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International Journal of Disaster Risk Science 2024年第3期15卷 434-452页

作者： jian Ma Katsuichiro Goda Kai Liu Silva Vitor Anirudh Rao ming Wang Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency Management School of National Safety and Emergency Management Beijing Normal University Shenzhen Key Laboratory of Urban Disasters Digital Twin Department of Earth Sciences Western University Global Earthquake Model Foundation

This study presents a probabilistic seismic risk model for the Beijing–Tianjin–Hebei region in China. The model comprises a township-level residential building exposure model, a vulnerability model derived from the Chinese building taxonomy,and a regional probabilistic seismic hazard model. The three components are integrated by a stochastic event-based method of the OpenQuake engine to assess the regional seismic risk in terms of average annual loss and exceedance probability curve at the city, province, and regional levels. The novelty and uniqueness of this study are that a probabilistic seismic risk model for the Beijing–Tianjin–Hebei region in China is developed by considering the impact of site conditions and epistemic uncertainty from the seismic hazard model.

关键词： Beijing–Tianjin–Hebei region Epistemic uncertainty Seismic risk assessment Seismic risk model

Elevational distribution of forests and its spatiotemporal dynamics in subtropical China from 2000 to 2019

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Science China Earth Sciences 2024年第8期67卷 2563-2582页

作者： Zhencan ZHENG Liuwen ZHUANG Guofang MIAO Han LIU Zhiqiang CHENG Wenyu LI Rong shang Peng GONG Jing ming CHEN Institute of Geography Fujian Normal University Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education) Fujian Normal University School of Geographical Sciences Fujian Normal University National Land Consolidation Center Ministry of Natural Resources Key Laboratory of Land Consolidation and Rehabilitation Ministry of Natural Resources Key Laboratory of Digital Mapping and Land Information Application Ministry of Natural Resources Department of Geography & Planning University of Toronto Department of Geography The University of Hong Kong

The subtropical region of China possesses abundant forest resources and features a mountainous *** the implementation of policies such as natural forest protection,the Grain for Green Project,and other initiatives since the beginning of the 21st century,coupled with climate change,the forest resources in this region have undergone significant changes compared to historical *** addition,forest resources distributing mainly in mountainous areas also implies that these changes may vary significantly with *** explore the spatiotemporal dynamics of forest distribution in subtropical China since 2000,especially the trend of changes with elevation,we analyzed the data from two land cover products focusing on forest cover and forest *** used a hierarchical approach,in which coarse-classification forest cover data with relatively small uncertainties impose constraints on forest type data with larger uncertainties,to achieve a reasonable balance between obtaining more details and reducing data *** first divided the forest cover data into‘unchanged'and‘changed'*** the constraints by the forest cover results,we further analyzed the‘unchanged'and‘changed'forest *** results indicated that,since the implementation of ecological engineering and management policies,54%of the area in the subtropical region had maintained unchanged forest cover attributes over the past 20 years,which implied the good state of ecological *** results also showed that dynamic conversions existed in the long term between forests and lands for essential production needs like *** elevational variations of forest cover suggested that the dominant changes came from the conversion between forests and croplands in low-elevation regions below 700 m,the conversion between forests and shrublands in mid-elevation regions of 700–1500 m,and the conversion between forests and grasslands in high-elevation regions above 2000 *** the regio

关键词： Subtropical China Land cover Forest cover Forest type Elevational distribution

Cloud Top Pressure Retrieval Using Polarized and Oxygen A-band Measurements from GF5 and PARASOL Satellites

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Advances in Atmospheric Sciences 2024年第4期41卷 680-700页

作者： Lesi WEI Huazhe shang jian XU Chong SHI Gegen TANA Kefu CHAO Shanhu BAO Liangfu CHEN Husi LETU State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China National Space Science Center Chinese Academy of SciencesBeijing 101407China College of Physics and Electronic Information Inner Mongolia Normal UniversityHohhot 010022China College of Geographical Science Inner Mongolia Normal UniversityHohhot 010022China University of Chinese Academy of Sciences Beijing 100101China

Cloud top pressure(CTP)is one of the critical cloud properties that significantly affects the radiative effect of ***-angle polarized sensors can employ polarized bands(490 nm)or O_(2)A-bands(763 and 765 nm)to retrieve the ***,the CTP retrieved by the two methods shows inconsistent results in certain cases,and large uncertainties in low and thin cloud retrievals,which may lead to challenges in subsequent *** study proposes a synergistic algorithm that considers both O_(2)A-bands and polarized bands using a random forest(RF)*** CTP data are used as the true values and the polarized and non-polarized measurements are concatenated to train the RF model to determine ***,through analysis,we proposed that the polarized signal becomes saturated as the cloud optical thickness(COT)increases,necessitating a particular treatment for cases where COT<10 to improve the algorithm's *** synergistic method was then applied to the directional polarized camera(DPC)and Polarized and Directionality of the Earth’s Reflectance(POLDER)measurements for evaluation,and the resulting retrieval accuracy of the POLDER-based measurements(RMSEPOLDER=205.176 hPa,RMSEDPC=171.141 hPa,R^(2)POLDER=0.636,R^(2)DPC=0.663,respectively)were higher than that of the MODIS and POLDER Rayleigh pressure *** synergistic algorithm also showed good performance with the application of DPC *** algorithm is expected to provide data support for atmosphere-related fields as an atmospheric remote sensing algorithm within the Cloud Application for Remote Sensing,Atmospheric Radiation,and Updating Energy(CARE)platform.

关键词： atmospheric remote sensing cloud top pressure multi-angle polarized O_(2)A-band GF-5/DPC PARASOL/POLDER-3

Self-adaptive gas flow and phase change behaviors during hydrate exploitation by alternate injection of N_(2) and CO_(2)

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Petroleum Science 2024年第3期21卷 2120-2129页

作者： Bo-jian Cao Yi-Fei Sun Hong-Nan Chen Jin-Rong Zhong ming-Long Wang ming Wang Chang-Yu Sun Guang-Jin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China School of Chemistry and Chemical Engineering Changsha University of Science&TechnologyChangsha410114HunanChina

Since hydrate resources play a part of the stratigraphic framework structure in sediments,establishing a safe and economic method for hydrates exploitation remains the primary challenge to this *** the proposed methods,the spontaneous displacement of CH_(4) from hydrate cages by CO_(2) seems to be a perfect mechanism to address gas production and CO_(2) storage,especially in today's strong demand for carbon reduction and replacing clean *** extensive lab researches,in the past decade,injecting a mixture of CO_(2) and small molecule gas has become a key means to enhance displacement efficiency and has great potential for ***,there is a lack of in-depth research on gas flow in the reservoir,while the injected gas always passes through low-saturated hydrate areas with high permeability and then occurs gas channel in a short term,finally resulting in the decreases in gas production efficiency and produced gas ***,we explored a new injection-production mode of alternate injection of N2 and CO_(2) in order to fully coordinate the advantages of N_(2) in enhanced hydrate decomposition and CO_(2) in solid storage and heat *** alternate"taking"and"storing"processes perfectly repair the problem of the gas channel,achieving self-regulation effect of CH_(4) recovery and CO_(2) *** 3-D experimental results show that compared to the mixed gas injection,CH_(4) recovery is increased by>50%and CO_(2) storage is increased by>70%.Additionally,this alternate injection mode presented a better performance in CH_(4) concentration of produced gas and showed outstanding N_(2) utilization ***,we analyzed its self-adaptive gas flow mechanism and proposed an application model of"one injection and multiple production".We look forward to this study accelerating the application of CO_(2)-CH_(4) replacement technology.

关键词： Hydrate Replacement CH_(4)recovery CO_(2)storage Reservoir remediation

Magnesium-containing pellet regulating blast furnace ferrous burden interaction:softening-melting behavior and mechanism

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Journal of Iron and Steel Research International 2024年第7期31卷 1623-1635页

作者： Li-ming Ma jian-liang Zhang Yao-zu Wang Xiao-yong Ma Gui-lin Wang Zhuo Li Hui-qing jiang Zheng-jian Liu School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 100083China Lingyuan Iron and Steel Group Co. Lingyuan 122500LiaoningChina

MgO participates in all stages of sintering,pelletizing,and blast furnace ironmaking,and synergistically optimizing the distribution of MgO in ferrous burden can effectively enhance the interaction within the ferrous burdens and optimize the softening-melting properties of the mixed ***-containing pellets mixed with low-MgO sinter or mixed with high-MgO sinter in the blast furnace ferrous burden structure have opposite softening-melting performance *** the structure of the ferrous burden is magnesium-containing pellets mixed with low-MgO sinter,the magnesium-containing pellets can enhance the interaction of the ferrous burden in the process of softening-melting,which can optimize the composition of the slag phase and improve the slag *** the structure of the ferrous burden is magnesium-containing pellets mixed with high-MgO sinter,the magnesium-containing pellets weaken the interaction of the ferrous burden in the process of softening-melting,increase the content of the high melting point solid-phase particles in the slag,lead to an increase in the viscosity of the slag and difficult separation of the slag and iron,and decrease the permeability of the charge ***,to ensure good permeability of the mixed burden,the following measures are suggested:optimizing the MgO distribution of the ferrous burden,reducing the MgO content of the sinter to 1.96 wt.%,increasing the MgO content of the pellets to 1.03-1.30 wt.%,controlling the MgO/Al_(2)O_(3) ratio of the mixed burden within 1.15-1.32,narrowing the position of the cohesive zone,and maintaining an S value(permeability index)of approximately 150 kPa℃.

关键词： Ironmaking Ferrous burden Softening-melting property Interaction Permeability Slag

Integrating machine learning and CALPHAD method for exploring low-modulus near-β-Ti alloys

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Rare Metals 2024年第1期43卷 309-323页

作者： Hao Zou Yue-Yan Tian Li-Gang Zhang Ren-Hao Xue Zi-Xuan Deng ming-ming Lu jian-Xin Wang Li-Bin Liu School of Computer Science and Engineering Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Traditional theoretical and empirical calculation methods can guide the design of β-and metastable β-alloys for bio-titanium. However, it is still difficult to obtain novel near-β-Ti alloys with low modulus. This study developed a method that combines machine learning with calculation of phase diagrams(CALPHAD) to facilitate the design of near-β-Ti alloys. An elastic modulus database of Ti–Nb–Zr–Mo–Ta–Sn system was constructed first, and then three features(the electron to atom ratio, mean absolute deviation of atom mass, and mean electronegativity) were selected as the key factors of modulus by performing a three-step feature selection. With these features, a highly accurate model was built for predicting the modulus of near-β-Ti alloys. To further ensure the accuracy of modulus prediction, machine learning with the elastic constants calculated was leveraged by CALPHAD database. The root mean square error of the well-trained model can be as low as 6.75 GPa. Guided by the prediction of machine learning and CALPHAD, three novel near-β-Ti alloys with elastic modulus below 50 GPa were successfully designed in this study. The best candidate alloy(Ti–26Nb–4Zr–4Sn–1Mo–Ta) exhibits an ultra-low modulus(36.6 GPa) after cold rolling with a thickness reduction of 20%. Our method can greatly save time and resources in the development of novel Ti alloys, and experimental verifications have demonstrated the reliability of this method.

关键词： Near-β-Ti alloy Machine learning Calculation of phase diagram Low-modulus alloy Feature selection

Preparation and Rheological Characterization of Long Chain Branching Polyglycolide

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Chinese Journal of Polymer Science 2024年第8期42卷 1177-1184页

作者： Wei-Lin Liu ming-Fu Lyu Heng-Yuan Zhang jian-Ye Liu Shi-Jun Zhang Beijing University of Chemical Technology Beijing 100029China SINOPEC(Beijing)Research Institute of Chemical Industry Co. Ltd.Beijing 100013China

The long chain branching(LCB)polyglycolide(PGA)was successfully prepared by the successive reactions of the terminal hydroxyl groups of PGA with triglycidyl isocyanurate(TGIC)and pyromellitic dianhydride(PMDA).The influence of LCB produced by functional group reaction on rheological and crystallization behavior was studied and discussed through linear rheology,uniaxial elongation and DSC(differential scanning calorimetry).The much higher viscosity and the more notable strain hardening behavior of modified PGA indicates the LCB with high degree of entanglements are *** melt strength of PGA is finally improved greatly and can make su re that the supercritical CO_(2)foaming can be carried out successfully.

关键词： Polyglycolide(PGA) Long chain branching(LCB) Rheology

Defect-modulated and heteroatom-functionalized Ti_(3−x)C_(2)T_(y)MXene 3D nanocavities induce growth of MoSe_(2)nanoflakes toward electrocatalytic hydrogen evolution in all pH electrolytes

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Nano Research 2024年第7期17卷 6294-6304页

作者： ming Du Xianzhi Yang jian Zhang Wei Chen Huajie Huang Xinbao Zhu Xing’ao Li State Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Centre for Advanced Materials(SICAM)Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023China College of Electronic and Optical Engineering and College of Flexible Electronics Nanjing University of Posts and Telecommunications(NJUPT) Nanjing 210023China New Energy Technology Engineering Lab of jiangsu Province College of ScienceNanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023China College of Pharmaceutical and Chemical Engineering Taizhou UniversityJiaojiang 318000China College of Mechanics and Materials Hohai UniversityNanjing 210098China College of Chemical Engineering Nanjing Forestry UniversityNanjing 210037China

Reducing kinetic energy barriers and developing accessible active sites are critical to deliver high hydrogen evolution reaction(HER)*** this paper,we synthesized defect-modulated and heteroatom(boron)-functionalized three-dimensional(3D)bowl-shaped Ti_(3−x)C_(2)T_(y)MXene(B-TCT)nanocavities coupled with the vertical growth of MoSe_(2)*** B-TCT@MoSe_(2)nanohybrids catalyst delivers the overpotentials of 49.9,52.7,and 67.8 mV to reach a HER current density of 10 mA·cm^(−2)under acidic,alkaline,and neutral conditions,*** outstanding HER activity is predominantly attributed to the heteroatom functionalization,self-adapting Ti vacancy(VTi)defect modulation,and spatial configuration design in the 3D B-TCT nanocavity,which synergistically regulate the electronic structure,activate the basal plane/edge unsaturated sites,and reduce the reaction energy *** and theoretical calculations demonstrate that strong heterogeneous interfacial bonding interactions between B-TCT and MoSe_(2)can dramatically reduce the free energy of hydrogen adsorption and facilitate efficient interfacial charge migration,thus essentially improving the HER *** used this 3D porous nanohybrid system assembled by defectrich lamellar structures to elucidate the advantageous synergistic effects of multiple mechanisms among defect structure,heteroatom functionalization,and interfacial coupling,which provided important insights for the development of efficient hybridtype catalysts.

关键词： electrocatalytic H_(2)evolution three-dimensional(3D)MXene nanocavity MoSe_(2)nanoflake self-adapting Ti vacancy defect heteroatom-functionalized interfacial interaction

Postoperative accurate pain assessment of children and artificial intelligence: A medical hypothesis and planned study

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World Journal of Clinical Cases 2024年第4期12卷 681-687页

作者： jian-ming Yue Qi Wang Bin Liu Leng Zhou Department of Anesthesiology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

Although the pediatric perioperative pain management has been improved in recent years,the valid and reliable pain assessment tool in perioperative period of children remains a challenging *** perioperative pain management is intractable not only because children cannot express their emotions accurately and objectively due to their inability to describe physiological characteristics of feeling which are different from those of adults,but also because there is a lack of effective and specific assessment tool for *** addition,exposure to repeated painful stimuli early in life is known to have short and long-term adverse *** short-term sequelae can induce a series of neurological,endocrine,cardiovascular system stress related to psychological trauma,while long-term sequelae may alter brain maturation process,which can lead to impair neurodevelopmental,behavioral,and cognitive ***’s facial expressions largely reflect the degree of pain,which has led to the developing of a number of pain scoring tools that will help improve the quality of pain mana-gement in children if they are continually studied in *** artificial inte-lligence(AI)technology represented by machine learning has reached an unprecedented level in image processing of deep facial models through deep convolutional neural networks,which can effectively identify and systematically analyze various subtle features of children’s facial *** on the construction of a large database of images of facial expressions in children with perioperative pain,this study proposes to develop and apply automatic facial pain expression recognition software using AI *** study aims to improve the postoperative pain management for pediatric population and the short-term and long-term quality of life for pediatric patients after operational event.

关键词： Pediatric Perioperative pain Assessment tool Facial expression Machine learning Artificial intelligence

Oscillation properties of eigenfunctions for Sturm-Liouville problems with interface conditions via Prufer transformation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 191-200页

作者： LI Zhi-yu LI Kun CAI Jin-ming QIN jian-fang ZHENG Zhao-wen School of Mathematical Sciences Qufu Normal UniversityQufu 273165China College of Mathematics and Systems Science Guangdong Polytechnic Normal UniversityGuangzhou 510665China

A class of Sturm-Liouville problems with discontinuity is studied in this *** oscillation properties of eigenfunctions for Sturm-Liouville problems with interface conditions are *** main method used in this paper is based on Prufer transformation,which is different from the classical ***,we give two examples to verify our main results.

关键词： Sturm-Liouville problem interface condition oscillatory solution