检索结果-南通市图书馆

Comparison of microstructure,mechanical property,and degradation rate of Mg-1Li-1Ca and Mg-4Li-1Ca alloys

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2023年第8期26卷 279-291页

作者： Li-Xin Long Fen-Fen Chen Lan-Yue Cui ze-song wei Hai-Tao Wang Rong-Chang zeng Yu-Feng Zheng College of Materials Science and Engineering Shandong University of Science and TechnologyQingdao266590China Institute of Corrosion Science and Technology Guangzhou510530China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450002China School of Materials Science and Engineering Peking UniversityBeijing100871China International Research Organization for Advanced Science and Technology(IROAST) Kumamoto University2-39-2 Kumamoto860-8555Japan

Mg-1 wt.%Li-1 wt.%Ca(LX11)and Mg-4 wt.%Li-1 wt.%Ca(LX41)alloys share the same hexagonal closed-packed crystalline ***,the differences in microstructure,mechanical properties,and degradation rates between the two alloys are not well ***,the above three aspects of LX11 and LX41 alloys were studied via optical microscopy,tensile tests,and electrochemical polarization and electrochemical impedance spectroscopy,together with hydrogen *** concentration of the released Mg^(2+),Ca^(2+),and Li+ions was analyzed using a flame atomic absorption *** demonstrated that the LX11 alloy was composed of finerα-Mg grains,fewer twins,and smaller volume fractions of the intermetallic phases Mg_(2)Ca than the LX41 *** increasing Li concentration generated a weak decrease in the yield strength of the Mg-Li-Ca alloys,a remarkable increase in elongation to failure,and a stable ultimate tensile *** LX11 alloy had better corrosion resistance than the LX41 *** release rate of the cations(Mg^(2+),Ca^(2+),and Li+)varied significantly with *** release rate of metallic ions in Hank’s solution cannot reflect the true corrosion rate of Mg-Li-Ca alloys due to the formation of the precipitated corrosion products and their difference in *** dealloying corrosion mechanism of the Mg_(2)Ca phase in Mg-Li-Ca alloys was proposed.

关键词： Magnesium alloys Dealloying Intermetallic compound Biomaterial Ionic release

Exfoliation Corrosion of As‑Extruded Mg–1Li–1Ca:the Influence of the Superficial Layer

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

Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1339-1353页

作者： ze‑song wei Zi‑You Ding Lei Cai Shao‑Xia Ma Dong‑Qing Zhao Lan‑Yue Cui Cheng‑Bao Liu Yuan‑Sheng Yang Yuan‑Ding Huang Rong‑Chang zeng Corrosion Laboratory for Light Metals College of Materials Science and EngineeringShandong University of Science and TechnologyQingdao 266590China Engineering Research Center for Magnesium‑Based New Materials Center for Advancing Materials Performance from the Nanoscale(CAMP‑Nano)State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan 250014China Institute of Metals Research Chinese Academy of SciencesShenyang 110016China Institute of Metallic Biomaterials Helmholtz-Zentrum HereonMax‑Planck‑Str.121502 GeesthachtGermany

Exfoliation corrosion(EFC)has rarely been reported for wrought magnesium *** EFC of the as-extruded Mg–1Li–1Ca alloy was observed after the removal of outermost fine-grained *** microstructure and corrosion products were investigated using optical microscopy,scanning electron microscopy,electron backscattered diffraction,X-ray diffraction,and Fourier transform infrared *** corrosion behavior was analyzed using electrochemical polarization,electrochemical impedance spectroscopy,and scanning Kelvin probe *** results indicated that the surface of Mg–1Li–1Ca,with the superficial layer removed,was more susceptible to EFC.A linear correlation between grain boundary density and corrosion resistance was ***,the influence of factors such as grain size,intermetallic compounds,different alloy surfaces,and corrosion products on EFC were discussed,and the corresponding EFC mechanism was clarified.

关键词： Magnesium alloys Exfoliation corrosion Microstructure Intermetallic compound Metamorphic skin

西双版纳热带季节雨林的粗死木质残体及其养分元素

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

生态学杂志 2008年第12期27卷 2033-2041页

作者：宋泽伟唐建维中国科学院西双版纳热带植物园云南勐腊666303 中国科学院研究生院北京100049

对西双版纳热带季节雨林的粗死木质残体及养分元素贮量进行了研究。结果表明,西双版纳热带季节雨林粗死木质残体的贮量为16.2 t·hm-2,约占地上活体生物量的4%左右。其中枯立木占32.5%,倒木占33.2%,倒木残体占12.6%,大枝占21.7%。本研... 详细信息

对西双版纳热带季节雨林的粗死木质残体及养分元素贮量进行了研究。结果表明,西双版纳热带季节雨林粗死木质残体的贮量为16.2 t·hm-2,约占地上活体生物量的4%左右。其中枯立木占32.5%,倒木占33.2%,倒木残体占12.6%,大枝占21.7%。本研究的粗死木质残体贮量低于巴西和东南亚的热带雨林,处于全球热带雨林的下限。粗死木质残体的氮、磷、钾、钙、镁5种元素的贮量分别为61.8、3.4、30.4、118.3和16.5kg·hm-2。其中倒木所占比例最大,为31.9%～44.8%;枯立木次之(21.5%～28.7%);倒木残体占10.3%～25.5%;3个径级的大枝占14.4%～28.9%。枯立木的C/N、C/P和N/P要高于倒木、倒木残体和大枝。

关键词：粗死木质残体养分元素贮量热带季节雨林西双版纳

酶联免疫试剂盒测定植物油中黄曲霉毒素B_1的样品前处理的改进

在线全文

学校读者我要写书评

暂无评论

粮油食品科技 2013年第6期21卷 92-94页

作者：宋泽伟山西粮食质量监测中心山西太原030024

对现行的酶联免疫分析法测定植物油中黄曲霉毒素B1的样品前处理进行了改进,用适当器具替代分液漏斗进行萃取,以简化操作环节,减少误差,提高前处理效率。试验结果表明,两种前处理方法在测定结果的准确度、精密度没有显著差异,均符合检测... 详细信息

对现行的酶联免疫分析法测定植物油中黄曲霉毒素B1的样品前处理进行了改进,用适当器具替代分液漏斗进行萃取,以简化操作环节,减少误差,提高前处理效率。试验结果表明,两种前处理方法在测定结果的准确度、精密度没有显著差异,均符合检测方法要求,而改进方法在操作方便性和处理效率等方面都优于原方法,可实现对油脂样品的批量化处理,有效解决了"前处理慢"和"检测快"这一矛盾,更好地适应了酶联免疫分析法批量化检测的特点,使其优越性得到充分体现。本改进对同类实验和相关检测也提供了一定参考。

关键词：酶联免疫分析植物油黄曲霉毒素B1 前处理改进

Domain generalization with semi-supervised learning for people-centric activity recognition

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年第1期68卷 171-188页

作者： Jing LIU wei ZHU Di LI Xing HU Liang song Academy for Engineering & Technology Fudan University Shanghai East-bund Research Institute on Networking Systems of AI School of Optoelectronic Information and Computer Engineering University of Shanghai for Science & Technology

People-centric activity recognition is one of the most critical technologies in a wide range of real-world applications,including intelligent transportation systems, healthcare services, and brain-computer interfaces. Large-scale data collection and annotation make the application of machine learning algorithms prohibitively expensive when adapting to new tasks. One way of circumventing this limitation is to train the model in a semi-supervised learning manner that utilizes a percentage of unlabeled data to reduce the labeling burden in prediction tasks. Despite their appeal, these models often assume that labeled and unlabeled data come from similar distributions, which leads to the domain shift problem caused by the presence of distribution gaps. To address these limitations, we propose herein a novel method for people-centric activity recognition,called domain generalization with semi-supervised learning(DGSSL), that effectively enhances the representation learning and domain alignment capabilities of a model. We first design a new autoregressive discriminator for adversarial training between unlabeled and labeled source domains, extracting domain-specific features to reduce the distribution gaps. Second, we introduce two reconstruction tasks to capture the task-specific features to avoid losing information related to representation learning while maintaining task-specific consistency. Finally, benefiting from the collaborative optimization of these two tasks, the model can accurately predict both the domain and category labels of the source domains for the classification task. We conduct extensive experiments on three real-world sensing datasets. The experimental results show that DGSSL surpasses the three state-of-the-art methods with better performance and generalization.

关键词： activity recognition deep learning domain generalization semi-supervised learning adversarial training

同方期刊数据库

Precise gradient separation of nanoparticles using reduced graphene oxide-polyoxomolybdate membranes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 209-216页

作者： Yixin Yang Wanlei Zhao Ruoxuan Zheng Hongqiang Li wei Chen Yu-Fei song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Quzhou Institute for Innovation in Resource Chemical Engineering

The purification and size sieving of nanoparticles （NPs） represents a significant scientific ***,the r GO-polyoxometalates (POMs=PMo12,Mo132and Mo368) membranes were fabricated successfully via a simple and scalable POMsassisted in-situ photoreduction *** the mass ratio of r GO to PMo12was 1:30,the resultant r GO-PMo12membranes with highly ordered and uniform nanochannels of 1.0 nm can be obtained,which showed an accurate carbon quantum dots（CQDs） separation with a cut-off size approximately 1.0 *** increase of the size of the interlayered POMs from PMo12（1.0 nm）,{Mo132}（2.9 nm） to{Mo368}（3.8 nm）,the resultant r GO-PMo12,r GO-Mo132and r GO-Mo368exhibited precise gradient separation of CQDs and Au nanoparticles by size exclusion *** results pave a promising way to construct new twodimensional （2D） membranes for highly efficient size-selective separation.

关键词： reduced graphene oxide polyoxometalates membranes gradient separation nanoparticles

Passive activity enhances residual control ability in patients with complete spinal cord injury

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第8期20卷 2337-2347页

作者： Yanqing Xiao Mingming Gao zejia He Jia Zheng Hongming Bai Jia-Sheng Rao Guiyun song wei song Xiaoguang Li Beijing Key Laboratory for Biomaterials and Neural Regeneration Beijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijingChina Department of Rehabilitation Evaluation China Rehabilitation Research CenterBeijingChina Cardiac Center Beijing Children’s HospitalCapital Medical UniversityBeijingChina The State Key Laboratory of Virtual Reality Technology and Systems Beihang UniversityBeijingChina Department of Rehabilitation Engineering China Rehabilitation Science InstituteBeijingChina

Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury ***,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface *** this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord *** patients with chronic complete thoracic spinal cord injury were *** electromyography data from eight major leg muscles were acquired and compared before and after the passive activity *** results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of *** the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically *** findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.

关键词： complete spinal cord injury cycle training epidural electrical stimulation motor training passive activity physiological state spinal cord circuit surface electromyography volitional control task

Research progress of catalysts for direct coal liquefaction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 481-497页

作者： wei song Penggao Liu Xinyue Chen Ting Wang Chunrong He Rui Hao Kaiyu Liu State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of Chemistry Xinjiang University College of Chemistry and Chemical Engineering Henan Polytechnic University Hunan Provincial Key Laboratory of Chemical Power Sources College of Chemistry and Chemical Engineering Central South University

Coal direct liquefaction technology is a crucial contemporary coal chemical technology for efficient and clean use of coal resources. The development of direct coal liquefaction technology and the promotion of alternative energy sources are important measures to guarantee energy security and economic security. However, several challenges need to be addressed, including low conversion rate, inadequate oil yield, significant coking, demanding reaction conditions, and high energy consumption. Extensive research has been conducted on these issues, but further exploration is required in certain aspects such as pyrolysis of macromolecules during the liquefaction process, hydrogen activation, catalysts' performance and stability, solvent hydrogenation, as well as interactions between free radicals to understand their mechanisms better. This paper presents a comprehensive analysis of the design strategy for efficient catalysts in coal liquefaction, encompassing the mechanism of coal liquefaction, catalyst construction,and enhancement of catalytic conversion efficiency. It serves as a comprehensive guide for further research endeavors. Firstly, it systematically summarizes the conversion mechanism of direct coal liquefaction, provides detailed descriptions of various catalyst design strategies, and especially outlines the catalytic mechanism. Furthermore, it addresses the challenges and prospects associated with constructing efficient catalysts for direct coal liquefaction based on an understanding of their action mechanisms.

关键词： Direct coal liquefaction Catalysts Mechanism of action Solvent hydrogenation

Electrochemical conversion of methane to bridge the gap in the artificial carbon cycle

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 286-308页

作者： Yuhao Peng Yuefeng song Ihar Razanau Juanxiu Xiao wei Xiao Di Hu Guoxiong Wang College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Dalian Institute of Chemical Physics Chinese Academy of Sciences Laboratory of Physical-Chemical Technologies SSPA Scientific and Practical Materials Research Centre of NAS of Belarus State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University Department of Chemical and Environmental Engineering University of Nottingham Ningbo China

Methane, an abundant one-carbon（C1） resource, is extensively used in the industrial production of vital fuels and value-added chemicals. However, current industrial methane conversion technologies are energy-and carbon-intensive, mainly due to the high activation energy required to break the inert C–H bond, low selectivity, and problematic side reactions, including CO2emissions and coke deposition. Electrochemical conversion of methane（ECM） using intermittent renewable energy offers an attractive solution, due to its modular reactor design and operational flexibility across a broad spectrum of temperatures and pressures. This review emphasizes conversion pathways of methane in various reaction systems, highlighting the significance and advantages of ECM in facilitating a sustainable artificial carbon cycle. This work provides a comprehensive overview of conventional methane activation mechanisms and delineates the complete pathways of methane conversion in electrolysis contexts. Based on surface/interface chemistry, this work systematically analyzes proposed reaction pathways and corresponding strategies to enhance ECM efficiency towards various target products, including syngas, hydrocarbons, oxygenates, and advanced carbon materials. The discussion also encompasses opportunities and challenges for the ECM process, including insights into ECM pathways, rational electrocatalyst design, establishment of benchmarking protocols, electrolyte engineering, enhancement of CH4conversion rates, and minimization of CO2emission.

关键词： Activation energy