检索结果-南通市图书馆

Ecological-Based Mining:A Coal-Water-Thermal Collaborative Paradigm in Ecologically Fragile Areas in Western China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2024年第7期38卷 209-222页

作者： Xiaoxiu Liu Yifan zeng Qiang Wu Shihao meng Jiyue Liang Zhuping Hou National Engineering Research Center of Coal Mine Water Hazard Controlling China University of Mining and TechnologyBeijing 100083China College of Geoscience and surveying Engineering China University of Mining and TechnologyBeijing 100083China University of Mining and Technology(Beijing)Inner Mongolia Research Institute Ordos 017000China

A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining ***’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources *** on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is *** integrated system for the production,supply,and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hydrothermal quality improvement,and deep-injection geological *** active preventive and control system achieved by adjusting the mining technology and a passive system centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dynamic process of water *** implementing advanced multi-objective drainage,specifically designed to address the“skylight-type”water inrush mode in the Yulin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively ensure subsequent safe coal *** integrated-energy complementary model that incorporates the clean production concept of heat utilization is also *** findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy conservation of 50.2%and a notable 24.2%reduction in carbon *** ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively stored in the Liujiagou Formation,presenti

关键词： Dual carbon targets Coal-water-thermal co-mining Ecologically fragile areas Mine-water control Resource utilization

Gadoxetic acid-enhanced magnetic resonance imaging for the detection of small hepatocellular carcinoma(≤ 2.0 cm) in patients with chronic liver disease:A meta-analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Meta-Analysis 2016年第4期4卷 95-104页

作者： Yan Shan Jian Gao meng-su zeng Jiang Lin Peng-Ju Xu Department of Radiology Zhongshan HospitalFudan UniversityShanghai Institute of Medical Imaging Center of Clinical Epidemiology and Evidence-based Medicine Fudan University

AIM To perform a meta-analysis assessing the value of gadoxetic acid-enhanced magnetic resonance imaging(Gd-EOB-MRI)in detecting small hepatocellular carcinoma(HCC)(≤2.0 cm)in patients with chronic liver *** Databases,including MEDLINE and EMBASE,were searched for relevant original articles published from January 2008 to February *** were extracted,and summary estimates of diagnostic accuracy indexes such as sensitivity,specificity,diagnostic odds ratio,predictive value,and areas under summary receiver operating characteristic curve were obtained using a random-effects model,with further exploration employing meta-regression and subgroup *** In 10 studies evaluating 768 patients,pooled perlesion sensitivity of Gd-EOB-DTPA was 91%(95%CI:83%-95%),with a specificity of 95%(95%CI:87%-98%).Overall positive likelihood ratio was 18.1(95%CI:6.6-49.4),for negative likelihood ratio(NLR)of 0.10(95%CI:0.05-0.19)and diagnostic odds ratio of182(95%CI:57-581).subgroup analysis suggested that diagnostic performance of Gd-EOB-MRI for sub-centimeter HCC(≤1.0 cm)detection was low,with a sensitivity of69%(95%CI:59%-78%).In studies with both Gd-EOBMRI and diffusion-weighted imaging(DWI)performed,Gd-EOB-MRI/DWI combination was more sensitive than Gd-EOB-DTPA alone,whether for small lesions(86%vs77%)or sub-centimeter ones(80%vs 56%).CONCLUSION A limited number of small studies suggested that GdEOB-MRI has good diagnostic performance in the detection of small HCC(≤2.0 cm)among patients with chronic liver disease,but relatively lower performance for detection of sub-centimeter HCC(≤1.0 cm).Combination of Gd-EOB-MRI and DWI can improve the diagnostic sensitivity of MRI.

关键词： Liver-specifc agent Gadoxetic acid-enhanced Magnetic resonance imaging Hepatocellular carcinoma Meta-analysis

Recent progress in polymerization-induced self-assembly:From the perspective of driving forces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aggregate

Aggregate 2024年第1期5卷 47-66页

作者： Zizhuo Zhao Shujing Lei Min zeng meng Huo Department of Chemistry Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhouP.R.China Department of Chemistry University of WarwickCoventryUK

Polymerization-induced self-assembly(PISA)enables the simultaneous growth and self-assembly of block copolymers in one pot and therefore has developed into a high-efficiency platform for the preparation of polymer assemblies with high concentration and excellent *** the past decade,the driving force of PISA has extended from hydrophobic interactions to other supramolecular interactions,which has greatly innovated the design of PISA,enlarged the monomer/solvent toolkit,and endowed the polymer assemblies with intrinsic dynamicity and *** unravel the important role of driving forces in the formation of polymeric assemblies,this review summarized the recent development of PISA from the perspective of driving *** by this goal,here we give a brief overview of the basic principles of PISA and systematically discuss the various driving forces in the PISA system,including hydrophobic interactions,hydrogen bonding,electrostatic interactions,andπ-π***,PISA systems that are driven and regulated by crystallization or liquid crystalline ordering were also highlighted.

关键词： driving forces electrostatic interactions hydrogen bonding hydrophobic interactions polymerizationinduced self-assembly

The main strategies for soil pollution apportionment:A review of the numerical methods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 95-109页

作者： Bin Shi Jing meng TieyuWang Qianqian Li Qifan Zhang Guijin su Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention Shantou UniversityShantou 515063China

Nowadays,a large number of compounds with different physical and chemical properties have been determined in *** behaviors and source identification of pollutants in soil are the foundation of soil pollution *** and quantitative analysis of potential pollution sources are the prerequisites for its prevention and *** efforts have made to develop methods for identifying the sources of soil *** efforts have involved the measurement of source and receptor parameters and the analysis of their relationships via numerical statistics *** have comprehensively reviewed the progress made in the development of source apportionment methodologies to date and present our *** numerical methods,such as spatial geostatistics analysis,receptor models,and machine learning methods are addressed in *** most cases,however,the effectiveness of any single approach for source apportionment remains *** multiple methods to address soil quality problems can reduce uncertainty about the sources of soil *** review also constructively highlights the key strategies of combining mathematical models with the assessment of chemical profiles to provide more accurate source *** review intends to provide a comprehensive summary of source apportionment methodologies to help promote further development.

关键词： Soil pollutants Source attribution Methodologies Chemical profiles Mathematical models

Advances in environmental DNA monitoring:standardization,automation,and emerging technologies in aquatic ecosystems

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第7期67卷 1368-1384页

作者： suxiang Lu Honghui zeng Fan Xiong meng Yao Shunping He State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China Institute of Ecology College of Urban and Environmental SciencesPeking UniversityBeijing 100871China School of Life Sciences Peking UniversityBeijing 100871China Institute of Deep Sea Science and Engineering Chinese Academy of SciencesSanyaChina Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingChina

Environmental DNA(eDNA)monitoring,a rapidly advancing technique for assessing biodiversity and ecosystem health,offers a noninvasive approach for detecting and quantifying species from various environmental *** this review,a comprehensive overview of current eDNA collection and detection technologies is provided,emphasizing the necessity for standardization and automation in aquatic ecological ***,the intricacies of water bodies,from streams to the deep sea,and the associated challenges they pose for eDNA capture and analysis are *** paper delineates three primary eDNA survey methods,namely,bringing back water,bringing back filters,and bringing back data,each with specific advantages and constraints in terms of labor,transport,and data ***,innovations in eDNA sampling equipment,including autonomous drones,subsurface samplers,and in-situ filtration devices,and their applications in monitoring diverse taxa are ***,recent advancements in species-specific detection and eDNA metabarcoding are addressed,highlighting the integration of novel techniques such as CRISPR-Cas and nanopore sequencing that enable precise and rapid detection of *** implications of environmental RNA and epigenetic modifications are considered for future applications in providing nuanced ecological ***,the review stresses the critical role of standardization and automation in enhancing data consistency and comparability for robust long-term *** propose that the amalgamation of these technologies represents a paradigm shift in ecological monitoring,aligning with the urgent call for biodiversity conservation and sustainable management of aquatic ecosystems.

关键词： eDNA methodology sampler environment biomonitoring ecogenomic sensors ocean observation instrument

Robust video question answering via contrastive cross-modality representation learning

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第10期67卷 211-226页

作者： Xun YANG Jianming zeng Dan GUO Shanshan WANG Jianfeng DONG meng WANG School of Information Science and Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center School of Computer Science and Information Engineering Hefei University of Technology Institutes of Physical Science and Information Technology Anhui University School of Computer Science and Technology Zhejiang Gongshang University

Video question answering(VideoQA) is a challenging yet important task that requires a joint understanding of low-level video content and high-level textual semantics. Despite the promising progress of existing efforts, recent studies revealed that current VideoQA models mostly tend to over-rely on the superficial correlations rooted in the dataset bias while overlooking the key video content, thus leading to unreliable results. Effectively understanding and modeling the temporal and semantic characteristics of a given video for robust VideoQA is crucial but, to our knowledge, has not been well investigated. To fill the research gap, we propose a robust VideoQA framework that can effectively model the cross-modality fusion and enforce the model to focus on the temporal and global content of videos when making a QA decision instead of exploiting the shortcuts in datasets. Specifically, we design a self-supervised contrastive learning objective to contrast the positive and negative pairs of multimodal input, where the fused representation of the original multimodal input is enforced to be closer to that of the intervened input based on video perturbation. We expect the fused representation to focus more on the global context of videos rather than some static keyframes. Moreover, we introduce an effective temporal order regularization to enforce the inherent sequential structure of videos for video representation. We also design a Kullback-Leibler divergence-based perturbation invariance regularization of the predicted answer distribution to improve the robustness of the model against temporal content perturbation of videos. Our method is model-agnostic and can be easily compatible with various VideoQA backbones. Extensive experimental results and analyses on several public datasets show the advantage of our method over the state-of-the-art methods in terms of both accuracy and robustness.

关键词： video question answering cross-modality fusion contrastive learning cross-media reasoning

Unsteady aerodynamic noise prediction of contra-rotating open rotor using meshless method

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 144-165页

作者： Zhiliang HONG meng su Haitao ZHANG Zerui XU Lin DU Lingfeng CHEN College of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China Civil Aviation Administration of China Beijing 100710China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

The Contra-Rotating Open Rotor(CROR)design confronts significant noise challenges despite being one of the possible options for future green *** efficiently estimate the noise emitted from a CROR,a three-dimensional unsteady prediction model based on the meshless method is *** unsteady wake flow and the aerodynamic load fluctuations on the blade are solved through the viscous vortex particle method,the blade element momentum theory and vortex lattice ***,the acoustic field is obtained through the Farassat’s formulation *** of this method is conducted on a CROR,and a mesh-based method,e.g.,Nonlinear Harmonic(NLH)method,is also employed for *** is found that the presented method is three times faster than NLH method while maintaining a comparable precision.A thorough parametric analysis is also carried out to illustrate the effects of rotational speed,rotor-rotor spacing and rear rotor diameter on the noise *** rotor speed is found to be the most influencing factor,and by optimizing the speed difference between the front and rear rotors,a notable noise reduction can be *** current findings not only contribute to a deeper comprehension of the CROR’s aeroacoustic properties but also offer an effective tool for engineering applications.

关键词： Contra-Rotating Open Rotor(CROR) Aerodynamic noise Blade element momentum theory Viscosity vortex particle method Farassat’s formulation 1A

The Trend of Smoking-Related Cognition and Its Association with Smoking Behaviors Among Junior High School Students—China,2013–2021

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China CDC weekly 2024年第22期6卷 503-508页

作者： Wenzhao Liu Xinying zeng Qi su Lin Xiao Shiwei Liu Tobacco Control Office Chinese Center for Disease Control and PreventionBeijingChina

What is already known about this topic?In 2013,31.61%of students perceived quitting smoking as difficult,61.73%considered smoking less attractive,and 73.89%believed that secondhand smoke is definitely harmful to *** is added by this report?The percentage of students who perceived quitting smoking as difficult increased from 31.61%in 2013 to 38.83%in 2021,while the percentage of students who found smoking less attractive rose from 61.73%to 69.40%.Conversely,there was a decrease in the percentage of students who perceived secondhand smoke as harmful,from 73.89%to 68.46%.An increased awareness of the hazards of secondhand smoke was associated with a reduction in smoking *** are the implications for public health practice?It is imperative to enhance health education efforts that aim to raise awareness of the hazards of secondhand smoke.

关键词： smoke attractive Junior

A star-like photodetector for angle-based light sensing in 3D space

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7567-7573页

作者： Qi Pan Sisi Chen Hongfei Xie Qiling Xu meng su Yanlin Song College of Chemistry Zhengzhou UniversityZhengzhou 450051China Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(ICCAS)Beijing Engineering Research Center of Nanomaterials for Green Printing TechnologyBeijing National Laboratory for Molecular Sciences(BNLMS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The development of three-dimensional(3D)space light angle detection is vital in optical technology for applications such as 3D imaging,computer vision,and augmented *** methods involve advanced sensors and algorithms,including time-offlight cameras,which need multiple cameras and light sources to improve ***,it is a great challenge to integrate these complex components into compact *** semiconductor structures offer optical resonance characteristics,enabling precise light–matter interaction regulation.A 3D star-like photodetector,fabricated using a template assistant printing strategy,demonstrates optical resonances of the subwavelength facade and the shielding effect of spatial *** achieves light angle detection with the resolution of 10°in vertical space and the resolution of 36°in horizontal space,making it a promising prototype for various applications.

关键词： photodetector light angle detection printing subwavelength structure shielding effect