检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

排水限压治理在降低地下室抗浮设计中的应用

建筑技术开发 2024年第6期51卷 19-21页

作者：李智于重阳魏强同圆设计集团股份有限公司济南250001

由于地下水的赋存,补给关系存在较大的不确定性,基岩裂隙水的流动及补给方式更为复杂,大量带有纯地下室的高层建筑、地下车库及下沉式广场的兴建,使得抗浮问题较突出。目前工程中常用的建筑物抗浮措施有采用底板设置抗浮锚杆、抗浮桩、... 详细信息

由于地下水的赋存,补给关系存在较大的不确定性,基岩裂隙水的流动及补给方式更为复杂,大量带有纯地下室的高层建筑、地下车库及下沉式广场的兴建,使得抗浮问题较突出。目前工程中常用的建筑物抗浮措施有采用底板设置抗浮锚杆、抗浮桩、压载之类的方法来被动地抵抗水浮力。这里主要介绍一种较新型的利用拟建场区的地理优势,采用盲沟疏导地下水,达到降低地下室抗浮设计水位的目的。

关键词：抗浮设防水位排水限压排水盲沟

Structural Regulations of Layered Borates:From Centric Layers to Chiral Porous Layers

在线全文

学校读者我要写书评

暂无评论

Precision Chemistry 2024年第6期2卷 256-262页

作者： chong-An Chen Guo-yu yang MOE Key Laboratory of Cluster Science School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 102488China

Three pentaborates were made by precise structural regulations under hydrothermal conditions,namely,K_(2)Cs-[B_(5)O_(8)(OH)]·0.5CO_(3)(1),KNa_(4)Cs[B_(5)O_(8)(OH)]_(2)·2OH(2),and NaBa[B_(5)O_(8.5)(OH)](3).Compound 1 features the typical 2D layers constructed from the four-connected B_(5)O_(10)(OH)*** adjustment of the reactants and pH values of the systems to remove interlayered CO_(3)^(2−)groups,the centric layers in 1 were transformed to the chiral layers of *** further adjusting cationic templates based on host−guest charge matching,the B_(5)O_(10)(OH)cluster unit was transformed to B_(5)O_(11)(OH),which built the chiral porous layers of *** chiral compounds 2 and 3 exhibit moderate second harmonic generation(SHG)responses of 1.1 and 1.7 times that of KDP(KH_(2)PO_(4)).The structural regulations actualize the evolutions on both structural symmetries and dimensions.

关键词： oxoboron cluster hydrothermal syntheses layers structural regulation nonlinear optical property

Oxidation behavior of Ni-based superalloy GH4738 under tensile stress

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 3913-3920页

作者： Ji-chong Hu Hai-Liang Huang chong-chong Wu Xiao-yu Sun Jie Wang Yan-Hong yang Jing-Long Qu Liang Jiang Jin-He Dou yang Chen Institute for Advanced Studies in Precision Materials Yantai University Department of Management and Engineering Link?ping University Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences Gaona Aero Material Co. Ltd College of Artificial Intelligence and Big Data Shandong First Medical University and Shandong Academy of Medical Sciences

Revealing the oxidation behavior of superalloys is crucial for optimizing material properties and extending service *** study investigated the oxidation behavior of superalloy GH4738 under stress states at 850℃.High-throughput specimens were fabricated to withstand different stresses at the same *** oxidation s amples were analyzed using the mass gain method to obtain oxidation kinetic *** results show that the external stress below 200 MPa could improve the oxidation resistance of the *** tensile stress increasing,the oxide layer becomes thinner,denser and more complete,while internal oxidation *** tensile stress alters the structure of the external oxide layer from a two-layer to a threelayer *** Cr2O3oxide layer inhibits the outward diffusion of Ti,leading to Ti enrichment at the oxide-matrix interface and altering the oxidation mechanism of GH4738.

关键词： Ni-based Superalloy Oxidation behavior Tensile stress Oxide layer

Doping engineering of iron oxide nanoparticles towards high performance and biocompatible T_(1)-weighted MRI contrast agents

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 298-308页

作者： Xue Xu Ping-Li Dong yu-yun Chai Run yang Zhen-Hui Ma Chi-chong Lu Department of Chemistry College of Chemistry and Materials EngineeringBeijing Technology and Business UniversityBeijing 100048China Department of Physics Beijing Technology and Business UniversityBeijing 100048China

Extremely small-sized iron oxide nanoparticles(IONPs) are of great interest in magnetic resonance imaging(MRI) due to their biosafety as an alternative to clinical gadolinium(Ⅲ) complexes-based contrast *** when the particle size is less than 10 nm,it has strong diffusion ability and deep penetration distance in tumor *** doping can significantly enhance the T_(1)contrast effect of nanoparticles by regulating the surface exposed ***,the nucleation and growth processes of multi-component synthesis systems are complex and difficult to be accurately controlled,leading to great challenges in the synthesis of ultra-small-sized nanoparticles with different components and ***,extremely smallsized superparamagnetic gadolinium-doped iron oxide nanoparticles(GdIONPs,Gd_(x)Fe_(3-x)O_(4) NPs) with adjustable doping amount and controllable size in the range of 3.5-7.5 nm were synthesized by thermal ***,as-synthesized GdIONPs were surface modified with a highly water-soluble and biocompatible carboxyl-polyethylene glycol-phosphoric acid ligand with high binding ***_(0.65)Fe_(2.35)O_(4) NPs exhibited very high r_(1) relaxivity of 10.6 mmol^(-1)·L·s^(-1) in terms of all metal concentrations and 49.0 mmol^(-1)·L·s^(-1) in terms of gadolinium alone,respectively,3 and 14 times higher than clinical T_(1) contrast agents(Gd-DTPA).GdIONPs can continuously obtain high resolution images of blood vessels,and can be used as an efficient and multifunctional contrast agent for MR T_(1)*** stable and efficient doping strategy provides an easy and effective method to individually optimize the magnetic properties of complex oxides and their relaxation effects for a variety of biomedical applications.

关键词： Iron oxide nanoparticles Small size Magnetic resonance imaging Substitutional doping Gd dopant

CMMCAN:Lightweight Feature Extraction and Matching Network for Endoscopic Images Based on Adaptive Attention

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第8期80卷 2761-2783页

作者： Nannan chong Fan yang School of Electronic and Information Engineering Hebei University of TechnologyTianjin300401China School of Information and Intelligence Engineering Tianjin Renai CollegeTianjin301636China

In minimally invasive surgery,endoscopes or laparoscopes equipped with miniature cameras and tools are used to enter the human body for therapeutic purposes through small incisions or natural ***,in clinical operating environments,endoscopic images often suffer from challenges such as low texture,uneven illumination,and non-rigid structures,which affect feature observation and *** can severely impact surgical navigation or clinical diagnosis due to missing feature points in endoscopic images,leading to treatment and postoperative recovery issues for *** address these challenges,this paper introduces,for the first time,a Cross-Channel Multi-Modal Adaptive Spatial Feature Fusion(ASFF)module based on the lightweight architecture of ***,a novel lightweight feature extraction and matching network based on attention mechanism is *** network dynamically adjusts attention weights for cross-modal information from grayscale images and optical flow images through a dual-branch Siamese *** extracts static and dynamic information features ranging from low-level to high-level,and from local to global,ensuring robust feature extraction across different widths,noise levels,and blur *** and local matching are performed through a multi-level cascaded attention mechanism,with cross-channel attention introduced to simultaneously extract low-level and high-level *** ablation experiments and comparative studies are conducted on the HyperKvasir,EAD,M2caiSeg,CVC-ClinicDB,and UCL synthetic *** results demonstrate that the proposed network improves upon the baseline EfficientViT-B3 model by 75.4%in accuracy(Acc),while also enhancing runtime performance and storage *** compared with the complex DenseDescriptor feature extraction network,the difference in Acc is less than 7.22%,and IoU calculation results on specific datasets outperform complex dense ***

关键词： Feature extraction and matching lightweighted network medical images endoscopic attention

Spatial distribution of shallow landslides caused by Typhoon Lekima in 2019 in Zhejiang Province, 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

Journal of Mountain Science 2024年第5期21卷 1564-1580页

作者： CUI yulong yang Liu XU chong ZHENG Jun School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Department of Civil Engineering Zhejiang UniversityHangzhou 310058China

In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous terrain of this area, combined with rapid rainfall accumulation, has led to a surge in flash floods and severe geological hazards. On August 10, 2019, Typhoon Lekima made landfall in Zhejiang Province, China, and its torrential rainfall triggered extensive landslides, resulting in substantial damage and economic losses. Utilizing high-resolution satellite images, we compiled a landslide inventory of the affected area, which comprises a total of 2,774 rainfallinduced landslides over an area of 2965 km2. The majority of these landslides were small to mediumsized and exhibited elongated, clustered patterns. Some landslides displayed characteristics of high-level initiation, obstructing or partially blocking rivers, leading to the formation of debris dams. We used the inventory to analyze the distribution pattern of the landslides and their relationship with topographical, geological, and hydrological factors. The results showed that landslide abundance was closely related to elevation, slope angle, faults, and road density. The landslides were predominantly located in hilly and low mountainous areas, with elevations ranging from 150 to 300 m, slopes of 20 to 30 degrees, and a NE-SE aspect. Notably, we observed the highest Landslide Number Density(LND) and Landslide Area Percentage(LAP) in the rhyolite region. Landslides were concentrated within approximately 4 km on either side of fault zones, with their size and frequency negatively correlated with distances to faults, roads, and river systems. Furthermore, under the influence of typhoons, regions with denser vegetation cover exhibited higher landslide density, reaching maximum values in shrubland areas. In areas experiencing significantly increased concentrated rainfall, landslide density also showed a corr

关键词： Typhoon rainfall Landslide characteristics Spatial distribution Southeast coastal region

Capturing and visualizing the phase transition mediated thermal stress of thermal barrier coating materials via a cross-scale integrated computational approach

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第4期13卷 413-428页

作者： Mengdi Gan Tianlong Lu Wei yu Jing Feng Xiaoyu chong Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The generation and evaluation of severely high thermal stress(σ)is known to be responsible for failure of thermal barrier coatings(TBCs)during thermal *** is crucial and challenging to capture fluctuations inσcaused by the phase transition,which has motivated us to develop a high-throughput multiscale evaluation method forσin TBCs that considers the phase transition of the top ceramic materials by coupling first-principles calculations with finite element *** method quantitatively evaluates and visualizesσof the real TBC structure under thermal cycling by multifield ***,the thermophysical properties calculated by the first-principles calculations consider the effects of temperature and phase transition,which not only reduces the cost of obtaining data but also has a more physical *** this work,rare earth tantalites(RETaO_(4))are introduced as ceramic layers,and the results demonstrate thatσundergoes a rapid escalation near the phase transition temperature(T_(t)),particularly in the TBCs_GdTaO_(4) system,where it rises from 224 to 435 *** discontinuity inσmay originate from the significant alterations in Young’s modulus(increase by 27%–78%)and thermal conductivity(increase by 53%–146%)near T_(t).The TBCs_NdTaO_(4) and TBCs_SmTaO_(4) systems exhibit noteworthy temperature drop gradients and minimalσfluctuations,which are beneficial for extending service lifetime of *** approach facilitates the prediction of failure mechanisms and provides theoretical guidance for the reverse design of TBC materials to obtain low thermal stress systems.

关键词： thermal conductivity first-principles calculations thermodynamics thermal stress thermophysical properties

Observing eddy dye patches induced by shear instabilities in the surf zone on a plane beach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第3期43卷 15-29页

作者： Chunping Ren Nannan Fu chong yu yuchuan Bai Kezhao Fang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China College of Water Resource Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are ***,a tracer release laboratory experiment was conducted under monochromatic,unidirectional incident waves with a large incident angle(30°)on a plane beach with a 1:100 slope in a large wave basin.A charge-coupled device suspended above the basin recorded the dye patch *** evolution of eddy dye patch was observed and the transport and diffusion were analyzed based on the collected ***,a linear instability numerical model was adopted to calculate the perturbation velocity field at the initial *** observation and image processing results show that surf zone eddy patches occurred and were separated from the original dye *** numerical analysis results demonstrate that the structure of the perturbation velocity field is consistent with the experimental observations,and that the ejection of eddy patches shoreward or offshore may be ascribed to the double vortex.

关键词： surf zone tracer release experiment evolution of eddy patch shear instability of alongshore currents

Side-Chain-Type Polyimide-Cu Complexes with Suppressed Activation Energy of Relaxation for Advanced High-Temperature Capacitor

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第8期42卷 1038-1048页

作者： Bai-yang Zhou Ze-Tong Ma Shi-Long Zhong Zhen-Jie Huang Qi Guo Deng-chong Feng Zhong-Ke yuan Shao-Lin Lu yu-Zhao yang Cheng Wang Ding-Shan yu Xu-Dong Chen Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education Guangdong Engineering Technology Research Centre for High Performance Organic and Polymer Photoelectric Functional FilmsSchool of ChemistrySun Yat-sen UniversityGuangzhou 510275China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Guangdong Provincial Laboratory of Chemistry and Fine Chemical Industry Jieyang Centre Jieyang 515200China Chemistry and Chemical Engineering Guangdong Laboratory Shantou 515031China

The burgeoning growth of the new energy vehicles and aviation industry has escalated the need for energy storage capacitors capable of stable operation in harsh *** advent of metal-polyimide complexes has illuminated a novel approach for preparing tem perature-resistant ***,the general application of these metal-polyimide com plexes is impeded by the high dielectric loss and low breakdown strength,consequences of main-chain coordination and excessive metal ions ***,our study proposes a novel polyimideCu complex material(POP-Cu)predicated on side-chain-type pyridine-Cu coordination,utilizing the structural backbone PMDA-ODA of mature commercial PI(Kapton)with reliable *** to the high degree of freedom afforded by the side chain with suppressed relaxation activation energy and the long-range electron delocalization formed by d-πcoordination,the dielectric constant of this material containing merely 2.7 mol%Cu increases from 3.25(POPI)to 5.58,while maintaining a remarkably low dielectric loss of ***,this material exhibits a substantial DC breakdown strength of 436.2 MV·m^(-1)and a high energy density of 5.42 J·cm^(-3),coupled with superior mechanical and thermal *** at 150℃,it retains over 90%of its room-temperature energy density,demon strating notable dielectric stability under high *** attributes underscore its promising application for capacitors operating in harsh environments.

关键词： Dielectric performance Polyimide complexes Side-Chain-Type High-temperature capacitor