检索结果-南通市图书馆

Digital light processing based multimaterial 3D printing:challenges,solutions and perspectives

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第4期6卷 151-174页

作者： Jianxiang Cheng Shouyi yu rong wang Qi Ge Shenzhen Key Laboratory of Soft Mechanics&Smart Manufacturing Southern University of Science and TechnologyShenzhen 518055People's Republic of China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055People's Republic of China

Multimaterial(MM)3D printing shows great potential for application in metamaterials,flexible electronics,biomedical devices and robots,since it can seamlessly integrate distinctive materials into one printed *** numerous MM 3D printing technologies,digital light processing(DLP)MM 3D printing is compatible with a wide range of materials from hydrogels to ceramics,and can print MM 3D structures with high resolution,high complexity and fast *** paper introduces the fundamental mechanisms of DLP 3D printing,and reviews the recent advances of DLP MM 3D printing technologies with emphasis on material switching methods and material contamination *** also summarizes a number of typical examples of DLP MM 3D printing systems developed in the past decade,and introduces their system structures,working principles,material switching methods,residual resin removal methods,printing steps,as well as the representative structures and ***,we provide perspectives on the directions of the further development of DLP MM 3D printing technology.

关键词： multimaterial 3D printing digital lightprocessing multimaterial 3Dstructures

Exceptional mechanical performance and macroscale superlubricity enabled by core-shell-like MoS_(2)/B_(4)C film

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第7期67卷 2018-2030页

作者： REN siming GAO Zhenrong FAN Xin wang HaiXin wang LiPing Key Laboratory of Advanced Marine Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China

Molybdenum disulfide(MoS_(2)) films are widely deployed in industrial applications owing to their inherent interlayer slip characteristics, offering energy consumption savings and prolonged mechanical part performance. Nevertheless, their practical utility is limited by environmental constraints and the limitations of preparation techniques, which hinder the attainment of robust superlubricity(friction coefficient < 0.01). Herein, through magnetron sputtering technology, we synthesize a core-shell-like nanocomposite composed of MoS_(2)nanosheets encapsulating B_(4)C. The core-shell-like structure enables the resulting films to preferentially grow crystalline MoS_(2), providing them with outstanding mechanical properties and efficient lubrication over a wide range of temperatures. Remarkably, such film achieves robust macroscale superlubricity and an ultralow wear rate(1.7 ×10^(-8)mm^(3)N-1m^(-1)) under high contact stress in a mild vacuum environment. This noteworthy outcome is primarily attributable to the self-segmentation of the macroscale contact interface during the friction process, involving:(1) a large amount of wear debris is embedded into the wear track to create extensive micro-sized asperities;(2) a nanolayer of amorphous carbon enriched with oxide nanoparticles is formed on the uppermost part of these asperities;(3) numerous incommensurate nanocontacts comprising nanoparticles and highly oriented MoS_(2)nanosheets are established, culminating in the achievement of robust superlubricity. Our pioneering design, coupled with the elucidation of the underlying superlubricity mechanism, holds significant promise for advancing the development of robust and high-performance lubricants.

关键词： MoS_(2)/B_(4)C nanocomposites core-shell-like structure H/E ratio high-temperature friction macroscale superlubricity

Primordial black holes and curvature perturbations from false vacuum islands

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 58-72页

作者： rong-Gen Cai yu-Shi Hao Shao-Jiang wang School of Physical Science and Technology Ningbo UniversityNingbo 315211China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Asia Pacific Center for Theoretical Physics Pohang 37673Republic of Korea

Recently,much attention has been focused on the false vacuum islands that are flooded by an expanding ocean of true-vacuum bubbles slightly later than most of the other parts of the *** delayed decay regions will accumulate locally larger vacuum energy density by staying in the false vacuum longer than those already transited into the true vacuum.A false vacuum island with thus acquired density contrast of a super-horizon size will evolve locally from radiation dominance to vacuum dominance,creating a local baby Universe that can be regarded effectively as a local closed *** such density contrasts of super-horizon sizes can ever grow large enough to exceed the threshold of gravitational collapse,primordial black holes will form similar to those collapsing curvature perturbations on super-horizon scales induced by small-scale enhancements during *** not,such density contrasts can still induce curvature perturbations potentially observable *** this paper,we revisit and elaborate on the generations of primordial black holes and curvature perturbations from delayed-decayed false vacuum islands during asynchronous first-order phase transitions with fitting formulas convenient for future model-independent studies.

关键词： first-order phase transitions primordial black holes curvature perturbations

Atomistic mechanism of high ionic conductivity in lithium ytterbium-based halide solid electrolytes:A first-principles study

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 155-162,I0006页

作者： Limin wang Wei Xiao Lu Sun rong Yang Jinqiu yu Ligen wang State Key Laboratory of Nonferrous Metals and Processes China GRINM Group Co.Ltd.Beijing100088China GRIMAT Engineering Institute Co. Ltd.Beijing101407China General Research Institute for Nonferrous Metals Beijing100088China China Automotive Battery Research Institute Co. Ltd.Beijing101407China Rare Earth Functional Materials(Xiong'an)Innovation Center Co. Ltd.Xiong'an071700China

As the next generation of commercial automotive power batteries begins replacing liquid lithium batteries,many look towards all-solid-state batteries to pioneer the ***-so lid-state batteries have attracted the attention of countless researchers around the world because of their high safety and high energy *** recent times,halide solid-state electrolytes have become a research hotspot within solid-state electrolytes because of their potentially superior *** this paper,in the framework of DFT,we investigated the atomic mechanisms of improving the ionic conductivity and stability of Li_(3)YbCl_(6).Our calculations show that both trigonal and orthorhombic Li_(3)YbCl_(6) exhibit wide electrochemical windows and metastable properties(100 meV/atom>Ehull>0 meV/atom).However,the orthorhombic Li_(3)YbCl_(6) can be stabilized at high temperatures by taking the vibrational entropy into account,which is supported by the experimental ***,it is expected that because of the Yb/Li synergistic interactions that,due to their strong mutual coulomb repulsion,influence the Li^(+)transport behavior,the orthorhombic Li_(3)YbCl_(6) might have superior ionic conductivities with appropriate Li+migration paths determined by the Yb^(3+) ***,higher ionic conductivities can be obtained by regulating the random distribution of Li^(+) *** Li^(+)-deficiency can also largely increase the ionic conductivity by invoking *** study helps gain a deeper understanding of the laws that govern ionic conductivities and stabilities and provides a certain theoretical reference for the experimental development and design of halide solid-state electrolytes.

关键词： Halide solid-state electrolytes Phase stability Ionic conductivity First-principles calculations Rare earths

Optimized parameters of downhole all-metal PDM based on genetic algorithm

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2663-2676页

作者： Jia-Xing Lu Ling-rong Kong yu wang Chao Feng yu-Lin Gao China University of Geosciences (Beijing) Key Laboratory on Deep Geo-Drilling Technology of Ministry of Natural Resources

Currently, deep drilling operates under extreme conditions of high temperature and high pressure,demanding more from subterranean power motors. The all-metal positive displacement motor, known for its robust performance, is a critical choice for such drilling. The dimensions of the PDM are crucial for its performance output. To enhance this, optimization of the motor's profile using a genetic algorithm has been undertaken. The design process begins with the computation of the initial stator and rotor curves based on the equations for a screw cycloid. These curves are then refined using the least squares method for a precise fit. Following this, the PDM's mathematical model is optimized, and motor friction is assessed. The genetic algorithm process involves encoding variations and managing crossovers to optimize objective functions, including the isometric radius coefficient, eccentricity distance parameter,overflow area, and maximum slip speed. This optimization yields the ideal profile parameters that enhance the motor's output. Comparative analyses of the initial and optimized output characteristics were conducted, focusing on the effects of the isometric radius coefficient and overflow area on the motor's performance. Results indicate that the optimized motor's overflow area increased by 6.9%, while its rotational speed reduced by 6.58%. The torque, as tested by Infocus, saw substantial improvements of38.8%. This optimization provides a theoretical foundation for improving the output characteristics of allmetal PDMs and supports the ongoing development and research of PDM technology.

关键词： Positive displacement motor Genetic algorithm Profile optimization Matlab programming Overflow area

Hydrodynamic Performance of An Integrated System of Breakwater and A Multi-Chamber OWC Wave Energy Converter

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 543-556页

作者： NING De-zhi ZHANG Xiang-yu wang rong-quan ZHAO Ming State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Dalian Key Laboratory of Offshore Renewable Energy Dalian University of TechnologyDalian 116024China School of Computing Engineering and MathematicsUniversity of Western SydneyPenrith NSW 2751Australia

A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is *** hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine *** effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber OWC-WEC are *** results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency *** device with a chamber-width-ratio of 1:3 performs better in terms of power ***,results from the analysis of a triplechamber OWC-WEC demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the *** the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.

关键词： oscillating water column power extraction efficiency potential flow theory wave energy converter multi-chamber

Benefit-Risk Assessment of Chinese Medicine Injections for Primary Liver Cancer Based on Multi-criteria Decision Analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第6期30卷 559-564页

作者： ZHANG rong-rong SHAO Ming-yi FU yu ZHAO Rui-xia wang Jing-wen FANG yu-xuan The First Clinical Medical College of Henan University of Traditional Chinese Medicine Zhengzhou450046China Personal Department the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou450000China Scientific Research Department the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou450000China Digestive Department the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou450000China

ObjectiveTo evaluate the benefit-risk of 3 commonly used Chinese medicine injections, Aidi Injection (ADI), Cinobufagin Injection (CINI) and Compound Kushen Injection (CKI), in the treatment of primary liver cancer (PLC), so as to provide a reference for clinical *** controlled trials (RCTs) of ADI, CINI and CKI in the treatment of PLC published in the databases of China National Knowledge Infrastructure, Wanfang, China Science and Technology Journal Database, SinoMed, PubMed, Cochrane Library, and Web of Science were retrieved from January 2020 to October 2022. The data of benefit and risk indicators were combined to obtain the effect value. The multi-criteria decision analysis (MCDA) model was applied to build the decision tree. The benefit value, risk value and benefit risk value of the 3 injections in PLC treatment were calculated. Monte Carlo simulation was carried out to calculate the 95% confidence interval and probability of differences among the 3 injections, so as to optimize the evaluation *** total of 71 RCTs were included. The benefit values of ADI, CINI and CKI combined with transcatheter arterial chemoembolization (TACE) were 42, 38 and 36, respectively. The risk values were 42, 25 and 37, respectively. The benefit risk values were 42, 31 and 37, respectively. The benefit risk differences of ADI vs. CINI, ADI vs. CKI, and CKI vs. CINI were 11 (−0.86, 17.75), 5 (−5.01, 11.09), and 6 (−1.87, 12.63), respectively. The probability that ADI superior to CINI, ADI superior to CKI, and CKI superior to CINI was 96.26%, 77.27%, and 92.62%, *** on the results of MCDA model, CINI combined with TACE has the greatest risk in the treatment of the PLC. Considering the efficacy and safety, the possible priority of the 3 Chinese medicine injections combined with TACE in the treatment of PLC is ADI, CKI and CINI.

关键词： multi-criteria decision analysis benefit-risk assessment Chinese medicine injections primary livercancer

Characterization of the pheromone receptors in Mythimna loreyi reveals the differentiation of sex pheromone recognition in Mythimna species

在线全文

学校读者我要写书评

暂无评论

Insect Science 2024年第1期31卷 173-185页

作者： Chan wang Lei Liu Tian-yu Huang yu Zhang Yang Liu Gui-rong wang State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina Guangdong Laboratory of Lingnan Modern Agriculture ShenzhenGenome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina School of Forestry Northeast Forestry UniversityHarbinChina Key Laboratory of Biohazard Monitoring Green Prevention and Control for Artificial GrasslandMinistry of Agriculture and Rural AffairsInstitute of Grassland Research of Chinese Academy of Agricultural SciencesInner Mongolia HohhotChina

Pheromone receptors(PRs)are key proteins in the molecular mechanism of pheromone recognition,and exploring the functional differentiation of PRs between closely related species helps to understand the evolution of moth mating *** components of the agricultural pest Mythimna loreyi have turned into(Z)-9-tetradecen-1-yl acetate(Z9-14:OAc),(Z)-7-dodecen-1-yl acetate(Z7-12:OAc),and(Z)-11-hexadecen-1-yl acetate,while the composition differs from that of *** in the genus *** understand the molecular mechanism of pheromone recognition,we sequenced and analyzed antennal transcriptomes to identify 62 odorant receptor(OR)*** expression levels of all putative ORs were analyzed using differentially expressed gene *** candidate PRs were quantified and functionally characterized in the Xenopus oocytes ***6 and MlorPR3 were determined to be the receptors of major and minor components Z9-14:OAc and Z7-12:***1 and female antennae(FA)-biased MlorPR5 both possessed the ability to detect pheromones of sympatric species,including(Z,E)-9,12-tetradecadien-1-ol,(Z)-9-tetradecen-1-ol,and(Z)-*** on the comparison of PR functions between *** and ***,we analyzed the differentiation of pheromone recognition mechanisms during the evolution of the mating systems of 2 Mythimna species.

关键词： antennal transcriptome Mythimna loreyi pheromone receptor sex pheromone Xenopus oocyte

Machine Learning-based Identification of Contaminated Images in Light Curve Data Preprocessing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第4期24卷 287-295页

作者： Hui Li rong-wang Li Peng Shu yu-Qiang Li yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Space Object and Debris Observation Chinese Academy of SciencesNanjing 210023China

Attitude is one of the crucial parameters for space objects and plays a vital role in collision prediction and debris *** light curves to determine attitude is the most commonly used *** photometric observations,outliers may exist in the obtained light curves due to various ***,preprocessing is required to remove these outliers to obtain high quality light *** statistical analysis,the reasons leading to outliers can be categorized into two main types:first,the brightness of the object significantly increases due to the passage of a star nearby,referred to as“stellar contamination,”and second,the brightness markedly decreases due to cloudy cover,referred to as“cloudy contamination.”The traditional approach of manually inspecting images for contamination is time-consuming and ***,we propose the utilization of machine learning methods as a *** Neural Networks and SVMs are employed to identify cases of stellar contamination and cloudy contamination,achieving F1 scores of 1.00 and 0.98 on a test set,*** also explore other machine learning methods such as ResNet-18 and Light Gradient Boosting Machine,then conduct comparative analyses of the results.

关键词： techniques:image processing methods:data analysis light pollution