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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

Rainfall-triggered waste dump instability analysis based on surface 3D deformation in physical model test

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Journal of Mountain Science 2024年第5期21卷 1549-1563页

作者： LI Hanlin jin xiaoguang HE Jie XUE Yunchuan YANG Zhongping School of Civil Engineering Chongqing UniversityChongqing 400038China

Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the rainfall-triggered waste dump instability model test, we studied the failure mechanisms of the waste dump by integrating surface deformation and internal slope stress and proposed novel parameters for identifying landslide stability. We developed a noncontact measurement device, which can obtain millimeter-level 3D deformation data for surface scene in physical model test;Then we developed the similar materials and established a test model for a waste dump. Based on the failure characteristics of slope surface, internal stress of slope body and displacement contours during the whole process, we divided the slope instability process in model test into four stages: rainfall infiltration and surface erosion, shallow sliding, deep sliding, and overall instability. Based on the obtained surface deformation data, we calculated the volume change during slope instability process and compared it with the point displacement on slope surface. The results showed that the volume change can not only reflect the slow-ultra acceleration process of slope failure, but also fully reflect the above four stages and reduce the fluctuations caused by random factors. Finally, this paper proposed two stability identification parameters: the volume change rate above the slip surface and the relative velocity of volume change rate. According to the calculation of these two parameters in model test, they can be used for study the deformation and failure mechanism of slope stability.

关键词： Waste dump stability Physical model test Surface 3D deformation Stability identification

DEVELOPMENT OF DC MILL——WITH WORK ROLLS DEVIATED AND CROSSED

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Chinese Journal of Mechanical Engineering 1998年第4期11卷 47-52页

作者： Liu Yuli jin xiaoguang Lian Jiachuang Kong Xiangdong (Yanshan University) Yanshan Univ China

A new type of 4 high strip mill is developed, in which gauge and shape are combinatively controlled by work roll deviating and crossing. The neewly developed 300 mm 4 h mill and its control system are introduced. Both static and dynamic experiments as well as theoretical study are carried out to verify the advantages and the combined shape and gauge control function of this new mill.

关键词： DC mill Shape Control

Development, dilemma and potential strategies for the application of nanocatalysts in wastewater catalytic ozonation: A review

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Journal of Environmental Sciences 2023年第2期124卷 330-349页

作者： xiaoguang jin Changyong Wu Liya Fu Xiangmiao Tian Panxin Wang Yuexi Zhou Jiane Zuo State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China Research Center of Environmental Pollution Control Engineering Technology Chinese Research Academy of Environment SciencesBeijing 100012China

With the continuous development of nanomaterials in recent years,the application of nanocatalysts in catalytic ozone oxidation has attracted more and more researchers’attention due to their excellent catalytic *** this review,we systematically summarized the current research status of nanocatalysts mainly involving material categories,mechanisms and catalytic *** on summary and analysis,we found most of the reported nanocatalysts were in the stage of laboratory research,which was caused by the nanocatalysts defects such as easy aggregation,difficult separation,and easy *** defects might result in severe resource waste,economic loss and potentially adverse effects imposed on the ecosystem and human *** at solving these defects,we further analyzed the reasons and the existing reports,and revealed that coupling nano-catalyst and membrane,supported nanocatalysts and magnetic nanocatalysts had promising potential in solving these problems and promoting the actual application of nanocatalysts in wastewater ***,the advantages,shortages and our perspectives of these methods are summarized and discussed.

关键词： Catalytic ozonation Nanocatalyst limitation Membrane Supported nanocatalysts Magnetic nanocatalysts

Rapamycin attenuates bleomycin-induced pulmonary fibrosis in rats and the expression of metalloproteinase-9 and tissue inhibitors of metalloproteinase-1 in lung tissue

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Chinese Medical Journal 2014年第7期127卷 1304-1309页

作者： jin xiaoguang Department of Respiratory and Critical Care Medicine Beijing Chao-Yang Hospital Capital Medical University Beijing 100020 China Beijing Institute of Respiratory Medicine Beijing 100020 China Beijing Hospital Beijing 100730 China

Background Idiopathic pulmonary fibrosis （IPF） is the most common and devastating form of interstitial lung disease （ILD） in the *** is no effective therapy except for lung *** is an immunosuppressive drug with potent antifibrotic *** purpose of this study was to examine the effects of rapamycin on bleomycininduced pulmonary fibrosis in rats and the relation to the expression of metalloproteinase-9 （MMP-9） and tissue inhibitor of metalloproteinase-1 （TIMP-1）.Methods Sprague-Dawley rats were treated with intratracheal injection of 0.3 ml of bleomycin （5 mg/kg） in sterile 0.9％ saline to make the pulmonary fibrosis *** was given at a dose of 0.5 mg/kg per gavage,beginning one day before bleomycin instillation and once daily until animal *** rats in each group were sacrificed at 3,7,14,28 and 56 days after bleomycin *** and pulmonary fibrosis were semi-quantitatively assessed after HE staining and Masson staining under an Olympus BX40 microscope with an IDA-2000 Image Analysis *** Ⅰ and Ⅲ collagen fibers were identified by *** content in lung tissue was quantified by a colorimetric-based spectrophotometric assay,MMP-9 and TIMP-1 were detected by immunohistochemistry and by realtime quantitative reverse transcriptase polymerase chain reaction （RT-PCR）.Results Bleomycin induced alveolitis and pulmonary fibrosis of rats was inhibited by *** inhibition of alveolitis and hydroxyproline product were demonstrated when daily administration of rapamycin lasted for at least 14 *** inhibitory efficacy on pulmonary fibrosis was unremarkable until rapamycin treatment lasted for at least 28 days （P ＜0.05）.It was also demonstrated that rapamycin treatment reduced the expression of MMP-9 and TIMP-1 in lung tissue that was increased by *** These results highlight the significance of rapamycin in alleviating alveolitis an

关键词： rapamycin pulmonary fibrosis bleomycin metalloproteinase-9 tissue inhibitor ofmetalloproteinase-1

A magnetic-void-porous MnFe_(2)O_(4)/carbon microspheres nano-catalyst for catalytic ozonation:Preparation,performance and mechanism

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Environmental Science and Ecotechnology 2021年第3期7卷 35-47页

作者： xiaoguang jin Changyong Wu Xiangmiao Tian Panxin Wang Yuexi Zhou Jiane Zuo State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing100012China Research Center of Environmental Pollution Control Engineering Technology Chinese Research Academy of Environment SciencesBeijing100012China

Wastewater treatment is essential to guarantee human health and ecological *** ozonation with nanocatalysts is a widely studied and efficient treatment ***,this method has always been limited by nanocatalysts disadvantages such as easily loss,difficult to separate and reuse,and catalytic ability decay caused by aggregation,which could cause severe resources waste and potential risk to human health and *** remedy these challenges,a magnetic-void-porous MnFe_(2)O_(4)/carbon microsphere shell nanocatalyst(CMS-MnFe_(2)O_(4))was successfully synthesized using renewable natural *** separation test showed CMS-MnFe_(2)O_(4) was rapidly separated within 2 min under an external magnetic *** catalytic ozonation of oxalic acid(OA),CMS-MnFe_(2)O_(4) showed efficient and stable catalytic efficiency,reaching a maximum total organic carbon removal efficiency of 96.59% and maintained a 93.88% efficiency after 4 *** stable catalytic efficiency was due to the supporting effects of the carbon microsphere shell,which significantly enhanced CMS-MnFe_(2)O_(4) chemical stability and reduced the metal ions leaching to 10-20% of MnFe_(2)O_(4) through electron *** explore the catalytic mechanism,radical experiments were conducted and a new degradation pathway of OA involving superoxide anions rather than hydroxyl radicals was ***,this study suggests that an efficient,recyclable,stable,and durable catalyst for catalytic ozonation could be prepared.

关键词： Catalytic ozonation Magnetic nanocatalyst Separation recycling Catalytic mechanism Metal leaching

Special Issue for the 20th Anniversary of Key Laboratory of Management, Decision and Information Systems, Chinese Academy of Sciences

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Journal of Systems Science & Complexity 2008年第4期21卷 5-6页

作者： Zhi jin xiaoguang Yang Hanqin Zhang

With this special issue we celebrate the 20th anniversary of Key Laboratory of Manage-ment,Decision and Information Systems(MADIS),Chinese Academy of *** wasfounded in 1988 by Chinese Academy of *** is China’s first ... 详细信息

关键词： Chinese Academy of Sciences Decision and Information Systems

Evaluation of Microwave Plasma Torch (MPT) as an Excitation Source for Determination of Mercury

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Chemical Research in Chinese Universities 1992年第1期8卷 31-32页

作者： Duan Yixiang, Du xiaoguang and jin Qinhan (Department of Chemistry, Jilin University, Changchun)

The microwave plasma atomic spectrometry is an important branch of the plasma atomic spectrometry. Since the first use of microwave induced plasma（MIP） as an excitation source for spectral Chemical analysis by Broida and Chapmanin in 1958, especially the introduction of TM;cavity by Beenakker in 1976 and of surfatron by Moisan in 1979 with which an atmospheric pressure helium MIP could be obtained, MIP has received considerable attention as a new excitation source for spectrometric analysis. However, since MIP suffers from the in ability to analyse the aqueous sam-

关键词： Microwave plasma torch Atomic spectrometry Mercury determination

Calculation of Surrounding Rock Pressure of Undercut Subway Station Based on Multi-Factor Affecting Pressure Arch Theory

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Engineering（科研） 2020年第2期12卷 59-70页

作者： Bin Shang xiaoguang jin Guiyong Ao Qiao Chen Qiong Qiu China Construction Tunnel Construction Co. Ltd. Chongqing China School of Civil Engineering Chongqing University Chongqing China.

The formation mechanism of surrounding rock pressure in large-section tunnels of underground excavation is still unclear. The traditional methods for calculating surrounding rock pressure have certain limitations. Based on the theory of pressure arch and parameter sensitivity analysis, the internal and external boundaries of the pressure arch are solved by numerical simulation. The loose pressure is obtained according to the distance from the inner boundary to the inner wall of the tunnel. The pressure arch deformation is analyzed based on the Winkler model. The surrounding rock pressure is calculated, and the surrounding rock pressure based on the pressure arch theory is calculated. The calculation method of surrounding rock pressure based on the pressure arch theory large section tunnel is proposed. The orthogonal experimental design method was used to select four representative factors: tunnel depth H, span B, internal friction angle φ and rock weight γ. The calculation results of each group of experiments were compiled and multivariate linear regression was used. The method is statistically analyzed, and finally, the calculation formula of the surrounding rock pressure of the large-section tunnel affected by multiple factors is obtained and applied to the calculation of the surrounding rock pressure of the metro station.

关键词： Pressure Arch Theory Sensitivity Analysis Surrounding Rock Pressure Orthogonal Test Numerical Simulation