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Early-age strength property improvement and stability analysis of unclassified tailing paste backfill materials

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1191-1202页

作者： Qian Zhou juan-hong Liu Ai-xiang Wu hong-jiang Wang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Urban Underground Space Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of High-Efficient Mining and Safety of Metal Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China

High-density tailings,small cementitious materials,and additives are used for backfill materials with poor early compressive strength(ECS),which may greatly affect the mining and backfill cycle,to prepare paste backfill materials(PBMs)with a high *** effects and mechanisms of different early strength agents on the property of PBM are *** action mechanism of additives on the properties of PBM is also analyzed through X-ray diffraction,scanning electron microscope,and energy dispersive *** show that the effects of single-component additives 1,3,and 6 are better than those of the other additives,and their optimal dosages are 3wt%,1wt%,and 3wt%,*** optimum multicomponent combinations are 1wt%of additive 1 and 1.5wt%of additive *** ECS of the paste with additive 10 increases to a greater extent than that of the other pastes because of the synergistic action of additive 1 with additive *** hydration product of Ca(OH)2 is consumed,and more C-S-H gels are generated with the addition of additives to *** particles,ettringite crystals,and gels intertwined with one another form a dense net-like structure that fills the *** structure can significantly improve the ECS of PBM.

关键词： paste backfill unclassified tailings binder powder early-age strength microstructure

Reconstruction of broken Si–O–Si bonds in iron ore tailings (IOTs) in concrete

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International Journal of Minerals,Metallurgy and Materials 2019年第10期26卷 1329-1336页

作者： juan-hong Liu Yu-cheng Zhou Ai-xiang Wu hong-jiang Wang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Urban Underground Space Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of High-efficient Mining and Safety of Metal Mines Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China

This paper reports a study on the reconstruction of broken Si O Si bonds in iron ore tailings (IOTs) in concrete. Limestone and IOTs were used to investigate the influence of different types of coarse aggregates on the compressive strengths of concrete samples. The dif- ferences in interfacial transition zones (ITZs) between aggregate and paste were analyzed by scanning electron microscopy (SEM) and ener- gy-dispersive spectroscopy (EDS). Meanwhile, X-ray diffraction (XRD) and infrared spectroscopy (IR) were used to study microscopic changes in limestone and IOTs powders in a simple alkaline environment that simulated cement. The results show that the compressive strengths of IOTs concrete or paste are higher than those of limestone concrete or paste under identical conditions. The Ca/Si atom ratios in the ITZs of IOTs con- crete samples are lower than those of limestone concrete;the diffraction peak of the calcium silicate phase at 2θ = 29.5°, as well as the bands of Si O bonds shifting to lower wavenumbers, indicates reconstruction of the broken Si-O-Si bonds on the surfaces of IOTs with Ca(OH)2.

关键词： iron ore tailings broken Si O Si bonds alkaline environment reconstruction

Flexible Gradient Poly(ether-ester)from the Copolymerization of Epoxides and c-Caprolactone Mediated by a Hetero-bimetallic Complex

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Chinese Journal of Polymer Science 2021年第8期39卷 1013-1019,I0007页

作者： Wei-Min Ren hong-juan Gao Tian-Jun Yue State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

Copolymerization is a commonly employed method for optimizing the properties of polymer *** ether segments into polyesters main chain to obtain polyether-polyester copolymers is an effective strategy to realize the integration of multiple properties of polyester and polyether,and to develop more high-performance,multi-purpose polymer ***,the synthesis of poly(ether-ester)s is accessible by employing the biphenyl-linked heterodinuclear salen Cr-AI complex in the presence of PPNCI for the copolymerization of epoxides and£-caprolactone(CL).Monitoring the copolymerization process reveals that catalyst 1 exhibited good performance for the copolymerization of epoxides and CL,affording copolymers with a gradient sequence *** dynamic thermomechanical analysis(DMA)study indicates the obtained poly(ether-ester)s possess enhanced flexibility compared with the block copolymers or blend of PPO and PCL homopolymers with the same *** study provides a theoretical basis for the preparation of high-performance polymer materials.

关键词： Lactone Epoxide Copolymerization Poly(ether-ester)copolymer Dynamic mechanical analysis

Research on Feature Extraction of Remnant Particles of Aerospace Relays

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Chinese Journal of Aeronautics 2007年第3期20卷 253-259页

作者： WANG Shu-juan GAO hong-liang ZHAI Guo-fu Department of Electrical Engineering Harbin Institute of Technology Harbin 150001 China

The existence of remnant particles, which significantly reduce the reliability of relays, is a serious problem for aerospace relays. The traditional method for detecting remnant particles-particle impact noise detection （PIND）-can be used merely to detect the existence of the particle; it is not able to provide any information about the particles＇ material. However, information on the material of the particles is very helpful for analyzing the causes of remnants. By analyzing the output acoustic signals from a PIND tester, this paper proposes three feature extraction methods： unit energy average pulse durative time, shape parameter of signal power spectral density （PSD）, and pulse linear predictive coding coefficient sequence. These methods allow identified remnants to be classified into four categories based on their material. Furthermore, we prove the validity of this new method by processing P1ND signals from actual tests.

关键词： feature extraction aerospace relays remnant particles particle impact noise detection

Psychological impacts of the COVID-19 epidemic on Chinese people: Exposure, post-traumatic stress symptom, and emotion regulation

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Asian Pacific Journal of Tropical Medicine 2020年第6期13卷 252-259页

作者： hong-juan Jiang Jiang Nan Zhi-yue Lv juan Yang Department of Psychology The First Affliated HospitalHainan Medical UniversityHaikou 571199China Student Affairs Office Hainan Medical UniversityHaikou 571199China Key Laboratory of Tropical Translational Medicine of Ministry of Education Hainan Medical UniversityHaikou571199China Key Laboratory of Emegency and Trauma of Ministry of Education Key Laboratory of Brain Science Research&Transformation in Tropical Environment of Hainan ProvinceDepartment of PsychologyThe First Affliated HospitalHainan Medical UniversityHaikou 571199China

Objective:To examine the effects of coronavirus disease-2019(COVID-19)exposure,expressive suppression/cognitive reappraisal,and demographic variables on post-traumatic stress symptoms(PTS)among ***:Participants were recruited by social media through We Chat and 6049 Chinese(aged from 17 to 63 years;median=24)from 31 provinces were included in the *** symptoms,expressive suppression,and cognitive reappraisal were assessed after the outbreak of COVID-19.A regression mixture analysis was conducted in Mplus ***:A regression mixture model identified three latent classes that were primarily distinguished by differential effects of COVID-19 exposures on PTS symptoms:(1)Class 1(mildly PTS symptoms,80.9%),(2)Class 2(moderate PTS symptoms,13.0%),and(3)Class 3(high PTS symptoms,6.1%).The results demonstrated that the young,women and people with responsibilities and concerns for others were more vulnerable to PTS symptoms;and they had more expression inhibition and less cognitive reappraisal in three latent ***:The findings suggest that more attention needs to be paid to vulnerable groups such as the young,women and people with responsibilities and concerns for *** to encourage emotional expression and increase cognitive reappraisal may also be helpful for trauma survivors.

关键词： COVID-19 exposures Post-traumatic stress symptoms Expressive suppression Cognitive reappraisal

Posttraumatic stress symptom trajectories of Chinese university students during the first eight months of the COVID-19 pandemic and their association with cognitive reappraisal,expressive suppression,and posttraumatic growth

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Asian Pacific Journal of Tropical Medicine 2022年第10期15卷 451-460页

作者： hong-juan Jiang Jiang Nan Zhi-yue Lv juan Yang The First Affiliated Hospital of Hainan Medical University Haikou 571199China Student Affairs Office Hainan Medical UniversityHaikou 571199China Centre for Research in Psychology and Human Well-Being Faculty of Social Sciences and HumanitiesUniversiti Kebangsaan MalaysiaBangi 43600Malaysia Affiliated Hainan Hospital Key Laboratory of Tropical Translational Medicine of Ministry of EducationHainan Medical UniversityHaikou571199China Zhongshan School of Medicine Sun Yat-Sen UniversityGuangzhou510275China Affiliated Maternal and Child Health Hospital/Affiliated Children's Hospital Hainan Medical UniversityHaikou 571199China Key Laboratory of Brain Science Research&Transformation in Tropical Environment of Hainan Province Hainan Medical UniversityHaikou 571199China

Objective: To identify the moderating effects of cognitive reappraisal(CR) and expressive suppression(ES) on the relationship between posttraumatic stress(PTS) symptoms and posttraumatic growth(PTG) in university students. Methods: The survey included 1 987 Chinese university students who completed questionnaires on PTS symptoms in February 2020, with three follow-up surveys at two-month intervals until August 2020. We assessed CR and ES at February 2020 and PTG at August 2020. Growth mixture modeling was used to classify the PTS symptom trajectories. Multinomial logistic regression was used to recognize the predictors of class membership. The relationships among PTS symptoms, CR, ES, and PTG were examined using multi-group path ***: Sex, SARS-Co V-2 infection of a family member or friend, number of siblings, CR, and ES were significantly associated with PTS symptoms. Three latent classes were identified: ‘Increasing PTS’(n=205, 10.0%) who had rapid deterioration of PTS symptoms, ‘Moderate PTS’(n=149, 8.0%) who had a high level of PTS symptoms at the beginning and slightly increasing, and ‘Persistent Minimal PTS’(n=1 633, 82.0%), who had slow resolution of PTS symptoms over time. Male, SARS-Co V-2 infection of a family member or friend, and having a lower CR and a higher ES, were more likely to have ‘Increasing PTS’. PTS at February 2020 predicted PTG only in ‘Increasing PTS’ class, and both CR and ES had moderating effects on the conversion between ***: Most students recovered from posttraumatic stress of COVID-19 pandemic, but a small proportion expeienced increasing PTS symptoms, and those with this condition may benefit from emotional regulation intervention.

关键词： COVID-19 pandemic Posttraumatic stress symptoms Cognitive reappraisal Expressive suppression Posttraumatic growth Chinese university students

A density functional theory study on the interaction between UO_2^(2+) and the carbamoylphosphoramidic acid ligand for uranium extraction from seawater

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Nuclear Science and Techniques 2018年第6期29卷 128-140页

作者： Xiao-Jing Guo Cheng Li Jiang-Tao Hu hong-juan Ma hong-Liang Qian Shanghai Institute of Applied Physics Chinese Academy of Sciences School of Engineering China Pharmaceutical University

Phosphorylurea molecules, which contain both phosphoryl and carbonyl groups, are considered efficient extractants for UO_2^(2+). This study aims to explain the complexation of UO_2^(2+)with carbamoylphosphoramidic acid(CPO), a simple model for phosphorylurea, for ligand design for uranium recovery from seawater using density functional theory calculations, natural bond order analysis,and the quantum theory of atoms in molecules. The results showed that, when CPO acts as a monodentate ligand, the affinity of phosphoryl for UO_2^(2+)is stronger than that of carbonyl, and CPO coordinates with UO_2^(2+)through the phosphoryl oxygen atom. When CPO serves as a bidentate ligand, both the phosphoryl and carbonyl oxygen atoms connect to UO_2^(2+), and the U–O(carbonyl) bond plays a more important role than the U–O(phosphoryl) bond in the interaction between UO_2^(2+)and CPO. This paradox may be caused by the significant charge transfer from the U–O(carbonyl) p bond orbital to the C–N σ antibond orbital of the bidentate CPO. The NH spacer between the phosphoryl and carbonyl groups could ensure the delocalization of the electron system of the molecule. The bidentate binding motif is favored by entropy and opposed by enthalpy, while the monodentate binding motif is favored by enthalpy and opposed by entropy. Ultimately, the bidentate binding motif is more favorable than the monodentate one. As expected, the interaction between UO_2^(2+)and the deprotonated CPO is stronger than that between UO_2^(2+)and the neutral CPO. Comparing the interaction between UO_2^(2+)and CPO with that between UO_2^(2+)and Nphenylcarbamoylphosphoramidic acid(Ph CPO), formed by replacing one hydrogen atom from the terminal nitrogen atom of CPO with a phenyl group, the phenyl substituent at the terminal nitrogen atom of Ph CPO shows a slightly negative effect on the interaction between UO_2^(2+)and Ph CPO.

关键词：相互作用理论学习海水密度抽取 CPO 铀苯基取代

Changes of Reactive Oxygen Species and Related Enzymes in Mitochondrial Respiration During Storage of Harvested Peach Fruits

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Agricultural Sciences in China 2011年第1期10卷 149-158页

作者： KAN juan WANG hong-mei JIN Chang-hai College of Food Science and Engineering Yangzhou University Yangzhou 225127 P.R.China

Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then their influence on senescence of harvested Peach fruits was studied. The results showed that low temperature （5℃） strongly inhibited the reduction of firmness and the increase in respiration rate. During storage at ambient temperature （20℃）, ROS had a cumulative process while malondialdehye （MDA） content continued to increase in associated with enhanced membrane lipid peroxidation. Lipoxygenase （LOX） activity was strongly inhibited under the low temperature condition. The activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, and Ca^2＋-ATPase declined to a certain extent at ambient temperature, while they showed higher activities at low temperature, which may be related to lower membrane lipid peroxidation at low temperature. Higher Ca^2＋ content at ambient temperature may be responsible for impairment of mitochondrial function, thus, leading to fruit senescence. The results showed that under low temperature condition, the low accumulation of ROS and the low level of membrane lipid peroxidation could maintain the function of mitochondria that would help to delay the senescence of peach fruits. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration. It can be inferred that the low temperature helps to delay senescence of peach fruits via suppression of ROS and related enzymes, maintain better homeostasis of Ca^2＋ in mitochondria and thus better mitochondrial functions.

关键词： peach fruits ripening active oxygen enzymes related to mitochondria respiratory metabolism

K-19 mRNA RT-PCR in detecting micrometastasis in regional lymph nodes of gastric cancer

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World Journal of Gastroenterology 2006年第32期12卷 5219-5222页

作者： Jian Suo Quan Wang hong-juan Jin hong Li Hang Zhao Department of General Surgery First Hospital Changchun 130021 Jilin Province China

AIM： To investigate the value and prospect of RT-PCR in detecting micrometastasis in regional lymph nodes of gastric cancer. METHODS： Histopathology was used and K19 mRNA expression was detected by RT-PCR in tumor tissues and lymph nodes from gastric cancer patients undergoing radical resection of gastric carcinoma. RESULTS： K19 mRNA was expressed in all tumor specimens of 30 cases; of the 126 lymph nodes, 26 were histopathologically positive （20.6%）, and 42 positive （33.3%） by RT-PCR. Amplification fragments of 460 and 540 bp were shown in all the tumor tissues and metastatic lymph nodes after K19 and β-actin RT-PCR, while only a 540 bp fragment appeared in the lymph nodes of non-tumor patients. CONCLUSION： K19 mRNA RT-PCR is sensitive and specific in testing micrometastasis in regional lymph nodes of gastric cancer, and it is superior to routine histopathology.

关键词： K-19 mRNA RT-PCR Micrometastasis Gastric cancer