl2） to Ammonia-N （N） ratio. Pilot-scale studies indicated that, in comparison to the case without preoxidation, the turbidity removal efficiency of flotation and filtration effluent water was significantly improved, the particle counts of filtered water were decreased 63.4%, the average rate of filter head loss was reduced 18.2%, and filter run time was prolonged 15.7%. Therefore, chloramine preoxidation may substantially enhance the particle separation efficiency.

关键词： Preoxidation Chloramine Pilot plant Turbidity Particle counts Filter run time

Effect mechanisms of micro-alloying element La on microstructure and mechanical properties of hypoeutectic Al-Si alloys

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Journal of Materials Science & Technology 2020年第12期47卷 142-151页

作者： Qiuju Zheng Lili Zhang Hongxiang Jiang Jiuzhou Zhao jie he Institute of Metal Research Chinese Academy of SciencesShenyang 110016PR China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016PR China

The rare earth influence on the as-cast micro structures and mechanical properties of aluminum alloys attracted great attentions in the last *** up to date no reports can be found on the effect of microalloying element La(La addition is below 0.1 wt.%) on the solidification of hypoeutectic Al-Si *** study carried out solidification experiments with Al-6 Si alloys micro-alloyed by element *** α-Al grain refinement,the eutectic Si modification and the tensile properties improvement caused by microalloying element La were *** effect mechanisms of La were *** is demonstrated that the addition of La as low as 100 ppm can deprave the more effective heterogeneous nucleation conditions for the eutectic Si caused by the impurity *** addition of 0.06 wt.% La is sufficient to achieve an ideal α-Al grain refinement,eutectic Si modification and ductility improvement of the *** phase forms in the Al-Si alloy with the additive amount of La higher than 0.06 wt.%.It has a tetragonal ***-alloying element La refines the α-Al grains by working as a surfactant and modifies the eutectic Si by promoting the formation of the significant multiple Si twins.

关键词： Aluminum alloy Micro-alloying element La Microstructure Tensile properties Mechanisms

Do civil engineering fronts emerge from interdisciplinary research?

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Frontiers of Structural and Civil Engineering 2023年第1期17卷 1-9页

作者： jie he Junlan YAO Xin CheN Fang LIU hehua ZHU College of Civil Engineering Tongji UniversityShanghai 200092China State Key Laboratory for Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China School of Economics and Management Tongji UniversityShanghai 200092China Library Tongji UniversityShanghai 200092China

Interdisciplinary research is considered a source of innovativeness and creativity, serving as a key mechanism for creating recombination necessary for the evolution of science systems. The aim of this study is to quantitatively establish the connection between interdisciplinary research and the research fronts that have recently emerged in civil engineering. The degree of interdisciplinarity of the research fronts was measured by developing metrics from bibliographic analyses. As indicated by the consistent increase in the metrics of interdisciplinarity over time, research fronts tend to emerge in studies with increasing diversity in the disciplines involved. The active disciplines involved in the fronts vary over time. The most active disciplines are no longer fundamental but those associated with energy, environment, and sustainable development, focusing on solutions to climate change and integrating intelligence technologies.

关键词： interdisciplinary research research front bibliographic analysis

Deciphering of advantageous electrocatalytic water oxidation behavior of metal-organic framework in alkaline media

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Nano Research 2021年第12期14卷 4680-4688页

作者： Ming Liu Lingjun Kong Xuemin Wang jie he Jijie Zhang Jian Zhu Xian-he Bu School of Materials Science and Engineering National Institute for Advanced MaterialsTKL of Metal and Molecule Based Material ChemistryNankai UniversityTianjin300350China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin300071China

Carboxylic acid-based metal-organic frameworks(MOFs)are normally passed for the“pre-catalysts”for oxygen evolution reaction(OER)due to the hydroxides constructed in-situ during its alkaline hydrolysis process(AHP)in ***,it remains a mystery that they show advantageous activity over prototypical hydroxides when they are directly acted as OER ***,we propose for the first time that the steric hindrance effect of Nafion can induce enhanced catalytic activity of such *** from conventional catalysts without AHP,the Nafion with 3D structure weakens the AHP of Co-MOF nanoribbons,thus forming small size and low crystallinity species(cobalt hydroxide)with more active *** the existence of Nafion also optimizes its electronic structure,which is confirmed by transmission electron microscopy(TEM),in-situ UV absorption spectra,in-situ Raman spectroscopy and so *** with Co-MOF-K obtained by directly immersing the Co-MOF nanoribbons in 1.0 M KOH,the Co-MOF-NK obtained by AHP of Co-MOF mixed with Nafion shows better catalytic *** on the above inspiration,we realized the low overpotential of 268 mV at 10 mA·cm^(−2) by preparing *** work provides a new understanding of the structural reconstruction of MOFs in the field of electrocatalysis.

关键词： metal-organic frameworks structural reconstruction Nafion stereo hindrance water oxidation

Constructing bifunctional Co/MoC@N-C catalyst via an in-situ encapsulation strategy for efficient oxygen electrocatalysis

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Journal of Energy Chemistry 2021年第8期30卷 538-546,I0011页

作者： Hui Huang Lingjun Kong Ming Liu jie he Wei Shuang Yunhua Xu Xian-he Bu School of Materials Science and Engineering National Institute for Advanced MaterialsTKL of Metal and Molecule Based Material ChemistryNankai University300071 TianjinChina School of Materials Science and Engineering Key Laboratory of Advanced Ceramics and Machining Technology(Ministry of Education)and Tianjin Key Laboratory of Composite and Functional MaterialsTianjin University300072 TianjinChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai University300071 TianjinChina

The large-scale application of Zn-air battery requires the development of efficient,low-cost,and stable bifunctional electrocatalysts for the oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).herein,an electrocatalyst of a Co/Mo C-nanoparticles embedded N-doped carbon(Co/Mo C@N-C)was prepared via the in-situ encapsulation of Co_(2)(CO)_(8)and Mo(CO)6 in ZIF-8 using ball-milling,followed by pyrolysis under an Ar *** used as a bifunctional electrocatalyst,the as-prepared Co/Mo C@N-C showed an ORR half-wave potential of 0.824 V in an alkaline medium and an overpotential of only 290 m V for the OER at 10 m A cm^(-2),which was 70 m V lower than Ru O_(2).The Co/Mo C@N-C was also evaluated as a cathode in a solid-state Zn-air battery and delivered a higher peak discharge power density and better cycling stability(over 1600 min)than Pt/C-Ru O_(2).Most importantly,our work provides a new strategy to prepare bifunctional catalysts and promotes their applications in the energy conversion field.

关键词： In-situ ZIF-8 Bifunctional electrocatalyst New strategy

Adjuvant immunotherapy in resected esophageal squamous cell carcinoma:a gospel to the non-pCRs

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Signal Transduction and Targeted Therapy 2021年第9期6卷 2611-2612页

作者： Zhihui Zhang Nan Sun jie he Department of Thoracic Surgery National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina State Key Laboratory of Molecular Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

A recent study1 published in The New England Journal of Medicine by Kelly RJ presented interim results from a phase 3 clinical trial(CheckMate 577),a global,randomized,double-blind,interventional trial to evaluate a novel approach of adjuvant nivolumab after neoadjuvant chemoradiotherapy(nCRT)and surgery for esophageal or gastroesophageal junction(GEJ)cancer.

关键词： esophageal clinical Kelly